Peri-urbanisation, Social Heterogeneity and Ecological Simplification

Peri-urban development pressure on and near Australian coastlines is resulting in the conversion of agricultural land for rural-residential use. The impact of larger and more diverse human populations upon the ecological assets remaining in agricultural landscapes has consequently become a policy concern. This paper contributes to these policy debates by integrating the results of parallel social and ecological research projects commissioned to improve natural resource management in peri-urbanising regions. The research was undertaken in the case study region of South East Queensland, the region supporting Australia’s most rapid population growth. Our results indicate that both social and ecological communities cross a fragmentation threshold due to peri-urban development whereby they become ecologically simple and socially heterogeneous in a coupling that cedes a poor diagnosis for biodiversity retention.stored soil water, dryland grain cropping, extension, social systems, RD&E, differentiation

Experimental Synthetic Aperture Radar with Dynamic Metasurfaces

We investigate the use of a dynamic metasurface as the transmitting antenna for a synthetic aperture radar (SAR) imaging system. The dynamic metasurface consists of a one-dimensional microstrip waveguide with complementary electric resonator (cELC) elements patterned into the upper conductor. Integrated into each of the cELCs are two diodes that can be used to shift each cELC resonance out of band with an applied voltage. The aperture is designed to operate at K band frequencies (17.5 to 20.3 GHz), with a bandwidth of 2.8 GHz. We experimentally demonstrate imaging with a fabricated metasurface aperture using existing SAR modalities, showing image quality comparable to traditional antennas. The agility of this aperture allows it to operate in spotlight and stripmap SAR modes, as well as in a third modality inspired by computational imaging strategies. We describe its operation in detail, demonstrate high-quality imaging in both 2D and 3D, and examine various trade-offs governing the integration of dynamic metasurfaces in future SAR imaging platforms

Examining the Gap: Compensation Disparities between Male and Female Physician Assistants.

BACKGROUND: Compensation disparities between men and women have been problematic for decades, and there is considerable evidence that the gap cannot be entirely explained by nongender factors. The current study examined the compensation gap in the physician assistant (PA) profession. METHODS: Compensation data from 2014 was collected by the American Academy of PAs in 2015. Practice variables, including experience, specialty, and hours worked, were controlled for in an ordinary least-squares sequential regression model to examine whether there remained a disparity in total compensation. In addition, the absolute disparity in compensation was compared with historical data collected by American Academy of PAs over the previous 1.5 decades. RESULTS: Without controlling for practice variables, a total compensation disparity of $16,052 existed between men and women in the PA profession. Even after PA practice variables were controlled for, a total compensation disparity of$9,695 remained between men and women (95% confidence interval, $8,438-$10,952). A 17-year trend indicates the absolute disparity between men and women has not lessened, although the disparity as a percent of male compensation has decreased in recent years. CONCLUSIONS: There remain challenges to ensuring pay equality in the PA profession. Even when compensation-relevant factors such as experience, hours worked, specialty, postgraduate training, region, and call are controlled for, there is still a substantial gender disparity in PA compensation. Remedies that may address this pay inequality include raising awareness of compensation disparities, teaching effective negotiation skills, assisting employers as they develop equitable compensation plans, having less reliance on past salary in position negotiation, and professional associations advocating for policies that support equal wages and opportunities, regardless of personal characteristics

Polarimetric Properties of the Crab Pulsar between 1.4 and 8.4 GHz

New polarimetric observations of the Crab pulsar at frequencies between 1.4 and 8.4 GHz are presented. Additional pulse components discovered in earlier observations (Moffett & Hankins 1996, astro-ph/9604163) are found to have high levels of linear polarization, even at 8.4 GHz. No abrupt sweeps in position angle are found within pulse components; however, the position angle and rotational phase of the interpulse do change dramatically between 1.4 and 4.9 GHz. The multi-frequency profile morphology and polarization properties indicate a non-standard origin of the emission. Several emission geometries are discussed, but the one favored locates sites of emission both near the pulsar surface and in the outer magnetosphere.Comment: 20 pages, 7 postscript figures, uses aaspp4 Latex style. To appear in Volume 522 of The Astrophysical Journa

Sampling techniques for and interpretation of milk urea nitrogen concentration

Representative MUN values can be obtained by testing a milk sample before milking, at AM or PM milking, or with an in-line siphon sampling device. MUN values obtained from homogenous milking strings are as accurate as an average MUN value obtained by sampling each cow in the string. Bulk tank sampling is not advisable because of the variation in MUN caused by stage of lactation. Small herds that feed a single TMR should use the average MUN from cows between 60 and 200 days in milk. Monthly sampling is recommended to build a database. The effect of diet changes on MUN can be assessed within 7 days.; Dairy Day, 1998, Kansas State University, Manhattan, KS, 1998

The evolution of the natural killer complex; a comparison between mammals using new high-quality genome assemblies and targeted annotation.

