Comprehensive analysis of glacier recession(2000-2020)in the Nun-Kun Group of Glaciers,Northwestern Himalaya

Himalayan glaciers are shrinking rapidly,especially after 2000.Glacier shrinkage,however,shows a differential pattern in space and time,emphasizing the need to monitor and assess glacier changes at a larger scale.In this study,changes of 48 glaciers situated around the twin peaks of the Nun and Kun mountains in the northwestern Himalaya,hereafter referred to as Nun-Kun Group of Glaciers(NKGG),were investigated using Landsat satellite data during 2000-2020.Changes in glacier area,snout position,Equilibrium Line Altitude(ELA),surface thickness and glacier velocity were assessed using remote sensing data supplemented by field observations.The study revealed that the NKGG glaciers have experienced a recession of 4.5%±3.4%and their snouts have retreated at the rate of 6.4±1.6 m·a^(-1).Additionally,there was a 41%increase observed in the debris cover area during the observation period.Using the geodetic approach,an average glacier elevation change of-1.4±0.4 m·a^(-1)was observed between 2000 and 2012.The observed mass loss of the NKGG has resulted in the deceleration of glacier velocity from 27.0±3.7 m·a^(-1)in 2000 to 21.2±2.2 m·a^(-1)in 2020.The ELA has shifted upwards by 83.0±22 m during the period.Glacier morphological and topographic factors showed a strong influence on glacier recession.Furthermore,a higher recession of 12.9%±3.2%was observed in small glaciers,compared to 2.7%±3.1%in larger glaciers.The debris-covered glaciers showed lower shrinkage(2.8%±1.1%)compared to the clean glaciers(9.3%±5%).The glacier depletion recorded in the NKGG during the last two decades,if continued,would severely diminish glacial volume and capacity to store water,thus jeopardizing the sustainability of water resources in the basin.

Preserving glacier mass:Cellulosic LENZING^(TM) fibers provide snow and ice protection solution

In field trials on Austrian glaciers,nonwovens made of ce u osic LENZING^(TM) fibers are being used to cover glacier mass.They are showing promising results and offer a sustainable solution for glacier protection.Nonwovens containing fossilbased synthetic fibers might cause negative environmental consequences such as microplastics on glaciers.Geotextiles with ce u osic LENZINGTMfibers won the prestigious Swiss BIO TOP,an award for wood and material innovations.Geotextiles are already widely used to protect snow and ice on glaciers frommelting.

基于51单片机外部中断的亮度可调手电筒设计

介绍了51单片机中断系统的结构,对基于51单片机外部中断的亮度可调节手电筒的硬件电路和控制程序进行了设计,并利用Keil C51和Proteus软件对硬件电路和控制程序进行了软硬件联调仿真实验。实验结果表明:设计的基于单片机外部中断的亮度可调手电筒电路能满足控制要求。

Bedrock outcropping in the accumulation zone of the largest glacier in Mexico(Glaciar Norte of Citlaltépetl),as evidence of a possible accelerated extinction

The highest volcano in Mexico,at the same time the third largest mountain in North America(Citlaltépetl,5610 m a.s.l.),is home to the largest glacier in the country.Because of the extinction of the Popocatépetl glacier(5500 m a.s.l.)caused by eruptive activity,and the almost disappearance of the Iztaccíhuatl glaciers(5220 m a.s.l.)due to the lower elevation of the mountain,the Glaciar Norte of Citlatépetl has been the only glacier that has shown a certain degree of stability as a response to the altitude in which it is located.However,as occurs in almost all glaciers on the planet,the retreat of its glacier terminus has been continuous.Furthermore,during the last years the thickness of its upper part began to decrease rapidly until its bedrock was exposed for the first time in 2019.Due to its ecosystem importance and because it is the main glacier in Mexico,as well as the only one in the world located at latitude 19°N,in this work its current dimensions are updated,as well as the local climatology that governs the current state of the glacier is pointed out.The study was based on the analysis of high-resolution Sentinel-2 optical images,as well as through Sentinel-1 SAR images,with the support of climatological information from the study area.Therefore,the outcropping of the bedrock in the accumulation zone and the consequent horizontal retreat of the upper part of the glacier are documented;at the same time,the decrease in the thickness of the ice along it is noted.The rocky outcrop in the accumulation zone suggests that the flow dynamics of the ice towards the ablation zone will be considerably less,accelerating the retreat of the glacier terminus.Finally,the ascent of the glacial front to 5102 m a.s.l.and the modelled altitude of the equilibrium line to 5276 m a.s.l.are reported as a warning signal in terms of snow catchment and mass balance;likewise,the decrease of 23%of its surface is also indicated regarding the surface reduction monitoring that has been done until 2017.These findings may indicate that the future of this glacier is related to its possible extinction sooner than previously thought,with severe environmental consequences,especially in terms of the provision of drinking water for thousands of inhabitants of the slopes of the volcano.This research is expected to help reflect on the impacts of current climate variability and at the same time serve as a reference for the tropical glaciers on the planet.

