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PubMed1997

Observed family interaction during clinical interviews: a comparison of families containing preschool boys with and without disruptive behavior.

The clinical intake interview is an opportunity to observe family interactions and formulate hypotheses about their influence on presenting problems. In this study family interactions were assessed during an unstructured segment of a clinical intake. Families with disruptive preschool boys were compared with those having nonproblem boys. Mother's and fathers' reports of marital satisfaction, parenting involvement, and child behavior problems were examined in relation to observed behavior during intake. Patterns of family interaction emerged which were consistent with previous research and with family systems theory. Clinic boys oriented more toward mothers than fathers and interacted more negatively with their fathers than did comparison boys. Implications for integrating the assessment of family interactions into clinical practice and research with behavior problem children are discussed.

Adult↗
PubMed1974

Analysis of code relating sequences to conformation in globular prtoeins. Theory and application of expected information.

1. An information theory analysis of the folding of a globular protein is proposed. 2. The folding is seen as a transfer of information between two messages, the primary sequence and the biologically active conformation. 3. It is shown how the information transferred was estimated by inspection of proteins of known primary sequence and conformation. 4. In this estimation, concerted use of subjective (Bayesian) probabilities leads to a more robust approach which can be employed whether the number of proteins of known sequence and conformation is large or small. 5. Further, it is demonstrated that the problem then becomes a very simple algebraic formulation for information estimates. 6. Finally, it is shown how this process of information theory analysis can be reversed to predict the conformation of a protein by using its primary sequence and the above information estimates obtained from other proteins. 7. The present paper provides the theoretical basis for the derivation and application of a stereochemical alphabet (Robson & Pain, 1974a,c), and for an investigation of the effects of residues on the conformations of their neighbours (Robson & Pain, 1974b).

Amino Acid Sequence↗
PubMed2002

A procedure for differentiating between the intentional release of biological warfare agents and natural outbreaks of disease: its use in analyzing the tularemia outbreak in Kosovo in 1999 and 2000.

The events of 11 September and the subsequent anthrax outbreaks in the USA have opened the world's eyes to the threat posed by terrorist groups, criminal organizations and lone operators who will stop at nothing to achieve their goals. The open or covert use of pathogens and toxins as biological warfare agents can no longer be ruled out. Against this background, the appearance of an unusual disease must be studied in order to clarify whether it is a natural or artificially caused occurrence. This issue was recently raised in discussions with local representatives and relief organizations during a tularemia epidemic in Kosovo from October 1999 to May 2000. This paper will present a procedure which attempts to use certain criteria to identify or rule out the use of biological warfare agents in the event of an unusual outbreak of disease. Data and findings gathered by routine epidemiologic and microbiological studies often provide only an indirect answer to this problem. For this reason, various criteria were formulated and points allocated to represent their importance, allowing us to deduce in a semiquantitative manner the degree of possibility of an artificial genesis of outbreaks. The significance and characterization of each criterion are discussed. An analysis of the tularemia epidemic in Kosovo based on the procedure described here indicates that a deliberate release of the causative agent of tularemia, Francisella tularensis, as a biological warfare agent is doubtful. In this paper, an approach is described to discriminate between the intentional use of biological warfare agents and natural outbreaks of infectious diseases. The developed model is flexible and considers the political, military and social analysis of the crisis-afflicted region, the specific features of the pathogen, and the epidemiologic and clinical characteristics of the epidemic.

Animals↗
PubMed2000

Comparison of the hematological effects of a sustained release chitosan formulation of pentoxifylline with a commercial formulation.

In the present study the hematological effects of a sustained release chitosan formulation of pentoxifylline (CAS 6493-05-6) were examined and compared with those of a commercial product. The study was carried out on 12 healthy volunteers. Both formulations were tolerated well clinically. The results demonstrated no antiaggregatory effect of the two different formulations of pentoxifylline in platelet rich plasma. Both drugs resulted in a decrease of plasma fibrinogen levels. A remarkable side effect of the new formulation was mild basophilia, without any clinical problems.

