370 research outputs found
WONDERFULLY AND FEARFULLY MADE: Hans Urs von Balthasar on the Metaphysical Significance of the Wonder of a Child and the Fruitfulness of Human Sexual Difference
Hans Urs von Balthasar promotes a concrete metaphysics whereby humans disclose the reality of being as a whole within their lives. Beingâs superabundant mystery is encountered and manifested in the beauty, goodness and truth of human interactions. This receives its fullest articulation in interpersonal love wherein created being shines most brightly as a loving gift of participation in divine being. For Balthasar, the human capacity to grasp and share being as whole, and so the task of metaphysics, rests in childlike wonder at beingâs radiant beauty. Against perspectives that laud the autonomous adult self, I develop this aspect of Balthasarâs vision to defend the abiding significance of the child-parent relationship and human sexual difference. In this, however, I also critique Balthasarâs views on the latter. I claim his univocal identification of the female with receptivity and the male with activity contravenes his metaphysics. Working critically within Balthasarâs thought, I extend what is implicit therein: the relationships between mother, father and child, and male and female humanity primordially and paradigmatically communicate created being's fruitful openness to, and difference from, divine being. I maintain these relationships carry a mantle at once fundamental, fragile and full of promise. They inscribe in human nature a predilection for gratuitous wonder at being's beauty. I argue the male-female difference and child-parent relationship serve as co-principles of beingâs beauty. As such, they underpin the metaphysical expression of human fruitfulness which cannot, however, be limited to procreation and family, but is communicated in the richness of human creativity. Nevertheless, whenever these constitutive relationships are threatened so too is beauty and, therefore, beingâs goodness and truth, and the human vocation to love to the fullest. Here metaphysics receives its concrete measure of truthfulness in its ability to celebrate, safeguard and pass on the wonder of a child
Functional assessment of peripheral mechanisms controlling energy homeostasis in the domestic chicken
Heavily-selected livestock production traits rarely come without compromise; altered
physiology arising from intensive selection often gives rise to concern of a welfare
trade-off. A particularly clear example of welfare challenge caused by genetic
selection in chickens is the âbroiler-breeder paradoxâ, wherein breeding populations of
broiler-type birds selected for fast growth are feed-restricted in order to reduce growth
and maintain reproductive viability at sexual maturity. In order to better-inform
management and breeding strategies for alleviating reproductive problems resulting
from genetic selection for growth, it is essential to develop a better understanding of
the physiological processes underpinning growth. Whereas the molecular
mechanisms governing energy balance in mammals have been relatively welldescribed,
analogous avian systems have not received as much research attention
and remain somewhat poorly understood. The broad aim of this doctoral project was
to contribute to understanding of avian energy balance, particularly in the context of
selection for high growth.
Using an advanced broiler-layer intercross chicken line (AIL), high- and low-growth
haplotypes at the locus encoding the cholecystokinin A receptor (CCKAR), underlying
the most significant QTL for growth in chickens, were characterised. Of over 300
variations detected, a select panel spaced across the CCKAR locus were tested for
prediction of bodyweight in a diverse cohort of chicken populations. One intronic SNP
was found to be significant (p<0.05) and proximal to transcription factor binding sites.
The effect of this locus on gross bodyweight remained significant into the 20th AIL
generation (~20% at 10wk, p<0.05). In this otherwise effectively genetically
homogeneous population, several specific physiological traits were predicted by
CCKAR haplotype alone, yielding some clues as to the significance of perturbed
cholecystokinin (CCK) signalling in broiler strains. While birds with high-growth
CCKAR haplotype (HG) did not appear to consume more, feed conversion efficiency
(FCE) was improved, at least for males, compared to low-growth (LG) (p<0.05).
Visceral organ anatomies were morphologically disparate, with HG individuals
exhibiting ~1/3 less gallbladder mass (p<0.01), and ~10% shorter GI tract (p<0.01)
and metatarsal bone (p<0.05).
Further gaps in knowledge of the expression of peripheral satiety hormones in chicken
are addressed in this thesis. Tissue distributions for expression of CCK, gastrin,
pancreatic polypeptide (PPY) and peptide YY (PYY), were mapped and their
respective dynamic responses to nutritive state examined. CCK was found to be most
highly expressed in the brain, whereas PYY, PPY and gastrin were far more abundant
in distinct regions of the periphery. Interestingly, peripheral CCK was not responsive
to short-term (<10h) satiety in experimental populations where PYY and gastrin were.
PYY expression was found to be greatest in the pancreas and consistently
upregulated within hours after feeding (p<0.01), whereas gastrin expression was
confined to the gastric antrum and paradoxically highest in fasting birds (p<0.01).
