Rotation Type Research Articles

Designing a Motion-Onset Visual-Evoked Potential-Based Brain–Computer Interface to Control a Computer Game

Brain-computer interface (BCI) establishes an alternative direct communication channel between the brain and computer or other external devices. Motion-onset visual evoked potential (mVEP) related to the individual perception of movement is among synchronous BCI system that utilizes external stimulus. mVEPs stimulation paradigm is like an oddball stimulation paradigm. Researchers have recently been investigating mVEPs to control a computer game. To control a computer game, they used translation stimulus to evoke these potentials in EEG brain signals. In this study, we examine designing a computer game with four different types of stimuli, including translation, contraction, expansion, and rotation. We also used time-domain and wavelet coefficients for the feature extraction. Also, we used different types of linear discriminant analysis (LDA) classification methods, including least absolute shrinkage and selection operator (LASSO), stepwise LDA (SWLDA); moreover, and spatial-temporal discriminant analysis (STDA) for detecting the target stimulus. Our results demonstrate that contraction, expansion, and rotation stimuli, as well as translation, could be employed to control a BCI game. Our results showed that subjects got higher scores, game accuracy control, and information transfer rate using the rotation stimulus with SWLDA/STDA classification methods.

A structured literature review of empirical research on mandatory auditor rotation

This study reviews 128 empirical studies on mandatory auditor rotation (MAR) in light of the long-standing debate on the effectiveness of MAR and the different regulatory choices made worldwide over time. A structured literature review was conducted to address three research questions. How has empirical research on MAR developed from 2000 to 2022? What is the focus and critique of the empirical research on MAR? What is the future of MAR empirical research? The findings reveal growing empirical evidence on MAR. However, this evidence is fragmented and country-based. Scholars have primarily focused on audit firm rotation rather than audit partner rotation. While quantitative research based on archival data predominates, survey questionnaires prevail in a few regions. Evidence on how MAR impacts auditor independence, the auditor–client relationship, and audit market concentration is scant, whereas audit quality is the most investigated research question. Nonetheless, assessing whether MAR benefits audit quality remains challenging because the research outcomes depend on the research question, rotation type, research method, and regulations enforced in the empirical setting. Based on this comprehensive and rigorous overview of worldwide MAR empirical research, knowledge gaps are underlined, avenues for future research are suggested, and warnings are issued to shareholders and policymakers.

ANATOMY OF THE INSERTION OF THE POSTERIOR INFERIOR TIBIOFIBULAR LIGAMENT AND ITS RELEVANCE TO POSTERIOR MALLEOLAR ROTATIONAL PILON FRACTURES

IntroductionThe treatment of posterior malleolar fractures is developing. Mason and Molloy (Foot Ankle Int. 2017 Nov;38(11):1229-1235) identified only 49% of posterior malleolar rotational pilon type fractures had syndesmotic instabilities. This was against general thinking that fixation of such a fragment would stabilize the syndesmosis.MethodsWe examined 10 cadaveric lower limbs that had been preserved for dissection at the Human Anatomy and Resource Centre at Liverpool University in a solution of formaldehyde. The lower limbs were carefully dissected to identify the ligamentous structures on the posterior aspect of the ankle. To compare the size to the rotational pilon posterior malleolar fracture (Mason and Molloy 2A and B) we gathered information from our posterior malleolar fracture database. 3D CT imaging was analysed using our department PACS system.ResultsThe PITFL insertion on the posterior aspect of the tibia is very large. The average size of insertion was 54.9×47.1mm across the posterior aspect of the tibia. Medially the PITFL blends into the sheath of tibialis posterior and laterally into the peroneal tendon sheath.78 posterior lateral and 35 posterior medial fragments were measured. On average, the lateral to medial size of the posteromalleolar fragment was 24.5mm in the posterolateral fragment, and 43mm if there is a posteromedial fragment present also. The average distal to proximal size of the posterolateral fragment was 24.5mm and 18.5mm for the posteromedial fragment.ConclusionThe PITFL insertion on the tibia is broad. In comparison to the average size of the posterior malleolar fragments, the PITFL insertion is significantly bigger. Therefore, for a posterior malleolar fracture to cause posterior syndesmotic instability, a ligamentous injury will also have to occur. This explains the finding by Mason and Molloy that only 49% of type 2 injuries had a syndesmotic injury on testing.

