Successful weed management, particularly use of chemical control, is very important for commercial lettuce production on organic soils in the Everglades Agricultural Area in south Florida. Field experiments were conducted in 2016 and 2017 to determine the efficacy of herbicides (pronamide, bensulide, imazethapyr, or oxyfluorfen) applied preemergence (PRE) either alone or followed by a postemergence (POST) application of imazethapyr for weed control and lettuce (romaine and iceberg) yield. Preemergence-applied oxyfluorfen (0.56 kg ha−1) resulted in significant lettuce injury, including stand loss, while PRE applications of pronamide (4.44 kg ha−1), bensulide (5.6 and 10.1 kg ha−1), or imazethapyr (0.035 g ha−1) resulted in transient lettuce injury and no significant stand loss. Similarly, PRE-applied pronamide, bensulide, and imazethapyr followed by POST-applied imazethapyr did not result in significant lettuce stand loss or injury. When contrasted as a group, PRE-applied herbicides followed by a POST application of imazethapyr provided better spiny amaranth and common lambsquarters control compared with PRE-applied herbicides or POST-applied imazethapyr-only treatments. Lettuce yield was highest with PRE herbicides followed by POST imazethapyr compared with PRE herbicides or POST-applied imazethapyr-only treatments, indicating a yield benefit of having a PRE followed by POST herbicide weed control program in lettuce grown on organic soils. However, oxyfluorfen is not an option for lettuce on organic soils because of unacceptable stand reduction and crop injury. Whether to apply pronamide, bensulide, or imazethapyr PRE followed by a POST application of imazethapyr for broadleaf weed control in lettuce on organic soils depends on the species present, cost, and ease of application.

We explain how two landmark Supreme Court cases, Motor Vehicles Manufacturers Association of the U.S. v. State Farm Mutual Automobile Insurance Co. (1983) and Chevron U.S.A., Inc., v. Natural Resources Defense Council, Inc. (1984), have constrained congressional and presidential control of the bureaucracy. We provide an overview of these cases, and we note how the dominant theories of bureaucratic policy making in the political science literature fail to account for judicial doctrine in a meaningful way. We illustrate the implications of these cases for recent debates regarding regulatory rollbacks in the Trump administration, and we argue that bureaucratic control over the past forty years has tilted in favor of the judicial branch of American national government.

Background: The CMS and the CDC recommend that all healthcare facilities have an effective water management program (WMP). Our WMP has been in place since 2010; it includes members from facilities operations, infection prevention and control, environmental services, and industrial hygiene. The team meets regularly to discuss current water issues, reviews validation data and water testing reports. Description of event: In April 2018, we suddenly experienced discolored water and sediment at multiple water fixtures throughout the 3.3 million square-foot hospital campus. The hospital incident command structure (HICS) was activated to assist in investigating and managing the situation. Immediate response: Water was deemed unsafe while the cause was being investigated. Bottled water was distributed to 950 hospital patients, and >8,000 staff and visitors. The impact included alternative methods for hand hygiene, the use of bottled water for food preparation and drinking, and the elimination of showers for patients and staff. The dialysis unit used an independent water supply that was not affected. Investigation and remediation: The hospital had 2 sources of domestic cold water: municipal water and a private well that had been in use since 1912. An investigation revealed that the well pump had malfunctioned, drawing gravel into the potable water supply. This overwhelmed the plumbing, blocked toilets and likely dislodged biofilm from the pipes. Early testing showed high levels of corrosion byproducts (ie, iron, copper, and lead) and bacterial contamination in the water, including presence of Legionella. Remediation involved isolating the well, switching to municipal water as the sole source of potable water, flushing the system, and retesting. Overall, 105 technicians flushed the water system including 6,000 water fixtures, 125 drinking fountains, and 95 emergency showers and eyewashes; they sanitized and cleaned 130 ice machines and tested 240 backflow preventers. We retested 437 water samples after remediation; all parameters had returned to the normal range. The existing water process flow diagrams were used to guide sampling for water testing. Conclusions: The hospital’s water system was brought back on line in 78 hours after the first report of “black water.” An active, mature WMP with multiple facilities technicians trained in water sampling enabled a quick response. Coordination through the HICS structure streamlined the response and enabled clear communication throughout the process.

