Complete traumatic laryngo-tracheal separation.

Laryngotracheal separation injuries are rare and potentially fatal. Immediate respiratory signs may include dysphonia, aphonia, hemoptysis, subcutaneous emphysema and a sucking wound. Patients with this injury usually die at the site of the trauma. The absolute life saving intervention for patients with laryngotracheal injury is airway control via routine intubation or emergency tracheostomy. We present an extremely rare case of complete laryngotracheal separation in a teenager driving a quad bike in a \u27clothes line\u27 type injury with chicken wire. This case highlights the need for prompt airway evaluation, radiological imaging required, surgical management and long term injury sequelae

Pentastomids of Wild Snakes in Australia

Pentastomids are endoparasites of the respiratory system of vertebrates, maturing primarily in carnivorous reptiles. Adult and larval pentastomids can cause severe pathology resulting in the death of their intermediate and definitive hosts. The study of pentastomids is a neglected field, impaired by risk of zoonoses, difficulties in species identification, and life cycle complexities. We surveyed wild snakes in the tropics of Australia to clarify which host species possess these parasites, and then sought to identify these pentastomids using a combination of morphological and molecular techniques. We detected pentastomid infections in 59% of the 81 snakes surveyed. The ubiquity of pentastomid infections in snakes of the Australian tropics sampled in this study is alarmingly high considering the often-adverse consequences of infection and the recognized zoonotic potential of these parasites. The pentastomids were of the genera Raillietiella and Waddycephalus and infected a range of host taxa, encompassing seven snake species from three snake families. All seven snake species represent new host records for pentastomids of the genera Raillietiella and/or Waddycephalus. The arboreal colubrid Dendrelaphis punctulatus and the terrestrial elapid Demansia vestigiata had particularly high infection prevalences (79% and 100% infected, respectively). Raillietiella orientalis infected 38% of the snakes surveyed, especially frog-eating species, implying a frog intermediate host for this parasite. Raillietiella orientalis was previously known only from Asian snakes and has invaded Australia via an unknown pathway. Our molecular data indicated that five species of Waddycephalus infect 28% of snakes in the surveyed area. Our morphological data indicate that features of pentastomid anatomy previously utilized to identify species of the genus Waddycephalus are unreliable for distinguishing species, highlighting the need for additional taxonomic work on this genus

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

Can measurements of the near-infrared solar spectral irradiance be reconciled? A new ground-based assessment between 4000-10000 cm-1

The near-infrared solar spectral irradiance (SSI) is of vital importance for understanding the Earth’s radiation budget, and in Earth observation applications. Differences between previously published solar spectra (including the commonly-used ATLAS3 spectrum) reach up to 10% at the low-wavenumber end of the 4000-10000 cm-1 (2.5 – 1 μm) spectral region. The implications for the atmospheric sciences are significant, since this spectral region contains 25% of the incoming total solar irradiance. This work details an updated analysis of the CAVIAR SSI, featuring additional analysis techniques and an updated uncertainty budget using a Monte Carlo method. We report good consistency with ATLAS3 in the 7000-10000 cm-1 region where there is confidence in these results due to agreement with other spectra, but ~7% lower in the 4000-7000 cm-1 region, in general agreement with several other analyses

A sub-field scale critical source area index for legacy phosphorus management using high resolution data

AbstractDiffuse phosphorus (P) mitigation in agricultural catchments should be targeted at critical source areas (CSAs) that consider source and transport factors. However, development of CSA identification needs to consider the mobilisation potential of legacy soil P sources at the field scale, and the control of (micro)topography on runoff generation and hydrological connectivity at the sub-field scale. To address these limitations, a ‘next generation’ sub-field scale CSA index is presented, which predicts the risk of dissolved P losses in runoff from legacy soil P. The GIS-based CSA Index integrates two factors; mobile soil P concentrations (water extractable P; WEP) and a hydrologically sensitive area (HSA) index. The HSA Index identifies runoff-generating-areas using high resolution LiDAR Digital Elevation Models (DEMs), a soil topographic index (STI) and information on flow sinks and effects on hydrological connectivity. The CSA Index was developed using four intensively monitored agricultural catchments (7.5–11km2) in Ireland with contrasting agri-environmental conditions. Field scale soil WEP concentrations were estimated using catchment and land use specific relationships with Morgan P concentrations. In-stream total reactive P (TRP) concentrations and discharge were measured sub-hourly at catchment outlet bankside analysers and gauging stations during winter closed periods for fertiliser spreading in 2009–14, and hydrograph/loadograph separation methods were used to estimate TRP loads and proportions from quickflow (surface runoff). A strong relationship between TRP concentrations in quickflow and soil WEP concentrations (r2=0.73) was used to predict dissolved P concentrations in runoff at the field scale, which were then multiplied by the HSA Index to generate sub-field scale CSA Index maps. Evaluation of the tool showed a very strong relationship between the total CSA Index value within the HSA and the total TRP load in quickflow (r2=0.86). Using a CSA Index threshold value of ≥0.5, the CSA approach identified 1.1–5.6% of catchment areas at highest risk of legacy soil P transfers, compared with 4.0–26.5% of catchment areas based on an existing approach that uses above agronomic optimum soil P status. The tool could be used to aid cost-effective targeting of sub-field scale mitigation measures and best management practices at delivery points of CSA pathways to reduce dissolved P losses from legacy P stores and support sustainable agricultural production

