Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 13 de 13
1.
Palliat Med ; 37(6): 875-883, 2023 06.
Article En | MEDLINE | ID: mdl-37092529

BACKGROUND: The need for home-based palliative care is accelerating internationally. At the same time, health systems face increased complexity, funding constraints and global shortages in the healthcare workforce. As such, ambulance services are increasingly tasked with providing palliative care. Where paramedics with additional training in palliative care have been integrated into models of care, evaluations have been largely positive. Studies of patient and family carer experiences of paramedic involvement, however, are limited. AIM: To explore patient and family caregiver experiences of paramedics' contribution to palliative care at home. DESIGN: Qualitative interview study. We analysed data within a social constructionist epistemology using reflexive thematic analysis. SETTING/PARTICIPANTS: Participants receiving specialist palliative care in the community of a metropolitan city of Australia who requested an ambulance between January and August 2018, inclusive. RESULTS: Participants considered paramedics with expertise and experience in palliative care as an extension of the specialist community palliative care team and held them in high regard. Participants highlighted the importance of: critical palliative care at home and a timely, responsive approach; person-centred paramedics; as well as safety and security. CONCLUSION: Patients and carers feel safe and secure when they know that highly responsive skilled professional support is available when an unexpected problem or sudden change arises, especially out-of-hours, and that support is delivered in an empathic and person-centred manner.


Caregivers , Hospice and Palliative Care Nursing , Humans , Palliative Care , Ambulances , Qualitative Research
2.
Palliat Med ; 36(8): 1228-1241, 2022 09.
Article En | MEDLINE | ID: mdl-35941755

BACKGROUND: Palliative care is an emerging scope of practice for paramedicine. The COVID-19 pandemic has highlighted the opportunity for emergency settings to deliver palliative and end-of-life care to patients wishing to avoid intensive life-sustaining treatment. However, a gap remains in understanding the scope and limitations of current ambulance services' approach to palliative and end-of-life care. AIM: To examine the quality and content of existing Australian palliative paramedicine guidelines with a sample of guidelines from comparable Anglo-American ambulance services. DESIGN: We appraised guideline quality using the AGREE II instrument and employed a collaborative qualitative approach to analyse the content of the guidelines. DATA SOURCES: Eight palliative care ambulance service clinical practice guidelines (five Australian; one New Zealand; one Canadian; one United Kingdom). RESULTS: None of the guidelines were recommended by both appraisers for use based on the outcomes of all AGREE II evaluations. Scaled individual domain percentage scores varied across the guidelines: scope and purpose (8%-92%), stakeholder involvement (14%-53%), rigour of development (0%-20%), clarity of presentation (39%-92%), applicability (2%-38%) and editorial independence (0%-38%). Six themes were developed from the content analysis: (1) audience and approach; (2) communication is key; (3) assessing and managing symptoms; (4) looking beyond pharmaceuticals; (5) seeking support; and (6) care after death. CONCLUSIONS: It is important that ambulance services' palliative and end-of-life care guidelines are evidence-based and fit for purpose. Future research should explore the experiences and perspectives of key palliative paramedicine stakeholders. Future guidelines should consider emerging evidence and be methodologically guided by AGREE II criteria.


COVID-19 , Palliative Care , Australia , Canada , Humans , Pandemics
3.
Bull Math Biol ; 81(4): 1122-1142, 2019 04.
Article En | MEDLINE | ID: mdl-30569326

In addition to their unusually long life cycle, periodical cicadas, Magicicada spp., provide an exceptional example of spatially synchronized life stage phenology in nature. Within regions ("broods") spanning 50,000-500,000 km[Formula: see text], adults emerge synchronously every 13 or 17 years. While satiation of avian predators is believed to be a key component of the ability of these populations to reach high densities, it is not clear why populations at a single location remain entirely synchronized. We develop nonlinear Leslie matrix-type models of periodical cicadas that include predation-driven Allee effects and competition in addition to reproduction and survival. Using both analytical and numerical techniques, we demonstrate the observed presence of a single brood critically depends on the relationship between fecundity, competition and predation. We analyze the single-brood, two-brood and all-brood equilibria in the large life span limit using a tractable hybrid approximation to the Leslie matrix model with continuous time competition in between discrete reproduction events. Within the hybrid model, we prove that the single-brood equilibrium is the only stable equilibrium. This hybrid model allows us to quantitatively predict population sizes and the range of parameters for which the stable single-brood and unstable two-brood and all-brood equilibria exist. The hybrid model yields a good approximation to the numerical results for the Leslie matrix model for the biologically relevant case of a 17-year life span.


