Seeing the wood through the trees: the current state of higher systematics in the Strepsirhini.

Strepsirhines comprise 10 living or recently extinct families, ≥50% of extant primate families. Their phylogenetic relationships have been intensively studied, but common topologies have only recently emerged; e.g. all recent reconstructions link the Lepilemuridae and Cheirogaleidae. The position of the indriids, however, remains uncertain, and molecular studies have placed them as the sister to every clade except Daubentonia, the preferred sister group of morphologists. The node subtending Afro-Asian lorisids has been similarly elusive. We probed these phylogenetic inconsistencies using a test data set including 20 strepsirhine taxa and 2 outgroups represented by 3,543 mtDNA base pairs, and 43 selected morphological characters, subjecting the data to maximum parsimony, maximum likelihood and Bayesian inference analyses, and reconstructing topology and node ages jointly from the molecular data using relaxed molecular clock analyses. Our permutations yielded compatible but not identical evolutionary histories, and currently popular techniques seem unable to deal adequately with morphological data. We investigated the influence of morphological characters on tree topologies, and examined the effect of taxon sampling in two experiments: (1) we removed the molecular data only for 5 endangered Malagasy taxa to simulate 'extinction leaving a fossil record'; (2) we removed both the sequence and morphological data for these taxa. Topologies were affected more by the inclusion of morphological data only, indicating that palaeontological studies that involve inserting a partial morphological data set into a combined data matrix of extant species should be interpreted with caution. The gap of approximately 10 million years between the daubentoniid divergence and those of the other Malagasy families deserves more study. The apparently contemporaneous divergence of African and non-daubentoniid Malagasy families 40-30 million years ago may be related to regional plume-induced uplift followed by a global period of cooling and drying.

Children's consensual knowledge about the experiential determinants of emotion.

Kindergarten, third-, and sixth-grade children were given vignettes describing experiences that were likely to produce emotional states, and their consensus about the probable affective reaction was determined. A sample of eight social and personal (private) experiences was utilized in the vignettes: success, failure, dishonesty (caught or not caught), experiencing nurturance or aggression, and experiencing justified or unjustified punishment. The potential affective reactions that children were asked to choose among included happiness, sadness, anger, fear, and neutral affect. There were no sex differences. Children of all ages agreed that relatively simple experiences such as success and nurturance would elicit a happy reaction. For other categories of experience, multiple consensuses appeared for more than one affective reaction. There were developmental differences in the affective reactions anticipated to five of the eight experience categories. Results are discussed in terms of cognitive and social learning determinants of knowledge about the experimental antecedents of emotion for oneself and others.

Factors governing the effective remediation of negative affect and its cognitive and behavioral consequences.

The present experiment tested the hypothesis that the remediation of negative emotion will be most effective when the remedial procedure matches the experience or cognition that induced the negative state--process-specificity hypothesis. Other hypotheses examined were that negative states induced by cognitive reflection related to the self would be resistant to remediation, even by a same-process positive procedure, and that changes in emotional expressions may make it appear that a negative state has been effectively remediated when lingering effects on behavior and cognition indicate that it has not. Negative emotional states were induced in second-grade children by one of four processes, all of which involved social rejection content: cognition that focused on (a) the self (thinking about oneself being rejected by a peer) or (b) another person (thinking about a peer being rejected); or experience that related to (c) oneself (actually being socially rejected) or (d) observing another (vicarious: seeing a peer be socially rejected). These inductions were then followed by a positive, remedial induction whose content was the reverse (social acceptance) and whose process did or did not match that of the negative induction. As predicted, except for negative self-cognitions, it was found that the behavioral (altruism) and cognitive (performance on a block design task) consequences of negative emotion were alleviated when the positive remediation was of the same type as the original induction. Emotional expressions were consistently positive following remediation, regardless of their type. The results are discussed in terms of differing processes for maintaining negative emotion as a function of the character of induction, and the implications for the understanding of clinical depression in children are noted.

Highly repeated DNA sequences as phylogenetic markers among the galaginae.

