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PubMed2006

Reducing depression stigma using a web-based program.

OBJECTIVE: This study was designed to investigate the efficacy and feasibility of a web-based depression stigma education tool for healthcare professionals. METHODS: A web-based depression stigma program utilizing adult learning theories was developed. Forty-two consecutive subjects were enrolled from University of Maryland staff and graduate students. Primary outcomes were Bogardus Social Distance Scale with a vignette on major depression disorder (BSDS-MDD) and the Depression Stigma Scale (DSS) administered before and after the intervention. RESULTS: Internet-based education significantly decreased the level of depression stigma (BSDS-MDD 10.6+/-4.4 versus 7.2+/-4.4, p<0.001; DSS-personal 12.7+/-7.2 versus 7.8+/-5.3, p<0.001; DSS-perceived 21.7+/-5.5 versus 12.4+/-5.5, p<0.001). After the educational intervention the subjects' knowledge about depression significantly improved (pre-test DKS=18.2+/-8.2 versus post-test DKS=20.6+/-4.1, p<0.001). The program was very well accepted by participants. For 100% of participants, it was not difficult to operate the program. CONCLUSIONS: Computer-assisted education was effective in reducing the stigma of depression and increasing knowledge about depressive disorder. A web-based intervention has the potential to be used for educating graduate students and university staff about depression and for reducing depression stigmata. Healthcare professionals interacting with people with stigmatizing conditions can benefit from web-based computer education.

Computers↗

PubMed2006

Experiences of recently relocated residents of a long-term care facility in Ontario: assessing quality qualitatively.

BACKGROUND: Canadians overwhelmingly support universal coverage for health services and seniors' entitlement to high standards of care in long-term care facilities (LTCFs). Government rhetoric reflects these values, but claims of fiscal prudence often means translation into policy and improved care is uneven. Ontario is moving towards standardized "quality of care" measures, but such measures often ignore residents' views and socio-psychological issues. OBJECTIVES AND SETTING: Assessment of residents' experiences in a new "state of the art" LTCF and their understanding of "quality of care" shortly after relocation from two older hospital style facilities. DESIGN AND METHODS: Unobtrusive observations of activities of residents and staff in the LTCF by several researchers generated an analysis of field notes. In addition, one-on-one, in-depth, semi-structured interviews with residents generated qualitative interview data, analyzed utilizing a grounded theory approach. PARTICIPANTS: All residents deemed either moderately cognitively impaired or not impaired were invited to participate. Of these two groups, 18 seniors (five male and 13 female) with a mean age of 84.35yr agreed to be interviewed. Participants were all Caucasian and from a wide variety of social-economic levels. RESULTS: Two meta-themes "Relationships are the foundation of quality care" and "Waiting, activity & grieving loss of personhood" best explained residents' experiences of the LTCF. The two meta-themes were inter-connected and reflected the centrality of socio-psychological "quality of life" issues, especially resident-staff relationships as prominent aspects of seniors' understanding of quality of care. Improvements in facilities and programs were undermined by inattention to staff-patient ratios and continuity in staffing. CONCLUSIONS: Seniors said little regarding the fabulous new facility, but discussed quality of care as a socio-psychological concept intimately connected to staff relations. Government and administrative inattention to issues of sufficient funding for staff, relationship needs and continuity of care for seniors threatened to undermine residents' experiences of meaning, as well as any potential benefits from facilities and program improvements.

Adaptation, Psychological↗

PubMed2006

Bayesian analysis of population structure based on linked molecular information.

The Bayesian model-based approach to inferring hidden genetic population structures using multilocus molecular markers has become a popular tool within certain branches of biology. In particular, it has been shown that heterogeneous data arising from genetically dissimilar latent groups of individuals can be effectively modelled using an unsupervised classification formulation. However, most currently employed models ignore potential linkage within the employed molecular information, and can therefore lead to biased inferences under certain circumstances. Utilizing the general theory of graphical models, we develop a framework that accounts for dependences both within linked molecular marker loci and DNA sequence data. Due to a high level of sequence conservation among eukaryotic species, the latter aspect is particularly relevant for analyzing rapidly evolving microbial species. The advantages of incorporating the dependence due to linkage in the classification models are illustrated by analyses of both simulated data and real samples of Bacillus cereus.

