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Humans evolved as an athletic species able to run in the midday heat, to throw with exquisite accuracy and to strike powerfully despite relatively weak upper arms compared to those of the great apes. The true extent to which humans could run long distances was first tested in a unique series of 6-day foot races contested between 1874 and 1888 by professional athletes from England and the United States. These athletes typically would have expended approximately 60 000kcal (24.12MJ) of energy during these races. The discovery of the bicycle soon caused the replacement of these races by 6-day cycling races which, in turn, led to the modern day Tour de France, the cycling race across America (RaAM) and two running races across the width of the United States in 1928 and 1929. The total energy expenditures during these different events can be estimated at approximately 168 000, 180 000 and 340 000kcal respectively. But, in terms of the total energy expenditure, all these performances pale somewhat when compared to that of Robert Falcon Scott's Polar party during the 1911/12 British Antarctic Expedition. For most of 159 consecutive days, Scott's team man-hauled for 10 hours a day to the South Pole and back covering a distance of 2 500km. Their predicted total energy expenditure per individual would have been about 1 million kcal, making theirs, by some margin, the greatest sustained endurance athletic performance of all time. Interestingly, the dogs that provided the pulling power for Norwegian Roald Amundsen's team that was the first to reach the South Pole, 35 days before Scott's party, would have expended about 500 000kcal in their 97 day trip, making theirs the greatest animal "sporting" performance on record. By contrast, mountain climbers expend only approximately4 000kcal/day when climbing at extreme altitudes (above 4 000m). This relatively low rate of energy expenditure results from the low exercise intensities that can be sustained at extreme altitude. Here I argue that this slow rate of energy expenditure is caused, not by either myocardial or skeletal muscle hypoxia as is usually argued, but is more likely the result of a process integrated HYPoXia and tHE CiRCulation Chapter 0 centrally in the brain, the function of which is to protect the body from harm. At extreme altitude the organ at greatest risk is the brain which must be protected from the catastrophic consequences of profound hypoxia. A key feature of this control is that it acts "in anticipation" specifically to insure that a catastrophic biological failure does not occur. The evidence for this interpretation is presented. [ABSTRACT FROM AUTHOR]

Polycystic ovary syndrome (POCS) is a common disorder in women resulting in anovulation and reproductive dysfunction. Androgen excess and hyperinsulinemia are key contributing features that are exacerbated by obesity. Both weight reduction and increases in physical activity are highly effective in increasing insulin sensitivity but underutilized in clinical practice as evidence on effective strategies to achieve this are lacking. The use of metformin is effective in restoring ovulatory function through improvement in insulin sensitivity, possibly also mediated by weight loss. Orlistat and sibutramine have also been shown to assist in weight loss and thereby restore reproductive function. In the morbidly obese with PCOS, bariatric surgery has been shown to achieve substantial weight loss and to be effective in improving fertility. The literature on effective diet and exercise programs for PCOS has been sparse. Studies examining the role of meal replacements as well as structured dietary patterns with higher protein composition and/or lower glycemic-index carbohydrates show promise. Further studies on novel lifestyle programs are needed compared to standard care and pharmacotherapy to guide clinical practice. [ABSTRACT FROM AUTHOR]

Bill Ricker was an internationally recognized expert on the stone fishes (Plecoptera). These insects have aquatic larvae that live mostly in cool and clear running water. They are of ecological signi.cance in the breakdown of leaf-litter and the cycling of detritus in aquatic lotic habitats. Since they can account for a signicant portion of the diet of some .shes in cold northern waters, they are linked with Ricker,s other work in fisheries. Within 1 year of taking up the study of stone.ies, Ricker was describing species new to science. He continued such activity through most of his life, describing or co-describing some 108 species and 46 genera. Ricker made other outstanding contributions, publishing in 1952 what is regarded as the most important publication dealing with stone.y systematics in the 20th century. Many names he coined in his studies clearly demonstrated his linguistic .air and humour. He made signi.cant contributions to an understanding of the biogeography of stone.ies, and received many honours and citations for his research. [ABSTRACT FROM AUTHOR]

Through three versions of a handbook on computations for biological statistics of fish populations, W.E. "Bill' Ricker played a pivotal role in founding the field of quantitative fishery science. His interests, however, extended far beyond the con.nes of quantifiable events to a deep appreciation for the natural world. In this article, I trace his development of fishery models from the 1940s to the 1970s, using examples that illustrate his approach to statistics and biological systems analysis. I describe changes in technology and statistics that have made it possible to extend his research in new directions, although his approach still lies at the core of all modern fishery models. His gentle, inquiring spirit persisted long after his retirement in 1973, as I illustrate from personal experiences with him during the 1990s. [ABSTRACT FROM AUTHOR]