Highly repeated DNA sequences were investigated as potential phylogenetic indicators among five species of galagines. One lorisine, one cheirogaleid, and two lemurid species were also investigated as progressively more distant outgroups. The lorisids displayed strong conservatism with regard to these sequences, to the point where the galegine species proved difficult to differentiate. When restriction fragment differences were observed, the galagine species fell into two groups: one containing the greater galagos and G. alleni and the other comprising the lesser galagos. The sequences of the cheirogaleid Microcebus murinus were found to be highly species-specific, bearing little resemblance to those of the galagines or the lemurids. Common sequences detected between M. murinus and G. senegalensis may be ancient sequences shared by all strepsirhines. © 1994 Wiley-Liss, Inc.

Assessment of multiple-choice questions in selected test banks accompanying text books used in nursing education.

The purpose of this study was to assess multiple-choice questions used in test-banks accompanying selected nursing textbooks. A random sample of 2,913 questions was selected from a convenience sample of 17 test banks. Questions were evaluated on (a) adherence to generally accepted guidelines for writing multiple-choice questions; (b) cognitive level as defined by Bloom's (1961) taxonomy; and (c) distribution of correct answers as A, B, C, or D. The results were 2,233 violations of item-writing guidelines, most of which were minor but some were serious. A large number of questions (47.3%) were written at the knowledge level and only 6.5% were written at the analysis level. The correct answers were evenly distributed: c2s ranged from 0.00 to 4.84; chi square value needed to reach .05 probability was 26.30. Faculty are encouraged to evaluate multiple-choice questions from test banks carefully before using them for exams.

Normal pressure hydrocephalus. A potentially reversible form of dementia.

1. Normal pressure hydrocephalus (NPH) is a rare but potentially treatable form of dementia. Shunting will improve functioning in 40% to 50% of patients. 2. The classic symptoms of NPH are dementia characterized by mild memory impairment and apathy, ataxic gait, and urinary hesitancy or incontinence. 3. The patient with NPH may present with psychiatric symptoms of depression, paranoia, visual hallucinations, irrational hostility, and aggression or mania. 4. Patients with NPH are indifferent about activities of daily living and personal safety and require close supervision.

Taking phylogenetics beyond pattern analysis: can models of genome dynamics guide predictions about homoplasy in morphological and behavioral data sets?

Despite the considerable amount of interest in phylogeny reconstruction, patterns of homoplasy in morphological and behavioral data have received only limited attention to date, whereas the patterns of homoplasy in molecular data are relatively well understood. First, because the number of alternative molecular character states is strictly limited (particularly for nucleotide sequence data), higher rates of substitution generate higher levels of homoplasy. Second, depending on the relative proportions of constrained and unconstrained sites, each molecular data set has a time frame of applicability outside of which resolution becomes ambiguous. There is good evidence to suggest that numbers of alternative character states for morphological and even behavioral data may be similarly limited and that higher rates of evolution are often linked to higher rates of homoplasy. Like molecular data sets, morphological and behavioral data sets contain rapidly evolving characters as well as more conservative elements. Morphologies and behaviors related to sexual recognition and reproduction show low levels of intraspecific variation, but high levels of lability between species, making them crucial for species identification but often poor as markers of relationship at greater time depths. The organization theory of speciation derived by Carson is a model based on genome dynamics, and it predicts exactly this window of applicability for characters related to sexual reproduction. Nonsexual characters related to environmental adaptation should be applicable at greater phylogenetic depths. A better understanding of patterns of homoplasy enables a more sophisticated approach to the assessment of the relative reliabilities of alternative tree topologies.

Reconciling the origins of Africa, India and Madagascar with vertebrate dispersal scenarios.

Africa, India and Madagascar were once part of the supercontinent of Gondwana. This land mass began to fragment approx. 170 million years ago, and by 83 million years, all of the major components we recognize today were separated by tracts of water. Madagascar's fossil record and estimates of the timing of the extant vertebrate radiations in Madagascar are not easily reconciled with this history of fragmentation. Fossil faunas that lived prior to approx. 65 million years had a cosmopolitan flavour, but this was lost after the Cretaceous-Tertiary boundary. Phylogenetic reconstructions of most extant Malagasy vertebrate radiations indicate divergence times that postdate the End-Cretaceous (lemurs, tenrecs, cichlid fish) and even the Early Miocene (chameleons, carnivores, rodents). Most biogeographic explanations of these groups rely, therefore, on Simpson's model of sweepstakes dispersal (see also cover figure), but there are significant problems in applying the model to migrations from Africa to Madagascar, although its application is not so intractable between India and Madagascar. Alternative migration routes for consideration lie: (1) along the suite of fracture zones between Antarctica and Africa/Madagascar (known as the Antarctic-Africa Corridor), which may have been exposed episodically above sea level; (2) along a series of submerged basaltic ridges/plateaus with known or suspected continental crust between Antarctica and Africa/Madagascar/India flanking the Antarctic-Africa Corridor (e.g. the Madagascar Ridge, Mozambique Ridge, Conrad Plateau, Gunnerus Ridge); (3) between Africa and Madagascar along the Davie Ridge (parts of which are known to have been exposed episodically above sea level); (4) along the Deccan hotspot corridor between India and greater Africa.

