The milling of pristine and brominated P-100 graphite fibers

Techniques were developed for the ball milling of pristine and brominated P-100 graphite fibers. Because of the lubrication properties of graphite, large ball loads (50 percent by volume) were required. Use of 2-propanol as a milling medium enhanced the efficiency of the process. Milled brominated P-100 fibers had resistivities which were indistinguishable from milled pristine P-100 fibers. Apparent loss of bromine from the brominated fibers suggests that bromine would not be the intercalate of choice in applications where milled fibers of this type are required. Other intercalates which do not degas may be more appropriate for a milled fiber application. These same results, however, do provide evidence that bromine molecules leave the fiber surface when removed from overpressure of bromine. While exploring possible solvent media for milling purposes, it was found that brominated fibers are stable in a wide variety of organic solvents

The "Arauco State" against the spanish conquest: Ritual and socio-political structure of the araucano-mapuches in the Nahuelbuta valleys during the 16th and 17th centuries

Este artículo presenta evidencias arqueológicas y etnohistóricas que muestran la complejidad de la organización sociopolítica de las poblaciones que habitaban los valles que entrecruzan y circundan la cordillera de Nahuelbuta durante el siglo XVI y principios del siglo XVII, particularmente en el valle de Purén-Lumaco. La hipótesis que se sostiene es que la estructura sociopolítica, la densidad demográfica y las características económicas y culturales de las poblaciones de dicha área presentan una mayor complejidad y dimensiones superiores a lo que comúnmente se admite en la literatura arqueológica, histórica y antropológica. Las formas de organización sociopolíticas y los modos de asentamiento de las poblaciones araucano-mapuches de los siglos XVI y principios del siglo XVII tenderían a aproximarse, desde esta perspectiva, a modelos complejos característicos del mundo andino

Inhibition of Defocus-Induced Myopia in Chickens

Woods, J., Guthrie, S. E., Keir, N., Dillehay, S., Tyson, M., Griffin, R., … Irving, E. (2013). Inhibition of Defocus-Induced Myopia in Chickens. Investigative Opthalmology & Visual Science, 54(4), 2662. https://doi.org/10.1167/iovs.12-10742Purpose.: To determine the effect of wearing a lens with a unique peripheral optical design on the development and progression of defocus-induced myopia in newly hatched chickens.Methods.: Eighty-five newly hatched chickens underwent bilateral retinoscopy and A-scan ultrasound to determine their refractive error and axial length. They were randomly divided into Control and two Test groups, in which each chicken was fitted with a goggle-lens over the right eye, with the left eye remaining untreated. The Control group wore a lens of power −10.00 diopters (D) of standard spherical optical design. The two Test lenses both had a central optical power −10.00 D, but used different peripheral myopia progression control (MPC) designs. For all groups, retinoscopy was repeated on days 3, 7, 10, and 14; ultrasound was repeated on day 14. Results.: On day 0 there was no statistical difference in refractive error (mean +6.92 D) or axial length (mean 8.06 mm) between Test and Control groups or treated and untreated eyes (all P > 0.05). At day 14, 37 (43.5%) of 85 chickens had not experienced goggle detachment and were included in the final analyses. In this cohort there was a significant refractive difference between the treated eyes of the Control group (n = 17) and those of Test 1 (n = 14) and Test 2 (n = 6) groups (both P < 0.01): Control −4.65 ± 2.11 D, Test 1 +4.57 ± 3.11 D, Test 2 +1.08 ± 1.24 D (mean ± SEM). There was also a significant axial length difference (both P < 0.01): Control 10.55 ± 0.36 mm, Test 1 9.99 ± 0.14 mm, Test 2 10.17 ± 0.18 mm. Conclusions.: Use of these unique MPC lens designs over 14 days caused a significant reduction in the development of defocus-induced myopia in chickens; the degree of reduction appeared to be design specific

An integrated science unit : ants

This instructional development project integrated language arts and the science areas. A print-rich environment extended content and offered models of language, thus energizing children to become actively involved in the study. Many literature genres and.related expressive activities provided children with many options for learning experiences. The focus for this science unit for grade two was on ants. A print-rich environment was provided along with computer software and access to information on the internet

