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Rural and remote Australian general practitioners' educational needs in radiology.

BACKGROUND: The Australian College of Rural and Remote Medicine (ACRRM) was funded by the Commonwealth Department of Health and Aged Care to set up a quality assurance and continuing medical education program for rural and remote general practitioners in radiology to begin in January 2001. An extensive literature search failed to uncover any previous publications on the specific educational or quality assurance needs for rural general practitioners in radiology. Broader educational needs assessments of rural general practitioners in Australia had identified radiology as an important skill for which improvement was desired. METHOD: A national steering committee consisting of four rural general practitioners and three radiologists, with the assistance of a program manager, developed and piloted a self-administered postal questionnaire to determine the educational and quality assurance needs of rural and remote general practitioners. The questionnaire was sent to all rural and general practitioners holding a remote radiology exemption using the Health Insurance Commission database. RESULTS: A total of 287 completed questionnaires were returned from all states in the country, except the Australian Capital Territory. The information gave a comprehensive picture of the self-reported radiology education needs of these doctors, who practice in isolation from radiologists and other specialists. The three areas in which the general practitioners were least confident in radiology were chest, cervical spine, and skull radiology. Their highest priority areas of need for education were chest radiology, film interpretation, and spinal radiology. The top preferred quality assurance activity was image review with a radiologist, followed by clinical audit, image review by peers, and measuring practice against guidelines. FINDINGS: Local ownership of education is important to successful program development and evaluation. Information obtained from the educational needs assessment was used to develop the Radiology Quality Assurance and Continuing Medical Education Program for Rural and Remote General Practitioners.

Australia↗

Ascending general visceral pathways within the brainstems of two teleost fishes: Ictalurus punctatus and Carassius auratus.

The primary general visceral nucleus in goldfish (Carassius auratus) and catfish (Ictalurus punctatus) is located at the ventroposterior boundary of the vagal gustatory lobe and receives coelomic visceral, but not gustatory inputs. The neuronal tracer horseradish peroxidase (HRP) was employed to visualize sources of input to and ascending projections from the primary general visceral nucleus in these species. In addition, immunocytochemical techniques were utilized to define the cytological divisions within the pontine gustatory-visceral complex. The pontine secondary visceral nuclei in both catfish and goldfish contains numerous somata and fibers immunoreactive for calcitonin gene-related peptide (CGRP). In contrast, the secondary gustatory nuclei are devoid of fibers and cells immunoreactive for CGRP. In both the goldfish and the channel catfish, the primary general visceral nucleus receives input from the vagal gustatory lobe, as well as the medullary reticular formation. In the channel catfish, the primary general visceral nucleus projects bilaterally to the secondary visceral nucleus, which lies rostrolateral to the secondary gustatory nucleus in the dorsal pons. Fibers cross the midline via the rostral part of the isthmic commissure. Injection of HRP into the primary general visceral nucleus of a goldfish labels ascending fibers that project to a secondary visceral nucleus situated ventral, lateral, and rostral to the secondary gustatory complex. In general, the results indicate that general visceral systems ascend in parallel to gustatory systems within the brainstem, and that general visceral but not gustatory nuclei are immunoreactive for the peptide CGRP.

Afferent Pathways↗

Recognition of general patterns using neural networks.

The Hopfield model of neural network stores memory in its symmetric synaptic connections and can only learn to recognize sets of nearly "orthogonal" patterns. A new algorithm is put forth to permit the recognition of general ("non-orthogonal") patterns. The algorithm specifies the construction of the new network's memory matrix Tij, which is, in general, asymmetrical and contains the Hopfield neural network (Hopfield 1982) as a special case. We find further that in addition to this new algorithm for general pattern recognition, there exists in fact a large class of Tij memory matrices which permit the recognition of non-orthogonal patterns. The general form of this class of Tij memory matrix is presented, and the projection matrix neural network (Personnaz et al. 1985) is found as a special case of this general form. This general form of memory matrix extends the library of memory matrices which allow a neural network to recognize non-orthogonal patterns. A neural network which followed this general form of memory matrix was modeled on a computer and successfully recognized a set of non-orthogonal patterns. The new network also showed a tolerance for altered and incomplete data. Through this new method, general patterns may be taught to the neural network.

