Comparative influence of forest management and habitat structural factors on the abundances of hollow-nesting bird species in subtropical Australian eucalypt forest

We examined the impact of single-tree selective logging and fuel reduction bums on the abundance of hollow-nesting bird species at a regional scale in southeastern Queensland, Australia. Data were collected on species abundance and habitat structure of dry sclerophyll production forest at 36 sites with known logging and fire histories. Sixteen bird species were recorded with most being resident, territorial, obligate hollow nesters that used hollows that were either small (18 cm diameter). Species densities were typically low, but combinations of two forest management and three habitat structural variables influenced the abundances of eight bird species in different and sometimes conflicting ways. The results suggest that habitat tree management for biodiversity in production forests cannot depend upon habitat structural characteristics alone. Management histories appear to have independent influence (on some bird species) that are distinguishable from their impacts on habitat structure per se. Rather than managing to maximize species abundances to maintain biodiversity, we may be better off managing to avoid extinctions of populations by identifying thresholds of acceptable fluctuations in populations of not only hollow-nesting birds but other forest dependent wildlife relative to scientifically valid forest management and habitat structural surrogates.

Explicit evidence-based prescribing criteria - an important step in achieving quality therapeutics in nursing homes

Reaction between 5-(4-amino-2-thiabutyl)-5-methyl-3,7-dithianonane-1, 9-diamine (N3S3) and 5- methyl-2,2-bipyridine-5-carbaldehyde and subsequent reduction of the resulting imine with sodium borohydride results in a potentially ditopic ligand (L). Treatment of L with one equivalent of an iron( II) salt led to the monoprotonated complex [Fe(HL)](3+), isolated as the hexafluorophosphate salt. The presence of characteristic bands for the tris( bipyridyl) iron( II) chromophore in the UV/vis spectrum indicated that the iron( II) atom is coordinated octahedrally by the three bipyridyl (bipy) groups. The [Fe( bipy) 3] moiety encloses a cavity composed of the N3S3 portion of the ditopic ligand. The mononuclear and monomeric nature of the complex [Fe(HL)](3+) has been established also by accurate mass analysis. [Fe(HL)](3+) displays reduced stability to base compared with the complex [Fe(bipy)(3)](2+). In aqueous solution [Fe(HL)](3+) exhibits irreversible electrochemical behaviour with an oxidation wave ca. 60 mV to more positive potential than [Fe(bipy)(3)](2+). Investigations of the interaction of [Fe(L)](2+) with copper( II), iron( II), and mercury( II) using mass spectroscopic and potentiometric methods suggested that where complexation occurred, fewer than six of the N3S3 cavity donors were involved. The high affinity of the complex [Fe(L)](2+) for protons is one reason suggested to contribute to the reluctance to coordinate a second metal ion.

Cenozoic continental weathering and its implications for the palaeoclimate: evidence from Ar-40/Ar-39 geochronology of supergene K-Mn oxides in Mt Tabor, central Queensland, Australia

One hundred and twenty-five mineral grains from 45 visually pure K-bearing Mn oxide (hollandite group) samples collected from weathering profiles in the Mt Tabor region of central Queensland, Australia, were analysed by the Ar-40/Ar-39 laser probe technique. These K-Mn oxides precipitated mainly through a process of cavity filling (direct precipitation from weathering solution), with botryoidal texture formed by micrometric mineral bands. Well-defined and reproducible plateau ages have been obtained for most samples, ranging from 27.2 +/- 0.8 to 6.8 +/- 0.5 Ma (2 sigma). Statistical analysis of the geochronological results by mixture modelling suggests an episodic mineral precipitation history, with two major peaks at 20.2 +/- 0.22 Ma and 16.5 +/- 0.17 Ma. The geochronological results, when combined with information on paragenetic relationships and mineralogical textures obtained from petrographic, scanning electron microscopy, and electron microprobe investigations, indicate that warm and humid palaeoclimatic conditions favourable to intense chemical weathering prevailed in central Queensland from late Oligocene to middle Miocene, particularly in the early Miocene. These results, in conjunction with previous and ongoing investigations in NW and eastern Queensland, suggest that most of Queensland was dominated by humid climates during the Miocene. (C) 2002 Elsevier Science BN. All rights reserved.

