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Concerns over the environmental impact and economics of harvesting sphagnum and reed-sedge peat have increased the desire to identify acceptable peat substitutes for use in container substrates. This preliminary study evaluated the use of composted dairy manure solids as a substitute for sphagnum or reed-sedge peat in container substrates for production of woody ornamental shrubs and assessed potential leaching of nutrients. Walter's viburnum (Viburnum obovatum), sandankwa viburnum (Viburnum suspensum), and japanese privet (Ligustrum japonicum) were grown in 3-gal plastic containers with seven substrates containing (by vol.) 60% pine bark, 10% sand, and 30% sphagnum peat (S), reed-sedge peat (R), and/or composted dairy manure solids (C). Substrate composition had no effect on plant quality ratings for any species, growth index (GI) of walter's viburnum, or shoot and root dry weight of walter's viburnum and japanese privet. However, the GI of japanese privet and sandankwa viburnum was the lowest when grown in substrates containing a high percentage of reed-sedge peat (0S:3R:0C). Substrate effects on average nitrate + nitrite nitrogen leachate losses were minimal over the 88-day leachate collection period. However, the substrate containing the highest proportions of composted dairy manure solids (0S:0R:3C) generally had the highest average ammonium nitrogen and dissolved reactive phosphorus losses compared with other substrates. All substrates tested as part of this study appeared to be commercially acceptable for production of container-grown woody ornamental shrub species based on growth and quality. However, average nutrient losses from containers differed depending on the peat or peat substitute used to formulate the substrates. [ABSTRACT FROM AUTHOR]

Previous research on #3 nursery container-grown shrubs suggests that some common shrub species could be established in the Florida landscape under natural rainfall when irrigated with 3 L of water every 4 days in U.S. Department of Agriculture hardiness zones 8b and 9a or every 2 days in zone 10b until first roots reached the canopy edge (≈20 weeks after planting). The current study evaluated the effects of these irrigation frequency recommendations on plant vigor, canopy growth, root growth, and aesthetic quality of 21 common landscape shrub species (10 Florida native and 11 non-native) planted in Florida in zones 8b, 9a, or 10b. Data suggests that it may be appropriate to adopt the 20-week low-volume irrigation recommendations for the establishment of a wide variety of container-grown Florida native and non-native shrubs. However, Florida native and non-native shrubs should be monitored for symptoms of drought stress for 2 years after planting. [ABSTRACT FROM AUTHOR]

Although new and innovative measures to reduce landscape water consumption are being sought, traditional methods of water restrictions and plant selection prevail. Species native to North America are often promoted as drought tolerant with little information to support or refute such claims. Furthermore, species performance is unknown in maintained environments such as commercial and residential landscapes. Thus, 10 native and 10 exotic species, commonly used in landscapes, were evaluated independently for postestablishment growth and aesthetics under irrigated and nonirrigated landscape conditions. Growth indices were recorded monthly, with dieback and plant density evaluated at termination of the experiment. At termination of the experiment, canopy size of eight native [beautyberry (Callicarpa americana), fringe tree (Chionanthus virginicus), yaupon holly (Ilex vomitoria 'Nana'), virginia sweetspire (Itea virginica), wax myrtle (Myrica cerifera), chickasaw plum (Prunus angustifolia), saw palmetto (Serenoa repens), and coontie (Zamia floridana)] and eight exotic [golden dewdrop (Duranta erecta), cape jasmine (Gardenia augusta), crape myrtle (Lagerstroemia indica), oleander ( Nerium oleander), japanese pittosporum (Pittosporum tobira), indian hawthorn (Rhaphiolepis indica), sweet viburnum (Viburnum odoratissimum), and sandankwa viburnum (V. suspensum)] species were similar for irrigated and nonirrigated treatments. Irrigation resulted in larger canopy sizes for two native [waiter's viburnum (V. obovatum) and inkberry (I. glabra)] and two nonnative [japanese privet (Ligustrum japonicum) and fringe flower (Loropetalum chinensis)] species. Among the native species with larger canopy sizes under irrigated conditions, all are indigenous to swamps and streams. With the exception of virginia sweetspire, plant density and dieback were similar for irrigated and nonirrigated plants of all taxa examined. Irrigated virginia sweetspire plants had higher plant density and dieback ratings than nonirrigated plants. Results indicate that, aesthetically, irrigated and nonirrigated plants were similar. Data emphasize the importance of selecting plant material adapted to existing environmental landscape conditions. [ABSTRACT FROM AUTHOR]

