Hank Lazer is a well-known American innovative and experimental poet and Professor Emeritus and Associate Provost Emeritus for the University of Alabama.The author of 35 books of poetry and several collections of essa...Hank Lazer is a well-known American innovative and experimental poet and Professor Emeritus and Associate Provost Emeritus for the University of Alabama.The author of 35 books of poetry and several collections of essays,his most recent books of poetry explore the intersection of poetic innovation and spirituality,with attention to his ongoing Zen meditation practice.This interview explores in depth Lazer's poetry and poetics,especially the relationship between Chinese Zen-Taoism thoughts,such as emptiness,nothingness,and silence,etc.,and his poetics and poetry creation,focusing on a particular phase of Lazer's poetryshape-writing-an improvisatory practice invented by Lazer(poems written without drafts in abstract shapes).Lazer's shape-writing has an important relationship to Zen-Taoism,Chinese characters,calligraphy,and improvisatory jazz among others.His writing explores the nature of being,consciousness,nature,the complex life in language,and the presence that occurs through the practice of meditation.展开更多
Visuality can be generically described as the quality of the visual,that is,as the given visual field in which a subject’s attention is concentrated.In fact,the visual is intrinsically linked to human vision,and this...Visuality can be generically described as the quality of the visual,that is,as the given visual field in which a subject’s attention is concentrated.In fact,the visual is intrinsically linked to human vision,and this presupposes the existence of a visible horizon from which(visual)images are given.However,this formulation presents something uncanny paradoxical because it forgets,on one hand,the broader status of the image(such as auditory and olfactory images)-seeing is not just a visual process(at least since Diderot we know it)and there are mental mechanisms in the visual constitution process that help to fabricate reality and that gestalt theory has explained-and on the other hand,the possibility of seeing beyond what is visible,after all,everything(or almost everything)that presents itself in a digital and virtual environment it can be quite ontologically suspect.Based on some of these premises,we will trace a path of analysis that leads us to the current blindness:unconditional faith in digital technology and the fragile hope of happiness in a way that rejects the reality of the visible.展开更多
Synaptic plasticity is essential for maintaining neuronal function in the central nervous system and serves as a critical indicator of the effects of neurodegenerative disease.Glaucoma directly impairs retinal ganglio...Synaptic plasticity is essential for maintaining neuronal function in the central nervous system and serves as a critical indicator of the effects of neurodegenerative disease.Glaucoma directly impairs retinal ganglion cells and their axons,leading to axonal transport dysfuntion,subsequently causing secondary damage to anterior or posterior ends of the visual system.Accordingly,recent evidence indicates that glaucoma is a degenerative disease of the central nervous system that causes damage throughout the visual pathway.However,the effects of glaucoma on synaptic plasticity in the primary visual cortex remain unclear.In this study,we established a mouse model of unilateral chronic ocular hypertension by injecting magnetic microbeads into the anterior chamber of one eye.We found that,after 4 weeks of chronic ocular hypertension,the neuronal somas were smaller in the superior colliculus and lateral geniculate body regions of the brain contralateral to the affected eye.This was accompanied by glial cell activation and increased expression of inflammatory factors.After 8 weeks of ocular hypertension,we observed a reduction in the number of excitatory and inhibitory synapses,dendritic spines,and activation of glial cells in the primary visual cortex contralateral to the affected eye.These findings suggest that glaucoma not only directly damages the retina but also induces alterations in synapses and dendritic spines in the primary visual cortex,providing new insights into the pathogenesis of glaucoma.展开更多
Peng Xiaolian is a rare and prolific Chinese author who writes both fiction and non-fiction works and directs both dramatic and documentary films. Peng has not only written, cowritten, or rewritten all the screenplays...Peng Xiaolian is a rare and prolific Chinese author who writes both fiction and non-fiction works and directs both dramatic and documentary films. Peng has not only written, cowritten, or rewritten all the screenplays of her eight dramatic features and two documentaries but is also the author of one novel, twelve novellas, over a dozen short stories, four book-length memoirs, three collections of film reviews, and numerous essays. The existing scholarly studies, however, nearly all focus on Peng＇s dramatic films, with much less, if any, attention directed at her writing and documentaries. To