981 research outputs found
Proceedings from the ECFIN Workshop "The budgetary implications of structural reforms" - Brussels, 2 December 2005
Most of the reforms discussed within the framework of the Lisbon strategy will benefit public finances in the long term. However, in the short-term, there could a trade-off between some structural reforms and budgetary discipline. This possible tension between reforms and fiscal discipline was identified by academic economists as a possible drawback of the Stability and Growth Pact since its inception.budgetary discipline, Stability and Growth Pact, Lisbon strategy, fiscal discipline, Deroose, Flores, Turrini
Olivine on Vesta as exogenous contaminants brought by impacts: Constraints from modeling Vesta's collisional history and from impact simulations
The survival of asteroid Vesta during the violent early history of the Solar
System is a pivotal constraint on theories of planetary formation. Particularly
important from this perspective is the amount of olivine excavated from the
vestan mantle by impacts, as this constrains both the interior structure of
Vesta and the number of major impacts the asteroid suffered during its life.
The NASA Dawn mission revealed that olivine is present on Vesta's surface in
limited quantities, concentrated in small patches at a handful of sites and
interpreted as the result of the excavation of endogenous olivine. Later works
raised the possibility that the olivine had an exogenous origin, based on the
geologic and spectral features of the deposits. In this work we quantitatively
explore the proposed scenario of a exogenous origin for the detected olivine to
investigate whether its presence on Vesta can be explained as a natural outcome
of the collisional history of the asteroid. We took advantage of the impact
contamination model previously developed to study the origin and amount of dark
and hydrated materials observed by Dawn on Vesta, which we updated by
performing dedicated hydrocode impact simulations. We show that the exogenous
delivery of olivine by impacts can offer a viable explanation for the currently
identified olivine-rich sites without violating the constraint posed by the
lack of global olivine signatures on Vesta. Our results indicate that no mantle
excavation is in principle required to explain the observations of the Dawn
mission and support the idea that the vestan crust could be thicker than
indicated by simple geochemical models based on the Howardite-Eucrite-Diogenite
family of meteorites.Comment: 24 pages, 6 figures, accepted for publication on the journal Icaru
The late accretion and erosion of Vesta's crust recorded by eucrites and diogenites as an astrochemical window into the formation of Jupiter and the early evolution of the Solar System
For decades the limited thickness of Vesta's basaltic crust, revealed by the
link between the asteroid and the howardite-eucrite-diogenite family of
meteorites, and its survival to collisional erosion offered an important
constraint for the study of the early evolution of the Solar System. Some
results of the Dawn mission, however, cast doubts on our understanding of
Vesta's interior composition and of the characteristics of its basaltic crust,
weakening this classical constraint. In this work we investigate the late
accretion and erosion experienced by Vesta's crust after its differentiation
and recorded in the composition of eucrites and diogenites and show that it
offers an astrochemical window into the earliest evolution of the Solar System.
