403 research outputs found
Patterns of Change Over Time in Knee Bone Shape Are Associated with Sex.
BackgroundKnee osteoarthritis (OA) is more common in females than in males; however, the biological mechanisms for the difference in sex in patients with knee OA are not well understood. Knee shape is associated with OA and with sex, but the patterns of change in the bone's shape over time and their relation to sex and OA are unknown and may help inform how sex is associated with shape and OA and whether the effect is exerted early or later in life.Questions/purposes (1) Does knee shape segregate stably into different groups of trajectories of change (groups of knees that share similar patterns of changes in bone shape over time)? (2) Do females and males have different trajectories of bone shape changes? (3) Is radiographic OA at baseline associated with trajectories of bone shape changes?MethodsWe used data collected from the NIH-funded Osteoarthritis Initiative (OAI) to evaluate a cohort of people aged 45 to 79 years at baseline who had either symptomatic knee OA or were at high risk of having it. The OAI cohort included 4796 participants (58% females; n = 2804) at baseline who either had symptomatic knee OA (defined as having radiographic tibiofemoral knee OA and answering positively to the question "have you had pain, aching or stiffness around the knee on most days for at least one month during the past 12 months") or were at high risk of symptomatic knee OA (defined as having knee symptoms during the prior 12 months along with any of the following: overweight; knee injury; knee surgery other than replacement; family history of total knee replacement for OA; presence of Heberden's nodes; daily knee bending activity) or were part of a small nonexposed subcohort. From these participants, we limited the eligible group to those with radiographs available and read at baseline, 2 years, and 4 years, and randomly selected participants from each OAI subcohort in a manner to enrich representation in the study of the progression and nonexposed subcohorts, which were smaller in number than the OA incidence subcohort. From these patients, we randomly sampled 473 knees with radiographs available at baseline, 2 years, and 4 years. We outlined the shape of the distal femur and proximal tibia on radiographs at all three timepoints using statistical shape modelling. Five modes (each mode represents a particular type of knee bone shape variation) were derived for the proximal tibia and distal femur's shape, accounting for 78% of the total variance in shape. Group-based trajectory modelling (a statistical approach to identify the clusters of participants following a similar progression of change of bone shape over time, that is, trajectory group) was used to identify distinctive patterns of change in the bone shape for each mode. We examined the association of sex and radiographic OA at baseline with the trajectories of each bone shape mode using a multivariable polytomous regression model while adjusting for age, BMI, and race.ResultsKnee bone shape change trajectories segregated stably into different groups. In all modes, three distinct trajectory groups were derived, with the mean posterior probabilities (a measure of an individual's probability of being in a particular group and often used to characterize how well the trajectory model is working to describe the population) ranging from 84% to 99%, indicating excellent model fitting. For most of the modes of both the femur and tibia, the intercepts for the three trajectory groups were different; however, the rates of change were generally similar in each mode. Females and males had different trajectories of bone shape change. For Mode 1 in the femur, females were more likely to be in trajectory Groups 3 (odds ratio 30.2 [95% CI 12.2 to 75.0]; p < 0.001) and 2 than males (OR 4.1 [95% CI 2.3 to 7.1]; p < 0.001); thus, females had increased depth of the intercondylar fossa and broader shaft width relative to epicondylar width compared with males. For Mode 1 in the tibia, females were less likely to be in trajectory Group 2 (OR 0.5 [95% CI 0.3 to 0.9]; p = 0.01) than males (that is, knees of females were less likely to display superior elevation of tibial plateau or decreased shaft width relative to head width). Radiographic OA at baseline was associated with specific shape-change trajectory groups. For Mode 1 in the femur, knees with OA were less likely