320 research outputs found
España. 1:4745470
Escala gráfica además en 'Kilométres' y 'Milles romains'. Coordenadas : O12 42'-E3 00'/N43 54'-N35 37'. Meridiano de ParÃs?Relieve : sombread
Montmort-Lucy (Francia, Champaña). Batallas. 1887 (53-44 a. d. C). 1:28000
Escala gráfica además en 'Milles romains', y 'Kilométres'Relieve : curvas de configuración, puntos acotados, sombreadoInserta : 'Marche des Helvètes depuis le pas de L'Écluse' y tres perfilesFigura leyenda alfabétic
Emerg. Infect. Dis
The multidrug-resistant (MDR) Salmonella enterica serotype Newport strain that produces CMY-2 β-lactamase(Newport MDR-AmpC) was the source of sporadic cases and outbreaks in humans in France during 2000–2005. Because this strain was not detected in food animals, it was most likely introduced into France through imported food products
Seasonal Patterns in Stable Isotope and Fatty Acid Profiles of Southern Stingrays (Hypanus americana) at Stingray City Sandbar, Grand Cayman
Ecotourism opportunities in the marine environment often rely heavily on provisioning to ensure the viewing of cryptic species by the public. However, intentional feeding of wildlife can impact numerous aspects of an animals’ behavior and ecology. Southern stingrays (Hypanus americana) provisioned at Stingray City Sandbar (SCS) in Grand Cayman have altered diel activity patterns and decreased measures of health. This study looked at seasonal changes in stable isotope (SI) and fatty acid (FA) profiles of provisioned stingrays at SCS. Plasma δ15N was higher in male stingrays (11.86 ± 1.71‰) compared to females (10.70 ± 1.71‰). Lower values for δ15N in males and females were measured in October during low tourist season, suggesting stingrays may be forced to rely on native prey items to supplement the decreased amount of provisioned squid available during this time. Plasma FA profiles were significantly different between sexes and across sampling time points, with FAs 22:6n3, 16:0, 20:5n3, 18:1n3C, 18:0 and 18:1n9T contributing to dissimilarity scores between groups. Dietary FAs primarily contributed to differences between males and females lending further evidence to differences in foraging patterns at SCS, likely due to intraspecific competition. Further, canonical analysis of principal coordinates (CAP) analysis of FA profiles suggest similar diets during peak tourist season and differences in diet between males and females during the low season. This study demonstrates alterations in feeding ecology in stingrays at SCS which is of critical importance for effective management of the SCS aggregation
Identification of new transitions and mass assignments of levels in Pr
The previously reported levels assigned to 151,152,153Pr have recently been
called into question regarding their mass assignment. The above questioned
level assignments are clarified by measuring g-transitions tagged with A and Z
in an in-beam experiment in addition to the measurements from 252Cf spontaneous
fission (SF) and establish new spectroscopic information from to
in the Pr isotopic chain. The isotopic chain 143-153Pr has been studied from
the spontaneous fission of 252Cf by using Gammasphere and also from the
measurement of the prompt g-rays in coincidence with isotopically-identified
fission fragments using VAMOS++ and EXOGAM at GANIL. The latter were produced
using 238U beams on a 9Be target at energies around the Coulomb barrier. The
g-g-g-g data from 252Cf (SF) and those from the GANIL in-beam A- and Z-gated
spectra were combined to unambiguously assign the various transitions and
levels in 151,152,153Pr and other isotopes. New transitions and bands in
145,147,148,149,150Pr were identified by using g-g-g and g-g-g-g coincidences
and A and Z gated g-g spectra. The transitions and levels previously assigned
to 151,153Pr have been confirmed by the (A,Z) gated spectra. The transitions
previously assigned to 152Pr are now assigned to 151Pr on the basis of the
(A,Z) gated spectra. Two new bands with 20 new transitions in 152Pr and one new
band with 7 new transitions in 153Pr are identified from the g-g-g-g
coincidence spectra and the (A,Z) gated spectrum. In addition, new g-rays are
also reported in 143-146Pr. New levels of 145,147-153Pr have been established,
reliable mass assignments of the levels in 151,152,153Pr have been reported and
new transitions have been identified in 143-146Pr showing the new avenues that
are opened by combining the two experimental approaches.Comment: Accepted in Phys. Rev.
