Shear strength characteristics of crushed glass

Drained and undrained triaxial compression tests were performed on two gradations of crushed glass in order to determine the compressibility and shear strength characteristics. Consolidation pressures varied from 10 to 100 psi. Volume changes during consolidation were discussed because of the dependency of shear strength behavior on the density condition at the end of consolidation. Stress-strain-volume change characteristics were observed in order to discuss the load-deformation and dilatancy relationships and the effects of varying density, gradation and consolidation pressure. Stress-strain properties were also determined for the undrained tests. The undrained tests were constant volume tests, thus having no dilatancy effects. The undrained tests did have changes in pore pressure which reflected volume change tendencies. Variations in the modulus of deformation, which is analogous to the modulus of elasticity, with respect to consolidation pressure, gradation, density and drainage condition were reported. Shear strength was analyzed in terms of failure envelopes developed by series of tests having the same initial density and in terms of the maximum friction angles developed on an individual test basis. Effects of varying density, gradation and consolidation pressure were noted. The undrained tests were analyzed on both total and effective stress basis --Abstract, page ii

The natural resources of Elkhorn Slough: their present and future use

This report summarizes the history of the slough, ecological attractions, educational value, and problems facing its continued existence. Appended references provide the interested and concerned citizen with sources of more specific information. As a result of the initial survey of estuarine areas of California (California Department of Fish and Game, 1969), the critical status of the coastal marshes became obvious. This report on Elkhorn Slough is part of the high priority inventory and assessment of coastal wetlands by the Department of Fish and Game, and it is intended as a guide for citizens, planners, administrators, and all others interested in the use and development of coastal lands and waters. As such, this report transcends local issues on pollution and development and, in fact, documents the status and future of natural resources that should be a part of the inheritance of following generations. This publication is one of a scheduled series. It follows similar documents on Upper Newport Bay (orange county), Goleta Slough (Santa Barbara County) and the Bolinas Lagoon (Marin county). (Document has 126 pages

Comparison of Spectral/Fourier Domain Optical Coherence Tomography Instruments for Assessment of Normal Macular Thickness

Author Manuscript 2011 February 1.Purpose: The purpose of this study was to report normal macular thickness measurements and assess reproducibility of retinal thickness measurements acquired by a time-domain optical coherence tomography (OCT) (Stratus, Carl Zeiss Meditec, Inc., Dublin, CA) and three commercially available spectral/Fourier domain OCT instruments (Cirrus HD-OCT, Carl Zeiss Meditec, Inc.; RTVue-100, Optovue, Inc., Fremont, CA; 3D OCT-1000, Topcon, Inc., Paramus, NJ). Methods: Forty randomly selected eyes of 40 normal, healthy volunteers were imaged. Subjects were scanned twice during 1 visit and a subset of 25 was scanned again within 8 weeks. Retinal thickness measurements were automatically generated by OCT software and recorded after manual correction. Regression and Bland-Altman plots were used to compare agreement between instruments. Reproducibility was analyzed by using intraclass correlation coefficients, and incidence of artifacts was determined. Results: Macular thickness measurements were found to have high reproducibility across all instruments with intraclass correlation coefficients values ranging 84.8% to 94.9% for Stratus OCT, 92.6% to 97.3% for Cirrus Cube, 76.4% to 93.7% for RTVue MM5, 61.1% to 96.8% for MM6, 93.1% to 97.9% for 3D OCT-1000 radial, and 31.5% to 97.5% for 3D macular scans. Incidence of artifacts was higher in spectral/Fourier domain instruments, ranging from 28.75% to 53.16%, compared with 17.46% in Stratus OCT. No significant age or sex trends were found in the measurements. Conclusion: Commercial spectral/Fourier domain OCT instruments provide higher speed and axial resolution than the Stratus OCT, although they vary greatly in scanning protocols and are currently limited in their analysis functions. Further development of segmentation algorithms and quantitative features are needed to assist clinicians in objective use of these newer instruments to manage diseases.National Institutes of Health (U.S.) (Contract RO1-EY11289-23)National Institutes of Health (U.S.) (Contract R01-EY13178-07)National Institutes of Health (U.S.) (Contract P30-EY008098)United States. Air Force Office of Scientific Research (FA9550-07-1-0101)United States. Air Force Office of Scientific Research (FA9550-07-1-0014

