Two appendages homologous between basal bodies and centrioles are formed using distinct Odf2 domains.

PubMed

Tateishi, Kazuhiro; Yamazaki, Yuji; Nishida, Tomoki; Watanabe, Shin; Kunimoto, Koshi; Ishikawa, Hiroaki; Tsukita, Sachiko

2013-11-11

Ciliogenesis is regulated by context-dependent cellular cues, including some transduced through appendage-like structures on ciliary basal bodies called transition fibers and basal feet. However, the molecular basis for this regulation is not fully understood. The Odf2 gene product, ODF2/cenexin, is essential for both ciliogenesis and the formation of the distal and subdistal appendages on centrioles, which become basal bodies. We examined the effects of Odf2 deletion constructs on ciliogenesis in Odf2-knockout F9 cells. Electron microscopy revealed that ciliogenesis and transition fiber formation required the ODF2/cenexin fragment containing amino acids (aa) 188-806, whereas basal foot formation required aa 1-59 and 188-806. These sequences also formed distal and subdistal appendages, respectively, indicating that the centriole appendages are molecularly analogous to those on basal bodies. We used the differential formation of appendages by Odf2 deletion constructs to study the incorporation and function of molecules associated with each appendage type. We found that transition fibers and distal appendages were required for ciliogenesis and subdistal appendages stabilized the centrosomal microtubules.

Laparoscopic anatomy of the equine abdomen.

PubMed

Galuppo, L D; Snyder, J R; Pascoe, J R

1995-04-01

Laparoscopy was performed on 6 horses (2 mares, 2 geldings, 2 stallions) to determine the normal laparoscopic anatomy of the equine abdomen. After withholding feed for 36 hours, horses were examined from the left and right paralumbar fossae, and the visceral anatomic structures were recorded by videotape and photography. One mare developed emphysema located subcutaneously at the primary laparoscopic portal; otherwise, there were no complications. The anatomic structures of diagnostic importance that were observed in the left half of the abdomen were the hepatic duct; left lateral and quadrate lobes of the liver; stomach; spleen; left kidney with the associated nephrosplenic ligament; segments of jejunum, descending colon, and ascending colon; left side of the male and female reproductive tracts; urinary bladder; vaginal ring; and mesorchium. Important structures observed in the right side of the abdomen were portions of the common hepatic duct; left lateral, quadrate, and right lobes of the liver; caudate process of the liver; stomach; duodenum; right dorsal colon, epiploic foramen; omental bursa; right kidney; base of the cecum; segments of jejunum, descending colon, and ascending colon; urinary bladder; right half of the male and female reproductive tracts; and rectum.

Significantly Elevated C-Reactive Protein Levels After Epicardial Clipping of the Left Atrial Appendage.

PubMed

Verberkmoes, Niels J; Akca, Ferdi; Vandevenne, Ann-Sofie; Jacobs, Luuk; Soliman Hamad, Mohamed A; van Straten, Albert H M

Besides mechanical and anatomical changes of the left atrium, epicardial closure of the left atrial appendage has also possible homeostatic effects. The aim of this study was to assess whether epicardial clipping of the left atrial appendage has different biochemical effects compared with complete removal of the left atrial appendage. Eighty-two patients were included and underwent a totally thoracoscopic AF ablation procedure. As part of the procedure, the left atrial appendage was excluded with an epicardial clip (n = 57) or the left atrial appendage was fully amputated with an endoscopic vascular stapler (n = 25). From all patients' preprocedural and postprocedural blood pressure, electrolytes and inflammatory parameters were collected. The mean age and left atrial volume index were comparable between the epicardial clip and stapler group (64 ± 8 years vs. 60 ± 9 years, P = non-significant; 44 ± 15 mL/m vs. 40 ± 13 mL/m, P = non-significant). Patients receiving left atrial appendage clipping had significantly elevated C-reactive protein levels compared with patients who had left atrial appendage stapling at the second, third, and fourth postoperative day (225 ± 84 mg/L vs. 149 ± 76 mg/L, P = 0.002, 244 ± 78 vs. 167 ± 76, P = 0.004, 190 ± 74 vs. 105 ± 48, P < 0.001, respectively). Patients had a significant decrease in sodium levels, systolic, and diastolic blood pressure at 24 and 72 hours after left atrial appendage closure. However, this was comparable for both the left atrial appendage clipping and stapling group. Increased activation of the inflammatory response was observed after left atrial appendage clipping compared with left atrial appendage stapling. Furthermore, a significant decrease in blood pressure was observed after surgical removal of the left atrial appendage. Whether the inflammatory response affects the outcome of arrhythmia surgery needs to be further evaluated.

Two appendages homologous between basal bodies and centrioles are formed using distinct Odf2 domains

PubMed Central

Tateishi, Kazuhiro; Yamazaki, Yuji; Nishida, Tomoki; Watanabe, Shin; Kunimoto, Koshi; Ishikawa, Hiroaki

2013-01-01

Ciliogenesis is regulated by context-dependent cellular cues, including some transduced through appendage-like structures on ciliary basal bodies called transition fibers and basal feet. However, the molecular basis for this regulation is not fully understood. The Odf2 gene product, ODF2/cenexin, is essential for both ciliogenesis and the formation of the distal and subdistal appendages on centrioles, which become basal bodies. We examined the effects of Odf2 deletion constructs on ciliogenesis in Odf2-knockout F9 cells. Electron microscopy revealed that ciliogenesis and transition fiber formation required the ODF2/cenexin fragment containing amino acids (aa) 188–806, whereas basal foot formation required aa 1–59 and 188–806. These sequences also formed distal and subdistal appendages, respectively, indicating that the centriole appendages are molecularly analogous to those on basal bodies. We used the differential formation of appendages by Odf2 deletion constructs to study the incorporation and function of molecules associated with each appendage type. We found that transition fibers and distal appendages were required for ciliogenesis and subdistal appendages stabilized the centrosomal microtubules. PMID:24189274

[Right atrial appendage thrombosis during atrial fibrillation: an element to look for].

PubMed

Barbati, Giovanni; De Domenico, Renato; Rossi, Stefania; Vecchiato, Elena; Zeppellini, Roberto

2017-03-01

Oral anticoagulant therapy (OAT) is a mainstay of atrial fibrillation (AF) pharmacological treatment. Left atrial appendage closure is a possible treatment, when feasible, in patients with intracerebral hemorrhage during OAT. We report a case of right atrial appendage thrombosis in a patient with chronic AF admitted for syncope due to diuretic-induced orthostatic hypotension. Two years previously, he had undergone left atrial appendage closure with the Amplatzer Cardiac Plug device because of intracerebral hemorrhage during OAT. After neurological consult, OAT was resumed with apixaban 5 mg twice daily, and transesophageal echocardiography performed two months later showed complete resolution of the right atrial appendage thrombosis. This particular case underlines the importance of searching for a possible right atrial appendage thrombosis in patients affected by AF, and suggests that left atrial appendage closure in AF patients not suitable for OAT does not fully eliminate the risk of thromboembolism.

Assessment of Device-Related Thrombus and Associated Clinical Outcomes With the WATCHMAN Left Atrial Appendage Closure Device for Embolic Protection in Patients With Atrial Fibrillation (from the PROTECT-AF Trial).

PubMed

Main, Michael L; Fan, Dali; Reddy, Vivek Y; Holmes, David R; Gordon, Nicole T; Coggins, Tina R; House, John A; Liao, Lawrence; Rabineau, Dawn; Latus, George G; Huber, Kenneth C; Sievert, Horst; Wright, Richard F; Doshi, Shephal K; Douglas, Pamela S

2016-04-01

Left atrial appendage closure with the WATCHMAN device is an alternative to anticoagulation for stroke prevention in selected patients with atrial fibrillation (AF). LA device-related thrombus (DRT) is poorly defined and understood. We aimed to (1) develop consensus echocardiographic diagnostic criteria for DRT; (2) estimate the incidence of DRT; and (3) determine clinical event rates in patients with DRT. In phase 1 (training), a training manual was developed and reviewed by 3 echocardiographers with left atrial appendage closure device experience. All available transesophageal (TEE) studies in the WATCHMAN left atrial appendage system for embolic protection in patients with atrial fibrillation (PROTECT-AF) trial patients with suspected DRT were reviewed in 2 subsequent phases. In phase 2 (primary blind read), each reviewer independently scored each study for DRT, and final echo criteria were developed. Unanimously scored studies were considered adjudicated, whereas all others were reevaluated by all reviewers in phase 3 (group adjudication read). DRT was suspected in 35 of 485 patients by the site investigator, the echocardiography core laboratory, or both; 93 of the individual TEE studies were available for review. In phase 2, 3 readers agreed on 67 (72%) of time points. Based on phases 1 and 2, 5 DRT criteria were developed. In phase 3, studies without agreement in phase 2 were adjudicated using these criteria. Overall, at least 1 TEE was DRT positive in 27 (5.7%) PROTECT-AF patients. Stroke, peripheral embolism, or cardiac/unexplained death occurred in subjects with DRT at a rate of 3.4 per 100 patient-years follow-up. In conclusion, DRT were identified on at least 1 TEE in 27 PROTECT-AF patients, indicating a DRT incidence of 5.7%. Primary efficacy events in patients with DRT occurred at a rate of 3.4 per 100 patient-years follow-up, intermediate in frequency between event rates previously reported for the overall device and warfarin arms in PROTECT-AF. Copyright © 2016 Elsevier Inc. All rights reserved.

Role of the AP2 β-Appendage Hub in Recruiting Partners for Clathrin-Coated Vesicle Assembly

PubMed Central

Burtey, Anne; Praefcke, Gerrit J. K; Peak-Chew, Sew-Yeu; Mills, Ian G; Benmerah, Alexandre; McMahon, Harvey T

2006-01-01

Adaptor protein complex 2 α and β-appendage domains act as hubs for the assembly of accessory protein networks involved in clathrin-coated vesicle formation. We identify a large repertoire of β-appendage interactors by mass spectrometry. These interact with two distinct ligand interaction sites on the β-appendage (the “top” and “side” sites) that bind motifs distinct from those previously identified on the α-appendage. We solved the structure of the β-appendage with a peptide from the accessory protein Eps15 bound to the side site and with a peptide from the accessory cargo adaptor β-arrestin bound to the top site. We show that accessory proteins can bind simultaneously to multiple appendages, allowing these to cooperate in enhancing ligand avidities that appear to be irreversible in vitro. We now propose that clathrin, which interacts with the β-appendage, achieves ligand displacement in vivo by self-polymerisation as the coated pit matures. This changes the interaction environment from liquid-phase, affinity-driven interactions, to interactions driven by solid-phase stability (“matricity”). Accessory proteins that interact solely with the appendages are thereby displaced to areas of the coated pit where clathrin has not yet polymerised. However, proteins such as β-arrestin (non-visual arrestin) and autosomal recessive hypercholesterolemia protein, which have direct clathrin interactions, will remain in the coated pits with their interacting receptors. PMID:16903783

Development of a new laparoscopic Foramen Epiploicum Mesh Closure (FEMC) technique in 6 horses.

PubMed

van Bergen, T; Wiemer, P; Bosseler, L; Ugahary, F; Martens, A

2016-05-01

Epiploic foramen entrapment (EFE) is, based on the number of reports in the literature, a relatively important life-threatening cause of colic in horses that could be prevented by closing the epiploic foramen (EF) in horses at risk of developing EFE. To describe the laparoscopic foramen epiploicum mesh closure (FEMC) technique and its outcome. Descriptive experimental study. The EF of 6 horses was closed with the FEMC technique. A diabolo-shaped constructed mesh was introduced into the omental vestibule through the EF under laparoscopic visualisation in the standing sedated horse. Clinical and laboratory parameters were recorded during the post operative period. Four weeks after the intervention, repeat laparoscopy was performed in all horses. Three horses were subjected to euthanasia one, 2 and 3 months after the intervention, and were examined on necropsy and histopathology. The remaining 3 horses were followed clinically for 6 months. The 6 FEMC procedures were performed successfully in a median surgery time of 22 min (range 18-27 min). One horse was treated for large colon impaction in the immediate post operative period. On repeat laparoscopy at 4 weeks all 6 EFs were closed and no undesired adhesions were identified. This was confirmed on gross and histopathological examination of the 3 horses that were subjected to euthanasia. The 3 remaining horses were clinically normal in the 6-month post operative observation period. This FEMC technique provides a fast, simple, reliable and safe procedure to obliterate the EF and may be useful in horses at risk for EFE. © 2015 EVJ Ltd.

Appendage mountable electronic devices conformable to surfaces

DOEpatents

Rogers, John; Ying, Ming; Bonifas, Andrew; Lu, Nanshu

2017-01-24

Disclosed are appendage mountable electronic systems and related methods for covering and conforming to an appendage surface. A flexible or stretchable substrate has an inner surface for receiving an appendage, including an appendage having a curved surface, and an opposed outer surface that is accessible to external surfaces. A stretchable or flexible electronic device is supported by the substrate inner and/or outer surface, depending on the application of interest. The electronic device in combination with the substrate provides a net bending stiffness to facilitate conformal contact between the inner surface and a surface of the appendage provided within the enclosure. In an aspect, the system is capable of surface flipping without adversely impacting electronic device functionality, such as electronic devices comprising arrays of sensors, actuators, or both sensors and actuators.

Attitude dynamics simulation subroutines for systems of hinge-connected rigid bodies with nonrigid appendages

NASA Technical Reports Server (NTRS)

Fleischer, G. E.; Likins, P. W.

1975-01-01

Three computer subroutines designed to solve the vector-dyadic differential equations of rotational motion for systems that may be idealized as a collection of hinge-connected rigid bodies assembled in a tree topology, with an optional flexible appendage attached to each body are reported. Deformations of the appendages are mathematically represented by modal coordinates and are assumed small. Within these constraints, the subroutines provide equation solutions for (1) the most general case of unrestricted hinge rotations, with appendage base bodies nominally rotating at a constant speed, (2) the case of unrestricted hinge rotations between rigid bodies, with the restriction that those rigid bodies carrying appendages are nominally nonspinning, and (3) the case of small hinge rotations and nominally nonrotating appendages. Sample problems and their solutions are presented to illustrate the utility of the computer programs.

Primary and Secondary Stroke Prevention Using Left Atrial Appendage Closure with Watchman Devices in Atrial Fibrillation Patients: A Single Center Experience from Mainland China.

PubMed

Chen, Yanhong; Zhang, Yonghua; Huang, Weiping; Huang, Keqiang; Xu, Bei; Su, X I

2017-06-01

Atrial fibrillation (AF) is associated with increased stroke risk resulting from cardiac embolism of the left atrial appendage (LAA). Stroke tends to recur in NVAF patients. Yet safety and feasibility of secondary stroke preventions with LAA closure (LAAC) have not been assessed in detail. This retrospective study was designed to compare the feasibility and safety of LAAC in primary and secondary stroke preventions, in a real-world setting of Chinese patients. From 2014 to 2015, non-valvular AF patients with CHA2DS2-VASc ≥1 were selected for percutaneous LAAC operations. Outcome observations of primary and secondary stroke preventions with Watchman devices were analyzed and compared. Overall, 122 patients were included. LAAC with Watchman devices were attempted in 115 patients, of whom 68 were for primary stroke prevention and 47 were for secondary prevention. Both the CHA2DS2-VASc score and the HASBLED score were significantly higher in the secondary prevention group (4.09 ± 1.06 vs. 1.93 ± 1.09 for CHA2DS2-VASc and 1.83 ± 1.03 vs. 1.26 ± 0.87 for HASBLED, P < 0.01). In both groups LAAC were achieved with high successful rate (98.53% in the primary prevention group and 100% in the secondary prevention group, P > 0.05) and low complication rates. The stroke rates were at a low level in both groups (1.47% in primary prevention group vs. 2.13% in secondary prevention group, P > 0.05). In our initial single-center experience, percutaneous LAA closure was a feasible and safe procedure for both primary and secondary stroke preventions in Chinese patients with nonvalvular AF. © 2017 Wiley Periodicals, Inc.

Safety of percutaneous left atrial appendage closure: results from the Watchman Left Atrial Appendage System for Embolic Protection in Patients with AF (PROTECT AF) clinical trial and the Continued Access Registry.

PubMed

Reddy, Vivek Y; Holmes, David; Doshi, Shephal K; Neuzil, Petr; Kar, Saibal

2011-02-01

The Watchman Left Atrial Appendage System for Embolic Protection in Patients With AF (PROTECT AF) randomized trial compared left atrial appendage closure against warfarin in atrial fibrillation (AF) patients with CHADS₂ ≥1. Although the study met the primary efficacy end point of being noninferior to warfarin therapy for the prevention of stroke/systemic embolism/cardiovascular death, there was a significantly higher risk of complications, predominantly pericardial effusion and procedural stroke related to air embolism. Here, we report the influence of experience on the safety of percutaneous left atrial appendage closure. The study cohort for this analysis included patients in the PROTECT AF trial who underwent attempted device left atrial appendage closure (n=542 patients) and those from a subsequent nonrandomized registry of patients undergoing Watchman implantation (Continued Access Protocol [CAP] Registry; n=460 patients). The safety end point included bleeding- and procedure-related events (pericardial effusion, stroke, device embolization). There was a significant decline in the rate of procedure- or device-related safety events within 7 days of the procedure across the 2 studies, with 7.7% and 3.7% of patients, respectively, experiencing events (P=0.007), and between the first and second halves of PROTECT AF and CAP, with 10.0%, 5.5%, and 3.7% of patients, respectively, experiencing events (P=0.006). The rate of serious pericardial effusion within 7 days of implantation, which had made up >50% of the safety events in PROTECT AF, was lower in the CAP Registry (5.0% versus 2.2%, respectively; P=0.019). There was a similar experience-related improvement in procedure-related stroke (0.9% versus 0%, respectively; P=0.039). Finally, the functional impact of these safety events, as defined by significant disability or death, was statistically superior in the Watchman group compared with the warfarin group in PROTECT AF. This remained true whether significance was defined as a change in the modified Rankin score of ≥1, ≥2, or ≥3 (1.8 versus 4.3 events per 100 patient-years; relative risk, 0.43; 95% confidence interval, 0.24 to 0.82; 1.5 versus 3.7 events per 100 patient-years; relative risk, 0.41; 95% confidence interval, 0.22 to 0.82; and 1.4 versus 3.3 events per 100 patient-years; relative risk, 0.43; 95% confidence interval, 0.22 to 0.88, respectively). As with all interventional procedures, there is a significant improvement in the safety of Watchman left atrial appendage closure with increased operator experience. Clinical Trial Registration- URL: http://clinicaltrials.gov. Unique identifier: NCT00129545.

Larval leg integrity is maintained by Distal-less and is required for proper timing of metamorphosis in the flour beetle, Tribolium castaneum

PubMed Central

Suzuki, Yuichiro; Squires, Diego C.; Riddiford, Lynn M.

2009-01-01

The dramatic transformation from a larva to an adult must be accompanied by a coordinated activity of genes and hormones that enable an orchestrated transformation from larval to pupal/adult tissues. The maintenance of larval appendages and their subsequent transformation to appendages in holometabolous insects remains elusive at the developmental genetic level. Here the role of a key appendage patterning gene Distal-less (Dll) was examined in mid- to late- larval stages of the flour beetle, Tribolium castaneum. During late larval development, Dll was expressed in appendages in a similar manner as previously reported for the tobacco hornworm, Manduca sexta. Removal of this late Dll expression resulted in disruption of adult appendage patterning. Intriguingly, earlier removal resulted in dramatic loss of structural integrity and identity of larval appendages. A large amount of variability in appendage morphology was observed following Dll dsRNA injection, unlike larvae injected with dachshund dsRNA. These Dll dsRNA-injected larvae underwent numerous supernumerary molts, which could be terminated with injection of either JH methyltransferase or Methoprene-tolerant dsRNA. Apparently, the partial dedifferentiation of the appendages in these larvae acts to maintain high JH and, hence, prevents metamorphosis. PMID:19022238

EWOLUTION: Design of a registry to evaluate real-world clinical outcomes in patients with AF and high stroke risk-treated with the WATCHMAN left atrial appendage closure technology.

PubMed

Boersma, Lucas V A; Schmidt, Boris; Betts, Tim R; Sievert, Horst; Tamburino, Corrado; Teiger, Emmanuel; Stein, Kenneth M; Bergmann, Martin W

2016-09-01

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and the rate of ischemic stroke attributed to non-valvular AF is estimated at 5% per year. Several multi-center studies established left atrial appendage closure as a safe and effective alternative to oral anticoagulation, but there is a need for additional real world data. The purpose of this observational, prospective, single-arm, multicenter clinical study is to compile real-world clinical outcome data for WATCHMAN™ LAA (left atrial appendage) Closure Technology. One thousand subjects at up to 70 institutions in Europe, the Middle East, and Russia will be enrolled. Patients will be followed for 2 years after WATCHMAN implantation, according to standard medical practice. Primary endpoints include procedural and long-term data including stroke/embolism, bleeding, and death. This article presents the background of the LAAC device and describes the design of the study. Results for peri-procedural analyses are expected toward the end of 2015; long-term follow-up data are expected in the latter half of 2017. The EWOLUTION study will formally expand knowledge of LAA closure into a broader real world setting. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Origin of archosaurian integumentary appendages: the bristles of the wild turkey beard express feather-type beta keratins.

PubMed

Sawyer, Roger H; Washington, Lynette D; Salvatore, Brian A; Glenn, Travis C; Knapp, Loren W

2003-06-15

The discovery that structurally unique "filamentous integumentary appendages" are associated with several different non-avian dinosaurs continues to stimulate the development of models to explain the evolutionary origin of feathers. Taking the phylogenetic relationships of the non-avian dinosaurs into consideration, some models propose that the "filamentous integumentary appendages" represent intermediate stages in the sequential evolution of feathers. Here we present observations on a unique integumentary structure, the bristle of the wild turkey beard, and suggest that this non-feather appendage provides another explanation for some of the "filamentous integumentary appendages." Unlike feathers, beard bristles grow continuously from finger-like outgrows of the integument lacking follicles. We find that these beard bristles, which show simple branching, are hollow, distally, and express the feather-type beta keratins. The significance of these observations to explanations for the evolution of archosaurian integumentary appendages is discussed.

Selection on bristle length has the ability to drive the evolution of male abdominal appendages in the sepsid fly Themira biloba.

PubMed

Herath, B; Dochtermann, N A; Johnson, J I; Leonard, Z; Bowsher, J H

2015-12-01

Many exaggerated and novel traits are strongly influenced by sexual selection. Although sexual selection is a powerful evolutionary force, underlying genetic interactions can constrain evolutionary outcomes. The relative strength of selection vs. constraint has been a matter of debate for the evolution of male abdominal appendages in sepsid flies. These abdominal appendages are involved in courtship and mating, but their function has not been directly tested. We performed mate choice experiments to determine whether sexual selection acts on abdominal appendages in the sepsid Themira biloba. We tested whether appendage bristle length influenced successful insemination by surgically trimming the bristles. Females paired with males that had shortened bristles laid only unfertilized eggs, indicating that long bristles are necessary for successful insemination. We also tested whether the evolution of bristle length was constrained by phenotypic correlations with other traits. Analyses of phenotypic covariation indicated that bristle length was highly correlated with other abdominal appendage traits, but was not correlated with abdominal sternite size. Thus, abdominal appendages are not exaggerated traits like many sexual ornaments, but vary independently from body size. At the same time, strong correlations between bristle length and appendage length suggest that selection on bristle length is likely to result in a correlated increase in appendage length. Bristle length is under sexual selection in T. biloba and has the potential to evolve independently from abdomen size. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Wound healing and skin regeneration.

PubMed

Takeo, Makoto; Lee, Wendy; Ito, Mayumi

2015-01-05

The skin is a complex organ consisting of the epidermis, dermis, and skin appendages, including the hair follicle and sebaceous gland. Wound healing in adult mammals results in scar formation without any skin appendages. Studies have reported remarkable examples of scarless healing in fetal skin and appendage regeneration in adult skin following the infliction of large wounds. The models used in these studies have offered a new platform for investigations of the cellular and molecular mechanisms underlying wound healing and skin regeneration in mammals. In this article, we will focus on the contribution of skin appendages to wound healing and, conversely, skin appendage regeneration following injuries. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

Cephalic and Limb Anatomy of a New Isoxyid from the Burgess Shale and the Role of “Stem Bivalved Arthropods” in the Disparity of the Frontalmost Appendage

PubMed Central

Aria, Cédric; Caron, Jean-Bernard

2015-01-01

We herein describe Surusicaris elegans gen. et sp. nov. (in Isoxyidae, amended), a middle (Series 3, Stage 5) Cambrian bivalved arthropod from the new Burgess Shale deposit of Marble Canyon (Kootenay National Park, British Columbia). Surusicaris exhibits 12 simple, partly undivided biramous trunk limbs with long tripartite caeca, which may illustrate a plesiomorphic “fused” condition of exopod and endopod. We construe also that the head is made of five somites (= four segments), including two eyes, one pair of anomalocaridid-like frontalmost appendages, and three pairs of poorly sclerotized uniramous limbs. This fossil may therefore be a candidate for illustrating the origin of the plesiomorphic head condition in euarthropods, and questions the significance of the “two-segmented head” in, e.g., fuxianhuiids. The frontalmost appendage in isoxyids is intriguingly disparate, bearing similarities with both dinocaridids and euarthropods. In order to evaluate the relative importance of bivalved arthropods, such as Surusicaris, in the hypothetical structuro-functional transition between the dinocaridid frontal appendage and the pre-oral—arguably deutocerebral—appendage of euarthropods, we chose a phenetic approach and computed morphospace occupancy for the frontalmost appendages of 36 stem and crown taxa. Results show different levels of evolutionary decoupling between frontalmost appendage disparity and body plans. Variance is greatest in dinocaridids and “stem bivalved” arthropods, but these groups do not occupy the morphospace homogeneously. Rather, the diversity of frontalmost appendages in “stem bivalved” arthropods, distinct in its absence of clear clustering, is found to link the morphologies of “short great appendages,” chelicerae and antennules. This find fits the hypothesis of an increase in disparity of the deutocerebral appendage prior to its diversification in euarthropods, and possibly corresponds to its original time of development. The analysis of this pattern, however, is sensitive to the—still unclear—extent of polyphyly of the “stem bivalved” taxa. PMID:26038846

Space station rotational equations of motion

NASA Technical Reports Server (NTRS)

Rheinfurth, M. H.; Carroll, S. N.

1985-01-01

Dynamic equations of motion are developed which describe the rotational motion for a large space structure having rotating appendages. The presence of the appendages produce torque coupling terms which are dependent on the inertia properties of the appendages and the rotational rates for both the space structure and the appendages. These equations were formulated to incorporate into the Space Station Attitude Control and Stabilization Test Bed to accurately describe the influence rotating solar arrays and thermal radiators have on the dynamic behavior of the Space Station.

Concomitant surgical closure of left atrial appendage: A systematic review and meta-analysis.

PubMed

Ando, Masahiko; Funamoto, Masaki; Cameron, Duke E; Sundt, Thoralf M

2018-03-12

Although percutaneous closure of the left atrial appendage is supported as a potential alternative to lifelong anticoagulation in patients with atrial fibrillation, comprehensive evidence on surgical left atrial appendage closure in heart surgery is limited. We conducted a meta-analysis of studies comparing patients who underwent open cardiac surgery with or without left atrial appendage closure. A literature search was performed on PubMed, Embase, and Cochrane Trials databases. Outcomes of interest were 30-day/in-hospital mortality and cerebrovascular accident. I 2 statistics were used to evaluate heterogeneity, and publication bias was evaluated by Begg's and Egger's tests. We reviewed 1284 articles and selected for main analysis 7 articles including 3897 patients (1963 in the left atrial appendage closure group and 1934 in the non-left atrial appendage closure group). Among the 7 studies, 3 were randomized-controlled studies, 3 were propensity-matched studies, and 1 was a case-matching study. At 30-day/in-hospital follow-up, left atrial appendage closure was significantly associated with decreased risk of mortality and cerebrovascular accident (odds ratio, 0.384, 95% confidence interval, 0.233-0.631 for mortality, and odds ratio, 0.622, 95% confidence interval, 0.388-0.998 for cerebrovascular accident). Stratified analysis demonstrated that this association was more prominent in preoperative atrial fibrillation strata. Concomitant surgical left atrial appendage closure should be considered at the time of open cardiac surgery, particularly among those in atrial fibrillation preoperatively. The benefit of left atrial appendage closure for patients not in atrial fibrillation and for those undergoing nonvalvular surgery is still unclear. Further prospective investigations are indicated. Copyright © 2018. Published by Elsevier Inc.

Genomic determinants of epidermal appendage patterning and structure in domestic birds

PubMed Central

Boer, Elena F.; Van Hollebeke, Hannah F.; Shapiro, Michael D.

2017-01-01

Variation in regional identity, patterning, and structure of epidermal appendages contributes to skin diversity among many vertebrate groups, and is perhaps most striking in birds. In pioneering work on epidermal appendage patterning, John Saunders and his contemporaries took advantage of epidermal appendage diversity within and among domestic chicken breeds to establish the importance of mesoderm-ectoderm signaling in determining skin patterning. Diversity in chickens and other domestic birds, including pigeons, is driving a new wave of research to dissect the molecular genetic basis of epidermal appendage patterning. Domestic birds are not only outstanding models for embryonic manipulations, as Saunders recognized, but they are also ideal genetic models for discovering the specific genes that control normal development and the mutations that contribute to skin diversity. Here, we review recent genetic and genomic approaches to uncover the basis of epidermal macropatterning, micropatterning, and structural variation. We also present new results that confirm expression changes in two limb identity genes in feather-footed pigeons, a case of variation in appendage structure and identity. PMID:28347644

Possible role for cryoballoon ablation of right atrial appendage tachycardia when conventional ablation fails.

PubMed

Amasyali, Basri; Kilic, Ayhan

2015-06-01

Focal atrial tachycardia arising from the right atrial appendage usually responds well to radiofrequency ablation; however, successful ablation in this anatomic region can be challenging. Surgical excision of the right atrial appendage has sometimes been necessary to eliminate the tachycardia and prevent or reverse the resultant cardiomyopathy. We report the case of a 48-year-old man who had right atrial appendage tachycardia resistant to multiple attempts at ablation with use of conventional radiofrequency energy guided by means of a 3-dimensional mapping system. The condition led to cardiomyopathy in 3 months. The arrhythmia was successfully ablated with use of a 28-mm cryoballoon catheter that had originally been developed for catheter ablation of paroxysmal atrial fibrillation. To our knowledge, this is the first report of cryoballoon ablation without isolation of the right atrial appendage. It might also be an alternative to epicardial ablation or surgery when refractory atrial tachycardia originates from the right atrial appendage.

The cobra's tongue: Rethinking the function of the "fishtail appendage" on the pitcher plant Darlingtonia californica.

PubMed

Armitage, David W

2016-04-01

Carnivorous pitcher plants employ a variety of putative adaptations for prey attraction and capture. One example is the peculiar forked "fishtail appendage", a foliar structure widely presumed to function as a prey attractant on adult leaves of Darlingtonia californica (Sarraceniaceae). This study tests the prediction that the presence of the appendage facilitates prey capture and can be considered an example of an adaptation to the carnivorous syndrome. In a field experiment following a cohort of Darlingtonia leaves over their growing season, before the pitcher traps opened, the fishtail appendages from half of the leaves were removed. Additionally, all appendages were removed from every plant at two small, isolated populations. After 54 and 104 d, prey items were collected to determine whether differences in prey composition and biomass existed between experimental and unmanipulated control leaves. Removal of the fishtail appendage did not reduce pitcher leaves' prey biomass nor alter their prey composition at either the level of individual leaves or entire populations. Fishtail appendages on plants growing in shaded habitats contained significantly greater chlorophyll concentrations than those on plants growing in full sun. These results call into question the longstanding assumption that the fishtail appendage on Darlingtonia is an adaptation critical for the attraction and capture of prey. I suggest alternative evolutionary explanations for the role of the fishtail structure and repropose a hypothesis on the mutualistic nature of pitcher plant-arthropod trophic interactions. © 2016 Botanical Society of America.

Passive control of a falling sphere by elliptic-shaped appendages

NASA Astrophysics Data System (ADS)

Lācis, Uǧis; Olivieri, Stefano; Mazzino, Andrea; Bagheri, Shervin

2017-03-01

The majority of investigations characterizing the motion of single or multiple particles in fluid flows consider canonical body shapes, such as spheres, cylinders, discs, etc. However, protrusions on bodies—either surface imperfections or appendages that serve a function—are ubiquitous in both nature and applications. In this work, we characterize how the dynamics of a sphere with an axis-symmetric wake is modified in the presence of thin three-dimensional elliptic-shaped protrusions. By investigating a wide range of three-dimensional appendages with different aspect ratios and lengths, we clearly show that the sphere with an appendage may robustly undergo an inverted-pendulum-like (IPL) instability. This means that the position of the appendage placed behind the sphere and aligned with the free-stream direction is unstable, similar to how an inverted pendulum is unstable under gravity. Due to this instability, nontrivial forces are generated on the body, leading to turn and drift, if the body is free to fall under gravity. Moreover, we identify the aspect ratio and length of the appendage that induces the largest side force on the sphere, and therefore also the largest drift for a freely falling body. Finally, we explain the physical mechanisms behind these observations in the context of the IPL instability, i.e., the balance between surface area of the appendage exposed to reversed flow in the wake and the surface area of the appendage exposed to fast free-stream flow.

Left Atrial Appendage Closure for Stroke Prevention: Devices, Techniques, and Efficacy.

PubMed

Iskandar, Sandia; Vacek, James; Lavu, Madhav; Lakkireddy, Dhanunjaya

2016-05-01

Left atrial appendage closure can be performed either surgically or percutaneously. Surgical approaches include direct suture, excision and suture, stapling, and clipping. Percutaneous approaches include endocardial, epicardial, and hybrid endocardial-epicardial techniques. Left atrial appendage anatomy is highly variable and complex; therefore, preprocedural imaging is crucial to determine device selection and sizing, which contribute to procedural success and reduction of complications. Currently, the WATCHMAN is the only device that is approved for left atrial appendage closure in the United States. Copyright © 2016 Elsevier Inc. All rights reserved.

A suspension-feeding anomalocarid from the Early Cambrian.

PubMed

Vinther, Jakob; Stein, Martin; Longrich, Nicholas R; Harper, David A T

2014-03-27

Large, actively swimming suspension feeders evolved several times in Earth's history, arising independently from groups as diverse as sharks, rays and stem teleost fishes, and in mysticete whales. However, animals occupying this niche have not been identified from the early Palaeozoic era. Anomalocarids, a group of stem arthropods that were the largest nektonic animals of the Cambrian and Ordovician periods, are generally thought to have been apex predators. Here we describe new material from Tamisiocaris borealis, an anomalocarid from the Early Cambrian (Series 2) Sirius Passet Fauna of North Greenland, and propose that its frontal appendage is specialized for suspension feeding. The appendage bears long, slender and equally spaced ventral spines furnished with dense rows of long and fine auxiliary spines. This suggests that T. borealis was a microphagous suspension feeder, using its appendages for sweep-net capture of food items down to 0.5 mm, within the size range of mesozooplankton such as copepods. Our observations demonstrate that large, nektonic suspension feeders first evolved during the Cambrian explosion, as part of an adaptive radiation of anomalocarids. The presence of nektonic suspension feeders in the Early Cambrian, together with evidence for a diverse pelagic community containing phytoplankton and mesozooplankton, indicate the existence of a complex pelagic ecosystem supported by high primary productivity and nutrient flux. Cambrian pelagic ecosystems seem to have been more modern than previously believed.

Immunity by Hydrophobic Appendage Bearing Antigens

DTIC Science & Technology

2006-07-01

primary disease is important. The importance rests with a better quality of life and decrease medical costs. To reach the immunopreventive level a...with alanine and one of following synthetic amino acids: γ-aminobutyric acid, norvaline, or norleucine. ( Advanced Chemtech, Louisville,KY) The...sufficiently strong to bring TCR together in the appropriate conformation for wild-type Ag recognition. This may have the advantage of extending the life of

46 CFR 160.151-29 - Additional approval tests for SOLAS A and SOLAS B inflatable liferafts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT... appendage must be attached to a testing jig similar in material and construction to the appendage's intended... water. The dry weight must be recorded. (2) The appendage and jig must then be quickly lowered into the...

The Left Atrial Appendage Revised

PubMed Central

Evora, Paulo Roberto Barbosa; Menardi, Antonio Carlos; Celotto, Andrea Carla; Albuquerque, Agnes Afrodite S.; Chagas, Hannah Miranda Araujo; Rodrigues, Alfredo José

2017-01-01

Nonvalvular atrial fibrillation is associated with a 4- to 5-fold strokes increase and may be responsible for 15% to 20% of all strokes in the elderly. In this scenario, the left atrial appendage thrombus would be the associated with 90% of cases. The use of anticoagulants, percutaneous devices, and the left atrial appendage surgical exclusion is still an open discussion. For left atrial appendage procedures, relevant anatomic spatial relationships have to be emphasized, besides the chance of the normal physiological functioning would be eliminated with the proceedings. There are evidences that the left atrial appendage closure during routine cardiac surgery is significantly associated with an increased risk of early postoperative atrial fibrillation. Therefore, the purpose of this review is to focus basic aspects for continuous medical education. In summary, the rationale of this text is to emphasize anatomical and pharmacological aspects involved in the simple surgical exclusion of left atrial appendage under cardiopulmonary bypass. There are several operative techniques, but to conclude this revision it will present one of them based on the discussed basic sciences. PMID:29267615

Genomic determinants of epidermal appendage patterning and structure in domestic birds.

PubMed

Boer, Elena F; Van Hollebeke, Hannah F; Shapiro, Michael D

2017-09-15

Variation in regional identity, patterning, and structure of epidermal appendages contributes to skin diversity among many vertebrate groups, and is perhaps most striking in birds. In pioneering work on epidermal appendage patterning, John Saunders and his contemporaries took advantage of epidermal appendage diversity within and among domestic chicken breeds to establish the importance of mesoderm-ectoderm signaling in determining skin patterning. Diversity in chickens and other domestic birds, including pigeons, is driving a new wave of research to dissect the molecular genetic basis of epidermal appendage patterning. Domestic birds are not only outstanding models for embryonic manipulations, as Saunders recognized, but they are also ideal genetic models for discovering the specific genes that control normal development and the mutations that contribute to skin diversity. Here, we review recent genetic and genomic approaches to uncover the basis of epidermal macropatterning, micropatterning, and structural variation. We also present new results that confirm expression changes in two limb identity genes in feather-footed pigeons, a case of variation in appendage structure and identity. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

[Left atrial function and left atrial appendage flow velocity in hypertrophic cardiomyopathy: comparison of patients with and without paroxysmal atrial fibrillation].

PubMed

Akasaka, K; Kawashima, E; Shiokoshi, T; Ishii, Y; Hasebe, N; Kikuchi, K

1998-07-01

The involvement of left atrial (LA) appendage flow velocity in reduced left atrial function was investigated in 24 patients with hypertrophic cardiomyopathy, who retained sinus rhythm at the examination. Patients were divided into 11 with a history of paroxysmal atrial fibrillation [PAf(+)] and 13 without such history [PAf(-)]. Transthoracic echocardiography was performed to evaluate LA fractional shortening (LA%FS) and mean velocity of circumferential LA fiber shortening (LAmVcf), as contractile functions of the left atrium at the phase of active atrial contraction. Transesophageal echocardiographic Doppler examination was performed in all patients to measure the LA appendage velocity. In all patients, significant positive correlations were observed between the LA appendage velocity and LA%FS (r = 0.50, p < 0.05) or LAmVcf (r = 0.82, p < 0.001). LAmVcf and LA appendage velocity in patients with paroxysmal fibrillation were significantly lower than in those without (0.84 +/- 0.15 vs 1.28 +/- 0.37 circ/sec, 44 +/- 12 vs 65 +/- 20 cm/sec, both p < 0.01), whereas LA diameter was greater in the former compared to the latter (45 +/- 5 vs 38 +/- 5 mm, p < 0.01). LAmVcf and LA appendage velocity were low in four patients with cerebral infarction or transient cerebral ischemic attack (LAmVcf < 1.0 circ/sec, LA appendage velocity < or = 40 cm/sec). Importantly, all these patients had a history of paroxysmal fibrillation. These results indicate that there is a close relationship between LA appendage velocity and LA contractile function in patients with hypertrophic cardiomyopathy with paroxysmal atrial fibrilation, and these patients have potential risk of cerebral infarction.

The dynamics of spin stabilized spacecraft with movable appendages, part 1

NASA Technical Reports Server (NTRS)

Bainum, P. M.; Sellappan, R.

1975-01-01

The motion and stability of spin stabilized spacecraft with movable external appendages are treated both analytically and numerically. The two basic types of appendages considered are: (1) a telescoping type of varying length and (2) a hinged type of fixed length whose orientation with respect to the main part of the spacecraft can vary. Two classes of telescoping appendages are considered: (a) where an end mass is mounted at the end of an (assumed) massless boom; and (b) where the appendage is assumed to consist of a uniformly distributed homogeneous mass throughout its length. For the telescoping system Eulerian equations of motion are developed. During all deployment sequences it is assumed that the transverse component of angular momentum is much smaller than the component along the major spin axis. Closed form analytical solutions for the time response of the transverse components of angular velocities are obtained when the spacecraft hub has a nearly spherical mass distribution.

Left atrial appendage closure with the Watchman device in patients with a contraindication for oral anticoagulation: the ASAP study (ASA Plavix Feasibility Study With Watchman Left Atrial Appendage Closure Technology).

PubMed

Reddy, Vivek Y; Möbius-Winkler, Sven; Miller, Marc A; Neuzil, Petr; Schuler, Gerhard; Wiebe, Jens; Sick, Peter; Sievert, Horst

2013-06-25

The purpose of this study was to assess the safety and efficacy of left atrial appendage (LAA) closure in nonvalvular atrial fibrillation (AF) patients ineligible for warfarin therapy. The PROTECT AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) trial demonstrated that LAA closure with the Watchman device (Boston Scientific, Natick, Massachusetts) was noninferior to warfarin therapy. However, the PROTECT AF trial only included patients who were candidates for warfarin, and even patients randomly assigned to the LAA closure arm received concomitant warfarin for 6 weeks after Watchman implantation. A multicenter, prospective, nonrandomized study was conducted of LAA closure with the Watchman device in 150 patients with nonvalvular AF and CHADS₂ (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score ≥1, who were considered ineligible for warfarin. The primary efficacy endpoint was the combined events of ischemic stroke, hemorrhagic stroke, systemic embolism, and cardiovascular/unexplained death. The mean CHADS₂ score and CHA₂DS₂-VASc (CHADS₂ score plus 2 points for age ≥75 years and 1 point for vascular disease, age 65 to 74 years, or female sex) score were 2.8 ± 1.2 and 4.4 ± 1.7, respectively. History of hemorrhagic/bleeding tendencies (93%) was the most common reason for warfarin ineligibility. Mean duration of follow-up was 14.4 ± 8.6 months. Serious procedure- or device-related safety events occurred in 8.7% of patients (13 of 150 patients). All-cause stroke or systemic embolism occurred in 4 patients (2.3% per year): ischemic stroke in 3 patients (1.7% per year) and hemorrhagic stroke in 1 patient (0.6% per year). This ischemic stroke rate was less than that expected (7.3% per year) based on the CHADS₂ scores of the patient cohort. LAA closure with the Watchman device can be safely performed without a warfarin transition, and is a reasonable alternative to consider for patients at high risk for stroke but with contraindications to systemic oral anticoagulation. (ASA Plavix Feasibility Study With Watchman Left Atrial Appendage Closure Technology [ASAP]; NCT00851578). Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Relative uptake of minoxidil into appendages and stratum corneum and permeation through human skin in vitro.

PubMed

Grice, Jeffrey E; Ciotti, Susan; Weiner, Norman; Lockwood, Peter; Cross, Sheree E; Roberts, Michael S

2010-02-01

We examined uptake of the model therapeutic agent, minoxidil, into appendages, stratum corneum (SC), and through human skin, under the influence of different vehicles. Quantitative estimation of therapeutic drug deposition into all three areas has not previously been reported. Finite doses of minoxidil (2%, w/v) in formulations containing varying amounts of ethanol, propylene glycol (PG), and water (60:20:20, 80:20:0, and 0:80:20 by volume, respectively) were used. Minoxidil in SC (by tape stripping), appendages (by cyanoacrylate casting), and receptor fluid was determined by liquid scintillation counting. At early times (30 min, 2 h), ethanol-containing formulations (60:20:20 and 80:20:0) caused significantly greater minoxidil retention in SC and appendages, compared to the formulation lacking ethanol (0:80:20). A significant increase in minoxidil receptor penetration occurred with the PG-rich 0:80:20 formulation after 12 h. We showed that deposition of minoxidil into appendages, SC, and skin penetration into receptor fluid were similar in magnitude. Transport by the appendageal route is likely to be a key determinant of hair growth promotion by minoxidil. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association.

The comparative hydrodynamics of rapid rotation by predatory appendages.

PubMed

McHenry, M J; Anderson, P S L; Van Wassenbergh, S; Matthews, D G; Summers, A P; Patek, S N

2016-11-01

Countless aquatic animals rotate appendages through the water, yet fluid forces are typically modeled with translational motion. To elucidate the hydrodynamics of rotation, we analyzed the raptorial appendages of mantis shrimp (Stomatopoda) using a combination of flume experiments, mathematical modeling and phylogenetic comparative analyses. We found that computationally efficient blade-element models offered an accurate first-order approximation of drag, when compared with a more elaborate computational fluid-dynamic model. Taking advantage of this efficiency, we compared the hydrodynamics of the raptorial appendage in different species, including a newly measured spearing species, Coronis scolopendra The ultrafast appendages of a smasher species (Odontodactylus scyllarus) were an order of magnitude smaller, yet experienced values of drag-induced torque similar to those of a spearing species (Lysiosquillina maculata). The dactyl, a stabbing segment that can be opened at the distal end of the appendage, generated substantial additional drag in the smasher, but not in the spearer, which uses the segment to capture evasive prey. Phylogenetic comparative analyses revealed that larger mantis shrimp species strike more slowly, regardless of whether they smash or spear their prey. In summary, drag was minimally affected by shape, whereas size, speed and dactyl orientation dominated and differentiated the hydrodynamic forces across species and sizes. This study demonstrates the utility of simple mathematical modeling for comparative analyses and illustrates the multi-faceted consequences of drag during the evolutionary diversification of rotating appendages. © 2016. Published by The Company of Biologists Ltd.

Homeobox genes Msx-1 and Msx-2 are associated with induction and growth of skin appendages.

PubMed

Noveen, A; Jiang, T X; Ting-Berreth, S A; Chuong, C M

1995-05-01

The mechanism involved in the morphogenesis of skin appendages is a fundamental issue underlying the development and healing of skin. To identify molecules involved in the induction and growth of skin appendages, we studied the expression of two homeobox genes, Msx-1 and Msx-2, during embryonic chicken skin development. We found that i) both Msx-1 and Msx-2 are early markers of epithelial placodes for skin appendages; ii) both Msx-1 and Msx-2 are expressed in the growing feather bud epithelia but not in the interbud epithelia; iii) although mostly overlapping, there are differences between the expression of the two Msx genes, Msx-1 being expressed more toward the anterior whereas Msx-2 is expressed more toward the distal feather bud; iv) there is no body-position-specific expression pattern as was observed for members of the Hox A-D clusters; v) in the feather follicle, Msx-1 and 2 are expressed in the collar and barb ridge epithelia, both regions of continuous cell proliferation; vi) when feather-bud growth was inhibited by forskolin, an activator of adenylyl cyclase, the expression of both genes was reduced. These results showed that Msx genes are specifically expressed in epithelial domains destined to become skin appendages. Its function in skin-appendage morphogenesis may be twofold, first in making epithelial cells competent to become skin appendages and, second, in making epithelial cells maintain their potential for continuous growth.

Nonlinear model and attitude dynamics of flexible spacecraft with large amplitude slosh

NASA Astrophysics Data System (ADS)

Deng, Mingle; Yue, Baozeng

2017-04-01

This paper is focused on the nonlinearly modelling and attitude dynamics of spacecraft coupled with large amplitude liquid sloshing dynamics and flexible appendage vibration. The large amplitude fuel slosh dynamics is included by using an improved moving pulsating ball model. The moving pulsating ball model is an equivalent mechanical model that is capable of imitating the whole liquid reorientation process. A modification is introduced in the capillary force computation in order to more precisely estimate the settling location of liquid in microgravity or zero-g environment. The flexible appendage is modelled as a three dimensional Bernoulli-Euler beam and the assumed modal method is employed to derive the nonlinear mechanical model for the overall coupled system of liquid filled spacecraft with appendage. The attitude maneuver is implemented by the momentum transfer technique, and a feedback controller is designed. The simulation results show that the liquid sloshing can always result in nutation behavior, but the effect of flexible deformation of appendage depends on the amplitude and direction of attitude maneuver performed by spacecraft. Moreover, it is found that the liquid sloshing and the vibration of flexible appendage are coupled with each other, and the coupling becomes more significant with more rapid motion of spacecraft. This study reveals that the appendage's flexibility has influence on the liquid's location and settling time in microgravity. The presented nonlinear system model can provide an important reference for the overall design of the modern spacecraft composed of rigid platform, liquid filled tank and flexible appendage.

46 CFR 160.151-17 - Additional requirements for design and performance of SOLAS A and SOLAS B inflatable liferafts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the following requirements: (i) The total volume of the appendages must not be less than 220 liters (7.77 ft3) for liferafts approved to accommodate up to 10 persons. The volume of an appendage is... deducting the volume of any objects inside the appendage. No opening designed to close as water is forced...

Skin appendage-derived stem cells: cell biology and potential for wound repair.

PubMed

Xie, Jiangfan; Yao, Bin; Han, Yutong; Huang, Sha; Fu, Xiaobing

2016-01-01

Stem cells residing in the epidermis and skin appendages are imperative for skin homeostasis and regeneration. These stem cells also participate in the repair of the epidermis after injuries, inducing restoration of tissue integrity and function of damaged tissue. Unlike epidermis-derived stem cells, comprehensive knowledge about skin appendage-derived stem cells remains limited. In this review, we summarize the current knowledge of skin appendage-derived stem cells, including their fundamental characteristics, their preferentially expressed biomarkers, and their potential contribution involved in wound repair. Finally, we will also discuss current strategies, future applications, and limitations of these stem cells, attempting to provide some perspectives on optimizing the available therapy in cutaneous repair and regeneration.

Exceptional appendage and soft-tissue preservation in a Middle Triassic horseshoe crab from SW China.

PubMed

Hu, Shixue; Zhang, Qiyue; Feldmann, Rodney M; Benton, Michael J; Schweitzer, Carrie E; Huang, Jinyuan; Wen, Wen; Zhou, Changyong; Xie, Tao; Lü, Tao; Hong, Shuigen

2017-10-26

Horseshoe crabs are classic "living fossils", supposedly slowly evolving, conservative taxa, with a long fossil record back to the Ordovician. The evolution of their exoskeleton is well documented by fossils, but appendage and soft-tissue preservation is extremely rare. Here we analyse details of appendage and soft-tissue preservation in Yunnanolimulus luopingensis, a Middle Triassic (ca. 244 million years old) horseshoe crab from Yunnan Province, SW China. The remarkable preservation of anatomical details including the chelicerae, five pairs of walking appendages, opisthosomal appendages with book gills, muscles, and fine setae permits comparison with extant horseshoe crabs. The close anatomical similarity between the Middle Triassic horseshoe crabs and their recent analogues documents anatomical conservatism for over 240 million years, suggesting persistence of lifestyle. The occurrence of Carcinoscorpius-type claspers on the first and second walking legs in male individuals of Y. luopingensis indicates that simple chelate claspers in males are plesiomorphic for horseshoe crabs, and the bulbous claspers in Tachypleus and Limulus are derived.

Three-dimensionally preserved minute larva of a great-appendage arthropod from the early Cambrian Chengjiang biota

NASA Astrophysics Data System (ADS)

Liu, Yu; Melzer, Roland R.; Haug, Joachim T.; Haug, Carolin; Briggs, Derek E. G.; Hörnig, Marie K.; He, Yu-yang; Hou, Xian-guang

2016-05-01

A three-dimensionally preserved 2-mm-long larva of the arthropod Leanchoilia illecebrosa from the 520-million-year-old early Cambrian Chengjiang biota of China represents the first evidence, to our knowledge, of such an early developmental stage in a short-great-appendage (SGA) arthropod. The larva possesses a pair of three-fingered great appendages, a hypostome, and four pairs of well-developed biramous appendages. More posteriorly, a series of rudimentary limb Anlagen revealed by X-ray microcomputed tomography shows a gradient of decreasing differentiation toward the rear. This, and postembryonic segment addition at the putative growth zone, are features of late-stage metanauplii of eucrustaceans. L. illecebrosa and other SGA arthropods, however, are considered representative of early chelicerates or part of the stem lineage of all euarthropods. The larva of an early Cambrian SGA arthropod with a small number of anterior segments and their respective appendages suggests that posthatching segment addition occurred in the ancestor of Euarthropoda.

A 3D anatomical atlas of appendage musculature in the chelicerate arthropod Limulus polyphemus

PubMed Central

Wroe, Stephen; Paterson, John R.

2018-01-01

Limulus polyphemus, an archetypal chelicerate taxon, has interested both biological and paleontological researchers due to its unique suite of anatomical features and as a useful modern analogue for fossil arthropod groups. To assist the study and documentation of this iconic taxon, we present a 3D atlas on the appendage musculature, with specific focus on the muscles of the cephalothoracic appendages. As L. polyphemus appendage musculature has been the focus of extensive study, depicting the muscles in 3D will facilitate a more complete understanding thereof for future researchers. A large museum specimen was CT scanned to illustrate the major exoskeletal features of L. polyphemus. Micro-CT scans of iodine-stained appendages from fresh, non-museum specimens were digitally dissected to interactively depict appendage sections and muscles. This study has revealed the presence of two new muscles: one within the pushing leg, located dorsally relative to all other patella muscles, and the other within the male pedipalp, located in the modified tibiotarsus. This atlas increases accessibility to important internal and external morphological features of L. polyphemus and reduces the need for destructive fresh tissue dissection of specimens. Scanning, digitally dissecting, and documenting taxa in 3D is a pivotal step towards creating permanent digital records of life on Earth. PMID:29444161

Effect of left ventricular diastolic dysfunction on left atrial appendage function and thrombotic potential in nonvalvular atrial fibrillation.

PubMed

Demirçelik, Muhammed Bora; Çetin, Mustafa; Çiçekcioğlu, Hülya; Uçar, Özgül; Duran, Mustafa

2014-05-01

We aimed to investigate effects of left ventricular diastolic dysfunction on left atrial appendage functions, spontaneous echo contrast and thrombus formation in patients with nonvalvular atrial fibrillation. In 58 patients with chronic nonvalvular atrial fibrilation and preserved left ventricular systolic function, left atrial appendage functions, left atrial spontaneous echo contrast grading and left ventricular diastolic functions were evaluated using transthoracic and transoesophageal echocardiogram. Patients divided in two groups: Group D (n=30): Patients with diastolic dysfunction, Group N (n=28): Patients without diastolic dysfunction. Categorical variables in two groups were evaluated with Pearson's chi-square or Fisher's exact test. The significance of the lineer correlation between the degree of spontaneous echo contrast (SEC) and clinical measurements was evaluated with Spearman's correlation analysis. Peak pulmonary vein D velocity of the Group D was significantly higher than the Group N (p=0.006). However, left atrial appendage emptying velocity, left atrial appendage lateral wall velocity, peak pulmonary vein S, pulmonary vein S/D ratio were found to be significantly lower in Group D (p=0.028, p<0.001, p<0.001; p<0.001). Statistically significant negative correlation was found between SEC in left atrium and left atrial appendage emptying, filling, pulmonary vein S/D levels and lateral wall velocities respectively (r=-0.438, r=-0.328, r=-0.233, r=-0.447). Left atrial appendage emptying, filling, pulmonary vein S/D levels and lateral wall velocities were significantly lower in SEC 2-3-4 than SEC 1 (p=0.003, p=0.029, p<0.001, p=0.002). In patients with nonvalvular atrial fibrillation and preserved left ventricular ejection fraction, left atrial appendage functions are decreased in patients with left ventricular diastolic dysfunction. Left ventricular diastolic dysfunction may constitute a potential risk for formation of thrombus and stroke.

Factors associated with survival of epiploic foramen entrapment colic: a multicentre, international study.

PubMed

Archer, D C; Pinchbeck, G L; Proudman, C J

2011-08-01

Epiploic foramen entrapment (EFE) has been associated with reduced post operative survival compared to other types of colic but specific factors associated with reduced long-term survival of these cases have not been evaluated in a large number of horses using survival analysis. To describe post operative survival of EFE cases and to identify factors associated with long-term survival. A prospective, multicentre, international study was conducted using clinical data and long-term follow-up information for 126 horses diagnosed with EFE during exploratory laparotomy at 15 clinics in the UK, Ireland and USA. Descriptive data were generated and survival analysis performed to identify factors associated with reduced post operative survival. For the EFE cohort that recovered following anaesthesia, survival to hospital discharge was 78.5%. Survival to 1 and 2 years post operatively was 50.6 and 34.3%, respectively. The median survival time of EFE cases undergoing surgery was 397 days. Increased packed cell volume (PCV) and increased length of small intestine (SI) resected were significantly associated with increased likelihood of mortality when multivariable analysis of pre- and intraoperative variables were analysed. When all pre-, intra- and post operative variables were analysed separately, only horses that developed post operative ileus (POI) were shown to be at increased likelihood of mortality. Increased PCV, increased length of SI resected and POI are all associated with increased likelihood of mortality of EFE cases. This emphasises the importance of early diagnosis and treatment and the need for improved strategies in the management of POI in order to reduce post operative mortality in these cases. The present study provides evidence-based information to clinicians and owners of horses undergoing surgery for EFE about long-term survival. These results are applicable to university and large private clinics over a wide geographical area. © 2011 EVJ Ltd.

Ectodermal dysplasia (ED) syndrome.

PubMed

Chee, Siew-Yin; Wanga, Chung-Hsing; Lina, Wei-De; Tsaia, Fuu-Jen

2014-01-01

Ectodermal dysplasia (ED) syndrome comprises a large, heterogeneous group of inherited disorders that are defined by primary defects in the development of 2 or more tissues derived from the embryonic ectoderm. The tissues primarily involved are the skin and its appendages (including hair follicles, eccrine glands, sebaceous glands, nails) and teeth. The clinical features include sparse hair, abnormal or missing teeth, and an inability to sweat due to lack of sweat glands. One such case report of ectodermal dysplasia is presented here.

Developmental origin of the clavicle, and its implications for the evolution of the neck and the paired appendages in vertebrates.

PubMed

Nagashima, Hiroshi; Sugahara, Fumiaki; Watanabe, Keisuke; Shibata, Masahiro; Chiba, Akina; Sato, Noboru

2016-10-01

In fish, the pectoral appendage is adjacent to the head, but during vertebrate evolution a long neck region emerged via caudal relocation of the pectoral appendage. The pectoral appendage is comprised of endochondral portions, such as the humerus and the scapula, and a dermal portion, such as the clavicle, that contributes to the shoulder girdle. In the search for clues to the mechanism of the caudal relocation of the pectoral appendage, the cell lineage of the rostral lateral plate mesoderm was analyzed in chickens. It was found that, despite the long neck region in chickens, the origin of the clavicle attached to the head mesoderm ranged between 1 and 14 somite levels. Because the pectoral limb bud and the endochondral pectoral appendage developed on 15-20 and 15-24 somite levels, respectively, the clavicle-forming region corresponds to the embryonic neck, which suggests that the relocation would have been executed by the expansion of the source of the clavicle. The rostral portion of the clavicle-forming region overlaps the source of the cucullaris muscle, embraces the pharyngeal arches caudally, and can be experimentally replaced with the head mesoderm to form the cucullaris muscle, which implies that the mesodermal portion could have been the head mesoderm and that the clavicle would have developed at the head/trunk boundary. The link between the head mesoderm and the presumptive clavicle appears to have been the developmental constraint needed to create the evolutionarily conserved musculoskeletal connectivities characterizing the gnathostome neck. In this sense, the dermal girdle of the ganathostomes would represent the wall of the branchial chamber into which the endochondral pectoral appendage appears to have attached since its appearance in evolution. © 2016 Anatomical Society.

Percutaneous closure of the left atrial appendage in patients with diabetes mellitus.

PubMed

Azizy, Obayda; Rammos, Christos; Lehmann, Nils; Rassaf, Tienush; Kälsch, Hagen

2017-09-01

Left atrial appendage closure is a preventive treatment of atrial fibrillation-related thrombo-embolism. Patients with diabetes mellitus have increased risk for a negative outcome in percutaneous cardiac interventions. We assessed whether percutaneous left atrial appendage closure is safe and effective in patients with diabetes mellitus. We included 78 patients (mean age of 74.4 ± 8.3 years) with indication for left atrial appendage closure in an open-label observational single-centre study. Patients with diabetes mellitus ( n = 31) were at higher thrombo-embolic and bleeding risk (CHA 2 DS 2 -VASc: 4.5 ± 0.9, HAS-BLED: 4.7 ± 0.7) compared to patients without diabetes mellitus ( n = 47, CHA 2 DS 2 -VASc: 3.5 ± 1.0, HAS-BLED: 4.1 ± 0.8; p < 0.001 for both). Pre- and periprocedural risk was elevated in patients with diabetes mellitus (Euro II-Score: 6.6 ± 3.7 vs 3.9 ± 1.9, p < 0.01; Society of Thoracic Surgeons (STS)-Score: 4.0 ± 2.5 vs 2.6 ± 1.2, p < 0.01). Procedural success was similar. Periprocedural major adverse cardiac and cerebrovascular events occurred in one patient from the control group (2.1%), whereas patients with diabetes mellitus had no events ( p = 0.672). Follow-up of 6 months revealed no bleeding complication in both groups. No stroke occurred in follow-up, and left atrial appendage flow velocity reduction (55.6 ± 38.6 vs 51.4 ± 19.1 cm/s, p = 0.474) and rate of postinterventional leakage in the left atrial appendage were comparable (0% vs 2.1%, p = 0.672). Despite patients with diabetes mellitus are high-risk patients, the outcome of percutaneous left atrial appendage closure is similar to patients without diabetes mellitus.

Ablation of a resistant right atrial appendage tachycardia using a magnetic navigation system.

PubMed

Khan, Mohsin K; Elmouchi, Darryl

2013-01-01

The right atrial appendage is an uncommon site of origin for ectopic atrial tachycardia. Right atrial appendage tachycardia (RAAT) has been noted to be prevalent in young males and responds well to radiofrequency ablation. We report a case of RAAT resistant to multiple attempts of ablation that responded to ablation using Stereotaxis Niobe™ Magnetic Navigation System (RMN, Stereotaxis, St. Louis, MO, USA). ©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.

bullwinkle and shark regulate dorsal-appendage morphogenesis in Drosophila oogenesis.

PubMed

Tran, David H; Berg, Celeste A

2003-12-01

bullwinkle (bwk) regulates embryonic anteroposterior patterning and, through a novel germline-to-soma signal, morphogenesis of the eggshell dorsal appendages. We screened for dominant modifiers of the bullwinkle mooseantler eggshell phenotype and identified shark, which encodes an SH2-domain, ankyrin-repeat tyrosine kinase. At the onset of dorsal-appendage formation, shark is expressed in a punctate pattern in the squamous stretch cells overlying the nurse cells. Confocal microscopy with cell-type-specific markers demonstrates that the stretch cells act as a substrate for the migrating dorsal-appendage-forming cells and extend cellular projections towards them. Mosaic analyses reveal that shark is required in follicle cells for cell migration and chorion deposition. Proper shark RNA expression in the stretch cells requires bwk activity, while restoration of shark expression in the stretch cells suppresses the bwk dorsal-appendage phenotype. These results suggest that shark plays an important downstream role in the bwk-signaling pathway. Candidate testing implicates Src42A in a similar role, suggesting conservation with a vertebrate signaling pathway involving non-receptor tyrosine kinases.

Dynamic analysis of a system of hinge-connected rigid bodies with nonrigid appendages. [equations of motion

NASA Technical Reports Server (NTRS)

Likins, P. W.

1974-01-01

Equations of motion are derived for use in simulating a spacecraft or other complex electromechanical system amenable to idealization as a set of hinge-connected rigid bodies of tree topology, with rigid axisymmetric rotors and nonrigid appendages attached to each rigid body in the set. In conjunction with a previously published report on finite-element appendage vibration equations, this report provides a complete minimum-dimension formulation suitable for generic programming for digital computer numerical integration.

Temperature regulates limb length in homeotherms by directly modulating cartilage growth

PubMed Central

Serrat, Maria A.; King, Donna; Lovejoy, C. Owen

2008-01-01

Allen's Rule documents a century-old biological observation that strong positive correlations exist among latitude, ambient temperature, and limb length in mammals. Although genetic selection for thermoregulatory adaptation is frequently presumed to be the primary basis of this phenomenon, important but frequently overlooked research has shown that appendage outgrowth is also markedly influenced by environmental temperature. Alteration of limb blood flow via vasoconstriction/vasodilation is the current default hypothesis for this growth plasticity, but here we show that tissue perfusion does not fully account for differences in extremity elongation in mice. We show that peripheral tissue temperature closely reflects housing temperature in vivo, and we demonstrate that chondrocyte proliferation and extracellular matrix volume strongly correlate with tissue temperature in metatarsals cultured without vasculature in vitro. Taken together, these data suggest that vasomotor changes likely modulate extremity growth indirectly, via their effects on appendage temperature, rather than vascular nutrient delivery. When combined with classic evolutionary theory, especially genetic assimilation, these results provide a potentially comprehensive explanation of Allen's Rule, and may substantially impact our understanding of phenotypic variation in living and extinct mammals, including humans. PMID:19047632

The (temporary?) queering of Japanese TV.

PubMed

Miller, S D

2000-01-01

One of the primary texts of the "out" queer cinema of Japan is the television serial D s kai, first aired in 1993. Unlike Western television shows positing queer characters, D s kai presents its gay characters without apology or excuses, and as leads rather than as colorful appendages. At the same time, however, the show filters gay eroticism through the (hetero)normative mode of serial melodrama, at once pushing the boundaries of national permissiveness while normalizing and homogenizing homosexuality by rendering it within a conventional form.

Passive appendages generate drift through symmetry breaking

PubMed Central

Lācis, U.; Brosse, N.; Ingremeau, F.; Mazzino, A.; Lundell, F.; Kellay, H.; Bagheri, S.

2014-01-01

Plants and animals use plumes, barbs, tails, feathers, hairs and fins to aid locomotion. Many of these appendages are not actively controlled, instead they have to interact passively with the surrounding fluid to generate motion. Here, we use theory, experiments and numerical simulations to show that an object with a protrusion in a separated flow drifts sideways by exploiting a symmetry-breaking instability similar to the instability of an inverted pendulum. Our model explains why the straight position of an appendage in a fluid flow is unstable and how it stabilizes either to the left or right of the incoming flow direction. It is plausible that organisms with appendages in a separated flow use this newly discovered mechanism for locomotion; examples include the drift of plumed seeds without wind and the passive reorientation of motile animals. PMID:25354545

A new crustacean from the Herefordshire (Silurian) Lagerstätte, UK, and its significance in malacostracan evolution

PubMed Central

Briggs, Derek E. G.; Siveter, Derek J.; Sutton, Mark D.; Legg, David

2017-01-01

Cascolus ravitis gen. et sp. nov. is a three-dimensionally preserved fossil crustacean with soft parts from the Herefordshire (Silurian) Lagerstätte, UK. It is characterized by a head with a head shield and five limb pairs, and a thorax (pereon) with nine appendage-bearing segments followed by an apodous abdomen (pleon). All the appendages except the first are biramous and have a gnathobase. The post-mandibular appendages are similar one to another, and bear petal-shaped epipods that probably functioned as a part of the respiratory–circulatory system. Cladistic analysis resolves the new taxon as a stem-group leptostracan (Malacostraca). This well-preserved arthropod provides novel insights into the evolution of appendage morphology, tagmosis and the possible respiratory–circulatory physiology of a basal malacostracan. PMID:28330926

Effects of novel oral anticoagulants on left atrial and left atrial appendage thrombi: an appraisal.

PubMed

Marsico, Fabio; Cecere, Milena; Parente, Antonio; Paolillo, Stefania; de Martino, Fabiana; Dellegrottaglie, Santo; Trimarco, Bruno; Perrone Filardi, Pasquale

2017-02-01

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and predisposes to an increased risk of thromboembolic events. Patients affected by AF exhibit an increased risk of stroke compared with those in sinus rhythm, with the most common location of thrombi in the left atrial appendage. Until 2009, warfarin and other vitamin K antagonists were the only class of oral anticoagulants available. More recently, dabigatran, rivaroxaban, apixaban, and edoxaban have been approved by regulatory authorities for prevention of stroke in patients with non-valvular AF. Few data are available about the efficacy of novel oral anticoagulants for the treatment of left atrial and left atrial appendage thrombosis. Aim of this review is to summarize available evidence regarding the effectiveness of novel oral anticoagulants on left atrial appendage thrombosis.

Copper Oxide Nanograss for Efficient and Stable Photoelectrochemical Hydrogen Production by Water Splitting

NASA Astrophysics Data System (ADS)

Borkar, Rajnikant; Dahake, Rashmi; Rayalu, Sadhana; Bansiwal, Amit

2018-03-01

A biphasic copper oxide thin film of grass-like appendage morphology is synthesized by two-step electro-deposition method and later investigated for photoelectrochemical (PEC) water splitting for hydrogen production. Further, the thin film was characterized by UV-Visible spectroscopy, x-ray diffraction (XRD), Scanning electron microscopy (SEM) and PEC techniques. The XRD analysis confirms formation of biphasic copper oxide phases, and SEM reveals high surface area grass appendage-like morphology. These grass appendage structures exhibit a high cathodic photocurrent of - 1.44 mAcm-2 at an applied bias of - 0.7 (versus Ag/AgCl) resulting in incident to photon current efficiency (IPCE) of ˜ 10% at 400 nm. The improved light harvesting and charge transport properties of grass appendage structured biphasic copper oxides makes it a potential candidate for PEC water splitting for hydrogen production.

A Review of the Relevant Embryology, Pathohistology, and Anatomy of the Left Atrial Appendage for the Invasive Cardiac Electrophysiologist

PubMed Central

DeSimone, Christopher V.; Gaba, Prakriti; Tri, Jason; Syed, Faisal; Noheria, Amit; Asirvatham, Samuel J.

2016-01-01

The three-dimensional morphology of the left atrial appendage provides the substrate for thrombus generation, and is a harbinger for embolic material due to its direct connection to the left-sided circulation. Appreciating the development of the appendage from mesodermal layer to its adult form provides the basis to improve exclusion from the atrial circulation, and thereby can lead to a significant reduction in stroke risk. This process also provides insight into the role of the left atrial appendage as an endocrine organ, its involvement in fluid homeostasis, and its connection to the autonomic nervous system. Knowledge of the surrounding structural arrangement is critical to identify landmarks from both an endocardial and epicardial perspective to improve targeted device placement. Furthermore, correlation of the left atrial appendage body, neck, and ostium to the surrounding anatomy can also improve both procedural efficacy and safety. In addition, a working knowledge of the regional anatomy adds a prudent degree of awareness for procedural complications, and allows for early identification and timely intervention as these situations arise. A detailed understanding of the left atrial appendage embryology, histology, and gross anatomy is imperative to identify the correct device and approach for each individual patient. In addition, this increased awareness can identify areas that are in need of further innovation, and thus provide the ability to adapt and refine existing technologies to overcome pitfalls currently facing catheter-based approaches. PMID:27087889

Defensive Abdominal Rotation Patterns of Tenebrionid Beetle, Zophobas atratus, Pupae

PubMed Central

Ichikawa, Toshio; Nakamura, Tatsuya; Yamawaki, Yoshifumi

2012-01-01

Exarate pupae of the beetle Zophobas atratus Fab. (Coleoptera: Tenebrionidae) have free appendages (antenna, palp, leg, and elytron) that are highly sensitive to mechanical stimulation. A weak tactile stimulus applied to any appendage initiated a rapid rotation of abdominal segments. High-speed photography revealed that one cycle of defensive abdominal rotation was induced in an all-or-none fashion by bending single or multiple mechanosensory hairs on a leg or prodding the cuticular surface of appendages containing campaniform sensilla. The direction of the abdominal rotation completely depended on the side of stimulation; stimulation of a right appendage induced a right-handed rotation about the anterior-posterior axis of the pupal body and vice versa. The trajectories of the abdominal rotations had an ellipsoidal or pear-shaped pattern. Among the trajectory patterns of the rotations induced by stimulating different appendages, there were occasional significant differences in the horizontal (right-left) component of abdominal rotational movements. Simultaneous stimulation of right and left appendages often induced variable and complex patterns of abdominal movements, suggesting an interaction between sensory signals from different sides. When an abdominal rotation was induced in a freely lying pupa, the rotation usually made the pupa move away from or turn its dorsum toward the source of stimulation with the aid of the caudal processes (urogomphi), which served as a fulcrum for transmitting the power of the abdominal rotation to the movement or turning of the whole body. Pattern generation mechanisms for the abdominal rotation were discussed. PMID:23448289

Defensive abdominal rotation patterns of tenebrionid beetle, Zophobas atratus, pupae.

