Abstract P-9: Excess of Nhp6 over Spt16/Pob3 is Necessary for Efficient Nucleosome Unfolding by yFACT

Background: DNA accessibility in chromatin is important for proper gene expression and is regulated by multiple factors. One of them is histone chaperone FACT, which conducts large-scale ATP-independent nucleosome unfolding that increases the accessibility of nucleosomal DNA. FACT binding results in dramatic DNA uncoiling from nucleosome, occurs without apparent loss of histones, and proceeds via an ‘all-or-none’ mechanism, but the detailed mechanism of this process is still unknown. FACT-dependent nucleosome unfolding modulates the accessibility of nucleosomal DNA, and it is an important function of FACT in the processes of transcription, DNA replication, and repair in vivo. Methods: Nucleosome-positioning DNA sequences containing fluorescent labels (Cy3 and Cy5) at positions 13/91 or 35/112 from the nucleosome boundary were used. Nucleosomes were assembled by transfer of histone octamers from chicken chromatin to nucleosomal DNA during dialysis from 2M NaCl. After dialysis nucleosomes were gel purified and used at a final concentration of 0.5nM for spFRET measurements or at 10nM for EMSA analysis. For complex formation nucleosomes were incubated in the presence of Spt16/Pob3(0.13μM) and Nhp6(1.3μM) for 10 min at 30°C in buffer containing 17mM HEPES, 2mM Tris-HCl, 0.8mM Na3EDTA, 0.11mM 2-merсaptoethanol, 150mM KCl, 11mM NaCl, 1.1%glycerin, 12% sucrose. In spFRET microscopy analysis, the proximity ratio EPR from each nucleosome was calculated based on the intensity of the signals, corrected to the background and plotted as relative frequency distribution. Each plot was fitted as a sum of two Gaussians to describe two conformational states of nucleosomes. The fractions of nucleosomes in different states were estimated by calculating the surface of areas under the corresponding Gaussian peaks as a fraction of the total area of the plot. Results: Here we report the results of our analysis of nucleosome unfolding by yeast FACT (yFACT) at different ratios of Spt16/Pob3 and Nhp6 using single-particle Förster resonance energy transfer (spFRET) microscopy. Our analysis suggests that the optimal ratio of Spt16/Pob3 to Nhp6 for the most efficient FACT-dependent nucleosome unfolding is 1:10. Importantly, a mere increase in the concentration of FACT results in a decrease of the functional activity, suggesting that the formation of a functional complex having a certain stoichiometry of Spt16/Pob3 to Nhp6 is essential for efficient FACT-dependent nucleosome unfolding. Conclusion: We determined that a certain ratio of Spt16/Pob3 to Nhp6 is essential for efficient FACT-dependent nucleosome unfolding, suggesting the formation of a functional FACT: Nhp6 complex.

A new approach to quantify angles and time of changes-of-direction during soccer matches

Background and aims Soccer players frequently perform change-of-directions (CODs) at various speeds during matches. However, tracking systems have shown limitations to measure these efforts. Therefore, the aim of the present study was to propose a new approach to measure CODs using a local positioning system (LPS), and clarify position-related difference in profile of CODs by using the approach. Methods The x- and y-coordinate data for each soccer player were measured with a local positioning system. Speed, acceleration, jerk, and direction of speed were derived from the coordinate data. Based on accelerations of above 2 m/s2, the onsets and ends of CODs derived from jerk were identified (COD duration). Changes of direction of speed (θCOD) were determined for the corresponding period. Six collegiate male soccer players performed CODs according to 13 set angles (0–180°; every 15°) so that differences between θCOD and set angle could be determined (Exp. 1). Relative frequency distributions of θCOD and number of CODs were determined in 79 collegiate and amateur male soccer players during 9 soccer matches (Exp. 2). Results In Exp. 1, θCOD was positively related to set angle (r = 0.99). Each θCOD was smaller than the corresponding set angle, and the difference became greater with increasing COD angle. In Exp. 2, The number of CODs in a match was 183 ± 39 across all positions. There were no significant position-related differences in the number of CODs. The duration of a COD was 0.89 ± 0.49 s across all positions. The relative frequency distribution of θCOD revealed that the number of CODs at 0–15° and 105–135° tended to be higher than those at other angles during soccer matches. Further, θCOD was affected by the speed at the onset of COD during soccer matches (Exp. 2). Conclusions The current findings demonstrate that θCOD derived from direction of speed and jerk may be a new indicator for evaluating COD during soccer matches.

Experience

Over the past few years, online reviews have become very important, since they can influence the purchase decision of consumers and the reputation of businesses. Therefore, the practice of writing fake reviews can have severe consequences on customers and service providers. Various approaches have been proposed for detecting opinion spam in online reviews, especially based on supervised classifiers. In this contribution, we start from a set of effective features used for classifying opinion spam and we re-engineered them by considering the Cumulative Relative Frequency Distribution of each feature. By an experimental evaluation carried out on real data from Yelp.com, we show that the use of the distributional features is able to improve the performances of classifiers.

