Oxidative Stress in Collegiate Cross Country Skiers in Mid- and Post-Seasons

Purpose: The oxidative stress (OS) hypothesis of overtraining syndrome argues that increased production of free radicals through exercise cause muscle fatigue and damage resulting in lower athletic performance. Several studies have investigated OS immediately before and after exercise bouts in a training macrocycle. Our study aimed to compare OS of endurance athletes between a competition macrocycle and the immediate post-season recovery macrocycle. In addition, we aimed to identify athletes who experienced an unexplainable drop in athletic performance during the competition season in order to compare their OS to those who experienced no drop in performance. Methods: Fifteen members of the University of Alaska Fairbanks cross country ski team volunteered for this study. Blood samples were taken in early February (“mid-season”) and late April (“post-season”). Participants completed questionnaires regarding physical activity and athletic performance at the time of the blood draws. Plasma was analyzed for 4-hydroxynonenal (HNE), nitrotyrosine, nitric oxide (NOX), and superoxide dismutase (SOD). Significance was determined by Wilcoxon and Mann-Whitney tests. Results: Participants displayed significantly higher (p Conclusion: Signs of oxidative stress and mitigation during the post-season recovery macrocycle were higher in athletes who reported experiencing a drop in athletic performance during the competition season macrocycle.

Antimicrobial Activity of Some Commercial Toothpastes and Antibiotics on Two Oral Pathogenic Bacteria—An in-Vitro Study

Oral health problems such as periodontal diseases, dental caries, and endodontic infections have a significant negative impact on oral health and impose a substantial financial burden on the global population. The prevalence of these issues is increasing due to the buildup of bacterial plaque and the growing resistance of bacteria to antimicrobial treatments. The aims of this study to evaluate the anti-bacterial activity of four types of antibiotics (Amoxicillin, Augmentin, Azithromycin and Metronidazole) and four types of toothpastes (Sensodyne, ipana, denta and cariax Gingival Kin) on two oral pathogenic bacteria (Streptococcus mutans and Staphylococcus epidermidis). Bacterial samples of previously isolated Streptococcus mutans and Staphylococcusepidermidis were used as test organisms and the Kirby-Bauer disc diffusion method was employed to assess the antibacterial efficacy of various antibiotics and evaluate the impact of different toothpastes using a filter paper disc agar measurement technique. Each filter disc was saturated with toothpaste solution in a test tube for approximately 30 to 40 seconds, after which they were placed on Mueller-Hinton broth bacterial cultures in petri dishes. These Petri dishes were then incubated at 37°C for 24 hours, and the clear zone’s diameter (inhibition zone in mm) was subsequently measured and the results were recorded. The results demonstrated that Sensodyne toothpaste and Metronidazole antibiotic were ineffective against both types of bacteria, while Augmentin and Amoxicillin were effective by high diameter inhibition zones of growth against S. mutans and Azithromycine against S. epidermidis. Also Ipana, Denta, and Cariax Gingival Kin toothpastes exhibited a moderate effect against the two bacteria. This study suggests that certain antibiotics and toothpastes can effectively inhibit the growth of harmful oral bacteria, but not all of them are effective.

Intelligent Recognition Using Ultralight Multifunctional Nano‑Layered Carbon Aerogel Sensors with Human‑Like Tactile Perception

Humans can perceive our complex world through multi-sensory fusion.Under limited visual conditions,people can sense a variety of tactile signals to identify objects accurately and rapidly.However,replicating this unique capability in robots remains a significant challenge.Here,we present a new form of ultralight multifunctional tactile nano-layered carbon aerogel sensor that provides pressure,temperature,material recognition and 3D location capabilities,which is combined with multimodal supervised learning algorithms for object recognition.The sensor exhibits human-like pressure(0.04–100 kPa)and temperature(21.5–66.2℃)detection,millisecond response times(11 ms),a pressure sensitivity of 92.22 kPa^(−1)and triboelectric durability of over 6000 cycles.The devised algorithm has universality and can accommodate a range of application scenarios.The tactile system can identify common foods in a kitchen scene with 94.63%accuracy and explore the topographic and geomorphic features of a Mars scene with 100%accuracy.This sensing approach empowers robots with versatile tactile perception to advance future society toward heightened sensing,recognition and intelligence.