PubMed

Ichikawa, Toshio; Nakamura, Tatsuya; Yamawaki, Yoshifumi

2012-01-01

Exarate pupae of the beetle Zophobas atratus Fab. (Coleoptera: Tenebrionidae) have free appendages (antenna, palp, leg, and elytron) that are highly sensitive to mechanical stimulation. A weak tactile stimulus applied to any appendage initiated a rapid rotation of abdominal segments. High-speed photography revealed that one cycle of defensive abdominal rotation was induced in an all-or-none fashion by bending single or multiple mechanosensory hairs on a leg or prodding the cuticular surface of appendages containing campaniform sensilla. The direction of the abdominal rotation completely depended on the side of stimulation; stimulation of a right appendage induced a right-handed rotation about the anterior-posterior axis of the pupal body and vice versa. The trajectories of the abdominal rotations had an ellipsoidal or pear-shaped pattern. Among the trajectory patterns of the rotations induced by stimulating different appendages, there were occasional significant differences in the horizontal (right-left) component of abdominal rotational movements. Simultaneous stimulation of right and left appendages often induced variable and complex patterns of abdominal movements, suggesting an interaction between sensory signals from different sides. When an abdominal rotation was induced in a freely lying pupa, the rotation usually made the pupa move away from or turn its dorsum toward the source of stimulation with the aid of the caudal processes (urogomphi), which served as a fulcrum for transmitting the power of the abdominal rotation to the movement or turning of the whole body. Pattern generation mechanisms for the abdominal rotation were discussed.

Depth and Patterns of Adnexal Involvement in Primary Extramammary (Anogenital) Paget Disease: A Study of 178 Lesions From 146 Patients.

PubMed

Konstantinova, Anastasia M; Shelekhova, Ksenya V; Stewart, Colin J; Spagnolo, Dominic V; Kutzner, Heinz; Kacerovska, Denisa; Plaza, Jose A; Suster, Saul; Bouda, Jiri; Pavlovsky, Michal; Kyrpychova, Liubov; Michal, Michal; Guenova, Emmanuella; Kazakov, Dmitry V

2016-11-01

Extramammary Paget disease (EMPD) is a rare neoplasm usually presenting in the anogenital area, most commonly in the vulva. Adnexal involvement in primary EMPD is a very common feature and serves as a pathway for carcinoma to spread into deeper tissue. The depth of carcinomatous spread along the appendages and the patterns of adnexal involvement were studied in 178 lesions from 146 patients with primary EMPD. Hair follicles and eccrine ducts were the adnexa most commonly affected by carcinoma cells. The maximal depth of involvement was 3.6 mm in this series. When planning topical therapy or developing novel local treatment modalities for EMPD, this potential for significant deep spread along adnexa should be taken into account.

Titanium Nanoparticle Size Influences Trace Concentration Levels in Skin Appendages.

PubMed

Tasat, Deborah R; Domingo, Mariela G; Bruno, Marcos E; Guglielmotti, María B; Olmedo, Daniel G

2017-07-01

As a result of biotribocorrosion, the surface of a titanium (Ti) biomedical device can be a potential source of systemic contamination with Ti nanoparticles (NPs). Although NPs can be chemically similar, differences in particle size may lead to different biological responses. The aim of this experimental study was to determine Ti trace levels in skin appendages and plasma and explore the influence of NP size on trace levels using a murine model. Results showed the presence of Ti traces in the nails, hair, and plasma. The concentration of the smallest NPs (5 Nm) was higher than that of 10 Nm NPs in all the studied samples. Irrespective of NP size, Ti levels were always lower in plasma than in skin appendages. Ti levels were higher in nails than in hair. Ti NPs size influenced trace concentration levels in hair/nails, suggesting that 5 Nm Ti particles are more easily eliminated through these skin appendages. Given that the nails showed the highest levels of Ti, and that these skin appendages are not exposed to agents that can leach out Ti, as occurs with hair, we propose the nails as the most suitable and reliable bioindicator for monitoring systemic contamination with Ti.

Passive appendages improve the maneuverability of fish-like robots

NASA Astrophysics Data System (ADS)

Pollard, Beau; Tallapragada, Phanindra

2017-11-01

It is known that the passive mechanics of fish appendages play a role in the high efficiency of their swimming. A well known example of this is the experimental demonstration that a dead fish could swim upstream. However little is known about the role if any of passive deformations of a fish-like body that could aid in its maneuverability. Part of the difficulty investigating this lies in clearly separating the role of actuated body deformations and passive deformations in response to the fluid structure interaction. In this paper we compare the maneuverability of several fish shaped robotic models that possess varying numbers of passive appendages with a fish shaped robot that has no appendages. All the robots are propelled by the oscillations of an internal momentum wheel thereby eliminating any active deformations of the body. Our experiments clearly reveal the significant improvement in maneuverability of robots with passive appendages. In the broader context of swimming robots our experiments show that passive mechanisms could be useful to provide mechanical feedback that can help maneuverability and obstacle avoidance along with propulsive efficiency. This work was partly supported by a Grant from the NSF CMMI 1563315.

Special considerations for children with hyperhidrosis.

PubMed

Bohaty, Benjamin R; Hebert, Adelaide A

2014-10-01

Hyperhidrosis, characterized by excess sweat production, affects children and adults. Primary focal hyperhidrosis affects any anatomic region with sweat appendages present. Primary hyperhidrosis has traditionally been considered a problem for adults, but approximately 1.6% of adolescents and 0.6% of prepubertal children are affected. Psychological and social development and well-being are often affected, leading to profound emotional and social distress. Quality of life can be improved by early diagnosis and therapy; however, underdiagnosis and lack of knowledge regarding therapeutic options has hindered optimization of therapy in the pediatric population. This article reviews the treatment options for hyperhidrosis with a focus on the pediatric population. Copyright © 2014 Elsevier Inc. All rights reserved.

A Tale of Two Tails: Not Just Skin Deep

PubMed Central

Dutta, Abhijit; Ghosh, Sudip Kumar; Mandal, Asok Kumar

2015-01-01

The dorsal cutaneous appendage or the so called human tail is a rare congenital anomaly protruding from the lumbo-sacro-coccygeal area. These caudal appendages are divided into true-tails and pseudo-tails. We report here two cases of congenital pseudo-tail with underlying spina bifida and lipo-meningocele. In this article we seek to emphasize that, as the skin and nervous systems are intimately linked by their similar ectodermal origin, a dorsal appendage may be regarded as a cutaneous marker of the underlying spinal dysraphism. PMID:26288414

Centriole maturation requires regulated Plk1 activity during two consecutive cell cycles.

PubMed

Kong, Dong; Farmer, Veronica; Shukla, Anil; James, Jana; Gruskin, Richard; Kiriyama, Shigeo; Loncarek, Jadranka

2014-09-29

Newly formed centrioles in cycling cells undergo a maturation process that is almost two cell cycles long before they become competent to function as microtubule-organizing centers and basal bodies. As a result, each cell contains three generations of centrioles, only one of which is able to form cilia. It is not known how this long and complex process is regulated. We show that controlled Plk1 activity is required for gradual biochemical and structural maturation of the centrioles and timely appendage assembly. Inhibition of Plk1 impeded accumulation of appendage proteins and appendage formation. Unscheduled Plk1 activity, either in cycling or interphase-arrested cells, accelerated centriole maturation and appendage and cilia formation on the nascent centrioles, erasing the age difference between centrioles in one cell. These findings provide a new understanding of how the centriole cycle is regulated and how proper cilia and centrosome numbers are maintained in the cells.

Centriole maturation requires regulated Plk1 activity during two consecutive cell cycles

PubMed Central

Kong, Dong; Farmer, Veronica; Shukla, Anil; James, Jana; Gruskin, Richard; Kiriyama, Shigeo

2014-01-01

Newly formed centrioles in cycling cells undergo a maturation process that is almost two cell cycles long before they become competent to function as microtubule-organizing centers and basal bodies. As a result, each cell contains three generations of centrioles, only one of which is able to form cilia. It is not known how this long and complex process is regulated. We show that controlled Plk1 activity is required for gradual biochemical and structural maturation of the centrioles and timely appendage assembly. Inhibition of Plk1 impeded accumulation of appendage proteins and appendage formation. Unscheduled Plk1 activity, either in cycling or interphase-arrested cells, accelerated centriole maturation and appendage and cilia formation on the nascent centrioles, erasing the age difference between centrioles in one cell. These findings provide a new understanding of how the centriole cycle is regulated and how proper cilia and centrosome numbers are maintained in the cells. PMID:25246616

Stress physiology and weapon integrity of intertidal mantis shrimp under future ocean conditions

PubMed Central

deVries, Maya S.; Webb, Summer J.; Tu, Jenny; Cory, Esther; Morgan, Victoria; Sah, Robert L.; Deheyn, Dimitri D.; Taylor, Jennifer R. A.

2016-01-01

Calcified marine organisms typically experience increased oxidative stress and changes in mineralization in response to ocean acidification and warming conditions. These effects could hinder the potency of animal weapons, such as the mantis shrimp’s raptorial appendage. The mechanical properties of this calcified weapon enable extremely powerful punches to be delivered to prey and aggressors. We examined oxidative stress and exoskeleton structure, mineral content, and mechanical properties of the raptorial appendage and the carapace under long-term ocean acidification and warming conditions. The predatory appendage had significantly higher % Mg under ocean acidification conditions, while oxidative stress levels as well as the % Ca and mechanical properties of the appendage remained unchanged. Thus, mantis shrimp tolerate expanded ranges of pH and temperature without experiencing oxidative stress or functional changes to their weapons. Our findings suggest that these powerful predators will not be hindered under future ocean conditions. PMID:27974830

Mother Centriole Distal Appendages Mediate Centrosome Docking at the Immunological Synapse and Reveal Mechanistic Parallels with Ciliogenesis.

PubMed

Stinchcombe, Jane C; Randzavola, Lyra O; Angus, Karen L; Mantell, Judith M; Verkade, Paul; Griffiths, Gillian M

2015-12-21

Cytotoxic T lymphocytes (CTLs) are highly effective serial killers capable of destroying virally infected and cancerous targets by polarized release from secretory lysosomes. Upon target contact, the CTL centrosome rapidly moves to the immunological synapse, focusing microtubule-directed release at this point [1-3]. Striking similarities have been noted between centrosome polarization at the synapse and basal body docking during ciliogenesis [1, 4-8], suggesting that CTL centrosomes might dock with the plasma membrane during killing, in a manner analogous to primary cilia formation [1, 4]. However, questions remain regarding the extent and function of centrosome polarization at the synapse, and recent reports have challenged its role [9, 10]. Here, we use high-resolution transmission electron microscopy (TEM) tomography analysis to show that, as in ciliogenesis, the distal appendages of the CTL mother centriole contact the plasma membrane directly during synapse formation. This is functionally important as small interfering RNA (siRNA) targeting of the distal appendage protein, Cep83, required for membrane contact during ciliogenesis [11], impairs CTL secretion. Furthermore, the regulatory proteins CP110 and Cep97, which must dissociate from the mother centriole to allow cilia formation [12], remain associated with the mother centriole in CTLs, and neither axoneme nor transition zone ciliary structures form. Moreover, complete centrosome docking can occur in proliferating CTLs with multiple centriole pairs. Thus, in CTLs, centrosomes dock transiently with the membrane, within the cell cycle and without progression into ciliogenesis. We propose that this transient centrosome docking without cilia formation is important for CTLs to deliver rapid, repeated polarized secretion directed by the centrosome. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Genomics of Clostridium taeniosporum, an organism which forms endospores with ribbon-like appendages

PubMed Central

Cambridge, Joshua M.; Blinkova, Alexandra L.; Salvador Rocha, Erick I.; Bode Hernández, Addys; Moreno, Maday; Ginés-Candelaria, Edwin; Goetz, Benjamin M.; Hunicke-Smith, Scott; Satterwhite, Ed; Tucker, Haley O.

2018-01-01

Clostridium taeniosporum, a non-pathogenic anaerobe closely related to the C. botulinum Group II members, was isolated from Crimean lake silt about 60 years ago. Its endospores are surrounded by an encasement layer which forms a trunk at one spore pole to which about 12–14 large, ribbon-like appendages are attached. The genome consists of one 3,264,813 bp, circular chromosome (with 26.6% GC) and three plasmids. The chromosome contains 2,892 potential protein coding sequences: 2,124 have specific functions, 147 have general functions, 228 are conserved but without known function and 393 are hypothetical based on the fact that no statistically significant orthologs were found. The chromosome also contains 101 genes for stable RNAs, including 7 rRNA clusters. Over 84% of the protein coding sequences and 96% of the stable RNA coding regions are oriented in the same direction as replication. The three known appendage genes are located within a single cluster with five other genes, the protein products of which are closely related, in terms of sequence, to the known appendage proteins. The relatedness of the deduced protein products suggests that all or some of the closely related genes might code for minor appendage proteins or assembly factors. The appendage genes might be unique among the known clostridia; no statistically significant orthologs were found within other clostridial genomes for which sequence data are available. The C. taeniosporum chromosome contains two functional prophages, one Siphoviridae and one Myoviridae, and one defective prophage. Three plasmids of 5.9, 69.7 and 163.1 Kbp are present. These data are expected to contribute to future studies of developmental, structural and evolutionary biology and to potential industrial applications of this organism. PMID:29293521

Genomics of Clostridium taeniosporum, an organism which forms endospores with ribbon-like appendages.

PubMed

Cambridge, Joshua M; Blinkova, Alexandra L; Salvador Rocha, Erick I; Bode Hernández, Addys; Moreno, Maday; Ginés-Candelaria, Edwin; Goetz, Benjamin M; Hunicke-Smith, Scott; Satterwhite, Ed; Tucker, Haley O; Walker, James R

2018-01-01

Clostridium taeniosporum, a non-pathogenic anaerobe closely related to the C. botulinum Group II members, was isolated from Crimean lake silt about 60 years ago. Its endospores are surrounded by an encasement layer which forms a trunk at one spore pole to which about 12-14 large, ribbon-like appendages are attached. The genome consists of one 3,264,813 bp, circular chromosome (with 26.6% GC) and three plasmids. The chromosome contains 2,892 potential protein coding sequences: 2,124 have specific functions, 147 have general functions, 228 are conserved but without known function and 393 are hypothetical based on the fact that no statistically significant orthologs were found. The chromosome also contains 101 genes for stable RNAs, including 7 rRNA clusters. Over 84% of the protein coding sequences and 96% of the stable RNA coding regions are oriented in the same direction as replication. The three known appendage genes are located within a single cluster with five other genes, the protein products of which are closely related, in terms of sequence, to the known appendage proteins. The relatedness of the deduced protein products suggests that all or some of the closely related genes might code for minor appendage proteins or assembly factors. The appendage genes might be unique among the known clostridia; no statistically significant orthologs were found within other clostridial genomes for which sequence data are available. The C. taeniosporum chromosome contains two functional prophages, one Siphoviridae and one Myoviridae, and one defective prophage. Three plasmids of 5.9, 69.7 and 163.1 Kbp are present. These data are expected to contribute to future studies of developmental, structural and evolutionary biology and to potential industrial applications of this organism.

Development of the CSI phase-3 evolutionary model testbed

NASA Technical Reports Server (NTRS)

Gronet, M. J.; Davis, D. A.; Tan, M. K.

1994-01-01

This report documents the development effort for the reconfiguration of the Controls-Structures Integration (CSI) Evolutionary Model (CEM) Phase-2 testbed into the CEM Phase-3 configuration. This step responds to the need to develop and test CSI technologies associated with typical planned earth science and remote sensing platforms. The primary objective of the CEM Phase-3 ground testbed is to simulate the overall on-orbit dynamic behavior of the EOS AM-1 spacecraft. Key elements of the objective include approximating the low-frequency appendage dynamic interaction of EOS AM-1, allowing for the changeout of components, and simulating the free-free on-orbit environment using an advanced suspension system. The fundamentals of appendage dynamic interaction are reviewed. A new version of the multiple scaling method is used to design the testbed to have the full-scale geometry and dynamics of the EOS AM-1 spacecraft, but at one-tenth the weight. The testbed design is discussed, along with the testing of the solar array, high gain antenna, and strut components. Analytical performance comparisons show that the CEM Phase-3 testbed simulates the EOS AM-1 spacecraft with good fidelity for the important parameters of interest.

Roles of Transesophageal Echocardiography and Cardiac Computed Tomography for Evaluation of Left Atrial Thrombus and Associated Pathology: A Review and Critical Analysis.

PubMed

Pathan, Faraz; Hecht, Harvey; Narula, Jagat; Marwick, Thomas H

2018-04-01

Evaluation of the left atrium and left atrial appendage for the presence of thrombus prior to cardioversion and pulmonary vein isolation, and of the entire heart for embolic sources in the setting of cryptogenic stroke, has long been standard medical care. Guidelines have uniformly recommended transesophageal echocardiography (TEE) to accomplish these goals. In recent years, computed tomographic angiography has demonstrated diagnostic accuracy similar to that of TEE for the detection of thrombus. Analysis of the pertinent data and relative merits of the 2 technologies leads to the conclusions that: 1) both modalities have some unique, nonoverlapping capabilities that may dictate their use in specific situations; 2) computed tomographic angiography is a reasonable alternative to TEE when the primary aim is to exclude left atrial and left atrial appendage thrombus and in patients in whom the risks associated with TEE outweigh the benefits; and 3) both options should be discussed with the patient in the setting of shared decision making. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

First order coupled dynamic model of flexible space structures with time-varying configurations

NASA Astrophysics Data System (ADS)

Wang, Jie; Li, Dongxu; Jiang, Jianping

2017-03-01

This paper proposes a first order coupled dynamic modeling method for flexible space structures with time-varying configurations for the purpose of deriving the characteristics of the system. The model considers the first time derivative of the coordinate transformation matrix between the platform's body frame and the appendage's floating frame. As a result it can accurately predict characteristics of the system even if flexible appendages rotate with complex trajectory relative to the rigid part. In general, flexible appendages are fixed on the rigid platform or forced to rotate with a slow angular velocity. So only the zero order of the transformation matrix is considered in conventional models. However, due to neglecting of time-varying terms of the transformation matrix, these models introduce severe error when appendages, like antennas, for example, rotate with a fast speed relative to the platform. The first order coupled dynamic model for flexible space structures proposed in this paper resolve this problem by introducing the first time derivative of the transformation matrix. As a numerical example, a central core with a rotating solar panel is considered and the results are compared with those given by the conventional model. It has been shown that the first order terms are of great importance on the attitude of the rigid body and dynamic response of the flexible appendage.

Space robots with flexible appendages: Dynamic modeling, coupling measurement, and vibration suppression

NASA Astrophysics Data System (ADS)

Meng, Deshan; Wang, Xueqian; Xu, Wenfu; Liang, Bin

2017-05-01

For a space robot with flexible appendages, vibrations of flexible structure can be easily excited during both orbit and/or attitude maneuvers of the base and the operation of the manipulators. Hence, the pose (position and attitude) of the manipulator's end-effector will greatly deviate from the desired values, and furthermore, the motion of the manipulator will trigger and exacerbate vibrations of flexible appendages. Given lack of the atmospheric damping in orbit, the vibrations will last for quite a while and cause the on-orbital tasks to fail. We derived the rigid-flexible coupling dynamics of a space robot system with flexible appendages and established a coupling model between the flexible base and the space manipulator. A specific index was defined to measure the coupling degree between the flexible motion of the appendages and the rigid motion of the end-effector. Then, we analyzed the dynamic coupling for different conditions, such as modal displacements, joint angles (manipulator configuration), and mass properties. Moreover, the coupling map was adopted and drawn to represent the coupling motion. Based on this map, a trajectory planning method was addressed to suppress structure vibration. Finally, simulation studies of typical cases were performed, which verified the proposed models and method. This work provides a theoretic basis for the system design, performance evaluation, trajectory planning, and control of such space robots.

Boundary control of anti-symmetric vibration of satellite with flexible appendages in planar motion with exponential stability

NASA Astrophysics Data System (ADS)

Rad, Hossein Kaviani; Salarieh, Hassan; Alasty, Aria; Vatankhah, Ramin

2018-06-01

In this research, we have investigated the planar maneuver of a flexible satellite with appendages anti-symmetric vibration. The hybrid governing equations are comprised of coupled partial and ordinary differential equations which are derived by employing Hamilton's principle. In this paper, control goals are the tracking desired pitch angle along with the flexible appendages vibration suppression simultaneously by using only one control torque which is applied to the central hub. The boundary control is proposed to fulfill these control aims; furthermore, this boundary control ensures that spillover instability phenomenon is eliminated, and in-domain sensors and actuators implement are excluded. Indeed, the proposed boundary control is able to stabilize an infinite number of vibration modes, which is one of the important benefits of the proposed control when it is considered that different factors including external disturbances and even the satellite maneuver can excite the various vibration modes of the flexible appendages and consequently the excitement of the high order vibration modes will be possible. Lyapunov's direct method is used to prove the exponential stability; moreover, this Proof is achieved in absence of any damping effect in modeling the vibrations of flexible appendages. In addition, the procedure for finding the boundary control coefficients which ensures the exponential stability is provided. Eventually, numerical simulations are presented to illustrate the effectiveness of the proposed boundary control.

Design and fabrication of a full-scale actively controlled satellite appendage simulator unit

NASA Astrophysics Data System (ADS)

Jacobs, Jack H.; Quenon, Dan; Hadden, Steve; Self, Rick

1999-07-01

Modern satellites require the ability to slew and settle quickly in order to acquire or transmit data efficiently. Solar arrays and communication antennas cause low frequency disturbances to the satellite bus during these maneuvers causing undesirable induced vibration of the payload. The ability to develop and experimentally demonstrate attitude control laws which compensate for these flexible body disturbances is of prime importance to modern day satellite manufacturers. Honeywell has designed and fabricated an actively controlled Appendage Simulator Unit (ASU) which can physically induce the modal characteristics of satellite appendages on to a ground based satellite test bed installed on an air bearing. The ASU consists of two orthogonal fulcrum beams weighting over 800 pounds each utilizing two electrodynamic shakers to induce active torques onto the bus. The ASU is programmed with the state space characteristics of the desired appendage and responds in real time to the bus motion to generate realistic disturbances back onto the satellite. Two LVDT's are used on each fulcrum beam to close the loop and insure the system responds in real time the same way a real solar array would on-orbit. Each axis is independently programmable in order to simulate various orientations or modal contributions from an appendage. The design process for the ASU involved the optimization of sensors, actuators, control authority, weight, power and functionality. The smart structure system design process and experimental results are described in detail.

Golgi-type I and Golgi-type II neurons in the ventral anterior thalamic nucleus of the adult human: morphological features and quantitative analysis.

PubMed

Al-Hussain Bani Hani, Saleh M; El-Dwairi, Qasim A; Bataineh, Ziad M; Al-Haidari, Mohammad S; Al-Alami, Jamil

2008-05-01

The morphological and quantitative features of neurons in the adult human ventral anterior thalamic nucleus were studied in Golgi preparations. Two neuronal types were found and their quantitative features were studied. Golgi-type I neurons were medium to large cells with dense dendritic trees and dendritic protrusions and short hair-like appendages. They have somatic mean diameter of 30.8 microm (+/-9.4, n = 85). They have an average 100.3 dendritic branches, 48.97 dendritic branching points, and 58.85 dendritic tips. The mean diameters of their primary, secondary, and tertiary dendrites were 3.1 microm (+/-1, n = 80), 1.85 microm (+/-0.8, n = 145), and 1.5 microm (+/-0.4, n = 160), respectively. Golgi-type II neurons were small to medium cells with few sparsely branching dendrites and dendritic stalked appendages with or without terminal swellings. They have somatic mean diameters of 22.2 microm (+/-5.8, n = 120). They have an average 33.76 dendritic branches, 16.49 dendritic branching points, and 21.97 dendritic tips. The mean diameters of their primary, secondary, and tertiary dendrites were 1.6 microm (+/-0.86, n = 70), 1.15 microm (+/-0.55, n = 118), and 1 microm (+/-0.70, n = 95), respectively. These quantitative data may form the basis for further quantitative studies involving aging or some degenerative diseases that may affect cell bodies and/or dendritic trees of the Golgi-type I and/or Golgi-type II thalamic neurons.

Pulmonary artery perforation by plug anchoring system after percutaneous closure of left appendage.

PubMed

Bianchi, Giacomo; Solinas, Marco; Gasbarri, Tommaso; Bevilacqua, Stefano; Tiwari, Kaushal Kishore; Berti, Sergio; Glauber, Mattia

2013-07-01

Patients receiving oral anticoagulant therapy for atrial fibrillation who are at high risk of bleeding are increasingly referred for percutaneous left atrial appendage exclusion. Although effective, this procedure is not free from risk. We report a case of pericardial tamponade due to pulmonary artery tear caused by a trespassing anchoring hook of an AGA plug. Intraoperatively, no actual bleeding was found from the left appendage, a proof of its complete occlusion by the device. The patient underwent successful surgical repair and radio-frequency ablation of atrial fibrillation was performed by pulmonary veins encircling. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

78 FR 67365 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-12

... reduce the risk of life-threatening bleeding events in patients with non-valvular atrial fibrillation who... premarket approval application regarding the Boston Scientific WATCHMAN Left Atrial Appendage (LAA) Closure... placed in the left atrial appendage. This device is intended to prevent thrombus embolization from the...

Design of hair-like appendages and comparative analysis on their coordination toward steady and efficient swimming.

PubMed

Kwak, Bokeon; Bae, Joonbum

2017-05-22

The locomotion of water beetles has been widely studied in biology owing to their remarkable swimming skills. Inspired by the oar-like legs of water beetles, designing a robot that swims under the principle of drag-powered propulsion can lead to highly agile mobility. But its motion can easily be discontinuous and jerky due to backward motions (i.e. retraction) of the legs. Here we proposed novel hair-like appendages and consider their coordination to achieve steady and efficient swimming on the water surface. First of all, we propose several design schemes and fabrication methods of the hair-like appendages, which can passively adjust their projected area while obtaining enough thrust. The coordination between the two pairs of legs, as with water beetles in nature, were also investigated to achieve steady swimming without backward movement by varying the beating frequency and phase of the legs. To verify the functionality of the hair-like appendages and their coordinations, six different types of appendages were fabricated, and two robots (one with a single pair of legs and the other with two pairs of legs) were built. Locomotion of the robots was extensively compared through experiments, and it was found that steady swimming was achieved by properly coordinating the two pairs of legs without sacrificing their speed. Also, owing to the lower velocity fluctuation during swimming, it was shown that using two pairs of legs was more energy efficient than the robot with single pair of legs.

Development and evolution of the mammalian limb: adaptive diversification of nails, hooves, and claws.

PubMed

Hamrick, M W

2001-01-01

Paleontological evidence indicates that the evolutionary diversification of mammals early in the Cenozoic era was characterized by an adaptive radiation of distal limb structures. Likewise, neontological data show that morphological variation in distal limb integumentary appendages (e.g., nails, hooves, and claws) can be observed not only among distantly related mammalian taxa but also among closely related species within the same clade. Comparative analysis of nail, claw, and hoof morphogenesis reveals relatively subtle differences in mesenchymal and epithelial patterning underlying these adult differences in distal limb appendage morphology. Furthermore, studies of regulatory gene expression during vertebrate claw development demonstrate that many of the signaling molecules involved in patterning ectodermal derivatives such as teeth, hair, and feathers are also involved in organizing mammalian distal limb appendages. For example, Bmp4 signaling plays an important role during the recruitment of mesenchymal cells into the condensations forming the terminal phalanges, whereas Msx2 affects the length of nails and claws by suppressing proliferation of germinal epidermal cells. Evolutionary changes in the form of distal integumentary appendages may therefore result from changes in gene expression during formation of mesenchymal condensations (Bmp4, posterior Hox genes), induction of the claw fold and germinal matrix (shh), and/or proliferation of epidermal cells in the claw matrix (Msx1, Msx2). The prevalence of convergences and parallelisms in nail and claw structure among mammals underscores the existence of multiple morphogenetic pathways for evolutionary change in distal limb appendages.

The role of feeding morphology and competition in governing the diet breadth of sympatric stomatopod crustaceans.

PubMed

deVries, Maya S

2017-04-01

Competition for food drives divergence and specialization in feeding morphology. Stomatopod crustaceans have two kinds of highly specialized feeding appendages: either elongate spear-like appendages ( spearers ) used to ambush soft-bodied evasive prey or hammer-like appendages ( smashers ) that produce extremely high forces used both to break hard-shelled prey and to capture evasive prey. To evaluate associations between appendage type and feeding ecology, the diet of two small smasher and spearer species (size range: 21-27 mm) that co-occur were compared. Stable isotope analysis and the Bayesian mixing model MixSIAR were used to estimate the proportional contributions of prey types to the diet. Both species had relatively wide diets that included hard-shelled and soft-bodied prey, albeit in different proportions; the smasher consumed a greater proportion of hard-shelled prey, and the spearer consumed mostly soft-bodied prey. Appendage kinematics in stomatopods is known to scale linearly across species. These two small species may produce similar kinematics allowing them both to capture evasive prey and hammer hard-shelled prey, thereby widening their diets. Yet, the spearer species is more highly adept at capturing evasive prey, indicating that small spearers are stronger competitors for soft-bodied prey. These findings suggest that a smasher's ability to access hard prey reduced competition for soft prey, and therefore conferred an important benefit favouring the evolution of the impressive smashing strike. © 2017 The Author(s).

Human basal body basics.

PubMed

Vertii, Anastassiia; Hung, Hui-Fang; Hehnly, Heidi; Doxsey, Stephen

2016-01-01

In human cells, the basal body (BB) core comprises a ninefold microtubule-triplet cylindrical structure. Distal and subdistal appendages are located at the distal end of BB, where they play indispensable roles in cilium formation and function. Most cells that arrest in the G0 stage of the cell cycle initiate BB docking at the plasma membrane followed by BB-mediated growth of a solitary primary cilium, a structure required for sensing the extracellular environment and cell signaling. In addition to the primary cilium, motile cilia are present in specialized cells, such as sperm and airway epithelium. Mutations that affect BB function result in cilia dysfunction. This can generate syndromic disorders, collectively called ciliopathies, for which there are no effective treatments. In this review, we focus on the features and functions of BBs and centrosomes in Homo sapiens.

Hox genes require homothorax and extradenticle for body wall identity specification but not for appendage identity specification during metamorphosis of Tribolium castaneum.

PubMed

Smith, Frank W; Jockusch, Elizabeth L

2014-11-01

The establishment of segment identity is a key developmental process that allows for divergence along the anteroposterior body axis in arthropods. In Drosophila, the identity of a segment is determined by the complement of Hox genes it expresses. In many contexts, Hox transcription factors require the protein products of extradenticle (exd) and homothorax (hth) as cofactors to perform their identity specification functions. In holometabolous insects, segment identity may be specified twice, during embryogenesis and metamorphosis. To glean insight into the relationship between embryonic and metamorphic segmental identity specification, we have compared these processes in the flour beetle Tribolium castaneum, which develops ventral appendages during embryogenesis that later metamorphose into adult appendages with distinct morphologies. At metamorphosis, comparisons of RNAi phenotypes indicate that Hox genes function jointly with Tc-hth and Tc-exd to specify several region-specific aspects of the adult body wall. On the other hand, Hox genes specify appendage identities along the anteroposterior axis independently of Tc-hth/Tc-exd and Tc-hth/Tc-exd specify proximal vs. distal identity within appendages independently of Hox genes during this stage. During embryogenesis, Tc-hth and Tc-exd play a broad role in the segmentation process and are required for specification of body wall identities in the thorax; however, contrasting with results from other species, we did not obtain homeotic transformations of embryonic appendages in response to Tc-hth or Tc-exd RNAi. In general, the homeotic effects of interference with the function of Hox genes and Tc-hth/Tc-exd during metamorphosis did not match predictions based on embryonic roles of these genes. Comparing metamorphic patterning in T. castaneum to embryonic and post-embryonic development in hemimetabolous insects suggests that holometabolous metamorphosis combines patterning processes of both late embryogenesis and metamorphosis of the hemimetabolous life cycle. Copyright © 2014 Elsevier Inc. All rights reserved.

Selected Disorders of Skin Appendages--Acne, Alopecia, Hyperhidrosis.

PubMed

Vary, Jay C

2015-11-01

This article reviewed some of the more common diseases of the skin appendages that are encountered in medicine: hyperhidrosis, acne, AA, FPHL, AGA, and TE. The pathophysiology behind the conditions and their treatments were discussed so that the clinician can make logical therapeutic choices for their affected patients. Copyright © 2015 Elsevier Inc. All rights reserved.

The chemosensory appendage proteome of Amblyomma americanum (Acari: Ixodidae) reveals putative odorant-binding and other chemoreception-related proteins

USDA-ARS?s Scientific Manuscript database

Proteomic analyses were done on 2 chemosensory appendages of the lone star tick, Amblyomma americanum. Proteins in the fore tarsi, which contain the olfactory Haller's organ, and in the palps, that include gustatory sensilla, were compared with proteins in the third tarsi. Also, male and female tick...

[Prophylaxis of thromboembolism in atrial fibrillation: new oral anticoagulants and left atrial appendage closure].

PubMed

Zeus, Tobias; Kelm, Malte; Bode, Christoph

2015-08-01

Thrombo-embolic prophylaxis is a key element within the therapy of atrial fibrillation/atrial flutter. Besides new oral anticoagulants the concept of left atrial appendage occlusion has approved to be a good alternative option, especially in patients with increased risk of bleeding. © Georg Thieme Verlag KG Stuttgart · New York.

Thrombophilia-Related Complications in the Treatment of a Left Atrial Appendage Thrombus: A Case Report

PubMed Central

Parato, Vito Maurizio; Scarano, Michele; Labanti, Benedetto

2014-01-01

Trans-esophageal echocardiography (TEE) revealed a left atrial appendage (LAA) thrombus in an 84-year-old woman with nonvalvular atrial fibrillation not known before our evaluation. In her medical history, there were hypertension, dyslipidemia and a previous pulmonary embolism. She was taking warfarin at time of our evaluation and presented signs and symptoms of heart failure. Together with heart failure treatment, intravenous anticoagulation with unfractionated heparin was initiated. Treatment was complicated by additional right lower limb embolic event and the LAA thrombus remained unchanged. Testing revealed heterozygosity for both the factor V Leiden and the methylenetetrahydrofolate reductase C677T mutations inducing resistance to activated protein C. The patient refused transcatheter closure of the left atrial appendage. PMID:28465906

Left atrial appendage myxofibrosarcoma: A rare masquerader of myxoma and thrombus-"all that glitters is not gold".

PubMed

Khan, Muhammad Shoaib; Reddy, Sahadev; Lombardi, Richard; Isabel, Pitti; Mcgregor, Walter E; Tang, Bang; Gabriel, George; Biederman, Robert W

2018-02-01

Left atrial appendage mass can occasionally pose a serious challenge to physicians to identify the nature of the mass with the aid of imaging techniques. We present a case of 67-year-old man, who was evaluated for suspected left atria myxoma. Transesophageal echocardiography revealed a heterogeneous density originating from left atrial appendage, thought to be most consistent with a myxoma. Cardiac magnetic resonance imaging, uncharacteristically, gave an equivocal picture, suggesting the mass to be a myxoma on initial imaging and a thrombus with evidence of liquefaction necrosis following postcontrast enhancement. Surprisingly, histopathology of the mass following its surgical excision yielded a rare diagnosis of myxofibrosarcoma. © 2017, Wiley Periodicals, Inc.

Adding left atrial appendage closure to open heart surgery provides protection from ischemic brain injury six years after surgery independently of atrial fibrillation history: the LAACS randomized study.

PubMed

Park-Hansen, Jesper; Holme, Susanne J V; Irmukhamedov, Akhmadjon; Carranza, Christian L; Greve, Anders M; Al-Farra, Gina; Riis, Robert G C; Nilsson, Brian; Clausen, Johan S R; Nørskov, Anne S; Kruuse, Christina R; Rostrup, Egill; Dominguez, Helena

2018-05-23

Open heart surgery is associated with high occurrence of atrial fibrillation (AF), subsequently increasing the risk of post-operative ischemic stroke. Concomitant with open heart surgery, a cardiac ablation procedure is commonly performed in patients with known AF, often followed by left atrial appendage closure with surgery (LAACS). However, the protective effect of LAACS on the risk of cerebral ischemia following cardiac surgery remains controversial. We have studied whether LAACS in addition to open heart surgery protects against post-operative ischemic brain injury regardless of a previous AF diagnosis. One hundred eighty-seven patients scheduled for open heart surgery were enrolled in a prospective, open-label clinical trial and randomized to concomitant LAACS vs. standard care. Randomization was stratified by usage of oral anticoagulation (OAC) planned to last at least 3 months after surgery. The primary endpoint was a composite of post-operative symptomatic ischemic stroke, transient ischemic attack or imaging findings of silent cerebral ischemic (SCI) lesions. During a mean follow-up of 3.7 years, 14 (16%) primary events occurred among patients receiving standard surgery vs. 5 (5%) in the group randomized to additional LAACS (hazard ratio 0.3; 95% CI: 0.1-0.8, p = 0.02). In per protocol analysis (n = 141), 14 (18%) primary events occurred in the control group vs. 4 (6%) in the LAACS group (hazard ratio 0.3; 95% CI: 0.1-1.0, p = 0.05). In a real-world setting, LAACS in addition to elective open-heart surgery was associated with lower risk of post-operative ischemic brain injury. The protective effect was not conditional on AF/OAC status at baseline. LAACS study, clinicaltrials.gov NCT02378116 , March 4th 2015, retrospectively registered.

The fluid dynamics of Balanus glandula barnacles: Adaptations to sheltered and exposed habitats.

PubMed

Vo, Maureen; Mehrabian, Sasan; Villalpando, Fernando; Etienne, Stephane; Pelletier, Dominique; Cameron, Christopher B

2018-04-11

Suspension feeders use a wide range of appendages to capture particles from the surrounding fluid. Their functioning, either as a paddle or a sieve, depends on the leakiness, or amount of fluid that passes through the gaps between the appendages. Balanus glandula is the most common species of barnacle distributed along the Pacific coast of North America. It shows a strong phenotypic response to water flow velocity. Individuals from exposed, high flow sites have short and robust cirral filters, whereas those from sheltered, low velocity sites have long, spindly appendages. Computational fluid dynamics (CFD) simulations of these two ecophenotypes were done using a finite volume method. Leakiness was determined by simulating flow velocity fields at increasing Reynolds numbers, results that have been unattainable at higher velocities by observation. CFD also allowed us to characterize flow in hard to see regions of the feeding legs (rami). Laser-illumination experiments were performed at low to medium flow velocities in a flume tank and corroborated results from CFD. Barnacle filters from a sheltered site become completely leaky at Re=2.24(0.16m/s), well above the maximum habitat velocity, suggesting that this ecophenotype is not mechanically optimized for feeding. Barnacles from exposed environments become fully leaky within the range of habitat velocities Re=3.50(0.18m/s). Our CFD results revealed that the drag force on exposed barnacles feeding appendages are the same as the sheltered barnacles feeding appendages despite their shape difference and spacing ratio. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ovule Morphogenesis in Ranunculaceae and its Systematic Significance

PubMed Central

Wang, Zi-Fen; Ren, Yi

2008-01-01

Background and Aims Ranunculaceae has a prominent phylogenetic position in Ranunculales which appears at the base of eudicots. The aims of the present paper are to reveal the features of ovule morphogenesis in different taxa and gain a better understanding of the systematics of Ranunculaceae. Methods Flowers of 17 species from three subfamilies, nine tribes and 16 genera of Ranunculaceae, at successive developmental stages, were collected in the wild and studied with a scanning electron microscope. Key Results The integuments in the unitegmic ovules in Helleborus, Ranunculus and Oxygraphis, as well as the inner integuments in the bitegmic genera, initiate annularly and eventually become cup-shaped. However, the integuments in the unitegmic ovules in Anemone and Clematis, as well as the outer integuments in the bitegmic genera, arise semi-annularly and eventually become hood-shaped. Different kinds of appendages appear on the ovules during development. In Coptis of subfamily Coptidoideae, a wrap-shaped appendage arises outside the ovule and envelopes the ovule entirely. In the genera of subfamily Thalictroideae and tribe Anemoneae of subfamily Ranunculoideae, appendages appear on the placenta, the funicle or both. In tribe Helleboreae of subfamily Ranunculoideae, an alary appendage is initiated where the integument and the funicle join and becomes hood-shaped. Conclusions Ovule morphogenesis characteristics are significant in classification at the levels of subfamilies and tribes. The initiation patterns of the integuments and the development of appendages show diversity in Ranunculaceae. The present observations suggest that the bitegmic, hood-shaped outer integument and endostomic micropyle are primitive while the unitegmic, cupular-shaped outer integument and bistomic micropyle are derivative. PMID:18065776

Active damping of spacecraft structural appendage vibrations

NASA Technical Reports Server (NTRS)

Fedor, Joseph V. (Inventor)

1990-01-01

An active vibration damper system, for bending in two orthogonal directions and torsion, in each of three mutually perpendicular axes is located at the extremities of the flexible appendages of a space platform. The system components for each axis includes: an accelerometer, filtering and signal processing apparatus, and a DC motor-inertia wheel torquer. The motor torquer, when driven by a voltage proportional to the relative vibration tip velocity, produces a reaction torque for opposing and therefore damping a specific modal velocity of vibration. The relative tip velocity is obtained by integrating the difference between the signal output from the accelerometer located at the end of the appendage with the output of a usually carried accelerometer located on a relatively rigid body portion of the space platform. A selector switch, with sequential stepping logic or highest modal vibration energy logic, steps to another modal tip velocity channel and receives a signal voltage to damp another vibration mode. In this manner, several vibration modes can be damped with a single sensor/actuator pair. When a three axis damper is located on each of the major appendages of the platform, then all of the system vibration modes can be effectively damped.

STS-74/Mir photogrammetric appendage structural dynamics experiment

NASA Technical Reports Server (NTRS)

Welch, Sharon S.; Gilbert, Michael G.

1996-01-01

The Photogrammetric Appendage Structural Dynamics Experiment (PASDE) is an International Space Station (ISS) Phase-1 risk mitigation experiment. Phase-1 experiments are performed during docking missions of the U.S. Space Shuttle to the Russian Space Station Mir. The purpose of the experiment is to demonstrate the use of photogrammetric techniques for determination of structural dynamic mode parameters of solar arrays and other spacecraft appendages. Photogrammetric techniques are a low cost alternative to appendage mounted accelerometers for the ISS program. The objective of the first flight of PASDE, on STS-74 in November 1995, was to obtain video images of Mir Kvant-2 solar array response to various structural dynamic excitation events. More than 113 minutes of high quality structural response video data was collected during the mission. The PASDE experiment hardware consisted of three instruments each containing two video cameras, two video tape recorders, a modified video signal time inserter, and associated avionics boxes. The instruments were designed, fabricated, and tested at the NASA Langley Research Center in eight months. The flight hardware was integrated into standard Hitchhiker canisters at the NASA Goddard Space Flight Center and then installed into the Space Shuttle cargo bay in locations selected to achieve good video coverage and photogrammetric geometry.

Correlation of right atrial appendage velocity with left atrial appendage velocity and brain natriuretic Peptide.

PubMed

Kim, Bu-Kyung; Heo, Jung-Ho; Lee, Jae-Woo; Kim, Hyun-Soo; Choi, Byung-Joo; Cha, Tae-Joon

2012-03-01

Left atrial appendage (LAA) anatomy and function have been well characterized both in healthy and diseased people, whereas relatively little attention has been focused on the right atrial appendage (RAA). We sought to evaluate RAA flow velocity and to compare these parameters with LAA indices and with a study of biomarkers, such as brain natriuretic peptide, among patients with sinus rhythm (SR) and atrial fibrillation (AF). In a series of 79 consecutive patients referred for transesophageal echocardiography, 43 patients (23 with AF and 20 controls) were evaluated. AF was associated with a decrease in flow velocity for both LAA and RAA [LAA velocity-SR vs. AF: 61 ± 22 vs. 29 ± 18 m/sec (p < 0.01), RAA velocity-SR vs. AF: 46 ± 20 vs. 19 ± 8 m/sec (p < 0.01)]. Based on simple linear regression analysis, LAA velocity and RAA velocity were positively correlated, and RAA velocity was inversely correlated with brain natriuretic peptide (BNP). AF was associated with decreased RAA and LAA flow velocities. RAA velocity was found to be positively correlated with LAA velocity and negatively correlated with BNP. The plasma BNP concentration may serve as a determinant of LAA and RAA functions.

Genome wide analysis in a discordant monozygotic twin with caudal appendage and multiple congenital anomalies.

PubMed

Cogulu, O; Pariltay, E; Koroglu, O A; Aykut, A; Ozyurek, R; Levent, E; Kultursay, N; Ozkinay, F

2013-01-01

Caudal appendage is a rare dysmorphic feature of which etiologic mechanisms are not well understood. Here we report monozygotic (MZ) twin brothers who are discordant for the caudal appendage and multiple congenital anomalies. Twins were the product of a 33 weeks of gestation, monochorionic-diamniotic pregnancy. On admission the proband had micrognathia, beaked nose, hypospadias, caudal appendage and juxtaductal aorta coarctation. At birth, he was small for gestational age and he had transient hypothyroidism which was detected in the newborn period. Karyotype analysis showed 46,XY. Monozygosity was shown by 15 microsatellite markers plus amelogenin (AmpFlSTR Identifiler PCR Amplification Kit, Applied Biosystems). Genome-wide copy number analysis of the twins by DNA-DNA hybridization of whole genomic DNA (NimbleGen Human CGH 385K WG-T v2.0 array) showed a significant difference at two neighboring probes with Log2 ratio: 0.72088 which are located on chromosome 3p12.3. Further analysis by high resolution of chromosome 3 array (Roche NimbleGen Human HG18 CHR3 FT Median Probe Spacing 475 bp) and quantitative PCR analysis did not confirm the deletion.

Use of cardiovascular magnetic resonance in the evaluation of a giant right atrial appendage aneurysm: a case report and review of the literature.

PubMed

Sivakumaran, Lojan; Sayegh, Karl; Mehanna, Emile; Sanchez, Frank W; Fields, Jonathan; Cury, Ricardo

2017-12-04

Right atrial appendage aneurysms are rare entities that may have significant clinical consequences. When co-existing with atrial fibrillation, patients are at risk of developing pulmonary or paradoxical systemic emboli. An elderly patient presented to medical attention with symptoms of acute diverticulitis. On abdominal computed tomography, a massively enlarged right atrial appendage aneurysm was discovered incidentally. The aneurysm caused marked compression of the right ventricle and contained an area of hypoenhancement concerning for an intraluminal thrombus. Gadolinium-enhanced cardiovascular magnetic resonance was performed and first-pass perfusion images demonstrated that the area of hypoenhancement was in fact poorly mixing blood. The patient was therefore managed medically. Right atrial appendage aneurysms are infrequently encountered cardiac abnormalities. In the literature, surgery has been offered to patients who are young, symptomatic, or have evidence of thrombotic disease, although whether this practice pattern is associated with superior clinical outcomes is unclear. In the present case, gadolinium-enhanced cardiovascular magnetic resonance imaging was used to exclude the presence of intraluminal thrombus in an elderly patient, which helped orient the patient's treating team towards medical-rather than surgical-therapy.

Transcatheter closure of the left atrial appendage: initial experience with the WATCHMAN device

PubMed Central

Ding, Jiandong; Zhu, Jian; Lu, Jing; Ding, Xiuxia; Zhang, Xiaoli; Lu, Wenbin; Ao, Mingqiang; Ma, Genshan

2015-01-01

Background: Atrial fibrillation (AF) is the most commonly encountered clinical arrhythmia, accounting for approximately one third of hospitalizations for cardiac rhythm disturbance. In patients with non-valvular AF, approximately 90% of thrombi are thought to arise from the left atrial appendage (LAA). Anticoagulation with warfarin has been the mainstay of therapy to reduce stroke risk in these patients; however, it is not without its complications including bleeding and drug interactions. Percutaneous left atrial appendage closure can be an alternative to warfarin treatment in patients with AF at high risk for thromboembolic events and/or bleeding complications. Methods: Patients with atrial fibrillation and CHADSVASc score ≥ 2, not eligible for anticoagulation, were submitted to left atrial appendage closure using the WATCHMAN device. The procedure was performed under general anaesthesia, and was guided by fluoroscopy and transoesophageal echocardiography. Results: Percutaneous LAA closure with the WATCHMAN device was performed in all patients. At 45-day follow-up no recurrent major adverse events and especially no thromboembolic events occurred. Conclusions: Transcatheter closure of the LAA with the WATCHMAN device is generally safe and feasible. Long-term follow-up will further reveal the risk and benefits of this therapy. PMID:26629008

Aneurysm of the Left Atrial Appendage

PubMed Central

Victor, Solomon; Nayak, Vijaya M.

2001-01-01

A 43-year-old woman underwent excision of an aneurysm of the left atrial appendage, which had been causing cerebrovascular embolic episodes. We attribute the aneurysm to congenital dysplasia of the musculi pectinati in the left atrial appendage and of the bands of atrial muscle from which they arise. In Appendix I, we draw attention to the morphologically similar arrangements of inner and outer bands that emanate from a common transverse interatrial band and yield morphologically similar medial, descending, and ascending palm-leaf arrangements of musculi pectinati. In addition, we observe that the strap-like arrangements of musculi in both atria connect the outer band with the para-annular segment of the inner band. In Appendix II, we briefly review the literature concerning musculi pectinati and related bands. PMID:11453121

Large Advanced Space Systems (LASS) computer-aided design program additions

NASA Technical Reports Server (NTRS)

Farrell, C. E.

1982-01-01

The LSS preliminary and conceptual design requires extensive iteractive analysis because of the effects of structural, thermal, and control intercoupling. A computer aided design program that will permit integrating and interfacing of required large space system (LSS) analyses is discussed. The primary objective of this program is the implementation of modeling techniques and analysis algorithms that permit interactive design and tradeoff studies of LSS concepts. Eight software modules were added to the program. The existing rigid body controls module was modified to include solar pressure effects. The new model generator modules and appendage synthesizer module are integrated (interfaced) to permit interactive definition and generation of LSS concepts. The mass properties module permits interactive specification of discrete masses and their locations. The other modules permit interactive analysis of orbital transfer requirements, antenna primary beam n, and attitude control requirements.

The Center for Regenerative Biology and Medicine at Mount Desert Island Biological Laboratory

DTIC Science & Technology

2015-08-01

TERMS limb regeneration Positional Memory Code Axolotl microRNAs Zebrafish Polypterus 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18...injury induced regeneration of limbs/appendage tissues in Ambystoma ( axolotl ) and Polypterus animals. The defining feature of limb/appendage...downregulated in UPREGULATED DOWNREGULATED Figure 1: Venn diagram of UniProt protein sequence IDs among Axolotl and Polypterus contigs that

The implications of a Silurian and other thylacocephalan crustaceans for the functional morphology and systematic affinities of the group

PubMed Central

2014-01-01

Background Thylacocephala is a group of enigmatic extinct arthropods. Here we provide a full description of the oldest unequivocal thylacocephalan, a new genus and species Thylacares brandonensis, which is present in the Silurian Waukesha fauna from Wisconsin, USA. We also present details of younger, Jurassic specimens, from the Solnhofen lithographic limestones, which are crucial to our interpretation of the systematic position of Thylacocephala. In the past, Thylacocephala has been interpreted as a crustacean ingroup and as closely related to various groups such as cirripeds, decapods or remipeds. Results The Waukesha thylacocephalan, Thylacares brandonensis n. gen. n. sp., bears compound eyes and raptorial appendages that are relatively small compared to those of other representatives of the group. As in other thylacocephalans the large bivalved shield encloses much of the entire body. The shield lacks a marked optical notch. The eyes, which project just beyond the shield margin, appear to be stalked. Head appendages, which may represent antennulae, antennae and mandibles, appear to be present. The trunk is comprised of up to 22 segments. New details observed on thylacocephalans from the Jurassic Solnhofen lithographic limestones include antennulae and antennae of Mayrocaris bucculata, and endites on the raptorial appendages and an elongate last trunk appendage in Clausocaris lithographica. Preserved features of the internal morphology in C. lithographica include the muscles of the raptorial appendage and trunk. Conclusions Our results indicate that some ‘typical’ thylacocephalan characters are unique to the group; these autapomorphies contribute to the difficulty of determining thylacocephalan affinities. While the new features reported here are consistent with a eucrustacean affinity, most previous hypotheses for the position of Thylacocephala within Eucrustacea (as Stomatopoda, Thecostraca or Decapoda) are shown to be unlikely. A sister group relationship to Remipedia appears compatible with the observed features of Thylacocephala but more fossil evidence is required to test this assertion. The raptorial appendages of Thylacocephala most likely projected 45 degrees abaxially instead of directly forward as previously reconstructed. The overall morphology of thylacocephalans supports a predatory mode of life. PMID:25927449

The implications of a Silurian and other thylacocephalan crustaceans for the functional morphology and systematic affinities of the group.

PubMed

Haug, Carolin; Briggs, Derek E G; Mikulic, Donald G; Kluessendorf, Joanne; Haug, Joachim T

2014-08-22

Thylacocephala is a group of enigmatic extinct arthropods. Here we provide a full description of the oldest unequivocal thylacocephalan, a new genus and species Thylacares brandonensis, which is present in the Silurian Waukesha fauna from Wisconsin, USA. We also present details of younger, Jurassic specimens, from the Solnhofen lithographic limestones, which are crucial to our interpretation of the systematic position of Thylacocephala. In the past, Thylacocephala has been interpreted as a crustacean ingroup and as closely related to various groups such as cirripeds, decapods or remipeds. The Waukesha thylacocephalan, Thylacares brandonensis n. gen. n. sp., bears compound eyes and raptorial appendages that are relatively small compared to those of other representatives of the group. As in other thylacocephalans the large bivalved shield encloses much of the entire body. The shield lacks a marked optical notch. The eyes, which project just beyond the shield margin, appear to be stalked. Head appendages, which may represent antennulae, antennae and mandibles, appear to be present. The trunk is comprised of up to 22 segments. New details observed on thylacocephalans from the Jurassic Solnhofen lithographic limestones include antennulae and antennae of Mayrocaris bucculata, and endites on the raptorial appendages and an elongate last trunk appendage in Clausocaris lithographica. Preserved features of the internal morphology in C. lithographica include the muscles of the raptorial appendage and trunk. Our results indicate that some 'typical' thylacocephalan characters are unique to the group; these autapomorphies contribute to the difficulty of determining thylacocephalan affinities. While the new features reported here are consistent with a eucrustacean affinity, most previous hypotheses for the position of Thylacocephala within Eucrustacea (as Stomatopoda, Thecostraca or Decapoda) are shown to be unlikely. A sister group relationship to Remipedia appears compatible with the observed features of Thylacocephala but more fossil evidence is required to test this assertion. The raptorial appendages of Thylacocephala most likely projected 45 degrees abaxially instead of directly forward as previously reconstructed. The overall morphology of thylacocephalans supports a predatory mode of life.

Making maxillary barbels with a proximal-distal gradient of Wnt signals in matrix-bound mesenchymal cells

PubMed Central

Figueroa, Francisco; Singer, Susan S.; LeClair, Elizabeth E.

2015-01-01

The evolution of specific appendages is made possible by the ontogenetic deployment of general cell signaling pathways. Many fishes, amphibians and reptiles have unique skin appendages known as barbels, which are poorly understood at the cellular and molecular level. In this study, we examine the cell arrangements, cell division patterns, and gene expression profiles associated with the zebrafish maxillary barbel, or ZMB. The earliest cellular organization of the ZMB is an internal whorl of mesenchymal cells in the dermis of the maxilla; there is no epithelial placode, nor any axially-elongated epithelial cells as expected of an apical ectodermal ridge (AER). As the ZMB develops, cells in S-phase are at first distributed randomly throughout the appendage, gradually transitioning to a proliferative population concentrated at the distal end. By observing ZMB ontogenetic stages in a Wnt-responsive transgenic reporter line, TCFsiam, we identified a strongly fluorescent mesenchymal cell layer within these developing appendages. Using an in vitro explant culture technique on developing barbel tissues, we co-localized the fluorescent label in these cells with the mitotic marker EdU. Surprisingly, TCF+ cells showed little proliferation, indicating a slow-cycling subpopulation. Transmission electron microscopy of the ZMB located the TCF+ cells in a single, circumferential layer within the barbel’s matrix core. Morphologically, these cells resemble fibroblasts or osteoblasts; in addition to their matrix-bound location, they are identified by their pancake-shaped nuclei, abundant rough endoplasmic reticulum, and cytoplasmic extensions into the surrounding extracellular matrix. Taken together, these features define a novel mesenchymal cell population in zebrafish, the ‘TCF+ core cells.’ A working model of barbel development is proposed, in which these minimally mitotic mesodermal cells produce collagenous matrix in response to ectodermally-derived Wnt signals deployed in a proximal-distal gradient along the appendage. This documents a novel mechanism of vertebrate appendage outgrowth. Similar genetic signals and cell behaviors may be responsible for the independent and repeated evolution of barbel structures in other fish species. PMID:26492827

Percutaneous left atrial appendage occlusion for stroke prevention in patients with atrial fibrillation and contraindication for anticoagulation.

PubMed

Grosset-Janin, D; Barth, E; Bertrand, B; Detante, O

2015-05-01

Stroke, as the third cause of death in developed countries, is a public health issue. Atrial fibrillation is an important cause of ischemic stroke and its prevention is efficient with oral anticoagulation. However, oral anticoagulation can be contraindicated because of hemorrhagic risk related to these treatments. Percutaneous left atrial appendage occlusion is a new alternative of oral anticoagulation for patients with atrial fibrillation and high risk of cardio-embolic stroke but contraindicated for oral anticoagulation. We describe in this paper the procedure of left atrial appendage occlusion with the Amplatzer cardiac plug device, used in our center in Grenoble university hospital, for the first three patients who have been treated with this device. These three patients (one man and two women) have all atrial fibrillation with neurological complication of this arrhythmia, as ischemic stroke. Oral anticoagulation is indicated to prevent another ischemic stroke. However, they all have a high risk of cerebral bleeding for different reasons (cavernomatosis, history of intracerebral hemorrhage and aneurysm of the polygon of Willis). Consequently, they have a high risk of cardio-embolic complication but contraindication for oral anticoagulation. They have been treated by left atrial appendage occlusion with Amplatzer cardiac plug device by percutaneous and trans-septal access. Then, they have been followed by neurologist and cardiologist, with clinical and paraclinical evaluation by echocardiography. Our three first patients have been successfully implanted, without periprocedural complication. No latest adverse event was observed, and particularly no cardiac or neurologic adverse event. The technique of left atrial appendage occlusion is a very interesting and promising technique for ischemic stroke prevention in patient with high risk of cardio-embolic complication because of atrial fibrillation, but high risk of bleeding and contraindication for oral anticoagulation. Because of frequency of both atrial fibrillation and contraindication for oral anticoagulation, occlusion of the left atrial appendage should become an interesting alternative for many patients. However, it remains an invasive procedure and efficacy and indications need to be evaluated in further clinical trials. Risk/benefit ratio must be carefully assessed and compared to that of the new anticoagulant drugs. Copyright © 2015. Published by Elsevier Masson SAS.

Lrp4 and Wise interplay controls the formation and patterning of mammary and other skin appendage placodes by modulating Wnt signaling.

PubMed

Ahn, Youngwook; Sims, Carrie; Logue, Jennifer M; Weatherbee, Scott D; Krumlauf, Robb

2013-02-01

The future site of skin appendage development is marked by a placode during embryogenesis. Although Wnt/β-catenin signaling is known to be essential for skin appendage development, it is unclear which cellular processes are controlled by the signaling and how the precise level of the signaling activity is achieved during placode formation. We have investigated roles for Lrp4 and its potential ligand Wise (Sostdc1) in mammary and other skin appendage placodes. Lrp4 mutant mice displayed a delay in placode initiation and changes in distribution and number of mammary precursor cells leading to abnormal morphology, number and position of mammary placodes. These Lrp4 mammary defects, as well as limb defects, were associated with elevated Wnt/β-catenin signaling and were rescued by reducing the dose of the Wnt co-receptor genes Lrp5 and Lrp6, or by inactivating the gene encoding β-catenin. Wise-null mice phenocopied a subset of the Lrp4 mammary defects and Wise overexpression reduced the number of mammary precursor cells. Genetic epistasis analyses suggest that Wise requires Lrp4 to exert its function and that, together, they have a role in limiting mammary fate, but Lrp4 has an early Wise-independent role in facilitating placode formation. Lrp4 and Wise mutants also share defects in vibrissa and hair follicle development, suggesting that the roles played by Lrp4 and Wise are common to skin appendages. Our study presents genetic evidence for interplay between Lrp4 and Wise in inhibiting Wnt/β-catenin signaling and provides an insight into how modulation of Wnt/β-catenin signaling controls cellular processes important for skin placode formation.

Left atrial accessory appendages, diverticula, and left-sided septal pouch in multi-slice computed tomography. Association with atrial fibrillation and cerebrovascular accidents.

PubMed

Hołda, Mateusz K; Koziej, Mateusz; Wszołek, Karolina; Pawlik, Wiesław; Krawczyk-Ożóg, Agata; Sorysz, Danuta; Łoboda, Piotr; Kuźma, Katarzyna; Kuniewicz, Marcin; Lelakowski, Jacek; Dudek, Dariusz; Klimek-Piotrowska, Wiesława

2017-10-01

The aim of this study is to provide a morphometric description of the left-sided septal pouch (LSSP), left atrial accessory appendages, and diverticula using cardiac multi-slice computed tomography (MSCT) and to compare results between patient subgroups. Two hundred and ninety four patients (42.9% females) with a mean of 69.4±13.1years of age were investigated using MSCT. The presence of the LSSP, left atrial accessory appendages, and diverticula was evaluated. Multiple logistic regression analysis was performed to check whether the presence of additional left atrial structures is associated with increased risk of atrial fibrillation and cerebrovascular accidents. At least one additional left atrial structure was present in 51.7% of patients. A single LSSP, left atrial diverticulum, and accessory appendage were present in 35.7%, 16.0%, and 4.1% of patients, respectively. After adjusting for other risk factors via multiple logistic regression, patients with LSSP are more likely to have atrial fibrillation (OR=2.00, 95% CI=1.14-3.48, p=0.01). The presence of a LSSP was found to be associated with an increased risk of transient ischemic attack using multiple logistic regression analysis after adjustment for other risk factors (OR=3.88, 95% CI=1.10-13.69, p=0.03). In conclusion LSSPs, accessory appendages, and diverticula are highly prevalent anatomic structures within the left atrium, which could be easily identified by MSCT. The presence of LSSP is associated with increased risk for atrial fibrillation and transient ischemic attack. Copyright © 2017 Elsevier B.V. All rights reserved.

Percutaneous transvenous mitral commissurotomy in mitral stenosis and left atrial appendage clot patients in special conditions: Hospital-based study.

PubMed

Rajbhandari, Rajib; Malla, Rabi; Maskey, Arun; Bhatta, Yadav; Limbu, Yubraj; Sharma, Ranjit; Singh, Satish; Adhikari, Chandramani; Mishra, Sundeep

The percutaneous transvenous mitral commissurotomy is an important procedure for the treatment of mitral stenosis. A lot of mitral stenosis cases have left atrial appendage clot which precludes the patient from the benefit of this procedure. The aim of the study was to study the feasibility and safety of the procedure in a patient with appendage clot in the setup of certain urgent conditions. All cases of mitral stenosis with significant dyspnea and mitral valve area <1.5cm 2 with left atrial appendage clot and a condition which would preclude the patient from continuing on anticoagulation and needed urgent intervention were included in the study. From January 2011 to December 2013, twenty patients coming to Shahid Gangalal National Heart Centre, Kathmandu were selected for the procedure with conventional sampling technique. Informed written consent was obtained from the patients explaining all possible complications. The approval of the study was taken from the ethical committee of the hospital. Mean mitral valve area increased from 0.90cm 2 (SD±0.14) to 1.5cm 2 (SD±0.21) (p=0.02). Left atrial mean pressure decreased from mean of 20 to 10mmHg. Subjective improvement was reported in all. All of the patients had fulfilled criteria for successful PTMC. There was no mortality during hospital stay or in one-week follow-up period. There were no neurological complications or any need for emergency surgery. The immediate result of percutaneous transvenous mitral commissurotomy in selected cases of mitral stenosis with left atrial appendage clot is safe and acceptable in certain urgent situations in experienced hands. Copyright © 2016. Published by Elsevier B.V.

Cost effectiveness of left atrial appendage closure with the Watchman device for atrial fibrillation patients with absolute contraindications to warfarin

PubMed Central

Reddy, Vivek Y.; Akehurst, Ronald L.; Armstrong, Shannon O.; Amorosi, Stacey L.; Brereton, Nic; Hertz, Deanna S.; Holmes, David R.

2016-01-01

Abstract Aims Atrial fibrillation (AF) patients with contraindications to oral anticoagulation have had few options for stroke prevention. Recently, a novel oral anticoagulant, apixaban, and percutaneous left atrial appendage closure (LAAC) have emerged as safe and effective therapies for stroke risk reduction in these patients. This analysis assessed the cost effectiveness of LAAC with the Watchman device relative to apixaban and aspirin therapy in patients with non-valvular AF and contraindications to warfarin therapy. Methods and results A cost-effectiveness model was constructed using data from three studies on stroke prevention in patients with contraindications: the ASAP study evaluating the Watchman device, the ACTIVE A trial of aspirin and clopidogrel, and the AVERROES trial evaluating apixaban. The cost-effectiveness analysis was conducted from a German healthcare payer perspective over a 20-year time horizon. Left atrial appendage closure yielded more quality-adjusted life years (QALYs) than aspirin and apixaban by 2 and 4 years, respectively. At 5 years, LAAC was cost effective compared with aspirin with an incremental cost-effectiveness ratio (ICER) of €16 971. Left atrial appendage closure was cost effective compared with apixaban at 7 years with an ICER of €9040. Left atrial appendage closure was cost saving and more effective than aspirin and apixaban at 8 years and remained so throughout the 20-year time horizon. Conclusions This analysis demonstrates that LAAC with the Watchman device is a cost-effective and cost-saving solution for stroke risk reduction in patients with non-valvular AF who are at risk for stroke but have contraindications to warfarin. PMID:26838691

In search of the Golden Fleece: Unraveling principles of morphogenesis by studying the integrative biology of skin appendages

PubMed Central

Hughes, Michael W.; Wu, Ping; Jiang, Ting-Xin; Lin, Sung-Jan; Dong, Chen-Yuan; Li, Ang; Hsieh, Fon-Jou; Widelitz, Randall B.; Choung, Cheng Ming

2013-01-01

Summary The mythological story of the Golden Fleece symbolizes the magical regenerative power of skin appendages. Similar to the adventurous pursuit of the Golden Fleece by the multi-talented Argonauts, today we also need an integrated multi-disciplined approach to understand the cellular and molecular processes during development, regeneration and evolution of skin appendages. To this end, we have explored several aspects of skin appendage biology that contribute to the Turing activator / inhibitor model in feather pattern formation, the topo-biological arrangement of stem cells in organ shape determination, the macro-environmental regulation of stem cells in regenerative hair waves, and potential novel molecular pathways in the morphological evolution of feathers. Here we show our current integrative biology efforts to unravel the complex cellular behavior in patterning stem cells and the control of regional specificity in skin appendages. We use feather / scale tissue recombination to demonstrate the timing control of competence and inducibility. Feathers from different body regions are used to study skin regional specificity. Bioinformatic analyses of transcriptome microarrays show the potential involvement of candidate molecular pathways. We further show Hox genes exhibit some region specific expression patterns. To visualize real time events, we applied time-lapse movies, confocal microscopy and multiphoton microscopy to analyze the morphogenesis of cultured embryonic chicken skin explants. These modern imaging technologies reveal unexpectedly complex cellular flow and organization of extracellular matrix molecules in three dimensions. While these approaches are in preliminary stages, this perspective highlights the challenges we face and new integrative tools we will use. Future work will follow these leads to develop a systems biology view and understanding in the morphogenetic principles that govern the development and regeneration of ectodermal organs. PMID:21437328

Glycoproteomics Reveals Decorin Peptides With Anti-Myostatin Activity in Human Atrial Fibrillation.

PubMed

Barallobre-Barreiro, Javier; Gupta, Shashi K; Zoccarato, Anna; Kitazume-Taneike, Rika; Fava, Marika; Yin, Xiaoke; Werner, Tessa; Hirt, Marc N; Zampetaki, Anna; Viviano, Alessandro; Chong, Mei; Bern, Marshall; Kourliouros, Antonios; Domenech, Nieves; Willeit, Peter; Shah, Ajay M; Jahangiri, Marjan; Schaefer, Liliana; Fischer, Jens W; Iozzo, Renato V; Viner, Rosa; Thum, Thomas; Heineke, Joerg; Kichler, Antoine; Otsu, Kinya; Mayr, Manuel

2016-09-13

Myocardial fibrosis is a feature of many cardiac diseases. We used proteomics to profile glycoproteins in the human cardiac extracellular matrix (ECM). Atrial specimens were analyzed by mass spectrometry after extraction of ECM proteins and enrichment for glycoproteins or glycopeptides. ECM-related glycoproteins were identified in left and right atrial appendages from the same patients. Several known glycosylation sites were confirmed. In addition, putative and novel glycosylation sites were detected. On enrichment for glycoproteins, peptides of the small leucine-rich proteoglycan decorin were identified consistently in the flowthrough. Of all ECM proteins identified, decorin was found to be the most fragmented. Within its protein core, 18 different cleavage sites were identified. In contrast, less cleavage was observed for biglycan, the most closely related proteoglycan. Decorin processing differed between human ventricles and atria and was altered in disease. The C-terminus of decorin, important for the interaction with connective tissue growth factor, was detected predominantly in ventricles in comparison with atria. In contrast, atrial appendages from patients in persistent atrial fibrillation had greater levels of full-length decorin but also harbored a cleavage site that was not found in atrial appendages from patients in sinus rhythm. This cleavage site preceded the N-terminal domain of decorin that controls muscle growth by altering the binding capacity for myostatin. Myostatin expression was decreased in atrial appendages of patients with persistent atrial fibrillation and hearts of decorin null mice. A synthetic peptide corresponding to this decorin region dose-dependently inhibited the response to myostatin in cardiomyocytes and in perfused mouse hearts. This proteomics study is the first to analyze the human cardiac ECM. Novel processed forms of decorin protein core, uncovered in human atrial appendages, can regulate the local bioavailability of antihypertrophic and profibrotic growth factors. © 2016 American Heart Association, Inc.

Sustained periodic terrestrial locomotion in air-breathing fishes.

PubMed

Pace, C M; Gibb, A C

2014-03-01

While emergent behaviours have long been reported for air-breathing osteichthyians, only recently have researchers undertaken quantitative analyses of terrestrial locomotion. This review summarizes studies of sustained periodic terrestrial movements by air-breathing fishes and quantifies the contributions of the paired appendages and the axial body to forward propulsion. Elongate fishes with axial-based locomotion, e.g. the ropefish Erpetoichthys calabaricus, generate an anterior-to-posterior wave of undulation that travels down the axial musculoskeletal system and pushes the body against the substratum at multiple points. In contrast, appendage-based locomotors, e.g. the barred mudskipper Periophthalmus argentilineatus, produce no axial bending during sustained locomotion, but instead use repeated protraction-retraction cycles of the pectoral fins to elevate the centre of mass and propel the entire body anteriorly. Fishes that use an axial-appendage-based mechanism, e.g. walking catfishes Clarias spp., produce side-to-side, whole-body bending in co-ordination with protraction-retraction cycles of the pectoral fins. Once the body is maximally bent to one side, the tail is pressed against the substratum and drawn back through the mid-sagittal plane, which elevates the centre of mass and rotates it about a fulcrum formed by the pectoral fin and the ground. Although appendage-based terrestrial locomotion appears to be rare in osteichthyians, many different species appear to have converged upon functionally similar axial-based and axial-appendage-based movements. Based on common forms observed across divergent taxa, it appears that dorsoventral compression of the body, elongation of the axial skeleton or the presence of robust pectoral fins can facilitate effective terrestrial movement by air-breathing fishes. © 2014 The Fisheries Society of the British Isles.

Mechanical Properties of Primary Cilia

NASA Astrophysics Data System (ADS)

Battle, Christopher; Schmidt, Christoph F.

2013-03-01

Recent studies have shown that the primary cilium, long thought to be a vestigial cellular appendage with no function, is involved in a multitude of sensory functions. One example, interesting from both a biophysical and medical standpoint, is the primary cilium of kidney epithelial cells, which acts as a mechanosensitive flow sensor. Genetic defects in ciliary function can cause, e.g., polycystic kidney disease (PKD). The material properties of these non-motile, microtubule-based 9 +0 cilia, and the way they are anchored to the cell cytoskeleton, are important to know if one wants to understand the mechano-electrochemical response of these cells, which is mediated by their cilia. We have probed the mechanical properties, boundary conditions, and dynamics of the cilia of MDCK cells using optical traps and DIC/fluorescence microscopy. We found evidence for both elastic relaxation of the cilia themselves after bending and for compliance in the intracellular anchoring structures. Angular and positional fluctuations of the cilia reflect both thermal excitations and cellular driving forces.

