Journal of Ichthyology - Juvenile specimens of opahs (Lampridae) from the Southwest Atlantic, southeastern Pacific Ocean, and Gulf of Guinea are described. A taxonomic review of the composition of... 相似文献
Methods have been developed which permit measurements of cardiac output and sampling of mixed venous and arterial blood in the elasmobrach, Squalus acanthias. These methods have been utilized to characterize some of the parameters involved in gill gas exchange. A total of 17 animals have been studied with the following results. Cardiac output: 1.49±0.57 1/kg/hr.; V?o2: 38.3±22.1 ml/kg/hr.; V?co2: 32.1±19.0 ml/kg/hr.; RER: 0.92±0.17; PaO2: 104±27 mmHg; Pv?o2: 18±8.8 mmHg; PaCO2: 2.9±0.75 mmHg; Pv?co2: 4.6±1.1 mmHg; CaO2: 3.8±0.75 vol. %; Cv?o2: 1.26±0.59 vol. %; pHa: 7.52±0.10 units; Pv?: 7.42±0.11 units; [HCO3?]a: 3.92± 1.14 meq/1; [HCO3?]v?: 4.80±1.15 meq/1; [dissolved CO2]a: 0.17± 0.04 mM/1; [dissolved CO2]v?: 0.24±0.04 mM/1; [lactate?]a: 13.47±7.17 meq/1; [Lactate?]v?: 13.01±8.18 meq/1. Some of the mechanisms involved in gill gas exchange have been characterized. 相似文献
Otoliths and gonads of blackbelly rosefish Helicolenus dactylopterus dactylopterus were collected from the commercial fishery off the Carolinas in 1994–1997. Opaque bands on transverse sections of otoliths were determined to be annuli by analysis of marginal increments. Opaque zone formation occurs between July and January. Ages ranged from 7 to 30 years. Blackbelly rosefish have intraovarian gestation. Fertilization is internal, as free spermatozoa were found primarily in resting ovaries from July through early December with peak occurrence in September through November. There was a delay of 1–3 months before fertilization, as oocyte development did not begin until December. Occurrence during January through April of early-celled embryos, the most advanced stage observed, and postovulatory follicles indicated that oocyte development was rapid. Egg development occurs in a clear gelatinous matrix secreted into the ovarian cavity. The reproductive mode is a zygoparous form of oviparity, intermediate between oviparity and viviparity. Population sex ratio departed markedly from 1: 1 for most length intervals. Males were more abundant at lengths >250 mm L T and the overall male: female ratio was 1 : 0·60. 相似文献
A new genus, Papillonema gen.n., is erected to accomodate the two species P. danieli gen. et sp. n. and P. clavatum (Gerlach, 1957) comb.n. from intertidal sediments of a tropical mangrove. Papillonema gen.n. is characterized by prominent papilliform labial sensillae, an elongate muscular terminal bulb (up to 60% of pharyngeal length), and three precloacal supplements. Comments are given on the use of the terms head capsule, head region, and cervical setae.Abbreviations a:
body length divided by maximum body diameter
- abd:
anal body diameter
- amph %:
diameter of the amphid as a percentage of the corresponding head diameter
- aw:
amphidial width
- b:
body length divided by pharyngeal length
- bdcs:
body diameter at level of the cephalic setae
- bdnr:
body diameter at level of nerve ring
- c:
body length divided by tail length
- cs:
length of cephalic setae
- da:
distance from anterior to anus
- dcs:
distance from anterior edge to cephalic setae
- dnr:
distance from anterior edge to nerve ring
- dv:
distance from anterior to vulva
- gub:
length of the gubernaculum
- hw:
head width
- L:
body length
- Isp:
length of sperm cells
- mbd:
maximum body diameter
- mbd ph:
body diameter at level of pharynx
- ph:
pharyngeal length
- spic:
length of spicules measured along the arc
- t:
tail length
- tmr:
length of non-annulated tail end
- V:
position of vulva as a percentage of the total body length from anterior
- wsp:
width of sperm cells 相似文献
Growth and dark respiration rates of the marine diatom Leptocylindrus danicus Cleve were measured in axenic batch culture under 49 combinations of temperature (5, 10, 15, 20°C), daylength(15:9, 12:12, 9:15 LD), and irradiance (at least four irradiances per daylength). Cell division rates exhibited a temperature-dependent daylength effect. Optimal temperatures occurred between 15 and 20°C. Both the initial slope () and the growth rate at light saturation (μmax) were strongly influenced by temperature; increased five-fold and μmax by an order of magnitude between 5 and 20°C. The compensation irradiance (Ic) was independent of temperature. μmax was 2.7 div day−1 at 20°C, 2.6 at 15°C, 1.1 at 10°C, and 0.3 at 5 °C. Cells grown under 15:9 and 12:12 LD exhibited similar growth-light curves at 20°C and at 15°C. μmax of cells grown under 9:15 LD at these temperatures were substantially lower than μmax under longer daylengths. Growth at 10 and 5°C was independent of daylength.
