Visual biofeedback training reduces quantitative drugs index scores associated with fall risk.

OBJECTIVE: Drugs increase fall risk and decrease performance on balance and mobility tests. Conversely, whether biofeedback training to reduce fall risk also decreases scores on a published drug-based fall risk index has not been documented. Forty-eight community-dwelling older adults underwent either treadmill gait training plus visual feedback (+VFB), or walked on a treadmill without feedback. The Quantitative Drug Index (QDI) was derived from each participant's drug list and is based upon all cause drug-associated fall risk. Analysis of covariance assessed changes in the QDI during the study, and data is presented as mean ± standard error of the mean. RESULTS: The QDI scores decreased significantly (p = 0.031) for participants receiving treadmill gait training +VFB (- 0.259 ± 0.207), compared to participants who walked on the treadmill without VFB (0.463 ± 0.246). Changes in participants QDI scores were dependent in part upon their age, which was a significant covariate (p = 0.007). These preliminary results demonstrate that rehabilitation to reduce fall risk may also decrease use of drugs associated with falls. Determination of which drugs or drug classes that contribute to the reduction in QDI scores for participants receiving treadmill gait training +VFB, compared to treadmill walking only, will require a larger participant investigation. Trial Registration ISRNCT01690611, ClinicalTrials.gov #366151-1, initial 9/24/2012, completed 4/21/2016.

Spatio-temporal analysis of foraging behaviors of Anelosimus studiosus utilizing mathematical modeling of multiple spider interaction on a cooperative web.

In this paper, we develop a model for predation movements of a subsocial spider species, Anelosimus studiosus. We expand on a previous model to include multiple spider interaction on the web as well as a latency period during predation. We then use the model to test different spatial configurations to determine the optimal spacing of spiders within a colony for successful capture during predation. The model simulations indicate that spiders uniformly spacing out along the edge of the web results in the most successful predation strategy. This is similar to the behavior observed by Ross (2013) in which it was determined to be statistically significant that during certain times of the day, spiders were positioned along the edge more than expected under complete spatial randomness.

Extensive reorganization of behavior accompanies ontogeny of aggression in male flesh flies.

Aggression, costly in both time and energy, is often expressed by male animals in defense of valuable resources such as food or potential mates. Here we present a new insect model system for the study of aggression, the male flesh fly Sarcophaga crassipalpis, and ask whether there is an ontogeny of aggression that coincides with reproductive maturity. After establishing that reproductive maturity occurs by day 3 of age (post-eclosion), we examined the behavior of socially isolated males from different age cohorts (days 1, 2, 3, 4, and 6) upon introduction, in a test arena, with another male of the same age. The results show a pronounced development of aggression with age. The change from relative indifference to heightened aggression involves a profound increase in the frequency of high-intensity aggressive behaviors between days 1 and 3. Also noteworthy is an abrupt increase in the number of statistically significant transitions involving these full-contact agonistic behaviors on day 2. This elevated activity is trimmed back somewhat by day 3 and appears to maintain a stable plateau thereafter. No convincing evidence was found for escalation of aggression nor the establishment of a dominance relationship over the duration of the encounters. Despite the fact that aggressive interactions are brief, lasting only a few seconds, a major reorganization in the relative proportions of four major non-aggressive behaviors (accounting for at least 96% of the total observation time for each age cohort) accompanies the switch from low to high aggression. A series of control experiments, with single flies in the test arenas, indicates that these changes occur in the absence of the performance of aggressive behaviors. This parallel ontogeny of aggressive and non-aggressive behaviors has implications for understanding how the entire behavioral repertoire may be organized and reorganized to accommodate the needs of the organism.

Lipidomic analysis of N-acylphosphatidylethanolamine molecular species in Arabidopsis suggests feedback regulation by N-acylethanolamines.

N-Acylphosphatidylethanolamine (NAPE) and its hydrolysis product, N-acylethanolamine (NAE), are minor but ubiquitous lipids in multicellular eukaryotes. Various physiological processes are severely affected by altering the expression of fatty acid amide hydrolase (FAAH), an NAE-hydrolyzing enzyme. To determine the effect of altered FAAH activity on NAPE molecular species composition, NAE metabolism, and general membrane lipid metabolism, quantitative profiles of NAPEs, NAEs, galactolipids, and major and minor phospholipids for FAAH mutants of Arabidopsis were determined. The NAPE molecular species content was dramatically affected by reduced FAAH activity and elevated NAE content in faah knockouts, increasing by as much as 36-fold, far more than the NAE content, suggesting negative feedback regulation of phospholipase D-mediated NAPE hydrolysis by NAE. The N-acyl composition of NAPE remained similar to that of NAE, suggesting that the NAPE precursor pool largely determines NAE composition. Exogenous NAE 12:0 treatment elevated endogenous polyunsaturated NAE and NAPE levels in seedlings; NAE levels were increased more in faah knockouts than in wild-type or FAAH overexpressors. Treated seedlings with elevated NAE and NAPE levels showed impaired growth and reduced galactolipid synthesis by the "prokaryotic" (i.e., plastidic), but not the "eukaryotic" (i.e., extraplastidic), pathway. Overall, our data provide new insights into the regulation of NAPE-NAE metabolism and coordination of membrane lipid metabolism and seedling development.

Diminishing returns: the influence of experience and environment on time-memory extinction in honey bee foragers.

