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PubMed2005

Infection transmission science and models.

Infection transmission systems circulate infection through complex contact patterns related to both contact patterns and patterns of factors that affect the risk of transmission given contact. The nonlinear dynamics of infection transmission cause these patterns to make big differences in population infection levels. A science of infection transmission system analysis is needed to focus on those details that affect the control of infection transmission. This science must have a strong theoretical base because there is little chance that a dominantly data based approach not using mechanistic models of transmission will have any predictive value. The theoretical base should be built on linked transmission system models that are focused on making needed inferences for both building the theoretical base and making infection control decisions. The linking of different models is needed for a strategy of inference robustness assessment that is designed to find the model that is simple enough to effectively analyze the transmission system but not so simple that realistic violation of simplifying assumptions will change an inference. Types of models that should be used in such linked analyses include deterministic and stochastic compartmental models, discrete individual models with individual event histories but structured mass action mixing, network models that provide more detail as to who has contact with whom, and intermediate model forms such as correlation models that address some aspects of contact details while preserving the flexibility of deterministic compartmental models to structure mixing and analyze the system. While transmission system science is currently weak in regards both to its data base and its theory base, many things are now coming together that could make this science flourish. On the data side these include greater ability to detect infectious agent sequences in the environment and greater ability to sequence and genetically relate agents identified at different sites in the transmission system. On the theory sides, new model construction and model analysis methods are providing new potential to use the new sources of data. Also new parameter estimation methods provide new potential to combine models and data in effective analytic strategies.

Communicable Diseases↗
PubMed2001

Managing for the next big thing. Interview by Paul Hemp.

In this HBR interview, CEO Michael Ruettgers speaks in detail about the managerial practices that have allowed EMC to anticipate and exploit disruptive technologies, market opportunities, and business models ahead of its competitors. He recounts how the company repeatedly ventured into untested markets, ultimately transforming itself from a struggling maker of minicomputer memory boards into a data storage powerhouse and one of the most successful companies of the past decade. The company has achieved sustained and nearly unrivaled revenue, profit, and shareprice growth through a number of means. Emphasizing timing and speed, Ruettgers says, is critical. That's meant staggering products rather than developing them sequentially and avoiding the excessive refinements that slow time to market. Indeed, a sense of urgency, Ruettgers explains, has been critical to EMC's success. Processes such as quarterly goal setting and monthly forecasting meetings help maintain a sense of urgency and allow managers to get early glimpses of changes in the market. So does an environment in which personal accountability is stressed and the corporate focus is single-minded. Perhaps most important, the company has procedures to glean insights from customers. Intensive forums involving EMC engineers and leading-edge customers, who typically push for unconventional solutions to their problems, often yield new product features. Similarly, a customer service system that includes real-time monitoring of product use enables EMC to understand customer needs firsthand.

Administrative Personnel↗
PubMed1997

Computational methods for the identification of genes in vertebrate genomic sequences.

Research into new methods to identify genes in anonymous genomic sequences has been going on for more than 15 years. Over this period of time, the field has evolved from the designing of programs to identify protein coding regions in compact mitochondrial or bacterial genomes, to the challenge of predicting the detailed organization of multi-exon vertebrate genes. The best program currently available perfectly locates more than 80% of the internal coding exons, and only 5% of the predictions do not overlap a real exon. Given such accuracy, computational methods are indeed very useful; however, they do not alleviate the need for experimental validation. If the performances are satisfactory for the identification of the coding moiety of genes (internal coding exons), the determination of the full extent of the transcript (5' and 3' extremities of the gene) and the location of promoter regions are still unreliable. As the human and mouse genome sequencing projects enter a production mode, the fully automated annotation of megabase-long anonymous genomic sequences is the next big challenge in bioinformatics.

Animals↗
PubMed2002

Adipocyte differentiation and transdifferentiation: plasticity of the adipose organ.

