Posterior Section Research Articles

Effect of Nosema ceranae infection and season on the gut bacteriome composition of the European honeybee (Apis mellifera)

Nosema ceranae is an intracellular parasite that infects honeybees’ gut altering the digestive functions; therefore, it has the potential of affecting the composition of the gut microbiome. In this work, individual bees of known age were sampled both in spring and autumn, and their digestive tracts were assessed for N. ceranae infection. Intestinal microbiome was assessed by sequencing the bacterial 16S rRNA gene in two different gut sections, the anterior section (AS; midgut and a half of ileum) and the posterior section (PS; second half of ileum and rectum). A preliminary analysis with a first batch of samples (n = 42) showed that AS samples had a higher potential to discriminate between infected and non-infected bees than PS samples. As a consequence, AS samples were selected for subsequent analyses. When analyzing the whole set of AS samples (n = 158) no changes in α- or β-diversity were observed between infected and non-infected bees. However, significant changes in the relative abundance of Proteobacteria and Firmicutes appeared when a subgroup of highly infected bees was compared to the group of non-infected bees. Seasonality and bees’ age had a significant impact in shaping the bacteriome structure and composition of the bees’ gut. Further research is needed to elucidate possible associations between the microbiome and N. ceranae infection in order to find efficient strategies for prevention of infections through modulation of bees’ microbiome.

Monitoring of Enzymatic Activity in the Gastrointestinal Tract of Black Sea Salmon (Salmo labrax Pallas, 1814)

In this study, it was aimed to determine the activity of digestive enzymes at different time intervals after-feeding throughout the gastrointestinal tract of Black Sea salmon (Salmo labrax). The study was conducted at freshwater recirculating aquaculture systems (RAS). The fish were fed by hand up to satiation for 60 days with diets containing 46.25% protein and 14.90% lipid. The fish gastrointestinal tract including stomach, anterior (with pyloric caeca), middle and posterior sections were taken together at 45th minute, 3rd, 6th, 12th, 24th, 48th, 72nd, and 96th hours post-feeding. The tissues were were stored at -80°C until analyzed. In terms of digestive enzyme activity, at the end of the study, anterior and middle intestine sections had the highest level at 3rd-hour post-feeding. Similarly, pepsin, trypsin, and lipase in the stomach had the highest activity at 3rd-hour post-feeding. However, amylase in the stomach was the highest level at 45th minute and 3rd-hour post-feeding. At 3rd-hours post-feeding, the pepsin in the stomach, the trypsin, and lipase in the anterior section, and the amylase in the middle intestine had the highest levels. Moreover, the correlations between these enzymes were strong in the positive direction. Also, the difference in pepsin, trypsin, amylase, and lipase levels in the samples dissected at different time intervals after feeding was statistically significant. Our results revealed that stomach, anterior, middle, and posterior sections in the gastrointestinal tract of Black Sea salmon had enzyme activity in the different levels, and enzyme activity of these sections changed depending on time post-feeding.

Phosphatase of Regenerating Liver-1 Regulates Wing Vein Formation through TGF-β Pathway in Drosophila melanogaster.

Drosophila Phosphatase of Regenerating Liver-1 (PRL-1) is the only homolog of the mammalian PRLs with which it shares high sequence and structural similarities. Whilst PRLs are most notable for their high expression in malignant cancers and related promotion of cancer progression, the specific biological functions of the PRLs remain largely elusive. Here, using a gain-of-function approach, we found that PRL-1 functions during wing vein development in Drosophila melanogaster (Drosophila). Overexpression of Drosophila PRL-1 caused dose-dependent wing vein proliferation. Genetic screening of the main TGF-β signaling factors, Mad and Smox, showed that the RNAi-mediated knockdown of Mad could alleviate the extra vein phenotype caused by overexpressed PRL-1 and lead to loss of the posterior section of longitudinal veins. However, knockdown of Smox resulted in an identical phenotype with or without the overexpression of Drosophila PRL-1. Clonal analyses revealed that overexpression of PRL-1 led to decreased expressions of activated phospho-Mad protein, as measured by immunostaining. Real-time PCR showed that the transcriptional levels of Smox were significantly increased upon overexpression of the Drosophila PRL-1 in wing discs, with a dose dependent effect. We propose that the main function of Drosophila PRL-1 in wing development is to affect the phospho-Mad levels and Smox transcriptional levels, therefore influencing the competitive balance for Medea between Mad and Smox. Our study demonstrates the novel role for Drosophila PRL-1 in regulating TGF-β signaling to influence wing vein formation which may also provide insight into the understanding of the relationship between PRLs and TGF-β signaling in mammals.

