449 research outputs found
Dynamics of Dense Cores in the Perseus Molecular Cloud
We survey the kinematics of over one hundred and fifty candidate (and
potentially star-forming) dense cores in the Perseus molecular cloud with
pointed N2H+(1-0) and simultaneous C18O(2-1) observations. Our detection rate
of N2H+ is 62%, rising to 84% for JCMT SCUBA-selected targets. In agreement
with previous observations, we find that the dense N2H+ targets tend to display
nearly thermal linewidths, particularly those which appear to be starless
(using Spitzer data), indicating turbulent support on the small scales of
molecular clouds is minimal. For those N2H+ targets which have an associated
SCUBA dense core, we find their internal motions are more than sufficient to
provide support against the gravitational force on the cores. Comparison of the
N2H+ integrated intensity and SCUBA flux reveals fractional N2H+ abundances
between 10^-10 and 10^-9. We demonstrate that the relative motion of the dense
N2H+ gas and the surrounding C18O gas is less than the sound speed in the vast
majority of cases (~90%). The point-to-point motions we observe within larger
extinction regions appear to be insufficient to provide support against
gravity, although we sparsely sample these regions.Comment: 49 pages, 20 figures. Accepted for publication in the Astrophysical
Journa
A revision of the fish genus Oxyurichthys (Gobioidei: Gobiidae) with descriptions of four new species
The widespread tropical gobionelline fish genus Oxyurichthys is monophyletic due to its species sharing two characters considered derived within the Stenogobius Group of the Gobionellinae (Gobioidei: Gobiidae), a transversely broadened (spatulate) third neural spine that is usually bifid, and no preopercular cephalic lateralis canal. It is most closely related to Oligolepis, also of the Indo-west Pacific, and Ctenogobius, an Atlantic-eastern Pacific genus. Sixteen valid species of Oxyurichthys are redescribed and illustrated and four new species are described, O. limophilus from the western Indian Ocean, O. rapa from French Polynesia, and O. chinensis and O. zeta from the western Pacific. Nineteen species share two additional synapomorphies, a rounded fleshy tongue and a palatine lacking an elongate posterior strut, and form the sister group to the plesiomorphous Oxyurichthys keiensis, known from South Africa and Madagascar. One species, O. stigmalophius, occurs in the western Atlantic. There are no records of this genus from the continental eastern Pacific or the eastern Atlantic. Previous accounts from the Gulf of Guinea region of West Africa are references to Gobionellus occidentalis. Many Oxyurichthys species are limited to shallow estuarine and coastal waters with bottom substrates of silt or other fine sediments, but several are known from depths exceeding 10 m and are often collected by trawling
A revision of the fish genus Oxyurichthys (Gobioidei: Gobiidae) with descriptions of four new species
The widespread tropical gobionelline fish genus Oxyurichthys is monophyletic due to its species sharing two characters considered derived within the Stenogobius Group of the Gobionellinae (Gobioidei: Gobiidae), a transversely broadened (spatulate) third neural spine that is usually bifid, and no preopercular cephalic lateralis canal. It is most closely related to Oligolepis, also of the Indo-west Pacific, and Ctenogobius, an Atlantic-eastern Pacific genus. Sixteen valid species of Oxyurichthys are redescribed and illustrated and four new species are described, O. limophilus from the western Indian Ocean, O. rapa from French Polynesia, and O. chinensis and O. zeta from the western Pacific. Nineteen species share two additional synapomorphies, a rounded fleshy tongue and a palatine lacking an elongate posterior strut, and form the sister group to the plesiomorphous Oxyurichthys keiensis, known from South Africa and Madagascar. One species, O. stigmalophius, occurs in the western Atlantic. There are no records of this genus from the continental eastern Pacific or the eastern Atlantic. Previous accounts from the Gulf of Guinea region of West Africa are references to Gobionellus occidentalis. Many Oxyurichthys species are limited to shallow estuarine and coastal waters with bottom substrates of silt or other fine sediments, but several are known from depths exceeding 10 m and are often collected by trawling
Planning the Future of North American Cold-Formed Steel Design Standards