Response of the Maize Variety EV87-28 to a Fertilization Strategy Involving Indorama Granular Urea on Ferralsol in the Central Ivory Coast

In Côte d’Ivoire, the decline in soil fertility strongly impacts the productivity of maize (Zea mays L.) on heavily leached ferralitic soil. In this study, the general objective was therefore to improve the productivity of maize EV87-28 on the Ferralsols in pre-forested areas during different cropping seasons. Eight (8) micro-plots were set up according to a total randomization device with three repetitions. Two factors were studied: nitrogen fertilizer modalities (main factor) and crop season (secondary factor). Growth, flowering and yield parameters were measured and analyzed. The results showed that there was no interaction between the nitrogen fertilizer factor and the cropping season factor. In addition, this study showed the short rainy season had the most positive impact on growth, flowering and yield parameters than the long rainy season. The results also showed that the different nitrogen fertilizer modalities had no statistically different effects on growth, flowering and yield parameters. However, quantitative differences were reported, highlighting one nitrogen fertilizer modality, which is the combination of urea granule + farm manure (75% urea indorama granules and 25% farm manure). The combination of urea granule + farm manure (75% urea indorama granules and 25% farm manure) had the best effect on corn grain yield. So, the combination of urea (75%) and manure (25%), that resulted in yield gain, could be recommended for corn fertilization during the small rainy season.

“我们”和“他们”的冲突与融合:国外群际关系研究的主要方向与前沿

目前国内社会心理学领域较多关注个体心理机制的内部层面和人际层面,而对于群际层面的心理学理论研究较少。为了群际关系研究发展的本土化,需要批判性地思考和借鉴国际群际关系的最新研究成果。针对此,研究利用文献计量的方法,系统梳理并回顾了国外群际关系研究当前的主要研究方向和前沿主题。基于k-核理论的文献聚类发现:当前群际关系领域内有群际接触、外群体非人化、积极回应、人际过程模型、群际行为、具象识解和社会分类七个主要研究方向。根据文献突变率检测,近三年群际关系研究的前沿主题为集体行动倾向、社会网络和社会规范,但它们各自形成的知识场域尚不完善。针对文献计量结果,研究进一步讨论了群际关系研究在生理心理学和社会网络分析领域的跨领域发展潜力及需要进一步明确的社会规范影响,为群际关系研究的发展提供方向。

Gut microbiome supplementation as therapy for metabolic syndrome

The gut microbiome is defined as an ecological community of commensal symbiotic and pathogenic microorganisms that exist in our body.Gut microbiome dysbiosis is a condition of dysregulated and disrupted intestinal bacterial homeostasis,and recent evidence has shown that dysbiosis is related to chronic inflammation,insulin resistance,cardiovascular diseases(CVD),type 2 diabetes mellitus(T2DM),and obesity.It is well known that obesity,T2DM and CVD are caused or worsened by multiple factors like genetic predisposition,environmental factors,unhealthy high calorie diets,and sedentary lifestyle.However,recent evidence from human and mouse models suggest that the gut microbiome is also an active player in the modulation of metabolic syndrome,a set of risk factors including obesity,hyperglycemia,and dyslipidemia that increase the risk for CVD,T2DM,and other diseases.Current research aims to identify treatments to increase the number of beneficial microbiota in the gut microbiome in order to modulate metabolic syndrome by reducing chronic inflammation and insulin resistance.There is increasing interest in supplements,classified as prebiotics,probiotics,synbiotics,or postbiotics,and their effect on the gut microbiome and metabolic syndrome.In this review article,we have summarized current research on these supplements that are available to improve the abundance of beneficial gut microbiota and to reduce the harmful ones in patients with metabolic syndrome.

