1,847 research outputs found

    Age, growth and feeding of the blue hottentot Pachymetopon aeneum (Pisces: Sparidae) with notes on reproductive biology

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    The sparid Pachymetopon aeneum is a benthic carnivore feeding predominantly on hydroids, tunicates and octocorals. Juveniles and subadults occur on shallower reefs than the adults but the diet of all sizes is similar. The species is a protogynous hermaphrodite, sex reversal occurring between 200 and 300 mm forklength. Fifty per cent maturity in females occurs between 200 and 250 mm forklength. Peak reproductive activity was recorded between September and March. Otoliths were used to determine growth rate. Growth in length was described by the equation, Lt(mm) = 467,06(1 -e-0,1328(t-0,2473)). The relationship between length and weight, W(g) = 0,00001L(mm)3,149, was used to determine somatic growth as, Wt(g) = 2545,98(1 - e-0, 1328(t-0, 24731))3,149. P. aeneum have a potential for exploitation but the combination of late maturation and protogynous hermaphroditism could lead I to over-exploitation in a size-selective fishery

    The Biology of the bronze bream, Pachymetopon grande (Teleostei: Sparidae) from the south-east Cape coast, South Africa

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    The biology of the sparid fish, Pachymetopon grande, was investigated from data collected on the southeastern Cape coast between August 1984 and March 1987. Sectioned sagittal otoliths revealed that they are a slow-growing, long-lived species capable of reaching ages in excess of 40 years. Detailed histological examination of gonadal development showed that they are rudimentary hermaphrodites, males and females maturing after a non-functional intersexual stage. The breeding season is restricted to between January and June, and observations suggest that they are group spawners with pelagic eggs. Maturity was reached at 300 mm fork length or approximately 5,5 years old. P.grande is primarily herbivorous, feeding selectively on rhodophytes found on inshore reefs down to approximately 20 m. Minor dietary components included hydrozoans, octocorals and other small invertebrates. Macroalgal degradation by gut endosymbbnts or the utilization of macroalgal epibionts was not evident, suggesting that storage and extracellular carbohydrates of the macroalgae were utilized in the diet. The importance of P.grande to the inshore recreational angling fishery, together with certain aspects of its biology, underline the need for conservation measures aimed at ensuring the sustainability of this resource

    Jesse Stuart: Essays on His Work

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    J. R. LeMaster and Mary Washington Clarke have here assembled a distinguished collection of essays on the works of Jesse Stuart. A prolific writer, Stuart is at home in many different genres; his poetry, his short stories, his novels, and his autobiographical writings are widely known, and his books for children have enjoyed great popularity. Despite the variety of his work and despite the diversity of the ten essayists\u27 points of view, there emerges from this volume a consistent view of a man whose close contact with the land and the people of his region has produced a distinctive body of writing. H. Edward Richardson offers us a glimpse of Jesse Stuart at home, freely and earnestly discussing his work and relating it to the scenes about him. This essay forms a background for the other contributors\u27 discussions of Stuart\u27s humor, his use of folklore, and his persistent agrarian point of view. This, the first collection of all new critical essays on Stuart\u27s writings, succeeds admirably in what criticism is supposed to do-making more accessible the important work of a significant writer. J. R. LeMaster is director of the American Studies Program at Baylor University, Waco, Texas. Mary Washington Clarke is emeritus professor of English and folklore, Western Kentucky University, Bowling Green.https://uknowledge.uky.edu/upk_english_language_and_literature_north_america/1025/thumbnail.jp

    Are observer ratings influenced by prescription? A comparison of Free Choice Profiling and Fixed List methods of Qualitative Behavioural Assessment

