Migration Tracks Research Articles

Bilateral maxillary canine impaction with comparable migration track: Prevalence, sociodemographics and radiographic observations

Introduction: Canines are perceived as cornerstones of the dental arch and plays an essential role in maintaining the facial coordination. When impacted, these functions are lost. We present the prevalence and radiographic presentation of distinctive bilateral maxillary canine. Materials and Methods: This was a retrospective study of patients presenting for routine dental treatment between 2018 and 2020 at a dental center, Najran. A total of 2016 panoramic radiographs were screened and all patients with bilateral impacted canines were further screened radiologically using cone beam computed tomography. Data such demographics and presence of bilateral maxillary impacted canines were identified. Data analyzed using IBM SPSS Statistics for IOS Version 25 (Armonk, NY, USA: IBM Corp). Results: A total of 2016 panoramic radiographs were examined out of which 149 cases were the total impacted canines. Of these, 42 cases were bilateral impacted maxillary canines in comparable migration tract with a prevalence rate of 28.2%. There were 18 males and 24 females with an M: F of 1:1.3. Age ranged from 15 to 75 years with mean age ± standard deviation (27.9 ± 10.6) years. We observed the bilateral impacted canine positions were in relation to the central and lateral incisors in the anterio-posterior plane and the cervical and root portions of the roots of the central and lateral incisors in the inferior-superior plane. We attempted to group them into 3 main types (Types 1-3) with 3 subtypes (Subtypes a-c) each. Limitations: This a hospital based study and findings may not be generalized. Population based study is which is required to find out the prevalent rate in the community. Conclusion: These observed positions can be used to predict the favorability or otherwise of orthodontic traction of the impacted bilateral canines.

Studying the Pro-Migratory Effects of MIF.

Macrophage migration inhibitory factor (MIF) is an upstream regulator of innate immunity and dysregulated MIF is a key mediator of acute and chronic inflammatory processes, autoimmune and cardiovascular diseases, as well as cancer. MIF is a pleiotropic cytokine with chemokine-like functions that has been designated as an atypical chemokine (ACK). It orchestrates leukocyte recruitment and migration into inflamed tissues through non-cognate interactions with the classical chemokine receptors CXCR2 and CXCR4, pathways that are further facilitated by MIF's cognate receptor CD74. Here, we describe two complementary methods that can be used to characterize immune cell migration and motility responses controlled by MIF and its receptors. These are the Transwell filter migration assay, also known as modified Boyden chamber assay, a two-dimensional (2D) device, and a matrix-based three-dimensional (3D) chemotaxis assay. The Transwell system is primarily suitable to study chemotactic cell transmigration responses toward a chemoattractant such as MIF through a porous filter membrane. The 3D chemotaxis setup enables for the cellular tracking of migration, invasion, and motility of single cells using live cell imaging.

Dendritic Cell-Activating Magnetic Nanoparticles Enable Early Prediction of Antitumor Response with Magnetic Resonance Imaging.

Cancer vaccines initiate antitumor responses in a subset of patients, but the lack of clinically meaningful biomarkers to predict treatment response limits their development. Here, we design multifunctional RNA-loaded magnetic liposomes to initiate potent antitumor immunity and function as an early biomarker of treatment response. These particles activate dendritic cells (DCs) more effectively than electroporation, leading to superior inhibition of tumor growth in treatment models. Inclusion of iron oxide enhances DC transfection and enables tracking of DC migration with magnetic resonance imaging (MRI). We show that T2*-weighted MRI intensity in lymph nodes is a strong correlation of DC trafficking and is an early predictor of antitumor response. In preclinical tumor models, MRI-predicted "responders" identified 2 days after vaccination had significantly smaller tumors 2-5 weeks after treatment and lived 73% longer than MRI-predicted "nonresponders". These studies therefore provide a simple, scalable nanoparticle formulation to generate robust antitumor immune responses and predict individual treatment outcome with MRI.

