A preliminary investigation of L-phenylalanine ammonialyase activity in asparagus: Distribution and response to storage, excision and incubation

The level of L-phenylalanine ammonia-lyase (PAL) (E.C. 4.3.1.5 [EC] )activity was greatest in the basal portion of freshly harvestedasparagus spears and decreased toward the tips. Basal disksdeveloped large increases in L-phenylalanine ammonia-lyase activityin response to excision and incubation. The level of PAL activitymeasured in basal tissue of intact spears increased with storage,while the ability of the same tissue to respond to excisionand incubation with increased PAL activity was lost. (Received March 23, 1971; )     

Final Days: Japanese Culture and Choice at the End of Life

Final Days: Japanese Culture and Choice at the End of Life . Susan Orpett Long. Honolulu: University of Hawai'i Press, 2005. 287 pp.     

The participation of phosphate in the formation of a carrier for the transport of Mg++ and Mn++ ions into yeast cells

During the absorption of phosphate by yeast, the cells acquire the capacity to absorb Mn⁺⁺ and Mg⁺⁺, a capacity which is retained even after phosphate is no longer present in the medium. Cells pretreated with phosphate and then washed, slowly lose their ability to absorb Mn⁺⁺, the rate of loss depending on the temperature and on the metabolic state. The fermentation of sugars induces a very rapid loss of absorptive capacity, whereas the respiration of ethyl alcohol, lactate, or pyruvate has little effect. Inhibitor studies with sodium acetate, redox dyes, and arsenate, reveal parallel effects on Mn⁺⁺ absorption, and on phosphate absorption. It is concluded that the synthesis of a carrier for the transport of Mg⁺⁺ and Mn⁺⁺ involves a phosphorylation step closely coupled with reactions involved in the absorption of phosphate.     

Confronting assumptions about spontaneous autogamy in populations of Eulophia alta (Orchidaceae) in south Florida: assessing the effect of pollination treatments on seed formation,seed germination and seedling development

The breeding system of the terrestrial orchid Eulophia alta was investigated in south Florida where it has previously been reported as an auto‐pollinated species. The effect of breeding system on seed viability and germinability and seedling development was also investigated. Incidences of spontaneous autogamy in E. alta were rare at the study site, resulting in only 7.1% of observed flowers forming capsules. In addition, hand pollination resulted in significantly greater capsule formation when flowers were subjected to induced autogamy (46.4%), artificial geitonogamy (64.3%) and xenogamy at both short (pollen source 10–100 m away; 42.9%) and long (pollen source > 10 km away; 67.9%) distances. Pollen source had little effect on seed viability and germinability or seedling growth rates. However, seed resulting from spontaneous autogamy developed more slowly than seed originating from the other treatments. These data indicate that spontaneous autogamy is rare in E. alta and that naturally forming capsules may be the result of unobserved pollination events. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161 , 78–88.     

Points, patches, and regions: scaling soil biogeochemical patterns in an urbanized arid ecosystem

Cities are rapidly growing throughout the world and are altering biologic processes in many regions, with global consequences. Urbanization in the Phoenix, USA metropolitan region has dramatically altered regional ecosystem patterns, but little is known about how these changes have influenced soil organic matter, total nitrogen, and the distribution of nitrogen stable isotopes. Because urban development is a phenomenon occurring at multiple scales, ecological consequences of urbanization will likely differ between individual patches and the entire metropolitan region. To investigate such changes we conducted spatially explicit surveys including three dominant land‐use types in this region: native desert, agriculture, and mesic residential. These data were combined for analysis with previously collected samples from a synoptic regional survey. A landscape scaling approach was implemented to compare the dependence of soil variability on the sampled extent and the uncertainty associated with scaling from points to patches, land‐use types, and the Phoenix metropolitan region. The multiple‐scale analysis of soil properties showed that variation in total soil nitrogen, soil organic matter, and δ⁵N content of soils differed between patch and regional scales. The majority of variation in the urbanized patch types was exhibited between patches while for the native desert the majority of variation was observed within individual patches. These differences show the impact of urbanization on the scaling relations of ecosystem components. Overall, urbanization in this region appears to have increased soil organic matter by 44%, total nitrogen by 48%, and has elevated δ¹⁵N by 21%.     

Low mtDNA diversity among widespread Australian diamondback moth Plutella xylostella （L,） suggests isolation and a founder effect

Populations of Australian diamondback moth （DBM） Plutella xylostella （L.）, a serious pest of cruciferous crops, display extremely low levels of genetic differentiation across Australia and New Zealand sample locations, as determined previously using microsatellite markers. These data suggest high levels of contemporary gene flow that is consistent with Australian DBM being a vagile species. Here we examine Australian DBM samples for haplotype variation using the mitochondrial DNA sequences of a 257 bp fragment of the CO1 gene. We compare this variation to equivalent mtDNA sequence variation in samples from New Zealand, Kenya and Korea. Using 42 moths collected throughout Australia we show that Australian DBM have both low mtDNA haplotype and nucleotide diversities. The three Australian haplotypes detected are closely related and they cluster with the common haplotype group from Indonesia. In addition the Australian haplotype frequency distribution resembled more that from Indonesia than that from Kenya or Korea. These data are consistent with an original strong Australian/New Zealand founder effect, from a south-eastern Asian source, with subsequent continued isolation. In a single season, the frequency of PXMt01, the most common Australian haplotype, was estimated at 15 locations spread across southern Australia and New Zealand using a polymerase chain reaction BiPASA method. The PXMt01 haplotype frequency variation was heterogenous, suggesting a small degree of population isolation that was not detected using microsatellites. Differentiation was not a function of geographical distance. These data suggest transient and sporadic local colonisation events by small numbers of founding females.     

Effects of Maternal Status on the Movement and Mortality of Sterilized Female White-Tailed Deer

Abstract: Surgical sterilization by tubal ligation has been proposed as a technique for controlling white-tailed deer (Odocoileus virginianus) populations in urban or suburban areas where other forms of population control are impractical, but little is known about demographic rates in populations under management with surgical sterilization. We analyzed seasonal movement and mortality data collected during a 4-year study of surgical sterilization in suburban Chicago, Illinois, USA. We calculated 323 home range size estimates for 62 individual females within season and year. Non-gravid females without young exhibited home range sizes 52% larger than gravid females and females with fawns. Mortality rate was positively correlated with home range size. We suggest that the increased mortality rate observed in surgically sterilized females may be due to greater movement by non-maternal females. Population managers will need to account for potential effects of maternal status on movement and mortality when considering the use of sterilization for management of suburban populations of white-tailed deer.