In our proof-of-concept case study focusing on the late accretion and erosion
of Vesta's crust during the growth and migration of Jupiter, the water
enrichment of eucrites appears to be a sensitive function of Jupiter's
migration while the enrichment in highly-siderophile elements of diogenites
appears to be particularly sensitive to the size-frequency distribution of the
planetesimals. The picture depicted by the enrichments created by late
accretion in eucrites and diogenites is not qualitatively affected by the
uncertainty on the primordial mass of Vesta. Crustal erosion, instead, is more
significantly affected by said uncertainty and Vesta's crust survival appears
to be mainly useful to study violent collisional scenarios where highly
energetic impacts can strip significant amounts of vestan material while
limitedly contributing to Vesta's late accretion. Our results suggest that the
astrochemical record of the late accretion and erosion of Vesta's crust
provided by eucrites and diogenites can be used as a tool to investigate any
process or scenario associated to the evolution of primordial Vesta and of the
early Solar System.Comment: 21 pages, 15 figures, accepted for publication on Icaru
The quest for Magrathea planets I: formation of second generation exoplanets around double white dwarfs
The evolution of binaries that become double white dwarf (DWD) can cause the
ejection of high amounts of dust and gas. Such material can give rise to
circumbinary discs and become the cradle of new planets, yet no studies so far
have focused on the formation of circumbinary planets around DWDs. These
binaries will be the main sources of gravitational waves (GWs) detectable by
the ESA Laser Interferometer Space Antenna (LISA) mission, opening the
possibility to detect circumbinary planets around short-period DWDs everywhere
in the Milky Way. We investigate the formation of Magrathea planets by
simulating multiple planet formation tracks to explore how seeds growing first
by pebble accretion, and then by gas accretion, are affected by the disc
environments surrounding DWDs. We present both planetary formation tracks
taking place in steady-state discs, and formation tracks taking place in discs
evolving with time. The time-dependent tracks account for both the disc
accretion rate onto the central binary and the disc photoevaporation rate
caused by stellar irradiation. Our results show that planetary formation in
circumbinary discs around DWDs can be possible. In particular, the extreme
planetary formation environment implies three main significant results: (i) the
accretion rate and the metallicity of the disc should be high in order to form
sub-stellar objects with masses up to 31 M, this is achieved only if planet
formation starts soon after the onset of the disc and if first generation seeds
are present in the disc; (ii) seeds formed within 0.1 Myr, or within 1 Myr,
from the onset of the disc can only produce sub-Neptune and Neptunian planets,
unless the disc accommodates first generation seeds with mass 10 M;
(iii) most of the planets are finally located within 1 au from the disc centre,
while they are still undergoing the gas accretion phase.Comment: Accepted for publication in A&A on 05/04/2023, abstract shortened, 28
pages, 11 figures, 14 table
PENGARUH PEMBERIAN AIR REBUSAN KUNYIT (Curcuma domestica)TERHADAP TOTAL MIKROBA DAN Escherichia coli SERTA BOBOT SEKUM AYAM BROILER
IRFA SULISTYA WARNI. 23010113120095. 2018. Pengaruh Pemberian Air
Rebusan Kunyit (Curcuma domestica) terhadap Total Mikroba dan Escherichia
coli serta Bobot Sekum Ayam Broiler. (Pembimbing : TURRINI YUDIARTI
dan ENDANG WIDIASTUTI).
Penelitian dilaksanakan pada tanggal 25 Oktober – 28 November 2016, di
kandang Tiktok Fakultas Peternakan dan Pertanian Universitas Diponegoro
Semarang. Analisis total mikroba dan Escherichia coli serta penimbangan bobot
sekum dilaksanakan di laboratorium Fisiologi dan Biokimia Fakultas Peternakan
dan Pertanian Universitas Diponegoro Semarang.
Materi yang digunakan yaitu 200 ekor Day Old Chick (DOC) dengan ratarata
bobot
badan
41,48
g.
Bahan
yang
digunakan
yaitu
kunyit,
larutan
gula,
pakan
dan
air minum. Perlakuan yang digunakan yaitu pemberian air rebusan Kunyit
dengan penambahan 0%, 25%, 50%, 75% dan 100%. Air rebusan kunyit diberikan
pada ayam mulai umur 11 - 35 hari. Parameter yang diamati yaitu total bakteri dan
jumlah bakteri Escherichia coli serta bobot sekum pada ayam broiler. Ayam
Broiler dibagi menjadi 5 kelompok dengan 5 ulangan sehingga berjumlah 25 unit
percobaan, dimana setiap unit percobaan terdiri dari 8 ekor ayam broiler.
Rancangan yang digunakan dalam penelitian ini adalah rancangan acak lengkap
(RAL).
