VespAI: a deep learning-based system for the detection of invasive hornets

The invasive hornet Vespa velutina nigrithorax is a rapidly proliferating threat to pollinators in Europe and East Asia. To effectively limit its spread, colonies must be detected and destroyed early in the invasion curve, however the current reliance upon visual alerts by the public yields low accuracy. Advances in deep learning offer a potential solution to this, but the application of such technology remains challenging. Here we present VespAI, an automated system for the rapid detection of V. velutina. We leverage a hardware-assisted AI approach, combining a standardised monitoring station with deep YOLOv5s architecture and a ResNet backbone, trained on a bespoke end-to-end pipeline. This enables the system to detect hornets in real-time-achieving a mean precision-recall score of ≥0.99-and send associated image alerts via a compact remote processor. We demonstrate the successful operation of a prototype system in the field, and confirm its suitability for large-scale deployment in future use cases. As such, VespAI has the potential to transform the way that invasive hornets are managed, providing a robust early warning system to prevent ingressions into new regions.

Bibliometric analysis of parasite vaccine research from 1990 to 2019

Bibliometric and bibliographic analyses are popular tools for investigating publication metrics and thematic transitions in an expanding codex of biomedical literature. Bibliometric techniques have been employed in parasitology and vaccinology, with only a few malaria-specific literature analyses being reported specifically on parasite vaccines. The pursuit of parasite prophylactics is an important, global endeavour both medically and economically. As such, a comprehensive understanding of the research topics would be a valuable tool in assessing the current status and future directions of parasite vaccine development. Consequently, this study investigated parasite vaccinology from 1990 to 2019 by analysing literature exported from the Web of Science and Dimensions databases using two, commonly used, bibliometric programs: SciMAT and VOSviewer. The results of this study show the common, emerging, and transient themes within the discipline, and where the future lies as vaccine development moves further into the age of omics and informatics.

Quantifying the impact of an invasive Hornet on Bombus terrestris Colonies

The invasive hornet Vespa velutina nigrithorax is considered a proliferating threat to pollinators in Europe and Asia. While the impact of this species on managed honey bees is well-documented, effects upon other pollinator populations remain poorly understood. Nonetheless, dietary analyses indicate that the hornets consume a diversity of prey, fuelling concerns for at-risk taxa. Here, we quantify the impact of V. velutina upon standardised commercially-reared colonies of the European bumblebee, Bombus terrestris terrestris. Using a landscape-scale experimental design, we deploy colonies across a gradient of local V. velutina densities, utilising automated tracking to non-invasively observe bee and hornet behaviour, and quantify subsequent effects upon colony outcomes. Our results demonstrate that hornets frequently hunt at B. terrestris colonies, being preferentially attracted to those with high foraging traffic, and engaging in repeated-yet entirely unsuccessful-predation attempts at nest entrances. Notably however, we show that B. terrestris colony weights are negatively associated with local V. velutina densities, indicating potential indirect effects upon colony growth. Taken together, these findings provide the first empirical insight into impacts on bumblebees at the colony level, and inform future mitigation efforts for wild and managed pollinators.

Are Opioid Infusions Used Inappropriately at End of Life? Results From a Quality/Safety Project

CONTEXT

Opioid continuous infusions are commonly used for end-of-life (EOL) symptoms in hospital settings. However, prescribing practices vary, and even the recent literature contains conflicting protocols and guidelines for best practice.

OBJECTIVES

To determine the prevalence of potentially inappropriate opioid infusion use for EOL comfort care at an academic medical center, and determine if inappropriate use is associated with distress.

METHODS

Through literature review and iterative interdisciplinary discussion, we defined three criteria for "potentially inappropriate" infusion use. We conducted a retrospective, observational study of inpatients who died over six months, abstracting demographics, opioid use patterns, survival time, palliative care (PC) involvement, and evidence of patient/caregiver/staff distress from the electronic medical record.

RESULTS

We identified 193 decedents who received opioid infusions for EOL comfort care. Forty-four percent received opioid infusions that were classified as "potentially inappropriate." Insufficient use of as-needed intravenous opioid boluses and use of opioid infusions in opioid-naïve patients were the most common problems observed. Potentially inappropriate infusions were associated with more frequent patient (24% vs. 2%; P < 0.001) and staff distress (10% vs. 2%; P = 0.02) and were less common when PC provided medication recommendations (20% vs. 50%; P < 0.001).