Funding: None

Disclosures: None

Background:Clostridioides difficile is a leading cause of nosocomial infectious diarrhea in developed countries, and it has a significant economic impact throughout the world. Early detection of the pathogen and its toxins is critical because early treatment significantly reduces infection-related morbidity, mortality, and medical cost. Surveillance of healthcare-associated infections (HAIs) is conducted using the NHSN standardized infection ratio (SIR). This metric allows comparison of a facility’s observed infection rate to a national benchmark. The SIR can be elevated due to both a lack of institutional criteria for stool submission and the use of highly sensitive but poorly specific testing as a standalone test for diagnosis. The SIR can be artificially elevated by inclusion of C difficile carriers rather than infected patients due to inappropriate testing and overly sensitive methods. We aimed to determine the impact of an institutional nursing-driven protocol for stool submission as well as 2-step testing on the SIR. Methods: Starting from the fourth quarter of 2018, we instituted a nursing protocol for initiation of C. difficile testing. If the patient had ≥3 soft, loose, or liquid stools in 24 hours within the first 3 days of admission, they were placed on contact precautions and an unformed stool sample was submitted for C. difficile nucleic acid amplification testing (NAAT). A positive result prompted further evaluation with a stool enzyme immunoassay toxin test for confirmation of active infection. From hospital day 4 onward, stricter criteria were implemented for testing for C. difficile infection. Data were extrapolated for calculation of a quarterly SIR. This value was then compared to retrospective SIR data from the first quarter of 2016 to the third quarter of 2018. Results: The quarterly total of hospital-onset C. difficile infections from the first quarter of 2016 to the third quarter of 2018 ranged from 24 to 39 incidents per quarter. After implementing the nursing-driven protocol and 2-step testing, the quarterly total of hospital onset C. difficile infections decreased to 5–6 per quarter. The SIR prior to initiation ranged from 0.66 to 1.37 and decreased to 0.306–0.386 after the nursing-driven protocol and 2-step testing were implemented. Conclusions: Implementation of both an institutional nursing-driven protocol for stool submission and a 2-step testing protocol reduced the number of quarterly hospital-onset C. difficile events as well as our facility’s quarterly SIR to below the national standard.

Funding: None

Disclosures: Ioana Chirca, University Hospital

There is remarkably little documented information in the scientific literature on any of the 18 species of buttonquail as they are very difficult to observe in the wild. This lack of information has hampered informed conservation decision making. We undertook the first biome-wide survey for the fynbos endemic Hottentot Buttonquail Turnix hottentottus, using flush transect surveys covering 275 km. We used location data for sightings as well as from records reported by the bird-watching community and modelled distribution using MaxEnt. Encounters were restricted to the fynbos biome, and the top contributors to our prediction of suitable habitat were habitat transformation, slope and time since fire. We obtained a density estimate of 0.032 individuals per hectare which, across an estimated median range of 27,855 km2, provides a population estimate of 89,136 individuals. Given the extent of the range and the population estimate we suggest the IUCN Red List status could be ‘Vulnerable’, rather than ‘Endangered’. Agricultural and alien-vegetation encroachment means that the future of the species is certainly under threat and further studies are needed to inform conservation management.

This study sought to identify factors which influenced how a group of people with dementia living in their own homes participated in community-based physical activity and explored the effect that exercise groups, dance and walking had on their wellbeing. A broadly ethnographic approach was adopted in which participant observation and interviews were employed. Nineteen people with dementia and seven formal and informal carers were included in the participant observation phase. Eleven people with dementia were interviewed. The analysis and interpretation of data was informed by embodiment and social constructionist theoretical perspectives. Findings suggest that a complex interplay between attitudes and beliefs, retained embodied abilities, and aspects of the physical and social environment influenced how individuals engaged in physical activity and the degree to which they experienced wellbeing as a result. Findings suggest that when certain factors co-exist, physical activity can provide a context within which people with dementia are able to use embodied skills in order to support fragile identities, connect with others and express themselves.

The biraderi (brotherhood) is a long-established, widely prevalent dimension of social stratification in Pakistani communities worldwide. Alongside consanguinity, it offers a route for cementing social solidarities and so has strong socio-biological significance. A detailed breakdown of biraderi affiliation among participants in an ongoing birth cohort study in the northern English city of Bradford is presented. There is historical resilience of intra-biraderi marriage, but with a secular decline in prevalence across all biraderi and considerable reductions in some. While a majority of marriages in all biraderi are consanguineous the prevalence varies, ranging from over 80% to under 60%. In consanguineous unions, first cousin marriages account for more than 50% in five of the fifteen biraderi and >40% in six others. Within-biraderi marriage and consanguinity enhance genetic stratification, thereby increasing rates of genomic homozygosity and the increased expression of recessive genetic disorders. The trends reported constitute putative signals of generational change in the marital choices in this community.

The PKSCAT90 database consists of radio and optical data for 8264 radio sources. It covers all the sky south of declination +27 degrees. Most of the galactic plane and the Magellanic Cloud regions are excluded from this catalogue but have been the subject of other specialised surveys. A few data errors in the initial PKSCAT90 version 1.00 released in March 1990 have been corrected in the current version 1.01 edition.

