RESTORATION WORKFLOWS BY MEANS OF PHOTOGRAMMETRY: THE CASE STUDY OF PASHAS BRIDGE

The restoration of cultural heritage sites is a complex and challenging process, particularly when the structure holds significant historical and cultural value. This paper refers to the first stages of the restoration study of Pashas Bridge, one of the largest stone bridges in Greece that was destroyed during World War II and further damaged by an earthquake in 1995. The project was assigned to multiple research groups from the Aristotle University of Thessaloniki (AUTh) for a period of 18 months by the Greek Ministry of Culture and Sports. To restore the bridge effectively, it is essential to accurately record, document, and assess its current condition. Through the use of photogrammetry, which creates 3D models of objects or structures using images, and unmanned aerial vehicles (UAVs) which assisted in capturing multiple shots with various angles of the bridge, a detailed 3D model of the bridge’s current condition was generated. In addition to these technical approaches, historical research and documentation were utilized to understand the bridge's cultural heritage value. The process included an examination of historical photographs and records related to the bridge, with a constant effort to discover additional information about its history and importance. Ultimately, the restoration process of Pashas Bridge serves as a valuable case study for the effective restoration of cultural heritage sites. Through utilizing these resources, the team aims to restore the bridge to its former glory, preserving its cultural heritage value and ensuring its place as a valuable and integral part of the community for generations to come

Investigating the Electromechanical Behavior of Unconventionally Ferroelectric Hf0.5Zr0.5O2-Based Capacitors Through Operando Nanobeam X-Ray Diffraction

Understanding various aspects of ferroelectricity in hafnia-based nanomaterials is of vital importance for the development of future nonvolatile memory and logic devices. Here, the unconventional and weak electromechanical response of epitaxial La0.67Sr0.33MnO3/Hf0.5Zr0.5O2/La0.67Sr0.33MnO3 ferroelectric capacitors is investigated, via the sensitivity offered by nanobeam X-ray diffraction experiments during application of electrical bias. It is shown that the pristine rhombohedral phase exhibits a linear piezoelectric effect with piezoelectric coefficient (|d33|) ≈ 0.5–0.8 pmV−1. It is found that the piezoelectric response is suppressed above the coercive voltage. For higher voltages, and with the onset of DC conductivity throughout the capacitor, a second-order effect is observed. The work sheds light into the electromechanical response of rhombohedral Hf0.5Zr0.5O2 and suggests its (un)correlation with ferroelectric switching

Tailoring interfacial effect in multilayers with Dzyaloshinskii-Moriya interaction by helium ion irradiation

We show a method to control magnetic interfacial effects in multilayers with Dzyaloshinskii–Moriya interaction (DMI) using helium (He+) ion irradiation. We report results from SQUID magnetometry, ferromagnetic resonance as well as Brillouin light scattering results on multilayers with DMI as a function of irradiation fluence to study the effect of irradiation on the magnetic properties of the multilayers. Our results show clear evidence of the He+irradiation effects on the magnetic properties which is consistent with interface modification due to the effects of the He+ irradiation. This external degree of freedom offers promising perspectives to further improve the control of magnetic skyrmions in multilayers, that could push them towards integration in future technologies

Global bundle adjustment with variable orientation point distance for precise mars express orbit reconstruction

The photogrammetric bundle adjustment of line scanner image data requires a precise description of the time-dependent image orientation. For this task exterior orientation parameters of discrete points are used to model position and viewing direction of a camera trajectory via polynomials. This paper investigates the influence of the distance between these orientation points on the quality of trajectory modeling. A new method adapts the distance along the trajectory to the available image information. Compared to a constant distance as used previously, a better reconstruction of the exterior orientation is possible, especially when image quality changes within a strip. In our research we use image strips of the High Resolution Stereo Camera (HRSC), taken to map the Martian surface. Several experiments on the global image data set have been carried out to investigate how the bundle adjustment improves the image orientation, if the new method is employed. For evaluation the forward intersection errors of 3D points derived from HRSC images, as well as their remaining height differences to the MOLA DTM are used. In 13.5 % (515 of 3,828) of the image strips, taken during this ongoing mission over the last 12 years, high frequency image distortions were found. Bundle adjustment with a constant orientation point distance was able to reconstruct the orbit in 239 (46.4 %) cases. A variable orientation point distance increased this number to 507 (98.6 %).German Federal Ministry for Economic Affairs and Energy (BMWi)German Aerospace Center (DLR)/50 QM 130

