儿童开放Seymour骨折的近期随访研究

目的探讨儿童开放Seymour骨折的一般规律、有效治疗方法、早期随诊结果及并发症。方法收集2016年9月至2017年5月在本院行早期清创复位固定治疗的21例儿童开放Seymour骨折患儿作为研究对象。收集患儿术前人口学资料、影像学资料、术后功能、满意度评分及并发症情况。该组患儿年龄中位数为8岁(1～14岁),平均随访时间5个月(4～20个月)。早期予以清创、解除软组织嵌压、复位、克氏针内固定、拔甲、甲床甲根修补及石膏固定。结果 21例患儿中,11例为SalterHarrisⅠ型骺损伤,10例为Salter-HarrisⅡ型骺损伤。21例均合并甲床损伤,其中9例还合并周围皮肤软组织裂伤。固定方式:15例(72%)采用单枚克氏针贯穿固定,6例(28%)采用交叉克氏针固定。20例获得随访。术后17例获得完整远指间关节活动度,18例随访时无疼痛。2例术后发生感染。所有患儿获得影像学愈合,总体满意度9. 3分(8～10分)。术后指甲并发症14例,但均未影响功能及满意度。结论 Seymour骨折需早期清创复位固定。感染和指甲并发症为Seymour骨折的常见并发症。经早期正规处理的该型骺损伤短期功能及满意度好,但应继续随访其是否发生远期并发症,且应认识到感染及指甲相关并发症都可在晚期出现。

准传递定向图上的Seymour点

有向图D是准传递的,如果对D中任意三个不同的顶点x, y和z,只要在D中存在弧xy, yz, x和z之间就至少存在一条弧. Seymour二次邻域猜想为:在任何一个定向图D中都存在一个顶点x,满足d^+D(x)d^++D(x).这里,定向图是指没有2圈的有向图.称满足Seymour二次邻域猜想的点为Seymour点. Fisher证明了Seymour二次邻域猜想适用于竞赛图,也就是每个竞赛图至少包含一个Seymour点. Havet和Thomassé证明了,无出度为零的点的竞赛图至少包含两个Seymour点.注意到,竞赛图是准传递有向图的子图类.研究Seymour二次邻域猜想在准传递定向图上的正确性,通过研究准传递定向图与扩张竞赛图的Seymour点之间的关系,证明了准传递定向图上Seymour二次邻域猜想的正确性,得到:每个准传递定向图至少包含一个Seymour点;无出度为零的点的准传递定向图至少包含两个Seymour点.

关于图的Seymour问题的一个注记

对Ｓｅｙｍｏｕｒ的问题给出了定性的结论，得到了无穷多３－连通３－正则的偶数顶点图都没有两个边不交的１－因子．

Antarctic Paleontological Heritage:Late Cretaceous–Paleogene vertebrates from Seymour(Marambio)Island,Antarctic Peninsula

Antarctica has significant environmental,scientific,historic,and intrinsic values,all of which are worth protecting into the future.This continent has a discrete number of places of scientific interest that exhibit great potential as natural heritage sites;its geodiversity is of fundamental importance to scientific values of the continent,and the pursuit of geological and paleontological knowledge has had a strong influence on its historical values.Seymour Island was once called the‘Rosetta Stone’of Southern Hemisphere paleobiology,because this small island provides the most complete and richly fossiliferous Late Cretaceous–Paleogene sequence in Antarctica.In particular,fossil vertebrates form part of the evidence used in reconstructing the history of life on Antarctica.Paleontological heritage is considered a subset of geo-heritage that embodies both natural and historical components which has received only indirect recognition.Seymour Island is an outstanding paleontological area with high heritage value of its Late Cretaceous/Paleogene vertebrates and should be considered for geo-conservation and protection.This paper reviews vertebrate fossil occurrences and outcrops on Seymour Island and discusses some threats to these fossil sites.