We give a progress report on a programme of observations to obtain flux densities at 8.4 GHz for a large sample of radio sources selected from the Parkes 2700 MHz Survey. So far, about 1000 flux measurements have been made with a typical accuracy of 10%.

A sensitive search has been made for OH maser emission from a sample of 16 symbiotic stars. This sample has been selected on the basis of infrared optical depth and variability, so that the stars within it have circumstellar shells similar to those seen in the well-known OH/IR and OH/Mira stars. There were no significant detections, except for one unassociated background source, and we conclude that the presence of a hot binary companion inhibits any possible OH maser action.

We describe bright microwave events that were first detected with the Parkes 64-m telescope at 8.4 or 22 GHz from six active-chromosphere stars. In some flares spectral data were obtained over a large frequency range from simultaneous measurements with the Parkes reflector (8.4 or 22 GHz), the Tidbinbilla interferometer (8.4 and 2.29 GHz), the Fleurs synthesis telescope (1.42 GHz) and the Molonglo Observatory synthesis telescope (0.843 GHz). Data on circular polarization were obtained from the Parkes observations at 8.4 GHz.

The stars were in a wide variety of evolutionary states, ranging from a single pre-main-sequence star (HD 36705), two RS CVn binaries (HD 127535, HD 128171), an Algol (HD 132742) and two apparently single K giants (HD 32918 and HD 196818). Their high brightness temperatures, positive spectral indices and low polarization are consistent with optically thick gyrosynchrotron emission from mildly relativistic electrons with average energies 0.5 to 3 MeV gyrating in inhomogeneous magnetic fields of 5 to 100 G.

Very sensitive low-noise amplifiers designed to receive transmissions from spacecraft are not necessarily suitable receivers for radio astronomy. In the former case a good signalto- noise ratio is required so that high data rates can be achieved. In the latter the ratio of signal to noise power may be as low as 10-4 and the stability of receiver gain and that of ail sources of noise during long integration times become of equal importance.

This paper describes a novel solution to the problem, which allowed important astronomy to be performed while the ruby maser receivers belonging to the European Space Agency were installed on the Parkes radio telescope for an extended period of time.

We present here the low-dispersion optical spectra of 295 QSO candidates. The great majority of the objects were originally selected as QSOs from the Parkes 2700 MHz radio survey, although we have also included spectra of several optically selected QSOs. A few of the QSO candidates are now better described as radio galaxies and BL Lac objects. This collection of spectra is not suitable for statistical studies unless due consideration is given to selection effects.

We report on a new method of determining radio source positions with the Parkes radio telescope. The method is appreciably quicker than, but has a comparable accuracy to, established methods such as orthogonal scanning. It has been particularly useful during 1989 in tracking the Voyager II spacecraft as it approaches Neptune; a method of accurately pointing at the source of the radio signal was required without the signal degradation which is introduced by moving appreciably off source.

We question Newton’s inverse square law of universal gravitation in the light of recent, alternative formulations. In addition, we present numerical simulations of galaxy interactions which were used in an attempt to distinguish between an inverse square law and an inverse linear law. We conclude that an inverse linear relation is as compatible with the observational data on interacting galaxy systems as the inverse square law.

We present an overview of the survey for radio emission from active stars that has been in progress for the last six years using the observatories at Fleurs, Molonglo, Parkes and Tidbinbilla. The role of complementary optical observations at the Anglo-Australian Observatory, Mount Burnett, Mount Stromlo and Siding Spring Observatories and Mount Tamborine are also outlined. We describe the different types of star that have been included in our survey and discuss some of the problems in making the radio observations.

We present some preliminary results of an optical and radio study of the very active RS CVn binary HD 127535. Photometric measurements show the presence of a large amplitude wave which exhibits marked changes in shape and range on time scales as short as a few months. This photometric variation is almost certainly due to large cool starspots on the cooler, more luminous component. As part of a survey of southern active-chromosphere stars with the Parkes radio telescope, HD 127535 has been observed at 5, 8.4 and 22 GHz. No detection was made at 5 GHz, possibly because of confusion due to the angular proximity of the star to the galatic plane. However, it is one of the strongest sources detected in the 8.4 GHz survey, and is one of only two stars detected at 22 GHz. Photometry obtained two cycles before the 8.4 GHz observations suggest a possible correlation between the radio emission and the photometric wave, i.e. spot visibility, but more data are needed.

It is the usual practice during continuum radio observations at Parkes to observe ‘pointing sources’ concurrently with the program objects.