Single-Mode Raman Fiber Laser in a Multimode Fiber

The feasibility of a transverse single-mode Raman fiber laser using a multimode fiber has been investigated. The Raman fiber laser operates in low-order transverse modes despite the fact the fiber supports multimode beam propagation. The performance characteristics of the Raman fiber laser are compared with those of the single-pass SRS beam

Probability of Woody Debris Passage at Rock Weirs

Often, large woody debris (LWD) at hydraulic structures is considered hazardous from a performance and public safety perspective. However, the sustainable management of rivers requires the consideration of ecological impacts of LWD such as cover for aquatics and the natural movement of LWD through a catchment. Therefore, this study explores the interaction of natural (nonuniform) LWD with rock weirs through field observations in the Blacksmith Fork River in Utah, USA and laboratory testing at the Utah Water Research Laboratory. The passage probability of individual LWD at rock weirs is observed and tested in an effort to describe the balance between hydraulic structure performance and river ecology via the natural transport of LWD by the river at rock weirs.Results demonstrate that LWD entrapment is a function of rock weir geometry, hydraulic conditions at the weir, and LWD element length and representative diameter. Orientation of LWD elements approaching the rock weir also contributes to entrapment probability. For lesser flow depths, minor accumulations of LWD at rock weirs do not negatively impact the hydraulic performance as evidenced by the head-discharge rating curve

Apron and cutoff wall scour protection for piano key weirs

Piano key (PK) weirs are used in a variety of flow control structure applications, including spillway crests and open channel diversion structures. However, to the best of authors’ knowledge, structure-specific design guidance for scour mitigation is still needed. To fill this gap of knowledge, a systematic experimental campaign was conducted by testing different configurations of horizontal aprons with a cutoff wall. Protection structures were located at the toe of the PK weir. Namely, experiments were performed at large-scale to assess the effect of three apron lengths on downstream scour hole geometry under different hydraulic conditions. It was observed that a horizontal apron deflects the plunging jets originating from the PK weir, thus significantly reducing scour. Experimental evidence allowed corroboration that significant scour depth reduction occurs for an apron length 1.5 times the weir height, with longer aprons found to provide marginal benefits. Finally, also provided herein are tools to estimate the main scour characteristics and help practitioners in optimizing apron design

Comprehensive Family Hygiene Promotion in Peri-Urban Cape Town: Reduction of Respiratory Illness in Children Under Five

Background: Examination with Cone Beam CT (CBCT) is common for localizing maxillary canines with eruption disturbance. The benefits and costs of these examinations are unclear. Objectives: To measure: 1. the proportion of orthodontists' treatment decisions that were different based on intraoral and panoramic radiography (M1) compared with CBCT and panoramic radiography (M2); and 2. the costs of producing different treatment plans, regarding patients with maxillary canines with eruption disturbance. Subjects and methods: Orthodontists participated in a web-based survey and were randomly assigned to denote treatment decisions and the level of confidence in this decision for four patient cases presented with M1 or M2 at two occasions for the same patient case. Results: One hundred and twelve orthodontists made 445 assessments based on M1 and M2, respectively. Twenty-four per cent of the treatment decisions were different depending on which method the raters had access to, whereof one case differed significantly from all other cases. The mean total cost per examination was €99.84 using M1 and €134.37 using M2, resulting in an incremental cost per examination of €34.53 for M2. Limitations: Benefits in terms of number of different treatment decisions must be considered as an intermediate outcome for the effectiveness of a diagnostic method and should be interpreted with caution. Conclusions: For the patient cases presented in this study, most treatment decisions were the same irrespective of radiological method. Accordingly, this study does not support routine use of CBCT regarding patients with maxillary canine with eruption disturbance

Piano Key Weir for Enlargement of the West Fork of Eno River Reservoir

The West Fork of Eno River Reservoir Dam is located near Hillsborough, North Carolina, USA. The earthen embankment dam provides an impoundment used by the town for water supply. The project was originally completed in 2000 with forethought by the owner for an expansion, which was anticipated in the original design. Currently, the design of that expansion to raise the reservoir level for increased water supply is underway. Following a detailed analysis of viable upgrades, a piano key (PK) weir (anticipated as the first to be constructed in the USA) was selected by the owner due to its effectiveness in meeting project requirements. Presented herein are the site-specific characteristics of the existing auxiliary chute spillway, the proposed PK weir, and additional modifications to the chute. This paper also presents site-specific information including the existing auxiliary chute spillway, the new PK weir, and additional modifications to the auxiliary chute. The results include the comparison of four PK weir hydraulic design methods for sizing the spillway. Details and results of a CFD model are also included. Finally, additional significant design considerations are presented, which include: anticipated hydraulic conditions in the downstream chute and identified existing structure deficiencies; estimated spillway design flood hydraulic force distributions taken from the CFD model; the PK key weir stability summary; and other important project aspects including embankment modifications and seepage control measures. It is anticipated that this project will be of interest to those concerned with dam safety and will further encourage the consideration of PK weirs in the USA

Disparities in Children’s Vocabulary and Height in Relation to Household Wealth and Parental Schooling: A Longitudinal Study in Four Low- and Middle-Income Countries