On the information hidden in a classifier distribution

Classification tasks are a common challenge to every field of science. To correctly interpret the results provided by a classifier, we need to know the performance indices of the classifier including its sensitivity, specificity, the most appropriate cut-off value (for continuous classifiers), etc. Typically, several studies should be conducted to find all these indices. Herein, we show that they already exist, hidden in the distribution of the variable used to classify, and can readily be harvested. An educated guess about the distribution of the variable used to classify in each class would help us to decompose the frequency distribution of the variable in population into its components—the probability density function of the variable in each class. Based on the harvested parameters, we can then calculate the performance indices of the classifier. As a case study, we applied the technique to the relative frequency distribution of prostate-specific antigen, a biomarker commonly used in medicine for the diagnosis of prostate cancer. We used nonlinear curve fitting to decompose the variable relative frequency distribution into the probability density functions of the non-diseased and diseased people. The functions were then used to determine the performance indices of the classifier. Sensitivity, specificity, the most appropriate cut-off value, and likelihood ratios were calculated. The reference range of the biomarker and the prevalence of prostate cancer for various age groups were also calculated. The indices obtained were in good agreement with the values reported in previous studies. All these were done without being aware of the real health status of the individuals studied. The method is even applicable for conditions with no definite definitions (e.g., hypertension). We believe the method has a wide range of applications in many scientific fields.

Fragmented Rockfall Volume Distribution from Photogrammetry-Based Structural Mapping and Discrete Fracture Networks

The design of rockfall protection structures requires information about the falling block volumes. Computational tools for rockfall trajectory simulation are now capable of modeling block fragmentation, requiring the fragmented volume-relative frequency distribution of rockfalls as input. This can be challenging at locations with scarce or nonexistent rockfall records and where block surveys are not feasible. The work in this paper shows that simple discrete fracture network realizations from structural mapping based on photogrammetric techniques can be used to reliably estimate rock fall block volumes. These estimates can be used for dimensioning rockfall protection structures in cases where data is scarce or not available. The methodology is tested at two sites in the Canadian Cordillera where limestone outcrops have been the source of recurrent rockfalls. The results suggest that fragmentation will largely tend to occur through weak planes and expansion of non-persistent discontinuities, while other block breakage mechanisms exert less influence in the fragmented volume-relative frequency distribution of rockfalls. Therefore, block volume distribution can be estimated using a simple discrete fracture network (DFN) with fully persistent discontinuities. Limitations of the methods are also discussed, as well as potential future research to address such limitations.

Acceptance of Leadership Empowerment Efforts for Female Employees in Three Dental Hospitals

Introduction. Empowerment is an organisational effort in increasing the willingness and ability of employees to be more independent in performing their duties. Employee leadership empowerment substantially increases motivation, performance, and commitment to the organisation. Leadership empowerment includes self-determination, competence, meaning, and impact. The purpose of this study was to determine the acceptance of leadership empowerment efforts for female employees in three dental hospitals in Bandung. Methods. A descriptive survey was conducted and the study population was dental hospitals in Bandung. The exclusion criteria were dental hospitals which unwillingly followed the research. The inclusion criteria were dental hospitals that have empowered female employees. The data collection technique was performed with total sampling. The research sample amounted to 102 people from three dental hospitals—all data were collected using a validated questionnaire. Data analysis was performed using relative frequency distribution. Results. Leadership empowerment for female employees in three dental hospitals in Bandung has been given by each. The highest acceptance of empowerment efforts for female employees was shown by employees of Dental Hospital of Jenderal Achmad Yani University, followed by Dental Hospital of Universitas Padjadjaran, and subsequently Dental Hospital of Maranatha Christian University. The level of acceptance of empowerment efforts that need to be improved in three Dental Hospitals in Bandung was self-determination or autonomy at work. Employees must be given more freedom on performing their duties, developing their careers, and acting more independently. Conclusion. Acceptance of leadership empowerment for female employees in three dental hospitals in Bandung has been demonstrated in each. Acceptance of leadership empowerment efforts in all subdimensions of empowerment needs to be improved, primarily related to self-determination.

