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Eighteenth-century naval ships were impressive infrastructures, but subjected to extraordinary strain. To assist with their “voyage repairs,” the Royal Navy gradually established numerous overseas bases, displaying the power, reach, and ruthless logistical efficiency of the British state. This article, however, is concerned with what happened where no such bases (yet) existed, in parts of the world falling in between areas of direct British administration, control, or influence. The specific restrictions imposed by technology and infrastructures have been studied by historians interested in naval strategy, but they can also help to reframe national narratives of power or observe the transnational interactions surrounding access to knowledge and resources. This paper discusses the material, cultural, and diplomatic constraints that could appear when vessels, and especially “discovery ships,” sailed in strange waters or sought technical assistance in allied ports. I argue that the “mortification” of some commanders at their vessels’ unfitness for service was an important – and often neglected – element on the palette of emotions undergone by voyagers, capturing their strong sense of ultimate material powerlessness. Such frustration even became embedded in imperial cartography, as shown by the case study of Matthew Flinders. This perspective highlights the limits of naval technology, complicating imperialistic “success stories” and better reintegrating the navy into the history of maritime travel and transportation, from which it is often singled out.

Early creation of arteriovenous fistulas (AVFs) decreases morbidity and mortality in patients with end-stage renal disease and is the standard of care in the United States. However, this procedure is frequently not accessible in low- and middle-income countries (LMICs). We present the first reported case of successful AVF creation as part of a humanitarian assistance mission. The patient was a 51-year-old male with diabetes, hypertension, and end-stage renal disease on hemodialysis via a temporary dialysis catheter. Preoperative assessment and patient selection were coordinated with the host nation (HN) nephrologist and dialysis team. The visiting surgical team provided education on AVF anatomy, complications, and cannulation techniques to the HN dialysis team. A left brachiocephalic AVF was created under regional anesthesia performed by the visiting surgeon and anesthesiologists. There were no postoperative complications, and the AVF was matured and accessed successfully by the HN dialysis team 7 weeks after creation. Performing AVFs as part of humanitarian assistance missions has the potential to significantly reduce morbidity and mortality in LMICs.

The Medical Officer's Journal of HMAS Sydney was a record kept by the ship's Surgeon, Leonard Darby, of the conditions on the ship and the health, diseases, injuries and treatment of the sailor's under his care. Records of anaesthesia and surgery indicate chloroform was mostly administered as was ether occasionally. There was some use of intravenous and subcutaneous fluids for resuscitation. The journal also provides an eyewitness account of the Sydney-Emden battle on 9 November 1914 which occurred off the Cocos Keeling Islands and was a famous first victory for the young Australian Navy, making headlines around the world. The treatment of the many injured, mostly Germans, is described; with the two Australian surgeons and the surviving German surgeon working together.

The framework of casualty care during the Anglo-Dutch Wars has been found severely wanting by historians of naval medicine. This judgement is grounded on the fact that naval hospitals were constructed eventually in the 1750s, and because the hospitalization of sick and hurt mariners conforms better to a Weberian model of state and military modernization. This article argues that the measures for casualty care erected during the Dutch wars adhered to an early modern model of state formation. The framework of care extended the scope and social depth of politically involved people. It failed because the carers were consistently underfunded, not because locally based care was inherently unworkable or insufficiently bureaucratic and centralized.

We assessed the satisfaction of onboard caregivers with the maritime telehealth service provided by the Centre de Consultations Médicales Maritimes (CCMM). We conducted a survey of captains and caregivers by email. Of the 385 surveys sent out, 165 (43%) were completed. Eighty four percent of responders ( n = 110) thought that waiting time was satisfactory or very satisfactory, and 97% ( n = 128) were satisfied or very satisfied with their relationship with the remote physician. Thirty eight per cent of participants ( n = 50) considered that the physician understood the medical problem very well; understanding was good in 58% of cases ( n = 76) and bad in only 4% of cases ( n = 5). Sixty two per cent of participants ( n = 83) sent pictures before consultation. The respondents were also satisfied with the telephone advice overall, the competence of the physicians providing the advice, the length of time spent waiting, the verbal prescription and the medical advice given. Onboard caregivers were generally well satisfied with the maritime teleconsultations and the advice provided by the CCMM physicians.

This paper traces the career of William Anderson, naval surgeon and naturalist, who served in Cook's ship Resolution on the second and final voyages, and died of tuberculosis high in the Arctic.

