Osmotic and ionic regulation in different populations of the new zealand freshwater crayfish Paranephrops zealandicus

1976 ◽  
Vol 64 (3) ◽  
pp. 645-663
Author(s):  
T. M. Wong ◽  
R. F. Freeman

1. Some features of the osmoregulatory mechanism are compared in four populations of Paranephrops zeal andicus White collected form freshwaters of different ionic concentrations. 2. Crayfish from freshwaters of ca, 2-0 mM-NaCl concentration show a sustained decrease in blood concentration of ca. 8% when placed in 0-2 mM-NaCl. 3. Populations from freshwaters of ca. 0-2-0-4 mM-NaCl show lower rates of net salt loss in distilled water and higher rates of net salt uptake form dilute NaCl solutions than do populations from freshwaters of ca. 0-8-2-0 mM-NaCl. 4. Renal salt losses over the first 24 h in distilled water account for ca. 18% of the total salt loss. 5. It is suggested that P. zealandicus from environments of lowest concentration shows a similar degree of adaptation to freshwater as do crayfish of the northern hemisphere. It differs in possessing a substantially higher blood concentration.

Author(s):  
J. Walker

Abstract A description is provided for Melampsora medusae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Pycnia and aecia on Coniferae, especially Larix and Pseudotsuga, less commonly on Pinus and other genera (Ziller, 1965). Uredinia and telia on species of Populus, especially Populus deltoides, and its varieties and hybrids P. balsamifera, P. nigra var. italica and others. Its exact host range on species of Populus is not known due to confusion with other species of Melampsora and to uncertainty in the reported identity of some species of Populus and clones (Walker, Hartigan & Bertus, 1974). DISEASE: Leaf rust of poplars, causing severe leaf damage and early defoliation on susceptible species and clones. Continued defoliation of successive flushes of growth predisposes trees to winter injury and dieback (Peace, 1962) and can cause death of trees, especially nursery stock and trees 1-2 yr old (25, 204; 47, 241; Walker Haitigan & Bertus, 1974). Reduction in incremental growth of timber occurs with susceptible varieties. Some damage can occur to the conifer hosts. It is often severe on Pseudotsuga menziesii (45, 459; 47, 126) and in nurseries Pinus spp. and Larix spp. can be heavily attacked (Ziller, 1965). GEOGRAPHICAL DISTRIBUTION: North America (Canada, USA), Asia (Japan); Australasia and Oceania (Australia, New Zealand); Europe (France, Spain). Reports of Melampsora spp. on poplars (including P. deltoides and P. canadensis) from South America (Argentina, 21, 173), Uruguay (Lindquist & de Rosengurtt, 1967) may refer in part to M. medusae. TRANSMISSION: By air-borne urediniospores, often over long distances (suspected from eastern Australia to New Zealand). Urediniospores survive the winter in milder climates on semi-evergreen lines and on green sucker growth of deciduous trees. This is probably the main method of overwintering in the Southern Hemisphere and in warmer parts of the Northern Hemisphere. The possibility of bud carryover as occurs with M. epitea on Salix in Iceland (Jorstad, 1951) and the Canadian Arctic (Savile, 1972) should be investigated. Telia survive the winter and basidiospores formed in spring infect susceptible conifers in parts of the Northern Hemisphere (Ziller, 1965) but no conifer infection has so far been found in Australia.


1962 ◽  
Vol 12 (1) ◽  
pp. 25-42
Author(s):  
Paul Woldstedt

Abstract. The Pleistocene sequence of Wanganui (North Island of New Zealand) and the succession of glaciations in the South Island are shortly reviewed. The Last Glaciation and the Postglacial time in New Zealand were, as C14 determinations definitly show, contemporaneous with those of the Northern Hemisphere. If the Last Glaciation was contemporaneous on the two Hemispheres, then the older ones must also have been contemporaneous. This does not agree with the MILANKOVITCH-curve, which in the form, as it has been given by M., cannot have been the cause of the ice ages.