STS-74/MIR Photogrammetric Appendage Structural Dynamics Experiment Preliminary Data Analysis

NASA Technical Reports Server (NTRS)

Gilbert, Michael G.; Welch, Sharon S.; Pappa, Richard S.; Demeo, Martha E.

1997-01-01

The Photogrammetric Appendage Structural Dynamics Experiment was designed, developed, and flown to demonstrate and prove measurement of the structural vibration response of a Russian Space Station Mir solar array using photogrammetric methods. The experiment flew on the STS-74 Space Shuttle mission to Mir in November 1995 and obtained video imagery of solar array structural response to various excitation events. The video imagery has been digitized and triangulated to obtain response time history data at discrete points on the solar array. This data has been further processed using the Eigensystem Realization Algorithm modal identification technique to determine the natural vibration frequencies, damping, and mode shapes of the solar array. The results demonstrate that photogrammetric measurement of articulating, nonoptically targeted, flexible solar arrays and appendages is a viable, low-cost measurement option for the International Space Station.

High precision active nutation control for a flexible momentum biased spacecraft

NASA Technical Reports Server (NTRS)

Laskin, R. A.; Kopf, E. H.

1984-01-01

The controller design for the Solar Dynamics Observatory (SDO) is presented. SDO is a momentum biased spacecraft with three flexible appendages. Its primary scientific instrument, the solar oscillations imager (SOI), is rigidly attached to the spacecraft bus and has arc-second pointing requirements. Meeting these requirements necessitates the use of an active nutation controller (ANC) which is here mechanized with a small reaction wheel oriented along a bus transverse axis. The ANC does its job by orchestrating the transfer of angular momentum out of the bus transverse axes and into the momentum wheel. A simulation study verifies that the controller provides quick, stable, and accurate response.

Percutaneous left atrial appendage closure vs warfarin for atrial fibrillation: a randomized clinical trial.

PubMed

Reddy, Vivek Y; Sievert, Horst; Halperin, Jonathan; Doshi, Shephal K; Buchbinder, Maurice; Neuzil, Petr; Huber, Kenneth; Whisenant, Brian; Kar, Saibal; Swarup, Vijay; Gordon, Nicole; Holmes, David

2014-11-19

While effective in preventing stroke in patients with atrial fibrillation (AF), warfarin is limited by a narrow therapeutic profile, a need for lifelong coagulation monitoring, and multiple drug and diet interactions. To determine whether a local strategy of mechanical left atrial appendage (LAA) closure was noninferior to warfarin. PROTECT AF was a multicenter, randomized (2:1), unblinded, Bayesian-designed study conducted at 59 hospitals of 707 patients with nonvalvular AF and at least 1 additional stroke risk factor (CHADS2 score ≥1). Enrollment occurred between February 2005 and June 2008 and included 4-year follow-up through October 2012. Noninferiority required a posterior probability greater than 97.5% and superiority a probability of 95% or greater; the noninferiority margin was a rate ratio of 2.0 comparing event rates between treatment groups. Left atrial appendage closure with the device (n = 463) or warfarin (n = 244; target international normalized ratio, 2-3). A composite efficacy end point including stroke, systemic embolism, and cardiovascular/unexplained death, analyzed by intention-to-treat. At a mean (SD) follow-up of 3.8 (1.7) years (2621 patient-years), there were 39 events among 463 patients (8.4%) in the device group for a primary event rate of 2.3 events per 100 patient-years, compared with 34 events among 244 patients (13.9%) for a primary event rate of 3.8 events per 100 patient-years with warfarin (rate ratio, 0.60; 95% credible interval, 0.41-1.05), meeting prespecified criteria for both noninferiority (posterior probability, >99.9%) and superiority (posterior probability, 96.0%). Patients in the device group demonstrated lower rates of both cardiovascular mortality (1.0 events per 100 patient-years for the device group [17/463 patients, 3.7%] vs 2.4 events per 100 patient-years with warfarin [22/244 patients, 9.0%]; hazard ratio [HR], 0.40; 95% CI, 0.21-0.75; P = .005) and all-cause mortality (3.2 events per 100 patient-years for the device group [57/466 patients, 12.3%] vs 4.8 events per 100 patient-years with warfarin [44/244 patients, 18.0%]; HR, 0.66; 95% CI, 0.45-0.98; P = .04). After 3.8 years of follow-up among patients with nonvalvular AF at elevated risk for stroke, percutaneous LAA closure met criteria for both noninferiority and superiority, compared with warfarin, for preventing the combined outcome of stroke, systemic embolism, and cardiovascular death, as well as superiority for cardiovascular and all-cause mortality. clinicaltrials.gov Identifier: NCT00129545.

Epibulbar lipodermoids, preauricular appendages and polythelia in four generations: a new hereditary syndrome?

PubMed

Goldschmidt, Ernst; Jacobsen, Nina

2010-06-01

A new syndrome with abnormalities along the first branchial arch and the milk list is described in a family of four affected generations. The characteristics of the syndrome are epibulbar lipodermoids, preauricular appendages and polythelia. The expressivity varies but all affected have supernumerary nipples and preauricular manifestations while visible epibulbar lipodermoids do not seem obligatory. The syndrome has a typical dominant pattern of heredity.

The Relationship between Appendage Geometry and Propeller Blade Unsteady Forces.

DTIC Science & Technology

1987-11-01

unsteady thrust and torque for a given propeller geometry. The results indicate that unsteady force reduction can be obtained by modification of the flow ... unsteady force calculation methods available are: 1) quasi-steady using uniform flow ; 2) quasi-steady using lifting-line theory; 3) two-dimensional... experimental data and the calculated unsteady forces that both the flow field near the body surface and behind the appendage tip must be

Surgical management of the left superior vena cava draining into the left atrium: a novel off-pump technique using the left atrial appendage

PubMed Central

Boutayeb, Alaae; Marmade, Lahcen; Bensouda, Adil; Moughil, Said

2012-01-01

The left superior vena cava is the most common congenital venous anomaly in the chest; however, its drainage into the left atrium is exceptional. The aim of the paper is to describe our novel technique to connect the left superior vena cava to the right cavities using the left atrial appendage, without cardiopulmonary bypass. PMID:22802356

Attitude dynamic of spin-stabilized satellites with flexible appendages

NASA Technical Reports Server (NTRS)

Renard, M. L.

1973-01-01

Equations of motion and computer programs have been developed for analyzing the motion of a spin-stabilized spacecraft having long, flexible appendages. Stability charts were derived, or can be redrawn with the desired accuracy for any particular set of design parameters. Simulation graphs of variables of interest are readily obtainable on line using program FLEXAT. Finally, applications to actual satellites, such as UK-4 and IMP-1 have been considered.

Role of cardiac imaging and three-dimensional printing in percutaneous appendage closure.

PubMed

Iriart, Xavier; Ciobotaru, Vlad; Martin, Claire; Cochet, Hubert; Jalal, Zakaria; Thambo, Jean-Benoit; Quessard, Astrid

2018-06-06

Atrial fibrillation is the most frequent cardiac arrhythmia, affecting up to 13% of people aged>80 years, and is responsible for 15-20% of all ischaemic strokes. Left atrial appendage occlusion devices have been developed as an alternative approach to reduce the risk of stroke in patients for whom oral anticoagulation is contraindicated. The procedure can be technically demanding, and obtaining a complete left atrial appendage occlusion can be challenging. These observations have emphasized the importance of preprocedural planning, to optimize the accuracy and safety of the procedure. In this setting, a multimodality imaging approach, including three-dimensional imaging, is often used for preoperative assessment and procedural guidance. These imaging modalities, including transoesophageal echocardiography and multislice computed tomography, allow acquisition of a three-dimensional dataset that improves understanding of the cardiac anatomy; dedicated postprocessing software integrated into the clinical workflow can be used to generate a stereolithography file, which can be printed in a rubber-like material, seeking to replicate the myocardial tissue characteristics and mechanical properties of the left atrial appendage wall. The role of multimodality imaging and 3D printing technology offers a new field for implantation simulation, which may have a major impact on physician training and technique optimization. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Centrosomal protein Dzip1l binds Cby, promotes ciliary bud formation, and acts redundantly with Bromi to regulate ciliogenesis in the mouse.

PubMed

Wang, Chengbing; Li, Jia; Takemaru, Ken-Ichi; Jiang, Xiaogang; Xu, Guoqiang; Wang, Baolin

2018-03-15

The primary cilium is a microtubule-based organelle required for Hedgehog (Hh) signaling and consists of a basal body, a ciliary axoneme and a compartment between the first two structures, called the transition zone (TZ). The TZ serves as a gatekeeper to control protein composition in cilia, but less is known about its role in ciliary bud formation. Here, we show that centrosomal protein Dzip1l is required for Hh signaling between Smoothened and Sufu. Dzip1l colocalizes with basal body appendage proteins and Rpgrip1l, a TZ protein. Loss of Dzip1l results in reduced ciliogenesis and dysmorphic cilia in vivo Dzip1l interacts with, and acts upstream of, Cby, an appendage protein, in ciliogenesis. Dzip1l also has overlapping functions with Bromi (Tbc1d32) in ciliogenesis, cilia morphogenesis and neural tube patterning. Loss of Dzip1l arrests ciliogenesis at the stage of ciliary bud formation from the TZ. Consistent with this, Dzip1l mutant cells fail to remove the capping protein Cp110 (Ccp110) from the distal end of mother centrioles and to recruit Rpgrip1l to the TZ. Therefore, Dzip1l promotes ciliary bud formation and is required for the integrity of the TZ. © 2018. Published by The Company of Biologists Ltd.

Live 3D TEE demonstrates and guides the management of prosthetic mitral valve obstruction.

PubMed

Chahal, Mangeet; Pandya, Utpal; Adlakha, Satjit; Khouri, Samer J

2011-08-01

A 43-year-old woman, with a remote history of rheumatic mitral stenosis and a St. Jude prosthetic mitral valve replacement, presented with shortness of breath and palpitations, shortly after a long flight. On admission, atrial fibrillation with a rapid ventricular response was noted in the setting of a long history of noncompliance with her anticoagulation. Transesophageal echocardiography (TEE) demonstrated multiple laminated thrombi in the left atrial appendage. Live three-dimensional (3D) TEE confirmed this diagnosis and demonstrated an immobile posterior leaflet of the mitral prosthesis, which had direct implications in her management. She successfully underwent surgery for mitral valve replacement, left atrial appendage ligation, and a Maze procedure on the following day. The multiple thrombi within the atrial appendage were confirmed intraoperatively and pannus formation was determined to be the etiology of the leaflet immobility. © 2011, Wiley Periodicals, Inc.

Levers and linkages: mechanical trade-offs in a power-amplified system.

PubMed

Anderson, Philip S L; Claverie, Thomas; Patek, S N

2014-07-01

Mechanical redundancy within a biomechanical system (e.g., many-to-one mapping) allows morphologically divergent organisms to maintain equivalent mechanical outputs. However, most organisms depend on the integration of more than one biomechanical system. Here, we test whether coupled mechanical systems follow a pattern of amplification (mechanical changes are congruent and evolve toward the same functional extreme) or independence (mechanisms evolve independently). We examined the correlated evolution and evolutionary pathways of the coupled four-bar linkage and lever systems in mantis shrimp (Stomatopoda) ultrafast raptorial appendages. We examined models of character evolution in the framework of two divergent groups of stomatopods-"smashers" (hammer-shaped appendages) and "spearers" (bladed appendages). Smashers tended to evolve toward force amplification, whereas spearers evolved toward displacement amplification. These findings show that coupled biomechanical systems can evolve synergistically, thereby resulting in functional amplification rather than mechanical redundancy. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

A cellular, molecular, and pharmacological basis for appendage regeneration in mice

PubMed Central

Leung, Thomas H.; Snyder, Emily R.; Liu, Yinghua; Wang, Jing; Kim, Seung K.

2015-01-01

Regenerative medicine aims to restore normal tissue architecture and function. However, the basis of tissue regeneration in mammalian solid organs remains undefined. Remarkably, mice lacking p21 fully regenerate injured ears without discernable scarring. Here we show that, in wild-type mice following tissue injury, stromal-derived factor-1 (Sdf1) is up-regulated in the wound epidermis and recruits Cxcr4-expressing leukocytes to the injury site. In p21-deficient mice, Sdf1 up-regulation and the subsequent recruitment of Cxcr4-expressing leukocytes are significantly diminished, thereby permitting scarless appendage regeneration. Lineage tracing demonstrates that this regeneration derives from fate-restricted progenitor cells. Pharmacological or genetic disruption of Sdf1–Cxcr4 signaling enhances tissue repair, including full reconstitution of tissue architecture and all cell types. Our findings identify signaling and cellular mechanisms underlying appendage regeneration in mice and suggest new therapeutic approaches for regenerative medicine. PMID:26494786

[The computed tomographic semiotics of inflammatory diseases of the adnexa uteri].

PubMed

Todua, F I; Karmazanovskiĭ, G G; Podzolkova, N M

1990-01-01

The authors sum up the results of CT and clinical investigation of 46 women with inflammatory diseases of the uterine appendages: salpingo-oophoritis, pyosalpinx, pyoovarium, and 2 types of tuboovarian abscesses. They have shown CT potentialities in differential diagnosis of inflammations of the uterine appendages with cysts and true ovarian tumors on the basis of routine investigation and an iv contrast study of intensified images. Retrospective analysis of the most typical diagnostic errors is given.

Incremental value of live/real time three-dimensional transesophageal echocardiography over the two-dimensional technique in the assessment of a tuberculoma involving the left atrium and appendage.

PubMed

Kemaloğlu Öz, Tuğba; Elsayed, Mahmoud; Nanda, Navin C; Kalenderoğlu, Koray; Akyüz, Şükrü; Atasoy, Işıl; Ösken, Altuğ; Onuk, Tolga; Eren, Mehmet

2016-09-01

Intracardiac tuberculomas are extremely rare, and cardiac involvement in tuberculosis accounts for only 0.5% of extrapulmonary tuberculosis. We report for the first time incremental value of live/real time three-dimensional transesophageal echocardiography over two-dimensional transesophageal echocardiography in the assessment of a tuberculoma involving the left atrium and left atrial appendage. © 2016, Wiley Periodicals, Inc.

Phylogenetic relationships of Echinolaena and Ichnanthus within Panicoideae (Poaceae) reveal two new genera of tropical grasses.

PubMed

Silva, Christian; Snak, Cristiane; Schnadelbach, Alessandra Selbach; van den Berg, Cássio; Oliveira, Reyjane Patrícia

2015-12-01

Echinolaena and Ichnanthus are two tropical grass genera distributed mostly in the Americas, characterized by the presence of rachilla appendages in the shape of convex swellings, scars or wings at the base of the upper anthecium. However, recent studies have shown that rachilla appendages arose several times independently in several groups within Paniceae and Paspaleae (Panicoideae). Thus, this study aimed to assess the monophyly of Echinolaena and Ichnanthus and their relationship to other genera of Paniceae and Paspaleae, especially those including species with rachilla appendages. Parsimony and Bayesian analyses of the cpDNA regions ndhF, rpl16, trnH-(rps19)-psbA, trnL-trnF, trnS-(psbZ)-trnG, and the rDNA ITS region included 29 of the 39 known species of Echinolaena and Ichnanthus, 23 of which were sampled for the first time. The multiple loci analyses indicated that Echinolaena and Ichnanthus are polyphyletic in their current circumscriptions, with species in four distinct lineages within subtribe Paspalinae, each one characterized by a single type of rachilla appendage. Thus, Echinolaena and Ichnanthus are each circumscribed in a narrow sense, and the other two lineages excluded from them are proposed as the new genera Hildaea and Oedochloa, resulting in 15 new combinations and the restablishment of I. oplismenoides Munro ex Döll. Copyright © 2015 Elsevier Inc. All rights reserved.

Muscle precursor cells in the developing limbs of two isopods (Crustacea, Peracarida): an immunohistochemical study using a novel monoclonal antibody against myosin heavy chain

PubMed Central

Kreissl, S.; Uber, A.

2008-01-01

In the hot debate on arthropod relationships, Crustaceans and the morphology of their appendages play a pivotal role. To gain new insights into how arthropod appendages evolved, developmental biologists recently have begun to examine the expression and function of Drosophila appendage genes in Crustaceans. However, cellular aspects of Crustacean limb development such as myogenesis are poorly understood in Crustaceans so that the interpretative context in which to analyse gene functions is still fragmentary. The goal of the present project was to analyse muscle development in Crustacean appendages, and to that end, monoclonal antibodies against arthropod muscle proteins were generated. One of these antibodies recognises certain isoforms of myosin heavy chain and strongly binds to muscle precursor cells in malacostracan Crustacea. We used this antibody to study myogenesis in two isopods, Porcellio scaber and Idotea balthica (Crustacea, Malacostraca, Peracarida), by immunohistochemistry. In these animals, muscles in the limbs originate from single muscle precursor cells, which subsequently grow to form multinucleated muscle precursors. The pattern of primordial muscles in the thoracic limbs was mapped, and results compared to muscle development in other Crustaceans and in insects. Electronic supplementary material The online version of this article (doi:10.1007/s00427-008-0216-1) contains supplementary material, which is available to authorized users. PMID:18443823

The Relationship between Diaspore Characteristics with Phylogeny, Life History Traits, and Their Ecological Adaptation of 150 Species from the Cold Desert of Northwest China

PubMed Central

Liu, Hui-Liang; Zhang, Dao-Yuan; Duan, Shi-Min; Wang, Xi-Yong; Song, Ming-Fang

2014-01-01

Diaspore characteristics of 22 families, including 102 genera and 150 species (55 represented by seeds and 95 by fruits) from the Gurbantunggut Desert were analyzed for diaspore biological characteristics (mass, shape, color, and appendage type). The diaspore mass and shape were significantly different in phylogeny group (APG) and dispersal syndromes; vegetative periods significantly affected diaspore mass, but not diaspore shape; and ecotypes did not significantly affect diaspore mass and shape, but xerophyte species had larger diaspore mass than mesophyte species. Unique stepwise ANOVA results showed that variance in diaspore mass and shape among these 150 species was largely dependent upon phylogeny and dispersal syndromes. Therefore, it was suggested that phylogeny may constrain diaspore mass, and as dispersal syndromes may be related to phylogeny, they also constrained diaspore mass and shape. Diaspores of 85 species (56.67%) had appendages, including 26 with wings/bracts, 18 with pappus/hair, 14 with hooks/spines, 10 with awns, and 17 with other types of appendages. Different traits (mass, shape, color, appendage, and dispersal syndromes) of diaspore decided plants forming different adapted strategies in the desert. In summary, the diaspore characteristics were closely related with phylogeny, vegetative periods, dispersal syndromes, and ecotype, and these characteristics allowed the plants to adapt to extreme desert environments. PMID:24605054

Abnormal primary and permanent dentitions with ectodermal symptoms predict WNT10A deficiency.

PubMed

Bergendal, Birgitta; Norderyd, Johanna; Zhou, Xiaolei; Klar, Joakim; Dahl, Niklas

2016-11-24

The WNT10A protein is critical for the development of ectodermal appendages. Variants in the WNT10A gene may be associated with a spectrum of ectodermal abnormalities including extensive tooth agenesis. In seven patients with severe tooth agenesis we identified anomalies in primary dentition and additional ectodermal symptoms, and assessed WNT10A mutations by genetic analysis. Investigation of primary dentition revealed peg-shaped crowns of primary mandibular incisors and three individuals had agenesis of at least two primary teeth. The permanent dentition was severely affected in all individuals with a mean of 21 missing teeth. Primary teeth were most often present in positions were succedaneous teeth were missing. Furthermore, most existing molars had taurodontism. Light, brittle or coarse hair was reported in all seven individuals, hyperhidrosis of palms and soles in six individuals and nail anomalies in two individuals. The anomalies in primary dentition preceded most of the additional ectodermal symptoms. Genetic analysis revealed that all seven individuals were homozygous or compound heterozygous for WNT10A mutations resulting in C107X, E222X and F228I. We conclude that tooth agenesis and/or peg-shaped crowns of primary mandibular incisors, severe oligodontia of permanent dentition as well as ectodermal symptoms of varying severity may be predictors of bi-allelic WNT10A mutations of importance for diagnosis, counselling and follow-up.

Left cardiac isomerism in the Sonic hedgehog null mouse.

PubMed

Hildreth, Victoria; Webb, Sandra; Chaudhry, Bill; Peat, Jonathan D; Phillips, Helen M; Brown, Nigel; Anderson, Robert H; Henderson, Deborah J

2009-06-01

Sonic hedgehog (Shh) is a secreted morphogen necessary for the production of sidedness in the developing embryo. In this study, we describe the morphology of the atrial chambers and atrioventricular junctions of the Shh null mouse heart. We demonstrate that the essential phenotypic feature is isomerism of the left atrial appendages, in combination with an atrioventricular septal defect and a common atrioventricular junction. These malformations are known to be frequent in humans with left isomerism. To confirm the presence of left isomerism, we show that Pitx2c, a recognized determinant of morphological leftness, is expressed in the Shh null mutants on both the right and left sides of the inflow region, and on both sides of the solitary arterial trunk exiting from the heart. It has been established that derivatives of the second heart field expressing Isl1 are asymmetrically distributed in the developing normal heart. We now show that this population is reduced in the hearts from the Shh null mutants, likely contributing to the defects. To distinguish the consequences of reduced contributions from the second heart field from those of left-right patterning disturbance, we disrupted the movement of second heart field cells into the heart by expressing dominant-negative Rho kinase in the population of cells expressing Isl1. This resulted in absence of the vestibular spine, and presence of atrioventricular septal defects closely resembling those seen in the hearts from the Shh null mutants. The primary atrial septum, however, was well formed, and there was no evidence of isomerism of the atrial appendages, suggesting that these features do not relate to disruption of the contributions made by the second heart field. We demonstrate, therefore, that the Shh null mouse is a model of isomerism of the left atrial appendages, and show that the recognized associated malformations found at the venous pole of the heart in the setting of left isomerism are likely to arise from the loss of the effects of Shh in the establishment of laterality, combined with a reduced contribution made by cells derived from the second heart field.

Sweat Gland Progenitors in Development, Homeostasis, and Wound Repair

PubMed Central

Lu, Catherine; Fuchs, Elaine

2014-01-01

The human body is covered with several million sweat glands. These tiny coiled tubular skin appendages produce the sweat that is our primary source of cooling and hydration of the skin. Numerous studies have been published on their morphology and physiology. Until recently, however, little was known about how glandular skin maintains homeostasis and repairs itself after tissue injury. Here, we provide a brief overview of sweat gland biology, including newly identified reservoirs of stem cells in glandular skin and their activation in response to different types of injuries. Finally, we discuss how the genetics and biology of glandular skin has advanced our knowledge of human disorders associated with altered sweat gland activity. PMID:24492848

Book gill development in embryos and first and second instars of the horseshoe crab Limulus polyphemus L. (Chelicerata, Xiphosura).

PubMed

Farley, Roger D

2010-09-01

The scanning electron microscope (SEM) was used to study the development of the opisthosomal appendages and book gills of the horseshoe crab, Limulus polyphemus. Later embryonic stages were examined as well as the first and second instars. The observations are compared with a much earlier light microscopic description of book gill development in the horseshoe crab and with book lung development in scorpion embryos and first and second instars in a recent study with SEM. After the third embryonic molt in the horseshoe crab, the opisthosomal appendages are of sufficient size so they could be fractured or dissected open so internal cells and other structures could be examined. The opisthosomal appendages and book gill lamellae of first and second instars were also opened. The observations support the earlier histological report that the gill lamellae are a hypodermal outgrowth from the posterior surface of the preceding branchial appendages. The genital operculum, branchial appendages and gill lamellae are very thin and consist of external cuticle, hypodermis and space holders. The latter help hold the cuticle walls in place so hemolymph can flow through the narrow channels. The space holders are formed from cell processes that extend into the lumen from the hypodermis just inside the external cuticle. In the recent SEM study in scorpion embryos and in some histological investigations in spider embryos, the book lung lamellae are formed by alignment of cells from an invaginated sac or mass of cells. This clearly differs from the mode of formation of gill lamellae as observed in this and earlier investigations. These reports of differences in embryology refine but do not preclude hypotheses about book gill/book lung homology since addition, deletion or modification of ancestral features often occur for the benefit of the embryos and larvae. Copyright © 2010 Elsevier Ltd. All rights reserved.

Pathophysiologic correlates of thromboembolism in nonvalvular atrial fibrillation: I. Reduced flow velocity in the left atrial appendage (The Stroke Prevention in Atrial Fibrillation [SPAF-III] study).

PubMed

Goldman, M E; Pearce, L A; Hart, R G; Zabalgoitia, M; Asinger, R W; Safford, R; Halperin, J L

1999-12-01

Stroke associated with atrial fibrillation (AF) is mainly due to embolism of thrombus formed during stasis of blood in the left atrial appendage (LAA). Pathophysiologic correlates of appendage flow velocity as assessed by transesophageal echocardiography (TEE) in patients with AF have not been defined. To evaluate the hypothesis that reduced velocity is associated with spontaneous echocardiographic contrast and thrombus in the LAA and with clinical embolic events, we measured LAA flow velocity by TEE in 721 patients with nonvalvular AF entering the Stroke Prevention in Atrial Fibrillation (SPAF-III) study. Patient features, TEE findings, and subsequent cardioembolic events were correlated with velocity by multivariate analysis. Patients in AF during TEE displayed lower peak antegrade (emptying) flow velocity (Anu(p)) than those with intermittent AF in sinus rhythm during TEE (33 cm/s vs 61 cm/s, respectively, P <.0001). Anu(p) < 20 cm/s was associated with dense spontaneous echocardiographic contrast (P <.001), appendage thrombus (P <.01), and subsequent cardioembolic events (P <.01). Independent predictors of Anu(p) < 20 cm/s included age (P =.009), systolic blood pressure (P <.001), sustained AF (P =.01), ischemic heart disease (P =.01), and left atrial area (P =.04). Multivariate analysis found both Anu(p) <20 cm/s (relative risk 2.6, P =.02) and clinical risk factors (relative risk 3.3, P =.002) independently associated with LAA thrombus. LAA Anu(p) is reduced in AF and associated with spontaneous echocardiographic contrast, appendage thrombus, and cardioembolic stroke. Systolic hypertension and aortic atherosclerosis, independent clinical predictors of stroke in patients with AF, also correlated with LAA Anu(p). Our results support the role of reduced LAA Anu(p) in the generation of stasis, thrombus formation, and embolism in patients with AF, although other mechanisms also contribute to stroke.

Embryonic development of Carabus insulicola (Insecta, Coleoptera, Carabidae) with special reference to external morphology and tangible evidence for the subcoxal theory.

PubMed

Kobayashi, Yukimasa; Niikura, Kazuhiro; Oosawa, Yuuki; Takami, Yasuoki

2013-12-01

The egg morphology and successive changes in the developing embryos of the carabid ground beetle Carabus insulicola (Carabidae) are described based on light and scanning electron microscopy observations. Newly laid eggs of this species are ellipsoid and measure approximately 6.1 × 2.9 mm, before increasing to 6.6 × 3.4 mm at hatching. The egg period is about 11 days at 23°C. The egg shell is characterized by a thin fragile chorion covering a hard serosal cuticle. The embryo forms on the ventral egg surface, where it develops for the duration of the egg period. During the process of thoracic leg formation, two subcoxal rings, subcoxae-1 and 2, are clearly discernible at the basalmost region of the leg rudiments, and these subcoxae participate in the formation of the larval pleura and sterna. The result thus provides tangible evidence for the subcoxal theory, that is, that thoracic pleura and sterna are derived from subcoxal regions. Despite the complete absence of abdominal appendages in the larvae of this species, two pairs of appendage-like swellings, the medial and lateral ones, temporarily arise in the first eight abdominal segments during the middle of embryonic development. The medial swellings are assumed to be serially homologous with the coxal part of the thoracic leg, and they later flatten out and participate in the formation of the larval pleura (hypopleurites). In the light of the serially homologous relationships among gnathal appendages, thoracic legs, and abdominal appendage-like swellings, we identified the subcoxal regions in both the gnathal and abdominal segments. Although, the lateral swellings soon degenerate and disappear, it is considered that the swellings originate in the abdominal subcoxae-2 and may be homologous to the tracheal gills of larvae of Gyrinidae. Based on the embryological results, new interpretations for the constituent of gnathal appendages are proposed. Copyright © 2013 Wiley Periodicals, Inc.

Heart Transplant in Patient With Isolated Left Superior Vena Cava by Atrial Appendage Rotation.

PubMed

Reyes, Karl M; Gupta, Dipankar; Fricker, Frederick Jay; Cooke, Susan; Bleiweis, Mark S

2018-06-01

Orthotopic heart transplantation in patients with an isolated persistent left superior vena cava is extremely rare, and the anastomotic connection between a right-sided donor superior vena cava and left-sided recipient superior vena cava can be challenging to perform. We present a novel technique used in an infant female, using the left atrial appendage to extend the superior vena cava anastomosis. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Computation of the Hydrodynamic Forces and Moments on a Body of Revolution with and without Appendages

DTIC Science & Technology

1991-08-01

SUPPLEMENTARY NOTATION 1 COSA. CODES 18 SUBJECT TERMS (,ontnuo 0 ner of necessary Atdi, block n" mbr ) FIELD GROUP SUB.GROUP Submarine ’hyoroaynamic ’~ aDS...hydrodynamic forces and moments developed on the hull and appendages of a submerged vehicle is required for determining its stability, control, and...an approximate method has been developed to compute the hydrodynamic forces and moments for a submerged vehicle. As discussed in Reference 1, the

Ndel1 suppresses ciliogenesis in proliferating cells by regulating the trichoplein-Aurora A pathway.

PubMed

Inaba, Hironori; Goto, Hidemasa; Kasahara, Kousuke; Kumamoto, Kanako; Yonemura, Shigenobu; Inoko, Akihito; Yamano, Shotaro; Wanibuchi, Hideki; He, Dongwei; Goshima, Naoki; Kiyono, Tohru; Hirotsune, Shinji; Inagaki, Masaki

2016-02-15

Primary cilia protrude from the surface of quiescent cells and disassemble at cell cycle reentry. We previously showed that ciliary reassembly is suppressed by trichoplein-mediated Aurora A activation pathway in growing cells. Here, we report that Ndel1, a well-known modulator of dynein activity, localizes at the subdistal appendage of the mother centriole, which nucleates a primary cilium. In the presence of serum, Ndel1 depletion reduces trichoplein at the mother centriole and induces unscheduled primary cilia formation, which is reverted by forced trichoplein expression or coknockdown of KCTD17 (an E3 ligase component protein for trichoplein). Serum starvation induced transient Ndel1 degradation, subsequent to the disappearance of trichoplein at the mother centriole. Forced expression of Ndel1 suppressed trichoplein degradation and axonemal microtubule extension during ciliogenesis, similar to trichoplein induction or KCTD17 knockdown. Most importantly, the proportion of ciliated and quiescent cells was increased in the kidney tubular epithelia of newborn Ndel1-hypomorphic mice. Thus, Ndel1 acts as a novel upstream regulator of the trichoplein-Aurora A pathway to inhibit primary cilia assembly. © 2016 Inaba et al.

Textured fluorapatite bonded to calcium sulphate strengthen stomatopod raptorial appendages.

PubMed

Amini, Shahrouz; Masic, Admir; Bertinetti, Luca; Teguh, Jefri Sanusi; Herrin, Jason S; Zhu, Xi; Su, Haibin; Miserez, Ali

2014-01-01

Stomatopods are shallow-water crustaceans that employ powerful dactyl appendages to hunt their prey. Deployed at high velocities, these hammer-like clubs or spear-like devices are able to inflict substantial impact forces. Here we demonstrate that dactyl impact surfaces consist of a finely-tuned mineral gradient, with fluorapatite substituting amorphous apatite towards the outer surface. Raman spectroscopy measurements show that calcium sulphate, previously not reported in mechanically active biotools, is co-localized with fluorapatite. Ab initio computations suggest that fluorapatite/calcium sulphate interfaces provide binding stability and promote the disordered-to-ordered transition of fluorapatite. Nanomechanical measurements show that fluorapatite crystalline orientation correlates with an anisotropic stiffness response and indicate significant differences in the fracture tolerance between the two types of appendages. Our findings shed new light on the crystallochemical and microstructural strategies allowing these intriguing biotools to optimize impact forces, providing physicochemical information that could be translated towards the synthesis of impact-resistant functional materials and coatings.

Dichloro-tetrafluoro-ethane as a Freezing Agent

PubMed Central

Luikart, Ralph; Ayres, Samuel; Wilson, J. Walter

1956-01-01

Surgical skin planing is, in the hands of an experienced operator, a safe and highly effective procedure for treating a number of cutaneous defects, most notably pitted acne scars. The operation is facilitated by the use of a new instrument (jet-spray handpiece) which allows the operator to freeze the skin and plane it almost simultaneously, and by a new freezing agent, dichlorotetrafluoro-ethane, which adds to the safety by eliminating the old hazards of inflammability, explosion, and the toxic inhalation of ethyl chloride. The ability to sharply differentiate between keloid and hypertrophic scar is fundamental to surgical skin planing. A hypertrophic scar results from the removal or destruction of the cutaneous appendages (hair follicles, oil and sweat glands and ducts); whereas a keloid is an idiosyncratic response without regard to damage of the appendages. Properly performed surgical planing does not entirely remove these appendages and therefore healing occurs without scarring. ImagesFigure 1.Figure 2.Figure 3.Figure 4. PMID:13304667

Effects of environmental factors and appendage injury on the wing variation in the cricket Velarifictorus ornatus

PubMed Central

Zhao, Lü-Quan; Zhu, Dao-Hong

2014-01-01

Abstract The effects of environmental factors and appendage injury on the wing variation in Velarifictorus ornatus (Shiraki) (Orthoptera: Gryllidae) were investigated. The percentage of micropters was more than 95% when the nymphs were reared at constant photoperiods, and changing photoperiod did not affect wing variation in V. ornatus at 25 or 30°C. In the crowding experiment, the percentage of macropters was only 11.2% when the nymphs were reared separately at 25°C. In contrast, the percentage of macropters was significantly higher when the rearing density was increased to two nymphs per container and lower when the rearing density was increased to five or 10 nymphs per container. These results indicate that low and high rearing densities induce micropters, but intermediate rearing density stimulates the formation of macropters. Meanwhile, severance of appendages, such as antennae, femora, and tibiae, in the nymph stage exerted a micropterizing effect. The period sensitive to such stresses ranged from 35 to 60 days of nymph development. PMID:25368061

Modal identities for multibody elastic spacecraft: An aid to selecting modes for simulation

NASA Technical Reports Server (NTRS)

Hablani, Hari B.

1989-01-01

The question: Which set of modes furnishes a higher fidelity math model of dynamics of a multibody, deformable spacecraft (hinges-free or hinges-locked vehicle modes) is answered. Two sets of general, discretized, linear equations of motion of a spacecraft with an arbitrary number of deformable appendages, each articulated directly to the core body, are obtained using the above two families of modes. By a comparison of these equations, ten sets of modal identities are constructed which involve modal momenta coefficients and frequencies associated with both classes of modes. The sums of infinite series that appear in the identities are obtained in terms of mass, and first and second moments of inertia of the appendages, core body, and vehicle by using certain basic identities concerning appendage modes. Applying the above identities to a four-body spacecraft, the hinges-locked vehicle modes are found to yield a higher fidelity model than hinges-free modes, because the latter modes have nonconverging modal coefficients; a characteristic proved and illustrated.

A cellular, molecular, and pharmacological basis for appendage regeneration in mice.

PubMed

Leung, Thomas H; Snyder, Emily R; Liu, Yinghua; Wang, Jing; Kim, Seung K

2015-10-15

Regenerative medicine aims to restore normal tissue architecture and function. However, the basis of tissue regeneration in mammalian solid organs remains undefined. Remarkably, mice lacking p21 fully regenerate injured ears without discernable scarring. Here we show that, in wild-type mice following tissue injury, stromal-derived factor-1 (Sdf1) is up-regulated in the wound epidermis and recruits Cxcr4-expressing leukocytes to the injury site. In p21-deficient mice, Sdf1 up-regulation and the subsequent recruitment of Cxcr4-expressing leukocytes are significantly diminished, thereby permitting scarless appendage regeneration. Lineage tracing demonstrates that this regeneration derives from fate-restricted progenitor cells. Pharmacological or genetic disruption of Sdf1-Cxcr4 signaling enhances tissue repair, including full reconstitution of tissue architecture and all cell types. Our findings identify signaling and cellular mechanisms underlying appendage regeneration in mice and suggest new therapeutic approaches for regenerative medicine. © 2015 Leung et al.; Published by Cold Spring Harbor Laboratory Press.

Structural properties of the tubular appendage spinae from marine bacterium Roseobacter sp. strain YSCB

PubMed Central

Bernadac, A.; Wu, L.-F.; Santini, C.-L.; Vidaud, C.; Sturgis, J. N.; Menguy, N.; Bergam, P.; Nicoletti, C.; Xiao, T.

2012-01-01

Spinae are tubular surface appendages broadly found in Gram-negative bacteria. Little is known about their architecture, function or origin. Here, we report structural characterization of the spinae from marine bacteria Roseobacter sp. YSCB. Electron cryo-tomography revealed that a single filament winds into a hollow flared base with progressive change to a cylinder. Proteinase K unwound the spinae into proteolysis-resistant filaments. Thermal treatment ripped the spinae into ribbons that were melted with prolonged heating. Circular dichroism spectroscopy revealed a dominant beta-structure of the spinae. Differential scanning calorimetry analyses showed three endothermic transformations at 50–85°C, 98°C and 123°C, respectively. The heating almost completely disintegrated the spinae, abolished the 98°C transition and destroyed the beta-structure. Infrared spectroscopy identified the amide I spectrum maximum at a position similar to that of amyloid fibrils. Therefore, the spinae distinguish from other bacterial appendages, e.g. flagella and stalks, in both the structure and mechanism of assembly. PMID:23230515

Congenital left atrial appendage aneurysm

PubMed Central

Wang, Bin; Li, He; Zhang, Li; He, Lin; Zhang, Jing; Liu, Cong; Wang, Jing; Lv, Qing; Shang, Xiaoke; Liu, Jinping; Xie, Mingxing

2018-01-01

Abstract Rationale: Left atrial appendage aneurysms (LAAA) are rare. Patients with LAAA are often diagnosed incidentally or after cardiac tachyarrhythmia or systemic thromboembolism happen. Early diagnosis and surgical resection is of utmost importance to prevent hazardous adverse events. Patient concerns: We present a case of 46-year-old man with congenital LAAA. The individual in this manuscript has given written informed consent to publish these case details. Diagnoses: Imaging studies, such as echocardiography, cardiovascular computed tomography (CT) and magnetic resonance imaging (MRI), demonstrated the large cavity arising from the left atrial appendage. The diagnosis of LAAA was confirmed. Interventions: The patient underwent an aneurysmectomy without any complications. Outcomes: TTE confirmed the disappearance of the LAAA from the left parasternal short-axis view of the aortic root postoperatively. The patient remained asymptomatic without any adverse events at his 3-month follow-up visits. Lessons: The associated high risk of life-threatening complications and the relative ease of surgical removal suggest that prompt evaluation should be considered in patients with lesions adjacent to the left heart border. PMID:29480827

Textured fluorapatite bonded to calcium sulphate strengthen stomatopod raptorial appendages

NASA Astrophysics Data System (ADS)

Amini, Shahrouz; Masic, Admir; Bertinetti, Luca; Teguh, Jefri Sanusi; Herrin, Jason S.; Zhu, Xi; Su, Haibin; Miserez, Ali

2014-01-01

Stomatopods are shallow-water crustaceans that employ powerful dactyl appendages to hunt their prey. Deployed at high velocities, these hammer-like clubs or spear-like devices are able to inflict substantial impact forces. Here we demonstrate that dactyl impact surfaces consist of a finely-tuned mineral gradient, with fluorapatite substituting amorphous apatite towards the outer surface. Raman spectroscopy measurements show that calcium sulphate, previously not reported in mechanically active biotools, is co-localized with fluorapatite. Ab initio computations suggest that fluorapatite/calcium sulphate interfaces provide binding stability and promote the disordered-to-ordered transition of fluorapatite. Nanomechanical measurements show that fluorapatite crystalline orientation correlates with an anisotropic stiffness response and indicate significant differences in the fracture tolerance between the two types of appendages. Our findings shed new light on the crystallochemical and microstructural strategies allowing these intriguing biotools to optimize impact forces, providing physicochemical information that could be translated towards the synthesis of impact-resistant functional materials and coatings.

JAK/STAT controls organ size and fate specification by regulating morphogen production and signalling

PubMed Central

Recasens-Alvarez, Carles; Ferreira, Ana; Milán, Marco

2017-01-01

A stable pool of morphogen-producing cells is critical for the development of any organ or tissue. Here we present evidence that JAK/STAT signalling in the Drosophila wing promotes the cycling and survival of Hedgehog-producing cells, thereby allowing the stable localization of the nearby BMP/Dpp-organizing centre in the developing wing appendage. We identify the inhibitor of apoptosis dIAP1 and Cyclin A as two critical genes regulated by JAK/STAT and contributing to the growth of the Hedgehog-expressing cell population. We also unravel an early role of JAK/STAT in guaranteeing Wingless-mediated appendage specification, and a later one in restricting the Dpp-organizing activity to the appendage itself. These results unveil a fundamental role of the conserved JAK/STAT pathway in limb specification and growth by regulating morphogen production and signalling, and a function of pro-survival cues and mitogenic signals in the regulation of the pool of morphogen-producing cells in a developing organ. PMID:28045022

Characterization of a filamentous biofilm community established in a cellulose-fed microbial fuel cell.

PubMed

Ishii, Shun'ichi; Shimoyama, Takefumi; Hotta, Yasuaki; Watanabe, Kazuya

2008-01-10

Microbial fuel cells (MFCs) are devices that exploit microorganisms to generate electric power from organic matter. Despite the development of efficient MFC reactors, the microbiology of electricity generation remains to be sufficiently understood. A laboratory-scale two-chamber microbial fuel cell (MFC) was inoculated with rice paddy field soil and fed cellulose as the carbon and energy source. Electricity-generating microorganisms were enriched by subculturing biofilms that attached onto anode electrodes. An electric current of 0.2 mA was generated from the first enrichment culture, and ratios of the major metabolites (e.g., electric current, methane and acetate) became stable after the forth enrichment. In order to investigate the electrogenic microbial community in the anode biofilm, it was morphologically analyzed by electron microscopy, and community members were phylogenetically identified by 16S rRNA gene clone-library analyses. Electron microscopy revealed that filamentous cells and rod-shaped cells with prosthecae-like filamentous appendages were abundantly present in the biofilm. Filamentous cells and appendages were interconnected via thin filaments. The clone library analyses frequently detected phylotypes affiliated with Clostridiales, Chloroflexi, Rhizobiales and Methanobacterium. Fluorescence in-situ hybridization revealed that the Rhizobiales population represented rod-shaped cells with filamentous appendages and constituted over 30% of the total population. Bacteria affiliated with the Rhizobiales constituted the major population in the cellulose-fed MFC and exhibited unique morphology with filamentous appendages. They are considered to play important roles in the cellulose-degrading electrogenic community.

Characterization of a filamentous biofilm community established in a cellulose-fed microbial fuel cell

PubMed Central

Ishii, Shun'ichi; Shimoyama, Takefumi; Hotta, Yasuaki; Watanabe, Kazuya

2008-01-01

Background Microbial fuel cells (MFCs) are devices that exploit microorganisms to generate electric power from organic matter. Despite the development of efficient MFC reactors, the microbiology of electricity generation remains to be sufficiently understood. Results A laboratory-scale two-chamber microbial fuel cell (MFC) was inoculated with rice paddy field soil and fed cellulose as the carbon and energy source. Electricity-generating microorganisms were enriched by subculturing biofilms that attached onto anode electrodes. An electric current of 0.2 mA was generated from the first enrichment culture, and ratios of the major metabolites (e.g., electric current, methane and acetate) became stable after the forth enrichment. In order to investigate the electrogenic microbial community in the anode biofilm, it was morphologically analyzed by electron microscopy, and community members were phylogenetically identified by 16S rRNA gene clone-library analyses. Electron microscopy revealed that filamentous cells and rod-shaped cells with prosthecae-like filamentous appendages were abundantly present in the biofilm. Filamentous cells and appendages were interconnected via thin filaments. The clone library analyses frequently detected phylotypes affiliated with Clostridiales, Chloroflexi, Rhizobiales and Methanobacterium. Fluorescence in-situ hybridization revealed that the Rhizobiales population represented rod-shaped cells with filamentous appendages and constituted over 30% of the total population. Conclusion Bacteria affiliated with the Rhizobiales constituted the major population in the cellulose-fed MFC and exhibited unique morphology with filamentous appendages. They are considered to play important roles in the cellulose-degrading electrogenic community. PMID:18186940

Efficacy of low interatrial septum and right atrial appendage pacing for prevention of permanent atrial fibrillation in patients with sinus node disease: results from the electrophysiology-guided pacing site selection (EPASS) study.

PubMed

Verlato, Roberto; Botto, Giovanni Luca; Massa, Riccardo; Amellone, Claudia; Perucca, Antonello; Bongiorni, Maria Grazia; Bertaglia, Emanuele; Ziacchi, Vigilio; Piacenti, Marcello; Del Rosso, Attilio; Russo, Giovanni; Baccillieri, Maria Stella; Turrini, Pietro; Corbucci, Giorgio

2011-12-01

The role of pacing sites and atrial electrophysiology on the progression of atrial fibrillation (AF) to the permanent form in patients with sinus node dysfunction (SND) has never been investigated. The aim of the study was to investigate the relationship between atrial electrophysiology and the efficacy of atrial pacing at the low interatrial septum (IAS) or at the right atrial appendage (RAA) to prevent persistent/permanent AF in patients with SND. The Electrophysiology-Guided Pacing Site Selection (EPASS) Study was a prospective, controlled, randomized study. Atrial refractoriness, basal and incremental conduction times from the RAA to the coronary sinus ostium were measured before implantation, and the difference (ΔCTos) was calculated. Patients with ΔCTos ≥ 50 ms (study group) and those with ΔCTos <50 ms (control group) were randomly assigned to RAA or IAS with algorithms for continuous atrial stimulation "on." The primary end point was time to development of permanent or persistent AF within a 2-year follow-up in the study group, IAS versus RAA. Data were analyzed by intention to treat. One hundred two patients (77 ± 7 years, 44 mol/L) were enrolled, 69 (68%) in the study group and 33 (32%) in the control group. Of these, 97 ended the study, respectively, randomly assigned: 29 IAS versus 36 RAA and 18 IAS versus 14 RAA. After a mean follow-up of 15 ± 7 (median, 17) months, 11 (16.6%) patients in the study group met the primary end point: 2 IAS versus 9 RAA (log rank=3.93, P=0.047). In patients with SND and intra-atrial conduction delay, low IAS pacing was superior to RAA pacing in preventing progression to persistent or permanent AF. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00239226.

p38α MAPK Is Required for Tooth Morphogenesis and Enamel Secretion*

PubMed Central

Greenblatt, Matthew B.; Kim, Jung-Min; Oh, Hwanhee; Park, Kwang Hwan; Choo, Min-Kyung; Sano, Yasuyo; Tye, Coralee E.; Skobe, Ziedonis; Davis, Roger J.; Park, Jin Mo; Bei, Marianna; Glimcher, Laurie H.; Shim, Jae-Hyuck

2015-01-01

An improved understanding of the molecular pathways that drive tooth morphogenesis and enamel secretion is needed to generate teeth from organ cultures for therapeutic implantation or to determine the pathogenesis of primary disorders of dentition (Abdollah, S., Macias-Silva, M., Tsukazaki, T., Hayashi, H., Attisano, L., and Wrana, J. L. (1997) J. Biol. Chem. 272, 27678–27685). Here we present a novel ectodermal dysplasia phenotype associated with conditional deletion of p38α MAPK in ectodermal appendages using K14-cre mice (p38αK14 mice). These mice display impaired patterning of dental cusps and a profound defect in the production and biomechanical strength of dental enamel because of defects in ameloblast differentiation and activity. In the absence of p38α, expression of amelogenin and β4-integrin in ameloblasts and p21 in the enamel knot was significantly reduced. Mice lacking the MAP2K MKK6, but not mice lacking MAP2K MKK3, also show the enamel defects, implying that MKK6 functions as an upstream kinase of p38α in ectodermal appendages. Lastly, stimulation with BMP2/7 in both explant culture and an ameloblast cell line confirm that p38α functions downstream of BMPs in this context. Thus, BMP-induced activation of the p38α MAPK pathway is critical for the morphogenesis of tooth cusps and the secretion of dental enamel. PMID:25406311

Quality of life assessment in the randomized PROTECT AF (Percutaneous Closure of the Left Atrial Appendage Versus Warfarin Therapy for Prevention of Stroke in Patients With Atrial Fibrillation) trial of patients at risk for stroke with nonvalvular atrial fibrillation.

PubMed

Alli, Oluseun; Doshi, Shepal; Kar, Saibal; Reddy, Vivek; Sievert, Horst; Mullin, Chris; Swarup, Vijay; Whisenant, Brian; Holmes, David

2013-04-30

This study sought to assess quality of life parameters in a subset of patients enrolled in the PROTECT AF (Percutaneous Closure of the Left Atrial Appendage Versus Warfarin Therapy for Prevention of Stroke in Patients With Atrial Fibrillation) trial. The PROTECT AF (Percutaneous Closure of the Left Atrial Appendage Versus Warfarin Therapy for Prevention of Stroke in Patients With Atrial Fibrillation) trial demonstrated that in patients with nonvalvular atrial fibrillation (AF) and CHADS2 (congestive heart failure, hypertension, age, diabetes mellitus, and prior stroke, transient ischemic attack, or thromboembolism) score ≥1, a left atrial appendage closure device is noninferior to long-term warfarin for stroke prevention. Given this equivalency, quality of life (QOL) indicators are an important metric for evaluating these 2 different strategies. QOL using the Short-Form 12 Health Survey, version 2, measurement tool was obtained at baseline and 12 months in a subset of 547 patients in the PROTECT AF trial (361 device and 186 warfarin patients). The analysis cohort consisted of patients for whom either paired quality of life data were available after 12 months of follow-up or for patients who died. With the device, the total physical score improved in 34.9% and was unchanged in 29.9% versus warfarin in whom 24.7% were improved and 31.7% were unchanged (p = 0.01). Mental health improvement occurred in 33.0% of the device group versus 22.6% in the warfarin group (p = 0.06). There was a significant improvement in QOL in patients randomized to device for total physical score, physical function, and in physical role limitation compared to control. There were significant differences in the change in total physical score among warfarin naive and not-warfarin naive subgroups in the device group compared to control, but larger gains were seen with the warfarin naive subgroup with a 12-month change of 1.3 ± 8.8 versus -3.6 ± 6.7 (p = 0.0004) device compared to warfarin. Patients with nonvalvular AF at risk for stroke treated with left atrial appendage closure have favorable QOL changes at 12 months versus patients treated with warfarin. (WATCHMAN Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation [WATCHMAN PROTECT]; NCT00129545). Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Simulation of solar array slewing of Indian remote sensing satellite

NASA Astrophysics Data System (ADS)

Maharana, P. K.; Goel, P. S.

The effect of flexible arrays on sun tracking for the IRS satellite is studied. Equations of motion of satellites carrying a rotating flexible appendage are developed following the Newton-Euler approach and utilizing the constrained modes of the appendage. The drive torque, detent torque and friction torque in the SADA are included in the model. Extensive simulations of the slewing motion are carried out. The phenomena of back-stepping, step-missing, step-slipping and the influences of array flexibility in the acquisition mode are observed for certain combinations of parameters.

Left Atrial Appendage Exclusion for Atrial Fibrillation

PubMed Central

Syed, Faisal F.; DeSimone, Christopher V.; Friedman, Paul A.; Asirvatham, Samuel J.

2015-01-01

SYNOPSIS Percutaneous left atrial appendage (LAA) closure is increasingly being used as a treatment strategy to prevent stroke in patients with atrial fibrillation (AF) who have contraindications to anticoagulants. A number of approaches and devices have been developed in the last few years, each with their own unique set of advantages and disadvantages. We review the published studies on surgical and percutaneous approaches to LAA closure; focusing on stroke mechanisms in AF, LAA structure and function relevant to stroke prevention, practical differences in procedural approach, and clinical considerations surrounding management. PMID:25443240

Remote Medical Diagnosis System (RMDS) Advanced Development Model (ADM) Radiology Performance Test Results.

DTIC Science & Technology

1981-12-01

necrosis of lunate 6 6 Skull Nasal spine Fx D 1 4 Chest Pancoast tumor j 2 5 Skull Multiple myeloma 3 2 Abdomen Air under (R) diaphragm 4 6 Appendage...of lunate 6 6 Skull Nasal spine Fx D 1 4 Chest Pancoast tumor 2 5 Skull Multiple myeloma 3 2 Abdomen Air under (R) diaphragm 4 6 Appendage...nose and maxilla FINDINGS: Fx - inferior nasal spine (P) DIAGNOSES: Fx - inferior nasal spine (P) 86 I I I I I I RADIOGRAPH: D-1 HISTORY: 57-year old

Outcomes and costs of left atrial appendage closure from randomized controlled trial and real-world experience relative to oral anticoagulation

PubMed Central

Panikker, Sandeep; Lord, Joanne; Jarman, Julian W.E.; Armstrong, Shannon; Jones, David G.; Haldar, Shouvik; Butcher, Charles; Khan, Habib; Mantziari, Lilian; Nicol, Edward; Hussain, Wajid; Clague, Jonathan R.; Foran, John P.; Markides, Vias; Wong, Tom

2016-01-01

Aims The aim of this study was to analyse randomized controlled study and real-world outcomes of patients with non-valvular atrial fibrillation (NVAF) undergoing left atrial appendage closure (LAAC) with the Watchman device and to compare costs with available antithrombotic therapies. Methods and results Registry data of LAAC from two centres were prospectively collected from 110 patients with NVAF at risk of stroke, suitable and unsuitable for long-term anticoagulation (age 71.3 ± 9.2 years, CHADS2 2.8 ± 1.2, CHA2DS2-VASc 4.5 ± 1.6, and HAS-BLED 3.8 ± 1.1). Outcomes from PROTECT AF and registry study LAAC were compared with warfarin, dabigatran, rivaroxaban, apixaban, aspirin, and no treatment using a network meta-analysis. Costs were estimated over a 10-year horizon. Uncertainty was assessed using sensitivity analyses. The procedural success rate was 92% (103/112). Follow-up was 24.1 ± 4.6 months, during which annual rates of stroke, major bleeding, and all-cause mortality were 0.9% (2/223 patient-years), 0.9% (2/223 patient-years), and 1.8% (4/223 patient-years), respectively. Anticoagulant therapy was successfully stopped in 91.2% (93/102) of implanted patients by 12 months. Registry study LAAC stroke and major bleeding rates were significantly lower than PROTECT AF results: mean absolute difference of stroke, 0.89% (P = 0.02) and major bleeding, 5.48% (P < 0.001). Left atrial appendage closure achieved cost parity between 4.9 years vs. dabigatran 110 mg and 8.4 years vs. warfarin. At 10 years, LAAC was cost-saving against all therapies (range £1162–£7194). Conclusion Left atrial appendage closure in NVAF in a real-world setting may result in lower stroke and major bleeding rates than reported in LAAC clinical trials. Left atrial appendage closure in both settings achieves cost parity in a relatively short period of time and may offer substantial savings compared with current therapies. Savings are most pronounced among higher risk patients and those unsuitable for anticoagulation. PMID:26935273

Characterization and autoradiographic localization of beta-adrenoceptor subtypes in human cardiac tissues.

PubMed Central

Buxton, B. F.; Jones, C. R.; Molenaar, P.; Summers, R. J.

1987-01-01

1 Receptor autoradiography using (-)-[125I]-cyanopindolol (CYP) was used to study the distribution of beta-adrenoceptor subtypes in human right atrial appendage, left atrial free wall, left ventricular papillary muscle and pericardium. 2 The binding of (-)-[125I]-CYP to slide-mounted tissue sections of human right atrial appendage was time-dependent (K1 = 4.11 +/- 1.01 X 10(8) M-1 min-1, K-1 = 1.47 +/- 0.25 X 10(-3) min-1, n = 3), saturable (42.02 +/- 2.96 pM, n = 4) and stereoselective with respect to the optical isomers of propranolol (pKD (-):8.97 +/- 0.02, (+):6.88 +/- 0.06, n = 3). 3 The proportions of beta-adrenoceptor subtypes were determined in slide-mounted tissue sections using the antagonists CGP 20712A (beta 1-selective) and ICI 118,551 (beta 2-selective). In right atrial appendage and left ventricular papillary muscle 40% (34-45%) of the beta-adrenoceptors were of the beta 2-subtype. 4 Images from X-ray film and nuclear emulsion coated coverslips exposed to (-)-[125I]-CYP-labelled sections showed an even distribution of beta-adrenoceptor subtypes over the myocardium of the right atrial appendage, left ventricular papillary muscle and left atrial free wall. Sections of pericardium exhibited predominantly beta 2-adrenoceptors. beta 2-Adrenoceptors were localized to the intimal surface of coronary arteries. 5 The selective beta 1-adrenoceptor agonist RO363 and beta 2-selective agonist procaterol produced concentration-dependent inotropic responses in right atrial appendage strips. Responses to RO363 were antagonized by CGP 20712A (pKB = 9.29) suggesting an interaction with beta 1-adrenoceptors. Responses to procaterol were antagonized by ICI 118,551 (pKB = 9.06) suggesting an interaction at beta 2-adrenoceptors. 6 The finding that a significant proportion of human myocardial adrenoceptors are of the beta 2-subtype has important clinical implications for the involvement of these receptors in the control of heart rate and force, and the autoradiographic evidence suggests other roles in the coronary vasculature and pericardium. Images Figure 5 Figure 6 PMID:2823947

Usefulness of Doppler assessment of pulmonary vein and left atrial appendage flow following pulmonary vein isolation of chronic atrial fibrillation in predicting recovery of left atrial function.

PubMed

Donal, Erwan; Grimm, Richard A; Yamada, Hirotsugu; Kim, Yong Jin; Marrouche, Nassir; Natale, Andrea; Thomas, James D

2005-04-15

Atrial fibrillation (AF) is a widespread condition that causes significant morbidity and mortality. Recently, pulmonary venous (PV) isolation using radiofrequency ablation has been used successfully to exclude the pulmonary venous ostia, resulting in correction of AF. Further, miniaturized high-frequency ultrasound phased-array transducers currently provide Doppler and 2-dimensional imaging during the ablation procedure. We examined atrial function and its determinants using intracardiac echocardiography before and after PV isolation in 45 patients who had chronic AF (56 +/- 11 years old). PV, left atrial (LA) appendage, and mitral and tricuspid flows were recorded. Recovery of booster pump function (defined by the presence of mitral inflow A wave, LA appendage a-wave, and PV A-reversal wave velocities >10 cm/s) was observed in 39 of 45 patients (86.6%). PV flow systolic wave before and after ablation correlated with the degree of LA booster pump function after PV isolation. An early systolic PV flow peak velocity >57.47 cm/s predicted "good" LA booster pump function recovery with 96% specificity. Diastolic LA appendage emptying in AF correlated (p <0.001) and predicted good LA booster pump function with 92% specificity for velocities >46.4 cm/s. Thus, monitoring LA function during PV isolation for chronic AF is feasible. Most patients recovered LA booster pump function immediately after PV isolation, and the degree of recovery correlated with LA reservoir function. Preserved reservoir function during AF is predictive of satisfactory recovery of booster pump function after PV isolation.

Evolution of Cell Size Homeostasis and Growth Rate Diversity during Initial Surface Colonization of Shewanella oneidensis.

PubMed

Lee, Calvin K; Kim, Alexander J; Santos, Giancarlo S; Lai, Peter Y; Lee, Stella Y; Qiao, David F; Anda, Jaime De; Young, Thomas D; Chen, Yujie; Rowe, Annette R; Nealson, Kenneth H; Weiss, Paul S; Wong, Gerard C L

2016-09-06

Cell size control and homeostasis are fundamental features of bacterial metabolism. Recent work suggests that cells add a constant size between birth and division ("adder" model). However, it is not known how cell size homeostasis is influenced by the existence of heterogeneous microenvironments, such as those during biofilm formation. Shewanella oneidensis MR-1 can use diverse energy sources on a range of surfaces via extracellular electron transport (EET), which can impact growth, metabolism, and size diversity. Here, we track bacterial surface communities at single-cell resolution to show that not only do bacterial motility appendages influence the transition from two- to three-dimensional biofilm growth and control postdivisional cell fates, they strongly impact cell size homeostasis. For every generation, we find that the average growth rate for cells that stay on the surface and continue to divide (nondetaching population) and that for cells that detach before their next division (detaching population) are roughly constant. However, the growth rate distribution is narrow for the nondetaching population, but broad for the detaching population in each generation. Interestingly, the appendage deletion mutants (ΔpilA, ΔmshA-D, Δflg) have significantly broader growth rate distributions than that of the wild type for both detaching and nondetaching populations, which suggests that Shewanella appendages are important for sensing and integrating environmental inputs that contribute to size homeostasis. Moreover, our results suggest multiplexing of appendages for sensing and motility functions contributes to cell size dysregulation. These results can potentially provide a framework for generating metabolic diversity in S. oneidensis populations to optimize EET in heterogeneous environments.

Can direct extracellular electron transfer occur in the absence of outer membrane cytochromes in Desulfovibrio vulgaris?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elias, Dwayne A; Zane, Mr. Grant M.; Auer, Dr. Manfred

2010-01-01

Extracellular electron transfer has been investigated over several decades via forms of soluble electron transfer proteins that are exported for extracellular reoxidation. More recently, several organisms have been shown to reduce extracellular metals via the direct transfer of electron through appendages; also known as nanowires. They have been reported most predominantly in Shewanella and Geobacter. While the relevancy and composition of these structures in each genus has been debated, both possess outer membrane cytochrome complexes that could theoretically come into direct contact with solid phase oxidized metals. Members of the genus Desulfovibrio apparently have no such cytochromes although similar appendagesmore » are present, are electrically conductive, and are different from flagella. Upon U(VI)-reduction, the structures in Desulfovibrio become coated with U(IV). Deletion of flagellar genes did not alter soluble or amorphous Fe(III) or U(VI) reduction, or appendage appearance. Removal of the chromosomal pilA gene hampered amorphous Fe(III)-reduction by ca. 25%, but cells lacking the native plasmid, pDV1, reduced soluble Fe(III) and U(VI) at ca. 50% of the wild type rate while amorphous Fe(III)-reduction slowed to ca. 20% of the wild type rate. Appendages were present in all deletions as well as pDV1, except pilA. Gene complementation restored all activities and morphologies to wild type levels. This suggests that pilA encodes the structural component, whereas genes within pDV1 may provide the reactive members. How such appendages function without outer membrane cytochromes is under investigation.« less

Mapping of the left-sided phrenic nerve course in patients undergoing left atrial catheter ablations.

PubMed

Huemer, Martin; Wutzler, Alexander; Parwani, Abdul S; Attanasio, Philipp; Haverkamp, Wilhelm; Boldt, Leif-Hendrik

2014-09-01

Catheter ablation of atrial fibrillation has been associated with left-sided phrenic nerve palsy. Knowledge of the individual left phrenic nerve course therefore is essential to prevent nerve injury. The aim of this study was to test the feasibility of an intraprocedural pace mapping and reconstruction of the left phrenic nerve course and to characterize which anatomical areas are affected. In patients undergoing left atrial catheter ablation, a three-dimensional map of the left atrial anatomical structures was created. The left-sided phrenic nerve course was determined by high-output pace mapping and reconstructed in the map. In this study, 40 patients with atrial fibrillation or atrial tachycardias were included. Left phrenic nerve capture was observed in 23 (57.5%) patients. Phrenic nerve was captured in 22 (55%) patients inside the left atrial appendage, in 22 (55%) in distal parts, in 21 (53%) in medial parts, and in two (5%) in ostial parts of the appendage. In three (7.5%) patients, capture was found in the distal coronary sinus and in one (2.5%) patient in the left atrium near the left atrial appendage ostium. Ablation target was changed due to direct spatial relationship to the phrenic nerve in three (7.5%) patients. No phrenic nerve palsy was observed. Left-sided phrenic nerve capture was found inside and around the left atrial appendage in the majority of patients and additionally in the distal coronary sinus. Phrenic nerve mapping and reconstruction can easily be performed and should be considered prior catheter ablations in potential affected areas. ©2014 Wiley Periodicals, Inc.

Heat loss regulation: role of appendages and torso in the deer mouse and the white rabbit.

PubMed

Conley, K E; Porter, W P

1985-01-01

Thermal conductance was subdivided into the component conductances of the appendages and torso using a heat transfer analysis for the deer mouse, Peromyscus maniculatus, and the white rabbit, Oryctolagus cuniculus. Our analysis was based on laboratory measurements of skin temperature and respiratory gas exchange made between air temperatures of 8 and 34 degrees C for the deer mouse, and from published data for the white rabbit. Two series conductances to heat transfer for each appendage and torso were evaluated: internal (hin), for blood flow and tissue conduction to the skin surface, and external (hex), for heat loss from the skin surface to the environment. These two series conductances were represented in a single, total conductance (htot). The limit to htot was set by hex and was reached by the torso htot of both animals. The increase in torso htot observed with air temperature for the mouse suggests that a pilomotor change in fur depth occurred. A control of htot below the limit set by hex was achieved by the hin of each appendage. Elevation of mouse thermal conductance (C) resulted from increases in feet, tail, and torso htot. In contrast, the rabbit showed no change in torso htot between 5 and 30 degrees C and ear htot exclusively increased C over these air temperatures. We suggest that the hyperthermia reported for the rabbit at 35 degrees C resulted from C reaching the physical limit set by torso and near hex. Thus the ear alone adjusted rabbit C, whereas the feet, tail, and the torso contributed to the adjustment of mouse C.

[Quantitative Measurements on the Blood Flow Fields of Left Atrial Appendage using Vector Flow Mapping in Patients with Nonvalvular Atrial Fibrillation].

PubMed

Cai, Yu-Yan; Wei, Xin; Zhang, Xiao-Ling; Liu, Gu-Yue; Li, Xi; Tang, Hong

2018-01-01

To quantify the hemodynamic characteristics of patients with nonvalvular atrial fibrillation. Twenty patients with paroxysmal atrial fibrillation and 15 patients with persistent atrial fibrillation enrolled in this study,while 12 patients with sinus rhythms served as controls. The hemodynamic characteristics of the patients in left atrial appendage were measured by transesophageal echocardiography (TEE) and vector flow mapping (VFM) using indicators such as vectors,vortex and energy loss (EL). ① Significant differences appeared between the patients with atrial fibrillation and the controls in heart rate,size of left atrium,size of left atrial appendage (LAA),and velocities of LAA filling and emptying. ② Regular vectors in LAA in early systole and late diastole were found in the patients with paroxysmal atrial fibrillation and the controls; whereas,irregular vectors with direction alternating were visualized in the whole cardiac cycle in the patients with persistent atrial fibrillation. ③ Small vortexes were observed at the opening of the left atrial appendage in late diastole in the patients with paroxysmal atrial fibrillation and the controls. ④ Peak EL values occurred in early systole and late diastole in the patients with paroxysmal atrial fibrillation and the controls. But the patients with persistent atrial fibrillation had increased EL values over the whole cardiac cycle. VFM can visualize and quantify the hemodynamics of LAA in patients with different heart rhythms. It may provide a new method for assessing atrial fibrillation. CopyrightCopyright© by Editorial Board of Journal of Sichuan University (Medical Science Edition).

Head patterning and Hox gene expression in an onychophoran and its implications for the arthropod head problem.

PubMed

Eriksson, Bo Joakim; Tait, Noel N; Budd, Graham E; Janssen, Ralf; Akam, Michael

2010-09-01

The arthropod head problem has puzzled zoologists for more than a century. The head of adult arthropods is a complex structure resulting from the modification, fusion and migration of an uncertain number of segments. In contrast, onychophorans, which are the probable sister group to the arthropods, have a rather simple head comprising three segments that are well defined during development, and give rise to the adult head with three pairs of appendages specialised for sensory and food capture/manipulative purposes. Based on the expression pattern of the anterior Hox genes labial, proboscipedia, Hox3 and Deformed, we show that the third of these onychophoran segments, bearing the slime papillae, can be correlated to the tritocerebrum, the most anterior Hox-expressing arthropod segment. This implies that both the onychophoran antennae and jaws are derived from a more anterior, Hox-free region corresponding to the proto and deutocerebrum of arthropods. Our data provide molecular support for the proposal that the onychophoran head possesses a well-developed appendage that corresponds to the anterior, apparently appendage-less region of the arthropod head.

Structural changes of bacteriophage [phi]29 upon DNA packaging and release

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiang, Y.; Morais, M.C.; Battisti, A.J.

2008-04-24

Cryo-electron microscopy three-dimensional reconstructions have been made of mature and of emptied bacteriophage {phi}29 particles without making symmetry assumptions. Comparisons of these structures with each other and with the {phi}29 prohead indicate how conformational changes might initiate successive steps of assembly and infection. The 12 adsorption capable 'appendages' were found to have a structure homologous to the bacteriophage P22 tailspikes. Two of the appendages are extended radially outwards, away from the long axis of the virus, whereas the others are around and parallel to the phage axis. The appendage orientations are correlated with the symmetry-mismatched positions of the five-fold relatedmore » head fibers, suggesting a mechanism for partial cell wall digestion upon rotation of the head about the tail when initiating infection. The narrow end of the head-tail connector is expanded in the mature virus. Gene product 3, bound to the 5-foot ends of the genome, appears to be positioned within the expanded connector, which may potentiate the release of DNA-packaging machine components, creating a binding site for attachment of the tail.« less

Topsy-turvy: Turning the counter-current heat exchange of leatherback turtles upside down

USGS Publications Warehouse

Davenport, John; Jones, T. Todd; Work, Thierry M.; Balazs, George H.

2015-01-01

Counter-current heat exchangers associated with appendages of endotherms feature bundles of closely applied arteriovenous vessels. The accepted paradigm is that heat from warm arterial blood travelling into the appendage crosses into cool venous blood returning to the body. High core temperature is maintained, but the appendage functions at low temperature. Leatherback turtles have elevated core temperatures in cold seawater and arteriovenous plexuses at the roots of all four limbs. We demonstrate that plexuses of the hindlimbs are situated wholly within the hip musculature, and that, at the distal ends of the plexuses, most blood vessels supply or drain the hip muscles, with little distal vascular supply to, or drainage from the limb blades. Venous blood entering a plexus will therefore be drained from active locomotory muscles that are overlaid by thick blubber when the adults are foraging in cold temperate waters. Plexuses maintain high limb muscle temperature and avoid excessive loss of heat to the core, the reverse of the accepted paradigm. Plexuses protect the core from overheating generated by muscular thermogenesis during nesting.

Topsy-turvy: turning the counter-current heat exchange of leatherback turtles upside down.

PubMed

Davenport, John; Jones, T Todd; Work, Thierry M; Balazs, George H

2015-10-01

Counter-current heat exchangers associated with appendages of endotherms feature bundles of closely applied arteriovenous vessels. The accepted paradigm is that heat from warm arterial blood travelling into the appendage crosses into cool venous blood returning to the body. High core temperature is maintained, but the appendage functions at low temperature. Leatherback turtles have elevated core temperatures in cold seawater and arteriovenous plexuses at the roots of all four limbs. We demonstrate that plexuses of the hindlimbs are situated wholly within the hip musculature, and that, at the distal ends of the plexuses, most blood vessels supply or drain the hip muscles, with little distal vascular supply to, or drainage from the limb blades. Venous blood entering a plexus will therefore be drained from active locomotory muscles that are overlaid by thick blubber when the adults are foraging in cold temperate waters. Plexuses maintain high limb muscle temperature and avoid excessive loss of heat to the core, the reverse of the accepted paradigm. Plexuses protect the core from overheating generated by muscular thermogenesis during nesting. © 2015 The Author(s).

Attitude tracking control of flexible spacecraft with large amplitude slosh

NASA Astrophysics Data System (ADS)

Deng, Mingle; Yue, Baozeng

2017-12-01

This paper is focused on attitude tracking control of a spacecraft that is equipped with flexible appendage and partially filled liquid propellant tank. The large amplitude liquid slosh is included by using a moving pulsating ball model that is further improved to estimate the settling location of liquid in microgravity or a zero-g environment. The flexible appendage is modelled as a three-dimensional Bernoulli-Euler beam, and the assumed modal method is employed. A hybrid controller that combines sliding mode control with an adaptive algorithm is designed for spacecraft to perform attitude tracking. The proposed controller has proved to be asymptotically stable. A nonlinear model for the overall coupled system including spacecraft attitude dynamics, liquid slosh, structural vibration and control action is established. Numerical simulation results are presented to show the dynamic behaviors of the coupled system and to verify the effectiveness of the control approach when the spacecraft undergoes the disturbance produced by large amplitude slosh and appendage vibration. Lastly, the designed adaptive algorithm is found to be effective to improve the precision of attitude tracking.

