The relation of the true conjugate to maternal height and obstetric performance in Ghanaians

The true conjugate was determined intraoperatively with a caliper in 114 Ghanaian women and was correlated with their height, obstetric performance and fetal dimensions. Those patients undergoing cesarean section for cephalopelvic disproportion (Group Ia) were found to have a significantly shorter mean true conjugate (9.54 cm +/- 0.63 S.D.) and mean body height (152.68 cm +/- 5.46 S.D.) and a smaller true conjugate -- fetal biparietal diameter difference (10.93 mm) than those who had no cephalopelvic disproportion (Group Ib) and whose mean measurements were 10.61 cm +/- 0.81 S.D., 157.20 cm +/- 5.69 S.D. and 21.50 mm, respectively (P = 0.0001). Recommendations for appropriate referral of rural clinic patients and for selection of patients for repeat cesarean sections are based on the above findings.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28033/1/0000472.pd

Parental Height Differences Predict the Need for an Emergency Caesarean Section

More than 30% of all pregnancies in the UK require some form of assistance at delivery, with one of the more severe forms of assistance being an emergency Caesarean section (ECS). Previously it has been shown that the likelihood of a delivery via ECS is positively associated with the birth weight and size of the newborn and negatively with maternal height. Paternal height affects skeletal growth and mass of the fetus, and thus might also affect pregnancy outcomes. We hypothesized that the effect of newborn birth weight on the risk of ECS would decrease with increasing maternal height. Similarly, we predicted that there would be an increase in ECS risk as a function of paternal height, but that this effect would be relative to maternal height (i.e., parental height differences). We used data from the Millennium Cohort Study: a large-scale survey (N = 18,819 births) with data on babies born and their parents from the United Kingdom surveyed 9 to 12-months after birth. We found that in primiparous women, both maternal height and parental height differences interacted with birth weight and predicted the likelihood of an ECS. When carrying a heavy newborn, the risk of ECS was more than doubled for short women (46.3%) compared to tall women (21.7%), in agreement with earlier findings. For women of average height carrying a heavy newborn while having a relatively short compared to tall partner reduced the risk by 6.7%. In conclusion, the size of the baby, the height of the mother and parental height differences affect the likelihood of an ECS in primiparous women

Association between adolescent idiopathic scoliosis prevalence and age at menarche in different geographic latitudes

BACKGROUND: Age at menarche is considered a reliable prognostic factor for idiopathic scoliosis and varies in different geographic latitudes. Adolescent idiopathic scoliosis prevalence has also been reported to be different in various latitudes and demonstrates higher values in northern countries. A study on epidemiological reports from the literature was conducted to investigate a possible association between prevalence of adolescent idiopathic scoliosis and age at menarche among normal girls in various geographic latitudes. An attempt is also made to implicate a possible role of melatonin in the above association. MATERIAL-METHODS: 20 peer-reviewed published papers reporting adolescent idiopathic scoliosis prevalence and 33 peer-reviewed papers reporting age at menarche in normal girls from most geographic areas of the northern hemisphere were retrieved from the literature. The geographic latitude of each centre where a particular study was originated was documented. The statistical analysis included regression of the adolescent idiopathic scoliosis prevalence and age at menarche by latitude. RESULTS: The regression of prevalence of adolescent idiopathic scoliosis and age at menarche by latitude is statistically significant (p < 0.001) and are following a parallel declining course of their regression curves, especially in latitudes northern than 25 degrees. CONCLUSION: Late age at menarche is parallel with higher prevalence of adolescent idiopathic scoliosis. Pubarche appears later in girls that live in northern latitudes and thus prolongs the period of spine vulnerability while other pre-existing or aetiological factors are contributing to the development of adolescent idiopathic scoliosis. A possible role of geography in the pathogenesis of idiopathic scoliosis is discussed, as it appears that latitude which differentiates the sunlight influences melatonin secretion and modifies age at menarche, which is associated to the prevalence of idiopathic scoliosis

Chemotaxis Increases the Retention of Bacteria in Porous Media with Residual NAPL Entrapment

