To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Mastoid surgery is an aerosol-generating procedure that involves the use of a high-speed drill, which produces a mixture of water, bone, blood and tissue that may contain the viable coronavirus disease 2019 pathogen. This potentially puts the surgeon and other operating theatre personnel at risk of acquiring the severe acute respiratory syndrome coronavirus-2 from contact with droplets or aerosols. The use of an additional drape designed to limit the spread of droplets and aerosols has been described; such drapes include the ‘Southampton Tent’ and ‘OtoTent’.
To evaluate the use of a novel drape ‘tent’ that has advantages over established ‘tent’ designs in terms of having: (1) a CE marking; (2) no requirement for modification during assembly; and (3) no obstruction to the surgical visual field.
Results and conclusion
During mastoid surgery, the dispersion of macroscopic droplets and other particulate matter was confined within the novel drape ‘tent’. Use of this drape ‘tent’ had no adverse effects upon the surgeon's manual dexterity or efficiency, the view of the surgical field, or the sterility. Hence, our findings support its use during mastoid surgery in the coronavirus disease 2019 era.
Introduction: Hand fractures in children are common and most are adequately managed with immobilization alone. There is a subset of fractures that require surgery as well as a fear of growth plate disturbance. For these reasons, triaging the so-called “complex” fractures that require specialized care by a hand surgeon is critical. In an effort to improve triaging for pediatric hand fractures, we previously derived and internally validated a prediction model for pediatric hand fracture triage using multivariable logistic regression with bootstrapping. The primary outcome was “complex fracture”, a definition we assigned to any fractures that required surgery, closed reduction or more than four appointments with a plastic surgeon. The model identified six significant predictors of complex fractures: angulation, condylar involvement, dislocation or subluxation, displacement, open fracture, and malrotation with strong performance (C-statistic 0.88) and was named the Calgary Kids’ Hand Rule (CKHR). Methods: A prospective cohort study was conducted at the Alberta Children's Hospital from April 1 until December 31, 2019. Eligible patients included children 17 years and younger with a radiographically confirmed hand fracture. Both emergency physicians and plastic surgeons completed independent CKHR forms for each new hand fracture. The fracture was predicted as “complex” if any one of the six predictors were present on the form. If none of the six predictors were present, the predicted outcome was “simple”. The observed outcome was “complex” if the fracture required surgery, closed reduction, or four or more appointments with a plastic surgeon at three months follow-up. All other fractures were observed outcome “simple”. The classification performance of the CKHR was assessed via sensitivity, specificity, and C-statistic. The kappa coefficient for inter-rater reliability between emergency physicians and plastic surgeons was calculated for each predictor. Results: To date, 102 pediatric hand fractures have been included in this prospective cohort study. Of the 74 observed simple fractures, 49 were predicted as “simple” and 25 were predicted as “complex”. Of the 28 observed “complex” fractures, 25 were predicted as “complex” and 3 were predicted as “simple”. These findings correspond to a sensitivity of 89%, specificity of 66%, and a C-statistic of 0.78. Of the 3 observed “complex” fractures that were predicted as “simple”, i.e. the 3 false negatives, one was a Seymour fracture of the fourth distal phalanx for which the emergency physician did not tick any boxes on the form. Upon further investigation, we learned that the physician had commented that the fracture was open, thus alluding to their acknowledgement of the predictor “open fracture” as being present). This fracture went on to require surgery. The second false-negative fracture was a non-displaced, intra-articular fracture of the fourth metacarpal head that required multiple appointments with the plastic surgeon. The third false-negative fracture was a non-displaced Salter-Harris II fracture of the thumb proximal phalanx without malrotation that received a closed reduction by the emergency physician. The kappa coefficient for inter-rater reliability between emergency physician and plastic surgeon evaluation of predictors varied by predictor from fair to almost perfect agreement. Condylar involvement had the highest kappa coefficient (kappa = 0.85) followed by malrotation (kappa = 0.65) and dislocation (kappa = 0.64). The predictors with the lowest kappa coefficients were displacement (kappa = 0.42), open fractures (kappa = 0.50), and angulation (kappa = 0.53). Conclusion: The Calgary Kids’ Hand Rule had a sensitivity of 89% in a prospective cohort of pediatric hand fractures referred to the Alberta Children's Hospital. The sensitivity could likely be improved with knowledge translation and specific education regarding use of the prediction tool. Emergency physicians and plastic surgeons displayed the lowest inter-rater reliability when assessing displacement, open fractures, and angulation. These predictors may represent areas of future research and physician education to delineate and decrease the discordance between emergency physicians and plastic surgeons.