Migration routes and habitat use of a highly adaptable salmonid (sea trout, Salmo trutta) in a complex marine area

BackgroundUnderstanding fish movements and migrations are paramount for management and conservation efforts. By applying Hidden Markov Models (HMMs) on records from electronic tags, migration routes of tagged fish can be reconstructed and new insights to the movement ecology of a species can be gained. We demonstrate the usability of HMMs on a widespread, iteroparous salmonid (sea trout, Salmo trutta) in a complex marine area with highly variable temperatures and salinities within small geographic distances. Understanding how the highly adaptable sea trout cope with these complex conditions could shed new light on factors driving the movement ecology of salmonids. Migration tracks of fish migrating at sea are reconstructed by applying an HMM on temperature and depth records from eight wild post-spawned sea trout from four Danish rivers.ResultsThe fish migrated at sea for 47–142 days. Estimated positions of all fish were close to the coast (< 100 km) throughout the marine period, but migrations along coastlines up to 580 km away from the natal river occurred. Seven of eight individuals resided in or actively migrated into stratified or shallow marine areas that heat up fast during spring, while all eight individuals resided in deeper and more heterogeneous areas that heat up slow during summer. All fish entered the Skagerrak (located between Denmark and Norway) at some stage during summer. Migrations were directed into less saline areas during the first 15 days at sea for all individuals. Mean linear progression of the fish was 16 km day−1 (range 0–58 km day−1).ConclusionsThe results corroborate the expectation that sea trout are more coastally orientated than other salmonids, but also suggest that longer migrations occur in the seas surrounding Denmark compared to elsewhere. This could be a consequence of the fish seeking out habitats with optimal conditions (e.g. salinity, temperature, predation and foraging options) for growth in different parts of the year. The coinciding movement from shallow or stratified marine areas that heat up fast during spring to deeper, more well-mixed areas that heat up slow during summer suggested that some habitat selection had occurred. These results shed new light on factors influencing marine migrations in salmonids and demonstrate how HMMs can expand our knowledge on behaviour and movement ecology of marine fishes.

Chips-on-a-plate device for monitoring cellular migration in a microchannel-based intestinal follicle-associated epithelium model.

This paper describes a chips-on-a-plate (COP) device for monitoring the migration of Raji cells in the Caco-2/Raji coculture. To generate a model of the human intestinal follicle-associated epithelium (FAE), the coculture method using a conventional Transwell cell culture insert was established. Due to the structural limitations of the Transwell insert, live-cell tracking studies have not been performed previously using the existing FAE model. In this study, we designed a COP device to conduct long-term live-cell tracking of Raji cell migration using a microchannel-based FAE model. The COP device incorporates microfluidic chips integrated on a standard well plate, consistent humidity control to allow live-cell microscopy for 2 days, and microchannels connecting the two cell culture chambers of the COP device, which serve as a monitoring area for cellular migration. Using the COP device, we provide the first analysis of various migratory characteristics of Raji cells, including their chemotactic index in the microchannel-based FAE model. We showed that the migration of Raji cells could be controlled by modulating the geometry of the connecting microchannels. Cellular treatments with cytokines revealed that the cytokines increased the permeability of an FAE model with a detachment of Caco-2 cells. Live-cell monitoring of Raji cells treated with a fluorescent reagent also indicated exocytosis as a key agent of the Caco-2/Raji interaction. The COP device allows live-cell tracking analyses of cocultured cells in the microchannel-based FAE model, providing a promising tool for investigating cellular behavior associated with the recruitment of Raji to Caco-2 cells.

Experimental study on the migration regularity of sand outside a large, deep-water, open caisson during sinking

Based on the sinking construction of the largest open caisson across the world, a sinking simulation test is designed and conducted in this work. Data from sensors during subsidence, the migration track of the sand outside the caisson and the settlement of the riverbed after the sinking are measured and analysed. The relationships between the influence range of sand migration outside the caisson and the sinking depth, and the characteristics of the subsidence space formed after migration are described. Combined with measured data from caisson construction, the migration of sand outside the caisson is concluded to be mainly related to the depth of the caisson and the spatial position of the sand outside the caisson and to be influenced by the seepage force, the blade foot reaction force and the lateral pressure. A calculation model describing the behaviour of the migration is established through dynamic comparison and analysis. It is found that the seepage force, the blade foot reaction force, the lateral pressure, sand gushing and sudden sinking of the caisson are all related to the sand migration. A migration coefficient is defined to describe the migration rate and different degrees of sand gushing and sudden sinking.

Spring Migration Behavior of a Perimyotis subflavus (Tri-Colored Bat) from Tennessee

On the nights of 27, 28, and 29 April 2018, we used aerial radio-telemetry to track a female Perimyotis subflavus (Tri-colored Bat) as she migrated a straight-line distance of 243 km from a cave in southern Tennessee to a roost in Peachtree City, GA. To our knowledge, this represents the longest and most detailed spring migration track recorded for this species and places the Tri-colored Bat in the category of regional migrant.