2007 ◽  
Vol 59 (3) ◽  
pp. 227-231 ◽  
Author(s):  
S. Zivkovic ◽  
M. Devic ◽  
B. Filipovic ◽  
Z. Giba ◽  
D. Grubisic

The influence of high NaCl concentrations on seed germination in both light and darkness was examined in the species Centaurium pulchellum, C. erythraea, C. littorale, C. spicatum, and C. tenuiflorum. Salt tolerance was found to depend on the life history of the seeds. To be specific, seeds of all five species failed to complete germination when exposed to continuous white light if kept all the time in the presence of 100-200 mM and greater NaCl concentrations. However, when after two weeks NaCl was rinsed from the seeds and the seeds were left in distilled water under white light for an additional two weeks, all species completed germination to a certain extent. The percent of germination not only depended on NaCl concentration in the prior medium, but was also species specific. Thus, seeds of C. pulchellum, C. erythraea, and C. littorale completed germination well almost irrespective of the salt concentration previously experienced. On the other hand, seeds of C. tenuiflorum completed germination poorly if NaCl concentrations in the prior media were greater than 200 mM. When seeds after washing were transferred to darkness for an additional 14 days, they failed to complete germination if previously imbibed on media containing NaCl concentrations greater than 400 mM. However, the seeds of all species, even if previously imbibed at 800 mM NaCl, could be induced to complete germination in darkness by 1 mM gibberellic acid. .


2016 ◽  
Author(s):  
Jocelyn C. Turnbull ◽  
Sara E. Mikaloff Fletcher ◽  
India Ansell ◽  
Gordon Brailsford ◽  
Rowena Moss ◽  
...  

Abstract. We present 60 years of Δ14CO2 measurements from Wellington, New Zealand (41° S, 175° E). The record has been extended and fully revised. New measurements have been used to evaluate the existing record and to replace original measurements where warranted. This is the earliest atmospheric Δ14CO2 record and records the rise of the 14C "bomb spike", the subsequent decline in Δ14CO2 as bomb 14C moved throughout the carbon cycle and increasing fossil fuel CO2 emissions further decreased atmospheric Δ14CO2. The initially large seasonal cycle in the 1960s reduces in amplitude and eventually reverses in phase, resulting in a small seasonal cycle of about 2 ‰ in the 2000s. The seasonal cycle at Wellington is dominated by the seasonality of cross-tropopause transport, and differs slightly from that at Cape Grim, Australia, which is influenced by anthropogenic sources in winter. Δ14CO2 at Cape Grim and Wellington show very similar trends, with significant differences only during periods of known measurement uncertainty. In contrast, Northern Hemisphere clean air sites show a higher and earlier bomb 14C peak, consistent with a 1.4-year interhemispheric exchange time. From the 1970s until the early 2000s, the Northern and Southern Hemisphere Δ14CO2 were quite similar, apparently due to the balance of 14C-free fossil fuel CO2 emissions in the north and 14C-depleted ocean upwelling in the south. The Southern Hemisphere sites show a consistent and marked elevation above the Northern Hemisphere sites since the early 2000s, which is most likely due to reduced upwelling of 14C-depleted and carbon-rich deep waters in the Southern Ocean. This developing Δ14CO2 interhemispheric gradient is consistent with recent studies that indicate a reinvigorated Southern Ocean carbon sink since the mid-2000s, and suggests that upwelling of deep waters plays an important role in this change.


1989 ◽  
Vol 3 (6) ◽  
pp. 721
Author(s):  
DA Duckhouse

Australasian pericomoids, psychodids resembling northern hemisphere species of Pericoma Walker (tribe Pericomini), are mostly members of the tribe Maruinini, here re-defined. Amongst Maruinini, they are like several neotropical genera named by Enderlein (1937), but their actual relationship to Enderlein's genera, and hence their identity, has been a long-standing taxonomic problem. Consideration of extensive new collections and observations made in the southern hemisphere now shows that they consist of the following: Genus Notiocharis Eaton. Tribe Maruinini: genus Didicrum Enderlein, and five new genera, Eremolobulosa, Rotundopteryx, Alloeodidicrurn, Satchellomyia and Ancyroaspis. Of these, the Australian Eremolobulosa is the possible sister group of the European Lobulosa Szabo, and the New Zealand genera Satchellomyia and Ancyroaspis are possible sister groups. Of Enderlein's neotropical genera, five classified by Quate (1963) as synonyms, or in one case a subgenus, of Pericoma (Didicrum, Desmioza, Synmormia, Syntomolaba and Podolepria) are recognised as full genera. A key to Australasian pericomoid genera is provided.