to be in trajectory Groups 3 (OR 0.4 [95% CI 0.2 to 0.8]; p = 0.008) and 2 (OR 0.6 [95% CI 0.3 to 1.0]; p = 0.03) than knees without OA; thus, knees with OA had decreased depth of the intercondylar fossa and narrower shaft width relative to epicondylar width compared with knees without OA. For Mode 1 in the tibia, knees with OA were not associated with trajectory.ConclusionsThe shapes of the distal femur and proximal tibia did not change much over time. Sex and baseline knee radiographic OA status are associated with the trajectory of change in the bone's shape, suggesting that both may contribute earlier in life to the associations among trajectories observed in older individuals. Future studies might explore sex-related bone shape change earlier in life to help determine when the sex-specific shapes arise and also the degree to which these sex-related shapes are alterable by injury or other events.Level of evidenceLevel III, prognostic study
Escape the welcome cliché
The University of Surrey Library and Learning Support Services (LLSS) recognised an increasing need to transform its welcome, induction and orientation activities for students. Past activities have entailed delivering information to students in ways which may have led to information overload and lack of engagement by students with library services. The LLSS have been exploring innovative ways to welcome students to university, moving away from didactic approaches. This paper presents one such innovation produced among a series of activities during 2017/18, an educational escape room, informed by the work of Walsh (2017). This activity invited students to solve a series of themed puzzles in the escape room, introducing them to library services and information literacy (IL) skills to support their studies. This report provides an account of the challenges and positive outcomes encountered in designing the escape room, with a view to sharing good learning and teaching practice
Dissociation of sensitivity to spatial frequency in word and face preferential areas of the fusiform gyrus
Different cortical regions within the ventral occipitotemporal junction have been reported to show preferential responses to particular objects. Thus, it is argued that there is evidence for a left-lateralized visual word form area and a right-lateralized fusiform face area, but the unique specialization of these areas remains controversial. Words are characterized by greater power in the high spatial frequency (SF) range, whereas faces comprise a broader range of high and low frequencies. We investigated how these high-order visual association areas respond to simple sine-wave gratings that varied in SF. Using functional magnetic resonance imaging, we demonstrated lateralization of activity that was concordant with the low-level visual property of words and faces; left occipitotemporal cortex is more strongly activated by high than by low SF gratings, whereas the right occipitotemporal cortex responded more to low than high spatial frequencies. Therefore, the SF of a visual stimulus may bias the lateralization of processing irrespective of its higher order properties
Probing the IGM/Galaxy Connection V: On the Origin of Lya and OVI Absorption at z<0.2
We analyze the association of galaxies to Lya and OVI absorption, the most
commonly detected transitions in the low-z intergalactic medium (IGM), in the
fields of 14 quasars with z_em = 0.06-0.57. Confirming previous studies, we
observe a high covering fraction for Lya absorption to impact parameter rho =
300kpc: 33/37 of our L>0.01L* galaxies show Lya equivalent width W_Lya>50mA.
Galaxies of all luminosity L>0.01L* and spectral type are surrounded by a
diffuse and ionized circumgalactic medium (CGM), whose baryonic mass is
estimated at ~10^(10.5 +/- 0.3) Msun for a constant N_H. The virialized halos
and extended CGM of present-day galaxies are responsible for most strong Lya
absorbers (W_Lya > 300mA) but cannot reproduce the majority of observed lines
in the Lya forest. We conclude that the majority of Lya absorption with
W_Lya=30-300mA occurs in the cosmic web predicted by cosmological simulations
and estimate a characteristic width for these filaments of ~400kpc. Regarding
OVI, we observe a near unity covering fraction to rho=200kpc for L>0.1L*
galaxies and to rho = 300kpc for sub-L* (0.1 L*<L<L*) galaxies. Similar to our
Lya results, stronger OVI systems (W_OVI > 70mA) arise in the virialized halos
