Segmenting root systems in X-ray computed tomography images using level sets

The segmentation of plant roots from soil and other growing media in X-ray computed tomography images is needed to effectively study the root system architecture without excavation. However, segmentation is a challenging problem in this context because the root and non-root regions share similar features. In this paper, we describe a method based on level sets and specifically adapted for this segmentation problem. In particular, we deal with the issues of using a level sets approach on large image volumes for root segmentation, and track active regions of the front using an occupancy grid. This method allows for straightforward modifications to a narrow-band algorithm such that excessive forward and backward movements of the front can be avoided, distance map computations in a narrow band context can be done in linear time through modification of Meijster et al.'s distance transform algorithm, and regions of the image volume are iteratively used to estimate distributions for root versus non-root classes. Results are shown of three plant species of different maturity levels, grown in three different media. Our method compares favorably to a state-of-the-art method for root segmentation in X-ray CT image volumes.Comment: 11 page

Modelling Organic Dairy Production Systems

In this study, a large number of organic dairy production strategies were compared in terms of physical and financial performance through the integrated use of computer simulation models and organic case study farm data. Production and financial data from three organic case study farms were used as a basis for the modelling process to ensure that the modelled systems were based on real sets of resources that might be available to a farmer. The case study farms were selected to represent a range of farming systems in terms of farm size, concentrate use and location. This paper describes the process used to model the farm systems: the integration of the three models used and the use of indicators to assess the modelled farm systems in terms of physical sustainability and financial performance

The Effects of a Closed-Chain, Eccentric Training Program on Hamstring Injuries of a Professional Football Cheerleading Team

Objective Hamstring injuries are a common occurrence among professional football cheerleaders. The purpose of this study is to identify the effects of an eccentric, closed-chain hamstring exercise intervention on hamstring injury–associated pain during the course of the football season among professional football cheerleaders. Methods Forty-three female cheerleaders participated in an eccentric, closed-chain hamstring exercise intervention protocol provided by doctors of chiropractic that incorporated loops of elastic-band or Thera-Band Loops (Hygenic Corporation, Akron, OH) during practice and at home during the regular football season. Hamstring injury–related pain was assessed in June, during team selection; in September, at the start of the season; and in December, at the end of season. No intervention was applied between June and September, although the sample participated in 4 hours of practice 2 to 3 times per week. The intervention was applied to the entire sample regardless of hamstring injury–related pain during the regular football season between September and December. The interventions included 2 exercises and were completed bilaterally 2 times per week at each biweekly practice and were encouraged to be done at least 3 additional times per week at home on nonpractice days. Results Among the subsample who reported hamstring-related injury pain between June and September, the exercise intervention significantly decreased (P \u3c .007) pain between September (6.07 ± 0.58) and December (3.67 ± 0.65). Conclusions The eccentric, closed-chain hamstring exercise intervention reduced hamstring injury–related pain among this group of professional football cheerleaders

DNA Binding of Centromere Protein C (CENPC) Is Stabilized by Single-Stranded RNA

Centromeres are the attachment points between the genome and the cytoskeleton: centromeres bind to kinetochores, which in turn bind to spindles and move chromosomes. Paradoxically, the DNA sequence of centromeres has little or no role in perpetuating kinetochores. As such they are striking examples of genetic information being transmitted in a manner that is independent of DNA sequence (epigenetically). It has been found that RNA transcribed from centromeres remains bound within the kinetochore region, and this local population of RNA is thought to be part of the epigenetic marking system. Here we carried out a genetic and biochemical study of maize CENPC, a key inner kinetochore protein. We show that DNA binding is conferred by a localized region 122 amino acids long, and that the DNA-binding reaction is exquisitely sensitive to single-stranded RNA. Long, single-stranded nucleic acids strongly promote the binding of CENPC to DNA, and the types of RNAs that stabilize DNA binding match in size and character the RNAs present on kinetochores in vivo. Removal or replacement of the binding module with HIV integrase binding domain causes a partial delocalization of CENPC in vivo. The data suggest that centromeric RNA helps to recruit CENPC to the inner kinetochore by altering its DNA binding characteristics

Health and healthcare access among Zambia's female prisoners: a health systems analysis.

