The evolutionary state of short-period magnetic white dwarf binaries

We present phase-resolved spectroscopy of two new short-period low accretion rate magnetic binaries, SDSS J125044.42+154957.3 (Porb= 86 min) and SDSS J151415.65+074446.5 (Porb= 89 min). Both systems were previously identified as magnetic white dwarfs from the Zeeman splitting of the Balmer absorption lines in their optical spectra. Their spectral energy distributions exhibit a large near-infrared excess, which we interpret as a combination of cyclotron emission and possibly a late-type companion star. No absorption features from the companion are seen in our optical spectra. We derive the orbital periods from a narrow, variable Hα emission line which we show to originate on the companion star. The high radial velocity amplitude measured in both systems suggests a high orbital inclination, but we find no evidence for eclipses in our data. The two new systems resemble the polar EF Eri in its prolonged low state and also SDSS J121209.31+013627.7, a known magnetic white dwarf plus possible brown dwarf binary, which was also recovered by our method

Design, ancillary testing, analysis and fabrication data for the advanced composite stabilizer for Boeing 737 aircraft. Volume 1: Technical summary

The horizontal stabilizer of the 737 transport was redesigned. Five shipsets were fabricated using composite materials. Weight reduction greater than the 20% goal was achieved. Parts and assemblies were readily produced on production-type tooling. Quality assurance methods were demonstrated. Repair methods were developed and demonstrated. Strength and stiffness analytical methods were substantiated by comparison with test results. Cost data was accumulated in a semiproduction environment. FAA certification was obtained

Optimizing passive acoustic sampling of bats in forests

Passive acoustic methods are increasingly used in biodiversity research and monitoring programs because they are cost-effective and permit the collection of large datasets. However, the accuracy of the results depends on the bioacoustic characteristics of the focal taxa and their habitat use. In particular, this applies to bats which exhibit distinct activity patterns in three-dimensionally structured habitats such as forests. We assessed the performance of 21 acoustic sampling schemes with three temporal sampling patterns and seven sampling designs. Acoustic sampling was performed in 32 forest plots, each containing three microhabitats: forest ground, canopy, and forest gap. We compared bat activity, species richness, and sampling effort using species accumulation curves fitted with the clench equation. In addition, we estimated the sampling costs to undertake the best sampling schemes. We recorded a total of 145,433 echolocation call sequences of 16 bat species. Our results indicated that to generate the best outcome, it was necessary to sample all three microhabitats of a given forest location simultaneously throughout the entire night. Sampling only the forest gaps and the forest ground simultaneously was the second best choice and proved to be a viable alternative when the number of available detectors is limited. When assessing bat species richness at the 1-km(2) scale, the implementation of these sampling schemes at three to four forest locations yielded highest labor cost-benefit ratios but increasing equipment costs. Our study illustrates that multiple passive acoustic sampling schemes require testing based on the target taxa and habitat complexity and should be performed with reference to cost-benefit ratios. Choosing a standardized and replicated sampling scheme is particularly important to optimize the level of precision in inventories, especially when rare or elusive species are expected

Design, ancillary testing, analysis and fabrication data for the advanced composite stabilizer for Boeing 737 aircraft, volume 2

Results of tests conducted to demonstrate that composite structures save weight, possess long term durability, and can be fabricated at costs competitive with conventional metal structures are presented with focus on the use of graphite-epoxy in the design of a stabilizer for the Boeing 737 aircraft. Component definition, materials evaluation, material design properties, and structural elements tests are discussed. Fabrication development, as well as structural repair and inspection are also examined

Virtual reality in pediatric psychology

Copyright © 2017 by the American Academy of Pediatrics. Virtual reality (VR) technologies allow for controlled simulations of affectively engaging background narratives. These virtual environments offer promise for enhancing emotionally relevant experiences and social interactions. Within this context, VR can allow instructors, therapists, neuropsychologists, and service providers to offer safe, repeatable, and diversifiable interventions that can benefit assessments and learning in both typically developing children and children with disabilities. Research has also pointed to VR's capacity to reduce children's experience of aversive stimuli and reduce anxiety levels. Although there are a number of purported advantages of VR technologies, challenges have emerged. One challenge for this field of study is the lack of consensus on how to do trials. A related issue is the need for establishing the psychometric properties of VR assessments and interventions. This review investigates the advantages and challenges inherent in the application of VR technologies to pediatric assessments and interventions

From Navas to Kaltoft: The European Court of Justice’s evolving definition of disability and the implications for HIV-positive individuals

This article will examine the definition of disability developed by the European Court of Justice for the purposes of the Employment Equality Directive and examine whether it is sufficient for the purpose of bringing People Living with HIV/AIDS within its scope. The article will argue that in order to adequately protect People Living with HIV/AIDS within the EU from discrimination, the European Court of Justice needs to ensure that a coherent EU wide definition of disability, based fully upon the social model of disability, is adopted. This is necessary in order to ensure adequate protection not only for People Living with HIV/AIDS but for all individuals with disabilities from discrimination throughout the EU. In addition to this central argument, this paper will argue that the lack of a coherent definition of disability grounded in the social model fragments protection for People Living with HIV/AIDS across the EU leading to a number of possible unintended consequences

Therapeutic effect of the matrix metalloproteinase inhibitor, batimastat, in a human colorectal cancer ascites model.

