Sex differences in sustained attention across the adult life span.

We used a life span sample of 18- to 91-year-old men (n?=?176) and women (n?=?108) to investigate sex differences and the effect of age on sex differences in performance and arousal during a 62-min no-memory-demand sensory vigilance task (Mackworth's Clock-Test). We observed sex differences in target response time and on measures of autonomic arousal; women were slower and less aroused than men. A review of the literature, in conjunction with the results of this study, led to our concluding that women are slower to respond to targets than men and that women may tend to detect fewer targets than men only when they are young (18–29 years old). Sex differences in arousal levels were consistent with an arousal explanation of sex differences in response time. However, detection accuracy and false alarm rates were not consistent with sex differences in arousal levels. Sex differences in the time course of vigilance performance were inconsistent. Age did not significantly moderate the sex differences in vigilance decrement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of age on consistent and varied semantic-category search performance.

Three experiments examined age-related consistent mapping (CM) and varied mapping (VM) practice effects. In separate experiments, young (age, 19–22), middle-aged (37–50), and older (64–88) adults' performance was examined using semantic-category and letter-based search paradigms. After extensive practice, major age differences occurred in CM search. Young and middle-aged subjects showed near-zero comparison slopes, large reductions in mean reaction times, and substantial reductions in response variability. Although older adults' reaction time decreased with CM practice, the reduction in reaction time, comparison slope, and response variability was small compared with the other groups. In VM search, older subjects were slower than the other age groups, but all groups exhibited similar linear set-size functions, search termination, and comparison-load effects. We concluded that age-associated declines in cognitive performance may be due in large part to the degree with which older adults can acquire or use automatic processes to perform tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Verbal mediation on a nonvisual formboard task with blind, partially sighted, and sighted subjects.

Previous studies indicate that verbal mediation can only enhance formboard performance when Ss can visually associate formboard blocks with verbal mediators. The present study compared the performance of a total of 46 congenitally blind, partially sighted, and sighted adolescents. Results fail to confirm the facilitating effects of verbal mediation on formboard performance. This result was replicated in a 2nd study using 20 sighted undergraduates who were visually acquainted with the blocks before the nonvisual formboard task. It is concluded that since visual impairment played little or no role in formboard performance, the formboard could be useful as an indicator of brain damage in congenitally blind and partially sighted Ss as it is in sighted Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comment on "equivalence of information in concept identification."

Presents evidence to show that D. Arenberg's (see record 1971-03494-001) equivalence-of-information method is: (a) dependent upon a nonfixed solution procedure 1st used by J. S. Bruner, J. J. Goodnow, and G. A. Austin in their monograph A Study of Thinking; and (b) nonapplicable for stimulus universes where there are dimensions that are not binary. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Triple Culture of Primary Human Osteoblasts,Osteoclasts and Osteocytes as an In Vitro Bone Model

In vitro evaluation of bone graft materials is generally performed by analyzing the interaction with osteoblasts or osteoblast precursors. In vitro bone models comprising different cell species can give specific first information on the performance of those materials. In the present study, a 3D co-culture model was established comprising primary human osteoblasts, osteoclasts and osteocytes. Osteocytes were differentiated from osteoblasts embedded in collagen gels and were cultivated with osteoblast and osteoclasts seeded in patterns on a porous membrane. This experimental setup allowed paracrine signaling as well as separation of the different cell types for final analysis. After 7 days of co-culture, the three cell species showed their typical morphology and gene expression of typical markers like ALPL, BSPII, BLGAP, E11, PHEX, MEPE, RANKL, ACP5, CAII and CTSK. Furthermore, relevant enzyme activities for osteoblasts (ALP) and osteoclasts (TRAP, CTSK, CAII) were detected. Osteoclasts in triple culture showed downregulated TRAP (ACP5) and CAII expression and decreased TRAP activity. ALP and BSPII expression of osteoblasts in triple culture were upregulated. The expression of the osteocyte marker E11 (PDPN) was unchanged; however, osteocalcin (BGLAP) expression was considerably downregulated both in osteoblasts and osteocytes in triple cultures compared to the respective single cultures.     

Suspension and Mixing Characterization of Intermittent Agitation Modes in DASGIP Bioreactors

Intermittent agitation strategies have been increasingly used for a range of process development applications, i.e., to modulate physical cues, to improve stem cell differentiation yields, and to control hydrodynamic shear stresses in microcarrier suspension; however, there is a distinct lack of characterization. Both continuous and intermittent agitation modes in relation to suspension and mixing dynamics within a DASGIP bioreactor were characterized. Suspension dynamics were found to be affected by microcarrier porosity and the degree of settling was found to be more pronounced at the top of the bioreactor. Mixing time characterization showed a marked improvement in mixing efficiency for intermittent agitation, with an overall dependence on the timing of tracer insertion.     

The Emerging Clinical Role of Spermine in Prostate Cancer

Spermine, a member of polyamines, exists in all organisms and is essential for normal cell growth and function. It is highly expressed in the prostate compared with other organs and is detectable in urine, tissue, expressed prostatic secretions, and erythrocyte. A significant reduction of spermine level was observed in prostate cancer (PCa) tissue compared with benign prostate tissue, and the level of urinary spermine was also significantly lower in men with PCa. Decreased spermine level may be used as an indicator of malignant phenotype transformation from normal to malignant tissue in prostate. Studies targeting polyamines and key rate-limiting enzymes associated with spermine metabolism as a tool for PCa therapy and chemoprevention have been conducted with various polyamine biosynthesis inhibitors and polyamine analogues. The mechanism between spermine and PCa development are possibly related to the regulation of polyamine metabolism, cancer-driving pathways, oxidative stress, anticancer immunosurveillance, and apoptosis regulation. Although the specific mechanism of spermine in PCa development is still unclear, ongoing research in spermine metabolism and its association with PCa pathophysiology opens up new opportunities in the diagnostic and therapeutic roles of spermine in PCa management.