The electrical conductivity of Na-montmorillonite suspensions in various salt and clay concentrations was measured. The weight conductance of the clay suspension was found to decrease with increase in clay concentration between 0 and approximately 0·5 g clay/100 ml, then rose to a plateau at 6–10 g clay/100 ml. The weight conductance of the clay suspensions also increased with an increase in the salt solution concentration. If the model of two resistors in parallel is used in interpreting the experimental data, these changes can be attributed to an increase in the mobility of the adsorbed Na ions. It is proposed that the two resistors in series model is more realistic in describing the conductivity of the suspensions. This model predicts the observed weight conductance changes of the suspensions, while the mobility of the adsorbed ions remains constant. A constant mobility of the adsorbed Na ions in clay-water systems of low to medium salt and clay concentrations also is predicted by the diffuse double layer.

An experimentally determined Ca-Mg exchange isotherm of montmorillonite is reported. The selectivity coefficient of this exchange over a wide range of Mg saturation was calculated and found constant.

Standard free energies of exchange, thermodynamic equilibrium constants and activity coefficients of the exchangeable Ca and Mg ions in vermiculite and montmorillonite, were predicted from knowledge of the microstructure of these two clays, assuming that coulombic forces are the main ones playing a role in the interaction between the counterions and the charged clay surface. The standard free energies of exchange (ΔGCa°Mg = 238 cal/mole) predicted a preference for Ca in montmorillonite and a preference for Mg in vermiculite (ΔGCa°Mg = - 1665 cal/mole). The predicted thermodynamic equilibrium constants were compatible with the experimentally determined selectivity coefficients KsCaMg = 0·67 as compared with KsCaMg = 0·68 in montmorillonite, which remains constant over all the range of Mg saturation, and KCaMg = 16·7 as compared with KsCaMg = 13·9 in vermiculite at 95% Mg saturation. The activity coefficients of Ca and Mg counterions in montmorillonite were found to be and , respectively, and to remain constant. The activity coefficients of exchangeable Ca and Mg in vermiculite were found to be and , respectively, at an equivalent fraction of unity. The activity coefficient of exchangeable Mg increased as the saturation with Mg decreased, and was found to be 1·7 × 10-3 in the range of the low Mg saturation.

The microstructure, the isomorphic substitution and the surface charge density provided an understanding of the changes taking place in the activity coefficients of the counterions.

A quantitative method for determination of montmorillonite in the soil clay fraction, using X-ray spectrometry, is proposed. The method is based on the fact that polyvinylpyrrolidone (PVP) is adsorbed on the interlayer surfaces of montmorillonite, giving a first order c-axis spacing of 26 Å, while it is not adsorbed on other swelling clays. The experimental conditions to obtain a maximum height of the X-ray diffraction peak, and the effect of the mass adsorption coefficient of vermiculite on the intensity of montmorillonite, were investigated. Soil montmorillonite was determined by the method of known additions, measuring the intensity of the X-ray diffraction peak before and after the addition of small and known amounts of Wyoming montmorillonite.

OBJECTIVES/GOALS: The time between lower extremity amputations and prosthetic acquisition profoundly influences patient rehabilitation and mortality outcomes. Our primary outcome was time to prosthetic acquisition following major limb amputation. We hypothesize that women face an increased time lag between amputation and prosthetic acquisition compared to men. METHODS/STUDY POPULATION: We used the 2015-2021 Truven Marketscan Medicare and Commercial Claims Administrative dataset to identify individuals with lower extremity amputations based on CPT codes. We excluded patients < 18 years old, those with prior/concurrent major extremity amputations, and those with <= 31 days discontinuity in enrollment. To estimate time to prosthetic acquisition after initial amputation, Weibull Accelerated Failure Time multivariable regression models were used to estimate unadjusted and adjusted time ratios and 95% confidence intervals comparing men to women. We adjusted models for age, Medicare supplement/commercial payer, Metropolitan Statistical Area (MSA), amputation type, social deprivation index, and Elixhauser comorbidities. RESULTS/ANTICIPATED RESULTS: We identified 4,054 patients with major lower extremity amputations (75% below knee and 25% at or above knee). Patients were predominantly male (72%). For patients who received prosthetics, 39.06% of men and 31.28% of women received prosthetics within the first three months of amputation (p<0.001). Time ratios > 1 indicated longer time to prosthetic acquisition between comparison groups. The adjusted time ratio for women compared to men for the time to acquisition of prosthetics was increased; this was statistically significant (TR 1.3281, 95% CI 1.1667, 1.5118). This time ratio suggests that if a man received a prosthetic in 100 days, a women would receive her prosthetic in 133 days. DISCUSSION/SIGNIFICANCE: We found a significant difference in the time to prosthetic acquisition following major limb amputation and acquisition rate in the first three months of amputation among men and women. Successful rehabilitation, quality of life, and healthcare costs are influenced by the timeliness of prosthetic acquisition.