A new subspecies of the Asiatic softshell turtle Amyda ornata (Gray, 1861) from its northern distribution range

We describe a new subspecies ofAmyda ornata(Gray, 1861) from the southeastern parts of Bangladesh (Chittagong hill tracts), adjacent regions of north-eastern India (Mizoram, Assam and Tripura) and Myanmar, based on morphological characteristics. The holotype comprises some skeletal elements held by the Natural History Museum of Vienna; the five paratypes consist of living specimens in the private collection of PP “Turtle Island” (a turtle conservation zoo in Graz, Austria). After the genetic identity had been determined in a previous investigation, the morphological description was carried out by examining living specimens and photo documents; and additionally, by evaluating the computed tomography of further living animals with exact location data.Amyda ornata jonglissp. nov. differs from the otherAmyda ornatasubspecies mainly by its relatively compact and stout head in subadults and adults, its paler, greyish and less contrasting colouration missing distinct bright yellow pigments, ochre-coloured irises, and the existence of more distinct tubercles in the neck region and in the posterior section of the carapace than both other subspecies ofAmyda ornata. The tubercles along the front of the carapace protrude clearly in subadult and adult specimens. This softshell turtle is heavily exploited within its limited distribution. Therefore, special comments on conservation aspects are given together with a final discussion on distribution and systematics.

Morphological Analysis of Hip Joint of Patients Suffering From Recurrent Patella Dislocation.

The purpose was to investigate morphological changes of the hip joint in patients with recurrent dislocation of the patella combined with trochlear dysplasia. There was a retrospective analysis of 148 patients and 150 control subjects. The selection of participants was randomized. Hip and knee data for all participants were obtained from X-ray or computed tomography measurements. Nine values, that is, central edge angle (CEA), acetabulum index angle (AIA), femoral neck-shaft angle, sharp angle, the depth of the acetabulum, femoral anteversion angle (FAA), anterior acetabular section angle (AASA), posterior acetabular section angle (PASA), and sulcus angle, were measured to evaluate differences between the control group and the patient group and analyze the correlation of the sulcus angle in patients to FAA and CEA. Patients with recurrent dislocation of the patella had less acetabular coverage and are more likely to develop developmental dysplasia of the hip than the hips of patients with normal knees. For the patient group, three values, that is, CEA (27.68 ± 5.25 vs. 34.30 ± 3.51 degrees, p < 0.001), AASA (57.14 ± 6.17 vs. 63.08 ± 7.23 degrees, p < 0.001), and PASA (89.53 ± 6.51 vs. 99.63 ± 5.94 degrees, p < 0.001), were decreased. The sharp angle (43.77 ± 3.23 vs. 39.28 ± 3.19 degrees, p < 0.001), AIA (11.52 ± 4.41 vs. 3.73 ± 2.51 degrees, p < 0.001), and FAA (24.68 ± 3.44 vs. 18.49 ± 3.55 degrees, p < 0.001) were increased. The acetabulum became shallower in-depth (7.05 ± 2.18 vs. 10.45 ± 1.61 mm, p < 0.001). There was a weak correlation between the sulcus angle and CEA (r = - 0.302, p < 0.001) and FAA (r = 0.212, p = 0.022). Recurrent patellar dislocation combined with trochlear dysplasia may be associated with the hip morphology. Developmental disorders of the knee joint, and hip joint should be considered in the treatment of patients with recurrent dislocation of the patella.

FEATURES OF THE STRUCTURE OF INTRANASAL STRUCTURES AT DIFFERENT FORMS OF THE NOSE CAVITY ACCORDING TO THE DATA OF COMPUTED TOMOGRAPHY