really understand Peng as a film auteur, however, it is necessary to look at her films and writings together. Given the quantity and complexity of her works and the space limitations of this article, I examine Peng＇s subversion of the conventional treatment of character, location, and time in three thematic sections reflecting the key narrative motifs in her work. I first summarize existing studies of Peng＇s films, highlighting the rarely examined interaction between visuality and spatiality in her films. Then, after defining her sense of time in narrative, I demonstrate how family history and self-reflexivity are the major difference between her films and her nonfiction works. Last but not least, I discuss how, through her use of multilayered narratives constructed by the female voice and subjectivity, her complete repertoire constitutes a unique history of modern Chinese women. This article aims to demonstrate how, through her use of multilayered narratives constructed by the female voice and subjectivity, her complete repertoire constitutes a unique history of modern Chinese women.展开更多
The visual system of teleost fish grows continuously,which is a useful model for studying regeneration of the central nervous system.Glial cells are key for this process,but their contribution is still not well define...The visual system of teleost fish grows continuously,which is a useful model for studying regeneration of the central nervous system.Glial cells are key for this process,but their contribution is still not well defined.We followed oligodendrocytes in the visual system of adult zebrafish during regeneration of the optic nerve at 6,24,and 72 hours post-lesion and at 7 and 14 days post-lesion via the sox10:tagRFP transgenic line and confocal microscopy.To understand the changes that these oligodendrocytes undergo during regeneration,we used Sox2 immunohistochemistry,a stem cell marker involved in oligodendrocyte differentiation.We also used the Click-iT™ Plus TUNEL assay to study cell death and a BrdU assay to determine cell proliferation.Before optic nerve crush,sox10:tagRFP oligodendrocytes are located in the retina,in the optic nerve head,and through all the entire optic nerve.Sox2-positive cells are present in the peripheral germinal zone,the mature retina,and the optic nerve.After optic nerve crush,sox10:tagRFP cells disappeared from the optic nerve crush zone,suggesting that they died,although they were not TUNEL positive.Concomitantly,the number of Sox2-positive cells increased around the crushed area,the optic nerve head,and the retina.Then,between 24 hours post-lesion and 14 days post-lesion,double sox10:tagRFP/Sox2-positive cells were detected in the retina,optic nerve head,and whole optic nerve,together with a proliferation response at 72 hours post-lesion.Our results confirm that a degenerating process may occur prior to regeneration.First,sox10:tagRFP oligodendrocytes that surround the degenerated axons stop wrapping them,change their“myelinating oligodendrocyte”morphology to a“nonmyelinating oligodendrocyte”morphology,and die.Then,residual oligodendrocyte progenitor cells in the optic nerve and retina proliferate and differentiate for the purpose of remyelination.As new axons arise from the surviving retinal ganglion cells,new sox10:tagRFP oligodendrocytes arise from residual oligodendrocyte progenitor cells to guide,nourish and myelinate them.Thus,oligodendrocytes play an active role in zebrafish axon regeneration and remyelination.展开更多
Ischemic retinopathy is a leading cause of blindness:Ischemic retinopathies including diabetic retinopathy(DR),retinopathy of prematurity,and retinal artery and vein occlusion are major causes of visual impairment.Isc...Ischemic retinopathy is a leading cause of blindness:Ischemic retinopathies including diabetic retinopathy(DR),retinopathy of prematurity,and retinal artery and vein occlusion are major causes of visual impairment.Ischemic retinopathy can be acute,such as in central or branch retinal artery occlusion,or chronic,such as with DR(Figure 1).Although the causes of retinopathies are diverse,one pathogenic event shared by these conditions is the myeloid cell response to retinal ischemia(Shahror et al.,2024a).展开更多
Diabetic retinopathy is a prominent cause of blindness in adults,with early retinal ganglion cell loss contributing to visual dysfunction or blindness.In the brain,defects inγ-aminobutyric acid synaptic transmission ...Diabetic retinopathy is a prominent cause of blindness in adults,with early retinal ganglion cell loss contributing to visual dysfunction or blindness.In the brain,defects inγ-aminobutyric acid synaptic transmission are associated with pathophysiological and neurodegenerative disorders,whereas glucagon-like peptide-1 has demonstrated neuroprotective effects.However,it is not yet clear whether diabetes causes alterations in inhibitory input to retinal ganglion cells and whether and how glucagon-like peptide-1 protects against neurodegeneration in the diabetic retina through regulating inhibitory synaptic transmission to retinal ganglion cells.In the present