Physico-chemical Characteristics and Environmental Significance of Snow Deposition on Haxilegen Glacier No.51 in Tian Shan,China

Snow chemistry on the glaciers of alpine regions is a good indicator of atmospheric environmental change.We examine snow chemistry in three snowpits at different altitudes on the Haxilegen Glacier No.51,in the Kuitun River source,Tian Shan,China,during July-September 2004 to 2007.We use correlation analysis,factor analysis and sea-salt tracing methods to examine the characteristics and sources of major ions and mineral dust particles in the snow.Results show that mineral dust particles and major ions in the snow pits vary seasonally.During the Asian dust period in springtime,the concentration of mineral dust particles and major ions deposited in snow is high,while the concentration is relatively low during the non-dust period of summer and autumn.This may be caused by dust storm activity in central Asia.The order of major ionic concentrations in the snow packs was determined to be Ca2+ > SO42-> NH4+ > NO3-> Cl-> Na+ > Mg2+ > K+.Ca2+ was the dominant cation;SO42- was the dominant anion.We find,with the exception of NO3-,that the variabilities of ionic concentrations are highly correlated.Results show that the glacier region was significantly affected by dust activity and anthropogenic source.The major ions,especially Na+,originate from dust sources of central Asia and from the Ocean,transported by the westerly winds.

基于VIC_glacier模型的拉萨河水文模拟及冰川径流研究

拉萨河作为青藏高原南部雅鲁藏布江最大的支流,冰川融水是其径流的重要组成部分。本文基于VIC模型和度日模型构建的VIC_glacier模型,模拟了1990—2010年拉萨河流域径流过程。结果表明:(1)与VIC模型相比,VIC_glacier模型在研究区的径流模拟效果更好,日径流模拟值与观测值的相关系数接近0.8,纳什效率系数在0.75以上;(2)从上游到下游,冰川融水对径流的贡献率分别为21.4%(旁多站)、17.7%(唐加站)、14.5%(拉萨站),呈逐渐减少趋势;(3)冰川径流和非冰川径流年内变化均呈现“单峰型”形态,且在8月份达到峰值;(4)1990—2010年间,年冰川径流量整体呈现上升趋势,与同期气温上升的变化规律一致;年冰川融水对径流的贡献率与年降水量呈反比关系。研究成果可为拉萨河流域的水资源管理提供参考。

Ice flux of alpine glaciers controls erosion and landscape in the Nianbaoyeze Shan,northeastern Tibetan Plateau

The evolution of mountainous topography is the result of the interactions of climate,topography,and erosion.Glaciers are one of the most active erosional forces sculpting mountainous regions.However,our ability to understand this erosional force is limited by the controversy regarding the major factors controlling glacial erosion.We selected the Nianbaoyeze Shan,which is occupied by subcontinental glaciers(likely cold-based or polythermal glaciers)in the northeastern Tibetan Plateau,to study how erosion by alpine glaciers sculpts the landscape.We first applied a power law model(y=axb)fit to the cross-profiles of glacial valleys and analyzed the controlling factor of glacial erosion;we then identified the morphometric characteristics of the cirques to analyze the influencing factors,and investigated the development patterns of glacial valleys and cirques.Finally,we used hypsometry and the slopealtitude curves and reconstructed the palaeo-glacier surfaces and palaeo-Equilibrium Line Altitudes(ELAs)to determine if the glacial buzzsaw effect had impacted this glaciated region with subcontinental glaciers.Our findings show that ice flux is the main factor controlling glacial erosion.In this region,decreasing temperatures promote an increase in glacier mean size(i.e.,ice flux),which enhances the rate of glacial erosion.Cirque morphology is mainly influenced by aspect and the ELA.The development patterns of glacial valleys and cirques were dominated by a widening process.The ELAs of Marine Isotope Stage(MIS)-3 derived from the cirque floor altitudes or the Accumulation Area Ratio(AAR)and Area-Altitude Balance Ratio(AABR)coincide with the hypsometric maximum and the reduction in slopealtitude curves,which indicates that glacial buzzsaw has impacted this region.Furthermore,the glacial buzzsaw effect has profoundly influenced the mountain heights and topographic evolution in this subcontinental glaciated region.