Late Maastrichtian–Paleocene chronostratigraphy from Seymour Island,James Ross Basin,Antarctic Peninsula:Eustatic controls on sedimentation

The Paleocene(66–56 Ma)was a critical time interval for understanding the geological history in high palaeolatitudes after the end of Cretaceous event(recovery from mass extinction,palaeoclimate,global sea level changes,among others).The sedimentary succession from Seymour Island(Antarctic Peninsula)provides key reference material from this important phase of the early Cenozoic.A detailed age model is proposed for the López de Bertodano Formation(LBF),Sobral Formation(SF)and Cross Valley–Wiman Formation(CVWF)based on a new magnetostratigraphic section which integrates previous dinoflagellate cyst biostratigraphy,Iridium anomaly(K-Pg boundary),U-Pb zircon dating(airfall tuff)and strontium isotope values from macrofossils.The new composite magnetostratigraphic section,which includes the Cretaceous–Paleogene boundary,has been correlated to the GPTS from C29r up to C24r.The top of the LBF is confirmed as latest Maastrichtian to earliest Danian(~65.4 Ma)in age.The overlying SF is mostly Danian in age(~65.2–~63 Ma)and CVWF is Selandian–Thatenian(~61.3–56.9 Ma).LBF,SF and CVWF are unconformity-bounded units(alloformations)that record the geological evolution of the James Ross Basin during a period of relative decreasing tectonism but coeval with volcanic activity.Unconformity based internal units have been recognized,dividing each formation into allomembers(LBF:Molluscan and Cenozoic;SF:A,B and C;CVWF:Díaz,Ara?ado,Bahía Pingüino).The new age model allows correlation of base-level changes with eustatic sea-level fluctuations.The bases of the SF and CVWF are correlated with the 65.3 and 61.5 Ma sea level lowstands.

Middle Eocene chondrichthyan fauna from Antarctic Peninsula housed in the Museo de La Plata,Argentina

In recent years,the taxonomy and systematics of the cartilaginous fish taxa from the Eocene La Meseta Formation of Seymour(Marambio)Island,Antarctica have been extensively discussed in a series of papers,resulting in a complete revision of the Antarctic Eocene ichthyofauna housed in the Vertebrate Paleontology collection of the Museo de La Plata,Argentina.This collection constitutes one of the largest and taxonomically most diverse in the world,with approximately 20000 specimens,which provides a solid database used for the analysis of qualitative and quantitative chondrichthyan taxonomic composition.The information provided herein might be useful to understand the sudden decline in chondrichthyan taxonomic diversity towards the top of La Meseta Formation as well as its potential relationship with environmental changes during the Eocene.

Contributions to the knowledge of Antarctodon sobrali(Mammalia:Astrapotheria)from the Eocene of Antarctica

The Astrapotheria constitutes one of the five orders of extinct South American native ungulates,with a fossil record that also extends to the Eocene of the Antarctic Peninsula.In contrast to the abundant specimens known for litoptern Sparnotheriodontidae and metatherians,astrapotheres are represented by scant remains assigned to the endemic Antarctodon sobrali and indeterminate astrapotheres,restricted to levels 35C_(u0)and 35n of the Cucullaea I Allomember of the La Meseta Formation.The discovery of alower molar assignable to this species in the Eocene levels of Seymour(Marambio)Island,enables a revision of the diagnosis and the homologies of the dental characters used to describe this taxon.A reanalysis of its phylogenetic relationships reveals the nearly simultaneous presence of basal astrapotheres in the early Eocene of Itaboraí(Brazil),Patagonia,and West Antarctica.These taxa are characterized by lacking dental specializations usually associated with more abrasive diets like terminal forms of Uruguaytheriinae and Astrapotheriinae.Antarctodon appears to have thrived on the Antarctic continent during the Early Eocene Climatic Optimum within the paleoclimatic context of a hot-house world.Unlike present conditions in Antarctica where no terrestrial mammals inhabit,the early Eocene climate was characterized by warmer temperatures and a biologically diverse environment rich in primary producers,dominated by Nothofagus forests,encompassing both deciduous and evergreen forests,which supported a diverse assemblage of continental vertebrates.

Review of the Cretaceous avian diversity of Antarctica:a changing scenario for the evolution of early Neornithine birds

The worldwide record of Cretaceous Neornithes and Neornithine-like birds is both controversial and poorly understood.However,in recent years,the Antarctic continent has yielded a substantial number of Maastrichtian avian specimens,contributing significantly to our understanding of the early evolution of this group.Simultaneously,the keen interest and collaborative efforts of various paleornithologists have resulted in a wealth of knowledge,which we have thoroughly reviewed,updated,and discussed in the context of recent discoveries.

SEYMOUR’S SECOND NEIGHBORHOOD IN 3-FREE DIGRAPHS

In this paper,we consider Seymour’s Second Neighborhood Conjecture in3-free digraphs,and prove that for any 3-free digraph D,there exists a vertex say v,such that d^++(v)≥[λd+(v)],λ=0.6958….This slightly improves the known results in 3-free digraphs with large minimum out-degree.