Development and Microbiological Evaluation of Natural Diaper Rash (Diaper Dermatitis) Cream Formulations

Backround: Rosa damascena Mill, released into the environment as waste in rose products production facilities, contains antioxidant, antimicrobial, and antiseptic phenolic components. It is the development of an effective natural cream formulation for baby diaper rash by taking advantage of the antimicrobial properties of rose pulp and adding natural ingredients (zinc oxide ZnO, natural oils, and beeswax). Material and Methods: The emulsification method was used to prepare diaper rash cream formulations. Rotational type viscosity determination was performed to examine the rheological behavior of the formulations. In selecting the optimum formulation, pH, viscosity, hydrophilic-lipophilic balance, and physical appearance of the product were considered. To examine its stability properties, its stability was examined in three different environments in line with ICH directives for 6months. The optimum DR-C-7 formulation was subjected to physicochemical and stability tests. Results: It was observed that the DR-C-7 formulation had a viscosity between 9,820 and 26,130 (Pa.s) in terms of rheological properties. As a result of the challenge test, no microbiological units were found. At the end of a 6-month stability study under different conditions, it was observed that it retained all its features. Conclusion: It was concluded that R. damascena pulp, which has important phenolic contents such as phenylethyl alcohol, flavonoids, and terpenoids, can be used for thick products such as diaper rash cream with its antioxidant antimicrobial properties.

Biomechanical Effects of Hindfoot Alignment in Supination External Rotation Malleolar Fractures: A Human Cadaveric Model.

Pressure distribution in the ankle joint is known to be dependent on various factors, including hindfoot alignment. We seek to evaluate how hindfoot alignment affects contact pressures in the ankle joint in the setting of supination external rotation (SER) type ankle fractures. SER fractures were created in 10 human cadaver lower extremity specimens, simulating progressive stages of injury: without fracture (step 0), SER fracture and intact deltoid ligament (step 1), superficial deltoid ligament disruption (step 2), and deep deltoid ligament disruption (step 3). At each step, varus and valgus alignment was simulated by displacing the calcaneal tuberosity 7 mm medial or lateral. Each limb was axially loaded following each osteotomy at a static load of 350 N. The center of force (COF), contact area (CA), and peak contact pressure (PP) under load were measured, and radiographs of the ankle mortise were taken to analyze the medial clear space (MCS) and talar tilt (TT). The COF (5.3 mm, P = .030) and the CA (-188.4 mm2, P = .015) changed in step 3 in the valgus hindfoot alignment compared to baseline parameters, indicating the importance of deep deltoid ligament integrity in maintaining normal ankle joint contact stress in the valgus hindfoot. These changes were not seen in the setting of varus alignment (COF: 2.3 mm, P = .059; CA -121 mm2, P = .133). PP were found to not change significantly in either varus or valgus (varus: -4.9 N, P = .132; valgus: -4 N, P = .464).The MCS demonstrated widening in step 3 compared to step 2 (0.7 mm, P = .020) in both varus and valgus hindfoot. The TT increased significantly in step 3 in the valgus hindfoot (2.8 degrees, P = .020) compared to step 0. SER-IV fractures with valgus hindfoot alignment showed significant changes in pressure distribution and radiographic parameters when compared to SER-IV fractures with varus hindfoot alignment. Based on this cadaver modeling study, patients with SERIV fracture with varus hindfoot alignment and complete deltoid ligament lesion may not need fracture fixation, whereas those with valgus hindfoot alignment likely need fracture fixation.

Depression and associated risk factors among emergency medicine interns: Results from a national longitudinal cohort study.