Percutaneous Occlusion of the Left Atrial Appendage with the Watchman Device in an Active Duty Sailor with Atrial Fibrillation and Recurrent Thromboembolism Despite Appropriate Use of Oral Anticoagulation.

PubMed

Cox, Justin M; Choi, Anthony J; Oakley, Luke S; Francisco, Gregory M; Nayak, Keshav R

2018-05-23

Atrial fibrillation is the most common significant cardiac arrhythmia and is associated with a five-fold increased risk of stroke from thromboembolism. Over 94% of these emboli arise from the left atrial appendage. Systemic embolic phenomena are rare, accounting for less than 1 out of 10 of all embolic events, but have a similar prevention strategy. Anticoagulation significantly reduces the risk of these events, and thus forms the cornerstone of therapy for most patients with atrial fibrillation. Left atrial appendage occlusion with the Watchman device is a recently approved alternative for stroke prevention in selected patients. We present a case of an active duty U.S. Navy sailor at low risk for thromboembolism who nonetheless suffered recurrent thromboembolic events despite appropriate anticoagulation, and thus underwent Watchman implantation. The therapy in this case will ideally provide a lifetime of protection from recurrent systemic embolization while allowing the patient to continue his active duty military career without restriction due to oral anticoagulation.

EOS-AM precision pointing verification

NASA Technical Reports Server (NTRS)

Throckmorton, A.; Braknis, E.; Bolek, J.

1993-01-01

The Earth Observing System (EOS) AM mission requires tight pointing knowledge to meet scientific objectives, in a spacecraft with low frequency flexible appendage modes. As the spacecraft controller reacts to various disturbance sources and as the inherent appendage modes are excited by this control action, verification of precision pointing knowledge becomes particularly challenging for the EOS-AM mission. As presently conceived, this verification includes a complementary set of multi-disciplinary analyses, hardware tests and real-time computer in the loop simulations, followed by collection and analysis of hardware test and flight data and supported by a comprehensive data base repository for validated program values.

Left Atrial Appendage Morphology and Embolic Stroke of Undetermined Source: A Cross-Sectional Multicenter Pilot Study.

PubMed

Yaghi, Shadi; Chang, Andrew D; Hung, Peter; Mac Grory, Brian; Collins, Scott; Gupta, Ajay; Reynolds, Jacques; Finn, Caitlin B; Hemendinger, Morgan; Cutting, Shawna M; McTaggart, Ryan A; Jayaraman, Mahesh; Leasure, Audrey; Sansing, Lauren; Panda, Nikhil; Song, Christopher; Chu, Antony; Merkler, Alexander; Gialdini, Gino; Sheth, Kevin N; Kamel, Hooman; Elkind, Mitchell S V; Greer, David; Furie, Karen; Atalay, Michael

2018-06-01

The left atrial appendage (LAA) is the main source of thrombus in atrial fibrillation, and there is an association between non-chicken wing (NCW) LAA morphology and stroke. We hypothesized that the prevalence of NCW LAA morphology would be higher among patients with cardioembolic (CE) stroke and embolic stroke of undetermined source (ESUS) than among those with noncardioembolic stroke (NCS). This multicenter retrospective pilot study included consecutive patients with ischemic stroke from 3 comprehensive stroke centers who previously underwent a qualifying chest computed tomography (CT) to assess LAA morphology. Patients underwent inpatient diagnostic evaluation for ischemic stroke, and stroke subtype was determined based on ESUS criteria. LAA morphology was determined using clinically performed contrast enhanced thin-slice chest CT by investigators blinded to stroke subtype. The primary predictor was NCW LAA morphology and the outcome was stroke subtype (CE, ESUS, NCS). We identified 172 patients with ischemic stroke who had a clinical chest CT performed. Mean age was 70.1 ± 14.3 years and 51.7% were male. Compared with patients with NCS, the prevalence of NCW LAA morphology was higher in patients with CE stroke (58.7% versus 46.3%, P = .1) and ESUS (58.8% versus 46.3%, P = .2), but this difference did not achieve statistical significance. The prevalence of NCW LAA morphology may be similar in patients with ESUS and CE, and may be higher than that in those with NCS. Larger studies are needed to confirm these associations. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

First in vivo evaluation of a flexible self-apposing left atrial appendage closure device in the canine model.

PubMed

Cheng, Yanping; Conditt, Gerard; Yi, Genghua; Tellez, Armando; Corcoran, Michael; Rousselle, Serge; Kaluza, Greg L; Granada, Juan F

2015-07-01

Aimed to evaluate the feasibility of deployment and healing response of a novel transcatheter left atrial appendage (LAA) occlusion device in the canine model LAA occlusion is proposed to reduce the risk of stroke in atrial fibrillation patients Transseptal puncture and device deployment was guided under fluoroscopy and transesophageal echocardiography (TEE) in five dogs. First, a distal cylindrical bulb occluder was released and secured to the appendage wall with hooks. Subsequently, a proximal sail was unfolded, covering the LAA ostium. Rotational angiography, TEE, and histology outcomes were assessed 30 days following implantation Pre-operative TEE revealed the mean diameter of the LAA ostium to be 17.2 ± 1.6 mm with a depth of 18.5 ± 1.7 mm. The landing zone for the distal bulb was measured to be 12.8 ± 1.3 mm. The mean bulb diameter at implant was 16.8 ± 1.8 mm. Post-operative TEE showed adequate positioning and successful LAA occlusion with all implanted devices. Pericardial effusion requiring pericardiocentesis was seen in one animal following device implantation. At 30 days, TEE revealed full occlusion of all LAA ostia with the exception of a minimal peri-device leak (<3 mm) observed in one animal. No pericardial effusion or device-related thrombus formation was found at termination. Histological analysis confirmed circumferential occlusion of all appendages and complete neointimal coverage on the luminal aspect of the occluder The percutaneous delivery of a novel self-positioning LAA occlusion device is feasible and safe in a canine model. At 30 days, all devices displayed complete healing and occlusion of the LAA without any device related adverse events. © 2015 Wiley Periodicals, Inc.

Remodeling of atrial ATP-sensitive K+ channels in a model of salt-induced elevated blood pressure

PubMed Central

Lader, Joshua M.; Vasquez, Carolina; Bao, Li; Maass, Karen; Qu, Jiaxiang; Kefalogianni, Eirini; Fishman, Glenn I.; Coetzee, William A.

2011-01-01

Hypertension is associated with the development of atrial fibrillation; however, the electrophysiological consequences of this condition remain poorly understood. ATP-sensitive K+ (KATP) channels, which contribute to ventricular arrhythmias, are also expressed in the atria. We hypothesized that salt-induced elevated blood pressure (BP) leads to atrial KATP channel activation and increased arrhythmia inducibility. Elevated BP was induced in mice with a high-salt diet (HS) for 4 wk. High-resolution optical mapping was used to measure atrial arrhythmia inducibility, effective refractory period (ERP), and action potential duration at 90% repolarization (APD90). Excised patch clamping was performed to quantify KATP channel properties and density. KATP channel protein expression was also evaluated. Atrial arrhythmia inducibility was 22% higher in HS hearts compared with control hearts. ERP and APD90 were significantly shorter in the right atrial appendage and left atrial appendage of HS hearts compared with control hearts. Perfusion with 1 μM glibenclamide or 300 μM tolbutamide significantly decreased arrhythmia inducibility and prolonged APD90 in HS hearts compared with untreated HS hearts. KATP channel density was 156% higher in myocytes isolated from HS animals compared with control animals. Sulfonylurea receptor 1 protein expression was increased in the left atrial appendage and right atrial appendage of HS animals (415% and 372% of NS animals, respectively). In conclusion, KATP channel activation provides a mechanistic link between salt-induced elevated BP and increased atrial arrhythmia inducibility. The findings of this study have important implications for the treatment and prevention of atrial arrhythmias in the setting of hypertensive heart disease and may lead to new therapeutic approaches. PMID:21724863

Distinct Fibroblasts in the Papillary and Reticular Dermis: Implications for Wound Healing.

PubMed

Woodley, David T

2017-01-01

Human skin wounds heal largely by reparative wound healing rather than regenerative wound healing. Human skin wounds heal with scarring and without pilosebaceous units or other appendages. Dermal fibroblasts come from 2 distinct lineages of cells that have distinct cell markers and, more importantly, distinct functional abilities. Human skin wound healing largely involves the dermal fibroblast lineage from the reticular dermis and not the papillary dermis. If scientists could find a way to stimulate the dermal fibroblast lineages from the papillary dermis in early wound healing, perhaps human skin wounds could heal without scarring and with skin appendages. Copyright © 2016 Elsevier Inc. All rights reserved.

Soft-part anatomy of the Early Cambrian bivalved arthropods Kunyangella and Kunmingella: significance for the phylogenetic relationships of Bradoriida

PubMed Central

Hou, Xianguang; Williams, Mark; Siveter, David J.; Siveter, Derek J.; Aldridge, Richard J.; Sansom, Robert S.

2010-01-01

Bradoriids are small bivalved marine arthropods that are widespread in rocks of Cambrian to Early Ordovician age. They comprise seven families and about 70 genera based on shield (‘carapace’) morphology. New bradoriid specimens with preserved soft-part anatomy of Kunmingella douvillei (Kunmingellidae) are reported from the Early Cambrian Chengjiang Lagerstätte of China together with, for the first time to our knowledge, a second bradoriid species with preserved soft parts, Kunyangella cheni (Comptalutidae). Kunmingella douvillei has a 10-segmented limb-bearing body with uniramous ninth and tenth appendages and a series of homogeneous, apparently (proximal parts not preserved) unspecialized post-antennal biramous limbs with setose leaf-shaped exopods. Each endopod consists of five podomeres. A presumed penultimate instar of Ky. cheni preserves remnants of three head and two trunk appendages, and the adult is reconstructed as having four head appendages. This material allows testing of the affinity of the Bradoriida. Kunmingella is identified as a stem crustacean in character-based analyses, through both morphological comparisons and cladistic reconstructions. Global parsimony analysis recovers a monophyletic Bradoriida as the sister group to crown crustaceans. PMID:20181565

Viscous constraints on predator:food size ratios in microscale feeding

NASA Astrophysics Data System (ADS)

Jabbarzadeh, Mehdi; Fu, Henry

2014-11-01

Small organisms such as protists or copepods may try to capture food by manipulating food with cilia, limbs, or feeding appendages. At these small scales, viscous flow may complicate the ability of a feeding appendage to closely approach a food particle. As a simplified but tractable model of such feeding approach, we consider the problem of two spheres approaching in a Stokes fluid. The first ``feeding'' sphere, which represents a body part or feeding appendage, is pushed with a constant force towards a force-free ``food'' sphere. When the feeding sphere reaches within a cutoff distance of the food sphere we assume that nonhydrodynamic interactions lead to capture. We examine approach for a range of size ratios between the feeding and food sphere. To investigate the approach efficiency, we examine the time required for the feeding sphere to capture the food sphere, as well as how far the feeding sphere must move before it captures the food sphere. We also examine the effect of varying the cutoff distance for capture. We find that hydrodynamic interactions strongly affect the results when the size of the spheres is comparable. We describe what relative sizes between feeding sphere and food particles may be most effective for food capture.

Effects of environmental factors and appendage injury on the wing variation in the cricket Velarifictorus ornatus.

PubMed

Zhao, Lü-Quan; Zhu, Dao-Hong

2014-01-01

The effects of environmental factors and appendage injury on the wing variation in Velarifictorus ornatus (Shiraki) (Orthoptera: Gryllidae) were investigated. The percentage of micropters was more than 95% when the nymphs were reared at constant photoperiods, and changing photoperiod did not affect wing variation in V. ornatus at 25 or 30°C. In the crowding experiment, the percentage of macropters was only 11.2% when the nymphs were reared separately at 25°C. In contrast, the percentage of macropters was significantly higher when the rearing density was increased to two nymphs per container and lower when the rearing density was increased to five or 10 nymphs per container. These results indicate that low and high rearing densities induce micropters, but intermediate rearing density stimulates the formation of macropters. Meanwhile, severance of appendages, such as antennae, femora, and tibiae, in the nymph stage exerted a micropterizing effect. The period sensitive to such stresses ranged from 35 to 60 days of nymph development. This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.

The role of canonical Wnt signaling in leg regeneration and metamorphosis in the red flour beetle Tribolium castaneum.

PubMed

Shah, Mita V; Namigai, Erica K O; Suzuki, Yuichiro

2011-01-01

Many organisms across the Metazoa have regenerative abilities with potentially conserved genetic mechanisms that can enlighten both medicine and evolutionary studies. Here, the role of canonical Wnt signaling was examined in the red flour beetle Tribolium castaneum in order to explore its role during metamorphosis and larval leg regeneration. Double-stranded RNA mediated silencing of Wnt-1 signaling resulted in a loss of wings and appendages with a dramatic reduction in width, indicating that the Wnt-1 signaling pathway is necessary for proper post-embryonic appendage development in T. castaneum. Furthermore, disruption of canonical Wnt signaling led to the complete impairment of limb regeneration in T. castaneum. Our findings suggest that Wnt-1 signaling is a conserved mechanism for appendage development across all holometabolous insects and indicate that the role of Wnt-1 signaling in limb regeneration has been retained across all insects as various modes of limb development evolved. Importantly, this study shows that the availability of the genome sequence and the ease of performing leg ablations make Tribolium an excellent holometabolous insect model for studying regeneration. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Outcomes and costs of left atrial appendage closure from randomized controlled trial and real-world experience relative to oral anticoagulation.

PubMed

Panikker, Sandeep; Lord, Joanne; Jarman, Julian W E; Armstrong, Shannon; Jones, David G; Haldar, Shouvik; Butcher, Charles; Khan, Habib; Mantziari, Lilian; Nicol, Edward; Hussain, Wajid; Clague, Jonathan R; Foran, John P; Markides, Vias; Wong, Tom

2016-12-07

The aim of this study was to analyse randomized controlled study and real-world outcomes of patients with non-valvular atrial fibrillation (NVAF) undergoing left atrial appendage closure (LAAC) with the Watchman device and to compare costs with available antithrombotic therapies. Registry data of LAAC from two centres were prospectively collected from 110 patients with NVAF at risk of stroke, suitable and unsuitable for long-term anticoagulation (age 71.3 ± 9.2 years, CHADS 2 2.8 ± 1.2, CHA 2 DS 2 -VASc 4.5 ± 1.6, and HAS-BLED 3.8 ± 1.1). Outcomes from PROTECT AF and registry study LAAC were compared with warfarin, dabigatran, rivaroxaban, apixaban, aspirin, and no treatment using a network meta-analysis. Costs were estimated over a 10-year horizon. Uncertainty was assessed using sensitivity analyses. The procedural success rate was 92% (103/112). Follow-up was 24.1 ± 4.6 months, during which annual rates of stroke, major bleeding, and all-cause mortality were 0.9% (2/223 patient-years), 0.9% (2/223 patient-years), and 1.8% (4/223 patient-years), respectively. Anticoagulant therapy was successfully stopped in 91.2% (93/102) of implanted patients by 12 months. Registry study LAAC stroke and major bleeding rates were significantly lower than PROTECT AF results: mean absolute difference of stroke, 0.89% (P = 0.02) and major bleeding, 5.48% (P < 0.001). Left atrial appendage closure achieved cost parity between 4.9 years vs. dabigatran 110 mg and 8.4 years vs. warfarin. At 10 years, LAAC was cost-saving against all therapies (range £1162-£7194). Left atrial appendage closure in NVAF in a real-world setting may result in lower stroke and major bleeding rates than reported in LAAC clinical trials. Left atrial appendage closure in both settings achieves cost parity in a relatively short period of time and may offer substantial savings compared with current therapies. Savings are most pronounced among higher risk patients and those unsuitable for anticoagulation. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

3D Viscous Free-Surface Flow around a Combatant Ship Hull

NASA Astrophysics Data System (ADS)

Pacuraru, Florin; Lungu, Adrian; Maria, Viorel

2009-09-01

The prediction of the total drag experienced by an advancing ship is a complicated problem which requires a thorough understanding of the hydrodynamic forces acting on the hull, the physical processes from which these forces arise and their mutual interaction. A general numerical method to predict the hydrodynamic performance of a twin-propeller combatant ship hull is presented in the paper. For practical reasons, the technique couples a body forces method and a RANS-based finite volume solver to account for the interactions between the hull and the appendages mounted on it: propellers, rudders, shaft lines, bossings and brackets. The chimera approach has been found the most versatile way for grid generation of hull and appendages.

Deployment hinge using wraparound strips

NASA Technical Reports Server (NTRS)

Blanc, Eric

1992-01-01

Aerospatiale developed a new appendage deployment concept called AMEDE (French acronym for improvement of deployment mechanisms) with a view toward increased simplicity and functional reliability. This new concept, applicable to the deployment of any type of spaceborne appendage (in particular to solar arrays), enables deployment without synchronization or speed regulation devices. On the other hand, it requires the use of hinges with low driving or resistive torques. The AMEDE concept is compared with the conventional deployment concept. The conceptual and functional principles for the ADELE hinge are presented, as well as the hinges' main characteristics. The development status of both the AMEDE concept and the ADELE (French acronym for deployment hinge using wraparound strips) hinge are addressed.

The morphology and evolution of the female postabdomen of Holometabola (Insecta).

PubMed

Hünefeld, Frank; Missbach, Christine; Beutel, Rolf Georg

2012-07-01

In the present article homology issues, character evolution and phylogenetic implications related to the female postabdomen of the holometabolan insects are discussed, based on an earlier analysis of a comprehensive morphological data set. Hymenoptera, the sistergroup of the remaining Holometabola, are the only group where the females have retained a fully developed primary ovipositor of the lepismatid type. There are no characters of the female abdomen supporting a clade Coleopterida + Neuropterida. The invagination of the terminal segments is an autapomorphy of Coleoptera. The ovipositor is substantially modified in Raphidioptera and distinctly reduced in Megaloptera and Neuroptera. The entire female abdomen is extremely simplified in Strepsiptera. The postabdomen is tapering posteriorly in Mecopterida and retractile in a telescopic manner (oviscapt). The paired ventral sclerites of segments VIII and IX are preserved, but valvifers and valvulae are not distinguishable. In Amphiesmenoptera sclerotizations derived from the ventral appendages VIII are fused ventromedially, forming a solid plate, and the appendages IX are reduced. The terminal segments are fused and form a terminal unit which bears the genital opening subapically. The presence of two pairs of apophyses and the related protraction of the terminal unit by muscle force are additional autapomorphies, as is the fusion of the rectum with the posterior part of the genital chamber (cloaca). Antliophora are supported by the presence of a transverse muscle between the ventral sclerites of segment VIII. Secondary egg laying tubes have evolved independently within Boreidae (absent in Caurinus) and in Tipulomorpha. The loss of two muscle associated with the genital chamber are likely autapomorphies of Diptera. The secondary loss of the telescopic retractability of the postabdomen is one of many autapomorphies of Siphonaptera. Copyright © 2012 Elsevier Ltd. All rights reserved.

Benthodytes violeta, a new species of a deep-sea holothuroid (Elasipodida: Psychropotidae) from Mar del Plata Canyon (south-western Atlantic Ocean).

PubMed

Martinez, Mariano I; Solís-Marín, Francisco A; Penchaszadeh, Pablo E

2014-01-30

A new species of elasipodid holothuroid, Benthodytes violeta sp. nov., is described from the Mar del Plata Canyon off Buenos Aires Province (around 38ºS-54ºW). It was taken at four locations at depths ranging from 1500 to 1950 m. This new species has a violet gelatinous body of up to 200 mm in length, with eight pairs of dorsal appendages, lateral festooned edges and four rows of tube feet ventrally. Body wall ossicles comprise rods and crosses with three or four arms and a central bipartite apophysis borne on the primary cross; tentacles and gonad deposits comprise rods and crosses with three and four arms. This is the first report of a holothuroid from the Mar del Plata Canyon area.

Comedones

MedlinePlus

Skin bumps - acne-like; Acne-like skin bumps; Whiteheads; Blackheads ... of cutaneous appendages. In: Patterson JW, ed. Weedon's Skin Pathology . 4th ed. Philadelphia, PA: Elsevier Churchill Livingstone; ...

First description of a musculoskeletal linkage in an adipose fin: innovations for active control in a primitively passive appendage

PubMed Central

Stewart, Thomas A.; Hale, Melina E.

2013-01-01

Adipose fins are enigmatic appendages found between the dorsal and caudal fins of some teleostean fishes. Long thought to be vestigial, degenerate second dorsal fins, remnants of the primitive gnathostome condition, adipose fins have since been recognized as novel morphologies. Unique among the fins of extant fishes, adipose fins have uniformly been described as passive structures, with no associated musculature. Here we provide the first description of a musculoskeletal linkage in an adipose fin, identified in the sun catfish Horabagrus brachysoma. Modified supracarinalis posterior muscles insert from the dorsal midline anterior to the adipose fin by tendons onto the fin base. An additional pair of posterior adipose-fin muscles also inserts upon the fin base and lay posterolateral to the fin, superficial to the axial muscle. This musculoskeletal linkage is an evolutionary innovation, a novel mechanism for controlling adipose-fin movement. These muscles appear to exemplify two approaches by which fins evolve to be actively controlled. We hypothesize that the anterior muscles arose through co-option of an existing fin linkage, while the posterior muscles originated as de novo fin muscles. These findings present adipose fins as a rich system within which to explore the evolution of novel vertebrate appendages. PMID:23135670

Arthropod visual predators in the early pelagic ecosystem: evidence from the Burgess Shale and Chengjiang biotas.

PubMed

Vannier, J; García-Bellido, D C; Hu, S-X; Chen, A-L

2009-07-22

Exceptional fossil specimens with preserved soft parts from the Maotianshan Shale (ca 520 Myr ago) and the Burgess Shale (505 Myr ago) biotas indicate that the worldwide distributed bivalved arthropod Isoxys was probably a non-benthic visual predator. New lines of evidence come from the functional morphology of its powerful prehensile frontal appendages that, combined with large spherical eyes, are thought to have played a key role in the recognition and capture of swimming or epibenthic prey. The swimming and steering of this arthropod was achieved by the beating of multiple setose exopods and a flap-like telson. The appendage morphology of Isoxys indicates possible phylogenetical relationships with the megacheirans, a widespread group of assumed predator arthropods characterized by a pre-oral 'great appendage'. Evidence from functional morphology and taphonomy suggests that Isoxys was able to migrate through the water column and was possibly exploiting hyperbenthic niches for food. Although certainly not unique, the case of Isoxys supports the idea that off-bottom animal interactions such as predation, associated with complex feeding strategies and behaviours (e.g. vertical migration and hunting) were established by the Early Cambrian. It also suggests that a prototype of a pelagic food chain had already started to build-up at least in the lower levels of the water column.

Ecologically Driven Ultrastructural and Hydrodynamic Designs in Stomatopod Cuticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grunenfelder, Lessa Kay; Milliron, Garrett; Herrera, Steven

Ecological pressures and varied feeding behaviors in a multitude of organ-isms have necessitated the drive for adaptation. One such change is seen in the feeding appendages of stomatopods, a group of highly predatory marine crustaceans. Stomatopods include “spearers,” who ambush and snare soft bodied prey, and “smashers,” who bludgeon hard-shelled prey with a heavily mineralized club. The regional substructural complexity of the stomatopod dactyl club from the smashing predator Odontodactylus scyllarus represents a model system in the study of impact tolerant biominerals. The club consists of a highly mineralized impact region, a characteristic Bouligand architec-ture (common to arthropods), and amore » unique section of the club, the striated region, composed of highly aligned sheets of mineralized fibers. Detailed ultrastructural investigations of the striated region within O. scyllarus and a related species of spearing stomatopod, Lysiosquillina maculate show consistent organization of mineral and organic, but distinct differences in macro-scale architecture. Evidence is provided for the function and substructural exaptation of the striated region, which facilitated redeployment of a rapto-rial feeding appendage as a biological hammer. Furthermore, given the need to accelerate underwater and “grab” or “smash” their prey, the spearer and smasher appendages are specifically designed with a significantly reduced drag force.« less

Ecologically Driven Ultrastructural and Hydrodynamic Designs in Stomatopod Cuticles

DOE PAGES

Grunenfelder, Lessa Kay; Milliron, Garrett; Herrera, Steven; ...

2018-01-16

Ecological pressures and varied feeding behaviors in a multitude of organ-isms have necessitated the drive for adaptation. One such change is seen in the feeding appendages of stomatopods, a group of highly predatory marine crustaceans. Stomatopods include “spearers,” who ambush and snare soft bodied prey, and “smashers,” who bludgeon hard-shelled prey with a heavily mineralized club. The regional substructural complexity of the stomatopod dactyl club from the smashing predator Odontodactylus scyllarus represents a model system in the study of impact tolerant biominerals. The club consists of a highly mineralized impact region, a characteristic Bouligand architec-ture (common to arthropods), and amore » unique section of the club, the striated region, composed of highly aligned sheets of mineralized fibers. Detailed ultrastructural investigations of the striated region within O. scyllarus and a related species of spearing stomatopod, Lysiosquillina maculate show consistent organization of mineral and organic, but distinct differences in macro-scale architecture. Evidence is provided for the function and substructural exaptation of the striated region, which facilitated redeployment of a rapto-rial feeding appendage as a biological hammer. Furthermore, given the need to accelerate underwater and “grab” or “smash” their prey, the spearer and smasher appendages are specifically designed with a significantly reduced drag force.« less

The origin of crustaceans: new evidence from the Early Cambrian of China.

PubMed Central

Chen, J. Y.; Vannier, J.; Huang, D. Y.

2001-01-01

One of the smallest arthropods recently discovered in the Early Cambrian Maotianshan Shale Lagerstätte is described. Ercaia gen. nov. has an untagmatized trunk bearing serially repeated biramous appendages (long and segmented endopods and flap-like exopods), a head with an acron bearing stalked lateral eyes and a sclerite and two pairs of antennae. The position of this 520 million-year-old tiny arthropod within the Crustacea is supported by several anatomical features: (i) a head with five pairs of appendages including two pairs of antennae, (ii) highly specialized antennae (large setose fans with a possible function in feeding), and (iii) specialized last trunk appendages (segmented pediform structures fringed with setae). The segmentation pattern of Ercaia (5 head and 13 trunk) is close to that of Maxillopoda but lacks the trunk tagmosis of modern representatives of the group. Ercaia is interpreted as a possible derivative of the stem group Crustacea. Ercaia is likely to have occupied an ecological niche similar to those of some Recent meiobenthic organisms (e.g. copepods living in association with sediment). This new fossil evidence supports the remote ancestry of crustaceans well before the Late Cambrian and shows, along with other fossil data (mainly Early Cambrian in China), that a variety of body plans already coexisted among the primitive crustacean stock. PMID:11674864

A new species of Pseudocrepidobothrium (Cestoda: Proteocephalidea) from Pseudoplatystoma reticulatum (Pisces: Siluriformes) in the Paraná River basin (Argentina).

PubMed

Arredondo, Nathalia J; De Pertierra, Alicia A Gil; De Chambrier, Alain

2014-10-01

This study describes the proteocephalidean tapeworm Pseudocrepidobothrium chanaorum sp. n. (Proteocephalidae: Proteocephalinae), which was found in the intestine of Pseudoplatystoma reticulatum (Eigenmann et Eigenmann) from the Colastiné River, a tributary of the Paraná River. The new species differs from the two other species of the genus, P. eirasi (Rego et de Chambrier, 1995) and P. ludovici Ruedi et de Chambrier, 2012, parasites of Phractocephalus hemioliopterus (Bloch et Schneider) from the Amazon River in Brazil, in having fewer proglottides (4-8 without ventral appendages vs 7-12 with ventral appendages and 20-36 without ventral appendages, respectively), a smaller scolex (350-450 μm wide vs 495-990 μm and 515-1020 μm wide, respectively), in the total number of testes (21-25 vs 21-51 and 37-79, respectively), a cirrus-sac usually directed anteriorly if the vagina is posterior to the cirrus-sac vs transversely situated in the known species. The study of the tegumental surface of Pseudocrepidobothrium spp. revealed the presence of four types of microtriches: papilliform, acicular and capilliform filitriches, and gladiate spinitriches. The three species have a similar microthrix pattern, with minor differences on the immature proglottis surface. Pseudocrepidobothrium chanaorum sp. n. is the ninth proteocephalid reported from P. reticulatum.

Changes during late-stage embryonic development from egg-juvenile to free-living hatchling in Chinese freshwater crab Sinopotamon yangtsekiense (Decapoda, Brachyura, Potamidae)

NASA Astrophysics Data System (ADS)

Xue, Junzeng; Liu, Yan; Cumberlidge, Neil; Wu, Huixian

2013-05-01

This study expands on recent reports that direct development in the Chinese potamid freshwater crab Sinopotamon yangtsekiense involves the completion of all brachyuran larval stages (nauplius, zoea, and megalopa) inside the egg case during embryonic development. Detailed studies of embryonic development in this species revealed the presence of an additional larval stage (the egg-juvenile) between the megalopa and the free-living hatchling crab. We described and compared the appendages of the head, thorax, and abdomen of the egg-juvenile with those of the hatchling crab in S. yangtsekiense. Significant differences were found between most of the appendages of these two stages with a soft exoskeleton in the egg-juvenile, no joint articulation, a slimmer appearance, and a lack of setae when compared with the newly emerged free-living hatchling crab. These modifications of the appendages are related to the confinement within the egg case of the egg-megalopa and egg-juvenile during direct development, and the need for the free-living hatchling freshwater crab to move, feed, and respire. In marine crabs, the megalopa gives rise to the first crab stage whereas in freshwater crabs the egg-juvenile follows the megalopa and immediately precedes the free-living first crab stage.

Frequency-tuning input-shaped manifold-based switching control for underactuated space robot equipped with flexible appendages

NASA Astrophysics Data System (ADS)

Kojima, Hirohisa; Ieda, Shoko; Kasai, Shinya

2014-08-01

Underactuated control problems, such as the control of a space robot without actuators on the main body, have been widely investigated. However, few studies have examined attitude control problems of underactuated space robots equipped with a flexible appendage, such as solar panels. In order to suppress vibration in flexible appendages, a zero-vibration input-shaping technique was applied to the link motion of an underactuated planar space robot. However, because the vibrational frequency depends on the link angles, simple input-shaping control methods cannot sufficiently suppress the vibration. In this paper, the dependency of the vibrational frequency on the link angles is measured experimentally, and the time-delay interval of the input shaper is then tuned based on the frequency estimated from the link angles. The proposed control method is referred to as frequency-tuning input-shaped manifold-based switching control (frequency-tuning IS-MBSC). The experimental results reveal that frequency-tuning IS-MBSC is capable of controlling the link angles and the main body attitude to maintain the target angles and that the vibration suppression performance of the proposed frequency-tuning IS-MBSC is better than that of a non-tuning IS-MBSC, which does not take the frequency variation into consideration.

The flipflop orphan genes are required for limb bud eversion in the Tribolium embryo.

PubMed

Thümecke, Susanne; Beermann, Anke; Klingler, Martin; Schröder, Reinhard

2017-01-01

Unlike Drosophila but similar to other arthropod and vertebrate embryos, the flour beetle Tribolium castaneum develops everted limb buds during embryogenesis. However, the molecular processes directing the evagination of epithelia are only poorly understood. Here we show that the newly discovered genes Tc-flipflop1 and Tc-flipflop2 are involved in regulating the directional budding of appendages. RNAi-knockdown of Tc-flipflop results in a variety of phenotypic traits. Most prominently, embryonic limb buds frequently grow inwards rather than out, leading to the development of inverted appendages inside the larval body. Moreover, affected embryos display dorsal closure defects. The Tc-flipflop genes are evolutionarily non-conserved, and their molecular function is not evident. We further found that Tc-RhoGEF2 , a highly-conserved gene known to be involved in actomyosin-dependent cell movement and cell shape changes, shows a Tc-flipflop -like RNAi-phenotype. The similarity of the inverted appendage phenotype in both the flipflop - and the RhoGEF2 RNAi gene knockdown led us to conclude that the Tc-flipflop orphan genes act in a Rho-dependent pathway that is essential for the early morphogenesis of polarised epithelial movements. Our work describes one of the few examples of an orphan gene playing a crucial role in an important developmental process.

ANMCO/AIAC/SICI-GISE/SIC/SICCH Consensus Document: percutaneous occlusion of the left atrial appendage in non-valvular atrial fibrillation patients: indications, patient selection, staff skills, organisation, and training

PubMed Central

Gulizia, Michele Massimo; Molon, Giulio; Mazzone, Patrizio; Audo, Andrea; Casolo, Giancarlo; Di Lorenzo, Emilio; Portoghese, Michele; Pristipino, Christian; Ricci, Renato Pietro; Themistoclakis, Sakis; Padeletti, Luigi; Tondo, Claudio; Berti, Sergio; Oreglia, Jacopo Andrea; Gerosa, Gino; Zanobini, Marco; Ussia, Gian Paolo; Musumeci, Giuseppe; Romeo, Francesco; Di Bartolomeo, Roberto

2017-01-01

Abstract Atrial fibrillation (AF) is the most common arrhythmia and its prevalence is increasing due to the progressive aging of the population. About 20% of strokes are attributable to AF and AF patients are at five-fold increased risk of stroke. The mainstay of treatment of AF is the prevention of thromboembolic complications with oral anticoagulation therapy. Drug treatment for many years has been based on the use of vitamin K antagonists, but recently newer and safer molecules have been introduced (dabigatran etexilate, rivaroxaban, apixaban, and edoxaban). Despite these advances, many patients still do not receive adequate anticoagulation therapy because of contraindications (relative and absolute) to this treatment. Over the last decade, percutaneous closure of left atrial appendage, main site of thrombus formation during AF, proved effective in reducing thromboembolic complications, thus offering a valid medical treatment especially in patients at increased bleeding risk. The aim of this consensus document is to review the main aspects of left atrial appendage occlusion (selection and multidisciplinary assessment of patients, currently available methods and devices, requirements for centres and operators, associated therapies and follow-up modalities) having as a ground the significant evolution of techniques and the available relevant clinical data. PMID:28751849

Tonganoxichnus, a new insect trace from the Upper Carboniferous of eastern Kansas

USGS Publications Warehouse

Mangano, M.G.; Buatois, L.A.; Maples, C.G.; Lanier, Wendy E.

1997-01-01

Upper Carboniferous tidal rhythmites of the Tonganoxie Sandstone Member (Stranger Formation) at Buildex Quarry, eastern Kansas, USA, host a relatively diverse arthropod-dominated ichnofauna. Bilaterally symmetrical traces displaying unique anterior and posterior sets of morphological features are well represented within the assemblage. A new ichnogenus, Tonganoxichnus, is proposed for these traces. T. buildexensis, the type ichnospecies, has an anterior region characterized by the presence of a frontal pair of maxillary palp impressions, followed by a head impression and three pairs of conspicuous thoracic appendage imprints symmetrically opposite along a median axis. The posterior region commonly exhibits numerous delicate chevron-like markings, recording the abdominal appendages, and a thin, straight, terminal extension. T. buildexensis is interpreted as a resting trace. A second ichnospecies, T. ottawensis, is characterized by a fan-like arrangement of mostly bifid scratch marks at the anterior area that records the head- and thoracic-appendage backstrokes against the substrate. The posterior area shows chevron-like markings or small subcircular impressions that record the abdominal appendages of the animal, also ending in a thin, straight, terminal extension. Specimens display lateral repetition, and are commonly grouped into twos or threes with a fix point at the posteriormost tail-like structure. T. ottawensis is interpreted as a jumping structure, probably in connection with feeding purposes. The two ichnospecies occur in close association, and share sufficient morphologic features to support the same type of arthropod producer. T. buildexensis closely mimics the ventral anatomy of the tracemaker, whereas T. ottawensis records the jumping abilities of the animal providing significant ethologic and paleoecologic information. The presence of well-differentiated cephalic, thoracic, and abdominal features, particularly in T. buildexensis, resembles the diagnostic tagmosis and segmentation of insects. Detailed analysis of trace morphology and comparison with described Paleozoic insect fossils and extant related forms suggest a monuran as the most likely tracemaker.

Percutaneous left atrial appendage occlusion – treatment outcomes and 6 months of follow-up – a single-center experience

PubMed Central

Karczewski, Michał; Skowronek, Radomir; Burysz, Marian; Fischer, Marcin; Anisimowicz, Lech; Demkow, Marcin; Konka, Marek; Ogorzeja, Wojciech

2016-01-01

Aim To present the results of treatment and evaluate 6 months of follow-up in a group of patients with non-valvular atrial fibrillation, who underwent the procedure of percutaneous left atrial appendage occlusion (PLAAO). Material and methods Percutaneous left atrial appendage occlusion was performed in 34 patients with non-valvular atrial fibrillation and contraindications for oral anticoagulation therapy. The risk of thromboembolic and bleeding complications was determined based on the CHA2DS2VASc and HAS-BLED scales. The Amplatzer Amulet system from St. Jude Medical was used. On the first postoperative day, all patients were started on double antiplatelet therapy with 75 mg/day of acetylsalicylic acid (ASA) and 75 mg/day of clopidogrel (CLO). On the 30th postoperative day, the efficacy of the antiplatelet therapy was assessed with impedance aggregometry using a Multiplate analyzer (Roche). Echocardiographic examinations were performed intraoperatively and on the first postoperative day; subsequently, follow-up examinations were conducted 1 and 6 months after the implantation. Results In all patients, proper occluder position was observed throughout the follow-up. No leakage or thrombi around the implants were found. No strokes or bleeding complications associated with the antiplatelet therapy were observed. Multiplate assessment of platelet activity was conducted in 20 out of 34 patients. The efficacy of ASA treatment was demonstrated in all patients; no response to clopidogrel treatment was observed in 5 out of 20 patients. One patient suffered from cardiac tamponade, which required the performance of full sternotomy. Local complications (hematomas of the inguinal region) were observed in 3 patients. One of the patients died for reasons unrelated to the procedure. Conclusions Percutaneous left atrial appendage occlusion is an effective procedure in patients with non-valvular atrial fibrillation and contraindications for chronic anticoagulation therapy. Further observation is necessary to evaluate the longterm results. PMID:27516780

Deep-etch visualization of proteins involved in clathrin assembly

PubMed Central

1988-01-01

Assembly proteins were extracted from bovine brain clathrin-coated vesicles with 0.5 M Tris and purified by clathrin-Sepharose affinity chromatography, then adsorbed to mica and examined by freeze-etch electron microscopy. The fraction possessing maximal ability to promote clathrin polymerization, termed AP-2, was found to be a tripartite structure composed of a relatively large central mass flanked by two smaller mirror-symmetric appendages. Elastase treatment quantitatively removed the appendages and clipped 35 kD from the molecule's major approximately 105-kD polypeptides, indicating that the appendages are made from portions of these polypeptides. The remaining central masses no longer promote clathrin polymerization, suggesting that the appendages are somehow involved in the clathrin assembly reaction. The central masses are themselves relatively compact and brick-shaped, and are sufficiently large to contain two copies of the molecule's other major polypeptides (16- and 50-kD), as well as two copies of the approximately 70-kD protease-resistant portions of the major approximately 105-kD polypeptides. Thus the native molecule seems to be a dimeric, bilaterally symmetrical entity. Direct visualization of AP-2 binding to clathrin was accomplished by preparing mixtures of the two molecules in buffers that marginally inhibit AP-2 aggregation and cage assembly. This revealed numerous examples of AP-2 molecules binding to the so-called terminal domains of clathrin triskelions, consistent with earlier electron microscopic evidence that in fully assembled cages, the AP's attach centrally to inwardly-directed terminal domains of the clathrin molecule. This would place AP-2s between the clathrin coat and the enclosed membrane in whole coated vesicles. AP-2s linked to the membrane were also visualized by enzymatically removing the clathrin from brain coated vesicles, using purified 70 kD, uncoating ATPase plus ATP. This revealed several brick-shaped molecules attached to the vesicle membrane by short stalks. The exact stoichiometry of APs to clathrin in such vesicles, before and after uncoating, remains to be determined. PMID:3417785

Presynaptic imidazoline receptors and non-adrenoceptor[3H]-idazoxan binding sites in human cardiovascular tissues

PubMed Central

Molderings, G J; Likungu, J; Jakschik, J; Göthert, M

1997-01-01

In segments of human right atrial appendages and pulmonary arteries preincubated with [3H]-noradrenaline and superfused with physiological salt solution containing desipramine and corticosterone, the involvement of imidazoline receptors in the modulation of [3H]-noradrenaline release was investigated. In human atrial appendages, the guanidines aganodine and DTG (1,3-di(2-tolyl)guanidine) which activate presynaptic imidazoline receptors, inhibited electrically-evoked [3H]-noradrenaline release. The inhibition was not affected by blockade of α2-adrenoceptors with 1 μM rauwolscine, but antagonized by extremely high concentrations of this drug (10 and/or 30 μM; apparent pA2 against aganodine and DTG: 5.55 and 5.21, respectively). In the presence of 1 μM rauwolscine, [3H]-noradrenaline release in human atrial appendages was also inhibited by the imidazolines idazoxan and cirazoline, but not by agmatine and noradrenaline. The inhibitory effects of 100 μM idazoxan and 30 μM cirazoline were abolished by 30 μM rauwolscine. In the atrial appendages, the rank order of potency of all guanidines and imidazolines for their inhibitory effect on electrically-evoked [3H]-noradrenaline release in the presence of 1 μM rauwolscine was: aganodine⩾BDF 6143 [4-chloro-2-(2-imidazolin-2-yl-amino)-isoindoline]>DTG⩾clonidine>cirazoline>idazoxan (BDF 6143 and clonidine were previously studied under identical conditions). This potency order corresponded to that previously determined at the presynaptic imidazoline receptors in the rabbit aorta. When, in the experiments in the human pulmonary artery, rauwolscine was absent from the superfusion fluid, the concentration-response curve for BDF 6143 (a mixed α2-adrenoceptor antagonist/imidazoline receptor agonist) for its facilitatory effect on electrically-evoked [3H]-noradrenaline release was bell-shaped. In the presence of 1 μM rauwolscine, BDF 6143 and cirazoline concentration-dependently inhibited the evoked [3H]-noradrenaline release. In human atrial appendages, non-adrenoceptor [3H]-idazoxan binding sites were identified and characterized. The binding of [3H]-idazoxan was specific, reversible, saturable and of high affinity (KD: 25.5 nM). The specific binding of [3H]-idazoxan (defined by cirazoline 0.1 mM) to membranes of human atrial appendages was concentration-dependently inhibited by several imidazolines and guanidines, but not by rauwolscine and agmatine. In most cases, the competition curves were best fitted to a two-site model. The rank order of affinity for the high affinity site (in a few cases for the only detectable site; cirazoline=idazoxan>BDF 6143>DTG⩾clonidine) is compatible with the pharmacological properties of I2-imidazoline binding sites, but is clearly different from the rank order of potency for inhibiting evoked noradrenaline release from sympathetic nerves in the same tissue. It is concluded that noradrenaline release in the human atrium and, less well established, in the pulmonary artery is inhibited via presynaptic imidazoline receptors. These presynaptic imidazoline receptors appear to be related to those previously characterized in rabbit aorta and pulmonary artery, but differ clearly from I1 and I2 imidazoline binding sites. PMID:9298527

Extracolonic Findings on Computed Tomography (CT) Colonography

ClinicalTrials.gov

2017-03-16

Solitary Pulmonary Nodules; Multiple Pulmonary Nodules; Renal Neoplasms; Adrenal Gland Neoplasms; Aortic Aneurysm, Abdominal; Liver Neoplasms; Adnexal and Skin Appendage Neoplasms; Lymphadenopathy; Pancreatic Neoplasms

Vertically aligned gas-insulated transmission line having particle traps at the inner conductor

DOEpatents

Dale, Steinar J.

1984-01-01

Gas insulated electrical apparatus having first and second conductors separated by an insulating support within an insulating gas environment, and particle traps disposed along the surface of the high potential conductor for trapping and inactivating foreign particles which may be present within the insulating gas medium. Several embodiments of the invention were developed which are particularly suited for vertically aligned gas insulated transmission lines. The particle traps are grooves or cavities formed into the walls of the tubular inner conductor, without extending into the hollow portion of the conductor. In other embodiments, the traps are appendages or insert flanges extending from the inner conductor, with the insulator supports contacting the appendages instead of the inner conductor.

Coherex WAVECREST I Left Atrial Appendage Occlusion Study

ClinicalTrials.gov

2015-01-13

Non-valvular Paroxysmal, Persistent, or Permanent Atrial Fibrillation; LAA Anatomy Amenable to Treatment by Percutaneous Technique; Anticoagulation Indication for Potential Thrombus Formation in the Left Atrium

The functional-morphological adaptive strategy of digestive organs of decapodiform cephalopods

PubMed Central

OMURA, Ayano; ENDO, Hideki

2015-01-01

The digestive organs in decapodiform cephalopod species morphologically vary by individual lifestyle. We examined the following six species of adult decapodiformes cephalopods representing different habitats: Todarodes pacificus, Loligo bleekeri, Loligo edulis, Watasenia scintillans (pelagic), Sepia lycidas and Euprymna morsei (benthic). L. bleekeri and L. edulis possess a bursiform cecal sac connected to the cecum. Pelagic species have a single digestive gland smaller than in benthic species. T. pacificus has an oval digestive gland larger than that of L. bleekeri and L. edulis, which possess withered-looking and smaller digestive glands. In contrast, the digestive glands in benthic species are paired. S. lycidas and E. morsei have well-developed and larger digestive glands than those of the pelagic species. Well-developed digestive duct appendages are found in benthic species. In qualification of the mass of digestive organs, pelagic species have smaller stomachs, digestive glands and digestive ducts’ appendages than benthic species. Because pelagic species need to swim, they may possess smaller stomachs and larger cecums for more rapid digestion. A smaller digestive gland may have the advantage of reducing the body weight in pelagic species for rapid swimming. In contrast, since benthic species require a longer time for digestion than pelagic species, they compact more food in their stomachs and absorb nutrients via more organs, such as the digestive grand and digestive duct appendages, in addition to cecum. PMID:26369293

Pelvic girdle and fin of Tiktaalik roseae

PubMed Central

Shubin, Neil H.; Daeschler, Edward B.; Jenkins, Farish A.

2014-01-01

A major challenge in understanding the origin of terrestrial vertebrates has been knowledge of the pelvis and hind appendage of their closest fish relatives. The pelvic girdle and appendage of tetrapods is dramatically larger and more robust than that of fish and contains a number of structures that provide greater musculoskeletal support for posture and locomotion. The discovery of pelvic material of the finned elpistostegalian, Tiktaalik roseae, bridges some of these differences. Multiple isolated pelves have been recovered, each of which has been prepared in three dimensions. Likewise, a complete pelvis and partial pelvic fin have been recovered in association with the type specimen. The pelves of Tiktaalik are paired and have broad iliac processes, flat and elongate pubes, and acetabulae that form a deep socket rimmed by a robust lip of bone. The pelvis is greatly enlarged relative to other finned tetrapodomorphs. Despite the enlargement and robusticity of the pelvis of Tiktaalik, it retains primitive features such as the lack of both an attachment for the sacral rib and an ischium. The pelvic fin of Tiktaalik (NUFV 108) is represented by fin rays and three endochondral elements: other elements are not preserved. The mosaic of primitive and derived features in Tiktaalik reveals that the enhancement of the pelvic appendage of tetrapods and, indeed, a trend toward hind limb-based propulsion have antecedents in the fins of their closest relatives. PMID:24449831

Control of submersible vortex flows

NASA Technical Reports Server (NTRS)

Bushnell, D. M.; Donaldson, C. D.

1990-01-01

Vortex flows produced by submersibles typically unfavorably influence key figures of merit such as acoustic and nonacoustic stealth, control effectiveness/maneuverability, and propulsor efficiency/body drag. Sources of such organized, primarily longitudinal, vorticity include the basic body (nose and sides) and appendages (both base/intersection and tip regions) such as the fairwater, dive planes, rear control surfaces, and propulsor stators/tips. Two fundamentally different vortex control approaches are available: (1) deintensification of the amplitude and/or organization of the vortex during its initiation process; and (2) downstream vortex disablement. Vortex control techniques applicable to the initiation region (deintensification approach) include transverse pressure gradient minimization via altered body cross section, appendage dillets, fillets, and sweep, and various appendage tip and spanload treatment along with the use of active controls to minimize control surface size and motions. Vortex disablement can be accomplished either via use of control vortices (which can also be used to steer the vortices off-board), direct unwinding, inducement of vortex bursting, or segmentation/tailoring for enhanced dissipation. Submersible-applicable vortex control technology is also included derived from various aeronautical applications such as mitigation of the wing wake vortex hazard and flight aircraft maneuverability at high angle of attack as well as the status of vortex effects upon, and mitigation of, nonlinear control forces on submersibles. Specific suggestions for submersible-applicable vortex control techniques are presented.

A new probable stem lineage crustacean with three-dimensionally preserved soft parts from the Herefordshire (Silurian) Lagerstätte, UK

PubMed Central

Siveter, Derek J; Sutton, Mark D; Briggs, Derek E.G; Siveter, David J

2007-01-01

A new arthropod with three-dimensionally preserved soft parts, Tanazios dokeron, is described from the Wenlock Series (Silurian) of Herefordshire, England, UK. Serial grinding, digital photographic and computer rendering techniques yielded ‘virtual fossils’ in the round for study. The body tagmata of T. dokeron comprise a head shield and a long trunk. The head shield bears six pairs of horn-like spines and the head bears five pairs of appendages. The antennule, antenna and mandible are all uniramous, and the mandible includes a gnathobasic coxa. Appendages four and five are biramous and similar to those of the trunk: each comprises a limb base with an endite, an enditic membrane, and two epipodites, plus an endopod and exopod. The hypostome bears a large cone-like projection centrally, and there may be a short labrum. The trunk has some 64 segments and at least 60 appendage pairs. A very small telson has the anus sited ventrally in its posterior part and also bears a caudal furca. Comparative morphological and cladistic analyses of T. dokeron indicate a crustacean affinity, with a probable position in the eucrustacean stem group. As such the epipodites in T. dokeron are the first recorded in a eucrustacean stem taxon. The new species is interpreted as a benthic or nektobenthic scavenger. PMID:17609185

Notch signaling is significantly suppressed in basal cell carcinomas and activation induces basal cell carcinoma cell apoptosis.

PubMed

Shi, Feng-Tao; Yu, Mei; Zloty, David; Bell, Robert H; Wang, Eddy; Akhoundsadegh, Noushin; Leung, Gigi; Haegert, Anne; Carr, Nicholas; Shapiro, Jerry; McElwee, Kevin J

2017-04-01

A subset of basal cell carcinomas (BCCs) are directly derived from hair follicles (HFs). In some respects, HFs can be defined as 'ordered' skin appendage growths, while BCCs can be regarded as 'disordered' skin appendage growths. The aim of the present study was to examine HFs and BCCs to define the expression of common and unique signaling pathways in each skin appendage. Human nodular BCCs, along with HFs and non‑follicular skin epithelium from normal individuals, were examined using microarrays, qPCR, and immunohistochemistry. Subsequently, BCC cells and root sheath keratinocyte cells from HFs were cultured and treated with Notch signaling peptide Jagged1 (JAG1). Gene expression, protein levels, and cell apoptosis susceptibility were assessed using qPCR, immunoblotting, and flow cytometry, respectively. Specific molecular mechanisms were found to be involved in the process of cell self‑renewal in the HFs and BCCs, including Notch and Hedgehog signaling pathways. However, several key Notch signaling factors showed significant differential expression in BCCs compared with HFs. Stimulating Notch signaling with JAG1 induced apoptosis of BCC cells by increasing Fas ligand expression and downstream caspase-8 activation. The present study showed that Notch signaling pathway activity is suppressed in BCCs, and is highly expressed in HFs. Elements of the Notch pathway could, therefore, represent targets for the treatment of BCCs and potentially in hair follicle engineering.

The functional-morphological adaptive strategy of digestive organs of decapodiform cephalopods.

PubMed

Omura, Ayano; Endo, Hideki

2016-01-01

The digestive organs in decapodiform cephalopod species morphologically vary by individual lifestyle. We examined the following six species of adult decapodiformes cephalopods representing different habitats: Todarodes pacificus, Loligo bleekeri, Loligo edulis, Watasenia scintillans (pelagic), Sepia lycidas and Euprymna morsei (benthic). L. bleekeri and L. edulis possess a bursiform cecal sac connected to the cecum. Pelagic species have a single digestive gland smaller than in benthic species. T. pacificus has an oval digestive gland larger than that of L. bleekeri and L. edulis, which possess withered-looking and smaller digestive glands. In contrast, the digestive glands in benthic species are paired. S. lycidas and E. morsei have well-developed and larger digestive glands than those of the pelagic species. Well-developed digestive duct appendages are found in benthic species. In qualification of the mass of digestive organs, pelagic species have smaller stomachs, digestive glands and digestive ducts' appendages than benthic species. Because pelagic species need to swim, they may possess smaller stomachs and larger cecums for more rapid digestion. A smaller digestive gland may have the advantage of reducing the body weight in pelagic species for rapid swimming. In contrast, since benthic species require a longer time for digestion than pelagic species, they compact more food in their stomachs and absorb nutrients via more organs, such as the digestive grand and digestive duct appendages, in addition to cecum.

Ultrastructural study and ontogenesis of the appendages and related musculature of Paraspadella (Chaetognatha).

PubMed

Casanova, J-P; Duvert, M; Goto, T

2003-10-01

A lineage of benthic chaetognaths has developed limb-like appendages on the caudal part of the body, resulting from a local modification of the lateral fins, which are folds of the epidermis and have a role in balance when swimming. The most complex are those of Paraspadella gotoi which are used as props with the tip of the tail, allowing an elaborated mating behaviour comprising different movements: complete erection of the body, swings and jumps, astonishing for so simple-bodied animals. In the tail, the epidermis and the connective tissue, together with the longitudinal musculature, are involved in this innovation. All the components of the fins, i.e. connective tissue, fin rays and multilayered epidermic cells are conserved, but their function has changed. The movements of appendages are adjusted by one pair of small appendicular muscles localised in the body wall, while posture movements of the body are allowed by four longitudinal bundles of raising muscle. These two new muscles have successively appeared in the evolutive series previously described in Paraspadella. They have definitely arisen from the secondary muscle: the two lateral bundles for the former, and the two dorsal and two ventral ones for the latter. All are supercontracting muscles, a muscle kind also observed in the other benthic genus Spadella, but unknown in planktonic and benthoplanktonic chaetognaths.

A revision of brain composition in Onychophora (velvet worms) suggests that the tritocerebrum evolved in arthropods

PubMed Central

2010-01-01

Background The composition of the arthropod head is one of the most contentious issues in animal evolution. In particular, controversy surrounds the homology and innervation of segmental cephalic appendages by the brain. Onychophora (velvet worms) play a crucial role in understanding the evolution of the arthropod brain, because they are close relatives of arthropods and have apparently changed little since the Early Cambrian. However, the segmental origins of their brain neuropils and the number of cephalic appendages innervated by the brain - key issues in clarifying brain composition in the last common ancestor of Onychophora and Arthropoda - remain unclear. Results Using immunolabelling and neuronal tracing techniques in the developing and adult onychophoran brain, we found that the major brain neuropils arise from only the anterior-most body segment, and that two pairs of segmental appendages are innervated by the brain. The region of the central nervous system corresponding to the arthropod tritocerebrum is not differentiated as part of the onychophoran brain but instead belongs to the ventral nerve cords. Conclusions Our results contradict the assumptions of a tripartite (three-segmented) brain in Onychophora and instead confirm the hypothesis of bipartite (two-segmented) brain composition. They suggest that the last common ancestor of Onychophora and Arthropoda possessed a brain consisting of protocerebrum and deutocerebrum whereas the tritocerebrum evolved in arthropods. PMID:20727203

Postoperative pulmonary hypertensive crisis caused by inverted left atrial appendage after cardiopulmonary bypass surgery for congenital heart disease in a neonate.

PubMed

Zhao, Qifeng; Hu, Xingti

2013-09-01

Postoperative pulmonary hypertensive crisis (PHC) caused by an inverted left atrial appendage (ILAA) is a rare complication following cardiac surgery. We present a case of 23 day-old male infant who developed postoperative PHC attacks after undergoing cardiopulmonary bypass (CPB) surgery for repair of the coactation of aorta. A hyperechogenic left atrial mass was detected via bedside transthoracic echocardiography (TTE), which was identified as an ILAA and corrected following repeat surgery. In this case, both the negative pressure in vent catheter and the long left atrial appendage (LAA) with a narrow base led to an irreversible ILAA. As in this neonate, ILAA had significant influence on the left atrial volume and caused PHC since the ILAA was located on the mitral valve orifice and interfered with the blood flow through the valve. Therefore, we recommend that the vent catheter should be turned off before removing to avoid this potential complication. Additionally, LAA should be carefully inspected after CPB surgery, and intra-operative and post-operative transoesophageal echocardiography (TEE) should be performed to detect ILAA intraoperatively so as to avoid the reoperation. When an ILAA is diagnosed postoperatively, whether conservative treatment or surgery will depend on the balance of benefit and risk for a particular patient. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Expression and localization of the vascular endothelial growth factor and changes of microvessel density during hair follicle development of Liaoning cashmere goats.

PubMed

Zhang, Q L; Li, J P; Li, Y M; Chang, Q; Chen, Y; Jiang, H Z; Zhao, Z H; Guo, D

2013-12-10

Vascular endothelial growth factors (VEGFs) play important roles in neovascularization, tissue development, and angiogenesis. In this study, changes in VEGF expression patterns and microvessel density (MVD), and their correlations, were investigated during hair follicle development in epidermal appendages of Liaoning cashmere goats. Polyclonal antibodies to VEGF and microvessels were used for monthly immunohistochemical examinations of normal skin specimens from adult female goats for one year. VEGF was expressed in the hair bulb of primary and secondary hair follicles, the outer and inner root sheaths, sebaceous glands (ductal and secretory portions), eccrine sweat glands (ductal and secretory portions), and the epidermis. Abundant expression of VEGF was observed in the follicular basement membrane zone surrounding the bulb matrix and in ductal and secretory portions of eccrine sweat glands. The change in VEGFs in primary hair follicles showed a bimodal pattern, with the first peak observed from March to May, and the second in August. Maximal expression in secondary hair follicles occurred in May and August. Therefore, VEGF expression in primary and secondary hair follicles is synchronized throughout the year, and is correlated to hair development. In the later telogen and anagen phases, VEGF expression was higher in the secondary, compared to the primary, hair follicle. Changes in MVD also showed a bimodal pattern with peaks in May and August. VEGF expression and MVD showed moderate and strongly positive correlation in the primary and secondary hair follicles, respectively. Therefore, MVD and VEGF are closely related to the processes involved in hair cycle regulation.

The design and development of a spacecraft appendage tie down mechanism

NASA Technical Reports Server (NTRS)

Nygren, W. D.; Head, R.

1985-01-01

The design and evolution is described of a spacecraft Appendage Tie Down Mechanism (ATDM). Particular emphasis is paid to the mechanical aspects of using dry lubricants to increase the efficiency of acme threads and worm gearing. The ATDM consists of five major components. These are a dc torque motor, a worm gear speed reducer, the tension bolt (or T-bolt), nut capture and centering jaws and the capture nut. In addition, there are several minor components such as limit switch assemblies and an antibackdrive mechanism which couples the drive motor to the worm shaft. A development model of the ATDM in various configurations was under test for some time. In its latest version, it has successfully completed thermal vacuum testing, vibration testing, and extended life testing.

Epidermal dysplasia and abnormal hair follicles in transgenic mice overexpressing homeobox gene MSX-2.

PubMed

Jiang, T X; Liu, Y H; Widelitz, R B; Kundu, R K; Maxson, R E; Chuong, C M

1999-08-01

The homeobox gene Msx-2 is expressed specifically in sites of skin appendage formation. To explore its part in skin morphogenesis, we produced transgenic mice expressing Msx-2 under the control of the cytomegalovirus promoter. The skin of these transgenic mice was flaky, exhibiting desquamation and shorter hairs. Histologic analysis showed thickened epidermis with hyperproliferation, which was restricted to the basal layer. Hyperkeratosis was also evident. A wide zone of suprabasal cells were misaligned and coexpressed keratins 14 and 10. There was reduced expression of integrin beta 1 and DCC in the basal layer. Hair follicles were misaligned with a shrunken matrix region. The dermis showed increased cellularity and empty vacuoles. We suggest that Msx-2 is involved in the growth control of skin and skin appendages.

Keratosis pilaris

MedlinePlus

... eds. Treatment of Skin Disease: Comprehensive Therapeutic Strategies . 4th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 118. ... appendages. In: Patterson JW, ed. Weedon's Skin Pathology . 4th ed. Philadelphia, PA: Elsevier; 2016:chap 15.

Reconstructing the diet of a 505-million-year-old arthropod: Sidneyia inexpectans from the Burgess Shale fauna.

PubMed

Zacaï, Axelle; Vannier, Jean; Lerosey-Aubril, Rudy

2016-03-01

The feeding ecology of the 505-million-year-old arthropod Sidneyia inexpectans from the middle Cambrian (Series 3, Stage 5) Burgess Shale fauna (British Columbia, Canada) is revealed by three lines of evidence: the structure of its digestive system, the fossilized contents of its gut and the functional anatomy of its appendages. The digestive tract of Sidneyia is straight, tubular and relatively narrow in the trunk region. It is enlarged into a pear-shaped area in the cephalic region and stretches notably to form a large pocket in the abdomen. The mouth is ventral, posteriorly directed and leads to the midgut via a short tubular structure interpreted as the oesophagus. Anteriorly, three pairs of glands with internal, branching tubular structures open into the digestive tract. These glands have equivalents in various Cambrian arthropod taxa (e.g. naraoiids) and modern arthropods. Their primary function was most likely to digest and assimilate food. The abdominal pocket of Sidneyia concentrates undigested skeletal elements and various residues. It is interpreted here as the functional analogue of the stercoral pocket of some extant terrestrial arachnids (e.g. Araneae, Solifugae), whose primary function is to store food residuals and excretory material until defecation. Analysis of the gut contents indicates that Sidneyia fed largely on small ptychopariid trilobites, brachiopods, possibly agnostids, worms and other undetermined animals. Sidneyia was primarily a durophagous carnivore with predatory and/or scavenging habits, feeding on small invertebrates that lived at the water-sediment interface. There is no evidence for selective feeding. Its food items (e.g. living prey or dead material) were grasped and manipulated ventrally by its anterior appendages, then macerated into ingestible fragments and conveyed to the mouth via the converging action of strong molar-like gnathobases. Digestion probably took place within the anterior midgut via enzymes secreted in the glands. Residues were transported through the digestive tract into the abdominal pocket. The storage of faeces suggests infrequent feeding. The early diagenetic three-dimensional preservation of the digestive glands and abdominal pocket may be due to the capacity of Sidneyia to store Phosphorus and Calcium (e.g. spherites) in its digestive tissues during life as do, for example, modern horseshoe crabs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Propulsive forces of mudskipper fins and salamander limbs during terrestrial locomotion: implications for the invasion of land.

PubMed

Kawano, Sandy M; Blob, Richard W

2013-08-01

The invasion of land was a pivotal event in vertebrate evolution that was associated with major appendicular modifications. Although fossils indicate that the evolution of fundamentally limb-like appendages likely occurred in aquatic environments, the functional consequences of using early digited limbs, rather than fins, for terrestrial propulsion have had little empirical investigation. Paleontological and experimental analyses both have led to the proposal of an early origin of "hind limb-driven" locomotion among tetrapods or their ancestors. However, the retention of a pectoral appendage that had already developed terrestrial adaptations has been proposed for some taxa, and few data are available from extant functional models that can provide a foundation for evaluating the relative contributions of pectoral and pelvic appendages to terrestrial support among early stem tetrapods. To examine these aspects of vertebrate locomotor evolution during the invasion of land, we measured three-dimensional ground reaction forces (GRFs) produced by isolated pectoral fins of mudskipper fishes (Periophthalmus barbarus) during terrestrial crutching, and compared these to isolated walking footfalls by the forelimbs and hind limbs of tiger salamanders (Ambystoma tigrinum), a species with subequally-sized limbs that facilitate comparisons to early tetrapods. Pectoral appendages of salamanders and mudskippers exhibited numerous differences in GRFs. Compared with salamander forelimbs, isolated fins of mudskippers bear lower vertical magnitudes of GRFs (as a proportion of body weight), and had GRFs that were oriented more medially. Comparing the salamanders' forelimbs and hind limbs, although the peak net GRF occurs later in stance for the forelimb, both limbs experience nearly identical mediolateral and vertical components of GRF, suggesting comparable contributions to support. Thus, forelimbs could also have played a significant locomotor role among basal tetrapods that had limbs of sub-equal size. However, the salamander hind limb and mudskipper pectoral fin had a greater acceleratory role than did the salamander forelimb. Together, data from these extant taxa help to clarify how structural change may have influenced locomotor function through the evolutionary invasion of land by vertebrates.

Subdivision of arthropod cap-n-collar expression domains is restricted to Mandibulata

PubMed Central

2014-01-01

Background The monophyly of Mandibulata - the division of arthropods uniting pancrustaceans and myriapods - is consistent with several morphological characters, such as the presence of sensory appendages called antennae and the eponymous biting appendage, the mandible. Functional studies have demonstrated that the patterning of the mandible requires the activity of the Hox gene Deformed and the transcription factor cap-n-collar (cnc) in at least two holometabolous insects: the fruit fly Drosophila melanogaster and the beetle Tribolium castaneum. Expression patterns of cnc from two non-holometabolous insects and a millipede have suggested conservation of the labral and mandibular domains within Mandibulata. However, the activity of cnc is unknown in crustaceans and chelicerates, precluding understanding of a complete scenario for the evolution of patterning of this appendage within arthropods. To redress these lacunae, here we investigate the gene expression of the ortholog of cnc in Parhyale hawaiensis, a malacostracan crustacean, and two chelicerates: the harvestman Phalangium opilio, and the scorpion Centruroides sculpturatus. Results In the crustacean P. hawaiensis, the segmental expression of Ph-cnc is the same as that reported previously in hexapods and myriapods, with two distinct head domains in the labrum and the mandibular segment. In contrast, Po-cnc and Cs-cnc expression is not enriched in the labrum of either chelicerate, but instead is expressed at comparable levels in all appendages. In further contrast to mandibulate orthologs, the expression domain of Po-cnc posterior to the labrum is not confined within the expression domain of Po-Dfd. Conclusions Expression data from two chelicerate outgroup taxa suggest that the signature two-domain head expression pattern of cnc evolved at the base of Mandibulata. The observation of the archetypal labral and mandibular segment domains in a crustacean exemplar supports the synapomorphic nature of mandibulate cnc expression. The broader expression of Po-cnc with respect to Po-Dfd in chelicerates further suggests that the regulation of cnc by Dfd was also acquired at the base of Mandibulata. To test this hypothesis, future studies examining panarthropod cnc evolution should investigate expression of the cnc ortholog in arthropod outgroups, such as Onychophora and Tardigrada. PMID:24405788

Tracking the development of the petaloid fertile stamen in Canna indica: insights into the origin of androecial petaloidy in the Zingiberales

PubMed Central

Almeida, Ana M. R.; Brown, Andrew; Specht, Chelsea D.

2013-01-01

Flowers of the order Zingiberales demonstrate a remarkable trend of reduction in the number of fertile stamens; from five or six fertile, filamentous stamens bearing two thecae each in Musaceae and Strelitziaceae to just a single petaloid stamen bearing a single theca in Cannaceae and Marantaceae. As one progresses from ancestral to derived floral forms, 5–6 fertile stamens are replaced by 4–5 petaloid staminodes. In Cannaceae and Costaceae, all members of the androecial whorls exhibit petaloidy, including the fertile stamen. In Costaceae, a single fertile stamen develops two thecae embedded on a broad petaloid appendage, while in Cannaceae the single fertile stamen is further reduced to a single theca with a prominent, expanded petaloid appendage. Whether petaloidy of the fertile stamen is a synapomorphy of the entire ginger clade (including Cannaceae, Costaceae, Zingiberaceae and Marantaceae), or the result of independent convergent evolution in Cannaceae, Costaceae, and some Zingiberaceae, is unclear. We combine a developmental series of the formation of the petaloid fertile stamen in Canna indica with data on the expression of B- and C-class floral organ identity genes to elucidate the organogenetic identity of the petaloid stamen and staminodes. Our data indicate that the single fertile theca in C. indica and its petaloid appendage are derived from one-half of the primordium of a single stamen, with no contribution from the remaining part of the stamen (i.e. the second theca primordium) which aborts early in development. The petaloid appendage expands later, and develops from the position of the filament/connective of the developing theca. Floral identity gene expression shows that petal identity genes (i.e. B-class genes) are expressed in all floral organs studied while C-class gene AG-1 is expressed in an increasing gradient from sepals to gynoecium, and AG-2 is expressed in all floral organs except the petals. The canonical model for molecular specification of floral organ identity is not sufficient to explain petaloidy in the androecial whorl in Canna sp. Further studies understanding the regulation of gene networks are required. PMID:23539493

Tracking the development of the petaloid fertile stamen in Canna indica: insights into the origin of androecial petaloidy in the Zingiberales.

PubMed

Almeida, Ana M R; Brown, Andrew; Specht, Chelsea D

2013-01-01

Flowers of the order Zingiberales demonstrate a remarkable trend of reduction in the number of fertile stamens; from five or six fertile, filamentous stamens bearing two thecae each in Musaceae and Strelitziaceae to just a single petaloid stamen bearing a single theca in Cannaceae and Marantaceae. As one progresses from ancestral to derived floral forms, 5-6 fertile stamens are replaced by 4-5 petaloid staminodes. In Cannaceae and Costaceae, all members of the androecial whorls exhibit petaloidy, including the fertile stamen. In Costaceae, a single fertile stamen develops two thecae embedded on a broad petaloid appendage, while in Cannaceae the single fertile stamen is further reduced to a single theca with a prominent, expanded petaloid appendage. Whether petaloidy of the fertile stamen is a synapomorphy of the entire ginger clade (including Cannaceae, Costaceae, Zingiberaceae and Marantaceae), or the result of independent convergent evolution in Cannaceae, Costaceae, and some Zingiberaceae, is unclear. We combine a developmental series of the formation of the petaloid fertile stamen in Canna indica with data on the expression of B- and C-class floral organ identity genes to elucidate the organogenetic identity of the petaloid stamen and staminodes. Our data indicate that the single fertile theca in C. indica and its petaloid appendage are derived from one-half of the primordium of a single stamen, with no contribution from the remaining part of the stamen (i.e. the second theca primordium) which aborts early in development. The petaloid appendage expands later, and develops from the position of the filament/connective of the developing theca. Floral identity gene expression shows that petal identity genes (i.e. B-class genes) are expressed in all floral organs studied while C-class gene AG-1 is expressed in an increasing gradient from sepals to gynoecium, and AG-2 is expressed in all floral organs except the petals. The canonical model for molecular specification of floral organ identity is not sufficient to explain petaloidy in the androecial whorl in Canna sp. Further studies understanding the regulation of gene networks are required.

Ultrastructure of book gill development in embryos and first instars of the horseshoe crab Limulus polyphemus L. (Chelicerata, Xiphosura)

PubMed Central

2012-01-01

Background The transmission electron microscope (TEM) is used for the first time to study the development of book gills in the horseshoe crab. Near the end of the nineteenth century the hypothesis was presented for homology and a common ancestry for horseshoe crab book gills and arachnid book lungs. The present developmental study and the author's recent ones of book gills (SEM) and scorpion book lungs (TEM) are intended to clarify early histological work and provide new ultrastructural details for further research and for hypotheses about evolutionary history and relationships. Results The observations herein are in agreement with earlier reports that the book gill lamellae are formed by proliferation and evagination of epithelial cells posterior to opisthosomal branchial appendages. A cartilage-like endoskeleton is produced in the base of the opisthosomal appendages. The lamellar precursor cells in the appendage base proliferate, migrate outward and secrete the lamellar cuticle from their apical surface. A series of external, posteriorly-directed lamellae is formed, with each lamella having a central channel for hemolymph and pillar-type space holders formed from cells of the opposed walls. This repeated, page-like pattern results also in water channels (without space holders) between the sac-like hemolymph lamellae. Conclusions The developmental observations herein and in an earlier study (TEM) of scorpion book lungs show that the lamellae in book gills and book lungs result from some similar activities and features of the precursor epithelial cells: proliferation, migration, alignment and apical/basal polarity with secretion of cuticle from the apical surface and the basal surface in contact with hemolymph. These cellular similarities and the resulting book-like structure suggest a common ancestry, but there are also substantial developmental differences in producing these organs for gas exchange in the different environments, aqueous and terrestrial. For scorpion book lungs, the invaginated precursor cells align in rows and secrete rows of cell fragments that are the basis for the internal, anterior-directed air sacs. The hemolymph sacs of book gills are formed by epithelial evagination or outfolding from the posterior surface of the branchial appendages. PMID:22433580

15 CFR 917.30 - General.

Code of Federal Regulations, 2013 CFR

2013-01-01

... appendage to the ongoing Sea Grant program, will also be an important evaluation factor. The U.S. Department... area between Sea Grant and UNESCO, the Division of Marine Sciences (UNESCO) will be informed of all...

