Tumors of the respiratory tract observed at the German Primate Center, 1978–1994

Abstract: Eight spontaneous pulmonary tumors (four bronchiolar tubular adenomas, two bronchiolar adenocarcinomas, two squamous-cell carcinomas) occurred in a total of 54 adult tree shrews (Tupaia belangeri) of the GPC colonies between 1978 and 1994. The adenomas and adenocarcinomas consisted of tubularly or trabecularly arranged cuboidal to cylindrical cells interspersed with some PAS-positive goblet cells, thus resembling the epithelial lining of respiratory bronchioles of tree shrews. The two squamous-cell carcinomas probably originated from the pulmonary alveoles. Three more pulmonary tumors (one small-cell carcinoma, one bronchial adenoma, one squamous-cell carcinoma) developed in 409 adult callitrichids of the GPC colonies during the same period, and one more bronchial adenoma was observed in a common marmoset (Callithrix jacchus) of another colony located in Göttingen. With regard to the adenomas and squamous-cell carcinomas, a similar cellular origin with the tree shrews is assumed. The small-cell carcinoma possibly developed from the bronchial epithelium, provided a pathogenesis parallel to that of human small-cell carcinoma is suggested. Four of the tree shrew pulmonary adenomas/adenocarcinomas and the small-cell Ca were macroscopically visible as yellowish-grey nodules of 1 mm × 1 mm to 15 mm × 15 mm diameter, predominantly involving the main lobes (2 × right main lobes, 2 × left main lobes, 1 × all lobes). The pulmonary tumors of the other animals were below macroscopical detectability.     

Preliminary investigations on somatic embryogenesis from leaf discs of red oak (Quercus rubra L.)

Somatic embryos were obtained from leaf discs of juvenile red oak plants. Basal inductive nutrient medium was a modified Murashige and Skoog solution enriched with 500 mg L^–1 casein hydrolysate, 100 mg L^–1 polyvinylpyrrolidone, 5.4 M naphthaleneacetic acid and 0.09 M benzyladenine. Embryogenesis was obtained only from leaf discs in the presence of light and increased when the adaxial surface of the explants (with midrib or main veins present) was in contact with the medium. Large variation was observed in all experiments. Recurrent embryogenesis was observed at the base of embryo clusters with callus present; conversely, embryogenic potential was rapidly lost by subculturing full calli. Maturation, germination and development of isolated somatic embryos were obtained. However, the vast majority of embryos did not have viable apical bud meristems and on only a few occasions were shoots produced.Abbreviations BA N⁶-benzyladenine - CH casein hydrolysate - 2iP isopentenyladenine - NAA naphthaleneacetic acid - 2.4-D 2.4-dichlorophenoxyacetic acid - GA gibberellic acid - PVP polyvinylpyrrolidone     

Cryptic, genetically extremely divergent, polytypic, convergent, and polymorphic taxa in Madagascan Tropidophora (Gastropoda: Pomatiasidae)

Madagascar's magnificent and environmentally threatened endemic radiation of the land-snail genus Tropidophora Troschel has recently been classified into three subgenera, 95 species and 142 varieties, based on often subtle conchological variation among small samples; it seems best to ignore temporarily this confusing plethora of names until true biological species and their relationships are better understood. The author's field work in 1990 succeeded in obtaining live Tropidophora from 40 populations distributed throughout the island. Allozyme analysis (108 snails, 15 loci, 117 alleles) yielded a cladogram suggesting nine genetically coherent taxa (T. taxa A-I), each represented in the collections by 1–10 populations. Comparisons among shells (total 1634) and penes (total 31 from 20 populations representing eight of the nine taxa) revealed: (1) two conchologically indistinguishable taxa (H and I) fixed for alternative alleles at 13 of 15 loci, with only a very subtle difference in penes, and with mosaic and overlapping geographical distributions in the Northeast; (2) two extremely polytypic taxa (C in the Southwest, F in the Southeast) with parallel trends toward depressed, broadly umbilicate, heavily sculptured shells with apertural lips widely reflected at the umbilicus at inland, more arid sites, resulting in sympatric convergence; (3) one southeastern taxon (G) in which the penis apparently doubles in length but the shell does not change 6.0 km to the northwest, but in which the shell shifts dramatically in sculpture, colour, and lip reflection 0.5 km to the westnorthwest; and (4) generally such extreme intra- and inter-population variation in shell and male-genital characters as to render many of them dubious at best for systematics. Thus the Madagascan Tropidophora present a fascinatingly complex problem in evolutionary morphology/ecology, the solution of which will require even more extensive collecting, followed by molecular comparisons or detailed anatomical comparisons, or both. The total number of biological species is still likely to be quite large, despite irrelevance of much of the current taxonomy, because many smaller species remain to be discovered.     

The influence of stand development on nutrient demand,growth and allocation

As an even-aged stand develops growth is concentrated first on leaves and fine roots, as a result nutrient accumulation is very rapid. During this early stage there is a distinct species effect whereas later nutrient uptake becomes a function of growth rate irrespective of species. Once canopy is closed up to two thirds of the nutrients required for growth can be obtained by retranslocation from older or dying tissues, an efficient conservation mechanism that leads to a reduction in the demands that are further reduced by the cycle through the litter layer. In consequence nutritional problems are most likely in the early years while the green crown is being constructed. Later in the rotation problems are unlikely unless nutrient cycles are disturbed, for example by thinning or as a result of excessive accumulation of humus. The eventual clear felling is a major disruption to nutrient cycles. Accelerated litter decomposition can lead to leaching losses, although this can be short lived, and burning if practised can have a major impact on poor sites. Nutrient loss in material removed from the felling site, whether or not harvested, is not high but is much increased if crowns are removed, particularly for the heavily crowned species. The importance of such loss clearly varies with site but may be significant for more than just loss of nitrogen, with loss of calcium, phosphorus or even organic matter per se all being possibly causes of worry.     