First Tracking of Post-Breeding Migration of the Ruddy Kingfisher Halcyon coromanda by GPS Data Logger

The migratory strategies of kingfishers are poorly understood. In the first study of its kind, by means of Global Positioning System data loggers, we were able to describe the migration and wintering sites of the Ruddy Kingfisher Halcyon coromanda population breeding on Miyako Island, Japan. Birds were found to reach altitudes of almost 4,000 m during their migration to winter on Polillo and Tablas islands in The Philippines.

The topology of vitronectin: A complementary feature for neuroblastoma risk classification based on computer-aided detection.

Tumors are complex networks of constantly interacting elements: tumor cells, stromal cells, immune and stem cells, blood/lympathic vessels, nerve fibers and extracellular matrix components. These elements can influence their microenvironment through mechanical and physical signals to promote tumor cell growth. To get a better understanding of tumor biology, cooperation between multidisciplinary fields is needed. Diverse mathematic computations and algorithms have been designed to find prognostic targets and enhance diagnostic assessment. In this work, we use computational digital tools to study the topology of vitronectin, a glycoprotein of the extracellular matrix. Vitronectin is linked to angiogenesis and migration, two processes closely related to tumor cell spread. Here, we investigate whether the distribution of this molecule in the tumor stroma may confer mechanical properties affecting neuroblastoma aggressiveness. Combining image analysis and graph theory, we analyze different topological features that capture the organizational cues of vitronectin in histopathological images taken from human samples. We find that the Euler number and the branching of territorial vitronectin, two topological features, could allow for a more precise pretreatment risk stratification to guide treatment strategies in neuroblastoma patients. A large amount of recently synthesized VN would create migration tracks, pinpointed by both topological features, for malignant neuroblasts, so that dramatic change in the extracellular matrix would increase tumor aggressiveness and worsen patient outcomes.

Reconstruction of long-distance bird migration routes using advanced machine learning techniques on geolocator data.

Geolocators are a well-established technology to reconstruct migration routes of animals that are too small to carry satellite tags (e.g. passerine birds). These devices record environmental light-level data that enable the reconstruction of daily positions from the time of twilight. However, all current methods for analysing geolocator data require manual pre-processing of raw records to eliminate twilight events showing unnatural variation in light levels, a step that is time-consuming and must be accomplished by a trained expert. Here, we propose and implement advanced machine learning techniques to automate this procedure and we apply them to 108 migration tracks of barn swallows ( Hirundo rustica). We show that routes reconstructed from the automated pre-processing are comparable to those obtained from manual selection accomplished by a human expert. This raises the possibility of fully automating light-level geolocator data analysis and possibly analysing the large amount of data already collected on several species.

Space- and Ground-Based Geophysical Data Tracking of Magma Migration in Shallow Feeding System of Mount Etna Volcano

After a month-long increase in activity at the summit craters, on 24 December 2018, the Etna volcano experienced a short-lived lateral effusive event followed by a rapid resumption of low-level explosive and degassing activity at the summit vents. By combining space (Moderate Resolution Imaging Spectroradiometer; MODIS and SENTINEL-2 images) and ground-based geophysical data, we track, in near real-time, the thermal, seismic and infrasonic changes associated with Etna’s activity during the September–December 2018 period. Satellite thermal data reveal that the fissural eruption was preceded by a persistent increase of summit activity, as reflected by overflow episodes in New SouthEast Crater (NSE) sector. This behavior is supported by infrasonic data, which recorded a constant increase both in the occurrence and in the energy of the strombolian activity at the same crater sectors mapped by satellite. The explosive activity trend is poorly constrained by the seismic tremor, which shows instead a sudden increase only since the 08:24 GMT on the 24 December 2018, almost concurrently with the end of the infrasonic detections occurred at 06:00 GMT. The arrays detected the resumption of infrasonic activity at 11:13 GMT of 24 December, when tremors almost reached the maximum amplitude. Infrasound indicates that the explosive activity was shifting from the summit crater along the flank of the Etna volcano, reflecting, with the seismic tremor, the intrusion of a gas-rich magma batch along a ~2.0 km long dyke, which reached the surface generating an intense explosive phase. The dyke propagation lasted for almost 3 h, during which magma migrated from the central conduit system to the lateral vent, at a mean speed of 0.15–0.20 m s−1. Based on MODIS and SENTINEL 2 images, we estimated that the summit outflows erupted a volume of lava of 1.4 Mm3 (±0.5 Mm3), and that the lateral effusive episode erupted a minimum volume of 0.85 Mm3 (±0.3 Mm3). The results presented here outline the support of satellite data on tracking the evolution of volcanic activity and the importance to integrate satellite with ground-based geophysical data in improving assessments of volcanic hazard during eruptive crises.