The dynamics and optimal control of spinning spacecraft and movable telescoping appendages, part B: Effect of gravity-gradient torques on the dynamics of a spinning spacecraft with telescoping appendages

NASA Technical Reports Server (NTRS)

Bainum, P. M.; Rajan, M.

1977-01-01

The effects of gravity gradient torques during boom deployment maneuvers of a spinning spacecraft are examined. Configurations where the booms extended only along the hub principal axes and where one or two booms are offset from the principal axes were considered. For the special case of symmetric deployment (principal axes booms) the stability boundaries are determined, and a stability chart is used to study the system behavior. Possible cases of instability during this type of maneuver are identified. In the second configuration an expression for gravity torque about the hub center of mass was developed. The nonlinear equations of motion are solved numerically, and the substantial influence of the gravity torque during asymmetric deployment maneuvers is indicated.

The left atrial appendage: from embryology to prevention of thromboembolism.

PubMed

Patti, Giuseppe; Pengo, Vittorio; Marcucci, Rossella; Cirillo, Plinio; Renda, Giulia; Santilli, Francesca; Calabrò, Paolo; De Caterina, Alberto Ranieri; Cavallari, Ilaria; Ricottini, Elisabetta; Parato, Vito Maurizio; Zoppellaro, Giacomo; Di Gioia, Giuseppe; Sedati, Pietro; Cicchitti, Vincenzo; Davì, Giovanni; Golia, Enrica; Pariggiano, Ivana; Simeone, Paola; Abbate, Rosanna; Prisco, Domenico; Zimarino, Marco; Sofi, Francesco; Andreotti, Felicita; De Caterina, Raffaele

2017-03-21

The left atrial appendage (LAA) is the main source of thromboembolism in patients with non-valvular atrial fibrillation (AF). As such, the LAA can be the target of specific occluding device therapies. Optimal management of patients with AF includes a comprehensive knowledge of the many aspects related to LAA structure and thrombosis. Here we provide baseline notions on the anatomy and function of the LAA, and then focus on current imaging tools for the identification of anatomical varieties. We also describe pathogenetic mechanisms of LAA thrombosis in AF patients, and examine the available evidence on treatment strategies for LAA thrombosis, including the use of non-vitamin K antagonist oral anticoagulants and interventional approaches. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

A True Human Tail in a Neonate: Case report and literature review.

PubMed

Pillai, Mahesh K; Nair, Smitha T

2017-02-01

A true human tail is a benign vestigial caudal cutaneous structure composed of adipose, connective tissue, muscle, vessels, nerves and mechanoreceptors. A true human tail can be distinguished from a pseudotail as the latter is commonly associated with underlying spinal dysraphism, which requires specialised management. True human tails are very rare, with fewer than 40 cases reported to date. We report a healthy one-day-old male newborn who was referred to the Bharath Hospital, Kottayam, Kerala, India, in 2014 with a cutaneous appendage arising from the lumbosacral region. Magnetic resonance imaging of the spine ruled out spinal dysraphism. The appendage was removed by simple surgical excision. Clinicians should emphasise use of 'true tail' and 'pseudotail' as specific disparate terms as the clinical, radiological and histological findings of these conditions differ significantly, along with management strategies and outcomes.

Evo-Devo of Amniote Integuments and Appendages

PubMed Central

Wu, Ping; Hou, Lianhai; Plikus, Maksim; Hughes, Michael; Scehnet, Jeffrey; Suksaweang, Sanong; Widelitz, Randall B.; Jiang, Ting-Xin; Chuong, Cheng-Ming

2015-01-01

Integuments form the boundary between an organism and the environment. The evolution of novel developmental mechanisms in integuments and appendages allows animals to live in diverse ecological environments. Here we focus on amniotes. The major achievement for reptile skin is an adaptation to the land with the formation of a successful barrier. The stratum corneum enables this barrier to prevent water loss from the skin and allowed amphibian/reptile ancestors to go onto the land. Overlapping scales and production of β-keratins provide strong protection. Epidermal invagination led to the formation of avian feather and mammalian hair follicles in the dermis. Both adopted a proximal - distal growth mode that maintains endothermy. Feathers form hierarchical branches which produce the vane that makes flight possible. Recent discoveries of feathered dinosaurs in China inspire new thinking on the origin of feathers. In the laboratory, epithelial - mesenchymal recombinations and molecular mis-expressions were carried out to test the plasticity of epithelial organ formation. We review the work on the transformation of scales into feathers, conversion between barbs and rachis, and the production of “chicken teeth”. In mammals, tilting the balance of the BMP pathway in K14 noggin transgenic mice alters the number, size and phenotypes of different ectodermal organs, making investigators rethink the distinction between morpho-regulation and pathological changes. Models on the evolution of feathers and hairs from reptile integuments are discussed. A hypothetical Evo-Devo space where diverse integument appendages can be placed according to complex phenotypes and novel developmental mechanisms is presented. PMID:15272390

Left atrial appendages from adult hearts contain a reservoir of diverse cardiac progenitor cells.

PubMed

Leinonen, Jussi V; Emanuelov, Avishag K; Platt, Yardanna; Helman, Yaron; Feinberg, Yael; Lotan, Chaim; Beeri, Ronen

2013-01-01

There is strong evidence supporting the claim that endogenous cardiac progenitor cells (CPCs) are key players in cardiac regeneration, but the anatomic source and phenotype of the master cardiac progenitors remains uncertain. Our aim was to investigate the different cardiac stem cell populations in the left atrial appendage (LAA) and their fates. We investigated the CPC content and profile of adult murine LAAs using immunohistochemistry and flow cytometry. We demonstrate that the LAA contains a large number of CPCs relative to other areas of the heart, representing over 20% of the total cell number. We grew two distinct CPC populations from the LAA by varying the degree of proteolysis. These differed by their histological location, surface marker profiles and growth dynamics. Specifically, CD45(pos) cells grew with milder proteolysis, while CD45(neg) cells grew mainly with more intense proteolysis. Both cell types could be induced to differentiate into cells with cardiomyocyte markers and organelles, albeit by different protocols. Many CD45(pos) cells expressed CD45 initially and rapidly lost its expression while differentiating. Our results demonstrate that the left atrial appendage plays a role as a reservoir of multiple types of progenitor cells in murine adult hearts. Two different types of CPCs were isolated, differing in their epicardial-myocardial localization. Considering studies demonstrating layer-specific origins of different cardiac progenitor cells, our findings may shed light on possible pathways to study and utilize the diversity of endogenous progenitor cells in the adult heart.

Museomics resolve the systematics of an endangered grass lineage endemic to north-western Madagascar

PubMed Central

Silva, Christian; Besnard, Guillaume; Piot, Anthony; Razanatsoa, Jacqueline; Oliveira, Reyjane P.; Vorontsova, Maria S.

2017-01-01

Background and Aims Recent developments in DNA sequencing, so-called next-generation sequencing (NGS) methods, can help the study of rare lineages that are known from museum specimens. Here, the taxonomy and evolution of the Malagasy grass lineage Chasechloa was investigated with the aid of NGS. Methods Full chloroplast genome data and some nuclear sequences were produced by NGS from old herbarium specimens, while some selected markers were generated from recently collected Malagasy grasses. In addition, a scanning electron microscopy analysis of the upper floret and cross-sections of the rachilla appendages followed by staining with Sudan IV were performed on Chasechloa to examine the morphology of the upper floret and the presence of oils in the appendages. Key Results Chasechloa was recovered within tribe Paniceae, sub-tribe Boivinellinae, contrary to its previous placement as a member of the New World genus Echinolaena (tribe Paspaleae). Chasechloa originated in Madagascar between the Upper Miocene and the Pliocene. It comprises two species, one of them collected only once in 1851. The genus is restricted to north-western seasonally dry deciduous forests. The appendages at the base of the upper floret of Chasechloa have been confirmed as elaiosomes, an evolutionary adaptation for myrmecochory. Conclusions Chasechloa is reinstated at the generic level and a taxonomic treatment is presented, including conservation assessments of its species. Our study also highlights the power of NGS technology to analyse relictual or probably extinct groups. PMID:28028020

Compensatory escape mechanism at low Reynolds number

PubMed Central

Gemmell, Brad J.; Sheng, Jian; Buskey, Edward J.

2013-01-01

Despite high predation pressure, planktonic copepods remain one of the most abundant groups on the planet. Their escape response provides one of most effective mechanisms to maximize evolutionary fitness. Owing to their small size (100 µm) compared with their predators (>1 mm), increasing viscosity is believed to have detrimental effects on copepods’ fitness at lower temperature. Using high-speed digital holography we acquire 3D kinematics of the nauplius escape including both location and detailed appendage motion. By independently varying temperature and viscosity we demonstrate that at natural thermal extremes, contrary to conventional views, nauplii achieve equivalent escape distance while maintaining optimal velocity. Using experimental results and kinematic simulations from a resistive force theory propulsion model, we demonstrate that a shift in appendage timing creates an increase in power stroke duration relative to recovery stroke duration. This change allows the nauplius to limit losses in velocity and maintain distance during escapes at the lower bound of its natural thermal range. The shift in power stroke duration relative to recovery stroke duration is found to be regulated by the temperature dependence of swimming appendage muscle groups, not a dynamic response to viscosity change. These results show that copepod nauplii have natural adaptive mechanisms to compensate for viscosity variations with temperature but not in situations in which viscosity varies independent of temperature, such as in some phytoplankton blooms. Understanding the robustness of escapes in the wake of environmental changes such as temperature and viscosity has implications in assessing the future health of performance compensation. PMID:23487740

Hydrodynamic pumping by serial gill arrays in the mayfly nymph Centroptilum triangulifer.

PubMed

Sensenig, Andrew T; Kiger, Ken T; Shultz, Jeffrey W

2010-10-01

Aquatic nymphs of the mayfly Centroptilum triangulifer produce ventilatory flow using a serial array of seven abdominal gill pairs that operates across a Reynolds numbers (Re) range from 2 to 22 during ontogeny. Net flow in small animals is directed ventrally and essentially parallel to the stroke plane (i.e. rowing), but net flow in large animals is directed dorsally and essentially transverse to the stroke plane (i.e. flapping). Detailed flow measurements based on Particle Image Velocimetry (PIV) ensemble-correlation analysis revealed that the phasing of the gills produces a time-dependent array of vortices associated with a net ventilatory current, a fluid kinematic pattern, here termed a 'phased vortex pump'. Absolute size of vortices does not change with increasing animal size or Re, and thus the vortex radius (R(v)) decreases relative to inter-gill distance (L(is)) during mayfly growth. Given that effective flapping in appendage-array animals requires organized flow between adjacent appendages, we hypothesize that rowing should be favored when L(is)/R(v)<1 and flapping should be favored when L(is)/R(v)>1. Significantly, the rowing-to-flapping transition in Centroptilum occurs at Re∼5, when the mean dynamic inter-gill distance equals the vortex radius. This result suggests that the Re-based rowing-flapping demarcation observed in appendage-array aquatic organisms may be determined by the relative size of the propulsive mechanism and its self-generated vortices.

Change in cognitive process during dance video game play with different appendages for motor output

NASA Astrophysics Data System (ADS)

Suzuki, Kota; Ono, Yumie; Shimada, Sotaro; Tachibana, Atsumichi; Noah, Jack Adam

2018-02-01

Playing a dance video game (DVG) requires fine temporal control of foot positions based on simultaneous visuoauditory integration. Despite the highly-demanding nature of its cognitive processes, DVG could offer promising exercise opportunities for elderly people to maintain their cognitive abilities due to its strong adherence. Using functional near-infrared spectroscopy, we have previously shown that DVG play with the foot activates prefrontal and temporoparietal cortices. However, it is still in debate whether this brain-stimulatory effect of DVG could also be maintained in case that DVG is played with the hand by people who have difficulty to play DVG in a standing position. We therefore investigated the regional brain activity of 12 healthy, right-handed young-adults when they played DVG with their dominant hand and foot. We found that the DVG-related hemodynamic activity was comparable in the prefrontal area regardless of the appendages while that was significantly smaller in case of playing with the hand related to the foot in the left superior/middle temporal gyrus (S/MTG). A similar trend was also observed in the right S/MTG. These results suggest that the motor preparatory function mediated by the prefrontal cortices is equally employed regardless of appendages while more cognitive load is required in the temporal cortices with foot-played DVG, possibly to integrate visual, auditory, and proprioceptive information. Hand-played DVG may partially substitute foot-played DVG in the sense of cognitive training in the elderly.

Holocephalan embryos provide evidence for gill arch appendage reduction and opercular evolution in cartilaginous fishes

PubMed Central

Gillis, J. Andrew; Rawlinson, Kate A.; Bell, Justin; Lyon, Warrick S.; Baker, Clare V. H.; Shubin, Neil H.

2011-01-01

Chondrichthyans possess endoskeletal appendages called branchial rays that extend laterally from their hyoid and gill-bearing (branchial) arches. Branchial ray outgrowth, like tetrapod limb outgrowth, is maintained by Sonic hedgehog (Shh) signaling. In limbs, distal endoskeletal elements fail to form in the absence of normal Shh signaling, whereas shortened duration of Shh expression correlates with distal endoskeletal reduction in naturally variable populations. Chondrichthyans also exhibit natural variation with respect to branchial ray distribution—elasmobranchs (sharks and batoids) possess a series of ray-supported septa on their hyoid and gill arches, whereas holocephalans (chimaeras) possess a single hyoid arch ray-supported operculum. Here we show that the elongate hyoid rays of the holocephalan Callorhinchus milii grow in association with sustained Shh expression within an opercular epithelial fold, whereas Shh is only transiently expressed in the gill arches. Coincident with this transient Shh expression, branchial ray outgrowth is initiated in C. milii but is not maintained, yielding previously unrecognized vestigial gill arch branchial rays. This is in contrast to the condition seen in sharks, where sustained Shh expression corresponds to the presence of fully formed branchial rays on the hyoid and gill arches. Considered in light of current hypotheses of chondrichthyan phylogeny, our data suggest that the holocephalan operculum evolved in concert with gill arch appendage reduction by attenuation of Shh-mediated branchial ray outgrowth, and that chondrichthyan branchial rays and tetrapod limbs exhibit parallel developmental mechanisms of evolutionary reduction. PMID:21220324

Three-dimensional morphological and textural complexity of Archean putative microfossils from the Northeastern Pilbara Craton: indications of biogenicity of large (>15 microm) spheroidal and spindle-like structures.

PubMed

Sugitani, Kenichiro; Grey, Kathleen; Nagaoka, Tsutomu; Mimura, Koichi

2009-09-01

We recently reported a diverse assemblage of carbonaceous structures (thread-like, film-like, spheroidal, and spindle-like) from chert in the ca. 3.0 Ga Farrel Quartzite of the Gorge Creek Group in the Pilbara Craton, Western Australia. Results from a rigorous examination of occurrence, composition, morphological complexity, size distributions, and taphonomy provided presumptive evidence for biogenicity. In this study, we present new data of morphological and textural complexity of large (>15 microm) spheroidal and spindle-like structures, using an in-focus, 3-D image reconstruction system, which further raises the scale of credibility that these structures are microfossils. While many of the large spheroids are single-walled, and the wall is irregularly folded, a few specimens are partially blistered, double walled, or have a dimpled wall. The wall-surface texture varies from smooth and homogeneous (hyaline) to patchy, granular or reticulate. Such variation is best explained as resulting from taphonomic processes. Additionally, an inner solitary body, present in some large spheroids, is hollow and partially broken, which indicates a primary origin for this substructure. Spindle-like structures have two types of flange-like appendage; one is attached at the equatorial plane of the body, whereas the other appears to be attached peripherally. In both cases, the appendage tends to have a flat geometry, a tapering thickness, and constancy in shape, proportions, and dimensions. Spindle-wall surfaces are variously textured and heterogeneous. These morphological and textural complexities and heterogeneity refute potential abiogenic formation models for these structures, such as crystals coated with organic matter, fenestrae, and the diagenetic redistribution of carbonaceous matter. When coupled with other data from Raman spectroscopy, NanoSIMS analysis, and palynology, the evidence that these large carbonaceous structures are biogenic appears compelling, though it is still equivocal as to whether they are cells or outer envelopes of colonies of smaller cells.

Locomotion Dynamics for Bio-inspired Robots with Soft Appendages: Application to Flapping Flight and Passive Swimming

NASA Astrophysics Data System (ADS)

Boyer, Frédéric; Porez, Mathieu; Morsli, Ferhat; Morel, Yannick

2017-08-01

In animal locomotion, either in fish or flying insects, the use of flexible terminal organs or appendages greatly improves the performance of locomotion (thrust and lift). In this article, we propose a general unified framework for modeling and simulating the (bio-inspired) locomotion of robots using soft organs. The proposed approach is based on the model of Mobile Multibody Systems (MMS). The distributed flexibilities are modeled according to two major approaches: the Floating Frame Approach (FFA) and the Geometrically Exact Approach (GEA). Encompassing these two approaches in the Newton-Euler modeling formalism of robotics, this article proposes a unique modeling framework suited to the fast numerical integration of the dynamics of a MMS in both the FFA and the GEA. This general framework is applied on two illustrative examples drawn from bio-inspired locomotion: the passive swimming in von Karman Vortex Street, and the hovering flight with flexible flapping wings.

Attitude stability of spinning flexible spacecraft

NASA Technical Reports Server (NTRS)

Likins, P. W.; Barbera, F. J.

1971-01-01

The stability of spinning flexible satellites in a force-free environment was analyzed. The satellite was modeled as a rigid core having attached to it a flexible appendage idealized as a collection of particles (point masses) interconnected by springs. Both Liapunov and Routh-Hurwitz stability procedures are used. In the former, the Hamiltonian of the system, constrained through the angular momentum integral so as to admit complete damping, is used as a testing function. Equations of motion are written using the hybrid coordinate formulation, which readily accepts a modal coordinate transformation ultimately allowing truncation to a level amenable to literal stability analysis. Closed form stability criteria are generated for the first mode of a restricted appendage model lying in a plane containing the system center of mass and orthogonal to the spin axis. The effects of spin on flexible bodies are discussed by considering a very elementary particle model. Control of passively unstable spacecraft is briefly considered.

Bio-inspired robot design for viscous fluids

NASA Astrophysics Data System (ADS)

Ma, Grace; Lipman, Tyler; Jung, Sunghwan

Many modern micro-robots are designed for biomedical applications to transport drugs to targets or to operate tests in the body for diagnosis. However, most micro-robots simply mimic the morphology and the propulsive mechanism of micro-organisms without understanding the underlying physics of low-Re swimming. Two types of swimming motions have been observed in micro-organisms; stresslet and source-dipole swimming. The stresslet swimmer (e.g. E. coli) uses a rotating helical appendage, whereas the source-dipole swimmer (e.g. Paramecium) creates surface velocity for propulsion. Using this principle, we designed a robot to swim in very viscous fluids either by rotating a helix or creating surface velocity, simply by changing the orientation of the appendage. Further, we will discuss the performance of this robot (swimming speed and rotation speed) with respect to the number, winding angle, and radius of helices in a very viscous fluid.

The dynamics and optimal control of spinning spacecraft with movable telescoping appendages. Part C: Effect of flexibility during boom deployment

NASA Technical Reports Server (NTRS)

Bainum, P. M.; James, P. K.

1977-01-01

The dynamics of a spinning symmetrical spacecraft system during the deployment (or retraction) of flexible boom-type appendages were investigated. The effect of flexibility during boom deployment is treated by modelling the deployable members as compound spherical pendula of varying length (according to a control law). The orientation of the flexible booms with respect to the hub, is described by a sequence of two Euler angles. The boom members contain a flexural stiffness which can be related to an assumed effective restoring linear spring constant, and structural damping which effects the entire system. Linearized equations of motion for this system, when the boom length is constant, involve periodic coefficients with the frequency of the hub spin. A bounded transformation is found which converts this system into a kinematically equivalent one involving only constant coefficients.

Rivaroxaban as an effective alternative to warfarin in a patient with atrial fibrillation, thrombophilia, and left atrial appendage thrombus: a case report.

PubMed

Scarano, Michele; Casale, Matteo; Mantini, Cesare; Imbalzano, Egidio; Consorti, Cristiana; Clemente, Daniela; Dattilo, Giuseppe

2017-04-09

Atrial fibrillation is the most common cardiac arrhythmia. It is responsible for up to 20% of all ischemic strokes. Rate control and anticoagulation are crucial for atrial fibrillation management and stroke prevention. We present the case of an 84-year-old Italian woman with a left atrial appendage thrombus that developed despite her use of anticoagulant therapy with warfarin for a previous pulmonary embolism. She had atrial fibrillation and heterozygosity for both factor V Leiden and methylenetetrahydrofolate reductase C677T mutation, thus creating resistance to activated protein C. Anticoagulant therapy was switched to heparin for 1 week and then to rivaroxaban. After 3 months of rivaroxaban use, the thrombus disappeared. This case raises the issue of the ineffectiveness of warfarin therapy in complex cases involving particular thrombophilic conditions and the possibility of using rivaroxaban as a safe and effective alternative.

Description of Alaeuris stehlini n. sp. and Alaeuris numidica canariensis n. ssp. (Nematoda, Pharyngodonidae), parasite of Gallotia stehlini, lacertid of Grand Canary Island (Spain).

PubMed

Zapatero, C; Castaño, C; Zapatero, L M

1999-03-01

Pharyngodonid nematodes (Oxyuroidea) belonging to the genus Alaeuris Thapar, 1925, were collected from the posterior gut of Gallotia stehlini (Lacertidae) from Grand Canary Island. Two species Alaeuris stehlini n. sp. and Alaeuris numidica canariensis n. ssp. were identified. The new species is described in which the long thin males are characterized by narrow caudal alae, a rounded first pair of adanal papillae non pedunculate, the second pair attached and elongate, the three pair teated; a short narrow V plate and a relatively long caudal appendage. The females are also long and thin with a slightly salient vulva, a conical pointed caudal appendage, oesophageal length approximately one third of body, excretory pore below the oesophageal bulb. The new subspecies most closely resembles Alaeuris numidica numidica. (Seurat, 1918) Petter, 1966 and Alaeuris numidica madagascariensis Petter, 1966.

Thermally induced vibrations of smart solar panel in a low-orbit satellite

NASA Astrophysics Data System (ADS)

Azadi, E.; Fazelzadeh, S. Ahmad; Azadi, M.

2017-03-01

In this paper, a smart flexible satellite moving in a circular orbit with two flexible panels are studied. The panels have been modeled as clamped-free-free-free rectangular plates with attached piezoelectric actuators. It is assumed that the satellite has a pitch angle rotation maneuver. Rapid temperature changes at day-night transitions in orbit generate time dependent bending moments. Satellite maneuver and temperature varying induce vibrations in the appendages. So, to simulate the system, heat radiation effects on the appendages have been considered. The nonlinear equations of motion and the heat transfer equations are coupled and solved simultaneously. So, the governing equations of motion are nonlinear and very complicated ones. Finally, the whole system is simulated and the effects of the heat radiation, radius of the orbit, piezoelectric voltages, and piezoelectric locations on the response of the system are studied.

Left Atrial Appendage Closure in Atrial Fibrillation: A World without Anticoagulation?

PubMed Central

Contractor, Tahmeed; Khasnis, Atul

2011-01-01

Atrial Fibrillation (AF) is a common arrhythmia with an incidence that is as high as 10% in the elderly population. Given the large proportion of strokes caused by AF as well as the associated morbidity and mortality, reducing stroke burden is the most important part of AF management. While warfarin significantly reduces the risk of AF-related stroke, perceived bleeding risks and compliance limit its widespread use in the high-risk AF population. The left atrial appendage is believed to be the “culprit” for thrombogenesis in nonvalvular AF and is a new therapeutic target for stroke prevention. The purpose of this review is to explore the evolving field of percutaneous LAA occlusion. After briefly highlighting the risk of stroke with AF, problems with warfarin, and the role of the LAA in clot formation, this article discusses the feasibility and efficacy of various devices which have been developed for percutaneous LAA occlusion. PMID:21559225

Unusual anal fin in a Devonian jawless vertebrate reveals complex origins of paired appendages

PubMed Central

Sansom, Robert S.; Gabbott, Sarah E.; Purnell, M. A.

2013-01-01

Jawed vertebrates (gnathostomes) have undergone radical anatomical and developmental changes in comparison with their jawless cousins (cyclostomes). Key among these is paired appendages (fins, legs and wings), which first evolved at some point on the gnathostome stem. The anatomy of fossil stem gnathostomes is, therefore, fundamental to our understanding of the nature and timing of the origin of this complex innovation. Here, we show that Euphanerops, a fossil jawless fish from the Devonian, possessed paired anal-fin radials, but no pectoral or pelvic fins. This unique condition occurs at an early stage on the stem-gnathostome lineage. This condition, and comparison with the varied condition of paired fins in other ostracoderms, indicates that there was a large amount of developmental plasticity during this episode—rather than a gradual evolution of this complex feature. Apparently, a number of different clades were exploring morphospace or undergoing multiple losses. PMID:23576777

Hierarchical assembly of centriole subdistal appendages via centrosome binding proteins CCDC120 and CCDC68.

PubMed

Huang, Ning; Xia, Yuqing; Zhang, Donghui; Wang, Song; Bao, Yitian; He, Runsheng; Teng, Junlin; Chen, Jianguo

2017-04-19

In animal cells, the centrosome is the main microtubule-organizing centre where microtubules are nucleated and anchored. The centriole subdistal appendages (SDAs) are the key structures that anchor microtubules in interphase cells, but the composition and assembly mechanisms of SDAs are not well understood. Here, we reveal that centrosome-binding proteins, coiled-coil domain containing (CCDC) 120 and CCDC68 are two novel SDA components required for hierarchical SDA assembly in human cells. CCDC120 is anchored to SDAs by ODF2 and recruits CEP170 and Ninein to the centrosome through different coiled-coil domains at its N terminus. CCDC68 is a CEP170-interacting protein that competes with CCDC120 in recruiting CEP170 to SDAs. Furthermore, CCDC120 and CCDC68 are required for centrosome microtubule anchoring. Our findings elucidate the molecular basis for centriole SDA hierarchical assembly and microtubule anchoring in human interphase cells.

Museomics resolve the systematics of an endangered grass lineage endemic to north-western Madagascar.

PubMed

Silva, Christian; Besnard, Guillaume; Piot, Anthony; Razanatsoa, Jacqueline; Oliveira, Reyjane P; Vorontsova, Maria S

2017-02-01

Recent developments in DNA sequencing, so-called next-generation sequencing (NGS) methods, can help the study of rare lineages that are known from museum specimens. Here, the taxonomy and evolution of the Malagasy grass lineage Chasechloa was investigated with the aid of NGS. Full chloroplast genome data and some nuclear sequences were produced by NGS from old herbarium specimens, while some selected markers were generated from recently collected Malagasy grasses. In addition, a scanning electron microscopy analysis of the upper floret and cross-sections of the rachilla appendages followed by staining with Sudan IV were performed on Chasechloa to examine the morphology of the upper floret and the presence of oils in the appendages. Chasechloa was recovered within tribe Paniceae, sub-tribe Boivinellinae, contrary to its previous placement as a member of the New World genus Echinolaena (tribe Paspaleae). Chasechloa originated in Madagascar between the Upper Miocene and the Pliocene. It comprises two species, one of them collected only once in 1851. The genus is restricted to north-western seasonally dry deciduous forests. The appendages at the base of the upper floret of Chasechloa have been confirmed as elaiosomes, an evolutionary adaptation for myrmecochory. Chasechloa is reinstated at the generic level and a taxonomic treatment is presented, including conservation assessments of its species. Our study also highlights the power of NGS technology to analyse relictual or probably extinct groups. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Tissue Regeneration and Biomineralization in Sea Urchins: Role of Notch Signaling and Presence of Stem Cell Markers

PubMed Central

Reinardy, Helena C.; Emerson, Chloe E.; Manley, Jason M.; Bodnar, Andrea G.

2015-01-01

Echinoderms represent a phylum with exceptional regenerative capabilities that can reconstruct both external appendages and internal organs. Mechanistic understanding of the cellular pathways involved in regeneration in these animals has been hampered by the limited genomic tools and limited ability to manipulate regenerative processes. We present a functional assay to investigate mechanisms of tissue regeneration and biomineralization by measuring the regrowth of amputated tube feet (sensory and motor appendages) and spines in the sea urchin, Lytechinus variegatus. The ability to manipulate regeneration was demonstrated by concentration-dependent inhibition of regrowth of spines and tube feet by treatment with the mitotic inhibitor, vincristine. Treatment with the gamma-secretase inhibitor DAPT resulted in a concentration-dependent inhibition of regrowth, indicating that both tube feet and spine regeneration require functional Notch signaling. Stem cell markers (Piwi and Vasa) were expressed in tube feet and spine tissue, and Vasa-positive cells were localized throughout the epidermis of tube feet by immunohistochemistry, suggesting the existence of multipotent progenitor cells in these highly regenerative appendages. The presence of Vasa protein in other somatic tissues (e.g. esophagus, radial nerve, and a sub-population of coelomocytes) suggests that multipotent cells are present throughout adult sea urchins and may contribute to normal homeostasis in addition to regeneration. Mechanistic insight into the cellular pathways governing the tremendous regenerative capacity of echinoderms may reveal processes that can be modulated for regenerative therapies, shed light on the evolution of regeneration, and enable the ability to predict how these processes will respond to changing environmental conditions. PMID:26267358

[Stroke. are there any difference between patients with or without patent foramen ovale in left atrial appendage systolic function?].

PubMed

Contreras, Alejandro E; Perrote, Federico; Concari, Ignacio; Brenna, Eduardo J; Lucero, Cecilia

2012-01-01

The aim of this study was to evaluate the systolic function of the left atrial appendage (LAA) in a group with and without patent foramen ovale (PFO) who suffered ischemic cerebrovascular events. Between September 2010 and October 2011, 17 patients were referred for transesophageal echocardiography (TEE) after suffering a stroke. PFO was defined as the passage of at least one bubble through atrial septum with bubble test. We compared systolic velocity in the appendage between patients with and without PFO and a control group. Were 8 women and 9 men, mean age 54.1 ± 19.5 years and 8 patients were under 55 years of age. All patients had suffered a ischemic cerebrovascular events, 41.2% had stroke, 52.9% transient ischemic attack and amaurosis fugax 5.9%. In the assessment of TEE, 11.8% had atrial septal aneurysm and 35.3% PFO. Mean LAA systolic velocity was 66.3 ± 20.3 cm / sec. There was no difference in systolic velocity of the LAA between patients with and without PFO (67.5 ± 11.8 cm / sec vs 65.7 ± 24.3 cm / sec respectively, p = 0.87). The control group of 8 patients, 5 women and 3 men, mean age 39.5 ± 18 years, had a LAA systolic velocity of 77.6 ± 28.9 cm / sec, no significant differences with ischemic patients. There were no differences in systolic function of the LAA between patients with and without PFO with ischemic cerebrovascular event.

Patient-specific catheter shaping for the minimally invasive closure of the left atrial appendage.

PubMed

Graf, Eva C; Ott, Ilka; Praceus, Julian; Bourier, Felix; Lueth, Tim C

2018-06-01

The minimally invasive closure of the left atrial appendage is a promising alternative to anticoagulation for stroke prevention in patients suffering from atrial fibrillation. One of the challenges of this procedure is the correct positioning and the coaxial alignment of the tip of the catheter sheath to the implant landing zone. In this paper, a novel preoperative planning system is proposed that allows patient-individual shaping of catheters to facilitate the correct positioning of the catheter sheath by offering a patient-specific catheter shape. Based on preoperative three-dimensional image data, anatomical points and the planned implant position are marked interactively and a patient-specific catheter shape is calculated if the standard catheter is not considered as suitable. An approach to calculate a catheter shape with four bends by maximization of the bending radii is presented. Shaping of the catheter is supported by a bending form that is automatically generated in the planning program and can be directly manufactured by using additive manufacturing methods. The feasibility of the planning and shaping of the catheter could be successfully shown using six data sets. The patient-specific catheters were tested in comparison with standard catheters by physicians on heart models. In four of the six tested models, the participating physicians rated the patient-individual catheters better than the standard catheter. The novel approach for preoperatively planned and shaped patient-specific catheters designed for the minimally invasive closure of the left atrial appendage could be successfully implemented and a feasibility test showed promising results in anatomies that are difficult to access with the standard catheter.

Anatomy of mole external genitalia: Setting the record straight

PubMed Central

Sinclair, Adriane Watkins; Glickman, Stephen; Baskin, Lawrence; Cunha, Gerald R.

2016-01-01

Anatomy of male and female external genitalia of adult mice (Mus musculus) and broad-footed moles (Scapanus latimanus) was re-examined to provide more meaningful anatomical terminology. In the past the perineal appendage of male broad-footed moles has been called the penis, while the female perineal appendage has been given several terms (e.g. clitoris, penile clitoris, peniform clitoris and others). Histological examination demonstrates that perineal appendages of male and female broad-footed moles are the prepuce, which in both sexes are covered externally with a hair-bearing epidermis and lacks erectile bodies. The inner preputial epithelium is non-hair-bearing and defines the preputial space in both sexes. The penis of broad-footed moles lies deep within the preputial space, is an “internal organ” in the resting state and contains the penile urethra, os penis, and erectile bodies. The clitoris of broad-footed moles is defined by a U-shaped clitoral epithelial lamina. Residing within clitoral stroma encompassed by the clitoral epithelial lamina is the corpus cavernosum, blood-filled spaces and the urethra. External genitalia of male and female mice are anatomically similar to that of broad-footed moles with the exception that in female mice the clitoris contains a small os clitoridis and lacks defined erectile bodies, while male mice have an os penis and a prominent distal cartilaginous structure within the male urogenital mating protuberance (MUMP). Clitori of female broad-footed moles lack an os clitoridis but contain defined erectile bodies, while male moles have an os penis similar to the mouse but lack the distal cartilaginous structure. PMID:26694958

Left Atrial Appendages from Adult Hearts Contain a Reservoir of Diverse Cardiac Progenitor Cells

PubMed Central

Platt, Yardanna; Helman, Yaron; Feinberg, Yael; Lotan, Chaim; Beeri, Ronen

2013-01-01

Aims There is strong evidence supporting the claim that endogenous cardiac progenitor cells (CPCs) are key players in cardiac regeneration, but the anatomic source and phenotype of the master cardiac progenitors remains uncertain. Our aim was to investigate the different cardiac stem cell populations in the left atrial appendage (LAA) and their fates. Methods and Results We investigated the CPC content and profile of adult murine LAAs using immunohistochemistry and flow cytometry. We demonstrate that the LAA contains a large number of CPCs relative to other areas of the heart, representing over 20% of the total cell number. We grew two distinct CPC populations from the LAA by varying the degree of proteolysis. These differed by their histological location, surface marker profiles and growth dynamics. Specifically, CD45pos cells grew with milder proteolysis, while CD45neg cells grew mainly with more intense proteolysis. Both cell types could be induced to differentiate into cells with cardiomyocyte markers and organelles, albeit by different protocols. Many CD45pos cells expressed CD45 initially and rapidly lost its expression while differentiating. Conclusions Our results demonstrate that the left atrial appendage plays a role as a reservoir of multiple types of progenitor cells in murine adult hearts. Two different types of CPCs were isolated, differing in their epicardial-myocardial localization. Considering studies demonstrating layer-specific origins of different cardiac progenitor cells, our findings may shed light on possible pathways to study and utilize the diversity of endogenous progenitor cells in the adult heart. PMID:23555001

Cor triatriatum or divided atriums: which approach provides the better understanding?

PubMed

Bharucha, Tara; Spicer, Diane E; Mohun, Timothy J; Black, David; Henry, G William; Anderson, Robert H

2015-02-01

It is frequent, in the current era, to encounter congenital cardiac malformations described in terms of "cor triatriatum". But can hearts be truly found with three atrial chambers? The morphological method, emphasised by Van Praagh et al, states that structures within the heart should be defined on the basis of their most constant components. In the atrial chambers, it is the appendages that are the most constant components, and to the best of our knowledge, hearts can only possess two appendages, which can be of either right or left morphology. The hearts described on the basis of "cor triatriatum", nonetheless, can also be analysed on the basis of division of either the morphologically right or the morphologically left atriums. In this review, we provide a description of cardiac embryology, showing how each of the atrial chambers possesses part of the embryological body, along with an appendage, a vestibule, a venous component, and a septum that separates them. We then show how it is, indeed, the case that the hearts described in terms of "cor triatriatum" can be readily understood on the basis of division of these atrial components. In the right atrium, it is the venous valves that divide the chamber. In the left atrium, it is harder to provide an explanation for the shelf that produces atrial division. We also contrast the classic examples of the divided atrial chambers with the vestibular shelf that produces supravalvar stenosis in the morphologically left atrium, showing that this form of obstruction needs to be distinguished from the fibrous shelves producing intravalvar obstruction.

Topographical mapping of α- and β-keratins on developing chicken skin integuments: Functional interaction and evolutionary perspectives

PubMed Central

Wu, Ping; Ng, Chen Siang; Yan, Jie; Lai, Yung-Chih; Chen, Chih-Kuan; Lai, Yu-Ting; Wu, Siao-Man; Chen, Jiun-Jie; Luo, Weiqi; Widelitz, Randall B.; Li, Wen-Hsiung; Chuong, Cheng-Ming

2015-01-01

Avian integumentary organs include feathers, scales, claws, and beaks. They cover the body surface and play various functions to help adapt birds to diverse environments. These keratinized structures are mainly composed of corneous materials made of α-keratins, which exist in all vertebrates, and β-keratins, which only exist in birds and reptiles. Here, members of the keratin gene families were used to study how gene family evolution contributes to novelty and adaptation, focusing on tissue morphogenesis. Using chicken as a model, we applied RNA-seq and in situ hybridization to map α- and β-keratin genes in various skin appendages at embryonic developmental stages. The data demonstrate that temporal and spatial α- and β-keratin expression is involved in establishing the diversity of skin appendage phenotypes. Embryonic feathers express a higher proportion of β-keratin genes than other skin regions. In feather filament morphogenesis, β-keratins show intricate complexity in diverse substructures of feather branches. To explore functional interactions, we used a retrovirus transgenic system to ectopically express mutant α- or antisense β-keratin forms. α- and β-keratins show mutual dependence and mutations in either keratin type results in disrupted keratin networks and failure to form proper feather branches. Our data suggest that combinations of α- and β-keratin genes contribute to the morphological and structural diversity of different avian skin appendages, with feather-β-keratins conferring more possible composites in building intrafeather architecture complexity, setting up a platform of morphological evolution of functional forms in feathers. PMID:26598683

Identification of BCAP, a new protein associated with basal bodies and centrioles.

PubMed

Ponsard, Cecile; Seltzer, Virginie; Perret, Eric; Tournier, Frederic; Middendorp, Sandrine

2007-05-01

Cilia exert critical functions in numerous organisms, including that of cell motility, fluid transport and protozoan locomotion. Defects in this organelle can lead to lethal pathologies in humans, including primary ciliary dyskinesia. An understanding of the cilia formation process would lead to better characterization of defects involved in such pathologies. In the present study, we identified a gene encoding a novel human protein, BCAP for Basal body Centriole-Associated Protein, which shares homologies with a previously described protein, Outer Dense Fiber 2 (ODF2). ODF2, a major component of the sperm tail cytoskeleton, is required for the formation of mother centriole distal/subdistal appendages and the generation of primary cilia. Here, we show that the bcap gene contains 18 alternatively spliced exons and encodes five different isoforms, three long and two short ones. BCAP is preferentially expressed in cilia/flagella containing tissues. Moreover, its expression is correlated with cilia formation during mucociliary differentiation of human nasal epithelial cells. Using immunofluorescence analyses, BCAP was localized within basal bodies of ciliated cells and within centrioles of proliferating cells. In light of the several spliced isoforms of BCAP and the particular localization of the protein, BCAP isoforms could play distinct roles in cilia and in centrosomes.

Tempo and scale of biogenic effects on high-frequency acoustic propagation near the marine sediment-water interface in shallow water

NASA Astrophysics Data System (ADS)

Jumars, Peter

2003-04-01

Organisms have natural scales, such as lifetimes, body sizes, frequencies of movement to new locations, and residence times of material in digestive systems, and each scale has potential implications for acoustic effects. The effects of groups of organisms, like organisms themselves, aggregate in space and time. This review, including an assortment of unpublished information, examines examples of such aggregations, many of them documented acoustically. Light synchronizes many activities. Macroscopic animals forage primarily under cover of darkness. This phasing applies both to animals that extend appendages above the sediment-water interface and to animals that leave the seabed at night. Whereas their bottom-modifying activities are concentrated in nocturnal or crepuscular fashion, the bottom-modifying activities of the visual feeders follow a different phasing and often dominate the rate of change in acoustic backscatter from the interface. Light also acts through its effects on primary production, often concentrated in a very thin surficial layer atop the seabed. The supersaturation of oxygen does, and microbubble nucleation may, result. Where tidal velocities are large, light-set patterns are often tidally modulated. Activities of animals living below the seabed, however, remain a mystery, whose primary hope for solution is acoustic. [Work supported by ONR and DEPSCoR.

Kinematic behavior of the human body during deceleration.

DOT National Transportation Integrated Search

1962-06-01

The geometry of motion of the head, trunk and appendages was established for one hundred male subjects restrained by a safety belt during forward and side dynamic loadings. Lethal structures of present aircraft seating and cockpit arrangements are re...

Male breast cancer arising in ectopic axillary breast tissue: A diagnostic dilemma.

PubMed

Xie, Yangchun; Huang, Jin; Xiao, Desheng; Zhong, Meizuo

2013-06-01

Male breast cancer arising in ectopic axillary breast tissue is a rare occurrence and few cases have been reported in the literature. Due to its rarity, male axillary breast cancer is easy to misdiagnose. As for adenocarcinoma in the axilla, it is difficult to identify whether the origin is the mammary tissue or the skin appendages, particularly in cases where there is a poor differentiation. The present study reports the case of a male patient with a right axillary lesion that had been present for 6 months. A histological evaluation revealed the features of a poorly-differentiated adenocarcinoma with regards to the pathological report. The patient was diagnosed with a metastatic adenocarcinoma with unknown primary origin. However, following 4 cycles of intensive chemotherapy, the patient experienced bone metastasis while the local lesion was in partial remission. Further immunohistochemistry confirmed its mammary origin. There is limited literature relating to male ectopic axillary breast cancer, and a high probability of misdiagnosis of this disease.

Male breast cancer arising in ectopic axillary breast tissue: A diagnostic dilemma

PubMed Central

XIE, YANGCHUN; HUANG, JIN; XIAO, DESHENG; ZHONG, MEIZUO

2013-01-01

Male breast cancer arising in ectopic axillary breast tissue is a rare occurrence and few cases have been reported in the literature. Due to its rarity, male axillary breast cancer is easy to misdiagnose. As for adenocarcinoma in the axilla, it is difficult to identify whether the origin is the mammary tissue or the skin appendages, particularly in cases where there is a poor differentiation. The present study reports the case of a male patient with a right axillary lesion that had been present for 6 months. A histological evaluation revealed the features of a poorly-differentiated adenocarcinoma with regards to the pathological report. The patient was diagnosed with a metastatic adenocarcinoma with unknown primary origin. However, following 4 cycles of intensive chemotherapy, the patient experienced bone metastasis while the local lesion was in partial remission. Further immunohistochemistry confirmed its mammary origin. There is limited literature relating to male ectopic axillary breast cancer, and a high probability of misdiagnosis of this disease. PMID:23833669

Traumatic injury pattern analysis in a light rail transit death: a retrospective case study.

PubMed

Kendell, Ashley E; Fleischman, Julie M; Fulginiti, Laura C

2015-05-01

Within the context of medical examiner's offices, forensic anthropologists are increasingly being asked to assist with the interpretation of traumatic skeletal injury. This case study presents an example of trauma analysis performed by forensic anthropologists at the Maricopa County Forensic Science Center in Phoenix, Arizona. The primary goal of this study is to document an uncommon pattern of traumatic injury-severe grinding abrasions of the lower appendage that macroscopically resemble sharp force trauma, especially as observed in dismemberment cases-resulting from an individual being dragged beneath a Light Rail train for c. 1.7 miles. The abraded skeletal elements include a femoral shaft fragment, a femoral head portion, and the right foot. Second, this study aims to illustrate the efficacy of forensic anthropological analysis of patterned skeletal trauma. Finally, this study demonstrates the critical importance of analyzing scene information before drawing conclusions as to the etiology of a traumatic injury pattern. © 2015 American Academy of Forensic Sciences.

Avian skin development and the evolutionary origin of feathers.

PubMed

Sawyer, Roger H; Knapp, Loren W

2003-08-15

The discovery of several dinosaurs with filamentous integumentary appendages of different morphologies has stimulated models for the evolutionary origin of feathers. In order to understand these models, knowledge of the development of the avian integument must be put into an evolutionary context. Thus, we present a review of avian scale and feather development, which summarizes the morphogenetic events involved, as well as the expression of the beta (beta) keratin multigene family that characterizes the epidermal appendages of reptiles and birds. First we review information on the evolution of the ectodermal epidermis and its beta (beta) keratins. Then we examine the morphogenesis of scutate scales and feathers including studies in which the extraembryonic ectoderm of the chorion is used to examine dermal induction. We also present studies on the scaleless (sc) mutant, and, because of the recent discovery of "four-winged" dinosaurs, we review earlier studies of a chicken strain, Silkie, that expresses ptilopody (pti), "feathered feet." We conclude that the ability of the ectodermal epidermis to generate discrete cell populations capable of forming functional structural elements consisting of specific members of the beta keratin multigene family was a plesiomorphic feature of the archosaurian ancestor of crocodilians and birds. Evidence suggests that the discrete epidermal lineages that make up the embryonic feather filament of extant birds are homologous with similar embryonic lineages of the developing scutate scales of birds and the scales of alligators. We believe that the early expression of conserved signaling modules in the embryonic skin of the avian ancestor led to the early morphogenesis of the embryonic feather filament, with its periderm, sheath, and barb ridge lineages forming the first protofeather. Invagination of the epidermis of the protofeather led to formation of the follicle providing for feather renewal and diversification. The observations that scale formation in birds involves an inhibition of feather formation coupled with observations on the feathered feet of the scaleless (High-line) and Silkie strains support the view that the ancestor of modern birds may have had feathered hind limbs similar to those recently discovered in nonavian dromaeosaurids. And finally, our recent observation on the bristles of the wild turkey beard raises the possibility that similar integumentary appendages may have adorned nonavian dinosaurs, and thus all filamentous integumentary appendages may not be homologous to modern feathers. Copyright 2003 Wiley-Liss, Inc.

Right versus left atrial pacing in patients with sick sinus syndrome and paroxysmal atrial fibrillation (Riverleft study): study protocol for randomized controlled trial.

PubMed

Ramdjan, Tanwier T T K; van der Does, Lisette J M E; Knops, Paul; Res, Jan C J; de Groot, Natasja M S

2014-11-17

The incidence of sick sinus syndrome will increase due to population ageing. Consequently, this will result in an increase in the number of pacemaker implantations. The atrial lead is usually implanted in the right atrial appendage, but this position may be ineffective for prevention of atrial fibrillation. It has been suggested that pacing distally in the coronary sinus might be more successful in preventing atrial fibrillation episodes. The aim of this trial is to study the efficacy of distal coronary sinus versus right atrial appendage pacing in preventing atrial fibrillation episodes in patients with sick sinus syndrome. This study is designed as a multicenter, randomized controlled trial. Patients with sick sinus syndrome and at least one atrial fibrillation episode of 30 seconds or more in the six months before recruitment will be eligible for participation in this study.All participants will be randomized between pacing distally in the coronary sinus and right atrial appendage. Randomization is stratified for all participating centers. Conventional dual-chamber pacemakers with advanced home monitoring functionality will be implanted. The ventricular lead will be implanted in the right ventricular apex. The first three months of the 36-month follow-up period are considered as run-in time. During the pre-randomization visit and follow-up, an interview, electrocardiogram and pacemaker assessment will be performed, prescribed antiarrhythmic medication will be reviewed and patients will be asked to complete an SF-36 questionnaire. An echocardiographic examination will be conducted in the pre-randomization phase and at the end of each follow-up year. Home monitoring will be used to send daily reports in case of atrial fibrillation episodes. This randomized controlled trial is the first in which home monitoring will be used to compare atrial fibrillation recurrences between pacing in the distal coronary sinus or right atrial appendage. Home monitoring gives the opportunity to accurately detect atrial fibrillation episodes and to study characteristics of atrial fibrillation episodes. Should distal coronary sinus pacing significantly diminish atrial fibrillation recurrences, this study will redefine the preferential location of an atrial lead for preventive pacing. Current Controlled Trials ISRCTN65911661, registered on 8 July 2013.

Ultrastructural characterization of primary cilia in pathologically characterized human glioblastoma multiforme (GBM) tumors.

PubMed

Moser, Joanna J; Fritzler, Marvin J; Rattner, Jerome B

2014-01-01

Primary cilia are non-motile sensory cytoplasmic organelles that are involved in cell cycle progression. Ultrastructurally, the primary cilium region is complex, with normal ciliogenesis progressing through five distinct morphological stages in human astrocytes. Defects in early stages of ciliogenesis are key features of astrocytoma/glioblastoma cell lines and provided the impetus for the current study which describes the morphology of primary cilia in molecularly characterized human glioblastoma multiforme (GBM) tumors. Seven surgically resected human GBM tissue samples were molecularly characterized according to IDH1/2 mutation status, EGFR amplification status and MGMT promoter methylation status and were examined for primary cilia expression and structure using indirect immunofluorescence and electron microscopy. We report for the first time that primary cilia are disrupted in the early stages of ciliogenesis in human GBM tumors. We confirm that immature primary cilia and basal bodies/centrioles have aberrant ciliogenesis characteristics including absent paired vesicles, misshaped/swollen vesicular hats, abnormal configuration of distal appendages, and discontinuity of centriole microtubular blades. Additionally, the transition zone plate is able to form in the absence of paired vesicles on the distal end of the basal body and when a cilium progresses beyond the early stages of ciliogenesis, it has electron dense material clumped along the transition zone and a darkening of the microtubules at the proximal end of the cilium. Primary cilia play a role in a variety of human cancers. Previously primary cilia structure was perturbed in cultured cell lines derived from astrocytomas/glioblastomas; however there was always some question as to whether these findings were a cell culture phenomena. In this study we confirm that disruptions in ciliogenesis at early stages do occur in GBM tumors and that these ultrastructural findings bear resemblance to those previously observed in cell cultures. This is the first study to demonstrate that defects in cilia expression and function are a true hallmark of GBM tumors and correlate with their unrestrained growth. A review of the current ultrastructural profiles in the literature provides suggestions as to the best possible candidate protein that underlies defects in the early stages of ciliogenesis within GBM tumors.

76 FR 9018 - National Center for Health Statistics (NCHS), Classifications and Public Health Data Standards...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-16

...: Acute kidney injury Acute interstitial pneumonia (re-presentation) Atrial fibrillation Highly calcified... encephalomyelitis Acute necrotizing hemorrhagic encephalopathy Atrial fibrillation and flutter Benign shuddering... resurfacing Lead extraction Left atrial appendage exclusion femoral/epicardial access Neuroflow endovascular...

Cost-effectiveness analysis of left atrial appendage occlusion compared with pharmacological strategies for stroke prevention in atrial fibrillation.

PubMed

Lee, Vivian Wing-Yan; Tsai, Ronald Bing-Ching; Chow, Ines Hang-Iao; Yan, Bryan Ping-Yen; Kaya, Mehmet Gungor; Park, Jai-Wun; Lam, Yat-Yin

2016-08-31

Transcatheter left atrial appendage occlusion (LAAO) is a promising therapy for stroke prophylaxis in non-valvular atrial fibrillation (NVAF) but its cost-effectiveness remains understudied. This study evaluated the cost-effectiveness of LAAO for stroke prophylaxis in NVAF. A Markov decision analytic model was used to compare the cost-effectiveness of LAAO with 7 pharmacological strategies: aspirin alone, clopidogrel plus aspirin, warfarin, dabigatran 110 mg, dabigatran 150 mg, apixaban, and rivaroxaban. Outcome measures included quality-adjusted life years (QALYs), lifetime costs and incremental cost-effectiveness ratios (ICERs). Base-case data were derived from ACTIVE, RE-LY, ARISTOTLE, ROCKET-AF, PROTECT-AF and PREVAIL trials. One-way sensitivity analysis varied by CHADS2 score, HAS-BLED score, time horizons, and LAAO costs; and probabilistic sensitivity analysis using 10,000 Monte Carlo simulations was conducted to assess parameter uncertainty. LAAO was considered cost-effective compared with aspirin, clopidogrel plus aspirin, and warfarin, with ICER of US$5,115, $2,447, and $6,298 per QALY gained, respectively. LAAO was dominant (i.e. less costly but more effective) compared to other strategies. Sensitivity analysis demonstrated favorable ICERs of LAAO against other strategies in varied CHADS2 score, HAS-BLED score, time horizons (5 to 15 years) and LAAO costs. LAAO was cost-effective in 86.24 % of 10,000 simulations using a threshold of US$50,000/QALY. Transcatheter LAAO is cost-effective for prevention of stroke in NVAF compared with 7 pharmacological strategies. The transcatheter left atrial appendage occlusion (LAAO) is considered cost-effective against the standard 7 oral pharmacological strategies including acetylsalicylic acid (ASA) alone, clopidogrel plus ASA, warfarin, dabigatran 110 mg, dabigatran 150 mg, apixaban, and rivaroxaban for stroke prophylaxis in non-valvular atrial fibrillation management.

Characterization of Cerebrovascular Events After Left Atrial Appendage Occlusion.

PubMed

Freixa, Xavier; Llull, Laura; Gafoor, Sameer; Cruz-Gonzalez, Ignacio; Shakir, Samera; Omran, Heyder; Berti, Sergio; Santoro, Gennaro; Kefer, Joelle; Landmesser, Ulf; Nielsen-Kudsk, Jens Erik; Kanagaratnam, Prapa; Nietlispach, Fabian; Gloekler, Steffen; Aminian, Adel; Danna, Paolo; Rezzaghi, Marco; Stock, Friederike; Stolcova, Miroslava; Paiva, Luis; Costa, Marco; Millán, Xavier; Ibrahim, Reda; Tichelbäcker, Tobias; Schillinger, Wolfgang; Park, Jai-Wun; Sievert, Horst; Meier, Bernhard; Tzikas, Apostolos

2016-12-15

Cardioembolic strokes are generally more lethal and disabling than other source of strokes. Data from PROTECT AF (Watchman Left Atrial Appendage Closure Technology for Embolic Protection in Patients With Atrial Fibrillation) suggest that strokes after left atrial appendage occlusion (LAAO) with the Watchman device are less disabling than those in the warfarin group. No data assessing the severity of strokes after LAAO with the AMPLATZER Cardiac Plug (ACP) are available. The objective of the study was to evaluate the severity of cerebrovascular events after LAAO with the ACP in a population mostly characterized by an absolute or relative contraindication to oral anticoagulation. Data from the ACP multicenter registry were analyzed. Disabling strokes were defined as those with a modified Rankin score of 3 to 6 at 90 days after the event. A total of 1,047 subjects were included. The mean age and CHADS 2 score were 75 ± 8 years and 2.8 ± 1.3, respectively. Procedural success was achieved in 97.3% and 4.9% of the patients presented procedural major adverse events. Clinical follow-up was complete in 98.2% of patients with a median of 13 months. There were 9 strokes (0.9%), 9 transient ischemic attacks (0.9%), and no intracranial hemorrhages (0%) at follow-up. After excluding 2 patients with pre-LAAO disability, functional assessment showed disabling events in 3 (19%) of the remaining 16 patients. The median time of presentation was 420 days (interquartile range 234 to 671) after LAAO, and 17 patients (94%) were on single-antiplatelet therapy when the event occurred. According to our results, cerebrovascular events after LAAO with the ACP system were infrequent and mostly nondisabling. Copyright © 2016 Elsevier Inc. All rights reserved.

Adaptation to the sky: Defining the feather with integument fossils from mesozoic China and experimental evidence from molecular laboratories.

PubMed

Chuong, Cheng-Ming; Wu, Ping; Zhang, Fu-Cheng; Xu, Xing; Yu, Minke; Widelitz, Randall B; Jiang, Ting-Xin; Hou, Lianhai

2003-08-15

In this special issue on the Evo-Devo of amniote integuments, Alibardi has discussed the adaptation of the integument to the land. Here we will discuss the adaptation to the sky. We first review a series of fossil discoveries representing intermediate forms of feathers or feather-like appendages from dinosaurs and Mesozoic birds from the Jehol Biota of China. We then discuss the molecular and developmental biological experiments using chicken integuments as the model. Feather forms can be modulated using retrovirus mediated gene mis-expression that mimics those found in nature today and in the evolutionary past. The molecular conversions among different types of integument appendages (feather, scale, tooth) are discussed. From this evidence, we recognize that not all organisms with feathers are birds, and that not all skin appendages with hierarchical branches are feathers. We develop a set of criteria for true avian feathers: 1) possessing actively proliferating cells in the proximal follicle for proximo-distal growth mode; 2) forming hierarchical branches of rachis, barbs, and barbules, with barbs formed by differential cell death and bilaterally or radially symmetric; 3) having a follicle structure, with mesenchyme core during development; 4) when mature, consisting of epithelia without mesenchyme core and with two sides of the vane facing the previous basal and supra-basal layers, respectively; and 5) having stem cells and dermal papilla in the follicle and hence the ability to molt and regenerate. A model of feather evolution from feather bud --> barbs --> barbules --> rachis is presented, which is opposite to the old view of scale plate --> rachis --> barbs --> barbules (Regal, '75; Q Rev Biol 50:35). Copyright 2003 Wiley-Liss, Inc.

Hair Follicle and Sebaceous Gland De Novo Regeneration With Cultured Epidermal Stem Cells and Skin-Derived Precursors.

PubMed

Wang, Xiaoxiao; Wang, Xusheng; Liu, Jianjun; Cai, Ting; Guo, Ling; Wang, Shujuan; Wang, Jinmei; Cao, Yanpei; Ge, Jianfeng; Jiang, Yuyang; Tredget, Edward E; Cao, Mengjun; Wu, Yaojiong

2016-12-01

: Stem cell-based organ regeneration is purported to enable the replacement of impaired organs in the foreseeable future. Here, we demonstrated that a combination of cultured epidermal stem cells (Epi-SCs) derived from the epidermis and skin-derived precursors (SKPs) was capable of reconstituting functional hair follicles and sebaceous glands (SG). When Epi-SCs and SKPs were mixed in a hydrogel and implanted into an excisional wound in nude mice, the Epi-SCs formed de novo epidermis along with hair follicles, and SKPs contributed to dermal papilla in the neogenic hair follicles. Notably, a combination of culture-expanded Epi-SCs and SKPs derived from the adult human scalp were sufficient to generate hair follicles and hair. Bone morphogenetic protein 4, but not Wnts, sustained the expression of alkaline phosphatase in SKPs in vitro and the hair follicle-inductive property in vivo when SKPs were engrafted with neonatal epidermal cells into excisional wounds. In addition, Epi-SCs were capable of differentiating into sebocytes and formed de novo SGs, which excreted lipids as do normal SGs. Thus our results indicate that cultured Epi-SCs and SKPs are sufficient to generate de novo hair follicles and SGs, implying great potential to develop novel bioengineered skin substitutes with appendage genesis capacity. In postpartum humans, skin appendages lost in injury are not regenerated, despite the considerable achievement made in skin bioengineering. In this study, transplantation of a combination of culture-expanded epidermal stem cells and skin-derived progenitors from mice and adult humans led to de novo regeneration of functional hair follicles and sebaceous glands. The data provide transferable knowledge for the development of novel bioengineered skin substitutes with epidermal appendage regeneration capacity. ©AlphaMed Press.

Principles of appendage design in robots and animals determining terradynamic performance on flowable ground.

PubMed

Qian, Feifei; Zhang, Tingnan; Korff, Wyatt; Umbanhowar, Paul B; Full, Robert J; Goldman, Daniel I

2015-10-08

Natural substrates like sand, soil, leaf litter and snow vary widely in penetration resistance. To search for principles of appendage design in robots and animals that permit high performance on such flowable ground, we developed a ground control technique by which the penetration resistance of a dry granular substrate could be widely and rapidly varied. The approach was embodied in a device consisting of an air fluidized bed trackway in which a gentle upward flow of air through the granular material resulted in a decreased penetration resistance. As the volumetric air flow, Q, increased to the fluidization transition, the penetration resistance decreased to zero. Using a bio-inspired hexapedal robot as a physical model, we systematically studied how locomotor performance (average forward speed, v(x)) varied with ground penetration resistance and robot leg frequency. Average robot speed decreased with increasing Q, and decreased more rapidly for increasing leg frequency, ω. A universal scaling model revealed that the leg penetration ratio (foot pressure relative to penetration force per unit area per depth and leg length) determined v(x) for all ground penetration resistances and robot leg frequencies. To extend our result to include continuous variation of locomotor foot pressure, we used a resistive force theory based terradynamic approach to perform numerical simulations. The terradynamic model successfully predicted locomotor performance for low resistance granular states. Despite variation in morphology and gait, the performance of running lizards, geckos and crabs on flowable ground was also influenced by the leg penetration ratio. In summary, appendage designs which reduce foot pressure can passively maintain minimal leg penetration ratio as the ground weakens, and consequently permits maintenance of effective locomotion over a range of terradynamically challenging surfaces.

Measurement of funny current (I(f)) channel mRNA in human atrial tissue: correlation with left atrial filling pressure and atrial fibrillation.

PubMed

Lai, L P; Su, M J; Lin, J L; Tsai, C H; Lin, F Y; Chen, Y S; Hwang, J J; Huang, S K; Tseng, Y Z; Lien, W P

1999-07-01

The funny current (I(f)) contributes to phase IV spontaneous depolarization in cardiac pacemaker tissue. Enhanced I(f) activity in myocardial tissue may lead to increased automaticity and therefore tachyarrhythmia. We measured the amount of I(f) activity in the messenger ribonucleic acid (mRNA) in human atrial tissue and correlated the mRNA amount to left atrial filling pressure and atrial fibrillation (AF). A total of 34 patients undergoing open heart surgery were included (15 men and 19 women, aged 55+/-10 years). Atrial tissue was obtained from the right atrial free wall, the right atrial appendage, the left atrial free wall, and the left atrial appendage, respectively. The mRNA amount of the I(f) channel was measured by reverse transcription polymerase chain reaction and was normalized to the mRNA levels of glyceraldehyde 3-phosphate dehydrogenase. We found that the I(f) channel mRNA was present at all the atrial sampling sites. A higher left atrial filling pressure, an indicator of congestive heart failure, was associated with a higher I(f) mRNA level (r2 = 0.446, P < 0.01 by linear regression). We also found that the mRNA amount was significantly higher in patients with AF than in patients without AF (1.68+/-0.49 vs 1.27+/-0.43; P < 0.05). Age, sex, right atrial filling pressure, left atrial dimension, and left ventricular ejection fraction had no significant effect on the mRNA level. The mRNA of the I(f) channel is present in the free-wall area and appendage area from both atria. Increased left atrial filling pressure and clinical AF are associated with increased I(f) mRNA level.

Short-term safety and efficacy of left atrial appendage closure with the WATCHMAN device in patients with small left atrial appendage ostia.

PubMed

Venkataraman, Ganesh; Strickberger, S Adam; Doshi, Shephal; Ellis, Christopher R; Lakkireddy, Dhanunjaya; Whalen, S Patrick; Cuoco, Frank

2018-01-01

Left atrial appendage (LAA) closure with the WATCHMAN device, according to FDA labelling, is recommended in patients with a maximal LAA ostial width between 17 and 31 mm. The safety and efficacy of LAA closure in patients with a maximal LAA ostial width < 17 mm has not been evaluated. The goal of this study was to determine the acute and short-term safety and efficacy of LAA closure with the WATCHMAN device in patients with a maximal LAA ostial width < 17 mm. Thirty-two consecutive patients with a maximal LAA ostial width < 17 mm as determined by a screening transesophageal echocardiogram (TEE) underwent LAA closure with the WATCHMAN device between March 2015 and November 2016 at five medical centers, and were included in this study. Mean age, body mass index (BMI), and CHA 2 DS 2 -VASC score were 70.8 ± 8.6 years, 29.3 ± 6.5 kg/m 2 , and 3.9 ±1.2, respectively. At the screening TEE, mean maximal LAA ostial width and depth were 15.6 ± 0.6 mm (range 14-16) and 23.2 ± 4.5 mm (range 13-31), respectively. Successful LAA closure with the WATCHMAN device was achieved in 31 of 32 patients (97%), with no major complications. TEE performed 45 days after LAA closure demonstrated no peridevice leak > 5 mm and no device related thrombi. Warfarin was discontinued in all 31 patients 45 days after LAA closure. LAA closure with the WATCHMAN device can be successfully and safely achieved in patients with a maximal LAA ostial width < 17 mm. © 2017 Wiley Periodicals, Inc.

The Musculature of Coleoid Cephalopod Arms and Tentacles

PubMed Central

Kier, William M.

2016-01-01

The regeneration of coleoid cephalopod arms and tentacles is a common occurrence, recognized since Aristotle. The complexity of the arrangement of the muscle and connective tissues of these appendages make them of great interest for research on regeneration. They lack rigid skeletal elements and consist of a three-dimensional array of muscle fibers, relying on a type of skeletal support system called a muscular hydrostat. Support and movement in the arms and tentacles depends on the fact that muscle tissue resists volume change. The basic principle of function is straightforward; because the volume of the appendage is essentially constant, a decrease in one dimension must result in an increase in another dimension. Since the muscle fibers are arranged in three mutually perpendicular directions, all three dimensions can be actively controlled and thus a remarkable diversity of movements and deformations can be produced. In the arms and tentacles of coleoids, three main muscle orientations are observed: (1) transverse muscle fibers arranged in planes perpendicular to the longitudinal axis; (2) longitudinal muscle fibers typically arranged in bundles parallel to the longitudinal axis; and (3) helical or obliquely arranged layers of muscle fibers, arranged in both right- and left-handed helixes. By selective activation of these muscle groups, elongation, shortening, bending, torsion and stiffening of the appendage can be produced. The predominant muscle fiber type is obliquely striated. Cross-striated fibers are found only in the transverse muscle mass of the prey capture tentacles of squid and cuttlefish. These fibers have unusually short myofilaments and sarcomeres, generating the high shortening velocity required for rapid elongation of the tentacles. It is likely that coleoid cephalopods use ultrastructural modifications rather than tissue-specific myosin isoforms to tune contraction velocities. PMID:26925401

Efficacy and safety of percutaneous left atrial appendage closure to prevent thromboembolic events in atrial fibrillation patients with high stroke and bleeding risk.

PubMed

Seeger, Julia; Bothner, Carlo; Dahme, Tillman; Gonska, Birgid; Scharnbeck, Dominik; Markovic, Sinisa; Rottbauer, Wolfgang; Wöhrle, Jochen

2016-03-01

The randomized PROTECT AF trial demonstrated non-inferiority of left atrial appendage (LAA) closure to oral anticoagulation with warfarin. Current guidelines give a class IIb recommendation for LAA closure. We evaluated the efficacy and safety of LAA closure in a consecutive series of non-valvular atrial fibrillation patients with contraindications to long-term oral anticoagulation or at high bleeding risk. 101 consecutive non-valvular atrial fibrillation patients (age 74.7 ± 7.5 years) at high risk for stroke (CHA2DS2-VASc Score 4.4 ± 1.6) and high bleeding risk (HAS-BLED Score 4.2 ± 1.3) received LAA closure with either the Watchman closure device (n = 38) or the Amplatzer cardiac plug (n = 63). Dual antiplatelet therapy with aspirin and clopidogrel was recommended for 3-6 months after device implantation, followed by long-term antiplatelet therapy with aspirin. No anticoagulation was given after device implantation. Mean follow-up was 400 days. One patient (1 %) experienced a transient ischemic attack, and two patients (2 %) suffered from ischemic stroke. While on recommended antiplatelet therapy, bleeding occurred in 12/101 patients (12 %). Bleeding was significantly reduced with 3 compared with 6 months dual antiplatelet therapy (3.0 vs. 16.2 %, p < 0.05) while ischemic or thrombotic events were similar. Left atrial appendage closure in patients with non-valvular atrial fibrillation and high risk for stroke and bleeding events effectively prevented stroke and reduced cerebral ischemic events compared to expected stroke rate according to CHA2DS2-VASc Score. Dual antiplatelet therapy for 3 months reduced the rate of bleeding events compared to 6 months therapy with no increase of thrombotic events.

Sensing the Underground – Ultrastructure and Function of Sensory Organs in Root-Feeding Melolontha melolontha (Coleoptera: Scarabaeinae) Larvae

PubMed Central

Hansson, Bill S.; Hilker, Monika; Reinecke, Andreas

2012-01-01

Introduction Below ground orientation in insects relies mainly on olfaction and taste. The economic impact of plant root feeding scarab beetle larvae gave rise to numerous phylogenetic and ecological studies. Detailed knowledge of the sensory capacities of these larvae is nevertheless lacking. Here, we present an atlas of the sensory organs on larval head appendages of Melolontha melolontha. Our ultrastructural and electrophysiological investigations allow annotation of functions to various sensory structures. Results Three out of 17 ascertained sensillum types have olfactory, and 7 gustatory function. These sensillum types are unevenly distributed between antennae and palps. The most prominent chemosensory organs are antennal pore plates that in total are innervated by approximately one thousand olfactory sensory neurons grouped into functional units of three-to-four. In contrast, only two olfactory sensory neurons innervate one sensillum basiconicum on each of the palps. Gustatory sensilla chaetica dominate the apices of all head appendages, while only the palps bear thermo-/hygroreceptors. Electrophysiological responses to CO2, an attractant for many root feeders, are exclusively observed in the antennae. Out of 54 relevant volatile compounds, various alcohols, acids, amines, esters, aldehydes, ketones and monoterpenes elicit responses in antennae and palps. All head appendages are characterized by distinct olfactory response profiles that are even enantiomer specific for some compounds. Conclusions Chemosensory capacities in M. melolontha larvae are as highly developed as in many adult insects. We interpret the functional sensory units underneath the antennal pore plates as cryptic sensilla placodea and suggest that these perceive a broad range of secondary plant metabolites together with CO2. Responses to olfactory stimulation of the labial and maxillary palps indicate that typical contact chemo-sensilla have a dual gustatory and olfactory function. PMID:22848471

Epidemiology of non-keratinocytic skin cancers among persons with acquired immunodeficiency syndrome in the U.S.

PubMed Central

Lanoy, Emilie; Dores, Graça M.; Madeleine, Margaret M.; Toro, Jorge R.; Fraumeni, Joseph F.; Engels, Eric A.

2009-01-01

Objective Immunosuppression may increase risk for some skin cancers. We evaluated skin cancer epidemiology among persons with acquired immunodeficiency syndrome (AIDS). Design We linked data from population-based U.S. AIDS and cancer registries to evaluate risk of non-keratinocytic skin cancers (melanoma, Merkel cell carcinoma, and appendageal carcinomas, including sebaceous carcinoma) in 497,142 persons with AIDS. Methods Standardized incidence ratios (SIRs) were calculated to relate skin cancer risk to that in the general population. We used logistic regression to compare risk according to demographic factors, CD4 count, and a geographic index of ultraviolet radiation exposure. Results From 60 months before to 60 months after AIDS onset, persons with AIDS had elevated risks of melanoma (SIR=1.3, 95%CI 1.1-1.4, n=292 cases) and, more strongly, of Merkel cell carcinoma (SIR=11, 95%CI 6.3-17, n=17) and sebaceous carcinoma (SIR=8.1, 95%CI 3.2-17, n=7). Risk for appendageal carcinomas increased with progressive time relative to AIDS onset (p-trend=0.03). Risk of these skin cancers was higher in non-Hispanic whites than other racial/ethnic groups, and melanoma risk was highest among men who have sex with men. Melanoma risk was unrelated to CD4 count at AIDS onset (p=0.32). Risks for melanoma and appendageal carcinomas rose with increasing ultraviolet radiation exposure (p-trend<10-4 and p-trend=10-3, respectively). Conclusions Among persons with AIDS, there is a modest excess risk of melanoma which is not strongly related to immunosuppression and may relate to ultraviolet radiation exposure. In contrast, the greatly increased risks for Merkel cell and sebaceous carcinoma suggest an etiologic role for immunosuppression. PMID:19114864

Bachmann's Bundle Pacing not Only Improves Interatrial Conduction but Also Reduces the Need for Ventricular Pacing.

