Influence of the Lower Jaw Position on the Running Pattern

Introduction

The effects of manipulated dental occlusion on body posture has been investigated quite often and discussed controversially in the literature. Far less attention has been paid to the influence of dental occlusion position on human movement. If human movement was analysed, it was mostly while walking and not while running. This study was therefore designed to identify the effect of lower jaw positions on running behaviour according to different dental occlusion positions.

Methods

Twenty healthy young recreational runners (mean age = 33.9±5.8 years) participated in this study. Kinematic data were collected using an eight-camera Vicon motion capture system (VICON Motion Systems, Oxford, UK). Subjects were consecutively prepared with four different dental occlusion conditions in random order and performed five running trials per test condition on a level walkway with their preferred running shoes. Vector based pattern recognition methods, in particular cluster analysis and support vector machines (SVM) were used for movement pattern identification.

Results

Subjects exhibited unique movement patterns leading to 18 clusters for the 20 subjects. No overall classification of the splint condition could be observed. Within individual subjects different running patterns could be identified for the four splint conditions. The splint conditions lead to a more symmetrical running pattern than the control condition.

Discussion

The influence of an occlusal splint on running pattern can be confirmed in this study. Wearing a splint increases the symmetry of the running pattern. A more symmetrical running pattern might help to reduce the risk of injuries or help in performance. The change of the movement pattern between the neutral condition and any of the three splint conditions was significant within subjects but not across subjects. Therefore the dental splint has a measureable influence on the running pattern of subjects, however subjects individuality has to be considered when choosing the optimal splint condition for a specific subject.     

Microwear evidence for Plio-Pleistocene bovid diets from Makapansgat Limeworks Cave, South Africa

Makapansgat Limeworks Cave is a well-known Australopithecus africanus bearing locality that has spawned a considerable amount of paleoecological research because of its hominin component. Most recently, the paleoecology of this Plio-Pleistocene site has been studied by determining the diet and habitat of other extinct taxa, particularly the bovids. The diets of seven bovids (Aepyceros sp., Gazella vanhoepeni, Makapania broomi, Parmularius braini, Redunca darti, Tragelaphus sp. aff. T. angasii, and Tragelaphus pricei) have now been classified using taxonomic uniformitarianism, ecomorphology, stable carbon isotopes, and mesowear analysis. Here, dental microwear is applied to the same bovids for additional comparison and to further elucidate the strengths and weaknesses of each method. The different dietary proxy methods noted provide a temporal continuum, with genetic signals such as ecomorphology and taxonomic uniformitarianism indicating behavioral adaptations over geologic time, while nongenetic data such as stable carbon isotopes and mesowear reflect different aspects of average diet over extended portions of an animal's life, and dental microwear provides dietary snapshots.Microwear separated an extant baseline of ten bovid species into expected dietary categories and the Makapansgat bovids clearly fell into two groups with the same degree of separation as between extant grazers and browsers. The results indicate that a multidisciplinary approach produces a more accurate and robust reconstruction of past diets. In sum, the microwear analysis is in-line with the isotope and mesowear results, which suggest a stronger browsing component than either taxonomic uniformitarianism or ecomorphology imply.     

Human skeletal remains from the cave of Hearths,Makapansgat, Northern Transvaal

A detailed study has been made of the oldest South African Upper Pleistocene hominid remains found in Acheulian context in a well-stratified sealed cave deposit, the Cave of Hearths, Makapansgat, Northern Transvaal. Possibly 55,000 years of age, the remains comprise a juvenile right mandibular body with teeth, and part of a right radius. The mandible is highly robust, markedly prognathous, has a slight to moderate bony chin, an appreciable planum alveolare, a low supraspinous foramen, large alveolar part with big tooth roots, parallel upper and lower borders, a superior transverse torus and poorly developed genial apophysis. The teeth are fairly large, narrow and elongate; M₂ is smaller than M₁; both molars have a +5 cusp pattern, and the first molar shows moderate taurodontism. There is good evidence that the jaw shows congenital lack of M₃: after the Chinese Lantian jaw, this is the second oldest hominid mandible and the first African fossil man with this feature. The radius has a relatively large head atop a disproportionately narrow neck; marked angulation of neck on shaft; and a strongly developed bicipital tubercle. The remains show a cluster of features which ally them with African Neandertaloids and earlier hominids of N.W. Africa. These geographically widespread African remains may represent a transitional population between H. erectus and H. sapiens neanderthalensis. This population has been called by Campbell, this author and others H. sapiens rhodesiensis (after the first-discovered specimen from Broken Hill): to this taxon the Cave of Hearths bones are tentatively assigned.     

