1,327 research outputs found
Biological and statistical study of the development of the fleece of the Scottish mountain blackfaced breed of sheep from birth to maturity
The fleece of the Scottish Mountain Blackfaced sheep consists of an admixture of fibres which
differ amongst themselves in respect of physical
characterisation. The concensus of opinion amongst
producers ani users of Blackfaced wool is that the
fleece should consist of hair -like fibres, grouped into long, tapering staples which fall to either side
of the body with a "part" along the dorsal line, forming a long, smooth, outer coat, whilst beneath this
there should be an abundant growth of fine, shorter
fibres called, in contradistinction to the fibres of
the outer coat, wool. Ideally, each staple should
taper to a tip not less than the size of an ordinary
lead pencil. "Tithin the breed there is a great
variation in fleece quality and quantity. Usually it
is long and coarse and contains considerable numbers
of white, opaque, pointed, hair -like fibres which will
not take up dyes at all readily, which differ in their
structure from the other constituents of the fleece,
and which are known as kemp. In many animals a proportion of pigmented fibres can be found. Lying
entangled amidst the growing fibres are to be found
kemp fibres that have been shed.A detailed account of each of the types of
fibre constituting the Blackface fleece follows.
(see pages 45 -60) .It is reasonable to assume that the outer
coat of this fleece mainly serves to protect the inner
coat and skin from wet and injury, whilst the inner
coat, in virtue of its physical properties, conserves
bodily heat. Thus, the ideal type of fleece from the
point of view of the breeder is one which provides
adequate protection for the sheep in that it protects
the body from cold, wind, rain and injury
A Frequency-Controlled Magnetic Vortex Memory
Using the ultra low damping NiMnSb half-Heusler alloy patterned into
vortex-state magnetic nano-dots, we demonstrate a new concept of non-volatile
memory controlled by the frequency. A perpendicular bias magnetic field is used
to split the frequency of the vortex core gyrotropic rotation into two distinct
frequencies, depending on the sign of the vortex core polarity inside
the dot. A magnetic resonance force microscope and microwave pulses applied at
one of these two resonant frequencies allow for local and deterministic
addressing of binary information (core polarity)
Predictors of distress and anxiety during pregnancy
Objective: There is a high incidence of distressing psychological symptoms including anxiety in pregnancy. Nevertheless, predictors of distress and anxiety during pregnancy have not been well characterized. We determined whether temperament and character, trait anxiety, resilience, and social support predicted distress and anxiety symptoms in pregnancy.Method: Pregnant women (n=105) with low risk singleton pregnancies were recruited from Midwife Obstetric Units. Assessments of distress (usingthe K-10) and anxiety (using the Spielberger State Inventory) were undertaken in trimester 2 and 3. Measures of temperament and character, trait anxiety, resilience and social support were undertaken at the same time points. Regression analyses were used to determine predictors of distress and anxiety at each trimester.Results: Predictors of distress and anxiety were lower selfdirectedness,higher harm avoidance, higher trait anxiety, lower resilience, and lower social support, at each time point.Conclusion: Understanding predictors of distress and anxiety in pregnancy may be useful in developing interventions for addressing such symptoms, as well as perhaps in preventing potential sequelae such as anxiety and mood disorders.Keywords: Distress; Anxiety; Self-directedness; Harm avoidance; Resilience; Social suppor
A unique, ring-like radio source with quadrilateral structure detected with machine learning
We report the discovery of a unique object in the MeerKAT Galaxy Cluster
Legacy Survey (MGCLS) using a machine learning anomaly detection algorithm.