Influence of left ventricular size and hemodynamics on the systolic longitudinal myocardial Doppler velocity response to stress

Background Systolic myocardial Doppler velocity accurately identifies coronary artery disease. However, these velocities may be affected by age, hemodynamic responses to stress, and left ventricular cavity size. We sought to examine the influences of these variables on myocardial velocity during dobutamine stress in patients with normal wall motion. Methods One hundred seventy-nine consecutive patients with normal dobutamine echocardiograms were studied. Color myocardial tissue Doppler data were obtained at rest and peak stress, and peak systolic myocardial velocity (PSV) was measured in all basal and midventricular segments. Velocities at rest and peak stress were compared with left ventricular diastolic and systolic volumes, blood pressure, heart rate, and age by Pearson correlation and interdecile analysis by use of analysis of variance. Results The only clinical variable correlating with velocity was age; PSV showed only mild correlation with age at rest (r(2) = 0.01, P = .001) and peak stress (r(2) = 0.02, P = .001), but the normal peak velocity was significantly different between the extremes of age (<44 years and >74 years). There was very weak correlation of PSV with systolic and diastolic blood pressure (r(2) < 0.01), heart rate (r(2) < 0.01), systemic vascular resistance (r(2) = 0.08), and left ventricular volumes (r(2) < 0.01). Conclusions Peak systolic velocity during dobutamine stress is relatively independent of hemodynamic factors and left ventricular cavity size. The extremes of age may influence peak systolic Doppler velocities. These results suggest that peak systolic velocity may be a robust quantitative measure during dobutamine echocardiography across most patient subgroups.

Discrete teleportation protocol of continuum spectra field states

A discrete protocol for teleportation of superpositions of coherent states of optical-cavity fields is presented. Displacement and parity operators are unconventionally used in Bell-like measurement for field states.

Multiple axon guidance cues establish the olfactory topographic map: how do these cues interact?

Each primary olfactory neuron stochastically expresses one of similar to1000 odorant receptors. The total population of these neurons therefore consists of similar to1,000 distinct subpopulations, each of which are mosaically dispersed throughout one of four semi-annular zones in the nasal cavity. The axons of these different subpopulations are initially intermingled within the olfactory nerve. However, upon reaching the olfactory bulb, they sort out and converge so that axons expressing the same odorant receptor typically target one or two glomeruli. The spatial location of each of these 1800 glomeruli are topographically-fixed in the olfactory bulb and are invariant from animal to animal. Thus, while odorant receptors are expressed mosaically by neurons throughout the olfactory neuroepithelium their axons sort out, converge and target the same glomerulus within the olfactory bulb. How is such precise and reproducible topographic targeting generated? While some of the mechanisms governing the growth cone guidance of olfactory sensory neurons are understood, the cues responsible for homing axons to their target site remain elusive.

EphA receptors and ephrin-A ligands exhibit highly regulated spatial and temporal expression patterns in the developing olfactory system

The spatiotemporal expression patterns of the chemorepulsive EphA receptors, EphA4 and EphA7, and three ephrins-A2, A4 and A5, were examined in the developing rat primary olfactory system. Unlike the visual system that has simple and stable gradients of Ephs and ephrins, the olfactory system demonstrates complex spatiotemporal expression patterns of these molecules. Using immunohistochemistry, we demonstrate that expression of these molecules is dynamic and tightly regulated both within and between different cell types. We reveal restricted targeting of these proteins within subcellular compartments of some neurons. EphA4, ephrin-A2 and ephrin-A5 were expressed by primary olfactory axons during the embryonic formation of the olfactory nerve. There were no gradients in expression along the rostrocaudal or ventrodorsal axes in the nasal cavity and olfactory bulb. However, during the early neonatal period, axons expressing different levels of ephrin-A5 sorted out and terminated in a subpopulation of glomeruli that were mosaically dispersed throughout the bulb. The expression of EphA4 and ephrin-A2 was dramatically down-regulated on all axons during the early neonatal period of glomerular formation. The uniform co-expression of receptors and ligands before glomerular formation suggests they play a generic role in axon-axon interactions in the olfactory nerve and nerve fibre layer. In contrast, loss of EphA4 from axons during glomerular formation may facilitate the interaction of ephrin-A5 with Eph receptors on target cells in the bulb. While EphA4, EphA5 and EphA7 are not mosaically expressed by bulbar neurons, other Eph receptors may have expression patterns complementary to the ephrin-A5-positive subpopulation of glomeruli. (C) 2002 Elsevier Science B.V. All rights reserved.

