Measuring the human pelvis: A comparison of direct and radiographic techniques using a modern United States–based sample

Seven measurements were taken on a sample of 50 human cadaveric pelves, all white Texans born in the 20th century. Two separate methodologies were used to obtain these data: radiographs and direct measurements. These two methodologies were compared and contrasted, with the relative advantages and disadvantages of each explored. Results indicate that significant differences exist between the two methodologies. Pelvic height, breadth of symphysis, sacro-iliac breadth (P = 0.0001) and anterior upper spinal breadth (P = 0.0002) were larger when measured directly. Pelvic breadth, transverse diameter of the pelvic brim, and height of the ilium did not significantly differ between methodologies (P = 0.2037, P = 0.5253, P = 0.1752). Due to secular changes and inherent intrapopulational variation, taking measurements either directly from modern cadaveric specimens or radiographically on living volunteers in a limited geographic or socioeconomic grouping, rather than from skeletal collections or archived radiographs, may be more appropriate for providing data for current anthropometric applications. Am J Phys Anthropol 103:471–479, 1997. © 1997 Wiley-Liss, Inc.     

Effects of fire recurrence in Quercus coccifera L. shrublands of the Valencia Region (Spain): II. plant and soil nutrients

The consequences of fire recurrence (1, 2 and 3 fires in 16 years) on plant and soil C, N, P and K from Quercus coccifera garrigues were analysed in the Valencia Region (E Spain). Plant and forest floor (L horizon) nutrient concentrations either changed weakly or showed no change with fire recurrence. At the soil surface (0-2.5 cm), soil potential mineralisable nitrogen increased and available P decreased after an initial increase, whereas exchangeable K was not affected by successive fires. However, the significance of those observed trends for N and P was site-dependent. Despite the rapid formation of the L soil horizon, fire recurrence did not permit the development of the whole forest floor profile observed in the unburned garrigues. These organic layers contained a great proportion of the total nutrient pool, especially for N. Forest-floor and aboveground plant combustion by fire may produce significant losses of N and P compared with those available in mineral soil, whereas soil exchangeable K is large enough to replace these losses. Belowground nutrient reserves may account for the quick recovery of the Quercus coccifera aboveground biomass although successive fires could deplete these reserves and produce a loss of biomass and productivity in this species.     

Single rays as indicators of fin vestigialization in coho salmon: patterns and perspectives

Although finrays in salmon normally contain a pair of elements (biramous), finrays with a single element (uniramous) occasionally develop. Exposure to chronic stress during character development has been shown to increase fluctuating asymmetry, suggesting the occurrence of single finrays may be stress‐induced. On the other hand, single finrays may be evolutionary atavisms, reflecting fin vestigialization caused by reduced selection pressure. To assess the merits of these hypotheses, cleared and stained paired and median fins were examined for single finrays in juvenile coho salmon (Oncorhynchus kisutch Walbaum) from two compatible hatchery stocks and their reciprocal hybrids which had been exposed to different patterns of chronic temperature fluctuation throughout embryogenesis. In the median fins, uniramous secondary finrays predominated, and single primary finrays were infrequent. Single finrays in the median fins did not respond to thermal treatment or cross, suggesting the fins were evolutionarily stable and under strong developmental control. The paired fins were observed to contain only primary finrays. Frequencies of single pelvic finrays increased under thermal stress, as did fluctuating asymmetry, suggesting increased sensitivity to stress due to reduced developmental control in this fin. However, the presence or absence of single finrays in the paired fins did not alter the statistical significance of the conclusions regarding levels of fluctuating asymmetry, the number of asymmetric fish, or the contribution to meristic variation from asymmetry. Locations of single finrays in the paired fins were unaffected by thermal treatment or cross. Single finrays were most commonly observed in the trailing margins of both paired fins, a finding consistent with vestigialization theory. Frequency histograms of single pectoral finray locations revealed a second peak in the leading quarter of the fin. The esults support the hypothesis that single primary finrays are evolutionary atavisms, and that reduced selection pressure is differentially influencing the paired fins.     