PPY expression is strictly limited to the pancreas and appears dependent on longerterm
energy state. These results highlight similarities and differences to mammalian
systems; notably, the avian pancreas seems to fulfil an exceptional role as a site of
signal integration, perhaps unsurprising considering its disproportionate size
compared to mammals. Indeed, pancreatic PYY appears to act as a primary
peripheral short-term satiety hormone in birds.
This body of work contributes to the understanding of avian energy balance and
growth. An invaluable foundation for future research is formed by the identification of
the major locations of production, and basic nutrient-responsive trends, for several
peripheral avian hormones. Information on the growth role of CCKAR is consolidated
and expanded upon, demonstrating a clear genetic contribution to maintenance organ
morphology and overall growth. Such knowledge can be used to reliably assess and
advise on selection and management of chickens to stem welfare concerns without
compromising production. Comparisons between avian and other vertebrate
endocrine systems make for interesting insight into the adaptive role of energy
homeostatic mechanisms in divergent evolution of mammals and non-mammalian
vertebrates. In some aspects, birds might better represent the ancestral phenotype
from which each vertebrate clade arose
Examining outcomes following thrombolysis in an increasingly older and dependent stroke population
We are grateful for the support of the nurses from Chest, Heart and Stroke Scotland for assisting in obtaining follow-up functional status at three months.Peer reviewedPublisher PD
The effects of feed restriction, time of day and time since feeding on behavioral and physiological indicators of hunger in broiler breeder hens
Broiler breeder chickens are commercially feed restricted to slow their growth and improve their health and production, however, there is research demonstrating that this leads to chronic hunger resulting in poor welfare. A challenge in these studies is to account for possible daily rhythms or the effects of time since last meal on measures relating hunger. To address this, we used 3 feed treatments: AL (ad libitum fed), Ram (restricted, fed in the morning), and Rpm (restricted, fed in the afternoon) to control for diurnal effects. We then conducted foraging motivation tests and collected home pen behavior and physiological samples at 4 times relative to feeding throughout a 24-h period. The feed treatment had the largest influence on the data, with AL birds weighing more, having lower concentrations of plasma NEFA, and mRNA expression of AGRP and NPY alongside higher expression of POMC in the basal hypothalamus than Ram or Rpm birds (P < 0.001). R birds were more successful at and had a shorter latency to complete the motivation test, and did more walking and less feeding than AL birds in the home pen (P < 0.01). There was little effect of time since last meal on many measures (P > 0.05) but AGRP expression was highest in the basal hypothalamus shortly after a meal (P < 0.05), blood plasma NEFA was higher in R birds just before feeding (P < 0.001) and glucose was higher in Ram birds just after feeding (P < 0.001), and the latency to complete the motivation test was shortest before the next meal (P < 0.05). Time of day effects were mainly found in the difference in activity levels in the home pen when during lights on and lights off periods. In conclusion, many behavioral and physiological hunger measures were not significantly influenced by time of day or time since the last meal. For the measures that do change, future studies should be designed so that sampling is balanced in such a way as to minimize bias due to these effects.</p
The VPOS: a vast polar structure of satellite galaxies, globular clusters and streams around the Milky Way
It has been known for a long time that the satellite galaxies of the Milky
Way (MW) show a significant amount of phase-space correlation, they are
distributed in a highly inclined Disc of Satellites (DoS). We have extended the
previous studies on the DoS by analysing for the first time the orientations of
streams of stars and gas, and the distributions of globular clusters within the
halo of the MW. It is shown that the spatial distribution of MW globular
clusters classified as young halo clusters (YH GC) is very similar to the DoS,
while 7 of the 14 analysed streams align with the DoS. The probability to find
the observed clustering of streams is only 0.3 per cent when assuming isotropy.
The MW thus is surrounded by a vast polar structure (VPOS) of subsystems
(satellite galaxies, globular clusters and streams), spreading from
Galactocentric distances as small as 10 kpc out to 250 kpc. These findings
demonstrate that a near-isotropic infall of cosmological sub-structure
components onto the MW is essentially ruled out because a large number of
infalling objects would have had to be highly correlated, to a degree not
natural for dark matter sub-structures. The majority of satellites, streams and
YH GCs had to be formed as a correlated population. This is possible in tidal
tails consisting of material expelled from interacting galaxies. We discuss the
tidal scenario for the formation of the VPOS, including successes and possible
challenges. The potential consequences of the MW satellites being tidal dwarf
galaxies are severe. If all the satellite galaxies and YH GCs have been formed
in an encounter between the young MW and another gas-rich galaxy about 10-11
Gyr ago, then the MW does not have any luminous dark-matter substructures and
the missing satellites problem becomes a catastrophic failure of the standard
cosmological model.Comment: 21 pages, 8 figures, 2 tables. Accepted for publication in MNRAS. An
animation of Figure 5 can be found at http://youtu.be/nUwxv-WGfH
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