Executive Functioning and Risk for Alzheimer\u27s Disease in The Cognitively Intact: Family History Predicts Wisconsin Card Sorting Test Performance

Alzheimer’s disease (AD) research typically focuses on memory. However, executive functioning (EF) deficits are also common among AD patients; these deficits are associated with decreased functioning in activities of daily living, an important criterion in diagnosing AD. A classic test of EF ability, the Wisconsin Card Sort Test (WCST), has demonstrated sensitivity to differentiating individuals with AD from healthy controls, discriminating AD groups based on disease severity, and distinguishing AD from other types of dementia. Such sensitivity to AD raises the possibility that the WCST is also sensitive to very early, preclinical differences between those who have heightened risk for AD and those with lower risks. Method: The current study, therefore, examined WCST performance in healthy, cognitively intact older adults with a first-degree (i.e., sibling or parent) family history (FH) of AD (n _ 18) and those with no such FH of AD (n _ 24). Results: Results revealed significant group differences for Categories Achieved, Percent Conceptual Level Responses, Total Errors, Perseverative Errors, and Non-Perseverative Errors, with the FH_ group consistently exhibiting poorer performance. Moreover, hierarchical regression analyses indicated that after accounting for age, sex, and education, FH significantly predicted all 5 of these variables. Conclusions: These results speak to the potential role of EF in bolstering the current understanding of early cognitive markers of future decline. Furthering what is known about the relationship between AD and nonmemory specific domains of cognition such as executive functioning may allow for better prediction of cognitive decline and potential progression to AD

Predator Recognition and Learned Irrelevance in the Crayfish Orconectes virilis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75194/1/j.1439-0310.2003.00916.x.pd

Student Counselors \u27 Moral, Intellectual, and Professional Ethical Identity Development

Professional identity is characterized by the integration of individuals\u27 professional and personal selves. The authors used a multiple regression design to examine counselor professional ethical identity development, with specific attention to moral and intellectual development. Student counselors (N = 59) completed the Modified Subject-Object Interview (Monson & Hamilton, 2010), Defining Issues Test-2 (Rest, Narvaez, Bebeau, & Thoma, ), and Learning Environment Preferences scale (Moore, 1987). Moral development was the most significant predictor of professional ethical identity development. Preparatory and research strategies to enhance professional ethical identity formation are discussed

Forest edges benefit adults, but not seedlings, of the mistletoe Alepis flavida (Loranthaceae)

1   We tested the hypothesis that different life-history stages of the same plant species show different responses to forest edge and interior environments. We investigated the effects of forest edges on growth, survival and density of seedlings, juveniles and adults of an endemic New Zealand mistletoe, Alepis flavida , over a 5-year period. 2   Rates of establishment and growth were significantly higher for seedlings in forest interior than on forest edges but both juveniles and adults grew significantly faster on forest edges. 3   Mortality rates were greater for juveniles than for adults, but there was no significant difference between forest edge and interior. 4   Densities of seedlings and the larger size class of juvenile plants were significantly greater in the forest interior than on forest edges, whereas densities of the larger size class of adults were significantly greater on edges. 5   Changes in densities over 5 years showed that larger juveniles increased in density only in the forest interior, whereas larger adults increased in density only on forest edges. 6   Thus, seedlings of A. flavida have strong advantages in the forest interior, whereas juveniles and adults grow faster on forest edges. 7   This study emphasizes the need to examine multiple life-history stages in studies of edge effects. Journal of Ecology (2004) doi: 10.1111/j.1365-2745.2004.00961.xPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72224/1/j.1365-2745.2004.00961.x.pd

Flagellar membrane association via interaction with lipid rafts

The eukaryotic flagellar membrane has a distinct composition from other domains of the plasmalemma. Our work shows that the specialized composition of the trypanosome flagellar membrane reflects increased concentrations of sterols and saturated fatty acids, correlating with direct observation of high liquid order by laurdan fluorescence microscopy. These findings indicate that the trypanosome flagellar membrane possesses high concentrations of lipid rafts: discrete regions of lateral heterogeneity in plasma membranes that serve to sequester and organize specialized protein complexes. Consistent with this, a dually acylated Ca(2+) sensor that is concentrated in the flagellum is found in detergent-resistant membranes and mislocalizes if the lipid rafts are disrupted. Detergent-extracted cells have discrete membrane patches localized on the surface of the flagellar axoneme, suggestive of intraflagellar transport particles. Together, these results provide biophysical and biochemical evidence to indicate that lipid rafts are enriched in the trypanosome flagellar membrane, providing a unique mechanism for flagellar protein localization and illustrating a novel means by which specialized cellular functions may be partitioned to discrete membrane domains

A Review of Structural MRI and Diffusion Tensor Imaging in Schizotypal Personality Disorder

Individuals with schizotypal personality disorder (SPD) share genetic, phenomenologic, and cognitive abnormalities with people diagnosed with schizophrenia. To date, 15 structural MRI studies of the brain have examined size, and 3 diffusion tensor imaging studies have examined white matter connectivity in SPD. Overall, both types of structural neuroimaging modalities have shown temporal lobe abnormalities similar to those observed in schizophrenia, while frontal lobe regions appear to show more sparing. This intriguing pattern suggests that frontal lobe sparing may suppress psychosis, which is consistent with the idea of a possible neuroprotective factor. In this paper, we review these 18 studies and discuss whether individuals with SPD who both resemble and differ from schizophrenia patients in their phenomenology, share some or all of the structural brain imaging characteristics of schizophrenia. We attempt to group the MRI abnormalities in SPD into three patterns: 1) a spectrum of severity—abnormalities are similar to those observed in schizophrenia but not so severe; 2) a spectrum of region—abnormalities affecting some, but not all, brain regions affected in schizophrenia; and 3) a spectrum of compensation—abnormalities reflecting greater-than-normal white matter volume, possibly serving as a buffer or compensatory mechanism protecting the individual with SPD from the frank psychosis observed in schizophrenia

The effect of past experience on the size of shells selected by hermit crabs

The relationship between crab size and shell size selected, in a free-choice situation, was tested for crabs maintained under several conditions. Individuals of Calcinus tibicen that were held and presented with an excess of shells for 7 days prior to testing selected smaller shells than control crabs (either those maintained for 7 days with no excess shells available or those experiencing natural field conditions). This shift occurred whether the excess shell type was the same or different from the shell type tested after experience. In a similar set of experiments, individuals of C. laevimanus were held for 31 days and although the trends in shell choice were similar to those for C. tibicen, the differences were not significant.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29920/1/0000277.pd

The Impact of Burnout on Human Physiology and on Operational Performance: A Prospective Study of Soldiers Enrolled in the Combat Diver Qualification Course

(from p. 201) If little is known about the pathophysiology of burnout, even less is known about the actual impact of burnout on military operational performance. This is due to a lack of studies focused on military performance. Whether or not soldiers may feel symptoms of burnout is one thing - whether this state actually affects how they do their job is another. Within the current environment (reduced forces, increased training rates, increased deployment rates, extended tours) we believe that military personnel may be at significant risk for the development of burnout. Further, we wondered if there was a demonstrable impact of burnout on actual military performance as well as on human physiology. The present study was part of a larger investigation designed to assess the neurobiology of stress in soldiers participating in Combat Diver Qualification Training (CDQC). The portion of the study that we present here is that dealing with the assessment of burnout, HPA axis functioning and actual performance