Dark respiration rates were a linear function of cell division rates at 10, 15, and 20°C, and support the concept that growth rate is dependent on dark respiration rate. These relationships were not influenced by daylength. A detectable relationship between dark respiration and growth at 5°C was not observed.
Photosynthesis and excretion showed temperature-dependent curvilinear relationships with growth rate, reflecting the lower saturation irradiance for growth compared to light saturation of photosynthesis and excretion. The relationship between Chl a-specific photosynthesis and growth was controlled by the C:Chl a ratio, which showed a positive correlation with cell division rate. At 15 and 20°C, light saturation of growth was associated with C:Chl a ratios of 40 to 60; at 5 and 10°C, cells growing at μmax contained C:Chl a in ratios of 80 to 110. 相似文献
Ab initio minimal and split-valence basis set calculations have been performed on compounds that are involved in retro–inverso modifications, i.e., gem-diaminoalkyl and malonyl structures. These calculations are compared with empirical force field calculations and the minor differences discussed. All calculations agree that the preferred helical conformation of the isolated gem-diaminoalkyl and malonyl derivatives of residues found in the retro-inverso modified peptides is 5–8 kcal/mol lower than the C conformation preferred by the isolated peptide residues. Population analysis and contour plots of the charge distribution are used to help explain the differences between the model compounds. 相似文献
Besides the hydrophilic AH-B moiety in sweeteners, the morehydrophobic third binding sites play an essentialrole in inducing sweetness. The distances between these molecularfunctions seem to be very critical, but exact data are lacking.To describe stereochemical requirements more precisely, newconceptual parameters were introduced, namely , and (minimum,optimum and maximum distances between these third binding sitesand the atoms A, H and B of the AH-B moieties respectively,especially appropriate for homologous series) and the S value(shortest distance between the position of an atom and the planeformed by the atoms A, H and B of the AH-B moiety). The dimensionsof the relevant side chains of five homologous series of sweeteners sulphamates, oximes, nitroanilines, isocoumarins anddipeptides were determined. We calculated that the positionsof the , and parameters with regard to the AH-B moieties arelocated around two main axes forming 95? angles with the H-Baxis in the AH-B moieties for sulphamates and isocoumarins and125? angles for oximes, nitroanilines and dipeptides. The positionsof are, for all potent sweeteners, situated at 7085%of the maximum distance of viewed from the centre of the Aatom, while for , this value was found to be 15% for oximes,25% for nitroanilines, 40% for sulphamates, 5070% fordipeptides and 65% for isocoumarins. The results indicate thereare at least three but a maximum of four differentreceptor sites. They have very narrow site clefts with maximumheights of -0.6 nm. 相似文献
The previously introduced conceptual parameters (, , and S)to describe the stereochemical requirements for organic compoundsto taste sweet, were now applied to another series of sweetenersand to some well-known potent substances. With the help of anadapted STERIMOL computer program, the positions of relevant,hydrophobic side chains were determined in ureas, saccharins,tryptophans, chlorosugars and acesulfame derivatives in relationto their AH-B moieties. The results obtained were compared withprevious findings for five other homologous series of sweeteners.There is evidence to suggest that 6-substituted acesulfame derivativesand saccharin employ the same receptor site. in 5-substitutedacesulfame derivatives coincides with that of sulphamates calculatedearlier. in 6-chloro-D-tryptophan was found to be at equaldistances from H and B, a position which was earlier also observedfor the methyl ester group in aspartame. In the dulcin seriesof the urea derivatives, two AH-B moieties can be distinguished:the HN-CO group gives rise