Algorithms↗

What happens to long-term medication when general practice patients are referred to hospital?

OBJECTIVE: The aim of the study was to determine changes in drug treatment of general practitioners' patients on hospital admission and after discharge, and to identify communication problems. METHODS: During 15 months all chronically ill patients of one general practice who were referred to hospital (n = 130) were followed-up prospectively with regard to long-term medication in general practice, drugs recommended in hospital for continuing treatment and medication after discharge from hospital. RESULTS: Before hospital admission the 130 patients were receiving 420 medicines long-term (14% generic drugs). The hospital doctors cancelled 28% (116/420) of the drugs, 6% were replaced by other drugs, 11% by another brand name (identical chemical substance but different producer) and 31 generics were replaced by brand name drugs. Hospitals exhibited specific drug profiles (e.g., total replacement of some generics by brand name drugs; and exclusive administration of a certain preparation regardless of the general practitioner's prescription). After discharge from hospital, the general practitioner continued 329 of the 496 drugs (66.1%) recommended by hospital, 105 (21%) drugs were replaced by other drugs (49 of them by generics) and 62 drugs (13%) were cancelled. The general practitioner received detailed information about drug change in only five of the 130 hospital discharge letters. CONCLUSION: 50% turnover in drug use between general practice and hospital and some of the patterns of drug change in hospital may be unnecessary. They may also complicate the difficult task of the general practitioner of maintaining a patient's drug regimen.

Aged↗

Pharmaceutical care and its relationship to prescribing behaviour of general practitioners.

OBJECTIVE: To study the correlation between pharmaceutical care and prescribing routines of general practitioners (GPs). METHODS: Cross-sectional study; 201 pharmacies, 408 general practices, The Netherlands, 2000/2001. The variation in prescribing behaviour was characterised using 20 validated prescribing indicators based on general practice guidelines. The general construct 'adherence to guidelines' served as the dependent variable and was formed by summing the scores of the prescribing indicators. Four possible determinants of the variation were determined on the basis of survey questions: the construct 'the pharmacist's attitude towards pharmaceutical care', and three partial constructs derived from the pharmacist's care-providing function: the care for the individual patient, the cooperation with general practitioners and the registration of the care provided. A multiple linear regression analysis was then performed. MAIN OUTCOME MEASURE: The weighted score for the prescribing indicators. RESULTS: The weighted average score for the prescribing indicators was 65% (SD 3.7). The response rate to the survey was 71%. The pharmacist's attitude to pharmaceutical care, as well as the degree to which the pharmacist provided care for the individual patient, the degree to which he cooperated with the general practitioner and the degree to which he registered the care provided were not correlated with the 'adherence to guidelines' by the general practitioner with whom the pharmacist frequently cooperated. CONCLUSION: Variations between general practitioners in the quality of prescribing, as measured by their adherence to guidelines, were not correlated with pharmaceutical care by the pharmacist with whom they cooperated on a day-to-day basis.

Drug Prescriptions↗

Idiopathic Generalized Epilepsy.