Despite depression being common in residents, there are no published studies on the prevalence and risk factors for depression in emergency medicine (EM) interns. Our objectives were to explore the prevalence of depression among EM interns and to identify risk factors for depression including sleep, work hours, rotation type, race, ethnicity, sex, and age. The Intern Health Study is a national longitudinal cohort study on intern mental health in all specialties. Secondary analysis was performed for EM interns only in this study. Data were collected from 2007 to 2021 and study participants completed a pre-intern year baseline survey and quarterly surveys throughout intern year, which included demographics and information on depressive symptoms, work hours, sleep, and rotation specifics. Depression severity was objectified using the Patient Health Questionnaire (PHQ9) with scores of 10 and higher meeting criteria for moderate to severe depression. A total of 1123 EM interns completed all surveys. The prevalence of moderate to severe depression among EM interns before starting internship was 4.8%. At Months 3, 6, 9, and 12 of intern year, the prevalence of moderate to severe depression was 17.8%, 20.5%, 20.8%, and 18.8%, respectively. PHQ9 scores were significantly higher at Month 3 of intern year compared to pre-intern year, but there were no differences at subsequent time points during intern year (p < 0.001). Females were more likely to have PHQ9 scores of 10 or above at all time points (p < 0.001). Clinical rotation type had a significant effect on PHQ9 scores, with intensive care unit rotations having a significantly higher PHQ9 score than other rotations (p < 0.001). Pearson's correlation revealed significant weak positive correlations between work hours and PHQ9 at each time point (r = 0.195, 0.200, 0.202, 0.243) and significant weak negative correlations between sleep hours and time off with PHQ9 (-0.162, -0.223, -0.180, -0.178; all p < 0.001). Many EM interns experience moderate to severe depression. Female EM interns are more likely to be depressed than male interns. Numerous factors influence depression scores for interns, many of which are modifiable.

Review of: "The nucleus rotates around it, it also has a rotational motion around itself. This type of rotation in the structure of nanowires is called electron nanospin"

Review of: "The nucleus rotates around it, it also has a rotational motion around itself. This type of rotation in the structure of nanowires is called electron nanospin"

Association between trunk rotation and pelvic rotation in adolescents with idiopathic scoliosis.

Previous studies have suggested an association between pelvic rotation (PR) and scoliotic deformity in severe adolescent idiopathic scoliosis (AIS), but none have investigated this relationship in mild to moderate AIS. To investigate the relationship between PR and trunk rotation in mild to moderate AIS. This was a case-control study. The cases were 32 AIS patients with PR in the opposite direction to the thoracic curve, and the controls were 32 AIS patients with PR in the same direction as the thoracic curve. All patients were assessed with the Adams forwards bend test. Type II trunk rotation was selected as exposure. Logistic regression was used to estimate the association between PR direction and types of trunk rotation while accounting for confounders. Multiple linear regression was used to analyse the relationships between PR magnitude and the angle of trunk rotation (ATR). Logistic regression showed an unadjusted OR of 9.13 (95% CI 2.92-28.50, P< 0.001), and adjustment for sex and Cobb angle only slightly changed the OR (adjusted OR, 8.23; 95% CI, 2.51-27.01; P= 0.001). The concave/convex ratio was associated with ATR measurements in both cases (β=-0.379; P= 0.030) and controls (β=-0.468, P= 0.008). An association was found between PR and trunk rotation, which may help achieve more effective physiotherapy in mild to moderate AIS.

The Outcomes of Mini-Plate Fixation for Unstable Wagstaffe Tubercle Fracture, an Indirect Syndesmosis Injury in Rotational Ankle Fracture.

