1,803 research outputs found
Parental health and children’s cognitive and non-cognitive development: New evidence from the Longitudinal Survey of Australian Children
This paper examines the effects of parental health on cognitive and non-cognitive development in Australian children. The underlying nationally representative panel data and a child fixed effects estimator are used to deal with unobserved heterogeneity. We find that only father’s serious mental illness worsens selected cognitive and non-cognitive skills of children. Maternal poor health also deteriorates some cognitive and non-cognitive outcomes of children of lone mothers only. Our results demonstrate that either failing to account for parent-child fixed effects or using child non-cognitive skills reported by parents could over-estimate the harmful impact of poor parental health on child development
Refining foliage sampling protocols for white clover
White clover (Trifolium repens) foliar ‘grab’ samples were taken pre-grazing from two irrigated experiments at Lincoln University at ~6-week intervals from August 2019 to May 2021. Clover leaves were divided into lamina and petiole before analysis. Results for nitrogen (N), phosphorous (P), potassium (K) and sulphur (S) foliar concentrations are reported. While there were seasonal variations, N% and S% were consistently higher in the white clover lamina than the petiole, K% was higher in the petiole, and P% was higher in the lamina. With increasing clover sward height, the lamina to petiole DW ratio declined from 4:1 at a sward height of 5 cm, to 1:1 at 25 cm. The lamina+petiole sample had lower concentrations of N and S than lamina alone. Over time, foliar N% was relatively stable but concentrations of P, K and S showed ~two-fold variation and may have been affected by low soil moisture. Clover nutrient status should be based on lamina-only samples taken during spring, when plant growth is fastest, and just prior to grazing when there is sufficient herbage. Clover foliage sampling should routinely be used to inform fertiliser recommendations rather than relying on soil tests or visual symptoms of nutrient deficiency
High Prudent diet factor score predicts lower relapse hazard in early multiple sclerosis
Background: Dietary patterns and their association with subsequent clinical course have not been well studied in early multiple sclerosis (MS). Objectives: To describe dietary patterns in people in 5 years following first clinical demyelination and assess associations with MS conversion and relapse. Methods: This study included baseline food frequency questionnaire dietary intake (entry to the Ausimmune Study) and 5-year follow-up; iterated principal factor analysis was applied. MS conversion and relapse risks were assessed by Cox proportional hazards models, adjusted for age, sex, study site, education, body mass index (BMI), smoking and omega-3 supplement use. Results: In cases with a first clinical diagnosis of central nervous system (CNS) demyelination, we identified three major dietary patterns, 'Prudent', 'High-Vegetable' and 'Mixed', explaining 43%, 37% and 24% of diet variance in dietary intake, respectively. Fruits, vegetables, fish, wholegrains and nuts loaded highly on the Prudent pattern, starchy vegetables and legumes on the High-Vegetable pattern, and meats and alcohol on the Mixed pattern. Diet factor scores were not associated with MS conversion risk. Those with baseline Prudent scores above the median had significantly lower relapse risk (adjusted hazard ratio = 0.54, 95% confidence interval (CI) 0.37, 0.81) with some evidence of a plateau effect. Conclusion: Prudent diet factor score above the median was prospectively associated with lower relapse risk in the 5 years following the first clinical demyelinating event
Qualitative insights into the feelings, knowledge, and impact of SUDEP: A narrative synthesis
People with epilepsy (PWE) have a two- to threefold increased chance of premature death due to the condition. Interested in exploring the first-person perspective on this topic, we conducted a narrative synthesis to present the qualitative insight of PWE, their family, friends, and healthcare providers (HCPs) in relation to epilepsy-related death. A comprehensive electronic search of all peer-reviewed qualitative studies was conducted through databases using relevant keywords and Medical Subject Headings (MeSH) terms. Handsearching and exploration of pertinent gray literature was conducted thereafter. After a comprehensive literature search, the decisions of inclusion of literature were discussed and confirmed between the two authors. A total of 20 peer-reviewed papers were included. Within this, 17 were qualitative or mixed methods studies, and three were gray literature and guidelines/recommendations in discussing sudden unexpected death in epilepsy (SUDEP) with PWE and their families. The resultant main categories were the following: a) understanding of SUDEP and b) discussion of SUDEP. Findings show that there is an overall lack of understanding of unexpected epilepsy-related death for PWE and their relations. The literature focused on the education of PWE and their family in relation to SUDEP, and therefore, there is a lack of discussion on the general topic of epilepsy-related death. Findings show the conflicting perceptions, feelings, and thought processes that occur in learning about and deciding to discuss SUDEP as a HCP, PWE, or family/friend of a PWE. The literature suggests that it would be appropriate and necessary to discuss the topic of SUDEP with patients and their family members upon diagnosis
Theory of Star Formation
We review current understanding of star formation, outlining an overall
theoretical framework and the observations that motivate it. A conception of
star formation has emerged in which turbulence plays a dual role, both creating
overdensities to initiate gravitational contraction or collapse, and countering
the effects of gravity in these overdense regions. The key dynamical processes
involved in star formation -- turbulence, magnetic fields, and self-gravity --