Adult↗
PubMed1994

Matrix decompositions of two-dimensional nuclear magnetic resonance spectra.

Two-dimensional NMR spectra are rectangular arrays of real numbers, which are commonly regarded as digitized images to be analyzed visually. If one treats them instead as mathematical matrices, linear algebra techniques can also be used to extract valuable information from them. This matrix approach is greatly facilitated by means of a physically significant decomposition of these spectra into a product of matrices--namely, S = PAPT. Here, P denotes a matrix whose columns contain the digitized contours of each individual peak or multiple in the one-dimensional spectrum, PT is its transpose, and A is an interaction matrix specific to the experiment in question. The practical applications of this decomposition are considered in detail for two important types of two-dimensional NMR spectra, double quantum-filtered correlated spectroscopy and nuclear Overhauser effect spectroscopy, both in the weak-coupling approximation. The elements of A are the signed intensities of the cross-peaks in a double quantum-filtered correlated spectrum, or the integrated cross-peak intensities in the case of a nuclear Overhauser effect spectrum. This decomposition not only permits these spectra to be efficiently simulated but also permits the corresponding inverse problems to be given an elegant mathematical formulation to which standard numerical methods are applicable. Finally, the extension of this decomposition to the case of strong coupling is given.

Algorithms↗
PubMedDate not supplied

An accurate, convective energy equation based automated meshing technique for analysis of blood vessels and tissues.

An automated three-element meshing method for generating finite element based models for the accurate thermal analysis of blood vessels imbedded in tissue has been developed and evaluated. The meshing method places eight noded hexahedral elements inside the vessels where advective flows exist, and four noded tetrahedral elements in the surrounding tissue. The higher order hexahedrals are used where advective flow fields occur, since high accuracy is required and effective upwinding algorithms exist. Tetrahedral elements are placed in the remaining tissue region, since they are computationally more efficient and existing automatic tetrahedral mesh generators can be used. Five noded pyramid elements connect the hexahedrals and tetrahedrals. A convective energy equation (CEE) based finite element algorithm solves for the temperature distributions in the flowing blood, while a finite element formulation of a generalized conduction equation is used in the surrounding tissue. Use of the CEE allows accurate solutions to be obtained without the necessity of assuming ad hoc values for heat transfer coefficients. Comparisons of the predictions of the three-element model to analytical solutions show that the three-element model accurately simulates temperature fields. Energy balance checks show that the three-element model has small, acceptable errors. In summary, this method provides an accurate, automatic finite element gridding procedure for thermal analysis of irregularly shaped tissue regions that contain important blood vessels. At present, the models so generated are relatively large (in order to obtain accurate results) and are, thus, best used for providing accurate reference values for checking other approximate formulations to complicated, conjugated blood heat transfer problems.

Automation↗
PubMedDate not supplied

Factors associated with heroin addiction among male adults in Lahore, Pakistan.

The objective of this matched case control study was to evaluate the factors associated with heroin addiction among male heroin addicts of age 15 to 35 years in Lahore. A total of 233 heroin addicts, matched on neighborhood controls, were enrolled at a case control ratio of 1:2. Multivariate conditional logistic regression analysis was carried out to study the independent relationship of hypothesized factors with heroin addiction. The factors associated with heroin addiction were parental disharmony (i.e. occasional fights versus no fights: adjusted matched odds ratio (adj. mOR) = 4.3, 95% CI: 2.4-7.8; frequent fights versus no fights: adj. mOR = 6.0, 95% CI: 2.8-16.6), drug using peers (adj. mOR = 5.6, 95% CI, 2.6-12.1), alcohol use (adj. mOR = 4.2, 95% CI, 2.3-7.6). use of over the counter available drugs (adj. mOR = 4.1, 95% CI, 1.8-10.6), father's absence (adj. mOR = 2.9, 95% CI, 1.6-5.5), non-formal schooling of the mother (adj. mOR = 2.8, 95% CI, 1.7-4.7), non-formal schooling of the respondent (adj. mOR = 2.4, 95% CI, 1.5-3.8), and the presence of a drug user among similar age group family members (adj. mOR = 2.4, 95% CI, 1.3-4.8). It is recommended that public health strategies be formulated based on various facets of the problem revealed by this and previous research to prevent illicit drug use.

