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Rates of speciation and extinction are often linked to many ecological factors, traits (emergent and nonemergent) such as environmental tolerance, body size, feeding type, and geographic range. Marine gastropods in particular have been used to examine the role of larval dispersal in speciation. However, relatively few studies have been conducted placing larval modes in species-level phylogenetic context. Those that have, have not incorporated fossil data, while landmark macroevolutionary studies on fossil clades have not considered both phylogenetic context and net speciation (speciation–extinction) rates. This study utilizes Eocene volutid Volutospina species from the U.S. Gulf Coastal Plain and the Hampshire Basin, U.K., to explore the relationships among larval mode, geographic range, and duration. Based on the phylogeny of these Volutospina, we calculated speciation and extinction rates in order to compare the macroevolutionary effects of larval mode. Species with planktotrophic larvae had a median duration of 9.7 Myr, which compared significantly to 4.7 Myr for those with non-planktotrophic larvae. Larval mode did not significantly factor into geographic-range size, but U.S. and U.K. species do differ, indicating a locality-specific component to maximum geographic-range size. Non-planktotrophs (NPTs)were absent among the Volutospina species during the Paleocene–early Eocene. The relative proportions of NPTs increased in the early middle Eocene, and the late Eocene was characterized by disappearance of planktotrophs (PTs). The pattern of observed lineage diversity shows an increasing preponderance of NPTs; however, this is clearly driven by a dramatic extinction of PTs, rather than higher NPT speciation rates during the late Eocene. This study adds nuance to paleontology's understanding of the macroevolutionary consequences of larval mode.
This SHEA white paper identifies knowledge gaps and challenges in healthcare epidemiology research related to coronavirus disease 2019 (COVID-19) with a focus on core principles of healthcare epidemiology. These gaps, revealed during the worst phases of the COVID-19 pandemic, are described in 10 sections: epidemiology, outbreak investigation, surveillance, isolation precaution practices, personal protective equipment (PPE), environmental contamination and disinfection, drug and supply shortages, antimicrobial stewardship, healthcare personnel (HCP) occupational safety, and return to work policies. Each section highlights three critical healthcare epidemiology research questions with detailed description provided in supplementary materials. This research agenda calls for translational studies from laboratory-based basic science research to well-designed, large-scale studies and health outcomes research. Research gaps and challenges related to nursing homes and social disparities are included. Collaborations across various disciplines, expertise and across diverse geographic locations will be critical.
We use scanning electron microscopy imaging to examine the shell microstructure of fossil and living species in five families of caenogastropods (Strombidae, Volutidae, Olividae, Pseudolividae, and Ancillariidae) to determine whether parallel or convergent evolution is responsible for the development of a unique caenogastropod trait, the extreme parietal callus (EPC). The EPC is defined as a substantial thickening of both the spire callus and the callus on the ventral shell surface such that it covers 50% or more of the surface. Caenogastropods as a whole construct the EPC convergently, using a variety of low-density, poorly organized microstructures that are otherwise uncommon in caenogastropod non-callus shell construction. Within clades, however, we see evidence for parallelism in decreased regulation in both the shell and callus microstructure. Low-density and poorly ordered microstructure—such as used for the EPC—uses less organic scaffolding and is less energetically expensive than normal shell microstructure. This suggests the EPC functions to rapidly and inexpensively increase shell thickness and overall body size. Tests of functional ecology suggest that the EPC might function both to defend against crushing predation through increased body size and dissipation of forces while aiding in shell orientation of highly mobile gastropods. These interpretations hinge on the current phylogenetic placement of caenogastropod families, emphasizing the essential contribution of phylogeny when interpreting homoplasy.
On coronavirus disease 2019 (COVID-19) wards, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid was frequently detected on high-touch surfaces, floors, and socks inside patient rooms. Contamination of floors and shoes was common outside patient rooms on the COVID-19 wards but decreased after improvements in floor cleaning and disinfection were implemented.