Growth in cold-formed steel structures has long been tied to developing and advancing the engineering standards that govern their use in construction. The American Iron and Steel Institute (AISI) has taken a leadership role in this activity in North America since 1946. Conventional standards providing closed-formed solutions to member capacity, such as the recently completed suite of AISI Standards in 2015 and 2016. These standards have reached an impressive level of maturity given the complexity of designing entire (building) structural systems out of steel that is rarely greater than 2mm thick. However, the demands on the structural engineer designing cold-formed steel have evolved. System performance, resilience, and sustainability all present new challenges, while changing processes in construction and the integration of simulation tools in design alter engineering workflows and open up new opportunities. Cold-formed steel standards need to evolve to meet these demands and leverage new workflows. The Strategic Planning Committee of the AISI Standards Council facilitated a process that defined areas of focus (vision statements) for the AISI specification writing committees and then facilitated a process to generate prioritized issues for the subcommittees to address. Taken together the lists provide a snapshot of the needed work to evolve cold-formed steel standards, and in turn enable next-generation cold-formed steel structural systems. This paper provides a description of the strategic planning process and its significant outcomes, which will guide the efforts of AISI standards development over the next code development cycle and beyond
Implementation and Impact of the Patient Self-Determination Act
The Patient Self-Determination Act became effective in December 1991 and mandates that patients be given information about legal rights regarding living wills and durable powers of attorney for health care. We investigated the impact this law has had on hospitals, medical personnel, and patients. We conducted a survey of all hospitals in the state of Georgia, collecting data regarding implementation and knowledge of the law, as well as effects of the law and beliefs about it. The data indicated that hospitals relied primarily on the Georgia Hospital Association for implementation policy, that minimalist implementation of the law occurs in most hospitals, and that the biggest perceived problem with the law was the inappropriateness of presenting this information at hospital admission and problems patients had in comprehending the materials presented. Despite these concerns, most respondents did not want the law repealed
The Large and Small Scale Structures of Dust in the Star-Forming Perseus Molecular Cloud
We present an analysis of ~3.5 square degrees of submillimetre continuum and
extinction data of the Perseus molecular cloud. We identify 58 clumps in the
submillimetre map and we identify 39 structures (`cores') and 11 associations
of structures (`super cores') in the extinction map. The cumulative mass
distributions of the submillimetre clumps and extinction cores have steep
slopes (alpha ~ 2 and 1.5 - 2 respectively), steeper than the Salpeter IMF
(alpha = 1.35), while the distribution of extinction super cores has a shallow
slope (alpha ~ 1). Most of the submillimetre clumps are well fit by stable
Bonnor-Ebert spheres with 10K < T < 19K and 5.5 < log_10(P_ext/k) < 6.0. The
clumps are found only in the highest column density regions (A_V > 5 - 7 mag),
although Bonnor-Ebert models suggest that we should have been able to detect
them at lower column densities if they exist. These observations provide a
stronger case for an extinction threshold than that found in analysis of less
sensitive observations of the Ophiuchus molecular cloud. The relationship
between submillimetre clumps and their parent extinction core has been
analyzed. The submillimetre clumps tend to lie offset from the larger
extinction peaks, suggesting the clumps formed via an external triggering
event, consistent with previous observations.Comment: 38 pages, 12 figures, accepted by Astrophysical Journal slight
changes to original due to a slight 3" error in the coordinates of the SCUBA
ma
Patient Safety Climate: Variation in Perceptions by Infection Preventionists and Quality Directors
Background. Healthcare-associated infections (HAIs) are an important patient safety issue, and safety climate is an important organizational factor. This study explores perceptions of infection preventionists (IPs) and quality directors (QDs) regarding two safety microclimates, Senior Management Engagement (SME) and Leadership on Patient Safety (LOPS), across California hospitals. Methods. This was an analysis of two cross-sectional surveys. We conducted Wilcoxon signed-rank test, univariate analyses, and a multivariate ordinary least square regression. Results. There were 322 eligible hospitals; 149 hospitals (46.3%) responded to both surveys. The IP response rate was 59%, and the QD response rate was 79.5%. We found IPs perceived SME more positively than did QDs (21.4 vs. 20.4, P < 0.01). No setting characteristics predicted variation in perceptions. Presence of an independent budget predicted more positive perceptions of microclimates across personnel types (P < 0.01). Conclusions. Differences in perceptions continue to exist between essential leaders in acute health care settings which could have critical effects on outcomes such as HAIs. Having an independent budget for the infection prevention and control department may enhance the overall safety climate and in turn patient care