Successful treatment of idiopathic generalized epilepsy begins with accurate seizure classification. Seizure types, such as absence, myoclonic, and primary generalized tonic-clonic seizures (PGTCS), often can be classified based on a detailed history and inter-ictal electroencephalogram (EEG). Ideally, patients can be classified into specific epilepsy syndromes, such as childhood absence epilepsy, juvenile myoclonic epilepsy (JME), or generalized tonic-clonic seizures on awakening. Idiopathic generalized epilepsy should be distinguished from focal epilepsy with rapid secondary generalization. If this distinction is not clear after history, physical examination, and routine inter-ictal EEG, then ambulatory EEG, video EEG monitoring, or neuroimaging studies may be needed. Ethosuximide, valproate, or lamotrigine are all appropriate first-line choices in the treatment of childhood absence epilepsy. The specific medication should be chosen based on the side effect profiles, dosing formulations, and titration schedules of the medications. The available evidence best supports valproate as the first-line choice in the treatment of JME, although lamotrigine and topiramate may be appropriate choices in this setting. More data specific to JME are needed to clarify the role of medications such as levetiracetam and zonisamide in the treatment of JME. The available evidence to guide the treatment of PGTCS is limited, because most trials did not rigorously exclude patients with focal epilepsy with rapid secondary generalization. Available evidence suggests that valproate is an appropriate first-line choice for PGTCE. Lamotrigine or topiramate also may be appropriate choices. More data are needed to clarify the role of levetiracetam and zonisamide in the treatment of PGCTS. If it is unclear whether a patient has idiopathic generalized epilepsy or focal epilepsy with secondary generalization, then a broad-spectrum anticonvulsant, including valproate, lamotrigine, or topiramate, should be considered. More data are needed to support the broad-spectrum efficacy of levetiracetam and zonisamide.

Journal Article↗

Prevalence of HIV infection and cost of medical follow-up for asymptomatic seropositive patients followed in general practice in France.

To estimate the number of HIV patients followed by general practitioners and the average cost of their medical care, a questionnaire was mailed to 500 general practitioners of the French Communicable Diseases Network (1% sample, representative of French general practitioners). They were asked the number of HIV seropositive patients detected in 1987, the number of HIV positive asymptomatic patients regularly followed, the number of consultations and the type of biological and clinical examinations prescribed. The response rate was 78%. During the past year 29% of practitioners were caring for one or more infected patients. The mean number of HIV seropositive patients known per general practitioner was 1.37 corresponding to an estimated 69,000 +/- 3000 cases, (mean +/- S.D.) for France. The mean number of HIV seropositive patients diagnosed in 1987 was 0.60 per general practitioner (30,000 +/- 2000 cases) and the mean number of HIV seropositive patients followed regularly was 0.89 per general practitioner (45,000 +/- 2500 cases). Two-thirds of HIV seropositive patients were regular patients of general practitioners. The mean number of visits per patient was 3.6 per year. Biological examinations regularly prescribed were blood count, CD4/CD8 ratio, lymphocyte counts, thrombocyte counts, HBs antigen detection and HIV antigen detection. Average costs were 523 +/- 18 FF for the first visit and 446 +/- 36 FF for subsequent examinations. In total, the average cost of general practitioner visits per patient per year have been estimated at 2,288 +/- 251 FF (380 +/- 42 US$).

Attitude of Health Personnel↗

Validity of diagnoses of chronic diseases in general practice. The application of diagnostic criteria.

Certainty of a diagnosis is not only important for the patient but also for morbidity studies. In the absence of a gold standard, agreement with diagnostic criteria is often the best approach in measuring the certainty of a diagnosis. The agreement with diagnostic criteria has been studied for 5 chronic diseases (hypertension, chronic ischemic heart disease, diabetes mellitus, chronic nonspecific lung disease and osteoarthritis) in 7 general practices with a total practice population of 23,534 persons. Agreement with diagnostic criteria is operationalized into 3 categories. For each chronic disease a diagnostic quality measure per general practitioner is computed. Retrospective data have been collected in the practices on 2295 diseases in 1989 patients. Two-thirds of the diagnoses were made in general practice. The agreement with the diagnostic criteria for the cases diagnosed in general practice is high, ranging from 96% true positive cases in diabetes mellitus to 58% in chronic nonspecific lung disease. The highest rate of false positive cases is 4%. On the level of general practitioners diagnostic qualities vary from 62 to 96% true positive cases for the different diseases. The variation in diagnostic quality between general practitioners is substantial. The prevalence rates for the 5 chronic diseases are lower after adjustment by only including true positive cases. Diagnoses of the 5 chronic diseases recorded in general practice are generally valid with low numbers of false positive cases.