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    Qualitative methods of behavioural assessment use observer rating scales to score the overall demeanour or body language of animals. Establishing the reliability of such holistic approaches requires test and validation of the methods used. Here, we compare two methodologies used in Qualitative Behavioural Assessment (QBA): Fixed-Lists (FL) and Free-Choice Profiling (FCP). A laboratory class of 27 students was separated into two groups of 17 and 10 students (FL and FCP respectively). The FL group were given a list of 20 descriptive terms (used by the European Union's Welfare Quality Âź program), shown videos of group-housed sows, and as a group discussed how they would apply the descriptive terms in an assessment. The FCP group were shown the same footage but individually generated their own descriptive terms to describe body language of the animals. Both groups were then shown 18 video clips of group-housed sows and scored each clip using a visual analogue scale (VAS) system. We analysed the VAS scores using Generalised Procrustes Analysis (GPA) for each observer group separately, which indicated high inter-observer reliability for both groups (FL: 71.1% of scoring variation explained, and FCP: 63.5%). There were significant correlations between FL and FCP scores (GPA dimension 1: r 16 =0.946, P 0.7 is usually accepted to show strong agreement). This study demonstrates that, regardless of whether they are given their terms or are allowed to generate their own, observers score sow body language in a similar way. Strengths and weaknesses within the two methods were identified, which highlight the importance of providing thorough and consistent training of observers, including providing good quality training footage so that the full repertoire of demeanours can be identifie

    Rape, revenge and resurrection in Correr's Progne

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    Published online: 24 May 2018When Gregorio Correr selected the myth of Procne and Philomela for his c. 1427 adaptation of Seneca’s Thyestes, he was altering what is sometimes termed ‘a tragedy with no women’ into one which largely focuses on female protagonists. Yet he chose to omit the scene where Philomela (or Philomena) weaves a tapestry depicting her rape and mutilation by her sister’s husband Tereus. This scene, which is a key feature of Ovid’s Metamorphoses and also appears in all other medieval and Renaissance adaptations of the myth, has been interpreted by scholars as Philomena’s successful attempt to find an alternative voice for her outrage after Tereus has cut out her tongue. This paper addresses the implications of Correr’s omission of this important feature of the myth, analysing its effect on the portrayal of Philomena and the dynamics of her relationship with her avenger Procne. It shows how the agency in this relationship is shifted almost entirely to Procne and how Philomena is transformed into a type of ghost who is brought back by her sister’s rage and dreadful act of retribution on her husband. Within this analysis attention will be given to the Christian elements of Correr’s reception of the myth, in particular the motif of resurrection which permeates the play and the final scene which culminates in a distortion of the rites of the eucharist.Jacqueline Clark

    Effect of Ring Size and Migratory Groups on [1,n] Suprafacial Shift Reactions. Confirmation of Aromatic and Antiaromatic Transition-State Character by Ring-Current Analysis

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    Suprafacial sigmatropic shift reactions of 5-substituted cyclopentadienes, 3-substituted cyclopropenes, and 7-substituted cycloheptatrienes have been studied computationally at the MP2/6-31+G* level for structures and energetics, and using the ipsocentric method at the CHF/6-31G** level to calculate current-density maps. The hydrogen shifts in cyclopentadienes have a diatropic ring currents indicating aromatic, cyclopentadienide anion character. This result stands in contrast to the fluorine shift in 5- fluorocyclopentadiene which requires much more energy, and has a paratropic ring current in the TS pointing to antiaromatic, cyclopentadienyl cation character. [1,3] hydrogen shifts in cyclopropenes are very difficult, passing through transition states that have an extended C-C bond. For 3-fluorocyclopropene the [1,3] fluorine shift is much easier than the hydrogen shift. For 7-fluorocycloheptatriene the [1,7] hydrogen shift is predicted, but requires very high energy and has a paratropic ring current and antiaromatic character. The [1,7] suprafacial fluorine shift is relatively easy, having a TS with cycloheptatrienyl cation character. Patterns of currents, and the reversal for H and F migration, are rationalized by orbital analysis based on the ipsocentric method. Calculated charges and structural features for reactants and transition states support these conclusions

    Progressive horizon planning-planning exploratory-corrective behavior

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    The importance of regional, system-wide and local spatial scales in structuring temperate estuarine fish communities

