2,124 research outputs found
Games on classes of spaces
Using the construction of Containing Spaces given in [1] we define some kind of games considered on topological classes of spaces
Seasonal variation of fatty acids composition of milk from grazing ewes in Thessaly, central Greece
Σκοπός αυτής της εργασίας ήταν η αξιολόγηση των μεταβολών του προφίλ των λιπαρών οξέων και της συγκέντρωσης του συζευγμένου λινολεϊκού οξέος (CLA) του γάλακτος από προβατίνες ελευθέρας βοσκής το χειμώνα (Δεκέμβριος και Ιανουάριος) και την άνοιξη (Απρίλιος και Μάιος) στη Θεσσαλία της κεντρικής Ελλάδας. Δεν παρατηρήθηκαν σημαντικές μεταβολές (P>0,05) στις φυσικοχημικές ιδιότητες (pH και περιεκτικότητα σε πρωτεΐνη, λακτόζη και συνολικά στερεά) του γάλακτος χειμώνα και άνοιξης. Ωστόσο, η περιεκτικότητα σε λιπαρά του ανοιξιάτικου γάλακτος ήταν χαμηλότερη (P<0,05) εκείνης του χειμώνα. Η περιεκτικότητα σε κορεσμένα λιπαρά οξέα του γάλακτος δεν μεταβλήθηκε σημαντικά (P>0,05) τόσο κατά τη διάρκεια του χειμώνα όσο και κατά τη διάρκεια της άνοιξης, ενώ η περιεκτικότητα σε πολυακόρεστα λιπαρά οξέα μεταβλήθηκε σημαντικά (P <0,05) σε κάθε έναν από τους τέσσερις μήνες που εξετάστηκαν. Παρ ‘όλα αυτά, στο γάλα της άνοιξης, η περιεκτικότητα των κορεσμένων λιπαρών οξέων μειώθηκε σημαντικά (P<0,05), αλλά η συγκέντρωση των μονοακόρεστων και πολυακόρεστων λιπαρών οξέων αυξήθηκε σημαντικά (P<0,05) σε σύγκριση με το γάλα του χειμώνα. Σε αντίθεση με τη μείωση των κορεσμένων λιπαρών οξέων στο ανοιξιάτικο γάλα, η περιεκτικότητα του κορεσμένου στεατικού οξέος (C18:0) παρουσίασε σημαντική αύξηση (P<0,05) στο γάλα της άνοιξης σε σύγκριση με εκείνη του χειμώνα. Στο γάλα του χειμώνα, τα επίπεδα του C18:2 cis-9, trans-11 CLA ήταν 0.89±0.05 και 0.98±0.03 g/100g FAMEs τον Δεκέμβριο και τον Ιανουάριο, αντίστοιχα, ενώ στο γάλα της άνοιξης τα επίπεδα του CLA αυξήθηκαν σημαντικά Ρ<0,05) σε 1.36±0.04 και 1.27±0.03 g/100g FAMEs τον Απρίλιο και τον Μάϊο, αντίστοιχα. Ο δείκτης αθηρογένεσης (ΑΙ), που σχετίζεται με λιπαρά οξέα που ευνοούν την πρόκληση αθηροσκλήρωσης αλλά και με λιπαρά οξέα που δεν ευνοούν την πρόκληση αθηροσκλήρωσης, βρέθηκε σημαντικά μικρότερος (P<0,05) στο γάλα της άνοιξης σε σχέση με εκείνο του χειμώνα.The aim of this work was to evaluate the changes in fatty acids (FAs) profile and conjugated linoleic acid (CLA) concentration of milk from grazing ewes in winter (December and January) and spring (April and May) in Thessaly, central Greece. No significant changes (P>0.05) in the physicochemical properties (pH and protein, lactose and total solids content) of winter and spring milk were observed. However, the fat content of spring milk was lower (P<0.05) than the winter milk. The saturated FAs content of milk was not significantly changed (P>0.05) during winter neither during spring, whereas the polyunsaturated FAs content was significantly changed (P<0.05) in each of the four months examined. Nevertheless, in the ovine milk of spring, the saturated FAs content was significantly decreased (P<0.05), but the monounsaturated and polyunsaturated FAs content was significantly increased (P<0.05) as compared to that of winter milk. In contrast to the saturated FAs decrease in spring milk, the saturated stearic acid (C18:0) content showed a significant increase (P<0.05) in the spring milk as compared to winter milk. In winter milk, the C18:2 cis-9, trans-11 CLA levels were 0.89±0.05 and 0.98±0.03g/100 g Fatty Acid Methyl Esters (FAMEs) in December and January, respectively, whereas, in spring milk, the CLA levels were significantly increased (P<0.05) to 1.36±0.04 and 1.27±0.03g/100 g FAMEs in April and May, respectively. The atherogenicity index (AI) associated with proatherogenic and antiatherogenic FAs was found significantly (P<0.05) lower in spring milk compared to winter milk
Theoretical Studies of Accretion of Matter onto White Dwarfs and the Single Degenerate Scenario for Supernovae of Type Ia
We present a brief summary of the Single Degenerate Scenario for the
