2,690 research outputs found
AdS from M-branes at conical singularities
M-theory is known to possess supersymmetric solutions where the geometry is
warped over a Riemann surface
. The simplest examples in this class can be engineered by placing
M2 and M5 branes as defects inside of a stack of background M5 branes. In this
paper we show that a generalization of this construction yields more general
solutions in the aforementioned class. The background branes are now M5's
carrying M2 brane charge, while the defect branes are now placed at the origin
of a flat hyperplane with a conical defect. The equations of motion imply a
relation between the deficit angle produced by the conical defect and the M2
charge carried by the background branes.Comment: 16 page
AdS solutions with exceptional supersymmetry
Among the possible superalgebras that contain the AdS isometries, two
interesting possibilities are the exceptional and . Their
R-symmetry is respectively SO(7) and , and the amount of supersymmetry
and . We find that there exist two (locally) unique
solutions in type IIA supergravity that realize these superalgebras, and we
provide their analytic expressions. In both cases, the internal space is
obtained by a round six-sphere fibred over an interval, with an O8-plane at one
end. The R-symmetry is the symmetry group of the sphere; in the case, it
is broken to by fluxes. We also find several numerical
solutions with flavor symmetry, with various localized sources, including
O2-planes and O8-planes.Comment: 30 pages, 4 figures; v3: revised appendix, minor correction
Effects of lactation stage, parity, beta-lactoglobulin genotype and milk SCC on whey protein composition in Sarda dairy ewes
In 90 Sarda dairy ewes the effects of lactation stage, parity, beta-lactoglobulin genotypes, and somatic cell count (SCC) on
the milk content of total protein (TP), casein (CN), whey protein (WP) and its fractions alpha-lactalbumin (ALA), beta-lactoglobulin
(BLG), serum albumin (SA), immunoglobulin (IG) and lactoferrin (LF) were analysed using a linear mixed model.
Mean values of variables (g/l) were: TP (54.0), CN (43.0), WP (11.0), BLG (4.78), ALA (1.37), SA (0.61), IG (3.83) and
LF (0.28). The lactation stage significantly affected all the variables analysed. TP, CN and WP concentrations tended to
increase throughout lactation, with the increase of WP being more pronounced than the corresponding variation in CN.
There was no definite trend in BLG content, whereas ALA concentration decreased as lactation progressed. The parity
affected almost all variables studied. WP concentration differed significantly only between the second and fourth parity
(10.45 vs 11.44 g/l). BLG and SA concentrations were significantly lower in the youngest ewes. The BLG genotype affected
milk yield, but no effects were observed on the components of the milk. The SCC influenced almost all variables studied.
The TP concentration was significantly higher in milk with SCC >1,000,000 (55.0 g/l) than in milk with lower SCC
(53.4 g/l). This was mainly due to the increase of WP (12.52 and 10.24 g/l in milk with SCC above and below
1,000,000/ml respectively), especially in those WP fractions originating from blood
The Mathematical description of lactation curves in dairy cattle
This review gives an overview of the mathematical modelling of lactation curves in dairy cattle. Over the last ninety years, the development of this field of study has followed the main requirements of the dairy cattle industry. Non-linear parametric functions have represented the preferred tools for modelling average curves of homogeneous groups of animals, with the main aim of predicting yields for management purposes. The increased availability of records per individual lactations and the genetic evaluation based on test day records has shifted the interest of modellers towards more flexible and general linear functions, as polynomials or splines. Thus the main interest of modelling is no longer the reconstruction of the general pattern of the phenomenon but the fitting of individual deviations from an average curve. Other specific approaches based on the modelling of the correlation structure of test day records within lactation, such as mixed linear models or principal component analysis, have been used to test the statistical significance of fixed effects in dairy experiments or to create new variables expressing main lactation curve traits. The adequacy of a model is not an absolute requisite, because it has to be assessed according to the specific purpose it is used for. Occurrence of extended lactations and of new productive and functional traits to be described and the increase of records coming from automatic milking systems likely will represent some of the future challenges for the mathematical modelling of the lactation curve in dairy cattle
The rise of Intellectual Capital reporting. The relevance of IC disclosure in Italian Universities
2016 - 2017This thesis is the result of the research work carried out during the three years of PhD in Public Sector Accounting at the University of Salerno under the supervision of prof. Tartaglia Polcini, and during the four months, at the University of Ghent under the supervision of prof. Johan Christiaens.
The thesis represents a structured compendium of the results obtained from three empirical researches. However, it does not intend to offer a mere summary of these works, but to describe in detail, from a theoretical point of view, the phenomenon investigated, arriving in a consequential manner to the presentation of the results of the research conducted which represent its empirical developments.
The PhD research activity has been mainly focused on Intellectual Capital (IC) which in recent years has gained momentum first in the private sector and, then, more vigorously, in the public sector as critical success factor.
Intellectual Capital can be defined as “the collection of intangibles which allows an organization to transfer a collection of material, financial and human resources into a system capable of creating value for the stakeholders” European Commission (2006, p. 4).
Due to its intangible nature, the IC has progressively acquired more relevance in public sector and in particular in University sector which, among public sector entities, have the highest degree of intangibility. In particular, Universities are basically knowledge-based institutions in which IC plays a crucial role as it is both the result of the research and development activities and the driver that leads to the creation of greater value from those activities... [edited by Author]XVI n.s. (XXX ciclo
Milk composition and feeding in the Italian dairy sheep
Milk production represents a relevant quota of the energy consumption of the dairy ewe. Studies on relationships among
level of production, milk composition and metabolic aspects are the first fundamental step in the development of a feeding
system aimed at satisfying nutritive requirements of the animals. This paper reviews the knowledge about the milk
composition of main Italian dairy sheep breeds, the relationship among secretion kinetics of milk and protein and productive
level of animals, the algorithms used for estimating fat (6.5%) and protein (5.8%) corrected milk yield, the
evolution over time of milk production during lactation and the relationships between feeding and milk composition
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