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Emergency Psychiatry in Houston: Caring for Victims of the Katrina Catastrophe

Emergency Psychiatry in Houston: Caring for Victims of the Katrina Catastrophe

Emergency Psychiatry in Houston: Caring for Victims of the Katrina Catastrophe

Emergency Psychiatry in Houston: Caring for Victims of the Katrina Catastrophe

Effect of Surface Morphology on Dimerization of tert-Butyl Mercaptan on the Surface of Amorphous Aluminosilicate Impregnated with Mn and Cu

A powder of destructive adsorbent was prepared by impregnating Mn and Cu on the surface of amorphous aluminosilicate. It catalytically dimerized tert-butyl mercaptan into di-tert-butyl disulfide on its surface. Turnover of the dimerization was strongly dependent on the surface morphology of the adsorbent, which could be altered by modification of aluminosilicate support. During the process of impregnation, which involved heat treatment at 500 <TEX>${^{\circ}C}$</TEX>, the shape of the pore was preserved, though large fraction of micropores were eliminated. The reactive sites on the surface were poisoned as dimerization products strongly adhered on them. Therefore, high surface area was not always desirable. When the surface was heavily populated with “inkbottled” pores with a narrow entrance in uniform size, heavy poisoning of the reactive sites turned the destructive adsorbents almost useless.

Theologie und (Post)modernität. Philosophische Fragen zu Oswald Bayers Luther-Buch.

The focus of this article is to raise some philosophical questions concerning Bayer's aim of making topical the theology of Luther. The involvement of philosophy offers both opportunities and risks for theology. On the one hand, philosophy can mediate between a religious or theological vocabulary and contemporary secular society; on the other, however, theology runs the risk of being affected by the inner-worldly categories of philosophy. The latter position seems to be the one of Bayer since he defines the relation between philosophy and theology as a discordant one. In order to examine if and how philosophy can serve as a mediator between religion and secular society, I concentrate on a common characteristic of theology and philosophy, viz. that they query all kinds of traditional wisdom in order to offer true, theologically or philosophically corroborated wisdom. First, I analyse Bayer's idea of theology as personal, traditional wisdom. He develops it through a confrontation with Kant's critical assessment of wisdom in his Critique of Practical Reason, according to which science is the only narrow entrance gate that leads to wisdom. According to Bayer, the entrance fee is far too high, since is implies an imoverishing reduction of theology to (objective) science. Instead, he understands theological wisdom as meta-criticism, standing in the middle between dogmatism and scepticism. In my comment on Bayer's position, I start from the definition of wisdom as a kind of knowledge, helping humans to find the true destiny of their lives. However, in our post-modern times, the plausibility of the truth-claim implied in this definition is being challenged. All our vocabularies about the destinies of our lives, be they religious, theological, or philosophical, are perceived as radically contingent and equivocal. Consequently, wisdom has become a private opinion of a person or a group of like-minded people. Although I agree with Bayer's critique of the privatisation of wisdom, his argument in favour of a theological wisdom which claims to be above any suspicion of being ideological in character because of God's personal address, seems highly problematic to me. Although religion has an enormous critical potential with regard to the ideologies of our times, it does not convince contemporary, secularised people, because they perceive religion itself as a form of ideology. Therefore, I propose, with the help of Kant's, What Does it Mean to Orientate Oneself in Thinking, another approach of the necessary critique of religious wisdom, which is based on the concept of reason, as distinct from science. This leads to a less discordant view of the relationship between philosophy and theology than Bayer's.

The value of nest boxes in the research and management of Australian hollow-using arboreal marsupials

Nest boxes have been recognised as research and management tools for arboreal marsupials in Australia for over 20 years. We review the published literature with the aim of describing the scope of studies conducted in Australia thus far and providing guidance to future research. We recognise three types of application in research: (1) detection of species, (2) study of a species’ ecology, and (3) investigation of box designs preferred by different species. Several species of arboreal marsupial may be detected more readily in nest boxes than by conventional survey techniques, allowing description of key aspects of their ecology; e.g. feathertail glider (Acrobates pygmaeus), eastern pygmy possum (Cercartetus nanus) and brush-tailed phascogale (Phascogale tapoatafa). Identifying the most favoured nest-box design for any species has implications for detection and management uses of nest boxes. More research is needed but preliminary findings suggest that species prefer narrow entrance holes, while height of the nest box above 3 m may be inconsequential. We recognise three types of management application: (1) species introduction, (2) support of populations of endangered species, and (3) strategic placement such as to enhance habitat connectivity. Currently there have been few attempts to use nest boxes to manage arboreal marsupials but further research is needed to realise their potential as a management tool.