CONCLUSION

Potentially inappropriate opioid infusions are prevalent at our hospital, an academic medical center with an active PC team and existing contracts for in-hospital hospice care. Furthermore, potentially inappropriate opioid infusions are associated with increased patient and staff distress. We are developing an interdisciplinary intervention to address this safety issue.

Honey bee colony performance affected by crop diversity and farmland structure: a modeling framework

Forage availability has been suggested as one driver of the observed decline in honey bees. However, little is known about the effects of its spatiotemporal variation on colony success. We present a modeling framework for assessing honey bee colony viability in cropping systems. Based on two real farmland structures, we developed a landscape generator to design cropping systems varying in crop species identity, diversity, and relative abundance. The landscape scenarios generated were evaluated using the existing honey bee colony model BEEHAVE, which links foraging to in-hive dynamics. We thereby explored how different cropping systems determine spatiotemporal forage availability and, in turn, honey bee colony viability (e.g., time to extinction, TTE) and resilience (indicated by, e.g., brood mortality). To assess overall colony viability, we developed metrics, P_H and P_P, which quantified how much nectar and pollen provided by a cropping system per year was converted into a colony's adult worker population. Both crop species identity and diversity determined the temporal continuity in nectar and pollen supply and thus colony viability. Overall farmland structure and relative crop abundance were less important, but details mattered. For monocultures and for four-crop species systems composed of cereals, oilseed rape, maize, and sunflower, P_H and P_P were below the viability threshold. Such cropping systems showed frequent, badly timed, and prolonged forage gaps leading to detrimental cascading effects on life stages and in-hive work force, which critically reduced colony resilience. Four-crop systems composed of rye-grass-dandelion pasture, trefoil-grass pasture, sunflower, and phacelia ensured continuous nectar and pollen supply resulting in TTE > 5 yr, and P_H (269.5 kg) and P_P (108 kg) being above viability thresholds for 5 yr. Overall, trefoil-grass pasture, oilseed rape, buckwheat, and phacelia improved the temporal continuity in forage supply and colony's viability. Our results are hypothetical as they are obtained from simplified landscape settings, but they nevertheless match empirical observations, in particular the viability threshold. Our framework can be used to assess the effects of cropping systems on honey bee viability and to develop land-use strategies that help maintain pollination services by avoiding prolonged and badly timed forage gaps.

Searching for nests of the invasive Asian hornet (Vespa velutina) using radio-telemetry

Asian hornets (Vespa velutina) are voracious predators of bees, and are the latest emerging threat to managed and wild pollinator populations in Europe. To prevent establishment or reduce the rate of spread of V. velutina, early detection and destruction of nests is considered the only option. Detection is difficult as their nests are well hidden and flying hornets are difficult to follow over long distances. We address this challenge by tracking individual V. velutina workers flying back to their nests using radio telemetry for the first time, finding five previously undiscovered nests, up to 1.33 km from hornet release points. Hornets can fly with 0.28 g tags if the tag:hornet ratio is less than 0.8. This method offers a step-change in options to tackle the spread of this invader, providing an efficient means of finding V. velutina nests in complex environments to manage this emerging threat to pollinators.

Peter Kennedy et al. report on the successful tracking of Asian hornets, an invasive species in Europe that threatens bee populations. Their method enabled them to track individual hornets over long distances and follow them to locate five previously undiscovered nests in France and the Channel Islands.

Development of a Digram-Based Typing Key Layout for Single-Finger/Stylus Input

Hand-held devices often include a keyboard on which a user types with one finger or a stylus. When a user types with one finger, conventional key layouts are not optimal for typing throughput. We used a predictive human performance model based on the frequency of English-language digrams and interkey distances to evaluate alternative key layouts. We also analyzed English digrams with a path-analysis program to determine the strongest links among English letters. The path analysis combined with the predictive human performance model provided a basis for developing and evaluating typing-key layouts for single-finger input. A nonstandard typing-key layout (in a roughly 5 times 5 key matrix) based on digram analysis should, after the development of skilled use, be about 27% better than the QWERTY layout. A nonstandard alphabetic typing-key layout (in a roughly 5 times 5 key matrix) should be about 13% better than the QWERTY layout for single-finger entry.