In mammals, the adipose organ is a multi-depot organ made of two tissue types, the white and brown adipose tissues, which collaborate in partitioning the energy contained in lipids between thermogenesis and the other metabolic functions. It consists of several sc and visceral depots. Some areas of these depots are brown and correspond to brown adipose tissue, while many are white and correspond to white adipose tissue. White areas contain a variable amount of brown adipocytes and their number varies with age, strain and environmental conditions. Brown and white adipocyte are morphologically different. At light microscopy level, brown adipocytes have cytoplasmic lipids arranged as numerous small droplets (multilocularity), while white adipocytes have cytoplasmic lipids arranged in a unique vacuole (unilocularity). Ultrastructurally, brown adipocytes have numerous big mitochondria packed with cristae and containing the thermogenic uncoupling protein 1 (UCP1). In vivo and in vitro studies have shown that the differentiation process of brown and white adipocytes shows distinctive features. Nevertheless, the origin of the adipocyte precursor is still unknown. Recent data have stressed the plasticity of the adipose organ in adult animals. Indeed, under peculiar conditions fully differentiated, white adipocytes can transdifferentiate into brown adipocytes, and viceversa. The ability of the adipose organ to interconvert its main cytotypes in order to meet changing metabolic needs is highly pertinent to the physiopathology of obesity and related to therapeutic strategies.

Adipocytes↗
PubMed2000

[Knee endoprostheses: problems and technological developments from the manufacturer's point of view].

Modern-day knee arthroplasty is based principally on the experience gained in the course of the past three decades. In the 1980s and 1990s, for example, the full constraint models of the 1970s were replaced by surface replacement prostheses with a combined rolling/sliding motion approximating the natural motion of the human knee joint for a wide range of applications. Not all of the relevant questions in the areas of material science, biomechanics, tribology, implant fixation and surgical technique have been fully explored by any means. Nevertheless, the medium-term and long-term results presently attained by knee arthroplasty are comparable to those achieved in the field of hip-joint arthroplasty. Although the success achieved by today's knee-joint prostheses is impressive, a critical analysis of therapeutic failures and complications is necessary to discover areas where further research is necessary and to formulate the challenges presenting themselves in R&D and in the manufacture of artificial knee joints. Currently, research efforts are focused on optimizing materials (especially in light of the presently unsatisfactory wear behavior of artificial knee joints), biomechanically-assisted design optimization to achieve a better harmonization between mobility and stability in the knee joint to be treated, alternative anchoring concepts, including consistently cement-free anchoring, and solutions for simplifying implantation techniques and making them more precise. The latter area, in particular, appears to be of great importance, since the quality of artificial knee joints and the long-term therapeutic outcome of knee-joint arthroplasty depend to a great extent on the correct alignment of the leg axes, an optimal implant position, and the correct adjustment of soft tissue tension. Technical innovations in this area of implant technology exert a multifactorial impact on different aspects of arthroplasty--e.g., uniform force transfer to minimize wear, selective rotation of the femoral components to optimize patella tracking, and avoidance of load concentrations to improve fixation strength--and thus form the basis for a surgical approach that takes greater account of "the big picture". Today's sophisticated navigation systems are a case in point. The non-imaging systems, in particular, have proved to be exceptionally useful; their advantages lie in their simple handling which makes use of common surgical techniques, the avoidance of additional imaging data recording (e.g. CT images), and an inconsequential increase in operation times.

Arthroplasty, Replacement, Knee↗
PubMed2005

[Tobacco smoking by elderly people according to CINDI WHO research].

UNLABELLED: The epidemiological research results show that quitting smoking tobacco by elderly people (> or = 65 year old) reduces the risk of cancer both for men and women and there is a substantial cardiovascular system improvement after a one-year-period. From the medical and economic point of view it is purposeful to explore the smoking model of this age group in relation to sociodemographic features as well as analyzing the factors that may motivate them to quit smoking. The research included a random test group of people aged 65 and more, living in Lódź Górna district. The 57.4% turnout to the research enabled to obtain data from 828 people (288 men and 540 women). The respondents were 71.5 +/- 5.1 years old on average. The tool of the research was the interview questionnaire including smoking tobacco related questions. The research was conducted within CINDI WHO Program in 2002. In the big city population the elderly people smoking frequency was 10.8%, where there were 9.5% of regular smokers and 1.3% of occasional smokers. Twice as many men than women at the same age were smoking tobacco (16.6% vs. 7.8%). The majority of regular smokers represent the psychological nicotine dependence type assessed with the Fagerström Test of Nicotine Dependence. 65% of tobacco smokers declare the will to quit smoking and 68% have attempted to quit smoking. The percentage of ex-smokers was close to the percentage of current smokers and amounted to 10.7%. The predominant group of ex-smokers (87%) had stopped smoking before turning 65, however, the rest of the ex-smokers had quit before crossing the old age border. CONCLUSIONS: The smoking frequency of elderly people living in the city environment is quite high, especially within men. The intensification of actions towards limiting tobacco smoking in this age group may substantially contribute to decreasing the global risk of cardiovascular complications and life quality improvement.