Background: Wagstaffe fracture constitutes an indirect injury to the AITFL and can precipitate syndesmotic instability. The prevailing fixation methods often involve the use of mini-screws or K-wires, with absorbable suture repair reserved for cases with small or comminuted fragments exhibiting instability. In this study, we devised a mini-plate fixation method capable of securing the fracture fragment irrespective of its size or condition. Methods: A retrospective chart review was conducted on patients who underwent surgery for ankle fractures between May 2022 and October 2023. The surgical technique involved direct fixation of the Wagstaffe fracture using mini-plate fixation. Radiologic evaluation was performed using postoperative CT images, and clinical outcomes were assessed using the OMAS and VAS. Results: Fourteen patients with an average age of 62.5 years were included. Most fractures were associated with the supination-external rotation type. The average preoperative OMAS significantly improved from 5.95 to 83.57 postoperatively. The average VAS score decreased from 7.95 preoperatively to 0.19 postoperatively. Conclusions: The mini-plate technique for Wagstaffe fractures exhibited dependable fixation strength, effective fracture reduction, a minimal complication rate, and judicious surgical procedure duration.

Dynamics of humus in field crop rotations on drained lands

The purpose of the research is to study the influence of different types of field crop rotation, fertilizers, drainage and hydrothermal conditions on the dynamics of humus in reclaimed soil. The studies were carried out on the experimental fields of the All-Russian Research Institute of Reclaimed Lands (reclamation sites “Kuzminskoye Boloto 2”, “Semenovskoye” and “Gubino” in the Tver region). Waterlogged soils were drained using closed drainage (inter-drain distance is 18–20 m, drain depth is 0.9–1.2 m). The soils of the experimental plots are soddy-podzolic, light loamy, gleyic, formed on a moraine or thin binomial. Observations of the dynamics of humus were carried out in the grain-grass-row, grain-grass, grain and grain-row types of crop rotation. The influence of crop rotation on the content of humus in the soil was determined, first of all, by the composition, the structure of the crops grown and agricultural technology of their cultivation. Due to plant residues, 56.6–76.5 % of the volume of mineralized humus were restored in grain-grass-row crop rotation, 51.8 % in grain, 26.4 % in grain-row crop rotation. The most significant qualitative changes in the composition of humus were observed in grain-grass-row crop rotation: with a positive humus balance, the ratio of humic and fulvic acids increased from 0.63 to 0.74. The use of organic and mineral fertilizers significantly changes the balance of humus in the arable layer of the soil. With an organic-mineral fertilizer system, the annual loss of humus (in kg/ha) on the drained plot was 6.8–11.4 times less, on the non-drained plot – 2.1–2.6 times less than in the variant without fertilizers. Drainage of waterlogged soils increases the role of fertilizers in the accumulation of humus, reduces its losses and improves the quality parameters of humus – the ratio of humic and fulvic acids in the composition of humus under the influence of drainage increased from 0.61 to 0.88. The impact on the dynamics of humus of hydrothermal conditions has been established. In years with a dry first half of the growing season, an increase in humus content is observed; in excessively wet years, on the contrary, a decrease is observed. The correlation coefficients of humus content with hydrothermal conditions in May-June were – 0.84 (in 1985–1993) and 0.95 (in 2014–2022).

The Relationship Of Temporary Job Rotation And Nurse Work Stress

Background: Work rotation does not always have a positive impact; productivity will decrease due to moving nurses to a new position, so there needs to be an adjustment again. In this type of temporary work rotation, there is a risk of problems because it is carried out in a relatively short period, and there is a lack of opportunity to adapt to a new environment, which can increase the work stress of nurses. Objective: To analyze the relationship between temporary work rotation and work stress of nurses in the Inpatient Hospital of the Hospital. Methods: Descriptive analytical research design with a cross-sectional approach, a total sample of 54 respondents selected using the Proportional Random Sampling technique. Results: The analysis test showed that as many as (53.7%) of respondents rated the temporary work rotation activity as "not good," and most of the respondents (70.4%) experienced "moderate" work stress. From the statistical test results obtained, p-value= 0.008 &lt;0.05). Conclusion: There is a significant relationship between temporary work rotation and the work stress of nurses. Establish an appropriate policy regarding the appointment of officers and placement of work units according to their competence or clinical area, a schedule of rotation activities and a rotation process, a program of direction related to Rotation, and application of Rotation so that nurses are not bored and stressed

Dynamics of crop yields depending on fertilizer, cultivation method and crop rotation type

Dynamics of crop yields depending on fertilizer, cultivation method and crop rotation type

Open Reduction and Internal Fixation for Supination-External Rotation Type IV Ankle Fractures by Means of Anterolateral and Posterolateral Approaches.