Operational feasibility study of stagnation pressure reaction control for a mid-caliber non-spinning projectile

Controlled,guided munitions can reduce dispersion in the shot,while providing the capability of engaging both stationary and maneuvering targets.The Netherlands Organisation for Applied Scientific Research has developed a fin-less control technology called Stagnation Pressure Reaction Control(SPRC)that takes stagnation pressure air and directs it sideways to control non-spinning projectiles.In a previous study,this technology was demonstrated at Mach 2 wind-tunnel conditions to achieve up to 1.5°controllable angle of incidence for a non-spinning,aerodynamically unstable projectile-like test object.In an operational scenario,the decelerating projectile will experience a decline in control force while the simultaneous forward shift of the center of pressure increases the need for control force.Furthermore,angles of incidence exceeding 1.5°will be experienced under realistic flight conditions,especially against maneuvering targets.This work addresses these challenges and presents an operational feasibility study for a practical application of SPRC in a non-spinning mid-caliber gun-launched projectile,using experiment data on control latency and force of the earlier study.It illustrates the combined effect of the control-and stability dynamics and underlines the potential of an SPRC projectile as a precisionoperation ammunition.This research revealed that SPRC technology can stabilize and control the hypothesized projectile in a direct fire scenario against stationary and maneuvering targets.

Degree of style coiling is associated with corolla-tube length in the nectarless flowers of Roscoea schneideriana

The plant-pollinator‘arms race’model posits that a major driver of the evolution of elongated corollas in flowers is reciprocal selection for‘morphological fit’between pollinator-tongue length and access distance to nectar(usually corolla-tube length).Evidence for the pollinator-mediated selection on tube length and evolution of multiple,correlated floral traits remains inconclusive.To gain possible insights into the strength of stabilizing selection by assessing standing phenotypic variation,we measured a series of functionally important floral traits,including corolla tube length and‘effective’tube depth and degree of style coiling.We then calculated coefficients of variation(CV)for these traits in three field populations of R.schneideriana.Unlike in most long-tubed flowers,the bottom part of the corolla tube is completely occupied by the style,with no room for nectar.The length of this portion of the corolla tube was more variable(higher CV)than the upper part of the corolla tube,suggesting that functional tube depth was under stronger stabilizing selection.The degree of style coiling was negatively related to the corolla-tube length in all three populations of R.schneideriana,suggesting that there may be conflicting selection acting on style length and corolla-tube length,which are otherwise usually tightly correlated.Given the lack of nectar in the flowers of this species,the long corolla tubes and long styles may represent morphological holdovers from ancestors that were pollinated by long-tongued pollinators,as is still seen in related species in the western Himalayas.

A Novel IoT Architecture, Assessment of Threats and Their Classification withMachine Learning Solutions

The Internet of Things(IoT)will significantly impact our social and economic lives in the near future.Many Internet of Things(IoT)applications aim to automate multiple tasks so inactive physical objects can behave independently of others.IoT devices,however,are also vulnerable,mostly because they lack the essential built-in security to thwart attackers.It is essential to perform the necessary adjustments in the structure of the IoT systems in order to create an end-to-end secure IoT environment.As a result,the IoT designs that are now in use do not completely support all of the advancements that have been made to include sophisticated features in IoT,such as Cloud computing,machine learning techniques,and lightweight encryption techniques.This paper presents a detailed analysis of the security requirements,attack surfaces,and security solutions available for IoT networks and suggests an innovative IoT architecture.The Seven-Layer Architecture in IoT provides decent attack detection accuracy.According to the level of risk they pose,the security threats in each of these layers have been properly categorized,and the essential evaluation criteria have been developed to evaluate the various threats.Also,Machine Learning algorithms like Random Forest and Support Vector Machines,etc.,and Deep Learning algorithms like Artificial Neural Networks,Q Learning models,etc.,are implemented to overcome the most damaging threats posing security breaches to the different IoT architecture layers.