Evaluation of Typing Key Layouts for Stylus Input

We studied initial user performance with and preference for alternative typing-key layouts for typing with a stylus. Previous analyses have indicated that, after asymptotic practice with this kind of typing, users should type fastest with certain nonstandard layouts. Although asymptotic performance is important in selecting a layout, it also is important to evaluate initial performance with and preference for layouts. Twelve participants used paper models of six different layouts to type four sentences. The layouts were the QWERTY, Dvorak, standard alphabetic, square alphabetic, and two digraph-based layouts. Performance and preference favored the QWERTY over the other layouts. The square alphabetic layout took a distant second place. QWERTY should be a product's default layout even if users can type with only a single finger or a stylus. If the QWERTY layout is not feasible, designers should consider using the square alphabetic layout for limited typing or a digraph-based layout for extensive typing.

Development and Testing of the Operator Training Package for a Small Computer System

The training package for the System/23 Datamaster was developed in accordance with human factors principles and an interactive testing strategy. The viability of the training was assessed by observations, interviews, and post-training task assignments, using surrogate operators. Revisions were incorporated into the training materials and testing was repeated. The result of this interactive testing process was a highly successful training package.

Predicting Honeybee Colony Failure: Using the BEEHAVE Model to Simulate Colony Responses to Pesticides

To simulate effects of pesticides on different honeybee (Apis mellifera L.) life stages, we used the BEEHAVE model to explore how increased mortalities of larvae, in-hive workers, and foragers, as well as reduced egg-laying rate, could impact colony dynamics over multiple years. Stresses were applied for 30 days, both as multiples of the modeled control mortality and as set percentage daily mortalities to assess the sensitivity of the modeled colony both to small fluctuations in mortality and periods of low to very high daily mortality. These stresses simulate stylized exposure of the different life stages to nectar and pollen contaminated with pesticide for 30 days. Increasing adult bee mortality had a much greater impact on colony survival than mortality of bee larvae or reduction in egg laying rate. Importantly, the seasonal timing of the imposed mortality affected the magnitude of the impact at colony level. In line with the LD50, we propose a new index of "lethal imposed stress": the LIS50 which indicates the level of stress on individuals that results in 50% colony mortality. This (or any LISx) is a comparative index for exploring the effects of different stressors at colony level in model simulations. While colony failure is not an acceptable protection goal, this index could be used to inform the setting of future regulatory protection goals.

A sustained hypothalamic-pituitary-adrenal axis response to acute psychosocial stress in irritable bowel syndrome

BACKGROUND

Despite stress being considered a key factor in the pathophysiology of the functional gastrointestinal (GI) disorder irritable bowel syndrome (IBS), there is a paucity of information regarding the ability of IBS patients to respond to acute experimental stress. Insights into the stress response in IBS could open the way to novel therapeutic interventions. To this end, we assessed the response of a range of physiological and psychological parameters to the Trier Social Stress Test (TSST) in IBS.

METHOD

Thirteen female patients with IBS and 15 healthy female age-matched control participants underwent a single exposure to the TSST. Salivary cortisol, salivary C-reactive protein (CRP), skin conductance level (SCL), GI symptoms, mood and self-reported stress were measured pre- and post-exposure to the TSST.

RESULTS

The hypothalamic-pituitary-adrenal (HPA) axis response to the TSST was sustained in IBS, as shown by a greater total cortisol output throughout (p = 0.035) and higher cortisol levels measured by an area under the curve with respect to ground (AUCG) analysis (p = 0.044). In IBS patients, GI symptoms increased significantly during the recovery period following exposure to the TSST (p = 0.045). Salivary CRP and SCL activity showed significant changes in relation to stress but with no differential effect between experimental groups.

CONCLUSIONS

Patients with IBS exhibit sustained HPA axis activity, and an increase in problematic GI symptoms in response to acute experimental psychosocial stress. These data pave the way for future interventional studies aimed at identifying novel therapeutic approaches to modulate the HPA axis and GI symptom response to acute psychosocial stress in IBS.

BEEHAVE: a systems model of honeybee colony dynamics and foraging to explore multifactorial causes of colony failure

A notable increase in failure of managed European honeybee Apis mellifera L. colonies has been reported in various regions in recent years. Although the underlying causes remain unclear, it is likely that a combination of stressors act together, particularly varroa mites and other pathogens, forage availability and potentially pesticides. It is experimentally challenging to address causality at the colony scale when multiple factors interact. In silico experiments offer a fast and cost‐effective way to begin to address these challenges and inform experiments. However, none of the published bee models combine colony dynamics with foraging patterns and varroa dynamics.