Objectives Two biographies of Admiral Francis Beaufort (1774-1857) have stated that, aged 20-25 years, he suffered from porphyria cutanea tarda (PCT) that was ‘cured’ following severe blood loss during a naval skirmish. We have examined the evidence concerning the nature of his skin disease. Design Primary records, most notably Beaufort's correspondence with his family, his journals and his father's diaries were sought out and analysed. Setting This case report is discussed in the context of 18th-century naval medicine and concepts and treatment of skin disease. Results The description of his lesions, their age of onset, their progression and response to treatment, particularly topical tar and associated features are quite inconsistent with a diagnosis of PCT. His mother, Mary Waller Beaufort (1739-1821), consulted Dr Robert Darwin in 1803 about a painful skin disease affecting her legs. Detailed description of the lesions and a contemporary diagnosis are not available but possible diagnoses include chronic psoriasis and stasis eczema. Conclusions A more tenable diagnosis is that Francis Beaufort had chronic plaque psoriasis remitted by bed rest and convalescence in the sunny Mediterranean climate with cessation of alcohol consumption and improved nutrition as well as topical and oral medications.

In June 1813, during the War of 1812–1814 with America, the US Brig Argus embarked from New York with orders to raid British coastal commerce, causing panic in the British and Irish shipping trade. On the morning of 14 August, HM Brig Pelican engaged Argus off St David's Head. After a fierce battle, Argus surrendered. Her surgeon was James Inderwick whose journal tells of his work as a surgeon in the US Navy.

Between 1793 and 1815, The French Wars between Britain and France provided work for a generation of army surgeons. Military efficiency in record keeping and subsequent governmental archiving ensured that material is available for the biographers of such men. However, by contrast, information on these surgeons while in civilian practice is scant. Thomas Prosser is a typical example of a well-qualified early 19th century surgeon who chose a career with the army and who, while on half pay, was surgeon to a female convict ship.

Robert Robertson was born in Scotland and trained to be a surgeon. In 1760, he served briefly on a whaling ship and then entered the Royal Navy. He subsequently had many postings, several of them to the tropics. He recorded his observations on fevers, scurvy and other illnesses. After 23 years of active service, he retired to private practice in Hampshire. However, later he rejoined the service and was appointed physician to the Royal Hospital, Greenwich, where later he was made a Director. During this period, he addressed the problems of illness after the days of active service. Robertson was thus an early practitioner in the care of the elderly. He retired in 1807 and died at Greenwich at the age of 87.

Lind’s Treatise of the Scurvy1 is a good illustration of the basis for mid-18th century judgement and decision-making in at least two respects: it quotes the contributions of others at length, and its therapeutic recommendations had little impact.2,3 Lind dedicated his book to Lord Anson because an account of Anson’s circumnavigation published in 1748 had prompted Lind’s interest in scurvy: at least 380 out of a crew of 510 on one of Anson’s ships had died of the disease. When Lind began to read the literature on scurvy, he realized that the only existing descriptions of the disease were by lay seamen and doctors who had never been to sea. ‘No physician conversant with this disease at sea had undertaken to throw light upon the subject,’ and Lind felt that this was one of the reasons why there was so much confusion about the diagnosis, prevention and cure of the disease. As Lind wrote bluntly: ‘Indeed, before the subject could be set in clear and proper light, it was necessary to remove a great deal of rubbish’1 (p. viii).

Sir Andrew Halliday (1781–1839) was domestic physician to HRH the Duke of Clarence (1765–1837) (who was later to become King William IV). He also served in the Napoleonic Wars — in Portugal, Spain and Waterloo — as well as in the West Indies, and became the first physician to the Seamen's Hospital Society. Unlike many of his contemporaries, Halliday was also a prolific author, many of his publications being on lunatic asylums in Great Britain and Ireland.

