21 research outputs found
Use of UAV Imagery and Nutrient Analyses for Estimation of the Spatial and Temporal Contributions of Cattle Dung to Nutrient Cycling in Grazed Ecosystems
Nutrient inputs from cattle dung are crucial drivers of nutrient cycling processes in grazed ecosystems. These inputs are important both spatially and temporally and are affected by variables such as grazing strategy, water location, and the nutritional profile of forage being grazed. Past research has attempted to map dung deposition patterns in order to more accurately estimate nutrient input, but the large spatial extent of a typical pasture and the tedious nature of identifying and mapping individual dung pats has prohibited the development of a time- and cost-effective methodology. The first objective of this research was to develop and validate a new method for the detection and mapping of dung using an unmanned aerial vehicle (UAV) and multispectral imagery. The second objective was to quantify change over time in water-extractable organic carbon (WEOC), water-extractable phosphorus (WEP), and water-extractable nitrogen (WEN) in naturally-deposited dung that ranged from one to twenty-four days old. In addition, pre-analysis dung storage methods (refrigeration vs. freezing) were evaluated for their impact on laboratory analyses results. Multispectral images of pastures were classified using object-based image analysis. Post-classification accuracy assessment showed an overall accuracy of 82.6% and a Kappa coefficient of 0.71. Most classification errors were attributable to the misclassification of dung as vegetation, especially in spectrally heterogeneous areas such as trampled vegetation. Limitations to the implementation of this method for identifying and mapping cattle dung at large scales include the high degree of geospatial accuracy required for successful classification, and the need for additional method validation in diverse grassland environments. Dung WEN concentrations ranged from 1.20 g kg-1 at three days of age, to a low of 0.252 g kg-1 at 24 days. The highest WEOC values were in day-old dung, 19.25 g kg-1, and lowest in 14-day-old dung, 2.86 g kg-1. WEOC and WEN both followed exponential decay patterns of loss as dung aged. WEP was lowest at 1.28 g kg-1 (day one) and highest at 12 days (3.24 g kg-1), and dry matter and WEOC concentration were stronger determinants of WEP than age alone. Freezing consistently increased WEN and WEOC concentrations over fresh values, but WEP was inconsistent across ages in its response. This research provides new insight into dung nutrient dynamics and presents a novel method for studying them across large spatial and temporal scales.
Advisors: Martha Mamo and Jerry Volesk
Temporal changes in the nutrient content of cattle dung in the Nebraska Sandhills ecosystem
Dung excreted by cattle composes a significant portion of the nutrient inputs in a grazed ecosystem and can have wide-ranging effects on soil properties and vegetation. However, little research has been conducted on the nutrient dynamics of excreted dung in situ that has not been disturbed prior to field sampling. In this study, we analyzed 294 dung pats (1–24 days old) collected from a Nebraska Sandhills meadow to determine water-extractable organic carbon (WEOC), water-extractable nitrogen (WEN), water-extractable phosphorus (WEP), and percent dry matter (DM) changes over time. In addition, we investigated if sample handling - frozen storage – and the formation of surface crust during dung field drying affect dung nutrient concentrations. Dung WEOC and WEN both followed exponential decay curves of nutrient loss over time and were modeled as a function of age. In contrast, WEP was poorly correlated with age. The percent dry matter in conjunction with sample WEOC concentration were stronger determinants of WEP than age alone. Freezing samples prior to analysis increased WEOC (37–98%) and WEN (37–123%), but lowered WEP (0.8–65%) compared to the samples from the same dung pat analyzed fresh. The dry surface crusts of dung pats had higher WEOC (98–112%) and WEN (112%) compared to moist interiors (on average, 3 cm from surface). This research provides evidence that dung nutrient concentrations decreased by 73% (WEOC) and 76% (WEN) over 24 days and shows that frozen storage and subsequent thawing for analysis, as well as crust formation during field drying, can significantly affect dung nutrient concentrations and spatial partitioning of dung nutrients
Exposure to acute child psychiatry presentations for core psychiatrists
Declaration of interest -
R.C. sits on the College’s Emergency Care Taskforce, which is currently considering the value of out-of-hours training.