We have developed a honeybee model, BEEHAVE, which integrates colony dynamics, population dynamics of the varroa mite, epidemiology of varroa‐transmitted viruses and allows foragers in an agent‐based foraging model to collect food from a representation of a spatially explicit landscape.

We describe the model, which is freely available online (www.beehave-model.net). Extensive sensitivity analyses and tests illustrate the model's robustness and realism. Simulation experiments with various combinations of stressors demonstrate, in simplified landscape settings, the model's potential: predicting colony dynamics and potential losses with and without varroa mites under different foraging conditions and under pesticide application. We also show how mitigation measures can be tested.

Synthesis and applications. BEEHAVE offers a valuable tool for researchers to design and focus field experiments, for regulators to explore the relative importance of stressors to devise management and policy advice and for beekeepers to understand and predict varroa dynamics and effects of management interventions. We expect that scientists and stakeholders will find a variety of applications for BEEHAVE, stimulating further model development and the possible inclusion of other stressors of potential importance to honeybee colony dynamics.

BEEHAVE offers a valuable tool for researchers to design and focus field experiments, for regulators to explore the relative importance of stressors to devise management and policy advice and for beekeepers to understand and predict varroa dynamics and effects of management interventions. We expect that scientists and stakeholders will find a variety of applications for BEEHAVE, stimulating further model development and the possible inclusion of other stressors of potential importance to honeybee colony dynamics.

An amino acid substitution (L925V) associated with resistance to pyrethroids in Varroa destructor

The Varroa mite, Varroa destructor, is an important pest of honeybees and has played a prominent role in the decline in bee colony numbers over recent years. Although pyrethroids such as tau-fluvalinate and flumethrin can be highly effective in removing the mites from hives, their intensive use has led to many reports of resistance. To investigate the mechanism of resistance in UK Varroa samples, the transmembrane domain regions of the V. destructor voltage-gated sodium channel (the main target site for pyrethroids) were PCR amplified and sequenced from pyrethroid treated/untreated mites collected at several locations in Central/Southern England. A novel amino acid substitution, L925V, was identified that maps to a known hot spot for resistance within the domain IIS5 helix of the channel protein; a region that has also been proposed to form part of the pyrethroid binding site. Using a high throughput diagnostic assay capable of detecting the mutation in individual mites, the L925V substitution was found to correlate well with resistance, being present in all mites that had survived tau-fluvalinate treatment but in only 8 % of control, untreated samples. The potential for using this assay to detect and manage resistance in Varroa-infected hives is discussed.

Towards a systems approach for understanding honeybee decline: a stocktaking and synthesis of existing models

The health of managed and wild honeybee colonies appears to have declined substantially in Europe and the United States over the last decade. Sustainability of honeybee colonies is important not only for honey production, but also for pollination of crops and wild plants alongside other insect pollinators. A combination of causal factors, including parasites, pathogens, land use changes and pesticide usage, are cited as responsible for the increased colony mortality.However, despite detailed knowledge of the behaviour of honeybees and their colonies, there are no suitable tools to explore the resilience mechanisms of this complex system under stress. Empirically testing all combinations of stressors in a systematic fashion is not feasible. We therefore suggest a cross-level systems approach, based on mechanistic modelling, to investigate the impacts of (and interactions between) colony and land management.We review existing honeybee models that are relevant to examining the effects of different stressors on colony growth and survival. Most of these models describe honeybee colony dynamics, foraging behaviour or honeybee - varroa mite - virus interactions.We found that many, but not all, processes within honeybee colonies, epidemiology and foraging are well understood and described in the models, but there is no model that couples in-hive dynamics and pathology with foraging dynamics in realistic landscapes.Synthesis and applications. We describe how a new integrated model could be built to simulate multifactorial impacts on the honeybee colony system, using building blocks from the reviewed models. The development of such a tool would not only highlight empirical research priorities but also provide an important forecasting tool for policy makers and beekeepers, and we list examples of relevant applications to bee disease and landscape management decisions.

