447 research outputs found
A parallel compact-TVD method for compressible fluid dynamics employing shared and distributed-memory paradigms
No full textA novel multi-block compact-TVD finite difference method for the simulation of compressible flows is presented. The method combines distributed and shared-memory paradigms to take advantage of the configuration of modern supercomputers that host many cores per shared-memory node. In our approach a domain decomposition technique is applied to a compact scheme using explicit flux formulas at block interfaces. This method offers great improvement in performance over earlier parallel compact methods that rely on the parallel solution of a linear system. A test case is presented to assess the accuracy and parallel performance of the new method
Immunohistopathological findings in the lungs of calves naturally infected with Mycoplasma bovis
No full textHistology and immunohistochemistry were used to analyse the lesions and distribution of Mycoplasma bovis antigen in the lungs of 18 naturally infected calves. Microscopic examination of pneumonic lungs revealed two distinct patterns of necrosis and inflammation. The first pattern was observed in six of 18 (33.3%) calves in which microscopic lesions were characterized by large irregular areas of coagulative necrosis surrounded by a dense zone of degenerated neutrophils. Moderate amounts of mycoplasmal antigen were in the centre and periphery of these necrotic foci and, to a lesser extent, in mononuclear cells of the peribronchial lymphoid tissue. The second pattern was observed in 18 of 18 (100%) calves and consisted of rounded foci of caseous necrosis composed by granular eosinophilic material surrounded by a rim of granulation tissue. Large amounts of M. bovis antigen were detected in the centre and periphery of these necrotic foci and, to a lesser extent, in the peribronchial lymphoid tissue, and alveolar and interstitial macrophages. It was concluded that both caseous and coagulative necrosis of the lung parenchyma was primarily caused by M. bovis. Infection with M. bovis should be suspected in bovine necrotic bronchopneumonia, particularly in cases in which the pulmonary necrosis is part of a pyogranulomatous inflammation centred around airways. The pattern of caseous necrosis with pyogranulomatous inflammation is characteristic of M. bovis infection while the pattern of coagulative necrosis is similar to and must be differentiated from Mannheimia haemolytica and Haemophilus somnus infection.PT: J; CR: ADEGBOYE DS, 1995, J VET DIAGN INVEST, V7, P261 ADEGBOYE DS, 1995, J VET DIAGN INVEST, V7, P333 BENNETT RH, 1977, AM J VET RES, V38, P1731 BOOTHBY JT, 1988, CORNELL VET, V76, P188 BOUGHTON E, 1979, VET B, V49, P377 BRICE N, 2000, VET REC, V146, P643 BUCHVAROVA Y, 1989, ARCH EXP VET MED, V43, P685 DUNGWORTH DL, 1993, PATHOLOGY DOMESTIC A, P539 GEARY SJ, 1981, SCIENCE, V212, P1032 GOURLAY RN, 1985, RES VET SCI, V38, P377 GOURLAY RN, 1989, VET REC, V124, P420 HAINES DM, 1991, J VET DIAGN INVEST, V3, P101 HAINES DM, 2001, CAN VET J, V42, P857 HEWICKERTRAUTWEIN M, 2002, VET REC, V151, P699 KINDE H, 1993, J VET DIAGN INVEST, V5, P194 LOPEZ A, 1986, AM J VET RES, V47, P1283 LOPEZ A, 2001, SPECIAL VET PATHOLOG, P125 LOPEZ A, 2002, 18 PAN AM C VET SCI NICHOLAS RAJ, 2003, RES VET SCI, V74, P105 POTGIETER LND, 1995, VET CLIN N AM-FOOD A, V11, P501 RODRIGUEZ F, 1996, J COMP PATHOL, V115, P151 SHAHRIAR FM, 2002, CAN VET J, V43, P863 SLAUSON DO, 1990, MECH DIS TXB COMP GE THOMAS A, 2002, VET RES COMMUN, V26, P333; NR: 24; TC: 1; J9: J VET MED A-PHYSIOL PATHOL CL; PG: 5; GA: 818KGSource type: Electronic(1
Data used for analyzing a turning-ascending flight of a H. pratti bat