study,we used the patch-clamp technique to recordγ-aminobutyric acid subtype A receptor-mediated miniature inhibitory postsynaptic currents in retinal ganglion cells from streptozotocin-induced diabetes model rats.We found that early diabetes(4 weeks of hyperglycemia)decreased the frequency of GABAergic miniature inhibitory postsynaptic currents in retinal ganglion cells without altering their amplitude,suggesting a reduction in the spontaneous release ofγ-aminobutyric acid to retinal ganglion cells.Topical administration of glucagon-like peptide-1 eyedrops over a period of 2 weeks effectively countered the hyperglycemia-induced downregulation of GABAergic mIPSC frequency,subsequently enhancing the survival of retinal ganglion cells.Concurrently,the protective effects of glucagon-like peptide-1 on retinal ganglion cells in diabetic rats were eliminated by topical administration of exendin-9-39,a specific glucagon-like peptide-1 receptor antagonist,or SR95531,a specific antagonist of theγ-aminobutyric acid subtype A receptor.Furthermore,extracellular perfusion of glucagon-like peptide-1 was found to elevate the frequencies of GABAergic miniature inhibitory postsynaptic currents in both ON-and OFF-type retinal ganglion cells.This elevation was shown to be mediated by activation of the phosphatidylinositol-phospholipase C/inositol 1,4,5-trisphosphate receptor/Ca2+/protein kinase C signaling pathway downstream of glucagon-like peptide-1 receptor activation.Moreover,multielectrode array recordings revealed that glucagon-like peptide-1 functionally augmented the photoresponses of ON-type retinal ganglion cells.Optomotor response tests demonstrated that diabetic rats exhibited reductions in visual acuity and contrast sensitivity that were significantly ameliorated by topical administration of glucagon-like peptide-1.These results suggest that glucagon-like peptide-1 facilitates the release ofγ-aminobutyric acid onto retinal ganglion cells through the activation of glucagon-like peptide-1 receptor,leading to the de-excitation of retinal ganglion cell circuits and the inhibition of excitotoxic processes associated with diabetic retinopathy.Collectively,our findings indicate that theγ-aminobutyric acid system has potential as a therapeutic target for mitigating early-stage diabetic retinopathy.Furthermore,the topical administration of glucagon-like peptide-1 eyedrops represents a non-invasive and effective treatment approach for managing early-stage diabetic retinopathy.展开更多
气候变化和人类活动对水文循环产生了显著影响,尤其是在干旱半干旱区.为探究变化环境下典型半干旱生态脆弱区毛乌素沙地水循环演变特征,利用WEP-L(water and energy transfer processes in large river basin)地表水模型和Visual MODFLO...气候变化和人类活动对水文循环产生了显著影响,尤其是在干旱半干旱区.为探究变化环境下典型半干旱生态脆弱区毛乌素沙地水循环演变特征,利用WEP-L(water and energy transfer processes in large river basin)地表水模型和Visual MODFLOW(visual modular finite difference groundwater flow)地下水模型对毛乌素沙地水循环过程进行分布式模拟,基于白家川水文站实测月径流量和监测井地下水位数据进行模型参数率定与验证.结果表明,地表水模型率定期和验证期的模拟月径流量和实测月径流量的R2都在0.5以上,模拟的监测井地下水位和实测地下水位趋势较为一致,相关系数达到0.56以上.采用偏差校正的CMIP6多模式集合气候变化情景及当地取用水情景驱动地表水-地下水耦合模型,量化了变化环境下毛乌素沙地2021-2040年关键水循环要素变化特征.结果表明,未来情景下毛乌素沙地年降水量和年蒸散发量的平均增幅分别为8.0%和7.4%,年径流深呈现逐渐减少的趋势,2040年末地下水位相较于2021年末下降了约1 m.未来2种用水情景下区域地下水总补给量与排泄量的差值分别为-1.82亿、-0.97亿m^(3)·a^(-1),地表径流总量与地表用水量的差值分别为1.83亿、2.29亿m^(3)·a^(-1),地下水资源开发利用将面临更大挑战.研究成果可为毛乌素沙地区域水资源规划与管理提供科学支撑.展开更多
Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have ...Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging population.Posture and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous mechanisms.To effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory signals.The mechanisms which underpin the integration of these multisensory signals are the principal topic of the present work.Existing multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older adults.Insufficient emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and balance.In the present work,we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Parkinson’s disease.We also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk in older adults.Lastly,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases.展开更多
文摘Hank Lazer is a well-known American innovative and experimental poet and Professor Emeritus and Associate Provost Emeritus for the University of Alabama.The author of 35 books of poetry and several collections of essays,his most recent books of poetry explore the intersection of poetic innovation and spirituality,with attention to his ongoing Zen meditation practice.This interview explores in depth Lazer's poetry and poetics,especially the relationship between Chinese Zen-Taoism thoughts,such as emptiness,nothingness,and silence,etc.,and his poetics and poetry creation,focusing on a particular phase of Lazer's poetryshape-writing-an improvisatory practice invented by Lazer(poems written without drafts in abstract shapes).Lazer's shape-writing has an important relationship to Zen-Taoism,Chinese characters,calligraphy,and improvisatory jazz among others.His writing explores the nature of being,consciousness,nature,the complex life in language,and the presence that occurs through the practice of meditation.
