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How rational should bioethics be? The value of empirical approaches.

Rational justification of claims with empirical content calls for empirical and not only normative philosophical investigation. Empirical approaches to bioethics are epistemically valuable, i.e., such methods may be necessary in providing and verifying basic knowledge about cultural values and norms. Our assumptions in moral reasoning can be verified or corrected using these methods. Moral arguments can be initiated or adjudicated by data drawn from empirical investigation. One may argue that individualistic informed consent, for example, is not compatible with the Asian communitarian orientation. But this normative claim uses an empirical assumption that may be contrary to the fact that some Asians do value and argue for informed consent. Is it necessary and factual to neatly characterize some cultures as individualistic and some as communitarian? Empirical investigation can provide a reasonable way to inform such generalizations. In a multi-cultural context, such as in the Philippines, there is a need to investigate the nature of the local ethos before making any appeal to authenticity. Otherwise we may succumb to the same ethical imperialism we are trying hard to resist. Normative claims that involve empirical premises cannot be reasonable verified or evaluated without utilizing empirical methods along with philosophical reflection. The integration of empirical methods to the standard normative approach to moral reasoning should be reasonably guided by the epistemic demands of claims arising from cross-cultural discourse in bioethics.

Anthropology, Cultural↗

Design of the master's degree in occupational therapy, part 2. An empirical approach.

In this article an empirical approach is used to investigate the master's degree structure in a bachelor's level profession. The literature of nursing, business administration, social work, and physical therapy is reviewed to determine prevailing degree structures and attitudes, evaluate the adequacy of the master's degree structure in occupational therapy, and delineate factors entering into structural decisions. The review demonstrates the feasibility and desirability of requiring basic master's students to meet advanced master's degree criteria. However, it fails to substantiate unreservedly the logical necessity for so doing. Recommendations for educational practice and research are detailed.

Commerce↗

Changes in the healthfulness of life of the elderly population: an empirical approach.

This paper presents an empirical approach to measuring the healthfulness of life of the elderly population. It discusses information related to trends in disability-free and quality-adjusted life expectancy in the context of the current debate concerning prospects for a possible future compression of morbidity. Trends in each of the components underlying health expectancy are examined: survivorship and remaining life expectancy in each state of health, rates of institutionalization, as well as incidence of disability and prevalence of activity restriction in the household population. The effects on health expectancy of changes in these components are noted.

Aged↗

Functional capacity evaluation: an empirical approach.

This paper presents an empirical approach to selecting activities of daily living (ADL) to assess the functional capacity of noninstitutionalized individuals with polyarticular disability. The results of structural analyses illustrate the feasibility of substantially reducing the task of assessing functional capacity with a subset of ADL items without sacrificing the comprehensiveness of the assessment. The analyses reveal 5 common functional categories: physical mobility, transfers, home chores, kitchen chores, and personal care, which account for over 50% of the variance in the data.

Activities of Daily Living↗

Examining the influence of the Journal of Pediatric Psychology: an empirical approach.

OBJECTIVE: To empirically examine whether research published in the Journal of Pediatric Psychology (JPP) guides research both within and outside the field of pediatric psychology. METHODS: Articles published in JPP from 2000 to 2004 were evaluated to determine the frequency with which articles in JPP from 2000 influenced subsequent research. Citation rates by other journals were also examined. RESULTS: Articles in JPP from 2000 were frequently cited in subsequent research, but authors rarely cited previous research as being instrumental in the development of their study design. Articles in JPP from 2000 were also frequently cited by outside journals. Specifically, journals classified as "medical and medical subspecialties" had the highest rates of citing JPP articles. CONCLUSIONS: The finding that JPP is cited both within JPP and other journals provides further evidence that pediatric psychology is a thriving interdisciplinary field.

Humans↗

Screening for toxic effects on interspecies interactions: a mechanistic or an empirical approach?

The use of empirical and mechanistic approaches are possible in the development of tests to screen for a substance's potential to affect interspecies interactions. The advantages and disadvantages of the two approaches are discussed. An experimental study is presented, in which an empirical and a mechanistic screening test for effects on exploitative competition between bacterial species were established and perturbed with nalidixic acid. Comparison of test results indicates that the mechanistic test was faster, cheaper, more sensitive, and more quantitative. The empirical test attained similar sensitivity and quantification only if the dynamics of the competition event was continuously monitored; requiring even greater cost and time.

Bacteria↗

Bridging process-based and empirical approaches to modeling tree growth.