The surgeons of the Royal Navy in the late eighteenth and early nineteenth centuries were obliged to procure their own instruments before taking up post on ship. The Company of Surgeons (Royal College after 1800), as well as examining surgeons for their fitness to practise in the Royal Navy, was granted the privilege of examining the surgeons' instrument chests. This privilege was originally bestowed by Charter of Charles I1 and it was an honour that was jealously guarded by the Surgeons. They fought off an attempt to hand this duty over to the Surgeon and Physician of Greenwich Hospital in 1715 and once again in 1795. When the Company became the Royal College of Surgeons in 1800, they retained this ancient honour; but the Navy Regulations of 1805 no longer mention it, and when the College ceased this practice is not clear.2 Royal Navy Regulations of 1731 stated that, after examination, the chest was to be locked ‘and the seals of the Physician and of the Surgeons' Company to be affixed thereto in such a manner, as to prevent its being afterwards opened, before it comes on board; nor is the Captain to admit any Chest into the Ship without these marks upon it’.1 The purpose of this examination was twofold. First, it ensured that the surgeon had the correct instruments and these were of sufficient standard to cope with the variety of procedures encountered during a long sea voyage. Second, the seals prevented the surgeon from selling or pawning any of the instruments to recoup some of his capital before boarding the ship. The pay of the Navy surgeons was meagre and they were unlikely to be able to afford fine sets of matching instruments. A capital set of instruments, sufficient for most procedures, cost between 18 and 25 guineas at this time (Crumplin MKH, Personal communication). Full surgeons were paid £5 a month2 and the pay for assistant surgeons and surgeons' mates was between £2 and £3 a month.3 Since the time of Charles I, an allowance was granted to the surgeon to buy instruments and medicines; in 1781 the allowance for a senior surgeon was £62. This was hardly sufficient to provide the instruments and adequate medicines for the whole crew on a long sea voyage. The poorly paid surgeon would fulfil his duty as cheaply as possible, gathering together instruments of varying makes and quality. After 1805, the medicines were provided by the Navy but the surgeon still had to buy his own instruments.2 This was not the case for Army surgeons during this period; each company purchased an instrument chest for its surgeon. The list of instruments in Box 1 dates from 1812.1 It was provided by Messrs Evans and Co, Old Change, London, and was presented to the College of Surgeons for approval. The College suggested removal of the lenticular and the tobacco from the apparatus for restoring suspended animation, and also the ‘probe scissors’ since they were ‘improper to be used in any operation of surgery’.2 Box 1 List of surgical instruments which were to be included in the naval surgeon's chest (Supplied by Messrs Evans & Co, c. 1812) Using this list as a guide, I attempt in this article to bring together the instruments carried on board ship by surgeons in the era of Nelson. These instruments are not all from a single matching set but are by a variety of makers and of varying dates and quality and therefore mirror those bought and used by the surgeons. The instrument list of Evans and Co falls easily into distinct parts according to purpose—amputation, trephining, drainage of fluid, dentistry, probing of wounds and other minor procedures, bleeding and cupping, and miscellaneous. Although this classification is to some extent my own, complete instrument sets, particularly from a little later, in the mid-nineteenth century, are often arranged and described by operation.

Historically, requests from shipping in UK coastal waters for emergency medical advice have been handled on an ad hoc basis by various accident and emergency departments on behalf of the Coastguard. A formal contract to provide this service has recently been established with the Aberdeen Royal Infirmary in Scotland and the Royal Alexandra Hospital in Portsmouth, England. A pre-contract audit showed that the involvement of medical professionals in the evacuation decision improved the quality of triage and intervention. The medical staff at both hospitals received training in giving medical advice and the level of medical knowledge that could reasonably be expected of ships' crews. Providing advice to commercial airlines developed from the maritime service. In association with a private company, staff at the Aberdeen Royal Infirmary have developed procedures to support cabin crew and medical professionals on board (initial figures suggest that a medical professional is present on about 45% of flights). At present, although there are insufficient data to draw any firm conclusions, it appears that up to two-thirds of diversions could be avoided using this service.

This is a shortened account of the bitter experiences of American prisoners of the British during the war of 1812–14 as seen through the eyes of a young New Englander who kept a diary of events in various prisons on both sides of the Atlantic. Resentment against the delay in release from captivity at Dartmoor prison boiled over in April 1815 and an attempt at mass escape resulted in many casualties. These were admirably dealt with by Surgeon George Magrath (1775–1857) who had been Flag Medical Officer to Nelson in the Mediterranean. His skill and humanity to the American prisoners at Dartmoor earned their deep respect.

Nurses at various times and in various places find their aims as nurses in conflict with their situation, such as having too many patients to do any justice to any of them. Nursing in the military requires prioritizing the mission of the department of defense, that is to say maintain the readiness of the fighting force and to function within a strict hierarchical organization with respect to authority. Within this context, nurses in the United States military today are asked to assist members of the armed forces who are struggling with sacrifices during very confusing and uncertain times.