The matrix metalloproteinase inhibitor batimastat was administered to a human colorectal cancer ascites model, which was initiated by injection of C170HM2 cells into the peritoneal cavity of SCID mice and resulted in solid tumour deposits and ascites formation. The cell line expressed both the 72 and 92 kDa forms of gelatinase by zymography. Batimastat administered from day 0 (40 mg kg-1) reduced the volume of ascites to 21% of control in mice treated from day 0 (P < 0.002) but not day 10. Formation of solid peritoneal deposits was significantly reduced to 77% of vehicle control when batimastat was administered from day 0 (P < 0.01) and 69% of control when administered from day 10 (P < 0.05). Thus, batimastat has the ability to reduce the volume of ascites forming in SCID mice injected intraperitoneally with the human colorectal cell line, C170HM2, when administered from day 0 but not from day 10. Solid peritoneal tumour deposits were significantly reduced in both treatment groups, highlighting the therapeutic potential of batimastat in this clinical condition

The Threat of Multiâ Year Drought in Western Amazonia

Recent â onceâ inâ aâ centuryâ Amazonian droughts highlight the impacts of drought and climate change on this region’s vegetation, carbon storage, water cycling, biodiversity, land use, and economy. The latest climate model simulations suggest this region will experience worsening future drought. However, the instrumental record is too short to quantify the range of background drought variability, or to evaluate extended drought risk in climate models. To overcome these limitations, we generated a new, highly resolved lake record of hydroclimatic variability within the western Amazon Basin. We find that Amazonia has regularly experienced multiâ year droughts over the last millennium. Our results indicate that current climate model simulations likely underestimate the background risk of multiâ year Amazonian drought. These findings illustrate that the future sustainability of the Amazonian forest and its many services may require management strategies that consider the likelihood of multiâ year droughts superimposed on a continued warming trend.Plain Language SummaryThe Amazon basin recently experienced multiple â onceâ inâ aâ centuryâ droughts that impacted the region’s water cycle, economy, vegetation, and carbon storage. However, the instrumental record in this region tends to be too short to determine if these droughts are abnormal in a longâ term context. Paleoclimate data can extend drought records that help water and land managers plan for these events in the face of climate change. To provide additional information about preâ instrumental drought, here we present results from a new paleoclimate lake record based on sediments we recovered from Lake Limón in the Peruvian Amazon. We find that concentrations of elements in the Lake Limón sediment cores are likely recording past changes in rainfall variability. We use this elemental variability to generate a new, millennialâ length record of drought for the western Amazon. We show that this region has experienced multiâ year droughts at least twice a century over the last â ¼1,400 years. The frequency and severity of these paleoclimateâ inferred droughts may exceed most climate model and instrumentalâ era drought risk estimates. Our findings illustrate that the future sustainability of the Amazonian forest and its many ecosystem services may require management strategies that consider the likelihood of multiâ year droughts in addition to continued warming.Key PointsWe present results from a highâ resolution paleoclimate record of hydroclimatic variability in western AmazoniaOur paleoclimate record suggests western Amazonia has regularly experienced multiâ year drought over the last millenniumEarth system model simulations may underestimate the background risk of multiâ year western Amazonian droughtPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146272/1/wrcr23386_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146272/2/wrcr23386.pd

The quest for companions to post-common envelope binaries: I. Searching a sample of stars from the CSS and SDSS

As part of an ongoing collaboration between student groups at high schools and professional astronomers, we have searched for the presence of circum-binary planets in a bona-fide unbiased sample of twelve post-common envelope binaries (PCEBs) from the Catalina Sky Survey (CSS) and the Sloan Digital Sky Survey (SDSS). Although the present ephemerides are significantly more accurate than previous ones, we find no clear evidence for orbital period variations between 2005 and 2011 or during the 2011 observing season. The sparse long-term coverage still permits O-C variations with a period of years and an amplitude of tens of seconds, as found in other systems. Our observations provide the basis for future inferences about the frequency with which planet-sized or brown-dwarf companions have either formed in these evolved systems or survived the common envelope (CE) phase.Comment: accepted by A&