Elastic Correlations in Nucleosomal DNA Structure

The structure of DNA in the nucleosome core particle is studied using an elastic model that incorporates anisotropy in the bending energetics and twist-bend coupling. Using the experimentally determined structure of nucleosomal DNA [T.J. Richmond and C.A. Davey, Nature {\bf 423}, 145 (2003)], it is shown that elastic correlations exist between twist, roll, tilt, and stretching of DNA, as well as the distance between phosphate groups. The twist-bend coupling term is shown to be able to capture these correlations to a large extent, and a fit to the experimental data yields a new estimate of G=25 nm for the value of the twist-bend coupling constant

A Precision Angle Sensor using an Optical Lever inside a Sagnac Interferometer

We built an ultra low noise angle sensor by combining a folded optical lever and a Sagnac interferometer. The instrument has a measured noise floor of 1.3 prad / Hz^(1/2) at 2.4 kHz. We achieve this record angle sensitivity using a proof-of-concept apparatus with a conservative N=11 bounces in the optical lever. This technique could be extended to reach sub-picoradian / Hz^(1/2) sensitivities with an optimized design.Comment: 3 pages, 4 figure

Antibiotic Stewardship Among Primary Care Providers In Mississippi

The World Health Organization states antimicrobial resistance is the ability of a microorganism to stop an antimicrobial from working which results in ineffective treatment and persistent infections. The Center for Disease Control and Prevention (CDC, 2017) reported that in the year 2015, 269.4 million antibiotic prescriptions were written in the outpatient setting, and approximately 30% of antibiotics written are unwarranted. Of those cases, most patients receive an antibiotic related to acute uncomplicated bronchitis, pharyngitis, or rhinosinusitis. The CDC reported that Americans spend nearly $11 billion yearly on antibiotics alone. However, up to 50% of all antibiotics prescribed are not indicated or optimally effective which eventually leads to resistance. Antibiotic resistant infections are associated with loss of productivity, poorer health outcomes, and greater healthcare costs. The CDC launched The Get Smart: Know When Antibiotics Work campaign in 2003 which aimed to direct appropriate antibiotic use (CDC, 2017). Within this campaign, the CDC provides outpatient regarding condition, epidemiology, diagnosis, and management for providers to follow for appropriate prescription. The purpose of this study was to determine if primary care providers in Mississippi are following the CDC Adult Treatment Recommendations for antibiotic use in the treatment of acute uncomplicated bronchitis, streptococcal pharyngitis, and acute unspecified pharyngitis (CDC, 2016). The researchers collected data in six rural clinics across Mississippi. This study consisted of a quantitative, retrospective chart review with descriptive statistics. A convenience sampling of 582 charts were obtained for the retrospective review. For data collection, the researchers used a data collection tool which included information related to age, gender, insurance, title o f provider, and diagnoses related to the current research and CDC Adult Treatment Recommendations. Prior to conducting the study, consent was obtained from the Institutional Review Board (IRB) at the Mississippi University for Women. After data collection, data were subjected to analyses using descriptive statistics including, but not limited to, frequency, distributions, and percentages. The findings suggested that primary care providers in Mississippi are not consistently following the CDC Adult Treatment Recommendations for acute pharyngitis and uncomplicated bronchitis

Antibiotic repeat prescriptions: are patients not re-filling them properly?

Objective: This study aimed to explore patients’ utilization of repeat prescriptions for antibiotics indicated in upper respiratory tract infections (URTI). An emphasis was placed on whether the current system of repeat prescriptions contributes to patients self-diagnosing infections and if so, identify the common reasons for this. Methods: This is a prospective study of self-reported use of repeat antibiotic prescriptions by pharmacy consumers presenting with repeat prescriptions for antibiotics commonly indicated in URTIs. Data were collected via self-completed surveys in Perth metropolitan pharmacies. Results: A total of 123 respondents participated in this study from 19 Perth metropolitan pharmacies. Of the respondents, approximately a third of them (33.9%) presented to the pharmacy to fill their antibiotic repeat prescription one month or more from the time the original prescription was written (i.e. time when original diagnosis was made by a doctor). Over two thirds of respondents indicated to not have consulted their doctor prior to presenting to the pharmacy to have their antibiotic repeat prescription dispensed (i.e. 68.3%). The most common reasons for this were that their ‘doctor had told them to take the second course’ (38%), followed by potential self-diagnosis (29%), i.e. ‘they had the same symptoms as the last time they took the antibiotics’. Approximately one third (33.1%) of respondents indicated they ‘were not told what the repeat prescription was needed for’ when they were originally prescribed the antibiotic. Respondents who presented to fill their repeat prescription more than 2 weeks after the original prescription written were more likely not have consulted their doctor (p = 0.006, 95% CI [1.16, 2.01]) and not to know why their repeat was needed (p = 0.010, 95% CI [1.07,2.18]).Conclusions: Findings of this study suggested that the current 12 month validity of antibiotics repeat prescriptions is potentially contributing to patients’ self-diagnosis of URTIs and therefore potential misuse of antibiotics. This may be contributing to the rise of antimicrobial resistance. The study also outlines some common reasons for patients potentially self-diagnosing URTIs when using repeat prescriptions. Larger Australian studies are needed to confirm these findings

