Segmental Pattern Research Articles

PS‐InSAR post‐processing for assessing the spatio‐temporal differential kinematics of complex landslide systems: A case study of DeBeque Canyon Landslide (Colorado, USA)

AbstractThe complex superimposition of different kinematics and nested sectors within landslide systems amplifies the challenge of interpreting their heterogeneous displacement pattern and targeting effective mitigation solutions. As an example of such peculiar spatio‐temporal behaviour, the DeBeque Canyon Landslide (Colorado, USA) is emblematic of the application of interferometric post‐processing analysis for a detailed, remotely‐based investigation. We employed a multi‐geometry Persistent Scatterers (PS) InSAR dataset to provide continuous information on the spatio‐temporal scale and achieve a solid representation of the segmented kinematics and timings. Using an updated geomorphological map of the landslide system, we performed a two‐dimensional decomposition of the Persistent Scatterers (PS) dataset to determine the displacement orientation and inclination for each internal sector of the landslide system. We then conducted statistical analyses on the displacement vector characteristics and time series data. These analyses enabled us to spatially characterize the segmented activity patterns of the landslide system and identify abrupt changes in trends associated with preparatory and triggering factors. A clear differentiation of the rotational or translational kinematics within the landslide system was accomplished solely using surface displacement measures. Moreover, the application of a Bayesian model on the bi‐dimensional vector time series leads to the identification of significant differences in the deformational behaviour of each sector with respect to precipitation and temperature factors. Our approach represents a replicable method for local‐scale characterization and monitoring of landslides exhibiting complex spatio‐temporal displacement patterns and providing an effective, low‐cost solution for transportation agencies from a risk‐reduction perspective.

Preoperative evaluation of the segmental artery of left upper lobe by thin-section CT and 3d-CTA.

Understanding pulmonary artery (PA) branches and their variations is crucial for successful lung resection. We aimed to evaluate the segmental PA branching pattern of the left upper lobe (LUL) using thin-section computed tomography (TSCT) images and 3D-CT angiography (3D-CTA). This study included 108 patients who underwent CTA and left upper lobectomy. The segmental PA branching pattern of the LUL was meticulously identified by two thoracic radiologists using 3D-CTA and TSCT images. The lingular artery branches from the left PA (LPA) were classified into mediastinal type (pars mediastinalis: PM), interlobar type (pars interlobaris: PI), and PI originating from the lower portion (PI'), specifically from A8. The intraoperative findings of the PA branches of the LUL were compared with the preoperatively obtained 3D-CTA and TSCT images in each patient's case. The median (range) number of LPA branches of the LUL was 4.36 (3-8). The most common number of A1 + 2 branches was two, seen in 34 cases (31.5%). One or more branches of A1 + 2c directly originating from the LPA were found in 63 cases (58.3%). The number of branches of A3 was single in 85 cases and the most frequent (78.7%). Instances where one or more branches of A3a directly originated from the LPA were found in seven cases (6.5%). A1 + 2 and A3 origins were separate and independent in 40 cases (37.0%). As the branching pattern of the lingular artery, PI/PI' was most frequent (61.1%). PI´ was observed in 26 cases (24.1%). Inter-observer agreement for A1 + 2, A1 + 2c, A3, A3a, and lingular artery branching patterns was moderate to substantial (κ = 0.53-0.72). Preoperative 3D-CTA and TSCT images identified 99.8% of LPA branches compared to intraoperative findings, except one. The segmental PA branching pattern of the LUL can be evaluated using TSCT and 3D-CTA images, providing precise preoperative information.

Genotypes and phenotypes of capillary malformation-arteriovenous malformation: characterization and correlation analysis.