No full textBats exhibit a high degree of agility and provide an excellent model system for bioinspired flight. The current study investigates an ascending right turn of a H. pratti bat and elucidates on the kinematic features and aerodynamic mechanisms used to effectuate the maneuver. To initiate and sustain the turn, the bat utilizes roll and yaw rotations of the body to different extents synergistically to generate the centripetal force for a stable turn. The turning moments are generated by drawing the wing inside the turn closer to the body, by introducing phase lags in force generation between the wings and redirecting force production to the outer part of the wing outside of the turn. Deceleration in flight speed, an increase in flapping frequency, shortening of the upstroke, and thrust generation at the end of the upstroke was observed during the ascending maneuver. The bat consumes about 0.67 W power to execute the turning ascending maneuver which is approximately two times the power consumed by similar bats during level flight. Upon comparison with a similar maneuver by a H. armiger bat [P. Windes, D.K. Tafti, R. Müller, Kinematic and aerodynamic analysis of a bat performing a turning-ascending maneuver, Bioinspiration and Biomimetics. 16 (2020). doi:10.1088/1748-3190/abb78d.], some commonalities as well as differences were observed in the detailed wing kinematics and aerodynamics.Description of uploaded files and codes:
1. Maneuvering_flight_trajectory.mp4 = Bat flight video recording.
2. Raw_data_for_an_ascending_right_turn_of_Hipposiderous_Pratti.xlsx = x, y, z coordinates of the wing marker points making up the 3D wing kinematics.
3. ctr_pts.ucd = Connectivity information for the triangulated marker/control points on the wing surface.
4. surfgrid.s001 = Surface grid (fine resolution) used as an input for CFD.
5. splines.dat = This file contains the time dependent kinematic information of the flight trajectory for all the control points on the wing surface (discrete time step used = 1/120 s).
6. ibm_movement_bat.f90 = Fortran subroutine that reads the bat wing surface grid (surfgrid.s001), the connectivity information (ctr_pts.ucd) and the spline data (splines.dat) to generate the wing kinematics to be used as a boundary condition for CFD calculations.
7. ibm_force_all.dat = This file contains the aerodynamic force information on the bat wing coming out of the CFD simulation. The 11 columns are respectively, time, total force in x direction, total force in y direction, total force in z direction, pressure force in x direction, pressure force in y direction, pressure force in z direction, shear force in x direction, shear force in y direction, shear force in z direction and power
8. animation1.avi = This is an animation showing the wing perturbation of the bat as it follows the trajectory. This animation shows the pressure difference between the top and bottom surface of the bat wing calculated from the CFD simulation.The bat used for current study is an adult female Pratt's roundleaf bat (Hipposideros pratti) weighing 55 g. The animal was kept with a group of conspecifics in a controlled indoor environment designed to allow natural movement given its typical flight behavior. Ethical procedures according to Virginia Tech's Institutional Animal Care and Use Committee (protocol number 15-067) were followed. Kinematic data were collected using an optical 3D motion capture system put together inside a 1.2 m×1.2 m×5 m open-ended flight tunnel. The system comprised of 21 synchronized video cameras arranged in 3 rings located about 40 cm apart. The details of the camera specification and their arrangement is given in a prior work [P. Windes, X. Fan, M. Bender, D.K. Tafti, R. Müller, A computational investigation of lift generation and power expenditure of Pratt's roundleaf bat (Hipposideros pratti) in forward flight, PLoS One. 13 (2018) 1–26. doi:10.1371/journal.pone.0207613.]. After being released, the bat flew without interruption through the tunnel and the camera arrays recorded the flight featuring different maneuvers at 120 frames per second and in 1920×1080 pixel resolution. The camera array was calibrated using the Svoboda multi-camera self-calibration method [T. Svoboda, D. Martinec, T. Pajdla, A convenient multicamera self-calibration for virtual environments, Presence Teleoperators Virtual Environ. 14 (2005) 407–422.doi:10.1162/105474605774785325.].