Growth response of subalpine fir (Abies lasiocarpa) to climate in the Olympic Mountains, Washington, USA

Growth response of subalpine fir (Abies lasiocarpa) to climate was studied across its local geographical and elevation range in the Olympic Mountains, Washington. A dendroecological analysis of subalpine fir across a range of elevations (1350-1850 m) and annual precipitation (125-350 cm y^?1), was used to compare environmental factors affecting growth. Climate-growth relationships were explored using Pearson product-moment correlation coefficients; partial correlation analysis was used to assess relationships among site chronologies and climatic variables. Radial growth is negatively correlated with winter precipitation at high elevation and wet sites, but not at low and middle elevation dry sites. Growth is positively correlated with current growing season temperature at all sites; however, growth is negatively correlated with previous year August temperature, indicating that climate affects growth in subsequent years. Positive correlations between growth and summer precipitation during the growing season at low and middle elevation dry sites suggest that soil moisture is partially limiting to growth on these sites. If the climate of the Pacific Northwest becomes warmer and drier, then subalpine fir growth may increase at high elevation and wet sites, but may decrease at lower elevation dry sites in the Olympic Mountains. However, the growth response of subalpine fir to potentially rapid climate change will not be uniform because subalpine fir grows over a wide range of topographic features, habitats, and local climates at different geographical scales. A comparison of growth response to current growing season temperature suggests that the temperature-related growth response of subalpine fir is not adequately described by the parabolic curve used in JABOWA-based models.     

Heavy metal accumulation in tissue/organs of a sea cucumber, Holothuria leucospilota

Holothuria leucospilota Brandt, the large black sea cucumber, is a non-selective deposit feeder, and is commonly found in the bottom of shallow waters in Hong Kong, where the sediments are often polluted with heavy metals. This study was designed to test the possibility of heavy metal accumulation by the sea cucumber at two sites in Hong Kong. Atomic absorption spectrophotometer was used to measure Cu and Zn concentrations in various tissue/organs of the animal as well as in the sediments. The result indicated that H. leucospilota accumulated zinc in the longitudinal muscle bands (97.27–98.07 ppm in dry weight) and in the respiratory tree (83.92–89.64 ppm in dry weight). Copper concentrations in these two organs were much lower than that of zinc. After the animals were kept in the aquarium without sediment for40 days, zinc concentration of the longitudinal muscle and respiratory tree decreased by 48% and 39%respectively whereas copper concentration remained unchanged. The concentrations of zinc and copper in the sediment at the two sites differed significantly but the metal level in the animals from the two sites were similar, suggesting that this sea cucumber was not an ideal bioindicator of heavy metal pollution in the sediment. This revised version was published online in August 2006 with corrections to the Cover Date.     

PP333对苹果幼树越冬期间过氧化物酶同工酶的影响

以越冬性强的元帅苹果幼树为对照,用PP333处理越冬性弱的金冠苹果幼树,测定越冬期间其枝条过氧化物酶同工酶的变化,并在翌年春季田间调查越冬情况。结果表明,PP333处理大大增加了过氧化物酶同工酶中与抗寒性有关酶的酶活,并提高了金冠苹果幼树的越冬性。     

Relationships between branch spacing, growth rate and light in tropical forest saplings

1. The spacing of branches along central stems was related to growth rate and light level in forest saplings and trees in tropical moist forest on Barro Colorado Island (BCI), Panama. The study included 14 species with tiers of plagiotropic branches (having planar leaf arrangements) and four species with continuous distributions of plagiotropic branches.
2. All species showed increases in branch spacing with increasing light and growth rate of diameter, similar to the patterns in leaf spacing noted previously in species which initially bear large leaves on unbranched stems.
3. Non-tiered species had shorter internodes than tiered species but because the latter bear more branches per node, both groups had similar numbers of branches per unit stem length, when compared at similar growth rates.
4. Differences in the relationship between internode length and growth rate among tiered species were related to demographic characteristics, suggesting that tree architecture may influence forest composition.
5. The strong correlation observed between branch spacing and growth rate suggests that branch spacing may be used to estimate past growth histories of forest tree species with plagiotropic branches.     

A serious canker disease of Eucalyptus in South Africa caused by a new species of Coniothyrium

Eucalyptus spp. are being propagated extensively as exotics in plantations in South Africa, and many other parts of the world. In South Africa, a number of diseases result in serious losses to this resource. This paper describes a new and very damaging stem canker disease, which has recently appeared on plantation-grown eucalyptus in South Africa. The disease, first noted in an isolated location in Zululand is now common in other parts of the country, and is typified by discrete necrotic lesions on stems. These lesions coalesce to form large, gum-impregnated cankers and malformed stems. The causal agent of the disease, as inferred from pathogenicity tests, is a new species of Coniothyrium described here as C. zuluense. This fungus is a serious impediment to eucalypt propagation in South Africa, and is most likely a threat to similar forest industries elsewhere in the world.