We are writing to draw attention to the lack of clarity provided by the Royal College of Psychiatrists regarding the role of the core trainee psychiatrist in assessing child and adolescent psychiatry patients out of hours. We believe it is important this issue is addressed as it confers broad implications for training, recruitment and service delivery. Crises of paediatric mental health tend to present out of hours. Ireland’s 4th annual child and adolescent mental health service report details ‘striking patterns in the number of [self-harm] presentations seen’: 51% of presentations were in the 8-hour period of 7pm to 3am.1 This finding appears typical for paediatric psychiatry liaison services around the UK.
It is well known that in some trusts core trainees are excluded from child and adolescent mental health services (CAMHS)-led out-of-hours care pathways. This situation seems particularly unsatisfactory given that placements in developmental psychiatry are no longer obligatory. By failing to adequately furnish our future adult psychiatrists with skills in child and adolescent mental health, we are reinforcing a culture whereby young people are potentially falling through the care gap between CAMHS and adult mental health services.2,3 Indeed, this very issue is highlighted in a joint paper from the inter-faculty group of the child and adolescent psychiatry and the general and community psychiatry faculties which presents recommendations for the provision of psychiatric services to adolescents and young adults.4 Furthermore, by restricting the level of exposure to child psychiatry, we are doing little to encourage core trainees to perceive the specialty as a future career option.
As well as having an impact on the quality of training, the issue has far-reaching implications for patient care. The current lack of clarity fosters an atmosphere of uncertainty as situations arise where no one knows who holds responsibility to clerk a young person on arrival, thereby leading to potential delays in the patient being seen. Emergency department delays are a source of great concern to acute care trusts and create negative attitudes to psychiatric services in general. If we cannot manage to work in a safe and effective way, we are further contributing to the hostility not only towards our specialty but also to our patients, who are at their most vulnerable.
It is therefore our view that there should be an explicit expectation for core trainees to have exposure to the full range of acute psychiatric presentations, including child and adolescent patients, out of hours. It is of course essential that this experience would be supported by robust and accessible supervision structures in the form of a second on-call specialty trainee or consultant child psychiatrist. Although we recognise that the College is unable to tell trusts how to deliver their out-of-hours services, it would be helpful if the core psychiatry curriculum contained more robust guidance as to the role of the core trainee in assessing child and adolescent psychiatry cases out of hours. Such a move would help to create clarity as well as holding local education providers to account
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Familiarity with a female does not affect a male's courtship intensity in garter snakes Thamnophis sirtalis parietalis
In many animal species, males direct more intense courtship towards females they have not previously encountered,
than towards females with which they have previously mated. To test the factors responsible for this "Coolidge Effect", we need
studies on a wide range of taxa – including those with mating systems in which we would not expect (based on current theory)
that such an effect would be evident. The Coolidge Effect has been documented in several lizard species, but has not been looked
for (and would not be expected) in snakes. We conducted experimental trials with red-sided garter snakes Thamnophis sirtalis parietalis
at a communal den in Manitoba, to see whether previous exposure to a female (either courting, or courting plus mating)
modified male mate choice or courtship intensity. In keeping with prediction from theory (but contrary to an early anecdotal report),
male garter snakes did not modify their courtship behaviour based upon their familiarity (or lack thereof) with a specific
female. At least in large courting aggregations, male snakes may maximize their fitness by basing mate-choice upon immediate
attributes of the female (body size, condition, mated status) and the intensity of competition (numbers and sizes of rival males)
rather than information derived from previous sexual encounters [Current Zoology 58 (6): 805–811, 2012].Keywords: Coolidge Effect, Reptile, Mating system, Mate choice, Courtshi
The Claiborne Corridor: Mid-Anchor Business Profiles 2014
The New Orleans Business Alliance and the Mayor’s Office of Place-based Planning are working closely with the Livable Claiborne Communities Initiatives to encourage the maintenance, development and expansion of businesses throughout the city with a special focus on the LCC. The reports that follow identify mid-anchor businesses that have contributed to the social and economic wealth of the City of New Orleans for, in some cases, hundreds of years. The hope is that these businesses will be supported through new City initiatives to improve façades, marketability and expand employment opportunities. The research and resources provided by the students at UNO will support these efforts and hopefully contribute to the reinvestment and redevelopment of the new New Orleans