progenitors of Type Ia Supernovae in which it is assumed that a low mass
carbon-oxygen white dwarf is growing in mass as a result of accretion from a
secondary star in a close binary system. Recent hydrodynamic simulations of
accretion of solar material onto white dwarfs without mixing always produce a
thermonuclear runaway and steady burning does not occur. For a broad range in
WD mass (0.4 Solar masses to 1.35 Solar Masses), the maximum ejected material
occurs for the 1.25 Solar Mass sequences and then decreases as the white dwarf
mass decreases. Therefore, the white dwarfs are growing in mass as a
consequence of the accretion of solar material and as long as there is no
mixing of accreted material with core material. In contrast, a thermonuclear
runaway in the accreted hydrogen-rich layers on the low luminosity WDs in close
binary systems where mixing of core matter with accreted material has occurred
is the outburst mechanism for Classical, Recurrent, and Symbiotic novae. The
differences in characteristics of these systems is likely the WD mass and mass
accretion rate. The high levels of enrichment of CN ejecta in elements ranging
from carbon to sulfur confirm that there is dredge-up of matter from the core
of the WD and enable them to contribute to the chemical enrichment of the
interstellar medium. Therefore, studies of CNe can lead to an improved
understanding of Galactic nucleosynthesis, some sources of pre-solar grains,
and the Extragalactic distance scale. The characteristics of the outburst
depend on the white dwarf mass, luminosity, mass accretion rate, and the
chemical composition of both the accreting material and WD material. The
properties of the outburst also depends on when, how, and if the accreted
layers are mixed with the WD core and the mixing mechanism is still unknown.Comment: 25 Pages, Bulletin of the Astronomical Society of India (BASI) in
pres
Midwives’ emotion and body work in two hospital settings : personal strategies and professional projects
Much has been written in recent years of a ‘crisis’ in the recruitment and retention of midwives in the NHS. The crisis has been attributed variously to burnout, a lack of professional autonomy, a bullying culture, and an ideological conflict between the way in which midwives wish to practise and the way they are required to practise within large bureaucratic institutions, such as NHS Trusts. Negotiating these experiences requires a significant amount of emotional labour by midwives, which they may find intolerable. This thesis explores the strategies NHS midwives deploy in order to continue working in NHS maternity services when many of their colleagues are leaving. It examines the extent to which working in a midwife-led service rather than a consultant-led service helps or hinders midwives’ capacity to manage the emotional and ideological demands of their practice. Ethnographic fieldwork was carried out in a consultant unit and an Alongside Midwife-led Unit (AMU) in two NHS Trusts in England. The findings from negotiated interactive observation and in-depth unstructured interviews with eighteen midwives were analysed using inductive ethnographic principles. In order to ameliorate the emotional distress they experienced, the midwives used coping strategies to organise the people and spaces around them. These strategies of organisation and control were part of a personal and professional project which they found almost impossible to articulate because it ran contrary to the ideals of the midwifery discourse. Midwives explained these coping strategies as firstly, necessary in order to deal with institutional constraints and regulations; secondly, out of their control and thirdly, destructive and bad for midwifery. In practice it appeared that the midwives played a role in sustaining these strategies because they formed part of a wider professional project to promote their personal and professional autonomy. These coping strategies