Bill Ricker,s career went through many twists in his academic years. He had taken botany in his senior matriculation year at high school and he had collected over 100 species of flora before commencement of university life. At the conclusion of his first university year, he set out over the summer to collect a much larger sample of species, primarily from the Great Lakes-St. Lawrence ecoregion, to fulfil a requirement for a second year botany course (spermatophytes). He identifed about 390 species, and some 254 were collected and pooled with those from previous years to make a final submission of 354 spermatophyte species. Field plant identification continued in each academic year thereafter, in concert with collections and identifications of aquatic invertebrates in his summer projectswhile under the employment of theOntario Fisheries ResearchLaboratory. At the conclusion of his undergraduate years, Bill had taken more courses in botany than in zoology, and it was the summer employment that had really prepared him for postgraduate work in fisheries biology, which was ecologically oriented. When Bill left Ontario in the autumn of 1931 he had identi.ed over 600 species of plants, excluding lower cryptogams, but including many aquatic species of higher plants. In western North America Bill,s botanical careerbegan atCultusLake in 1931. Heagain studied all aspects of the basinwhileemployed with the federal government, and from the work he assembled a Ph.D. thesis. At the time of thesis completion he had identi.ed over 300 species of .ora, including alpine plants at timberline, 1500 - 1800 m above lake level, and planktonic algae in its water column. In 1939, after more field fisheries work in the Fraser River basin of British Columbia, Bill accepted a position with the biological staff at IndianaUniversity. In this periodwhich concluded in 1950 he identi.ed another 50 - 110 species of flora, all in the Carolinian ecoregion, and hitherto not seen by him. Considering all floral classes, Bill,s eastern North American repertoire had by then added up to 791 species, representative of more than 112 families of plants. Returning west for the remainder of his life, new identifications elsewhere added to his Cultus Lake list which slowly added up to about 1000 species for the west coastal region ofNorthAmerica. Flora was also identified elsewhere in the mid-continental region of NorthAmerica, in Eurasiawhere theAbisko region ofLappland was a highlight, and in SouthAmerica and New Zealand. Records of his botanical prowess, were kept primarily in his diaries, which began in 1923 and were maintained consistently to the end of 1934, and thereafter intermittently to 1949. The diaries reveal that his career as a budding botanist was subtly hijacked by a wily Professor W.H.K. Harkness in the rival Biology Department who outmanoeuvred Drs. R.B. Thompson and R.A. Sifton in the Botany Department. The former always managed to employ Bill in summer and keep him occupied in the department,s labs during the autumnandwinter and spring, tying up any free time when the botanist had approached him on lab work. Certainly, the botany courses taken andwhich he excelled atweremore appropriate for his aquatic ecological pursuits. Salesmanshipwon the day for the zoologists, but Bill was a life-long botanist regardless of whatever else he studied or managed throughout his professional career. The last days of his life had a botanical conclusion. [ABSTRACT FROM AUTHOR]

William Edwin (Bill) Ricker (1908 - 2001) is best known as one of the founders of fishery science. He was also internationally recognized as an entomologist and a scientific editor. In an accompanying article written shortly before his death, Bill gives his own recollections of his career and intellectual development. A bibliography of Bill,s scientific publications, translations and manuscripts has been compiled by his son Karl, and accompanies this article. Karl has also written a detailed account of Bill,s early education and his accomplishments in botany and ornithology. Geo. Scudder summarizes Bill,s contributions to entomology, Jon Schnute provides both personal and professional insights into Bill,s mathematical accomplishments, and Dick Beamish and Don Noakes present personal recollections of Bill as a scientist and colleague. [ABSTRACT FROM AUTHOR]

A mass immunization campaign is a rapid vaccination intervention across age groups as opposed to provision through routine vaccination at a specified age attainment. Some countries use campaigns routinely as they have experience that shows that in their health systems higher coverage can be reached through campaigns than by routine service provision. Whilst many industrialized and non-industrialized countries have introduced new vaccines into their routine programme, the UK is unusual in deliberately doing this via campaigns. A number ofmass immunization campaigns have been implemented in the UK, either integrated into the routine immunization programme such as the annual influenza immunization campaign; as a catch-up campaign alongside the introduction of a new vaccine into the routine vaccination schedule (MMR, Haemophilus influenzae b, Meningococcal C conjugate vaccine); or as a one-off campaign, to boost immunity in a particular age group, without introducing the vaccination into the schedule routinely at that age (Haemophilus influenzae b). Campaigns require intense planning at national and local level with leadership to achieve propermanagement.Although the components of an immunization campaign can be described separately-strategic planning, vaccine supply, communication and surveillance; for a programme to be successful integrated planning is essential. [ABSTRACT FROM AUTHOR]