The Claiborne Corridor: Mid-Anchor Business Profiles 2014
The New Orleans Business Alliance and the Mayor’s Office of Place-based Planning are working closely with the Livable Claiborne Communities Initiatives to encourage the maintenance, development and expansion of businesses throughout the city with a special focus on the LCC. The reports that follow identify mid-anchor businesses that have contributed to the social and economic wealth of the City of New Orleans for, in some cases, hundreds of years. The hope is that these businesses will be supported through new City initiatives to improve façades, marketability and expand employment opportunities. The research and resources provided by the students at UNO will support these efforts and hopefully contribute to the reinvestment and redevelopment of the new New Orleans
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Global warming and ocean stratification : a potential result of large extraterrestrial impacts
We acknowledge the support of resources provided by UK National Centre for Atmospheric Science (NCAS), the High Performance Computing Cluster supported by the Research and Specialist Computing Support service at the University of East Anglia, UK Natural Environment Research Council (NERC), grants "CPE" (NE/K014757/1), and "Paleopolar" (NE/I005722/1). Data can be obtained from MJ on request. ACM acknowledges support from an AXA Postdoctoral Fellowship and the ERC ACCI grant Project No 267760, and NERC grant NE/M018199/1.The prevailing paradigm for the climatic effects of large asteroid or comet impacts is a reduction in sunlight and significant short-term cooling caused by atmospheric aerosol loading. Here we show, using global climate model experiments, that the large increases in stratospheric water vapor that can occur upon impact with the ocean cause radiative forcings of over +20 W m−2 in the case of 10 km sized bolides. The result of such a positive forcing is rapid climatic warming, increased upper ocean stratification, and potentially disruption of upper ocean ecosystems. Since two thirds of the world's surface is ocean, we suggest that some bolide impacts may actually warm climate overall. For impacts producing both stratospheric water vapor and aerosol loading, radiative forcing by water vapor can reduce or even cancel out aerosol-induced cooling, potentially causing 1–2 decades of increased temperatures in both the upper ocean and on the land surface. Such a response, which depends on the ratio of aerosol to water vapor radiative forcing, is distinct from many previous scenarios for the climatic effects of large bolide impacts, which mostly account for cooling from aerosol loading. Finally, we discuss how water vapor forcing from bolide impacts may have contributed to two well-known phenomena: extinction across the Cretaceous/Paleogene boundary and the deglaciation of the Neoproterozoic snowball Earth.Publisher PDFPeer reviewe
Use of UAV Imagery and Nutrient Analyses for Estimation of the Spatial and Temporal Contributions of Cattle Dung to Nutrient Cycling in Grazed Ecosystems
Nutrient inputs from cattle dung are crucial drivers of nutrient cycling processes in grazed ecosystems. These inputs are important both spatially and temporally and are affected by variables such as grazing strategy, water location, and the nutritional profile of forage being grazed. Past research has attempted to map dung deposition patterns in order to more accurately estimate nutrient input, but the large spatial extent of a typical pasture and the tedious nature of identifying and mapping individual dung pats has prohibited the development of a time- and cost-effective methodology. The first objective of this research was to develop and validate a new method for the detection and mapping of dung using an unmanned aerial vehicle (UAV) and multispectral imagery. The second objective was to quantify change over time in water-extractable organic carbon (WEOC), water-extractable phosphorus (WEP), and water-extractable nitrogen (WEN) in naturally-deposited dung that ranged from one to twenty-four days old. In addition, pre-analysis dung storage methods (refrigeration vs. freezing) were evaluated for their impact on laboratory analyses results. Multispectral images of pastures were classified using object-based image analysis. Post-classification accuracy assessment showed an overall accuracy of 82.6% and a Kappa coefficient of 0.71. Most classification errors were attributable to the misclassification of dung as vegetation, especially in spectrally heterogeneous areas such as trampled vegetation. Limitations to the implementation of this method for identifying and mapping cattle dung at large scales include the high degree of geospatial accuracy required for successful classification, and the need for additional method validation in diverse grassland environments. Dung WEN concentrations ranged from 1.20 g kg-1 at three days of age, to a low of 0.252 g kg-1 at 24 days. The highest WEOC values were in day-old dung, 19.25 g kg-1, and lowest in 14-day-old dung, 2.86 g kg-1. WEOC and WEN both followed exponential decay patterns of loss as dung aged. WEP was lowest at 1.28 g kg-1 (day one) and highest at 12 days (3.24 g kg-1), and dry matter and WEOC concentration were stronger determinants of WEP than age alone. Freezing consistently increased WEN and WEOC concentrations over fresh values, but WEP was inconsistent across ages in its response. This research provides new insight into dung nutrient dynamics and presents a novel method for studying them across large spatial and temporal scales.
Advisors: Martha Mamo and Jerry Volesk