The present study aimed to analyze and compare the efficacy of the anterolateral and posterolateral approaches for surgical treatment of supination-external rotation type IV ankle fractures. This retrospective study enrolled 60 patients (60 feet) with supination-external rotation type IV ankle fractures, including 30 patients (30 feet) treated by means of the anterolateral approach and 30 patients (30 feet) treated by means of the posterolateral approach. Postoperative clinical efficacy was compared between the groups based on operation time, intraoperative blood loss, postoperative complications, fracture healing time, visual analog scale scores, Short Form-36 Health Survey scores, and American Orthopedic Foot and Ankle Society scores. Comparisons between the two groups were performed using independent-samples t tests and analyses of variance. Intragroup differences were compared using paired t tests, and the χ2 test was used to compare categorical variables. All 60 included patients completed follow-up ranging from 12 to 18 months (mean duration, 14.8 ± 3.5 months). Although baseline characteristics were similar in the two groups, there were significant differences in operation time (86.73 ± 17.44 min versus 111.23 ± 10.05 min; P < .001) and intraoperative blood loss (112.60 ± 25.05 mL versus 149.47 ± 44.30 mL; P < .001). Although fracture healing time (10.90 ± 0.66 weeks versus 11.27 ± 0.94 weeks; P = .087) was shorter in the anterolateral group than in the posterolateral group, the difference was not significant. Postoperative complications occurred in one and three patients in the anterolateral and posterolateral approach groups, respectively. Visual analog scale scores were significantly lower in the anterolateral group than in the posterolateral group (1.43 ± 0.50 versus 1.83 ± 0.75; P = .019), although there was no significant difference in Short Form-36 Health Survey scores between the groups (73.63 ± 4.07 versus 72.70 ± 4.04; P = .377). However, American Orthopedic Foot and Ankle Society scores were higher in the anterolateral group than in the posterolateral group (80.43 ± 4.32 versus 75.43 ± 11.32; P = .030). Both the anterolateral and posterolateral approaches can achieve good results in the treatment of supination-external rotation type IV ankle fractures. Compared with the posterolateral approach, the anterolateral approach is advantageous for the treatment of supination-external rotation type IV ankle fractures given its safety and ability to reduce trauma, clear field of view revealed, and allow for exploration and repair of the inferior tibiofibular anterior syndesmosis within the same incision.

Effects of motion type on motion-onset and steady-state visual evoked potentials: rotation vs. flicker.

The underlying mechanisms of information processing for two basic motion types, rotation and flicker, are not fully understood. Rotational and flickering animations at four speeds - 7 frames per second (fps), 8 fps, 11 fps, and 12 fps, respectively - are presented as visual stimuli. The motion-onset visual evoked potentials (VEPs) and steady-state VEPs (SSVEP) elicited by these motion stimuli were compared between the rotation and flicker motion types at time windows of 0-500 ms and 1000-5000 ms post-stimulus, respectively. The standardized low-resolution electromagnetic tomography (sLORETA) source localization was investigated as well. Four motion speeds had no effect on the whole VEP waveform in either the rotation or the flicker groups. Significant differences in motion-onset VEPs and sLORETA source localization were found between the rotation and the flicker motion types at time windows of 200-500 ms post-stimulus. For the time windows of 1000-5000 ms post-stimulus, both the rotation and flicker groups all demonstrated the characteristics of SSVEP, with the peak spectral topographies showing at the four different frequencies, which correspond to the four motion speeds. Additionally, a higher power of spectral topography at each of the four motion speeds was found in the rotation relative to the flicker stimulation. The perceptual and cognitive processes are distinct for two types of motion: rotation and flicker. In terms of motion-onset VEPs and the characteristics of SSVEP, rotating visual stimulation is superior to flicker stimulation and may be more appropriate for clinical and engineering applications.