Aged↗
PubMed1989

[Recent viewpoints in the theory and practice of autogenic training].

The authors give a brief review over papers presented on the "International Symposion on Autogenic Training" in Berlin, March 1988. A study based on empirical data from 48 managers was presented, showing how Autogenic Training (AT) could reduce cardiovascular riskfactors, e.g. cardiac-functions and levels of bloodcholesterol and -triglycerids (Carruthers). Of high actual importance was a report about grouptherapy with AIDS-patients, in which AT played a big role. The quality of life of the patients was improved considerably (Kermani). A multidimensional therapeutic approach combining psychopharmaca, AT and psychoanalytic grouptherapy was presented (Barolin). In the field of psychophysiology there was a report about a thermometric study carried out with a group of psychovegetative impaired patients demonstrating the "vasodilatatory potence" of the AT (Stetter). Müller-Hegemann reported about misunderstandings in teaching AT and made some remarks in the changing of tension and relaxation in human life being influenced by practicing AT and physical training.

Arousal↗
PubMed1995

[14C-urea breath test in the diagnosis of Helicobacter pylori infection in the stomach].

We developed a modified 14C-urea breath test (14C-UBT) to diagnose Helicobacter pylori (Hp) infection in 70 patients in which subjects were given 92.5 kBq (2.5 microCi) 14C-urea with 25 mg nonradioactive urea, without nutrient-dense meal. Using the mean value +3s as a cutoff value, the 20 min sample gave a sensitivity of 97.36%, a specificity of 90.00%, a positive predictive value of 97.36%, and a negative predictive value of 90.0%. Our data showed: (1) A satisfying accuracy of the modified 14C-UBT for the detection of Hp infection was obtained. (2) Taking 92.5 kBq (2.5 microCi) 14C-urea and 20 min collected sample may be of great use and to replace the previous big dose and long time methods. (3) This test may be applied routinely as a noninvasive, accurate, low cost, safe and rapid method. (4) It played an important role in reflecting the susceptibility of Hp to various drugs in vivo and monitoring the recurence of Hp.

Adult↗
PubMed1995

A relational database in neurosurgery.

UNLABELLED: This paper describes teh automatic procedure for a clinical record management in a Neurosurgery ward. The automated record allows the storage, querying and effective management of clinical data. This is useful during the patient stay and also for data processing and analysis aiming at clinical research and statistical studies. The clinical record is problem-oriented. It contains a minimum data set regarding every patient and a data set which is defined by a classification nomenclature (using an inner protocol). The main parts of the clinical record are the following tables: PERSONAL DATA: contains the fields relating to personal and admission data of the patient. The compilation of some fields is compulsory because they serve as input for the automated discharge letter. This table is used as an identifier for patient retrieval. ANAMNESIS: composed of five different tables according to the kind of data. They are: familiar anamnesis, physiological anamnesis, past and next pathology anamnesis, and trauma anamnesis. GENERAL OBJECTIVITY: contains the general physical information of a patient. The field hold default values, which quickens the compilation and assures the recording of normal values. NEUROLOGICAL EXAMINATION: contains information about the neurological status of the patient. Also in this table, ther are default values in the fields. COMA: contains standardized ata and classifications. The multiple choices are automated and driven and belong to homogeneous classes. SURGICAL OPERATIONS: the information recording is made defining the general kind of operation and then defining the peculiar kind of operation. INSTRUMENTAL EXAMINATIONS: some examination results are recorded in a free structure, while other ones (TAC, etc.) follow codified structure. In order to identify a pathology by means of TAC, it is enough to record three values corresponding to three variables. THis classification fully describes a lot of neurosurgical pathologies. DISCHARGE: contains conclusions, therapies, result, and hospital course. Medical language is closer to the natural one and presents some abiguities. In order to solve this problem, a classification nomenclature was used for diagnosis definition. DISCHARGE LETTER: the document given to the patient when he is discharged. It extracts data from the previously described modules and contains standard headings. The information stored int he database is structured (e.g., diagnosis, name, surname, etc.) and access to this data takes place when the user wants to search the database, using particular queries where the identifying data of a patient is put as conditions for the research (SELECT age, name WHERE diagnosis="TRAUMA"). Logical operators and relational algebra of the relational DBMS allows more complex queries ((diagnosis="TRAUMA" AND age="19") OR sex="M"). The queries are deterministic, because data management uses a classification nomenclature. Data retrieval takes place through a matching, and the DBMS answers directly to the queries. The information retrieval speed depends upon the kind of system that is used; in our case retrieval time is low because the accesses to disk are few even for big databases. In medicine, clinical records can have a hierarchical structure and/or a relational one. Nevertheless, the hierarchical model presents a disadvantage: it is not very flexible because it is linked to a pre-defined structure; as a matter of fact, the definition of path is established in the beginning and not during the execution. Thus, a better representation of the system at a logical level requries a relational DBMS which exploits the relationships between entities in a vertical and horizontal way. That is why the developers adopted a mixed strategy which exploits the advantages of both models and which is provided by M Technology with SQL language (M/SQL). For the future, it is important to have at one's disposal multimedia technologies, which integrate different kinds of information (alp