Organic microcavity light-emitting diodes with metal mirrors: dependence of the emission wavelength on the viewing angle

Organic microcavity light-emitting diodes typically exhibit a blueshift of the emitting wavelength with increasing viewing angle. We have modeled the shift of the resonance wavelength for several metal mirrors. Eight metals (Al, Ag, Cr, Ti, Au, Ni, Pt, and Cu) have been considered as top or bottom mirrors, depending on their work functions. The model fully takes into account the dependence of the phase change that occurs on reflection on angle and wavelength for both s and p polarization, as well as on dispersion in the organic layers. Different contributions to the emission wavelength shift are discussed. The influence of the thickness of the bottom mirror and of the choice and thickness of the organic materials inside the cavity has been investigated. Based on the results obtained, guidelines for a choice of materials to reduce blueshift; are given. (C) 2002 Optical Society of America.

Characterization of the retinoid orphan-related receptor-alpha coactivator binding interface: A structural basis for ligand-independent transcription

The retinoid orphan-related receptor-alpha (RORalpha) is a member of the ROR subfamily of orphan receptors and acts as a constitutive activator of transcription in the absence of exogenous ligands. To understand the basis of this activity, we constructed a homology model of Rill using the closely related TRbeta as a template. Molecular modeling suggested that bulky hydrophobic side chains occupy the RORa ligand cavity leaving a small but distinct cavity that may be involved in receptor stabilization. This model was subject to docking simulation with a receptor-interacting peptide from the steroid receptor coactivator, GR-interacting protein-1, which delineated a coactivator binding surface consisting of the signature motif spanning helices 3-5 and helix 12 [activation function 2 (AF2)]. Probing this surface with scanning alanine mutagenesis showed structural and functional equivalence between homologous residues of RORalpha and TRbeta. This was surprising (given that Rill is a ligand-independent activator, whereas TRbeta has an absolute requirement for ligand) and prompted us to use molecular modeling to identify differences between Rill and TRbeta in the way that the All helix interacts with the rest of the receptor. Modeling highlighted a nonconserved amino acid in helix 11 of RORa (Phe491) and a short-length of 3.10 helix at the N terminus of AF2 which we suggest i) ensures that AF2 is locked permanently in the holoconformation described for other liganded receptors and thus 2) enables ligand-independent recruitment of coactivators. Consistent with this, mutation of RORa Phe491 to either methionine or alanine (methionine is the homologous residue in TRbeta), reduced and ablated transcriptional activation and recruitment of coactivators, respectively. Furthermore, we were able to reconstitute transcriptional activity for both a deletion mutant of Ill lacking All and Phe491 Met, by overexpression of a GAL-AF2 fusion protein, demonstrating ligand-independent recruitment of AF2 and a role for Phe491 in recruiting AF2.