This strange, ring-like source is 30' from the MGCLS field centred on Abell
209, and is not readily explained by simple physical models. With an assumed
host galaxy at redshift 0.55, the luminosity (10^25 W/Hz) is comparable to
powerful radio galaxies. The source consists of a ring of emission 175 kpc
across, quadrilateral enhanced brightness regions bearing resemblance to radio
jets, two ``ears'' separated by 368 kpc, and a diffuse envelope. All of the
structures appear spectrally steep, ranging from -1.0 to -1.5. The ring has
high polarization (25%) except on the bright patches (<10%). We compare this
source to the Odd Radio Circles recently discovered in ASKAP data and discuss
several possible physical models, including a termination shock from starburst
activity, an end-on radio galaxy, and a supermassive black hole merger event.
No simple model can easily explain the observed structure of the source. This
work, as well as other recent discoveries, demonstrates the power of
unsupervised machine learning in mining large datasets for scientifically
interesting sources.Comment: 7 pages, 5 figures, to be submitted to MNRA
Predictors of Comorbid Eating Disorders and Association with Other Obsessive-Compulsive Spectrum Disorders in Trichotillomania
Trichotillomania (TTM) and eating disorders (ED) share many phenomenological similarities, including ritualized compulsive behaviors. Given this, and that comorbid EDs may represent additional functional burden to hair pullers, we sought to identify factors that predict diagnosis of an ED in a TTM population. Subjects included 555 adult females (age range 18–65) with DSM-IV-TR TTM or chronic hair pullers recruited from multiple sites. 7.2% (N = 40) of our TTM subjects met criteria for an ED in their lifetime. In univariable regression analysis, obsessive-compulsive disorder (OCD), Yale-Brown Obsessive Compulsive Scale (Y-BOCS) worst-ever compulsion and total scores, certain obsessive-compulsive spectrum disorders, anxiety disorder, attention-deficit/hyperactivity disorder (ADHD), and substance disorder all met the pre-specified criteria for inclusion in the multivariable analysis. In the final multivariable model, diagnosis of OCD (OR: 5.68, 95% CI: 2.2–15.0) and diagnosis of an additional body-focused repetitive behavior disorder (BFRB) (OR: 2.69, 95% CI: 1.1–6.8) were both associated with increased risk of ED in TTM. Overall, our results provide further support of the relatedness between ED and TTM. This finding highlights the importance of assessing for comorbid OCD and additional BFRBs in those with TTM. Future research is needed to identify additional predictors of comorbid disorders and to better understand the complex relationships between BFRBs, OCD and EDs
Childhood trauma in adults with social anxiety disorder and panic disorder: a cross-national study
Objectives: The influence of childhood trauma as a specific environmental factor on the development of adult psychopathology is far from being elucidated. As part of a collaborative project between research groups from South Africa (SA) and Sweden focusing on genetic and environmental factors contributing to anxiety disorders, this study specifically investigated rates of childhood trauma in South African and Swedish patients respectively, and whether, in the sample as a whole, different traumatic experiences in childhood are predictive of social anxiety (SAD) or panic disorder (PD) in adulthood. Method: Participants with SAD or PD (85 from SA, 135 from Sweden) completed the Childhood Trauma Questionnaire (CTQ). Logistic regression was performed with data from the two countries separately, and from the sample as a whole, with primary diagnoses as dependent variables, gender, age, and country as covariates, and the CTQ subscale totals as independent variables. The study also investigated the internal consistency (Cronbach alpha) of the CTQ subscales. Results: SA patients showed higher levels of childhood trauma than Swedish patients. When data from both countries were combined, SAD patients reported higher rates of childhood emotional abuse compared to those with PD. Moreover, emotional abuse in childhood was found to play a predictive role in SAD/PD in adulthood in the Swedish and the combined samples, and the same trend was found in the SA sample. The psychometric qualities of the CTQ subscales were adequate, with the exception of the physical neglect subscale. Conclusion: Our findings suggest that anxiety disorder patients may differ across countries in terms of childhood trauma. Certain forms of childhood abuse may contribute specific vulnerability to different types of psychopathology. Longitudinal studies should focus on the potential sequential development of SAD/PD among individuals with childhood emotional abuse.Keywords: Childhood trauma; Social anxiety disorder; Panic disorder; Cross-nationa