Capillary malformation-arteriovenous malformation (CM-AVM) is a rare genetic disorder characterized by multiple small capillary malformations (CMs) and arteriovenous malformations (AVMs), which has been linked with pathogenic variants in RASA1 and EPHB4. However, more data are needed to explore the phenotypic characteristics and the association between genotypes and clinical phenotypes. Our aim was to investigate the phenotypic and genetic characteristics of CM-AVM in East Asians, identify potential unique phenotypes, and conduct genotype-phenotype association analyses. This is a single-center study prospectively collecting CM-AVM patients' clinical data, with genetic data from blood or tissue samples. A total of 59 patients were enrolled. Thirty-two individuals had a leading CM greater than Schobinger stage II. The trigeminal nerve branches and greater auricular, transverse cervical, and lesser occipital nerves' somatosensory innervation zones divided head and neck CMs into six zones: V1, V2, V3, GA, TC, and LO zones. GA, TC, and LO zones had a positive correlation with one another but a negative correlation with V2 zone involvement. The RASA1 and EPHB4 pathogenic variants were detected in 41 out of 59, which showed two types of variant allele frequency (VAF) distributions. VAF above 30% made RASA1 pathogenic variants more susceptible to multifocal CMs than those below 30%. Leading CMs in the head and neck exhibit two segmentation patterns, anterior and lateral, which may differ in ear involvement and progression. Germline RASA1 pathogenic variants increased multifocal CM risk more than the somatic variants.

A Transtensional Fault Zone on the Northeastern Margin of the Tibetan Plateau: Millennial Earthquake Recurrence and High Earthquake Hazard

AbstractThe seismic gaps between ruptures of large earthquakes in tectonically active deformation zones are usually considered to be dangerous areas for future earthquakes. The Western Tianzhu Basin fault (WTBF) with an oblique normal motion is located in the middle of the Tianzhu seismic gap between the M 8.5 Haiyuan and M 8.0 Gulang earthquakes, NE Tibetan Plateau. The faulting activity of the WTBF is key to understanding the seismic hazards of the seismic gap, but it remains poorly constrained. Using satellite images, field investigations, paleoseismic trenching, and radiocarbon dating, we found that the WTBF produced seven paleoearthquakes since ∼8,000 cal. yr BP, with the latest event occurring at 1,005 ± 584 cal. yr BP, yielding an average recurrence interval of 1,102 ± 100 yr and a coefficient of variation of 0.38, indicating that it features a millennial quasi‐periodic recurrence. Based on the comparative analysis of geometry, kinematics, and tectonic activity, we suggest that the Tianzhu seismic gap can be divided into three sections and is characterized by a segmented rupture pattern. Among them, the WTBF and Jinqianghe fault exhibit similar geometry and kinematics and together form the ∼55 km‐long Jinqianghe‐Tianzhu transtensional fault zone (JTTFZ) that is capable of producing earthquakes of Mw 7.2. Given the long elapsed time since the latest event and strong seismogenic potential, it is believed that the JTTFZ poses a high seismic hazard. Our results enhance the understanding of the high seismic hazard in seismic gaps and provide new insights into the seismic rupture behavior in the NE Tibetan Plateau.

Translation Consistent Semi-supervised Segmentation for 3D Medical Images.

3D medical image segmentation methods have been successful, but their dependence on large amounts of voxel-level annotated data is a disadvantage that needs to be addressed given the high cost to obtain such annotation. Semi-supervised learning (SSL) solves this issue by training models with a large unlabelled and a small labelled dataset. The most successful SSL approaches are based on consistency learning that minimises the distance between model responses obtained from perturbed views of the unlabelled data. These perturbations usually keep the spatial input context between views fairly consistent, which may cause the model to learn segmentation patterns from the spatial input contexts instead of the foreground objects. In this paper, we introduce the Translation Consistent Co-training (TraCoCo) which is a consistency learning SSL method that perturbs the input data views by varying their spatial input context, allowing the model to learn segmentation patterns from foreground objects. Furthermore, we propose a new Confident Regional Cross entropy (CRC) loss, which improves training convergence and keeps the robustness to co-training pseudo-labelling mistakes. Our method yields state-of-the-art (SOTA) results for several 3D data benchmarks, such as the Left Atrium (LA), Pancreas-CT (Pancreas), and Brain Tumor Segmentation (BraTS19). Our method also attains best results on a 2D-slice benchmark, namely the Automated Cardiac Diagnosis Challenge (ACDC), further demonstrating its effectiveness. Our code, training logs and checkpoints are available at https://github.com/yyliu01/ TraCoCo.

The Use of Nitinol Staples as Reduction Aids in Fixation of Forearm Diaphyseal Fractures: Surgical Technique and Case Series.