PubMed

Sławuta, Agnieszka; Kliś, Magdalena; Skoczyński, Przemysław; Bańkowski, Tomasz; Moszczyńska-Stulin, Joanna; Gajek, Jacek

2016-01-01

Patients treated for sick sinus syndrome may have interatrial conduction disorder leading to atrial fibrillation. This study was aimed to assess the influence of the atrial pacing site on interatrial and atrioventricular conduction as well as the percentage of ventricular pacing in patients with sick sinus syndrome implanted with atrioventricular pacemaker. The study population: 96 patients (58 females, 38 males) aged 74.1 ± 11.8 years were divided in two groups: Group 1 (n = 44) with right atrial appendage pacing and group 2 (n = 52) with Bachmann's area pacing. We assessed the differences in atrioventricular conduction in sinus rhythm and atrial 60 and 90 bpm pacing, P-wave duration and percentage of ventricular pacing. No differences in baseline P-wave duration in sinus rhythm between the groups (102.4 ± 17 ms vs. 104.1 ± 26 ms, p = ns.) were noted. Atrial pacing 60 bpm resulted in longer P-wave in group 1 vs. group 2 (138.3 ± 21 vs. 106.1 ± 15 ms, p < 0.01). The differences between atrioventricular conduction time during sinus rhythm and atrial pacing at 60 and 90 bpm were significantly longer in patients with right atrial appendage vs. Bachmann's pacing (44.1 ± 17 vs. 9.2 ± 7 ms p < 0.01 and 69.2 ± 31 vs. 21.4 ± 12 ms p < 0.05, respectively). The percentage of ventricular pacing was higher in group 1 (21 vs. 4%, p < 0.01). Bachmann's bundle pacing decreases interatrial and atrioventricular conduction delay. Moreover, the frequency-dependent atrioventricular conduction lengthening is much less pronounced during Bachmann's bundle pacing. Right atrial appendage pacing in sick sinus syndrome patients promotes a higher percentage of ventricular pacing.

Hair Follicle and Sebaceous Gland De Novo Regeneration With Cultured Epidermal Stem Cells and Skin-Derived Precursors

PubMed Central

Wang, Xiaoxiao; Wang, Xusheng; Liu, Jianjun; Cai, Ting; Guo, Ling; Wang, Shujuan; Wang, Jinmei; Cao, Yanpei; Ge, Jianfeng; Jiang, Yuyang; Tredget, Edward E.; Cao, Mengjun

2016-01-01

Stem cell-based organ regeneration is purported to enable the replacement of impaired organs in the foreseeable future. Here, we demonstrated that a combination of cultured epidermal stem cells (Epi-SCs) derived from the epidermis and skin-derived precursors (SKPs) was capable of reconstituting functional hair follicles and sebaceous glands (SG). When Epi-SCs and SKPs were mixed in a hydrogel and implanted into an excisional wound in nude mice, the Epi-SCs formed de novo epidermis along with hair follicles, and SKPs contributed to dermal papilla in the neogenic hair follicles. Notably, a combination of culture-expanded Epi-SCs and SKPs derived from the adult human scalp were sufficient to generate hair follicles and hair. Bone morphogenetic protein 4, but not Wnts, sustained the expression of alkaline phosphatase in SKPs in vitro and the hair follicle-inductive property in vivo when SKPs were engrafted with neonatal epidermal cells into excisional wounds. In addition, Epi-SCs were capable of differentiating into sebocytes and formed de novo SGs, which excreted lipids as do normal SGs. Thus our results indicate that cultured Epi-SCs and SKPs are sufficient to generate de novo hair follicles and SGs, implying great potential to develop novel bioengineered skin substitutes with appendage genesis capacity. Significance In postpartum humans, skin appendages lost in injury are not regenerated, despite the considerable achievement made in skin bioengineering. In this study, transplantation of a combination of culture-expanded epidermal stem cells and skin-derived progenitors from mice and adult humans led to de novo regeneration of functional hair follicles and sebaceous glands. The data provide transferable knowledge for the development of novel bioengineered skin substitutes with epidermal appendage regeneration capacity. PMID:27458264

DYNAMIC TUNING OF INSECT AND BIRD WINGS AND COPEPOD AND DAPHNIA APPENDAGES

EPA Science Inventory

Compressible flow theory suggests, and dimensional analysis and growing empirical evidence confirm that, to aid flight, many insects and even some birds, notably hummingbirds, tune their wing-beat frequency to a corresponding characteristic harmonic frequency of air. The same pro...

Crystallographic Insights into the Autocatalytic Assembly Mechanism of a Bacteriophage Tail Spike

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiang, Ye; Leiman, Petr G.; Li, Long

2010-02-03

The tailed bacteriophage phi29 has 12 'appendages' (gene product 12, gp12) attached to its neck region that participate in host cell recognition and entry. In the cell, monomeric gp12 undergoes proteolytic processing that releases the C-terminal domain during assembly into trimers. We report here crystal structures of the protein before and after catalytic processing and show that the C-terminal domain of gp12 is an 'autochaperone' that aids trimerization. We also show that autocleavage of the C-terminal domain is a posttrimerization event that is followed by a unique ATP-dependent release. The posttranslationally modified N-terminal part has three domains that function tomore » attach the appendages to the phage, digest the cell wall teichoic acids, and bind irreversibly to the host, respectively. Structural and sequence comparisons suggest that some eukaryotic and bacterial viruses as well as bacterial adhesins might have a similar maturation mechanism as is performed by phi29 gp12 for Bacillus subtilis.« less

Control-structure interaction in precision pointing servo loops

NASA Technical Reports Server (NTRS)

Spanos, John T.

1989-01-01

The control-structure interaction problem is addressed via stability analysis of a generic linear servo loop model. With the plant described by the rigid body mode and a single elastic mode, structural flexibility is categorized into one of three types: (1) appendage, (2) in-the-loop minimum phase, and (3) in-the-loop nonminimum phase. Closing the loop with proportional-derivative (PD) control action and introducing sensor roll-off dynamics in the feedback path, stability conditions are obtained. Trade studies are conducted with modal frequency, modal participation, modal damping, loop bandwidth, and sensor bandwidth treated as free parameters. Results indicate that appendage modes are most likely to produce instability if they are near the sensor rolloff, whereas in-the-loop modes are most dangerous near the loop bandwidth. The main goal of this paper is to provide a fundamental understanding of the control-structure interaction problem so that it may benefit the design of complex spacecraft and pointing system servo loops. In this framework, the JPL Pathfinder gimbal pointer is considered as an example.

Ofd1, a human disease gene, regulates the length and distal structure of centrioles.

PubMed

Singla, Veena; Romaguera-Ros, Miriam; Garcia-Verdugo, Jose Manuel; Reiter, Jeremy F

2010-03-16

Centrosomes and their component centrioles represent the principal microtubule organizing centers of animal cells. Here, we show that the gene underlying orofaciodigital syndrome 1, Ofd1, is a component of the distal centriole that controls centriole length. In the absence of Ofd1, distal regions of centrioles, but not procentrioles, elongate abnormally. These long centrioles are structurally similar to normal centrioles but contain destabilized microtubules with abnormal posttranslational modifications. Ofd1 is also important for centriole distal appendage formation and centriolar recruitment of the intraflagellar transport protein Ift88. To model OFD1 syndrome in embryonic stem cells, we replaced the Ofd1 gene with missense alleles from human OFD1 patients. Distinct disease-associated mutations cause different degrees of excessive or decreased centriole elongation, all of which are associated with diminished ciliogenesis. Our results indicate that Ofd1 acts at the distal centriole to build distal appendages, recruit Ift88, and stabilize centriolar microtubules at a defined length. Copyright 2010 Elsevier Inc. All rights reserved.

Biomimetic model systems of rigid hair beds: Part I - Theory

NASA Astrophysics Data System (ADS)

Hood, Kaitlyn; Jammalamadaka, Mani S. S.; Hosoi, Anette

2017-11-01

Crustaceans - such as lobsters, crabs, and stomapods - have hairy appendages that they use to recognize and track odorants in the surrounding fluid. An array of rigid hairs impedes flow at different rates depending on the spacing between hairs and the Reynolds number, Re. At larger Reynolds numbers (Re >1), fluid travels through the hairs rather than around them, a phenomenon called leakiness. Crustaceans flick their appendages at different speeds in order to manipulate the leakiness between the hairs, allowing the hairs to either detect odors in a sample of fluid or collect a new sample. A single hair can be represented as a slender body attached at one end to a wall. Using both slender body theory and numerical methods, we observe that there is a region of flow around the hair that speeds up relative to the unobstructed flow. As the Reynolds number increases, this fast flow region moves closer to the hair. Using this model, we predict that an array of hairs can be engineered to have a desired leakiness profile.

Photodynamic Therapy and Skin Appendage Disorders: A Review

PubMed Central

Megna, Matteo; Fabbrocini, Gabriella; Marasca, Claudio; Monfrecola, Giuseppe

2017-01-01

Photodynamic therapy (PDT) is a noninvasive treatment that utilizes light treatment along with application of a photosensitizing agent. In dermatology, PDT is commonly used and approved for the treatment of oncological conditions such as actinic keratosis, Bowen disease and superficial basal cell carcinoma. In the last 2 decades however, PDT has also been used for the treatment of several nonneoplastic dermatological diseases. The present review summarizes published data on PDT application in skin appendage disorders. Our literature review shows that: (a) PDT may be a suitable treatment for acne, folliculitis decalvans, hidradenitis suppurativa, nail diseases, and sebaceous hyperplasia; (b) there is a lack of agreement on PDT features (type, concentrations and incubation period of used substances, number and frequency of PDT sessions, optimal parameters of light sources, and patient characteristics [e.g., failure to previous treatments, disease severity, body surface area involved, etc.] which should guide PDT use in these diseases); (c) further research is needed to establish international guidelines helping dermatologists to choose PDT for the right patient at the right time. PMID:28232927

Percutaneous left atrial appendage occlusion: the Munich consensus document on definitions, endpoints, and data collection requirements for clinical studies.

PubMed

Tzikas, Apostolos; Holmes, David R; Gafoor, Sameer; Ruiz, Carlos E; Blomström-Lundqvist, Carina; Diener, Hans-Christoph; Cappato, Riccardo; Kar, Saibal; Lee, Randal J; Byrne, Robert A; Ibrahim, Reda; Lakkireddy, Dhanunjaya; Soliman, Osama I; Nabauer, Michael; Schneider, Steffen; Brachmann, Johannes; Saver, Jeffrey L; Tiemann, Klaus; Sievert, Horst; Camm, A John; Lewalter, Thorsten

2017-01-01

The increasing interest in left atrial appendage occlusion (LAAO) for ischaemic stroke prevention in atrial fibrillation (AF) fuels the need for more clinical data on the safety and effectiveness of this therapy. Besides an assessment of the effectiveness of the therapy in specific patients groups, comparisons with pharmacological stroke prophylaxis, surgical approaches, and other device-based therapies are warranted. This paper documents the consensus reached among clinical experts in relevant disciplines from Europe and North America, European cardiology professional societies, and representatives from the medical device industry regarding definitions for parameters and endpoints to be assessed in clinical studies. Adherence to these definitions is proposed in order to achieve a consistent approach across clinical studies on LAAO among the involved stakeholders and various clinical disciplines and thereby facilitate continued evaluation of therapeutic strategies available. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Congenital aneurysm of both left ventricle and left atrium.

PubMed

Halas, Ryan F; Schmehil, Christopher J; Ten Eyck, Gary R; Loker, James L

2018-01-01

This is a case of both congenital left ventricular (LV) free wall submitral aneurysm and left atrial appendage aneurysm with 6 years of clinical follow-up. Each lesion is a rare entity, and to the best of our knowledge, this is the first case in medical literature of both lesions occurring in the same patient, raising the likelihood of a common etiology. The workup was initiated in the third trimester of fetal life with irregular heart rate and abnormal fetal ultrasound and echocardiogram at that time. The patient required emergent atrial appendage plication due to blood clot formation and suffered from multiple other complications including ventricular ectopy and surgically induced pseudoaneurysm. Follow-up interval echocardiograms have revealed continued good LV function with persistent LV aneurysm. In review of the case, there were several potential in utero causes including maternal viral upper respiratory infection and bacteriuria with exposure to amoxicillin. These as well as other considerations are discussed along with a brief review of these rare lesions, usual presentation, and known associations.

Osteoblast Production by Reserved Progenitor Cells in Zebrafish Bone Regeneration and Maintenance.

PubMed

Ando, Kazunori; Shibata, Eri; Hans, Stefan; Brand, Michael; Kawakami, Atsushi

2017-12-04

Mammals cannot re-form heavily damaged bones as in large fracture gaps, whereas zebrafish efficiently regenerate bones even after amputation of appendages. However, the source of osteoblasts that mediate appendage regeneration is controversial. Several studies in zebrafish have shown that osteoblasts are generated by dedifferentiation of existing osteoblasts at injured sites, but other observations suggest that de novo production of osteoblasts also occurs. In this study, we found from cell-lineage tracing and ablation experiments that a group of cells reserved in niches serves as osteoblast progenitor cells (OPCs) and has a significant role in fin ray regeneration. Besides regeneration, OPCs also supply osteoblasts for normal bone maintenance. We further showed that OPCs are derived from embryonic somites, as is the case with embryonic osteoblasts, and are replenished from mesenchymal precursors in adult zebrafish. Our findings reveal that reserved progenitors are a significant and complementary source of osteoblasts for zebrafish bone regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

Spacecraft with gradual acceleration of solar panels

NASA Technical Reports Server (NTRS)

Merhav, Tamir R. (Inventor); Festa, Michael T. (Inventor); Stetson, Jr., John B. (Inventor)

1996-01-01

A spacecraft (8) includes a movable appendage such as solar panels (12) operated by a stepping motor (28) driven by pulses (311). In order to reduce vibration andor attitude error, the drive pulses are generated by a clock down-counter (312) with variable count ratio. Predetermined desired clock ratios are stored in selectable memories (314a-d), and the selected ratio (R) is coupled to a comparator (330) together with the current ratio (C). An up-down counter (340) establishes the current count-down ratio by counting toward the desired ratio under the control of the comparator; thus, a step change of solar panel speed never occurs. When a direction change is commanded, a flag signal generator (350) disables the selectable memories, and enables a further store (360), which generates a count ratio representing a very slow solar panel rotational rate, so that the rotational rate always slows to a low value before direction is changed. The principles of the invention are applicable to any movable appendage.

A superarmored lobopodian from the Cambrian of China and early disparity in the evolution of Onychophora

PubMed Central

Yang, Jie; Ortega-Hernández, Javier; Gerber, Sylvain; Butterfield, Nicholas J.; Hou, Jin-bo; Lan, Tian; Zhang, Xi-guang

2015-01-01

We describe Collinsium ciliosum from the early Cambrian Xiaoshiba Lagerstätte in South China, an armored lobopodian with a remarkable degree of limb differentiation including a pair of antenna-like appendages, six pairs of elongate setiferous limbs for suspension feeding, and nine pairs of clawed annulated legs with an anchoring function. Collinsium belongs to a highly derived clade of lobopodians within stem group Onychophora, distinguished by a substantial dorsal armature of supernumerary and biomineralized spines (Family Luolishaniidae). As demonstrated here, luolishaniids display the highest degree of limb specialization among Paleozoic lobopodians, constitute more than one-third of the overall morphological disparity of stem group Onychophora, and are substantially more disparate than crown group representatives. Despite having higher disparity and appendage complexity than other lobopodians and extant velvet worms, the specialized mode of life embodied by luolishaniids became extinct during the Early Paleozoic. Collinsium and other superarmored lobopodians exploited a unique paleoecological niche during the Cambrian explosion. PMID:26124122

Spacecraft on-orbit deployment anomalies - What can be done?

NASA Astrophysics Data System (ADS)

Freeman, Michael T.

1993-04-01

Modern communications satellites rely heavily upon deployable appendage (i.e. solar arrays, communications antennas, etc.) to perform vital functions that enable the spacecraft to effectively conduct mission objectives. Communications and telemetry antennas provide the radiofrequency link between the spacecraft and the earth ground station, permitting data to be transmitted and received from the satellite. Solar arrays serve as the principle source of electrical energy to the satellite, and recharge internal batteries during operation. However, since satellites cannot carry backup systems, if a solar array fails to deploy, the mission is lost. This article examines the subject of on-orbit anomalies related to the deployment of spacecraft appendage, and possible causes of such failures. Topics discussed shall include mechanical launch loading, on-orbit thermal and solar concerns, reliability of spacecraft pyrotechnics, and practical limitations of ground-based deployment testing. Of particular significance, the article will feature an in-depth look at the lessons learned from the successful recovery of the Telesat Canada Anik-E2 satellite in 1991.

On-orbit deployment anamolies: What can be done?

NASA Technical Reports Server (NTRS)

Freeman, Michael

1992-01-01

Modern communications satellites rely heavily upon deployable appendage (i.e., solar arrays, communications antennas, etc.) to perform vital functions that enable the spacecraft to effectively conduct mission objectives. Communications and telemetry antennas provide the radio-frequency link between the spacecraft and the earth ground station, permitting data to be transmitted and received from the satellite. Solar arrays serve as the principle source of electrical energy to the satellite, and re-charge internal batteries during operation. However, since satellites cannot carry back-up systems, if a solar array fails to deploy, the mission is lost. The subject of on-orbit anomalies related to the deployment of spacecraft appendage, and possible causes of such failures are examined. Topics discussed include mechanical launch loading, on-orbit thermal and solar concerns, reliability of spacecraft pyrotechnics, and practical limitations of ground-based deployment testing. Of particular significance, the article features an in-depth look at the lessons learned from the successful recovery of the Telesat Canada Anik-E2 satellite in 1991.

Mouse models for human hair loss disorders

PubMed Central

Porter, Rebecca M

2003-01-01

The outer surface of the hand, limb and body is covered by the epidermis, which is elaborated into a number of specialized appendages, evolved not only to protect and reinforce the skin but also for social signalling. The most prominent of these appendages is the hair follicle. Hair follicles are remarkable because of their prolific growth characteristics and their complexity of differentiation. After initial embryonic morphogenesis, the hair follicle undergoes repeated cycles of regression and regeneration throughout the lifetime of the organism. Studies of mouse mutants with hair loss phenotypes have suggested that the mechanisms controlling the hair cycle probably involve many of the major signalling molecules used elsewhere in development, although the complete pathway of hair follicle growth control is not yet understood. Mouse studies have also led to the discovery of genes underlying several human disorders. Future studies of mouse hair-loss mutants are likely to benefit the understanding of human hair loss as well as increasing our knowledge of mechanisms controlling morphogenesis and tumorigenesis. PMID:12587927

Larval cannibalism and pupal defense against cannibalism in two species of tenebrionid beetles.

PubMed

Ichikawa, Toshio; Kurauchi, Toshiaki

2009-08-01

Cannibalism of pupae by larvae has been documented In many species of Insects, but the features of larval cannibalism and pupal defensive mechanisms against larval cannibalism have been largely Ignored. Pupae of tenebrionld beetles rotate their abdominal segments in a circular motion in response to the tactile stimulation of appendages, including legs, antennae, maxillary pulps, and wings. When the pupal abdominal rotation responses of Tenebrio molitor and Zophobas atratus were completely blocked by transecting the ventral nerve cord (VNC) of the pupae, the appendages of the paralytic pupae became initial, major targets for attack by larval cannibals. The majority of 20 paralytic pupae was cannibalized by 100 larvae within 6 h, and almost all the pupae were killed within 2-3 days. In contrast, only a few pupae of Z. atratus and several pupae of T. molitor were cannibalized when the VNC was Intact. The abdominal rotation response of the pupae thus functions as an effective defense against larval cannibalism.

Newton-Euler Dynamic Equations of Motion for a Multi-body Spacecraft

NASA Technical Reports Server (NTRS)

Stoneking, Eric

2007-01-01

The Magnetospheric MultiScale (MMS) mission employs a formation of spinning spacecraft with several flexible appendages and thruster-based control. To understand the complex dynamic interaction of thruster actuation, appendage motion, and spin dynamics, each spacecraft is modeled as a tree of rigid bodies connected by spherical or gimballed joints. The method presented facilitates assembling by inspection the exact, nonlinear dynamic equations of motion for a multibody spacecraft suitable for solution by numerical integration. The building block equations are derived by applying Newton's and Euler's equations of motion to an "element" consisting of two bodies and one joint (spherical and gimballed joints are considered separately). Patterns in the "mass" and L'force" matrices guide assembly by inspection of a general N-body tree-topology system. Straightforward linear algebra operations are employed to eliminate extraneous constraint equations, resulting in a minimum-dimension system of equations to solve. This method thus combines a straightforward, easily-extendable, easily-mechanized formulation with an efficient computer implementation.

LGN plays distinct roles in oral epithelial stratification, filiform papilla morphogenesis and hair follicle development

PubMed Central

Lough, Kendall J.; Patel, Jeet H.; Descovich, Carlos Patiño; Curtis, T. Anthony

2016-01-01

Oral epithelia protect against constant challenges by bacteria, viruses, toxins and injury while also contributing to the formation of ectodermal appendages such as teeth, salivary glands and lingual papillae. Despite increasing evidence that differentiation pathway genes are frequently mutated in oral cancers, comparatively little is known about the mechanisms that regulate normal oral epithelial development. Here, we characterize oral epithelial stratification and describe multiple distinct functions for the mitotic spindle orientation gene LGN (Gpsm2) in promoting differentiation and tissue patterning in the mouse oral cavity. Similar to its function in epidermis, apically localized LGN directs perpendicular divisions that promote stratification of the palatal, buccogingival and ventral tongue epithelia. Surprisingly, however, in dorsal tongue LGN is predominantly localized basally, circumferentially or bilaterally and promotes planar divisions. Loss of LGN disrupts the organization and morphogenesis of filiform papillae but appears to be dispensable for embryonic hair follicle development. Thus, LGN has crucial tissue-specific functions in patterning surface ectoderm and its appendages by controlling division orientation. PMID:27317810

Sensitivity analysis of geometrical parameters to study haemodynamics and thrombus formation in the left atrial appendage.

PubMed

García-Isla, Guadalupe; Olivares, Andy Luis; Silva, Etelvino; Nuñez-Garcia, Marta; Butakoff, Constantine; Sanchez-Quintana, Damian; G Morales, Hernán; Freixa, Xavier; Noailly, Jérôme; De Potter, Tom; Camara, Oscar

2018-05-08

The left atrial appendage (LAA) is a complex and heterogeneous protruding structure of the left atrium (LA). In atrial fibrillation patients, it is the location where 90% of the thrombi are formed. However, the role of the LAA in thrombus formation is not fully known yet. The main goal of this work is to perform a sensitivity analysis to identify the most relevant LA and LAA morphological parameters in atrial blood flow dynamics. Simulations were run on synthetic ellipsoidal left atria models where different parameters were individually studied: pulmonary veins and mitral valve dimensions; LAA shape; and LA volume. Our computational analysis confirmed the relation between large LAA ostia, low blood flow velocities and thrombus formation. Additionally, we found that pulmonary vein configuration exerted a critical influence on LAA blood flow patterns. These findings contribute to a better understanding of the LAA and to support clinical decisions for atrial fibrillation patients. Copyright © 2018 John Wiley & Sons, Ltd.

Rationale of cerebral protection devices in left atrial appendage occlusion.

PubMed

Meincke, Felix; Spangenberg, Tobias; Kreidel, Felix; Frerker, Christian; Virmani, Renu; Ladich, Elena; Kuck, Karl-Heinz; Ghanem, Alexander

2017-01-01

Aims of this case-series were to assess the feasibility of cerebral protection devices in interventional left atrial appendage occlusion (iLAAO) procedures and to yield insight into the pathomorphological correlate of early, procedural cerebral embolization during iLAAO. Five consecutive patients underwent iLLO flanked by the Sentinel CPS® (Claret Medical, Inc., Santa Rosa, CA) cerebral protection system. Placement and recapture of the Sentinel ® device as well as the iLAAO were successful and safe in all cases. Histomorphometric analysis of the collected filters showed embolized debris in all patients. Acute thrombus was found in three patients, organizing thrombus in four. Interestingly, two patients had endocardial or myocardial tissue in their filters. Cerebral protection during iLAAO with the Sentinel CPS ® device is feasible. Furthermore, this dataset identifies the formation and embolization of thrombus and cardiac tissue as emboligeneic sources and potential future targets to reduce procedural complications. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Concentrations of teicoplanin in serum and atrial appendages of patients undergoing cardiac surgery.

PubMed Central

Bergeron, M G; Saginur, R; Desaulniers, D; Trottier, S; Goldstein, W; Foucault, P; Lessard, C

1990-01-01

The concentrations of teicoplanin in sera and heart tissues of 49 patients undergoing coronary bypass were measured. Each patient received a 6- or 12-mg/kg dose of teicoplanin administered in a slow intravenous bolus injection over 3 to 5 min beginning at the time of induction of anesthesia. Mean +/- standard error of the mean concentrations in serum were, for the two doses, respectively, 58.1 +/- 1.7 and 123.3 +/- 7.4 micrograms/ml 5 min after administration and 22.2 +/- 0.7 and 56.5 +/- 2.8 micrograms/ml at the time of removal of atrial appendages. Mean +/- standard error of the mean concentrations in tissue were 70.6 +/- 1.7 and 139.8 +/- 2.2 micrograms/g, respectively, giving mean tissue/serum ratios of 3.7 +/- 0.3 and 2.8 +/- 0.2, respectively. Teicoplanin penetrates heart tissue readily and reaches levels in the serum far in excess of the MICs for most pathogens that have been found to cause infections following open heart surgery. PMID:2149493

Experimental foundation of the Gabor-Nelson theory applied to boundaries which are non-insulating.

PubMed

Troquet, J; Lambin, P; Nelson, C V

1985-06-07

In order to found the application of the Gabor-Nelson theory to non-insulating boundaries, we have used a network which we have divided into two parts: a core energized by a source sink pair and an appendage, the conductivity of which may or may not differ from that of the core. By ignoring the appendage and by applying the Gabor-Nelson method to the restricted perimeter as if it were totally insulating, we stress the errors made in computing the dipole strength, orientation and position and how they are influenced by the dipole eccentricity, by its orientation with respect to the junction between the added portion and the core, and by a change in conductivity between the same compartments. Finally, we restore the dipole characteristics by using the appropriate correction derived from theory. Comparing the later results to those obtained by applying the Gabor-Nelson method to the whole insulating boundary leads to the conclusion that the correction is founded and must be taken into account.

A suite of citrate-derived siderophores from a marine Vibrio species isolated following the Deepwater Horizon oil spill.

PubMed

Gauglitz, Julia M; Zhou, Hongjun; Butler, Alison

2012-02-01

Nearly all microbes require iron for growth. The low concentration of iron found in the ocean makes iron acquisition a particularly difficult task. In response to these low iron conditions, many bacteria produce low-molecular-weight iron-binding molecules called siderophores to aid in iron uptake. We report herein the isolation and structural characterization of a suite of amphiphilic siderophores called the ochrobactins-OH, which are produced by a Vibrio species isolated from the Gulf of Mexico after the 2010 Deepwater Horizon oil spill. The citrate-based ochrobactins-OH are derivatives of aerobactin, replacing the acetyl groups with fatty acid appendages ranging in size from C8 to C12, and are distinctly different from the ochrobactins in that the fatty acid appendages are hydroxylated rather than unsaturated. The discovery of the marine amphiphilic ochrobactin-OH suite of siderophores increases the geographic and phylogenetic diversity of siderophore-producing bacteria. Copyright © 2011. Published by Elsevier Inc.

Cap’n’collar differentiates the mandible from the maxilla in the beetle Tribolium castaneum

PubMed Central

2012-01-01

Background The biting mandible of the arthropods is thought to have evolved in the ancestor of the insects, crustaceans and myriapods: the Mandibulata. A unique origin suggests a common set of developmental genes will be required to pattern the mandible in different arthropods. To date we have functional studies on patterning of the mandibular segment of Drosophila melanogaster showing in particular the effects of the gene cap’n’collar (cnc), however, the dipteran head is far from representative of insects or of more distantly related mandibulates; Drosophila does not even possess a mandibular appendage. To study the development of a more representative insect mandible, we chose the red flour beetle Tribolium castaneum and investigated the function of the Tribolium orthologs of cap’n’collar (Tc-cnc) and the Hox gene Deformed (Tc-Dfd). In order to determine the function of Tc-cnc and Tc-Dfd, transcripts were knocked down by maternal RNA interference (RNAi). The effects of gene knockdown were examined in the developing embryos and larvae. The effect of Tc-cnc and Tc-Dfd knockdown on the expression of other genes was determined by using in situ hybridization on Tribolium embryos. Results Our analyses show that Tc-cnc is required for specification of the identity of the mandibular segment of Tribolium and differentiates the mandible from maxillary identity. Loss of Tc-cnc function results in a transformation of the mandible to maxillary identity as well as deletion of the labrum. Tc-Dfd and the Tribolium homolog of proboscipedia (Tc-mxp = maxillopedia), Hox genes that are required to pattern the maxillary appendage, are expressed in a maxilla-like manner in the transformed mandible. Tribolium homologs of paired (Tc-prd) and Distal-less (Tc-Dll) that are expressed in the endites and telopodites of embryonic appendages are also expressed in a maxilla-like manner in the transformed mandible. We also show that Tc-Dfd is required to activate the collar of Tc-cnc expression in the mandibular segment but not the cap expression in the labrum. Tc-Dfd is also required for the activation of Tc-prd in the endites of the mandible and maxillary appendages. Conclusions Tc-cnc is necessary for patterning the mandibular segment of Tribolium. Together, Tc-cnc and Tc-Dfd cooperate to specify mandibular identity, as in Drosophila. Expression patterns of the homologs of cnc and Dfd are conserved in mandibulate arthropods suggesting that the mandible specifying function of cnc is likely to be conserved across the mandibulate arthropods. PMID:23114106

Morphology of congenital portosystemic shunts involving the right gastric vein in dogs.

PubMed

White, R N; Parry, A T

2015-07-01

To describe the anatomy of congenital portosystemic shunts involving the right gastric vein in dogs. Retrospective review of a consecutive series of dogs managed for congenital portosystemic shunt. Twenty-two dogs met the inclusion criteria of a congenital portosystemic shunt involving the right gastric vein with recorded intraoperative mesenteric portovenography or computed tomography angiography and gross observations at the time of surgery. Of these, 20 (91%) had a shunt that entered the pre-hepatic caudal vena cava at the level of the epiploic foramen and two (9%) had a shunt that entered the post-hepatic caudal vena cava at the level of the diaphragm. Shunts entering the pre-hepatic caudal vena cava could be further classified into three consistent subdivisions. The morphology of each shunt type described appeared to be a result of an abnormal communication between the left gastric vein and the caudal vena cava, the presence or absence of an abnormal communication between the splenic, left gastric and portal veins and the subsequent development of preferential blood flow through essentially normal portal vessels within the portal venous system. The abnormal communication (shunt) was through the left gastric vein and not the right gastric vein, as might have been expected. This information may help with surgical planning in cases undergoing shunt closure surgery. © 2015 British Small Animal Veterinary Association.

Assessment of the effect of left atrial cryoablation enhanced by ganglionated plexi ablation in the treatment of atrial fibrillation in patients undergoing open heart surgery.

PubMed

Bárta, Jiří; Brát, Radim

2017-08-17

The aim of our study was to investigate, whether enhancement of left atrial cryoablation by ablation of the autonomic nervous system of left atrium leads to influencing the outcomes of surgical treatment of atrial fibrillation in patients with structural heart disease undergoing open-heart surgery. The observed patient file consisted of 100 patients, who have undergone a combined open-heart surgery at our department between July 2012 and December 2014. The patients were indicated for the surgical procedure due to structural heart disease, and suffered from paroxysmal, persistent, or long-standing persistent atrial fibrillation. In all cases, left atrial cryoablation was performed in the extent of isolation of pulmonary veins, box lesion, connecting lesion with mitral annulus, amputation of the left atrial appendage and connecting lesion of the appendage base with left pulmonary veins. Furthermore, 35 of the patients underwent mapping and radiofrequency ablation of ganglionated plexi, together with discision and ablation of the ligament of Marshall (Group GP). A control group was consisted of 65 patients without ganglionated plexi intervention (Group LA). The main primary outcome was establishment and duration of sinus rhythm in the course of one-year follow-up. Evaluation of the number of patients with a normal sinus rhythm in per cent has shown comparable values in both groups (Group GP - 93.75%, Group LA - 86.67%, p = 0.485); comparable results were also observed in patients with normal sinus rhythm without anti-arrhythmic treatment in the 12th month (Group GP - 50%, Group LA - 47%, p = 0.306). We have not observed any relation between the recurrence of atrial fibrillation and the presence of a mitral valve surgery, or between the presence of a mitral and tricuspid valves surgery and between the left atrial diameter > 50 mm. Enhancement of left atrial cryoablation by gangionated plexi ablation did not influence the outcomes of surgical ablation due to atrial fibrillation in our population in the course of 12-month follow-up. The study was approved retrospectively by the Ethics Committee of the University Hospital Ostrava ( reference number 867/2016).

Stabilizing a spinning Skylab

NASA Technical Reports Server (NTRS)

Seltzer, S. M.; Patel, J. S.; Justice, D. W.; Schweitzer, G. E.

1972-01-01

The results are presented of a study of the dynamics of a spinning Skylab space station. The stability of motion of several simplified models with flexible appendages was investigated. A digital simulation model that more accurately portrays the complex Skylab vehicle is described, and simulation results are compared with analytically derived results.

An Examination of the Feasibility of Administering Prophylactic Pyridostigmine by the Percutaneous Route.

DTIC Science & Technology

1981-01-01

skin; possibly the compound is bound to anionic polymers. These results do not allow appendageal diffusion (through hair follicles) to be...R.M. "Carbamylation and Decarbamylation of Acetylcholinesterase: Effect of Choline , 3,3-dimethyl-l-butanol and some Allosteric Effectors". J. Neurocnem

The channel catfish genome sequence provides insights into the evolution of scale formation in teleosts

USDA-ARS?s Scientific Manuscript database

Channel catfish (Ictalurus punctatus), characteristic of its scaleless skin and prominent barbels, is an ideal species to study osteogenesis, development of appendages, olfactory sensing, and immunological adaptation. It is the leading aquaculture species in the United States. A high quality refere...

Physiological recordings and RNA sequencing of the gustatory appendages of the yellow-fever mosquito Aedes aegypti

USDA-ARS?s Scientific Manuscript database

Electrophysiological recording of action potentials from sensory neurons of mosquitoes provides investigators a glimpse into the chemical perception of these disease vectors. We have recently identified a bitter sensing neuron in the labellum of female Aedes aegypti that responds to DEET and other ...

Healing Hearts

ERIC Educational Resources Information Center

Brown, Susan

2007-01-01

This article discusses regeneration which is actually the dream of a scattering of biologists working in a relatively unheralded field called regenerative medicine. They hope to learn how other animals make whole their damaged parts, recreating complete working organs and appendages just as they did as embryos, but swiftly, and on a scale that…

The Strange Game of Prestige Scholarships

ERIC Educational Resources Information Center

Knox, John A.

2017-01-01

Honors programs, as home to the highest test scores and highest GPAs on many campuses (for reasons that are not particularly justifiable), can become assembly lines for prestige-scholarship applications and their dangling appendages, the applicants themselves. As honors programs become cogs in universities' PR machines, they decouple from their…

Functional and morphological analysis of putative chemoreception-related proteins in the lone star tick, Amblyomma americanum

USDA-ARS?s Scientific Manuscript database

Ehrlichiosis, a potentially fatal infection, is caused by rickettsial bacteria transmitted by the lone star tick, Amblyomma americanum. We previously analyzed the chemosensory appendage proteome of A. americanum as part of a project to develop new chemosensory-based vector control methods. Among the...

Appendange deployment mechanism for the Hubble Space Telescope program

NASA Technical Reports Server (NTRS)

Greenfield, H. T.

1985-01-01

The key requirements, a design overview, development testing (qualification levels), and two problems and their solutions resolved during the mechanism development testing phase are presented. The mechanism described herein has demonstrated its capability to deploy/restow two large Hubble Space Telescope deployable appendages in a varying but controlled manner.

A new Cantharocybe from Belize with notes on the type of Cantharocybe gruberi

Treesearch

Clark L. Ovrebo; D. Jean Lodge; M. Catherine Aime

2011-01-01

A new species of Cantharocybe, C. brunneovelutina, is described and illustrated from the Orange Walk District of Belize. The species is characterized by the subvelutinous brown pileus, brownish gray stipe and microscopically by cheilocystidia that have prong-like appendages. Analysis of nLSU rDNA sequences relates this species to ...

50 CFR 654.21 - Harvest limitations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... body when the entire appendage is extended. (See Appendix A, Figure 1, of this part.) (b) Egg-bearing stone crabs. An egg-bearing stone crab in or from the management area must be returned immediately to the water unharmed—without removal of a claw. An egg-bearing stone crab may not be stripped of its...

The School Foodservice Handbook (A Guide for School Administrators).

ERIC Educational Resources Information Center

Association of School Business Officials International, Reston, VA.

School food service should be considered a vital aspect of school operations, not an appendage to the educational program. This handbook revolves around the federal Child Nutrition and National School Lunch program serving about 24 million pupils daily in over 90 percent of the nation's 89,200 public schools. The booklet helps explain various…

The 18th Aerospace Mechanisms Symposium

NASA Technical Reports Server (NTRS)

1984-01-01

Topics concerning aerospace mechanisms, their functional performance, and design specifications are presented. Discussed subjects include the design and development of release mechanisms, actuators, linear driver/rate controllers, antenna and appendage deployment systems, position control systems, and tracking mechanisms for antennas and solar arrays. Engine design, spaceborne experiments, and large space structure technology are also examined.

Effect of spinach cultivar and strain variation on survival of Escherichia coli O157:H7 on spinach leaves

USDA-ARS?s Scientific Manuscript database

Introduction: Escherichia coli O157:H7 outbreaks of infections associated with the consumption of fresh produce have increased in recent years. Bacterial cell surface appendages such as curli and the spinach leaf structure topography influence pathogen attachment and subsequent survival on spinach ...

DEVELOPMENT OF A NINE INCH DIAMETER, MACH 5.5, MONORAIL, ROCKET SLED.

DTIC Science & Technology

A nine inch diameter monorail rocket sled was designed, fabricated and tested at Holloman Air Force Base. The vehicle was designed to allow easy...replacement of appendages which were subject to severe aerodynamic heating and/or high wear rates. The monorail vehicle as described was shown to be

Adherence of curli producing Shiga-toxigenic Escherichia coli to baby spinach leaves

USDA-ARS?s Scientific Manuscript database

Cellular appendages, such as curli fibers have been suggested to be involved in STEC persistence in fresh produce as these curli are critical in biofilm formation and adherence to animal cells. We determined the role of curli in attachment of STEC on spinach leaves. The curli expression by wild-ty...

Role of curli expression by Escherichia coli O157:H7 on the cell’s ability to attach to spinach

USDA-ARS?s Scientific Manuscript database

Introduction: Shiga-toxigenic Escherichia coli O157:H7 (STEC) outbreaks have been linked to consumption of fresh produce. Mechanisms of bacterial interaction with plant surfaces should be investigated to develop mitigation strategies. Cellular appendages, such as curli fibers have been suggested t...

Influence of curli expression on biofilm formation and attachment to plant surface by shiga toxigenic E. coli

USDA-ARS?s Scientific Manuscript database

Shiga-toxigenic Escherichia coli O157:H7 (STEC) outbreaks have been linked to consumption of fresh produce. Bacteria extracellular appendages, such as curli fibers and cellulose may play critical role in STEC biofilm formation and adherence to plant surface. We determined cellulose and curli product...

Window Design Strategies to Conserve Energy. NBS Building Science Series 104.

ERIC Educational Resources Information Center

Hastings, S. Robert; Crenshaw, Richard W.

A multitude of design strategies are available to achieve energy-efficient windows. Opportunities for improving window performance fall into six groups: site, exterior appendages, frame, glazing, interior accessories, and building interior. Design strategies within these groups can improve one or more of the six energy functions of windows: solar…

26 CFR 48.4042-3 - Certain types of commercial waterway transportation excluded.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Inland Waterways § 48.4042-3 Certain types of commercial waterway transportation excluded. (a) Deep draft... waters other than the territorial waters of the United States or any other country. Thus, the high seas... measured from the deepest appendage. A separage determination of draft must be made for each voyage when...

The South's Rural Community Colleges in the New Millennium.

ERIC Educational Resources Information Center

Rosenfeld, Stuart A.

2000-01-01

During the second half of the 20th century, two-year colleges in the rural South were transformed from "junior" appendages of other institutions to community colleges that responded to the needs of local workers and businesses. This paper examines how the South's rural community colleges contribute to economic development today and what…

Sea Butterfly Swimming: Time-resolved Tomographic PIV measurements

NASA Astrophysics Data System (ADS)

Murphy, David; Zheng, Lingxiao; Mittal, Rajat; Webster, Donald; Yen, Jeannette

2011-11-01

The planktonic sea butterfly Limacina helicina swims by flapping its flexible, wing-like parapodia. The appendage stroke kinematics of this shell-bearing pteropod are three-dimensional and likely contain elements of both drag-based (rowing) and lift-based (flapping) propulsion. Unsteady lift-generating mechanisms such as clap-and-fling may also be present. Upstroke and downstroke motions both propel the animal upward and roll it forwards and backwards, resulting in a sawtooth trajectory. We present time-resolved, tomographic PIV measurements of flow generated by free-swimming pteropods (Limacina helicina) moving upwards with average swimming speeds of 5 - 17 mm/s. The pteropods beat their appendages with a stroke frequency of 4 - 5 Hz. With a size range of 1 - 2 mm, the animals filmed in this study operate in a viscous environment with a Reynolds number of 5 to 20. The volumetric flow measurements provide insight into the three dimensional nature of the flow and into the relative importance of drag- and lift-based propulsion at this low Reynolds number. Preliminary results from Navier-Stokes simulations of the flow associated with the swimming of this organism will also be presented.

Thoracoscopic resection of right auricular masses in dogs: 9 cases (2003-2011).

PubMed

Ployart, Stéphane; Libermann, Stéphane; Doran, Ivan; Bomassi, Eric; Monnet, Eric

2013-01-15

To determine the feasibility of thoracoscopic resection of masses located on the right auricle in dogs. Retrospective case series. Dogs (n = 9) with a mass on the right auricle. Hospital records from 2003 to 2011 were reviewed. Only dogs that underwent thoracoscopic resection of a mass on the right auricle were selected. Data collected included history, clinicopathologic findings, surgical technique, and outcome. All dogs with pericardial effusion were examined by means of echocardiography. Cardiac masses on the right auricle were identified in 5 dogs. Eight dogs had clinical signs of cardiac tamponade and right-sided heart failure. All dogs underwent thoracoscopic resection of a mass on the right atrium. Eight hemangiosarcomas and 1 pyogranulomatous lesion were resected. One dog with a mass located at the base of the right auricle died during surgery. No postoperative complications were noted. Right auricular masses were successfully removed in 8 dogs. Masses close to the base of the right atrial appendage may not be amenable to resection with thoracoscopy. Resection of small masses at the tip of the right auricular appendage can be performed thoracoscopically.

Patients With Undetermined Stroke Have Increased Atrial Fibrosis: A Cardiac Magnetic Resonance Imaging Study.

PubMed

Fonseca, Ana Catarina; Alves, Pedro; Inácio, Nuno; Marto, João Pedro; Viana-Baptista, Miguel; Pinho-E-Melo, Teresa; Ferro, José M; Almeida, Ana G

2018-03-01

Some patients with ischemic strokes that are currently classified as having an undetermined cause may have structural or functional changes of the left atrium (LA) and left atrial appendage, which increase their risk of thromboembolism. We compared the LA and left atrial appendage of patients with different ischemic stroke causes using cardiac magnetic resonance imaging. We prospectively included a consecutive sample of ischemic stroke patients. Patients with structural changes on echocardiography currently considered as causal for stroke in the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification were excluded. A 3-T cardiac magnetic resonance imaging was performed. One hundred and eleven patients were evaluated. Patients with an undetermined cause had a higher percentage of LA fibrosis ( P =0.03) than patients with other stroke causes and lower, although not statistically significant, values of LA ejection fraction. Patients with atrial fibrillation and undetermined stroke cause showed a similar value of atrial fibrosis. The LA phenotype that was found in patients with undetermined cause supports the hypothesis that an atrial disease may be associated with stroke. © 2018 American Heart Association, Inc.

An acercostracan marrellomorph (Euarthropoda) from the Lower Ordovician of Morocco.

PubMed

Legg, David A

2016-04-01

Enosiaspis hrungnir gen. et sp. nov., a new species of marrellomorph arthropod from the Lower Ordovician (Tremadocian) Fezouata biota of Morocco, is described. This taxon is characterised by the possession of a cordiform dorsal carapace with an anterior notch and a doublure-like structure formed from fused marginal spines, covering the entire body. The head comprises at least five segments which bear an anterior pair of antenna, followed by three pairs of potentially biramous, geniculate appendages. The trunk possesses around 25 pairs of delicate, almost filamentous appendages, which decrease in size posteriorly. Similar features are also found in Xylokorys chledophilia from the Silurian of England, and Vachonisia rogeri from the Devonian of Germany, indicating acercostracan affinities for E. hrungnir. This was tested using a phylogenetic analysis which resolved this taxon as sister taxon to a group composed of the formerly mentioned taxa. The similarities between the ventral spinose carapace doublure of E. hrungnir and the mediolateral spines of marrellid marrellomorphs further support claims that the dorsal shield of acercostracans evolved from the fusion of spinose anlagen, akin to the formation of the carapace of crustaceans.

Anatomy of the left atrium for interventional electrophysiologists.

PubMed

Ho, Siew Yen; McCarthy, Karen P

2010-05-01

Increasingly, interventional procedures require accessing the left atrium from the inside of the heart as well as from the pericardial space. The right phrenic nerve running along the fibrous pericardium is close to the atrial insertion of the right superior pulmonary vein while the left phrenic nerve passes over the left atrial appendage. Posteriorly, the esophagus descends adjacent to the fibrous pericardium covering the posterior and postero-inferior walls of the left atrium. The component parts of the left atrium are reviewed with emphasis on the structure of the atrial septum, the left atrial ridge, the mitral isthmus, and the left atrial walls. Although the atrial walls are mainly smooth, pits and crevices are common in the region of the mitral isthmus and the vicinity of the os of the atrial appendage. The muscular rim around the valve of the oval fossa delimits the extent of the true atrial septum. Interatrial muscular connections exist at the septum, along Bachmann's bundle and also at the muscular sleeves of the coronary sinus and pulmonary veins. Anatomical features relevant to interventional electrophysiologists are highlighted.

The pattern of a specimen of Pycnogonum litorale (Arthropoda, Pycnogonida) with a supernumerary leg can be explained with the "boundary model" of appendage formation

NASA Astrophysics Data System (ADS)

Scholtz, Gerhard; Brenneis, Georg

2016-02-01

A malformed adult female specimen of Pycnogonum litorale (Pycnogonida) with a supernumerary leg in the right body half is described concerning external and internal structures. The specimen was maintained in our laboratory culture after an injury in the right trunk region during a late postembryonic stage. The supernumerary leg is located between the second and third walking legs. The lateral processes connecting to these walking legs are fused to one large structure. Likewise, the coxae 1 of the second and third walking legs and of the supernumerary leg are fused to different degrees. The supernumerary leg is a complete walking leg with mirror image symmetry as evidenced by the position of joints and muscles. It is slightly smaller than the normal legs, but internally, it contains a branch of the ovary and a gut diverticulum as the other legs. The causes for this malformation pattern found in the Pycnogonum individual are reconstructed in the light of extirpation experiments in insects, which led to supernumerary mirror image legs, and the "boundary model" for appendage differentiation.

Experimentally induced metamorphosis in axolotls reduces regenerative rate and fidelity

PubMed Central

Stier, Adrian C.; Michonneau, François; Smith, Matthew D.; Pasch, Bret; Maden, Malcolm

2014-01-01

Abstract While most tetrapods are unable to regenerate severed body parts, amphibians display a remarkable ability to regenerate an array of structures. Frogs can regenerate appendages as larva, but they lose this ability around metamorphosis. In contrast, salamanders regenerate appendages as larva, juveniles, and adults. However, the extent to which fundamental traits (e.g., metamorphosis, body size, aging, etc.) restrict regenerative ability remains contentious. Here we utilize the ability of normally paedomorphic adult axolotls (Ambystoma mexicanum) to undergo induced metamorphosis by thyroxine exposure to test how metamorphosis and body size affects regeneration in age‐matched paedomorphic and metamorphic individuals. We show that body size does not affect regeneration in adult axolotls, but metamorphosis causes a twofold reduction in regeneration rate, and lead to carpal and digit malformations. Furthermore, we find evidence that metamorphic blastemal cells may take longer to traverse the cell cycle and display a lower proliferative rate. This study identifies the axolotl as a powerful system to study how metamorphosis restricts regeneration independently of developmental stage, body size, and age; and more broadly how metamorphosis affects tissue‐specific changes. PMID:27499857

Flagella, flexibility and flow: Physical processes in microbial ecology

NASA Astrophysics Data System (ADS)

Brumley, D. R.; Rusconi, R.; Son, K.; Stocker, R.

2015-12-01

How microorganisms interact with their environment and with their conspecifics depends strongly on their mechanical properties, on the hydrodynamic signatures they generate while swimming and on fluid flows in their environment. The rich fluid-structure interaction between flagella - the appendages microorganisms use for propulsion - and the surrounding flow, has broad reaching effects for both eukaryotic and prokaryotic microorganisms. Here, we discuss selected recent advances in our understanding of the physical ecology of microorganisms, which have hinged on the ability to directly interrogate the movement of individual cells and their swimming appendages, in precisely controlled fluid environments, and to image them at appropriately fast timescales. We review how a flagellar buckling instability can unexpectedly serve a fundamental function in the motility of bacteria, we elucidate the role of hydrodynamics and flexibility in the emergent properties of groups of eukaryotic flagella, and we show how fluid flows characteristic of microbial habitats can strongly bias the migration and spatial distribution of bacteria. The topics covered here are illustrative of the potential inherent in the adoption of experimental methods and conceptual frameworks from physics in understanding the lives of microorganisms.

Biomimetic model systems of rigid hair beds: Part II - Experiment

NASA Astrophysics Data System (ADS)

Jammalamadaka, Mani S. S.; Hood, Kaitlyn; Hosoi, Anette

2017-11-01

Crustaceans - such as lobsters, crabs and stomapods - have hairy appendages that they use to recognize and track odorants in the surrounding fluid. An array of rigid hairs impedes flow at different rates depending on the spacing between hairs and the Reynolds number, Re. At larger Reynolds number (Re>1), fluid travels through the hairs rather than around them, a phenomenon called leakiness. Crustaceans flick their appendages at different speeds in order to manipulate the leakiness between the hairs, allowing the hairs to either detect the odors in a sample of fluid or collect a new sample. Theoretical and numerical studies predict that there is a fast flow region near the hairs that moves closer to the hairs as Re increases. Here, we test this theory experimentally. We 3D printed rigid hairs with an aspect ratio of 30:1 in rectangular arrays with different hair packing fractions. We custom built an experimental setup which establishes poiseuille flow at intermediate Re, Re <=200. We track the flow dynamics through the hair beds using tracer particles and Particle Imaging Velocimetry. We will then compare the modelling predictions with the experimental outcomes.

Predominant bacteria in an activated sludge reactor for the degradation of cutting fluids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, C.A.; Claus, G.W.; Taylor, P.A.

1983-01-01

For the first time, an activated sludge reactor, established for the degradation of cutting fluids, was examined for predominant bacteria. In addition, both total and viable numbers of bacteria in the reactor were determined so that the percentage of each predominant type in the total reactor population could be determined. Three samples were studied, and a total of 15 genera were detected. In each sample, the genus Pseudomonas and the genus Microcyclus were present in high numbers. Three other genera, Acinetobacter, Alcaligenes, and Corynebacterium, were also found in every sample but in lower numbers. In one sample, numerous appendage bacteriamore » were present, and one of these, the genus Seliberia, was the most predominant organism in that sample. However, in the other two samples no appendage bacteria were detected. Six genera were found in this reactor which have not been previously reported in either cutting fluids in use or in other activated sludge systems. These genera were Aeromonas, Hyphomonas, Listeria, Microcyclus, Moraxella, and Spirosoma. None of the predominant bacterial belonged to groups of strict pathogens. 22 references, 6 figures, 3 tables.« less

Surgical approach to left ventricular inflow obstruction due to dilated coronary sinus.

PubMed

Vargas, Florentino J; Rozenbaum, Jorge; Lopez, Ricardo; Granja, Miguel; De Dios, Ana; Zarlenga, Beatriz; Flores, Enrique; Fischman, Enrique; Kreutzer, Eduardo

2006-07-01

Left superior vena cava draining to a dilated coronary sinus can cause left ventricular inflow obstruction. Our purpose is to report 4 severely ill patients with this malformation who were operated upon and in whom repair was accomplished using an original surgical approach. An operative procedure was designed, which included complete resection of the wall of the coronary sinus along its entire extension in the left atrium; division of the left superior vena cava; and establishment of the left superior vena cava-right atrial continuity by a wide left superior vena cava-right atrial appendage anastomosis. The series included 1 patient with interrupted inferior vena cava-hemiazygous continuation to left superior vena cava. There were no deaths. Absence of residual left ventricular inflow obstruction was demonstrated at follow-up in all cases, together with an unobstructed left superior vena cava-right atrial appendage-right atrial connection. A predictable relief of the left ventricular inflow obstruction, together with preservation of an adequate drainage for the systemic venous return, were both achieved with this repair.

An acercostracan marrellomorph (Euarthropoda) from the Lower Ordovician of Morocco

NASA Astrophysics Data System (ADS)

Legg, David A.

2016-04-01

Enosiaspis hrungnir gen. et sp. nov., a new species of marrellomorph arthropod from the Lower Ordovician (Tremadocian) Fezouata biota of Morocco, is described. This taxon is characterised by the possession of a cordiform dorsal carapace with an anterior notch and a doublure-like structure formed from fused marginal spines, covering the entire body. The head comprises at least five segments which bear an anterior pair of antenna, followed by three pairs of potentially biramous, geniculate appendages. The trunk possesses around 25 pairs of delicate, almost filamentous appendages, which decrease in size posteriorly. Similar features are also found in Xylokorys chledophilia from the Silurian of England, and Vachonisia rogeri from the Devonian of Germany, indicating acercostracan affinities for E. hrungnir. This was tested using a phylogenetic analysis which resolved this taxon as sister taxon to a group composed of the formerly mentioned taxa. The similarities between the ventral spinose carapace doublure of E. hrungnir and the mediolateral spines of marrellid marrellomorphs further support claims that the dorsal shield of acercostracans evolved from the fusion of spinose anlagen, akin to the formation of the carapace of crustaceans.

Numerical simulation of a self-propelled copepod during escape

NASA Astrophysics Data System (ADS)

Sotiropoulos, Fotis; Borazjani, Iman; Malkiel, Edwin; Katz, Josef

2008-11-01

Obtaining the 3D flow field, forces, and power is essential for understanding the high accelerations of a copepod during the escap. We carry out numerical simulations to study a free swimming copepod using the sharp-interface immersed boundary, fluid-structure interaction (FSI) approach of Borazjani et al. (J Compu Phys, 2008, 227, p 7587-7620). We use our previous tethered copepod model with a realistic copepod-like body, including all the appendages with the appendages motion prescribed from high-resolution, cinematic dual digital holography. The simulations are performed in a frame of reference attached to the copepod whose velocity is calculated by considering the forces acting on the copepod. The self-propelled simulations are challenging due to the destabilizing effects of the large added mass resulting from the low copepod mass and fast acceleration during the escape. Strongly-coupled FSI with under-relaxation and the Aitken acceleration technique is used to obtain stable and robust FSI iterations. The computed results for the self-propelled model are analyzed and compared with our earlier results for the tethered model.

Integrated dynamic analysis simulation of space stations with controllable solar array

NASA Technical Reports Server (NTRS)

Heinrichs, J. A.; Fee, J. J.

1972-01-01

A methodology is formulated and presented for the integrated structural dynamic analysis of space stations with controllable solar arrays and non-controllable appendages. The structural system flexibility characteristics are considered in the dynamic analysis by a synthesis technique whereby free-free space station modal coordinates and cantilever appendage coordinates are inertially coupled. A digital simulation of this analysis method is described and verified by comparison of interaction load solutions with other methods of solution. Motion equations are simulated for both the zero gravity and artificial gravity (spinning) orbital conditions. Closed loop controlling dynamics for both orientation control of the arrays and attitude control of the space station are provided in the simulation by various generic types of controlling systems. The capability of the simulation as a design tool is demonstrated by utilizing typical space station and solar array structural representations and a specific structural perturbing force. Response and interaction load solutions are presented for this structural configuration and indicate the importance of using an integrated type analysis for the predictions of structural interactions.

[New technology for prevention of embolic events in atrial fibrillation: a systematic review on percutaneous endovascular left atrial appendage closure].

PubMed

Danna, Paolo; Sagone, Antonio; Proietti, Riccardo; Arensi, Andrea; Viecca, Maurizio; Santangeli, Pasquale; Di Biase, Luigi; Natale, Andrea

2012-09-01

Atrial fibrillation (AF) is the most common cardiac arrhythmia. The mortality rate of patients with AF is doubled as compared to non-fibrillating controls. The most relevant complication of AF is a major increase in the risk of stroke. The gold standard in reducing cerebrovascular events in AF is warfarin therapy, which is not free from contraindications and limitations. The left atrial appendage (LAA) is the main source of emboli causing stroke in AF. LAA closure is a seducing approach to stroke risk reduction in AF without anticoagulation. Since 1949, heart surgeons have performed LAA closure or amputation in patients with AF. Percutaneous endovascular LAA closure is a new, less invasive, technique to reach the goal. Several devices have been used to perform this intervention, and the results of published trials are encouraging in terms of effectiveness and relative safety of this attractive technique. In this review we examine the published trials and data on percutaneous LAA closure, with particular attention to the risks and benefits of this procedure.

Heterochronic shift in Hox-mediated activation of sonic hedgehog leads to morphological changes during fin development.

PubMed

Sakamoto, Koji; Onimaru, Koh; Munakata, Keijiro; Suda, Natsuno; Tamura, Mika; Ochi, Haruki; Tanaka, Mikiko

2009-01-01

We explored the molecular mechanisms of morphological transformations of vertebrate paired fin/limb evolution by comparative gene expression profiling and functional analyses. In this study, we focused on the temporal differences of the onset of Sonic hedgehog (Shh) expression in paired appendages among different vertebrates. In limb buds of chick and mouse, Shh expression is activated as soon as there is a morphological bud, concomitant with Hoxd10 expression. In dogfish (Scyliorhinus canicula), however, we found that Shh was transcribed late in fin development, concomitant with Hoxd13 expression. We utilized zebrafish as a model to determine whether quantitative changes in hox expression alter the timing of shh expression in pectoral fins of zebrafish embryos. We found that the temporal shift of Shh activity altered the size of endoskeletal elements in paired fins of zebrafish and dogfish. Thus, a threshold level of hox expression determines the onset of shh expression, and the subsequent heterochronic shift of Shh activity can affect the size of the fin endoskeleton. This process may have facilitated major morphological changes in paired appendages during vertebrate limb evolution.

Animal regeneration: ancestral character or evolutionary novelty?

PubMed

Slack, Jonathan Mw

2017-09-01

An old question about regeneration is whether it is an ancestral character which is a general property of living matter, or whether it represents a set of specific adaptations to the different circumstances faced by different types of animal. In this review, some recent results on regeneration are assessed to see if they can throw any new light on this question. Evidence in favour of an ancestral character comes from the role of Wnt and bone morphogenetic protein signalling in controlling the pattern of whole-body regeneration in acoels, which are a basal group of bilaterian animals. On the other hand, there is some evidence for adaptive acquisition or maintenance of the regeneration of appendages based on the occurrence of severe non-lethal predation, the existence of some novel genes in regenerating organisms, and differences at the molecular level between apparently similar forms of regeneration. It is tentatively concluded that whole-body regeneration is an ancestral character although has been lost from most animal lineages. Appendage regeneration is more likely to represent a derived character resulting from many specific adaptations. © 2017 The Author.

Cost-Effectiveness of Percutaneous Closure of the Left Atrial Appendage in Atrial Fibrillation Based on Results From PROTECT AF Versus PREVAIL.

PubMed

Freeman, James V; Hutton, David W; Barnes, Geoffrey D; Zhu, Ruo P; Owens, Douglas K; Garber, Alan M; Go, Alan S; Hlatky, Mark A; Heidenreich, Paul A; Wang, Paul J; Al-Ahmad, Amin; Turakhia, Mintu P

2016-06-01

Randomized trials of left atrial appendage (LAA) closure with the Watchman device have shown varying results, and its cost effectiveness compared with anticoagulation has not been evaluated using all available contemporary trial data. We used a Markov decision model to estimate lifetime quality-adjusted survival, costs, and cost effectiveness of LAA closure with Watchman, compared directly with warfarin and indirectly with dabigatran, using data from the long-term (mean 3.8 year) follow-up of Percutaneous Closure of the Left Atrial Appendage Versus Warfarin Therapy for Prevention of Stroke in Patients With Atrial Fibrillation (PROTECT AF) and Prospective Randomized Evaluation of the Watchman LAA Closure Device in Patients With Atrial Fibrillation (PREVAIL) randomized trials. Using data from PROTECT AF, the incremental cost-effectiveness ratios compared with warfarin and dabigatran were $20 486 and $23 422 per quality-adjusted life year, respectively. Using data from PREVAIL, LAA closure was dominated by warfarin and dabigatran, meaning that it was less effective (8.44, 8.54, and 8.59 quality-adjusted life years, respectively) and more costly. At a willingness-to-pay threshold of $50 000 per quality-adjusted life year, LAA closure was cost effective 90% and 9% of the time under PROTECT AF and PREVAIL assumptions, respectively. These results were sensitive to the rates of ischemic stroke and intracranial hemorrhage for LAA closure and medical anticoagulation. Using data from the PROTECT AF trial, LAA closure with the Watchman device was cost effective; using PREVAIL trial data, Watchman was more costly and less effective than warfarin and dabigatran. PROTECT AF enrolled more patients and has substantially longer follow-up time, allowing greater statistical certainty with the cost-effectiveness results. However, longer-term trial results and postmarketing surveillance of major adverse events will be vital to determining the value of the Watchman in clinical practice. © 2016 American Heart Association, Inc.

Evolution of hard proteins in the sauropsid integument in relation to the cornification of skin derivatives in amniotes.

PubMed

Alibardi, Lorenzo; Dalla Valle, Luisa; Nardi, Alessia; Toni, Mattia

2009-04-01

Hard skin appendages in amniotes comprise scales, feathers and hairs. The cell organization of these appendages probably derived from the localization of specialized areas of dermal-epidermal interaction in the integument. The horny scales and the other derivatives were formed from large areas of dermal-epidermal interaction. The evolution of these skin appendages was characterized by the production of specific coiled-coil keratins and associated proteins in the inter-filament matrix. Unlike mammalian keratin-associated proteins, those of sauropsids contain a double beta-folded sequence of about 20 amino acids, known as the core-box. The core-box shows 60%-95% sequence identity with known reptilian and avian proteins. The core-box determines the polymerization of these proteins into filaments indicated as beta-keratin filaments. The nucleotide and derived amino acid sequences for these sauropsid keratin-associated proteins are presented in conjunction with a hypothesis about their evolution in reptiles-birds compared to mammalian keratin-associated proteins. It is suggested that genes coding for ancestral glycine-serine-rich sequences of alpha-keratins produced a new class of small matrix proteins. In sauropsids, matrix proteins may have originated after mutation and enrichment in proline, probably in a central region of the ancestral protein. This mutation gave rise to the core-box, and other regions of the original protein evolved differently in the various reptilians orders. In lepidosaurians, two main groups, the high glycine proline and the high cysteine proline proteins, were formed. In archosaurians and chelonians two main groups later diversified into the high glycine proline tyrosine, non-feather proteins, and into the glycine-tyrosine-poor group of feather proteins, which evolved in birds. The latter proteins were particularly suited for making the elongated barb/barbule cells of feathers. In therapsids-mammals, mutations of the ancestral proteins formed the high glycine-tyrosine or the high cysteine proteins but no core-box was produced in the matrix proteins of the hard corneous material of mammalian derivatives.

Low Energy Multi-Stage Atrial Defibrillation Therapy Terminates Atrial Fibrillation with Less Energy than a Single Shock

PubMed Central

Li, Wenwen; Janardhan, Ajit H.; Fedorov, Vadim V.; Sha, Qun; Schuessler, Richard B.; Efimov, Igor R.

2011-01-01

Background Implantable device therapy of atrial fibrillation (AF) is limited by pain from high-energy shocks. We developed a low-energy multi-stage defibrillation therapy and tested it in a canine model of AF. Methods and Results AF was induced by burst pacing during vagus nerve stimulation. Our novel defibrillation therapy consisted of three stages: ST1 (1-4 low energy biphasic shocks), ST2 (6-10 ultra-low energy monophasic shocks), and ST3 (anti-tachycardia pacing). Firstly, ST1 testing compared single or multiple monophasic (MP) and biphasic (BP) shocks. Secondly, several multi-stage therapies were tested: ST1 versus ST1+ST3 versus ST1+ST2+ST3. Thirdly, three shock vectors were compared: superior vena cava to distal coronary sinus (SVC>CSd), proximal coronary sinus to left atrial appendage (CSp>LAA) and right atrial appendage to left atrial appendage (RAA>LAA). The atrial defibrillation threshold (DFT) of 1BP shock was less than 1MP shock (0.55 ± 0.1 versus 1.38 ± 0.31 J; p =0.003). 2-3 BP shocks terminated AF with lower peak voltage than 1BP or 1MP shock and with lower atrial DFT than 4 BP shocks. Compared to ST1 therapy alone, ST1+ST3 lowered the atrial DFT moderately (0.51 ± 0.46 versus 0.95 ± 0.32 J; p = 0.036) while a three-stage therapy, ST1+ST2+ST3, dramatically lowered the atrial DFT (0.19 ± 0.12 J versus 0.95 ± 0.32 J for ST1 alone, p=0.0012). Finally, the three-stage therapy ST1+ST2+ST3 was equally effective for all studied vectors. Conclusions Three-stage electrotherapy significantly reduces the AF defibrillation threshold and opens the door to low energy atrial defibrillation at or below the pain threshold. PMID:21980076

Brain anatomy of the marine tardigrade Actinarctus doryphorus (Arthrotardigrada).

PubMed

Persson, Dennis K; Halberg, Kenneth A; Jørgensen, Aslak; Møbjerg, Nadja; Kristensen, Reinhardt M

2014-02-01

Knowledge of tardigrade brain structure is important for resolving the phylogenetic relationships of Tardigrada. Here, we present new insight into the morphology of the brain in a marine arthrotardigrade, Actinarctus doryphorus, based on transmission electron microscopy, supported by scanning electron microscopy, conventional light microscopy as well as confocal laser scanning microscopy. Arthrotardigrades contain a large number of plesiomorphic characters and likely represent ancestral tardigrades. They often have segmented body outlines and each trunk segment, with its paired set of legs, may have up to five sensory appendages. Noticeably, the head carries numerous cephalic appendages that are structurally equivalent to the sensory appendages of the trunk segments. Our data reveal that the brain of A. doryphorus is partitioned into three paired lobes, and that these lobes exhibit a more pronounced separation as compared to that of eutardigrades. The first brain lobe in A. doryphorus is located anteriodorsally, with the second lobe just below it in an anterioventral position. Both of these two paired lobes are located anterior to the buccal tube. The third pair of brain lobes are situated posterioventrally to the first two lobes, and flank the buccal tube. In addition, A. doryphorus possesses a subpharyngeal ganglion, which is connected with the first of the four ventral trunk ganglia. The first and second brain lobes in A. doryphorus innervate the clavae and cirri of the head. The innervations of these structures indicate a homology between, respectively, the clavae and cirri of A. doryphorus and the temporalia and papilla cephalica of eutardigrades. The third brain lobes innervate the buccal lamella and the stylets as described for eutardigrades. Collectively, these findings suggest that the head region of extant tardigrades is the result of cephalization of multiple segments. Our results on the brain anatomy of Actinarctus doryphorus support the monophyly of Panarthropoda. Copyright © 2013 Wiley Periodicals, Inc.

Long Frontal Projections Help Battus philenor (Lepidoptera: Papilionidae) Larvae Find Host Plants.

PubMed

Kandori, Ikuo; Tsuchihara, Kazuko; Suzuki, Taichi A; Yokoi, Tomoyuki; Papaj, Daniel R

2015-01-01

Animals sometimes develop conspicuous projections on or near their heads as, e.g., weaponry, burrowing or digging tools, and probes to search for resources. The frontal projections that insects generally use to locate and assess resources are segmented appendages, including antennae, maxillary palps, and labial palps. There is no evidence to date that arthropods, including insects, use projections other than true segmental appendages to locate food. In this regard, it is noteworthy that some butterfly larvae possess a pair of long antenna-like projections on or near their heads. To date, the function of these projections has not been established. Larvae of pipevine swallowtail butterflies Battus philenor (Papilionidae) have a pair of long frontal fleshy projections that, like insect antennae generally, can be actively moved. In this study, we evaluated the possible function of this pair of long moveable frontal projections. In laboratory assays, both frontal projections and lateral ocelli were shown to increase the frequency with which search larvae found plants. The frontal projections increased finding of host and non-host plants equally, suggesting that frontal projections do not detect host-specific chemical cues. Detailed SEM study showed that putative mechanosensillae are distributed all around the frontal as well as other projections. Taken together, our findings suggest that the frontal projections and associated mechanosensillae act as vertical object detectors to obtain tactile information that, together with visual information from lateral ocelli and presumably chemical information from antennae and mouthparts, help larvae to find host plants. Field observations indicate that host plants are small and scattered in southern Arizona locations. Larvae must therefore find multiple host plants to complete development and face significant challenges in doing so. The frontal projections may thus be an adaptation for finding a scarce resource before starving to death. This is the first evidence that arthropods use projections other than true segmental appendages such as antennae, mouthparts and legs, to locate food resources.

Long Frontal Projections Help Battus philenor (Lepidoptera: Papilionidae) Larvae Find Host Plants

PubMed Central

Kandori, Ikuo; Tsuchihara, Kazuko; Suzuki, Taichi A.; Yokoi, Tomoyuki; Papaj, Daniel R.

2015-01-01

Animals sometimes develop conspicuous projections on or near their heads as, e.g., weaponry, burrowing or digging tools, and probes to search for resources. The frontal projections that insects generally use to locate and assess resources are segmented appendages, including antennae, maxillary palps, and labial palps. There is no evidence to date that arthropods, including insects, use projections other than true segmental appendages to locate food. In this regard, it is noteworthy that some butterfly larvae possess a pair of long antenna-like projections on or near their heads. To date, the function of these projections has not been established. Larvae of pipevine swallowtail butterflies Battus philenor (Papilionidae) have a pair of long frontal fleshy projections that, like insect antennae generally, can be actively moved. In this study, we evaluated the possible function of this pair of long moveable frontal projections. In laboratory assays, both frontal projections and lateral ocelli were shown to increase the frequency with which search larvae found plants. The frontal projections increased finding of host and non-host plants equally, suggesting that frontal projections do not detect host-specific chemical cues. Detailed SEM study showed that putative mechanosensillae are distributed all around the frontal as well as other projections. Taken together, our findings suggest that the frontal projections and associated mechanosensillae act as vertical object detectors to obtain tactile information that, together with visual information from lateral ocelli and presumably chemical information from antennae and mouthparts, help larvae to find host plants. Field observations indicate that host plants are small and scattered in southern Arizona locations. Larvae must therefore find multiple host plants to complete development and face significant challenges in doing so. The frontal projections may thus be an adaptation for finding a scarce resource before starving to death. This is the first evidence that arthropods use projections other than true segmental appendages such as antennae, mouthparts and legs, to locate food resources. PMID:26222554

The effect of transient balloon occlusion of the mitral valve on left atrial appendage blood flow velocity and spontaneous echo contrast.

PubMed

Wang, J; Chung Ann Choo, D; Zhang, X; Yang, Q; Xian, T; Lu, D; Jiang, S

2000-07-01

Spontaneous echo contrast (SEC) is a phenomenon that is commonly seen in areas of blood stasis. It is a slowly moving, cloud-like swirling pattern of "smoke" or increased echogenicity recorded on echocardiography. SEC is commonly seen in the left atrium of patients with mitral stenosis or atrial fibrillation. The presence of SEC has been shown to be a marker of increased thromboembolic risk. By using transesophageal echocardiography during percutaneous balloon mitral valvotomy (PBMV), the study investigated the relationship between SEC and varying left atrial appendage (LAA) blood flow velocity in the human heart. Thirty-five patients with rheumatic mitral stenosis underwent percutaneous balloon mitral valvotomy with intraoperative transesophageal echocardiography monitoring. We alternatively measured LAA velocities and observed the left atrium for various grades of SEC (0 = none to 4 = severe) before and after each balloon inflation. Left atrial appendage maximal ejection velocity was reduced from 35 +/- 14 to 6 +/- 2 mm/s at peak balloon inflation and increased to 40 +/- 16 mm/s after balloon deflation. In comparison with the values before balloon inflation and after balloon deflation, LAA velocities were significantly lower (p < 0.001). New or increased SEC grade was observed during 54 of 61 (88%) inflations and unchanged in 7 (12%) inflations at peak balloon inflation. Spontaneous echo contrast became lower in grade after 55 balloon deflations (90%), completely disappeared after 18 deflations (30%), and remained unchanged after 6 deflations (10%). The mean time to achieve maximal SEC grade (2.5 +/- 1.2 s) coincided with the mean time to trough LAA velocities (2.3 +/- 1.1 s) after balloon inflation. Upon deflation, the mean time to lowest SEC grade (2.9 +/- 1.8 s) coincided with mean time to achieve maximal LAA velocities (2.7 +/- 1.6 s). During balloon inflation, the severity of SEC was enhanced with corresponding reduction in LAA flow velocity. Upon balloon deflation, SEC lightens or disappears with increase in LAA flow velocity.