Bacillus licheniformis Variant DY Proteinase: Specificity in Relation to the Geometry of the Substrate Recognition Site

S1-S4 specificity of the Bacillus licheniformis variant DY proteinase (subtilisin DY) was determined by a series of peptide nitroanilides. The broad S1 specificity is due to the relative flexibility of the binding loop, which exhibits a preference for phenylalanine and accepts poorly the side chains of alanine, valine, lysine, and especially that of glutamic acid, due probably to a steric repulsion by Asn 155 and the narrow entrance of the "pocket." Alanine in position P2 of the substrate is more favorable for the catalysis than glycine. S3 is located on the protein surface. It is more open than the other subsites and can accept a variety of residues. S4 exhibits an extremely high affinity for the aromatic group of phenylalanine. Evidently, hydrophobic forces predominate in the S4--P4 interactions. The results characterize subtilisin DY as a bacterial proteinase with a broad specificity due to the specific geometry and flexibility of the substrate recognition site, which can accommodate different types of amino acid side chains.

Micropore Adsorption Dynamics in Synthetic Hard Carbons

The kinetics of the adsorption of CO2 at 296 K in the micropores of sol-gel derived, monolithic carbons indicates two different types of micropores. While the micropore volume as well as the micropore width of both species turns out to be very similar, their accessibility is significantly different. To study the adsorption kinetics in more detail a set of sol-gel derived hard carbons was prepared with average macropore sizes ranging from about 50 nm to 5 micron at a total porosity of about 85%. To characterize the morphology of the samples small-angle X-ray scattering and N2 sorption at 77 K were applied. Evaluation of the structural characteristics and the adsorption kinetics of the carbons investigated reveals that the two different types of micropores are homogeneously spread throughout the carbon backbone. The adsorption kinetics in the readily accessible type of micropores is dominated by the gas phase transport through the macropores combined with transport along the inner surface. In contrast, the access to the second category of micropores is highly restricted even at 296 K; this is reflected in equilibration times of about 500 s. The characteristics of the slow adsorption component is almost independent of the macroscopic size and the morphology of the specimen, suggesting that the slow kinetics is controlled by the local accessibility of the micropores. Surprisingly, the equilibrium data of the two adsorption components as a function of the relative pressure reveal that the micropores that are only slowly filled are actually characterized by a lower (Dubinin-Raduskevich) energy and thus a larger micropore width than the ones that are readily filled. This can be interpreted in terms of micropores with a very narrow entrance (restricted diffusion) or a widening of the micropores due to swelling of the carbon upon CO2 adsorption.

Inhibition of the A-Type K+Channels of Dorsal Root Ganglion Neurons by the Long-Duration Anesthetic Butamben

n-Butyl-p-aminobenzoate (BAB; butamben) is a long-duration anesthetic used for the treatment of chronic pain. Epidural administration of BAB is thought to reduce the electrical excitability of dorsal root nociceptor fibers by inhibiting voltage-gated ion channels. To further investigate this mechanism, we examined the effects of BAB on the potassium currents of acutely dissociated neurons from the rat dorsal root ganglion (DRG). These neurons express a rapidly inactivating A-type K(+) current (I(A)) that is resistant to tetraethylammonium (20 mM) but inhibited by 4-aminopyridine (5 mM). At low concentrations, BAB (< or =1 microM) selectively inhibited the I(A) component of DRG K(+) current. The voltage dependence of activation and inactivation, kinetics of recovery from inactivation, and the pharmacology of the DRG I(A) were similar to those of the Kv4 family of K(+) channels. Reverse transcription-polymerase chain reaction was used to establish that the messages encoding for all three of the mammalian Kv4 channel subunits (Kv4.1-Kv4.3) were present in the rat DRG. BAB produced a high-affinity, partial inhibition of heterologously expressed Kv4.2 channels (K(D) = 59 nM) but did not alter the kinetics or voltage sensitivity of gating. Substituting polar threonines for conserved hydrophobic residues of the S6 segment weakened BAB binding but did not alter the voltage-dependent gating of the Kv4.2 channel. At physiological pH, BAB is uncharged, suggesting that hydrophobic interactions may contribute to drug binding. The data support a mechanism in which BAB binds near the narrow cytoplasmic entrance of Kv4 channels and inhibits current by a pore blocking mechanism.

Mild Supravalvular Aortic Stenosis With Left Coronary Obstruction in a Neonate

A premature infant with a large patent ductus arteriosus and mild supravalvular aortic stenosis had evidence of severe myocardial ischemia after ductus ligation. Urgent reoperation was required to relieve severe obstruction of the left coronary orifice and the supravalvular stenosis was repaired. This unusual presentation early in infancy emphasizes that left coronary artery obstruction should be suspected even in the presence of mild supravalvular stenosis.

Bottom Stratification and Water Exchange in Enclosed Bay with Narrow Entrance

Abstract The water quality in an enclosed bay with the limited exchange of water between the ocean and bay is strongly affected by water stratification. Omura Bay in Japan is a highly enclosed bay with a very narrow entrance to the ocean and is an ideal bay to examine the water stratification and its effect on water quality. The characteristics of water and currents in Omura Bay can be divided into two regions. One is the bay mouth region where strong tidal currents cause vertical mixing all the year round. The other is the region of the center and end of the bay where strong stratification is formed in summer and anoxic water occurs in the bottom layer every summer. This occurrence of the anoxic water is related strongly to the thermocline in the bottom layer. The currents associated with the difference of the vertical structures of water density in the two regions influence the formation of stratification. When the stratification in the center and end of the bay is the strongest in July, the density of ...

From peptide-bond formation to cotranslational folding: dynamic, regulatory and evolutionary aspects

Ribosomes are ribozymes exerting substrate positioning and promoting substrate-mediated catalysis. Peptide-bonds are formed within a symmetrical region, thus suggesting that ribosomes evolved by gene-fusion. Remote interactions dominate substrate positioning at stereochemistry suitable for peptide-bond formation and elaborate architectural-design guides the processivity of the reaction by rotatory motion. Nascent proteins are directed into the exit tunnel at extended conformation, complying with the tunnel’s narrow entrance. Tunnel dynamics facilitate its interactive participation in elongation, discrimination, cellular signaling and nascent-protein trafficking into the chaperon-aided folding site. Conformational alterations, induced by ribosomal-recycling factor, facilitate subunit dissociation. Remarkably, although antibiotics discrimination is determined by the identity of a single nucleotide, involved also in resistance, additional nucleotides dictate antibiotics effectiveness.

A nanodevice for rectification and pumping ions

The transport properties of single asymmetric nanopores in polyetheylene terephthalate (PET) are examined. The pores were produced by a track etching technique based on the irradiation of the foils by swift heavy ions and subsequent chemical etching. Electrical conductivity measurements show that the nanopores in PET are cation selective and rectify the current with the preferential direction of cation flow from the narrow entrance toward the wide opening of the pore. Moreover, the pore transports potassium ions against the concentration gradient if stimulated by external field fluctuations. We show that the rectifying and pumping effects are based on the ratchet mechanism.

Molecular basis for the binding of competitive inhibitors of maize polyamine oxidase.

Maize polyamine oxidase (MPAO), the only member of the polyamine oxidase (PAO) family whose three-dimensional structure is known, is characterized by a 30 A long U-shaped catalytic tunnel located between the substrate binding domain and the FAD. To shed light on the MPAO ligand binding mode, we studied the inhibition properties of linear diamines, agmatine, prenylagmatine (G3), G3 analogues, and guazatine, and analyzed the structural determinants of their biological activity. Linear diamines competitively inhibited MPAO, with the inhibitory activity increasing as a function of the number of methylene groups. With regard to the guanidino competitive inhibitors, including agmatine, G3, and G3 analogues, the presence of a hydrophobic substituent constitutes the principal factor influencing MPAO inhibition, as the addition of a hydrophobic substituent to the guanidino group of both G3 and G3 analogues greatly increases the inhibitory activity. Moreover, results obtained by a molecular modeling procedure indicated that in their preferred orientation, G3 analogues point the ammonium group toward the narrow entrance of the tunnel, while the terminal hydrophobic group is located within the large entrance. The high binding affinity for MPAO exhibited by G3 and G3 analogues bearing a prenyl group as a substituent on the guanidino moiety is in agreement with the observation that the prenyl group binds in a well-defined hydrophobic pocket, mainly formed by aromatic residues. Finally, docking simulations performed with the charged and uncharged forms of MPAO inhibitors indicate that the stereoelectronic properties of the MPAO active site are consistent with the binding of inhibitors in the protonated form.

Transfer of pollinaria on birds? feet: a new pollination system in orchids

We report the discovery of a new mechanism of pollination in orchids: transfer of pollinaria on the feet of birds. Observations carried out in South Africa and Malawi showed that the orchids Disa chrysostachya Sw. and Disa satyriopsis Kraenzl. are pollinated by sunbirds. Pollinaria of these orchids become attached firmly to the birds’ toes when they perch on the tall narrow inflorescences which are packed tightly with numerous small orange flowers. Birds typically perch on the lower part of an inflorescence while reaching up to feed on nectar in flowers on the upper part, but occasionally reverse this position to probe the lower flowers. The nectar is contained within a short bulbous spur with a narrow entrance that permits entrance of a sunbirds’ slender tongue. Contrary to expectation, the pollination mechanism in D. chrysostachya is remarkably efficient with about 6.1% of pollen reaching stigmas on other plants and fruit set occurring in 95% of flowers at one site. Birds seldom move their feet once perched, thus minimizing the incidence of self-pollination, either within or between flowers on an inflorescence.

The crystal structure of shikimate dehydrogenase (AroE) reveals a unique NADPH binding mode.

Shikimate dehydrogenase catalyzes the NADPH-dependent reversible reduction of 3-dehydroshikimate to shikimate. We report the first X-ray structure of shikimate dehydrogenase from Haemophilus influenzae to 2.4-A resolution and its complex with NADPH to 1.95-A resolution. The molecule contains two domains, a catalytic domain with a novel open twisted alpha/beta motif and an NADPH binding domain with a typical Rossmann fold. The enzyme contains a unique glycine-rich P-loop with a conserved sequence motif, GAGGXX, that results in NADPH adopting a nonstandard binding mode with the nicotinamide and ribose moieties disordered in the binary complex. A deep pocket with a narrow entrance between the two domains, containing strictly conserved residues primarily contributed by the catalytic domain, is identified as a potential 3-dehydroshikimate binding pocket. The flexibility of the nicotinamide mononucleotide portion of NADPH may be necessary for the substrate 3-dehydroshikimate to enter the pocket and for the release of the product shikimate.

Proteasome-cytochrome c interactions: a model system for investigation of proteasome host-guest interactions.

Owing to its high thermal stability and structural simplicity, the archaebacterium Thermoplasma Acidophilum 20S proteasome was selected for mechanistic studies in this work. This oligomeric enzyme complex consists of a barrel-shaped 20S core (approximately 700kDa) comprised of four stacked seven-membered rings with a alpha(7)beta(7)beta(7)alpha(7) subunit structure situated around a 7-fold symmetry axis. The hollow interior of the proteasome has three large interconnected chambers with narrow (13 A diameter) entrances from solution located at either end of the barrel. The 14 beta-subunit proteolytic sites are located on the inner surface of the central chamber. Herein, we demonstrate that unfolded horse heart ferricytochrome c (Cyt c) is a novel chromophoric probe for investigation of the mechanism of proteasome action. Under conditions of temperature and denaturant which unfold Cyt c but do not alter the thermophilic proteasome, Cyt c is extensively cleaved by the proteasome. Ten peptides were isolated and sequenced from the proteasome digest. Analysis of the cleavage products established that unfolded Cyt c and its covalently attached heme prosthetic group are translocated to the central chamber where proteolysis occurs. In the presence of site-specific inhibitors of the proteasome, we demonstrate that unfolded cytochrome c can be sequestered inside the proteasome complex. Upon cooling, a quasistable host-guest complex is formed. Analysis of the complex via UV/visible spectroscopy and mass spectrometry gave evidence that the sequestered Cyt c is essentially intact within the inhibited proteasome. High-performance liquid chromatography data show that (1) complexes with an apparent stoichiometry of approximately one Cyt c per proteasome can be formed and (2) when inhibition is removed from the complex, a rapid turnover of the sequestered Cyt c occurs.

Multifunctional Xylooligosaccharide/Cephalosporin C Deacetylase Revealed by the Hexameric Structure of the Bacillus subtilis Enzyme at 1.9 Å Resolution

Esterases and deacetylases active on carbohydrate ligands have been classified into 14 families based upon amino acid sequence similarities. Enzymes from carbohydrate esterase family seven (CE-7) are unusual in that they display activity towards both acetylated xylooligosaccharides and the antibiotic, cephalosporin C. The 1.9 Å structure of the multifunctional CE-7 esterase (hereinafter CAH) from Bacillus subtilis 168 reveals a classical α/β hydrolase fold encased within a 32 hexamer. This is the first example of a hexameric α/β hydrolase and is further evidence of the versatility of this particular fold, which is used in a wide variety of biological contexts. A narrow entrance tunnel leads to the centre of the molecule, where the six active-centre catalytic triads point towards the tunnel interior and thus are sequestered away from cytoplasmic contents. By analogy to self-compartmentalising proteases, the tunnel entrance may function to hinder access of large substrates to the poly-specific active centre. This would explain the observation that the enzyme is active on a variety of small, acetylated molecules. The structure of an active site mutant in complex with the reaction product, acetate, reveals details of the putative oxyanion binding site, and suggests that substrates bind predominantly through non-specific contacts with protein hydrophobic residues. Protein residues involved in catalysis are tethered by interactions with protein excursions from the canonical α/β hydrolase fold. These excursions also mediate quaternary structure maintenance, so it would appear that catalytic competence is only achieved on protein multimerisation. We suggest that the acetyl xylan esterase (EC 3.1.1.72) and cephalosporin C deacetylase (EC 3.1.1.41) enzymes of the CE-7 family represent a single class of proteins with a multifunctional deacetylase activity against a range of small substrates.