Size measurements are crucial for studies on the growth, maturation, maximum size, and population structure of cartilaginous fishes. However, researchers use a variety of measurement techniques even when working on the same species. Accurate comparison of results among studies is only possible if the measurement technique used is adequately defined and, if different techniques are used, a conversion equation can be derived. These conditions have not always been met, leading to invalid comparisons and incorrect conclusions. This paper reviews methods used for measuring chondrichthyans, and summarises the variety of constraints that influence the choice of a measurement technique. Estimates of the variability present in some measurement techniques are derived for shortfin mako shark, Isurus oxyrinchus, porbeagle shark, Lamna nasus, blue shark, Prionace glauca, Antarctic thorny skate, Amblyraja georgiana, and Pacific electric ray, Torpedo californica. Total length measured with the tail in the natural position (sharks) and disc widths (batoids) have higher variability than other methods, and are not recommended. Instead, the longest longitudinal axis should be measured where possible and practical; i.e., flexed total length for sharks, total length for batoids (excluding suborder Myliobatoidei), pelvic length for batoids of the suborder Myliobatoidei, and chimaera length (snout to posterior end of supracaudal fin) for chimaeroids (except for Callorhinchus, for which fork length should be measured from the anterior edge of the snout protuberance). Straight-line measurements are preferred to measurements over the curve of the body. Importantly, measurement methods must be clearly defined, giving information on the anterior reference point, the posterior reference point, and how the measurement was made between these two. Measurements using at least two different methods are recommended on at least a subsample of the fish in order to develop conversion regression relationships. [ABSTRACT FROM AUTHOR]

Inter- and intra-regional variations in vertebrae morphology and growth increment counts (band counts) were analyzed for two carcharhinid shark species, Carcharhinus plumbeus (n = 10) and C. limbatus (n = 11). Five sequential vertebrae were removed from the cervical region, above the branchial chamber and posterior to the chondrocrainium, and thoracic region, below the first dorsal fin. Dorsal-ventral height, medial-lateral breadth, and caudal-cranial length were measured for each sampled vertebra. Results indicate no significant difference in vertebral morphology within a sampled region of the vertebral column. However, a significant difference in vertebral morphology was noted between regions for both shark species, with thoracic vertebrae consistently larger than cervical vertebrae. A sub-set of three vertebrae was taken from each sampled region of each shark for sectioning and counting of growth increments. Analyses of growth increment counts by two readers indicated no significant difference in band counts within and between sampled regions. [ABSTRACT FROM AUTHOR]

Sandbar sharks, Carcharhinus plumbeus, collected from commercial shark fisheries in Western Australia were aged by examination of sectioned vertebrae and analysis of tag-recapture data. Growth curves were derived from consensus counts of growth bands from the vertebrae of 238 individuals ranging in size between 47 and 154 cm fork length (FL). The annual periodicity of growth band formation was validated using vertebrae from tagged sharks, which were injected with oxytetracycline (n = 9) and calcein (n = 23) and were at liberty for up to 8.1 years. The oldest female was estimated to be 25 years of age and the oldest male was 19 years. The ages at which 50% of female and male sharks were mature were estimated to be 16.2 and 13.8 years, respectively. Growth increment data from 104 tagged C. plumbeus, which were at liberty for up to 7.4 years, were used to construct growth curves for comparison with those derived from vertebral analysis. The two methods yielded noticeably different results. Based on a known size at birth of 42.5 cm FL, von Bertalanffy parameters estimated using length at age data from vertebral analysis were: K = 0.039 year−1 and L∞ = 245.8 cm; K = 0.044 year−1 and L∞ = 226.3 cm; and K = 0.040 year− and L∞ = 239.6 cm for females, males and both sexes combined. The von Bertalanffy parameters derived from tag-recapture data were: K = 0.153 year−1 and L∞ = 142.0 cm for combined sexes. However, as sharks longer than 142.0 cm were commonly encountered during sampling, these estimates appear to be biologically unrealistic. Also, given the high variability in growth rates of tagged sharks, compared to those derived from the larger vertebral analysis dataset, vertebral ageing was concluded to provide a better description of age and growth in this study. These results confirm that C. plumbeus is a slow-growing and late maturing species and thus recovery times from periods of overexploitation would be considerable. [ABSTRACT FROM AUTHOR]