Solutions of sucrose, glucose, raffinose, and stachyose were fed via the petiole to detached leaves of plant species known to transfer sugars during photosynthesis into the phloem using either the apoplastic or the symplastic pathway of phloem loading. Symplastic phloem loaders, which translocate raffinose-type oligosaccharides and sucrose in the phloem, and apoplastic plants, translocating exclusively sucrose, were selected for this study. As the sugars arrived with the transpiration stream in the leaf blade within little more than a minute, dark respiration increased. Almost simultaneously, fluorescence of a potential-indicating dye, which had been infiltrated into the leaves, indicated membrane depolarization. Another fluorescent dye used to record the apoplastic pH revealed apoplastic alkalinization that occurred with a slight lag phase after respiration and membrane depolarization responses. Occasionally, alkalinization was preceded by transient apoplastic acidification. Whereas membrane depolarization and apoplastic acidification are interpreted as initial responses of the proton motive force across the plasma membrane to the advent of sugars in the leaf apoplast, the following apoplastic alkalinization showed that sugars were taken up from the apoplast into the symplast in cotransport with protons. This was true not only for glucose and sucrose, but also for raffinose and stachyose. Similar observations were made for sugar uptake not only in leaves of plants known to export sugars by symplastic phloem loading but also of plants using the apoplastic pathway. Increased respiration during sugar uptake revealed tight coupling between respiratory ATP production and ATP consumption by proton-translocating ATPase of the plasma membrane, which exports protons into the apoplast, thereby compensating for the proton loss in the apoplast when protons are transported together with sugars into the symplast. The extent of stimulation of respiration by sugars indicated that sugar uptake was not limited to phloem tissue. Ratios of the extra CO2released during sugar uptake to the amounts of sugars taken up were variable, but lowest values were lower than 0.2. When a ratio of 0.2 is taken as a basis to calculate rates of sugar uptake from observed maxima of sugar-dependent increases in respiration, rates of sugar uptake approached 350 nmol/(m2leaf surface s). Sugar uptake rates were half-saturated at sugar concentrations in the feeding solutions of about 10–25 mM indicating a low in vivoaffinity of sugar uptake systems for sugars.

Inorganic and organic salts, amino acids, sugars, and phosphate esters (concentrations usually 25 mM) were fed via the transpiration stream through the petiole into detached leaves of Lepidium sativumand Solanum tuberosum.While water was lost by transpiration, solutes did not accumulate in the apoplast. Uptake into leaf cells was indicated by stimulation of respiration and by changes of membrane potential and apoplastic pH. Apoplastic alkalinization (followed by transient acidification) and membrane depolarization (followed by repolarization) indicated energization of transport at the expense of the proton motive force (PMF) across the plasma membrane in all examined cases. Loss of ATP in the symplast during proton extrusion into the apoplast by the plasmalemma ATPase is thought to be responsible for stimulation of respiration. Even unphysiological solutes such as β-morpholinoethane sulfonate (Mes), or potentially toxic salts such as CdCl2or AlCl3, and metabolites involved in energy conservation such as AMP and NAD, were readily transported into leaf cells at the expense of metabolic energy. At the maximum stimulation of CO2release by D-serine (which is unlikely to be metabolized) respiration exceeded basal respiration by an average of 33%. Occasionally, and with other solutes, basal respiration was almost doubled. The ratio of transported solute to released extra CO2was 6.9 ± 1.1 (n= 11) in the case of D-serine. From this, maximum energized transport of D-serine was calculated to be close to 500 nmol/(m2leaf area s). Solute/CO2ratios similar to those observed with D-serine were also obtained for sucrose. Lower ones were observed with organic solutes such as L-glycine, pyruvate, malate or citrate where secondary metabolic conversions may contribute to CO2release.

