Delayed Repositioning in Teeth with Horizontal Root Fracture: Two Case Reports

Introduction: Horizontal root fracture (HRF) generally has a good prognosis of healing at fracture line after repositioning and flexible splinting. However, various factors such as delayed referral may unfavorably influence close reduction of firmly displaced coronal fragments and the long-term prognosis of healing at fracture line. Case 1: A 25-year-old woman with HRF in her maxillary central incisors was referred 1 week after trauma. Repositioning of the displaced coronal fragment was not successful for the left central incisor. Despite questionable prognosis for this case, reduction and flexible splinting was performed after removing it’s coronal fragment, minor curettage in alveolar socket and immediate replanting. Calcium hydroxide dressing and MTA plug placement for the coronal fragment were carried out after 1 and 3 weeks, respectively. The crown was restored and a minor permanent splint was applied after splint removal. Case 2: The above protocol was applied for a 17-year-old boy with HRF in his left maxillary central incisor. He referred 3 weeks after trauma with a firmed displaced coronal fragment. At four-year follow-up in both patients, the teeth were clinically in function and the patients were asymptomatic. The periapical radiographs revealed complete healing at fracture lines

Square Kilometre Array Science Data Challenge 1: analysis and results

As the largest radio telescope in the world, the Square Kilometre Array (SKA) will lead the next generation of radio astronomy. The feats of engineering required to construct the telescope array will be matched only by the techniques developed to exploit the rich scientific value of the data. To drive forward the development of efficient and accurate analysis methods, we are designing a series of data challenges that will provide the scientific community with high-quality data sets for testing and evaluating new techniques. In this paper, we present a description and results from the first such Science Data Challenge 1 (SDC1). Based on SKA MID continuum simulated observations and covering three frequencies (560, 1400, and 9200 MHz) at three depths (8, 100, and 1000 h), SDC1 asked participants to apply source detection, characterization, and classification methods to simulated data. The challenge opened in 2018 November, with nine teams submitting results by the deadline of 2019 April. In this work, we analyse the results for eight of those teams, showcasing the variety of approaches that can be successfully used to find, characterize, and classify sources in a deep, crowded field. The results also demonstrate the importance of building domain knowledge and expertise on this kind of analysis to obtain the best performance. As high-resolution observations begin revealing the true complexity of the sky, one of the outstanding challenges emerging from this analysis is the ability to deal with highly resolved and complex sources as effectively as the unresolved source population

Numerical simulations of jets

When astrophysical jets were discovered one hundred years ago, the field of numerical simulations did not yet exit. Since the arrival of programmable computers though, numerical simulations have increasingly become an indispensable tool for dealing with “tough nut” problems which involve complex dynamic and non-linear phenomena. Astrophysical jets are an ideal example of such a tough nut, where multi-scale plasma physics, radiative and non-thermal processes, turbulence and relativity combine to present a formidable challenge to researchers. Highlighting major achievements obtained through numerical simulations concerning the validity and nature of the Blandford–Znajek mechanism, the launching, collimation, acceleration and stability of jets, their interaction with the surrounding plasma, jet-galaxy feedback mechanisms etc., we trace how the field developed from its first tentative steps into the age of “maturity”. We also give a brief and personal outlook on how the field may evolve in the foreseeable future