For patients with methicillin-resistant Staphylococcus aureus (MRSA) colonization, a traditional fist-bump greeting did not significantly reduce MRSA transfer in comparison to a handshake. However, transfer was reduced with a modified fist bump that minimized the surface area of contact and when hand hygiene was performed before the handshake.
We investigate the effect of constant-vorticity background shear on the properties of wavetrains in deep water. Using the methodology of Fokas (A Unified Approach to Boundary Value Problems, 2008, SIAM), we derive a higher-order nonlinear Schrödinger equation in the presence of shear and surface tension. We show that the presence of shear induces a strong coupling between the carrier wave and the mean-surface displacement. The effects of the background shear on the modulational instability of plane waves is also studied, where it is shown that shear can suppress instability, although not for all carrier wavelengths in the presence of surface tension. These results expand upon the findings of Thomas et al. (Phys. Fluids, vol. 24 (12), 2012, 127102). Using a modification of the generalized Lagrangian mean theory in Andrews & McIntyre (J. Fluid Mech., vol. 89, 1978, pp. 609–646) and approximate formulas for the velocity field in the fluid column, explicit, asymptotic approximations for the Lagrangian and Stokes drift velocities are obtained for plane-wave and Jacobi elliptic function solutions of the nonlinear Schrödinger equation. Numerical approximations to particle trajectories for these solutions are found and the Lagrangian and Stokes drift velocities corresponding to these numerical solutions corroborate the theoretical results. We show that background currents have significant effects on the mean transport properties of waves. In particular, certain combinations of background shear and carrier wave frequency lead to the disappearance of mean-surface mass transport. These results provide a possible explanation for the measurements reported in Smith (J. Phys. Oceanogr., vol. 36, 2006, pp. 1381–1402). Our results also provide further evidence of the viability of the modification of the Stokes drift velocity beyond the standard monochromatic approximation, such as recently proposed in Breivik et al. (J. Phys. Oceanogr., vol. 44, 2014, pp. 2433–2445) in order to obtain a closer match to a range of complex ocean wave spectra.
To test the hypothesis that long-term care facility (LTCF) residents with Clostridium difficile infection (CDI) or asymptomatic carriage of toxigenic strains are an important source of transmission in the LTCF and in the hospital during acute-care admissions.
A 6-month cohort study with identification of transmission events was conducted based on tracking of patient movement combined with restriction endonuclease analysis (REA) and whole-genome sequencing (WGS).
Veterans Affairs hospital and affiliated LTCF.
The study included 29 LTCF residents identified as asymptomatic carriers of toxigenic C. difficile based on every other week perirectal screening and 37 healthcare facility-associated CDI cases (ie, diagnosis >3 days after admission or within 4 weeks of discharge to the community), including 26 hospital-associated and 11 LTCF-associated cases.
Of the 37 CDI cases, 7 (18·9%) were linked to LTCF residents with LTCF-associated CDI or asymptomatic carriage, including 3 of 26 hospital-associated CDI cases (11·5%) and 4 of 11 LTCF-associated cases (36·4%). Of the 7 transmissions linked to LTCF residents, 5 (71·4%) were linked to asymptomatic carriers versus 2 (28·6%) to CDI cases, and all involved transmission of epidemic BI/NAP1/027 strains. No incident hospital-associated CDI cases were linked to other hospital-associated CDI cases.
Our findings suggest that LTCF residents with asymptomatic carriage of C. difficile or CDI contribute to transmission both in the LTCF and in the affiliated hospital during acute-care admissions. Greater emphasis on infection control measures and antimicrobial stewardship in LTCFs is needed, and these efforts should focus on LTCF residents during hospital admissions.