Study of the Thermal Characteristics of a Geomaterial:Case of SavèGranites in the Republic of Benin

This work focuses on the valorization of local materials.The rock that is granite,a material used in construction thanks to its mechanical resistance,is the subject of our study.The granite of the commune of Savè,made it possible to appreciate the thermal behavior of this rock studied with a view to its use as a building material.To this end,a thermal diffusivity measurement test was carried out on this material.Thus,we made samples which were then connected to a data acquisition box via thermocouples.A Python script is used to ensure the collection of temperature values over time.From this thermal diffusivity test carried out on the granite taken from the Savèbreasts,we obtained an average diffusivity a=5.84×10^(-6)m^(2)/s.As a result,the thermal effusivity and the heat capacity of the material were determined having respectively the value 1,351.09 J/(K·m^(2)·s^(1/2))and 547,945.21 J/(m^(3)·K).These different results highlight a thermal characterization of Savègranites as a relevant material in the design and construction of an energy-efficient eco-housing.

Changes in Avian Spring Arrival Dates of 115 Species in the Central Appalachians over 127 Years

Global climate change affects many facets of avian ecology, such as shifts in breeding phenology and migration patterns. Migrating bird species respond to changes in climate by shifting their temporal patterns of spring migration. However, variation in species’ responses exists based on various life history traits, which exposes some species to an increased risk of phenological mismatch. This study examined the spring arrival dates of 115 migrating species over 127 years (1889-2015) using archival sources in West Virginia, USA, making this research unique in the length of study, the high number of species studied, and the historical crowd-sourced observations analyzed. Of the 115 taxa, 45 showed significant negative slopes of spring arrival dates (arriving earlier in the spring) plotted against the year. In contrast, only nine species showed positive slopes (arriving later in the spring), albeit non-significant. The average advance of spring arrival date for all species was 1.7 days per decade, and an advance of 2.6 days per decade in species that showed significance. Arrival dates were associated with increasing spring temperatures—for each 1˚C increase, the arrival date advanced by 0.81 days/decade. Several life history traits were linked to species that advanced their first arrival dates, including a shorter distance migrated to reach wintering grounds, increasing populations, and foraging habitat. Most avian species are advancing their spring arrival dates in response to climate change. However, the implications of earlier spring arrival are unclear. We draw attention to shifts in arrival dates and wintering ranges, leading to a possible increase in overwintering in the mid-latitudes of North America.

Stabilization of Clay Soil for the Durability of Structures: Case Study of the Soils of the Locality of Zalimé, Commune of Zogbodomey in the Republic of Benin

Structures erected on swelling clay soils are subjected to several stresses which are at the origin of the premature deterioration of the infrastructures. The soils being supports for the works, the improvement of their weak characteristics with cotton fibers will not only increase the bearing capacities of these soils and the resolution of the environmental problem, by eliminating the CO2 produced by the burning of the stems after harvest. The objective of this study is to contribute to the improvement of the characteristics by cotton stalk powder of the swelling clay soils used as the foundation of the infrastructures in order to guarantee their durability. Identification and mechanical parameterization tests were carried out on raw soil samples taken at 1.5 meters deep and on samples improved with cotton stalk powder at different levels (3%, 6% and 10%). The results from the physical tests reveal that the soil studied is very plastic silt. As for the mechanical tests, it appears that by adding 3% cotton stalk powder to dry density which goes from 1.435 t/m3 compared to the control sample with a dry density of 1.50 t/m3;which reflects an improvement in the compaction characteristics of the soil studied. The dry densities are 1.445 t/m3 and 1.29 t/m3 for the samples improved with 6% and 10% cotton stalk powder.

On the Possible Cometary Nature of the Uchur Cosmic Body(Fall 3.08.1993)

An expeditionary study of the area of the alleged impact event that occurred on 3.08.1993 in the area of the Lower Konkuli River(southeast of the Aldan Highlands,Lurikan Range,Russia)was carried out.According to the materials of remote sensing,the places of collision with the earth of a cosmic body are determined.In the area of the impact of the shock wave on the Earth’s surface,peat samples were selected,the micro probe analysis of which showed the pres­ence of a cosmogenic substance in concentrations 6-8 times higher than the background.Silicate and magnetite micro spheres,native iron,moissanite,and carbon micro tubes coated with a film consisting of pure nickel were found.Of particular interest were the findings of specific Ni film micro structures that allow us to make an assumption about the cometary nature of the Uchur cosmic body.Most researchers associate the observed flights of fireballs with the sub­sequent fall of meteorites.Researchers are trying to find the massive body of the fallen space body.However,often,even after many years of searching,a massive cosmic body cannot be found.This happened when studying the site of the fall of the Tunguska cosmic body.In this case,it remains to be assumed that the cosmic body contained micro­scopic dust particles.The structure and composition of such particles can only be studied using microscopic research methods.When studying the Uchur cosmic body,the authors concluded that it could be of a cometary nature due to the findings of specific particles-thin films of pure nickel on the surface of plant remains of terrestrial origin.This hy­pothesis arose from the recent discovery of atomic nickel vapors in comets.