to , and 's which fit in the earliercalculated nitroaniline receptor site, while for the OC-NH2group they are located near those found for isocoumarins. Thechlorine atoms in 1' '16'-dichlorosucrose are located aboveand below the plane of the pyranose ring at almost the samepositions with respect to the OH groups at positions 3 and 4(in fact, two equal 's), which are supposed to form the AH-Bmoiety. The high relative sweetness values of 1',6'-dichlorosucroseand 1',4,6'-trichlorogalactosucrose are most probably due tothe fact that both sweeteners can interact with the receptorsite in two ways (as such and upside-down). It is remarkablethat the average positions belonging to sweeteners with similarAH-B moieties are located very close to each other. 相似文献
Objective: We examined the associations among physical activity, sedentary behavior, and metabolic syndrome in a representative sample of U.S. adults. Research Methods and Procedures: A total of 1626 men and women ≥20 years old from National Health and Nutrition Examination Survey 1999 to 2000 who attended the morning examination were evaluated. The metabolic syndrome was defined by using the definition from the National Cholesterol Education Program. Results: In unadjusted analysis, participants who did not engage in any moderate or vigorous physical activity during leisure time had almost twice the odds of having metabolic syndrome [odds ratio (OR), 1.90; 95% confidence interval (CI), 1.22 to 2.97] as those who reportedly engaged in ≥150 min/wk of such activity. Adjustment for age, sex, race or ethnicity, educational status, smoking status, and alcohol use attenuated the OR (OR, 1.46; 95% CI, 0.87 to 2.45). Compared with participants who watched television or videos or used a computer <1 h/d outside of work, the adjusted ORs for having metabolic syndrome were 1.41 (95% CI 0.80 to 2.51) for 1 h/d, 1.37 (95% CI 0.85 to 2.20) for 2 h/d, 1.70 (95% CI 0.92 to 3.14) for 3 h/d, and 2.10 (95% CI 1.27 to 3.47) for ≥4 h/d. Additional adjustment for physical activity or sedentary behavior minimally affected the ORs. Discussion: Sedentary behavior is an important potential determinant of the prevalence of the syndrome. Efforts to lessen the amount of time that U.S. adults spend watching television or videos or using a computer, especially if coupled to increases in physical activity, could result in substantial decreases in the prevalence of metabolic syndrome. 相似文献
Roscoea cangshanensis M. H. Luo, X. F. Gao & H. H. Lin, a new species of the Zingiberaceae from Yunnan, China, is described and illustrated. The new species is related to R. forrestii Cowley in habit, but differs in having 2-lobed labellum, each lobe 2-lobulate, base narrowed to a stalk with white lines, and narrower leaf blade, (2–)7–24×1.5–2.5 cm, with base narrow to petiole-like. The new species is also similar to R. debilis Gagnep. in having leaf base narrow to petiole-like, labellum obovate-cuneate, 2.5–3.5×2.5–3.0 cm, with white lines at throat, but differs in having bracts non-tubular, shorter, 5–15 mm long, concealed in leaf sheaths, corolla tubes longer, 10–12.5 cm long, labellum 2-lobed with each lobe further 2-lobulate. 相似文献
Turritopsoides marhei, a new species of the hydrozoan family Oceaniidae, is described from the Maldives. This species can be distinguished from the only other member of the genus by the presence of more branched colonies, branches not being adnate to pedicels, longer pedicels, larger nematocysts, nematocyst-rich nematophore-like outgrowths from pedicels, smaller male gonophores, and a different geographic distribution. This finding represents the first record of the genus outside the type locality of its type species, in Belize. Molecular phylogenetic analyses show that, as expected, T. marhei belongs to the clade Filifera IV. However, the phylogenetic hypothesis based on both mitochondrial and nuclear DNA sequences reveals that most of the families of this group are polyphyletic, including Oceaniidae, and suggests that the morphological characters used to discriminate among filiferan families need to be revised thoroughly.