Databases, Factual↗
PubMed1997

Pharmacogenetics in biological perspective.

What have we learned? Pharmacogenetics, heritable variation in response to xenobiotics, is present in all forms of life. Initially, human data perhaps have created the most excitement, and they provide much biochemical detail. However, if we look at pharmacogenetic variation of insects and bacteria, we see it as a characteristic of populations; individuals with inborn resistance to various toxicants can cause the survival of a population by the process of Darwinian selection. Diversity of a population and Darwinian selection are different milestones serving population survival. Variation of drug response may represent variation of drug targets, drug metabolism, and probably drug transport. Metabolic variation appears to be the most prominent; at present, it is not clear whether this prominence has historical or biological causes. It is an interesting exercise to compare pharmacogenetic resistance with intoxication and resistance to infection by invasion of disease-carrying bacteria or other pathogens. The big difference is that pathogens tend to show variabilities that drugs do not have. The immune system is made to deal with the genetic variabilities linked to the short life span of most pathogens. However, there are, besides the immune system, several cases of genetic host resistance associated with the long life span of mammalian hosts. Such genetic host resistances are factors equivalent to pharmacogenetic variation. Current data pertain to resistance against malaria, tuberculosis, cholera, and AIDS. Most pharmacogenetic variants within a population are preadaptive, that is, they are established before xenobiotic exposure. Hence, one must postulate a multiplicity of variants in a population capable of resisting a multiplicity of drugs. The persistence of this multiplicity suggests that most variants are either present in heterozygous form and are thereby advantageous for their carriers, or they are selectively neutral mutants. It means that the biological cost of pharmacogenetic diversity, measured in terms of reduced fertility, should be low in a population. The frequencies of variant genes are usually not the same in different populations. Also the nucleotide substitutions in a variable gene often differ between populations. In other words, pharmacogenetic differences between populations are typical events. Pharmacogenetics is usually thought of as the study of a situation in which a single gene product exerts control over a given drug response so that a failure to respond, or an excessive response, may result. However, one should not forget that random variation is always present, probably reflecting the randomness of mutations plus variation of any environmental factors that might contribute. This underlying randomness of variation will always affect the picture of any all-or-none variation. Future pharmacogenetics must deal with both random and monogenic variation.

Animals↗
PubMed2005

Getting the big picture in community science: methods that capture context.

Community science has a rich tradition of using theories and research designs that are consistent with its core value of contextualism. However, a survey of empirical articles published in the American Journal of Community Psychology shows that community scientists utilize a narrow range of statistical tools that are not well suited to assess contextual data. Multilevel modeling, geographic information systems (GIS), social network analysis, and cluster analysis are recommended as useful tools to address contextual questions in community science. An argument for increased methodological consilience is presented, where community scientists are encouraged to adopt statistical methodology that is capable of modeling a greater proportion of the data than is typical with traditional methods.

Cluster Analysis↗
PubMed2007

Big roles for small GTPases in the control of directed cell movement.

Small GTPases are involved in the control of diverse cellular behaviours, including cellular growth, differentiation and motility. In addition, recent studies have revealed new roles for small GTPases in the regulation of eukaryotic chemotaxis. Efficient chemotaxis results from co-ordinated chemoattractant gradient sensing, cell polarization and cellular motility, and accumulating data suggest that small GTPase signalling plays a central role in each of these processes as well as in signal relay. The present review summarizes these recent findings, which shed light on the molecular mechanisms by which small GTPases control directed cell migration.

Actins↗
PubMed2000

"Friendships are a big part of it": social relationships, social distance, and HIV risks.