Forearm diaphyseal fractures are common orthopedic injuries that typically require surgical intervention using various implants and approaches. Maintaining reduction while simultaneously achieving compression in radial and/or ulnar shaft fractures during compression plate application can be challenging, particularly with unstable segmental and/or transverse fracture patterns. Nitinol compression staples have become increasingly used as a reduction aid because of their ability to provide continuous compression between the staple legs at the fracture site, low profile, and ease of application. These staples have the potential to be an effective means of maintaining reduction and applying compression before definitive plate fixation for radial and ulnar shaft fractures. We present our surgical technique and an associated patient series detailing our institution's experience, highlighting favorable outcomes and potential considerations when using nitinol compression staples for forearm fracture management.

Experimental results using large area picosecond photo-detectors

We present experimental results obtained with the LAPPD Gen-II large-size MCP-PMT. Using a custom-designed PCB capacitively coupled to the anode backplane with different segmentation patterns, the photo-detector is read out using the PETsys TOFPET2 and FastIC ASICs. The results reported in this paper include characterization using focused laser light and temporal response to picosecond illumination at a single photon level.

Linear and whorled nevoid hypermelanosis: A report of two unusual cases of pigmentary mosaicism

Linear and whorled nevoid hypermelanosis (LWNH) is a rare pigmentary disorder presenting with brownish macules in a streaky configuration along the lines of Blaschko. A 5-year-old and a 6-year-old girl presented with multiple linear streaks of hyperpigmentation following the lines of Blaschko over the left half of their bodies for 2 years. The 5-year-old girl child also had several depigmented patches on her right arm and side of her back that were arranged in a segmental pattern. Dermoscopy of the depigmented patches showed a diffuse white color with leukotrichia, whereas hyperpigmented patches showed brownish curved lines, dots, and clods with focally dispersed whitish globules and lines. Here, we report one case of LWNH associated with segmental vitiligo and two girls with late-onset LWNH.

Programming gel automata shapes using DNA instructions

The ability to transform matter between numerous physical states or shapes without wires or external devices is a major challenge for robotics and materials design. Organisms can transform their shapes using biomolecules carrying specific information and localize at sites where transitions occur. Here, we introduce gel automata, which likewise can transform between a large number of prescribed shapes in response to a combinatorial library of biomolecular instructions. Gel automata are centimeter-scale materials consisting of multiple micro-segments. A library of DNA activator sequences can each reversibly grow or shrink different micro-segments by polymerizing or depolymerizing within them. We develop DNA activator designs that maximize the extent of growth and shrinking, and a photolithography process for precisely fabricating gel automata with elaborate segmentation patterns. Guided by simulations of shape change and neural networks that evaluate gel automata designs, we create gel automata that reversibly transform between multiple, wholly distinct shapes: four different letters and every even or every odd numeral. The sequential and repeated metamorphosis of gel automata demonstrates how soft materials and robots can be digitally programmed and reprogrammed with information-bearing chemical signals.

Rupture segmentation on the East Anatolian fault (Turkey) controlled by along-strike variations in long-term slip rates in a structurally complex fault system

Abstract The East Anatolian fault in Turkey exhibits along-strike rupture segmentation, typically resulting in earthquakes with moment magnitude (Mw) up to 7.5 that are confined to individual segments. However, on 6 February 2023, a catastrophic Mw 7.8 earthquake struck near Kahramanmaraş (southeastern Turkey), defying previous expectations by rupturing multiple segments spanning over 300 km and overcoming multiple geometric complexities. We explore the mechanics of successive single- and multi-segment ruptures using numerical models of the seismic cycle calibrated to historical earthquake records and geodetic observations of the 2023 doublet. Our model successfully reproduces the observed historical rupture segmentation and the rare occurrence of multi-segment earthquakes. The segmentation pattern is influenced by variations in long-term slip rate along strike across the kinematically complex fault network between the Arabian and Anatolian plates. Our physics-based seismic cycle simulations shed light on the long-term variability of earthquake size that shapes seismic hazards.