Natural killer (NK) cells are a diverse population of lymphocytes with a range of biological roles including essential immune functions. NK cell diversity is in part created by the differential expression of cell surface receptors which modulate activation and function, including multiple subfamilies of C-type lectin receptors encoded within the NK complex (NKC). Little is known about the gene content of the NKC beyond rodent and primate lineages, other than it appears to be extremely variable between mammalian groups. We compared the NKC structure between mammalian species using new high-quality draft genome assemblies for cattle and goat; re-annotated sheep, pig, and horse genome assemblies; and the published human, rat, and mouse lemur NKC. The major NKC genes are largely in the equivalent positions in all eight species, with significant independent expansions and deletions between species, allowing us to propose a model for NKC evolution during mammalian radiation. The ruminant species, cattle and goats, have independently evolved a second KLRC locus flanked by KLRA and KLRJ, and a novel KLRH-like gene has acquired an activating tail. This novel gene has duplicated several times within cattle, while other activating receptor genes have been selectively disrupted. Targeted genome enrichment in cattle identified varying levels of allelic polymorphism between the NKC genes concentrated in the predicted extracellular ligand-binding domains. This novel recombination and allelic polymorphism is consistent with NKC evolution under balancing selection, suggesting that this diversity influences individual immune responses and may impact on differential outcomes of pathogen infection and vaccination

Malpractice Liability and Defensive Medicine: A National Survey of Neurosurgeons

BACKGROUND: Concern over rising healthcare expenditures has led to increased scrutiny of medical practices. As medical liability and malpractice risk rise to crisis levels, the medical-legal environment has contributed to the practice of defensive medicine as practitioners attempt to mitigate liability risk. High-risk specialties, such as neurosurgery, are particularly affected and neurosurgeons have altered their practices to lessen medical-legal risk. We present the first national survey of American neurosurgeons' perceptions of malpractice liability and defensive medicine practices. METHODS: A validated, 51-question online-survey was sent to 3344 practicing U.S. neurosurgeon members of the American Association of Neurological Surgeons, which represents 76% of neurosurgeons in academic and private practices. RESULTS: A total of 1028 surveys were completed (31% response rate) by neurosurgeons representing diverse sub-specialty practices. Respondents engaged in defensive medicine practices by ordering additional imaging studies (72%), laboratory tests (67%), referring patients to consultants (66%), or prescribing medications (40%). Malpractice premiums were considered a "major or extreme" burden by 64% of respondents which resulted in 45% of respondents eliminating high-risk procedures from their practice due to liability concerns. CONCLUSIONS: Concerns and perceptions about medical liability lead practitioners to practice defensive medicine. As a result, diagnostic testing, consultations and imaging studies are ordered to satisfy a perceived legal risk, resulting in higher healthcare expenditures. To minimize malpractice risk, some neurosurgeons have eliminated high-risk procedures. Left unchecked, concerns over medical liability will further defensive medicine practices, limit patient access to care, and increase the cost of healthcare delivery in the United States

Assessing socio-economic vulnerability to climate change impacts and environmental hazards in New South Wales and Queensland, Australia

This article systematically reviews and synthesises academic, peer-reviewed literature to assess the state of knowledge concerning socio-economic vulnerability to climate change impacts and environmental hazards in New South Wales and Queensland, Australia. It focuses upon empirical research that identifies socio-economic factors associated with vulnerable subpopulations. Using systematic review methods, 35 articles met the inclusion criteria. These articles are analysed according to their general characteristics, the methods used, and the factors reported to be associated with socio-economic vulnerability. This body of evidence reveals that (1) the majority of the knowledge about socio-economic vulnerability in New South Wales and Queensland has only recently emerged; (2) more knowledge has been published about Queensland; and (3) extreme temperature is the most researched environmental hazard. Despite increased research activity over time, the number of factors repeatedly demonstrated to influence socio-economic vulnerability is small. Age, gender, place of residence, and pre-existing illness were the most commonly reported factors, although the influence of these factors upon socio-economic vulnerability is complex. There is scope to extend the empirical research base across a broader range of climate-related hazards and to better link findings from the domains of climate change vulnerability and population health

Ocean processes at the Antarctic continental slope

The Antarctic continental shelves and slopes occupy relatively small areas, but, nevertheless, are important for global climate, biogeochemical cycling and ecosystem functioning. Processes of water mass transformation through sea ice formation/melting and ocean-atmosphere interaction are key to the formation of deep and bottom waters as well as determining the heat flux beneath ice shelves. Climate models, however, struggle to capture these physical processes and are unable to reproduce water mass properties of the region. Dynamics at the continental slope are key for correctly modelling climate, yet their small spatial scale presents challenges both for ocean modelling and for observational studies. Cross-slope exchange processes are also vital for the flux of nutrients such as iron from the continental shelf into the mixed layer of the Southern Ocean. An © 2014 The Authors