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Biomedical subjects

D R Owen

Publications and source records attributed to D R Owen.

At least 19 recordsLinked to original sources
PubMed2007

Response to host volatiles by native and introduced populations of Dendroctonus valens (Coleoptera: Curculionidae, Scolytinae) in North America and China.

Bark beetles (Coleoptera: Curculionidae, Scolytinae) have specialized feeding habits, and commonly colonize only one or a few closely related host genera in their geographical ranges. The red turpentine beetle, Dendroctonus valens LeConte, has a broad geographic distribution in North America and exploits volatile cues from a wide variety of pines in selecting hosts. Semiochemicals have been investigated for D. valens in North America and in its introduced range in China, yielding apparent regional differences in response to various host volatiles. Testing volatiles as attractants for D. valens in its native and introduced ranges provides an opportunity to determine whether geographic separation promotes local adaptation to host compounds and to explore potential behavioral divergence in native and introduced regions. Furthermore, understanding the chemical ecology of host selection facilitates development of semiochemicals for monitoring and controlling bark beetles, especially during the process of expansion into new geographic ranges. We investigated the responses of D. valens to various monoterpenes across a wide range of sites across North America and one site in China, and used the resulting information to develop an optimal lure for monitoring populations of D. valens throughout its Holarctic range. Semiochemicals were selected based on previous work with D. valens: (R)-(+)-alpha-pinene, (S)-(-)-alpha-pinene, (S)-(-)-beta-pinene, (S)-(+)-3-carene, a commercially available lure [1:1:1 ratio of (R)-(+)-alpha-pinene:(S)-(-)-beta-pinene:(S)-(+)-3-carene], and a blank control. At the release rates used, (+)-3-carene was the most attractive monoterpene tested throughout the native range in North America and introduced range in China, confirming results from Chinese studies. In addition to reporting a more effective lure for D. valens, we present a straightforward statistical procedure for analysis of insect trap count data yielding cells with zero counts, an outcome that is common but makes the estimation of the variance with a Generalized Linear Model unreliable because of the variability/mean count dependency.

Animals↗
PubMed2001

Spirocyclic restriction of nucleosides. An analysis of protecting group feasibility while accessing prototype anti-1-oxaspiro[4.4]nonanyl mimics.

[reaction: see text] The first spirocyclic nucleoside featuring a beta-hydroxyl (anti) at C5' has yielded to synthesis. While the OMOM functionality proved to be sensitive to the conditions necessary to incorporate heterocyclic bases, PMB protection of the carbinol was readily accommodated. The remarkably similar minimum-energy conformations of the title compounds relative to natural thymidine as deduced by Amber calculations in the gas phase are noted.

DNA↗
PubMed2001

1-Oxaspiro[4.4]nonan-6-ones. Synthetic access via oxonium ion technology, optical resolution, and conversion into enantiopure spirocyclic alpha,beta-butenolides.

A general approach to the synthesis of enantiomerically pure spirocyclic alpha,beta-butenolides is presented where the fundamental framework is rapidly elaborated by acid- or bromonium ion-induced rearrangement of the carbinol derived by addition of 2-lithio-4,5-dihydrofuran to cyclobutanone. Subsequent resolution of the resulting ketones by either sulfoximine or mandelate acetal technology has been applied effectively. The availability of these building blocks makes possible in turn the acquisition of the enantiomers of dihydrofurans typified by 17, 35, and 38 and lactones such as 25 and 31, as well as the targeted title compounds. Complementary reductions of the early intermediates provide the added advantage that the alpha- and beta-stereoisomeric carbinol series can be obtained on demand. These capabilities have been coordinated to allow the crafting of any member of the series in relatively few steps.

Journal Article↗
PubMed2001

Cognitive abilities in left-handers: writing posture revisited.

Among 1848 young men appearing before the Danish draft board, 232 (13%) were left-handed. Of these, 118 (51%) used an inverted, or hook-like, writing posture, 49 (21%) used a non-inverted posture and the remaining 65 (28%) could not be categorized. There were no differences between left- and right-handers on a battery of four cognitive tests. However, inverted left-handers performed significantly or near-significantly better than the non-inverted left-handers on two of the four tests and significantly better on the total score for the test battery. These results support the contention that the inverted posture is adaptive for left-handers and suggest that it may be more likely to be adopted by those with better cognitive abilities. Our findings conflict with earlier reports from two decades ago, however, and the association may therefore be socially and culturally dependent.