Computed tomography of the skull has undeniable advantages over classical craniometric studies. With its help, it is possible to carry out a reliable assessment of the topographic and anatomical relationships of intranasal structures, which is especially important in choosing the tactics and extent of surgical intervention in a number of diseases of the upper respiratory tract, as well as computer modeling of various conditions in rhinology. For their successful implementation, precise knowledge of the morphometric parameters of the nasal cavity and intranasal structures is important. The purpose of the study was to determine the morphometric parameters of the nasal cavity and intranasal structures using computed tomography data, to determine the main features of their structure in narrow (leptocavitary), medium (mesocavitary) and wide (platycavitary) forms. A morphometric evaluation of computed tomograms of the head of 200 men and 198 women was performed, on which the shape of the nasal cavity, topographic-anatomical and morphometric characteristics of intranasal structures were evaluated. Computed tomography was performed on a spiral computed tomograph. The studies were performed in the axial scanning plane with a slice thickness of 0,625 mm and the same interval between them. Typical differences in the sizes of the nasal cavity and intranasal structures, as well as a number of parameters characterizing their topographic-anatomical relationships and angular characteristics with different forms of the nasal cavity, were revealed. In both male and female groups, the wide form of the nasal cavity, in contrast to the narrow one, is characterized by a decrease in the height of the nasal cavity in the anterior and posterior sections, a short middle turbinate, a greater angle of inclination of the main plate and a greater angle of inclination of its free end, a wide anterior end of the middle turbinate, narrow middle nasal passage, greater angle of inclination of the clivus. In persons with a mesocavitary form, the described craniometric signs have intermediate values. It is shown that the nasal cavity in women is distinguished by the largest number of craniometric features with a high degree of variability. The revealed features of the structure of intranasal structures should be taken into account when performing rhinosurgical and neurosurgical interventions.

Onyx disparamphis sp. n. (Nematoda, Desmodorida) from South Korea with a taxonomic review of the genus.

A new free-living marine nematode Onyx disparamphis sp. n. (Nematoda, Desmodorida) is described from sandy littoral of Jeju Island, South Korea. The new species differs from all other Onyx species by the unusual amphideal fovea morphology in males (elongated loop). O. disparamphis relates to O. balochinensis, and O. brevispiculatum by having simple non-double terminal pharyngeal bulb and relatively small and straight, non-sigmoid supplementary organs, but differs from them by smaller body length, shorter cephalic setae, smaller terminal pharyngeal bulb, smaller spicules, number of supplementary organs and tail shape expressed as ratio tail length/anal diameter. The genus Onyx is revised with updated genus diagnosis, and an annotated list of 23 valid species is presented. Onyx ferox is considered species inquirenda because the species is known only from a sole immature female specimen, while within Onyx, the males provide the most important distinguishing characters such as enlarged and complicated amphids, supplementary organs and copulatory spicules. For species identification, a pictorial key consisting of illustrations of simplified icons of male heads and posterior body sections, as well as a table of the most important morphometric and numerical characters are provided. Geographical distribution and habitat specifity of Onyx species is analysed briefly.

Demonstration of the right-side boundary of the caudate lobe in a liver cast.

There have been historical arguments about the boundary of the caudate lobe of the liver. Kumon M first advocated the definition of the caudate lobe based on the portal segmentation of the liver in 1985, and classified it into three parts, Spiegel lobe, paracaval portion and caudate process. Prof. Couinaud defined the dorsal liver as a union of segments I and IX in 1994, based on the spatial position to the major hepatic veins, hilar plate and inferior vena cava. In Couinaud's classification, right-side of the dorsal liver is supplied by the branches from the posterior and anterior sections. In the present study using a liver cast, we found a paracaval branch of the portal vein branching from the right portal vein on the dissecting plain along the Rex-Cantlie's line. We also found several branches from the posterior portal vein to the right-side of the paracaval portion, but they should be defined to belong to the posterior sections.

Solea senegalensis Bacterial Intestinal Microbiota Is Affected by Low Dietary Inclusion of Ulva ohnoi.

The inclusion of macroalgae in the diets of farmed fish offers the opportunity for an added-value dietary ingredient to the nutraceutical feed. The composition of algae varies greatly among species. Several Ulva species have been considered in aquafeed formulations for different farmed fish, and Ulva ohnoi is being applied recently. However, the effects of seaweed dietary inclusion on the host must be evaluated. Considering the important role of the host intestinal microbiota, the potential effects of U. ohnoi dietary inclusion need to be studied. In this study, the characterization of the intestinal microbiome of Solea senegalensis, a flatfish with high potential for aquaculture in South Europe, receiving U. ohnoi (5%)-supplemented diet for 90 days has been carried out. In addition, the functional profiles of bacterial communities have been determined by using PICRUSt, a computational approach to predict the functional composition of a metagenome by using marker gene data and a database of reference genomes. The results show that long-term dietary administration of U. ohnoi (5%)-supplemented feed modulates S. senegalensis intestinal microbiota, especially in the posterior intestinal section. Increased relative abundance of Vibrio jointly with decreased Stenotrophomonas genus has been detected in fish receiving Ulva diet compared to control-fed fish. The influence of the diet on the intestinal functionality of S. senegalensis has been studied for the first time. Changes in bacterial composition were accompanied by differences in predicted microbiota functionality. Increased abundance of predicted genes involved in xenobiotic biodegradation and metabolism were observed in the microbiota when U. ohnoi diet was used. On the contrary, predicted percentages of genes associated to penicillin and cephalosporin biosynthesis as well as beta-lactam resistance were reduced after feeding with Ulva diet.