Age and growth estimates for the shortfin mako, Isurus oxyrinchus, derived from vertebral centra of 258 specimens (118 males, 140 females), ranging in size from 64 to 340 cm fork length (FL) were compared with data from 22 tag- recaptured individuals (74-193 cm FL) and length-frequency data from 1822 individuals (1035 males, 787 females; 65-215 cm FL). Annual bandpair deposition, confirmed by a concurrent bomb radiocarbon validation study, was used as the basis for band interpretation. Validation was further confirmed with a tetracycline-injected male shortfin mako recaptured after being at liberty off South Africa for 1 year and aged at 18 years. Growth rates from tag-recapture analysis (GROTAG) were higher than those derived from vertebral annuli and were only available from sharks up to 193 cm FL at recapture. Modal length-frequency data were used to verify the first four age classes. Growth curves were fit using both von Bertalanffy and Gompertz models. The 3-parameter version of the von Bertalanffy growth function produced the most biologically reasonable values for males, based on observed data (L∞ = 253 cm FL, K = 0.125 year−1 (estimated longevity = 21 year), and L0 = 72 cm). The 3-parameter version of the Gompertz growth function produced the most biologically reasonable estimates, for females (L∞ = 366 cm FL, K = 0.087 year−1 (estimated longevity = 38 year) and L0 = 88 cm. Males and females were aged to 29 (260 cm FL) and 32 years (335 cm FL), respectively. Both sexes grew similarly to age 11 (207 cm FL, 212 cm FL for males and females, respectively) when the curve leveled in males and continued to rise in females. Age at 50% maturity was estimated at 8 years for males (185 cm FL) and 18 years for females (275 cm FL). The species grows slower, matures later and has a longer life span than previously reported in North Atlantic waters. [ABSTRACT FROM AUTHOR]

Age estimation is an issue for the shortfin mako, Isurus oxyrinchus, because of disagreement on vertebral band-pair deposition periodicity. In the 1950s-1960s, thermonuclear testing released large amounts of radiocarbon into the atmosphere, which diffused into the ocean through gas exchange. This influx created a time-specific marker that can be used in age validation. Annual band-pair deposition in the porbeagle, Lamna nasus, was validated in a previous study and indicated preliminary annual deposition in the shortfin mako, using four samples from one vertebra. In the present study, age estimates from 54 shortfin mako vertebrae collected in 1950-1984 ranged 1-31 years. Ageing error between readers was consistent, with 76% of the estimates ranging within 2 years. Twenty-one Δ14C values from eight shortfin mako vertebrae (collected in the western North Atlantic in 1963- 1984) ranged −154.8‰ to 86.8‰. The resulting conformity with the Δ14C timeline for the porbeagle supported annual band-pair deposition in vertebrae of the shortfin mako. [ABSTRACT FROM AUTHOR]

The white shark, Carcharodon carcharias, has a complex life history that is characterized by large scale movements and a highly variable diet. Estimates of age and growth for the white shark from the eastern North Pacific Ocean indicate they have a slow growth rate and a relatively high longevity. Age, growth, and longevity estimates useful for stock assessment and fishery models, however, require some form of validation. By counting vertebral growth band pairs, ages can be estimated, but because not all sharks deposit annual growth bands and many are not easily discernable, it is necessary to validate growth band periodicity with an independent method. Radiocarbon (14C) age validation uses the discrete 14C signal produced from thermonuclear testing in the 1950s and 1960s that is retained in skeletal structures as a time-specific marker. Growth band pairs in vertebrae, estimated as annual and spanning the 1930s to 1990s, were analyzed for Δ14C and stable carbon and nitrogen isotopes (δ13C and δ15N). The aim of this study was to evaluate the utility of 14C age validation for a wide-ranging species with a complex life history and to use stable isotope measurements in vertebrae as a means of resolving complexity introduced into the 14C chronology by ontogenetic shifts in diet and habitat. Stable isotopes provided useful trophic position information; however, validation of age estimates was confounded by what may have been some combination of the dietary source of carbon to the vertebrae, large-scale movement patterns, and steep 14C gradients with depth in the eastern North Pacific Ocean. [ABSTRACT FROM AUTHOR]