On Dorsal Prothoracic Appendages in Treehoppers (Hemiptera: Membracidae) and the Nature of Morphological Evidence

PubMed Central

Mikó, István; Friedrich, Frank; Yoder, Matthew J.; Hines, Heather M.; Deitz, Lewis L.; Bertone, Matthew A.; Seltmann, Katja C.; Wallace, Matthew S.; Deans, Andrew R.

2012-01-01

A spectacular hypothesis was published recently, which suggested that the “helmet” (a dorsal thoracic sclerite that obscures most of the body) of treehoppers (Insecta: Hemiptera: Membracidae) is connected to the 1st thoracic segment (T1; prothorax) via a jointed articulation and therefore was a true appendage. Furthermore, the “helmet” was interpreted to share multiple characteristics with wings, which in extant pterygote insects are present only on the 2nd (T2) and 3rd (T3) thoracic segments. In this context, the “helmet” could be considered an evolutionary novelty. Although multiple lines of morphological evidence putatively supported the “helmet”-wing homology, the relationship of the “helmet” to other thoracic sclerites and muscles remained unclear. Our observations of exemplar thoraces of 10 hemipteran families reveal multiple misinterpretations relevant to the “helmet”-wing homology hypothesis as originally conceived: 1) the “helmet” actually represents T1 (excluding the fore legs); 2) the “T1 tergum” is actually the anterior dorsal area of T2; 3) the putative articulation between the “helmet” and T1 is actually the articulation between T1 and T2. We conclude that there is no dorsal, articulated appendage on the membracid T1. Although the posterior, flattened, cuticular evagination (PFE) of the membracid T1 does share structural and genetic attributes with wings, the PFE is actually widely distributed across Hemiptera. Hence, the presence of this structure in Membracidae is not an evolutionary novelty for this clade. We discuss this new interpretation of the membracid T1 and the challenges of interpreting and representing morphological data more broadly. We acknowledge that the lack of data standards for morphology is a contributing factor to misinterpreted results and offer an example for how one can reduce ambiguity in morphology by referencing anatomical concepts in published ontologies. PMID:22272287

A Synergistic Transcriptional Regulation of Olfactory Genes Drives Blood-Feeding Associated Complex Behavioral Responses in the Mosquito Anopheles culicifacies.

PubMed

Das De, Tanwee; Thomas, Tina; Verma, Sonia; Singla, Deepak; Chauhan, Charu; Srivastava, Vartika; Sharma, Punita; Kumari, Seena; Tevatiya, Sanjay; Rani, Jyoti; Hasija, Yasha; Pandey, Kailash C; Dixit, Rajnikant

2018-01-01

Decoding the molecular basis of host seeking and blood feeding behavioral evolution/adaptation in the adult female mosquitoes may provide an opportunity to design new molecular strategy to disrupt human-mosquito interactions. Although there is a great progress in the field of mosquito olfaction and chemo-detection, little is known about the sex-specific evolution of the specialized olfactory system of adult female mosquitoes that enables them to drive and manage the complex blood-feeding associated behavioral responses. A comprehensive RNA-Seq analysis of prior and post blood meal olfactory system of An. culicifacies mosquito revealed a minor but unique change in the nature and regulation of key olfactory genes that may play a pivotal role in managing diverse behavioral responses. Based on age-dependent transcriptional profiling, we further demonstrated that adult female mosquito's chemosensory system gradually learned and matured to drive the host-seeking and blood feeding behavior at the age of 5-6 days. A time scale expression analysis of Odorant Binding Proteins (OBPs) unravels unique association with a late evening to midnight peak biting time. Blood meal-induced switching of unique sets of OBP genes and Odorant Receptors (Ors) expression coincides with the change in the innate physiological status of the mosquitoes. Blood meal follows up experiments further provide enough evidence that how a synergistic and concurrent action of OBPs-Ors may drive "prior and post blood meal" associated complex behavioral events. A dominant expression of two sensory appendages proteins (SAP-1 & SAP2) in the legs of An. culicifacies suggests that this mosquito species may draw an extra advantage of having more sensitive appendages than An. stephensi , an urban malarial vector in the Indian subcontinents. Finally, our molecular modeling analysis predicts crucial amino acid residues for future functional characterization of the sensory appendages proteins which may play a central role in regulating multiple behaviors of An. culicifacies mosquito. SIGNIFICANCE   Evolution and adaptation of blood feeding behavior not only favored the reproductive success of adult female mosquitoes but also make them important disease-transmitting vectors. An environmental exposure after emergence may favor the broadly tuned olfactory system of mosquitoes to drive complex behavioral responses. But, how these olfactory derived genetic factors manage female specific "pre and post" blood meal associated complex behavioral responses are not well known. Our findings suggest that a synergistic action of olfactory factors may govern an innate to prime learning strategy to facilitate rapid blood meal acquisition and downstream behavioral activities. A species-specific transcriptional profiling and an in-silico analysis predict that "sensory appendages protein" may be a unique target to design disorientation strategy against the mosquito Anopheles culicifacies .

JPRS Report, China.

DTIC Science & Technology

1991-12-03

BANKING Hidden Financial Distribution [CAIMAO JINGJI No8] .................................... .. . .. .. 25 Guangxi Tax Chief on Using Tax Levers [GUANGXI...assets is confused. economy. They are of major importance in the invigo- Under the financial contracting system, the conflict ration of large and...to various economic levers and legal strictures state, and to change enterprises from appendages of the such as financial , fiscal, and tax policies

Are You at Risk for Contact Dermatitis? | Poster

Cancer.gov

You probably don’t give much thought to hand health. Until something goes wrong, almost everyone takes for granted that these crucial appendages will continue working as they always have. But hand health is an important consideration, especially at work. According to the Centers for Disease Control and Prevention (CDC), allergic contact dermatitis and irritant contact

Cosmopolitanism "as" Education: A Philosophy for Educators in Our Time

ERIC Educational Resources Information Center

Hansen, David T.

2017-01-01

There could hardly be a more auspicious, if not urgent, time for renewing our commitment to the deep values in education. With reference to the United States, consider the ongoing pressure on educators to treat their work, and to regard themselves, as mere appendages of the economic system. Consider also the fractured, polarized state of public…

Xylanase 30 A from Clostridium thermocellum functions as a glucuronoxylan xylanohydrolase

Treesearch

Franz J. St John; Casey Crooks; Diane Dietrich; Jason Hurlbert

2017-01-01

Endoxylanases classified into glycoside hydrolase family 30 subfamily 8 (GH30-8) have been shown to hydrolyze glucuronoxylan with dependence upon the glucuronic acid (GlcA) appendage. In a recent report, the GH30-8 xylanase from Clostridium thermocellum (CtXyn30A) was shown to hydrolyze arabinoxylan which contains no GlcA. Protein structure...

Internode or stem unit: a problem of terminology

Treesearch

William B. Critchfield

1985-01-01

In recent years the term stem unit (SU) has increasingly supplanted internode in the literature of conifer shoot growth, especially since the adoption of SU in a collection of papers titled "Tree Physiology and Yield Improvement" (Cannell and Last 1976). In standard botanical terminology, a node is the point on a stem where one or more lateral appendages (...

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR FIRST STAGE OF CLEANING ELECTRONIC DATA (HAND ENTRY) (UA-D-16.0)

EPA Science Inventory

The purpose of this SOP is to provide a standard method for the "first stage" of cleaning data. The first cleaning stage takes place after data verification and before master database appendage. This procedure applies to (1) post-keypunch data collected by the NHEXAS Arizona st...

Assessment of Spacecraft Operational Status Using Electro-Optical Predictive Techniques

DTIC Science & Technology

2010-09-01

panel appendages, may require enhanced preflight characterization processes to support monitoring by passive, remote, nonimaging optical sensors...observing and characterizing key spacecraft features. The simulation results are based on electro-optical signatures apparent to nonimaging sensors, along...and communication equipment, may require enhanced preflight characterization processes to support monitoring by passive, remote, nonimaging optical

The cingulum: A unique structure of some Dolichopodidae

Treesearch

Justin Runyon

2008-01-01

The cingulum is a U-shaped structure of unknown function which arises between abdominal sterna 4 and 5 and terminates in a pair of variously modified flag-like appendages. This structure is well developed only in males of the genus Scellus. Richard Hurley discovered that Hydatostega have a much reduced cingulum, a finding that had broad implications for elucidating...

A COMPARATIVE INVESTIGATION OF THE INFLUENCE OF DERMAL APPENDAGES (HAIR FOLLICLES) ON THE PERCUTANEOUS ABSORPTION OF ORGANOPHOSPHORUS (OP) INSECTICIDES USING QSAR AND PBPK/PD MODELS FOR HUMAN RISK ASSESSMENT

EPA Science Inventory

The successful use of the Exposure Related Dose Estimating Model (ERDEM) for assessment of dermal exposure of humans to OP pesticides requires the input of representative and comparable input parameters. In the specific case of dermal exposure, regional anatomical variation in...

46 CFR 160.151-29 - Additional approval tests for SOLAS A and SOLAS B inflatable liferafts.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Resolution A.689(17): (a) Test of filling time for stability appendages. A representative sample of each type... 46 Shipping 6 2011-10-01 2011-10-01 false Additional approval tests for SOLAS A and SOLAS B... Inflatable Liferafts (SOLAS) § 160.151-29 Additional approval tests for SOLAS A and SOLAS B inflatable...

Telosticta fugispinosa sp. nov. from Sabah (Odonata: Zygoptera: Platystictidae).

PubMed

Dow, Rory A; Afendy, Aqilah; Rahman, Homathevi

2016-04-14

Telosticta fugispinosa sp. nov. (holotype male, from Borneo, Sabah, West Coast division, Crocker Range National Park, Inobong, Kimamabang waterfall stream system, 21 ix 2012, deposited in RMNH) is described from Kinabalu National Park and Crocker Range National Park in Sabah, Malaysian Borneo. It is distinguished from all other species of Telosticta by the form of the male anal appendages.

Hubble Space Telescope (HST) high gain antenna (HGA) deployment during STS-31

NASA Image and Video Library

1990-04-25

Held in appendage deploy position, the Hubble Space Telescope's (HST's) high gain antenna (HGA) has been released from its stowed position along the Support System Module (SSM) forward shell. The STS-31 crew aboard Discovery, Orbiter Vehicle (OV) oversees the automatic HGA deployment prior to releasing HST. HST HGA is backdropped against the blackness of space.

Uses of the Westrup brush machine

Treesearch

Jill Barbour

2002-01-01

The Westrup brush machine can be used as the first step in the conditioning process of seeds. Even though there are various sizes of the machine, only the laboratory model (LA-H) is described. The machine is designed to separate seed from pods or flowers, dewing tree seed, remove appendages or hairs from seed, split twin seed, de-lint cotton seed, scarify hard coated...

Role of curli and cellulose expression by Escherichia coli O157:H7 on the cell’s ability to attach to spinach

USDA-ARS?s Scientific Manuscript database

Shiga-toxigenic Escherichia coli O157:H7 (STEC) outbreaks have been linked to consumption of fresh produce. Cellular appendages, such as curli fibers have been suggested to be involved in STEC persistence in fresh produce as these curli are critical in biofilm formation and adherence to animal cell...

Vessel Biofouling Prevention and Management Options Report

DTIC Science & Technology

2015-03-01

Marine Reserve GNPD Galapagos National Park Directorate gpm Gallons per minute HST™ Hull Surface Treatment HullBUG Hull Bio -Mimetic Underwater...operators and hull cleaning equipment vendors. 2 VESSEL STRUCTURES SUBJECT TO BIOFOULING All submerged areas of the hull, including appendages and niche...categorized as proactive (preventative) and reactive (removal). Preventative measures include hull coatings that present bio -toxic surfaces to the immediate

Electron tomography study of isolated human centrioles.

PubMed

Ibrahim, Rana; Messaoudi, Cédric; Chichon, Francisco Javier; Celati, Claude; Marco, Sergio

2009-01-01

Centrioles are components of the centrosome, which is present in most eukaryotic cells (from protozoa to mammals). They organize the microtubule skeleton during interphase and the mitotic spindle during cell division. In ciliate cells, centrioles form basal bodies that are involved in cellular motility. Despite their important roles in biology, the detailed structure of centrioles remains obscure. This work contributes to a more complete model of centriole structure. The authors used electron tomography of isolated centrosomes from the human lymphoblast KE37 to explore the details of subdistal appendages and centriole lumen organization in mother centrioles. Their results reveal that each of the nine subdistal appendages is composed of two halves (20 nm diameter each) fused in a 40 nm tip that extends 100 nm from where it anchors to microtubules. The centriole lumen is filled at the distal domain by a 45 nm periodic stack of rings. Each ring has a 30 nm diameter, is 15 nm thick, and appears to be tilted at 53 degrees perpendicular to the centriole axis. The rings are anchored to microtubules by arms. Based on their results, the authors propose a model of the mother centriole distal structure. Copyright 2008 Wiley-Liss, Inc.

The origins of adipose fins: an analysis of homoplasy and the serial homology of vertebrate appendages.

PubMed

Stewart, Thomas A; Smith, W Leo; Coates, Michael I

2014-04-22

Adipose fins are appendages found on the dorsal midline between the dorsal and caudal fins in more than 6000 living species of teleost fishes. It has been consistently argued that adipose fins evolved once and have been lost repeatedly across teleosts owing to limited function. Here, we demonstrate that adipose fins originated repeatedly by using phylogenetic and anatomical evidence. This suggests that adipose fins are adaptive, although their function remains undetermined. To test for generalities in the evolution of form in de novo vertebrate fins, we studied the skeletal anatomy of adipose fins across 620 species belonging to 186 genera and 55 families. Adipose fins have repeatedly evolved endoskeletal plates, anterior dermal spines and fin rays. The repeated evolution of fin rays in adipose fins suggests that these fins can evolve new tissue types and increased structural complexity by expressing fin-associated developmental modules in these new territories. Patterns of skeletal elaboration differ between the various occurrences of adipose fins and challenge prevailing hypotheses for vertebrate fin origin. Adipose fins represent a powerful and, thus far, barely studied model for exploring the evolution of vertebrate limbs and the roles of adaptation and generative biases in morphological evolution.

Epidermal Micromorphology and Mesophyll Structure of Populus euphratica Heteromorphic Leaves at Different Development Stages

PubMed Central

Liu, Yubing; Li, Xinrong; Chen, Guoxiong; Li, Mengmeng; Liu, Meiling; Liu, Dan

2015-01-01

Leaf epidermal micromorphology and mesophyll structure during the development of Populus euphratica heteromorphic leaves, including linear, lanceolate, ovate, dentate ovate, dentate rhombic, dentate broad-ovate and dentate fan-shaped leaves, were studied by using electron and light microscopy. During development of heteromorphic leaves, epidermal appendages (wax crystals and trichomes) and special cells (mucilage cells and crystal idioblasts) increased in all leaf types while chloroplast ultrastructure and stomatal characters show maximum photosynthetic activity in dentate ovate and rhombic leaves. Also, functional analysis by subordinate function values shows that the maximum adaptability to adverse stress was exhibited in the broad type of mature leaves. The 12 heteromorphic leaf types are classified into three major groups by hierarchical cluster analysis: young, developing and mature leaves. Mature leaves can effectively obtain the highest stress resistance by combining the protection of xerophytic anatomy from drought stress, regulation of water uptake in micro-environment by mucilage and crystal idioblasts, and assistant defense of transpiration reduction through leaf epidermal appendages, which improves photosynthetic activity under arid desert conditions. Our data confirms that the main leaf function is differentiated during the developing process of heteromorphic leaves. PMID:26356300

Diversity, assembly and regulation of archaeal type IV pili-like and non-type-IV pili-like surface structures.

PubMed

Lassak, Kerstin; Ghosh, Abhrajyoti; Albers, Sonja-Verena

2012-01-01

Archaea have evolved fascinating surface structures allowing rapid adaptation to changing environments. The archaeal surface appendages display such diverse biological roles as motility, adhesion, biofilm formation, exchange of genetic material and species-specific interactions and, in turn, increase fitness of the cells. Intriguingly, despite sharing the same functions with their bacterial counterparts, the assembly mechanism of many archaeal surface structures is rather related to assembly of bacterial type IV pili. This review summarizes our state-of-the-art knowledge about unique structural and biochemical properties of archaeal surface appendages with a particular focus on archaeal type IV pili-like structures. The latter comprise not only widely distributed archaella (formerly known as archaeal flagella), but also different highly specialized archaeal pili, which are often restricted to certain species. Recent findings regarding assembly mechanisms, structural aspects and physiological roles of these type IV pili-like structures will be discussed in detail. Recently, first regulatory proteins involved in transition from both planktonic to sessile lifestyle and in assembly of archaella were identified. To conclude, we provide novel insights into regulatory mechanisms underlying the assembly of archaeal surface structures. Copyright © 2012. Published by Elsevier Masson SAS.

Ectodysplasin A Pathway Contributes to Human and Murine Skin Repair.

PubMed

Garcin, Clare L; Huttner, Kenneth M; Kirby, Neil; Schneider, Pascal; Hardman, Matthew J

2016-05-01

The highly conserved ectodysplasin A (EDA)/EDA receptor signaling pathway is critical during development for the formation of skin appendages. Mutations in genes encoding components of the EDA pathway disrupt normal appendage development, leading to the human disorder hypohidrotic ectodermal dysplasia. Spontaneous mutations in the murine Eda (Tabby) phenocopy human X-linked hypohidrotic ectodermal dysplasia. Little is known about the role of EDA signaling in adult skin homeostasis or repair. Because wound healing largely mimics the morphogenic events that occur during development, we propose a role for EDA signaling in adult wound repair. Here we report a pronounced delay in healing in Tabby mice, demonstrating a functional role for EDA signaling in adult skin. Moreover, pharmacological activation of the EDA pathway in both Tabby and wild-type mice significantly accelerates healing, influencing multiple processes including re-epithelialization and granulation tissue matrix deposition. Finally, we show that the healing promoting effects of EDA receptor activation are conserved in human skin repair. Thus, targeted manipulation of the EDA/EDA receptor pathway has clear therapeutic potential for the future treatment of human pathological wound healing. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

The sense of touch in the star-nosed mole: from mechanoreceptors to the brain

PubMed Central

Catania, Kenneth C.

2011-01-01

Star-nosed moles are somatosensory specialists that explore their environment with 22 appendages that ring their nostrils. The appendages are covered with sensory domes called Eimer's organs. Each organ is associated with a Merkel cell–neurite complex, a lamellated corpuscle, and a series of 5–10 free nerve endings that form a circle of terminal swellings. Anatomy and electrophysiological recordings suggest that Eimer's organs detect small shapes and textures. There are parallels between the organization of the mole's somatosensory system and visual systems of other mammals. The centre of the star is a tactile fovea used for detailed exploration of objects and prey items. The tactile fovea is over-represented in the neocortex, and this is evident in the modular, anatomically visible representation of the star. Multiple maps of the star are visible in flattened cortical preparations processed for cytochrome oxidase or NADPH-diaphorase. Star-nosed moles are the fastest known foragers among mammals, able to identify and consume a small prey item in 120 ms. Together these behavioural and nervous system specializations have made star-nosed moles an intriguing model system for examining general and specialized aspects of mammalian touch. PMID:21969683

Ontogeny and function of the fifth limb in Cypridocopain ostracods.

PubMed

Kaji, Tomonari

2010-08-01

The exoskeleton of arthropods undergoes reformation at every molting. Accordingly, external morphology can metamorphose through molting. In some crustaceans, the function of appendages is modified through ontogeny. These morphological modifications require accordant modification of the correlation between different body parts because the morphological function depends on the combined correlation between different parts. In the case of crustacean morphology, exoskeleton and muscles are correlated to each other. The functional morphology of the fifth limb of cypridoid ostracods transforms from "walking leg + mouthparts (+ possibly respiratory parts)" to "mouthparts + respiratory parts + grasping hook (in males only)" through ontogeny. In this study, the three-dimensional structures of the exoskeleton and muscular systems were observed by confocal laser-scanning microscopy in some species of suborder Cypridocopina. The muscular system is reportedly not changed by the ontogeny of appendages in females, but it does change in males. Furthermore, regional cell proliferation, which was detected previously, represented the causal factor of exoskeletal modification. I therefore conclude that the enlarged endite in the female fifth limb is produced by exoskeletal modification based on regional cell proliferation, rather than by a change in the muscular system. In contrast, modification in the male requires a change in the muscular system in addition to exoskeletal modification.

Gene Regulatory Networks, Homology, and the Early Panarthropod Fossil Record.

PubMed

Tweedt, Sarah M

2017-09-01

The arthropod body plan is widely believed to have derived from an ancestral form resembling Cambrian-aged fossil lobopodians, and interpretations of morphological and molecular data have long favored this hypothesis. It is possible, however, that appendages and other morphologies observed in extinct and living panarthropods evolved independently. The key to distinguishing between morphological homology and homoplasy lies in the study of developmental gene regulatory networks (GRNs), and specifically, in determining the unique genetic circuits that construct characters. In this study, I discuss character identity and panarthropod appendage evolution within a developmental GRN framework, with a specific focus on potential limb character identity networks ("ChINs"). I summarize recent molecular studies, and argue that current data do not rule out the possibility of independent panarthropod limb evolution. The link between character identity and GRN architecture has broad implications for homology assessment, and this genetic framework offers alternative approaches to fossil character coding, phylogenetic analyses, and future research into the origin of the arthropod body plan. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

The origins of adipose fins: an analysis of homoplasy and the serial homology of vertebrate appendages

PubMed Central

Stewart, Thomas A.; Smith, W. Leo; Coates, Michael I.

2014-01-01

Adipose fins are appendages found on the dorsal midline between the dorsal and caudal fins in more than 6000 living species of teleost fishes. It has been consistently argued that adipose fins evolved once and have been lost repeatedly across teleosts owing to limited function. Here, we demonstrate that adipose fins originated repeatedly by using phylogenetic and anatomical evidence. This suggests that adipose fins are adaptive, although their function remains undetermined. To test for generalities in the evolution of form in de novo vertebrate fins, we studied the skeletal anatomy of adipose fins across 620 species belonging to 186 genera and 55 families. Adipose fins have repeatedly evolved endoskeletal plates, anterior dermal spines and fin rays. The repeated evolution of fin rays in adipose fins suggests that these fins can evolve new tissue types and increased structural complexity by expressing fin-associated developmental modules in these new territories. Patterns of skeletal elaboration differ between the various occurrences of adipose fins and challenge prevailing hypotheses for vertebrate fin origin. Adipose fins represent a powerful and, thus far, barely studied model for exploring the evolution of vertebrate limbs and the roles of adaptation and generative biases in morphological evolution. PMID:24598422

Crucial advantages of tail use in the evolution of vertebrate terrestrial locomotion

NASA Astrophysics Data System (ADS)

Astley, Henry; McInroe, Benjamin; Kawano, Sandy; Blob, Rick; Goldman, Daniel

In the invasion of terrestrial environment, the first tetrapods faced the challenge of locomotion on flowable substrates (e.g. sand and mud), sometimes oriented at inclines. Although the morphology of many early tetrapods is known, robotic studies have revealed that effective locomotion on these substrates also depends strongly upon kinematics; slight differences in movements of the same appendage can lead to success or failure. Using a model organism (the mudskipper) and a robotic physical model, we demonstrate how muscular tails provided critical locomotor advantages on granular substrates that the first invaders of land likely encountered. Mudskippers use their tails for additional propulsion with increasing frequency as the slope of the granular material increases, and the decline in locomotor performance with slope is shallower when the tail is used. Experiments with a robotic model of the mudskipper showed that, while the tail did not always provide a benefit to locomotion, use of the tail made the robot's performance more robust, achieving effective locomotion on a wider range of slopes, limb postures and foot placements. These results suggest that, rather than simply being an inert appendage, the tails of early tetrapods were vital to their first forays into terrestrial habitats.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Xiao-Qing; Zhang, Dao-Liang; Zhang, Ming-Jian

Aims: Atrial fibroblasts and macrophages have long been thought to participate in atrial fibrillation (AF). However, which specific mediator may regulate the interaction between them remains unclear. Methods and results: We provided the evidence for the involvement of Toll/IL-1 receptor domain-containing adaptor inducing IFN-β (TRIF), an important inflammation-related molecule, in the pathophysiology of AF. Patients with AF showed higher levels of angiotensin II (AngII) and TRIF expression and larger number of macrophages infiltration in left atria appendage than individuals with sinus rhythm (SR). In the cell study, AngII induced chemokines expressions in mouse atrial fibroblasts and AngII-stimulated atrial fibroblasts inducedmore » the chemotaxis of macrophages, which were reduced by losartan and TRIF siRNA. Meanwhile, AngII-stimulated atrial fibroblasts proliferation was enhanced by macrophages. Conclusions: Our data demonstrated that TRIF may be a crucial factor promoting the interaction between atrial fibroblasts and macrophages, leading to atrial fibrosis. - Highlights: • Compared with SR, AF showed higher TRIF expression in left atrial appendage. • TRIF siRNA reversed macrophage chemotaxis induced by AngII-treated fibroblast. • TRIF siRNA reversed chemokines expressions induced by AngII in fibroblast. • AngII-stimulated atrial fibroblast proliferation was enhanced by macrophage.« less

Epidermal Micromorphology and Mesophyll Structure of Populus euphratica Heteromorphic Leaves at Different Development Stages.

PubMed

Liu, Yubing; Li, Xinrong; Chen, Guoxiong; Li, Mengmeng; Liu, Meiling; Liu, Dan

2015-01-01

Leaf epidermal micromorphology and mesophyll structure during the development of Populus euphratica heteromorphic leaves, including linear, lanceolate, ovate, dentate ovate, dentate rhombic, dentate broad-ovate and dentate fan-shaped leaves, were studied by using electron and light microscopy. During development of heteromorphic leaves, epidermal appendages (wax crystals and trichomes) and special cells (mucilage cells and crystal idioblasts) increased in all leaf types while chloroplast ultrastructure and stomatal characters show maximum photosynthetic activity in dentate ovate and rhombic leaves. Also, functional analysis by subordinate function values shows that the maximum adaptability to adverse stress was exhibited in the broad type of mature leaves. The 12 heteromorphic leaf types are classified into three major groups by hierarchical cluster analysis: young, developing and mature leaves. Mature leaves can effectively obtain the highest stress resistance by combining the protection of xerophytic anatomy from drought stress, regulation of water uptake in micro-environment by mucilage and crystal idioblasts, and assistant defense of transpiration reduction through leaf epidermal appendages, which improves photosynthetic activity under arid desert conditions. Our data confirms that the main leaf function is differentiated during the developing process of heteromorphic leaves.

Extracellular Control of Limb Regeneration

NASA Astrophysics Data System (ADS)

Calve, S.; Simon, H.-G.

Adult newts possess the ability to completely regenerate organs and appendages. Immediately after limb loss, the extracellular matrix (ECM) undergoes dramatic changes that may provide mechanical and biochemical cues to guide the formation of the blastema, which is comprised of uncommitted stem-like cells that proliferate to replace the lost structure. Skeletal muscle is a known reservoir for blastema cells but the mechanism by which it contributes progenitor cells is still unclear. To create physiologically relevant culture conditions for the testing of primary newt muscle cells in vitro, the spatio-temporal distribution of ECM components and the mechanical properties of newt muscle were analyzed. Tenascin-C and hyaluronic acid (HA) were found to be dramatically upregulated in the amputated limb and were co-expressed around regenerating skeletal muscle. The transverse stiffness of muscle measured in situ was used as a guide to generate silicone-based substrates of physiological stiffness. Culturing newt muscle cells under different conditions revealed that the cells are sensitive to both matrix coating and substrate stiffness: Myoblasts on HA-coated soft substrates display a rounded morphology and become more elongated as the stiffness of the substrate increases. Coating of soft substrates with matrigel or fibronectin enhanced cell spreading and eventual cell fusion.

Revision of the Lima clade (Miconia sect. Lima, Miconieae, Melastomataceae) of the Greater Antilles

PubMed Central

Majure, Lucas C.; Bécquer, Eldis R.; Judd, Walter S.

2016-01-01

Abstract Miconia sect. Lima is an entirely Greater Antillean clade that consists of 19 known species of shrubs and small trees, which were previously recognized under the polyphyletic genera Leandra and Ossaea. The highest species richness in the clade is represented on Cuba (10 species), followed by Hispaniola (8 species) and then Jamaica (1 species). Here we present a taxonomic revision of the clade based on the study of species in the field, herbarium specimens, as well as a DNA-based phylogeny reconstruction. The Lima clade most likely originated on Cuba and then spread to Jamaica once and Hispaniola multiple times. Species of this clade can be recognized by the well developed bulla-based hairs of the adaxial leaf surface, as well as the clavate-dendritic hairs produced along the primary, secondary and tertiary veins of the adaxial leaf surface, mostly towards the leaf base, terminal inflorescences, acute petal apices, slightly bulla-based hairs produced subapically along the petal abaxial surface, and anthers with a dorso-basal appendage and a single, dorsally oriented pore. Descriptions, synonymies, along with distribution maps and illustrations/figures, are given for each species. Miconia pagnolensis sp. nov. is newly described in this revision. PMID:27829802

5-Year Outcomes After Left Atrial Appendage Closure: From the PREVAIL and PROTECT AF Trials.

PubMed

Reddy, Vivek Y; Doshi, Shephal K; Kar, Saibal; Gibson, Douglas N; Price, Matthew J; Huber, Kenneth; Horton, Rodney P; Buchbinder, Maurice; Neuzil, Petr; Gordon, Nicole T; Holmes, David R

2017-12-19

The PROTECT AF (WATCHMAN Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) trial demonstrated that left atrial appendage closure (LAAC) with the Watchman device (Boston Scientific, St. Paul, Minnesota) was equivalent to warfarin for preventing stroke in atrial fibrillation, but had a high rate of complications. In a second randomized trial, PREVAIL (Evaluation of the WATCHMAN LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy), the complication rate was low. The warfarin cohort experienced an unexpectedly low ischemic stroke rate, rendering the efficacy endpoints inconclusive. However, these outcomes were based on relatively few patients followed for a relatively short time. The final results of the PREVAIL trial, both alone and as part of a patient-level meta-analysis with the PROTECT AF trial, are reported with patients in both trials followed for 5 years. PREVAIL and PROTECT AF are prospective randomized clinical trials with patients randomized 2:1 to LAAC or warfarin; together, they enrolled 1,114 patients for 4,343 patient-years. Analyses are by intention-to-treat, and rates are events per 100 patient-years. For the PREVAIL trial, the first composite coprimary endpoint of stroke, systemic embolism (SE), or cardiovascular/unexplained death did not achieve noninferiority (posterior probability for noninferiority = 88.4%), whereas the second coprimary endpoint of post-procedure ischemic stroke/SE did achieve noninferiority (posterior probability for noninferiority = 97.5%); the warfarin arm maintained an unusually low ischemic stroke rate (0.73%). In the meta-analysis, the composite endpoint was similar between groups (hazard ratio [HR]: 0.820; p = 0.27), as were all-stroke/SE (HR: 0.961; p = 0.87). The ischemic stroke/SE rate was numerically higher with LAAC, but this difference did not reach statistical significance (HR: 1.71; p = 0.080). However, differences in hemorrhagic stroke, disabling/fatal stroke, cardiovascular/unexplained death, all-cause death, and post-procedure bleeding favored LAAC (HR: 0.20; p = 0.0022; HR: 0.45; p = 0.03; HR: 0.59; p = 0.027; HR: 0.73; p = 0.035; HR: 0.48; p = 0.0003, respectively). These 5-year outcomes of the PREVAIL trial, combined with the 5-year outcomes of the PROTECT AF trial, demonstrate that LAAC with Watchman provides stroke prevention in nonvalvular atrial fibrillation comparable to warfarin, with additional reductions in major bleeding, particularly hemorrhagic stroke, and mortality. (WATCHMAN Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation; NCT00129545; and Evaluation of the WATCHMAN LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy; NCT01182441). Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

A new notodelphyid copepod, Doropygopsis arctica sp. nov. (Cyclopoida), parasitic in ascidian of the Molgula arctica from the White Sea

NASA Astrophysics Data System (ADS)

Marchenkov, A. V.

1998-06-01

Doropygopsis arctica, a new species of notodelphyid cyclopoid from the branchial cavity of Molgula arctica Kiaer, 1896 (Ascidiacea) in Chupa Bay (Kandalakshskiy Zaliv, White Sea) is described. The new species differs from the two other congeners by the fine structure of some cephalosomic appendages and swimming legs. The diagnosis for Doropygopsis is redefined.

Genome Sequence of Pedobacter arcticus sp. nov., a Sea Ice Bacterium Isolated from Tundra Soil

PubMed Central

Yin, Ye; Yue, Guidong; Gao, Qiang; Wang, Zhiyong; Peng, Fang; Fang, Chengxiang; Yang, Xu

2012-01-01

Pedobacter arcticus sp. nov. was originally isolated from tundra soil collected from Ny-Ålesund, in the Arctic region of Norway. It is a Gram-negative bacterium which shows bleb-shaped appendages on the cell surface. Here, we report the draft annotated genome sequence of Pedobacter arcticus sp. nov., which belongs to the genus Pedobacter. PMID:23144423

Synthesis and acetylcholinesterase inhibitory activity of several pyrimidone analogues of huperzine A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kozlkowski, A.P.; Campiani, G.; Saxena, A.

1995-12-31

Synthesis of four new pyrimidone analogues of the acetyicholinesterase (AChE) inhibitor huperzine A are reported together with the inhibitory potendes of these compounds for foetal bovine calf serum AChE; t3-lactone formation followed by a thermal cycloreversion reaction serves as the key step for introduction of the ethylidene appendage of analogue 12 in the stereochemically correct form.

Demodicosis in red-handed tamarins (Saguinus midas).

PubMed

James, S B; Raphael, B L

2000-06-01

Two nonrelated but paired red-handed tamarins (Saguinus midas) presented with diffuse, multifocal, raised, nonpruritic, hyperkeratotic lesions on the appendages and face. Skin biopsies identified acarids and skin scrapings confirmed demodex-like mites. The animals were treated with ivermectin, at the endoparasite dose, which initially resulted in resolution of clinical signs; however, signs recurred after numerous treatments. After four treatments with amitraz dips, demodicosis lesions resolved.

Shape Memory Actuation and Release Devices.

DTIC Science & Technology

1996-10-01

shelf devices such as pyrotechnics, gas-discharge systems, paraffin wax actuators, and other electro-mechanical devices may not be able to meet...shelf devices such as pyrotechnics, gas-discharge systems, paraffin wax actuators, and other electro-mechanical devices may not be able to meet future...shard mounts. They do have wide utility as pin-pullers and single point release devices for a variety of spacecraft appendages. Parrafin based mechanisms

Physiological regeneration of skin appendages and implications for regenerative medicine

PubMed Central

Chuong, Cheng-Ming; Randall, Valerie A; Widelitz, Randall B.; Wu, Ping; Jiang, Ting-Xin

2013-01-01

The concept of regenerative medicine is relatively new, but animals are well known to remake their hair and feathers regularly by normal regenerative physiological processes. Here we focus on 1) how extra-follicular environments can regulate hair and feather stem cell activities and 2) how different configurations of stem cells can shape organ forms in different body regions to fulfil changing physiological needs. PMID:22505663

Expedition 15 Progress 26 Launch

NASA Image and Video Library

2007-08-02

JSC2007-E-41113(2 Aug. 2007) --- The ISS Progress 26 launched Aug. 2 from the Baikonur Cosmodrome in Kazakhstan on time at 12:33:46 pm (CDT) and 11:33:46 pm, Baikonur time. Ascent was nominal and by the book. Once in orbit, the Progress separated from the third stage of the booster and all appendages and antennas were deployed on time. Photo Credit: NASA/Mark Bowman

Evolution of hard proteins in the sauropsid integument in relation to the cornification of skin derivatives in amniotes

PubMed Central

Alibardi, Lorenzo; Valle, Luisa Dalla; Nardi, Alessia; Toni, Mattia

2009-01-01

Hard skin appendages in amniotes comprise scales, feathers and hairs. The cell organization of these appendages probably derived from the localization of specialized areas of dermal–epidermal interaction in the integument. The horny scales and the other derivatives were formed from large areas of dermal–epidermal interaction. The evolution of these skin appendages was characterized by the production of specific coiled-coil keratins and associated proteins in the inter-filament matrix. Unlike mammalian keratin-associated proteins, those of sauropsids contain a double beta-folded sequence of about 20 amino acids, known as the core-box. The core-box shows 60%–95% sequence identity with known reptilian and avian proteins. The core-box determines the polymerization of these proteins into filaments indicated as beta-keratin filaments. The nucleotide and derived amino acid sequences for these sauropsid keratin-associated proteins are presented in conjunction with a hypothesis about their evolution in reptiles-birds compared to mammalian keratin-associated proteins. It is suggested that genes coding for ancestral glycine-serine-rich sequences of alpha-keratins produced a new class of small matrix proteins. In sauropsids, matrix proteins may have originated after mutation and enrichment in proline, probably in a central region of the ancestral protein. This mutation gave rise to the core-box, and other regions of the original protein evolved differently in the various reptilians orders. In lepidosaurians, two main groups, the high glycine proline and the high cysteine proline proteins, were formed. In archosaurians and chelonians two main groups later diversified into the high glycine proline tyrosine, non-feather proteins, and into the glycine-tyrosine-poor group of feather proteins, which evolved in birds. The latter proteins were particularly suited for making the elongated barb/barbule cells of feathers. In therapsids-mammals, mutations of the ancestral proteins formed the high glycine-tyrosine or the high cysteine proteins but no core-box was produced in the matrix proteins of the hard corneous material of mammalian derivatives. PMID:19422429

The Center for Regenerative Biology and Medicine at Mount Desert Island Biological Laboratory

DTIC Science & Technology

2014-06-01

Positional Memory Code Axolotl 15. SUBJECT TERMS microRNAs Zebrafish Polypterus 16...miR-7a, let-7j, miR-130c, miR-338, miR-204 and miR- 2184 that are shared between regenerating axolotl forelimbs, zebrafish caudal fins and...regeneration was defective in both zebrafish and Polypterus fin appendages and axolotl limbs (Fig. 1, 2). Polypterus caudal and pectoral fins

Anatomy of ageing face.

PubMed

Ilankovan, V

2014-03-01

Ageing is a biological process that results from changes at a cellular level, particularly modification of mRNA. The face is affected by the same physiological process and results in skeletal, muscular, and cutaneous ageing; ligamentous attenuation, descent of fat, and ageing of the appendages. I describe these changes on a structural and clinical basis and summarise possible solutions for a rejuvenation surgeon. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Dermatoses of the male genital area.

PubMed

Eichmann, Alfred R

2005-01-01

This is an overview of dermatoses which are predominantly seen in the genital area. Five large groups of dermatoses can be distinguished: inflammatory dermatoses without any causative organism, infections and dermatoses originating from cutaneous appendages, precancerous lesions, pigmented lesions and genital pruritus. The etiology, causative factors, clinical features and newer treatment options are considered. Because of local environmental factors, genital dermatoses often present in a different way than in other localizations.

A Useless Subject? Teaching Civic Education in Italy from the School Programs of 1958 to the Present Day

ERIC Educational Resources Information Center

Bianchini, Paolo; Morandini, Maria Cristina

2017-01-01

Civic education has always been an ancillary subject in the Italian school system. Introduced at the end of the 1950s as a sort of appendage to the history programs, it has recently been subject to multiple reforms although little or nothing has changed in reality. The analysis of a sample of civic education textbooks in use in schools explains…

An Ambulatory Surgery Service Feasibility Study at Madigan Army Medical Center, Tacoma, Washington

DTIC Science & Technology

1978-08-01

sturmdorf) Benign Intraoral lesions Cervical cone Branchial arch appendages, Colpotomy, diagnostic excision Cryotherapy (alone)" Basla cell CA...petrous pyramid, atti- ceantrotomy, closure of fistula, exteneeration of air cells of petrous pyramid, mastoid antrotomy, removal of outer attic wall...here admission forms will be filled out. Patients will then take those forms to the Admissions Office and return to that clinic for stamin up of 1

Early embryonic development of the head region of Gryllus assimilis Fabricius, 1775 (Orthoptera, Insecta).

PubMed

Liu, Yu; Maas, Andreas; Waloszek, Dieter

2010-09-01

We report our investigations on the embryonic development of Gryllus assimilis, with particular attention to the head. Significant findings revealed with scanning electron microscopy (SEM) images include: (1) the pre-antennal lobes represent the anterior-most segment that does not bear any appendages; (2) each of the lobes consists of central and marginal regions; (3) the central region thereof develops into the protocerebrum and the optic lobes, whereas the marginal region thereof becomes the anterior portion of the head capsule; (4) the initial position of the antennal segment is posterior to the mouth region; (5) appendage anlagen are transitorily present in the intercalary segment, and they later vanish together with the segment itself; (6) a bulged sternum appears to develop from the ventral surface of the mandibular, maxillary and labial segments. Embryonic features are then compared across the Insecta and further extended to the embryos of a spider (Araneae, Chelicerata). Striking similarities shared by the anterior-most region of the insect and spider embryos lead the authors to conclude that such comparison should be further undertaken to cover the entire Euarthropoda. This will help us to understand the embryology and evolution of the arthropod head. Copyright © 2010 Elsevier Ltd. All rights reserved.

NopB, a type III secreted protein of Rhizobium sp. strain NGR234, is associated with pilus-like surface appendages.

PubMed

Saad, Maged M; Kobayashi, Hajime; Marie, Corinne; Brown, Ian R; Mansfield, John W; Broughton, William J; Deakin, William J

2005-02-01

Rhizobium sp. strain NGR234 possesses a functional type three secretion system (TTSS), through which a number of proteins, called nodulation outer proteins (Nops), are delivered to the outside of the cell. A major constraint to the identification of Nops is their low abundance in the supernatants of NGR234 strains grown in culture. To overcome this limitation, a more sensitive proteomics-based strategy was developed. Secreted proteins from wild-type NGR234 were separated by two-dimensional gel electrophoresis, and the gel was compared to similar gels containing the proteins from a TTSS mutant (NGROmegarhcN). To identify the proteins, spots unique to the NGR234 gels were analyzed by matrix-assisted laser desorption ionization-time of flight mass spectrometry and the data were compared to the sequence of the symbiotic plasmid of NGR234. A nonpolar mutant of one of these proteins was generated called NopB. NopB is required for Nop secretion but inhibits the interaction with Pachyrhizus tuberosus and augments nodulation of Tephrosia vogelii. Flavonoids and a functional TTSS are required for the formation of some surface appendages on NGR234. In situ immunogold labeling and isolation of these pili showed that they contain NopB.

NopB, a Type III Secreted Protein of Rhizobium sp. Strain NGR234, Is Associated with Pilus-Like Surface Appendages

PubMed Central

Saad, Maged M.; Kobayashi, Hajime; Marie, Corinne; Brown, Ian R.; Mansfield, John W.; Broughton, William J.; Deakin, William J.

2005-01-01

Rhizobium sp. strain NGR234 possesses a functional type three secretion system (TTSS), through which a number of proteins, called nodulation outer proteins (Nops), are delivered to the outside of the cell. A major constraint to the identification of Nops is their low abundance in the supernatants of NGR234 strains grown in culture. To overcome this limitation, a more sensitive proteomics-based strategy was developed. Secreted proteins from wild-type NGR234 were separated by two-dimensional gel electrophoresis, and the gel was compared to similar gels containing the proteins from a TTSS mutant (NGRΩrhcN). To identify the proteins, spots unique to the NGR234 gels were analyzed by matrix-assisted laser desorption ionization-time of flight mass spectrometry and the data were compared to the sequence of the symbiotic plasmid of NGR234. A nonpolar mutant of one of these proteins was generated called NopB. NopB is required for Nop secretion but inhibits the interaction with Pachyrhizus tuberosus and augments nodulation of Tephrosia vogelii. Flavonoids and a functional TTSS are required for the formation of some surface appendages on NGR234. In situ immunogold labeling and isolation of these pili showed that they contain NopB. PMID:15659692

Food-resources and the influence of spatial pattern on feeding in the phoronid Phoronopsis viridis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronan, T.E. Jr.

1978-06-01

In the intertidal zone of Bodega Harbor, California, the phoronid, Phoronopsis viridis, aggregates in clusters often composed of thousands of tightly aggregated individuals (up to 150,000/m/sup 2/). Within a dense cluster, there is a spacing problem for expansion of the lophophores. When nearest-neighbor distances are small, a stratification of feeding appendages is a workable solution to the spacing problem, allowing simultaneous expansion of clustered feeding appendages. Suspension-feeding specimens of Phoronopsis expand their lophophores and collect food items from the turbid near-bottom layers of water. Comparison of ingested items with material collected where the phoronids feed indicates a preference for smallmore » (<100 ..mu..m) organic encrusted mineral grains, floc aggregates, and fecal material, all resuspended from the depositional interface. Also taken to a lesser extent are plankton bloom species, such as diatoms and dinoflagellates. The fact that Phoronopsis forms dense assemblages in the intertidal zone has consequences when the community structure of sandflat areas is considered. Although it is probable that no single factor can explain aggregation in Phoronopsis, two possible factors, constituting strong selection pressures for cluster formation, are relative immunity from disturbance by large burrowing infauna and protection from predation by crawling predators.« less

Comparative anatomy, evolution, and homologies of tetrapod hindlimb muscles, comparison with forelimb muscles, and deconstruction of the forelimb-hindlimb serial homology hypothesis.

PubMed

Diogo, Rui; Molnar, Julia

2014-06-01

For more than two centuries, the idea that the forelimb and hindlimb are serially homologous structures has been accepted without serious question. This study presents the first detailed analysis of the evolution and homologies of all hindlimb muscles in representatives of each major tetrapod group and proposes a unifying nomenclature for these muscles. These data are compared with information obtained previously about the forelimb muscles of tetrapods and the muscles of other gnathostomes in order to address one of the most central and enigmatic questions in evolutionary and comparative anatomy: why are the pelvic and pectoral appendages of gnathostomes generally so similar to each other? An integrative analysis of the new myological data, combined with a review of recent paleontological, developmental, and genetic works and of older studies, does not support serial homology between the structures of these appendages. For instance, many of the strikingly similar forelimb and hindlimb muscles found in each major extant tetrapod taxon were acquired at different geological times and/or have different embryonic origins. These similar muscles are not serial homologues, but the result of evolutionary parallelism/convergence due to a complex interplay of ontogenetic, functional, topological, and phylogenetic constraints/factors. Copyright © 2014 Wiley Periodicals, Inc.

S-layers at second glance? Altiarchaeal grappling hooks (hami) resemble archaeal S-layer proteins in structure and sequence

PubMed Central

Perras, Alexandra K.; Daum, Bertram; Ziegler, Christine; Takahashi, Lynelle K.; Ahmed, Musahid; Wanner, Gerhard; Klingl, Andreas; Leitinger, Gerd; Kolb-Lenz, Dagmar; Gribaldo, Simonetta; Auerbach, Anna; Mora, Maximilian; Probst, Alexander J.; Bellack, Annett; Moissl-Eichinger, Christine

2015-01-01

The uncultivated “Candidatus Altiarchaeum hamiconexum” (formerly known as SM1 Euryarchaeon) carries highly specialized nano-grappling hooks (“hami”) on its cell surface. Until now little is known about the major protein forming these structured fibrous cell surface appendages, the genes involved or membrane anchoring of these filaments. These aspects were analyzed in depth in this study using environmental transcriptomics combined with imaging methods. Since a laboratory culture of this archaeon is not yet available, natural biofilm samples with high Ca. A. hamiconexum abundance were used for the entire analyses. The filamentous surface appendages spanned both membranes of the cell, which are composed of glycosyl-archaeol. The hami consisted of multiple copies of the same protein, the corresponding gene of which was identified via metagenome-mapped transcriptome analysis. The hamus subunit proteins, which are likely to self-assemble due to their predicted beta sheet topology, revealed no similiarity to known microbial flagella-, archaella-, fimbriae- or pili-proteins, but a high similarity to known S-layer proteins of the archaeal domain at their N-terminal region (44–47% identity). Our results provide new insights into the structure of the unique hami and their major protein and indicate their divergent evolution with S-layer proteins. PMID:26106369

The lateral mesodermal divide: an epigenetic model of the origin of paired fins.

PubMed

Nuño de la Rosa, Laura; Müller, Gerd B; Metscher, Brian D

2014-01-01

By examining development at the level of tissues and processes, rather than focusing on gene expression, we have formulated a general hypothesis to explain the dorso-ventral and anterior-posterior placement of paired appendage initiation sites in vertebrates. According to our model, the number and position of paired appendages are due to a commonality of embryonic tissue environments determined by the global interactions involving the two separated layers (somatic and visceral) of lateral plate mesoderm along the dorso-ventral and anterior-posterior axes of the embryo. We identify this distribution of developmental conditions, as modulated by the separation/contact of the two LPM layers and their interactions with somitic mesoderm, ectoderm, and endoderm as a dynamic developmental entity which we have termed the lateral mesodermal divide (LMD). Where the divide results in a certain tissue environment, fin bud initiation can occur. According to our hypothesis, the influence of the developing gut suppresses limb initiation along the midgut region and the ventral body wall owing to an "endodermal predominance." From an evolutionary perspective, the lack of gut regionalization in agnathans reflects the ancestral absence of these conditions, and the elaboration of the gut together with the concomitant changes to the LMD in the gnathostomes could have led to the origin of paired fins. © 2013 Wiley Periodicals, Inc.

Multi-Objective Algorithm for Blood Supply via Unmanned Aerial Vehicles to the Wounded in an Emergency Situation

PubMed Central

Wen, Tingxi; Zhang, Zhongnan; Wong, Kelvin K. L.

2016-01-01

Unmanned aerial vehicle (UAV) has been widely used in many industries. In the medical environment, especially in some emergency situations, UAVs play an important role such as the supply of medicines and blood with speed and efficiency. In this paper, we study the problem of multi-objective blood supply by UAVs in such emergency situations. This is a complex problem that includes maintenance of the supply blood’s temperature model during transportation, the UAVs’ scheduling and routes’ planning in case of multiple sites requesting blood, and limited carrying capacity. Most importantly, we need to study the blood’s temperature change due to the external environment, the heating agent (or refrigerant) and time factor during transportation, and propose an optimal method for calculating the mixing proportion of blood and appendage in different circumstances and delivery conditions. Then, by introducing the idea of transportation appendage into the traditional Capacitated Vehicle Routing Problem (CVRP), this new problem is proposed according to the factors of distance and weight. Algorithmically, we use the combination of decomposition-based multi-objective evolutionary algorithm and local search method to perform a series of experiments on the CVRP public dataset. By comparing our technique with the traditional ones, our algorithm can obtain better optimization results and time performance. PMID:27163361

Inflammation and immunity in organ regeneration.

PubMed

Mescher, Anthony L; Neff, Anton W; King, Michael W

2017-01-01

The ability of vertebrates to regenerate amputated appendages is increasingly well-understood at the cellular level. Cells mediating an innate immune response and inflammation in the injured tissues are a prominent feature of the limb prior to formation of a regeneration blastema, with macrophage activity necessary for blastema growth and successful development of the new limb. Studies involving either anti-inflammatory or pro-inflammatory agents suggest that the local inflammation produced by injury and its timely resolution are both important for regeneration, with blastema patterning inhibited in the presence of unresolved inflammation. Various experiments with Xenopus larvae at stages where regenerative competence is declining show improved digit formation after treatment with certain immunosuppressive, anti-inflammatory, or antioxidant agents. Similar work with the larval Xenopus tail has implicated adaptive immunity with regenerative competence and suggests a requirement for regulatory T cells in regeneration, which also occurs in many systems of tissue regeneration. Recent analyses of the human nail organ indicate a capacity for local immune tolerance, suggesting roles for adaptive immunity in the capacity for mammalian appendage regeneration. New information and better understanding regarding the neuroendocrine-immune axis in the response to stressors, including amputation, suggest additional approaches useful for investigating effects of the immune system during repair and regeneration. Copyright © 2016 Elsevier Ltd. All rights reserved.

The anatomical placode in reptile scale morphogenesis indicates shared ancestry among skin appendages in amniotes

PubMed Central

Di-Poï, Nicolas; Milinkovitch, Michel C.

2016-01-01

Most mammals, birds, and reptiles are readily recognized by their hairs, feathers, and scales, respectively. However, the lack of fossil intermediate forms between scales and hairs and substantial differences in their morphogenesis and protein composition have fueled the controversy pertaining to their potential common ancestry for decades. Central to this debate is the apparent lack of an “anatomical placode” (that is, a local epidermal thickening characteristic of feathers’ and hairs’ early morphogenesis) in reptile scale development. Hence, scenarios have been proposed for the independent development of the anatomical placode in birds and mammals and parallel co-option of similar signaling pathways for their morphogenesis. Using histological and molecular techniques on developmental series of crocodiles and snakes, as well as of unique wild-type and EDA (ectodysplasin A)–deficient scaleless mutant lizards, we show for the first time that reptiles, including crocodiles and squamates, develop all the characteristics of an anatomical placode: columnar cells with reduced proliferation rate, as well as canonical spatial expression of placode and underlying dermal molecular markers. These results reveal a new evolutionary scenario where hairs, feathers, and scales of extant species are homologous structures inherited, with modification, from their shared reptilian ancestor’s skin appendages already characterized by an anatomical placode and associated signaling molecules. PMID:28439533

Generation and characterization of function-blocking anti-ectodysplasin A (EDA) monoclonal antibodies that induce ectodermal dysplasia.

PubMed

Kowalczyk-Quintas, Christine; Willen, Laure; Dang, Anh Thu; Sarrasin, Heidi; Tardivel, Aubry; Hermes, Katharina; Schneider, Holm; Gaide, Olivier; Donzé, Olivier; Kirby, Neil; Headon, Denis J; Schneider, Pascal

2014-02-14

Development of ectodermal appendages, such as hair, teeth, sweat glands, sebaceous glands, and mammary glands, requires the action of the TNF family ligand ectodysplasin A (EDA). Mutations of the X-linked EDA gene cause reduction or absence of many ectodermal appendages and have been identified as a cause of ectodermal dysplasia in humans, mice, dogs, and cattle. We have generated blocking antibodies, raised in Eda-deficient mice, against the conserved, receptor-binding domain of EDA. These antibodies recognize epitopes overlapping the receptor-binding site and prevent EDA from binding and activating EDAR at close to stoichiometric ratios in in vitro binding and activity assays. The antibodies block EDA1 and EDA2 of both mammalian and avian origin and, in vivo, suppress the ability of recombinant Fc-EDA1 to rescue ectodermal dysplasia in Eda-deficient Tabby mice. Moreover, administration of EDA blocking antibodies to pregnant wild type mice induced in developing wild type fetuses a marked and permanent ectodermal dysplasia. These function-blocking anti-EDA antibodies with wide cross-species reactivity will enable study of the developmental and postdevelopmental roles of EDA in a variety of organisms and open the route to therapeutic intervention in conditions in which EDA may be implicated.

Generation and Characterization of Function-blocking Anti-ectodysplasin A (EDA) Monoclonal Antibodies That Induce Ectodermal Dysplasia*

PubMed Central

Kowalczyk-Quintas, Christine; Willen, Laure; Dang, Anh Thu; Sarrasin, Heidi; Tardivel, Aubry; Hermes, Katharina; Schneider, Holm; Gaide, Olivier; Donzé, Olivier; Kirby, Neil; Headon, Denis J.; Schneider, Pascal

2014-01-01

Development of ectodermal appendages, such as hair, teeth, sweat glands, sebaceous glands, and mammary glands, requires the action of the TNF family ligand ectodysplasin A (EDA). Mutations of the X-linked EDA gene cause reduction or absence of many ectodermal appendages and have been identified as a cause of ectodermal dysplasia in humans, mice, dogs, and cattle. We have generated blocking antibodies, raised in Eda-deficient mice, against the conserved, receptor-binding domain of EDA. These antibodies recognize epitopes overlapping the receptor-binding site and prevent EDA from binding and activating EDAR at close to stoichiometric ratios in in vitro binding and activity assays. The antibodies block EDA1 and EDA2 of both mammalian and avian origin and, in vivo, suppress the ability of recombinant Fc-EDA1 to rescue ectodermal dysplasia in Eda-deficient Tabby mice. Moreover, administration of EDA blocking antibodies to pregnant wild type mice induced in developing wild type fetuses a marked and permanent ectodermal dysplasia. These function-blocking anti-EDA antibodies with wide cross-species reactivity will enable study of the developmental and postdevelopmental roles of EDA in a variety of organisms and open the route to therapeutic intervention in conditions in which EDA may be implicated. PMID:24391090

Live fate-mapping of joint-associated fibroblasts visualizes expansion of cell contributions during zebrafish fin regeneration.

PubMed

Tornini, Valerie A; Thompson, John D; Allen, Raymond L; Poss, Kenneth D

2017-08-15

The blastema is a mass of progenitor cells responsible for regeneration of amputated salamander limbs and fish fins. Previous studies have indicated that resident cell sources producing the blastema contribute lineage-restricted progeny to regenerating tissue. However, these studies have labeled general cell types rather than granular cell subpopulations, and they do not explain the developmental transitions that must occur for distal structures to arise from cells with proximal identities in the appendage stump. Here, we find that regulatory sequences of tph1b , which encodes an enzyme that synthesizes serotonin, mark a subpopulation of fibroblast-like cells restricted to the joints of uninjured adult zebrafish fins. Amputation stimulates serotonin production in regenerating fin fibroblasts, yet targeted tph1b mutations abrogating this response do not disrupt fin regeneration. In uninjured animals, tph1b -expressing cells contribute fibroblast progeny that remain restricted to joints throughout life. By contrast, upon amputation, tph1b + joint cells give rise to fibroblasts that distribute across the entire lengths of regenerating fin rays. Our experiments visualize and quantify how incorporation into an appendage blastema broadens the progeny contributions of a cellular subpopulation that normally has proximodistal restrictions. © 2017. Published by The Company of Biologists Ltd.

The Fat-Dachsous signaling pathway regulates growth of horns in Trypoxylus dichotomus, but does not affect horn allometry.

PubMed

Hust, James; Lavine, Mark D; Worthington, Amy M; Zinna, Robert; Gotoh, Hiroki; Niimi, T; Lavine, Laura

Males of the Asian rhinoceros beetle, Trypoxylus dichotomus, possess exaggerated head and thoracic horns that scale dramatically out of proportion to body size. While studies of insulin signaling suggest that this pathway regulates nutrition-dependent growth including exaggerated horns, what regulates disproportionate growth has yet to be identified. The Fat signaling pathway is a potential candidate for regulating disproportionate growth of sexually-selected traits, a hypothesis we advanced in a previous paper (Gotoh et al., 2015). To investigate the role of Fat signaling in the growth and scaling of the sexually dimorphic, condition-dependent traits of the in the Asian rhinoceros beetle T. dichotomus, we used RNA interference to knock down expression of fat and its co-receptor dachsous. Knockdown of fat, and to a lesser degree dachsous, caused shortening and widening of appendages, including the head and thoracic horns. However, scaling of horns to body size was not affected. Our results show that Fat signaling regulates horn growth in T. dichotomus as it does in appendage growth in other insects. However, we provide evidence that Fat signaling does not mediate the disproportionate, positive allometric growth of horns in T. dichotomus. Copyright © 2018 Elsevier Ltd. All rights reserved.

A mummified duck-billed dinosaur with a soft-tissue cock's comb.

PubMed

Bell, Phil R; Fanti, Federico; Currie, Philip J; Arbour, Victoria M

2014-01-06

Among living vertebrates, soft tissues are responsible for labile appendages (combs, wattles, proboscides) that are critical for activities ranging from locomotion to sexual display [1]. However, soft tissues rarely fossilize, and such soft-tissue appendages are unknown for many extinct taxa, including dinosaurs. Here we report a remarkable "mummified" specimen of the hadrosaurid dinosaur Edmontosaurus regalis from the latest Cretaceous Wapiti Formation, Alberta, Canada, that preserves a three-dimensional cranial crest (or "comb") composed entirely of soft tissue. Previously, crest function has centered on the hypertrophied nasal passages of lambeosaurine hadrosaurids, which acted as resonance chambers during vocalization [2-4]. The fleshy comb in Edmontosaurus necessitates an alternative explanation most likely related to either social signaling or sexual selection [5-7]. This discovery provides the first view of bizarre, soft-tissue signaling structures in a dinosaur and provides additional evidence for social behavior. Crest evolution within Hadrosaurinae apparently culminated in the secondary loss of the bony crest at the terminal Cretaceous; however, the new specimen indicates that cranial ornamentation was in fact not lost but substituted in Edmontosaurus by a fleshy display structure. It also implies that visual display played a key role in the evolution of hadrosaurine crests and raises the possibility of similar soft-tissue structures among other dinosaurs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multi-Objective Algorithm for Blood Supply via Unmanned Aerial Vehicles to the Wounded in an Emergency Situation.

PubMed

Wen, Tingxi; Zhang, Zhongnan; Wong, Kelvin K L

2016-01-01

Unmanned aerial vehicle (UAV) has been widely used in many industries. In the medical environment, especially in some emergency situations, UAVs play an important role such as the supply of medicines and blood with speed and efficiency. In this paper, we study the problem of multi-objective blood supply by UAVs in such emergency situations. This is a complex problem that includes maintenance of the supply blood's temperature model during transportation, the UAVs' scheduling and routes' planning in case of multiple sites requesting blood, and limited carrying capacity. Most importantly, we need to study the blood's temperature change due to the external environment, the heating agent (or refrigerant) and time factor during transportation, and propose an optimal method for calculating the mixing proportion of blood and appendage in different circumstances and delivery conditions. Then, by introducing the idea of transportation appendage into the traditional Capacitated Vehicle Routing Problem (CVRP), this new problem is proposed according to the factors of distance and weight. Algorithmically, we use the combination of decomposition-based multi-objective evolutionary algorithm and local search method to perform a series of experiments on the CVRP public dataset. By comparing our technique with the traditional ones, our algorithm can obtain better optimization results and time performance.

Regulation of synaptic vesicle recycling by complex formation between intersectin 1 and the clathrin adaptor complex AP2

PubMed Central

Pechstein, Arndt; Bacetic, Jelena; Vahedi-Faridi, Ardeschir; Gromova, Kira; Sundborger, Anna; Tomlin, Nikolay; Krainer, Georg; Vorontsova, Olga; Schäfer, Johannes G.; Owe, Simen G.; Cousin, Michael A.; Saenger, Wolfram; Shupliakov, Oleg; Haucke, Volker

2010-01-01

Clathrin-mediated synaptic vesicle (SV) recycling involves the spatiotemporally controlled assembly of clathrin coat components at phosphatidylinositiol (4, 5)-bisphosphate [PI(4,5)P2]-enriched membrane sites within the periactive zone. Such spatiotemporal control is needed to coordinate SV cargo sorting with clathrin/AP2 recruitment and to restrain membrane fission and synaptojanin-mediated uncoating until membrane deformation and clathrin coat assembly are completed. The molecular events underlying these control mechanisms are unknown. Here we show that the endocytic SH3 domain-containing accessory protein intersectin 1 scaffolds the endocytic process by directly associating with the clathrin adaptor AP2. Acute perturbation of the intersectin 1-AP2 interaction in lamprey synapses in situ inhibits the onset of SV recycling. Structurally, complex formation can be attributed to the direct association of hydrophobic peptides within the intersectin 1 SH3A-B linker region with the “side sites” of the AP2 α- and β-appendage domains. AP2 appendage association of the SH3A-B linker region inhibits binding of the inositol phosphatase synaptojanin 1 to intersectin 1. These data identify the intersectin-AP2 complex as an important regulator of clathrin-mediated SV recycling in synapses. PMID:20160082

New records for the Kosovo caddisfly fauna with the description of a new species, Drusus dardanicus sp. nov. (Trichoptera: Limnephilidae).

PubMed

Ibrahimi, Halil; Kučinić, Mladen; Vitecek, Simon; Waringer, Johann; Graf, Wolfram; Previšić, Ana; Bálint, Miklós; Keresztes, Lujza; Pauls, Steffen U

2015-10-20

The Balkan Peninsula is one of the most important European hotspots of freshwater biodiversity. The region is, however, to a large extent insufficiently investigated. Here we present data on distribution of caddisflies in one particularly understudied area, the Republic of Kosovo. Our data include the first records of Adicella altandroconia Botosaneanu & Novak and Halesus tessellatus (Rambur) for the Kosovo caddisfly fauna, and a new locality for the recently described Ecclisopteryx keroveci Previšić, Graf, & Vitecek. Further, we describe the new caddisfly species Drusus dardanicus sp. nov. from the Kopaonik Mountains. The new species belongs to the D. discophorus Species Group and differs morphologically from its most similar congeners (D. discophorus Radovanović, D. balcanicus Kumanski, and D. bureschi Kumanski) mainly in exhibiting (1) subtrianglar superior appendages; (2) a narrow, dorsal spinate area of tergite VIII; and (3) evenly rounded tips of intermediate appendages in caudal view. In phylogenetic analysis, D. dardanicus sp. nov. is well delineated and recovered as a sister taxon to D. osogovicus Kumanski, a species recorded from Bulgaria. The recent discovery of a new species and other rare or microendemic species presents important contributions to the knowledge on the rich freshwater biodiversity in Kosovo. These species face increasing anthropogenic pressure and threats to their conservation.

The anatomical placode in reptile scale morphogenesis indicates shared ancestry among skin appendages in amniotes.

PubMed

Di-Poï, Nicolas; Milinkovitch, Michel C

2016-06-01

Most mammals, birds, and reptiles are readily recognized by their hairs, feathers, and scales, respectively. However, the lack of fossil intermediate forms between scales and hairs and substantial differences in their morphogenesis and protein composition have fueled the controversy pertaining to their potential common ancestry for decades. Central to this debate is the apparent lack of an "anatomical placode" (that is, a local epidermal thickening characteristic of feathers' and hairs' early morphogenesis) in reptile scale development. Hence, scenarios have been proposed for the independent development of the anatomical placode in birds and mammals and parallel co-option of similar signaling pathways for their morphogenesis. Using histological and molecular techniques on developmental series of crocodiles and snakes, as well as of unique wild-type and EDA (ectodysplasin A)-deficient scaleless mutant lizards, we show for the first time that reptiles, including crocodiles and squamates, develop all the characteristics of an anatomical placode: columnar cells with reduced proliferation rate, as well as canonical spatial expression of placode and underlying dermal molecular markers. These results reveal a new evolutionary scenario where hairs, feathers, and scales of extant species are homologous structures inherited, with modification, from their shared reptilian ancestor's skin appendages already characterized by an anatomical placode and associated signaling molecules.

Mutation of Growth Arrest Specific 8 Reveals a Role in Motile Cilia Function and Human Disease.

PubMed

Lewis, Wesley R; Malarkey, Erik B; Tritschler, Douglas; Bower, Raqual; Pasek, Raymond C; Porath, Jonathan D; Birket, Susan E; Saunier, Sophie; Antignac, Corinne; Knowles, Michael R; Leigh, Margaret W; Zariwala, Maimoona A; Challa, Anil K; Kesterson, Robert A; Rowe, Steven M; Drummond, Iain A; Parant, John M; Hildebrandt, Friedhelm; Porter, Mary E; Yoder, Bradley K; Berbari, Nicolas F

2016-07-01

Ciliopathies are genetic disorders arising from dysfunction of microtubule-based cellular appendages called cilia. Different cilia types possess distinct stereotypic microtubule doublet arrangements with non-motile or 'primary' cilia having a 9+0 and motile cilia have a 9+2 array of microtubule doublets. Primary cilia are critical sensory and signaling centers needed for normal mammalian development. Defects in their structure/function result in a spectrum of clinical and developmental pathologies including abnormal neural tube and limb patterning. Altered patterning phenotypes in the limb and neural tube are due to perturbations in the hedgehog (Hh) signaling pathway. Motile cilia are important in fluid movement and defects in motility result in chronic respiratory infections, altered left-right asymmetry, and infertility. These features are the hallmarks of Primary Ciliary Dyskinesia (PCD, OMIM 244400). While mutations in several genes are associated with PCD in patients and animal models, the genetic lesion in many cases is unknown. We assessed the in vivo functions of Growth Arrest Specific 8 (GAS8). GAS8 shares strong sequence similarity with the Chlamydomonas Nexin-Dynein Regulatory Complex (NDRC) protein 4 (DRC4) where it is needed for proper flagella motility. In mammalian cells, the GAS8 protein localizes not only to the microtubule axoneme of motile cilia, but also to the base of non-motile cilia. Gas8 was recently implicated in the Hh signaling pathway as a regulator of Smoothened trafficking into the cilium. Here, we generate the first mouse with a Gas8 mutation and show that it causes severe PCD phenotypes; however, there were no overt Hh pathway phenotypes. In addition, we identified two human patients with missense variants in Gas8. Rescue experiments in Chlamydomonas revealed a subtle defect in swim velocity compared to controls. Further experiments using CRISPR/Cas9 homology driven repair (HDR) to generate one of these human missense variants in mice demonstrated that this allele is likely pathogenic.

Rural and urban Ugandan primary school children's alternative ideas about animals

NASA Astrophysics Data System (ADS)

Otaala, Justine

This study examined rural and urban Ugandan primary children's alternative ideas about animals through the use of qualitative research methods. Thirty-six children were selected from lower, middle, and upper primary grades in two primary schools (rural and urban). Data were collected using interview-about-instance technique. Children were shown 18 color photographs of instances and non-instances of familiar animals and asked to say if the photographed objects were animals or not. They were then asked to give reasons to justify their answers. The interviews were audiotaped and transcribed. The results indicate that children tended to apply the label "animal" to large mammals, usually found at home, on the farm, in the zoo, and in the wild. Humans were not categorized as animals, particularly by children in the lower grades. Although the children in upper grades correctly identified humans as animals, they used reasons that were irrelevant to animal attributes and improperly derived from the biological concept of evolution. Many attributes children used to categorize instances of animals were scientifically unacceptable and included superficial features, such as body outline, anatomical features (body parts), external features (visual cues), presence or absence and number of appendages. Movement and eating (nutrition) were the most popular attributes children used to identify instances of animals. The main differences in children's ideas emanated from the reasons used to identify animals. Older rural children drew upon their cultural and traditional practices more often than urban children. Anthropomorphic thinking was predominant among younger children in both settings, but diminished with progression in children's grade levels. Some of the implications of this study are: (1) teachers, teacher educators and curriculum developers should consider learners' ideas in planning and developing teaching materials and interventions. (2) Teachers should relate humans to other animals during instruction. (3) Textbooks and teaching materials need careful scrutiny to insure they include humans and other small animals as part of the animal kingdom. (4) Teaching interventions should begin with the basic attributes of animals and insure children understand the relationship between the attributes and concepts. (5) Encourage the use of examples and non-examples of the concept "animal" during instruction.

Polythelia (supernumerary nipple): an update.

PubMed

Johnson, C A; Felson, B; Jolles, H

1986-09-01

Supernumerary mammary gland, nipple, or areola (with neither nipple nor mammary tissue) have been well documented in the medical literature of the last two decades. Though predominantly a cosmetic blemish, the anomalous appendage may give rise to a neoplasm. Because of its atypical appearance and ectopic location, diagnosis of the anomaly may require a high index of suspicion and histologic verification. In our current concern with breast cancer, there is need to be aware of this entity.

Cylindrical Bragg mirrors on leg segments of the male Bolivian blueleg tarantula Pamphobeteus antinous (Theraphosidae).

PubMed

Simonis, Priscilla; Bay, Annick; Welch, Victoria L; Colomer, Jean-François; Vigneron, Jean Pol

2013-03-25

The large male tarantula Pamphobeteus antinous is easily recognized at the presence of blue-violet iridescent bristles on some of the segments of its legs and pedipalps. The optical properties of these colored appendages have been measured and the internal geometrical structure of the bristles have been investigated. The coloration is shown to be caused by a curved coaxial multilayer which acts as a "cylindrical Bragg mirror".

“Altiarchaeales”: Uncultivated Archaea from the Subsurface

PubMed Central

Probst, Alexander J.; Moissl-Eichinger, Christine

2015-01-01

Due to the limited cultivability of the vast majority of microorganisms, researchers have applied environmental genomics and other state-of-the-art technologies to gain insights into the biology of uncultivated Archaea and bacteria in their natural biotope. In this review, we summarize the scientific findings on a recently proposed order-level lineage of uncultivated Archaea called Altiarchaeales, which includes “Candidatus Altiarchaeum hamiconexum” as the most well-described representative. Ca. A. hamiconexum possesses a complex biology: thriving strictly anaerobically, this microorganism is capable of forming highly-pure biofilms, connecting the cells by extraordinary cell surface appendages (the “hami”) and has other highly unusual traits, such as a double-membrane-based cell wall. Indicated by genomic information from different biotopes, the Altiarchaeales seem to proliferate in deep, anoxic groundwater of Earth’s crust bearing a potentially very important function: carbon fixation. Although their net carbon fixation rate has not yet been determined, they appear as highly abundant organisms in their biotopes and may thus represent an important primary producer in the subsurface. In sum, the research over more than a decade on Ca. A. hamiconexum has revealed many interesting features of its lifestyle, its genomic information, metabolism and ultrastructure, making this archaeon one of the best-studied uncultivated Archaea in the literature. PMID:25984733

Intracardiac Echocardiography for Structural Heart and Electrophysiological Interventions.