Despite their importance in marine and freshwater microalgal assemblages, cold-adapted dinoflagellates have been the subject of few comprehensive lipid studies, particularly with respect to those lipids that comprise plastid membranes. In an effort to understand the differences between warm- and cold-adapted dinoflagellate glycolipid composition, four peridinin-containing, cold-adapted dinoflagellates were surveyed for intact forms of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), two common plastid lipids, using positive-ion electrospray ionization/mass spectrometry (ESI/MS) and electrospray ionization/mass spectrometry/mass spectrometry (ESI/MS/MS). It was determined that the dominant forms of MGDG and DGDG in these cold-adapted, peridinin-containing dinoflagellates possessed C18 fatty acids and did not, with the exception of a 20:5/18:5 form of DGDG in a cold-adapted Gymnodinium sp. from the Baltic Sea, have C20 fatty acids. This finding is in contrast to an earlier study of 35 peridinin-containing, warm-adapted dinoflagellates, which discovered a cluster dominated by C18 fatty acids and a cluster dominated by both C20 and C18 fatty acids. The key difference in MGDG and DGDG production between the former group and the cold-adapted dinoflagellates examined in this study is that the cold-adapted species’ DGDG fatty acids were less saturated. Each cold-adapted dinoflagellate possessed both 18:5/18:5 and 18:5/18:4 DGDG, while most of the warm-adapted dinoflagellates contained only 18:5/18:4 DGDG. This survey also revealed the presence of a putative 18:1/14:0 trigalactosyldiacylglycerol (TGDG) as a dominant glycolipid in Gymnodinium sp. TGDG, previously unreported in dinoflagellates, was also discovered in Gymnodinium sp. in the forms of 18:1/16:0 and 18:1/18:1 TGDG, as minor lipids. Since the fatty acids associated with TGDG are not those found with dominant forms of MGDG or DGDG, TGDG may be produced by a different biosynthetic pathway. 相似文献
The first exploration of the kinorhynch meiofauna in Portuguese marine waters has revealed the existence of two undescribed species of the cyclorhagid genus Echinoderes. In the present contribution we describe Echinoderes lusitanicus sp. nov. and Echinoderes reicherti sp. nov., both collected from subtidal regions of the coast of Algarve in the southernmost region of Portugal. Echinoderes lusitanicus sp. nov. is recognized by the presence of tubes on segment 2 in subdorsal and ventrolateral positions, on segment 5 in lateroventral positions, on segment 8 in lateral accessory positions, and on segment 10 in laterodorsal positions. Spines are present in middorsal position on segments 4 to 8, and in lateroventral positions on segments 8 and 9. The females have minute lateral terminal accessory spines. The second species, E. reicherti sp. nov., is characterized by tubes on segment 2 in subdorsal and ventrolateral positions, on segment 5 in lateroventral positions, and segment 8 in sublateral positions. In addition, the species possesses acicular spines in the middorsal position on segment 4, and in lateroventral positions on segments 6 to 9. Morphological aspects such as tube/spine pattern of the trunk or sexually dimorphic traits are discussed and compared with other Echinoderes species showing close resemblance.
OBJECTIVE: To examine patterns of self reported drinking, smoking, and illicit drug use among a representative United Kingdom sample of people born in 1979. DESIGN: Cross sectional, single phase survey based on a stratified cluster sample of 70 United Kingdom secondary schools during March and April 1995. Pupils completed a 406 item standardised questionnaire under examination conditions. SETTING: United Kingdom state and private secondary schools. SUBJECTS: 7722 pupils aged 15 and 16. MAIN OUTCOME MEASURES: Reported use of alcohol, tobacco, and illicit drugs. RESULTS: Almost all the pupils had drunk alcohol, 36% (2772/7689) had smoked cigarettes in the past 30 days, and 42.3% (3264/7722) had at some time used illicit drugs, mainly cannabis. 43% (1546/3546) of boys and 38% (1529/4009) of girls had tried cannabis. Higher levels of smoking were associated with poorer school performance (20.4% (783/3840) with average performance v 44.1% (214/486) with below average performance, F = 79.06, P < 0.01). Levels of drug use in 15 and 16 year olds in 1995 were higher in Scotland than in England, Wales, or Northern Ireland. CONCLUSIONS: Drug experimentation was high among 15 and 16 year olds, and use of cannabis was particularly high among smokers. Cigarette smoking was more common among girls than boys. 相似文献
Three strains of aerobic, Gram-negative, rod-shaped, non-spore-forming, yellow-pigmented bacteria (OD1T, YOxT and NS13), which were isolated in previous studies by enrichment in a mineral medium with potassium oxalate as the sole carbon source, were characterized. On the basis of 16S rRNA gene sequence similarity, strains OD1T, YOxT and NS13 belong to the Betaproteobacteria , most closely related to Oxalicibacterium flavum TA17T (97.2–99.7% sequence similarity). The major whole-cell fatty acids were C16:0, C16:1ω7c and C17:0 cyclo. The results of DNA–DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strains OD1T and YOxT from O. flavum TA17T and from each other. Therefore, it is concluded that the strains OD1T and YOxT represent novel species within the genus Oxalicibacterium , for which the names Oxalicibacterium horti sp. nov. (type strain OD1T=DSM 21640T=NBRC 13594T) and Oxalicibacterium faecigallinarum sp. nov. (type strain YOxT=DSM 21641T=CCM 2767T) are proposed. 相似文献