Body Composition in Early Alzheimer's Disease

Background: Alzheimer's disease (AD) is associated with unintended weight loss. We examined body composition in early AD and nondemented aging and its relation to brain volume and cognition. Methods: Brain magnetic resonance imaging (MRI) and neuropsychological testing were performed on nondemented (CDR 0, n=70) and early-stage AD (CDR 0.5 or 1, n=70) subjects. Dual energy x-ray absorptiometry (DEXA) determined whole-body fat mass and lean mass. Body mass index (BMI) was determined from height and weight. Linear regression analyses controlling for age and sex assessed the relationship between body composition, cognition, and brain volume. Results: Lean mass was reduced in early AD compared to nondemented controls (F=7.73, p=0.006) after controlling for sex. Lean mass was associated with whole-brain volume (beta=0.20, p<0.001) and white matter volume (beta=0.19, p<0.001) when controlling for age and sex. Lean mass was also associated with global cognitive performance (beta=0.12, p=0.007) when controlling for age and sex. Total body fat and percent body fat were not different across groups or related to cognition and brain volume. Conclusion: Loss of lean mass is accelerated in AD and associated with brain atrophy. AD and sarcopenia may share common underlying mechanisms or sarcopenia may be a direct or indirect consequence of AD pathophysiology

The validity of percent body fat estimates by Jackson & Pollock skinfold equation, near infrared, bioelectrical impedance and body mass index

This study compared the validity of percent fat estimates by the Jackson & Pollock sum of four skinfold equation (JPSF), bioeletrical impedance (BIA), near infrared (NIR) and body mass index (BMI) when compared to the criterion method of underwater weighing (UWW). Skinfolds were measured at four sites, the triceps, ilium, abdomen and thigh using the Harpenden skinfold caliper. The Jackson & Pollock sum of four skinfold equation was used to calculate percent body fat. Infrared interactance was determined on a Futrex 5000 measured at the biceps halfway between the axillary fold and the anticubital space. Bioelectrical impedance was determined with the Bio-analgenics ELG analyzer using the four electrode placement technique. Electrodes were placed on the dorsal surfaces of the ankle and wrist and the distal surfaces of the metacarpals and metatarsals. Underwater weighing was determined in a seated position with functional residual volume measured in the tank at the time of weighing. Statistical analysis was determined using an repeated measures ANOVA, Pearson correlation coefficient (r), standard error of estimate (SEE), R{dollar}\sp2{dollar}, and total error (TE). (Abstract shortened by UMI.)

Get a Cue on IS Security Training: Explaining the Difference between how Security Cues and Security Arguments Improve Secure Behavior

Secure behavior, defined as users’ compliance with their organization’s password policy, is critical for sustaining a profitable and operational organization. Training that provides security arguments and promotes systematic cognitive processing has been shown to be an effective mechanism for improving secure behavior. Training by providing security cues, on the other hand, has been criticized as having a short-lived and unpredictable influence on secure behavior. This paper challenges this criticism by explaining how security cues influence secure behavior and when they are more effective in influencing secure behavior than security arguments. We hypothesize the different theoretical mechanisms through which security arguments and security cues influence secure behavior. We further hypothesize that when users’ attitude toward behaving secure is poor, security arguments should be used. However, when users’ attitude toward behaving secure is positive, security cues should be used. This paper suggests how to test our proposed hypotheses in an experimental setting

Human chorionic gonadotropin and GnRH effects on pregnancy survival in pregnant cows and resynchronized pregnancy rates

Dairy Research, 2007 is known as Dairy Day, 2007Experiments have shown human chorionic gonadotropin (hCG) to be more effective than gondadotropin releasing hormone (GnRH) as a means to ovulate follicles. Experiment 1 determined the effects of replacing the first injection of GnRH (day 7) with hCG or saline in a Resynch-Ovsynch protocol on pregnancy rates in cows subsequently diagnosed not pregnant and pregnancy survival in cows subsequently diagnosed pregnant (day 0). A second study determined the ovulation potential of hCG compared with GnRH and saline (Exp. 2). In Exp. 1, cows in 4 herds were assigned randomly based on lactation number, number of previous AI, and last test-day milk yield to treatments of 1,000 IU of hCG, 100 μg of GnRH, or left as untreated controls 7 days before pregnancy diagnosis. Cows found not pregnant were given PGF2α (day 0), then inseminated 72 hours later, concurrent with a GnRH injection (3 herds) or given GnRH 16 to 24 hours before AI at 72 hours (1 herd). Timed AI pregnancy rates tended (P = 0.08) to be reduced by saline (12.9%; n = 505) compared with GnRH (17.9%; n = 703) but not hCG (16.5%; n = 541). Among pregnant cows treated, pregnancy survival 4 to 9 weeks after initial pregnancy diagnosis differed among herds (P < 0.001); but in 1 herd, GnRH reduced pregnancy survival, whereas hCG seemed to increase survival compared with control. Only small differences were detected in the other 3 herds, except for a slight negative effect of hCG compared with control in 1 herd. Ovarian structures were monitored in herd 1 by using transrectal ultrasonography 0 and 7 days after treatment with hCG, GnRH, or saline (Exp. 2). A tendency for a treatment × pregnancy status interaction (P = 0.07) was detected. Incidences of ovulation in nonpregnant cows were: hCG (51.6%; n = 126), GnRH (46.1%; n = 102), and control (28.1%; n = 96), whereas those in pregnant cows were: hCG (59.3%; n = 59), GnRH (24.5%; n = 49), and saline (6.9%; n = 58). We concluded that: 1) initiating a Resynch-Ovsynch protocol 7 days before pregnancy diagnosis with saline reduced timed AI pregnancy rates (Exp. 1); 2) in pregnant cows treated with GnRH, pregnancy survival was slightly reduced in 1 of 4 herds (Exp. 1); and 3) incidence of new corpus luteum (CL) was greater after hCG than GnRH in pregnant cows but not in nonpregnant cows (Exp. 2)

Preceramic cave use in Belize

Little evidence for human use of caves in Belize is available for the long span of time from the first human habitation of the area until the beginnings of Maya civilization. This thesis seeks to further the understanding of preceramic people in Belize by examining the information that is available from the few archaeological projects which have uncovered evidence of Paleoindian and Archaic use of caves throughout the Maya area and surrounding region, but with an emphasis on Belize, and explores what those data might indicate as to the nature and extent of preceramic cave use. The conclusions of this research suggest that significant cave use by preceramic peoples occurred throughout Mesoamerica, primarily for practical and not necessarily ritual purposes, such as short-term seasonal habitation and water procurement. While there is currently little evidence for this in Belize, the paucity of data probably stems from a lack of focused research, logistical challenges, the ephemeral nature of the preceramic archaeological record, and subsequent destruction or obfuscation of cultural residue by later Maya use of caves

An artificially generated atmosphere near a lunar base

We discuss the formation of an artificial atmosphere generated by vigorous lunar base activity in this paper. We developed an analytical, steady-state model for a lunar atmosphere based upon previous investigations of the Moon's atmosphere from Apollo. Constant gas-injection rates, ballistic trajectories, and a Maxwellian particle distribution for an oxygen-like gas are assumed. Even for the extreme case of continuous He-3 mining of the lunar regolith, we find that the lunar atmosphere would not significantly degrade astronomical observations beyond about 10 km from the mining operation