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The completion of a laser safety course remains a core surgical curriculum requirement for otolaryngologists training in the UK. This project aimed to develop a comprehensive laser safety course utilising both technical and non-technical skills simulation.
Otolaryngology trainees and consultants from the West of Scotland Deanery attended a 1-day course comprising lectures, two high-fidelity simulation scenarios and a technical simulation of safe laser use in practice.
The course, and in particular the use of simulation training, received excellent feedback from otolaryngology trainees and consultants who participated. Both simulation scenarios were validated for future use in laser simulation.
The course has been recognised as a laser safety course sufficient for the otolaryngology Certificate of Completion of Training. To the authors’ knowledge, this article represents the first description of using in situ non-technical skills simulation training for teaching laser use in otolaryngology.
The aquatic diplocaulid nectridean Keraterpeton galvani is the commonest taxon represented in the Jarrow Coal assemblage from Kilkenny, Ireland. The Jarrow locality has yielded the earliest known Carboniferous coal-swamp fauna in the fossil record and is, therefore, of importance in understanding the history and diversity of the diplocaulid clade. The morphology of Keraterpeton is described in detail with emphasis on newly observed anatomical features. A reconstruction of the palate includes the presence of interpterygoid vacuities and new morphological details of the pterygoid, parasphenoid and basicranial region. The hyoid apparatus comprising an ossified basibranchial element has not been reported previously in nectrideans. The structure of the scapulocoracoid and primitive nature of the humerus is described and the presence of a five-digit manus confirmed. Previously unrecognised accessory dermal ossifications are present in the pectoral girdle. Keraterpeton longtoni from the Bolsovian in Staffordshire, England, is also described and newly figured. The primitive condition in diplocaulids is defined on the basis of the earliest occurrence at Jarrow and discussed in relation to functional morphology and mode of life. The evolution of the diplocaulid clade is assessed in relation to the revised diagnoses that define the primitive condition in Keraterpeton.
To investigate the practice of hunting by local people in the southern Bahia region of Brazil and provide information to support the implementation of the National Action Plan for Conservation of the Central Atlantic Forest Mammals, we conducted 351 interviews with residents of three protected areas and a buffer zone. Thirty-seven percent of respondents stated that they had captured an animal opportunistically, 16% hunted actively and 47% did not hunt. The major motivation for hunting was consumption but people also hunted for medicinal purposes, recreation and retaliation. The most hunted and consumed species were the paca Cuniculus paca, the nine-banded armadillo Dasypus novemcinctus and the collared peccary Pecari tajacu; threatened species were rarely hunted. Opinions varied on whether wildlife was declining or increasing; declines were generally attributed to hunting. Our findings suggest there is illegal hunting for consumption in and around protected areas of the region. Management efforts should prioritize fairness in the expropriation process for people who must be relocated, and adopt an approach to wildlife management that involves residents living around the protected areas, and considers their needs.
We consider the spread of infectious disease through contact networks of Configuration
Model type. We assume that the disease spreads through contacts and infected individuals
recover into an immune state. We discuss a number of existing mathematical models used to
investigate this system, and show relations between the underlying assumptions of the
models. In the process we offer simplifications of some of the existing models. The
distinctions between the underlying assumptions are subtle, and in many if not most cases
this subtlety is irrelevant. Indeed, under appropriate conditions the models are
equivalent. We compare the benefits and disadvantages of the different models, and discuss
their application to other populations (e.g., clustered networks).
Finally we discuss ongoing challenges for network-based epidemic modeling.