Bacillus cereus↗

PubMed2006

Neuroeconomics: cross-currents in research on decision-making.

Despite substantial advances, the question of how we make decisions and judgments continues to pose important challenges for scientific research. Historically, different disciplines have approached this problem using different techniques and assumptions, with few unifying efforts made. However, the field of neuroeconomics has recently emerged as an inter-disciplinary effort to bridge this gap. Research in neuroscience and psychology has begun to investigate neural bases of decision predictability and value, central parameters in the economic theory of expected utility. Economics, in turn, is being increasingly influenced by a multiple-systems approach to decision-making, a perspective strongly rooted in psychology and neuroscience. The integration of these disparate theoretical approaches and methodologies offers exciting potential for the construction of more accurate models of decision-making.

Brain↗

PubMedDate not supplied

Can line clinicians master the conceptual complexities of dialectical behavior therapy? An evaluation of a State Department of Mental Health training program.

Dialectical behavior therapy for borderline personality disorder has rapidly attained wide-spread popularity, with one indication being the development of training initiatives by the Department of Mental Health within at least two States in USA. Efficacy data published by the originator of the treatment, Marsha Linehan, and her colleagues, probably accounts at least in part for this popularity. However, the complexity of DBT raises a fundamental question regarding these broader applications: can clinicians of diverse backgrounds acquire a shared and sophisticated understanding of the treatment theory? The clinical utility of a treatment rests heavily upon ease of dissemination (APA, Template for developing guidelines: Interventions for mental disorders and psychosocial aspects of physical disorders. Washington, DC: Author, 1995), and in that regard DBT--a complicated, multifaceted approach--could appear vulnerable. This vulnerability is heightened when institutional adoption involves the collaboration of numerous clinicians, who, despite occupying diverse roles, must nevertheless develop a shared understanding of the treatment. Using a detailed examination of DBT knowledge, we evaluated the conceptual mastery of 109 clinicians trained via a State Department of Mental Health initiative. Performance on the examination correlated specifically with DBT training. Prior education or background in behavior therapy accounted for little variance, indicating that clinicians occupying diverse roles acquired reasonable intellectual mastery over this complex model.

Adult↗

PubMed1992

The split rib bundle graft in mandibular reconstruction.

This article describes a modified technique for the use of free non-vascularized split ribs (bound together in the form of a tight bundle), to reconstruct different types of mandibular defects. Experience gained over the last 4 years in treating 38 patients with different pathological lesions is presented. The procedure, carried out simultaneously with bone resection proved to be highly effective in providing mesio-distal spanning of the defect, adequate mandibular height as well as bucco-lingual thickness. This technique utilizes the different theories of osteogenesis: (a) from the periosteal cells, (b) from the transplanted living osteocytes and from (c) stimulating host mesenchymal cells to form new bone by bone induction. The surgical technique, results and conclusions are presented in this report.

Adolescent↗

PubMed1996

What is computer-aided diagnosis?

A review of computer aided diagnostic principles is presented. A brief treatise on the definition and theory of the utilization of machines to aid human diagnostic reasoning forms a foundation for its practical use in current veterinary practice. Understanding a tool is the key to its proper use. Therefore, the intentions of the currently available software are discussed as well as the limitations. Finally, in light of the refined understanding of the use of computers to aid diagnosis, the scope of appropriate use is outlined as an encouragement to make the most of the tool.

Animals↗

PubMed2001

Heterometal substitution in the dimensional reduction of cluster frameworks: synthesis of soluble [Re(6-n)Os(n)Se(8)Cl(6)](4-n)- (n = 1-3) cluster-containing solids.