Hemiptera/growth & development , Models, Biological , Animals , Computer Simulation , Food Chain , Hemiptera/physiology , Life Cycle Stages , Mathematical Concepts , Nonlinear Dynamics , Periodicity , Population Dynamics
4.
Am Nat ; 192(4): 479-489, 2018 10.
Article En | MEDLINE | ID: mdl-30205023

Periodical cicadas are enigmatic organisms: broods spanning large spatial ranges consist of developmentally synchronized populations of 3-4 sympatric species that emerge as adults every 13 or 17 years. Only one brood typically occupies any single location, with well-defined boundaries separating distinct broods. The cause of such synchronous development remains uncertain, but it is known that synchronous emergence of large numbers of adults in a single year satiates predators, allowing a substantial fraction of emerging adults to survive long enough to reproduce. Competition among nymphs feeding on tree roots almost certainly plays a role in limiting populations. However, due to the difficulty of working with such long-lived subterranean life stages, the mechanisms governing competition in periodical cicadas have not been identified. A second process that may affect synchrony among periodical cicadas is their ability to delay or accelerate their emergence as adults by 1 year and accelerate it by 4 years (stragglers). We develop a nonlinear Leslie matrix-type model that describes cicada dynamics accounting for predation, competition, and stragglers. Using numerical simulations, we identify conditions that generate dynamics in which a single brood occupies a given geographical location. Our results show that while stragglers have the potential for introducing multiple sympatric broods, the interaction of interbrood competition with predation-driven Allee effects creates a system resistant to such invasions, and populations maintain developmental synchrony.


Animal Distribution , Hemiptera/growth & development , Periodicity , Animals , Homing Behavior , Models, Theoretical , Nymph , Population Dynamics , Predatory Behavior , Time Factors
5.
Proc Natl Acad Sci U S A ; 115(8): 1825-1830, 2018 02 20.
Article En | MEDLINE | ID: mdl-29437956

Spatial patterning of periodic dynamics is a dramatic and ubiquitous ecological phenomenon arising in systems ranging from diseases to plants to mammals. The degree to which spatial correlations in cyclic dynamics are the result of endogenous factors related to local dynamics vs. exogenous forcing has been one of the central questions in ecology for nearly a century. With the goal of obtaining a robust explanation for correlations over space and time in dynamics that would apply to many systems, we base our analysis on the Ising model of statistical physics, which provides a fundamental mechanism of spatial patterning. We show, using 5 y of data on over 6,500 trees in a pistachio orchard, that annual nut production, in different years, exhibits both large-scale synchrony and self-similar, power-law decaying correlations consistent with the Ising model near criticality. Our approach demonstrates the possibility that short-range interactions can lead to long-range correlations over space and time of cyclic dynamics even in the presence of large environmental variability. We propose that root grafting could be the common mechanism leading to positive short-range interactions that explains the ubiquity of masting, correlated seed production over space through time, by trees.


Agriculture/methods , Models, Biological , Pistacia/physiology , Plant Roots , Seeds
6.
Ambio ; 46(1): 4-17, 2017 Feb.
Article En | MEDLINE | ID: mdl-27405653

There is an ongoing debate on what constitutes sustainable intensification of agriculture (SIA). In this paper, we propose that a paradigm for sustainable intensification can be defined and translated into an operational framework for agricultural development. We argue that this paradigm must now be defined-at all scales-in the context of rapidly rising global environmental changes in the Anthropocene, while focusing on eradicating poverty and hunger and contributing to human wellbeing. The criteria and approach we propose, for a paradigm shift towards sustainable intensification of agriculture, integrates the dual and interdependent goals of using sustainable practices to meet rising human needs while contributing to resilience and sustainability of landscapes, the biosphere, and the Earth system. Both of these, in turn, are required to sustain the future viability of agriculture. This paradigm shift aims at repositioning world agriculture from its current role as the world's single largest driver of global environmental change, to becoming a key contributor of a global transition to a sustainable world within a safe operating space on Earth.