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    An extensive literature base worldwide demonstrates how spatial differences in estuarine fish assemblages are related to those in the environment at (bio)regional, estuary-wide or local (within-estuary) scales. Few studies, however, have examined all three scales, and those including more than one have often focused at the level of individual environmental variables rather than scales as a whole. This study has identified those spatial scales of environmental differences, across regional, estuary-wide and local levels, that are most important in structuring ichthyofaunal composition throughout south-western Australian estuaries. It is the first to adopt this approach for temperate microtidal waters. To achieve this, we have employed a novel approach to the BIOENV routine in PRIMER v6 and a modified global BEST test in an alpha version of PRIMER v7. A combination of all three scales best matched the pattern of ichthyofaunal differences across the study area (ρ = 0.59; P = 0.001), with estuary-wide and regional scales accounting for about twice the variability of local scales. A shade plot analysis showed these broader-scale ichthyofaunal differences were driven by a greater diversity of marine and estuarine species in the permanently-open west coast estuaries and higher numbers of several small estuarine species in the periodically-open south coast estuaries. When interaction effects were explored, strong but contrasting influences of local environmental scales were revealed within each region and estuary type. A quantitative decision tree for predicting the fish fauna at any nearshore estuarine site in south-western Australia has also been produced. The estuarine management implications of the above findings are highlighted

    Neonatal oxytocin administration and weaning onto a gruel based diet reduce weight loss at weaning and enhance gastric leptin expression

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    Administering oxytocin to neonatal rats has positive long-term effects on growth and development (Uvnas-Moberg and Petersson, 2005). These effects include a reduction in the stress response to weaning, increased post-weaning feed intake and alterations in the expression of gastrointestinal (GI) hormones regulating feed intake (Uvnas-Moberg et al., 1998; Sohlstrom et al., 1999). Two GI hormones of importance in regulating feed intake are ghrelin and leptin, which have antagonistic actions. Ghrelin expression is increased in response to fasting and leptin expression increases rapidly in response to feed intake. Since weaning the piglet is associated with stress and growth restriction, this study examined whether oxytocin given to young pigs could reduce the extent of the post-weaning growth check, along with any associated changes in ghrelin and leptin expression

    Characteristics of the ichthyofauna of a temperate microtidal estuary with a reverse salinity gradient, including inter-decadal comparisons

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    Data on the fish fauna of the Leschenault Estuary on the lower west coast of Australia were collected and used as a model to elucidate the characteristics of permanently open estuaries with a reverse salinity gradient, which undergo seasonal changes similar to many other estuaries with Mediterranean climate. Focus was placed on determining (1) the relationships of the number of species, density, life cycle category and species composition of fishes with region (within estuary), season and year and salinity, (2) whether species are partitioned along the lengths of such systems and (3) the extent and significance of any inter-decadal changes in species composition. The analyses and interpretation involved using multi-factorial permutational multivariate analysis of variance (PERMANOVA) and analysis of similarity (ANOSIM) designs, and three new or recently published visualization tools, i.e. modified non-metric multidimensional scaling (nMDS) plots, coherent species curves and segmented bubble plots. The base, lower, upper and apex regions of the Leschenault Estuary, along which the salinity increased in each season except in winter when most rainfall occurs, were sampled seasonally for the 2 years between winter 2008 and autumn 2010. Estuarine residents contributed twice as many individuals, but less than half the number of species as marine taxa. While the numbers of marine species and estuarine residents declined between the base or lower and apex regions, the individuals of marine species dominated the catches in the base region and estuarine residents in the other three regions. Ichthyofaunal composition in each region underwent conspicuous annual cyclical changes, due to time-staggered differences in recruitment among species, and changed sequentially along the estuary, both paralleling salinity trends. Different groups of species characterized the fauna in the different regions and seasons, thereby partitioning resources among species. The ichthyofauna of the apex region, in which salinities reached 54 and temperatures 36° C, recorded the highest maximum density and, in terms of abundance, was dominated (90%) by three atherinid species, emphasizing the ability of this family to tolerate extreme conditions. Comparisons between the data for 2008-2010 and 1994 demonstrate that the spotted hardyhead Craterocephalus mugiloides and the common hardyhead Atherinomorus vaigiensis had colonized and become abundant in the Leschenault Estuary in the intervening period. This represents a southwards extension of the distribution of these essentially tropical species during a period of increasing coastal water temperatures as a result of climate change. The abundance of weed-associated species, e.g. the western gobbleguts Ostorhinchus rueppellii and the soldier Gymnapistes marmoratus, increased, whereas that of the longfinned goby Favonigobius lateralis decreased, probably reflecting increases in eutrophication and siltation, respectively
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