1,471 research outputs found
Determinants of the implementation of a new practice in hormonal contraception by Quebec nurses
In 2007, a task-shifting strategy through which a nurse, in collaboration with a community pharmacist, could start a healthy woman on hormonal contraception without a medical consultation was implemented in the province of Quebec. The purpose of this study was to identify factors associated with the 1) implementation of this new practice by nurses, 2) delay of implementation and 3) intensity of the practice. A validated questionnaire based on Rogers' theory of the diffusion of innovation was sent by postal mail or internet to all nurses that had successfully completed training in hormonal contraception since 2007, were registered at the College of nurses of Quebec and currently worked as nurses. The questionnaire was completed by 745 nurses between November 2011 and March 2012 for a response rate of 26.6%. Results show that implementation of this new nursing practice was more successful when nurses had a high degree of cosmopoliteness, they perceived the new practice as simple, they worked in youth clinics and if health organizations where they worked were open to innovation, had low centralized decision-making and organizational slack. Various attributes of innovation, diffusion networks and characteristics of the organizations also explained intensity of the new practice. The findings suggest new avenues to simplify and scale up this strategy for use in other health organizations. </jats:p
Challenges of implementing task-shifting in contraceptive care--an experience in Quebec, Canada.
Lunar base CELSS: A bioregenerative approach
During the twenty-first century, human habitation of a self-sustaining lunar base could become a reality. To achieve this goal, the occupants will have to have food, water, and an adequate atmosphere within a carefully designed environment. Advanced technology will be employed to support terrestrial life-sustaining processes on the Moon. One approach to a life support system based on food production, waste management and utilization, and product synthesis is outlined. Inputs include an atmosphere, water, plants, biodegradable substrates, and manufacutured materials such as fiberglass containment vessels from lunar resources. Outputs include purification of air and water, food, and hydrogen (H2) generated from methane (CH4). Important criteria are as follows: (1) minimize resupply from Earth; and (2) recycle as efficiently as possible
The Spitzer Survey of the Small Magellanic Cloud: Discovery of Embedded Protostars in the HII Region NGC 346
We use Spitzer Space Telescope observations from the Spitzer Survey of the
Small Magellanic Cloud (S3MC) to study the young stellar content of N66, the
largest and brightest HII region in the SMC. In addition to large numbers of
normal stars, we detect a significant population of bright, red infrared
sources that we identify as likely to be young stellar objects (YSOs). We use
spectral energy distribution (SED) fits to classify objects as ordinary (main
sequence or red giant) stars, asymptotic giant branch stars, background
galaxies, and YSOs. This represents the first large-scale attempt at blind
source classification based on Spitzer SEDs in another galaxy. We firmly
identify at least 61 YSOs, with another 50 probable YSOs; only one embedded
protostar in the SMC was reported in the literature prior to the S3MC. We
present color selection criteria that can be used to identify a relatively
clean sample of YSOs with IRAC photometry. Our fitted SEDs indicate that the
infrared-bright YSOs in N66 have stellar masses ranging from 2 Msun to 17 Msun,
and that approximately half of the objects are Stage II protostars, with the
remaining YSOs roughly evenly divided between Stage I and Stage III sources. We
find evidence for primordial mass segregation in the HII region, with the most
massive YSOs being preferentially closer to the center than lower-mass objects.
Despite the low metallicity and dust content of the SMC, the observable
properties of the YSOs appear consistent with those in the Milky Way. Although
the YSOs are heavily concentrated within the optically bright central region of
N66, there is ongoing star formation throughout the complex and we place a
lower limit on the star formation rate of 3.2 x 10^-3 Msun/yr over the last ~1
Myr.Comment: 13 pages, 5 figures (3 in color), 2 tables. Accepted for publication
in Ap
The infrared dust bubble N22: an expanding HII region and the star formation around it
Aims. To increase the observational samples of star formation around
expanding Hii regions, we analyzed the interstellar medium and star formation
around N22.
Methods. We used data extracted from the seven large-scale surveys from
infrared to radio wavelengths. In addition we used the JCMT observations of the
J = 3-2 line of 12CO emission data released on CADC and the 12CO J = 2-1 and J
=3-2 lines observed by the KOSMA 3 m telescope. We performed a multiwavelength
study of bubble N22.