A multi-disciplinary expert group met to discuss vitamin D deficiency in the UK and strategies for improving population intakes and status. Changes to UK Government advice since the 1st Rank Forum on Vitamin D (2009) were discussed, including rationale for setting a reference nutrient intake (10 µg/d; 400 IU/d) for adults and children (4+ years). Current UK data show inadequate intakes among all age groups and high prevalence of low vitamin D status among specific groups (e.g. pregnant women and adolescent males/females). Evidence of widespread deficiency within some minority ethnic groups, resulting in nutritional rickets (particularly among Black and South Asian infants), raised particular concern. Latest data indicate that UK population vitamin D intakes and status reamain relatively unchanged since Government recommendations changed in 2016. Vitamin D food fortification was discussed as a potential strategy to increase population intakes. Data from dose–response and dietary modelling studies indicate dairy products, bread, hens’ eggs and some meats as potential fortification vehicles. Vitamin D3 appears more effective than vitamin D2 for raising serum 25-hydroxyvitamin D concentration, which has implications for choice of fortificant. Other considerations for successful fortification strategies include: (i) need for ‘real-world’ cost information for use in modelling work; (ii) supportive food legislation; (iii) improved consumer and health professional understanding of vitamin D’s importance; (iv) clinical consequences of inadequate vitamin D status and (v) consistent communication of Government advice across health/social care professions, and via the food industry. These areas urgently require further research to enable universal improvement in vitamin D intakes and status in the UK population.

Epidemiological studies have demonstrated an increased risk of developing non-transmittable diseases in adults subjected to adverse early developmental conditions. Metabolic and cardiovascular diseases have been the focus of most studies. Nevertheless, data from animal models also suggest early programming of fertility. In humans, it is difficult to assess the impact of the in utero environment retrospectively. Birthweight is commonly used as an indirect indicator of intrauterine development. This research is part of the ALIFERT study. We investigated a potential link between ponderal index at birth and female fertility in adulthood. Data from 51 infertile and 74 fertile women were analysed. BW was on average higher in infertile women, whereas birth length did not differ between the two groups; thus, resulting in a significantly higher ponderal index at birth in infertile women. Ponderal index at birth has been identified as a risk factor for infertility. These results suggest the importance of the intra-uterine environment, not only for long-term metabolic health but also for fertility.

In this paper, we present numerical simulations that demonstrate the effect of the particular choice of the equation of state (EoS) relating the surfactant concentration to the surface tension in surfactant-driven thin liquid films. Previous choices of the model EoS have been an ad-hoc decreasing function. Here, we instead propose an empirically motivated EoS; this provides a route to resolve some discrepancies and raises new issues to be pursued in future experiments. In addition, we test the influence of the choice of initial conditions and values for the non-dimensional groups. We demonstrate that the choice of EoS improves the agreement in surfactant distribution morphology between simulations and experiments, and influences the dynamics of the simulations. Because an empirically motivated EoS has regions with distinct gradients, future mathematical models may be improved by considering more than one timescale. We observe that the non-dimensional number controlling the relative importance of gravitational versus capillary forces has a larger influence on the dynamics than the other non-dimensional groups, but is nonetheless not a likely cause of discrepancy between simulations and experiments. Finally, we observe that the experimental approach using a ring to contain the surfactant could affect the surfactant and fluid dynamics if it disrupts the intended initial surfactant distribution. However, the fluid meniscus itself does not significantly affect the dynamics.

Alterations to the metabolic environment in utero can have an impact on subsequent female reproductive performance. Here, we used a model of rabbits receiving a high-fat diet (H diet; 7.7% fat and 0.2% cholesterol) or a control diet (C diet; 1.8% fat, no cholesterol) from 10 weeks of age up to mating at 27 weeks and throughout gestation and lactation. At weaning at 5 weeks of age, F1 female offspring were placed on either C or H diet, resulting in a total of four groups C/C, C/H, H/C and H/H diet. Female offspring were mated between 18 and 22 weeks of age and euthanized at 28 days of gestation. A few days before mating and/or just before euthanasia, F1 female rabbits were fasted overnight, weighed, and blood sampled for steroids and biochemistry. Organs were weighed at euthanasia and the ovaries were collected. C/H and H/H F1 offspring had higher cholesterol and high-density lipoprotein plasma concentrations, together with a higher fat mass compared with C/C does, reflecting the effect of the postnatal diet; however, no effect of the antenatal diet was observed on most parameters. The number of primordial, primary and secondary follicles were not different between the groups, but a significantly higher number of atretic follicles was observed in the C/H (P<0.001) and in the H/C (P<0.001) compared with control C/C ovaries, demonstrating both an effect of prenatal and postnatal maternal nutrition. These data indicated that both maternal and postnatal high-fat diet may induce follicular apoptosis; however, in this model, the reproduction was not affected.