The gulf between process-based and empirical approaches to modeling tree growth may be bridged, in part, by the use of a common model. To this end, we have formulated a process-based model of tree growth that can be fitted and applied in an empirical mode. The growth model is grounded in pipe model theory and an optimal control model of crown development. Together, the pipe model and the optimal control model provide a framework for expressing the components of tree biomass in terms of three standard inventory variables: tree height, crown height and stem cross-sectional area. Growth rates of the inventory variables and the components of biomass are formulated from a carbon balance. Fundamentally, the parameters of the model comprise physiological rates and morphological ratios. In principle, the values of these parameters may be estimated by lower-level process models. Alternatively, the physiological and morphological parameters combine, under reasonable assumptions, into a set of aggregate parameters, whose values can be estimated from inventory data with a statistical fitting procedure.

Biomass↗

An empirical approach to the bond additivity model in quantitative interpretation of sum frequency generation vibrational spectra.

Knowledge of the ratios between different polarizability betai'j'k' tensor elements of a chemical group in a molecule is crucial for quantitative interpretation and polarization analysis of its sum frequency generation vibrational spectroscopy (SFG-VS) spectrum at interface. The bond additivity model (BAM) or the hyperpolarizability derivative model along with experimentally obtained Raman depolarization ratios has been widely used to obtain such tensor ratios for the CH3, CH2, and CH groups. Successfully, such treatment can quantitatively reproduce the intensity polarization dependence in SFG-VS spectra for the symmetric (SS) and asymmetric (AS) stretching modes of CH3 and CH2 groups, respectively. However, the relative intensities between the SS and AS modes usually do not agree with each other within this model even for some of the simplest molecular systems, such as the air/methanol interface. This fact certainly has cast uncertainties on the effectiveness and conclusions based on the BAM. One of such examples is that the AS mode of CH3 group has never been observed in SFG-VS spectra from the air/methanol interface, while this AS mode is usually very strong for SFG-VS spectra from the air/ethanol interface, other short chain alcohol, as well as long chain surfactants. In order to answer these questions, an empirical approach from known Raman and IR spectra is used to make corrections to the BAM. With the corrected ratios between the betai'j'k' tensor elements of the SS and AS modes, all features in the SFG-VS spectra of the air/methanol and air/ethanol interfaces can be quantitatively interpreted. This empirical approach not only provides new understandings of the effectiveness and limitations of the bond additivity model but also provides a practical way for its application in SFG-VS studies of molecular interfaces.

Journal Article↗

[Electrical stimulation of the visual system. From empirical approach to visual prostheses].

The investigation of the influence of electrical stimulation on the visual system can be sub-divided into empirical, diagnostic and therapeutic phases of development. The first electrical stimulations of the visual system in animals dating back to the eighteenth century represent empirical approaches well before knowledge on the principles of bioelectrical nerve activity was available. Despite this lack of understanding, attempts were made at that time to treat blind people by electrical stimulation. More than 100 years later, with the advancement of technology and knowledge on nerve function, attempts were made to establish various methods of electrical stimulation for the diagnosis of different diseases of the visual system. For more than 30 years attempts to develop electrical devices have been made to by-pass defects of the visual system and to restore basic orientation. Presently nine different groups world-wide are focusing on retinal, optic or cortical implants. A short review on the historical use of electrical stimulation and new therapeutical attempts are given in this paper.

Action Potentials↗

Panic attacks in the nonclinical population: an empirical approach to case identification.

Although self-reports of panic attacks are common among student populations, it is not clear that their panic experiences are actually comparable to those of patients with clinical anxiety disorders. An empirical approach was taken to this problem by using a cluster analysis procedure to identify subjects within two samples of university students who reported panic attack symptom profiles that resembled those of patients with panic disorder. Such empirically defined "clinical" panic attacks were reported by 7.0% and 8.1% of the two samples. This predominantly female group accounted for most of the increased psychopathology that has been reported in previous studies of nonclinical panic.

Adolescent↗

An empirical approach to characterizing trunk muscle coactivation using simulation input modeling techniques.