Chemotaxis has the potential to decrease the persistence of nonaqueous phase liquid (NAPL) contaminants in aquifers by allowing pollutant-degrading bacteria to move toward sources of contamination and thus influence dissolution. This experimental study investigated the migratory response of chemotactic bacteria to a distribution of residual NAPL ganglia entrapped within a laboratory-scale sand column under continuous-flow at a superficial velocity of 0.05 cm/min. Naphthalene dissolved in a model NAPL 2,2,4,4,6,8,8-heptamethylnonane partitioned into the aqueous phase to create localized chemoattractant gradients throughout the column. A pulse mixture of equal concentrations of <i>Pseudomonas putida</i> G7, a strain chemotactic to naphthalene, and <i>Pseudomonas putida</i> G7 Y1, a nonchemotactic mutant, was introduced to the column and effluent bacterial concentrations were measured with time. Breakthrough curves (BTCs) for the two strains were noticeably different upon visual inspection. Differences in BTCs (compared to nonchemotactic controls) were quantified in terms of percent recovery and were statistically significant (<i>p</i> < 0.01). Chemotaxis reduced percent recovery in the effluent by 45% thereby increasing the population of bacteria that were retained within the column in the vicinity of residual NAPL contaminants. An increase in flow rate to a superficial velocity of 0.25 cm/min did not diminish cell retention associated with the chemotactic effect

Modeling Transport of Chemotactic Bacteria in Granular Media with Distributed Contaminant Sources

Chemotaxis has the potential to improve bioremediation strategies by enhancing the transport of pollutant-degrading bacteria to the source of contamination, leading to increased pollutant accessibility and biodegradation. This computational study extends work reported previously in the literature to include predictions of chemotactic bacterial migration in response to multiple localized contaminant sources within porous media. An advection-dispersion model, in which chemotaxis was represented explicitly as an additional advection-like term, was employed to simulate the transport of bacteria within a sand-packed column containing a distribution of chemoattractant sources. Simulation results provided insight into attractant and bacterial distributions within the column. In particular, it was found that chemotactic bacteria exhibited a distinct biased migration toward contaminant sources that resulted in a 30% decrease in cell recovery, and concomitantly an enhanced retention within the sand column, compared to the nonchemotactic control. Model results were consistent with experimental observations. Parametric studies were conducted to provide insight into the influence of chemotaxis parameters on bacterial migration and cell percent recovery. The model results provide a better understanding of the effect of chemotaxis on bacterial transport in response to distributed contaminant sources

Chemotaxis Increases the Residence Time of Bacteria in Granular Media Containing Distributed Contaminant Sources

The use of chemotactic bacteria in bioremediation has the potential to increase access to, and the biotransformation of, contaminant mass within the subsurface. This laboratory-scale study aimed to understand and quantify the influence of chemotaxis on the residence times of pollutant-degrading bacteria within homogeneous treatment zones. Focus was placed on a continuous-flow sand-packed column in which a uniform distribution of naphthalene crystals created distributed sources of dissolved-phase contaminant. A 10 mL pulse of Pseudomonas putida G7, which is chemotactic to naphthalene, and Pseudomonas putida G7 Y1, a nonchemotactic mutant strain, were simultaneously introduced into the sand-packed column at equal concentrations. Breakthrough curves obtained from experiments conducted with and without naphthalene were used to quantify the effect of chemotaxis on transport parameters. In the presence of the chemoattractant, longitudinal dispersion of <i>Pp</i>G7 increased by a factor of 3, and percent recovery decreased by 43%. In contrast, <i>Pp</i>G7 Y1 transport was not influenced by the presence of naphthalene. The results imply that pore-scale chemotaxis responses are evident at an interstitial velocity of 1.8 m/day, which is within the range of typical groundwater flow. Within the context of bioremediation, chemotaxis may work to enhance bacterial residence times in zones of contamination, thereby improving treatment

Sexual dimorphism in the human pelvis: Testing a new hypothesis

Sexual dimorphism in the human pelvis is inferentially related to parturition. Investigators disagree about the identification and obstetric significance of pelvic dimorphism. Benefiting from a large sample of complete skeletons from the Coimbra Identified Skeletal Collection, we show that the dimensions of the true pelvis (birth canal) that are most sexually dimorphic (that is, the dimensions of females are greater than males) are those which are related to biparietal deformation, which often leads to the death of the human neonate. These dimensions are: the anteroposterior diameter of the inlet (index of dimorphism=108.41), the transverse diameter of the bispinous midplane (index of dimorphism=117.13) and the transverse diameter of the outlet (index of dimorphism=112.3). Therefore, sexual dimorphism in the human pelvis is a reflection of differential selection on the two sexes. These results may stimulate further studies with a fresh approach regarding the fossil and comparative evidence for when and how the modern pattern of birth has evolved.http://www.sciencedirect.com/science/article/B7GW4-4GG8W5B-1/1/d5a210bbbf111453aceef7b3895130c