Macrophages, myofibroblasts and neointimal hyperplasia after coronary artery injury and repair

Macrophages participate in the restenosis process through the release of cytokines, metalloproteinases and growth factors. Studies of peritoneal granulation tissue suggest that macrophages may be precursors of myofibroblasts. This study examined the contribution of monocyte/macrophage lineage cells to neointimal cellular mass in a porcine model of thermal vascular injury. Thermal coronary artery injury caused medial smooth muscle cell necrosis and transformation of the media into an extracellular matrix barrier. The neointimal hyperplasia that developed over the injury sites was evaluated by light microscopy, electron microscopy and immunohistochemistry. At day 3, blood monocytes were adhered to the vessel wall and infiltrated the fibrotic media. At day 14, 42 +/- 3.9% of neointimal cells had a monocytic nuclear morphology and expressed macrophage-specific antigen SWC3 (identified by monoclonal antibody DH59B). Moreover, 9.2+/-1.8% of neointimal cells co-expressed SWC3 and alpha-smooth muscle actin and had ultrastructural characteristics intermediate between macrophages and myofibroblasts. At day 28, 10.5 +/- 3.5%, of cells expressed SWC3 and 5.2+/-1.8% of cells co-expressed SWC3 and alpha-smooth muscle actin. This study indicates that hematopoietic cells of monocyte/macrophage lineage abundantly populate the neointima in the process of lesion formation and may be precursors of neointimal myofibroblasts after thermal vascular injury. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.

Intraorbital anatomy of the koala (Phascolarctos cinereus)

This is the first documented study of the anatomical details of the contents of the normal koala orbit, excluding the bulbus oculi. Baseline data were established which are necessary for understanding and treating ocular disease in the koala (Phascolarctos cinereus). The anatomy of the orbital contents of the koala were examined and described from animals that presented dead or were euthanized for humane reasons. Dissections of the orbital cavity were performed under magnification. Polymethyl methacrylate (PMMA) casts of the nasolacrimal system and the vascular supply of the orbit were also made in order to study these systems. The superficial lymphatic drainage of the conjunctival tissues was studied by subcutaneous injection of Evan's Blue into the palpebral conjunctiva of a freshly deceased animal, and by Microfil casts of the efferent lymphatics. In general, the orbital contents of the koala are consistent with those of other carnivorous polyprotodont and herbivorous diprotodont marsupials.

Bony orbital anatomy of the koala (Phascolarctos cinereus)

This is the first documented study of the anatomical details of the normal koala orbit. Baseline data are established which are necessary for understanding and treating ocular disease in the koala (Phascolarctos cinereus). The bony anatomy of the orbit of the koala was examined and described from animals that presented dead or had been euthanized for humane reasons. Dissections of the orbital cavity were performed under magnification, and descriptions of the orbital bones were from macerated skulls that had been boiled and cleaned, In general, the orbital bones of the koala, and their respective foramina, are consistent with those of other carnivorous polyprotodont and herbivorous diprotodont marsupials.

Mixed gas equilibrium adsorption on zeolites and energetic heterogeneity of adsorption volume

A model for binary mixture adsorption accounting for energetic heterogeneity and intermolecular interactions is proposed in this paper. The model is based on statistical thermodynamics, and it is able to describe molecular rearrangement of a mixture in a nonuniform adsorption field inside a cavity. The Helmholtz free energy obtained in the framework of this approach has upper and lower limits, which define a permissible range in which all possible solutions will be found. One limit corresponds to a completely chaotic distribution of molecules within a cavity, while the other corresponds to a maximum ordered molecular structure. Comparison of the nearly ideal O-2-N-2-zeolite NaX system at ambient temperature with the system Of O-2-N-2-zeolite CaX at 144 K has shown that a decrease of temperature leads to a molecular rearrangement in the cavity volume, which results from the difference in the fluid-solid interactions. The model is able to describe this behavior and therefore allows predicting mixture adsorption more accurately compared to those assuming energetic uniformity of the adsorption volume. Another feature of the model is its ability to correctly describe the negative deviations from Raoult's law exhibited by the O-2-N-2-CaX system at 144 K. Analysis of the highly nonideal CO2-C2H6-zeolite NaX system has shown that the spatial molecular rearrangement in separate cavities is induced by not only the ion-quadrupole interaction of the CO2 molecule but also the significant difference in molecular size and the difference between the intermolecular interactions of molecules of the same species and those of molecules of different species. This leads to the highly ordered structure of this system.