Classical experiments demonstrated that honey bee foragers trained to collect food at virtually any time of day will return to that food source on subsequent days with a remarkable degree of temporal accuracy. This versatile time-memory, based on an endogenous circadian clock, presumably enables foragers to schedule their reconnaissance flights to best take advantage of the daily rhythms of nectar and pollen availability in different species of flowers. It is commonly believed that the time-memory rapidly extinguishes if not reinforced daily, thus enabling foragers to switch quickly from relatively poor sources to more productive ones. On the other hand, it is also commonly thought that extinction of the time-memory is slow enough to permit foragers to 'remember' the food source over a day or two of bad weather. What exactly is the time-course of time-memory extinction? In a series of field experiments, we determined that the level of food-anticipatory activity (FAA) directed at a food source is not rapidly extinguished and, furthermore, the time-course of extinction is dependent upon the amount of experience accumulated by the forager at that source. We also found that FAA is prolonged in response to inclement weather, indicating that time-memory extinction is not a simple decay function but is responsive to environmental changes. These results provide insights into the adaptability of FAA under natural conditions.

SYMBIOSIS: development, implementation, and assessment of a model curriculum across biology and mathematics at the introductory level.

"It takes a lot of courage to release the familiar and seemingly secure, to embrace the new. But there is no real security in what is no longer meaningful. There is more security in the adventurous and exciting, for in movement there is life, and in change there is power." Alan Cohen (Used by permission. All rights reserved. For more information on Alan Cohen's books and programs, see (www.alancohen.com.) With the support of the East Tennessee State University (ETSU) administration and a grant from Howard Hughes Medical Institute, the departments of Biological Sciences, Mathematics and Statistics, and Curriculum and Instruction have developed a biology-math integrated curriculum. An interdisciplinary faculty team, charged with teaching the 18 curriculum modules, designed this three-semester curriculum, known as SYMBIOSIS. This curriculum was piloted to two student cohorts during the developmental stage. The positive feedback and assessment results of this project have given us the foundation to implement the SYMBIOSIS curriculum as a replacement for the standard biology majors curriculum at the introductory level. This article addresses the history and development of the curriculum, previous assessment results and current assessment protocol, and the future of ETSU's approach to implementing the SYMBIOSIS curriculum.

Effect of precision error on T-scores and the diagnostic classification of bone status.

We quantified confidence intervals (CIs) for T-scores for the lumbar spine and hip and determined the practical effect (impact on diagnosis) of variability around the T-score cutpoint of -2.5. Using precision data from the literature for GE Lunar Prodigy dual-energy X-ray absorptiometry (DXA) systems, the 95% CI for the T-score was +/-0.23 at the lumbar spine (L1-L4), +/- 0.20 at the total hip, and +/-0.41 at the femoral neck. Thus, T-score variations of +/-0.23 or less at the spine, +/-0.20 at the total hip, and +/-0.41 at the femoral neck are not statistically significant. When diagnosing osteoporosis, T-scores in the interval -2.3 to -2.7 for spine or total hip (after rounding to conform to guidelines from the International Society for Clinical Densitometry) and -2.1 to -2.9 for femoral neck are not statistically different from -2.5. Better precision values resulted in smaller 95% CIs. This concept was applied to actual clinical data using Hologic DXA systems. The study cohort comprised 2388 white women with either normal or osteopenic spines in whom the densitometric diagnosis of osteoporosis would be determined by hip T-scores. When evaluating actual patient T-scores in the range -2.5+/-95% CI, we found that the diagnosis was indeterminate in approximately 12% of women when T-scores for femoral neck were used and in 4% of women when T-scores for total hip were used, with uncertainty as to whether the classification was osteopenia or osteoporosis. We conclude that precision influences the variability around T-scores and that this variability affects the reliability of diagnostic classification.

Confidence interval for a coefficient of dispersion in nonnormal distributions.

A new confidence interval for the coefficient of dispersion (mean absolute deviation from the median divided by median) is proposed and is shown to perform better than the BCa bootstrap confidence interval.

A quantitative analysis of secondary RNA structure using domination based parameters on trees.

BACKGROUND: It has become increasingly apparent that a comprehensive database of RNA motifs is essential in order to achieve new goals in genomic and proteomic research. Secondary RNA structures have frequently been represented by various modeling methods as graph-theoretic trees. Using graph theory as a modeling tool allows the vast resources of graphical invariants to be utilized to numerically identify secondary RNA motifs. The domination number of a graph is a graphical invariant that is sensitive to even a slight change in the structure of a tree. The invariants selected in this study are variations of the domination number of a graph. These graphical invariants are partitioned into two classes, and we define two parameters based on each of these classes. These parameters are calculated for all small order trees and a statistical analysis of the resulting data is conducted to determine if the values of these parameters can be utilized to identify which trees of orders seven and eight are RNA-like in structure. RESULTS: The statistical analysis shows that the domination based parameters correctly distinguish between the trees that represent native structures and those that are not likely candidates to represent RNA. Some of the trees previously identified as candidate structures are found to be "very" RNA like, while others are not, thereby refining the space of structures likely to be found as representing secondary RNA structure. CONCLUSION: Search algorithms are available that mine nucleotide sequence databases. However, the number of motifs identified can be quite large, making a further search for similar motif computationally difficult. Much of the work in the bioinformatics arena is toward the development of better algorithms to address the computational problem. This work, on the other hand, uses mathematical descriptors to more clearly characterize the RNA motifs and thereby reduce the corresponding search space. These preliminary findings demonstrate that graph-theoretic quantifiers utilized in fields such as computer network design hold significant promise as an added tool for genomics and proteomics.