To submit a letter in response to a JRSM article, please visit: http://jrsm.rsmjournals.com to find the article concerned, then click on the ‘send a quick comment’ link found in the article information section. Quick comments will automatically he considered for publication in print.

Iain Milne considered the possibility that Lind's report of a controlled trial may be a fabrication1 and kindly cited my review.2 However the credit should instead go to Graham Sutton who knew, as I did not, that the ship's papers of HMS Salisbury survived and there were no sailors sick with scurvy on this ship in May 1747.3

On 6 December 1805 HMS Isis, a 50 gun man-of-war, was stationed in home waters off Spithead when the ship's surgeon, Benjamin Lara, noted the addition to the sick-list of Able Seaman John Cummings. Cummings, a 29-year-old American, presented with 'excessive pain in the stomach and intestines, incapacity of retaining anything in the stomach and pain on walking or standing erect'. On questioning, he admitted to 'having swallowed on the preceding day 19 or 20 clasp knives and one clasp knife case, the latter of which was soon rejected, but the former retained'.1 Lara's journal ends before the completion of Cummings' clinical episode and the subsequent journal is lost. The end of the story, however, can be found in the library of the Royal Society of Medicine. Benjamin Lara, the surgeon, subsequently described the case in a letter dated 27 March 1809 and addressed to Dr Curry, a physician at Guy's Hospital. After Curry's death, this letter and other papers pertaining to the case, including the patient's own description of his story, were discovered by Alexander Marcet. Dr Alexander John Gaspard Marcet MD FRS (1770–1822) (Figure 1), likewise a Guy's man and a friend of the late Dr Curry, was a founding member and first secretary of the Medical and Chirurgical Society of London which subsequently became the Royal Society of Medicine. Marcet presented the case of John Cummings to the Society and this lecture and copies of both accounts are preserved in the Society's Transactions.2 Figure 1 Alexander John Gaspard Marcet, MD FRS (1770–1822). Painting by Sir Henry Raeburn, RA, which hangs in the dining room of The Royal Society of Medicine. (Reproduced by kind permission of The Royal Society of Medicine, London) In Cummings' own account of his illness, he revealed that this was not the first time he had swallowed knives. While stationed in France in 1799 he had watched a mountebank pretending to swallow knives in a circus near Havre de-Grace. He later bragged that he could do this in reality, and his shipmates wagered he could not. He swallowed four knives with no obvious ill effect, although only three of the four were seen again. Some six years later he was stationed in Boston, USA. His current shipmates did not believe his story and under the influence of grog (rum and water) he began again. After swallowing fourteen knives, he was admitted to Charleston Hospital with abdominal pain. After a few days the knives had all passed safely through and his symptoms resolved, just in time for him to sail back with his ship to France. His next ship was the Betty of Philadelphia. Early in the voyage back from France to the USA she was stopped by the Royal Navy and he was impressed into service aboard HMS Isis. On 4 December 1805, drunk once again, he swallowed his final twenty knives and two days later he reported to Benjamin Lara. He was given castor oil and 'glysters' (enemas) of thick water-gruel, and opium for the pain. When the symptoms continued, a dose of 30 or 40 drops of sulphuric acid daily was tried in an attempt to dissolve the iron. Finally he was given 'murinated tincture of iron', but this made his pain worse. After remaining on the sick list for three months he 'felt the knives drop into his bowel and felt much relieved' and was discharged back to light duties. In June 1806, Cummings vomited one side of a knife handle; in November and again the following February he passed more pieces. Although Lara was transferred off HMS Isis in November 1806 his successor, Mr Peter Kelly, kept him informed of the patient's progress. Cummings continued to pass pieces of iron and knife handles; each ejection was accompanied by considerable pain and in one instance the vomiting of two pounds of blood. He was finally discharged from the ship, as unfit, in June 1807. After leaving HMS Isis, Cummings travelled immediately to London and presented himself to Guy's Hospital for treatment. His admitting physician, Dr Babbington, did not believe his story and discharged him after a few days. He was readmitted in August, however, his condition much deteriorated. Examining the patient with Sir Astley Cooper, Babbington 'after minute discussion' asked for the opinion of the surgeon Mr Lucas. Lucas performed a rectal examination and felt one of the knives in the rectum. Although he was again discharged on 28 October 1807, Cummings was readmitted in September 1808, this time under the care of Dr Curry. He was given more acid, mucilage and opium but slowly deteriorated, suffering bouts of pain and indigestion and having difficulty eating. He finally died in March 1809 'in a state of extreme emaciation'. The necropsy was conducted by Mr Travers, surgeon and anatomy demonstrator at Guy's, supervised by Mr Lucas. The abdominal cavity was noted to have a 'black ferruginous' tinge from the iron knives. A knife blade and a knife back-spring were found in the intestines. The spring had chronically eroded through into the peritoneum, transfixing the colon near the left kidney but without causing peritonitis. The blade was wedged across the rectum, its end embedded in the pelvic wall. Thirty to forty fragments of wood, metal and horn were found when the stomach was opened. The case was presented to the Medical and Chirurgical Society of London by Alexander Marcet on 19 March 1822, just a few months before his own death. He displayed the pieces taken from Cummings' stomach to the audience in a glass case (Figure 2). Figure 2 Fragments of knives found in the stomach of John Cummings. Displayed to the members of the Medical and Chirurgical Society of London on 19 March 1822. The items on the bottom row were expelled whilst he was on board HMS Isis. The spring that transfixed ...