P381Conduction heterogeneity: impact of atrial fibrillation and underlying heart disease

Funding Acknowledgements CVON-AFFIP (914728), NWO-Vidi (91717339), Biosense Webster USA (ICD 783454) and Medical Delta. Background At present, it is unknown if intra-atrial conduction during sinus rhythm (SR) is influenced by prior atrial fibrillation (AF) episodes or by various underlying heart diseases (UHD). However, it is considered that structural and electrical remodeled atria contain more conduction abnormalities and prolonged conduction times (CTs). Purpose To determine the impact of AF episodes on conduction abnormalities and to distinguish conduction abnormalities between patients with ischemic heart disease (IHD), (ischemic and) valvular heart disease ((i)VHD) and congenital heart disease (CHD) by performing intraoperative high-resolution epicardial mapping. Methods The study population consists of 447 participants (325 male, age: 67.2 (58.9 – 73.1) years) with or without an history of AF (resp. N = 375 vs. N = 75) undergoing elective open heart surgery for either IHD (N = 238), (i)VHD (N = 169) or CHD (N = 40). High-resolution epicardial mapping of the right atrium (RA), Bachmann’s Bundle (BB), left atrium (LA) and pulmonary vein area (PVA) was performed during SR using a unipolar 128/192-electrode array (interelectrode distance: 2mm). Inter-electrode CTs (Δ local activation time between two adjacent electrodes) were quantified as the relative frequency distribution of CTs, cumulative incidence of CTs per patient (%) and the severity of CTs (%). Results Prior AF episodes were associated with prolongation of CTs (p < 0.05). Patients with AF had a higher cumulative incidence of CTs ≥4ms throughout both atria, with a predilection site at BB and LA (p < 0.05). In the RA, conduction delays ≥48 ms were more present in patients with AF (44.0% versus 30.7%, p = 0.03), whereas in BB patients with AF already had more prolonged conduction delays ³16 ms (91.8% versus 81.2%, p = 0.03). The relative frequency distribution of CTs did not differ between IHD, (i)VHD and CHD. Differences in the cumulative incidence of CTs between the three UHD were solely found at BB; patients with (i)VHD more frequently had incidence of CTs ³6ms than patients with IHD (p < 0.017). However, conduction delays were more pronounced in patients with CHD (≈≥30 – ≥84 ms) and with (i)VHD (≥72 – ≥84 ms)(p < 0.017). Also, more patients with (i)VHD had prolonged conduction delays (≥24 – ≥34 ms) than patients with IHD (p < 0.017). Conclusions Patients with AF had more and severer conduction abnormalities than patients without AF. Comparing the three UHD, mainly BB was affected by conduction abnormalities. (i)VHD was associated with more conduction abnormalities than IHD. Most severe conduction abnormalities were found in patients with CHD compared to both patients with IHD and (i)VHD. These findings indicate that the arrhythmogenic substrate is affected most by prior AF episodes, (i)VHD and CHD, and particularly present at BB.

Jenis-Jenis Vegetasi di Area Penangkaran Burung Maleo Desa Taima Kecamatan Bualemo Kabupaten Banggai

Macrocephalon maleo an endemic bird species to Sulawesi and classified as Endangered by the IUCN and on the Government of Indonesia's list of priority species for conservation. The study was conducted in April - July 2019, data collection was taken from nesting ground of the maleo bird in Taima Village, sub district Bualemo, districs Banggai. Data were collected from two transects on 5 plots, and were analysed its relative frequency distribution. The results showed that there were 18 plant species for all plots. In tree species plots are dominated by Quassia indica (29.42%), pole type plots are dominated by Thespesia populnea (11.86%), sapling plots are dominated by Cycas sp. (9.81%) and bush species plots were dominated by Justicia sp. L (31.98%). The results others showed that habitat Maleo at both locations consisted of trees with 7-15 meters tall and shrubs. Keywords: vegetation, plant, maleo, taima village.

The Use of Correlated Binomial Distribution in Estimating Error Rates for Firearm Evidence Identification

In the branch of forensic science known as firearm evidence identification, estimating error rates is a fundamental challenge. Recently, a new quantitative approach known as the congruent matching cells (CMC) method was developed to improve the accuracy of ballistic identifications and provide a basis for estimating error rates. To estimate error rates, the key is to find an appropriate probability distribution for the relative frequency distribution of observed CMCs overlaid on a relevant measured firearm surface such as the breech face of a cartridge case. Several probability models based on the assumption of independence between cell pair comparisons have been proposed, but the assumption of independence among the cell pair comparisons from the CMC method may not be valid. This article proposes statistical models based on dependent Bernoulli trials, along with corresponding methodology for parameter estimation. To demonstrate the potential improvement from the use of the dependent Bernoulli trial model, the methodology is applied to an actual data set of fired cartridge cases.

Assessing Curriculum Efficiency Through Monte Carlo Simulation

A Monte Carlo algorithm is designed to predict the average time to graduate by enrolling virtual students in a degree plan. The algorithm can be used to improve graduation rates by identifying bottlenecks in a degree plan (e.g., low pass rate courses and prerequisites). Random numbers are used to determine whether students pass or fail classes by comparing them to institutional pass rates. Courses cannot be taken unless prerequisites and corequisites are satisfied. The output of the algorithm generates a relative frequency distribution which plots the number of students who graduate by semester. Pass rates of courses can be changed to determine the courses that have the greatest impact on the time to graduate. Prerequisites can also be removed to determine whether certain prerequisites significantly affect the time to graduate.