884 research outputs found
Luminous Intensity for Traffic Signals: A Scientific Basis for Performance Specifications
Humnan factors experiments on visual responses to simulated traffic signals using incandescent lamps and light-emitting diodes are described
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Capturing the Daylight Dividend
Capturing the Daylight Dividend conducted activities to build market demand for daylight as a means of improving indoor environmental quality, overcoming technological barriers to effective daylighting, and informing and assisting state and regional market transformation and resource acquisition program implementation efforts. The program clarified the benefits of daylight by examining whole building systems energy interactions between windows, lighting, heating, and air conditioning in daylit buildings, and daylighting's effect on the human circadian system and productivity. The project undertook work to advance photosensors, dimming systems, and ballasts, and provided technical training in specifying and operating daylighting controls in buildings. Future daylighting work is recommended in metric development, technology development, testing, training, education, and outreach
Emission sparks around M 81 and in some dSph galaxies
We use H-alpha images of three clumps of young stars situated between M81 and
NGC3077 to estimate their star formation rate. Radial velocities of the clumps
measured by us, as well as the velocity of HII-region in the dSph galaxy KDG61
are compatible with their location at the outskirts of a large rotating gaseous
disc around M81. In contrast to KDG61, radial velocity of the emission knot in
the dSph galaxy DDO44, +213+-25 km/s, tells us that this H-alpha spark belongs
to the dSph galaxy itself. F475W and F814W images of DDO44 extracted from the
HST archive reveal 8 bluish (B-I < 0.8) stars apparently associated with the
H-alpha knot.Comment: 6 pages, 4 figures, accepte
Drug absorption through a cell monolayer: a theoretical work on a non-linear three-compartment model
The subject of analysis is a non-linear three-compartment model, widely used
in pharmacological absorption studies. It has been transformed into a general
form, thus leading automatically to an appropriate approximation. This made the
absorption profile accessible and expressions for absorption times, apparent
permeabilities and equilibrium values were given. These findings allowed a
profound analysis of results from non-linear curve fits and delivered the
dependencies on the systems' parameters over a wide range of values. The
results were applied to an absorption experiment with multidrug
transporter-affected antibiotic CNV97100 on Caco-2 cell monolayers.Comment: 21 pages, 8 figures (v4: detailed definition of the treated model -
additional information about limitations
Interpersonal sources of conflict in young people with and without mild to moderate intellectual disabilities at transition from adolescence to adulthood
<p><b>Background:</b> Interpersonal conflict is a source of stress and contributes to poor mental health in people with mild to moderate intellectual disabilities. Understanding the contexts in which conflict typically occurs can better equip services to help people with such difficulties. However, existing studies into the contexts of conflict have included participants with wide-ranging ages and may not reflect the experiences of young adults in particular.</p>
<p><b>Materials and Methods:</b> Twenty-six young adults (16-20 years) with intellectual disabilities and 20 non-disabled young adults completed a semi-structured interview about a recent experience of interpersonal conflict. Participants were asked to describe their beliefs and feelings about the event and their subsequent response.</p>
<p><b>Results:</b> Participants with intellectual disabilities were more likely to encounter conflict with strangers or peers outside their friendship group and to describe incidents of aggression than non-disabled participants. They were also more likely to characterize the other person globally as 'bad' and to perceive the other's actions as being personally directed at them. Young women with intellectual disabilities were less likely to describe responding aggressively to incidents.</p>
<p><b>Conclusions:</b> Findings suggest that young adults with intellectual disabilities are often the target of overt aggression from those outside their inner social sphere, while their non-disabled peers are more likely to experience conflict with people close to them. Young adults with intellectual disabilities may also be more likely to feel victimized by interpersonal conflict. Implications of these findings and limitations of the study are discussed.</p>
Luminous Intensity for Traffic Signals: A Scientific Basis for Performance Specifications - Appendices
Luminous Intensity for Traffic Signals: A Scientific Basis for Performance Specifications - Appendice
ADAM8 Enhances Osteoclast Precursor Fusion and Osteoclast Formation In Vitro and In Vivo