The recorded flight path consists of 3 full wingbeat cycles and an extra half-cycle at the end, i.e., 3.5 wingbeat cycles, captured over 55 video frames during which the bat executes an ascending right turn with deceleration in the flight direction similar to Windes et al. [P. Windes, D.K. Tafti, R. Müller, Kinematic and aerodynamic analysis of a bat performing a turning-ascending maneuver, Bioinspiration and Biomimetics. 16 (2020). doi:10.1088/1748-3190/abb78d.]. Each cycle is defined to start with an upstroke and end with a down-stroke. The last half cycle (upstroke) is included in spite of the second half of the cycle (down-stroke) being incomplete as the bat continues to ascend outside the range of the motion capture system. After the last upstroke that was analyzed in the current paper, the bat completes two full flaps before perching on the ceiling of the tunnel.
In order to track the wing motion, about 150 small white circular markers made of medical tape were set to the bat's wings to capture the detailed spatio-temporal kinematic features of the wing as it effectuates the maneuver. Stereo triangulation was performed for the 55 frames of the current flight using a custom MATLAB code to achieve a total of (150 points) × (55 frames) ~ 8250 points in 3D space. In the event of spatial or temporal occlusions among those points, a temporal spline curve and a spatial implicit surface reconstruction [P. Windes, D.K. Tafti, R. Müller, Determination of spatial fidelity required to accurately mimic the flight dynamics of a bat, Bioinspiration and Biomimetics. 14 (2019). doi:10.1088/1748-3190/ab3e2a.] was used to fill in the missing data. Afterwards a 3D reconstruction was done using a MATLAB code where a semi-automated technique was used to define point correspondences between frames, the details of which are described in previous works [P. Windes, D.K. Tafti, R. Müller, Kinematic and aerodynamic analysis of a bat performing a turning-ascending maneuver, Bioinspiration and Biomimetics. 16 (2020). doi:10.1088/1748-3190/abb78d.], [P. Windes, D.K. Tafti, R. Müller, Determination of spatial fidelity required to accurately mimic the flight dynamics of a bat, Bioinspiration and Biomimetics. 14 (2019). doi:10.1088/1748-3190/ab3e2a.], [P. Windes, X. Fan, M. Bender, D.K. Tafti, R. Müller, A computational investigation of lift generation and power expenditure of Pratt's roundleaf bat (Hipposideros pratti) in forward flight, PLoS One. 13 (2018) 1–26. doi:10.1371/journal.pone.0207613.]
The effect of diabetes training through social networks on metabolic control of individuals with type 2 diabetes; a randomized controlled trial
No full textBackground. Due to spread of smart phones, opportunity to train patients with diabetes and communicate with them using social media is rising. Aim of this study was to evaluate the effect of training through two popular social networks in Iran ("Telegram" and "Soroush") and the metabolic control of people with Type 2 diabetes. Methods. In this randomized controlled trial, we recruited 134 patients with type 2 diabetes, which randomly allocated into two groups: the intervention and the control group on a 1:1 basis. The studied tools included demographic information and awareness of diabetes and international physical activity questionnaires. The intervention comprised a training package that delivered to the intervention group via social media for 45 days. The primary outcome measures included awareness of diabetes management and physical activity level while secondary outcome measures were HbA1c and lipid profile. Results. Social network training led to the increase of the patients' awareness (44.31 ± 2.78 to 46.88 ± 2.25 in intervention group vs 44.14 ± 3.85 to 44.41 ± 3.87 in control group) and physical activities level (23.64 ± 8.46 to 31.68 ± 7.12 in intervention group vs 26.20 ± 9.39 to 30.20 ± 8.11 in control group) (p-value < 0.001). Besides, LDL and HDL levels, and HbA1c (8.19 ± 2.10 to 8.05 ± 1.96 in intervention group vs. 7.53 ± 1.67 to 7.45 ± 1.34 in control group) decreased significantly (p-value < 0.05). Conclusions. Changes in lifestyle and challenges of the patients' attendance in diabetes training sessions, declared that use of social networks can be useful to train diabetes patients remotely, and it is feasible to send training messages to help them improve their diabetes care
Electroencephalogram paroxysmal θ characterizes cataplexy in mice and children.