The Iowa Homemaker vol.16, no.6
Cooperation Transforms Work Into Play by Helen Clark and Charlotte Heffner, page 2
Modernize Your Walls by Virginia Berry, page 3
Take a Hint from Sally by Gaynold Carroll, page 4
Should Women Have Careers? by Josephine Betty, page 6
Many Foods Make Their Debut by Jean Reis and Clare Pell, page 7
Whatâs New in Home Economics, page 8
The Womanâs Place in Politics by Dorothy Fedderson, page 11
Mrs. Chang Serves a Chinese Dinner by Helen Peg Belken, page 12
Graduates in New Positions by Faithe Danielson, page 13
Extend the Holiday Hilarity by Marie Larson, page 14
Shopping for Hose by Rosalie Ralston, page 15
Hints for the Coed, page 1
The Dynamics of Dense Cores in the Perseus Molecular Cloud II: The Relationship Between Dense Cores and the Cloud
We utilize the extensive datasets available for the Perseus molecular cloud
to analyze the relationship between the kinematics of small-scale dense cores
and the larger structures in which they are embedded. The kinematic measures
presented here can be used in conjunction with those discussed in our previous
work as strong observational constraints that numerical simulations (or
analytic models) of star formation should match. We find that dense cores have
small motions with respect to the 13CO gas, about one third of the 13CO
velocity dispersion along the same line of sight. Within each extinction
region, the core-to-core velocity dispersion is about half of the total (13CO)
velocity dispersion seen in the region. Large-scale velocity gradients account
for roughly half of the total velocity dispersion in each region, similar to
what is predicted from large-scale turbulent modes following a power spectrum
of P(k) ~ k^{-4}.Comment: Accepted for publication in ApJ. 47 pages (preprint format), 20
figures, 5 table
Amphidromy Links a Newly Documented Fish Community of Continental Australian Streams, to Oceanic Islands of the West Pacific
BACKGROUND: Indo-Pacific high island streams experience extreme hydrological variation, and are characterised by freshwater fish species with an amphidromous life history. Amphidromy is a likely adaptation for colonisation of island streams following stochastic events that lead to local extirpation. In the Wet Tropics of north-eastern Australia, steep coastal mountain streams share similar physical characteristics to island systems. These streams are poorly surveyed, but may provide suitable habitat for amphidromous species. However, due to their ephemeral nature, common non-diadromous freshwater species of continental Australia are unlikely to persist. Consequently, we hypothesise that coastal Wet Tropics streams are faunally more similar, to distant Pacific island communities, than to nearby faunas of large continental rivers. METHODS/PRINCIPAL FINDINGS: Surveys of coastal Wet Tropics streams recorded 26 species, 10 of which are first records for Australia, with three species undescribed. This fish community is unique in an Australian context in that it contains mostly amphidromous species, including sicydiine gobies of the genera Sicyopterus, Sicyopus, Smilosicyopus and Stiphodon. Species presence/absence data of coastal Wet Tropics streams were compared to both Wet Tropics river networks and Pacific island faunas. ANOSIM indicated the fish fauna of north-eastern Australian coastal streams were more similar to distant Pacific islands (Râ=â0.76), than to nearby continental rivers (Râ=â0.98). MAIN CONCLUSIONS/SIGNIFICANCE: Coastal Wet Tropics streams are faunally more similar to distant Pacific islands (79% of species shared), than to nearby continental fauna due to two factors. First, coastal Wet Tropics streams lack many non-diadromous freshwater fish which are common in nearby large rivers. Second, many amphidromous species found in coastal Wet Tropics streams and Indo-Pacific islands remain absent from large rivers of the Wet Tropics. The evolutionary and conservation significance of this newly discovered Australian fauna requires clarification in the context of the wider amphidromous fish community of the Pacific
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