Bomb radiocarbon has previously been used to validate the age of large pelagic sharks based on incorporation into vertebrae. However, not all sharks produce interpretable vertebral growth bands. Here we report the first application of bomb radiocarbon as an age validation method based on date-specific incorporation into spine enamel. Our results indicate that the dorsal spines of spiny dogfish, Squalus acanthias, recorded and preserved a bomb radiocarbon pulse in growth bands formed during the 1960s with a timing which was very similar to that of marine carbonates. Using radiocarbon assays of spine growth bands known to have formed in the 1960s and 1970s as a dated marker, we confirm the validity of spine enamel growth band counts as accurate annual age indicators to an age of at least 45 year. Radiocarbon incorporation into northeast Atlantic dogfish spines occurred in similar years as those in the northwest Atlantic and northeast Pacific, although the amount of radiocarbon differed in keeping with the radiocarbon content of the different water masses. Published reports suggesting that Pacific dogfish are longer lived and slower growing than their Atlantic counterparts appear to be correct, and are not due to errors in interpreting the spine growth bands. Radiocarbon assays of fin spine enamel appears to be well suited to the age validation of sharks with fin spines which inhabit the upper 200 m of the ocean. [ABSTRACT FROM AUTHOR]

Although numerous studies have utilized elemental analysis techniques for age determination in bony fishes, little work has been conducted utilizing t'hese procedures to verify age assessments or temporal periodicity of growth band formation in elasmobranchs. The goal of this study was to determine the potential of laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) to provide information on the seasonal deposition of elements in the vertebrae of the round stingray collected from Seal Beach, California. Spatially resolved time scans for elements across the round stingray vertebrae showed peaks in calcium intensity that aligned with and corresponded to the number of seasonal growth bands identified using standard light microscopy. Higher signals of calcium were associated with the wide opaque bands while lower signals of calcium corresponded to the narrow translucent bands. While a close alignment between the numbers of calcium peaks and annual growth bands was observed in round stingray samples aged 5 years or younger, this relationship was less well defined in vertebral samples from round stingrays over 11 years old. To the best of our knowledge, this is the first study of its kind to utilize ICP-MS to verify age assessments and seasonal band formation in an elasmobranch. The results from this preliminary study indicate that LA-ICP-MS elemental analysis of the vertebral cartilage of the round stingray may have potential to independently verify optically derived age assessments and seasonal banding patterns in elasmobranch vertebrae. [ABSTRACT FROM AUTHOR]

Marginal increment ratio (MIR) analyses were conducted as part of age and growth studies on three coastal/semi-oceanic species, the smalltail shark, Carcharhinus porosus, dagger-nose shark, Isogomphodon oxyrhynchus and the night shark C. signatus, and two ubiquitous oceanic species, blue shark, Prionace glauca, and whitetip shark, C. longimanus, collected in equatorial areas off Brazil with the aim of establishing the interspecific temporal nature of vertebral band formation. Monthly variations in marginal bands were analyzed using mean MIR on the entire sample as the standard method for all species. Reasons for the inconclusive results regarding these species are critically appraised with respect to three main sources of bias that are associated with marginal increment analysis (MIA). Bias due to insufficient sample sizes may have hampered the analysis for I. oxyrhynchus and C. longimanus due to movements from shallow waters to seamounts for the former species and to extensive migrations for the latter. Bias due to data collection over too long a period is thought to have influenced monthly mean MIR for C. porosus and P. glauca. For the latter, individuals from different age groups lay down rings at different times, making band deposition inconsistent between individuals. Finally, bias due to births occurring over too long a period was the prevalent cause for confounding MIR values among I. oxyrhynchus and C. signatus species, whose birth period lasts several months and leads to different ages within the same cohort. Other approaches used for MIA in C. signatus and P. glauca led to distinct times of band formation by age-groups when compared to MIR applied on the entire sample. For the daggernose shark, delays in events related to the reproductive cycle from one year to the next were also found to confound MIR. Requirements for the use of MIR implying a band width that displays a sinusoidal cycle when temporally plotted (month or season) were not fulfilled for any of these species. The method has been of little utility for detecting the periodicity of band deposition among sharks from the tropics. This emphasizes the need for supplying information on the temporal periodicity of pair deposition based on other methods. [ABSTRACT FROM AUTHOR]