No full textAstute control of brain activity states is critical for adaptive behaviours and survival. In mammals and birds, electroencephalographic recordings reveal alternating states of wakefulness, slow wave sleep and paradoxical sleep (or rapid eye movement sleep). This control is profoundly impaired in narcolepsy with cataplexy, a disease resulting from the loss of orexin/hypocretin neurotransmitter signalling in the brain. Narcolepsy with cataplexy is characterized by irresistible bouts of sleep during the day, sleep fragmentation during the night and episodes of cataplexy, a sudden loss of muscle tone while awake and experiencing emotions. The neural mechanisms underlying cataplexy are unknown, but commonly thought to involve those of rapid eye movement-sleep atonia, and cataplexy typically is considered as a rapid eye movement sleep disorder. Here we reassess cataplexy in hypocretin (Hcrt, also known as orexin) gene knockout mice. Using a novel video/electroencephalogram double-blind scoring method, we show that cataplexy is not a state per se, as believed previously, but a dynamic, multi-phased process involving a reproducible progression of states. A knockout-specific state and a stereotypical paroxysmal event were introduced to account for signals and electroencephalogram spectral characteristics not seen in wild-type littermates. Cataplexy almost invariably started with a brief phase of wake-like electroencephalogram, followed by a phase featuring high-amplitude irregular theta oscillations, defining an activity profile distinct from paradoxical sleep, referred to as cataplexy-associated state and in the course of which 1.5-2 s high-amplitude, highly regular, hypersynchronous paroxysmal theta bursts (∼7 Hz) occurred. In contrast to cataplexy onset, exit from cataplexy did not show a predictable sequence of activities. Altogether, these data contradict the hypothesis that cataplexy is a state similar to paradoxical sleep, even if long cataplexies may evolve into paradoxical sleep. Although not exclusive to overt cataplexy, cataplexy-associated state and hypersynchronous paroxysmal theta activities are highly enriched during cataplexy in hypocretin/orexin knockout mice. Their occurrence in an independent narcolepsy mouse model, the orexin/ataxin 3 transgenic mouse, undergoing loss of orexin neurons, was confirmed. Importantly, we document for the first time similar paroxysmal theta hypersynchronies (∼4 Hz) during cataplexy in narcoleptic children. Lastly, we show by deep recordings in mice that the cataplexy-associated state and hypersynchronous paroxysmal theta activities are independent of hippocampal theta and involve the frontal cortex. Cataplexy hypersynchronous paroxysmal theta bursts may represent medial prefrontal activity, associated in humans and rodents with reward-driven motor impulse, planning and conflict monitoring
A review of gene- and cell-based therapies for familial hypercholesterolemia
No full textFamilial hypercholesterolemia (FH) is a genetic autosomal dominant disorder caused by an impaired receptor-mediated low-density lipoprotein (LDL) removal from the circulation, mainly due to disruptive autosomal co-dominant mutations in the LDL receptor (LDLr) gene, but also less frequently in the apolipoprotein B100 (APOB) and proprotein convertase subtilisin/kexin type 9 (PCSK9) genes. A rare form of autosomal recessive FH has been also described due to LDLr adaptor protein 1 (LDLRAP1) gene mutations. FH is characterized by very high levels of plasma LDL cholesterol associated with the high incidence of premature atherosclerotic cardiovascular disease (CVD). Despite heterozygous FH (HeFH) patients are still poorly recognized and treated, there is today a large availability of drugs (i.e., statins, ezetimibe and PCSK9 inhibitors) allowing theoretically the normalization of plasma LDL cholesterol levels in this population. Homozygous FH patients (HoFH) have a more severe form of FH, characterized by low responsiveness to the conventional lipid-lowering treatment and often associated with unfavorable prognosis in the young age. Inspired by promising outcomes obtained by orthotopic liver transplantation (OLT), scientists are investigating the possibility of correcting the defective LDLr in these patients by using gene therapy approaches to achieve a novel therapeutic solution with high efficiency. In this article, we tried to review the in vitro, ex vivo, and in vivo attempts conducted to correct FH-causing LDLr gene mutations by using different methods of gene delivery, gene editing, and stem cell manipulation. We also discussed some clinical trials performed in this context