Childhood trauma in adults with social anxiety disorder and panic disorder: a cross-national study
Objectives: The influence of childhood trauma as a specific environmental factor on the development of adult psychopathology is far from being elucidated. As part of a collaborative project between research groups from South Africa (SA) and Sweden focusing on genetic and environmental factors contributing to anxiety disorders, this study specifically investigated rates of childhood trauma in South African and Swedish patients respectively, and whether, in the sample as a whole, different traumatic experiences in childhood are predictive of social anxiety (SAD) or panic disorder (PD) in adulthood. Method: Participants with SAD or PD (85 from SA, 135 from Sweden) completed the Childhood Trauma Questionnaire (CTQ). Logistic regression was performed with data from the two countries separately, and from the sample as a whole, with primary diagnoses as dependent variables, gender, age, and country as covariates, and the CTQ subscale totals as independent variables. The study also investigated the internal consistency (Cronbach alpha) of the CTQ subscales. Results: SA patients showed higher levels of childhood trauma than Swedish patients. When data from both countries were combined, SAD patients reported higher rates of childhood emotional abuse compared to those with PD. Moreover, emotional abuse in childhood was found to play a predictive role in SAD/PD in adulthood in the Swedish and the combined samples, and the same trend was found in the SA sample. The psychometric qualities of the CTQ subscales were adequate, with the exception of the physical neglect subscale. Conclusion: Our findings suggest that anxiety disorder patients may differ across countries in terms of childhood trauma. Certain forms of childhood abuse may contribute specific vulnerability to different types of psychopathology. Longitudinal studies should focus on the potential sequential development of SAD/PD among individuals with childhood emotional abuse
Enhancement of the superconducting gap by nesting in CaKFe4As4 - a new high temperature superconductor
We use high resolution angle resolved photoemission spectroscopy and density
functional theory with experimentally obtained crystal structure parameters to
study the electronic properties of CaKFe4As4. In contrast to related CaFe2As2
compounds, CaKFe4As4 has high Tc of 35K at stochiometric composition. This
presents unique opportunity to study properties of high temperature
superconductivity of iron arsenic superconductors in absence of doping or
substitution. The Fermi surface consists of three hole pockets at and
two electron pockets at the point. We find that the values of the
superconducting gap are nearly isotropic, but significantly different for each
of the FS sheets. Most importantly we find that the overall momentum dependence
of the gap magnitudes plotted across the entire Brillouin zone displays a
strong deviation from the simple cos(kx)cos(ky) functional form of the gap
function, proposed in the scenario of the Cooper-pairing driven by a short
range antiferromagnetic exchange interaction. Instead, the maximum value of the
gap is observed for FS sheets that are closest to the ideal nesting condition
in contrast to the previous observations in some other ferropnictides. These
results provide strong support for the multiband character of superconductivity
in CaKFe4As4, in which Cooper pairing forms on the electron and the hole bands
interacting via dominant interband repulsive interaction, enhanced by FS
nesting}.Comment: 5 pages, 4 figure
Bistability of vortex core dynamics in a single perpendicularly magnetized nano-disk
Microwave spectroscopy of individual vortex-state magnetic nano-disks in a
perpendicular bias magnetic field, , is performed using a magnetic resonance
force microscope (MRFM). It reveals the splitting induced by on the
gyrotropic frequency of the vortex core rotation related to the existence of
the two stable polarities of the core. This splitting enables spectroscopic
detection of the core polarity. The bistability extends up to a large negative
(antiparallel to the core) value of the bias magnetic field , at which the
core polarity is reversed. The difference between the frequencies of the two
stable rotational modes corresponding to each core polarity is proportional to
and to the ratio of the disk thickness to its radius. Simple analytic
theory in combination with micromagnetic simulations give quantitative
description of the observed bistable dynamics.Comment: 4 pages, 3 figures, 1 table, 16 references. Submitted to Physical
Review Letters on December 19th, 200
- …