Agriculture , Conservation of Natural Resources , Ecosystem , Food Supply/standards , Agricultural Irrigation/methods , Agricultural Irrigation/trends , Agriculture/methods , Agriculture/trends , China , Conservation of Natural Resources/methods , Conservation of Natural Resources/trends , Humans , Social Environment
7.
Nat Commun ; 6: 6664, 2015 Apr 08.
Article En | MEDLINE | ID: mdl-25851364

Understanding the synchronization of oscillations across space is fundamentally important to many scientific disciplines. In ecology, long-range synchronization of oscillations in spatial populations may elevate extinction risk and signal an impending catastrophe. The prevailing assumption is that synchronization on distances longer than the dispersal scale can only be due to environmental correlation (the Moran effect). In contrast, we show how long-range synchronization can emerge over distances much longer than the length scales of either dispersal or environmental correlation. In particular, we demonstrate that the transition from incoherence to long-range synchronization of two-cycle oscillations in noisy spatial population models is described by the Ising universality class of statistical physics. This result shows, in contrast to all previous work, how the Ising critical transition can emerge directly from the dynamics of ecological populations.


Ecology , Models, Theoretical , Population Dynamics , Demography , Logistic Models
8.
Proc Biol Sci ; 280(1763): 20130523, 2013 Jul 22.
Article En | MEDLINE | ID: mdl-23720545

The maximum per capita rate of population growth, r, is a central measure of population biology. However, researchers can only directly calculate r when adequate time series, life tables and similar datasets are available. We instead view r as an evolvable, synthetic life-history trait and use comparative phylogenetic approaches to predict r for poorly known species. Combining molecular phylogenies, life-history trait data and stochastic macroevolutionary models, we predicted r for mammals of the Caniformia and Cervidae. Cross-validation analyses demonstrated that, even with sparse life-history data, comparative methods estimated r well and outperformed models based on body mass. Values of r predicted via comparative methods were in strong rank agreement with observed values and reduced mean prediction errors by approximately 68 per cent compared with two null models. We demonstrate the utility of our method by estimating r for 102 extant species in these mammal groups with unknown life-history traits.


Canidae/genetics , Carnivora/genetics , Models, Biological , Phylogeny , Survival Rate , Animals , Biological Evolution , Life Cycle Stages , Mammals/classification , Mammals/genetics , Population Growth , Predictive Value of Tests
9.
Phys Rev Lett ; 107(22): 228101, 2011 Nov 25.
Article En | MEDLINE | ID: mdl-22182042

For a population with any given number of types, we construct a new multivariate Moran process with frequency-dependent selection and establish, analytically, a correspondence to equilibrium Lotka-Volterra phenomenology. This correspondence, on the one hand, allows us to infer the phenomenology of our Moran process based on much simpler Lokta-Volterra phenomenology and, on the other, allows us to study Lotka-Volterra dynamics within the finite populations of a Moran process. Applications to community ecology, population genetics, and evolutionary game theory are discussed.


Physical Phenomena , Multivariate Analysis , Stochastic Processes
10.
J Theor Biol ; 273(1): 1-14, 2011 Mar 21.
Article En | MEDLINE | ID: mdl-21182847

We introduce the first analytical model of asymmetric community dynamics to yield Hubbell's neutral theory in the limit of functional equivalence among all species. Our focus centers on an asymmetric extension of Hubbell's local community dynamics, while an analogous extension of Hubbell's metacommunity dynamics is deferred to an appendix. We find that mass-effects may facilitate coexistence in asymmetric local communities and generate unimodal species abundance distributions indistinguishable from those of symmetric communities. Multiple modes, however, only arise from asymmetric processes and provide a strong indication of non-neutral dynamics. Although the exact stationary distributions of fully asymmetric communities must be calculated numerically, we derive approximate sampling distributions for the general case and for nearly neutral communities where symmetry is broken by a single species distinct from all others in ecological fitness and dispersal ability. In the latter case, our approximate distributions are fully normalized, and novel asymptotic expansions of the required hypergeometric functions are provided to make evaluations tractable for large communities. Employing these results in a bayesian analysis may provide a novel statistical test to assess the consistency of species abundance data with the neutral hypothesis.