复方地黄颗粒对帕金森病阴虚动风证6-OHDA模型大鼠黑质α-syn、VAPB、PTPIP51表达的影响

目的观察复方地黄颗粒对帕金森病(Parkinson’s disease,PD)大鼠黑质α-syn、VAPB、PTPIP51表达的影响,并探讨其潜在作用机制。方法构建6-羟基多巴胺(6-OHDA)PD大鼠模型,成模大鼠随机分为Model组、Madopar组、CLD组、CMD组、CHD组,NC组不做任何处理,SO组注射抗坏血酸,每组13只。检测大鼠神经行为学变化;Western blot、RT-PCR、免疫组化检测黑质α-syn、VAPB、PTPIP51表达;HE染色观察黑质组织病理形态变化;透射电镜观察黑质细胞线粒体超微结构;ELISA检测各组黑质组织ATP含量变化。结果与NC组和SO组比,Model组大鼠旋转圈数和爬杆时间增加,α-syn表达升高,VAPB、PTPIP51表达降低,神经元细胞数量减少、胞体皱缩,线粒体肿胀,线粒体嵴消失,ER-线粒体接触距离变大,ATP含量降低;与Model组相比,Madopar组和CLD组、CMD组、CHD组大鼠旋转圈数和爬杆时间减少,α-syn表达降低,VAPB、PTPIP51表达升高,神经元损伤程度减轻,线粒体形态有所改善,ATP含量增加,呈量效差异性,Madopar组和CHD组相对疗效较佳且差异无统计学意义。结论复方地黄颗粒能够减轻PD大鼠行为症状,并可能通过下调α-syn表达,上调PTPIP51、VAPB表达,改善线粒体功能,从而发挥治疗PD的作用。

RAD51连接蛋白1在恶性肿瘤中的研究进展

恶性肿瘤一直是严重威胁人类健康的医学难题,尽管科学技术在进步,人类生活质量在提高,恶性肿瘤的发病率依然持续上升,其发病机制及治疗也是错综复杂。RAD51连接蛋白1(RAD51AP1)属于RAD51连接蛋白家族的蛋白质,与DNA的同源重组和修复作用有关,其过表达与多种恶性肿瘤的发生发展密切相关,本文就RAD51AP1与多种恶性肿瘤的关系进行综述如下。

Short communication:Extreme glacier mass loss triggered by high temperature and drought during hydrological year 2022/2023 in Qilian Mountains

In the hydrological year 2022/2023,the glaciers in the Qilian Mountains experienced unprecedented mass loss.The glacier-wide mass balance was-1,188 mm w.e.,in contrast to-350 mm of average mass balance since 1990 over the Bailanghe Glacier No.12 in the middle of Qilian Mountains.The temperature during 2022–2023 reached the highest value ever recorded,second only to 2022,while at the same time the precipitation amount was less compared to other year since 2000,which together led to the strongest glacier mass loss during 2022–2023.The atmospheric circulation analysis shows that the high temperature in the Qilian Mountains in 2023 was jointly caused by the Arctic air mass and East Asian monsoon.

Glacier area change (1993-2019) and its relationship to debris cover, proglacial lakes, and morphological parameters in the Chandra-Bhaga Basin, Western Himalaya, India

Glacier inventories serve as critical baseline data for understanding the impacts of climate change on glaciers.The present study maps the outlines of glaciers in the Chandra-Bhaga Basin(western Himalaya)for the years 1993,2000,2010,and 2019 using Landsat Thematic Mapper(TM),Enhanced Thematic Mapper(ETM),and Operational Land Imager(OLI)datasets.A total of 251 glaciers,each having an area above 0.5 km^(2),were identified,which include 216 clean-ice and 35 debris-covered glaciers.Area changes are estimated for three periods:1993-2000,2000-2010,and 2010-2019.The total glacierized area was 996±62 km^(2) in 1993,which decreased to 973±70 km^(2) in 2019.The mean rate of glacier area loss was higher in the recent decade(2010-2019),at 0.036 km^(2),compared to previous decades(0.029 km^(2) in 2000-2010 and 0.025 km^(2) in 1993-2000).Supraglacial debris cover changes are also mapped over the period of 1993 and 2019.It is found that the supraglacial debris cover increased by 14.12±2.54 km^(2)(15.2%)during 1993-2019.Extensive field surveys on Chhota Shigri,Panchi II,Patsio,Hamtah,Mulkila,and Yoche Lungpa glaciers were carried out to validate the glacier outlines and supraglacial debris cover estimated using satellite datasets.Controls of various morphological parameters on retreat were also analyzed.It is observed that small,clean ice,south oriented glaciers,and glaciers with proglacial lakes are losing area at faster rates than other glaciers in the basin.