Results. A molecular shell composed of several clumps agrees very well with
the border of N22, suggesting that its expansion is collecting the surrounding
material. The high integrated 12CO line intensity ratio (ranging from 0.7 to
1.14) implies that shocks have driven into the molecular clouds. We identify
eleven possible O-type stars inside the Hii region, five of which are located
in projection inside the cavity of the 20 cm radio continuum emission and are
probably the exciting-star candidates of N22. Twenty-nine YSOs (young stellar
objects) are distributed close to the dense cores of N22. We conclude that star
formation is indeed active around N22; the formation of most of YSOs may have
been triggered by the expanding of the Hii region. After comparing the
dynamical age of N22 and the fragmentation time of the molecular shell, we
suggest that radiation-driven compression of pre-existing dense clumps may be
ongoing.Comment: accepted in A&A 30/05/2012. arXiv admin note: text overlap with
arXiv:1010.5430 by other author
Star Formation and Young Population of the HII Complex Sh2-294
The Sh2-294 HII region ionized by a single B0V star features several infrared
excess sources, a photodissociation region, and also a group of reddened stars
at its border. The star formation scenario in the region seems to be quite
complex. In this paper, we present follow-up results of Sh2-294 HII region at
3.6, 4.5, 5.8, and 8.0 microns observed with the Spitzer Space Telescope
Infrared Array Camera (IRAC), coupled with H2 (2.12 microns) observation, to
characterize the young population of the region and to understand its star
formation history. We identified 36 young stellar object (YSO, Class I, Class
II and Class I/II) candidates using IRAC color-color diagrams. It is found that
Class I sources are preferentially located at the outskirts of the HII region
and associated with enhanced H2 emission; none of them are located near the
central cluster. Combining the optical to mid-infrared (MIR) photometry of the
YSO candidates and using the spectral energy distribution fitting models, we
constrained stellar parameters and the evolutionary status of 33 YSO
candidates. Most of them are interpreted by the model as low-mass (< 4 solar
masses) YSOs; however, we also detected a massive YSO (~9 solar masses) of
Class I nature, embedded in a cloud of visual extinction of ~24 mag. Present
analysis suggests that the Class I sources are indeed younger population of the
region relative to Class II sources (age ~ 4.5 x 10^6 yr). We suggest that the
majority of the Class I sources, including the massive YSOs, are
second-generation stars of the region whose formation is possibly induced by
the expansion of the HII region powered by a ~ 4 x 10^6 yr B0 main-sequence
star.Comment: 12 pages, 7 figures, 2 tables. Accepted for publication in The
Astrophysical Journa
Characterizing star formation activity in infrared dark cloud MSXDC G048.65-00.29
Infrared Dark Clouds (IRDCs), condensed regions of the ISM with high column
densities, low temperatures and high masses, are suspected sites of star
formation. Thousands of IRDCs have already been identified. To date, it has not
been resolved whether IRDCs always show star formation activity and, if so, if
massive star formation (> 8 solar masses) is the rule or the exception in
IRDCs. Previous analysis of sub-millimeter cores in the cloud MSXDC
G048.65-00.29 (G48.65) indicates embedded star formation activity. To
characterize this activity in detail, mid-infrared photometry (3-30 micron) has
been obtained with the Spitzer Space Telescope. This paper analyzes the point
sources seen in the 24 micron band, combined with counterparts or upper limits
at shorter and longer wavelengths. Data points in wavelength bands ranging from
1 up to 850 micron are used to compare each 24 micron source to a set of
Spectral Energy Distributions of Young Stellar Object (YSO) models. By
assessing the models that fit the data, an attempt is made to identify YSOs as
such and determine their evolutionary stages and stellar masses. A total of 17
sources are investigated, 13 of which are classified as YSOs, primarily - but
not exclusively - in an early embedded phase of star formation. The modeled
masses of the central stellar objects range from sub-solar to ~8 solar masses.
Every YSO is at less than 1 pc projected distance from its nearest YSO
neighbor. We conclude that IRDC G48.65 is a region of active star formation. We
find YSOs in various evolutionary phases, indicating that the star formation in
this cloud is not an instantaneous process. The inferred masses of the central
objects suggest that this IRDC hosts only low to intermediate mass YSOs and
none with masses exceeding ~8 solar masses.Comment: 10 pages, 6 figures; v2: minor editorial changes to match published
versio
Star Formation in the Milky Way. The Infrared View
I present a brief review of some of the most recent and active topics of star
formation process in the Milky Way using mid and far infrared observations, and
motivated by the research being carried out by our science group using data
gathered by the Spitzer and Herschel space telescopes. These topics include
bringing together the scaling relationships found in extragalactic systems with
that of the local nearby molecular clouds, the synthetic modeling of the Milky
Way and estimates of its star formation rate.Comment: 12 pages, 9 figures. To apper in "Cosmic-ray induced phenomenology in
star-forming environments: Proceedings of the 2nd Session of the Sant Cugat
Forum of Astrophysics" (April 16-19, 2012), Olaf Reimer and Diego F. Torres
(eds.
An infrared-submillimeter study of star-forming regions selected by the ISOSS 170um survey
Using the ISOPHOT Serendipity Survey (ISOSS) at 170um a sample of galactic
star-forming regions exhibiting very cold dust temperatures (< 20 K) and high
masses (> 100 M_sun) has been established. We characterise the star-forming
content of five regions that were selected as potential sites for early stage
high-mass star formation using SCUBA (JCMT) and Spitzer observations. In every
region we identify one to four submillimeter clumps with projected sizes
between 0.1 and 0.4 pc. The dust temperatures range from 11.6 to 21.3 K and the
estimated clump masses are 2 to 166 M_sun. Towards the majority of
submillimeter peaks we find point sources in the near- to mid-infrared. Most
are interpreted as low-mass young stellar objects but we also detect very red
sources. They probably represent very young and deeply embedded protostars that
continue to accrete clump material and may reach higher masses. Several
candidate intermediate-mass proto- or pre-main-sequence stars embedded in the
clumps are identified. A subset of four clumps may be massive enough (> 100
M_sun) to form high-mass stars and accompanying clusters. The absence of
stellar precursors with current masses in the high-mass regime leave the type
of star formation occuring in the clumps unsettled. We confirm the presence of
large fractions of cold material as derived from large-scale far-infrared
measurements which dominates the emission of most clumps and suggests that the
star-forming process will continue.Comment: 11 pages, 11 figures, accepted for publication in A&
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