Confluent Orthogonal Drawings of Syntax Diagrams

We provide a pipeline for generating syntax diagrams (also called railroad diagrams) from context free grammars. Syntax diagrams are a graphical representation of a context free language, which we formalize abstractly as a set of mutually recursive nondeterministic finite automata and draw by combining elements from the confluent drawing, layered drawing, and smooth orthogonal drawing styles. Within our pipeline we introduce several heuristics that modify the grammar but preserve the language, improving the aesthetics of the final drawing.Comment: GD 201

Power-Based Droop Control in DC Microgrids Enabling Seamless Disconnection From Upstream Grids

This paper proposes a local power-based droop controller for distributed energy resource converters in dc microgrids that are connected to upstream grids by grid-interface converters. During normal operation, the grid-interface converter imposes the microgrid bus voltage, and the proposed controller allows power flow regulation at distributed energy resource converters\u2019 output. On the other hand, during abnormal operation of the grid-interface converter (e.g., due to faults in the upstream grid), the proposed controller allows bus voltage regulation by droop control. Notably, the controller can autonomously convert from power flow control to droop control, without any need of bus voltage variation detection schemes or communication with other microgrid components, which enables seamless transitions between these two modes of operation. Considering distributed energy resource converters employing the power-based droop control, the operation modes of a single converter and of the whole microgrid are defined and investigated herein. The controller design is also introduced. Furthermore, the power sharing performance of this control approach is analyzed and compared with that of classical droop control. The experimental results from a laboratory-scale dc microgrid prototype are reported to show the final performances of the proposed power-based droop control

An Atomic Gravitational Wave Interferometric Sensor in Low Earth Orbit (AGIS-LEO)

We propose an atom interferometer gravitational wave detector in low Earth orbit (AGIS-LEO). Gravitational waves can be observed by comparing a pair of atom interferometers separated over a ~30 km baseline. In the proposed configuration, one or three of these interferometer pairs are simultaneously operated through the use of two or three satellites in formation flight. The three satellite configuration allows for the increased suppression of multiple noise sources and for the detection of stochastic gravitational wave signals. The mission will offer a strain sensitivity of < 10^(-18) / Hz^(1/2) in the 50 mHz - 10 Hz frequency range, providing access to a rich scientific region with substantial discovery potential. This band is not currently addressed with the LIGO or LISA instruments. We analyze systematic backgrounds that are relevant to the mission and discuss how they can be mitigated at the required levels. Some of these effects do not appear to have been considered previously in the context of atom interferometry, and we therefore expect that our analysis will be broadly relevant to atom interferometric precision measurements. Finally, we present a brief conceptual overview of shorter-baseline (< 100 m) atom interferometer configurations that could be deployed as proof-of-principle instruments on the International Space Station (AGIS-ISS) or an independent satellite.Comment: 37 pages, 21 figure

Allocation in Practice

How do we allocate scarcere sources? How do we fairly allocate costs? These are two pressing challenges facing society today. I discuss two recent projects at NICTA concerning resource and cost allocation. In the first, we have been working with FoodBank Local, a social startup working in collaboration with food bank charities around the world to optimise the logistics of collecting and distributing donated food. Before we can distribute this food, we must decide how to allocate it to different charities and food kitchens. This gives rise to a fair division problem with several new dimensions, rarely considered in the literature. In the second, we have been looking at cost allocation within the distribution network of a large multinational company. This also has several new dimensions rarely considered in the literature.Comment: To appear in Proc. of 37th edition of the German Conference on Artificial Intelligence (KI 2014), Springer LNC