701 research outputs found
Ethical considerations for invertebrates
Mikhalevich & Powell (2020) have built on the discussion about which species deserve inclusion in animal ethics and welfare considerations. Here, we raise questions concerning the assessment criteria. We ask how to assess different species for their ability to fulfill the criteria, which criteria are most important, how we quantify them (absolute or on a continuum), and how non-animals such as fungi and plants fit into this paradigm
Ethical considerations for invertebrates
Mikhalevich & Powell (2020) have built on the discussion about which species deserve inclusion in animal ethics and welfare considerations. Here, we raise questions concerning the assessment criteria. We ask how to assess different species for their ability to fulfill the criteria, which criteria are most important, how we quantify them (absolute or on a continuum), and how non-animals such as fungi and plants fit into this paradigm
Gulf Arabic nouns and verbs: A standardized set of 319 object pictures and 141 action pictures, with predictors of naming latencies
Standardized pictorial stimuli and predictors of successful picture naming are not readily available for Gulf Arabic. On the basis of data obtained from Qatari Arabic, a variety of Gulf Arabic, the present study provides norms for a set of 319 object pictures and a set of 141 action pictures. Norms were collected from healthy speakers, using a picture-naming paradigm and rating tasks. Norms for naming latencies, name agreement, visual complexity, image agreement, imageability, age of acquisition, and familiarity were established. Furthermore, the database includes other intrinsic factors, such as syllable length and phoneme length. It also includes orthographic frequency values (extracted from Aralex; Boudelaa & Marslen-Wilson, 2010). These factors were then examined for their impact on picture-naming latencies in object- and action-naming tasks. The analysis showed that the primary determinants of naming latencies in both nouns and verbs are (in descending order) image agreement, name agreement, familiarity, age of acquisition, and imageability. These results indicate no evidence that noun- and verb-naming processes in Gulf Arabic are influenced in different ways by these variables. This is the first database for Gulf Arabic, and therefore the norms collected from the present study will be of paramount importance for researchers and clinicians working with speakers of this variety of Arabic. Due to the similarity of the Arabic varieties spoken in the Gulf, these different varieties are grouped together under the label “Gulf Arabic” in the literature. The normative databases and the standardized pictures from this study can be downloaded from http://qufaculty.qu.edu.qa/tariq-khwaileh/download-center
An investigation into the effects of, and interaction between, heel height and shoe upper stiffness on plantar pressure and comfort
High heeled shoes remain popular, nevertheless it is not clear what influence manipulating characteristics of this footwear has on their functioning. It is accepted that shoe features other than heel height can affect plantar pressures. However, few investigations have compared such features, and none have compared the influence of modifying upper material stiffness, whilst systematically increasing heel height. A firm understanding of the interactions of footwear properties is essential to ensure that footwear designers can optimise design for the comfort and health of the wearer. This paper investigates a feature that is known to reduce comfort (heel height) and a feature that is easy to change without affecting aesthetics (material stiffness) to better understand the effects of their interaction on plantar pressure and comfort. Sixteen female participants with experience wearing high heels wore a range of shoes with five effective heel heights (35-75 mm) and two upper materials (with different stiffness). In-shoe plantar pressure was recorded and participants completed a comfort questionnaire. Increasing heel height increased plantar pressure under the metatarsal heads, while reducing pressure in the hallux and heel. Higher heel heights also lead to increased discomfort, particularly in the toes where discomfort increased 154.3% from the 35 to 75 mm heels. Upper stiffness did not affect plantar pressure. However, stiffer uppers significantly increased reported discomfort, most notably on top of the foot (108.6%), the back of the heel (87.7%), the overall width (99%), and the overall comfort (100.7%). Significant interaction effects between heel height and upper material existed for comfort questionnaire data. Manipulating heel height alters plantar pressure and comfort, and choice of upper material is paramount to achieving wearer comfort in heels
Life path analysis: scaling indicates priming effects of social and habitat factors on dispersal distances
1. Movements of many animals along a life-path can be separated into repetitive ones within home ranges and transitions between home ranges. We sought relationships of social and environmental factors with initiation and distance of transition movements in 114 buzzards Buteo buteo that were marked as nestlings with long-life radio tags.
2. Ex-natal dispersal movements of 51 buzzards in autumn were longer than for 30 later in their first year and than 35 extra-natal movements between home ranges after leaving nest areas. In the second and third springs, distances moved from winter focal points by birds that paired were the same or less than for unpaired birds. No post-nuptial movement exceeded 2 km.
3. Initiation of early ex-natal dispersal was enhanced by presence of many sibs, but also by lack of worm-rich loam soils. Distances travelled were greatest for birds from small broods and with relatively little short grass-feeding habitat near the nest. Later movements were generally enhanced by the absence of loam soils and short grassland, especially with abundance of other buzzards and probable poor feeding habitats (heathland, long grass).
4. Buzzards tended to persist in their first autumn where arable land was abundant, but subsequently showed a strong tendency to move from this habitat.
5. Factors that acted most strongly in ½-km buffers round nests, or round subsequent focal points, usually promoted movement compared with factors acting at a larger scale. Strong relationships between movement distances and environmental characteristics in ½-km buffers, especially during early ex-natal dispersal, suggested that buzzards became primed by these factors to travel far.