Accurately describing trunk muscle coactivation is fundamental to quantifying the spine reaction forces that occur during lifting tasks and has been the focus of a great deal of research in the spine biomechanics literature. One limitation of previous approaches has been a lack of consideration given to the variability in these coactivation strategies. The research presented in this paper is an empirical approach to quantifying and modeling trunk muscle coactivation using simulation input modeling techniques. Electromyographic (EMG) data were collected from 28 human subjects as they performed controlled trunk extension exertions. These exertions included isokinetic (10 and 45 degrees /s) and constant acceleration (50 degrees /s/s) trunk extensions in symmetric and asymmetric (30 degrees ) postures at two levels of trunk extension moment (30 and 80Nm). The EMG data were collected from the right and left pairs of the erector spinae, latissimus dorsi, rectus abdominis, external obliques and internal obliques. Each subject performed nine repetitions of each combination of independent variables. The data collected during these trials were used to develop marginal distributions of trunk muscle activity as well as a 10x10 correlation matrix that described how the muscles cooperated to produce these extension torques. These elements were then combined to generate multivariate distributions describing the coactivation of the trunk musculature. An analysis of these distributions revealed that increases in extension moment, extension velocity and sagittal flexion angle created increases in both the mean and the variance of the distributions of the muscular response, while increases in the rate of trunk extension acceleration decreased both the mean and variance of the distributions of activity across all muscles considered. Increases in trunk asymmetry created a decrease in mean of the ipsi-lateral erector spinae and an increase in the mean of all other muscles considered, but there was little change in the variance of these distributions as a function of asymmetry.

Acceleration↗

Geographical resource allocation in the English National Health Service, 1971-1994: the tension between normative and empirical approaches.

The policy response to the problem of developing a geographical resource allocation formula sensitive to relative population needs for hospital and community health services resources in the National Health Service demonstrates a continuing tension between normative and empirical solutions. Since 1988, the balance has shifted in favour of a more empirical approach to identifying and weighting population needs indicators in response to concerns about the theoretically justified, but essentially approximate, nature of the Resource Allocation Working Party formula introduced in 1977-1978. However, judgements and assumptions about the nature of 'need' have still to be made in order to construct a usable resource allocation formula since empirical data on what is cannot provide a complete guide to what ought to be a fair distribution of resources in relation to need.

Capital Financing↗

Community care in child psychiatry. An empirical approach using the concept of travel time.

Community care is a crucial element in the organization and development of psychiatric services. The basic idea of community care is that it guarantees equal access to services for all people in need. In this study an empirical approach to community care is undertaken using the concept of travel time. The importance of distance to the use or nonuse of mental health services has been documented for a long time. But if distance is measured by travel time, additional elements, as for example the available transport system are considered relevant for the accessibility of services. It can be shown that most patients of two child psychiatric outpatient services do not accept a travel time exceeding half an hour. Outreach activities of services located in rural areas can partly compensate for the geographic disadvantage of those patients living at long distance to the service.

Adolescent↗

"Mind the gaps": an empirical approach to engineering ethics, 1997-2001.

A survey on ethical issues in engineering was administered over a five-year period to Stanford engineering students and practicing engineers. Analysis of its results strongly suggests that important disconnects exist between the education of engineering students regarding ethical issues in engineering on the one hand, and the realities of contemporary engineering practice on the other. Two noteworthy consequences of these gaps are that the views of engineering students differ substantially over what makes an issue an ethical issue, while practicing engineers exhibit significant disagreement over what is the most important non-technical aspect of being a responsible engineering professional in contemporary society. These divergences impede the recognition of ethical issues and of specific moral responsibilities of engineers in concrete professional practice. It is argued that the use of suitably refined and probing surveys of engineering students and practicing engineers about ethical issues in engineering is an important although neglected empirical approach to the study of engineering ethics. Such an approach can enhance the prevailing case study method and combat over-tidy theoretical-analytical approaches to the subject.

Attitude↗

A semi-empirical approach to the modeling of the electrophoretic mobility in free solution: application to polystyrenesulfonates of various sulfonation rates.