Resin migration tracking via real-time monitoring FTIR- ATR in a self-stratifying system

The importance of self-stratifying coatings in attaining two layers by one coat application makes it a point of interest to understand the mechanism of self-separating of resins into two distinct layers.Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (FTIR-ATR) is a good analysis method with the facility of real-time monitoring for tracking the position of components during the film formation. The migration of main components of silicon /epoxy as a self-stratifying coating system during film formation is followed on ZnSe and Ge cells as substrates. By following up the spectra of real-time monitoring during the film formation it was found that the mechanism of epoxy chains movement toward surface in a self-stratifying coating can not be diffusion.

A full annual perspective on sex-biased migration timing in long-distance migratory birds.

In many taxa, the most common form of sex-biased migration timing is protandry-the earlier arrival of males at breeding areas. Here we test this concept across the annual cycle of long-distance migratory birds. Using more than 350 migration tracks of small-bodied trans-Saharan migrants, we quantify differences in male and female migration schedules and test for proximate determinants of sex-specific timing. In autumn, males started migration about 2 days earlier, but this difference did not carry over to arrival at the non-breeding sites. In spring, males on average departed from the African non-breeding sites about 3 days earlier and reached breeding sites ca 4 days ahead of females. A cross-species comparison revealed large variation in the level of protandry and protogyny across the annual cycle. While we found tight links between individual timing of departure and arrival within each migration season, only for males the timing of spring migration was linked to the timing of previous autumn migration. In conclusion, our results demonstrate that protandry is not exclusively a reproductive strategy but rather occurs year-round and the two main proximate determinants for the magnitude of sex-biased arrival times in autumn and spring are sex-specific differences in departure timing and migration duration.

A Visible Codelivery Nanovaccine of Antigen and Adjuvant with Self-Carrier for Cancer Immunotherapy.

Codelivery nanovaccines of antigens and adjuvants have achieved positive therapy for cancer immunotherapy. The insufficient immunogenicity of these vaccines leads to the difficulty of eliciting robust immune effects for immune clearance due to the inadequate loading efficiency, complex preparation processes, low safety concerns, and weak immune responses. Herein, a visible codelivery nanovaccine of an antigen and adjuvant based on self-cross-linked antigen nanoparticles (ovalbumin nanoparticles (ONPs)) combined with the adjuvant (CpG) for cancer immunotherapy was prepared using antigens themselves as carriers. ONPs not only provide sufficient antigens for continuous simulation of the immune response with high antigen loading efficiency but also serve as natural carriers of CpG. In vitro and in vivo experiments proved that ONPs-CpG can elicit a robust immune response including DC maturity, T cell activation, and IFN-γ production. ONPs-CpG induced strong tumor-specific immunity and exhibited remarkable antitumor immunotherapy effects in vivo using mouse models of lymphoma. Furthermore, to perform the precise vaccine delivery, the dual fluorescent codelivery nanovaccine was monitored in real time in vivo by the visible imaging method. With regard to migration tracking, fluorescence imaging allowed for both high resolution and sensitivity of visible detection based on the fluorescence of ONPs and CpG. The multifunctional nanovaccine could function as a robust platform for cancer immunotherapy and a visible system for antigen-adjuvant tracking.

Click histochemistry for whole-mount staining of brain structures

Labeling of the replicating DNA with synthetic thymidine analogs is commonly used for marking the dividing cells. However, until now this method has only been applied to histological sections. A growing number of current approaches for three-dimensional visualization of large tissue samples requires detection of dividing cells within whole organs. Here we describe a method for labeling dividing cells with 5-ethynyl-2'-deoxyuridine (EdU) and their further detection in whole brain structures (for example, hippocampus) using the Cu (I) -catalyzed [3 + 2] cycloaddition reaction (so-called click-reaction). The presented method can be used for brain neurogenesis studies as well as for whole-mount staining of any preparations in which the terminal ethynyl group has been introduced.•New click histochemistry method based on Cu (I) -catalyzed [3 + 2] cycloaddition reaction allows whole-mount staining of brain structures and other tissues.•Our whole-mount click histochemistry method allows to visualize dividing cells in 3D and can be used in neurogenesis studies, i.e. for birthdating dividing early progenitors and further tracking of proliferation, survival, migration, differentiation, and fate of their progeny.•Our whole-mount click histochemistry staining demonstrates high staining specificity, high signal intensity, and low background levels in young and adult mouse brain tissue.