Facial nerve paresis is rare following cochlear implantation. Mechanisms underlying delayed-onset facial paresis are poorly understood. This paper describes the case of a patient who developed facial nerve paresis three years after implantation. A literature review was performed with the aim of identifying any similar cases.
The patient case is reported, and the literature reviewed using PubMed, Embase and Ovid databases.
The literature review revealed that the vast majority of delayed-onset facial nerve paresis cases occur within the first month of implantation. Only two other cases occurring years after device implantation were identified. Although potential causative factors have been suggested, as in our case this phenomenon may be idiopathic.
Prognosis for recovery of late-onset facial nerve paresis seems promising, despite the unfortunate requirement for device explantation in all previous cases including our own.
Dilation and abnormal tortuosity of retinal vessels are the hallmarks of severe retinopathy of prematurity (ROP) in premature infants. The stages of ROP are defined by vessel appearance at the interface between the vascular and avascular retinal areas. Deregulated signaling pathways involving hypoxia-inducible factors such as vascular endothelial growth factor (VEGF) are involved in the pathogenesis of ROP. VEGF-antagonists are increasingly being used as ‘off-label medication’ to treat this condition, with some success. We present Baby SM (female), who was born prematurely at 24 weeks gestation in a tertiary neonatal intensive care unit, and with a birth weight of 640 g. On screening at 35 weeks postmenstrual age (PMA), she was noted to have ROP, which became severe by 37 weeks PMA. She received one dose of intravitreal VEGF antagonist (Bevacizumab), resulting in a decrease in vessel tortuosity and dilation. However, repeat imaging at 4 weeks showed a re-emergence of vessel tortuosity. We believe the observed changes demonstrate an inherent retinal microvascular plasticity in premature neonates. With improved survival of extremely premature neonates and the availability of retinal imaging technology, we are now able to observe this plasticity.
A number of laser facilities coming online all over the world promise the capability of high-power laser experiments with shot repetition rates between 1 and 10 Hz. Target availability and technical issues related to the interaction environment could become a bottleneck for the exploitation of such facilities. In this paper, we report on target needs for three different classes of experiments: dynamic compression physics, electron transport and isochoric heating, and laser-driven particle and radiation sources. We also review some of the most challenging issues in target fabrication and high repetition rate operation. Finally, we discuss current target supply strategies and future perspectives to establish a sustainable target provision infrastructure for advanced laser facilities.
Freshwater fishes represent among the most diverse and threatened taxa globally, accounting for more than 25% of total vertebrates (> 30,000 species described), 37% of which are threatened with extinction (Darwall et al., 2008; Chapter 1). The poor conservation status of freshwater biodiversity is directly related to the pressure that these systems experience worldwide (Vörösmarty et al., 2010). Because of their importance to human welfare and development, freshwater ecosystems and biodiversity are subject to higher pressures and threats than are adjacent terrestrial ecosystems (Nel et al., 2007). Water pollution and abstraction coupled with invasive species and habitat modification (e.g. channelling and damming) are the principal threats to the conservation of freshwater biodiversity (Strayer & Dudgeon, 2010; Vörösmarty et al., 2010). These pressures are rapidly growing due to the increase of human population worldwide and the effect of climate change (Dudgeon et al., 2006; Chapter 3).
Although freshwater ecosystems and biodiversity are in urgent need of protection, there has been little emphasis on declaring protected areas for the primary purpose of conserving freshwater biodiversity (although see attempts in South Africa since the early 1970s (Roux & Nel, 2013 for a brief history) or the USA (Moyle & Yoshiyama, 1994)). Instead, uninformed opportunism has reigned, whereby the conservation of freshwater ecosystems has remained peripheral to conservation goals developed for terrestrial ecosystems, unless considered important for terrestrial biodiversity (Nel et al., 2007; Olden et al., 2010). The implementation of conservation is constrained by limited budgets and potential conflicts with other human uses. For this reason, it is unfeasible to protect all the areas that contribute to the persistence of biodiversity (Margules et al., 2002), and adequate planning is required. Conservation planning is a discipline that tries to deal with these issues to inform stakeholders and decision-makers on how to best invest limited resources available for conservation. The development of a conservation plan typically draws on knowledge spanning several scientific disciplines, increasingly also from the social sciences.