The association between regular cannabis smoking and oral human papillomavirus infection in young adults: a cross-sectional study using NHANES data, 2011-2016

Human papillomavirus (HPV) infection is the most common sexually transmitted infection in the U.S., and the incidence rates of HPV-related oropharyngeal cancers in the U.S. have doubled in the last 20 years. While cigarette smoking is a known risk factor for oral HPV infection, it is unknown if smoking cannabis is associated with greater occurrence of oral HPV infections. The objective of this study was to estimate the association between cannabis smoking status and oral HPV infection in U.S. young adults ages 18-30 years and examine whether this association differs by HPV vaccination status

Breakpoint mapping and haplotype analysis of translocation t(1;12)(q43;q21.1) in two apparently independent families with vascular phenotypes

Background The risk of serious congenital anomaly for de novo balanced translocations is estimated to be at least 6%. We identified two apparently independent families with a balanced t(1;12)(q43;q21.1) as an outcome of a ''Systematic Survey of Balanced Chromosomal Rearrangements in Finns. ''In the first family, carriers (n=6) manifest with learning problems in childhood, and later with unexplained neurological symptoms (chronic headache, balance problems, tremor, fatigue) and cerebral infarctions in their 50s. In the second family, two carriers suffer from tetralogy of Fallot, one from transient ischemic attack and one from migraine. The translocation cosegregates with these vascular phenotypes and neurological symptoms. Methods and Results We narrowed down the breakpoint regions using mate pair sequencing. We observed conserved haplotypes around the breakpoints, pointing out that this translocation has arisen only once. The chromosome 1 breakpoint truncates a CHRM3 processed transcript, and is flanked by the 5 end of CHRM3 and the 3 end of RYR2. TRHDE, KCNC2, and ATXN7L3B flank the chromosome 12 breakpoint. Conclusions This study demonstrates a balanced t(1;12)(q43;q21.1) with conserved haplotypes on the derived chromosomes. The translocation seems to result in vascular phenotype, with or without neurological symptoms, in at least two families. We suggest that the translocation influences the positional expression of CHRM3, RYR2,TRHDE, KCNC2, and/or ATXN7L3B.Peer reviewe

The effect of incorrect scanning distance on boundary detection errors and macular thickness measurements by spectral domain optical coherence tomography: a cross sectional study

BACKGROUND: To investigate the influence of scan distance on retinal boundary detection errors (RBDEs) and retinal thickness measurements by spectral domain optical coherence tomography (SD-OCT). METHODS: 10 eyes of healthy subjects, 10 eyes with diabetic macular edema (DME) and 10 eyes with neovascular age-related macular degeneration (AMD) were examined with RTVue SD-OCT. The MM5 protocol was used in two consecutive sessions to scan the macula. For the first session, the device was set 3.5 cm from the eye in order to obtain detectable signal with low fundus image quality (suboptimal setting) while in the second session a distance of 2.5 cm was set with a good quality fundus image. The signal strength (SSI) value was recorded. The score for retinal boundary detection errors (RBDE) was calculated for ten scans of each examination. RBDE scores were recorded for the whole scan and also for the peripheral 1.0 mm region. RBDE scores, regional retinal thickness values and SSI values between the two sessions were compared. The correlation between SSI and the number of RBDEs was also examined. RESULTS: The SSI was significantly lower with suboptimal settings compared to optimal settings (63.9+/-12.0 vs. 68.3+/-12.2, respectively, p = 0.001) and the number of RBDEs was significantly higher with suboptimal settings in the "all-eyes" group along with the group of healthy subjects and eyes with DME (9.1+/-6.5 vs. 6.8+/-6.3, p = 0.007; 4.4+/-2.6 vs. 2.5+/-1.6, p = 0.035 and 9.7+/-3.3 vs. 5.1+/-3.7, p = 0.008, respectively). For these groups, significant negative correlation was found between the SSI and the number of RBDEs. In the AMD group, the number of RBDEs was markedly higher compared to the other groups and there was no difference in RBDEs between optimal and suboptimal settings with the errors being independent of the SSI. There were significantly less peripheral RBDEs with optimal settings in the "all-eyes" group and the DME subgroup (2.7+/-2.6 vs. 4.2+/-2.8, p = 0.001 and 1.4+/-1.7 vs. 4.1+/-2.2, p = 0.007, respectively). Retinal thickness in the two settings was significantly different only in the outer-superior region in DME. CONCLUSIONS: Optimal distance settings improve SD-OCT SSI with a decrease in RBDEs while retinal thickness measurements are independent of scanning distance