Pengaruh Model Blended Learning terhadap Kemampuan Memecahkan Masalah Siswa pada Materi Faktor-Faktor yang Memengaruhi Laju Reaksi

Interviews with Chemistry teachers at SMA Negeri 3 Surabaya showed several problems, including low student motivation and teachers' lack of understanding of Chemistry concepts. The experimental study used a quantitative approach with a quasi-nonequivalent pretest-posttest control group experimental design. The Lab Rotation type Blended Learning model significantly improves students' problem-solving abilities in reaction rate chemicals. The results of statistical analysis showed P Alpha of 0.014 &lt; 0.05, and t count (t Stat) 2.53 &gt; t table (t Critical two-tail) 2.00. In conclusion, there is a positive influence of the blended learning model on the problem-solving ability of students in Chemistry material at SMA Negeri 3 Surabaya.

A block diagram approach to characterize the kinematic and torque relationship of three-port transmission mechanism

ABSTRACT This paper presents a kinematic and dynamic modeling of a three-port transmission mechanism using the block diagram technique. By exploiting the simplicity of the block diagram technique, unlike the more complex conventional approaches, the three-port transmission mechanism is systematically characterized to obtain the velocity kinematics and torque relationship. This is achieved by establishing a feedback connection of the three-port transmission mechanism in block diagram form, and obtain the close-loop input/output relationship using techniques known in the control community, such as Mason’s rule. Two categories of the three-port transmission mechanism were investigated including, the 1D rotation type (planetary gear) and the 2D rotation type (differential). The kinematic and dynamic expressions of both categories were shown to be easily obtained, identifying the characteristic differences. The velocity kinematics, torque relationships, and power analysis were expressed to validate the proposed modeling. Further verification using MATLAB Simulink shows a good agreement of the analytical expressions and the proposed block diagram model. To demonstrate the effective use of the proposed approach, the block diagram technique is applied in the design analysis of a south-pointing chariot device.

Epidemiology and Characteristics of Ankle and Foot Injuries in Electric Scooter-Related Accidents.

The use of electric scooters (e-scooters) continues to increase as a simple, inexpensive means of transport, resulting in a sharp increase in the incidence of scooter-related accidents. No study to date has closely examined the injury extent to the lower leg, joints, and extremities from e-scooter-related accidents. Here, we investigated the epidemiology and injury patterns of such accidents, focusing on injuries to the ankle and foot. Based on data from a single tertiary hospital's database, the demographics of 563 patients with scooter-associated injuries were analyzed retrospectively. Among the patients, 229 patients who were injured by e-scooter riding were further investigated. Based on the data, the general demographics of whole scooter-associated injuries and the injury characteristics and fracture cases of the lower leg, ankle, and foot were analyzed. During the 4-year study period, the number of patients injured by e-scooters increased every year. Lower extremities were the most common injury site (67.2%) among riders, whereas injuries to the head and neck (64.3%) were more common in riders of non-electric scooters. Among the lower leg, ankle, and foot injuries of riders (52 cases), the ankle joint (53.8%) was the most commonly injured site, followed by the foot (40.4%) and lower leg (21.2%). The fracture group scored significantly higher on the Abbreviated Injury Scale than the non-fracture group (p < 0.001). Among the fracture group (20 cases), ankle fractures (9 cases) were most common, including pronation external rotation type 4 injuries (4 cases) and pilon fractures (2 cases). Five patients (25%) had open fractures, and 12 patients (60%) underwent surgical treatment. The ankle and foot are the most common injury sites in e-scooter-related accidents. Given the high frequency and severity of e-scooter-related ankle and foot injuries, we suggest that more attention be paid to preventing these types of injuries with greater public awareness of the dangers of using e-scooters.