Segmentation and spending patterns in the Saudi Arabian coffee market

Segmentation and spending patterns in the Saudi Arabian coffee market

A Study on the Pattern of Arterial Segmentation in the Human Spleen

Abstract Background: Partial splenectomy is preferred after splenic injuries, which will help to preserve healthy splenic tissue, hence the immunity. During splenic surgery particularly in the resection of a segment of the spleen, ligation of branches of the splenic artery is necessary. A precise knowledge of the segmental arteries is prerequisite because the spleen is separated into avascular lobes and segments by splenic arterial branches. The aim of the present work was to study the pattern of arterial segmentation in the human spleen and variations of the splenic arterial pattern. Methodology: The present study was conducted on 31 spleens with intact splenic artery after getting the ethical clearance. Specimens were collected depending on the availability of cadaver or unclaimed autopsy body. Tracing from terminal branches, the segmental branches of the splenic artery were studied by piece-meal dissection. The terminal branches of the splenic artery and its segmental branches were cleaned and observed. The number of the segmental branches of the spleen and the presence of arterial anastomosis between adjacent segmental arteries were noted. Results: The splenic artery terminated as bifurcation in 66.73% and trifurcation in 33.27%. We also found two, three, four, five, six, and seven arterial segments in 2 (6.46%), 14 (45.16%), 7 (22.58%), 3 (9.67%), 3 (9.67%), and 2 (6.46%) specimens, respectively. These segments are separated by an avascular plane in all specimens except one where we found intersegmental arterial anastomosis. Conclusions: Knowledge of the splenic arterial branching pattern of the present study may help the general surgeon as well as surgical gastroenterologist in performing the surgery of the spleen, particularly partial splenectomy after splenic injuries. This may also help anatomists in learning and teaching arterial segmentation of the spleen.

An Unusual Glomerulopathy with Subepithelial Deposits Having Microspherular Structures Following COVID-19 Vaccine

We report an unusual glomerulopathy with nephrotic syndrome and acute kidney injury almost two weeks after the second injection of SARS CoV-2 vaccine covishield, ChAdOx1-nCoV-19 in a 75-year-old healthy man. Kidney biopsy revealed segmental stage 1 membranous glomerulopathy and collapsing focal segmental glomerulosclerosis pattern with immune complexes on IF. Electron microscopy (EM) revealed aggregates of spherular microparticles along glomerular capillary walls. After starting him on steroids, his kidney functions gradually improved with significantly reduced proteinuria. Our patient seems to be the only reported SARS CoV-2 vaccine-induced early membranous nephropathy showing a collapsing focal segmental glomerulosclerosis pattern and immune complexes on IF with subepithelial deposits consisting of microspherular particles on EM.

A Comparative Analysis on the Histomorphometric Pattern of Various Segments of Adult Male Long Bones: Forensic Implication

Abstract Background: Human bone analysis is a useful tool in assessing and identifying skeletal remains. To make this easier, newer and modified approaches have often being documented. Aims and Objectives: The aim of this study is to analyze the histomorphometric features of various bone segments and its relevance in forensic case diagnosis. Materials and Methods: The human bones used were that of cadaveric bone samples harvested from three adult male Nigerians. The proximal, midshaft and distal segments of the femur, tibia, and humerus were utilized for the study. The bone sections were subjected to processing using Frost’s rapid manual preparation of ground sections techniques. Histomorphometric evaluation studied the number of primary osteons, secondary osteons, and osteon fragments, as well as the Haversian canal diameter (HCD). Results: The primary osteons, secondary osteons, osteon fragments, and HCD in each of the segments of the long bones show that the F values are less than the F critical for an alpha level of 0.05. This shows that there is no statistically significant (P > 0.05) variation in the histomorphometric pattern for the various segments of the bones studied. Again differences in the haversian canal diameter of the various segments of the long bones shows statistically significant variation (P< 0.05) among the long bones investigated. Conclusion: These findings have laid to rest the challenges with using the only available bone fragment for forensic case investigation as no notable variations exist across various segments.

On Entropic Learning from Noisy Time Series in the Small Data Regime.

In this work, we present a novel methodology for performing the supervised classification of time-ordered noisy data; we call this methodology Entropic Sparse Probabilistic Approximation with Markov regularization (eSPA-Markov). It is an extension of entropic learning methodologies, allowing the simultaneous learning of segmentation patterns, entropy-optimal feature space discretizations, and Bayesian classification rules. We prove the conditions for the existence and uniqueness of the learning problem solution and propose a one-shot numerical learning algorithm that-in the leading order-scales linearly in dimension. We show how this technique can be used for the computationally scalable identification of persistent (metastable) regime affiliations and regime switches from high-dimensional non-stationary and noisy time series, i.e., when the size of the data statistics is small compared to their dimensionality and when the noise variance is larger than the variance in the signal. We demonstrate its performance on a set of toy learning problems, comparing eSPA-Markov to state-of-the-art techniques, including deep learning and random forests. We show how this technique can be used for the analysis of noisy time series from DNA and RNA Nanopore sequencing.

