Flow profiles and wall shear stress distribution at a hemodialysis venous anastomosis: preliminary study

The phasic velocity field in the vicinity of the venous anastomosis in a hemodialysis angioaccess arteriovenous fistula loop graft (AVLG) is investigated employing a laser Doppler anemometer (LDA) system. Detailed LDA velocity profiles are obtained by sectional survey performed in a transparent, elastic flow model which was fabricated to represent the geometry of the AVLG system under physiological pressure and flow waveforms. The geometry of the flow model was based on a silicone rubber cast obtained from an experimental dog model. In the present study, detailed distribution of velocity profiles is obtained. The distribution of wall shear stress in the model is computed from the slope of the local velocity profiles near the wall. The relationship between the results obtained by flow visualization and the LDA measurement is discussed.     

世居及移居高原青少年最大有氧能力的特征

本文报道海拔３４１７ｍ和４２８０ｍ地区世居藏族和移居汉族青少年运动状态下心肺功能的对比研究。结果显示：３４１７ｍ和４２８０ｍ世居藏族的最大氧耗量、无氧阈值及最大心输出量都明显大于汉族,血氧饱和度（Ｓａｏ２）随运动负荷的增加而降低。海拔３４１７ｍ藏、汉族的△Ｓａｏ２分别为７．４６％和１０．０３％,４２８０ｍ处为８．５７％和１３．７５％,最大心率随海拔升高而下降。研究提示,藏族青少年有较高的最大有氧能力,反映了他们对低氧环境的适应优势。     

Human medulloblastoma gangliosides

To establish a model system for the study of ganglioside metabolismof the human brain tumor, medulloblastoma, we have chemicallycharacterized the gangliosides of the Daoy cell line. Thesecells contain a high concentration of gangliosides (143 ±13 nmol LBSA/10⁸ cells). The major species have been structurallyconfirmed to be G_M2 (65.9%), G_M3 (13.0%), and G_Dla (10.3%).Isolation of individual gangliosides homogeneous in both carbohydrateand ceramide moieties by reversed-phase HPLC and analysis bynegative-ion fast atom bombardment collisionally activated dissociationtandem mass spectrometry have allowed us to unequivocally characterizeceramide structures. In the case of G_M2, 10 major ceramide subspecieswere identified: d18:1-hC16:0, d18:1-C16:0, d18:0-C16:0, d18:1-C18:0,d18:1-C20:0, d18:1-C22:0, d18:2-C24:1, d18: 1-C23:1, d18:1-C24:1,and d18:1-C24:0. Taken together with previous studies, thesefindings in human medullo-blastoma cells support the view thathigh expression and marked heterogeneity of ceramide structureare general characteristics of tumor gangliosides, moleculeswhich are shed by the tumor cells and which are biologicallyactive in vivo. medulloblastoma gangliosides ceramide structure HPLC mass spectrometry     

The phylogeny of the ant tribe Formicini (Hymenoptera: Formicidae) with the description of a new genus

Abstract. The holarctic ant tribe Formicini is revised, the new genus Bajcaridris described, and possible phylogenetic relationships are discussed. The subgenus Iberoformica is synonymized with Formica. A synopsis, diagnosis and keys to the genera are provided.     

Genetic mark-recapture analysis of winter faecal pellets allows estimation of population size in Sage Grouse Centrocercus urophasianus

The Sage Grouse Centrocercus urophasianus is a species of conservation concern throughout its range in western North America. Since the 1950s, the high count of males at leks has been used as an index for monitoring populations. However, the relationship between this lek-count index and population size is unclear, and its reliability for assessing population trends has been questioned. We used non-invasive genetic mark-recapture analysis of faecal and feather samples to estimate pre-breeding population size for the Parachute-Piceance-Roan, a small, geographically isolated population of Sage Grouse in western Colorado, during two consecutive winters from 2012 to 2014. We estimated total pre-breeding population size as 335 (95% confidence interval (CI): 287–382) in the first winter and 745 (95% CI: 627–864) in the second, an approximate doubling in abundance between years. Although we also observed a large increase in the spring lek-count index between those years, high male count data poorly represented mark-recapture estimates of male abundance in each year. Our data suggest that lek counts are useful for detecting the direction and magnitude of large changes in Sage Grouse abundance over time but they may not reliably reflect small changes in abundance that may be relevant to small populations of conservation concern.     

Wildlife conservation planning under the United States Forest Service's 2012 planning rule

In 2012, the United States Forest Service (USFS) promulgated new planning regulations in accordance with the National Forest Management Act (NFMA). These regulations represent the most significant change in federal forest policy in decades and have sweeping implications for wildlife populations. We provide a brief overview of the history of the NFMA planning regulations and their wildlife provisions and review the current science on planning for effective wildlife conservation at the landscape scale. We then discuss the approach to wildlife conservation planning in the 2012 rule and compare it to alternatives that were not selected and previous iterations of the planning rule. The new planning rule is of concern because of its highly discretionary nature and the inconsistency between its intent on the one hand and operational requirements on the other. Therefore, we recommend that the USFS include in the Directives for implementing the rule commitments to directly monitor populations of selected species of conservation concern and focal species and to maintain the viability of both categories of species. Additional guidance must be included to ensure the effective selection of species of conservation concern and focal species, and these categories should overlap when possible. If the USFS determines that the planning unit is not inherently capable of maintaining viable populations of a species, this finding should be made available for scientific review and public comment, and in such cases the USFS should commit to doing nothing that would further impair the viability of such species. In cases where extrinsic factors decrease the viability of species, the USFS has an increased, not lessened, responsibility to protect those species. Monitoring plans must include trigger points that will initiate a review of management actions, and plans must include provisions to ensure monitoring takes place as planned. If wildlife provisions in forest plans are implemented so that they are enforceable and ensure consistency between intent and operational requirements, this will help to prevent the need for additional listings under the Endangered Species Act and facilitate delisting. Although the discretionary nature of the wildlife provisions in the planning rule gives cause for concern, forward-thinking USFS officials have the opportunity under the 2012 rule to create a robust and effective framework for wildlife conservation planning. © 2013 The Wildlife Society.     

Serologic survey for antibodies to canine distemper virus in collared peccary (Tayassu tajacu) populations in Arizona

In 1989, a disease outbreak was observed among collared peccaries (javelina, Tayassu tajacu) in southern Arizona (USA) and canine distemper virus (CDV) was isolated from affected animals. Subsequently, 364 sera were collected from hunter-harvested javelina over a 4 yr period (1993-96) and were tested for antibody to CDV. Neutralizing antibody to CDV was detected in 58% of the serum samples suggesting that CDV infection is probably enzootic in the collared peccary populations of southern Arizona.