Children from low socio-economic status (SES) households often demonstrate worse growth and developmental outcomes than wealthier children, in part because poor children face a broader range of risk factors. It is difficult to characterize the trajectories of SES disparities in low- and middle-income countries because longitudinal data are infrequently available. We analyze measures of children’s linear growth (height) at ages 1, 5, 8 and 12y and receptive language (Peabody Picture Vocabulary Test) at ages 5, 8 and 12y in Ethiopia, India, Peru and Vietnam in relation to household SES, measured by parental schooling or household assets. We calculate children’s percentile ranks within the distributions of height-for-age z-scores and of age- and language-standardized receptive vocabulary scores. We find that children in the top quartile of household SES are taller and have better language performance than children in the bottom quartile; differences in vocabulary scores between children with high and low SES are larger than differences in the height measure. For height, disparities in SES are present by age 1y and persist as children age. For vocabulary, SES disparities also emerge early in life, but patterns are not consistent across age; for example, SES disparities are constant over time in India, widen between 5 and 12y in Ethiopia, and narrow in this age range in Vietnam and Peru. Household characteristics (such as mother’s height, age, and ethnicity), and community fixed effects explain most of the disparities in height and around half of the disparities in vocabulary. We also find evidence that SES disparities in height and language development may not be fixed over time, suggesting opportunities for policy and programs to address these gaps early in life

Linear growth through 12 years is weakly but consistently associated with language and math achievement scores at age 12 years in four low- or middle-income countries

Background: Whether linear growth through age 12 y is associated with language and math achievement at age 12 remains unclear. Objective: Our objective was to investigate associations of linear growth through age 12 with reading skill, receptive vocabulary, and mathematics performance at age 12 y in four low- or middle-income countries (LMICs). Methods: We analyzed data from the Young Lives Younger Cohort study in Ethiopia (N=1275), India (N=1350), Peru (N=1402), and Vietnam (N=1594). Age 1, 5, 8, and 12 y height-for-age z-scores (HAZ) were calculated. Language and math achievement at age 12 y was assessed using country-specific adaptations of the Peabody Picture Vocabulary Test, the Early Grades Reading Assessment, and a mathematics test; all test scores were standardized by age within country. We used path analysis to examine associations of HAZ with achievement scores. Twelve models were examined at each age (three tests across four countries). Results: Mean HAZ in each country was <-1.00 at all ages. Overall, linear growth through age 12 y was associated with 0.4% to 3.4% of the variance in achievement scores. HAZ at 1 y was positively and significantly associated with the test score in 11 of the 12 models. This association was significantly mediated through HAZ at 5, 8, and 12 y in 9 of the models. HAZ at 5, 8, and 12 y was positively and significantly associated with test scores in 8, 8, and 6 models, respectively. These associations were mediated through HAZ at older ages in 6 of the HAZ at 5 y models and in 6 of the HAZ at 8 y models. Conclusions: Child linear growth between ages 1-12 y was weakly though consistently associated with language and math achievement at age 12 y in four LMICs

Intergenerational Transmission of Poverty and Inequality: Young Lives

Parents play major roles in determining the human capital of children, and thus the income of children when they become adults. Models of investments in children’s human capital posit that these investments are determined by parental resources (financial and human capital) and child endowments within particular market and policy environments. Many empirical studies are consistent with significant associations between parental resources and investments in their children. And there is considerable emphasis in the scholarly and the policy literatures on the degree of intergenerational mobility and the intergenerational transmission of economic opportunities, and therefore the intergenerational transmission of poverty – or of affluence. Therefore policies or other developments that affect the extent of poverty and/or inequality in the parents’ generation are likely to have impacts on the extent of poverty and/or inequality in the children’s generation. However the extent of these intergenerational effects is an empirical question that this paper explores using the Young Lives data to estimate intergenerational associations between parental resources and investments in human capital of children and then, under the assumption that these associations reflect causal effects, to simulate what impacts changes in poverty and inequality in the parents’ generation have on poverty and inequality in the children’s generation. The results suggest that reductions in poverty and in inequality in the parents’ generation reduce poverty and inequality in the children’s generation some, but not much

Impact of shortened crop rotation of oilseed rape on soil and rhizosphere microbial diversity in relation to yield decline

Oilseed rape (OSR) grown in monoculture shows a decline in yield relative to virgin OSR of up to 25%, but the mechanisms responsible are unknown. A long term field experiment of OSR grown in a range of rotations with wheat was used to determine whether shifts in fungal and bacterial populations of the rhizosphere and bulk soil were associated with the development of OSR yield decline. The communities of fungi and bacteria in the rhizosphere and bulk soil from the field experiment were profiled using terminal restriction fragment length polymorphism (TRFLP) and sequencing of cloned internal transcribed spacer regions and 16S rRNA genes, respectively. OSR cropping frequency had no effect on rhizosphere bacterial communities. However, the rhizosphere fungal communities from continuously grown OSR were significantly different to those from other rotations. This was due primarily to an increase in abundance of two fungi which showed 100% and 95% DNA identity to the plant pathogens Olpidium brassicae and Pyrenochaeta lycopersici, respectively. Real-time PCR confirmed that there was significantly more of these fungi in the continuously grown OSR than the other rotations. These two fungi were isolated from the field and used to inoculate OSR and Brassica oleracea grown under controlled conditions in a glasshouse to determine their effect on yield. At high doses, Olpidium brassicae reduced top growth and root biomass in seedlings and reduced branching and subsequent pod and seed production. Pyrenochaeta sp. formed lesions on the roots of seedlings, and at high doses delayed flowering and had a negative impact on seed quantity and quality