A general method for deconstructing cluster frameworks via heterometal substitution is demonstrated with application to the two-dimensional phase Re(6)Se(8)Cl(2). Solid-state reactions intended to replace two of the Re(III) centers in the parent compound with Os(IV)Cl units indeed yield Re(4)Os(2)Se(8)Cl(4). The crystal structure of this new phase reveals a less tightly connected two-dimensional framework, wherein face-capped octahedral [Re(4)Os(2)Se(8)](4+) cluster cores are linked through mu(2)-chloride bridges in one dimension and unsupported metal-selenium bonds in the other. Use of CsCl as a standard dimensional reduction agent in conjunction with heterometal substitution affords Cs(3)Re(5)OsSe(8)Cl(6) and Cs(2)Re(4)Os(2)Se(8)Cl(6), soluble salts containing discrete molecular clusters. Reactions employing KCl and targeting a triosmium cluster further produce the soluble mixed-cluster salt K(2)[Re(3)Os(3)Se(8)Cl(6)][Re(4)Os(2)Se(7)Cl(7)]. FT-ICR mass spectra confirm the presence of [Re(6-n)Os(n)Se(8)Cl(6)](4-n)- (n = 1-3) clusters in solutions of these solids. Metathesis reactions supply (Bu(4)N)(3)[Re(5)OsSe(8)Cl(6)] and (Bu(4)N)(2)[Re(4)Os(2)Se(8)Cl(6)], which then react with PEt(3) under forcing conditions to give [Re(5)OsSe(8)(PEt(3))(6)](3+) and [Re(4)Os(2)Se(8)(PEt(3))(6)](4+) in high yield. Analysis of the latter diosmium species by (31)P NMR spectroscopy indicates a mixture of isomers, in which 55% of the clusters have the osmium atoms disposed trans to each other, while the remainder adopt the alternative cis configuration. Cyclic voltammetry measurements reveal a reversible one-electron reduction for [Re(5)OsSe(8)Cl(6)](3-) and multiple one-electron reductions for the mono- and diosmium hexaphosphine clusters; in the latter case, the trans isomer is observed to be more easily reduced than the cis isomer. Electronic structure calculations utilizing density functional theory show the trans isomer of [Re(4)Os(2)Se(8)Cl(6)](2-) to be 4.5 kcal/mol more stable than the cis isomer, in approximate agreement with the observed ratio of reaction products. Moreover, the calculations expose significant differences in the contributions of rhenium and osmium to the frontier orbitals of the clusters, suggesting the possibility of observing metal-selective reactivity. An initial example of such behavior is provided with the synthesis of trans,trans-[Re(4)Os(2)Se(8)(PEt(3))(2)Cl(4)], wherein PEt(3) ligands preferentially bind the osmium centers.

Journal Article↗

PubMed2004

Electronic structure of bent titanocene complexes with chelated dithiolate ligands.

Gas-phase photoelectron spectroscopy and density functional theory have been utilized to investigate the interactions between the p orbitals of dithiolate ligands and d orbitals of titanium in bent titanocene complexes as minimum molecular models of active site features of pyranopterin Mo/W enzymes. The compounds Cp(2)Ti(S-S) [where (S-S) is 1,2-ethenedithiolate (S(2)C(2)H(2)), 1, 1,2-benzenedithiolate (bdt), 2, or 1,3-propanedithiolate (pdt), 3, and Cp(-) is cyclopentadienyl] provide access to a formal 16-electron d(0) electronic configuration at the metal. A "dithiolate-folding-effect" involving an interaction of metal and sulfur orbitals is demonstrated in complexes with arene- and enedithiolates. This effect is not observed for the alkanedithiolate in complex 3.

Binding Sites↗

PubMed2005

Computational studies of the H-cluster of Fe-only hydrogenases: geometric, electronic, and magnetic properties and their dependence on the [Fe4S4] cubane.