Three-dimensional airway volumes and most constricted areas in children

poster abstractObjective: The objectives of this retrospective study using cone beam computed tomography (CBCT) were to determine if there are differences in the volume of various airway segments and the most constricted area (MCA) of children with different dentoskeletal patterns. Methods: The initial CBCTs of 83 orthodontic patients (30 Angle’s Class I; 26 Class II; and 27 Class III) were collected from a private orthodontic office. Following reliability studies, various parameters of the craniofacial complex, airway volume, and MCA were measured utilizing Dolphin 3D software. Comparisons among the three dental and the skeletal malocclusion classes were performed using one-way ANOVA and Fishers Protected Least Significant. Associations of the airway volumes and the MCA with other parameters were determined using correlation coefficients, accepting p < 0.05 as significant for all tests. Results: Maxillary right sinus volume was the only airway segment showing significant difference among different dental classes. Maxillary sinus volume also correlated moderately with anterior facial height and mandibular length. No significant differences were found between the MCA and different dentoskeletal classifications. Conclusions: The only significant difference in airway parameters among the dentoskeletal classes was that the dental Class II subjects had greater right sinus volume than the other classes. Shorter anterior facial height or mandibular length could be indicators for decreased airway volume in children. Funding: IUSD Graduate Research Committee, IUPUI Three-Dimensional Imaging of the Craniofacial Complex Center, Jarabak Endowed Professorshi

Mitochondrial phylogeography and demographic history of the Vicuña: implications for conservation

The vicuña (Vicugna vicugna; Miller, 1924) is a conservation success story, having recovered from near extinction in the 1960s to current population levels estimated at 275 000. However, lack of information about its demographic history and genetic diversity has limited both our understanding of its recovery and the development of science-based conservation measures. To examine the evolution and recent demographic history of the vicuña across its current range and to assess its genetic variation and population structure, we sequenced mitochondrial DNA from the control region (CR) for 261 individuals from 29 populations across Peru, Chile and Argentina. Our results suggest that populations currently designated as Vicugna vicugna vicugna and Vicugna vicugna mensalis comprise separate mitochondrial lineages. The current population distribution appears to be the result of a recent demographic expansion associated with the last major glacial event of the Pleistocene in the northern (18 to 22°S) dry Andes 14–12 000 years ago and the establishment of an extremely arid belt known as the 'Dry Diagonal' to 29°S. Within the Dry Diagonal, small populations of V. v. vicugna appear to have survived showing the genetic signature of demographic isolation, whereas to the north V. v. mensalis populations underwent a rapid demographic expansion before recent anthropogenic impacts

Early and Middle Holocene Hunter-Gatherer Occupations in Western Amazonia: The Hidden Shell Middens

We report on previously unknown early archaeological sites in the Bolivian lowlands, demonstrating for the first time early and middle Holocene human presence in western Amazonia. Multidisciplinary research in forest islands situated in seasonally-inundated savannahs has revealed stratified shell middens produced by human foragers as early as 10,000 years ago, making them the oldest archaeological sites in the region. The absence of stone resources and partial burial by recent alluvial sediments has meant that these kinds of deposits have, until now, remained unidentified. We conducted core sampling, archaeological excavations and an interdisciplinary study of the stratigraphy and recovered materials from three shell midden mounds. Based on multiple lines of evidence, including radiocarbon dating, sedimentary proxies (elements, steroids and black carbon), micromorphology and faunal analysis, we demonstrate the anthropogenic origin and antiquity of these sites. In a tropical and geomorphologically active landscape often considered challenging both for early human occupation and for the preservation of hunter-gatherer sites, the newly discovered shell middens provide evidence for early to middle Holocene occupation and illustrate the potential for identifying and interpreting early open-air archaeological sites in western Amazonia. The existence of early hunter-gatherer sites in the Bolivian lowlands sheds new light on the region's past and offers a new context within which the late Holocene "Earthmovers" of the Llanos de Moxos could have emerged. © 2013 Lombardo et al