Adolescent↗
PubMed1999

Adjusted and unadjusted energy usage rates both determine body fat and plasma leptin in male Fischer 344 rats.

Previous studies of the relationship between plasma leptin and energy usage have yielded contradictory findings. The present study was therefore conducted to clearly distinguish and measure the energy usage rate and the energy usage rate adjusted for a surrogate of metabolically active tissue mass. We investigated the simultaneous relationships between these two measures of energy usage, leptin, and body fat in 21-month-old adult male Fischer 344 rats on three different long-term dietary regimens: (1) continuous ad libitum feeding (Ad-lib); (2) ad libitum feeding until early adulthood, and then continuous 60% caloric restriction (CR); and (3) ad libitum feeding until early adulthood, then 60% caloric restriction until 16 months, and then ad libitum feeding for 5 months (CR/Ad-lib). Two versions of the daily usage rate were measured: daily dietary caloric intake (DCI), and daily energy expenditure (EE) based on indirect calorimetry. Two versions of the metabolically active tissue mass were also measured: fat-free mass (FFM), and the sum of the weight of the heart, brain, liver, and kidneys. Energy usage rates were adjusted for these measures of metabolically active tissue mass to yield measures of the energy metabolic rate. Correlation, regression, and path analyses showed that both the energy usage rate and adjusted energy usage rate played important independent roles in determining body fat and plasma leptin, but only after multivariate techniques were used to account for the simultaneous interactions between variables. Increases in the energy usage rate were associated with increases in body fat and the adjusted energy usage rate. Increases in the adjusted energy usage rate were associated with decreases in body fat and plasma leptin. These findings suggest that differences in subjects adjusted energy usage rate could explain some of the apparently contradictory findings concerning the relationship between energy usage and plasma leptin in previously published studies. In conclusion, this appears to be the first study to clearly separate and quantify the effects of the energy usage rate and adjusted energy usage rate on body fat and plasma leptin. The findings suggest that under conditions of long-term stable body weight, both of these measures of energy usage play independent simultaneous roles in determining body fat and plasma leptin.

Adipose Tissue↗
PubMed1998

Relation of low and moderate intensity exercise with acute mood change in college joggers.

This study investigated a possible relationship between exercise intensity and mood alteration that commonly is associated with physical activity. 91 college students completed the Profile of Mood States before and after 20 min. of jogging at three intensities: 55%, 75%, and 79% of age-adjusted maximum heart rate on different occasions. Exercisers also completed a demographic inventory, a Lie Scale, and the State-Trait Anxiety Inventory. Contrary to our expectations, the interaction between exercise intensity and pre-post mood benefits was not significant. Supporting the manipulation of exercise intensity, the univariate interaction between exercise intensity and pre-post exercise scores on Fatigue was significant. Joggers reported short-term mood benefits on the combined subscales of the Profile of Mood States, and each subscale contributed to the benefits. Thus, regardless of the low- or moderate-intensity, participants reported that they "felt better" after exercising.

Adult↗
PubMed1996

Dot Enumeration Perceptual Organization Task (DEPOT): evidence for a short-term visual memory deficit in schizophrenia.

The Dot Enumeration Perceptual Organization Task (DEPOT) evaluates the validity of 2 specific competing cognitive models of early input dysfunction in schizophrenic individuals: a primary Stage 1, sensory store, perceptual organization deficit vs. a Stage 2, short-term visual memory (STVM) deficit. DEPOT was also designed to assess the hypothesis that schizophrenic individuals tend to perform poorly on all cognitive tasks. In DEPOT both number and form judgments are made about the same dot patterns. A response delay manipulation assesses the persistence and operation of STVM. The study included 41 psychotic inpatients (8 with acute and 16 with chronic schizophrenia and 7 with bipolar and 10 with nonbipolar affective disorder) and 38 controls (22 college students and 16 hospital personnel). Although the pattern of results was consistent with neither the Stage 1 deficit nor the general deficit hypotheses, a Stage 2, STVM deficit hypothesis could account parsimoniously for the data.

Adult↗
PubMed1994

Thirty-year secular trends in the cognitive abilities of Danish male school-leavers at a high educational level.

