Evolving Molecular Cloud Structure and the Column Density Probability Distribution Function

The structure of molecular clouds can be characterized with the probability distribution function (PDF) of the mass surface density. In particular, the properties of the distribution can reveal the nature of the turbulence and star formation present inside the molecular cloud. In this paper, we explore how these structural characteristics evolve with time and also how they relate to various cloud properties as measured from a sample of synthetic column density maps of molecular clouds. We find that, as a cloud evolves, the peak of its column density PDF will shift to surface densities below the observational threshold for detection, resulting in an underlying lognormal distribution which has been effectively lost at late times. Our results explain why certain observations of actively star-forming, dynamically older clouds, such as the Orion molecular cloud, do not appear to have any evidence of a lognormal distribution in their column density PDFs. We also study the evolution of the slope and deviation point of the power-law tails for our sample of simulated clouds and show that both properties trend towards constant values, thus linking the column density structure of the molecular cloud to the surface density threshold for star formation.Comment: 10 pages, 9 figures, Accepted for publication by MNRA

Unbound Star-forming Molecular Clouds

We explore whether observed molecular clouds could include a substantial population of unbound clouds. Using simulations which include only turbulence and gravity, we are able to match observed relations and naturally reproduce the observed scatter in the cloud size-linewidth coefficient, at fixed surface density. We identify the source of this scatter as a spread in the intrinsic virial parameter. Thus these observational trends do not require that clouds exist in a state of dynamical equilibrium. We demonstrate that cloud virial parameters can be accurately determined observationally with an appropriate size estimator. All our simulated clouds eventually form collapsing cores, regardless of whether the cloud is bound overall. This supports the idea that molecular clouds do not have to be bound to form stars or to have observed properties like those of nearby low-mass clouds.Comment: 9 pages, 6 figures, Accepted for publication by MNRA

A conceptual design of a large aperture microwave radiometer geostationary platform

A conceptual design of a Large Aperture Microwave Radiometer (LAMR) Platform has been developed and technology areas essential to the design and on-orbit viability of the platform have been defined. Those technologies that must be developed to the requirement stated here for the LAMR mission to be viable include: advanced radiation resistant solar cells, integrated complex structures, large segmented reflector panels, sub 3 kg/m(exp 2) areal density large antennas, and electric propulsion systems. Technology areas that require further development to enhance the capabilities of the LAMR platform (but are not essential for viability) include: electrical power storage, on-orbit assembly, and on-orbit systems checkout and correction

Attempting to validate the over/under triage matrix at a level I trauma center.

The Optimal Resources Document (ORD) mandates trauma activation based on injury mechanism, physiologic and anatomic criteria and recommends using the over/undertriage matrix (Matrix) to evaluate the appropriateness of trauma team activation. The purpose of this study was to assess the effectiveness of the Matrix method by comparing patients appropriately triaged with those undertriaged. We hypothesized that these two groups are different and Matrix does not discriminate the needs or outcomes of these different groups of patients.Trauma registry data, from 1/2013-12/2015, at a Level I trauma center were reviewed. Over and undertriage rates were calculated by Matrix. Patients with ISS ≥16 were classified by activation level (full, limited, consultation), and triage category by Matrix. Patients in the limited activation and consultation groups were compared to patients with full activation by demographics, injuries, initial vital signs, procedures, delays to procedure, ICU admission, length of stay, and mortality.7031 patients met activation criteria. Compliance with ACS tiered activation criteria was 99%. The Matrix overtriage rate was 45% and undertriage was 24%. Of 2282 patients with an ISS ≥16, 1026 were appropriately triaged (full activation), and 1256 were under triaged. Undertriaged patients had better GCS, blood pressure, and BD than patients with full activation. ICU admission, hospital stays, and mortality were lower in the undertriaged group. The under triaged group required fewer operative interventions with fewer delays to procedure.Despite having an ISS ≥ 16, patients with limited activations were dissimilar to patients with full activation. Level of activation and triage are not equivalent. The ACS-COT full and tiered activation criteria are a robust means to have the appropriate personnel present based on available pre-hospital information. Evaluation of the process of care, regardless of level of activation should be used to evaluate trauma center performance.Level III Therapeutic and Care managementThis is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal

California preschool curriculum framework, Volume 2

Journal ArticleI am pleased to present the California Preschool Curriculum Framework, Volume 2, a publication I believe will be a major effort in working to close the school-readiness gap for young children in our state. Created as a companion to the California Preschool Learning Foundations, this framework presents strategies and information to enrich learning and development opportunities for all of California's preschool children

Current outcomes of blunt open pelvic fractures: how modern advances in trauma care may decrease mortality.

