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  • 1
    Electronic Resource
    Electronic Resource
    Reproductive variability over a four-year period in the sea urchin Evechinus chloroticus (Echinoidea: Echinodermata) from differing habitats in New Zealand (2000)
    Springer
    Marine biology 137 (2000), S. 543-557 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The endemic New Zealand echinoid, Evechinus chloroticus (Valenciennes), was sampled approximately monthly from September 1990 to October 1994 at three sites in Tory Channel, Marlborough Sounds, New Zealand. These channel sites (outer, mid and inner) were up to 20 km from the open ocean and differed in their shore type, exposure to wave action and macrophyte abundance. E. chloroticus showed an annual reproductive cycle at each site, with gametogenesis commencing in the late austral winter and spawning in summer. Maximum gonad indices (reproductive potential) varied spatially, with the outer site generally having higher maximum gonad indices than the inner site, and temporally, with maximum gonad indices occurring earlier in 3 of the 4 seasons at the outer site than the inner site. The mid and inner sites showed much greater variation in maximum gonad indices (range 15.83 to 26.99% and 11.87 to 20.90%, respectively) than the outer site (range 19.31 to 22.95%). Reproductive output (weight of gametes released per gram echinoid) also varied, with the different sites showing significantly different outputs in the different years. A regression of maximum reproductive potential against reproductive output was significant ( p 〈 0.001), and had a positive slope with an r 2 of 0.79. While, the initiation of gametogenesis was relatively synchronous between sites and years, and is possibly cued by increasing daylength, it progressed at different rates among populations. Spawning did show spatial and temporal variability, occurring near the time of highest sea-surface temperatures (∼15 °C). The observed variations in reproductive cycle may be related to small-scale variability in diet and environmental conditions. Furthermore, asynchronous spawning, variable spawning duration, and variable reproductive output are likely to strongly influence annual recruitment variability in E. chloroticus, with different larval subpopulations contributing unequally in different years. The ecological consequences of this, both for the ability of E. chloroticus to propagate itself in space and time and for the management of the developing E. chloroticus fishery in New Zealand, are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270000366
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  • 2
    Electronic Resource
    Electronic Resource
    Seasonal growth of the giant kelp Macrocystis pyrifera in New Zealand (1997)
    Springer
    Marine biology 129 (1997), S. 417-424 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The seasonal growth pattern of Macrocystis pyrifera (L.) C. Agardh in New Zealand was determined from measurements of blade-elongation rates between March 1986 and December 1987. Growth rates remained relatively constant throughout most of the year, but declined significantly during the summer months. Seawater nitrate levels had a marked seasonal cycle, with concentrations of 0.3 μM detected in summer. The timing of the decline in internal nitrogen concentrations varied for different-aged blades, but occurred ∼1 mo after the decrease in seawater nitrate concentrations. Sufficiently high irradiance levels and seawater nutrient concentrations support active growth for most of the year, but growth is nutrient-limited during summer. No carbon accumulation during summer was observed. Between March and August 1988, growth estimates were also derived from node-initiation rates and stipe-elongation rates to permit comparisons with previous studies from the northern and southern hemispheres. Direct comparisons of the three growth parameters determined for non-terminated canopy and sub-surface fronds were used to assess possible differential resource allocation in the two frond classes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050182
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  • 3
    Electronic Resource
    Electronic Resource
    Long-term effects of pinacidil in hypertensive dialysis patients (1985)
    Springer
    European journal of clinical pharmacology 28 (1985), S. 375-380 
    Details
    ISSN: 1432-1041
    Keywords: pinacidil ; hypertension ; dialysis ; vasodilator ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In an open study, thirteen chronic dialysis patients with nonvolume dependent uncontrolled hypertension were treated with pinacidil for a mean period of 43 weeks. Seven patients were taking concomitant antihypertensive therapy. Twelve patients achieved long-term blood pressure control on a mean dose of 33 mg/day. The baseline supine blood pressure was 184/116 mmHg. After 1 week it had fallen to 161/95 mmHg and blood pressure control was maintained over the study period. Patient weight remained stable. The baseline reading was 61.6 kg and at the end of the study it was 59.7 kg. Pulse rate did not change significantly. For the eight patients not taking beta-blockers the mean change in pulse rate was 7.6 beats/min supine and 6.3 beats/min erect (NS). Pretrial urea and creatinine were 27.6 mmol/l and 1027 µmol/l and after 25 weeks they were 29.6 mmol/l and 1087 µmol/l, respectively (NS). Four patients had ECG evidence of left ventricular hypertrophy before the study and one on completion of the trial. Five patients showed correction of T-waves on their ECG's. Six patients experienced side effects, none of which warranted withdrawal of treatment. These findings suggest that pinacidil is a valuable alternative treatment for hypertensive dialysis patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00544353
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Treatment of essential hypertension and hypertension associated with renal impairment with pinacidil: A new vasodilator (1985)
    Springer
    European journal of clinical pharmacology 28 (1985), S. 381-386 
    Details
    ISSN: 1432-1041
    Keywords: pinacidil ; renal impairment ; hypertension ; vasodilator ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Twenty patients with uncontrolled hypertension were treated with pinacidil for a mean period of 43 weeks (range 10–63 weeks). All patients achieved and maintained significant reductions in blood pressure. The supine blood pressure at base-line was 184/116 mmHg; after one week it was 161/95 mmHg and at 43 weeks it was 138/79 mmHg. The mean dose of pinacidil was 30 mg/day. There was no significant difference between the two groups with respect to the dose of pinacidil or the blood pressure response. Pulse rate and weight remained stable for the group as a whole. Five patients were not taking beta-blockers. The mean baseline pulse rate for this group was 78 beats/min and when maintained on pinacidil it was 82 beats/min (NS). Six patients were not taking diuretics. The mean baseline weight for this group was 78.5 kg and while maintained on pinacidil it was 79.2 kg (NS). There was no occurrence of oedema, hirsutism or first dose phenomenon. The mean glomerular filtration rate and renal plasma flow for the renal group was 35.4 ml/min and 192.3 ml/min before pinacidil and after six months they were 32.7 ml/min and 183.2 ml/min (NS) respectively. Six patients experienced minor side-effects. We conclude that pinacidil is a potent, well tolerated antihypertensive agent which merits further study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00544354
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    Paper (German National Licenses)
    Fulltext
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