The nutrient choline is necessary for membrane synthesis and methyl donation, with increased requirements during lactation. The majority of immune development occurs postnatally, but the importance of choline supply for immune development during this critical period is unknown. The objective of this study was to determine the importance of maternal supply of choline during suckling on immune function in their offspring among rodents. At parturition, Sprague–Dawley dams were randomised to either a choline-devoid (ChD; n 7) or choline-sufficient (ChS, 1 g/kg choline; n 10) diet with their offspring euthanised at 3 weeks of age. In a second experiment, offspring were weaned to a ChS diet until 10 weeks of age (ChD-ChS, n 5 and ChS-ChS, n 9). Splenocytes were isolated, and parameters of immune function were measured. The ChD offspring received less choline in breast milk and had lower final body and organ weight compared with ChS offspring (P<0·05), but this effect disappeared by week 10 with choline supplementation from weaning. ChD offspring had a higher proportion of T cells expressing activation markers (CD71 or CD28) and a lower proportion of total B cells (CD45RA+) and responded less to T cell stimulation (lower stimulation index and less IFN-γ production) ex vivo (P<0·05). ChD-ChS offspring had a lower proportion of total and activated CD4+ T cells, and produced less IL-6 after mitogen stimulation compared with cells from ChS-ChS (P<0·05). Our study suggests that choline is required in the suckling diet to facilitate immune development, and choline deprivation during this critical period has lasting effects on T cell function later in life.
Despite recommendations for higher choline intakes during pregnancy and lactation, there is limited research regarding maternal intake during these important periods. In the present study, we estimated dietary choline intake during pregnancy and lactation in a population of Albertan women and the contribution of egg and milk consumption to intake. Dietary intake data were collected from the first 600 women enrolled in a prospective cohort study carried out in Alberta, Canada. During the first and/or second trimester, the third trimester and 3 months postpartum, 24 h dietary intake recall data were collected. A database was constructed including foods consumed by the cohort and used to estimate dietary choline intake. The mean total choline intake value during pregnancy was 347 (sd 149) mg/d, with 23 % of the participants meeting the adequate intake (AI) recommendation. During lactation, the mean total choline intake value was 346 (sd 151) mg/d, with 10 % of the participants meeting the AI recommendation. Phosphatidylcholine was the form of choline consumed in the highest proportion and the main dietary sources of choline were dairy products, eggs and meat. Women who consumed at least one egg in a 24 h period had higher (P< 0·001) total choline intake and were eight times more likely (95 % CI 5·2, 12·6) to meet choline intake recommendations compared with those who did not consume eggs during pregnancy. Women who reported consuming ≥ 500 ml of milk in a 24 h period were 2·8 times more likely (95 % CI 1·7, 4·8) to meet daily choline intake recommendations compared with those consuming < 250 ml of milk/d during pregnancy. Choline intake is below the recommendation levels in this population and the promotion of both egg and milk consumption may assist in meeting the daily choline intake recommendations.
The objectives of this study were to develop a novel training model for using mass-casualty incident (MCI) scenarios that trained hospital and prehospital staff together using Microsoft Visio, images from Google Earth and icons representing first responders, equipment resources, local hospital emergency department bed capacity, and trauma victims. The authors also tested participants’ knowledge in the areas of communications, incident command systems (ICS), and triage.
Participants attended Managing Multiple-Casualty Incidents (MCIs), a one-day training which offered pre- and post-tests, two one-hour functional exercises, and four distinct, one-hour didactic instructional periods. Two MCI functional exercises were conducted. The one-hour trainings focused on communications, National Incident Management Systems/Incident Command Systems (NIMS/ICS) and professional roles and responsibilities in NIMS and triage. The trainings were offered throughout communities in western Montana. First response resource inventories and general manpower statistics for fire, police, Emergency Medical Services (EMS), and emergency department hospital bed capacity were determined prior to MCI scenario construction. A test was given prior to and after the training activities.