The association between bullying and early stages of suicidal ideation in late adolescents in Greece

<p>Abstract</p> <p>Background</p> <p>Bullying in schools has been associated with suicidal ideation but the confounding effect of psychiatric morbidity has not always been taken into account. Our main aim was to test the association between bullying behavior and early stages of suicidal ideation in a sample of Greek adolescents and to examine whether this is independent of the presence of psychiatric morbidity, including sub-threshold symptoms.</p> <p>Methods</p> <p>5614 pupils 16-18 years old and attending 25 senior high schools were screened in the first phase and a stratified random sample of 2431 were selected for a detailed interview at the second phase. Psychiatric morbidity and suicidal ideation were assessed with the revised Clinical Interview Schedule (CIS-R) while bullying was assessed with the revised Olweus bully/victim questionnaire.</p> <p>Results</p> <p>Victims of bullying behavior were more likely to express suicidal ideation. This association was particularly strong for those who were bullied on a weekly basis and it was independent of the presence of psychiatric morbidity (Odds Ratio: 7.78; 95% Confidence Interval: 3.05 - 19.90). In contrast, being a perpetrator ("bullying others") was not associated with this type of ideation after adjustment. These findings were similar in both boys and girls, although the population impact of victimization in the prevalence of suicidal ideation was potentially higher for boys.</p> <p>Conclusions</p> <p>The strong cross-sectional association between frequent victimization and suicidal ideation in late adolescence offers an opportunity for identifying pupils in the school setting that are in a higher risk for exhibiting suicidal ideation.</p

Bullying behaviour in schools, socioeconomic position and psychiatric morbidity: a cross-sectional study in late adolescents in Greece

<p>Abstract</p> <p>Background</p> <p>Bullying is quite prevalent in the school setting and has been associated with the socioeconomic position and psychiatric morbidity of the pupils. The aim of the study was to investigate the association between bullying and socioeconomic status in a sample of Greek adolescents and to examine whether this is confounded by the presence of psychiatric morbidity, including sub-threshold forms of illness.</p> <p>Methods</p> <p>5,614 adolescents aged 16-18 years old and attending 25 senior high schools were screened and a stratified random sample of 2,427 were selected for a detailed interview. Psychiatric morbidity was assessed with a fully structured psychiatric interview, the revised Clinical Interview Schedule (CIS-R), while bullying was assessed with the revised Olweus bully/victim questionnaire. The following socio-economic variables were assessed: parental educational level and employment status, financial difficulties of the family and adolescents' school performance. The associations were investigated using multinomial logit models.</p> <p>Results</p> <p>26.4% of the pupils were involved in bullying-related behaviours at least once monthly either as victims, perpetrators or both, while more frequent involvement (at least once weekly) was reported by 4.1%. Psychiatric morbidity was associated with all types of bullying-related behaviours. No socioeconomic associations were reported for victimization. A lower school performance and unemployment of the father were significantly more likely among perpetrators, while economic inactivity of the mother was more likely in pupils who were both victims and perpetrators. These results were largely confirmed when we focused on high frequency behaviours only. In addition, being overweight increased the risk of frequent victimization.</p> <p>Conclusions</p> <p>The prevalence of bullying among Greek pupils is substantial. Perpetration was associated with some dimensions of adolescents' socioeconomic status, while victimization showed no socioeconomic associations. Our findings may add to the understanding of possible risk factors for bullying behaviours in adolescence.</p

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks