971 research outputs found
Psychologists Collaborating With Clergy
If a patient adheres to religious values and practices, should the treating psychologist get input from a clergyperson? How frequent is clergy-psychologist collaboration? What obstacles impede such collaboration? An exploratory survey questionnaire was sent to 200 clergy, 200 psychologists interested in religious issues, and 200 psychologists selected without regard to religious interests or values. Four themes were assessed: types of collaborative activities, frequency of collaboration, obstacles to collaboration, and ways to enhance collaboration. Strategies for promoting clergy-psychologist collaboration include challenging unidirectional referral assumptions, building trust through proximity and familiarity, and considering the importance of shared values and beliefs
GFR and the concentration of urine in the absence of vasopressin. Berliner-Davidson re-explored
Robert W. Berliner made many important contributions to our understanding of the urinary concentrating mechanism. Among these, one must number his demonstration that urine can be rendered hyperosmotic to plasma even when vasopressin is absent, as well as his definition of the role of the glomerular filtration rate (GFR) in the concentrating process [1, 2]—points that had also been suggested by several other investigators [reviewed in 3, 4]. In postulating how urine might be concentrated without vasopressin purely by changes occurring within the kidney [1], Dr. Berliner expressed the essence of a message, which we still tend to overlook today, namely, that “…although it is commonly stated that the function of ADH is to cause the excretion of a hypertonic urine, its more important function might be better defined as preventing the excretion of a dilute urine.”The availability of the Brattleboro rat, which has an inherited deficiency for synthesizing vasopressin [5], made it possible to further explore the mechanisms by which urine can be concentrated in the apparent absence of the hormone. We here review these experiments, paying special attention to the role of GFR in the process
Runoff Quality Responses to Cattle-Gazing Strategy and Grassed Buffer Zone Length
Grazed pastures represent a source of potential nonpoint pollution. In comparison to other nonpoint sources (e.g., row-cropped lands), relatively little information exists regarding possible magnitudes of pollution from grazed pasture; how that pollution is affected by weather, soil, management and other variables; and how the pollution can be minimized. The objective of this study was to assess how the quality of runoff from simulated grazed pasture is influenced by grazing duration (4-12 weeks), grazing strategy (no grazing, conventional grazing and rotational grazing), and by the use of grassed buffer strips (ranging in length from O to 18.3 m) installed down-slope of simulated pasture. The study was conducted at the University of Kentucky Maine Chance Agricultural Experiment Station north of Lexington. Plots (2.4 m wide by 6.1 to 30.5 m long) were constructed and established in Kentucky 31 tall fescue (Festuca arundinacea Schreb.) to represent pasture. Grazing was simulated by application of beef cattle manure to the plots. Runoff was generated by applying simulated rainfall. Runoff samples were collected and analyzed according to standard methods for nitrogen (N), phosphorus (P), total suspended solids (TSS), and fecal coliform (FC). Runoff concentrations and transport of N and P from the plots used to simulate conventional and rotational grazing were low and, in many cases, not different from those measured for ungrazed plots. Runoff FC concentrations were greater for the simulated grazed plots than for the control plots, but there was no difference in concentrations between the simulated conventional and rotational grazing treatments. The buffer strips were very effective in removing TKN, P04-P, TSS and FC in incoming runoff from manured plots. Concentrations of all these parameters were indistinguishable from background levels after crossing a buffer length of 6.1 m. This finding is attributed largely to very high infiltration in the plots used to assess the buffer strips
Characterization and assembly of the Pseudomonas aeruginosa aspartate transcarbamoylase-pseudo dihydroorotase complex
Pseudomonas aeruginosa is a virulent pathogen that has become more threatening with the emergence of multidrug resistance. The aspartate transcarbamoylase (ATCase) of this organism is a dodecamer comprised of six 37 kDa catalytic chains and six 45 kDa chains homologous to dihydroorotase (pDHO). The pDHO chain is inactive but is necessary for ATCase activity. A stoichiometric mixture of the subunits associates into a dodecamer with full ATCase activity. Unlike other known ATCases, the P. aeruginosa catalytic chain does not spontaneously assemble into a trimer. Chemical-crosslinking and size-exclusion chro- matography showed that P. aeruginosa ATCase is monomeric which accounts for its lack of catalytic activity since the active site is a composite comprised of residues from adjacent monomers in the trimer. Circular dichroism spectroscopy indicated that the ATCase chain adopts a structure that contains secondary structure elements although neither the ATCase nor the pDHO subunits are very stable as determined by a thermal shift assay. Formation of the complex increases the melting temperature by about 30 ̊C. The ATCase is strongly inhibited by all nucleotide di- and triphosphates and exhibits extreme cooperativity. Previous studies suggested that the regulatory site is located in an 11-residue extension of the amino end of the catalytic chain. However, deletion of the extensions did not affect catalytic activity, nucleotide inhibition or the assembly of the dodecamer. Nucleotides destabilized the dode- camer which probably accounts for the inhibition and apparent cooperativity of the substrate saturation curves. Contrary to previous interpretations, these results suggest that P. aerugi- nosa ATCase is not allosterically regulated by nucleotides
Examples of Collaboration Between Psychologists and Clergy
Some psychologists may be interested in working collaboratively with clergy and yet may not know where to start. What kinds of collaborative projects are possible? A qualitative analysis of 77 narratives offered by psychologists and clergy involved in collaboration revealed that collaboration between psychologists and clergy currently takes place in at least four contexts: mental health services, parish life, community concerns, and academics. Reported obstacles to collaboration are also described. Essential attitudes for psychologists interested in collaborating with clergy include respecting clergy as professionals, willingness to venture out from traditional professional settings, and exploring innovative collaborative possibilities
Force distributions in a triangular lattice of rigid bars
We study the uniformly weighted ensemble of force balanced configurations on
a triangular network of nontensile contact forces. For periodic boundary
conditions corresponding to isotropic compressive stress, we find that the
probability distribution for single-contact forces decays faster than
exponentially. This super-exponential decay persists in lattices diluted to the
rigidity percolation threshold. On the other hand, for anisotropic imposed
stresses, a broader tail emerges in the force distribution, becoming a pure
exponential in the limit of infinite lattice size and infinitely strong
anisotropy.Comment: 11 pages, 17 figures Minor text revisions; added references and
acknowledgmen
Constitutive Extracellular Polysaccharide (EPS) Production by Specific Isolates of Crocosphaera watsonii
Unicellular dinitrogen (N2) fixing cyanobacteria have only recently been identified in the ocean and recognized as important contributors to global N2 fixation. The only cultivated representatives of the open ocean unicellular diazotrophs are multiple isolates of Crocosphaera watsonii. Although constituents of the genus are nearly genetically identical, isolates have been described in two size classes, large ∼5 μm and small ∼3 μm cell diameters. We show here that the large size class constitutively produces substantial amounts of extracellular polysaccharides (EPS) during exponential growth, up to 10 times more than is seen in the small size class, and does so under both N2 fixing and non-N2 fixing conditions. The EPS production exceeds the amount produced by larger phytoplankton such as diatoms and coccolithophores by one to two orders of magnitude, is ∼22% of the total particulate organic C in the culture, and is depleted in N compared to cellular material. The large difference in observed EPS production may be accounted for by consistently higher photochemical efficiency of photosystem II in the large (0.5) vs. small (∼0.35) strains. While it is known that Crocosphaera plays an important role in driving the biological carbon (C) pump through the input of new nitrogen (N) to the open ocean, we hypothesize that this species may also contribute directly to the C cycle through the constitutive production of EPS. Indeed, at two stations in the North Pacific Subtropical Gyre, ∼70% of large Crocosphaera cells observed were embedded in EPS. The evolutionary advantage of releasing such large amounts of fixed C is still unknown, but in regions where Crocosphaera can be abundant (i.e., the warm oligotrophic ocean) this material will likely have important biogeochemical consequences
Vegetated Filter Strip Removal of Cattle Manure Constituents in Runoff
Pasture runoff can contribute to elevated concentrations of nutrients, solids, and bacteria in downstream waters. The objective of this study was to determine the effects of vegetative filter strip (VFS) length on concentrations and transport of nitrogen, phosphorus, solids and fecal coliform in runoff from plots treated with cattle manure. Three plots with dimensions of 2.4 × 30.5 m were used. The upper 12.2 m of each plot was treated with cattle manure, while the lower 18.3 m acted as a VFS. Runoff produced by rainfall simulators was sampled at VFS lengths of 0, 6.1, 12.2, and 18.3 m and analyzed for total Kjeldahl nitrogen (N), ammonia N, nitrate N, total phosphorus (P), ortho-P, fecal coliforms, total suspended solids and other parameters. The VFS significantly reduced concentrations and mass transport of incoming solids, fecal coliform, and most nutrient forms, particularly P. The relationships among VFS length, concentration and mass transport were well-represented by first-order exponential decay functions. Approximately 75% of incoming total Kjeldahl N, total P, ortho-P, and total suspended solids was removed within the first 6.1 m of the filter strips. Runoff concentrations of fecal coliform concentrations entering the filter strips were as high as 2 × 107 FC/100 mL; after a filter length of 6.1 m, however, the runoff exhibited no measurable concentration of fecal coliforms. This experiment suggests that even relatively short filter strips can markedly improve quality of runoff from grassed areas receiving cattle manure
Diversity in leaf anatomy, and stomatal distribution and conductance, between salt marsh and freshwater species in the C\u3csub\u3e4\u3c/sub\u3e genus Spartina (Poaceae)
Leaf anatomy, stomatal density, and leaf conductance were studied in 10 species of Spartina (Poaceae) from low versus high salt marsh, and freshwater habitats. • Internal structure, external morphology, cuticle structure, and stomatal densities were studied with light and electron microscopy. Functional significance of leaf structure was examined by measures of CO2 uptake and stomatal distributions. • All species have Kranz anatomy and C 4 δ13C values. Freshwater species have thin leaves with small ridges on adaxial sides and stomata on both adaxial and abaxial sides. By contrast, salt marsh species have thick leaves with very pronounced ridges on the adaxial side and stomata located almost exclusively on adaxial leaf surfaces. Salt marsh species also have a thicker cuticle on the abaxial than on the adaxial side of leaves, and CO2 uptake during photosynthesis is restricted to the adaxial leaf surface. • Salt marsh species are adapted to controlling water loss by having stomata in leaf furrows on the adaxial side, which increases the boundary layer, and by having large leaf ridges that fit together as the leaf rolls during water stress. Differences in structural-functional features of photosynthesis in Spartina species are suggested to be related to adaptations to saline environments
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