A total of 175 firefighters, EMS, law enforcement, hospital personnel or other first-responders completed the pre- and post-test. Firefighters produced higher baseline scores than all other disciplines during pre-test analysis. At the end of the training all disciplines demonstrated significantly higher scores on the post-test when compared with their respective baseline averages. Improvements in post-test scores were noted for participants from all disciplines and in all didactic areas: communications, NIMS/ICS, and triage.
Mass-casualty incidents offer significant challenges for prehospital and emergency room workers. Fire, Police and EMS personnel must secure the scene, establish communications, define individuals’ roles and responsibilities, allocate resources, triage patients, and assign transport priorities. After emergency department notification and in advance of arrival, emergency department personnel must assess available physical resources and availability and type of manpower, all while managing patients already under their care. Mass-casualty incident trainings should strengthen the key, individual elements essential to well-coordinated response such as communications, incident management system and triage. The practice scenarios should be matched to the specific resources of the community. The authors also believe that these trainings should be provided with all disciplines represented to eliminate training “silos,” to allow for discussion of overlapping jurisdictional or organizational responsibilities, and to facilitate team building.
GlowSD, ColucciVJ, AllingtonDR, NoonanCW, HallEC. Managing Multiple-Casualty Incidents: A Rural Medical Preparedness Training Assessment. Prehosp Disaster Med. 2013;28(4):1-8.
In January 2009, the IAEA EMRAS II (Environmental Modelling for Radiation Safety II) program was launched. The goal of the program is to develop, compare and test models for the assessment of radiological impacts to the public and the environment due to radionuclides being released or already existing in the environment; to help countries build and harmonize their capabilities; and to model the movement of radionuclides in the environment. Within EMRAS II, nine working groups are active; this paper will focus on the activities of Working Group 1: Reference Methodologies for Controlling Discharges of Routine Releases. Within this working group environmental transfer and dose assessment models are tested under different scenarios by participating countries and the results compared. This process allows each participating country to identify characteristics of their models that need to be refined. The goal of this working group is to identify reference methodologies for the assessment of exposures to the public due to routine discharges of radionuclides to the terrestrial and aquatic environments. Several different models are being applied to estimate the transfer of radionuclides in the environment for various scenarios. The first phase of the project involves a scenario of nuclear power reactor with a coastal location which routinely (continuously) discharges 60Co, 85Kr, 131I, and 137Cs to the atmosphere and 60Co, 137Cs, and 90Sr to the marine environment. In this scenario many of the parameters and characteristics of the representative group were given to the modellers and cannot be altered. Various models have been used by the different participants in this inter-comparison (PC-CREAM, CROM, IMPACT, CLRP POSEIDON, SYMBIOSE and others). This first scenario is to enable a comparison of the radionuclide transport and dose modelling. These scenarios will facilitate the development of reference methodologies for controlled discharges.
An autosomal translocation in the tsetse fly Glossina austeni was studied genetically, cytogenetically and for its effects on viability. Flies homo-zygous for the structural change could be identified by outcrossing to wild-type and demonstrating semi-sterility in all the progeny.
A cytogenetical analysis of male meioses in samples of pupae which were sibs of the semi-sterile progeny showed them to be structurally heterozygous for the translocation. Matings of the translocation heterozygotes and homozygotes gave the expected progeny ratios, with the exception of a deficit of females classified as translocation homozygotes. This was due to their sterility or inviability. Those female homozygotes which did breed showed a subnormal lifetime pupal production. These deleterious recessive effects were probably due to the translocation itself although the influence of linked loci could not be ruled out. These effects would prevent the mass rearing of this particular translocation for a tesetse control project.
Two other stocks which showed semi-sterility were found to carry autosomal translocations and two which currently showed holandric inheritance have Y-autosome translocations. One stock with holandric inheritance of extreme sterility carries a double translocation involving two autosomes and the Y chromosome.