The fitness standards required for drivers in the transport industries are discussed. Ways of reducing the risks imposed by unfit drivers and pilots range from automatic safety systems to the use of a copilot trained to spot signs of unfitness. The risk of sudden cardiac event has long been a cause for concern although there are no quantitative data identifying the frequency of attributable transport accidents. For airline pilot fitness a risk of less than 1% of a fatal event in the subsequent year is considered acceptable in the presence of a copilot. The risk ceiling is 20% annually for car drivers and 2% for bus and lorry drivers. The risk of hypoglycaemia from diabletes is more complex to assess. Sight defects correctable by the use of glasses are not considered a problem but useful field of view should be checked. Other stable vision impairments may be assessed using practical driving tests under controlled conditions. The risks from variable impairments such as alcohol and fatigue are discussed. The development of common criteria across transport modes is considered.

Motor and cognitive tests were administered to four Navy divers under dry baseline conditions, in warm and cold shallow water, and again in cold water at 183 m. It was found that water resistance, cold water, and prolonged exposure to cold water at depth resulted in significant decrements in motor performance. None of these factors, however, consistently or reliably impaired cognitive performance. Those cognitive impairments which were found could probably be accounted for by impaired motor performance. The motor effects of prolonged exposure to cold water at 183 m may be related to either severe heat debt or CO2 retention. These results indicate that present heating techniques are inadequate to protect divers from significant motor impairments after entering cold water at any depth, and from additional decrements after exposure to cold water for an hour at 183 m.

This study examined the dimensionality and validity of Levenson's (1973a) multidimensional locus of control scale in two independent samples of Navy enlisted men. It was hypothesized that internal subjects would report better health, greater general satisfaction, and higher levels of family strain due to separation. Given the nature of the military environment, it was expected that external scores would be more pronounced for powerful other rather than chance-oriented expectancies. The results generally agreed with hypothesized relationships and are discussed in terms of the utility of a multidimensional locus of control construct in measuring generalized expectancies.

A group of 217 Saudi Arabian naval recruits were examined clinically, radiographically, and microbiologically for the prevalence of Streptococcus mutans. Caries experience was considerably lower than in US recruits of comparable age and showed a significant positive correlation with the prevalence of S mutans in dental plaque samples. The distribution of S mutans biotypes and their relationship to dental caries in the Saudi Arabians were studied.

A time-estimation task was considered for inclusion in the Performance Evaluation Tests for Environmental Research (PETER) battery. As part of this consideration, the effects of repeated testing on the reliability of time judgments were studied. The method of production was used to estimate eight time intervals. Five trials per day at each interval were administered individually to each of 19 subjects for 15 consecutive workdays. Two scores, constant error and variable error, were reported. The effect of days was not significant for constant error and was moderate for variable error ( p < .04). The standard deviations were relatively stable across trials. A pronounced decline in reliability over repeated days of testing was found for both errors. It was concluded that this time-estimation test would be a poor candidate for inclusion in PETER, but further research is warranted because of the potential unique contribution of a time-estimation task in a performance test battery.

