Phototropism and Pigment Production in Sordaria in Relation to Quality of Light

Experiments with Sordaria funicola are described giving evidencethat in phototropism of the perithecial necks and in the light-inducedproduction of yellow-orange intracellular pigment, light ofwave-lengths below 550 mµ is principally effective. Thisagrees with earlier findings on the sensitivity of light-stimulatedspore discharge in this fungus.     

Adaptive Significance of a Small Heat Shock/{alpha}-Crystallin Protein (p26) in Encysted Embryos of the Brine Shrimp, Artemia franciscana

Encysted embryos of the primitive crustacean, Artemia franciscana,are among the most resistant of all animal life history stagesto extremes of environmental stress. This resistance has likelybeen acquired during evolutionary adaptation to their harshecological setting. In the laboratory, for example, some ofthese embryos survive more than 6 years of continuous anoxiawhile fully hydrated and at room temperature, a phenomenal capabilitythat can easily be related to their frequent encounters withanoxic conditions in nature. A small heat shock protein belongingto the -crystallin family of proteins, referred to as p26, appearsto play a central role in the stress resistance of these embryos.Our evidence shows that this protein is an important componentin their adaptive repertoire, and vital for the survival ofArtemia in nature.     

Dynamics and precision of thermoregulatory responses of eastern skunk cabbage Symplocarpus foetidus

Inflorescences of the arum lily Symplocarpus foetidus are thermogenic and thermoregulatory. The spadix increases respiratory heat production rate as ambient temperature decreases. This study examined the relationships between spadix temperature (T_s), respiration rate () and ambient temperature (T_a) at equilibrium and during transient responses to step changes in T_a. Intact inflorescences inside a miniature constant temperature cabinet in the field showed the most precise temperature regulation yet recorded; over a 37.4 °C range in T_a (?10.3 to 27.1 °C), T_s changed only 3.5 °C (22.7 to 26.2 °C). Regulated temperatures were not related to spadix size (1.9–7.3 g) or circadian cycle. Dynamic responses to step changes in T_a involved a phasic change in T_s, first in the same direction as T_a, then reversing at 38.3 min, and finally approaching equilibrium at 87.6 min, on average. Meanwhile changed in a monotonic curve toward equilibrium. Models revealed that the dynamics of temperature change were inconsistent with simply a physical lag in the system, but involved some form of biochemical regulation, possibly by changes in activity of a rate‐limiting functional protein.     

An unusual lizard (Reptilia: Squamata) from the Early Cretaceous of Las Hoyas, Spain

The Early Cretaceous (Barremian) lepidosaurian assemblage of Las Hoyas (Cuenca Province, Castilla-La Mancha), Spain, resembles that of roughly contemporaneous localities at Montsec (Catalonia), Una (Castilla-La Mancha) and Galve (Aragon) in being dominated by the scincomorph lizard Meyasaums ( Ilerdaesaurus ). It differs in the presence of two previously unknown taxa, one of which, described here, shows a strikingly unusual morphology in its ribs and distal limb skeleton suggestive of climbing specialization. This form is sufficiently distinct from other known taxa to warrant the erection of a new genus and species, Scandensia ciervensis gen. et sp. nov. Cladistic analysis of Scandensia suggests that it forms a sister taxon to living squamates (Iguania + Scleroglossa and all descendants of their most recent common ancestor).     

Relationships between morphology, genetics and geography in the cave fruit bat Eonycteris spelaea (Dobson, 1871) from Indonesia

Morphological and genetic analyses of Eonycteris spelaea from 15 islands along the Banda Arc, from Sumatra to Timor and including Kalimantan and Sulawesi, revealed considerable divergence between islands and geographical patterning. On the basis of both morphology and genetics, the populations on the large islands of Greater Sunda (Sumatra, Java, Kalimantan and Sulawesi) are generally distinct from one another and from those on the islands in Nusa Tenggara (Lombok to Timor), which form a more cohesive cluster. These differences may be the result of the Nusa Tenggara populations having been colonized more recently than those on the Greater Sunda, and probably from a single source. All biological measures of the relationships between island populations are positively associated with the extent of the sea-crossing between them, indicating the sea is an important barrier to movement. Multivariate analyses show the presence of a marked trend for body size to increase from west to east. However, individuals from Kalimantan are not consistent with this trend, being smaller than predicted, and on the two outer Banda Arc islands of Sumba and Timor animals are a little larger than predicted from the longitudinal trend. These differences could be due to the relative isolation of these populations or differing environmental conditions. There is also a negative relationship between body size and island area, but this is confounded by the longitudinal trend. No significant longitudinal trends in the genetic data were detected and the trend in body size may be an adaptive response to an environmental cline that is known to occur in this region.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 79, 511–522.     

Changes in soil carbon and nitrogen properties and microbial communities in relation to growth of Pinus radiata and Nothofagus fusca trees after 6 years at ambient and elevated atmospheric CO2

Increasing atmospheric CO₂ concentration can influence the growth and chemical composition of many plant species, and thereby affect soil organic matter pools and nutrient fluxes. Here, we examine the effects of ambient (initially 362 μL L^?1) and elevated (654 μL L^?1) CO₂ in open‐top chambers on the growth after 6 years of two temperate evergreen forest species: an exotic, Pinus radiata D. Don, and a native, Nothofagus fusca (Hook. F.) Oerst. (red beech). We also examine associated effects on selected carbon (C) and nitrogen (N) properties in litter and mineral soil, and on microbial properties in rhizosphere and hyphosphere soil. The soil was a weakly developed sand that had a low initial C concentration of about 1.0 g kg^?1 at both 0–100 and 100–300 mm depths; in the N. fusca system, it was initially overlaid with about 50 mm of forest floor litter (predominantly FH material) taken from a Nothofagus forest. A slow‐release fertilizer was added during the early stages of plant growth; subsequent foliage analyses indicated that N was not limiting. After 6 years, stem diameters, foliage N concentrations and C/N ratios of both species were indistinguishable (P>0.10) in the two CO₂ treatments. Although total C contents in mineral soil at 0–100 mm depth had increased significantly (P<0.001) after 6 years growth of P. radiata, averaging 80±0.20 g m^?2 yr^?1, they were not significantly influenced by elevated CO₂. However, CO₂‐C production in litter, and CO₂‐C production, microbial C, and microbial C/N ratios in mineral soil (0–100 mm depth) under P. radiata were significantly higher under elevated than ambient CO₂. CO₂‐C production, microbial C, and numbers of bacteria (but not fungi) were also significantly higher under elevated CO₂ in hyphosphere soil, but not in rhizosphere soil. Under N. fusca, some incorporation of the overlaid litter into the mineral soil had probably occurred; except for CO₂‐C production and microbial C in hyphosphere soil, none of the biochemical properties or microbial counts increased significantly under elevated CO₂. Net mineral‐N production, and generally the potential utilization of different substrates by microbial communities, were not significantly influenced by elevated CO₂ under either tree species. Physiological profiles of the microbial communities did, however, differ significantly between rhizosphere and hyphosphere samples and between samples under P. radiata and N. fusca. Overall, results support the concept that a major effect on soil properties after prolonged exposure of trees to elevated CO₂ is an increase in the amounts, and mineralization rate, of labile organic components.     

A Companion to the Anthropology of American Indians

A Companion to the Anthropology of American Indians . Thomas Biolsi, ed. Williston, VT: Blackwell Publishers, 2004. 567 pp.