A year-long intervention trial was conducted to characterise the responses of multiple biomarkers of Se status in healthy American adults to supplemental selenomethionine (SeMet) and to identify factors affecting those responses. A total of 261 men and women were randomised to four doses of Se (0, 50, 100 or 200 μg/d as l-SeMet) for 12 months. Responses of several biomarkers of Se status (plasma Se, serum selenoprotein P (SEPP1), plasma glutathione peroxidase activity (GPX3), buccal cell Se, urinary Se) were determined relative to genotype of four selenoproteins (GPX1, GPX3, SEPP1, selenoprotein 15), dietary Se intake and parameters of single-carbon metabolism. Results showed that supplemental SeMet did not affect GPX3 activity or SEPP1 concentration, but produced significant, dose-dependent increases in the Se contents of plasma, urine and buccal cells, each of which plateaued by 9–12 months and was linearly related to effective Se dose (μg/d per kg0·75). The increase in urinary Se excretion was greater for women than men, and for individuals of the GPX1 679 T/T genotype than for those of the GPX1 679 C/C genotype. It is concluded that the most responsive Se-biomarkers in this non-deficient cohort were those related to body Se pools: plasma, buccal cell and urinary Se concentrations. Changes in plasma Se resulted from increases in its non-specific component and were affected by both sex and GPX1 genotype. In a cohort of relatively high Se status, the Se intake (as SeMet) required to support plasma Se concentration at a target level (Sepl-target) is: .
The aim of this analysis was to establish the basic mechanical principles of simple archosaur cranial form. In particular we estimated the influence of two key archosaur innovations, the secondary palate and the antorbital fenestra, on the optimal resistance of biting-induced loads. Although such simplified models cannot substitute for more complex cranial geometries, they can act as a clearly derived benchmark that can serve as a reference point for future studies incorporating more complex geometry. We created finite element (FE) models comprising either a tall, domed (oreinirostral) snout or a broad, flat (platyrostral) archosaur snout. Peak von Mises stress was recorded in models with and without a secondary palate and/or antorbital fenestra after the application of bite loads to the tooth row. We examined bilateral bending and unilateral torsion-inducing bites for a series of bite positions along the jaw, and conducted a sensitivity analysis of material properties. Pairwise comparison between different FE morphotypes revealed that oreinirostral models are stronger than their platyrostral counterparts. Oreinirostral models are also stronger in bending than in torsion, whereas platyrostral models are equally susceptible to either load type. As expected, we found that models with a fenestra always have greatest peak stresses and by inference are “weaker,” significantly so in oreinirostral forms and anterior biting platyrostral forms. Surprisingly, although adding a palate always lowers peak stress, this is rarely by large magnitudes and is not significant in bilateral bending bites. The palate is more important in unilateral torsion-inducing biting. Two basic principles of archosaur cranial construction can be derived from these simple models: (1) forms with a fenestra are suboptimally constructed with respect to biting, and (2) the presence or absence of a palate is significant to cranial integrity in unilaterally biting animals. Extrapolating these results to archosaur cranial evolution, it appears that if mechanical optimization were the only criterion on which skull form is based, then most archosaurs could in theory strengthen their skulls to increase resistance to biting forces. These strengthened morphotypes are generally not observed in the fossil record, however, and therefore archosaurs appear subject to various non-mechanical morphological constraints. Carnivorous theropod dinosaurs, for example, may retain large suboptimal fenestra despite generating large bite forces, owing to an interplay between craniofacial ossification and pneumatization. Furthermore, living crocodylians appear to strengthen their skull with a palate and filled fenestral opening in the most efficient way possible, despite being constrained perhaps by hydrodynamic factors to the weaker platyrostral morphotype. The future challenge is to ascertain whether these simple predictions are maintained when the biomechanics of complex cranial geometries are explored in more detail.
Since the Second World War, preferential trading arrangements (PTAs) have become increasingly pervasive features of the international economic system. A great deal of research has addressed the economic consequences of these arrangements, but far less effort has been made to identify the political factors leading states to enter them. In this article, the domestic political factors affecting whether countries enter PTAs are investigated, placing particular emphasis on the number of veto players within a state. It is argued that the probability of forming a PTA declines as the number of such players rises. The results, covering 194 countries from 1950 to 1999, strongly support this argument. Holding various political and economic factors constant, increasing the number of veto players within a country significantly reduces the probability of signing a PTA.
Nutrigenomics is the study of how constituents of the diet interact with genes, and their products, to alter phenotype and, conversely, how genes and their products metabolise these constituents into nutrients, antinutrients, and bioactive compounds. Results from molecular and genetic epidemiological studies indicate that dietary unbalance can alter gene–nutrient interactions in ways that increase the risk of developing chronic disease. The interplay of human genetic variation and environmental factors will make identifying causative genes and nutrients a formidable, but not intractable, challenge. We provide specific recommendations for how to best meet this challenge and discuss the need for new methodologies and the use of comprehensive analyses of nutrient–genotype interactions involving large and diverse populations. The objective of the present paper is to stimulate discourse and collaboration among nutrigenomic researchers and stakeholders, a process that will lead to an increase in global health and wellness by reducing health disparities in developed and developing countries.