文摘Visuality can be generically described as the quality of the visual,that is,as the given visual field in which a subject’s attention is concentrated.In fact,the visual is intrinsically linked to human vision,and this presupposes the existence of a visible horizon from which(visual)images are given.However,this formulation presents something uncanny paradoxical because it forgets,on one hand,the broader status of the image(such as auditory and olfactory images)-seeing is not just a visual process(at least since Diderot we know it)and there are mental mechanisms in the visual constitution process that help to fabricate reality and that gestalt theory has explained-and on the other hand,the possibility of seeing beyond what is visible,after all,everything(or almost everything)that presents itself in a digital and virtual environment it can be quite ontologically suspect.Based on some of these premises,we will trace a path of analysis that leads us to the current blindness:unconditional faith in digital technology and the fragile hope of happiness in a way that rejects the reality of the visible.
基金supported by the National Natural Science Foundation of China,No.82271115(to MY).
文摘Synaptic plasticity is essential for maintaining neuronal function in the central nervous system and serves as a critical indicator of the effects of neurodegenerative disease.Glaucoma directly impairs retinal ganglion cells and their axons,leading to axonal transport dysfuntion,subsequently causing secondary damage to anterior or posterior ends of the visual system.Accordingly,recent evidence indicates that glaucoma is a degenerative disease of the central nervous system that causes damage throughout the visual pathway.However,the effects of glaucoma on synaptic plasticity in the primary visual cortex remain unclear.In this study,we established a mouse model of unilateral chronic ocular hypertension by injecting magnetic microbeads into the anterior chamber of one eye.We found that,after 4 weeks of chronic ocular hypertension,the neuronal somas were smaller in the superior colliculus and lateral geniculate body regions of the brain contralateral to the affected eye.This was accompanied by glial cell activation and increased expression of inflammatory factors.After 8 weeks of ocular hypertension,we observed a reduction in the number of excitatory and inhibitory synapses,dendritic spines,and activation of glial cells in the primary visual cortex contralateral to the affected eye.These findings suggest that glaucoma not only directly damages the retina but also induces alterations in synapses and dendritic spines in the primary visual cortex,providing new insights into the pathogenesis of glaucoma.
文摘Peng Xiaolian is a rare and prolific Chinese author who writes both fiction and non-fiction works and directs both dramatic and documentary films. Peng has not only written, cowritten, or rewritten all the screenplays of her eight dramatic features and two documentaries but is also the author of one novel, twelve novellas, over a dozen short stories, four book-length memoirs, three collections of film reviews, and numerous essays. The existing scholarly studies, however, nearly all focus on Peng＇s dramatic films, with much less, if any, attention directed at her writing and documentaries. To really understand Peng as a film auteur, however, it is necessary to look at her films and writings together. Given the quantity and complexity of her works and the space limitations of this article, I examine Peng＇s subversion of the conventional treatment of character, location, and time in three thematic sections reflecting the key narrative motifs in her work. I first summarize existing studies of Peng＇s films, highlighting the rarely examined interaction between visuality and spatiality in her films. Then, after defining her sense of time in narrative, I demonstrate how family history and self-reflexivity are the major difference between her films and her nonfiction works. Last but not least, I discuss how, through her use of multilayered narratives constructed by the female voice and subjectivity, her complete repertoire constitutes a unique history of modern Chinese women. This article aims to demonstrate how, through her use of multilayered narratives constructed by the female voice and subjectivity, her complete repertoire constitutes a unique history of modern Chinese women.