Morphological and Functional Divergence of the Lower Jaw Between Native and Invasive Red Foxes

Journal of Mammalian Evolution - The introduction of European red foxes in Australia in the late mid-nineteenth century has resulted in the spread of this invasive species across the continent. The...     

护理干预对成年女性压力性尿失禁患者的影响

目的：探讨护理干预对成年女性压力性尿失禁患者的影响。方法：在患者自愿参与的情况下,随机抽取浏阳市市区80名有压力性尿失禁症状的成年女性,对她们进行护理干预,并对干预效果进行评价。结果：护理干预后,患者压力性尿失禁发作次数显著减少,盆底肌肉张力显著提高,漏尿量显著减少。结论：护理干预可减轻成年女性压力性尿失禁症状,减轻患者的身心痛苦,提高压力性尿失禁患者的生活质量。     

Adult Female Canaries Respond to Male Song by Calling

We describe a new assay for measuring the response to song playback by adult female domesticated canaries, Serinus canaria . We tested song perception and discrimination by measuring the frequency of particular female calls (`single calls') given in response to male song playbacks. We observed that females responded differently to songs of different species (canaries vs. pine siskin, Carduelis spinus ) and to songs of different canary strains (domesticated vs. wild canaries). In addition, females were especially responsive to songs containing a particular type of song phrase (`A' phrases).
This new assay provides equivalent results to the standard method (copulation solicitation displays) traditionally used to assess female song preferences. Our new assay has the advantage that it allows one to measure female song responsiveness without having to use estradiol implants and during both long and short day photoperiods. However, females responded differently in long and short days. We suggest that, by calling, females could both provide information about their sexual interest and attract the attention of particular males.     

The first complete skull of Simopithecus darti from Makapansgat,South Africa,and its systematic position

The skull of a subadult female of Simopithecus darti from the “Upper Phase I” of the Makapansgat Limeworks, South Africa, is described. It is the first complete skull of Simopithecus which is recorded from the lower Pleistocene “Australopithecine cave deposits” of southern Africa. The present skull shows an interesting mixture of primitive and advanced features. In some respects, it is reminiscent of Parapapio, in others it seems to have affinities with the extant Theropithecus gelada rather than with Simopithecus oswaldi. The systematics of the fossil genus Simopithecus and of the tribe Theropithecini Jolly (1966) are discussed.     

Infectivity and Recovery of Tetrahymena pyriformis Strain S from Adult Female Cockroaches (Periplaneta americana)*

Hemocoelomic injection of 5,800–8,000 cells of Tetrahymena pyriformis strain S per female cockroach resulted in lethargy of the insects within 24 hr and death within 72 hr. Ciliates could be recovered 24–48 hr after injection of these amounts of ciliates. Inoculation of smaller numbers of cells resulted in no apparent ill effects to the insects and ciliates could not be recovered. After recovery from cockroaches and reestablishment in axenic culture, the ciliates were rounded and contained large numbers of lipid droplets which decreased on continued cultivation. The ciliates underwent a sequence of morphologic alterations involving a decrease in length and width to form ovoid cells, an approach to the pyriform shapes (but smaller than normal size), an elongation to an abnormal length/width ratio, and then, after 6 days in culture, a return to the normal shape with usual dimensions.