Adult↗
PubMed2004

Scalable heuristics for design of DNA probe arrays.

Design of DNA arrays for very large-scale immobilized polymer synthesis (VLSIPS) (Fodor et al., 1991) seeks to minimize effects of unintended illumination during mask exposure steps. Hannenhalli et al. (2002) formulate this requirement as the Border Minimization Problem and give an algorithm for placement of probes at array sites under the assumption that the array synthesis is synchronous; i.e., nucleotides are synthesized in a periodic sequence (ACGT)(k) and every probe grows by exactly one nucleotide with every group of four masks. Drawing on the analogy with VLSI placement, in this paper we describe and experimentally validate the engineering of several scalable, high-quality placement heuristics for both synchronous and asynchronous DNA array design. We give empirical results on both randomly generated and industry test cases confirming the scalability and improved solution quality enjoyed by our methods. In general, our techniques improve on state-of-the-art industrial results by over 4% and surpass academically published results by up to 35%. Finally, we give lower bounds that offer insights into the amount of available further improvements.

Algorithms↗
PubMed1994

Pharmaceutical formulations--suspensions and solutions.

Solutions and suspensions of drugs are used widely in the pharmaceutical industry for production of dosage forms for different routes of administration; for example, oral, parenteral and inhalation. Pharmaceutical solutions and suspensions might appear to be simple formulations but they can present many technical problems both for the manufacturing industry and for the individual pharmacist. Substances can be chemically unstable, insoluble in water, distasteful etc. Suspensions are often used as a dosage form when the drug is insoluble in water and when use of solubilizing agents is not possible. Based on method of preparation, suspensions can be divided into two categories, flocculated and deflocculated systems.

Drug Administration Routes↗
PubMed2026

TPMM: three-component posterior mixture model enables robust inverton detection in low-depth metagenomes and suggests potential viral invertons.

SUMMARY: Bacterial phase variation enables reversible, locus-specific phenotypic switching, often driven by DNA inversion (invertons). To identify these events, researchers commonly rely on sequencing reads that provide orientation-specific support. Metagenomic sequencing, which captures total genetic material independent of cultivation, offers a powerful platform for the comprehensive study of invertons. However, computational inverton calling from metagenomic data is difficult at low sequencing depth: hard read-support cutoffs can miss true events, while sequence-only predictors lack read-backed interpretability and uncertainty quantification. To address this, we present TPMM, a three-component posterior mixture model for inverton calling in metagenomic data. TPMM explicitly incorporates sequencing depth to formulate inverton detection as a probabilistic mixture problem. Starting from candidates flanked by inverted repeats, the model classifies the candidates into noise, low-probability, or high-probability inversion signals using read evidence. Finally, TPMM assigns posterior probabilities as soft labels and applies cumulative Bayesian False Discovery Rate control to robustly identify true invertons. On two real gut metagenomic datasets, TPMM agrees well with PhaseFinder at high depth but recovers substantially more invertons under systematic downsampling, demonstrating superior performance in sparse-data regimes. We further examine potential reversible inversion elements in viral genomes and provide supporting analyses, suggesting a broader scope for inversion-mediated regulation. AVAILABILITY: The source code of TPMM is available via: https://github.com/KennyxxD/TPMM.

Metagenomics↗
PubMed2000

Very old drivers: findings from a population cohort of people aged 84 and over.