基金supported by the Lanzadera TCUE and C2 program(Universidad de Salamanca)(to ASL)the Spanish National Research Council(CSIC)funded by the Junta de Castilla y León and co-financed by the European Regional Development Fund(ERDF“Europe drives our growth”):Internationalization Project“CL-EI-2021-08-IBFG Unit of Excellence”,Grant(PID2022-138478OA-100)funded by MICIU/AEI/10.13039/501100011033 and,by FEDER,UE(to MGM)+3 种基金Junta de Castilla y León(SA225P23)Gerencia Regional de Salud(2701/A1/2023)(to AV)the Plan Especial Grado Medicina(USAL)(to CPM)a Ramón y Cajal researcher:Grant RYC2021-033684-I funded by MICIU/AEI/10.13039/501100011033 and,by European Union NextGenerationEU/PRTR.
文摘The visual system of teleost fish grows continuously,which is a useful model for studying regeneration of the central nervous system.Glial cells are key for this process,but their contribution is still not well defined.We followed oligodendrocytes in the visual system of adult zebrafish during regeneration of the optic nerve at 6,24,and 72 hours post-lesion and at 7 and 14 days post-lesion via the sox10:tagRFP transgenic line and confocal microscopy.To understand the changes that these oligodendrocytes undergo during regeneration,we used Sox2 immunohistochemistry,a stem cell marker involved in oligodendrocyte differentiation.We also used the Click-iT™ Plus TUNEL assay to study cell death and a BrdU assay to determine cell proliferation.Before optic nerve crush,sox10:tagRFP oligodendrocytes are located in the retina,in the optic nerve head,and through all the entire optic nerve.Sox2-positive cells are present in the peripheral germinal zone,the mature retina,and the optic nerve.After optic nerve crush,sox10:tagRFP cells disappeared from the optic nerve crush zone,suggesting that they died,although they were not TUNEL positive.Concomitantly,the number of Sox2-positive cells increased around the crushed area,the optic nerve head,and the retina.Then,between 24 hours post-lesion and 14 days post-lesion,double sox10:tagRFP/Sox2-positive cells were detected in the retina,optic nerve head,and whole optic nerve,together with a proliferation response at 72 hours post-lesion.Our results confirm that a degenerating process may occur prior to regeneration.First,sox10:tagRFP oligodendrocytes that surround the degenerated axons stop wrapping them,change their“myelinating oligodendrocyte”morphology to a“nonmyelinating oligodendrocyte”morphology,and die.Then,residual oligodendrocyte progenitor cells in the optic nerve and retina proliferate and differentiate for the purpose of remyelination.As new axons arise from the surviving retinal ganglion cells,new sox10:tagRFP oligodendrocytes arise from residual oligodendrocyte progenitor cells to guide,nourish and myelinate them.Thus,oligodendrocytes play an active role in zebrafish axon regeneration and remyelination.
基金supported by the National Institute of Health/National Eye Institute(NIH/NEI)grants(R00 EY029373,R01 EY035658)to AYFKnights Templar Eye Foundation Research Grant to ESIntramural UAMS Hornick and Sturgis grants to AYF and ES respectively。
文摘Ischemic retinopathy is a leading cause of blindness:Ischemic retinopathies including diabetic retinopathy(DR),retinopathy of prematurity,and retinal artery and vein occlusion are major causes of visual impairment.Ischemic retinopathy can be acute,such as in central or branch retinal artery occlusion,or chronic,such as with DR(Figure 1).Although the causes of retinopathies are diverse,one pathogenic event shared by these conditions is the myeloid cell response to retinal ischemia(Shahror et al.,2024a).