The active sites of Fe-only hydrogenases (FeHases) feature an unusual polynuclear iron-sulfur cluster, known as the H-cluster, that consists of a [Fe4S4] cubane linked to a di-iron subunit (the [2Fe]H component) via a bridging cysteine ligand (SCys). While previous computational studies of FeHases employed H-cluster models that only included the [2Fe]H component, we have utilized density functional theory (DFT), in conjunction with the broken-symmetry (BS) approach, to explore the geometric, electronic, and magnetic properties of the entire H-cluster. These calculations have allowed us to evaluate, for the first time, the influence of the [Fe4S4] cubane on the [2Fe]H component of the H-cluster in its active (Hox) and CO-inhibited (Hox-CO) states, both of which are paramagnetic (S=1/2). Our results reveal that the presence of the cubane tunes both the position and the donor strength of the SCys ligand, which, in turn, modulates the internal geometric and electronic structures of the [2Fe]H subcluster. Importantly, the BS methodology provides an accurate description of the exchange interactions within the H-cluster, permitting insight into the electronic origin of the changes in magnetic properties observed experimentally upon conversion of Hox to Hox-CO. Specifically, while the unpaired spin density in the Hox state is localized on the distal Fe center, in the Hox-CO state, it is delocalized over the [2Fe]H component, such that the proximal Fe center acquires significant spin density (where distal and proximal refer to the positions of the Fe centers relative to the cubane). To validate our H-cluster models on the basis of experimental data, two DFT-based approaches and the semiempirical INDO/S method have been employed to compute electron paramagnetic resonance parameters for the H-cluster states. While most computations yield reasonably accurate g values and ligand hyperfine coupling constants (i.e., A values) for the Hox and Hox-CO states, they fail to reproduce the isotropic 57Fe A tensors found experimentally. Finally, extension of the computational methodology employed successfully for the Hox and Hox-CO states to the metastable Hoxphoto state, generated by irradiation of the Hox-CO state at cryogenic temperatures, has allowed us to discriminate between proposed structural models for this species.

Computer Simulation↗

PubMed2003

Theoretical study of cisplatin binding to purine bases: why does cisplatin prefer guanine over adenine?

The thermodynamics and kinetics for the monofunctional binding of the antitumor drug cisplatin, cis-diamminedichloroplatinum(II), to a purine base site of DNA were studied computationally using guanine and adenine as model reactants. A dominating preference for initial attack at the N7-position of guanine is established experimentally, which is a crucial first step for the formation of a 1,2-intrastrand cross-link of adjacent guanine bases that leads to bending and unwinding of DNA. These structural distortions are proposed ultimately to be responsible for the anticancer activity of cisplatin. Utilizing density functional theory in combination with a continuum solvation model, we developed a concept for the initial Pt-N7 bond formation to atomic detail. In good agreement with experiments that suggested DeltaG++ = approximately 23 kcal/mol for the monofunctional platination of guanine, our model gives DeltaG++ = 24.6 kcal/mol for guanine, whereas 30.2 kcal/mol is computed when adenine is used. This result predicts that guanine is 3-4 orders of magnitude more reactive toward cisplatin than adenine. A detailed energy decomposition and molecular orbital analysis was conducted to explain the different barrier heights. Two effects are equally important to give the preference for guanine over adenine: First, the transition state is characterized by a strong hydrogen bond between the ammine-hydrogen of cisplatin and the O=C6 moiety of guanine in addition to a stronger electrostatic interaction between the two reacting fragments. When adenine binds, only a weak hydrogen bond forms between the chloride ligand of cisplatin and the H(2)N-C6 group of adenine. Second, a significantly stronger molecular orbital interaction is identified for guanine compared to adenine. A detailed MO analysis is presented to provide an intuitive view into the different electronic features governing the character of the Pt-N7 bond in platinated purine bases.

Adenine↗

PubMed2005

Self-assembly of small polycyclic aromatic hydrocarbons on graphite: a combined scanning tunneling microscopy and theoretical approach.