The von Bertalanffy growth equation (VBGE) is commonly used in ecology and fisheries management to model individual growth of an organism. Generally, a nonlinear regression is used with length-at-age data to recover key life history parameters: L∞ (asymptotic size), k (the growth coefficient), and t0 (a time used to calculate size at age 0). However, age data are often unavailable for many species of interest, which makes the regression impossible. To confront this problem, we have developed a Bayesian model to find L∞ using only length data. We use length-at- age data for female blue shark, Prionace glauca, to test our hypothesis. Preliminary comparisons of the model output and the results of a nonlinear regression using the VBGE show similar estimates of L∞. We also developed a full Bayesian model that fits the VBGE to the same data used in the classical regression and the length-based Bayesian model. Classical regression methods are highly sensitive to missing data points, and our analysis shows that fitting the VBGE in a Bayesian framework is more robust. We investigate the assumptions made with the traditional curve fitting methods, and argue that either the full Bayesian or the length-based Bayesian models are preferable to classical nonlinear regressions. These methods clarify and address assumptions made in classical regressions using von Bertalanffy growth and facilitate more detailed stock assessments of species for which data are sparse. [ABSTRACT FROM AUTHOR]

It is often assumed that the von Bertalanffy growth model (VBGM) is appropriate to describe growth in length-at-age of elasmobranchs. However, a review of the literature suggests that a two-phase growth model could better describe growth in elasmobranchs. We compare the two-phase growth model (TPGM) with the VBGM for 18 data sets of elasmobranch species, by fitting the models to 36 age-length-at-age data pairs available. The Akaike Information Criteria (AIC) and the difference in AIC between both models revealed that in 23 cases the probability that the TPGM was true ≥50%. The VBGM tends to estimate larger L∞ values than the two-phase growth model, while the k parameter tends to be underestimated. The growth rate in leng-that- age appears tends to decrease near the age at first maturity in several species of elasmobranch. The importance of the TPGM lies in that it may better describe this aspect of the life history of many elasmobranchs. In this context, we conclude that the TPGM should be used along with other growth models in order to precisely estimate elasmobranch life history parameters. [ABSTRACT FROM AUTHOR]

We examined life history traits (e.g., mean length-at-age, growth rate, age-at-maturity) for blacktip sharks collected from two separate geographical areas (eastern Gulf of Mexico and South Atlantic Bight) to address the potential for separate stocks in southeastern US waters. Samples were obtained from fishery-dependent and independent sources. Growth and logistic models were fitted to observed length-at-age and reproductive data, respectively. von Bertalanffy growth parameters derived for blacktip shark from the Gulf of Mexico show that they attain a statistically smaller theoretical maximum length (L∞ = 141.6 cm vs. L∞ = 158.5 cm for female and L∞ = 126.0 cm FL and L∞ = 147.4 cm FL for male) and have a faster growth rate (k = 0.24 yr−1 vs. k = 0.16 yr−1 for female and k = 0.27 yr−1 vs. k = 0.21 yr−1 for male) than conspecifics in the South Atlantic Bight. Median length- and age-at-maturity were significantly different between sex and area. Length at which 50% of the population is mature was 117.3 cm FL for females and 103.4 cm FL for males in the Gulf of Mexico and 126.6 cm FL for females and 116.7 cm FL for males in the South Atlantic Bight. Median age-at-maturity was 5.7 yrs and 4.5 yrs for females and males in the Gulf of Mexico, respectively, while age-at-maturity was 6.7 yrs for females and 5.0 yrs for males for sharks from the South Atlantic Bight. Due to varying statistical results, temporal problems of sampling, and potential for gear bias, we could not definitively conclude that differences in life history characteristics exist. [ABSTRACT FROM AUTHOR]

Dorsal-fin spines are becoming increasingly popular as a suitable structure for ageing some chondrichthyan fishes. However, the terminology used to describe dorsal-fin structure is often inconsistent between studies, and is consequently unclear. Standardised terms and definitions of the dorsal-fin spine structure are proposed, with particular focus on those areas that are used for age and growth studies. [ABSTRACT FROM AUTHOR]

The thorny skate, Amblyraja radiata, is the most widely distributed and abundant of all skate species worldwide, found on both sides of the north Atlantic Ocean. Large inter-regional size differences exist for this species and the few age and growth studies undertaken have revealed marked differences in life history traits for geographically distinct stocks. To facilitate the progression of further age and growth studies for this commercially important species, the effectiveness of caudal thorns as a rapid ageing tool was assessed. Twenty-eight male and 24 female thorny skates were collected off Greenland, covering the full size range of the species. Replicate age readings of crystal violet stained vertebral sagittal sections and whole silver nitrate stained caudal thorns revealed mean intra-reader age reading precision was higher for caudal thorns (Covariance (CV): reader 1 = 9.07, reader 2 = 9.73) than vertebrae (CV: reader 1 = 14.91, reader 2 = 14.27). Age bias plots revealed minimal inter-structure bias, apart from a higher average thorn age reading of 0.76 years from age classes 5-11 years for reader 1. Minor inter-reader bias was evident for vertebrae only; averaging 0.90 years higher for reader 1 from age classes 11 to 15 years. Preliminary evidence suggests caudal thorns could prove an effective non-invasive ageing tool for thorny skates. [ABSTRACT FROM AUTHOR]