基金supported by the National Natural Science Foundation of China,Nos.32070989(to YMZ),31872766(to YMZ),81790640(to XLY),and 82070993(to SJW)the grant from Sanming Project of Medicine in Shenzhen,No.SZSM202011015(to XLY)。
文摘Diabetic retinopathy is a prominent cause of blindness in adults,with early retinal ganglion cell loss contributing to visual dysfunction or blindness.In the brain,defects inγ-aminobutyric acid synaptic transmission are associated with pathophysiological and neurodegenerative disorders,whereas glucagon-like peptide-1 has demonstrated neuroprotective effects.However,it is not yet clear whether diabetes causes alterations in inhibitory input to retinal ganglion cells and whether and how glucagon-like peptide-1 protects against neurodegeneration in the diabetic retina through regulating inhibitory synaptic transmission to retinal ganglion cells.In the present study,we used the patch-clamp technique to recordγ-aminobutyric acid subtype A receptor-mediated miniature inhibitory postsynaptic currents in retinal ganglion cells from streptozotocin-induced diabetes model rats.We found that early diabetes(4 weeks of hyperglycemia)decreased the frequency of GABAergic miniature inhibitory postsynaptic currents in retinal ganglion cells without altering their amplitude,suggesting a reduction in the spontaneous release ofγ-aminobutyric acid to retinal ganglion cells.Topical administration of glucagon-like peptide-1 eyedrops over a period of 2 weeks effectively countered the hyperglycemia-induced downregulation of GABAergic mIPSC frequency,subsequently enhancing the survival of retinal ganglion cells.Concurrently,the protective effects of glucagon-like peptide-1 on retinal ganglion cells in diabetic rats were eliminated by topical administration of exendin-9-39,a specific glucagon-like peptide-1 receptor antagonist,or SR95531,a specific antagonist of theγ-aminobutyric acid subtype A receptor.Furthermore,extracellular perfusion of glucagon-like peptide-1 was found to elevate the frequencies of GABAergic miniature inhibitory postsynaptic currents in both ON-and OFF-type retinal ganglion cells.This elevation was shown to be mediated by activation of the phosphatidylinositol-phospholipase C/inositol 1,4,5-trisphosphate receptor/Ca2+/protein kinase C signaling pathway downstream of glucagon-like peptide-1 receptor activation.Moreover,multielectrode array recordings revealed that glucagon-like peptide-1 functionally augmented the photoresponses of ON-type retinal ganglion cells.Optomotor response tests demonstrated that diabetic rats exhibited reductions in visual acuity and contrast sensitivity that were significantly ameliorated by topical administration of glucagon-like peptide-1.These results suggest that glucagon-like peptide-1 facilitates the release ofγ-aminobutyric acid onto retinal ganglion cells through the activation of glucagon-like peptide-1 receptor,leading to the de-excitation of retinal ganglion cell circuits and the inhibition of excitotoxic processes associated with diabetic retinopathy.Collectively,our findings indicate that theγ-aminobutyric acid system has potential as a therapeutic target for mitigating early-stage diabetic retinopathy.Furthermore,the topical administration of glucagon-like peptide-1 eyedrops represents a non-invasive and effective treatment approach for managing early-stage diabetic retinopathy.
文摘气候变化和人类活动对水文循环产生了显著影响,尤其是在干旱半干旱区.为探究变化环境下典型半干旱生态脆弱区毛乌素沙地水循环演变特征,利用WEP-L(water and energy transfer processes in large river basin)地表水模型和Visual MODFLOW(visual modular finite difference groundwater flow)地下水模型对毛乌素沙地水循环过程进行分布式模拟,基于白家川水文站实测月径流量和监测井地下水位数据进行模型参数率定与验证.结果表明,地表水模型率定期和验证期的模拟月径流量和实测月径流量的R2都在0.5以上,模拟的监测井地下水位和实测地下水位趋势较为一致,相关系数达到0.56以上.采用偏差校正的CMIP6多模式集合气候变化情景及当地取用水情景驱动地表水-地下水耦合模型,量化了变化环境下毛乌素沙地2021-2040年关键水循环要素变化特征.结果表明,未来情景下毛乌素沙地年降水量和年蒸散发量的平均增幅分别为8.0%和7.4%,年径流深呈现逐渐减少的趋势,2040年末地下水位相较于2021年末下降了约1 m.未来2种用水情景下区域地下水总补给量与排泄量的差值分别为-1.82亿、-0.97亿m^(3)·a^(-1),地表径流总量与地表用水量的差值分别为1.83亿、2.29亿m^(3)·a^(-1),地下水资源开发利用将面临更大挑战.研究成果可为毛乌素沙地区域水资源规划与管理提供科学支撑.
文摘Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging population.Posture and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous mechanisms.To effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory signals.The mechanisms which underpin the integration of these multisensory signals are the principal topic of the present work.Existing multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older adults.Insufficient emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and balance.In the present work,we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Parkinson’s disease.We also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk in older adults.Lastly,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases.