To be effective for freshwater conservation in general and fish in particular, protected areas must consider some particularities of freshwater ecosystems from the early planning stages (e.g. when deciding where to implement conservation) to the daily management. Freshwater ecosystems pose some unique challenges to the implementation of effective conservation (Abell, 2002), such as the importance of connectivity at maintaining natural processes and facilitating the propagation of threats (Linke et al., 2011).
Migratory fishes are natural wonders. For many people, the term migratory fish evokes images of salmon audaciously jumping at waterfalls as they return to their own riverine birthplace to spawn after years of growth in the ocean, but freshwater fishes actually show a broad spectrum of migration strategies. Migratory fishes include small species – three-spined sticklebacks that spawn in coastal streams around the northern Pacific and gobies that move from the ocean into tropical island streams by climbing waterfalls (McDowall, 1988) – as well as some of the largest freshwater fishes in the world, such as the Mekong dog-eating catfish and the Chinese paddlefish (Stone, 2007). Aside from migratory habits, these species have few shared characteristics; they encompass numerous evolutionary lineages, enormous differences in life history, and every possible direction and distance of migration. Biologists treat migratory freshwater fishes as a functional group because their life-history strategy revolves around long-distance movement between ecosystems in a perilous quest to take advantage of both high-quality breeding sites and bountiful feeding areas. As humans have physically blocked fish migrations, degraded breeding and feeding grounds and relentlessly harvested migrants for their flesh and roe, many populations have declined or been extirpated. This chapter will provide an overview of fundamental and applied research that is helping to guide efforts to conserve migratory freshwater fishes.
For practical purposes, we define migratory behaviour as the synchronized movement of a substantial proportion of a population between distinct habitats, which is repeated through time within or across generations. Modern definitions of fish migrations typically recognise both the adaptive benefits of migrating and individual variation in executing the general strategy (see McDowall, 1988; Lucas & Baras, 2001). Not every individual must move, the timing may vary somewhat from year to year, and the motive for migrating may include seeking refuge from harsh conditions in addition to breeding and feeding. Nonetheless, in most cases, migration is critical to individual fitness and population persistence because it enables specialised use of different habitats for growth and reproduction. Where their migration routes are blocked or key habitats are lost, migratory fishes often suffer rapid and catastrophic losses.
Human appropriation and degradation of the Earth's freshwater ecosystems (Vörösmarty et al., 2010; Carpenter et al., 2011) have transformed this reliance on multiple habitats into a detriment for many migratory fishes.
Increasing research effort is being dedicated to investigating the links between emotional processes and psychosis, despite the traditional demarcation between the two. Particular focus has alighted upon two specific anxious and depressive processes, worry and rumination, given the potential for links with aspects of delusions and auditory hallucinations. This study rigorously explored the nature of these links in the context of the daily life of people currently experiencing psychosis.
Experience sampling methodology (ESM) was used to assess the momentary links between worry and rumination on the one hand, and persecutory delusional ideation and auditory hallucinations on the other. Twenty-seven participants completed the 6-day experience sampling period, which required repeated self-reports on thought processes and experiences. Multilevel modelling was used to examine the links within the clustered data.
We found that antecedent worry and rumination predicted delusional and hallucinatory experience, and the distress they elicited. Using interaction terms, we have shown that the links with momentary symptom severity were moderated by participants' trait beliefs about worry/rumination, such that they were reduced when negative beliefs about worry/rumination (meta-cognitions) were high.
The current findings offer an ecologically valid insight into the influence of worry and rumination on the experience of psychotic symptoms, and highlight possible avenues for future intervention strategies.