近50a西北地区年径流变化反映的区域气候差异

应用我国西部主要河流1951—2000年年径流资料,分析径流变化的区域特征.结果表明:中国西部地区大部分河流径流呈增加趋势,特别是天山南坡逐河流增加最为显著,最高达14%.(10a)-1,其年径流的变化过程相关分析和差积曲线显示,西北地区西部新疆地区与东部的黄河上游年径流变化呈反相变化特征,而西北地区东部河流径流变化则与黄河上游的径流呈正相关关系.西北地区东部黄河年径流和西北太平洋夏季季风指数及其差积曲线表现出一致的变化过程,这表明了黄河上游径流变化主要受东亚季风的影响,同时由于东亚季风与西风在西北地区的相互作用,间接的影响到了新疆地区的径流和降水.这从一个侧面反映的西风带、东亚季风和高原季风的相互作用.

降水观测误差修正对降水变化趋势的影响

依据中国气象局国家气候数据中心提供的660个气象站1951—2004年逐日气温、降水、风速资料,以及雨雪类型资料,在乌鲁木齐河源降水误差对比观测试验基础上,对我国的降水资料进行了系统的修正计算.这一修正不仅使降水量在数量上增加,更接近实际值,同时由于相关气象要素的变化,还会对降水的长期变化趋势产生影响,通过对比分析原始观测降水系列和修正后的降水系列的长期变化趋势,结合理论分析估计这一影响的大小.结果表明:我国观测和修正后的全国面积加权平均降水量分别为565.2 mm和654.9 mm,平均修正量为89.7 mm(16%);修正后的降水系列,绝对趋势大于实际观测系列趋势,而相对趋势则小于观测系列.全部台站统计结果表明,实际的降水变化趋势被低估了6%,而相对变化趋势被高估了约10%.同时,由于我国大部分地区风速呈减少趋势,导致降水观测误差减小,结果实际的降水变化趋势远小于观测资料显示的趋势值,1955—2004年全国实测降水的变化趋势为-1.9 mm.(10a)-1,而修正后降水的变化趋势高达-6.0 mm.(10a)-1.目前依据实测的降水观测资料得出的降水变化趋势远远小于实际的变化趋势.

中国黄土和阿拉斯加黄土磁化率气候记录的两种模式探讨

在中国和中欧黄土-古土壤研究中发现的磁化率与成壤作用(或古气候温湿程度)的正相关性已被第四纪科学家广泛认识,并应用于古气候研究中。成壤过程形成的亚铁磁性矿物被认为是古土壤磁化率增加的主要原因;然而,这一模式并不一定适用于其他黄土沉积地区,如阿拉斯加和西伯利亚黄土沉积显示了一个完全相反的磁化率行为,即在黄土层获高磁化率值而在古土壤层获低磁化率。这种相反的关系过去被解释为磁化率反映的是与风动力吹来的亚铁磁性矿物的含量,即与风速或风力大小有关。本研究发现阿拉斯加黄土与古土壤的磁性矿物性质有明显差异,不仅仅是粒径的大小,还有磁性矿物的种类即矿物相的差别。这一证据很难单纯以风力强度的大小来解释,意味着阿拉斯加古土壤的低磁化率至少部分是在成壤过程中亚铁磁性矿物发生改变(如溶解)而造成,表明阿拉斯加黄土和中国黄土的磁化率与古气候记录可能存在两种模式,即氧化和还原条件下的成土模式。黄土磁化率在不同的气候(温度湿度)条件下有着不同的对应关系:在低降水量、高蒸发量的干旱氧化成壤条件下,利于亚铁磁性矿物的生成,其磁化率与古气候的关系呈正相关,如中国和中亚黄土;在高纬高湿的还原成壤条件下,亚铁磁性矿物会被破坏被分解,其磁化率与古气候呈负相关关系,如阿拉斯加黄土。如果成壤条件在氧化和还原之间来回变换,那么就很难找到两者之间的联系。因此,将磁化率应用于古气候的重建时要加倍的小心。