Self-assembled monolayers of chrysene and indene on graphite have been observed and characterized individually with scanning tunneling microscopy (STM) at 80 K under low-temperature, ultrahigh vacuum conditions. These molecules are small, polycyclic aromatic hydrocarbons (PAHs) containing no alkyl chains or functional groups that are known to promote two-dimensional self-assembly. Energy minimization and molecular dynamics simulations performed for small groups of the molecules physisorbed on graphite provide insight into the monolayer structure and forces that drive the self-assembly. The adsorption energy for a single chrysene molecule on a model graphite substrate is calculated to be 32 kcal/mol, while that for indene is 17 kcal/mol. Two distinct monolayer structures have been observed for chrysene, corresponding to high- and low-density assemblies. High-resolution STM images taken of chrysene with different bias polarities reveal distinct nodal structure that is characteristic of the molecular electronic state(s) mediating the tunneling process. Density functional theory calculations are utilized in the assignment of the observed electronic states and possible tunneling mechanism. These results are discussed within the context of PAH and soot particle formation, because both chrysene and indene are known reaction products from the combustion of small hydrocarbons. They are also of fundamental interest in the fields of nanotechnology and molecular electronics.

Journal Article↗

PubMed2006

Structure and vibrational spectra of mononitrated benzo[a]pyrenes.

The molecules benzo[a]pyrene (BaP) and 1-, 3-, and 6-nitrobenzo[a]pyrene (1-NBaP, 3-NBaP, 6-NBaP) are currently of significant interest due to their presence in respirable combustion exhaust particulates and their mutagenic and carcinogenic properties. Structure-function correlations as well as spectroscopic signatures for trace analysis are necessary for these benzo[a]pyrene derivatives. In this paper, detailed infrared and Raman spectroscopic data of BaP and its three mononitrated isomers are provided for the first time. By utilizing density functional theory (DFT, B3LYP method with 6-311+G basis set), the molecular geometries and the vibrational spectra are calculated. Good agreement is noted between the calculated and experimental geometry for BaP, and predictions of the vibrational data for all compounds are within approximately 5 cm-1 of the experimental data. Normal mode assignments are proposed with particular emphasis on the nitro group vibrations. The geometrical distortions of the BaP structure upon nitro group substitution and correlations between structural parameters and vibrational data as well as structure-function relationships related to the mutagenicity of this important class of polycyclic aromatic hydrocarbons are discussed.

Air Pollutants↗

PubMed2006

Ammonium bisulfate/water: a pseudobinary system.

We have studied the ammonium bisulfate/water system using thermal analysis (differential scanning calorimetry) and infrared spectroscopy of thin films. Our results for the melting points for ice and letovicite are in good agreement with other experimental work. However, we report here the first measurements of the ice/ammonium bisulfate/letovicite invariant point. We have used our observations and solubility data to construct a complete phase diagram for this system. Utilizing phase diagram theory and the Gibbs phase rule, we conclude that this system is not a true binary system but rather a pseudobinary system, which has a range of concentrations that cannot be represented by a simple binary phase diagram and thus must be viewed as part of the ternary system: H(2)SO(4)/(NH(4))(2)SO(4)/H(2)O. We also compared our results to the phase diagram predictions of the aerosol inorganics model and found the predicted melting points are in good agreement with experimental work over a limited concentration range, but the transitions predicted by the model at lower temperatures are not in agreement with experimental results.

Journal Article↗

PubMed2006

Molecular-thermodynamic theory of micellization of pH-sensitive surfactants.