Spatiotemporal evolution and influencing factors of flood control storage sedimentation in the Three Gorges Reservoir, Changjiang River, China

Reservoir sedimentation is a pivotal concern in global reservoir management, exerting substantial influence on the long-term functionality, operational efficiency, and environmental sustainability of reservoirs. In this study, we investigated the spatiotemporal variations and influencing factors associated with sedimentation in the Three Gorges Reservoir (TGR) in China, focusing on the flood control storage (FCS) by using measured data from 2003 to 2022. The Sediment Budget Model (SBM) and the Section Topography Method (STM) were used to quantify sedimentation, and Pearson’s correlation analysis was performed to identify key factors affecting sedimentation. Results indicated that sedimentation in the FCS experienced two stages, it initially declined from 2011 to 2016, followed by a gradual increase since then. Sedimentation in the FCS resulted confined to the permanent backwater area, and it displayed a segmented distribution pattern. Although the sedimentation rate showed a decreasing trend since 2013, the heavy flood events in the tributary of the Jialing River could be the major sedimentation risk in the TGR in the future. Sedimentation in the FCS mainly occurred when the flood retention capacity was used during the wet season, and the increase in streamflow and flood retention amount could significantly stimulate sedimentation in the FCS. The current findings not only facilitate the understanding of sedimentation characteristics in the FCS of the TGR, but also benefit sustainable and effective sediment management strategies for other large reservoirs worldwide.

Measuring the roles of variation and phonological density into the development of branching CCV onsets in Brazilian Portuguese

This study focuses on the acquisition of CCV syllables (Consonant1+Consonant2+Vowel) in Brazilian Portuguese. Our aim is to cast light on the roles of linguistic variation and phonological density into the phonotactic development. We used adult and child directed speech corpora to quantify the optional process of CCV→CV reduction in unstressed contexts in the input, as well as the frequency, segmental pattern, and phonological density of CCV syllables. Based in their distributional properties, we argue that CCV acquisition in BP goes through a moment of incorrect structural and segmental contrast neutralization, modelled by the Tolerance Principle (Yang 2006). The neutralization is caused by an overgeneralization of CCV variation, combined with CCV-CV low density; and an overgeneralization of the C/ɾ/V frequent segmental pattern, combined with the low density of C/ɾ/V-C/l/V but high density and equal frequency of /ɾ/V-/l/V.Data from a mispronunciation detection task confirms that the phonological density influences the development: children who do not articulate CCV syllables detect more CCV→CV stimuli when there are phonological neighbors (/pɾato/→[ˈpa.tʊ], but not /pɾeto/→*[ˈpe.tʊ]) and high phonological density ([l]V↔[ɾ]V are detected, but not C[l]V↔C[ɾ]V, with the lowest rates of detection in the C/l/V→C[ɾ]V direction).

Pre-tension design and research of cable net structure for space modular deployable antenna

Modular deployable antennas represent an ideal structural form for the development of large-aperture antennas because of their flexibility, adaptability, and high versatility. To enhance the surface accuracy of the antenna after deployment, a comprehensive pre-tension design method that considers truss deformation and tension uniformity is proposed. First, the configuration design of the antenna cable net is constructed, and the mathematical models for cable length under surface accuracy requirements and boundary nodes are established considering catenary effects. Second, the distribution patterns of cable net structure nodes and segments are analyzed, leading to the creation of node coordinate matrices and cable net connection matrices. A basic model for cable net pre-tension design is developed based on the fundamental principles of force density. Furthermore, a multi-objective optimization of cable net pre-tension is performed using a genetic algorithm, considering truss structure deformation and tension uniformity as dual factors. Finally, the developed model is applied to design a single-module cable net structure, and numerical simulation is used for validation. Research results show that the overall surface form error is 0.32 mm, and the maximum tension ratio of cable net on the front cable net surface is 1.54, whereas the maximum tension ratio of tension ties is 2.28, thereby meeting the design requirements. Numerical simulation shows that the maximum deformation of the cable net structure is 0.16 mm, validating the correctness of the model. This research can provide valuable insights and references for the pre-tension design and research of cable net structures in other antennas.