The giant lantern shark, Etmopterus baxteri, is taken as bycatch of commercial fisheries that operate in deepwater off southeastern Australia. Bands on the second dorsal spine were used to obtain age estimates. The number of bands on the external surface of the spine and within the inner dentine layer increased with animal length. Most spines had more bands on the external surface, and the rate of band formation was significantly different between the external surface and the inner dentine layer. Females had a maximum of 57 external bands and 26 internal bands, while males had up to 48 external bands and 22 internal bands. Age estimates from external bands suggest maturity (A50) at 20 years for males and 30 years for females. Internal band age estimates suggest maturity at 10.5 years for males and 11.5 years for females. Although there is a large discrepancy between these two preliminary (i.e., unvalidated) age estimates, they both suggest that E. baxteri is a long-lived and late maturing species that is likely to be susceptible to over fishing. [ABSTRACT FROM AUTHOR]

Age and growth estimates for sand tiger sharks, Carcharias taurus, in the western North Atlantic were derived from 96 vertebral centra collected from sharks ranging from 94 to 277 cm total length (TL), and compared to previously published age and growth data. The oldest female and male sand tiger sharks aged in this study were 17 and 15 years of age, respectively. von Bertalanffy growth parameters derived from vertebral length-at-age data are L∞ = 295.8 cm TL, k = 0.11 year−1, and t0 = −4.2 years for females, and L∞ = 249.5 cm TL, k = 0.16 year−1, and t0 = −3.4 years for males. Sexual maturity is estimated to be 9-10 years for females and 6-7 years for males. Weight-to-length relationships determined for female and male sand tiger sharks in the western North Atlantic are; W = 1.3 × 10−4 × L2.4 (r2 = 0.84, n = 55) and W = 9.0 × 10−5 × L2.5 (r2 = 0.84, n = 47), respectively, and 7.9 × 10−5 × L2.5 (r2 = 0.84) for the sexes combined. Our results show sand tigers possess a slower rate of growth than previously thought. This information is crucial for accurately assessing this population's ability to recover, and further justifies the need for this species to be fully protected. [ABSTRACT FROM AUTHOR]

Age and growth estimates were determined for the sandbar shark, Carcharhinus plumbeus, from Oahu, Hawaii in the central Pacific Ocean. Age estimates were obtained through vertebral centra analysis of 187 sharks. We verified our age estimates through marginal increment analysis of centra and oxytetracycline marking methods of at liberty sandbar sharks. Sizes of sampled sharks ranged from 46 to 147 cm pre-caudal length. Four growth models were fitted to length-at-age data; two forms of the von Bertalanffy growth model, the Gompertz growth model, and a logistic growth model. Males and females exhibited statistically significant differences in growth, indicating that females grow slower and attain larger sizes than males. Growth parameter estimates revealed slower growth rates than previously estimated (based on captive specimens) for Hawaiian sandbar sharks. The von Bertalanffy growth model using empirical length-at-birth provided the best biological and statistical fit to the data. This model gave parameter estimates of L∞ = 138.5 cm PCL and k = 0.12 year−1 for males and L∞ = 152.8 cm PCL, k = 0.10 year−1 for females. Male and female sandbar sharks mature at approximately 8 and 10 years of age, respectively. [ABSTRACT FROM AUTHOR]

Validated age and growth estimates are important for constructing age-structured population dynamic models of chondrichthyan fishes, especially those which are exploited. We review age and growth studies of chondrichthyan fishes, using 28 recent studies to identify areas where improvements can be made in describing the characteristics of ageing structures (both traditional and novel) utilized to estimate ages of sharks, rays, and chimaeras. The topics identified that need consistency include the: (1) terminology used to describe growth features; (2) methods used to both verify and validate age estimates from chondrichthyan calcified structures, especially edge and marginal increment analyses; and (3) the functions used to produce and describe growth parameters, stressing the incorporation of size at birth (L0) and multiple functions to characterize growth characteristics, age at maturity and longevity. [ABSTRACT FROM AUTHOR]

The article focuses on the debate about the authenticity of the tenzone of Dante Alighieri with Forese Donati which has attracted the attention of Alighieri scholars on a work which is not ranked high even among Alighieri's minor works. The debate has turned on the codicological and textual history of the poems. Literary criticism requires a demonstration of how the poems can be read within the context about the lives of both individuals.