A predictive, molecular-thermodynamic theory is developed to model the micellization of pH-sensitive surfactants. The theory combines a molecular-thermodynamic description of micellization in binary surfactant mixtures with the protonation equilibrium of the surfactant monomers. The thermodynamic component of the theory models the pH-mediated equilibrium between micelles, surfactant monomers, and counterions. These counterions may originate from the surfactant or from added salt, acid, or base. The molecular component of the theory models the various contributions to the free energy of micellization, which corresponds to the free-energy change associated with forming a mixed micelle from the protonated and deprotonated forms of the surfactant and from the bound counterions. The free energy of micellization includes hydrophobic, interfacial, packing, steric, electrostatic, and entropic contributions, which are all calculated molecularly. The theory also requires knowledge of the surfactant molecular structure and the solution conditions, including the temperature and the amount of any added salt, acid, or base. To account for the pH sensitivity of the surfactant, the theory requires knowledge of the surfactant monomer equilibrium deprotonation constant (pK1), which may be obtained from experimental titration data obtained below the critical micelle concentration (cmc). The theory can be utilized to predict the equilibrium micelle and solution properties, including the cmc, the micelle composition, the micelle shape and aggregation number, the solution pH, and the micelle deprotonation equilibrium constant (pKm). Theoretical predictions of the cmc, the micelle aggregation number, and the pKm compare favorably with the available experimental data for alkyldimethylamine oxide surfactants. This class of pH-sensitive surfactants exhibits a form of self-synergy, which has previously been attributed to hydrogen-bond formation at the micelle interface. Instead, we show that much of the observed synergy is related to the electrostatic contribution to the free energy of micellization. Although we do not explicitly include hydrogen bonding in the molecular model of micellization, we briefly discuss how it may be incorporated and its anticipated effect on the predicted micellization behavior.

Journal Article↗

PubMed2005

Metal nanoshell assembly on a virus bioscaffold.

Chilo iridescent virus is demonstrated as a useful core substrate in the fabrication of metallodielectric, plasmonic nanostructures. A gold shell is assembled around the wild-type viral core by attaching small, 2-5-nm gold nanoparticles to the virus surface by means of the chemical functionality found inherently on the surface of the proteinaceous viral capsid. The density of these nucleation sites was maximized by reducing the repulsive forces between the gold particles through electrolyte addition. These gold nanoparticles then act as nucleation sites for the electroless deposition of gold ions from solution around the biotemplate. The optical extinction spectra of the metalloviral complex is in quantitative agreement with Mie scattering theory. Overall, the utilization of a native virus and the inherent chemical functionality of the capsid afford the ability to grow and harvest biotemplates for metallodielectric nanoshells in large quantities, potentially providing cores with a narrower size distribution and smaller diameters (below 80 nm) than for currently used silica.

Capsid↗

PubMed2003

Punishment insensitivity and parenting: temperament and learning as interacting risks for antisocial behavior.

We review ideas about individual differences in sensitivity or responsiveness to common disciplinary behaviors parents use to correct aggressive and antisocial behavior in children. At extremes, children may be seen as "punishment-insensitive," an heuristic with some value relevant to models of the development of antisocial and aggressive behavior disorders. Literature from diverse fields, such as psychopathy, child temperament, socialization and the development of moral conscience, conditioning theory, and personality theory, have all utilized the idea that humans differ in their sensitivity to aversive stimuli and the cues that signal their occurrence, as well as their ability to inhibit reward-driven behavior, in the presence of punishment cues. Contemporary thinking places these dispositions squarely as basic biological aspects of temperament that moderate the effects of the environment (e.g., parenting) on outcomes (e.g., mental health). We review a largely forgotten literature that shows clearly that sensitivity to punishment is also reliably influenced by the environment itself. An attempt is then made to model the interactional processes by which parenting and punishment sensitivities in children magnify or diminish each other's progress toward healthy or antisocial development. Implications for parenting of children with low responsiveness to punishment strategies are discussed.

Antisocial Personality Disorder↗

PubMed1997

Sport psychiatry in childhood and adolescence: an overview.

This review explores the importance and relevance of sport during childhood and adolescence, utilizing traditional stage theories of development. The literature supports the notion that sport is a necessary study as a health issue and a preventative tool in the field of psychiatry. Play and sport in childhood and adolescence enhance development physically, mentally, and socially. Participating in athletics encourages the development of leadership skills, self-esteem, muscle development and overall physical health. There is a lack of literature in the important area of sport psychiatry especially when considering beneficial, not deficit oriented youth athletic development. Child psychiatrists need to begin researching sport in order to develop a comprehensive understanding of how athletics can enhance the mental and physical health of youth.

Adolescent↗