Features of the clinical course of acute otitis media in patients with impaired carbohydrate metabolism

The aim of the research: study of the features of the clinical course of acute otitis media (AOM) in patients with impaired carbohydrate metabolism.&#x0D; Materials and methods. We examined 140 patients with AOM aged 19 to 72 years, of which 75 patients with impaired carbohydrate metabolism constituted the main group and 65 patients were included in the comparison group. Taking into account the peculiarities of the pathogenesis of AOM and disorders of carbohydrate metabolism, patients were randomized into 4 groups: 1 – patients with AOM (36), 2 – patients with AOM on the background of sinusitis (29), 3 – patients with AOM on the background of non-insulin-dependent diabetes mellitus (DM type II) (37), 4 – AOM patients with impaired glucose metabolism (38). The patients underwent a general clinical examination, determination of glycosylated hemoglobin, leukocyte indices of intoxication, audiometry, computed tomography (CT) of the temporal bones (if indicated).&#x0D; Results. The proportion of patients with impaired carbohydrate metabolism in 2020 was 32.6 %, of which DM type II was diagnosed in 49.3 % earlier. It was shown that a feature of the clinical course of AOM against the background of impaired carbohydrate metabolism is the discrepancy between the duration of the disease history, complaints and objective data to the state of the cellular structure of the mastoid process according to CT data and impaired auditory function mainly by the type of sound perception, which indicates the formation of latent mastoiditis. Clinically significant complaints and objective data for the differential diagnosis of latent mastoiditis in these patients were determined. The absence of statistical significance of differences in indicators in patients with DM type II and against the background of transient hyperglycemia was revealed, and the concept of the latter was characterized. A direct correlation between blood glucose levels and glycated hemoglobin levels was established in patients with DM type II and AOM.&#x0D; Conclusions. DM type II creates a favorable background for the formation of the clinical course of AOM complicated by latent mastoiditis.&#x0D; From the general contingent of patients with AOM, patients should be distinguished not only with DM type II, but also with transient hyperglycemia for its timely diagnosis. Significant symptoms: pain and a feeling of “heaviness” in the behind-the-ear region in the absence of reactive phenomena, a feeling of “pulsation” in the ear, dizziness, a cloudy eardrum with a protrusion or perforation in the posterior or posterior-upper section, an asymmetric increase in sound perception thresholds above 25 dB. Such patients should be observed with “early” CT scan of the temporal bones.

A Multidisciplinary Approach Evaluating Soybean Meal-Induced Enteritis in Rainbow Trout Oncorhynchus mykiss

This study evaluated a diverse range of markers of feeding stress to obtain a more precise assessment of the welfare of rainbow trout in relation to inadequate husbandry conditions. A feeding stress model based on dietary soybean meal was employed to identify suitable minimally invasive “classical” stress markers, together with molecular signatures. In a 56-day feeding experiment, rainbow trout were fed diets containing different levels of soybean meal. The impact of these different soybean meal diets on rainbow trout was assessed by water quality analyses, clinical health observations, classic growth and performance parameters, gut histopathology, blood-parameter measurements and multigene-expression profiling in RNA from whole blood. Soybean meal-induced enteritis was manifested phenotypically by an inflammatory reaction in the posterior section of the intestine and by diarrhoea in some trout. These inflammatory changes were associated with decreased supranuclear vacuolation. The haematocrit values and the levels of plasma cortisol and circulating lymphocytes in the blood were increased in trout that had consumed high amounts of SBM. Notably, the increased haematocrit depended significantly on the bodyweight of the individual trout. The transcript levels of certain genes (e.g., MAP3K1, LYG, NOD1, STAT1 and HSP90AB) emerged as potentially useful indicators in the blood of rainbow trout providing valuable information about inadequate nutrition. The expression-profiling findings provide a basis for improved, minimally invasive monitoring of feeding regimens in trout farming and may stimulate the development of practical detection devices for innovative aquaculture operations.