Preparation of synthetic nanopores with transport properties analogous to biological channels

Conically shaped pores have been prepared in polyethylene terephthalate (PET) and polyimide foils by applying the track-etching technique. For this purpose, a thin polymer foil was penetrated by a single heavy ion (e.g. Au, Bi, U) of total kinetic energy of several hundred MeV to some GeV, followed by preferential chemical etching of the ion track. Asymmetric etching conditions allowed the preparation of charged pores of conical shape, similar to biological voltage-sensitive channels. The nanopores in PET and polyimide behave as ion current rectifiers where the preferential direction of the cation flow is from the narrow entrance towards the wide aperture of the pore. The PET pore shows voltage-dependent ion current fluctuations with opening and closing kinetics similar to voltage-gated biological ion channels. In contrast to PET, the polyimide nanopore exhibits a stable ion current signal. We discuss the possibility of using the synthetic nanopores as model for voltage-gated biochannels.

Influence of an artificial entrance channel on the ichthyofauna of a large estuary

The opening in April 1994 of a deep artificial entrance channel into the shallow, microtidal and large Peel-Harvey Estuary (136 km2) in south-western Australia has led to major changes in the ichthyofauna of this system. This conclusion is based on statistical comparisons between data derived from samples of fish collected seasonally by seine net in the short, narrow and shallow natural entrance channel and in two large basins of the Peel-Harvey Estuary during 1996 and 1997, i.e. after the opening of the artificial channel, and data previously recorded seasonally using the same sampling regime during 1980 and 1981, i.e. before the construction of that channel. These comparisons show that the marked reduction in macroalgal growths that occurred between these two periods was accompanied by a decline in the abundance of fish, and particularly of macrophyte-associated species such as Pelates sexlineatus and Apogon rueppellii. There were also strong indications that the number of fish species usually present in the estuary declined, which would be consistent with a reduction in habitat heterogeneity. The comparisons also imply that the construction of the artificial channel led to: (1) a decline in the extent of interannual differences in the species richness and abundance of fish, presumably reflecting a reduction in the variability of environmental conditions in different years; (2) a greater penetration of the estuary by marine species and an increased contribution of these species to the fish fauna overall; (3) the influence of "season" on the ichthyofaunal compositions of assemblages within the estuary becoming more important than region. The second and third changes reflect a combination of increased tidal flow, which facilitates a more effective dispersal of fish, the exposure of fish to stronger tidal cues, a far greater proximity of the more distal regions of the estuary to the sea and, in the case of the third change, a far less pronounced difference between environmental conditions in the two basins.

The Response of a Strongly Stratified Fjord to Energetic Tidal Forcing

The response of Upper Loch Linnhe, a strongly stratified Scottish fjord, to energetic tidal forcing is studied by new analysis of two observational data sets. Using a ship-mounted Acoustic Doppler Current Profiler (ADCP) and an undulating Conductivity-Temperature-Depth (CTD) we are able to repeatedly sample over a tidal cycle at sufficiently high spatial and temporal resolutions to clearly define the tidal variability in the vertical and horizontal. Away from the near-sill region, horizontal velocities are generally orientated along the longitudinal axis of the fjord. Analysis of the along-fjord velocities shows that at the M 2-frequency there is a strong 1st mode internal tide with maximum horizontal velocity amplitudes of 23·4 cm s −1. The observed vertical structure of the complex amplitudes of the horizontal velocities are in close agreement with normal mode theory. Along-fjord variations of the fitted amplitude and phase lags from further analysis of the two independent data sets show that the 1st mode internal tide is behaving as a standing wave. Within the near-sill region, the circulation is complicated by the formation of a horizontal gyre and a large perturbation in the density field on the flood tide. These features are a response to the flood tide currents advecting denser water into the fjord in the form of a strong jet. Due to the narrow entrance sill being off-centre to the axis of the fjord, the strong flood tide jet gives rise to eddy formation. As the incoming flood tide water is denser than the resident surface water of the fjord the tidal jet sinks and advects the resident water landwards giving rise to the observed density perturbations.