Regional growth dynamics in the service sector: The determinants of employment change in UK regions 1971-2005

There is a need to better understand the dynamics relating to the evolving economic structure of regions, in particular factors concerning deindustrialisation and the growth of service sector activities. In order to unpick the dynamics relating to contemporary regional evolution, this paper examines regional employment in the UK's service sector from 1971-2005. The analysis utilises the statistical technique of multi-factor partitioning to examine the evolutionary dynamics of employment change in the UK service sector. Overall, differing growth trajectories in service sector employment across regions appear to be the result of the different underlying industrial structure observed within the regions themselves. The findings indicate that the industrial structure of a region has a significant influence on employment change in the service sector, with related variety being of greater consequence than specialisation. This suggests that diversity, or urbanisation, effects have a greater influence than specialisation effects on 'lighter' industries than 'heavier' industries. Spatio-temporal variations within the development of the service sector are evident in the analysis and there is evidence of convergence across the regions for all sub-sectors examined. It is concluded that in an increasingly service dominated economy, diversity and related variety have some weight in explaining regional development paths

Echolocation and stratum preference : key trait correlates of vulnerability of insectivorous bats to tropical forest fragmentation

Habitat loss and fragmentation rank high amongst the most pressing threats to biodiversity. Understanding how variation in functional traits is associated with species vulnerability in fragmented landscapes is central to the design of effective conservation strategies. Here, we used a whole-ecosystem ecological experiment in the Central Amazon to investigate which functional traits of aerial-hawking insectivorous bats best predict their sensitivity to forest fragmentation. During 2014, bats were surveyed using passive bat recorders in six continuous forest sites, eight forest fragments, eight fragment edges, and eight forest clearings. The interaction between functional traits, environmental characteristics, and species distribution was investigated using a combination of RLQ and fourth-corner analyses. Our results showed that echolocation call structure, vertical stratification, and wing aspect ratio were the strongest predictors of sensitivity to forest fragmentation. Frequency of maximum energy, body mass, and relative wing loading did not show any correlation with the environmental variables. Bat species with constant-frequency calls were associated with high vegetation density, being more susceptible to forest fragmentation than species with frequency-modulated calls. Vertical stratum preference was also correlated with vegetation structure, indicating that understory species were more sensitive to forest loss than canopy species. Finally, species with high aspect ratio wings were linked to forest edges and clearings. Our findings suggest that species functional traits determine the vulnerability of aerial-hawking insectivorous bats toward fragmentation and, similarly, environmental conditions determine if a species is likely to become locally extinct due to fragmentation. Preserving structurally complex forests will be crucial to ensure the long-term persistence of the most sensitive and vulnerable species of this bat ensemble in fragmented landscapes across the Neotropics

The natural resources of Humboldt Bay

In spite of its past abuses by man, Humboldt Bay is one of the few coastal estuaries remaining in California that has not been rendered largely unsuitable for wildlife by commercial development, dredging, filling or pollution. Its importance is emphasized considering that about 65 percent of the State's original estuarine tidelands have already been destroyed. The people have demonstrated their concern for our dwindling natural resources. If we are to preserve what remains it will be necessary for the people to exercise the wisest possible use of these resources. Because of the importance of coastal wetlands to the fish and wildlife of California, the Department of Fish and Game has initiated a high priority statewide inventory of these wetlands. This publication is an integral part of that program. It is intended as a guide for citizens, planners, administrators and all others interested in the use and development of coastal lands and waters. The Department has been charged with the responsibility of protecting and maintaining the fish and wildlife resources of the State. This publication is directed towards meeting this responsibility by outlining the specific resources and recreational aspects of Humboldt Bay, elucidating problems, and recommending courses of action for future development. Preservation of the Humboldt Bay resources is much more than a local issue. What is done or not done here can have statewide, national and international implications. It also must be recognized that there is an obligation to future generations. Decisions made today will affect all those who follow in our footsteps. (200pp.

Reconstructing Native American Population History

The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved1–5. One contentious issue is whether the settlement occurred via a single6–8 or multiple streams of migration from Siberia9–15. The pattern of dispersals within the Americas is also poorly understood. To address these questions at higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. We show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call “First American”. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan-speakers on both sides of the Panama Isthmus, who have ancestry from both North and South America