Is Cadinella ornatissima a chomodorid? Sperm ultra structure in an enigmatic nudibranch (Opisthobranchia Mollusca)

Sperm ultrastructure is described for the nudibranch gastropod Cadlinella ornatissima, type species of the genus Cadlinella (Thiele). Although C. ornatissima exhibits most of the sperm features characteristic of other Opisthobranchia and the Pulmonata (a small, rounded acrosomal vesicle, a complex, helical, mitochondrial derivative - partially paracrystalline, coarse fibres associated with the axoneme), it also possesses a number of previously undescribed and possibly unique features (a longitudinally inrolled acrosomal pedestal, an axial structure within the cavity of the acrosomal pedestal, an electron-dense collar at the anterior region of the acrosomal pedestal, the presence of crystalloid bodies within the glycogen helices of the mitochondrial derivative). To our knowledge this is the first report of crystalloid bodies in mature sperm of any mollusc. Collectively this evidence raises questions concerning the affinities and systematic position of Cadlinella within the Nudibranchia. The peculiar nature of the sperm differences, in comparison with other investigated nudibranchs, suggest that Cadlinella is not easily linked to either the Cadlinidae or Chromodorididae, and should be considered incertae sedis.

The 2000 Ogura Lecture: Olfactory neural cells: An untapped diagnostic and therapeutic resource

Objective. This is an over-view of the cellular biology of upper nasal mucosal cells that have special characteristics that enable them to be used to diagnose and study congenital neurological diseases and to aid neural repair. Study Design: After mapping the distribution of neural cells in the upper nose, the authors' investigations moved to the use of olfactory neurones to diagnose neurological diseases of development, especially schizophrenia. Olfactory-ensheating glial cells (OEGs) from the cranial cavity promote axonal penetration of the central nervous system and aid spinal cord repair in rodents. The authors sought to isolate these cells from the more accessible upper nasal cavity in rats and in humans and prove they could likewise promote neural regeneration, making these cells suitable for human spinal repair investigations. Methods: The schizophrenia-diagnosis aspect of the study entailed the biopsy of the olfactory areas of 10 schizophrenic patients and 10 control subjects. The tissue samples were sliced and grown in culture medium. The ease of cell attachment to fibronectin (artificial epithelial basement membrane), as well as the mitotic and apoptotic indices, was studied in the presence and absence of dopamine in those cell cultures. The neural repair part of the study entailed a harvesting and insertion of first rat olfactory lamina propria rich in OEGs between cut ends of the spinal cords and then later the microinjection of an OEG-rich suspension into rat spinal cords previously transected by open laminectomy. Further studies were done in which OEG insertion was performed up to 1 month after rat cord transection and also in monkeys. Results: Schizophrenic patients' olfactory tissues do not easily attach to basement membrane compared with control subjects, adding evidence to the theory that cell wall anomalies are part of the schizophrenic lesion of neurones. Schizophrenic patient cell cultures had higher mitotic and apoptotic indices compared with control subjects. The addition of dopamine altered these indices enough to allow accurate differentiation of schizophrenics from control patients, leading to, possibly for the first time, an early objective diagnosis of schizophrenia and possible assessment of preventive strategies. OEGs from the nose were shown to be as effective as those from the olfactory bulb in promoting axonal growth across transected spinal cords even when added I month after injury in the rat. These otherwise paraplegic rats grew motor and proprioceptive and fine touch fibers with corresponding behavioral improvement. Conclusions. The tissues of the olfactory mucosa are readily available to the otolaryngologist. Being surface cells, they must regenerate (called neurogenesis). Biopsy of this area and amplification of cells in culture gives the scientist a window to the developing brain, including early diagnosis of schizophrenia. The Holy Grail of neurological disease is the cure of traumatic paraplegia and OEGs from the nose promote that repair. The otolaryngologist may become the necessary partner of the neurophysiologist and spinal surgeon to take the laboratory potential of paraplegic cure into the day-to-day realm of clinical reality.