Ecosystem , Models, Biological , Sampling Studies , Species Specificity
11.
Environ Geochem Health ; 31(1): 71-9, 2009 Feb.
Article En | MEDLINE | ID: mdl-18311588

Research undertaken over the last 40 years has identified the irrefutable relationship between the long-term consumption of cadmium (Cd)-contaminated rice and human Cd disease. In order to protect public health and livelihood security, the ability to accurately and rapidly determine spatial Cd contamination is of high priority. During 2001-2004, a General Linear Regression Model Irr-Cad was developed to predict the spatial distribution of soil Cd in a Cd/Zn co-contaminated cascading irrigated rice-based system in Mae Sot District, Tak Province, Thailand (Longitude E 98 degrees 59'-E 98 degrees 63' and Latitude N 16 degrees 67'-16 degrees 66'). The results indicate that Irr-Cad accounted for 98% of the variance in mean Field Order total soil Cd. Preliminary validation indicated that Irr-Cad 'predicted' mean Field Order total soil Cd, was significantly (p < 0.001) correlated (R (2) = 0.92) with 'observed' mean Field Order total soil Cd values. Field Order is determined by a given field's proximity to primary outlets from in-field irrigation channels and subsequent inter-field irrigation flows. This in turn determines Field Order in Irrigation Sequence (Field Order(IS)). Mean Field Order total soil Cd represents the mean total soil Cd (aqua regia-digested) for a given Field Order(IS). In 2004-2005, Irr-Cad was utilized to evaluate the spatial distribution of total soil Cd in a 'high-risk' area of Mae Sot District. Secondary validation on six randomly selected field groups verified that Irr-Cad predicted mean Field Order total soil Cd and was significantly (p < 0.001) correlated with the observed mean Field Order total soil Cd with R (2) values ranging from 0.89 to 0.97. The practical applicability of Irr-Cad is in its minimal input requirements, namely the classification of fields in terms of Field Order(IS), strategic sampling of all primary fields and laboratory based determination of total soil Cd (T-Cd(P)) and the use of a weighed coefficient for Cd (Coeff(W)). The use of primary fields as the basis for Irr-Cad is also an important practical consideration due to their inherent ease of identification and vital role in the classification of fields in terms of Field Order(IS). The inclusion of mean field order soil pH (1:5(water)) to the Irr-Cad model accounted for over 79% of the variation in mean Field Order bio-available (DTPA (diethylenetriaminepentaacetic acid)-extractable) soil Cd. Rice is the staple food of countries of the Greater Mekong Sub-region (includes Vietnam, Myanmar, Lao PDR, Thailand and Yunnan Province, China). These countries also have actively and historically mined Zn, Pb, and Cu deposits where Cd is likely to be a potential hazard if un-controlled discharge/runoff enters areas of rice cultivation. As such, it is envisaged that the Irr-Cad model could be applied for Cd hazard assessment and effectively form the basis of intervention options and policy decisions to protect public health, livelihoods, and export security.


Cadmium/analysis , Cadmium/toxicity , Environmental Monitoring , Hazardous Substances/analysis , Hazardous Substances/toxicity , Soil Pollutants/analysis , Water Pollutants, Chemical/analysis , Agriculture , China , Food Contamination/analysis , Linear Models , Oryza/growth & development , Oryza/metabolism , Public Health , Reproducibility of Results , Risk Assessment , Soil Pollutants/toxicity , Thailand , Vietnam , Water Pollutants, Chemical/toxicity
12.
J Environ Qual ; 35(6): 2293-301, 2006.
Article En | MEDLINE | ID: mdl-17071900