Hasil penelitian menunjukan bahwa pemberian air rebusan Kunyit dalam air
minum ayam broiler tidak mempengaruhi total mikroba dan jumlah bakteri
Escherichia coli serta bobot sekum pada ayam broiler. Rerata hasil perhitungan
total mikroba dalam penelitian ini yaitu T
0
: 4,5 x 10
12
; T
1
: 3,6 x 10
: 4,5 x
10
12
; T
3
: 3,5 x 10
12
; T
4
: 4,6 x 10
12
cfu/g. Hasil rerata perhitungan bakteri
Escherichia coli yaitu T
0
: 2,4 x 10
6
; T
1
: 1,4 x 10
6
; T
2
: 3,4 x 10
6
; T
;
T
4
: 1,2 x 10
6
cfu/g. Hasil rerata perhitungan bobot sekum yaitu T0 : 4, 25 ; T1 :
5,11 ; T2 : 6,25 ; T3 : 4,20 dan T4 : 4,70 g.
Simpulan penelitian ini bahwa bahwa penambahan air rebusan Kunyit
belum mampu memberikan pengaruh terhadap total mikroba, Escherichia coli
dan bobot sekum ayam broiler
Model checking ω-regular properties for quantum Markov chains
© Yuan Feng, Ernst Moritz Hahn, Andrea Turrini, and Shenggang Ying. Quantum Markov chains are an extension of classical Markov chains which are labelled with super-operators rather than probabilities. They allow to faithfully represent quantum programs and quantum protocols. In this paper, we investigate model checking !-regular properties, a very general class of properties (including, e.g., LTL properties) of interest, against this model. For classical Markov chains, such properties are usually checked by building the product of the model with a language automaton. Subsequent analysis is then performed on this product. When doing so, one takes into account its graph structure, and for instance performs different analyses per bottom strongly connected component (BSCC). Unfortunately, for quantum Markov chains such an approach does not work directly, because super-operators behave differently from probabilities. To overcome this problem, we transform the product quantum Markov chain into a single super-operator, which induces a decomposition of the state space (the tensor product of classical state space and the quantum one) into a family of BSCC subspaces. Interestingly, we show that this BSCC decomposition provides a solution to the issue of model checking ω-regular properties for quantum Markov chains
Clustering of integral membrane proteins of the human erythrocyte membrane stimulates autologous IgG binding, complement deposition, and phagocytosis
Damaged or old erythrocytes are cleared rapidly from circulation. Because several common biochemical lesions can induce the clustering of integral membrane proteins, we have proposed that formation of microscopic protein aggregates in the membrane might constitute a cell surface marker that promotes removal of the defective/senescent cells. We demonstrate here that treatments that cluster integral membrane proteins in erythrocytes (1 mM ZnCl2, 1 mM acridine orange, and 0.35 microM melittin) induce autologous IgG binding, complement fixation, and phagocytosis by human monocytes in vitro. Removal of the clustering agents prior to incubation in autologous serum or cross-linking of cell surface proteins before addition of clustering agents prohibited the above response, while cross-linking after treatment with the clustering agents preserved the response even if the clustering agents were later removed. Furthermore, subsequent reversal of the chemical cross-link maintaining the clustered distribution also reversed the induction of IgG binding, complement deposition, and phagocytosis. Finally, by deleting or inactivating different steps in the phagocytosis pathway, the chronology of steps was shown to be: (i) integral protein clustering, (ii) IgG binding, (iii) complement deposition, and (iv) phagocytosis
Bessel beam illumination reduces random and systematic errors in quantitative functional studies using light-sheet microscopy
Light-sheet microscopy (LSM), in combination with intrinsically transparent zebrafish larvae, is a choice method to observe brain function with high frame rates at cellular resolution. Inherently to LSM, however, residual opaque objects cause stripe artifacts, which obscure features of interest and, during functional imaging, modulate fluorescence variations related to neuronal activity. Here, we report how Bessel beams reduce streaking artifacts and produce high-fidelity quantitative data demonstrating a fivefold increase in sensitivity to calcium transients and a 20 fold increase in accuracy in the detection of activity correlations in functional imaging. Furthermore, using principal component analysis, we show that measurements obtained with Bessel beams are clean enough to reveal in one-shot experiments correlations that can not be averaged over trials after stimuli as is the case when studying spontaneous activity. Our results not only demonstrate the contamination of data by systematic and random errors through conventional Gaussian illumination and but,furthermore, quantify the increase in fidelity of such data when using Bessel beams
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