It is unrealistic to achieve high-resolution biodiversity inventories required to support local conservation strategies over large areas; however, benchmark associations between arthropods and ecosystem classification can support landscape scale biomonitoring. We investigated habitat associations of ground-dwelling spiders (Araneae), staphylinid beetles (Coleoptera: Staphylinidae), and carabid beetles (Coleoptera: Carabidae) in three forest ecosystems in northwestern Alberta, Canada and also studied the effect of variation in depth of pitfall trap installation on catch. Composition and diversity of all three taxa were correlated with the ecosystem classification map, and 20 species were strong indicators of particular habitats. The black spruce (Picea mariana (Miller) Britton, Sterns, and Poggenburg; Pinaceae) bog supported fewer species and individuals of beetles but this trend was not observed for spiders because of natural history traits associated with their performance in this environment. Pitfall trapping biases were constant among habitats enabling proper comparison of ground-dwelling invertebrate assemblages. Three species of beetles (Agonum retractum LeConte (Coleoptera: Carabidae), Pterostichus brevicornis (Kirby) (Coleoptera: Carabidae), and Quedius velox Smetana (Coleoptera: Staphylinidae)) were disproportionally active beneath the soil surface, as catches were greater in pitfall traps with the lip situated 15–25 cm below the soil surface. Thus, even highly standardised trap placement will influence the concept of biodiversity achieved through pitfall trapping, because some target organisms are disproportionately active in subterranean zones.
Using the 22-m ‘Mopra’ antenna (near Coonabarabran, NSW) of the Australia Telescope National Facility (ATNF), we have observed emission from the 115-GHz J = 1−0 transition of CO towards the centre of each of the 1101 clouds listed in the Catalogue of Southern Dark Clouds (SDC) of Hartley et al. (1986). The velocity range covered was −96 to +70 km s−1, with a velocity resolution of 0· 120 km s−1. CO was detected at 1049 of the positions, with 367 spectra showing emission at more than one radial velocity. Here we present the most comprehensive general survey of the SDC catalogue, with the intensity, velocity and half-width of the CO detection and a code describing the profile shape. The presence of blue- or red-shifted wings in many observations can provide a starting point in searches for star-forming regions.
It is now clear that the epoch when the Universe was half of its current age is a crucial period during which galaxies assembled their mass and evolved into the galaxies we observe in the local Universe. However, so far only very few direct studies of mass assembly in action, hence galaxy merging, were conducted over z=1 and usually relied on very small or biased samples. Based on very deep near infrared survey data, the latest UKIDSS-UDS DR8, combined with the optical data conducted by Subaru and CFHT and Spitzer IRAC observations, we explored the evolution of the merging rate up to z = 2, over the largest volume of the Universe at 0.4<z<2 ever sampled. The pair fraction is found to decrease by a factor of two during this period, and wet (gas rich) mergers dominate largely. The dry mergers are very rare, ruling it out as the main mechanism for the mass assembly of passive massive galaxies. Also while massive galaxies undergo a decrease of their pair fraction during this period, less massive systems follow an increase during the same period.
We investigate the resolved star formation properties of a sample of 45 massive galaxies (M* > 1011 M⊙) within a redshift range of 1.5 ⩽ z ⩽ 3 detected in the GOODS NICMOS Survey (Conselice et al. 2011), a HST H160-band imaging program. We derive the star formation rate as a function of radius using rest frame UV data from deep z850 ACS imaging. The star formation present at high redshift is then extrapolated to z = 0, and we examine the stellar mass produced in individual regions within each galaxy. We also construct new stellar mass profiles of the in situ stellar mass at high redshift from Sérsic fits to rest-frame optical, H160-band, data. We combine the two stellar mass profiles to produce an evolved stellar mass profile. We then fit a new Sérsic profile to the evolved profile, from which we examine what effect the resulting stellar mass distribution added via star formation has on the structure and size of each individual galaxy.
Plant secondary metabolites (PSMs) such as terpenes and phenolic compounds are known to have numerous ecological roles, notably in defence against herbivores, pathogens and abiotic stresses and in interactions with competitors and mutualists. This book reviews recent developments in the field to provide a synthesis of the function, ecology and evolution of PSMs, revealing our increased awareness of their integrative role in connecting natural systems. It emphasises the multiple roles of secondary metabolites in mediating the interactions between organisms and their environment at a range of scales of ecological organisation, demonstrating how genes encoding for PSM biosynthetic enzymes can have effects from the cellular scale within individual plants all the way to global environmental processes. A range of recent methodological advances, including molecular, transgenic and metabolomic techniques, are illustrated and promising directions for future studies are identified, making this a valuable reference for researchers and graduate students in the field.