Abstract: Seasonal changes in the efficiency of charge separation in PSII were studied in Thuja occidentalis(L.) and Chamaecyparis lawsonia(A. Murray bis.). Maximum light‐dependent charge separation decreased with decreasing temperatures in early winter in both species, but this was less drastic in Chamaecyparisthan in Thuja.No positive relationship was seen between photoinhibition and irradiance. Rather, photoinhibition increased as photon flux densities decreased towards midwinter, and it decreased as photon flux densities increased towards spring. However, the decrease in maximum light‐dependent charge separation was much stronger on the light‐exposed upper surface of the twigs, where in Thujavisible browning occurred, than on the underside of the twigs. During spring, recovery of the photosynthetic efficiency and regreening were observed as both mean temperatures and irradiance increased. Transfer in midwinter of strongly photo‐inhibited twigs of Thujato temperatures close to 20 °C resulted in considerable recovery of PSII activity within several days when low light was also present. Recovery did not occur at temperatures close to freezing or at room temperature in darkness. An analysis of fluorescence quenching suggested photoprotective dissipation of excess radiation not only in the light harvesting antennae of PSII but also in the reaction centres. Reaction centre quenching appeared to be stronger in Thujathan in Chamaecyparis.PSI was fully active in twigs whether or not PSII was photoinhibited. The antioxidant ascorbate was almost fully reduced even in midwinter.

Seasonal changes in the efficiency of charge separation in PSII were studied in Thuja occidentalis (L.) and Chamaecyparis lawsonia (A. Murray bis.). Maximum light-dependent charge separation decreased with decreasing temperatures in early winter in both species, but this was less drastic in Chamaecyparis than in Thuja. No positive relationship was seen between photoinhibition and irradiance. Rather, photoinhibition increased as photon flux densities decreased towards midwinter, and it decreased as photon flux densities increased towards spring. However, the decrease in maximum light-dependent charge separation was much stronger on the light-exposed upper surface of the twigs, where in Thuja visible browning occurred, than on the underside of the twigs. During spring, recovery of the photosynthetic efficiency and regreening were observed as both mean temperatures and irradiance increased. Transfer in midwinter of strongly photo-inhibited twigs of Thuja to temperatures close to 20 °C resulted in considerable recovery of PSII activity within several days when low light was also present. Recovery did not occur at temperatures close to freezing or at room temperature in darkness. An analysis of fluorescence quenching suggested photoprotective dissipation of excess radiation not only in the light harvesting antennae of PSII but also in the reaction centres. Reaction centre quenching appeared to be stronger in Thuja than in Chamaecyparis. PSI was fully active in twigs whether or not PSII was photoinhibited. The antioxidant ascorbate was almost fully reduced even in midwinter. Abbreviations. FR: far red light MT: multiple turnover flash PAR: photosynthetically active radiation PSII, PSI: photosystems II and I ST: single turnover flash

We analyzed the pathway of nuclear envelope assembly in Xenopus egg extracts using field emission in-lens scanning electron microscopy. The binding, fusion, and flattening of vesicles onto the chromatin surface were visualized in detail. The first nuclear pore complexes assembled in flattened patches of nuclear envelope, before the chromatin was fully enclosed by membranes. Confirming previous transmission electron microscope observations, two morphologically distinct types of vesicles contributed to the nuclear membranes: ribosome-carrying ('rough') vesicles, many of which bound directly to chromatin, and 'smooth' vesicles, which appeared to associate primarily with other nuclear vesicles or membrane patches. The presence of ribosomes, an outer nuclear membrane marker, on many chromatin-binding vesicles suggested that chromatin-attachment proteins integral to the inner membrane were present on vesicles that also carried markers of the outer membrane and endoplasmic reticulum. Chromatin-associated vesicles also carried pore membrane proteins, since pore complexes formed when these vesicles were incubated with cytosol. A change in nuclear envelope morphology termed 'envelope smoothing' occurred 5-15 minutes after enclosure. Nuclear envelopes that were assembled in extracts depleted of wheat-germ-agglutinin-binding nucleoporins, and therefore unable to form functional pore complexes, remained wrinkled, suggesting that 'smoothing' required active nuclear transport. Lamins accumulated with time when nuclei were enclosed and had functional pore complexes, whereas lamins were not detected on nuclei that lacked functional pore complexes. Very low levels of lamins were detected on nuclear intermediates whose surfaces were substantially covered with patches of pore-complex-containing envelope, suggesting that pore complexes might be functional before enclosure.