SEYMOUR POWELL

设计有三个基本步骤：想法、执着的信仰和表现。这来源于道教的理论，但对我们很有效。

“不瞄准的瞄准”:《西摩:小传》诠释的文学与教育之道

J.D.塞林格的小说《西摩:小传》中,“不瞄准的瞄准”是主人公西摩对执着于赢得一场弹子游戏的弟弟的劝谏,更蕴含着身为诗人兼大学教师的主人公西摩对于文学和教育的主张,那便是:文学写作要让真朴之情自然流露,文学阅读(评论)要专注作品心无旁骛,文学教育要祛除功利回归诗意。这种摒弃人的主观执念、让文学和教育是其所是、循其本然的主张,内在地契合“无为而无不为”“道法自然”等道家思想,是对文学与教育之道的精当诠释。

指深屈肌腱及指伸肌腱止点的解剖研究

目的通过解剖研究指深屈肌腱及指伸肌腱在远节指骨基底掌侧和背侧止点平面的差别,为西摩骨折发生机制提供解剖学依据。方法手部残肢10具,其中左手3例,右手7例,均为男性患者,年龄24~58岁。2~5指分别有10指,全部手指无外伤手术史、无畸形。自远节指间关节水平掌侧及背侧分别切开,于末节指骨水平分离各指的指深屈肌腱及指伸肌腱,记录其与末节指骨掌侧及背侧关节面的距离,比较指深屈肌腱及指伸肌腱在末节指骨掌、背侧的止点水平。结果指深屈肌腱止点近端至关节面距离:示指(2.19±0.27)mm,中指(2.50±0.14)mm,环指(2.23±0.16)mm,小指(1.83±0.19)mm;指伸肌腱止点近端至关节面距离:示指(0.12±0.02)mm,中指(0.18±0.02)mm,环指(0.12±0.05)mm,小指(0.06±0.01)mm;各指差异有统计学意义(P<0.05)。指深屈肌腱止点中点至关节面距离:示指(3.73±0.45)mm,中指(4.33±0.45)mm,环指(3.53±0.46)mm,小指(3.16±0.41)mm;指伸肌腱止点中点至关节面距离:示指(1.77±0.06)mm,中指(1.76±0.20)mm,环指(1.77±0.06)mm,小指(1.47±0.10)mm;各指差异有统计学意义(P<0.05)。结论指伸肌腱在末节指骨基底的止点较指深屈肌腱的止点距关节面更近,为西摩骨折的发生机制提供了解剖依据。

论计算思维的培养--派珀特思维教育思想的审思

计算思维是当今教育领域的热点、话题,已有研究却多以半途出现的概念为参照与起点,缺乏对计算思维源头的追溯与反思。西蒙·派珀特(Seymour Papert)是最早提出计算思维的人,从他的思维教育核心思想出发,洞察出计算思维起源于“教会孩子思考”的理念;随后从特征、目标和方法论三个维度探寻了计算思维创造导向的深刻内涵;最后从理念、实践与对计算思维培养的超越三个层面来论证其培养策略,从而为计算思维的厘清与全局把握提供本源性的视角。

The fossil record of birds from the James Ross Basin,West Antarctica

The fossil record of birds from Antarctica is concentrated in the James Ross Basin,located in north-east of the Antarctic Peninsula.Birds are here represented by an extensive Paleogene record of penguins(Sphenisciformes)and Cretaceous–Paleogene record of Anseriformes,followed by other groups with a minor representation(Procellariiformes,Falconiformes,and Pelagornithidae),and others previously assigned controversially to“Ratites”,Threskiornithidae,Charadriiformes,Gruiformes,Phoenicopteriformes,and Gaviiformes.We provide a complete update of these records,commenting on the importance of some of these remains for the evolution of the major clades.

The fossil record of durophagous predation in the James Ross Basin over the last 125 million years

We review the evidence for predation of shelly benthic prey over 125 million years of earth history in the James Ross Basin,Antarctica(~65°S).Although poor in the Early Cretaceous lower parts of the sequence,which represent essentially deeper water facies,evidence for both potential crushers and drillers becomes more apparent in the Santonian–Campanian Santa Marta Formation,and by the Maastrichtian López de Bertodano Formation there is an extensive fossil record of drill holes attributable to naticid gastropods,and some evidence of crushing by decapods crustaceans and possibly other taxa too.This continues at a similar level of intensity across the K/Pg boundary into the Danian Sobral Formation,but is less well constrained in the latest Paleocene–Early Eocene.The most extensive record of predation occurs in the Middle Eocene section of the La Meseta Formation on Seymour Island which also records the highest levels of benthic diversity within the entire basin.This key section is providing some important new evidence to suggest that the rate of acceleration of benthic predation intensity through the Late Mesozoic–Early Cenozoic in the polar regions may be similar to that seen in lower latitude regions.Predator–prey interaction was a key factor in the evolution of polar marine faunas too.