Effects of semi-group housing and floor type on pododermatitis,spinal deformation and bone quality in rabbit does

The most common housing system for reproduction rabbits, individual cage housing on a wire floor, is increasingly scrutinized because of its potential detrimental impact on animal welfare. We compared three types of housing: (1) individual cage housing on a wire floor (3952 cm²/doe, maximum roof height 63 cm, one 1000 cm² plastic footrest/doe), (2) semi-group housing on a wire floor (5000 cm²/doe, roofless, one 1000 cm² plastic footrest/doe) and (3) the same semi-group housing, but with a fully plastic slatted floor. In all housing systems, does had free access to an elevated platform. In the semi-group housing pens, four does were housed communally during 21 days of the reproduction cycle (to allow more space for locomotion and to increase opportunities for social contact), and individually during the other 21 days of the cycle (to minimize doe–doe and doe–kit aggression that peaks around kindling). In all, 24 Hycole does were included per system. The does entered the experiment at 203 days of age (after their first parity). The experiment consisted of four reproductive cycles, ending at 369 days of age. Pododermatitis was scored in cycles 1, 2 and 4. At the end of the 4^th cycle the does were euthanized and X-rays were taken to assess spinal deformation. Tibia and femur length, width and cortical thickness were determined and bone strength was assessed using a shear test, as a measure of bone quality. Although severe pododermatitis was absent, the prevalence of plantar hyperkeratosis (hair loss and callus formation) at the end of the 4^th cycle was much greater on the wire floor (65% and 68% for semi-group housing and individual cages, respectively) than on the plastic floor (5%, P<0.0001), even though the wire floors were equipped with a plastic footrest known to decrease hyperkeratosis. In contrast to our expectations, semi-group housing did not affect the prevalence of spinal deformations (P>0.10), but in line with our expectations bone quality was affected favourably by semi-group housing. The tibial cortex (and to a lesser extent the femoral cortex) was thicker in semi-group housing than in individual cages (1.45, 1.46 and 1.38 mm for semi-group housing on wire, semi-group housing on plastic and individual housing on wire, respectively, P=0.045). What this increase in cortical thickness means in terms of doe welfare requires further study, as it may reflect an increase in activity resulting either from increased space for locomotion, or from fleeing aggressive pen mates.     

盆底重建术对盆腔器官脱垂患者生活质量的影响

目的:探讨盆底重建术对盆腔器官脱垂患者生活质量的影响。方法:选取2010年12月到2012年10月期间我院妇科46例盆腔器官脱垂患者,随机平均分为观察组与对照组,观察组予全盆底重建术治疗,对照组予传统阴式手术治疗,手术前后应用盆底功能障碍问卷PFDI-7及PFDI-20、性生活质量问卷POSQ对两组患者的生活质量进行评估。结果:两组术后PFDI-7及PFDI-20评分显著低于术前,差异有统计学意义(P0.05),且观察组术后PFDI-7评分及PFDI-20评分均优于对照组,差异有统计学意义(P0.05)。结论:与传统阴式手术相比,全盆底重建术术后患者生活质量有很大提高,对性生活影响较小,值得临床推广。     

A shell finite element model of the pelvic floor muscles

The pelvic floor gives support to the organs in the abdominal cavity. Using the dataset made public in (Janda et al. J. Biomech. (2003 Janda, S., van der Helm, F.C.T. and de Blok, B. 2003. Measuring morphological parameters of the pelvic floor for finite element modelling purposes. J. Biomech., 36(6): 749–757. [Crossref] , [Google Scholar]) 36(6), pp. 749–757), we have reconstructed the geometry of one of the most important parts of the pelvic floor, the levator ani, using NURB surfaces. Once the surface is triangulated, the corresponding mesh is used in a finite element analysis with shell elements.

Based on the 3D behavior of the muscle we have constructed a shell that takes into account the direction of the muscle fibers and the incompressibility of the tissue. The constitutive model for the isotropic strain energy and the passive strain energy stored in the fibers is adapted from Humphrey's model for cardiac muscles. To this the active behavior of the skeletal muscle is added.

We present preliminary results of a simulation of the levator ani muscle under pressure and with active contraction. This research aims at helping simulate the damages to the pelvic floor that can occur after childbirth.