A review of physicochemical properties of dissolved organic carbon and its impact over mountain glaciers

Investigating the characteristics and transformation of water-soluble carbonaceous matter in the cryosphere regions is important for understanding biogeochemical process in the earth system.Water-soluble carbonaceous matter is a heterogeneous mixture of organic compounds that is soluble in aquatic environments.Despite its importance,we still lack systematic understanding for dissolved organic carbon(DOC)in several aspects including exact chemical composition and physical interactions with microorganisms,glacier meltwater.This review presents the chemical composition and physical properties of glacier DOC deposited through anthropogenic emission,terrestrial,and biogenic sources.We present the molecular composition of DOC and its effect over snow albedo and associated radiative forcings.Results indicate that DOC in snow/ice is made up of aromatic protein-like species,fulvic acid-like materials,and humic acid-like materials.Light-absorbing impurities in surface snow and glacier ice cause considerable albedo reduction and the associated radiative forcing is definitely positive.Water-soluble carbonaceous matter dominated the carbon transport in the high-altitude glacial area.Owing to prevailing global warming and projected increase in carbon emission,the glacial DOC is expected to release,which will have strong underlying impacts on cryosphere ecosystem.The results of this work have profound implications for better understanding the carbon cycle in high altitude cryosphere regions.A new compilation of globally distributed work is required,including large-scale measurements of glacial DOC over high-altitude cryosphere regions,to overcome and address the scientific challenges to constrain climate impacts of light-absorbing impurities related processes in Earth system and climate models.

Crucial, But not Systematically Investigated: Rock Glaciers, the Concealed Water Reservoirs of the Himalayas: An Opinion

The current article is an opinion on the sensitivity of high mountain regions which are the most fragile,sensitive and vulnerable to ongoing climate change.Its impacts are especially severe on the high mountain communities owing to their weak socio-economic profile,limited livelihood resources and agricultural land.The melting of glaciers and changes in the snow cover under the climate change scenario is leading to the scarcity of freshwater supplies,affecting both local and downstream communities.Changes in the precipitation patterns have been suggested to cause droughts,impact restricted agriculture,and limit the availability of water for domestic use.Additionally,the high mountain areas contain distinct flora and fauna,and climate change is not just altering them,but also has resulted in biodiversity loss as species are unable to adapt to the changing climate.Because of its higher altitudes and semi-arid to arid climate,the consequences of climate change are more evident in the higher Himalayas.Climate change is affecting the availability of key resources,such as freshwater and agriculture and pasture lands,resulting in food and water insecurity and their reliance on imports from other regions.As a result,high mountain communities in the Himalayas are progressively shifting to higher glacier valleys in search of suitable cultivable land with adequate irrigation.People are engaging in agro-pastoral activities around thermokarst lakes(Oasis)atop rock glaciers as part of this endeavour.Such actions underscore the crucial role of rock glaciers in dealing with and adjusting to the consequences of climate change.Despite its relevance,rock glacier research in the Himalayan region is still in its infancy.The purpose of this work is to emphasise the significance of these major climate-resilient water resources,as well as the methodology that must be adopted for their systematic and compressive investigations.

Regulatory mechanism of RAD51-associated protein 1 and its upstream molecules in hepatocellular carcinoma