Assessment of the temporomandibular joint condition using two-dimensional ultrasound scanning and doppler ultrasonography methods in patients with chronic inflammatory periodontal diseases

Introduction. Currently, dentists are increasingly detecting changes in the temporomandibular joint in patients with chronic inflammatory periodontal disease.Aim of the study. To carry out a comprehensive dynamic assessment of the temporomandibular joint (TMJ) condition and the registration of regional blood flow using two-dimensional ultrasound scanning to improve the efficiency of diagnostics of inflammatory periodontal diseases.Materials and methods. The study included 2 groups of patients: group 1 (control) consisted of 20 volunteers aged 20–25; Group 2 consisted of 52 people aged 25–45 years with moderate chronic periodontitis. For TMJ ultrasound and Doppler ultrasound, a portable ultrasound scanner LogicScan 128 with an HL-10 linear ultrasound transducer with an operating frequency of 5 to 12 MHz was used.Results and discussion. During ultrasound examination of the temporomandibular joint and measuring the size of the joint space in patients with moderate chronic periodontitis in a state of relative physiological rest, the following values were obtained: in the anterior region – 2.3 ± 0.5 mm; in the upper section – 1.6 ± 0.6 mm; in the posterior section – 1.8 ± 0.3 mm. We also measured the area of the temporomandibular joint disc in various positions. According to ultrasound data, an increase in the size of the joint space from 12.2 to 16.1% and an increase in the area of the articular disc by 17.1 to 36.7% were found in patients with chronic periodontitis. When assessing the trajectory of the articular track, motion delay and joint wedging are determined. In addition, in the color Doppler mapping (CDM) mode, the speed and index indicators of Doppler ultrasonography of the external carotid and temporal arteries were calculated.Conclusions. Modern diagnostic methods of ultrasound and Doppler mapping, assessing the hemodynamics and functional state of the TMJ, allow early diagnosis of changes in order to prevent the development of TMJ disorders in patients with chronic inflammatory periodontal diseases.

Radiological analysis of size of bone elements of the temporomandibular joint in children and adolescents with class II malocclusion

The aim of the study was to assess the ratio of bone elements of the temporomandibular joint (TMJ) in children and adolescents with distal occlusion according to cone-beam computed tomography (CBCT). CBCT of the TMJ was analyzed in 121 patients aged 12-18 years, which were divided into two age groups: group I - children aged 12-15 years (62 cases in total, of which 47 patients with distal occlusion and 15 patients with physiological occlusion) and II group - adolescents aged 15-18 years (59 cases, of which 48 patients with distal occlusion and 11 patients with physiological occlusion). CBCT of the temporomandibular joint was performed by the standard method in the position of habitual occlusion and maximally open mouth. The size of the TMJ joint space in the anterior, upper and posterior sections was determined by the method of Rabukhina N.A., the analysis of the ratio of the bone elements of the TMJ was carried out using the Craniometry program. The size of the joint space and the angle β of the temporomandibular joint in the anterior section on the right and left in children aged 12-15 with distal occlusion is increased compared to children with physiological occlusion in the position of habitual occlusion. In adolescents 15-18 years old with distal occlusion, the size of the TMJ joint space is increased in the anterior section on the right and left and reduced in the posterior section on the right, angle α is reduced on the right and left, angle β is reduced on the right, angle γ is increased on the right compared to adolescents with physiological occlusion. The revealed deviations indicate the presence of violations in the ratio of the bone elements of the TMJ, which are aggravated with age. Analysis of the results obtained during CBCT in children and adolescents allows us to correct the plan of orthodontic treatment and predict its results.