First tracking of post-breeding migration of the Ruddy Kingfisher Halcyon coromanda by GPS data logger

First tracking of post-breeding migration of the Ruddy Kingfisher <i>Halcyon coromanda</i> by GPS data logger

Immature dendritic cells navigate microscopic mazes to find tumor cells.

Dendritic cells (DCs) are potent antigen-presenting cells with high sentinel ability to scan their neighborhood and to initiate an adaptive immune response. Whereas chemotactic migration of mature DCs (mDCs) towards lymph nodes is relatively well documented, the migratory behavior of immature DCs (imDCs) in tumor microenvironments is still poorly understood. Here, microfluidic systems of various geometries, including mazes, are used to investigate how the physical and chemical microenvironment influences the migration pattern of imDCs. Under proper degree of confinement, the imDCs are preferentially recruited towards cancer vs. normal cells, accompanied by increased cell speed and persistence. Furthermore, a systematic screen of cytokines, reveals that Gas6 is a major chemokine responsible for the chemotactic preference. These results and the accompanying theoretical model suggest that imDC migration in complex tissue environments is tuned by a proper balance between the strength of the chemical gradients and the degree of spatial confinement.

Local site use and first northbound migration track of non-breeding Steppe Whimbrel Numenius phaeopus alboaxillaris (Lowe 1921)

Local site use and first northbound migration track of non-breeding Steppe Whimbrel Numenius phaeopus alboaxillaris (Lowe 1921)

Annual Cycles of Wagtails (Passeriformes, Motacillidae) in Northwestern Siberia: Comparative Aspects

Abstract—The annual cycles of pipits and wagtails, which were studied during field and experimental observations in the Lower Ob River basin and Yamal Peninsula, have many common features. All species are similar in dates of arrival, nesting, molting, and departure onset; however, the timing of postnuptial migration and prenuptial molting differ somewhat. Positive air temperatures are an environmental factor that determines the beginning of arrival to the forest tundra and tundras. Only yellow wagtails arrive with developed gonads, while the other species require additional stimulation by a photoperiod of 24L : 0D. The reduction of some nesting stages is presumably an attempt of boreal populations to increase reproductive success. Differences in the annual cycle program are observed during the postnesting period. These variations include the timing of the onset and duration of postjuvenile and postnuptial molting, as well as the degree of overlap of postnuptial molting with nesting, the degree of overlap of the migration state with molting, photoperiodic molting conditions, and autumn migration. The intraspecific rhythm of migration in combination with environmental conditions along the migration track determines the timing of arrival to wintering sites. The threshold values of photoperiodic intervals of wintering and prenuptial molting in different species correspond to the latitude of hibernation and, possibly, determine this latitude.

Nanomaterials in Liver Regeneration: The Prospect for Application

Hepatocyte transplantation has been proved an effective method to help liver regeneration by replacing host deficient cells caused by various disorders or injuries. However, several problems existing in hepatocyte transplantation have limited the clinical application of the technology. These problems include limited survival time of transplanted cells, immune rejection in xenotransplantation and insufficient transplantation efficiency. The rapid development of nanotechnology provides an opportunity for solving these problems. Application of nanomaterials in liver regeneration has been frequently reported recently. According to these researches, nanomaterials have advantages on the aspects of helping cell adhesion and growth, maintaining cell function and inducing cell differentiation. What is more, nanomaterials also exhibited its advantage on cell migration tracking, thus could help to monitor the cells transplantation and noninvasive diagnosis. For the further application of nanomaterials in liver regeneration, a complete understanding of current progress will be necessary and helpful. Our goal in this review is to summarize the current status of the applications of nanomaterials in hepatocyte transplantation. We will focus on nanomaterials that acted as scaffolds for hepatocyte growth and function maintenance, delivery cargo for improving hepatocyte transplantation and trackers for in vivo monitoring.