BACKGROUND: Increases in longevity will involve a significant increase among the number of drivers in the very old, who are at greater risk of being involved in road accidents. Data are thus needed from studies of older populations to characterize those still driving, the reasons for giving up and to help formulate appropriate policies for dealing with the problems faced and created by an increase in older drivers. METHODS: A driving questionnaire was administered to surviving members of a cohort comprising a representative sample of individuals aged >/=84, the Cambridge City over 75 Cohort. Out of 546 survivors 404 completed the driving questionnaire at the 9-year follow-up. In addition, subjects were assessed, at baseline and at each follow-up, for cognitive performance using the Mini-Mental State Examination (MMSE) and for physical impairment using the Instrumental of Activities in Daily Living (IADL) scale. RESULTS: Of the sample, 37% had driven in the past, and 8.4% were still driving, the majority regularly. The drivers tended to be younger (mean age 86.6 years), men (71%) and to be married (67.7%). Although physical disability and cognitive impairment are common in this age group, current drivers had few physical limitations on their daily activities and were not impaired on MMSE. None of the current drivers had visual impairment and 22.6% had hearing loss. Of those who had given up driving, 48.5% had given up at the age of >/=80. The commonest reasons for giving up driving were health problems (28.6%), and loss of confidence (17.9%). One-third reported giving up driving on advice. CONCLUSION: A process of self-selection takes place among older drivers. People over the age of 84 who are still driving have generally high levels of physical fitness and mental functioning, although some have some sensory loss. Given the likely increase in the number of older drivers over the next decades, safety will be improved most by strategies aimed at the entire driving population with older drivers in mind, rather than relying on costly screening programmes to identify the relatively small numbers of impaired older people who continue to drive.

Accidents, Traffic↗
PubMed1976

Interacting with computer personnel in performing clinical rehabilitation research.

Computer usage by physical therapists performing clinical research is becoming a reality. In this article, the basic computer operations are discussed with emphasis placed upon the way in which the physical therapist may interact with knowledgeable computer personnel during the formulation and execution of a hypothetical research problem. Some essential points concerning the therapist's expectations from computer analysis of research data are provided.

Computers↗
PubMed1976

An analysis of 70 years of morphine classical conditioning: implications for clinical treatment of narcotic addition.

A review of all morphine classical conditioning studies performed since Pavlov reveals significant shifts in methodological and conceptual thinking during the past 7 decades. These shifts have tended to obscure the fact that a great deal of basic data are still needed before morphine classical conditioning can be understood. These data are needed to help clarify the relationship between drug conditioning and drug addiction. Recent evidence, for example, suggests that once morphine autonomic conditional reactions are established, they are highly resistant to extinction. The inclusion of these types of data in any conceptualization of drug dependency would appear to be of help in the formulation of new clinical approaches to this problem.

Animals↗
PubMed2006

Vomiting of liquid corticosteroids in children with asthma.

BACKGROUND: Oral corticosteroids are an essential part of the management of children with acute asthma exacerbations. Vomiting is a frequently cited problem attributed to oral corticosteroids. A new formulation of prednisolone, Orapred, claims to have improved palatability that may decrease the incidence of vomiting. OBJECTIVE: To compare the incidence of vomiting and taste between patients who are given the generic preparation of prednisolone with those given Orapred. DESIGN/METHODS: A randomized, double blind clinical trial was conducted at a tertiary care children s hospital emergency department. Children age 2 to 10 years presenting with acute asthma exacerbation were eligible. Patients with allergy to prednisolone, corticosteroid use within 2 weeks, history of vomiting in the last 24 hours, requirement for vascular access, and preference for other forms of corticosteroid were excluded. Enrolled patients were randomized and given either generic prednisolone (15 mg/5 ml) or Orapred (15 mg/5 ml). In children 6 years or older, a taste score was obtained using a 5 point hedonic face scale (1 = bad to 5 = great). After the administration, patients were observed for 30 minutes for vomiting. The Mann-Whitney U test was used to compare the median taste score between the two study groups. Relative risk (RR) of vomiting was calculated. Other confidence intervals were calculated when appropriate. RESULTS: During the study period, 211 eligible children were enrolled, of whom 23 were excluded. Of the remaining 188 subjects, 96 received generic prednisolone and 92 received Orapred. All baseline characteristics were similar in both groups. In the generic prednisolone group, 17 (17.7%) children vomited compared with 5 (5.4%) in the Orapred group (RR = 3.26, 95% CI, 1.25, 8.47). Taste scores were obtained from 18 children in the generic prednisolone group and from 19 children in the Orapred group. The median taste score was 2 for the generic prednisolone group and 4 for the Orapred group (Delta = -2.0, 95% CI, -3.0, -1.0) (P = 0.0001). CONCLUSIONS: In our study population, Orapred was associated with a significant less incidence of vomiting and better taste score compared to the generic prednisolone.

