Fluctuations of cell geometry and their nonequilibrium thermodynamics in living epithelial tissue

We measure different contributions to entropy production in a living functional epithelial tissue. We do this by extracting the functional dynamics of development while at the same time quantifying fluctuations. Using the translucent Drosophila melanogaster pupal epithelium as an ideal tissue for high-resolution live imaging, we measure the entropy associated with the stochastic geometry of cells in the epithelium. This is done using a detailed analysis of the dynamics of the shape and orientation of individual cells which enables separation of local and global aspects of the tissue behavior. Intriguingly, we find that we can observe irreversible dynamics in the cell geometries but without a change in the entropy associated with those degrees of freedom, showing that there is a flow of energy into those degrees of freedom. Hence, the living system is controlling how the entropy is being produced and partitioned into its different parts.

The effects of gluteal squeezes compared to bilateral bridges on gluteal strength, power, endurance, and girth

BACKGROUND

Hip extension weakness is correlated with low back, hip, and knee pathology. Isometric gluteal squeezes have been shown to elicit high electromyographic gluteal activity. However, there is little research regarding the specific effects of isometric gluteal squeezes on hip strength and functional outcomes. The purpose of this study was to identify the effects of gluteal squeezes on hip extension strength, vertical jump, broad jump, single-leg bridge endurance, and gluteal girth compared to bilateral gluteal bridging.

METHODS

A total of 32 healthy university students (mean age 23.28 ± 2.15 years) were randomly assigned to perform either gluteal squeezes or bilateral bridges daily. Subjects were tested at baseline and after 8 weeks of training. Subjects' hip extension strength, vertical jump, broad jump, single-leg bridge endurance, and gluteal girth were tested.

RESULTS

No statistically significant differences were found between the bridge and squeeze groups after 8 weeks of training. Both groups significantly improved hip extension strength bilaterally (p = 0.000-0.011). The squeeze group significantly increased gluteal girth at the level of the greater trochanter (p = 0.007), but no significant girth increase was seen in the bridge group (p = 0.742). Although increases were seen in both groups for the endurance and jump tasks, no statistically significant changes occurred for those outcomes. All outcome measurements demonstrated high reliability (ICC = 0.93-0.99).

CONCLUSION

Gluteal squeezes were as effective as bilateral bridges for increasing hip extension strength. Gluteal squeezes also significantly increased girth at the level of the greater trochanter. These results provide clinical and aesthetic reasons to perform gluteal squeezes.

Impact of audiovisual biofeedback on interfraction respiratory motion reproducibility in liver cancer stereotactic body radiotherapy

INTRODUCTION

Irregular breathing motion exacerbates uncertainties throughout a course of radiation therapy. Breathing guidance has demonstrated to improve breathing motion consistency. This was the first clinical implementation of audiovisual biofeedback (AVB) breathing guidance over a course of liver stereotactic body radiotherapy (SBRT) investigating interfraction reproducibility.

METHODS

Five liver cancer patients underwent a screening procedure prior to CT sim during which patients underwent breathing conditions (i) AVB, or (ii) free breathing (FB). Whichever breathing condition was more regular was utilised for the patient's subsequent course of SBRT. Respiratory motion was obtained from the Varian respiratory position monitoring (RPM) system (Varian Medical Systems). Breathing motion reproducibility was assessed by the variance of displacement across 10 phase-based respiratory bins over each patient's course of SBRT.

RESULTS

The screening procedure yielded the decision to utilise AVB for three patients and FB for two patients. Over the course of SBRT, AVB significantly improved the relative interfraction motion by 32%, from 22% displacement difference for FB patients to 15% difference for AVB patients. Further to this, AVB facilitated sub-millimetre interfraction reproducibility for two AVB patients.

CONCLUSION

There was significantly less interfraction motion with AVB than FB. These findings demonstrate that AVB is potentially a valuable tool in ensuring reproducible interfraction motion.

Empower U: effectiveness of an adolescent outreach and prevention program with sixth-grade boys and girls: a pilot study

Sixth graders are at a prime age to modify behaviors and beliefs regarding exercise, nutrition, body image, and smoking. Empower U was created to change knowledge, beliefs, and behaviors regarding these topics. This pilot study utilized pre/post assessments of 58 sixth graders from a private middle school in the midsouth. Results showed a significant increase in self-esteem as well as in exercise and nutrition knowledge and beliefs at posttest and a significant increase in body image as well as in self-reported exercise and nutrition behaviors at the 1-month follow-up. Empower U provides nurses with an effective educational program that may be useful in positively impacting health behaviors.

Nursing decision making and the science of the concrete

Information systems are going to change our understanding of nursing as a discipline and as a practice. The act of decision making will be the focus of the impact of information systems on nursing. The article models types of nursing knowledge, organizing them into concrete and abstract knowledge. Information systems will allow the inclusion of concrete science data, which has not been possible previously. Role performance is seen as a mechanism for the integration of the two sciences, and a new understanding for nursing decision making is proposed.

RRR-alpha-tocopheryl succinate inhibits proliferation and enhances secretion of transforming growth factor-beta (TGF-beta) by human breast cancer cells

The RRR-alpha-tocopheryl succinate form of vitamin E inhibits the proliferation of estrogen receptor-positive and estrogen receptor-negative human breast cancer cell lines in a dose-dependent manner in vitro. Analyses of cell-conditioned medium from RRR-alpha-tocopheryl succinate growth-inhibited cells revealed the presence of a potent antiproliferative activity. Characterization of the antiproliferative activity as transforming growth factor-beta (TGF-beta) was established by 1) growth inhibition of the TGF-beta-responsive Mv1Lu-CCL-64 mink lung and murine CTLL-2 cell lines, 2) combination of physical characteristics including heat stability, acid stability, and Bio-Gel P-60 column chromatography elution profile, and 3) neutralization of the antiproliferative activity in the conditioned media by antibodies specific for TGF-beta.

An examination of proton translocation and energy conservation during heterotrophic nitrification

Whether selected heterotrophic nitrifiers, as do the autotrophs, conserve energy during the oxidation of their nitrogenous substrates was studied. The examination of proton translocation of four different bacterial nitrifiers capable of pyruvic oxime [(PO), CH3-C(NOH)-COOH] nitrification and by an NH4+ oxidizing Arthrobacter sp. was initiated. Three of the PO nitrifying bacteria, all pseudomonads, oxidize hydroxylamine (NH2OH) at a greater rate than PO and yielded only stoichiometric protons when NH2OH was the reductant. The fourth bacterium, Alcaligenes faecalis ATCC 8750, an adept PO oxidizer, does not appreciably oxidize NH2OH. The bacterium displayed----H+NH2OH ratios far less than if NH2OH was stoichiometrically converted to nitrite. When given NH4+, the Arthrobacter sp. yielded proton translocation patterns which were inconsistent with the metabolic data collected concerning NH4+ oxidation. Thus no data was collected which supported energy conservation via proton translocation by these heterotrophic nitrifiers.