Measuring hospital performance--2008 forum summary

A Clinical Excellence Commission seminar explored how clinical practice variation can be monitored, and identified directions and opportunities in this field.

Clinical practice variation

Although difficult to quantify, there is known widespread variation in the way that best available evidence is applied in clinical practice. The reasons for gaps between evidence and practice are complex, and efforts to improve uptake are unlikely to be successful if they are one-dimensional or focus on individual health professionals. This article provides contextual reference for articles in this Supplement in addressing how and why clinical variation exists, the importance of reducing it and strategies to drive a more streamlined approach to evidence-based care in Australian health care systems.

The use of artificial dermis (Integra) and topical negative pressure to achieve limb salvage following soft-tissue loss caused by meningococcal septicaemia

Meningococcal sepsis leading to purpura fulminans leaves survivors with extensive areas of skin and soft-tissue necrosis. Soft-tissue loss in the limbs may result in large areas of exposed bone, leaving a choice between free tissue transfer and amputation. We present a case of meningococcal sepsis where the entire medial and lateral surfaces of the tibiae were exposed with loss of anterior muscle compartments on each side. Faced with the possibility of bilateral above-knee amputation, these were instead covered using the dermal replacement Integra (Integra LifeSciences Corp.), in conjunction with an antimicrobial dressing, topical negative pressure dressing and subsequent skin grafting. This management decision achieved rapid wound closure avoiding amputation. Additional secondary reconstruction with microvascular free flaps was performed to preserve joint function.

Management of Dysphagia in Toxic Epidermal Necrolysis (TEN) and Stevens-Johnson Syndrome (SJS)

Toxic epidermal necrolysis (TEN) is a rare and potentially fatal skin disorder, precipitated by severe allergic drug reaction, and is one of a spectrum of conditions, which includes Stevens-Johnson syndrome (SJS). Mucosal involvement is common, resulting in extreme pain on swallowing and poor oral intake. The aim of this study was to describe swallow function in TEN and SJS and define the role of Speech Pathology in management. The Burns Unit database was reviewed for patients that presented over a five-year period with TEN and SJS. Diagnosis of TEN and SJS was confirmed by skin biopsy. Information specific to swallow function, treatment approaches, and adequacy of oral intake was collected. Fourteen patients' medical records were studied: eight TEN, two TEN/SJS spectrum, and four SJS. The majority had mucosal involvement causing odynophagia, poor oral intake, an ability to tolerate fluids more easily than solids, and increased aspiration risk. These symptoms were confirmed by Speech Pathology swallowing assessment. Severe mucosal involvement resulting in odynophagia, dysphagia, and poor oral intake is common in TEN and SJS. The speech pathologist is able to assess swallow function and provide recommendations to promote safe oral intake, minimize odynophagia, and facilitate nutritional input critical to optimizing recovery.

Burns and Amputations: A 24-Year Experience

Although the management of the severely burnt extremity poses a significant therapeutic dilemma, burn injuries resulting in amputation are uncommon, In such cases, however, amputation can reduce the rate of mortality. In a total of 1858 patients from January 1980 to January 2004, there were 34 amputations in 27 patients. There were 23 men (age range, 14-64 years) and 4 women (age range, 34-85 years). The majority of amputations from burns caused by flame injury predominantly after motor vehicle accidents, with only eight cases resulting from high-voltage electrical injury. Nine patients required immediate amputations, with the rest being delayed. There were three deaths, with a survival rate of 89%. The majority of single lower-limb amputees and only one of seven bilateral amputees were independently mobile. The presence of pre-existing psychiatric disease significantly impaired rehabilitation. Free tissue transfer and the usage of bioengineered materials may help reduce the incidence of amputations.

The role of large-scale spatially explicit and small-scale localized processes on the population dynamics of cereal aphids

A field-scale study of the spatially explicit interaction between the carabid Poecilus cupreus Linnaeus, and two common aphid species (Sitobion avenae (Fabricius) and Metopolophium dirhodum (Walker)) in winter wheat was conducted. All three species showed considerable spatial pattern at the field scale. Activity-density of P. cupreus was an order of magnitude higher in the central part of the field compared to its periphery. Where P. cupreus activity-density was highest, S. avenae and M. dirhodum population peaks were delayed. Additionally, in the case of M. dirhodum, lower maximum counts were evident where P. cupreus activity-density was highest. An analysis of the movement of individual P. cupreus using release-recapture indicated that those beetles within the centre of the field exhibited reduced displacement, which may have caused the generation or maintenance of spatial pattern. Crop density was also measured throughout the field. Although crop density had no large-scale spatial pattern, its variability at the small-scale was consistent with an influence on aphid population dynamics. This study demonstrates empirically that both large-scale spatially explicit and small-scale localized processes influenced aphid population dynamics simultaneously.