Social distance, or how close or distant individuals consider others, is an important influence on drug injectors' HIV risk behavior. Qualitative in-depth interviews with a vignette were employed with a sample of drug injectors in England to explore the influence of social distance on HIV risk behavior. Analysis of these data distinguish between close and distant relationships in sexual behavior in the community and in drug-injecting behavior inside prison. These findings help to expose the constituents of social distance in relation to drug injectors' perceptions of HIV risk, which are discussed throughout this paper.

Adolescent↗
PubMedDate not supplied

U.S. high-rise fires: the big picture.

In the past, efforts to track fire experience in high-rise buildings have been less than systematic. Now, for the first time, we can provide an overall perspective on the problem.

Data Collection↗
PubMed1994

The importance of data in improving practice: effective clinical use of outcomes data.

We are in a transition stage from the widespread use of clinical judgment to the use of risk-adjusted outcomes data for clinical decision-making and quality assessment and improvement. The ultimate long-term goal for the use of predicted outcomes is to be able to inform patients at the earliest state of their symptoms as to the anticipated course of their disease and the results of alternative therapies. For outcomes analyses to be routinely used in clinical practice, they must be formulated succinctly. Because a small number of adverse outcomes may make a big difference in outcome statistics over a short period such as a year, it is important that purchasers of health services take a longer-term view. The demand for public disclosure of every aspect of medical therapy is on the increase, and it is likely that each physician, hospital, specialty group, and so on, is likely to receive some type of report card in the near future. However, I believe it will be very difficult to educate the public, given the enthusiasm we currently see in the press for producing headlines that are not always supported by the facts in the article. Although the importance of outcomes data is unquestioned, it is important to remember that our methods for utilizing the data are still somewhat infantile. Therefore, it is important for us as a profession to question the accuracy and the interpretations of outcomes data.

Cardiac Surgical Procedures↗
PubMed1996

A molecular model for human Big-Endothelin-1 (Big ET-1).

A molecular model has been developed for human Big Endothelin-1, which is the immediate precursor to the potent vasoconstrictor polypeptide endothelin-1 and the target of the highly specific endothelin converting enzyme. This model is produced by a threading algorithm protocol and is consistent with all the currently available structural and biochemical data for this molecule.

Algorithms↗
PubMed1997

Interpersonal perception and metaperception in nonoverlapping social groups.

Consensus, self-other agreement, and meta-accuracy were studied within and across nonoverlapping social groups. Thirty-one target persons were judged on the Big Five factors by 9 informants: 3 family members, 3 friends, and 3 coworkers. Although well acquainted within groups, informants were unacquainted between groups. A social relations analysis conducted within each social group showed reliable consensus on the Big Five personality factors. A model specified to estimate the consistency of a target person's effect on perceptions by others across social groups showed weaker agreement across groups. That is, targets were perceived consensually within groups, but these consensual perceptions differed between groups. The data suggest that personality and identity are context specific; however, there was some evidence of agreement in perceptions across groups.

Adult↗
PubMed2004

Developing a decision tree algorithm for the diagnosis of suspected spider bites.

OBJECTIVE: To develop a diagnostic algorithm (decision tree) to improve the ability to identify or predict medically important spider bites (funnel-web and redback spiders) from information about the circumstances and initial clinical effects of spider bites. METHODS: A dataset of definite spider bites with expert identification of all spiders was used from a previous Australia-wide prospective study. Spider bites were categorized as: big black spider (BBS), redback spider (RED) and other spider (OTH). Big black spider included funnel-web spiders (most medically significant), but also other spiders of similar appearance. Fifteen predictor variables were based on univariate analysis from previous studies and clinical experience. They included information about the circumstances and early clinical effects of bites. The data were analyzed using CART (Classification and Regression Trees), a 'decision tree' algorithm used to create a tree-like structure to describe a data set. RESULTS: Of 789 spider bites there were 49 (6.2%) bites by BBS, 68 (8.6%) bites by RED and 672 (85.2%) bites by OTH. A decision tree was developed that included six predictor variables (fang marks/bleeding; state/territory; local diaphoresis; month; time of day; and proximal or distal bite region). The decision tree accurately classified 47 out of the 49 (96%) BBS, and no funnel-web spiders were incorrectly classified (100% sensitivity). Two hundred and forty-four of 789 were classified as OTH and included no BBS. CONCLUSIONS: A decision tree based on a small amount of information about the circumstances and early clinical effects of spider bites safely predicted all funnel-web spider bites. Application of this algorithm would allow the early institution of appropriate treatment for funnel-web spider bites and the immediate discharge of 31% as other spider bites (reassurance only).

Algorithms↗