Neurocognitive impairment is a frequent complication of HIV infection and heralds a poor survival prognosis. With the availability of highly active antiretroviral therapy (HAART), survival times for HIV-infected patients have markedly increased although the effects of HAART on the prevalence of neurocognitive impairment remain uncertain.
To determine the relationship between self-reported neurocognitive symptoms and neuropsychological (NP) performance together with the impact of HAART among HIV-infected patients.
A cross-sectional study was performed in which patients without previously documented neurocognitive impairment attending an HIV community clinic were questioned about neurocognitive symptoms and a NP test battery was administered.
Of the eighty-three patients examined, neurocognitive symptoms were reported by 34% of patients and were associated with a shorter duration of HAART and higher viral loads. Patients reporting neurocognitive symptoms were also more likely to exhibit impaired NP performance (p<0.005) with NP impairment being detected in 46% of all patients examined (12% with HIV-associated dementia). Neuropsychological impairment was directly correlated with age (p<0.001), plasma viral load (p<0.005) and inversely correlated with the number of prescribed antiretroviral drugs (p<0.01).
These results suggest that neurocognitive symptoms are predictive of impaired NP performance and that NP impairment remains a frequent finding among older patients with higher viral loads. An increased number of antiretroviral drugs may be neuroprotective.
We present a case study of the use of simulation modelling to develop and test strategies for managing populations under uncertainty. Strategies that meet a stock conservation criterion under a base case scenario are subjected to a set of robustness trials, including biased and highly variable abundance estimates and poaching. Strategy performance is assessed with respect to a conservation criterion, the revenues achieved and their variability. Strategies that harvest heavily, even when the population is apparently very large, perform badly in the robustness trials. Setting a threshold below which harvesting does not take place, and above which all individuals are harvested, does not provide effective protection against over-harvesting. Strategies that rely on population growth rates rather than estimates of population size are more robust to biased estimates. The strategies that are most robust to uncertainty are simple, involving harvesting a relatively small proportion of the population each year. The simulation modelling approach to exploring harvesting strategies is suggested as a useful tool for the assessment of the performance of competing strategies under uncertainty.
This chapter reviews briefly the apparent responses to global events by the amphibians, reptiles and birds during the past 145 million years. The vast majority of living members of these groups are terrestrial or freshwater (aquatic or amphibious) dwellers. Some 4956 species of amphibians are represented by 28 families of Anura (frogs and toads), ten families of Caudata (newts and salamanders) and five families of Gymnophiona (caecilians) (Cogger & Zweifel, 1998). Over 7427 living species of reptiles are represented by 13 families of Testudinata (turtles and tortoises), 48 families of Lepidosauromorpha (comprising 26 lizard families, ca. 18 snake families, 4 amphisbaenid (worm lizard) families and a single relict rhynchocephalian genus, the Tuatara (Sphenodon)) and the Archosauria (Coggar & Zweifel, 1998). The last group includes the extinct Pterosauria and the wholly terrestrial Dinosauria, and is today represented by three families of Crocodylia (crocodiles and alligators) and by the birds, the most numerous terrestrial vertebrates with over 9700 species in more than 20 orders, more than 50% belonging to the Passeriformes (song birds) (Feduccia, 1996).
The geographical distribution patterns of these groups are intimately linked to the historical distribution of continental areas, and we can attempt to relate the patterns of their past and present distributions to the patterns produced by the global dynamics of plate tectonics. An understanding of the patterns of relationships within these (and other) groups of organisms is fundamental to attempts to interpret their vicariance and dispersal patterns.
A number of methods exist by which the pH of local anaesthetic solutions may be increased. Most commonly, these require the addition of differing amounts of sodium bicarbonate solution according to the local anaesthetic drugs. Sodium bicarbonate (1%) was titrated against pH in six commonly used local anaesthetic solutions. Titration curves of pH and volume of sodium bicarbonate solution added are shown for this group of local anaesthetics. This study demonstrates that 1 mL of 1% sodium bicarbonate solution may be used to alkalinize this range of local anaesthetics without the risk of precipitation. We also conclude that Ropivacaine (at concentration 0.75% and 1.0%), is unsuitable for alkalinization since it precipitates at a pH of 6.0.