An essay is presented on the effects of parent-induced trauma and how it affects the child's behavioral pattern. It presents the different aspects of psychological dysfunction cause by parents due to known and unknown causes as depicted in the novel of Gisèle Pineau. It also associates the problems of psychological damage of past slavery that has caused a negative affect to the Caribbean society as depicted and compared in the written novel of Pineau.

The generation of heat by the human body has been likened to that of a furnace. In response to winter conditions or prolonged immersion in cold water, heat may be lost from the body more quickly than it is produced leading to hypothermia. Various factors, environmental and individual, predispose a person to hypothermia when walking on dry land or during cold water immersion. Retention of the insulating properties of the clothing worn is of crucial importance in protecting against cold injury both on land and in water. Anthropometric characteristics and behavioural and physiological responses also influence the probability of survival under these conditions. Practical recommendations for behaviour that will enhance survival during prolonged exposure to cold on land or to immersion in cold water are considered. [ABSTRACT FROM AUTHOR]

The main aim of the Nazi regime was to create a new and unified national community. Therefore, they discriminated all those who were outside the national community. There were three main types of outsiders. The ideological enemies were those who propogated beliefs that were a threat to the national morale. Then there were the socially inefficient asocials. Then came the biological outsiders who were a threat due to their race.

Most of the research on endurance exercise has focussed on the physiological and metabolic demands during an event and on factors causing fatigueFatigue during and after prolonged submaximal running may have many origins. The conventional explanation for fatigue after running a marathon or ultra-marathon is that glycogen is depleted in the skeletal muscles, thus reducing their ability to produce force. This form of fatigue may occur only when the muscle glycogen concentrations fall below a critical level perhaps causing impaired sarcoplasmic reticulum function. Fatigue, particularly after prolonged exercise exceeding 4 hours, may also coincide with the development of hypoglycaemia. There is some evidence to suggest that this fatigue may be delayed if carbohydrate is ingested during the event. The fatigue associated with hypoglycaemia probably has its origins in the central nervous system (CNS). Another mechanism underlying CNS fatigue after prolonged exercise proposed by Newsholme et al. (1992)} is that as the duration of exercise increases, more plasma free-tryptophan crosses the blood brain barrier and is converted into serotonin, which increases the perception of fatigue.Fatigue after prolonged exercise, particularly in hot, humid environments may also be caused by factors affecting the CNS arising from sustained elevation of muscle and possibly brain temperature . Studies have also identified a type of neuromuscular fatigue which occurs during and after a marathon and which accounts for the decrement in running performance. The above discussion highlights some of the metabolic issues and aetiology of fatigue associated with prolonged submaximal exercise. [ABSTRACT FROM AUTHOR]

Patients with chronic heart failure have impaired exercise tolerance. An expected outcome of cardiac transplantation in such patients is an improvement in functional capacity. However, despite normal left ventricular ejection fraction after cardiac transplantation, compared to control subjects the exercise capacity of these patients remains impaired both during symptom-limited maximal exercise and during static exercise[1]'[6]. Indeed, the exercise capacity of patients after cardiac transplantation is often comparable to that of patients with medically stabilized heart failure[7]. The reasons for this phenomenon remain unclear, but it could indicate that the exercise capacity of these patients is limited by peripheral alterations, perhaps in skeletal muscle, which develop during heart failure and which are not reversed immediately after cardiac transplantation. [ABSTRACT FROM AUTHOR]

Provides an overview of reference sources on ether. "Conceptions of Ether: Studies in the History of Ether Theories, 1740-1900," edited by Geoffrey Cantor and Michael J. S. Hodge; "Origins and Consolidation of Field Theory in Nineteenth-Century Britain: From the Mechanical to the Electromagnetic View of Nature," by Barbara Giusti Doran in the "Historical Studies in the Physical Sciences"; "Nineteenth-Century Aether Theories," by Kenneth F. Schaffner; "The Thought of Late Victorian Physicists: Oliver Lodge's Ethereal Body," by David B. Wilson in the "Victorian Studies."

The guest editors would like to acknowledge the following referees for taking the time out of their schedules to review manuscripts for this volume. [ABSTRACT FROM AUTHOR]

Presents a list of books about spiritualism. "The Founders of Psychical Research," by Alan Gauld; "In Search of White Crows: Spiritualism, Parapsychology and American Culture," by Laurence R. Moore; "Modern Spiritualism: A History and a Criticism," by Frank Podmore.