BackgroundResearch exploring the drivers of health outcomes of women who are in prison in low- and middle-income settings is largely absent. This study aimed to identify and examine the interaction between structural, organisational and relational factors influencing Zambian women prisoners' health and healthcare access.MethodsWe conducted in-depth interviews of 23 female prisoners across four prisons, as well as 21 prison officers and health care workers. The prisoners were selected in a multi-stage sampling design with a purposive selection of prisons followed by a random sampling of cells and of female inmates within cells. Largely inductive thematic analysis was guided by the concepts of dynamic interaction and emergent behaviour, drawn from the theory of complex adaptive systems.ResultsWe identified compounding and generally negative effects on health and access to healthcare from three factors: i) systemic health resource shortfalls, ii) an implicit prioritization of male prisoners' health needs, and iii) chronic and unchecked patterns of both officer- and inmate-led victimisation. Specifically, women's access to health services was shaped by the interactions between lack of in-house clinics, privileged male prisoner access to limited transport options, and weak responsiveness by female officers to prisoner requests for healthcare. Further intensifying these interactions were prisoners' differential wealth and access to family support, and appointments of senior 'special stage' prisoners which enabled chronic victimisation of less wealthy or less powerful individuals.ConclusionsThis systems-oriented analysis revealed how Zambian women's prisoners' health and access to healthcare is influenced by weak resourcing for prisoner health, administrative biases, and a prevailing organisational and inmate culture. Findings highlight the urgent need for investment in structural improvements in health service availability but also interventions to reform the organisational culture which shapes officers' understanding and responsiveness to women prisoners' health needs

Adhesion of Three Brands of Elastic Therapeutic Tape

Purpose: The purpose of this study was to compare, over a period of 5 days, the rate of adhesion of TheraBand® Kinesiology Tape (TKT) with either KT Tape® (KT) or Kinesio® Tex Gold (KTEX) under 25% elongation among healthy adults. Methods: In this study, 2 independent cohorts of 20 healthy volunteers were randomly assigned to simultaneously receive applications of 2 brands of deidentified elastic therapeutic tape (ETT) applied to their lower back at 25% elongation. Cohort 1 received TKT and KTEX tape, whereas cohort 2 received TKT and KT. Data were collected at 1 h (D1), 3 days (D3), and 5 days (D5) following the initial application of the ETT. Data collected included 3 digital photographs of the subjects’ lower back. The percentage of the tape that remained adhered (0%–100%) was assessed independently by 3 evaluators and then averaged to arrive at a percentage of tape adhesion for each brand of tape at each data collection point. Results: Repeated-measures ANOVA of cohort 1 indicated no differences (P \u3e .05) in adhesion between the TKT and KTEX at any data collection point, although post hoc analysis of the significant time effect indicated that the rate of adhesion of the KTEX brand declined from D1 (97%) to D3 (74%) to D5 (59%), whereas that of the TKT tape did not change over the duration of the study (97%, D1; 86%, D2; 70%, D3). In cohort 2, the analysis indicated a significant interaction effect with the KT brand (99%, D1; 67%, D2; 35%), declining over the course of the study and exhibiting lower rate of adhesion than the TKT (99%, D1; 83%, D2; 76%, D3) brand at D3 and D5. The rate of adhesion of the TKT tape did not significantly decline in cohort 2. Conclusions: Clinicians can use evidence from this study when choosing different ETT brands

Elastic response of [111]-tunneling impurities

We study the dynamic response of a [111] quantum impurity, such as lithium or cyanide in alkali halides, with respect to an external field coupling to the elastic quadrupole moment. Because of the particular level structure of a eight-state system on a cubic site, the elastic response function shows a biexponential relaxation feature and a van Vleck type contribution with a resonance frequency that is twice the tunnel frequency $\Delta/\hbar$. This basically differs from the dielectric response that does not show relaxation. Moreover, we show that the elastic response of a [111] impurity cannot be reduced to that of a two-level system. In the experimental part, we report on recent sound velocity and internal friction measurements on KCl doped with cyanide at various concentrations. At low doping (45 ppm) we find the dynamics of a single [111] impurity, whereas at higher concentrations (4700 ppm) the elastic response rather indicates strongly correlated defects. Our theoretical model provides a good description of the temperature dependence of $\delta v/v$ and $Q^{-1}$ at low doping, in particular the relaxation peaks, the absolute values of the amplitude, and the resonant contributions. From our fits we obtain the value of the elastic deformation potential $\gamma_t=0.192$ eV.Comment: 19 pages, 5 figure

Beyond behaviour as individual choice: a call to expand understandings around social science in health research

The focus of behavioural sciences in shaping behaviour of individuals and populations is well documented. Research and practice insights from behavioural sciences improve our understanding of how people make choices that in turn determine their health, and in turn the health of the population. However, we argue that an isolated focus on behaviour - which is one link in a chain from macro to the micro interventions - is not in sync with the public health approach which per force includes a multi-level interest. The exclusive focus on behaviour manipulation then becomes a temporary solution at best and facilitator of reproduction of harmful structures at worst. Several researchers and policymakers have begun integrating insights from behavioural economics and related disciplines that explain individual choice, for example, by the establishment of Behavioural Insight Teams, or nudge units to inform the design and implementation of public health programs. In order to comprehensively improve public health, we discuss the limitations of an exclusive focus on behaviour change for public health advancement and call for an explicit integration of broader structural and population-level contexts, processes and factors that shape the lives of individuals and groups, health systems and differential health outcomes