长江三峡工程库首区InSAR测量的初步研究

正在进行的长江三峡水利枢纽工程将建成世界上最大的人工水库 ,已有的研究表明 ,高坝水库有可能诱发中强地震。合成孔径雷达干涉测量 (InSAR)已成为测量地球表面变化极具潜力的技术。对欧洲遥感卫星ERS - 1与ERS - 2的SAR数据的初步分析表明 :只要时间跨度不太长 ,在有植被覆盖、地形起伏较大的山区亦能获得较为理想的干涉图像。结合三峡地壳形变监测网络 。

我国新旧城区联动发展中的问题及其对策探讨

伴随着工业化与城市化进程的加快,我国许多城市面临着旧城区改造与新城区建设两大基本任务,如何正确处理新旧城区的整合及协调发展关系成为人们普遍关注的重大课题。首先分析了我国新城建设和旧城改造过程中存在的主要问题,包括新旧城区之间经济联系薄弱、规划建设各自为政、可达性差、通勤成本高以及拆迁安置不尽合理等,并阐述了问题产生的主要原因;其次,分析了驱动新旧城区联动发展的经济、社会和环境因素,探讨了旧城改造、产业升级、经营城市、市场力等方面在新城建设和旧城改造中的具体作用;最后,从新旧城区的内在联系出发,提出了推进新旧城区联动发展的对策措施:一是规划联动;二是空间联动;三是经济联动;四是政策联动。

1900—2000年地球主磁场的本征模分析

利用1900—2000年国际参考地磁场模型（IGRF），对地球主磁场的空间结构和长期变化进行了自然正交分量分析，得到了组成地磁场的主要成分（本征模）及其随时间的长期变化（SV）．第一本征模描述主磁场稳定结构的总体特征，其强度随时间单调减小；第二本征模主要描述印度洋和南大西洋地区正异常特征，其强度也随时间单调变化；第三本征模对应于加勒比地区正异常，其强度呈100a周期的变化，目前正处于下降阶段；第四本征模的主要特点是北美正异常和南亚负异常，其强度呈80a周期的变化；第五本征模对应尺度较小的局部磁异常，其强度的变化周期约60a；第六及其以后的本征模则对应空间尺度更小和时间变化更快的磁异常．分析表明，太平洋地区的磁场经历着缓慢的单调减小变化，其结构比较稳定，几乎完全包括在第一本征模中．但是，印度洋磁场结构较复杂，它是由空间结构不同和变化周期各异的多个本征模组成的．大西洋的北部、中部和南部分属不同本征模，它们有完全不同的时间变化特性．

经皮椎体成形术治疗骨质疏松性椎体压缩骨折的早期疗效

目的探讨经皮椎体成形术(PVP)治疗骨质疏松性椎体压缩骨折1周内的临床疗效。方法对64例骨质疏松性椎体压缩骨折患者(83椎)行PVP治疗,记录术前及术后1周内疼痛VAS评分、手术前后Cobb角。结果83椎中10椎骨水泥渗漏至椎体周围及椎间隙,1椎周围静脉内出现骨水泥。VAS评分术后各时点与术前比较差异均有统计学意义(P<0.05),术后各时点比较差异均无统计学意义(P>0.05)。Cobb角手术前后比较差异无统计学意义(P>0.05)。结论PVP治疗骨质疏松性椎体压缩骨折在疼痛与稳定性上效果明确,治疗效果可在术后1 d后显现,1周内疗效稳定;PVP对椎体压缩无改善。