of L>0.1L* galaxies. Unlike Lya, the weaker OVI systems (W_OVI~30mA) arise in
the extended CGM of sub-L* galaxies. The majority of OVI gas observed in the
low-z IGM is associated with a diffuse medium surrounding individual galaxies
with L~0.3L*, and rarely originates in the so-called warm-hot IGM (WHIM)
predicted by cosmological simulations.Comment: Submitted to the Astrophysical Journal; 26 pages, 9 figures. See
http://www.ucolick.org/~xavier/WFCCDOVI/index.html for mor
Mantle deformation beneath the Chicxulub impact crater
Accepted versio
Interspecific hybridization transfers a previously unknown glyphosate resistance mechanism in Amaranthus species
A previously unknown glyphosate resistance mechanism, amplification of the 5-enolpyruvyl shikimate-3-phosphate synthase gene, was recently reported in Amaranthus palmeri. This evolved mechanism could introgress to other weedy Amaranthus species through interspecific hybridization, representing an avenue for acquisition of a novel adaptive trait. The objective of this study was to evaluate the potential for this glyphosate resistance trait to transfer via pollen from A. palmeri to five other weedy Amaranthus species (Amaranthus hybridus, Amaranthus powellii, Amaranthus retroflexus, Amaranthus spinosus, and Amaranthus tuberculatus). Field and greenhouse crosses were conducted using glyphosate-resistant male A. palmeri as pollen donors and the other Amaranthus species as pollen recipients. Hybridization between A. palmeri and A. spinosus occurred with frequencies in the field studies ranging from <0.01% to 0.4%, and 1.4% in greenhouse crosses. A majority of the A. spinosus × A. palmeri hybrids grown to flowering were monoecious and produced viable seed. Hybridization occurred in the field study between A. palmeri and A. tuberculatus (<0.2%), and between A. palmeri and A. hybridus (<0.01%). This is the first documentation of hybridization between A. palmeri and both A. spinosus and A. hybridus
1958: Abilene Christian College Bible Lectures - Full Text
“GOD”
Being the
Abilene Christian College Annual
Bible Lectures
1958
Price: $3.00
Published by
FIRM FOUNDATION PUBLISHING HOUSE
Box 77 Austin, Texa
2019 American College of Rheumatology/Arthritis Foundation Guideline for the Management of Osteoarthritis of the Hand, Hip, and Knee
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153772/1/acr24131.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153772/2/acr24131_am.pd
The First Galaxies: Signatures of the Initial Starburst
Detection of the radiation emitted from the first galaxies at z > 10 will be
made possible in the next decade, with the launch of the James Webb Space
Telescope (JWST). We carry out cosmological radiation hydrodynamics simulations
of Population III (Pop III) starbursts in a 10^8 M_Sun dwarf galaxy at z =
12.5. For different star formation efficiencies and stellar initial mass
functions (IMFs), we calculate the luminosities and equivalent widths (EWs) of
the recombination lines H_alpha, Ly_alpha, and He II 1640, under the simple
assumption that the stellar population does not evolve over the first ~3 Myr of
the starburst. Although only < 40 percent of the gas in the central 100 pc of
the galaxy is photoionized, we find that photoheating by massive stars causes a
strong dynamical response, which results in a weak correlation between
luminosity emitted in hydrogen recombination lines and the total mass in stars.
However, owing to the low escape fraction of He II-ionizing photons, the
luminosity emitted in He II 1640 is much more strongly correlated with the
total stellar mass. The ratio of the luminosity in He II 1640 to that in
Ly_alpha or H_alpha is found to be a good indicator of the IMF in many cases.
The ratio of observable fluxes is F_1640/F_Halpha ~ 1 for clusters of 100 M_Sun
Pop III stars and F_1640/F_Halpha ~ 0.1 for clusters of 25 M_Sun Pop III stars.
The EW of the He II 1640 emission line is the most reliable IMF indicator, its
value varying between ~ 20 and ~ 200 angstrom for a massive and very massive
Pop III IMF, respectively. Even the bright, initial stages of Pop III
starbursts in the first dwarf galaxies will likely not be directly detectable
by the JWST. Instead, the JWST may discover only more massive, and hence more
chemically evolved, galaxies which host normal, Pop I/II, star formation.Comment: 13 pages, 10 figures; accepted for publication in MNRA
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