817 research outputs found
An algebraic formula for the index of a vector field on an isolated complete intersection singularity
Let (V,0) be a germ of a complete intersection variety in \CC^{n+k}, n>0,
having an isolated singularity at 0 and X be the germ of a holomorphic vector
field on \CC^{n+k} tangent to V and having on V an isolated zero at 0. We show
that in this case the homological index and the GSV-index coincide. In the case
when the zero of X is also isolated in the ambient space \CC^{n+k} we give a
formula for the homological index in terms of local linear algebra.Comment: 18 pages; added an example which is not quasi homogeneous. A script
calculating this example can be found at
http://www.iag.uni-hannover.de/~bothmer/gobelin/ or at the and of the source
file of this articl
Lichens and Mosses of Montana, a List Based on Material Collected during the Summer of 1901, with Additions
Academic journal published by the University of Montana Biological Station at Flathead Lake.https://scholarworks.umt.edu/umbiologicalseries/1006/thumbnail.jp
State-of-the-art in product service-systems
A Product Service-System (PSS) is an integrated combination of products and services.
This western concept embraces a service-led competitive strategy, environmental sustainability,
and the basis to differentiate from competitors who simply offer lower priced products. This
paper aims to report the state-of-the-art of PSS research by presenting a clinical review of
literature currently available on this topic. The literature is classified and the major outcomes
of each study are addressed and analysed. On this basis, this paper defines the PSS concept,
reports on its origin and features, gives examples of applications along with potential benefits
and barriers to adoption, summarises available tools and methodologies, and identifies future
research challenges
Kinematic Control of the Inertiality of the System of Tycho-2 and UCAC2 Stellar Proper Motions
Based on the Ogorodnikov-Milne model, we analyze the proper motions of
Tycho-2 and UCAC2 stars. We have established that the model component that
describes the rotation of all stars under consideration around the Galactic y
axis differs significantly from zero at various magnitudes. We interpret this
rotation found using the most distant stars as a residual rotation of the
ICRS/Tycho-2 system relative to the inertial reference frame. For the most
distant ( pc) Tycho-2 and UCAC2 stars, the mean rotation around
the Galactic y axis has been found to be mas yr.
The proper motions of UCAC2 stars with magnitudes in the range are
shown to be distorted appreciably by the magnitude equation in
, which has the strongest effect for northern-sky stars
with a coefficient of mas yr mag. We have detected
no significant effect of the magnitude equation in the proper motions of UCAC2
stars brighter than .Comment: 15 pages, 6 figure
Kinematic Control of the Inertiality of ICRS Catalogs
We perform a kinematic analysis of the Hipparcos and TRC proper motions of
stars by using a linear Ogorodnikov-Milne model. All of the distant (r more
than 0.2 kpc) stars of the Hipparcos catalog have been found to rotate around
the Galactic y axis with an angular velocity of -0.36 +/- 0.09 mas/year. One of
the causes of this rotation may be an uncertainty in the lunisolar precession
constant adopted when constructing the ICRS. In this case? the correction to
the IAU (1976) lunisolar precession constant in longitude is shown to be -3.26
+/- 0.10 mas/yr. Based on the TRC catalog, we have determined the main Oort
constants: A = 14.9 +/- 1.0 and B = -10.8 +/- 0.3 km/s/kpc. The component of
the model that describes the rotation of all TRC stars around the Galactic y
axis is nonzero for all magnitudes, My= -0.86 +/- 0.11 mas/yr.Comment: 10 pages, 4 figures, 2 table
Sexual vulnerability and HIV seroprevalence among the deaf and hearing impaired in Cameroon
<p>Abstract</p> <p>Background</p> <p>This quantitative cross-sectional study examines sexual behaviour of a target group of hearing-impaired persons in Yaounde, the capital city of the Republic of Cameroon. It measures their HIV prevalence to enable assessment of their sexual vulnerability and to help reduce the gap in existing HIV serology data among people with disabilities in general and the deaf in particular.</p> <p>Methods</p> <p>The snowball sampling procedure was adopted as an adequate approach to meet this hard-to-reach group. A total of 118 deaf participants were interviewed for the behavioural component, using sign language as a means of data collection, while 101 participants underwent HIV serology testing. Descriptive analyses were done for behavioural data with Epi info software, while sera were tested by health personnel, using rapid and confirmation test reagents.</p> <p>Results</p> <p>From the results, it was clear that the hearing impaired were highly involved in risky sexual practices, as observed through major sexual indicators, such as: age at first sexual intercourse; condom use; and knowledge of sexually transmitted infections and AIDS. Furthermore, it was noted that the HIV prevalence rate of the hearing impaired in the capital of Cameroon was 4%, close to the prevalence in the city's general population (4.7%).</p> <p>Conclusions</p> <p>Such results suggest that there is a need for in-depth behavioural research and serological studies in this domain to better understand the determinants of risky sexual behaviour among the hearing impaired, and to propose operational prevention approaches for this group.</p
- …