346 research outputs found
Development of a radiographic technique for porcine head ballistic research
Introduction: The porcine model shows structural features comparable to that of humans and are routinely used within research, due to the ethical, legal, and practical use of post-mortem human samples. Methods for obtaining high quality and comparable reference data using standardised acquisition protocols are essential.
Methods: The decapitated heads of three adult white sows were subjected to radiographic imaging before and after cranial trauma (9 mm, Heckler and Koch MP5). Digital radiographs were generated using a Siemens MULTIX TOP system with an Agfa digital detector, with foam blocks and sandbags as ancillary equipment. An iterative approach was adopted by the authors to generate reproducible radiographic views from two perpendicular angles. Specimens were kept at 5 °C and wrapped in polythene bags to reduce the impact of putrefaction.
Results: Standardised head radiography technique was developed for superior-inferior and lateral views demonstrating porcine anatomy. Key parameters included: automatic exposure control for tube current (∼4 mAs), tube voltage of 73 kVp, 100 cm source to image receptor distance, and an anti-scatter grid. Slight variances in specimen morphology, developmental status, and soft tissue changes did not affect imaging outcomes.
Conclusion: The technique and positioning proposed in this study allows for the acquisition of high quality and reproducible radiographic images for comparable ballistic research datasets. Specimen positioning and centring of the primary beam may be applied across porcine breeds, although individual radiographic parameters may differ according to equipment specifications and specimen size.
Implications for practice: Development of a reproducible radiographic technique of porcine heads in forensic and veterinary research
Electrical resistivity tomography array comparisons to detect cleared-wall foundations in brownfield sites
Electrical resistivity surveys are commonly used to detect and characterise near-surface buried objects in commercial developments of brownfield sites. 2D ERT profiles arrays predominate in such surveys due to their relatively rapid deployment, good penetration depths and fast data collection rates. However, there is a need to test the optimum array types in such surveys. A scaled-model was used to simulate a large cleared-building wall foundation at a test facility, before multiple 2D ERT profiles were acquired using different array configurations. Results were used to generate 2D resistivity models using both least-square smoothness-constraint and robust inversion. 2D profile array comparisons showed that the Wenner and dipole-dipole arrays were the best in detecting the cleared-wall foundation, although dipole-dipole arrays better delineated the top of the wall foundation. This study suggests that both Wenner and dipole-dipole array configurations should be utilised to detect buried wall foundations for 2D resistivity surveys
An interstellar precursor mission
A mission out of the planetary system, with launch about the year 2000, could provide valuable scientific data as well as test some of the technology for a later mission to another star. Primary scientific objectives for the precursor mission concern characteristics of the heliopause, the interstellar medium, stellar distances (by parallax measurements), low energy cosmic rays, interplanetary gas distribution, and mass of the solar system. Secondary objectives include investigation of Pluto. Candidate science instruments are suggested. Individual spacecraft systems for the mission were considered, technology requirements and problem areas noted, and a number of recommendations made for technology study and advanced development. The most critical technology needs include attainment of 50-yr spacecraft lifetime and development of a long-life NEP system
Field Analysis of Microbial Contamination Using Three Molecular Methods in Parallel
Advanced technologies with the capability of detecting microbial contamination remain an integral tool for the next stage of space agency proposed exploration missions. To maintain a clean, operational spacecraft environment with minimal potential for forward contamination, such technology is a necessity, particularly, the ability to analyze samples near the point of collection and in real-time both for conducting biological scientific experiments and for performing routine monitoring operations. Multiple molecular methods for detecting microbial contamination are available, but many are either too large or not validated for use on spacecraft. Two methods, the adenosine- triphosphate (ATP) and Limulus Amebocyte Lysate (LAL) assays have been approved by the NASA Planetary Protection Office for the assessment of microbial contamination on spacecraft surfaces. We present the first parallel field analysis of microbial contamination pre- and post-cleaning using these two methods as well as universal primer-based polymerase chain reaction (PCR)
Systematic review of multi-symptom conditions in Gulf War veterans
Background. GulfWar veterans have a number of health complaints. We therefore decided to carry out a systematic review to identify and summarize the findings from studies that have assessed multi-symptom conditions in Gulf War veterans and in an unexposed comparison group.
Method. Studies published between January 1990 and May 2004 were identified by searching a large number of electronic databases. Reference lists and websites were also searched and key researchers were contacted. Studies were included if they compared the prevalence of chronic fatigue syndrome, multiple chemical sensitivity, CDC-defined chronic multi-symptom illness, fibromyalgia,or symptoms of either fatigue or numbness and tingling in Gulf War veterans and non-Gulf veterans. A total of 2401 abstracts were independently reviewed by two authors.
Results. Twenty-three publications fulfilled the inclusion criteria. Gulf deployment was most strongly associated with chronic fatigue syndrome (OR 3.8, 95% CI 2.2–6.7). Gulf War veterans were also approximately three and a half times more likely than non-Gulf veterans to report multiple chemical sensitivity or chronic multi-symptom illness as defined by CDC. The methodological quality of the studies varied but the later and larger studies were of a high methodological standard with robust sampling strategies, adequate response rates and good adjustment for confounders.