Author(s):  
Preethi M. Iyer ◽  
Sanjay Kumar P. ◽  
Karthikeyan S. ◽  
P. K Krishnan Namboori

<p><strong>Objective: </strong>In the present pharmacogenomic work, the genetic, epigenetic and environmental factors associated with BRCA1 induced breast cancer, cancer proneness and its variants across different populations like Indian, Netherland, Belgium, Denmark, Austrian, New Zealand, Sweden, Malaysian and Norwegian and the ‘mutation and methylation-prone’ region of BRCA1 have been computed.</p><p><strong>Methods: </strong>The global variations associated with the disease have been identified from the ‘Leiden open variation database (LOVD 3.0)’ and ‘Indian genome variation database (IGVDB)’. The variants, ‘single nucleotide polymorphisms (SNPs)’ are then characterized. The epigenetic factors associated with breast cancer have been identified from the clinical reports and further scrutinized using EpiGRAPH tool. The various contributing environmental factors responsible for the variations have been considered.</p><p><strong>Results: </strong>All the variants across different populations such as Indian, Netherland, Belgium, Denmark, Austrian, New Zealand, Sweden, Malaysian and Norwegian are found to be in a specific transcript of BRCA1 that ranges within 41,196,312-41,277,500 (81,189 base pairs) of the chromosome 17. Two ‘single nucleotide variations (SNVs)’ (5266dupC: rs397507246 and 68_69delAG: rs386833395) have been identified as risk factors in hereditary breast and ovarian cancer syndrome in the global population and 39 SNPs have been identified as pathogenic and deleterious. ‘Evolutionary history’ seems to be the most significant attribute in the predictability of methylation of BRCA1. Unhealthy dietary habits, obesity, use of unsafe cosmetics, estrogen exposure, ‘hormone replacement therapy (HRT)’, use of oral contraceptives and smoking are the major environmental risk factors associated with breast cancer incidence.</p><p><strong>Conclusion: </strong>This chromosome location (41,196,312-41,277,500 (81,189 base pairs)) can be considered as the population-specific sensitive region corresponding to BRCA1 mutation. This supports the fact that stabilization within the region can be a promising technique to control the epigenetic variants associated with the global position. The global variation in the proneness of the disease may be due to a cumulative effect of genetic, epigenetic and environmental factors subject to further experimentations with identical variations and populations. </p>


2020 ◽  
Vol 232 ◽  
pp. 02002
Author(s):  
Walter Kutschera ◽  
Gernot Patzelt ◽  
Joerg M. Schaefer ◽  
Christian Schlüchter ◽  
Peter Steier ◽  
...  

A brief review of the movements of Alpine glaciers throughout the Holocene in the Northern Hemisphere (European Alps) and in the Southern Hemisphere (New Zealand Southern Alps) is presented. It is mainly based on glacier studies where 14C dating, dendrochronology and surface exposure dating with cosmogenic isotopes is used to establish the chronology of advances and retreats of glaciers. An attempt is made to draw some general conclusions on the temperature and climate differences between the Northern and Southern Hemisphere.


1983 ◽  
Vol 29 (11) ◽  
pp. 1493-1499 ◽  
Author(s):  
Patricia M. Stanley

To better understand the interaction between bacteria and surfaces, we studied the irreversible attachment of Pseudomonas aeruginosa to a common surfacing material. When brought into contact with the steel, cells began to attach in less than 1 min and the number adhering increased with time. An important physiological variable in attachment was cell motility since adherence decreased at least 90% when flagella were removed by blending. This treatment was shown to be effective because it caused motility loss and not because it removed a structure necessary for adherence. Cell viability was less important since adherence decreased only 50% when the number of viable cells was reduced 4.7 logs by heating or formaldehyde treatment. Significant environmental variables included turbulence and ionic strength. Attachment of motile cells was reduced 90% by agitation, although agitation had little effect on adherence of nonmotile cells. Both motile and nonmotile cells adhered poorly in distilled water with attachment increasing as CaCl2 or NaCl concentration increased to 10 mM. At 100 mM, attachment decreased. Viable cells, both motile and nonmotile, adhered best at a pH of 7 to 8, whereas nonviable cells attached most rapidly at a low pH.


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