A nationally representative sample of Danish males finishing school in 1989, or shortly before, with a studentereksamen (the highest qualification in the Danish school system) was found to score generally lower on a battery of four cognitive tests than a comparable sample of Danish males who had taken the same tests shortly after finishing school in the late 1950s or early 1960s. This decline appears attributable to the increasing proportions of students who obtain the studentereksamen and is quite compatible with an overall increase in test scores, also found in our data, for the general population over the same time period. For those who obtain the studentereksamen, the decline has been most marked in a test of verbal analogies. It has been smaller for tests of logical and spatial reasoning, and scores on a test of numerical ability have actually improved over the 30 years. This differential pattern may be the result of both student changes and curricular changes within Danish schools.

Adult↗
PubMed1992

Mood alteration with yoga and swimming: aerobic exercise may not be necessary.

The mood benefits of Hatha yoga and swimming, two activities that differ greatly in aerobic training benefits, were examined. College students (N = 87) in two swimming classes, a yoga class, and a lecture-control class completed mood and personality inventories before and after class on three occasions. A multivariate analysis of variance indicated that both yoga participants (n = 22) and swimmers (n = 37) reported greater decreases in scores on Anget, Confusion, Tension, and Depression than did the control students (n = 28). The consistent mood benefits of yoga supported our earlier observation that the exercise need not be aerobic to be associated with mood enhancement. However, underlying and causal mechanisms remain uncertain. Among the men, the acute decreases in Tension, Fatigue, and Anger after yoga were significantly greater than those after swimming. Yoga may be even more beneficial than swimming for men who personally select to participate. The women reported fairly similar mood benefits after swimming and yoga. It seems that aerobic exercise may not be necessary to facilitate the mood benefits. Also, students with greater mood changes attended class more regularly than those who reported fewer psychological benefits. Maximizing the immediate psychological benefits of exercise might be one way to encourage adults to be physically active.

Affect↗
PubMed1991

Intelligence and educational level in adult males at the extremes of stature.

Stature and intellectual ability are commonly found to correlate positively (r approximately 0.2). In this study we have assessed whether this relationship holds true at the extremes of stature in adults. From a representative study population of 76,111 young Danish men, we defined an extremely short group as those below the 2d percentile (less than or equal to 163 cm) and an extremely tall group as those above the 98th percentile (greater than or equal to 191 cm). The short group had intelligence test scores and educational levels lying at approximately two-thirds of a standard deviation below the overall means. The tall group had means lying approximately one-half standard deviation above the overall means. These deviations are to a large degree in agreement with the observed overall correlations of height with intelligence test scores (r = 0.244) and with educational level (r = 0.264). Both groups, however, appear to score somewhat below the levels expected from a purely linear relationship. For the short group there appear to be local factors that are particularly detrimental to intellectual ability. For the tall group corresponding local factors are relatively independent of intellectual ability.

Adolescent↗
PubMed1988

Sex chromosome anomalies, hormones, and sexuality.

Behavioral investigation of men with sex chromosome anomalies has been primarily limited to the study of institutionalized individuals or patient groups. A double-blind controlled investigation of XYY and XXY men found in a birth cohort of 4591 tall men born in Copenhagen gathered sexual information and assessed the role of hormonal determinants on sexual behavior. There were significant differences in several sexual dimensions and in gender role between XYY men and their controls and XXY men and their controls as well as between XYY and XXY men. Although both proband groups differed from each other and from their controls in pituitary gonadal function, there was no evidence that adult hormonal levels mediate the effect of sex chromosome anomalies on male sexuality.

Adult↗
PubMed1984

Sex chromosome anomalies, hormones, and aggressivity.

This double-blind, controlled study of XYY and XXY men found in a birth cohort of 4,591 tall men born in Copenhagen assessed evidence of delinquent and aggressive behavior and explored the role of hormonal determinants in the behavioral and psychological differences noted among groups. Information from social records, a structured psychological interview, and projective tests did not support the notion that men with sex chromosome anomalies are particularly violent or aggressive. Hormonally, XYY men had significantly higher concentrations of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) than matched control groups. In contrast, XXY men had higher levels of LH, FSH, and prolactin, but low concentrations of testosterone. There was a significantly positive relation among all subjects as well as XY controls alone between plasma testosterone level and evidence of criminal convictions. A proportionate increase in testosterone levels was noted when subjects were divided into nondelinquents, delinquents without violent convictions, and delinquents with violent convictions. The relation between testosterone level and criminal behavior was not reflected in measures of aggression derived from the psychological interview and projective tests. There was no specific evidence that testosterone is a mediating factor in the criminal behavior of XYY men.

Adult↗