We used field emission in-lens scanning electron microscopy to examine newly-assembled, growing nuclear envelopes in Xenopus egg extracts. Scattered among nuclear pore complexes were rare 'dimples' (outer membrane depressions, 5-35 nm diameter), more abundant holes (pores) with a variety of edge geometries (35-45 nm diameter; 3.3% of structures), pores containing one to eight triangular 'star-ring' subunits (2.1% of total), and more complicated structures. Neither mature complexes, nor these novel structures, formed when wheat germ agglutinin (which binds O-glycosylated nucleoporins) was added at high concentrations (>500 microg/ml) directly to the assembly reaction; low concentrations (10 microg/ml) had no effect. However at intermediate concentrations (50-100 microg/ml), wheat germ agglutinin caused a dramatic, sugar-reversible accumulation of 'empty' pores, and other structures; this effect correlated with the lectin-induced precipitation of a variable proportion of each major Xenopus wheat-germ-agglutinin-binding nucleoporin. Another inhibitor, dibromo-BAPTA (5,5'-dibromo-1,2-bis[o-aminophenoxylethane-N,N,N',N'-tetraacetic acid), had different effects depending on its time of addition to the assembly reaction. When 1 mM dibromo-BAPTA was added at time zero, no pore-related structures formed. However, when dibromo-BAPTA was added to growing nuclei 40-45 minutes after initiating assembly, star-rings and other structures accumulated, suggesting that dibromo-BAPTA can inhibit multiple stages in pore complex assembly. We propose that assembly begins with the formation and stabilization of a hole (pore) through the nuclear envelope, and that dimples, pores, star-rings, and thin rings are structural intermediates in nuclear pore complex assembly.

Schizophrenia is thought to be a multifactorial disease with complex mode of inheritance1,2. Using a two-stage strategy for another complex disorder, a number of putative IDDM-susceptibility genes have recently been mapped3. We now report the results of a two-stage genome-wide search for genes conferring susceptibility to schizophrenia. In stage I, model-free linkage analyses of large pedigrees from Iceland, a geographical isolate, revealed 26 loci suggestive of linkage. In stage II, ten of these were followed-up in a second international collaborative study comprising families from Austria, Canada, Germany, Italy, Scotland, Sweden, Taiwan and the United States. Potential linkage findings of stage I on chromosomes 6p, 9 and 20 were observed again in the second sample. Furthermore, in a third sample from China, fine mapping of the 6p region by association studies also showed evidence for linkage or linkage disequilibrium. Combining our results with other recent findings4,5revealed significant evidence for linkage to an area distal of the HLA region on chromosome 6p. However, in a fourth sample from Europe, the 6p fine mapping finding observed in the Chinese sample could not be replicated. Finally, evidence suggestive of locus heterogeneity and oligogenic transmission in schizophrenia was obtained.

Berichtet wird über die notärztliche Versorgung einer Patientin mit einem multipel metastasierten Ovarialkarzinom im finalen Krankheitsstadium. Anhand dieses Einsatzes soll verdeutlicht werden, dass palliativmedizinische Fragestellungen auch in der Notfallmedizin relevant sind. Eine strukturierte Kooperation der in dieser Situation involvierten medizinischen Fachgebiete erscheint dringend geboten.Berichtet wird über die notärztliche Versorgung einer Patientin mit einem multipel metastasierten Ovarialkarzinom im finalen Krankheitsstadium. Anhand dieses Einsatzes soll verdeutlicht werden, dass palliativmedizinische Fragestellungen auch in der Notfallmedizin relevant sind. Eine strukturierte Kooperation der in dieser Situation involvierten medizinischen Fachgebiete erscheint dringend geboten.