6. Movements were also farthest for buzzards that had already moved far from their natal nests, perhaps reflecting genetic predisposition, long-term priming or poor habitat beyond the study area
Single Spin Measurement using Single Electron Transistors to Probe Two Electron Systems
We present a method for measuring single spins embedded in a solid by probing
two electron systems with a single electron transistor (SET). Restrictions
imposed by the Pauli Principle on allowed two electron states mean that the
spin state of such systems has a profound impact on the orbital states
(positions) of the electrons, a parameter which SET's are extremely well suited
to measure. We focus on a particular system capable of being fabricated with
current technology: a Te double donor in Si adjacent to a Si/SiO2 interface and
lying directly beneath the SET island electrode, and we outline a measurement
strategy capable of resolving single electron and nuclear spins in this system.
We discuss the limitations of the measurement imposed by spin scattering
arising from fluctuations emanating from the SET and from lattice phonons. We
conclude that measurement of single spins, a necessary requirement for several
proposed quantum computer architectures, is feasible in Si using this strategy.Comment: 22 Pages, 8 Figures; revised version contains updated references and
small textual changes. Submitted to Phys. Rev.
Random Walks in Logarithmic and Power-Law Potentials, Nonuniversal Persistence, and Vortex Dynamics in the Two-Dimensional XY Model
The Langevin equation for a particle (`random walker') moving in
d-dimensional space under an attractive central force, and driven by a Gaussian
white noise, is considered for the case of a power-law force, F(r) = -
Ar^{-sigma}. The `persistence probability', P_0(t), that the particle has not
visited the origin up to time t, is calculated. For sigma > 1, the force is
asymptotically irrelevant (with respect to the noise), and the asymptotics of
P_0(t) are those of a free random walker. For sigma < 1, the noise is
(dangerously) irrelevant and the asymptotics of P_0(t) can be extracted from a
weak noise limit within a path-integral formalism. For the case sigma=1,
corresponding to a logarithmic potential, the noise is exactly marginal. In
this case, P_0(t) decays as a power-law, P_0(t) \sim t^{-theta}, with an
exponent theta that depends continuously on the ratio of the strength of the
potential to the strength of the noise. This case, with d=2, is relevant to the
annihilation dynamics of a vortex-antivortex pair in the two-dimensional XY
model. Although the noise is multiplicative in the latter case, the relevant
Langevin equation can be transformed to the standard form discussed in the
first part of the paper. The mean annihilation time for a pair initially
separated by r is given by t(r) \sim r^2 ln(r/a) where a is a microscopic
cut-off (the vortex core size). Implications for the nonequilibrium critical
dynamics of the system are discussed and compared to numerical simulation
results.Comment: 10 pages, 1 figur
Migratory monarchs that encounter resident monarchs show life‐history differences and higher rates of parasite infection
Environmental change induces some wildlife populations to shift from migratory to resident behaviours. Newly formed resident populations could influence the health and behaviour of remaining migrants. We investigated migrant–resident interactions among monarch butterflies and consequences for life history and parasitism. Eastern North American monarchs migrate annually to Mexico, but some now breed year‐round on exotic milkweed in the southern US and experience high infection prevalence of protozoan parasites. Using stable isotopes (δ2H, δ13C) and cardenolide profiles to estimate natal origins, we show that migrant and resident monarchs overlap during fall and spring migration. Migrants at sites with residents were 13 times more likely to have infections and three times more likely to be reproductive (outside normal breeding season) compared to other migrants. Exotic milkweed might either attract migrants that are already infected or reproductive, or alternatively, induce these states. Increased migrant–resident interactions could affect monarch parasitism, migratory success and long‐term conservation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146381/1/ele13144_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146381/2/ele13144.pd
The large longitudinal spread of solar energetic particles during the January 17, 2010 solar event
We investigate multi-spacecraft observations of the January 17, 2010 solar
energetic particle event. Energetic electrons and protons have been observed
over a remarkable large longitudinal range at the two STEREO spacecraft and
SOHO suggesting a longitudinal spread of nearly 360 degrees at 1AU. The flaring
active region, which was on the backside of the Sun as seen from Earth, was
separated by more than 100 degrees in longitude from the magnetic footpoints of
each of the three spacecraft. The event is characterized by strongly delayed
energetic particle onsets with respect to the flare and only small or no
anisotropies in the intensity measurements at all three locations. The presence
of a coronal shock is evidenced by the observation of a type II radio burst
from the Earth and STEREO B. In order to describe the observations in terms of
particle transport in the interplanetary medium, including perpendicular
diffusion, a 1D model describing the propagation along a magnetic field line
(model 1) (Dr\"oge, 2003) and the 3D propagation model (model 2) by (Dr\"oge et
al., 2010) including perpendicular diffusion in the interplanetary medium have
been applied, respectively. While both models are capable of reproducing the
observations, model 1 requires injection functions at the Sun of several hours.
Model 2, which includes lateral transport in the solar wind, reveals high
values for the ratio of perpendicular to parallel diffusion. Because we do not
find evidence for unusual long injection functions at the Sun we favor a
scenario with strong perpendicular transport in the interplanetary medium as
explanation for the observations.Comment: The final publication is available at http://www.springerlink.co
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