The Bali burn disaster: implications and lessons learned

In October 2002, a terrorist attack on a nightclub in Bali resulted in an explosion and fire, causing the deaths of more than 200 people, including 88 Australian citizens. After first aid and primary care, the injured were repatriated to Darwin for triage and continued treatment and were then disseminated to various burn units throughout Australia. At the Repatriation General Hospital Concord Sydney, we received 12 patients with burns and a variety of blast injuries. Their treatment was complicated by infection with multiresistant organisms that were previously unseen in our unit and the presence of complex shrapnel wounds. There were no deaths and, with two exceptions, all patients were discharged within 6 weeks. This incident had profound effects on our unit, particularly related to the management of high-velocity shrapnel injuries, serious ongoing septic complications, and the psychological effects on both patients and staff, all of which are detailed and discussed.

Clinical manifestations and outcomes in 17 cases of Stevens-Johnson syndrome and toxic epidermal necrolysis

The clinical features and outcomes of 17 patients with Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) were retrospectively reviewed. There were 11 males and six females with an average age of 61.5 years. Ten patients with SJS (seven males, three females) and seven patients with TEN (four males, three females) were identified. Antibiotics, mainly beta-lactams, were the most common cause of SJS/TEN in this series. The mean skin loss in TEN was 45.7% total body surface area in contrast to the lesser skin loss (< 10%) observed in three patients with SJS. Complications included septicaemia, pneumonia and multi-organ failure, mainly in the TEN group. Two patients died from TEN-related complications and one patient with SJS died from unrelated causes. Ocular involvement and skin pigmentary changes represented the most significant long-term sequelae.

Clinical management and treatment outcomes of Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC), first described in 1972, is an uncommon, highly malignant tumour of skin. Its aetiology is unknown although the tumour occurs most frequently in sun-exposed sites. This skin cancer is characterized by a high incidence of metastases, local and regional recurrence and has a high mortality. Few survival data beyond 3 years are available. Treatment strategies include wide local excision of the primary and lymph node dissection, as indicated together with adjuvant radiotherapy. The tumour has also been shown to be chemosensitive. Definitive treatment is inconclusive due to the relative rarity of this malignancy.

METHODS

A retrospective study was undertaken between the years 1985 and 1996 of 33 patients with MCC at Concord Repatriation General Hospital (CRGH). Demographic details were noted, together with the site and appearance of the primary lesion and the sites and date of metastases. The response and outcome to various modalities of treatment were documented.

RESULTS

There were 27 men and six women with an average age of 80 years (range: 60-86 years). The primary lesion in the present series most often resembled a basal cell carcinoma (BCC), with 53% occurring in the head and neck region. Twenty-seven patients (82%) developed metastatic disease, with an average interval of 13.4 months between diagnosis of the primary lesion and the development of metastases. The incidence of locoregional recurrence in the present series was 42%. Radiation combined with surgery achieved locoregional control in 15 of 19 patients with primary, regional or recurrent locoregional disease. Fourteen patients died of MCC and five others from unrelated causes. The 14 survivors have a mean survival of 54 months with six patients surviving more than 5 years.

CONCLUSIONS

Local excision together with regional lymph node clearance as indicated, combined with adjuvant radiation treatment was associated with an improved survival. The role of chemotherapy remains unclear.