are highly nonlinear and multidimensional. Physical arguments are used to
identify and explain the features and scalings involved in star formation, and
results from numerical simulations are used to quantify these effects. We
divide star formation into large-scale and small-scale regimes and review each
in turn. Large scales range from galaxies to giant molecular clouds (GMCs) and
their substructures. Important problems include how GMCs form and evolve, what
determines the star formation rate (SFR), and what determines the initial mass
function (IMF). Small scales range from dense cores to the protostellar systems
they beget. We discuss formation of both low- and high-mass stars, including
ongoing accretion. The development of winds and outflows is increasingly well
understood, as are the mechanisms governing angular momentum transport in
disks. Although outstanding questions remain, the framework is now in place to
build a comprehensive theory of star formation that will be tested by the next
generation of telescopes.Comment: 120 pages, to appear in ARAA. No changes from v1 text; permission
statement adde
The Complexity of Computing Minimal Unidirectional Covering Sets
Given a binary dominance relation on a set of alternatives, a common thread
in the social sciences is to identify subsets of alternatives that satisfy
certain notions of stability. Examples can be found in areas as diverse as
voting theory, game theory, and argumentation theory. Brandt and Fischer [BF08]
proved that it is NP-hard to decide whether an alternative is contained in some
inclusion-minimal upward or downward covering set. For both problems, we raise
this lower bound to the Theta_{2}^{p} level of the polynomial hierarchy and
provide a Sigma_{2}^{p} upper bound. Relatedly, we show that a variety of other
natural problems regarding minimal or minimum-size covering sets are hard or
complete for either of NP, coNP, and Theta_{2}^{p}. An important consequence of
our results is that neither minimal upward nor minimal downward covering sets
(even when guaranteed to exist) can be computed in polynomial time unless P=NP.
This sharply contrasts with Brandt and Fischer's result that minimal
bidirectional covering sets (i.e., sets that are both minimal upward and
minimal downward covering sets) are polynomial-time computable.Comment: 27 pages, 7 figure
Circumstellar molecular composition of the oxygen-rich AGB star IK~Tau: II. In-depth non-LTE chemical abundance analysis
Aims: Little information exists on the circumstellar molecular abundance
stratifications of many molecules. The aim is to study the circumstellar
chemical abundance pattern of 11 molecules and isotopologs (CO,
CO, SiS, SiO, SiO, SiO, HCN, CN, CS, SO, SO) in
the oxygen-rich evolved star IK~Tau. Methods: We have performed an in-depth
analysis of a large number of molecular emission lines excited in the
circumstellar envelope around IK~Tau. The analysis is done based on a non-local
thermodynamic equilibrium (non-LTE) radiative transfer analysis, which
calculates the temperature and velocity structure in a self-consistent way. The
chemical abundance pattern is coupled to theoretical outer wind model
predictions including photodestruction and cosmic ray ionization. Not only the
integrated line intensities, but also the line shapes, are used as diagnostic
tool to study the envelope structure. Results: The deduced wind acceleration is
much slower than predicted from classical theories. SiO and SiS are depleted in
the envelope, possibly due to the adsorption onto dust grains. For HCN and CS a
clear difference with respect to inner wind non-equilibrium predictions is
found, either indicating uncertainties in the inner wind theoretical modeling
or the possibility that HCN and CS (or the radical CN) participate in the dust
formation. The low signal-to-noise profiles of SO and CN prohibit an accurate
abundance determination; the modeling of high-excitation SO lines is
cumbersome, possibly related to line misidentifications or problems with the
collisional rates. The SiO isotopic ratios (SiO/SiO and
SiO/SiO) point toward an enhancement in SiO compared to
results of classical stellar evolution codes. Predictions for HO lines in
the spectral range of the Herschel/HIFI mission are performed. [abbreviated]Comment: 24 pagees, accepted for publication in Astronomy & Astrophysic
Excitation and Abundance of C3 in star forming cores:Herschel/HIFI observations of the sight-lines to W31C and W49N
We present spectrally resolved observations of triatomic carbon (C3) in
several ro-vibrational transitions between the vibrational ground state and the
low-energy nu2 bending mode at frequencies between 1654-1897 GHz along the
sight-lines to the submillimeter continuum sources W31C and W49N, using
Herschel's HIFI instrument. We detect C3 in absorption arising from the warm
envelope surrounding the hot core, as indicated by the velocity peak position
and shape of the line profile. The sensitivity does not allow to detect C3
absorption due to diffuse foreground clouds. From the column densities of the
rotational levels in the vibrational ground state probed by the absorption we
derive a rotation temperature (T_rot) of ~50--70 K, which is a good measure of
the kinetic temperature of the absorbing gas, as radiative transitions within
the vibrational ground state are forbidden. It is also in good agreement with
the dust temperatures for W31C and W49N. Applying the partition function
correction based on the derived T_rot, we get column densities N(C3)
~7-9x10^{14} cm^{-2} and abundance x(C3)~10^{-8} with respect to H2. For W31C,
using a radiative transfer model including far-infrared pumping by the dust
continuum and a temperature gradient within the source along the line of sight
we find that a model with x(C3)=10^{-8}, T_kin=30-50 K, N(C3)=1.5 10^{15}
cm^{-2} fits the observations reasonably well and provides parameters in very
good agreement with the simple excitation analysis.Comment: Accepted for publication in Astronomy and Astrophysics (HIFI first
results issue
- …