Reconstructing the evolutionary history of the Lorisidae using morphological, molecular, and geological data.

Major aspects of lorisid phylogeny and systematics remain unresolved, despite several studies (involving morphology, histology, karyology, immunology, and DNA sequencing) aimed at elucidating them. Our study is the first to investigate the evolution of this enigmatic group using molecular and morphological data for all four well-established genera: Arctocebus, Loris, Nycticebus, and Perodicticus. Data sets consisting of 386 bp of 12S rRNA, 535 bp of 16S rRNA, and 36 craniodental characters were analyzed separately and in combination, using maximum parsimony and maximum likelihood. Outgroups, consisting of two galagid taxa (Otolemur and Galagoides) and a lemuroid (Microcebus), were also varied. The morphological data set yielded a paraphyletic lorisid clade with the robust Nycticebus and Perodicticus grouped as sister taxa, and the galagids allied with Arctocebus. All molecular analyses maximum parsimony (MP) or maximum likelihood (ML) which included Microcebus as an outgroup rendered a paraphyletic lorisid clade, with one exception: the 12S + 16S data set analyzed with ML. The position of the galagids in these paraphyletic topologies was inconsistent, however, and bootstrap values were low. Exclusion of Microcebus generated a monophyletic Lorisidae with Asian and African subclades; bootstrap values for all three clades in the total evidence tree were over 90%. We estimated mean genetic distances for lemuroids vs. lorisoids, lorisids vs. galagids, and Asian vs. African lorisids as a guide to relative divergence times. We present information regarding a temporary land bridge that linked the two now widely separated regions inhabited by lorisids that may explain their distribution. Finally, we make taxonomic recommendations based on our results.

Speciation in the lesser galagos.

Species and their origins remain one of the outstanding enigmas of evolutionary biology. Many different views of the problem exist, but few have concrete predictions that open the problem to investigation. This study formalises predictions arising from the Recognition Concept of species (RC) and the Organization Theory of Speciation (OTS), and applies them to the pattern demonstrated by the lesser galago radiation. The RC and OTS are in agreement that one of the primary adaptive responses during animal speciation events involves the system of sexual recognition and reproduction, and indeed the lesser galago taxa show significant divergences in their communication systems relating to specific-mate recognition. On the other hand, only the RC predicts a concomitant adaptive response to the ecological conditions prevailing during speciation, and there are strong indications of shifts in habitat preference among these taxa. The predictions of the RC are supported above those of the OTS.

When lithium does not help: the use of anticonvulsants and calcium channel blockers in the treatment of bipolar disorder in the older person.

Although anticonvulsant agents and calcium channel blockers do not have any clear advantages over lithium, they do offer patients who cannot (or will not) take lithium another treatment option. It is not yet clear from the literature who will respond best to which drug or combination of drugs. The nurse should be supportive to the patients and family, in what may be a drawn out process, to find the best treatment. Optimism is justified because a lack of response to one drug is not indicative of nonresponse to other drugs. It is important to actively treat bipolar disorder because each episode of mania increases the risk of progression of the illness, with increasingly severe episodes occurring closer together. Bipolar disorder has high social costs (legal, financial, and relationship problems) that make improvements in treatment important for the patient and society. Anticonvulsant agents and calcium channel blockers may also be useful in treating depression. The number of people whose depressive symptoms respond is far less (25% to 30%) than the number who respond to the anti-manic effects, but this is an option when antidepressants and electroconvulsive therapy are not effective.