Squamous cell carcinoma of the skin of the trunk and limbs: the incidence of metastases and their outcome

The incidence and outcome of metastatic squamous cell carcinoma of the skin is poorly documented. This study, undertaken in a population accessible to long-term follow-up, documents the metastatic aspects of squamous cell carcinoma of the skin of the trunk and limbs. In a review of 695 cases, metastases occurred in 34 cases, with a metastatic rate of 4.9%, an overall mortality of 3.4%, and a 70.6% mortality in the metastatic group. Forty-six per cent of overall mortality was associated with inoperable or recurrent regional disease without evidence of distant metastases. The risk factor associated with the development of metastatic disease were; delayed presentation; large neglected lesions; misdiagnosis; and multiple treatments to the primary lesions. In this series no correlation was found between the histological degree of differentiation of the primary tumour and the development of metastases. The mean latent period between treatment of the primary and the diagnosis of metastases was 11 months. Histopathological review of the regional lymph nodes in the operable group showed that adverse pathology such as multiple nodes, extracapsular spread, vascular and perineural invasion, were associated with regional recurrence and short survival. Twenty-one patients with operable metastases had a mean survival of 53.8 months. This was compared with 13 patients with inoperable disease, in whom the mean survival was 12.2 months (P less than 0.05).

An extraskeletal chondrosarcoma arising in the brachial plexus

A case of extraskeletal chondrosarcoma of the left brachial plexus is described with emphasis on the diagnostic and therapeutic difficulties of this site. With combination therapy the patient survived 6 years. Recurrent disease in the plexus region and adjacent spinal cord resulted in a painful, flail limb.

Perineural spread of cutaneous head and neck cancer. Its orbital and central neurologic complications

The ability of cutaneous squamous cell carcinoma of the face to cause ophthalmoplegia or central nervous system dysfunction via perineural spread is not well recognized. Five patients presenting to a general neurology unit are described in whom partial or complete ophthalmoplegia developed following fifth and seventh cranial nerve involvement by cutaneous squamous cell carcinoma. Two patients subsequently developed a contralateral hemiparesis; and one, multiple cranial nerve palsies as the tumor spread centrally. Normal radiologic findings or complete healing of the primary skin lesion caused delay in the diagnosis in three of the patients. When ophthalmoplegia or central nervous system dysfunction develops as a consequence of perineural spread of cutaneous facial cancer, management is palliative.

Grazing management studies with Australian cashmere goats. 3. Effect of season on the selection of diet by cattle, sheep and goats from two tropical grass-legume pastures

Oesophageally fistulated cattle, sheep and I goats were grazed together to study species diet preferences from 2 different tropical grass-legume pastures during 3 seasons (summer, autumn, winter). In one pasture, Brachiaria decumbens (signal grass) was the dominant grass and in the other pasture, Paspalum plicatulum. Each pasture had a common suite of tropical legumes, mainly Desmodium intortum (greenleaf desmodium), Macroptilium atropurpureum (siratro) and Macrotyloma axillaris (axillaris). Axillaris was the major legume available in summer and autumn and greenleaf desmodium was the major legume in winter. There was no significant effect in any season of the basal grass available on the composition of the diet selected by the different species. Both goats and cattle had a high preference for legume leaf during summer and autumn, with goats having a higher preference (34-75% of diet) than cattle (1245%). Sheep selected against legume (5-19% of diet) and had a high preference for grass leaf (58-74% of diet) in all seasons. Cattle selected grass in preference to legume (greenleaf desmodium) in winter. Goats showed the greatest discrimination against both grass and legume stem. In summer sheep selected a higher quality (in vitro digestibility) diet (62.7%) than did cattle (53.4%) and goats (51.2%). In both autumn and winter cattle and sheep selected diets of similar digestibility (range 58.6-63.6%). In vitro digestibility of the extrusa samples was significantly (P<0.05) correlated (r = 0.74) with the proportion of grass selected. It was concluded that in their grazing preferences, goats were more like cattle than sheep. The different preferences of sheep and goats for tropical legume leaf was associated with location of these legumes in the sward, goats browsing from the top down and sheep grazing from the bottom of the sward.

Excision of the submandibular gland: minimizing the risk of nerve damage

Surgical texts do not clearly advise whether the ramus mandibularis should be identified in excision of the submandibular salivary gland for benign disease. An analysis of 74 patients was undertaken to assess the subsequent nerve function after submandibular salivary gland excision. Both glands were removed in two patients, making the total number of glands excised 76. In five cases the nerve was identified, in five patients the operative record did not clearly state whether the nerve was identified, and in the remaining 66 a non-identification technique was used. The subsequent analysis was unable to follow-up six patients fully. Seven patients had mild to moderate weakness in the early postoperative period, but all recovered, some taking up to 3 months to do so. Other complications were minor, except for two patients who had postoperative haemorrhage, one requiring a tracheostomy. As the majority of these patients had a non-identification technique, and because searching for the nerve is tedious and time-consuming, the former approach is recommended when operating for benign disease of the submandibular salivary gland.