A critical tracking test was considered for inclusion in the Performance Evaluation Tests for Environmental Research (PETER) Battery which was designed for use in unusual environments. Baseline measures were obtained by testing 18 subjects for 14 consecutive days. Mean performances increased but standard deviations were constant over the 14 days. Test-retest reliabilities improved over the first 8 days after which differential stability was seen. The implications for the use of this test in exotic environments are discussed. The critical tracking test is recommended as a good candidate for environmental research when practiced to total stability.

Streptococcus mutans was detected by a colorimetric test in all of 53 caries-active naval recruits and in 98 of 120 caries-free (DMFT = 0) recruits. The number of positive sites was greater in the caries-active subjects. The low percentage of false positive and false negative S. mutans isolations confirmed the value of the colorimetric test as a preliminary indicator of S. mutans.

Basal plasma hydroxyproline was measured in 104 male Navy Seal candidates 1 week into their intense physical training program, which lasted 7 weeks, and correlated to the incidence of connective tissue injuries incurred later in the training program. Eleven subjects (10.6%) were diagnosed as having connective tissue injuries. Those subjects with connective tissue injuries had a significantly higher (P less than 0.05) mean plasma hydroxyproline value (4.02 micrograms/ml) than subjects without injury (3.10 micrograms/ml). The majority of graduates (75%) had plasma hydroxyproline values less than 3.3 micrograms/ml. These graduates represented the strongest and most enduring injury-free subjects. Of the subject pool who incurred connective tissue injuries, only 27% had plasma hydroxyproline values less than 3.3 micrograms/ml. The majority of the injured subjects (73%) had plasma hydroxyproline values greater than or equal to 3.3 micrograms/ml. In conclusion, there is a relationship between initial training basal plasma hydroxyproline levels and connective tissue injuries later incurred in an intense physical training program. These data suggest that elevated plasma hydroxyproline levels may represent a risk factor associated with connective tissue injuries.

Summary.-Briggs and Nebes' ( 1975 ) handedness questionnaire was administered to three different groups of Navy men. Analys~s showed fewer left-handers and more mixed-handers than the data from Br~ggs and Nebes' study. Possible reasons for the differences and their implications are discussed. Many researchers have investigated the relationship between handedness and cerebral dominance for various language and visuospatial tasks (CarterSaltzman, 1979; Kocel, 1977; McGlone & Davidson, 1973). In general the approach used has been to administer a handedness questionnaire or series of motor tests to subjects and similarly to test their performance on a perceptual or cognitive test of interest. Conclusions are then drawn as to the pattern of hemispheric dominance for that task and its relationship to handedness. There appears to be, however, very little research that has examined the distribution of handedness across different groups of subjects. If it can be shown that different groups show different patterns of response on the same handedness questionnaire, then researchers must be particularly cautious in drawing conclusions relating handedness as measured by questionnaires to cerebral dominance across different groups. This study began, in line with Levy's work ( 1974), with the observation that very few U. S. Navy sonar operators were classified as left-handed by a standard handedness questionnaire. Because- the job performed by these men consists mainly of visuospatial tasks (Kinney & Luria, 1980), this seemed to support Levy's hypothesis (1969) that left handers are less clearly lateralized and suffer from deficits in some perceptual tasks. To examine this question the Briggs and Nebes' (1975) handedness questionnaire was administered to 289 Navy sonarmen; essentially all of those sonar operators receiving training at a local Navy Sonar School. The results did suggest that fewer Navy sonar operators were classified as left-handed. One criticism of this finding, however, addressed the question of whether the student population in the Briggs and Nebes' paper (1975) was an appropriate comparison group. This study, therefore, examines this criticism. The Briggs and Nebes' questionnaire was administered to two additional U. S.

Enamel solubility rates were determined in vivo to depths of 1 to 2 mum in the teeth from two samples of naval recruits that had been grouped, respectively, according to DMFT scores and visual indexes of oral hygiene status. No positive correlation between enamel solubility rates and DMFT scores were observed; rather there was a tendency for caries-resistant participants to have a highest apparent enamel solubility rates, even though mean differences among the DMFT groups were not generally significant. Intra-subject measurements on 12 teeth per participant for eight of the recruits showed, on the average, only about one half the variability founl incisors for more than 70 of the recruits. The least variability was found for measurements on paired maxillary central incisors. It was concluded that factors such as tooth morphology and, in particular, tooth-surface films could considerably affect enamel solubility rates measured in vivo.