This work focuses on the understanding of the electrophoretic behavior of flexible chains of polystyrenesulfonates (PSSs) in free solution. It deals mainly with the variation of the electrophoretic mobility with (i) the polymerization degree (N) of fully sulfonated PSSs and (ii) the sulfonation rate of randomly sulfonated PSSs. In both cases, the electrophoretic mobility was modeled following a semi-empirical approach which involves parameters retaining a physical meaning. Fully sulfonated PSS oligomers, having a length smaller than or similar to the Debye length, exhibit a particular electrophoretic behavior, in-between that observed for multicharged small molecules and that for polyelectrolytes. The electrophoretic mobility of these oligomers increases strongly with N, which is attributed to a hydrodynamic coupling between monomers. Then the mobility is maximum for an N of about 10, for which the PSS oligomers are still in a rod-like conformation. Afterwards, as N increases and the PSSs are larger than the Debye length, the electrophoretic mobility decreases slowly until it reaches a constant value corresponding to the free-draining behavior. Next, the electrophoretic behavior of long PSS (N about 1,200) differing in their sulfonation rates was investigated. The effective charge rates were determined independently by conductimetric measurements and the mobilities were modeled as a function of the sulfonation rate. The PSS behavior observed was compared to the one previously reported for classical polyelectrolytes having hydrophilic backbones, such as copolymers of poly(acryamide-coacrylic acid). A specific behavior has been pointed out for these partially sulfonated PSSs, which is attributed to the hydrophobicity of their backbone. Finally, it is shown that separations of PSSs of different sulfonation rates can be obtained with electrolytes containing an anionic surfactant or methanol.

Electrophoresis↗

A semi-empirical approach for the simulation of circular dichroism spectra of gramicidin A in a model membrane.

In an extension of our previous work (Bañó, M. C., Braco, L., and Abad, C. 1991. Biochemistry. 30:886-94), the kinetics of dissociation of gramicidin A double-stranded dimers into beta 6.3-helical monomers in small unilamellar vesicles prepared following different protocols, were investigated using in combination circular dichroism (CD) and high-performance liquid chromatography (HPLC). The analysis of the data from both techniques according to a two-component model strongly supports that any given CD pattern of gramicidin incorporated in the phospholipid bilayer can be deconvoluted essentially as a linear combination of the reference subspectra calculated for the double-stranded dimer and the helical monomer. An HPLC-based, semi-empirical approach is proposed for the simulation of gramicidin CD curves in the model membrane used, and it is shown that the congruence between theoretical and experimental spectra is very satisfactory.

Biophysical Phenomena↗

In the quest for a virtual pseudo receptor for sandalwood-like odorants. Part I: The empirical approach.

Based on similarities between naturally occurring (-)-(Z)-beta- or (+)-(Z)-alpha-santalol ((-)- 1 or (+)-2, resp.) and the reversed (E)-configured synthetic derivatives from campholenal (7a), a simple model A was developed. Besides reconciliation of this stereochemical aspect, this initial model also tentatively explained the enantiodiscriminations as well as the large spectra of distances separating the OH function from the lipophilic quaternary center(s) reported for different classes of substrates. Evolution, modifications, and refinement of this imperfect model allied with the research for alternative possibilities are illustrated, along with a historical guideline, in the light of olfactively challenging synthetic seco-substructures as well as literature reports. Despite evolution of the inadequate model A and a plausible interpretation of the lipophilic part, the topological positions of the OH function and its vicinal alkyl substituent could nevertheless not be fully ascertained by this approach. This apparently inconclusive empirical concept prompted us to turn our attention towards a computerized methodology, which will constitute the second and third part of this study.

Empirical Research↗

Cryoprotective agent and temperature effects on human sperm membrane permeabilities: convergence of theoretical and empirical approaches for optimal cryopreservation methods.

Previous reports have left unresolved discrepancies between human sperm cryopreservation methods developed using theoretical optimization approaches and those developed empirically. This study was designed to investigate possible reasons for the discrepancies. Human spermatozoa were exposed to 1 mol/l glycerol, 1 mol/l dimethyl sulphoxide (DMSO), 1 mol/l propylene glycol (PG) or 2 mol/l ethylene glycol (EG) at 22, 11 and 0 degrees C, then returned to isosmotic media while changes in cell volume were monitored. Activation energies (E(a)) of the hydraulic conductivity (L(p)) in the presence of cryoprotective agents (CPA) (L(p)(CPA)) were 22.2 (DMSO), 11.9 (glycerol), 15.8 (PG), and 7.8 (EG) kcal/mol. The E(a) values of the membrane permeability to CPA (P(CPA)) were 12.1 (DMSO), 10.4 (glycerol), 8.6 (PG) and 8.0 (EG) kcal/mol. These data indicated that even at low temperatures, EG permeates fastest. The high L(p)(CPA) in the presence of EG and low associated E(a) would allow spermatozoa to remain closer to equilibrium with the extracellular solution during slow cooling in the presence of ice. Collectively, these data suggest that the increase of the E(a) of L(p) in the presence of CPA at low temperature is the likely reason for the observed discrepancy between theoretical predictions of spermatozoa freezing response and empirical data.

Cell Membrane Permeability↗