Background:The DNA damage repair mechanism plays a crucial role in the occurrence and development of hepatocellular carcinoma(HCC),and RAD51-associated protein 1(RAD51AP1)has received increasing attention as an important protein in the homologous recombination repair pathway.However,the role of RAD51AP1 and its molecular regulatory mechanism in HCC still need further investigation.Methods:We first analysed RAD51AP1 expression,functional enrichment and prognostic value in HCC.Then,the miRWalk,miRDB,and Encyclopedia of RNA Interactomes databases were used to predict the corresponding microRNAs and long noncoding RNAs of RAD51AP1,and their expression levels and prognostic value were analysed.Results:RAD51AP1 was upregulated in the majority of cancers include HCC.The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that RAD51AP1 was mainly involved in pathways related to the cell cycle and repair in HCC.Moreover,the expression level of RAD51AP1 was significantly correlated with T stage,pathologic stage,histologic grade and the level of alpha-fetoprotein.In addition,RAD51AP1 was an independent risk factor significantly and had a high predictive value in HCC.Based on ceRNA network,RAD51AP1 may be regulated by upstream MSC-AS1 and hsa-miR-23c to affect the HCC occurrence and development.Conclusions:High expression of RAD51AP1 plays an important biological role in the cell cycle and repair pathways,and has important diagnostic and prognostic value in HCC.Based on the regulatory mechanism of ceRNA network,we speculate that lncRNA MSC-AS1 acts on hsa-miR-23c and regulates DNA damage repair of HCC through RAD51AP1.It provides a new perspective for further study of DNA damage repair mechanism and potential related treatment of HCC.

基于51单片机的核酸采样机械臂设计

本文设计了一种基于51单片机的核酸采样机械臂运动控制系统,系统由机械臂模块、消杀模块、样本保存模块、语音引导模块和照明模块等5个模块组成,各模块之间相互配合,共同完成核酸采集与样品保存过程。控制思想是通过计算机语言来调节PWM输出占空比产生控制电压,由控制电压对机械臂的舵机进行控制,同时配合传感器最终实现在一定范围内对核酸被采样人员进行自动化核酸采集。

Glacial Cover Assessment from 1993 to 2021 Using Normalized Difference Snow Index with Landsat Imagery in the Colorado Front Range, USA

Cirque glaciers found on the Colorado Front Range, USA are sensitive to climate change and are important for water supply and the delivery of water downstream. These glaciers are shrinking at a rapid rate in response to the global climate change, and thus it is important to track and analyze them. One of the ways to monitor these glaciers is by using multispectral satellite imagery (Landsat imagery). In this article, the feasibility of tracking glacial area via Landsat satellites has been discussed and the trend of 13 glaciers in the Colorado Front Range Region has been analyzed from 1993 to 2021. In this period, the total glacial area across 13 glaciers in the Colorado Front Range Region has decreased by 63.6%, and a significant correlation (p-value p < 0.05) found with the annual global average temperature indicates that the retraction of glaciers is likely a response to the global warming.

基于51单片机的智能拐杖系统的设计

老人独立外出时会遇到各种情况,如重心不稳导致摔倒,智能拐杖有传统拐杖防滑、支撑以控制身体重心和减少体力消耗的作用。因此,利用现代已有技术,研究出一种基于51单片机的智能拐杖系统,通过软硬件结合,实现障碍物避障、语音与发光提示、角度测量防摔以及音乐播放,以帮助老人解决出行时遇到的问题。拐杖可以伸缩以在不用时节省空间。测试表明,智能拐杖的系统简单、操作难度低、成本低,具有一定的出行辅助价值和经济价值。

基于51单片机与GSM的GPS卫星定位系统设计

设计了一款精准度较高、定位快速、方便携带的GPS卫星定位系统。卫星定位数据通过GPS信号接收模块传递给单片机,经单片机处理后通过LCD1602液晶屏幕显示定位信息,并通过GSM模块将定位信息发送至其他终端设备。测试结果表明:基于51单片机与GSM的GPS卫星定位系统可以实现定位信息的准确获取,而且结构简单、易于操作。

基于MCS-51的高精度信号发生器设计与仿真验证

本文设计的信号发生器以MCS-51单片机为核心,辅助以按键电路、显示电路、数模转换电路,能够发出三角波、正弦波、方波、锯齿波四种波形。通过引入DAC0823芯片,将数字量和模拟量进行转换,使得信号发生器发出的波形的误差和噪声干扰更小,并简化了滤波过程。仿真过程中通过软件程序控制硬件电路,利用Keil仿真平台的元器件仿真功能和程序编辑功能将程序搭建好,然后一同放入Proteus仿真平台中,通过后者的元器件选择和参数调节功能将信号发生器的主控电路搭建完成。最后,利用模拟示波器得到了满足设计要求的波形,验证了信号发生器的性能。

基于STC89C51多功能智能手杖的设计与研究

根据联合国的标准,我国已进入老年化社会。基于现有手杖的不足,结合物联网技术,开发出了一款多功能智能的老人健康辅助手杖。本文阐述智能手杖的总体外观设计、功能及软硬件设计,并进行功能测试。实践结果表明,基于STC89C51多功能智能手杖能够为老年人出行提供全方位的智能服务和安全保障。