Initial Experience of 60 Cases Pure-Laparoscopic Donor Hepatectomy in Cleveland Clinic

Introduction: The adoption of pure-laparoscopic donor hepatectomy (PLDH) has been slow in North America because of the associated technical complexity and concerns for donor safety. This study aimed to report our initial 60 PLDH and elaborate on the understanding of the pre-requisites for the successful introduction of PLDH. Method: Retrospective review during the initial 2 years after the introduction Results: Between August 2019 and August 2021, 60 PLDH were performed; 33 patients donated left lobe grafts, 25 cases were right lobe grafts, 1 case was right posterior section graft, and 1 patient donated left lateral segment. The characteristics of 60 PLDH were summarized in Table. The median operative time was 345 minutes in the left lobe group and 348 minutes in the right lobe group, respectively. No cases required intraoperative blood transfusion or open conversion. Two patients developed a postoperative surgical wound infection, one patient required postoperative blood transfusion, one patient required laparoscopic portal vein venoplasty for portal vein stenosis. The median in-patient stay was 5 days (4-9) and there were no 30-day readmissions. Conclusions: Seamless introduction of OLDH and donor safety were achieved by: 1) minimizing the learning curve through proctorship from experienced surgeon, 2) establish a dedicated surgical team and accumulate adequate surgical experience in living donor hepatectomy and laparoscopic hepatectomy, especially major hepatectomy, 3) active institutional support to have proper instrumentation necessary for operational efficiency, and 4) proper master planning including the ready availability of a crisis management protocol and team in case of an emergency.Tabled 1Left Lobe (N=33, 55.0%)Right lobe (N=25, 41.7%)Age34 (18-58)43 (25-58)male/Female22/117/18Height178 (158-196)168 (155-189)Weight82 (61-119)76 (54-122)BMI27.6 (21.3-36.6)27.7 (21.3-39.7)Operative time345 (256-501)348 (264-450)EBL200 (50-600)150 (30-500)Complicatio33LOS5 (4-8)5 (4-9) Open table in a new tab

Lower jaw virtual reposition accuracy research

The aim is to study of the accuracy of the virtual reposition of the mandible (LF) by comparing the virtual and real position of the LF heads, as well as the analysis of factors contributing to the occurrence of errors. An experimental model of a human skull with a movable LF was made of radiopaque material. The resulting computed tomogram (CT) of the upper and lower jaws and temporomandibular joint (TMJ) was combined with dental scans of dental rows and CT scans and a report on the position of the heads of the LF was obtained. Then the LF was shifted to another position and this position was fixed. Optical bite recorders were obtained using an intraoral scanner. An experimental model with a fixed new position of the LF was placed in a tomograph and repeated CT was obtained. In the program, according to optical registers, a virtual reposition of the LF was carried out. The correspondence of the virtual and real position of the mandibular heads was compared. The absolute difference of glenoid fossa space between the actual and virtual reconstruction was 0.542±0.3354 mm in the anterior joint section (M±δ, M - average mean, δ - standard deviation); for the upper joint section - 0.309±0.2246 mm; and 0.260±0.1862 mm for the posterior section. The integral indicator of surface coincidence (q) when the virtual and actual position are directly compared was 0.296±0.1254 (s.u.). The total margin of error depends on the following factors: repeated scanning error (teeth arches and bite scans), repeated CBCT error, a combination of scan and CBCT error, a combination of teeth arch scan and bite scan error, error of TMJ separation. The latter two factors were the most significant.

Automated pathological lung volume segmentation with anterior and posterior separation in X-ray CT images

3D volume lung segmentation is a precursor for morphometric and volumetric analysis. The proposed work is a fully automated lung segmentation method with due attention given to left and right lung separation in the anterior and posterior sections involving new concept of bounding box. The method proceeds in three steps: firstly, lung segmentation performed with morphological operations. Secondly, airways extracted using 3D region growing. Finally, left and right lung lobes separated by analysing bounding box characteristics of each image. The performance matrices and net volume of lung have been evaluated with manual analysis and the results are quite satisfactory with average F1 score 0.983, precision 0.989, recall 0.976, specificity 0.998 and Jaccard index 0.965 and comparative lung volumes. The proposed method showed the consistency with reliability index of 97.72%. The time taken for complete segmentation for each subject is between 60-70 sec on Intel Core i7-8750H, CPU @ 2.20 GHz.