Renewed in-depth multi-disciplinary investigation of a large coastal mound settlement in Peru has extended the occupation back more than 7000 years to a first human exploitation ~13720 BP. Research by the authors has chronicled the prehistoric sequence from the activities of the first maritime foragers to the construction of the black mound and the introduction of horticulture and monumentality. The community of Huaca Prieta emerges as innovative, complex and ritualised, as yet with no antecedents.

Prior studies suggest that autism spectrum disorders (ASD) are associated with a domain-specific memory impairment for faces. The underlying cause of this problem and its relation to impaired visual scanning of faces—particularly of the eyes—remains to be determined. We recorded eye movements while 22 high-functioning ASD and 21 typically developing (TD) adolescents encoded and later recognized faces and objects from a single, nonsocial object category (electric fans). Relative to TD subjects, ASD individuals had poorer memory for faces, but not fans. Correlational analyses showed significant relationships between recognition memory and fixations. Eye tracking during encoding revealed that TD subjects made more fixations to faces than fans, whereas ASD individuals did not differ in number of fixations made to each stimulus type. Moreover, although both the TD and ASD groups showed a strong preference for fixating the eyes more than the mouth, the ASD subjects were less likely than TD subjects to scan regions of the face outside of the primary facial features (i.e., eyes, nose, and mouth). We concluded that ASD individuals have a domain-specific memory impairment for faces relative to mechanical objects and that this impairment may be related to abnormal scanning during encoding. (JINS, 2011, 17, 1021–1029)

We compare learning of two inflection types – obligatory noun plurals and optional noun possessives. We tested 107 Hebrew-speaking children aged 6–7 on the same tasks at the beginning and end of first grade. Performance on both constructions improved during this short period, but plurals scored higher from the start, with improvement only in changing stems. The main remaining challenge in mastering noun plural marking in grade school is thus to learn the various types of stem changes. In contrast, possessives improved across the board in first grade, with higher success on non-changing stems and first person suffixes respectively. This intense gain in first grade occurs when children learn to read and write and turn to the written modality as their main source of linguistic input. The study thus testifies to the impact of the shift from spoken language to the ‘language of literacy’ on children's construal of Hebrew morphology.

The flow of a thin layer of fluid down an inclined plane is modified by the presence of insoluble surfactant. For any finite surfactant mass, traveling waves are constructed for a system of lubrication equations describing the evolution of the free-surface fluid height and the surfactant concentration. The one-parameter family of solutions is investigated using perturbation theory with three small parameters: the coefficient of surface tension, the surfactant diffusivity, and the coefficient of the gravity-driven diffusive spreading of the fluid. When all three parameters are zero, the nonlinear PDE system is hyperbolic/degenerate-parabolic, and admits traveling wave solutions in which the free-surface height is piecewise constant, and the surfactant concentration is piecewise linear and continuous. The jumps and corners in the traveling waves are regularized when the small parameters are nonzero; their structure is revealed through a combination of analysis and numerical simulation.

The modeling of the motion of a contact line, the triple point at which solid, liquid and air meet, is a major outstanding problem in the fluid mechanics of thin films [2, 9]. In this paper, we compare two well-known models in the specific context of Marangoni driven films. The precursor model replaces the contact line by a sharp transition between the bulk fluid and a thin layer of fluid, effectively pre-wetting the solid; the Navier slip model replaces the usual no-slip boundary condition by a singular slip condition that is effective only very near the contact line. We restrict attention to traveling wave solutions of the thin film PDE for a film driven up an inclined planar solid surface by a thermally induced surface tension gradient. This involves analyzing third order ODE that depend on several parameters. The two models considered here have subtle differences in their description, requiring a careful treatment when comparing traveling waves and effective contact angles. Numerical results exhibit broad agreement between the two models, but the closest comparison can be done only for a rather restricted range of parameters. The driven film context gives contact angle results quite different from the case of a film moving under the action of gravity alone. The numerical technique for exploring phase portraits for the third order ODE is also used to tabulate the kinetic relation and nucleation condition, information that can be used with the underlying hyperbolic conservation law to explain the rich combination of wave structures observed in simulations of the PDE and in experiments [3, 15].