Adolescent↗

The effect of local and general fatigue on knee proprioception.

PURPOSE: The purpose of this study was to compare the effects of local and general fatigue loads on knee proprioception. TYPE OF STUDY: Experimental controlled study. METHODS: Proprioception of the knee joint was evaluated by measuring absolute angular error (AAE) at matching defined index angles before and after 2 different types of fatigue protocols (local load and general load) in 27 healthy male volunteers. Local load was provided with maximum isokinetic knee flexion-extension on the isokinetic dynamometer, and general load was 5 minutes running on a treadmill. RESULTS: After local load, a significant decrease in peak torque of knee flexors and extensors was found, but no significant change in AAE was seen. In contrast, after general load, a significant increase of AAE was noted without significant muscle weakness. CONCLUSIONS: The different results in previous studies evaluating the effect of fatigue on knee proprioception may have been affected by the difference of fatigue protocols, whether local or general load. Although local load was intended to produce local fatigue of the knee, which may cause dysfunction of muscle mechanoreceptors, general load may have produced general fatigue and affected other mechanisms in the proprioceptional pathway. The results of the present study suggest that decreased reproduction ability after general load is not due to the loss of peripheral afferent signals, but to other factors, especially deficiency of central processing of proprioceptive signals. CLINICAL RELEVANCE: To prevent knee injury caused by fatigue-induced proprioceptional decline, muscle endurance training alone is not enough, and neuromuscular training, including central motor programming, is essential.

Adult↗

Perceptions of general environmental problems, willingness to expend federal funds on these problems, and concerns regarding the Los Alamos National Laboratory: Hispanics are more concerned than Whites.

Perceptions about general environmental problems, governmental spending for these problems, and major concerns about the US Department of Energy's Los Alamos National Laboratory (LANL) were examined by interviewing 356 people attending a gun show in Albuquerque, New Mexico. The hypothesis that there are differences in these three areas as a function of ethnicity was examined. We predicted that if differences existed, they would exist for all three evaluations (general environmental problems, government spending, and environmental concerns about LANL). However, this was not the case; there were fewer ethnic differences concerning LANL. Hispanics rated most general environmental problems higher than Whites and rated their willingness to expend federal funds higher than Whites, although all groups gave a lower score on willingness than on concern. Further, the congruence between these two types of ratings was higher for Hispanics than for others. In general, the concerns expressed by subjects about LANL showed few ethnic differences, and everyone was most concerned about contamination. These data indicate that Hispanics attending a gun show are equally or more concerned than others about environmental problems generally but are not more concerned about LANL. The data can be useful for developing future research and stewardship plans and for understanding general environmental problems and their relationship to concerns about LANL. More generally, they indicate that the attitudes and perceptions of Hispanics deserve increased study in a general population.

Conservation of Natural Resources↗

Choice of vascular surgery as a specialty: survey of vascular surgery residents, general surgery chief residents, and medical students at hospitals with vascular surgery training programs.