Uniqueness of inspiratory airflow patterns in a realistic rat nasal cavity

In this study, we present a detailed flow analysis using an anatomically accurate rat nasal cavity model, in which the anatomy and physiology of the nasal airway was thoroughly examined. Special efforts were given to the swirling flow structures in the nasal vestibule (anterior section of the nose, lined by squamous epithelium), fractional flow patterns in the olfactory (posterior superior section of the rat nose, lined by olfactory epithelium), and a designated method to precisely quantify flow apportionment in the olfactory region was developed. Results revealed distinct inspiratory flow patterns in the anterior vestibule region, where the accelerated airflow undergoes two sharp turns as traveling through the tortuous airway, making a route in a shape of 8. Besides this, exceptionally large flow apportionment was observed at the interface of the olfactory recess, which can be as much as 15 times greater than that in the human nose. The thorough understanding of the airflow dynamics in the rat nasal cavity is necessary to avoid potential misinterpretation of rat-derived inhalation toxicity results. Research findings are expected to play a fundamental role in developing unbiased rat to human interspecies data extrapolation schemes.

Active tail flexion in concert with passive hydrodynamic forces improves swimming speed and efficiency

Fish typically swim by periodic bending of their bodies. Bending seems to follow a universal rule; it occurs at about one-third from the posterior end of the fish body with a maximum bending angle of about $30^{\circ }$ . However, the hydrodynamic mechanisms that shaped this convergent design and its potential benefit to fish in terms of swimming speed and efficiency are not well understood. It is also unclear to what extent this bending is active or follows passively from the interaction of a flexible posterior with the fluid environment. Here, we use a self-propelled two-link model, with fluid–structure interactions described in the context of the vortex sheet method, to analyse the effects of both active and passive body bending on the swimming performance. We find that passive bending is more efficient but could reduce swimming speed compared with rigid flapping, but the addition of active bending could enhance both speed and efficiency. Importantly, we find that the phase difference between the posterior and anterior sections of the body is an important kinematic factor that influences performance, and that active antiphase flexion, consistent with the passive flexion phase, can simultaneously enhance speed and efficiency in a region of the design space that overlaps with biological observations. Our results are consistent with the hypothesis that fish that actively bend their bodies in a fashion that exploits passive hydrodynamics can at once improve speed and efficiency.

Application of Microspectral Imaging in Motor and Sensory Nerve Classification.

Objective It aimed to explore the application of the microscopic hyperspectral technique in motor and sensory nerve classification. Methods The self-developed microscopic hyperspectral acquisition system was applied to collect the data of anterior and posterior spinal cord sections of white rabbits. The joint correction algorithm was employed to preprocess the collected data, such as noise reduction. On the basis of pure linear light source index, a new pixel purification algorithm based on cross contrast was proposed to extract more regions of interest, which was used for feature extraction of motor and sensory nerves. Besides, the ML algorithm was employed to classify motor and sensory nerves based on feature extraction results. Results The joint correction algorithm was adopted to preprocess the data collected by the microscopic hyperspectral technique, so as to eliminate the influence of the incident light source and the system and improve the classification accuracy. The axon and myelin spectrum curves of the two kinds of nerves in the stained specimens had the same trend, but the values of all kinds of spectrum of sensory nerves were higher than those of motor nerves. However, the myelin sheath spectrum curves of motor nerves in the unstained specimens were greatly different from the curves of sensory nerves. The axon spectrum curves had the same trend, but the axon spectrum values of sensory nerves were higher than those of motor nerves. The ML algorithm had high accuracy and fast speed in motor and sensory nerve classification, and the classification effect of stained specimens was better than that of unstained specimens. Conclusion The microscopic hyperspectral technique had high feasibility in sensory and motor nerve classification and was worthy of further research and promotion.

REGENERATION IN EUDRILUS EUGENIAE KINBERG 1867 (OLIGOCHAETA, ANNELIDA)

Earthworm EudriluseugeniaeKinberg 1867, commonly known as African night crawler is an efficient organic waste decomposer. As the dedifferentiation patterns of these invertebrates are like vertebrates, they are excellent candidates for regeneration studies. We made 12 amputations along the earthworm to demarcate anterior and posterior sections for regeneration studies. Regeneration events included wound healing, blastema formation, segmentation, pigmentation and functional clitellum formation. Clitellum formation was noted in the posterior segments after 28-30 days of amputation, whereas anterior segments without clitellum did not survive after 30days. In both anterior and posterior segments, number of segments remaining after amputation proved to be a significant factor in determining the survival rate. Earthworms with less than one fourth of the body length showed very low survival rates.But no significant correlation existed between the lengths of regenerating fragment and number of remaining segments in the amputated worms. Analysis of variance showed no significant difference between regeneration rates of different segments in anterior segments whereas the posterior segments showed significant difference in the regeneration rates.