Targeted inactivation of hypocretin receptors in dopaminergic and noradrenergic systems alters brain activity in wakefulness
No full textSince the discovery of hypocretins/orexins (Hcrt/Ox) in 1998, several narcoleptic mouse models, such as Hcrt-KO, Hcrtrl-KO, Hcrtr2-KO and double receptors KO mice, and orexin-ataxin transgenic mice were generated. The available Hcrt mouse models do not allow the dissection of the specific role of Hcrt in each target region. Dr. Anne Vassalli generated loxP-flanked alleles for each Hcrt receptor, which are manipulated by Cre recombinase to generate mouse lines with disrupted Hcrtrl or Hcrtr2 (or both) in cell type-specific manner. The role of noradrenaline (NA) and dopamine (OA) in ttie regulation of vigilance states is well documented. The purpose of this thesis is to explore the role of the Hcrt input into these two monoaminergic systems. Chronic loss of Hcrtrl in NA neurons consolidated paradoxical sleep (PS), and altered wakefulness brain activity in baseline, during the sleep deprivation (SD), and when mice were challenged by a novel environment, or exposed to nest-building material. The analysis of alterations in the sleep EEG delta power showed a consistent correlation with the changes in the preceding waking quality in these mice. Targeted inactivation of Hcrt input into DA neurons showed that Hcrtr2 inactivation present the strongest phenotype. The loss of Hcrtr2 in DA neurons caused modified brain activities in spontaneous wakefulness, during SD, and in novel environmental conditions. In addition to alteration of wakefulness quality and quantity, conditional inactivation of Hcrtr2 in DA neurons caused an increased in time spent in PS in baseline and a delayed and less complete PS recovery after SD. In the first 30 min of sleep recovery, single (i.e. for Hcrtrl or Hcrtr2) conditional knockout receptor mice had opposite changes in delta activity, including an increased power density in the fast delta range with specific inactivation of Hcrtr2, but a decreased power density in the same range with specific inactivation of Hcrtrl in DA cells. These studies demonstrate a complex impact of Hcrt receptors signaling in both NA and DA system, not only on quantity and quality of wakefulness, but also on PS amount regulation as well as on SWS delta power expression.
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Depuis la découverte des hypocrétines/orexines (Hcrt/Ox) en 1998, plusieurs modèles de souris, narcoleptiques telles que Hcrt-KO, Hcrtr2-KO et récepteurs doubles KO et les souris transgéniques orexine-ataxine ont été générés. Les modèles de souris Hcrt disponibles ne permettaient pas la dissection du rôle spécifique de l'Hcrt dans chaque noyau neuronal cible. Notre laboratoire a généré des allèles loxP pour chacun des 2 gènes codant pour les récepteurs Hcrtr, qui sont manipulés par recombinase Cre pour générer des lignées de souris avec Hcrtrl inactivé, ou Hcrtr2 inactivé, (ou les deux), spécifiquement dans un type cellulaire particulier. Le rôle de la noradrénaline (NA) et la dopamine (DA) dans la régulation des états de vigilance est bien documentée. Le but de cette thèse est d'étudier le rôle de l'afférence Hcrt dans ces deux systèmes monoaminergiques au niveau de l'activité cérébrale telle qu'elle apparaît dans l'électroencéphalogramme (EEG). Mon travail montre que la perte chronique de Hcrtrl dans les neurones NA consolide le sommeil paradoxal (PS), et l'activité cérébrale de l'éveil est modifiée en condition spontanée, au cours d'une experience de privation de sommeil (SD), et lorsque les souris sont présentées à un nouvel environnement, ou exposées à des matériaux de construction du nid. Ces modifications de l'éveil sont corrélées à des modifications de puissance de l'activité delta du sommeil lent qui le suit. L'inactivation ciblée des Hcrtrs dans les neurones DA a montré que l'inactivation Hcrtr2 conduit au phénotype le plus marqué. La perte de Hcrtr2 dans les neurones DA mène à des modification d'activité cérébrale en éveil spontané, pendant SD, ainsi que dans des conditions environnementales nouvelles. En plus de l'altération de la qualité de l'éveil et de la quantité, l'inactivation conditionnelle de Hcrtr2 dans les neurones DA a provoqué une augmentation du temps passé en sommeil paradoxal (PS) en condition de base, et une