PURPOSE: Under the direction of the Association of Program Directors in Vascular Surgery, a survey was mailed to vascular surgery residents (VSRs), general surgery chief residents (GS-CRs), and fourth-year medical students (MSs) to better define reasons why trainees do and do not choose vascular surgery as a career. METHODS: Questionnaires were mailed to all accredited VSR programs and their associated GS programs in the United States and Canada in 2001 (survey 1) and in 2003 (survey 2) and to 2 medical schools with VSR programs in 2001. A total of 197 VSRs, 169 GS-CRs, and 78 MSs responded (overall program response rate of 78% for VSRs, 46% for GSRs, 20% for MSs). A scoring system was assigned, with 1.0 the least important and 5.0 the most important reasons to choose or not choose vascular surgery. RESULTS: Technical aspects, role of mentors, and complex decision making involved in vascular surgery were the most important reasons that VSRs, GS-CRs, and MSs would choose vascular surgery as a specialty (average scores > or =4.0 for VSRs and GS-CRs; > or =3.5 for MSs). Responses of GS-CRs and VSRs did not vary significantly between surveys 1 and 2, except endovascular capabilities of vascular surgeons had a more important role in choosing vascular surgery, and future loss of patients to other interventionalists had a more important role in not choosing this specialty in the more recent survey of GS-CRs and VSRs. MSs identified lifestyle as a surgical resident (4.3) and as a surgeon (4.2) as the most important negative factors. A training paradigm consisting of 4 years general surgery + 2 years vascular surgery with a GS certificate was favored by 64% of GS-CRs and 48% of VSRs, compared with a paradigm of 5 years + 2 years with a general surgery certificate, which was favored by 29% of GS-CRs and 25% of VSRs, or 3 years + 3 years without a general surgery certificate, favored by 7% of GS-CRs and 27% of VSRs. Of note, 86% of MSs favored 3 years general surgery + 3 years vascular surgery or 2 years general surgery + 4 years vascular surgery compared with longer general surgery training periods. CONCLUSION: These findings may help vascular surgery program directors devise strategies to attract future trainees. The importance of mentorship to general surgery junior residents and medical students in choosing vascular surgery cannot be overestimated. Endovascular capabilities of vascular surgeons have an increasingly positive role in career choice by GS-CRs and VSRs, but these residents express increasing concerns about potential loss of patients to other specialists. Lifestyle concerns are the most important reasons why medical students do not choose vascular surgery as a career.

Adult↗

Generalization of clozapine as compared to other antipsychotic agents to a discriminative stimulus elicited by the serotonin (5-HT)2A antagonist, MDL100,907.

Employing a two-lever, food-reinforced FR10 procedure, rats were trained to recognize a discriminative stimulus (DS) elicited by the 5-HT(2A) receptor antagonist and potential antipsychotic agent, MDL100,907 (0.16 mg/kg, i.p.). In generalization tests, by analogy to MDL100,907 itself (Effective Dose(50) (ED(50)), 0.002 mg/kg, s.c.), the 'atypical' antipsychotic, clozapine, which displays high affinity for 5-HT(2A) as compared to D(2) receptors, dose-dependently and fully generalized to MDL100,907 (ED(50), 0.2 mg/kg, s.c.). S16924 (0.05 mg/kg, s.c.), S18327 (0.09 mg/kg, s.c.), quetiapine (1.8 mg/kg, s.c.), risperidone (0.02 mg/kg, s.c.) and ziprasidone (0.01 mg/kg, s.c.), antipsychotics which possess-like clozapine-marked affinity for 5-HT(2A) versus D(2) receptors, also generalized to MDL100,907. In distinction, raclopride, an antipsychotic which selectively interacts with D(2) versus 5-HT(2A) receptors, did not display significant generalization. Interestingly, haloperidol, which shows only modest affinity for 5-HT(2A) versus D(2) sites, generalized to MDL100,907 (ED(50), 0.02 mg/kg, s.c.). In light of the antagonist properties of haloperidol, clozapine and all other antipsychotics tested (except raclopride) at alpha(1)-adrenoceptors (ARs), the selective alpha(1)-AR antagonists, prazosin and WB4101, were examined. Both dose-dependently and fully generalized to MDL100,907 (ED(50)s, 0.07 and 0.11 mg/kg, s.c., respectively). At doses showing pronounced generalization to MDL100,907, the only drugs which significantly suppressed response rates were haloperidol and, weakly, quetiapine. Raclopride also markedly decreased response rates. In conclusion, the antipsychotic agents, clozapine, ziprasidone, risperidone, S16924, S18327, quetiapine and haloperidol, all generalized to a DS elicited by MDL100,907. While D(2) receptors are not implicated in their actions, in addition to antagonist properties at 5-HT(2A) receptors, blockade of alpha(1)-ARs and other, as yet unidentified, mechanisms may be involved. These data underpin interest in MDL100,907 as a potential antipsychotic agent.

Animals↗

Alcohol high risk drinking, abuse and dependence among tobacco smoking medical care patients and the general population.