ADAM8 expression is increased in the interface tissue around a loosened hip prosthesis and in the pannus and synovium of patients with rheumatoid arthritis, but its potential role in these processes is unclear. ADAM8 stimulates osteoclast (OCL) formation, but the effects of overexpression or loss of expression of ADAM8 in vivo and the mechanisms responsible for the effects of ADAM8 on osteoclastogenesis are unknown. Therefore, to determine the effects of modulating ADAM expression, we generated tartrate-resistant acid phosphatase (TRAP)–ADAM8 transgenic mice that overexpress ADAM8 in the OCL lineage and ADAM8 knockout (ADAM8 KO) mice. TRAP-ADAM8 mice developed osteopenia and had increased numbers of OCL precursors that formed hypermultinucleated OCLs with an increased bone-resorbing capacity per OCL. They also had an enhanced differentiation capacity, increased TRAF6 expression, and increased NF-κB, Erk, and Akt signaling compared with wild-type (WT) littermates. This increased bone-resorbing capacity per OCL was associated with increased levels of p-Pyk2 and p-Src activation. In contrast, ADAM8 KO mice did not display a bone phenotype in vivo, but unlike WT littermates, they did not increase RANKL production, OCL formation, or calvarial fibrosis in response to tumor necrosis factor α (TNF-α) in vivo. Since loss of ADAM8 does not inhibit basal bone remodeling but only blocks the enhanced OCL formation in response to TNF-α, these results suggest that ADAM8 may be an attractive therapeutic target for preventing bone destruction associated with inflammatory disease. © 2011 American Society for Bone and Mineral Research
Elucidation of the preferred routes of C8-vinyl reduction in chlorophyll and bacteriochlorophyll biosynthesis
Most of the chlorophylls and bacteriochlorophylls utilized for light harvesting by phototrophic organisms carry an ethyl group at the C8 position of the molecule, the product of a C8-vinyl reductase acting on a chlorophyll/bacteriochlorophyll biosynthetic precursor. Two unrelated classes of C8-vinyl reductase are known to exist, BciA and BciB, found in the purple phototroph Rhodobacter sphaeroides and the cyanobacterium Synechocystis sp. PCC6803 respectively. We constructed strains of each bacterium with the native C8-vinyl reductase swapped for the other class of the enzyme, and combined these replacements with a series of deletions of the native bch and chl genes. In vivo data indicate that the preferred substrates for both classes of the enzyme is C8-vinyl chlorophyllide, with C8-vinyl protochlorophyllide reduced only under conditions in which this pigment accumulates as a result of perturbed formation of chlorophyllide
Constitutively Active Canonical NF-κB Pathway Induces Severe Bone Loss in Mice
Physiologic osteoclastogenesis entails activation of multiple signal transduction pathways distal to the cell membrane receptor RANK. However, atypical osteoclastogenesis driven by pro-inflammatory stimuli has been described. We have reported recently a novel mechanism whereby endogenous mutational activation of the classical NF-κB pathway is sufficient to induce RANKL/RANK-independent osteoclastogenesis. Here we investigate the physiologic relevance of this phenomenon in vivo. Using a knock-in approach, the active form of IKK2, namely IKK2SSEE, was introduced into the myeloid lineage with the aid of CD11b-cre mice. Phenotypic assessment revealed that expression of IKK2SSEE in the myeloid compartment induced significant bone loss in vivo. This observation was supported by a dramatic increase in the number and size of osteoclasts in trabecular regions, elevated levels of circulating TRACP-5b, and reduced bone volume. Mechanistically, we observed that IKK2SSEE induced high expression of not only p65 but also p52 and RelB; the latter two molecules are considered exclusive members of the alternative NF-κB pathway. Intriguingly, RelB and P52 were both required to mediate the osteoclastogenic effect of IKK2SSEE and co-expression of these two proteins was sufficient to recapitulate osteoclastogenesis in the absence of RANKL or IKK2SSEE. Furthermore, we found that NF-κB2/p100 is a potent inhibitor of IKK2SSEE-induced osteoclastogenesis. Deletion of p52 enabled more robust osteoclast formation by the active kinase. In summary, molecular activation of IKK2 may play a role in conditions of pathologic bone destruction, which may be refractory to therapeutic interventions targeting the proximal RANKL/RANK signal
Candidate Tidal Dwarf Galaxies in Arp 305: Lessons on Dwarf Detachment and Globular Cluster Formation
To search for Tidal Dwarf Galaxies (TDGs) and to study star formation in
tidal features, we are conducting a large UV imaging survey of interacting
galaxies selected from the Arp (1996) Atlas using the GALEX telescope. As part
of that study, we present a GALEX UV and SDSS and SARA optical study of the
gas-rich interacting galaxy pair Arp 305 (NGC 4016/7). The GALEX UV data reveal
much extended diffuse UV emission and star formation outside the disks. This
includes a luminous star forming region between the two galaxies, and a number
of such regions in tidal tails. We have identified 45 young star forming clumps
in Arp 305, including several TDG candidates. By comparing the UV and optical
colors to population synthesis models, we determined that the clumps are very
young, with several having ages of about 6 Myr. We do not find many
intermediate age clumps in spite of the fact that the last closest encounter
was about 300 Myr ago. We have used a smooth particle hydrodynamics code to
model the interaction and determine the fate of the star clusters and candidate
TDGs.Comment: 12 pages, 6 figures, and 5 tables. Accepted for publication in the
Astronomical Journa
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