Male Glossina morsitans were subjected to various doses of gamma radiation in air or nitrogen and mated to untreated females. The sex ratio of the F1 progeny was biased towards males, and this may be explained by the extra vulnerability to dominant lethal induction that the presence of the large X chromosome gives to female determining sperms. The mean fertility of the F1 progeny was subnormal. This was due to the induction of 50 % sterility in a large proportion of F1 individuals. Cytogenetic examination of the progeny of outcrosses of F1 individuals indicated that in most of the semi-steriles there were translocations involving the large autosomes or the Y chromosomes. Almost all the normally fertile F1 flies gave only cytogenetically normal progeny. The F1 sex-ratio distortion and semi-sterility would provide a ‘bonus’ in the application of the sterile male technique, which would amount to a 15–50% saving in the releases required to achieve a population control target compared with the requirement if the F1 was normal.
College undergraduate and high school teacher internships are significant factors in materials science education. Traditionally, NSF-supported internships are done in academia. The NSF-supported academic/industrial internship programs involving Stanford University, San Jose University and the IBM Almaden Research Center extend the impact by the inclusion of an industrial research component. Internships through San Jose State University have existed since 1994 under a variety of NSF grants, most recently with NSF-REU support for undergraduate internships. Internships through Stanford university have existed since 1995 through an NSF Materials Research Science and Engineering Center, the “Center for Polymer Interfaces and Macromolecular Interfaces” (CPIMA). In these programs, the interns become members of an existing research group for 10 weeks and have their own project under a mentor. The interns attend a weekly seminar series on industrial research frontiers, a career day, a Graduate Record Examination workshop, a graduate school workshop, and tours of industrial research labs. Every participant presents a poster at an internal technical meeting at IBM at the end of the summer. For the industrial internships at IBM, the research is publishable but closely related to a technical area important to IBM. While the undergraduate and teacher internship programs are the major components of educational outreach of CPIMA, many other projects have been pursued, including public science, programs with local high schools, and science outreach to local community colleges. Dr. Marni Goldman was the Director of Educational Outreach for CPIMA from 2000 until her death in 2007, and she started many of the educational projects and programs. She was especially interested in diversity and initiated an internship program for students who are disabled. The programs will be reviewed and her contributions emphasized.
Field-Assisted Simultaneous Synthesis and Transfer (FASST®) process offers a controllable and cost-effective method to produce Copper Indium Gallium Selenide (CIGS) films for high efficiency photovoltaic devices. In the first stage of the two-stage FASST® process two separate precursor films are formed, one deposited on the substrate and the other on a reusable printing plate. In the second stage, the precursors are brought into intimate contact and rapidly reacted under pressure in the presence of an applied electrostatic field, effectively creating a sealed micro-reactor that ensures high material utilization efficiency, direct control of reaction pressure, and low thermal budget. The unique ability to control both precursor films independently allows for composition and deposition technique optimization, eliminating pre-reaction prior to the synthesis of CIGS. This flexibility has proven immensely valuable as is demonstrated in the results of depositing the two-reactant films by various combinations of low-cost solution-based and conventional vacuum-based physical vapor deposition techniques, producing in several minutes' high quality “hybrid” CIGS with large grains on the order of several microns. Cell efficiencies as high as 12.2% have been achieved using the FASST® method.
Cysteine proteinases from the fruit and latex of plants, such as papaya, pineapple and fig, have previously been shown to have substantial anthelmintic efficacy, in vitro and in vivo, against a range of animal parasitic nematodes. In this paper, we describe the in vitro effects of these plant extracts against 2 sedentary plant parasitic nematodes of the genera Meloidogyne and Globodera. All the plant extracts examined caused digestion of the cuticle and decreased the activity of the tested nematodes. The specific inhibitor of cysteine proteinases, E-64, blocked this activity completely, indicating that it was essentially mediated by cysteine proteinases. In vitro, plant cysteine proteinases are active against second-stage juveniles of M. incognita and M. javanica, and some cysteine proteinases also affect the second-stage juveniles of Globodera rostochiensis. It is not known yet whether these plant extracts will interfere with, or prevent invasion of, host plants.