BACKGROUND: Little is known about the synergies of smoking and alcohol consumption in medical care patients. The objective, therefore, is to estimate the coincidence of hazardous and harmful alcohol consumption as well as alcohol abuse and dependence with tobacco smoking in a general hospital and general practices. METHODS: Three samples of 18-64 year olds include 510 consecutively admitted currently smoking in-patients of a general hospital, 271 patients of a randomized sample of general practices, and 1567 current smokers from a regional population in Germany. Data include the number of cigarettes and a diagnosis of alcohol dependence and abuse (DSM), harmful or hazardous alcohol use. RESULTS: The rates of current daily cigarette smokers with an alcohol dependence or abuse, harmful or hazardous alcohol consumption are 47.1% in the general hospital and 32.1% in the general practice sample compared with 18.4% in the general population. The rates increase from nonsmokers to smokers and with the number of cigarettes. CONCLUSIONS: The findings fit into the evidence about alcohol and tobacco interactions in morbidity and mortality. General medical care settings are appropriate for the detection of alcohol dependence or abuse via smoking.

Adolescent↗

Predictors of general surgical complications after heart transplantation.

BACKGROUND: Several studies have reported the incidence, morbidity, and mortality of general surgical conditions (GSCs) in orthotopic heart transplant (OHT) patients. The following is the largest reported series of such patients and the first study with sufficient patient numbers to formally evaluate peritransplant variables as risk factors for GSC development. STUDY DESIGN: A GSC was defined as a condition for which a general surgeon had been consulted or as a general surgical condition recognized at the time of autopsy. The records of 453 consecutive patients who underwent OHT between 1981 and 1999 were reviewed to identify patients who developed a GSC. Kaplan-Meier actuarial analysis on this cohort, and univariate and multivariate logistic regression models applied to a subpopulation of 324 consecutive OHT patients between 1987 and 1997 were used to determine factors associated with and predictive of GSC after OHT. RESULTS: Of 453 OHT patients, 371 (81.9%) were men, and the average age was 44.5 +/- 15 (standard deviation) years. Median followup was 2,086 days (range 1 to 6,642 days). Ninety-three patients (20.5%) developed 111 GSCs. Of these, 78 were men, and the average age was 49.9+/-10.2 years. There were 83 general surgical interventions. Actuarial analyses revealed that age greater than 50 years, pretransplant diagnosis of ischemic (PTDxI) versus nonischemic heart disease, and previous general surgical history were factors associated (p < 0.05) with a higher GSC incidence. Gender, more urgent transplant priority status, cardiopulmonary bypass time, total graft ischemic time, and intensive care unit length of stay were not associated with GSC. Factors associated with GSC on univariate analysis, with odds ratios (ORs) and 95% confidence intervals (CIs) included: age analyzed as a continuous variable (OR 1.04 per year; CI 1.01, 1.06 per year; p = 0.0021), PTDxI (OR 2.40; CI 1.39, 4.15; p = 0.0016), and pretransplant general surgical history (OR 3.35; CI 1.65, 6.82; p = 0.0008). Multivariate analysis revealed that only pretransplant general surgical history (OR 3.27; CI 1.58, 6.76; p = 0.0004) and PTDxI (OR 2.37; CI 1.35, 4.16; p = 0.0023) were associated with subsequent development of GSC. CONCLUSIONS: A pretransplant diagnosis of ischemic heart disease and previous history of a general surgical procedure are two independent risk factors that predispose OHT patients to development of GSC. Because GSC may arise insidiously in immunosuppressed patients, identification of OHT patients at higher risk for GSC will permit timely intervention decisions, decreasing morbidity and mortality in this challenging group of patients.

Adult↗

General practice nursing education in Australia.