Evaluation of Serum 25-Hydroxyvitamin D Levels in Benign Paroxysmal Positional Vertigo Patients

Background: Benign paroxysmal positional vertigo (BPPV) is characterized by the occurrence of a rotational type of vertigo and nystagmus due to the otoconia dislodgment from the utricle into semicircular canals. Repeated vertigo attacks reduce the quality of life by affecting the normal daily activities in the population of all age groups. The most accepted theory for BPPV is the displaced otoconia particle, which aggravates vertigo and nystagmus. The otoconia is made of calcium carbonate, which is regulated by calcium homeostasis. Vitamin D receptors are essential for calcium regulation and homeostasis. Objectives: The objectives of this study are to estimate the serum 25-hydroxyvitamin D levels in BPPV patients and compare them with the healthy participants/control. Materials and Methods: This study was conducted in a tertiary care hospital in south India. In Group A (case group), patients diagnosed with BPPV were included and their serum 25-hydroxyvitamin D levels were measured and compared with the healthy individuals’ serum 25-hydroxyvitamin D levels in Group B (control group). Results: This study showed no significant difference in age and gender between the two groups (P = 0.99 and 0.323, respectively). The serum 25-hydroxyvitamin D levels were lower in Group A than in Group B (P = 0.005). The prevalence of Vitamin D deficiency in Group A was higher than that in Group B. Conclusion: There is an association between 25-hydroxyvitamin D levels and BPPV patients. Further studies on Vitamin D supplementation in BPPV patients with long-term follow-up will be beneficial to know whether Vitamin D deficiency is an associated risk factor for BPPV.

Characterization and geophysical evaluation of the recent 2023 Alausí landslide in the northern Andes of Ecuador

The province of Chimborazo located in the northern Andes of Ecuador presents many intrinsic factors, which contribute to the occurrence of mass movements, leaving in many of the cases registered damages of materials and loss of life. The recent landslide of March 26, 2023, in the Alausí canton is an event of great interest due to the magnitude of the occurred destruction and the corresponding fatalities. Therefore, there are two predominant objectives of the current study, of which the first has been to determine the most relevant characteristics of this mass movement by identifying and analyzing the geomorphology of the recorded slope movement and the lithological units involved, by field work and through geophysical surveys. Secondly, we performed a preliminary study of the possible triggers of the movement by means of the historical analysis of the precipitations during the months of January to March of the last decade and the study of the recent seismic series. However, through the obtained analysis, it is determined that the study site is composed of three distinctive lithological units. The observed mass movement is of the rotational type, as result of the intense rainfall that occurred during the first quarter of 2023, being hereby the most probable triggering factor. This corresponds to a 600% increase in the average monthly rainfall compared to the period from 2010 to 2022.

Characterizing the Background Noise Level of Rotational Ground Motions on Earth

Abstract The development of high-sensitive ground-motion instrumentation for Earth and planetary exploration is governed by so-called low-noise models, which characterize the minimum level of physical ground motions, observed across a very broad frequency range (0.1 mHz–100 Hz). For decades, broadband instruments for seismic translational ground-motion sensing allowed for observations down to the Earth’s low-noise model. Knowing the lowermost noise level distribution across frequencies enabled not only to infer characteristics of Earth such as the ocean microseismic noise (microseisms) and seismic hum, but also to develop highly successful ambient seismic noise analysis techniques in seismology. Such a low-noise model currently does not exist for rotational ground motions. In the absence of a substantial observational database, we propose a preliminary rotational low-noise model (RLNM) for transverse rotations based on two main wavefield assumptions: the frequency range under investigation is dominated by surface-wave energy, and the employed phase velocity models for surface waves are representative. These assumptions hold, in particular, for a period range of about 2–50 s and lose validity towards long periods when constituents produced by atmospheric pressure dominate. Because noise levels of vertical and horizontal accelerations differ, we expect also different noise levels for transverse and vertical rotations. However, at this moment, we propose a common model for both types of rotations based on the transverse RLNM. We test our RLNM against available direct observations provided by two large-scale ring lasers (G-ring and ROMY) and array-derived rotations (Piñon Flats Observatory array, Gräfenberg array, and ROMY array). We propose this RLNM to be useful as guidance for the development of high-performance rotation instrumentation for seismic applications in a range of 2–50 s. Achieving broadband sensitivity below such a RLNM remains a challenging task, but one that has to be achieved.