Background:Open pelvic fracture, caused by a blunt mechanism, is an uncommon injury with a high mortality rate. In 2008, evidence-based algorithm for managing pelvic fractures in unstable patients was published by the Western Trauma Association (WTA). The use of massive transfusion protocols has become widespread as has the availability and use of pelvic angiography. The purpose of this study was to evaluate the outcome of open pelvic fractures in association with related advances in trauma care. Methods:A retrospective review was performed, at an American College of Surgeon verified level I trauma center, of patients with blunt open pelvic fractures from January 2010 to April 2016. The WTA algorithm, including massive transfusion protocol, and pelvic angiography were uniformly used. Data collected included injury severity score, demographic data, transfusion requirements, use of pelvic angiography, length of stay, and disposition. Data were compared with a similar study from 2005. Results:During the study period, 1505 patients with pelvic fractures were analyzed; 87 (6%) patients had open pelvic fractures. Of these, 25 were from blunt mechanisms and made up the study population. Patients in both studies had similar injury severity scores, ages, Glasgow Coma Scale, and gender distributions. Use of angiography was higher (44% vs. 16%; P=0.011) and mortality was lower (16% vs. 45%; P=0.014) than in the 2005 study. Conclusions:Changes in trauma care for patients with open blunt pelvic fracture include the use of an evidence-based algorithm, massive transfusion protocols and increased use of angioembolization. Mortality for open pelvic fractures has decreased with these advances. Level of evidence:Level IV

How effective is school-based deworming for the community-wide control of soil-transmitted helminths?

Background: The London Declaration on neglected tropical diseases was based in part on a new World Health Organization roadmap to “sustain, expand and extend drug access programmes to ensure the necessary supply of drugs and other interventions to help control by 2020”. Large drug donations from the pharmaceutical industry form the backbone to this aim, especially for soil-transmitted helminths (STHs) raising the question of how best to use these resources. Deworming for STHs is often targeted at school children because they are at greatest risk of morbidity and because it is remarkably cost-effective. However, the impact of school-based deworming on transmission in the wider community remains unclear. Methods: We first estimate the proportion of parasites targeted by school-based deworming using demography, school enrolment, and data from a small number of example settings where age-specific intensity of infection (either worms or eggs) has been measured for all ages. We also use transmission models to investigate the potential impact of this coverage on transmission for different mixing scenarios. Principal Findings: In the example settings <30% of the population are 5 to <15 years old. Combining this demography with the infection age-intensity profile we estimate that in one setting school children output as little as 15% of hookworm eggs, whereas in another setting they harbour up to 50% of Ascaris lumbricoides worms (the highest proportion of parasites for our examples). In addition, it is estimated that from 40–70% of these children are enrolled at school. Conclusions: These estimates suggest that, whilst school-based programmes have many important benefits, the proportion of infective stages targeted by school-based deworming may be limited, particularly where hookworm predominates. We discuss the consequences for transmission for a range of scenarios, including when infective stages deposited by children are more likely to contribute to transmission than those from adults

A bin-microphysics parcel model investigation of secondary ice formation in an idealised shallow convective cloud

We provide the first systematic study of ice formation in idealised shallow clouds from collisions of supercooled water drops with ice particles (&lsquo;mode 2&rsquo;). Using the University of Manchester bin-microphysics parcel model, we investigated the sensitivity of ice formation due to mode 2 for a wide range of parameters: aerosol particle size distribution, updraft speed, cloud base temperature, cloud depth, ice-nucleating particle concentration and freezing fraction of mode 2. We provide context to our results with other secondary ice production mechanisms as single mechanisms and combinations (rime-splintering, spherical freezing fragmentation of drops [&lsquo;mode 1&rsquo;] and ice-ice collisions). There was a significant sensitivity to aerosol particle size distribution when updraft speeds were low (0.5 m s&minus;1); secondary ice formation did not occur when the aerosol particle size distribution mimicked polluted environments. Where secondary ice formation did occur in simulated clouds, significant ice formation in the shallower clouds (1.3 km deep) was due to mode 2 or a combination which included mode 2. The deeper clouds (2.4 km deep) also had significant contributions from rime-splintering or ice-ice collisions SIP mechanisms. While simulations with cloud base temperatures of 7 &deg;C were relatively insensitive to ice-nucleating particle concentrations, there was a sensitivity in simulations cloud base temperatures of 0 &deg;C. Increasing the ice-nucleating particle concentration delayed ice formation. Our results suggest that collisions of supercooled water drops with ice particles may be a significant ice formation mechanism within shallow convective clouds where rime-splintering is not active.</p