In the Driver’s Seat: Driving towards a career in cancer prevention research

https://openworks.mdanderson.org/sumexp23/1021/thumbnail.jp

Improving the identification of hydrologically sensitive areas using LiDAR DEMs for the delineation and mitigation of critical source areas of diffuse pollution

AbstractIdentifying critical source areas (CSAs) of diffuse pollution in agricultural catchments requires the accurate identification of hydrologically sensitive areas (HSAs) at highest propensity for generating surface runoff and transporting pollutants. A new GIS-based HSA Index is presented that improves the identification of HSAs at the sub-field scale by accounting for microtopographic controls. The Index is based on high resolution LiDAR data and a soil topographic index (STI) and also considers the hydrological disconnection of overland flow via topographic impediment from flow sinks. The HSA Index was applied to four intensive agricultural catchments (~7.5–12km2) with contrasting topography and soil types, and validated using rainfall-quickflow measurements during saturated winter storm events in 2009–2014. Total flow sink volume capacities ranged from 8298 to 59,584m3 and caused 8.5–24.2% of overland-flow-generating-areas and 16.8–33.4% of catchment areas to become hydrologically disconnected from the open drainage channel network. HSA maps identified ‘breakthrough points’ and ‘delivery points’ along surface runoff pathways as vulnerable points where diffuse pollutants could be transported between fields or delivered to the open drainage network, respectively. Using these as proposed locations for targeting mitigation measures such as riparian buffer strips reduced potential costs compared to blanket implementation within an example agri-environment scheme by 66% and 91% over 1 and 5years respectively, which included LiDAR DEM acquisition costs. The HSA Index can be used as a hydrologically realistic transport component within a fully evolved sub-field scale CSA model, and can also be used to guide the implementation of ‘treatment-train’ mitigation strategies concurrent with sustainable agricultural intensification

Global warming potentials and radiative efficiencies of halocarbons and related compounds: a comprehensive review

In the mid-1970s it was recognized that, as well as being substances that deplete stratospheric ozone, chlorofluorocarbons (CFCs) were strong greenhouse gases that could have substantial impacts on radiative forcing of climate change. Around a decade later, this group of radiatively active compounds was expanded to include a large number of replacements for ozone-depleting substances such as chlorocarbons, hydrochlorocarbons, hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), bromofluorocarbons, and bromochlorofluorocarbons. This paper systematically reviews the published literature concerning the radiative efficiencies (REs) of CFCs, bromofluorocarbons and bromochlorofluorocarbons (halons), HCFCs, HFCs, PFCs, SF6, NF3, and related halogen containing compounds. In addition we provide a comprehensive and self-consistent set of new calculations of REs and global warming potentials (GWPs) for these compounds, mostly employing atmospheric lifetimes taken from the available literature. We also present Global Temperature change Potentials (GTPs) for selected gases. Infrared absorption spectra used in the RE calculations were taken from databases and individual studies, and from experimental and ab initio computational studies. Evaluations of REs and GWPs are presented for more than 200 compounds. Our calculations yield REs significantly (> 5%) different from those in the Intergovernmental Panel on Climate Change Fourth Assessment Report (AR4) for 49 compounds. We present new RE values for more than 100 gases which were not included in AR4. A widely-used simple method to calculate REs and GWPs from absorption spectra and atmospheric lifetimes is assessed and updated. This is the most comprehensive review of the radiative efficiencies and global warming potentials of halogenated compounds performed to date