Subsamples of termite mound soil used by chimpanzees for geophagy, and topsoil never ingested by them, from the forest floor in the Mahale Mountains National Park, Tanzania, were analysed to determine the possible stimulus or stimuli for geophagy. The ingested samples have a dominant clay texture equivalent to a claystone, whereas the control samples are predominantly sandy clay loam or sandy loam, which indicates that particle size plays a significant role in soil selection for this behaviour. One potential function of the clays is to bind and adsorb toxins. Although both termite mound and control samples have similar alkaloid-binding capacities, they are in every case very high, with the majority of the samples being above 80%. The clay size material (<2 μm) contains metahalloysite and halloysite, the latter a hydrated aluminosilicate (Al2Si2O4·nH2O), present in the majority of both the termite mound soil and control soil samples.Metahalloysite, one of the principal ingredients found in the pharmaceutical Kaopectate™, is used to treat minor gastric ailments in humans. The soils commonly ingested could also function as antacids, as over half had pH values between 7.2 and 8.6. The mean concentrations of the majority of elements measured were greater in the termite mound soils than in the control soils. The termite mound soils had more filamentous bacteria, whereas the control soils contained greater numbers of unicellular bacteria and fungi.
Tibial torsion, twisting of the tibia about its longitudinal
axis, varies during development and early
childhood. Knowledge of the normal range of tibial torsion at
various ages and its accurate clinical
measurement is important in the assessment of the extent of a
torsional deformity. To evaluate tibial torsion
a reliable technique for its measurement in vivo is therefore
required. The aim of this study was to
determine which of 4 existing in vivo methods of measuring tibial
torsion was the most accurate and had the
highest repeatability, by comparing them with direct measurement
of the tibia. A wide range of mean values
for tibial torsion was observed, using the various techniques,
with none of the indirect techniques employed
having a strong correlation with direct measurement of tibial
torsion. The repeatability of the indirect
techniques was observed to be low both in cadavers (n=4) and
the living (n=3). Since none of the in vivo
techniques appear to measure true tibial torsion or be of a
reasonable repeatability, alternative easy to use
and inexpensive methods need to be developed. Accurate clinical
measurement of tibial torsion is important
in the assessment of the extent of a torsional deformity. It is
recommended that data gained using the
methods reviewed here are interpreted with caution.
Compared with other joints, the ligaments of the ankle have
not been studied in great detail; consequently relatively little
literature exists. The positions of the 3 major bands of the
lateral collateral ligament are well known and documented
(Schafer et al. 1915; Sarrafian, 1983; McMinn, 1994;
Palastanga et al. 1994; Williams et al. 1995). The detailed
anatomy of the ligaments is, however, relatively complex
with variations of the major bands and several minor
additional bands being reported (Sarrafian, 1993; Burks &
Morgan, 1994; Rosenberg et al. 1995).
An immunocytochemical and cytochemical study has been made on
the ultrastructural localisation of type III (endothelial) nitric oxide
synthase, endothelin-1 and the binding sites of lectin from
Bandeirea simplicifolia to the endothelium surface-associated
glycoproteins in the rat left common carotid artery at 1 and 28 d after
Fogarty embolectomy balloon catheter-induced injury. Controls were
carotid arteries from sham operated rats. In the controls, the
immunoreactivity to nitric oxide synthase-III and endothelin-1 was
localised in different proportions in vascular endothelial cells
(36·9%±4·3 and 7·6%±2·7,
respectively); immunoreactivity was confined to the cytoplasm and the
membranes of intracellular organelles and structures. In contrast,
staining with lectin was localised on the luminal surface of all
endothelial cells. 1 d after injury, platelets were adherent to the
endothelium-denuded intima. Some of the platelets displayed
immunoreactivity to nitric oxide synthase-III and endothelin-1 and were
stained with lectin. 28 d after injury, a neointimal thickening of
substantial size was present. Subpopulations of the regrown endothelial
cells covering the luminal surface of the neointima showed positive
immunoreactivity to nitric oxide synthase-III and endothelin-1 but
there was a significant decrease in the proportion of nitric oxide
synthase-III-containing endothelial cells
(17·2%±1·9; P < 0·001) and a
significant increase in the proportion of endothelin-1-containing
endothelial cells (36·9%±4·7; P <
0·001) compared with the controls. Staining with lectin was
associated with the cell membrane of all endothelial cells and in
addition with cells located ‘deeper’ in the neointima which
showed lectin-positive plasmalemma, Golgi complex and multivesicular
bodies/lysosomes. In conclusion, regenerated endothelial cells of
the neointima showed reduced population (2–fold) of nitric oxide
synthase-III- and increased population (5–fold)
endothelin-1-positive cells. The subendothelial location of some
lectin-stained cells after balloon catheter injury indicates the
heterogeneity of the neointima and suggests that some of these cells
are involved in early angiogenesis. 24 h and 28 d after injury some
platelets showed positive immunoreactivity for nitric oxide
synthase-III and endothelin-1.