The quality of care delivered by nurses working in Australian general practices rests on a strong foundation of nursing educatlon and training. A national study of nurses working in general practice was conducted using qualitative and quantitative research techniques to explore their role and educational needs. Results from this research suggest that education for general practice nurses is seen by nurses and General Practitioners to be largely non-formal in nature and is seen by GPs and nurses to be tailored towards general practice nursing needs. Such education is often available locally through general practice support organisations; is strongly focused on National Health Priority Areas and clinical care; and is more appropriate for registered rather than enrolled nurses. The educational opportunities currently available to support nursing in general practice are largely ad hoc and vary in relation to quality, appropriateness and accessibility. Nurses working in general practices in Australia need a system of ongoing training and education to support their responsibilities and foster the development of the position as a viable career option for nurses.

Accreditation↗

Bulimia comorbidity in the general population and in the clinic.

This study compares rates of comorbidity of lifetime psychiatric disorder in a clinical sample of women with bulimia, with general population base rates, and with rates of comorbidity among bulimic women in the general population. Eighty-four per cent of the clinical sample of bulimic women had a lifetime affective disorder, and 44% a lifetime alcohol or drug disorder. These rates of disorder were significantly higher than the base rates in the general population. Bulimic women in the general population also had more affective and substance-use disorders than the general population base rates, but the rates of these disorders were lower than found in the clinical sample. In the general population, quite similar rates of other disorders including generalized anxiety, panic, phobia and obsessive-compulsive disorder, are found among those with bulimia, substance-use disorder and depression. Furthermore, among those with depression and substance-use disorder in the general population, rates of eating disorder are comparable. Rather than suggesting a specific relationship between bulimia and either depression or substance-use disorder, the data from this study suggest that the presence of any disorder is associated with a non-specific increase in the likelihood of other psychiatric disorder.

Adolescent↗

Null sex differences in general intelligence: evidence from the WAIS-III.

There is an increasing number of studies claiming that the sex differences in general intelligence are "real." The empirical evidence is based on the summation of the standardized sex differences in several cognitive batteries. However, the scientific construct of general ability rests on the correlations among test scores, rather than on their summation. The latter (ability in general) is an arbitrary variable, not a scientific construct. General ability is not a function of any particular cognitive test, but a source of variance evidenced by the correlation between several diverse tests, each of which reflects general ability (g) to some extent, but also group factors and test specificity. Because there are important educational, economic, and social consequences of a group difference in general ability, it is especially germane to evaluate the possibility of an average sex difference in its proxy measures, such as IQ. The Spanish standardization of the WAIS-III is analyzed in the present study. The sample was made up of 703 females and 666 males, aged 15-94, drawn as a representative sample of the population in terms of educational level and geographical location. Although a male advantage of 3.6 IQ points is observed, the difference is in "ability in general," not in "general ability" (g). Given that the main ingredient of the strong association between IQ and a broad range of social correlates is g, and given that there is no sex difference in g, then the average IQ sex-difference favoring males must be attributed to specific group factors and test specificity.

Adult↗

Mechanistic considerations for general acid-base catalysis by RNA: revisiting the mechanism of the hairpin ribozyme.

Several small ribozymes carry out self-cleavage at a specific phosphodiester bond to yield 2',3'-cyclic phosphate and 5'-hydroxyl termini. Prior mechanistic and structural studies on the HDV ribozymes led to the proposal that the pK(a) of C75 is shifted toward neutrality, making it an effective general acid. Recent mechanistic studies on the hairpin ribozyme have led to models in which protonation of G8 is required for phosphodiester cleavage, either for general acid catalysis or for electrostatic stabilization. Inspection of recent crystal structures of the hairpin ribozyme, including a complex with a vanadate transition state mimic, suggests an alternative model involving general acid-base catalysis with G8 serving as the general base and A38 as the general acid. This model is consistent with the literature on the hairpin ribozyme, including pH-rate profiles of wild-type and mutant ribozymes and solvent isotope effects. General mechanistic considerations for RNA catalysis suggest that the penalty for having general acids and bases with pK(a)s removed from neutrality is not as severe as expected. These considerations suggest that general acid-base catalysis may be a common mechanistic strategy of RNA enzymes.

Animals↗