reprise retardée et moins complète du PS après SD. Dans les 30 premières minutes de la récupération de sommeil, les modèles inactivés pour un seul des récepteurs (ie pour Hcrtrl ou Hcrtr2 seulement) montrent des changements opposés en activité delta, en particulier une densité de puissance accrue dans le delta rapide avec l'inactivation spécifique de Hcrtr2, mais une densité de puissance diminuée dans cette même gamme chez les souris inactivées spécifiquement en Hcrtrl dans les neurones DA. Ces études démontrent un impact complexe de l'inactivation de la neurotransmission au niveau des récepteurs d'Hcrt dans les deux compartiments NA et DA, non seulement sur la quantité et la qualité de l'éveil, mais aussi sur la régulation de quantité de sommeil paradoxal, ainsi que sur l'expression de la puissance delta pendant le sommeil lent
A retrospective study of sporadic bovine abortions, stillbirths, and neonatal abnormalities in Atlantic Canada, from 1990 to 2001
No full textIn a retrospective study on 265 cases of sporadic bovine abortions, stillbirths, and neonatal deaths in Atlantic Canada (1990 to 2001), an etiological diagnosis was made in 117 cases (44.2%). The cases were divided into 2 groups: 234 abortions, and 31 stillbirths and neonatal deaths. Identified causes of abortion were bacteria (24.4%), fungi (6.8%), viruses (6.0%), protozoa (Neospora spp.) (2.1%), congenital anomalies (0.4%), and miscellaneous conditions (1.3%). In addition, placentitis without demonstrable infectious agents was observed in 17 (7.3%). Of the 31 cases of stillbirth and neonatal death, identified causes were dystocia (22.5%), congenital anomalies (22.5%), meconium aspiration syndrome (16.1%), and miscellaneous conditions (6.5%). No etiological diagnosis was made in 59% of abortions and 32.4% of stillbirths and neonatal deaths. The 3 most common identifiable causes of abortion in this study were bacterial, fungal, and viral infections
Does a New Modification of the Two-Step Injection Technique for Inferior Alveolar Nerve Block Reduce Pain Compared to the Conventional Technique? A Randomized Clinical Trial
No full textBackground. The ability to control pain is an essential part of dental procedures and the need for optimal pain control and reduction of discomfort is the primary concern of every dentist. This study aims to compare the pain and vital signs during inferior alveolar nerve block between conventional and a new modification of the two-step injection techniques. Methods. In this institutional single-blind randomized clinical trial, attendees of dental school at Mazandaran University of Medical Sciences from February to May 2022 were included. Inclusion criteria were 20-60 years old and healthy (ASA1) individuals who were willing to participate in this study. Individuals who were taking medications affecting their understanding of pain and patients with active infections at the injection site were excluded. These individuals were divided into two groups. First, superficial anesthesia was performed and afterward, conventional and two-step injection techniques were performed. For the two-step injection method, 6 mm of the needle was injected into the mucosa and one-third of the local anesthetic solution was released from the computer-controlled injection toolkit. Afterward, a 25 mm 30-gauge needle was reinserted into the previous hole delivering the remaining local anesthetic. The pain during injection was measured by a patient-reported numerical rating scale (NRS). Moreover, vital signs were monitored immediately before and after the injection. Kolmogorov-Smirnov test, Mann-Whitney U test, independent T-test, and Fisher's exact χ2 test were performed for statistical analysis (α = 0.05). Results. This study involved 32 adults aged between 20 and 50 years old with 1: 1 female/male sex distribution. The pain score was significantly higher in the conventional injection technique compared to the two-step injection technique in all sex and age groups. There were no significant differences in vital signs between the conventional and two-step injection techniques. There was no significant difference in the mean pain scores of females and males, regardless of their injection techniques. Conclusion. Utilizing the two-step injection technique in patients for inferior alveolar block reduces pain during injection without altering patients' vital signs significantly. This trial is registered with IRCT20220106053646N1
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