Acute Disease↗
PubMed2004

Time-ordered fluctuation-dissipation relation for incompressible isotropic turbulence.

The Kraichnan-Wyld perturbation expansion is used to justify the introduction of a renormalized response function connecting two-point covariances at different times. The resulting relationship was specialized by a suitable choice of initial conditions to the form of a fluctuation-dissipation relation (FDR). This was further developed to reconcile the time symmetry of the covariance with the causality of the response by the introduction of time ordering along with a counterterm. This formulation provides a solution to an old problem, that of representing the time dependence of the covariance and response by exponential forms. We show that the derivative (with respect to difference time) of the covariance now vanishes at the origin. This allows one to study the relationships between two-time spectral closures and time-independent theories such as the self-consistent field theory of Edwards or the more recent renormalization group approaches. We also show that the renormalized response function is transitive with respect to intermediate times and report a different Langevin equation model for turbulence. We note the potential value of this time-ordering procedure in all applications of the FDR.

Journal Article↗
PubMed2005

Quantitative phase-field modeling of two-phase growth.

A phase-field model that allows for quantitative simulations of low-speed eutectic and peritectic solidification under typical experimental conditions is developed. Its cornerstone is a smooth free-energy functional, specifically designed so that the stable solutions that connect any two phases are completely free of the third phase. For the simplest choice for this functional, the equations of motion for each of the two solid-liquid interfaces can be mapped to the standard phase-field model of single-phase solidification with its quartic double-well potential. By applying the thin-interface asymptotics and by extending the antitrapping current previously developed for this model, all spurious corrections to the dynamics of the solid-liquid interfaces linear in the interface thickness W can be eliminated. This means that, for small enough values of W, simulation results become independent of it. As a consequence, accurate results can be obtained using values of W much larger than the physical interface thickness, which yields a tremendous gain in computational power and makes simulations for realistic experimental parameters feasible. Convergence of the simulation outcome with decreasing W is explicitly demonstrated. Furthermore, the results are compared to a boundary-integral formulation of the corresponding free-boundary problem. Excellent agreement is found, except in the immediate vicinity of bifurcation points, a very sensitive situation where noticeable differences arise. These differences reveal that, in contrast to the standard assumptions of the free-boundary problem, out of equilibrium the diffuse trijunction region of the phase-field model can (i) slightly deviate from Young's law for the contact angles, and (ii) advance in a direction that forms a finite angle with the solid-solid interface at each instant. While the deviation (i) extrapolates to zero in the limit of vanishing interface thickness, the small angle in (ii) remains roughly constant, which indicates that it might be a genuine physical effect, present even for an atomic-scale interface thickness.

Journal Article↗
PubMed2002

Quantum communication complexity protocol with two entangled qutrits.

We formulate a two-party communication complexity problem and present its quantum solution that exploits the entanglement between two qutrits. We prove that for a broad class of protocols the entangled state can enhance the efficiency of solving the problem in the quantum protocol over any classical one if and only if the state violates Bell's inequality for two qutrits.

Journal Article↗
PubMed2005

Quantum cosmology of the brane universe.

We canonically quantize the dynamics of the brane universe embedded into the five-dimensional Schwarzschild-anti-de Sitter bulk space-time. We show that in the brane-world settings the formulation of the quantum cosmology, including the problem of initial conditions, is conceptually more simple than in the (3+1)-dimensional case. The Wheeler-DeWitt equation is a finite-difference equation. It is exactly solvable in the case of a flat universe and we find the ground state of the system. The closed brane universe can be created as a result of decay of the bulk black hole.

Journal Article↗