Transplantation of cultured autologous epidermis to a patient with burns

Explant-derived cultured autologous epidermis was used as a graft in a 41-year-old female patient with burns, the first subject in a clinical trial of the technique. A small full-thickness biopsy specimen which was taken on Day 2 of the hospital admission was used to initiate epidermal cultures, four of which were grafted onto the patient's back and right leg 29 and 35 days later. Three of these epidermal cultures engrafted successfully, in spite of infection with Pseudomonas aeruginosa, which resulted in the loss of some of the conventional, split-thickness meshed autografts that were applied concurrently. The fourth graft, which may have been oriented incorrectly onto the graft bed, was largely unsuccessful, and only small islets of epithelial cells remained after 10 days. The successful grafts produced full-thickness, epidermal coverage with a good cosmetic result and little evidence of contraction during a six-months' follow-up.

The extended deep inferior epigastric flap: a case report

The extended deep inferior epigastric flap, described by Taylor et al. (1983), 1984), offers a versatile and reliable technique for covering defects in the lower limb. A case of shark bite is described in which extensive soft tissue loss in the thigh resulted in a denuded femoral shaft which was successfully treated using such a flap.

Metastatic tumours of the parotid region

Metastatic disease in the parotid gland and its associated lymph nodes is generally thought to be uncommon. A review of 121 cases was undertaken to study the incidence, histology and prognosis of secondary malignancy in the parotid region. Forty-two per cent of the cases were secondary malignancies. The majority of these were squamous cell carcinoma, and in this group the prognosis was poor.

Micro-lymphatic bypass in the treatment of obstructive lymphoedema of the arm: case report of a new technique

A report is presented of a case of secondary lymphoedema of the upper limb successfully treated by microlymphatic bypass with a composite graft containing three lymphocollectors from the lower limb to bypass the ablated portion of the pathway. To ensure success the surgery must be carried out before the peripheral lymphatics have been damaged or destroyed by increasing pressure and recurrent infection. Pre-operative lymphangiography is mandatory to assess suitability for the bypass procedure. Other methods of treatment are reviewed.

Isolation and restriction mapping of plasmids containing ribosomal DNA sequences from the rrn B cistron of E. coli

Recombinant plasmids containing the entire 16S RNA gene from the rrn B cistron of E. coli inserted in Col E1 and pBR322 plasmid vectors have been constructed. These plasmids have been mapped using several restriction endonucleases as well as by DNA-RNA hybridization. These maps reveal previously undetected restriction sites in the rrn B cistron and in Col E1 plasmid DNA.

Complete nucleotide sequence of a 16S ribosomal RNA gene from Escherichia coli

The complete nucleotide sequence of the 16S RNA gene from the rrnB cistron of Escherichia coli has been determined by using three rapid DNA sequencing methods. Nearly all of the structure has been confirmed by two to six independent sequence determinations on both DNA strands. The length of the 16S rRNA chain inferred from the DNA sequence is 1541 nucleotides, in close agreement with previous estimates. We note discrepancies between this sequence and the most recent version of it reported from direct RNA sequencing [Ehresmann, C., Stiegler, P., Carbon, P. & Ebel, J.P. (1977) FEBS Lett. 84, 337-341]. A few of these may be explained by heterogeneity among 16S rRNA sequences from different cistrons. No nucleotide sequences were found in the 16S rRNA gene that cannot be reconciled with RNase digestion products of mature 16S rRNA.

Analysis of tasks and human factors in anesthesia for coronary-artery bypass

A comprehensive task analysis of the anesthetist's activities during coronary-artery bypass procedures was carried out using time-lapse cinematography. This film was analyzed frame by frame to detect types of activities and the proportion of time spent on each. Link analysis was used to reveal recurring sequences of activities. Of the 9 activity categories, the anesthetist spends the greatest portion of time observing the patient and scanning the entire operative and monitoring field. Ten to 15% of the time is spent logging data on the anesthetic record. The challenge for the anesthetist is to optimize his performance, and those under his direction, in the face of the changing workload resulting from variations in patients' conditions. Use of an automated monitoring system that charts patient vital signs would allow the anesthetist to apportion this time among other tasks.