Conclusions. The results support the hypothesis that deployment to the Gulf War is associated with greater reporting of multi-symptom conditions
Geophysical monitoring of simulated homicide burials for forensic investigations
Finding hidden bodies, believed to have been murdered and buried, is problematic, expensive in terms of human resource and currently has low success rates for law enforcement agencies. Here we present, for the first time, ten years of multidisciplinary geophysical monitoring of simulated clandestine graves using animal analogues. Results will provide forensic search teams with crucial information on optimal detection techniques, equipment configuration and datasets for comparison to active and unsolved cold case searches. Electrical Resistivity (ER) surveys showed a naked burial produced large, low resistivity anomalies for up to four years, but then the body became difficult to image. A wrapped burial had consistent small, high-resistivity anomalies for four years, then large high-resistivity anomalies until the survey period end. Ground Penetrating Radar (GPR) 110–900 MHz surveys showed the wrapped burial could be detected throughout. 225 MHz GPR data was optimal, but the naked burial was poorly imaged after six years. Results suggested conducting both ER and GPR surveys if the burial style was unknown when searching for interred remains. Surveys in winter and spring produced the best datasets, and, as post-burial time increases, surveying in these seasons became increasingly important. This multidisciplinary study provides critical new insights for law enforcement and families of the disappeared worldwide
Implementation of a Referral Pathway and Peri-operative Checklist for Delivery of Surgical Tracheostomy Provision during the COVID-19 Pandemic
Association Between Neighborhood-Level Deprivation and Disability in a Community Sample of People With Diabetes
Pain in veterans of the Gulf War of 1991: a systematic review
BACKGROUND: Veterans of the Persian Gulf War of 1991 have reported a range of adverse health symptoms. This systematic review aims to identify all studies that have compared the prevalence of symptoms of pain in veterans of the Gulf War to that in a non-Gulf military comparison group, and to determine whether Gulf War veterans are at increased risk of reporting pain. METHODS: Studies published between January 1990 and May 2004 were identified by searching a large number of electronic databases. Reference lists and websites were also searched and key researchers were contacted. Studies were included if they reported the prevalence of any symptom or condition that included the word "pain" in Gulf War veterans and in a comparison group of non-Gulf veterans. 2401 abstracts were independently reviewed by two authors. RESULTS: Twenty studies fulfilled the inclusion criteria. Five main sites of pain were identified (muscle, joint, chest/heart, back and abdominal pain) and separate meta-analyses were performed to summarise the results related to each site. A greater proportion of Gulf veterans reported symptoms at each site of pain when compared to a non-Gulf military group. Gulf deployment was most strongly associated with abdominal pain, with Gulf veterans being more than three times more likely to report such pain than a comparison group (OR 3.23; 95%CI 2.31–4.51). Statistical heterogeneity between study estimates was significant, probably due to variation in measured periods of prevalence and symptom measurement methods. CONCLUSION: A higher proportion of veterans of the Persian Gulf War of 1991 reported symptoms of pain than military comparison groups. This is consistent with previously demonstrated increased reporting of more general symptoms (fatigue, multiple chemical sensitivity, post traumatic stress disorder) in these veterans compared with non-Gulf military groups. However, the primary studies were heterogeneous and varied greatly in quality
Infrapopliteal angioplasty using a combined angiosomal reperfusion strategy
Introduction
Infra-popliteal angioplasty continues to be widely performed with minimal evidence to guide
practice. Endovascular device selection is contentious and there is even uncertainty over
which artery to treat for optimum reperfusion. Direct reperfusion (DR) targets the artery supplying
the ischaemic tissue. Indirect reperfusion (IR) targets an artery supplying collaterals
to the ischaemic area. Our unit practice for the last eight years has been to attempt to open
all tibial arteries at the time of angioplasty. When successful, this results in both direct and
indirect; or combined reperfusion (CR). The aim was to review the outcomes of CR and
compare them with DR or IR alone.
Methods
An eight year retrospective review from a single unit of all infra-popliteal angioplasties was
undertaken. Wound healing, limb salvage, amputation-free and overall survival data as well
as re-intervention rates were captured for all patients. Subgroup analysis for diabetics was
undertaken. Kaplan Meier curves are presented for survival outcomes. All odds and hazard
ratios (HR) and p values were corrected for bias from confounders using multivariate analysis.
Results
250 procedures were performed: 22 (9%) were CR; 115 (46%) DR and 113 (45%) IR. Amputation-
free survival (HR 0.504, p = 0.039) and re-intervention and amputation-free survival
(HR 0.414, p = 0.005) were significantly improved in patients undergoing CR compared to
IR. Wound healing was similarly affected by reperfusion strategy (OR = 0.35, p = 0.047).
Effects of CR over IR were similar when only diabetic patients were considered.
Conclusions
Combined revascularisation can only be achieved in approximately 10% of patients. However,
when successful, it results in significant improvements in wound healing and amputation-
free survival over simple indirect reperfusion techniques
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