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M Matthews

Publications and source records attributed to M Matthews.

At least 37 records · Page 2Linked to original sources
PubMed1997

Phylogenetic utility of elongation factor-1 alpha in noctuoidea (Insecta: Lepidoptera): the limits of synonymous substitution.

To test its phylogenetic utility, nucleotide sequence variation in a 1,240-bp fragment of the elongation factor-1 alpha (EF-1 alpha) gene was examined in 49 moth species representing the major groups of the superfamily Noctuoidea. Both parsimony and distance analyses supported the monophyly of nearly all groups for which there are clear morphological synapomorphies. Clades of subfamily rank and lower, probably mid-Tertiary and younger, were strongly supported. The third codon position contains 88% of variable sites, and approaches saturation at approximately 20% sequence divergence, possibly due to among-site rate heterogeneity and composition bias; higher divergences occur only in association with shifts in composition. Surprisingly, the few nonsynonymous changes appear no more phylogenetically reliable than synonymous changes. Signal strength for basal divergences is weak and fails to improve with character weighting; thus, dense taxon sampling is probably needed for strong inference from EF-1 alpha regarding deeper splits in Noctuoidea (probably early Tertiary). EF-1 alpha synonymous changes show promise for phylogeny reconstruction within Noctuidae and other groups of Tertiary age.

Animals↗
PubMed1997

A new nuclear gene for insect phylogenetics: dopa decarboxylase is informative of relationships within Heliothinae (Lepidoptera: Noctuidae).

The lack of a readily accessible roster of nuclear genes informative at various taxonomic levels is a bottleneck for molecular systematics. In this report, we describe the first phylogenetic application of the sequence that encodes the enzyme dopa decarboxylase (DDC). For 14 test species within the noctuid moth subfamily Heliothinae that represent the previously best-supported groupings, a 690-bp fragment of DDC resolved relationships that are largely concordant with prior evidence from elongation factor-1 alpha (EF-1 alpha), morphology, and allozymes. Although both synonymous and nonsynonymous changes occur in DDC substantially more rapidly than they do in EF-1 alpha, DDC divergences within Heliothinae are below saturation at all codon positions. Analysis of DDC and EF-1 alpha in combination resulted in increased bootstrap support for several groupings. As a first estimate of previously unresolved relationships, DDC sequences were analyzed from 16 additional heliothines, for a total of 30 heliothine species plus outgroups. Previous relationships based on DDC were generally stable with increased taxon sampling, although a two- to eightfold downweighting of codon position 3 was required for complete concordance with the 14-species result. The weighted strict consensus trees were largely resolved and were congruent with most although not all previous hypotheses based on either morphology or EF-1 alpha. The proposed phylogeny suggests that the major agricultural pest heliothines belong to a single clade, characterized by polyphagy and associated life history traits, within this largely host-specific moth subfamily. DDC holds much promise for phylogenetic analysis of Tertiary-age animal groups.

Animals↗
PubMed1996

The ethic of care: stability over time, gender differences, and correlates in mid- to late adulthood.

This article examines the development of Gilligan's care ethic and its correlates in mature adults. Two studies showed that women scored significantly higher on the Ethic of Care Interview (ECI) than did men. More women than men generated interpersonal real-life dilemmas, and more men than women generated impersonal ones. In Study 2, longitudinal data indicated that care levels were moderately stable in mid- to late adulthood. The ECI was negatively related to authoritarianism and positively related to justice levels, role taking, and cognitive complexity. People scoring higher in care also felt more positively about their physical health and experience of aging. These results support the construct validity of the ECI and point to its potential role in adults' personal adaptation.

Age Factors↗
PubMed1996

"Is it cancer"?

Explore the source record for details and available documents.

Adult↗
PubMed1995

MEGX (monoethylglycinexylidide): a novel in vivo test to measure early hepatic dysfunction after hypovolemic shock.

A quantitative liver test based on the formation of the lidocaine metabolite monoethylglycinexylidide (MEGX), was used to evaluate the effect of hemorrhagic shock at 40 mmHg for 90 min on Sprague-Dawley rats. After 2 h of stabilization, lidocaine was injected (2 mg/kg). A second group received volume resuscitation with Ringer's lactate over 1 h (15 mL/kg) after shock, and after 1 h of stabilization lidocaine was administered. These groups were compared to control animals. Blood samples were drawn at 0 time (baseline), prior to lidocaine injection, and at 10, 15, 30, and 60 min after lidocaine injection. MEGX values in shocked animals were significantly lower than in the control group; in animals receiving volume resuscitation, levels were higher than the shocked animals without resuscitation, but did not reach control levels. Thus, shock produced a significant depression of hepatocyte function, which was partially reversed by Ringer's lactate resuscitation. The MEGX test appears to be a suitable tool for clinical evaluation and therapeutic intervention after shock.

Animals↗
PubMed1995

Fetal telemedicine: interactive transfer of realtime ultrasound and video via ISDN for remote consultation.

Current referral practice for ultrasonically detected fetal abnormalities contributes to parental anxiety, inconvenience to patients, diagnostic inaccuracy, and general service inefficiency. To determine whether telemedicine would reduce these disadvantages, we established a 30-channel ISDN link between a district general hospital on an island and a subspecialty referral centre approximately 120 km away on mainland Britain. Live ultrasound images of the fetus were transmitted in realtime from a commercial scanner in the hospital using a total data transfer rate of 2 Mbit/s. After decompression at the receiving end, there was almost no perceptible loss of picture quality or frame rate. This report describes the technical aspects of the link and our preliminary experience with it. In the first two months of its operation, the link worked well and the consultants who used it found themselves confidently making diagnoses and carrying out counselling over it. If confirmed, the success of this technology has implications for future referral practice in fetal medicine.

Artifacts↗