The objective of this study was to measure acceleration levels to which passengers would be subjected in the fonvard seating areas of two styles of bowrider recreational boats. Acceleration exposure data were collected aboard a monohull and a trihull boat as they crossed 0.48- and 0.76-m wakes at speeds of 24 and 40 km/h. Substantial increases in maximum peak accelerations and their rates of onset were found with increases in boat speed and wake height. Vertical acceleration levels and their onset rates were lowest aboard the monohull; however, the effects of boat speed and wake height upon vertical acceleration exposures were much greater than differences found between boats. Similar findings were obtained for longitudinal acceleration measures. Based upon presently available human acceleration tolerance information, the risk of spinal compression fracture aboard the boats examined appears remote due to the very short durations of the accelerations endured.

The present study was designed to investigate the relationship between changes, experienced both within the personal lives of individuals and within the work environment, and job satisfaction. Results suggest that negative life changes experienced within ones personal life are related to lower levels of satisfaction while both positive and negative changes experienced within the work environment are correlated with satisfaction, positive changes being related to higher levels and negative changes being related to lower levels of satisfaction. The implications of these findings for assessing organizational stress and for the prediction of attrition from organizations are discussed. (Author)

Most of the previous literature concerning otologic problems in compressed gas environments has emphasized middle ear barotrauma. With recent increases in commercial, military, and sport diving to deeper depths, inner ear disturbances during these exposures have been noted more frequently. Studies of inner ear physiology and pathology during diving indicate that the causes and treatment of these problems differ depending upon the phase and type of diving. Humans exposed to simulated depths of up to 305 meters without barotrauma or decompression sickness develop transient, conductive hearing losses with no audiometric evidence of cochlear dysfunction. Transient vertigo and nystagmus during diving have been noted with caloric stimulation, resulting from the unequal entry of cold water into the external auditory canals, and with asymmetric middle ear pressure equilibration during ascent and descent (alternobaric vertigo). Equilibrium disturbances noted with nitrogen narcosis, oxygen toxicity, hypercarbia, or hypoxia appear primarily related to the effects of these conditions upon the central nervous system and not to specific vestibular end-organ dysfunction. Compression of humans in helium-oxygen at depths greater than 152.4 meters results in transient symptoms of tremor, dizziness, and nausea plus decrements in postural equilibrium and psychomotor performance, the high pressure nervous syndrome. Vestibular function studies during these conditions indicate that these problems are due to central dysfunction and not to vestibular end-organ dysfunction. Persistent inner ear injuries have been noted during several phases of diving: 1) Such injuries during compression (inner ear barotrauma) have been related to round window ruptures occurring with straining, or a Valsalva's maneuver during inadequate middle ear pressure equilibration. Divers who develop cochlear and/or vestibular symptoms during shallow diving in which decompression sickness is unlikely or during compression in deeper diving, should be placed on bed rest with head elevation and avoidance of maneuvers which result in increased cerebrospinal fluid and intralabyrinthine pressure. With no improvement in symptoms after 48 hours, exploratory tympanotomy and repair of a possible labyrinthine window fistula should be considered. Recompression therapy is contraindicated in these cases. 2) Vestibular end-organ injuries have been noted in three divers after sudden changes in inspired inert gases at a stable deep depth. They are postulated to result from transient intralabyrinthine osmotic pressure differences, or from bubble formations at labyrinthine tissue interfaces occurring with the counter-diffusion of the two dissolved inert gases at high partial pressures. Such injuries should be preventable by avoiding changes in inert gases at deep depths. 3) Inner ear injuries can be the major or only manifestation of decompression sickness. In a series of 23 such cases, a significant correlation exists between prompt recompression, relief of symptoms, and lack of residual deficits. The management of otologic decompression sickness is discussed. 4) Loud noise has been noted during helmet and chamber diving and has been associated with temporary threshold shifts in helmet divers. Appropriate damage risk criteria for noise exposure in compressed gas environments are needed, and potentially damaging noise exposures should be avoided.

Twenty-one U.S. Navy divers were given several standard visual tests, the Purdue Peg-board, the Bennett Hand Tool Dexterity Test, and the Wechsler Memory Scale while breathing air or 30% nitrous oxide. The results showed that visual function, fine and gross motor performance, and long-term memory were normal under nitrous oxide, while learning and short-term memory were significantly impaired. The subjective effects of breathing nitrous oxide were similar to those experienced during compressed air narcosis. The selective impairment of short-term memory suggests that divers might be able to perform useful work at depths deeper than those currently authorized, provided the tasks were well learned and practiced.