Acid waste bentonite is a byproduct from vegetable oil bleaching that is acidic (pH < 3.0) and hydrophobic. These materials are currently disposed of in landfills and could potentially have a negative impact on the effective function of microbes that are intolerant of acidic conditions. A study was undertaken using three different sources of acid waste bentonites, namely soybean oil bentonite (SB), palm oil bentonite (PB), and rice bran oil bentonite (RB). These materials were co-composted with rice husk, rice husk ash, and chicken litter to eliminate their acid reactivity and hydrophobic nature. The organic carbon (OC) content, pH, exchangeable cations, and cation exchange capacity (CEC) of the acid-activated bentonites increased significantly after the co-composting phase. In addition, the hydrophobic nature of these materials as measured using the water drop penetration time (WDPT) decreased from >10 800 s to 16 to 80 s after composting. Furthermore, these composted materials showed positive impacts on soil physical attributes including specific surface area, bulk density, and available water content for crop growth. Highly significant increases in maize biomass (Zea mays L.) production over two consecutive cropping cycles was observed in treatments receiving co-composted bentonite. The study clearly demonstrates the potential for converting an environmentally hazardous material into a high-quality soil conditioner using readily available agricultural byproducts. It is envisaged that the application of these composted acid waste bentonites to degraded soils will increase productivity and on-farm income, thus contributing toward food security and poverty alleviation.


Bentonite/toxicity , Crops, Agricultural/drug effects , Environmental Monitoring , Refuse Disposal , Soil Pollutants/toxicity , Bentonite/chemistry , Biomass , Carbon/chemistry , Carbon/metabolism , Chromatography, Ion Exchange , Crops, Agricultural/growth & development , Humidity , Hydrogen-Ion Concentration , Organic Chemicals/chemistry , Organic Chemicals/metabolism , Soil Pollutants/chemistry , Time Factors
13.
J Bone Joint Surg Am ; 87(3): 521-9, 2005 Mar.
Article En | MEDLINE | ID: mdl-15741617

BACKGROUND: The extended trochanteric osteotomy was introduced as a safe and effective exposure technique for revision hip surgery; however, intraoperative iatrogenic femoral fractures have been reported. This study examined the effects of the extended trochanteric osteotomy on the torsional strength of the femur with use of cadaver bones. We hypothesized that repair of the osteotomy fragment would restore the torsional strength to that of an intact femur and that an osteotomized femur containing a well-fixed stem would have the same torsional strength as an intact femur with a stem. METHODS: Fifty-eight cadaveric human femora were divided into five groups, according to the repair technique, to examine the effects of the extended trochanteric osteotomy: intact, osteotomy, repaired osteotomy, implant, and implant-repaired osteotomy. Osteotomy fragments were reattached with use of three double-looped 18-gauge wires. A femoral stem was cemented into the last two groups. Specimens were tested mechanically in rotation until failure. Rotational properties were compared with one-way analysis of variance followed by post hoc pairwise comparisons. Linear regression analysis was performed for bone mineral density and torsional strength. RESULTS: Torque to failure was reduced by 73% for the specimens in the osteotomy group compared with the intact group (p < 0.0001). Repair of the osteotomy did not improve torque to failure (p > 0.99). Femora in the implant-repaired osteotomy group displayed significantly improved torque-to-failure values compared with the specimens in the osteotomy and repaired osteotomy groups (p < 0.0001). However, the strength of the femora in the implant-repaired osteotomy group remained significantly less than that of the specimens in the implant group (p < 0.007). A significant linear relationship was observed between bone mineral density and torque to failure for femora in the intact (p < 0.006), osteotomy (p < 0.002), and repaired osteotomy (p < 0.001) groups. CONCLUSIONS: The extended trochanteric osteotomy reduces torsional strength by 73% even when the osteotomy fragment is repaired. Bone mineral density directly affects absolute femoral strength in this model.


Femur/surgery , Osteotomy/methods , Adult , Aged , Aged, 80 and over , Biomechanical Phenomena , Bone Density , Cadaver , Femur/physiology , Humans , Middle Aged , Regression Analysis , Torque , Torsion Abnormality
...