A Proof Theoretic Analysis of Intruder Theories
We consider the problem of intruder deduction in security protocol analysis:
that is, deciding whether a given message M can be deduced from a set of
messages Gamma under the theory of blind signatures and arbitrary convergent
equational theories modulo associativity and commutativity (AC) of certain
binary operators. The traditional formulations of intruder deduction are
usually given in natural-deduction-like systems and proving decidability
requires significant effort in showing that the rules are "local" in some
sense. By using the well-known translation between natural deduction and
sequent calculus, we recast the intruder deduction problem as proof search in
sequent calculus, in which locality is immediate. Using standard proof
theoretic methods, such as permutability of rules and cut elimination, we show
that the intruder deduction problem can be reduced, in polynomial time, to the
elementary deduction problem, which amounts to solving certain equations in the
underlying individual equational theories. We show that this result extends to
combinations of disjoint AC-convergent theories whereby the decidability of
intruder deduction under the combined theory reduces to the decidability of
elementary deduction in each constituent theory. To further demonstrate the
utility of the sequent-based approach, we show that, for Dolev-Yao intruders,
our sequent-based techniques can be used to solve the more difficult problem of
solving deducibility constraints, where the sequents to be deduced may contain
gaps (or variables) representing possible messages the intruder may produce.Comment: Extended version of RTA 2009 pape
Privacy by Design: From Technologies to Architectures (Position Paper)
Existing work on privacy by design mostly focus on technologies rather than
methodologies and on components rather than architectures. In this paper, we
advocate the idea that privacy by design should also be addressed at the
architectural level and be associated with suitable methodologies. Among other
benefits, architectural descriptions enable a more systematic exploration of
the design space. In addition, because privacy is intrinsically a complex
notion that can be in tension with other requirements, we believe that formal
methods should play a key role in this area. After presenting our position, we
provide some hints on how our approach can turn into practice based on ongoing
work on a privacy by design environment
Small farms and development in sub‑Saharan Africa: farming for food, for income or for lack of better options?
Open Access Article; Published online: 15 Oct 2021Most food in sub-Saharan Africa is produced on small farms. Using large datasets from household surveys conducted across many countries, we find that the majority of farms are less than 1 ha, much smaller than previous estimates. Farms are larger in farming systems in drier climates. Through a detailed analysis of food self-sufficiency, food and nutrition security, and income among households from divergent farming systems in Ethiopia, Ghana, Mali, Malawi, Tanzania and Uganda, we reveal marked contrasts in food security and household incomes. In the south of Mali, where cotton is an important cash crop, almost all households are food secure, and almost half earn a living income. Yet, in a similar agroecological environment in northern Ghana, only 10% of households are food secure and none earn a living income. Surprisingly, the extent of food insecurity and poverty is almost as great in densely-populated locations in the Ethiopian and Tanzanian highlands that are characterised by much better soils and two cropping seasons a year. Where populations are less dense, such as in South-west Uganda, a larger proportion of the households are food self-sufficient and poverty is less prevalent. In densely-populated Central Malawi, a combination of a single cropping season a year and small farms results in a strong incidence of food insecurity and poverty. These examples reveal a strong interplay between population density, farm size, market access, and agroecological potential on food security and household incomes. Within each location, farm size is a major determinant of food self-sufficiency and a household’s ability to rise above the living income threshold. Closing yield gaps strongly increases the proportion of households that are food self-sufficient. Yet in four of the locations (Ethiopia, Tanzania, Ghana and Malawi), land is so constraining that only 42–53% of households achieve food self-sufficiency, and even when yield gaps are closed only a small proportion of households can achieve a living income. While farming remains of central importance to household food security and income, our results help to explain why off-farm employment is a must for many. We discuss these results in relation to sub-Saharan Africa’s increasing population, likely agricultural expansion, and agriculture’s role in future economic development
- …