were very similar in the Consultant Unit and the Midwifery Unit. A midwife-led service provided the midwives with a space within which to nurture their philosophy of practice. This provided some significant benefits for their emotional wellbeing, but it also polarised them against the neighbouring Delivery Suite. The resulting poor relationships profoundly affected their capacity to provide a service congruent with their professional ideals. This suggests that whilst Alongside Midwife-led Units may attempt to promote a midwifery model of care and a good working environment for midwives, their proximity to consultant-led services compounds the ideological conflict the midwives experience. The strength of their philosophy may have the unintended consequence of silencing open discussion about the negative influence on women of the strategies the midwives use to compensate for ideological conflict and a lack of institutional and professional support.EThOS - Electronic Theses Online ServiceEconomic and Social Research Council (Great Britain) (ESRC) (PTA−031−2006−00332)GBUnited Kingdo
Experimental evidence of a natural parity state in Mg and its impact to the production of neutrons for the s process
We have studied natural parity states in Mg via the
Ne(Li,d)Mg reaction. Our method significantly improves the
energy resolution of previous experiments and, as a result, we report the
observation of a natural parity state in Mg. Possible spin-parity
assignments are suggested on the basis of published -ray decay
experiments. The stellar rate of the Ne(,)Mg
reaction is reduced and may give rise to an increase in the production of
s-process neutrons via the Ne(,n)Mg reaction.Comment: Published in PR
Oxygen pressure-tuned epitaxy and optoelectronic properties of laser-deposited ZnO films on sapphire
Measurement of the 18Ne(a,p_0)21Na reaction cross section in the burning energy region for X-ray bursts
The 18Ne(a,p)21Na reaction provides one of the main HCNO-breakout routes into
the rp-process in X-ray bursts. The 18Ne(a,p_0)21Na reaction cross section has
been determined for the first time in the Gamow energy region for peak
temperatures T=2GK by measuring its time-reversal reaction 21Na(p,a)18Ne in
inverse kinematics. The astrophysical rate for ground-state to ground-state
transitions was found to be a factor of 2 lower than Hauser-Feshbach
theoretical predictions. Our reduced rate will affect the physical conditions
under which breakout from the HCNO cycles occurs via the 18Ne(a,p)21Na
reaction.Comment: 5 pages, 3 figures, accepted for publication on Physical Review
Letter
Nuclear uncertainties in the NeNa-MgAl cycles and production of 22Na and 26Al during nova outbursts
Classical novae eject significant amounts of nuclear processed material into
the interstellar medium. Among the isotopes synthesized during such explosions,
two radioactive nuclei deserve a particular attention: 22Na and 26Al. In this
paper, we investigate the nuclear paths leading to 22Na and 26Al production
during nova outbursts by means of an implicit, hydrodynamic code that follows
the course of the thermonuclear runaway from the onset of accretion up to the
ejection stage. New evolutionary sequences of ONe novae have been computed,
using updated nuclear reaction rates relevant to 22Na and 26Al production.
Special attention is focused on the role played by nuclear uncertainties within
the NeNa and MgAl cycles in the synthesis of such radioactive species. From the
series of hydrodynamic models, which assume upper, recommended or lower
estimates of the reaction rates, we derive limits on the production of both
22Na and 26Al. We outline a list of nuclear reactions which deserve new
experimental investigations in order to reduce the wide dispersion introduced
by nuclear uncertainties in the 22Na and 26Al yields.Comment: 46 pages, 4 figures. Accepted for publication in The Astrophysical
Journa
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