We have studied the late stages of the “pearling instability” in lipid bilayers, which is brought on by applying laser tweezers to a cylindrical vesicle. This produces a front that propagates down the vesicle, leaving behind it bilayer-covered droplets separated by thin tubes, which appear under the microscope as pearls on a string. At later times, the “pearls” are observed to drift slowly towards the “trap” (the spot where the tweezers are applied, into which the surfactant is drawn). We model the hydrodynamics of the drifting pearls as a combination of translation of the string of pearls, and “slipping” of the bilayer skin over the pearls, to relate the speed of the pearls to the underlying flux of the surfactant into the trap.
The following inscription was found at Oenoanda, an antique city in north Lycia, by the late Alan S. Hall in 1974. The text (inv. no. YÇ 1014) is inscribed on the short face of a large grey limestone statue base, found lying on its left side at the northern margin of the Upper Agora (the “Esplanade”), directly before the outer edge of the portico of the north stoa (cf. Figs. 1 and 2). Its position suggests that it has fallen forward, with other bases beside it to the west, from its original situation on the pavement of the Upper Agora, immediately fronting the podium of the stoa. There was no evidence that it had been re-used, as originally thought by Hall. Its dimensions are h. 0·73 m.; w. 0·74 m. (slightly broken to the left); th. 1·50+ m. (buried behind). Since it is unmoulded and there are no foot-holes in the top, it is probable that top and bottom sections have become detached. The large base beside it to the west, measuring h. 1·25 m.; w. 2·10 m.; th. 0·60+ m., has two sets of foot-holes and a moulded top; a connection between this and our base is perhaps not unlikely—possibly they formed part of a family monument. On architectural grounds it has been argued that the north stoa was built in either the first century B.C. or the first century A.D. Since it is reasonable to suppose that the base, which we date to the 90s B.C. for reasons that will become clear shortly, was erected after its construction, the stoa should probably be dated no later than second century B.C.
The effects of tree improvement on factors likely to influence tree stability were investigated using clonal Sitka spruce trees that had been grown for 11 years on an unploughed nursery site. The distribution of biomass between root and shoot, and within the root systems of trees from five improved clones, was examined and compared with control trees grown from unimproved cuttings and transplants. The direction (azimuth) of growth and dimensions of the main woody roots were also measured. Differences between clones were found in allocation of biomass between root and shoot, and in root system architecture. Large differences were found between clones in proportions of below-ground biomass allocated to stumps and woody roots (which function for anchorage). These results indicate that root: shoot ratio can be a poor indicator of tree stability when the stump is included as part of the root biomass. The distribution of root origins around the stump showed no significant clumping but the allocation of biomass between roots was found to differ between tree types. On average, the improved clones had allocated biomass to fewer roots than the controls. The amount of branching in the proximal 45 cm of the root system also differed between clones. Distribution of root cross-sectional area around the tree was significantly asymmetric in two of the clones. Overall, root biomass was allocated more to the lee side of the prevailing wind direction. The substantial differences found in allocation between root and shoot, and within the root system, may have implications for the wind stability of trees and could present opportunities for improving stability by clonal selection.
Damage by windthrow causes important economic losses to forestry in northern Europe.