The role of atrial pacing site in reducing filling pressures by accelerated pacing in virtual HFpEF patients

Abstract Background Patients with heart failure with preserved ejection fraction (HFpEF) and pacemakers have been shown to benefit from moderately accelerated pacing rates compared to the standard 60bpm. HFpEF patients often present with prolonged P-wave duration (PWD) and atrial fibrillation. Right atrial appendage pacing (RAAP) lengthens PWD, RA septal (RASP) has a neutral effect, while Bachmann’s bundle pacing (BBP) normalizes or shortens PWD compared to sinus rhythm. The mechanical and hemodynamic effects of atrial pacing site selection remain unknown. Aim To investigate the impact of RAAP, RASP and BBP on cardiac mechanics and hemodynamics in an established cohort of virtual HFpEF patients undergoing accelerated pacing. Method HFpEF with prolonged PWD was simulated using the validated CircAdapt computational model of the human cardiovascular system. First, left ventricular (LV) diastolic dysfunction was simulated by decreasing LV myocardial relaxation rate and compliance, such that mean left atrial (LA) pressure (mLAP) was 15mmHg. Second, PWD was prolonged by prescribing a gradual electrical activation delay from RA to LA of 140ms. We then simulated atrial pacing with three different lead positions (Fig.1, left) and gradually increased pacing rate with a constant 120-ms paced atrioventricular (AV) delay. The CircAdapt model computed regional LA strain and mLAP with RAAP, RASP, and BBP. Cardiac output (5L/min) and mean arterial pressure (92mmHg) were kept constant in all simulations. Results Simulated BBP demonstrated the most synchronous LA mechanical activation and function, characterized by uniform segmental LA strain patterns and highest LA reservoir strain (LASR) (Fig.1, middle, with colored arrows highlighting the mechanical dyssynchrony). Hemodynamically (Fig.1, right), BBP acutely decreased mLAP (-1.0mmHg) at the initial heart rate of 60bpm, while RAAP increased it (+0.3mmHg). As pacing rate accelerated, BBP reduces filling pressure (mLAP: -2.8mmHg), more than RASP (-1.8mmHg) or RAAP (-1.2mmHg) at 80bpm. At high pacing rates, RASP and RAAP adversely increase mLAP, due to the prolonged atrial contraction duration and shorter LV filling time. Conclusion Our simulations of different atrial pacing sites in virtual HFpEF patients suggest that BBP yields the most synchronous LA activation pattern and a more substantial reduction in filling pressures with accelerated atrial pacing compared to RASP. Reduction in mLAP with accelerated pacing was attenuated with RAAP. While our study concentrated on a specific paced AV interval, the favorable outcomes observed with BBP could be further improved by including different, rate-adaptive, AV protocols.Fig 1.

Représentations et pratiques nocturnes dans la société roumaine (XVIIIe – XXe siècles)

Folklorists, ethnographers and anthropologists have dedicated few studies to the night, and they especially emphasized its negative representations: an interval of darkness, of anxiety and fear, a time of intensified activities of evil supernatural forces. By favoring imaginary and mythical components, night was taken into consideration as an exceptional and extraordinary time, as a negative counterpart to the day, and not as a natural reverse of it. For a long time, the night did not draw the attention of historians, being perceived as a time when nothing happens, a time for rest and sleep. Starting with Jean Verdon’s pioneering book (“La Nuit au Moyen Âge”, 1994), historians have become increasingly interested in night habits, and explored the nightlife of people in ancient societies, bedtimes and waking times, sleep duration. The history of sleep has become a new field of research, opened by the American historian Roger Ekirch (2001, 2005), who advanced the theory that people in pre-industrial societies used to sleep differently. During the night, the sleep was biphasic (or segmented), divided into two moments and separated by a period of wakefulness (watch) at around midnight (between the first sleep and the second one). In our study we intend to verify if the results of Ekirch’s research are also applicable to the realities of the Romanian society in the 18th-20th centuries. We must recognize the difficulties of a history of nocturnal time, the fragmentary nature of the sources, the lack of direct and explicit testimonies (few people have been able to subjectivize their experience of sleep and transmit written testimonies). Therefore, we investigated sources such as chronicles, judiciary documents and literary texts, in search of the segmented sleep pattern. We have identified direct or indirect references to the two periods of sleep, and the intervening period of wakefulness. These references allow us to cautiously advance the hypothesis that this sleep pattern also existed in pre-modern Romanian society, in rural and urban environments. The future researches, based on teamwork, will more accurately determine the validity of this hypothesis.