Installing a prototype wind turbine to produce energy in Antarctica to allow a permanent Colombian scientific base to be established

This study was performed to support an expeditionary team of Colombian scientists seeking to promote and undertake research in various scientific fields in Antarctica.The work was part of the Colombian Antarctic Program,which comprises various projects intended to lead to a permanent Colombian scientific base being established in the Antarctic.The first step involved installing a Colombian-made wind turbine to produce electricity at a permanent base.The aeolian turbine was designed to provide sufficient electricity to illuminate and heat a small base.The turbine was constructed using readily accessible materials but taking the Madrid Protocol environmental regulations into consideration.The project was performed at the Argentinian Antarctic Marambio Station on Seymour Island,off the Antarctic Peninsula.An initial field study performed in 2015 was the first of three phases of the project.In the initial phase,local meteorological data were gathered to support development of a prototype turbine and to allow a design to be selected that was robust enough for the extreme environmental conditions.The wind turbine was then constructed in Colombia.The second phase involved transporting the turbine to Antarctica and installing it at the Marambio Station in 2018.Finally,the physical conditions of structural and electronic components of the turbine were carefully inspected at the beginning of 2020(after the turbine had operated continually for^2 years)to allow repairs to be made and any necessary re-engineering to be performed.

转型时期的争鸣——1930年代美国图书馆学科学化之争

1931年1月,哥伦比亚大学图书馆服务学院院长查尔斯·威廉姆森在《图书馆季刊》发表《研究在图书馆工作中的地位》,提倡借助于定量研究等其他学科的研究方法提升图书馆学的科学性。与此同时,芝加哥大学图书馆学研究生院大力倡导将社会科学研究方法应用于图书馆学研究,如道格拉斯·维普尔斯的阅读研究。1931年6月,查尔斯·汤普森发表《我们需要一个图书馆科学吗》一文,对量化研究方法提出批评,引起汤普森与维普尔斯就图书馆学科学化的论争。这场论争的核心是不同研究方法在图书馆学中的适用性问题,其实质是图书馆学转型时期新旧范式的相互适应,是一场"新"与"旧"、"内"与"外"的争鸣。

Eocene Antarctica:a window into the earliest history of modern whales

The Eocene–Oligocene Southern Ocean is thought to have played a major role in cetacean evolution.Yet,fossils from its heart—Antarctica—are rare,and come almost exclusively from the Eocene La Meseta and Submeseta formations of Marambio(Seymour)Island.Here,we provide a summary and update of this crucial fossil assemblage,and discuss its relevance in the broader context of cetacean evolution.To date,Eocene specimens from Antarctica include basilosaurids,a group of archaic stem cetaceans that had already fully adapted to life in water;and the archaic toothed mysticete Llanocetus,the second oldest crown cetacean on record(ca.34 Ma).This Eocene co-occurrence of stem and crown cetaceans is highly unusual,and otherwise only observed in Peru.Though related,at least some of the Antarctic species appear to be different from,and notably larger than their Peruvian counterparts,suggesting an early differentiation of the high latitude cetacean fauna.

儿童编程教育溯源与未来路向——人工智能教育先驱派珀特的“齿轮”与“小精灵”

Logo语言的出现成为儿童编程教育的开端,其创建者西蒙·派珀特有关儿童编程及人工智能教育的最初思想成就逐渐受到各界研究者的关注,并在此基础上不断继承与发展。儿童编程教育研究的推陈出新要求更坚实的理论根基支持,故文章首先对派珀特及其关于编程教育与人工智能发展的的理论观点进行了介绍梳理,其次分析总结派珀特的学生雷斯尼克和贝斯对派珀特关于儿童编程教育思想理论的继承与延续,同时简述派珀特对OLPC计划、创客教育、人工智能技术及乐高的创生及现代化发展的影响。基于此,文章提出了对儿童编程教育发展的思考与启示:超越工具形式,注重编程学习中儿童思维能力的提升;创设学习情境,使"建造主义"在编程课堂中真正落地;提炼编程思维与基础课程深度融合;培养儿童面向未来发展的生存技能。