PubMed

Basman, Craig; Parmar, Yuvrajsinh J; Kronzon, Itzhak

2017-09-06

With an increasing number of interventional procedures performed for structural heart disease and cardiac arrhythmias each year, echocardiographic guidance is necessary for safe and efficient results. The purpose of this review article is to overview the principles of intracardiac echocardiography (ICE) and describes the peri-interventional role of ICE in a variety of structural heart disease and electrophysiological interventions. Both transthoracic (TTE) and transesophageal echocardiography have limitations. ICE provides the advantage of imaging from within the heart, providing shorter image distances and higher resolution. ICE may be performed without sedation and avoids esophageal intubation as with transesophageal echocardiography (TEE). Limitations of ICE include the need for additional venous access with possibility of vascular complications, potentially higher costs, and a learning curve for new operators. Data supports the use of ICE in guiding device closure of interatrial shunts, transseptal puncture, and electrophysiologic procedures. This paper reviews the more recent reports that ICE may be used for primary guidance or as a supplement to TEE in patients undergoing left atrial appendage (LAA) closure, interatrial shunt closure, transaortic valve implantation (TAVI), percutaneous mitral valve repair (PMVR), paravalvular leak (PVL) closure, aortic interventions, transcatheter pulmonary valve replacement (tPVR), ventricular septal defect (VSD), and patent ductus arteriosus (PDA) closure. ICE imaging technology will continue to expand and help improve structural heart and electrophysiology interventions.

Effects of Nicotinamide Adenine Dinucleotide (NAD(+)) and Diadenosine Tetraphosphate (Ap4A) on Electrical Activity of Working and Pacemaker Atrial Myocardium in Guinea Pigs.

PubMed

Pustovit, K B; Abramochkin, D V

2016-04-01

Effects of nucleotide polyphosphate compounds (nicotinamide adenine dinucleotide, NAD(+); diadenosine tetraphosphate, Ap4A) on the confi guration of action potentials were studied in isolated preparations of guinea pig sinoatrial node and right atrial appendage (auricle). In the working myocardium, NAD(+) and Ap4A in concentrations of 10(-5) and 10(-4) M had no effect on resting potential, but significantly reduced the duration of action potentials; the most pronounced decrease was found at 25% repolarization. In the primary pacemaker of the sinoatrial node, both concentrations of NAD(+) and Ap4A induced hyperpolarization and reduction in the rate of slow diastolic depolarization, but significant slowing of the sinus rhythm was produced by these substances only in the concentration of 10(-4) M. Moreover, AP shortening and marked acceleration of AP upstroke were observed in the pacemaker myocardium after application of polyphosphates. Comparative analysis of the effects of NAD(+) and Ap4A in the working and pacemaker myocardium drove us to a hypothesis on inhibitory effects of these substances on L-type calcium current accompanied by stimulation of one or several potassium currents, which induce enhancement of repolarization and hyperpolarization of membranes probably mediated by the activation of purine receptors.

Satellite Articulation Characterization from an Image Trajectory Matrix Using Optimization

NASA Astrophysics Data System (ADS)

Curtis, D. H.; Cobb, R. G.

Autonomous on-orbit satellite servicing and inspection benefits from an inspector satellite that can autonomously gain as much information as possible about the primary satellite. This includes performance of articulated objects such as solar arrays, antennas, and sensors. This paper presents a method of characterizing the articulation of a satellite using resolved monocular imagery. A simulated point cloud representing a nominal satellite with articulating solar panels and a complex articulating appendage is developed and projected to the image coordinates that would be seen from an inspector following a given inspection route. A method is developed to analyze the resulting image trajectory matrix. The developed method takes advantage of the fact that the route of the inspector satellite is known to assist in the segmentation of the points into different rigid bodies, the creation of the 3D point cloud, and the identification of the articulation parameters. Once the point cloud and the articulation parameters are calculated, they can be compared to the known truth. The error in the calculated point cloud is determined as well as the difference between the true workspace of the satellite and the calculated workspace. These metrics can be used to compare the quality of various inspection routes for characterizing the satellite and its articulation.

Designing Comparative Effectiveness Trials of Surgical Ablation for Atrial Fibrillation: Experience of the Cardiothoracic Surgical Trials Network

PubMed Central

Gillinov, A. Marc; Argenziano, Michael; Blackstone, Eugene H.; Iribarne, Alexander; DeRose, Joseph J.; Ailawadi, Gorav; Russo, Mark J.; Ascheim, Deborah D.; Parides, Michael K.; Rodriguez, Evelio; Bouchard, Denis; Taddei-Peters, Wendy C.; Geller, Nancy L.; Acker, Michael A.; Gelijns, Annetine C.

2013-01-01

Background Since the introduction of the cut-and-sew Cox-Maze procedure for atrial fibrillation (AF) there has been substantial innovation in techniques for ablation. Use of alternate energy sources for ablation simplified the procedure and has resulted in dramatic increase in the number of AF patients treated by surgical ablation. Despite its increasingly widespread adoption, there is lack of rigorous clinical evidence to establish this as an effective clinical therapy. Methods and Results This paper describes a comparative effectiveness randomized trial, supported by the Cardiothoracic Surgical Trials Network, of surgical ablation with left atrial appendage (LAA) closure versus LAA closure alone in patients with persistent and longstanding persistent AF undergoing mitral valve surgery. Nested within this trial, is a further randomized comparison of 2 different lesions sets: pulmonary vein isolation and full Maze lesion set. This paper addresses trial design challenges, including how to best characterize the target population, operationalize freedom from AF as a primary endpoint, account for the impact of anti-arrhythmic drugs, and measure and analyze secondary endpoints, such as post-operative AF load. Conclusions This paper concludes by discussing how insights that emerge from this trial may affect surgical practice and guide future research in this area. PMID:21616507

The Value of 3D Printing Models of Left Atrial Appendage Using Real-Time 3D Transesophageal Echocardiographic Data in Left Atrial Appendage Occlusion: Applications toward an Era of Truly Personalized Medicine.

PubMed

Liu, Peng; Liu, Rijing; Zhang, Yan; Liu, Yingfeng; Tang, Xiaoming; Cheng, Yanzhen

The objective of this study was to assess the clinical feasibility of generating 3D printing models of left atrial appendage (LAA) using real-time 3D transesophageal echocardiogram (TEE) data for preoperative reference of LAA occlusion. Percutaneous LAA occlusion can effectively prevent patients with atrial fibrillation from stroke. However, the anatomical structure of LAA is so complicated that adequate information of its structure is essential for successful LAA occlusion. Emerging 3D printing technology has the demonstrated potential to structure more accurately than conventional imaging modalities by creating tangible patient-specific models. Typically, 3D printing data sets are acquired from CT and MRI, which may involve intravenous contrast, sedation, and ionizing radiation. It has been reported that 3D models of LAA were successfully created by the data acquired from CT. However, 3D printing of the LAA using real-time 3D TEE data has not yet been explored. Acquisition of 3D transesophageal echocardiographic data from 8 patients with atrial fibrillation was performed using the Philips EPIQ7 ultrasound system. Raw echocardiographic image data were opened in Philips QLAB and converted to 'Cartesian DICOM' format and imported into Mimics® software to create 3D models of LAA, which were printed using a rubber-like material. The printed 3D models were then used for preoperative reference and procedural simulation in LAA occlusion. We successfully printed LAAs of 8 patients. Each LAA costs approximately CNY 800-1,000 and the total process takes 16-17 h. Seven of the 8 Watchman devices predicted by preprocedural 2D TEE images were of the same sizes as those placed in the real operation. Interestingly, 3D printing models were highly reflective of the shape and size of LAAs, and all device sizes predicted by the 3D printing model were fully consistent with those placed in the real operation. Also, the 3D printed model could predict operating difficulty and the presence of a peridevice leak. 3D printing of the LAA using real-time 3D transesophageal echocardiographic data has a perfect and rapid application in LAA occlusion to assist with physician planning and decision making. © 2016 S. Karger AG, Basel.

Impact of preoperative atrial fibrillation on mortality and cardiovascular outcomes of mechanical mitral valve replacement for rheumatic mitral valve disease.

PubMed

Wang, Bin; Xu, Zhi-yun; Han, Lin; Zhang, Guan-xin; Lu, Fang-lin; Song, Zhi-gang

2013-03-01

The prognostic significance of preoperative atrial fibrillation on mitral valve replacement remains unclear. The aim of this study was to explore the effects of the presence of preoperative atrial fibrillation on mortality and cardiovascular outcomes of mitral valve replacement for rheumatic valve disease. A retrospective analysis was performed on a total of 793 patients who underwent mitral valve replacement with or without tricuspid valve repair in our hospital. The patients selected were divided into two groups according to preoperative rhythm status. Patients with preoperative atrial fibrillation were assigned to the AF group, while patients in preoperative sinus rhythm were assigned to the SR group. Postoperative follow-up was performed by outpatient visits, as well as by telephone and written correspondence. Data gathered included survivorship, postoperative complications, left ventricular function and tricuspid regurgitation. For patients with atrial fibrillation vs those in sinus rhythm, there was no difference in postoperative mortality and morbidity. Follow-up was a mean of 8.6 ± 2.4 years. For patients with preoperative atrial fibrillation, 10-year survival from a Kaplan-Meier curve was 88.7%, compared with 96.6% in patients with preoperative sinus rhythm (P = 0.002). Multivariate analysis identified low left ventricular ejection fraction, older age, large left atrium and preoperative atrial fibrillation as significant adverse predictors for overall survival. Freedom from thromboembolism complications at 13 years was lower for patients with preoperative atrial fibrillation without maze procedure and left atrial appendage ligation, compared with that for patients with preoperative sinus rhythm without maze procedure and left atrial appendage ligation, and patients with concomitant maze procedure and left atrial appendage ligation (76.3 vs 94.8 vs 94.0%, respectively; P = 0.001). On echocardiography, the proportion of patients with significant tricuspid regurgitation was 38.7% (atrial fibrillation patients) vs 25.4% (patients in sinus rhythm; P < 0.001). Left ventricular ejection fraction measured 5 years after surgery increased by an average of 1.2% in the AF group, while it increased by 5.3% in the SR group (P = 0.028). Preoperative atrial fibrillation is a risk factor for long-term mortality, thromboembolism complications and tricuspid regurgitation, and it also has an adverse effect on the degree of improvement when considering left ventricular function.

Advanced space system analysis software. Technical, user, and programmer guide

NASA Technical Reports Server (NTRS)

Farrell, C. E.; Zimbelman, H. F.

1981-01-01

The LASS computer program provides a tool for interactive preliminary and conceptual design of LSS. Eight program modules were developed, including four automated model geometry generators, an associated mass properties module, an appendage synthesizer module, an rf analysis module, and an orbital transfer analysis module. The existing rigid body controls analysis module was modified to permit analysis of effects of solar pressure on orbital performance. A description of each module, user instructions, and programmer information are included.

p63 in skin development and ectodermal dysplasias

PubMed Central

Koster, Maranke I.

2010-01-01

The transcription factor p63 is critically important for skin development and maintenance. Processes that require p63 include epidermal lineage commitment, epidermal differentiation, cell adhesion, and basement membrane formation. Not surprisingly, alterations in the p63 pathway underlie a subset of ectodermal dysplasias, developmental syndromes in which the skin and skin appendages do not develop normally. This review summarizes the current understanding of the role of p63 in normal development and ectodermal dysplasias. PMID:20445549

High frequency ultrasound with color Doppler in dermatology*

PubMed Central

Barcaui, Elisa de Oliveira; Carvalho, Antonio Carlos Pires; Lopes, Flavia Paiva Proença Lobo; Piñeiro-Maceira, Juan; Barcaui, Carlos Baptista

2016-01-01

Ultrasonography is a method of imaging that classically is used in dermatology to study changes in the hypoderma, as nodules and infectious and inflammatory processes. The introduction of high frequency and resolution equipments enabled the observation of superficial structures, allowing differentiation between skin layers and providing details for the analysis of the skin and its appendages. This paper aims to review the basic principles of high frequency ultrasound and its applications in different areas of dermatology. PMID:27438191

STS-31 Hubble Space Telescope (HST) solar array panel deploy aboard OV-103

NASA Image and Video Library

1990-04-25

Held in appendage deploy position by Discovery's, Orbiter Vehicle (OV) 103's, remote manipulator system (RMS), the Hubble Space Telescope's (HST's) starboard solar array (SA) bistem cassette is released from its stowed position on the Support System Module (SSM) forward shell. The spreader bar & bistem begin to unfurl the SA wing. View was taken by an STS-31 crewmember through an overhead window & is backdropped against the surface of the Earth.

Arthropod visual predators in the early pelagic ecosystem: evidence from the Burgess Shale and Chengjiang biotas

PubMed Central

Vannier, J.; García-Bellido, D.C.; Hu, S.-X.; Chen, A.-L.

2009-01-01

Exceptional fossil specimens with preserved soft parts from the Maotianshan Shale (ca 520 Myr ago) and the Burgess Shale (505 Myr ago) biotas indicate that the worldwide distributed bivalved arthropod Isoxys was probably a non-benthic visual predator. New lines of evidence come from the functional morphology of its powerful prehensile frontal appendages that, combined with large spherical eyes, are thought to have played a key role in the recognition and capture of swimming or epibenthic prey. The swimming and steering of this arthropod was achieved by the beating of multiple setose exopods and a flap-like telson. The appendage morphology of Isoxys indicates possible phylogenetical relationships with the megacheirans, a widespread group of assumed predator arthropods characterized by a pre-oral ‘great appendage’. Evidence from functional morphology and taphonomy suggests that Isoxys was able to migrate through the water column and was possibly exploiting hyperbenthic niches for food. Although certainly not unique, the case of Isoxys supports the idea that off-bottom animal interactions such as predation, associated with complex feeding strategies and behaviours (e.g. vertical migration and hunting) were established by the Early Cambrian. It also suggests that a prototype of a pelagic food chain had already started to build-up at least in the lower levels of the water column. PMID:19403536

Detailed expression profile of the six Glypicans and their modifying enzyme, Notum during chick limb and feather development.

PubMed

Saad, Kawakeb; Theis, Susanne; Otto, Anthony; Luke, Graham; Patel, Ketan

2017-04-30

The development of vertebrate appendages, especially the limb and feather buds are orchestrated by numerous secreted signalling molecules including Sonic Hedgehog, Bone Morphogenetic Proteins, Fibroblast Growth Factors and Wnts. These proteins coordinate the growth and patterning of ectodermal and mesenchymal cells. The influence of signalling molecules is affected over large distances by their concentration (morphogen activity) but also at local levels by the presence of proteins that either attenuate or promote their activity. Glypicans are cell surface molecules that regulate the activity of the major secreted signalling molecules expressed in the limb and feather bud. Here we investigated the expression of all Glypicans during chick limb and feather development. In addition we profiled the expression of Notum, an enzyme that regulates Glypican activity. We show that five of the six Glypicans and Notum are expressed in a dynamic manner during the development of limbs and feathers. We also investigated the expression of key Glypicans and show that they are controlled by signalling molecules highlighting the presence of feedback loops. Lastly we show that Glypicans and Notum are expressed in a tissue specific manner in adult chicken tissues. Our results strongly suggest that the Glypicans and Notum have many as yet undiscovered roles to play during the development of vertebrate appendages. Copyright © 2017 Elsevier B.V. All rights reserved.

Mechanical Performance of Two Left Atrial Appendage Occlusion Systems: In Vitro Comparison of Tug Force, Radial Force, Sealing and Deformation.

PubMed

Menne, Matthias F; Schrickel, Jan W; Nickenig, Georg; Al-Kassou, Baravan; Nelles, Dominik; Schmitz-Rode, Thomas; Steinseifer, Ulrich; Sedaghat, Alexander

2018-05-24

The aim of this study was to establish in vitro bench-tests of left atrial appendage occlusion (LAAo) devices regarding tug force, radial force and sealing capacity. Two LAAo devices, namely the WATCHMAN™ and the Occlutech ® , of three different sizes underwent testing in novel dedicated in vitro setups. Radial force was assessed in a commercial radial force tester. At baseline, tug force of the WATCHMAN™ was significantly higher when compared to Occlutech ® for all devices. Repeated resheathing resulted in a reduction of device-diameter in the WATCHMAN™ devices of max. 7.9%, whereas diameters of Occlutech ® occluders remained unchanged. Tug force was not significantly impacted by resheathing in both devices. At baseline, sealing capacity in a bench-test using silicone LAA-models did not differ between the devices. Resheathing lead to an in vitro loss of sealing capacity of the WATCHMAN™ devices, increasing with resheathing and resulting in a max. peridevice leak of 91.1 ± 7.9%. Radial force was higher for the Occlutech ® devices and decreased for WATCHMAN™ occluders after resheathing. The WATCHMAN™ occluder series showed progressive deformation, increased peridevice leakage and decreased radial force after resheathing, presumably as a result of diameter reduction. Tug force of the WATCHMAN™ was not impaired by resheathing and was significantly higher than that of the Occlutech ® device.

Laser-Induced Thermal Acoustics Theory and Expected Experimental Errors when Applied to a Scramjet Isolator Model

NASA Technical Reports Server (NTRS)

Middleton, Troy F.; Balla, Robert Jeffrey; Baurle, Robert A.; Wilson, Lloyd G.

2011-01-01

A scramjet isolator model test apparatus is being assembled in the Isolator Dynamics Research Lab (IDRL) at the NASA Langley Research Center in Hampton, Virginia. The test apparatus is designed to support multiple measurement techniques for investigating the flow field in a scramjet isolator model. The test section is 1-inch high by 2-inch wide by 24-inch long and simulates a scramjet isolator with an aspect ratio of two. Unheated, dry air at a constant stagnation pressure and temperature is delivered to the isolator test section through a Mach 2.5 planar nozzle. The isolator test section is mechanically back-pressured to contain the resulting shock train within the 24-inch isolator length and supports temperature, static pressure, and high frequency pressure measurements at the wall. Additionally, nonintrusive methods including laser-induced thermal acoustics (LITA), spontaneous Raman scattering, particle image velocimetry, and schlieren imaging are being incorporated to measure off-wall fluid dynamic, thermodynamic, and transport properties of the flow field. Interchangeable glass and metallic sidewalls and optical access appendages permit making multiple measurements simultaneously. The measurements will be used to calibrate computational fluid dynamics turbulence models and characterize the back-pressured flow of a scramjet isolator. This paper describes the test apparatus, including the optical access appendages; the physics of the LITA method; and estimates of LITA measurement uncertainty for measurements of the speed of sound and temperature.

New species of aquatic insects from Europe (Insecta: Trichoptera): Alps and Pyrenees as harbours of unknown biodiversity

PubMed Central

GRAF, WOLFRAM; VITECEK, SIMON; PREVIŠIĆ, ANA; MALICKY, HANS

2016-01-01

New species are described from the following genera: Consorophylax and Anisogamus, (Trichoptera, Limnephilidae). Additionally the larvae of the genus Anisogamus, and the larval stages of Anisogamus waringeri nov. sp. and A. difformis (McLachlan 1867) are described. The new species Consorophylax vinconi sp. nov. is a microendemic from the Southern Alps and differs distinctly from its congeners in the shape of the parameres, which are distinctly straitened in the distal quarter in the new species. The new species Anisogamus waringeri sp. nov. represents the second species in the hitherto monospecific genus Anisogamus. Compared to Anisogamus difformis, A. waringeri sp. nov. develops more slender superior appendages; a more rounded basal plate of the intermediate appendages, lacking pointed protuberances; and parameres shorter than the aedaegus, proximally with one dorsal and several ventral tines. Further, the two species are disjunctly distributed in the European mountain ranges (A. difformis: Alps, A. waringeri sp. nov.: Pyrenees). Larvae of the genus Anisogamus are characterized by the lack of a dorsal protuberance on the 1st abdominal segment, a unique feature among Limnephilidae. Anisogamus difformis and A. waringeri sp. nov. larvae differ in pronotum shape. The recovery of two new species demonstrates the significance of taxonomic studies in Europe, and the importance of adequate training for young scientists in order to assess a biodiversity under threat of extinction that has yet to be fully described. PMID:25661619

Association between left atrial function assessed by speckle-tracking echocardiography and the presence of left atrial appendage thrombus in patients with atrial fibrillation.

PubMed

Kupczynska, Karolina; Michalski, Blazej W; Miskowiec, Dawid; Kasprzak, Jaroslaw D; Wejner-Mik, Paulina; Wdowiak-Okrojek, Katarzyna; Lipiec, Piotr

2017-07-01

The aim of the study was to investigate whether the deformation of left atrium (LA) measured by speckle-tracking analysis (STE) is associated with the presence of LA appendage thrombus (LAAT) during non-valvular atrial fibrillation (AF). Eighty-seven patients (mean age 67 years, 59% men) were included to retrospective cross-sectional study. On top of standard echocardiography we assessed: LA longitudinal systolic strain (LS), systolic (LSSR) and early diastolic strain rate (LESR) in four-chamber and twochamber apical views. All patients underwent transesophageal echocardiography disclosing LAAT in 36 (41%) patients. Subgroups with and without thrombi did not differ with regard to clinical characteristics. Univariate factors associated with LAAT were as follows: CH2ADS2-VASc Score, left ventricular ejection fraction (LVEF), LV mass, and STE measurements. In a multivariate model only LVEF (p=0.002), LS (p=0.02), LESR (p=0.008), and LSSR (p=0.045) were independently associated with LAAT presence. Moreover, LVEF and LA STE measurements provided incremental value over the CH2ADS2-VASc Score. Speckle-tracking TTE may be used to describe LA reservoir and conduit function during AF, allowing the identification of patients with higher risk of LAAT and providing incremental value over the CH2ADS2-VASc Score.

Three new Batillipes species (Arthrotardigrada: Batillipedidae) from the Brazilian coast.

PubMed

Santos, Erika; Rocha, Clélia M C DA; Gomes, Edivaldo Jr; Fontoura, Paulo

2017-03-16

Three new tardigrade species, Batillipes brasiliensis sp. nov., Batillipes dandarae sp. nov. and Batillipes potiguarensis sp. nov., are described from shallow subtidal sediments of the Brazilian coast. B. brasiliensis sp. nov. and B. dandarae sp. nov. have toes 3 and 4 on leg IV different in length, so they can be included in the D group of species, while B. potiguarensis sp. nov., with toes 3 and 4 on leg IV equal in length belong to the A group. Batillipes brasiliensis sp. nov. is characterized by having an ala-like caudal expansion; cuticular projections on the coxal region of legs I-III, and lateral projections. The lateral projection located between the third and fourth legs is fringed with digit-shaped expansions. Batillipes dandarae sp. nov. has a dorsal blunt enlargement in the scapular region; a pointed triangular caudal appendage, and no lateral projections. The new species exhibits a sensorial spine on legs I inserted posteriorly and turning forward, and anus surrounded by a peculiar cuticular structure constituted by six platelets. Batillipes potiguarensis sp. nov. is characterized by a unique combination of characters: scapular region well developed, protruding laterally at the level of the first pair of legs; lateral blunt processes between legs, and prominent roundish caudal protrusion. In addition, the new species exhibits cephalic appendages with swollen tips, evident secondary clavae, and very short sense organs on the legs IV.

Resolution of massive left atrial appendage thrombi with rivaroxaban before balloon mitral commissurotomy in severe mitral stenosis: A case report and literature review.

PubMed

Li, Yuechun; Lin, Jiafeng; Peng, Chen

2016-12-01

Data on nonvitamin K antagonist oral anticoagulant being used for the treatment of LAA thrombi are limited only in nonvalvular atrial fibrillation. There are no data on the antithrombotic efficacy and safety of nonvitamin K antagonist oral anticoagulant in the resolution of left atrial appendage (LAA) thrombi in patients with rheumatic mitral stenosis. A 49-year-old woman with known rheumatic mitral stenosis and atrial fibrillation was referred for percutaneous transvenous mitral commissurotomy because of progressive dyspnea on exertion over a period of 3 months. Transesophageal echocardiography (TEE) demonstrated a large LAA thrombus protruding into left atria cavity before the procedure. Direct factor Xa (FXa) inhibitor rivaroxaban (20 mg/d) was started for the patient. After 3 weeks of rivaroxaban treatment TEE showed a relevantly decreased thrombus size, and a complete thrombus resolution was achieved after 5 weeks of anticoagulant therapy with the FXa inhibitor. To the best of our knowledge, this is the first documented case of large LAA thrombus resolution with nonvitamin K antagonist oral anticoagulant in severe mitral stenosis, and in which percutaneous transvenous mitral commissurotomy was performed subsequently. The report indicated that rivaroxaban could be a therapeutic option for mitral stenosis patients with LAA thrombus. Further study is required before the routine use of rivaroxaban in patients with rheumatic mitral stenosis and atrial fibrillation.

Common evolutionary trends underlie the four-bar linkage systems of sunfish and mantis shrimp.

PubMed

Hu, Yinan; Nelson-Maney, Nathan; Anderson, Philip S L

2017-05-01

Comparative biomechanics offers an opportunity to explore the evolution of disparate biological systems that share common underlying mechanics. Four-bar linkage modeling has been applied to various biological systems such as fish jaws and crustacean appendages to explore the relationship between biomechanics and evolutionary diversification. Mechanical sensitivity states that the functional output of a mechanical system will show differential sensitivity to changes in specific morphological components. We document similar patterns of mechanical sensitivity in two disparate four-bar systems from different phyla: the opercular four-bar system in centrarchid fishes and the raptorial appendage of stomatopods. We built dynamic linkage models of 19 centrarchid and 36 stomatopod species and used phylogenetic generalized least squares regression (PGLS) to compare evolutionary shifts in linkage morphology and mechanical outputs derived from the models. In both systems, the kinematics of the four-bar mechanism show significant evolutionary correlation with the output link, while travel distance of the output arm is correlated with the coupler link. This common evolutionary pattern seen in both fish and crustacean taxa is a potential consequence of the mechanical principles underlying four-bar systems. Our results illustrate the potential influence of physical principles on morphological evolution across biological systems with different structures, behaviors, and ecologies. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Increased myosin heavy chain-beta with atrial expression of ventricular light chain-2 in canine cardiomyopathy.

PubMed

Fuller, Geraldine A; Bicer, Sabahattin; Hamlin, Robert L; Yamaguchi, Mamoru; Reiser, Peter J

2007-10-01

Dilated cardiomyopathy is a naturally occurring disease in humans and dogs. Human studies have shown increased levels of myosin heavy chain (MHC)-beta in failing ventricles and the left atria (LA) and of ventricular light chain (VLC)-2 in the right atria in dilated cardiomyopathy. This study evaluates the levels of MHC-beta in all heart chambers in prolonged canine right ventricular pacing. In addition, we determined whether levels of VLC2 were altered in these hearts. Failing hearts demonstrated significantly increased levels of MHC-beta in the right atria, right atrial appendage, LA, left atrial appendage (LAA), and right ventricle compared with controls. Significant levels of VLC2 were detected in the right atria of paced hearts. Differences in MHC-beta expression were observed between the LA and the LAA of paced and control dogs. MHC-beta expression was significantly greater in the LA of paced and control dogs compared with their respective LAA. The cardiac myosin isoform shifts in this study were similar to those observed in end-stage human heart failure and more severe than those reported in less prolonged pacing models, supporting the use of this model for further study of end-stage human heart failure. The observation of consistent differences between sampling sites, especially LA versus LAA, indicates the need for rigorous sampling consistency in future studies.

Identification of Left Atrial Appendage Thrombi in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation Using Intra-Cardiac Echocardiography and Cardiac Computed Tomography.

PubMed

Ikegami, Yukinori; Tanimoto, Kojiro; Inagawa, Kohei; Shiraishi, Yasuyuki; Fuse, Jun; Sakamoto, Munehisa; Momiyama, Yukihiko; Takatsuki, Seiji

2017-12-25

Intracardiac echocardiography (ICE) and cardiac computed tomography (CCT), in addition to standard transesophageal echocardiography (TEE), have been used to identify left atrial (LA) thrombi prior to ablation for atrial fibrillation (AF). The clinical advantages of this, however, remain unclear. This study therefore investigated the advantages of additional pre-procedural LA appendage (LAA) thrombus evaluation using ICE and the clinical value of CCT in persistent and long-standing persistent AF.Methods and Results:We analyzed data from 108 consecutive patients with persistent and long-standing persistent AF who were scheduled to undergo AF ablation. TEE was performed within 24 h prior to ablation. ICE was performed for 97 patients in whom a thrombus was not detected on TEE. CCT was performed in 95 patients. Thrombus or sludge was detected on TEE in 11 patients (10.3%), for whom ablation was cancelled. Four additional patients were diagnosed with LAA thrombus on ICE. When TEE and ICE were used as the reference for thrombus detection, the sensitivity, specificity, positive predictive value, and negative predictive value of CCT for identifying contrast defects in the LAA were 100%, 81.0%, 40.7%, and 100%, respectively. ICE combined with TEE increased the detection rate of LAA thrombi in patients with persistent and long-standing persistent AF. Moreover, CCT had high sensitivity and negative predictive value for LAA thrombus detection.

Drusus sharrensis sp. n. (Trichoptera, Limnephilidae), a new species from Sharr National Park in Kosovo, with molecular and ecological notes

PubMed Central

Ibrahimi, Halil; Vitecek, Simon; Previšić, Ana; Kučinić, Mladen; Johann Waringer; Graf, Wolfram; Balint, Miklós; Keresztes, Lujza; Pauls, Steffen U.

2016-01-01

Abstract In this paper we describe Drusus sharrensis sp. n., from the Sharr Mountains in Kosovo. Males of the new species are morphologically most similar to Drusus krusniki Malicky, 1981, Drusus kerek Oláh, 2011 and Drusus juliae Oláh, 2011 but differ mainly in exhibiting (1) a differently shaped spinose area on tergite VIII; (2) intermediate appendages anteriorly curved in lateral view with broad tips in dorsal view; (3) inferior appendages with a distinct dorsal protrusion in the proximal half. Females of the new species are morphologically most similar to Drusus krusniki, Drusus kerek, Drusus juliae, and Drusus plicatus Radovanovic, 1942 but mainly differ in (1) segment X that is longer than the supragenital plate with distinctly pointed tips; (2) supragenital plate quadrangular with a distinct round dorsal protrusion; (3) a vulvar scale with a small median lobe. Results of phylogenetic species delimitation support monophyly of Drusus sharrensis sp. n. and recover it as sister to a clade comprising (Drusus pelasgus Oláh, 2010 + Drusus juliae + Drusus arbanios Oláh, 2010 + Drusus plicatus + (Drusus dacothracus Oláh, 2010 + Drusus illyricus Oláh, 2010)). The new species is a micro-endemic of the Sharr Mountains, a main biodiversity hotspot in the Balkan Peninsula. Main threats to the aquatic ecosystems of this part of the Balkan Peninsula are discussed. PMID:27006607

Antiarrhythmic properties of atrial pacing.

PubMed

Kliś, Magdalena; Sławuta, Agnieszka; Gajek, Jacek

2017-01-01

Bradycardia, atrial stretch and dilatation, autonomic nervous system disorders, and the presence of triggers such as atrial premature contractions, are factors which predispose a person to paroxysmal AF. Atrial pacing not only eliminates bradycardia but also prevents atrial premature contractions and dispersion of refractoriness, which are a substrate for atrial fibrillation. As the prolonged duration of atrial activation during pacing, especially from locations changing the physiological pattern of this activation (right atrium lateral wall, right atrium appendage), negatively influences both a mechanical and an electrical function of the atria, the atrial pacing site affects an atrial arrhythmogenesis. A conventional atrial lead location in the right atrium appendage causes non-physiological activation propagation, resulting in a prolongation of the activation time of both atria. This location is optimal according to a passive fixation of the atrial lead but the available contemporary active fixation leads could potentially be located in any area of the atrium. There is growing evidence of the benefit of pacing, imitating the physiological propagation of impulses within the atria. It seems that the Bachmann's bundle pacing is the best pacing site within the atria, not only positively influencing the atrial mechanical function but also best fulfilling the so-called atrial resynchronization function, in particular in patients with interatrial conduction delay. It can be effectively achieved using only one atrial electrode, and the slight shortening of atrioventricular conduction provides an additional benefit of this atrial pacing site.

New records for the Kosovo caddisfly fauna with the description of a new species, Drusus dardanicus sp. nov. (Trichoptera: Limnephilidae)

PubMed Central

Ibrahimi, Halil; Kučinić, Mladen; Vitecek, Simon; Waringer, Johann; Graf, Wolfram; Previšić, Ana; Bálint, Miklós; Keresztes, Lujza; Pauls, Steffen U.

2016-01-01

The Balkan Peninsula is one of the most important European hotspots of freshwater biodiversity. The region is, however, to a large extent insufficiently investigated. Here we present data on distribution of caddisflies in one particularly understudied area, the Republic of Kosovo. Our data include the first records of Adicella altandroconia Botosaneanu & Novak and Halesus tessellatus (Rambur) for the Kosovo caddisfly fauna, and a new locality for the recently described Ecclisopteryx keroveci Previšić, Graf, & Vitecek. Further, we describe the new caddisfly species Drusus dardanicus sp. nov. from the Kopaonik Mountains. The new species belongs to the D. discophorus Species Group and differs morphologically from its most similar congeners (D. discophorus Radovanović, D. balcanicus Kumanski, and D. bureschi Kumanski) mainly in exhibiting (1) subtrianglar superior appendages; (2) a narrow, dorsal spinate area of tergite VIII; and (3) evenly rounded tips of intermediate appendages in caudal view. In phylogenetic analysis, D. dardanicus sp. nov. is well delineated and recovered as a sister taxon to D. osogovicus Kumanski, a species recorded from Bulgaria. The recent discovery of a new species and other rare or microendemic species presents important contributions to the knowledge on the rich freshwater biodiversity in Kosovo. These species face increasing anthropogenic pressure and threats to their conservation. PMID:26624385

Percutaneous left atrial appendage occlusion in atrial fibrillation patients with a contraindication to oral anticoagulation: a focused review.

PubMed

Nishimura, Marin; Sab, Shiv; Reeves, Ryan R; Hsu, Jonathan C

2017-12-08

Stroke is the most feared complication of atrial fibrillation (AF). Although oral anticoagulation with non-vitamin K antagonist and non-vitamin K antagonist oral anticoagulants (NOACs) have been established to significantly reduce risk of stroke, real-world use of these agents are often suboptimal due to concerns for adverse events including bleeding from both patients and clinicians. Particularly in patients with previous serious bleeding, oral anticoagulation may be contraindicated. Left atrial appendage occlusion (LAAO), mechanically targeting the source of most of the thrombi in AF, holds an immense potential as an alternative to OAC in management of stroke prophylaxis. In this focused review, we describe the available evidence of various LAAO devices, detailing data regarding their use in patients with a contraindication for oral anticoagulation. Although some questions of safety and appropriate use of these new devices in patients who cannot tolerate anticoagulation remain, LAAO devices offer a significant step forward in the management of patients with AF, including those patients who may not be able to be prescribed OAC at all. Future studies involving patients fully contraindicated to OAC are warranted in the era of LAAO devices for stroke risk reduction. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

ABO blood groups: A risk factor for left atrial and left atrial appendage thrombogenic milieu in patients with non-valvular atrial fibrillation.

PubMed

Fu, Yuan; Li, Kuibao; Yang, Xinchun

2017-08-01

Previous studies have identified ABO blood groups as predictors of thromboembolic diseases. In patients with atrial fibrillation (AF), however, potential association between ABO blood groups and the risk of left atrial (LA) and/or left atrial appendage (LAA) thrombogenic milieu (TM) has not been established. This is a retrospective case-control study that included 125 consecutive patients with non-valvular atrial fibrillation (NVAF) plus TM, as evidenced by transesophageal echocardiography (TEE) during a period from1 January 2010 to 31 December 2016. The controls were selected randomly from 1072 NVAF without TM at a 1:2 ratio. Potential association between ABO blood groups and TM was analyzed using multivariate logistic regression analysis. The risk of TM was higher in patients with blood group A (33.6% vs. 20.2% in non-A blood groups, P=0.005). After adjusting for age, sex, oral anticoagulant use, AF type and duration, and relevant functional measures (e.g., NT-pro BNP level, left atrium diameter, and left ventricular ejection fraction), blood group A remained associated with an increased risk of TM (OR=2.99, 95% CI 1.4-6.388, P=0.005). Blood group A is an independent risk factor for TM in NVAF patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Infrared laser sealing of porcine vascular tissues using a 1,470 nm diode laser: Preliminary in vivo studies.

PubMed

Cilip, Christopher M; Kerr, Duane; Latimer, Cassandra A; Rosenbury, Sarah B; Giglio, Nicholas C; Hutchens, Thomas C; Nau, William H; Fried, Nathaniel M

2017-04-01

Infrared (IR) lasers are being explored as an alternative to radiofrequency (RF) and ultrasonic (US) devices for rapid hemostasis with minimal collateral zones of thermal damage and tissue necrosis. Previously, a 1,470 nm IR laser sealed and cut ex vivo porcine renal arteries of 1-8 mm diameter in 2 seconds, yielding burst pressures greater than 1,200 mmHg and thermal coagulation zones less than 3 mm. This preliminary study describes in vivo testing of a handheld laser probe in a porcine model. A handheld prototype with vessel/tissue clasping mechanism was tested on 73 blood vessels less than 6 mm diameter using 1,470 nm laser power of 35 W for 1-5 seconds. Device power settings, irradiation time, tissue type, vessel diameter, and histology sample number were recorded for each procedure. The probe was evaluated for hemostasis after sealing isolated and bundled arteriole/venous (A/V) vasculature of porcine abdomen and hind leg. Sealed vessel samples were collected for histological analysis of lateral thermal damage. Hemostasis was achieved in 57 of 73 seals (78%). The probe consistently sealed vasculature in small bowel mesentery, mesometrium, and gastrosplenic and epiploic regions. Seal performance was less consistent on hind leg vasculature including saphenous arteries/bundles and femoral and iliac arteries. Collagen denaturation averaged 1.6 ± 0.9 mm in eight samples excised for histologic examination. A handheld laser probe sealed porcine vessels, in vivo. Further probe development and laser parameter optimization is necessary before infrared lasers may be evaluated as an alternative to RF and US vessel sealing devices. Lasers Surg. Med. 49:366-371, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A new species of Coespeletia (Asteraceae, Millerieae) from Venezuela.

PubMed

Diazgranados, Mauricio; Morillo, Gilberto

2013-01-01

A new species of Coespeletia from the páramos of Mérida (Venezuela) is described here. This species, named Coespeletia palustris, is found in a few marshy areas of the páramo. It is closely related to C. moritziana, but differs from it in a smaller number of florets in the capitula, larger ray flowers with longer ligulae and longer linguiform appendages, smaller pollen grains, larger cypselae, ebracteate scapes, leaves and inflorescences with more whitish indumentum, larger leaf sheaths, and marshy habitat.

Oceanography: 1998 Paris Meeting Abstracts: Coastal and Marginal Seas. Volume 11, Number 2.

DTIC Science & Technology

1998-01-01

Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503. 1. AGENCY USE ONLY (Laave blank) 2. REPORT DATE 18 MAR 1999 3. REPORT...Richard W. Spinrad Small-Scale Hydrodynamics of Feeding Appendages of Marine Animals 10 M.A.R. Koehl Controls on Floe Size in the Sea 13 Paul S...we’ve included our first inter- view with one of community’s most influential leaders, the Chief of Naval Research, Rear Admiral Paul G. Gaffney, Jr

Anhidrotic ectodermal dysplasia presenting as atrophic rhinitis.

PubMed

Barman, Debasis; Mandal, Satadal; Nandi, Santanu; Banerjee, Pranabashish; Rashid, M A

2011-11-01

Ectodermal dysplasia is a complex group of familial disorders with numerous clinical characteristics, with an incidence of 7 in 10000 born alive children. Ectodermal dysplasia affects structures of ectodermal origin like the skin and its appendages as well as other non-ectodermal structures. The most common sites of involvement are the defects in the skin, hair, teeth, nails and sweat glands,which are of ectodermal origin. Though the dermatologists and paediatricians often manage such cases, we report one case of ectodermal dysplasia presenting with atrophic rhinitis.

Are You at Risk for Contact Dermatitis? | Poster

Cancer.gov

You probably don’t give much thought to hand health. Until something goes wrong, almost everyone takes for granted that these crucial appendages will continue working as they always have. But hand health is an important consideration, especially at work. According to the Centers for Disease Control and Prevention (CDC), allergic contact dermatitis and irritant contact dermatitis account for 15–20 percent of all reported occupational diseases, and they cost employers an estimated $1 billion each year in lost workdays and decreased productivity.

Description of two new Calicnemia from Vietnam and central Laos with notes on their congeners in Vietnam (Odonata: Platycnemididae).

PubMed

Phan, Quoc Toan; Kompier, Tom; Karube, Haruki

2017-02-16

Descriptions are given of two new species of Calicnemia: C. akahara sp. nov. from central and southern Vietnam and C. hamata sp. nov. from central Laos. C. soccifera Yu & Chen, 2013, and C. haksik Wilson & Reels, 2003, are recorded for the first time from Vietnam; C. uenoi Asahina, 1997, is redescribed with new illustrations provided of its anal appendages and genital ligula; and the occurrence of C. mortoni (Laidlaw, 1917) in Vietnam is discussed.

Current problems concerning parasitology and mycology with regard to diseases of the skin and its appendages.

PubMed

Błaszkowska, Joanna; Wójcik, Anna

2012-01-01

Current issues concerning Parasitology and Mycology with regard to diseases of the skin and its appendages are presented. Aspects of diagnostics, clinical picture and therapy of skin and nail mycoses, as well as difficulties in the diagnosis and treatment of both native parasitoses (toxoplasmosis) and imported human tropical parasitoses (malaria, filariosis) have been emphasised. The clinical importance of environmental mould fungi in nosocomial infections and fungal meningitis, as well as selected properties of fungi isolated from patients with head and neck neoplasms treated by radiotherapy are discussed. Other mycological topics include the characteristics of newly-synthesized thiosemicarbazides and thiadiazoles as potential drugs against toxoplasmosis and their biological activity against Toxoplasma gondii tachyzoites, selected molecular mechanisms of resistance to azoles, Candida albicans strains and a new tool (barcoding DNA) for describing the biodiversity of potential allergenic molds. The importance of environmental factors in pathogenesis of mycoses and parasitoses is noted. The characteristics of pathogenic fungi isolated from natural ponds in Bialystok and potentially pathogenic yeast-like fungi isolated from children's recreation areas in Lodz are presented. The ongoing problem of anthropozoonoses is considered, as are the roles of stray cats and dogs in contaminating soil with the developing forms of intestinal parasites. The characteristics of the human microbiome, including population composition, activity and their importance in normal human physiology, are presented, as are the major goals of the Human Microbiome Project initiated by National Institutes of Health (NIH).

LQG/LTR optimal attitude control of small flexible spacecraft using free-free boundary conditions

NASA Astrophysics Data System (ADS)

Fulton, Joseph M.

Due to the volume and power limitations of a small satellite, careful consideration must be taken while designing an attitude control system for 3-axis stabilization. Placing redundancy in the system proves difficult and utilizing power hungry, high accuracy, active actuators is not a viable option. Thus, it is customary to find dependable, passive actuators used in conjunction with small scale active control components. This document describes the application of Elastic Memory Composite materials in the construction of a flexible spacecraft appendage, such as a gravity gradient boom. Assumed modes methods are used with Finite Element Modeling information to obtain the equations of motion for the system while assuming free-free boundary conditions. A discussion is provided to illustrate how cantilever mode shapes are not always the best assumption when modeling small flexible spacecraft. A key point of interest is first resonant modes may be needed in the system design plant in spite of these modes being greater than one order of magnitude in frequency when compared to the crossover frequency of the controller. LQG/LTR optimal control techniques are implemented to compute attitude control gains while controller robustness considerations determine appropriate reduced order controllers and which flexible modes to include in the design model. Key satellite designer concerns in the areas of computer processor sizing, material uncertainty impacts on the system model, and system performance variations resulting from appendage length modifications are addressed.

Inferring Arthropod Phylogeny: Fossils and their Interaction with Other Data Sources.

PubMed

Edgecombe, Gregory D

2017-09-01

The past five years have witnessed a renewed interest in discrete morphological characters as a source of phylogenetic data, after a decade or more of their dismissal in favor of molecules-only approaches. This has stemmed in large part from refinements in total evidence dating, which requires morphological character matrices for extinct and extant taxa as well as temporal data from fossils. The unique contribution of palaeontology is stem groups, revealing the sequence of character acquisition in long-branch terminals and otherwise unknown character combinations and/or character states in extinct phenotypes. The origin of mandibles exemplifies an integrative approach to analyzing the origin of a complex phenotypic feature using molecular, anatomical, and palaeontological data: (1) transcriptomics defends a single origin of mandibles in the clade Mandibulata; (2) Cambrian fossils inform on morphological changes in the gnathal appendages in the mandibulate stem group; (3) molecular dating, calibrated by fossils in novel modes of exceptional preservation, draws the mandibulate crown group into the early Cambrian and constrains the timing of character evolution; and (4) functional studies in extant taxa identify genes that specify mandibular identity from a maxilla and, ultimately, a trunk limb-like precursor, as predicted by the serial similarity of these appendages in Cambrian stem-group fossils. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Babes in the wood – a unique window into sea scorpion ontogeny

PubMed Central

2013-01-01

Background Few studies on eurypterids have taken into account morphological changes that occur throughout postembryonic development. Here two species of eurypterid are described from the Pragian Beartooth Butte Formation of Cottonwood Canyon in Wyoming and included in a phylogenetic analysis. Both species comprise individuals from a number of instars, and this allows for changes that occur throughout their ontogeny to be documented, and how ontogenetically variable characters can influence phylogenetic analysis to be tested. Results The two species of eurypterid are described as Jaekelopterus howelli (Kjellesvig-Waering and Størmer, 1952) and Strobilopterus proteus sp. nov. Phylogenetic analysis places them within the Pterygotidae and Strobilopteridae respectively, both families within the Eurypterina. Jaekelopterus howelli shows positive allometry of the cheliceral denticles throughout ontogeny, while a number of characteristics including prosomal appendage length, carapace shape, lateral eye position, and relative breadth all vary during the growth of Strobilopterus proteus. Conclusions The ontogeny of Strobilopterus proteus shares much in common with that of modern xiphosurans, however certain characteristics including apparent true direct development suggest a closer affinity to arachnids. The ontogenetic development of the genital appendage also supports the hypothesis that the structure is homologous to the endopods of the trunk limbs of other arthropods. Including earlier instars in the phylogenetic analysis is shown to destabilise the retrieved topology. Therefore, coding juveniles as individual taxa in an analysis is shown to be actively detrimental and alternative ways of coding ontogenetic data into phylogenetic analyses should be explored. PMID:23663507

White spot syndrome virus epizootic in cultured Pacific white shrimp Litopenaeus vannamei (Boone) in Taiwan.

PubMed

Cheng, L; Lin, W-H; Wang, P-C; Tsai, M-A; Hsu, J-P; Chen, S-C

2013-12-01

White spot syndrome virus (WSSV) has caused significant losses in shrimp farms worldwide. Between 2004 and 2006, Pacific white shrimp Litopenaeus vannamei (Boone) were collected from 220 farms in Taiwan to determine the prevalence and impact of WSSV infection on the shrimp farm industry. Polymerase chain reaction (PCR) analysis detected WSSV in shrimp from 26% of farms. Juvenile shrimp farms had the highest infection levels (38%; 19/50 farms) and brooder shrimp farms had the lowest (5%; one of 20 farms). The average extent of infection at each farm was as follows for WSSV-positive farms: post-larvae farms, 71%; juvenile farms, 61%; subadult farms, 62%; adult farms, 49%; and brooder farms, 40%. Characteristic white spots, hypertrophied nuclei and basophilic viral inclusion bodies were found in the epithelia of gills and tail fans, appendages, cephalothorax and hepatopancreas, and virions of WSSV were observed. Of shrimp that had WSSV lesions, 100% had lesions on the cephalothorax, 96% in gills and tail fans, 91% on appendages and 17% in the hepatopancreas. WSSV was also detected in copepoda and crustaceans from the shrimp farms. Sequence comparison using the pms146 gene fragment of WSSV showed that isolates from the farms had 99.7-100% nucleotide sequence identity with four strains in the GenBank database--China (AF332093), Taiwan (AF440570 and U50923) and Thailand (AF369029). This is the first broad study of WSSV infection in L. vannamei in Taiwan. © 2013 John Wiley & Sons Ltd.

Left Atrial Appendage Eccentricity and Irregularity Are Associated With Residual Leaks After Percutaneous Closure.

PubMed

Rajwani, Adil; Shirazi, Masoumeh G; Disney, Patrick J S; Wong, Dennis T L; Teo, Karen S L; Delacroix, Sinny; Chokka, Ramesh G; Young, Glenn D; Worthley, Stephen G

2015-12-01

Predictors of residual leak following percutaneous LAA closure were evaluated. Left atrial appendage (LAA) closure aims to exclude this structure from the circulation, typically using a circular occluder. A noncircular orifice is frequently encountered however, and fibrous remodeling of the LAA in atrial fibrillation may restrict orifice deformation. Noncircularity may thus be implicated in the occurrence of residual leak despite an appropriately oversized device. Pre-procedural multislice computerized tomography was used to quantify LAA orifice eccentricity and irregularity. Univariate predictors of residual leak were identified with respect to the orifice, device, and relevant clinical variables, with the nature of any correlations then further evaluated. Eccentricity and irregularity indexes of the orifice in 31 individuals were correlated with residual leak even where the device was appropriately oversized. An eccentricity index of 0.15 predicted a residual leak with 85% sensitivity and 59% specificity. An irregularity index of 0.05 predicted a significant residual leak ≥3 mm with 100% sensitivity and 86% specificity. Orifice size, device size, degree of device oversize, left atrial volume, and pulmonary artery pressure were not predictors of residual leak. Eccentricity and irregularity of the LAA orifice are implicated in residual leak after percutaneous closure even where there is appropriate device over-size. Irregularity index in particular is a novel predictor of residual leak, supporting a closer consideration of orifice morphology before closure. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Imaging Techniques in Percutaneous Cardiac Structural Interventions: Atrial Septal Defect Closure and Left Atrial Appendage Occlusion.

PubMed

Rodríguez Fernández, Antonio; Bethencourt González, Armando

2016-08-01

Because of advances in cardiac structural interventional procedures, imaging techniques are playing an increasingly important role. Imaging studies show sufficient anatomic detail of the heart structure to achieve an excellent outcome in interventional procedures. Up to 98% of atrial septal defects at the ostium secundum can be closed successfully with a percutaneous procedure. Candidates for this type of procedure can be identified through a systematic assessment of atrial septum anatomy, locating and measuring the size and shape of all defects, their rims, and the degree and direction of shunting. Three dimensional echocardiography has significantly improved anatomic assessments and the end result itself. In the future, when combined with other imaging techniques such as cardiac computed tomography and fluoroscopy, 3-dimensional echocardiography will be particularly useful for procedure guidance. Percutaneous closure of the left atrial appendage offers an alternative for treating patients with atrial fibrillation and contraindication for oral anticoagulants. In the future, the clinical focus may well turn to stroke prevention in selected patients. Percutaneous closure is effective and safe; device implantation is successful in 94% to 99% of procedures. However, the procedure requires an experienced cardiac structural interventional team. At present, 3-dimensional echocardiography is the most appropriate imaging technique to assess anatomy suitability, select device type and size, guide the procedure alongside fluoroscopy, and to follow-up the patient afterwards. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Simulation studies using multibody dynamics code DART

NASA Technical Reports Server (NTRS)

Keat, James E.

1989-01-01

DART is a multibody dynamics code developed by Photon Research Associates for the Air Force Astronautics Laboratory (AFAL). The code is intended primarily to simulate the dynamics of large space structures, particularly during the deployment phase of their missions. DART integrates nonlinear equations of motion numerically. The number of bodies in the system being simulated is arbitrary. The bodies' interconnection joints can have an arbitrary number of degrees of freedom between 0 and 6. Motions across the joints can be large. Provision for simulating on-board control systems is provided. Conservation of energy and momentum, when applicable, are used to evaluate DART's performance. After a brief description of DART, studies made to test the program prior to its delivery to AFAL are described. The first is a large angle reorientating of a flexible spacecraft consisting of a rigid central hub and four flexible booms. Reorientation was accomplished by a single-cycle sine wave shape torque input. In the second study, an appendage, mounted on a spacecraft, was slewed through a large angle. Four closed-loop control systems provided control of this appendage and of the spacecraft's attitude. The third study simulated the deployment of the rim of a bicycle wheel configuration large space structure. This system contained 18 bodies. An interesting and unexpected feature of the dynamics was a pulsing phenomena experienced by the stays whole playout was used to control the deployment. A short description of the current status of DART is given.

Toward standardized mapping for left atrial analysis and cardiac ablation guidance

NASA Astrophysics Data System (ADS)

Rettmann, M. E.; Holmes, D. R.; Linte, C. A.; Packer, D. L.; Robb, R. A.

2014-03-01

In catheter-based cardiac ablation, the pulmonary vein ostia are important landmarks for guiding the ablation procedure, and for this reason, have been the focus of many studies quantifying their size, structure, and variability. Analysis of pulmonary vein structure, however, has been limited by the lack of a standardized reference space for population based studies. Standardized maps are important tools for characterizing anatomic variability across subjects with the goal of separating normal inter-subject variability from abnormal variability associated with disease. In this work, we describe a novel technique for computing flat maps of left atrial anatomy in a standardized space. A flat map of left atrial anatomy is created by casting a single ray through the volume and systematically rotating the camera viewpoint to obtain the entire field of view. The technique is validated by assessing preservation of relative surface areas and distances between the original 3D geometry and the flat map geometry. The proposed methodology is demonstrated on 10 subjects which are subsequently combined to form a probabilistic map of anatomic location for each of the pulmonary vein ostia and the boundary of the left atrial appendage. The probabilistic map demonstrates that the location of the inferior ostia have higher variability than the superior ostia and the variability of the left atrial appendage is similar to the superior pulmonary veins. This technique could also have potential application in mapping electrophysiology data, radio-frequency ablation burns, or treatment planning in cardiac ablation therapy.

Mechanisms regulating nutrition-dependent developmental plasticity through organ-specific effects in insects

PubMed Central

Koyama, Takashi; Mendes, Cláudia C.; Mirth, Christen K.

2013-01-01

Nutrition, via the insulin/insulin-like growth factor (IIS)/Target of Rapamycin (TOR) signaling pathway, can provide a strong molding force for determining animal size and shape. For instance, nutrition induces a disproportionate increase in the size of male horns in dung and rhinoceros beetles, or mandibles in staghorn or horned flour beetles, relative to body size. In these species, well-fed male larvae produce adults with greatly enlarged horns or mandibles, whereas males that are starved or poorly fed as larvae bear much more modest appendages. Changes in IIS/TOR signaling plays a key role in appendage development by regulating growth in the horn and mandible primordia. In contrast, changes in the IIS/TOR pathway produce minimal effects on the size of other adult structures, such as the male genitalia in fruit flies and dung beetles. The horn, mandible and genitalia illustrate that although all tissues are exposed to the same hormonal environment within the larval body, the extent to which insulin can induce growth is organ specific. In addition, the IIS/TOR pathway affects body size and shape by controlling production of metamorphic hormones important for regulating developmental timing, like the steroid molting hormone ecdysone and sesquiterpenoid hormone juvenile hormone. In this review, we discuss recent results from Drosophila and other insects that highlight mechanisms allowing tissues to differ in their sensitivity to IIS/TOR and the potential consequences of these differences on body size and shape. PMID:24133450

Is an Appreciation of Isomerism the Key to Unlocking the Mysteries of the Cardiac Findings in Heterotaxy?

PubMed

Anderson, Robert H; Spicer, Diane E; Loomba, Rohit

2018-02-06

Pediatric cardiologists treating patients with severe congenital cardiac defects define "visceral heterotaxy" on the basis of isomerism of the atrial appendages. The isomeric features represent an obvious manifestation of disruption of left-right asymmetry during embryonic development. Thus, there are two subsets of individuals within the overall syndrome, with features of either right or left isomerism. Within the heart, it is only the atrial appendages that are truly isomeric. The remainder of the cardiac components shows variable morphology, as does the arrangement of the remaining body organs. Order is provided in this potentially chaotic arrangement simply by describing the specific features of each of the systems. These features as defined by clinicians, however, seem less well recognized by those investigating the developmental origins of the disruption of symmetry. Developmental biologists place much greater emphasis on ventricular looping. Although the direction of the loop can certainly be interpreted as representing an example of asymmetry, it is not comparable to the isomeric features that underscore the clinical syndromes. This is because, thus far, there is no evidence of ventricular isomerism, with the ventricles distinguished one from the other on the basis of their disparate anatomical features. In similar fashion, some consider transposition to represent abnormal lateralization, but again, clinical diagnosis depends on recognition of the lateralized features. In this review, therefore, we discuss the key questions that currently underscore the mismatch in the approaches to "lateralization" as taken by clinicians and developmental biologists.

Transatrial Intrapericardial Tricuspid Annuloplasty

PubMed Central

Rogers, Toby; Ratnayaka, Kanishka; Sonmez, Merdim; Franson, Dominique N.; Schenke, William H.; Mazal, Jonathan R.; Kocaturk, Ozgur; Chen, Marcus Y.; Faranesh, Anthony Z.; Lederman, Robert J.

2015-01-01

OBJECTIVES This study sought to demonstrate transcatheter deployment of a circumferential device within the pericardial space to modify tricuspid annular dimensions interactively and to reduce functional tricuspid regurgitation (TR) in swine. BACKGROUND Functional TR is common and is associated with increased morbidity and mortality. There are no reported transcatheter tricuspid valve repairs. We describe a transcatheter extracardiac tricuspid annuloplasty device positioned in the pericardial space and delivered by puncture through the right atrial appendage. We demonstrate acute and chronic feasibility in swine. METHODS Transatrial intrapericardial tricuspid annuloplasty (TRAIPTA) was performed in 16 Yorkshire swine, including 4 with functional TR. Invasive hemodynamics and cardiac magnetic resonance imaging (MRI) were performed at baseline, immediately after annuloplasty and at follow-up. RESULTS Pericardial access via a right atrial appendage puncture was uncomplicated. In 9 naïve animals, tricuspid septal-lateral and anteroposterior dimensions, the annular area and perimeter, were reduced by 49%, 31%, 59%, and 24% (p < 0.001), respectively. Tricuspid leaflet coaptation length was increased by 53% (p < 0.001). Tricuspid geometric changes were maintained after 9.7 days (range, 7 to 14 days). Small effusions (mean, 46 ml) were observed immediately post-procedure but resolved completely at follow-up. In 4 animals with functional TR, severity of regurgitation by intracardiac echocardiography was reduced. CONCLUSIONS Transatrial intrapericardial tricuspid annuloplasty is a transcatheter extracardiac tricuspid valve repair performed by exiting the heart from within via a transatrial puncture. The geometry of the tricuspid annulus can interactively be modified to reduce severity of functional TR in an animal model. PMID:25703872

Structure and membrane affinity of a suite of amphiphilic siderophores produced by a marine bacterium

PubMed Central

Martinez, Jennifer S.; Carter-Franklin, Jayme N.; Mann, Elizabeth L.; Martin, Jessica D.; Haygood, Margo G.; Butler, Alison

2003-01-01

Iron concentrations in the ocean are low enough to limit the growth of marine microorganisms, which raises questions about the molecular mechanisms these organisms use to acquire iron. Marine bacteria have been shown to produce siderophores to facilitate iron(III) uptake. We describe the structures of a suite of amphiphilic siderophores, named the amphibactins, which are produced by a nearshore isolate, γ Proteobacterium, Vibrio sp. R-10. Each amphibactin has the same Tris-hydroxamate-containing peptidic headgroup composed of three ornithine residues and one serine residue but differs in the acyl appendage, which ranges from C-14 to C-18 and varies in the degree of saturation and hydroxylation. Although amphiphilic siderophores are relatively rare, cell-associated amphiphilic siderophores are even less common. We find that the amphibactins are cell-associated siderophores. As a result of the variation in the nature of the fatty acid appendage and the cellular location of the amphibactins, the membrane partitioning of these siderophores was investigated. The physiological mixture of amphibactins had a range of membrane affinities (3.8 × 103 to 8.3 × 102 M−1) that are larger overall than other amphiphilic siderophores, likely accounting for their cell association. This cell association is likely an important defense against siderophore diffusion in the oceanic environment. The phylogenetic affiliation of Vibrio sp. R-10 is discussed, as well as the observed predominance of amphiphilic siderophores produced by marine bacteria in contrast to those produced by terrestrial bacteria. PMID:12651947

A novel member of glycoside hydrolase family 30 subfamily 8 with altered substrate specificity

PubMed Central

St John, Franz J.; Dietrich, Diane; Crooks, Casey; Pozharski, Edwin; González, Javier M.; Bales, Elizabeth; Smith, Kennon; Hurlbert, Jason C.

2014-01-01

Endoxylanases classified into glycoside hydrolase family 30 subfamily 8 (GH30-8) are known to hydrolyze the hemicellulosic polysaccharide glucuronoxylan (GX) but not arabinoxylan or neutral xylooligosaccharides. This is owing to the specificity of these enzymes for the α-1,2-linked glucuronate (GA) appendage of GX. Limit hydrolysis of this substrate produces a series of aldouronates each containing a single GA substituted on the xylose penultimate to the reducing terminus. In this work, the structural and biochemical characterization of xylanase 30A from Clostridium papyro­solvens (CpXyn30A) is presented. This xylanase possesses a high degree of amino-acid identity to the canonical GH30-8 enzymes, but lacks the hallmark β8–α8 loop region which in part defines the function of this GH30 subfamily and its role in GA recognition. CpXyn30A is shown to have a similarly low activity on all xylan substrates, while hydrolysis of xylohexaose revealed a competing transglycosylation reaction. These findings are directly compared with the model GH30-8 enzyme from Bacillus subtilis, XynC. Despite its high sequence identity to the GH30-8 enzymes, CpXyn30A does not have any apparent specificity for the GA appendage. These findings confirm that the typically conserved β8–α8 loop region of these enzymes influences xylan substrate specificity but not necessarily β-1,4-xylanase function. PMID:25372685

The dynamics and control of large flexible asymmetric spacecraft

NASA Astrophysics Data System (ADS)

Humphries, T. T.

1991-02-01

This thesis develops the equations of motion for a large flexible asymmetric Earth observation satellite and finds the characteristics of its motion under the influence of control forces. The mathematical model of the structure is produced using analytical methods. The equations of motion are formed using an expanded momentum technique which accounts for translational motion of the spacecraft hub and employs orthogonality relations between appendage and vehicle modes. The controllability and observability conditions of the full spacecraft motions using force and torque actuators are defined. A three axis reaction wheel control system is implemented for both slewing the spacecraft and controlling its resulting motions. From minor slew results it is shown that the lowest frequency elastic mode of the spacecraft is more important than higher frequency modes, when considering the effects of elastic motion on instrument pointing from the hub. Minor slews of the spacecraft configurations considered produce elastic deflections resulting in rotational attitude motions large enough to contravene pointing accuracy requirements of instruments aboard the spacecraft hub. Active vibration damping is required to reduce these hub motions to acceptable bounds in sufficiently small time. A comparison between hub mounted collocated and hub/appendage mounted non-collocated control systems verifies that provided the non-collocated system is stable, it can more effectively damp elastic modes whilst maintaining adequate damping of rigid modes. Analysis undertaken shows that the reaction wheel controller could be replaced by a thruster control system which decouples the modes of the spacecraft motion, enabling them to be individually damped.

Evolution of mantis shrimps (Stomatopoda, Malacostraca) in the light of new Mesozoic fossils

PubMed Central

2010-01-01

Background We describe new specimens of Mesozoic mantis shrimps (Stomatopoda, Malacostraca) that exhibit morphological and developmental information previously unknown. Results Specimens assigned to the taxon Sculda exhibit preserved pleopods, thoracopods including all four raptorial limbs as well as details of antennae and antennulae. The pleopods and the antennulae resemble those of the modern mantis shrimps, but the raptorial limbs are not as differentiated as in the modern species. In some specimens, the first raptorial limb (second thoracopod) is not significantly larger than the similar-sized posterior three pairs (as in extant species), but instead these appendages become progressively smaller along the series. In this respect they resemble certain Palaeozoic stomatopods. Another specimen, most likely belonging to another species, has one pair of large anterior raptorial thoracopods, a median-sized pair and two more pairs of small-sized raptorial appendages and, thus, shows a new, previously unknown type of morphology. A single specimen of Pseudosculda laevis also exhibits the size of the raptorial limbs; they are differentiated as in modern species, one large pair and three small pairs. Furthermore, we report additional larval specimens and show also post-larval changes, e.g., of the tail fan. Conclusions These new data are used to reconsider the phylogeny of Stomatopoda. We still need a strict taxonomical revision of the Mesozoic mantis shrimps, but this first examination already demonstrates the importance of these fossils for understanding mantis shrimp evolution and the interpretation of evolutionary pathways of particular features. PMID:20858249

Microbial Distribution and Abundance in the Digestive System of Five Shipworm Species (Bivalvia: Teredinidae)

PubMed Central

Betcher, Meghan A.; Fung, Jennifer M.; Han, Andrew W.; O’Connor, Roberta; Seronay, Romell; Concepcion, Gisela P.; Distel, Daniel L.; Haygood, Margo G.

2012-01-01

Marine bivalves of the family Teredinidae (shipworms) are voracious consumers of wood in marine environments. In several shipworm species, dense communities of intracellular bacterial endosymbionts have been observed within specialized cells (bacteriocytes) of the gills (ctenidia). These bacteria are proposed to contribute to digestion of wood by the host. While the microbes of shipworm gills have been studied extensively in several species, the abundance and distribution of microbes in the digestive system have not been adequately addressed. Here we use Fluorescence In-Situ Hybridization (FISH) and laser scanning confocal microscopy with 16S rRNA directed oligonucleotide probes targeting all domains, domains Bacteria and Archaea, and other taxonomic groups to examine the digestive microbiota of 17 specimens from 5 shipworm species (Bankia setacea, Lyrodus pedicellatus, Lyrodus massa, Lyrodus sp. and Teredo aff. triangularis). These data reveal that the caecum, a large sac-like appendage of the stomach that typically contains large quantities of wood particles and is considered the primary site of wood digestion, harbors only very sparse microbial populations. However, a significant number of bacterial cells were observed in fecal pellets within the intestines. These results suggest that due to low abundance, bacteria in the caecum may contribute little to lignocellulose degradation. In contrast, the comparatively high population density of bacteria in the intestine suggests a possible role for intestinal bacteria in the degradation of lignocellulose. PMID:23028923

Rkr1/Ltn1 Ubiquitin Ligase-mediated Degradation of Translationally Stalled Endoplasmic Reticulum Proteins*

PubMed Central

Crowder, Justin J.; Geigges, Marco; Gibson, Ryan T.; Fults, Eric S.; Buchanan, Bryce W.; Sachs, Nadine; Schink, Andrea; Kreft, Stefan G.; Rubenstein, Eric M.

2015-01-01

Aberrant nonstop proteins arise from translation of mRNA molecules beyond the coding sequence into the 3′-untranslated region. If a stop codon is not encountered, translation continues into the poly(A) tail, resulting in C-terminal appendage of a polylysine tract and a terminally stalled ribosome. In Saccharomyces cerevisiae, the ubiquitin ligase Rkr1/Ltn1 has been implicated in the proteasomal degradation of soluble cytosolic nonstop and translationally stalled proteins. Rkr1 is essential for cellular fitness under conditions associated with increased prevalence of nonstop proteins. Mutation of the mammalian homolog causes significant neurological pathology, suggesting broad physiological significance of ribosome-associated quality control. It is not known whether and how soluble or transmembrane nonstop and translationally stalled proteins targeted to the endoplasmic reticulum (ER) are detected and degraded. We generated and characterized model soluble and transmembrane ER-targeted nonstop and translationally stalled proteins. We found that these proteins are indeed subject to proteasomal degradation. We tested three candidate ubiquitin ligases (Rkr1 and ER-associated Doa10 and Hrd1) for roles in regulating abundance of these proteins. Our results indicate that Rkr1 plays the primary role in targeting the tested model ER-targeted nonstop and translationally stalled proteins for degradation. These data expand the catalog of Rkr1 substrates and highlight a previously unappreciated role for this ubiquitin ligase at the ER membrane. PMID:26055716

Microbial distribution and abundance in the digestive system of five shipworm species (Bivalvia: Teredinidae).

PubMed

Betcher, Meghan A; Fung, Jennifer M; Han, Andrew W; O'Connor, Roberta; Seronay, Romell; Concepcion, Gisela P; Distel, Daniel L; Haygood, Margo G

2012-01-01

Marine bivalves of the family Teredinidae (shipworms) are voracious consumers of wood in marine environments. In several shipworm species, dense communities of intracellular bacterial endosymbionts have been observed within specialized cells (bacteriocytes) of the gills (ctenidia). These bacteria are proposed to contribute to digestion of wood by the host. While the microbes of shipworm gills have been studied extensively in several species, the abundance and distribution of microbes in the digestive system have not been adequately addressed. Here we use Fluorescence In-Situ Hybridization (FISH) and laser scanning confocal microscopy with 16S rRNA directed oligonucleotide probes targeting all domains, domains Bacteria and Archaea, and other taxonomic groups to examine the digestive microbiota of 17 specimens from 5 shipworm species (Bankia setacea, Lyrodus pedicellatus, Lyrodus massa, Lyrodus sp. and Teredo aff. triangularis). These data reveal that the caecum, a large sac-like appendage of the stomach that typically contains large quantities of wood particles and is considered the primary site of wood digestion, harbors only very sparse microbial populations. However, a significant number of bacterial cells were observed in fecal pellets within the intestines. These results suggest that due to low abundance, bacteria in the caecum may contribute little to lignocellulose degradation. In contrast, the comparatively high population density of bacteria in the intestine suggests a possible role for intestinal bacteria in the degradation of lignocellulose.

Mutations in human C2CD3 cause skeletal dysplasia and provide new insights into phenotypic and cellular consequences of altered C2CD3 function

PubMed Central

Cortés, Claudio R.; McInerney-Leo, Aideen M.; Vogel, Ida; Rondón Galeano, Maria C.; Leo, Paul J.; Harris, Jessica E.; Anderson, Lisa K.; Keith, Patricia A.; Brown, Matthew A.; Ramsing, Mette; Duncan, Emma L.; Zankl, Andreas; Wicking, Carol

2016-01-01

Ciliopathies are a group of genetic disorders caused by defective assembly or dysfunction of the primary cilium, a microtubule-based cellular organelle that plays a key role in developmental signalling. Ciliopathies are clinically grouped in a large number of overlapping disorders, including the orofaciodigital syndromes (OFDS), the short rib polydactyly syndromes and Jeune asphyxiating thoracic dystrophy. Recently, mutations in the gene encoding the centriolar protein C2CD3 have been described in two families with a new sub-type of OFDS (OFD14), with microcephaly and cerebral malformations. Here we describe a third family with novel compound heterozygous C2CD3 mutations in two fetuses with a different clinical presentation, dominated by skeletal dysplasia with no microcephaly. Analysis of fibroblast cultures derived from one of these fetuses revealed a reduced ability to form cilia, consistent with previous studies in C2cd3-mutant mouse and chicken cells. More detailed analyses support a role for C2CD3 in basal body maturation; but in contrast to previous mouse studies the normal recruitment of the distal appendage protein CEP164 suggests that this protein is not sufficient for efficient basal body maturation and subsequent axonemal extension in a C2CD3-defective background. PMID:27094867

Mammary and extramammary Paget's disease*

PubMed Central

Lopes, Lauro Lourival; Lopes, Ione Maria Ribeiro Soares; Lopes, Lauro Rodolpho Soares; Enokihara, Milvia M. S. S.; Michalany, Alexandre Osores; Matsunaga, Nobuo

2015-01-01

Paget's disease, described by Sir James Paget in 1874, is classified as mammary and extramammary. The mammary type is rare and often associated with intraductal cancer (93-100% of cases). It is more prevalent in postmenopausal women and it appears as an eczematoid, erythematous, moist or crusted lesion, with or without fine scaling, infiltration and inversion of the nipple. It must be distinguished from erosive adenomatosis of the nipple, cutaneous extension of breast carcinoma, psoriasis, atopic dermatitis, contact dermatitis, chronic eczema, lactiferous ducts ectasia, Bowen's disease, basal cell carcinoma, melanoma and intraductal papilloma. Diagnosis is histological and prognosis and treatment depend on the type of underlying breast cancer. Extramammary Paget's disease is considered an adenocarcinoma originating from the skin or skin appendages in areas with apocrine glands. The primary location is the vulvar area, followed by the perianal region, scrotum, penis and axillae. It starts as an erythematous plaque of indolent growth, with well-defined edges, fine scaling, excoriations, exulcerations and lichenification. In most cases it is not associated with cancer, although there are publications linking it to tumors of the vulva, vagina, cervix and corpus uteri, bladder, ovary, gallbladder, liver, breast, colon and rectum. Differential diagnoses are candidiasis, psoriasis and chronic lichen simplex. Histopathology confirms the diagnosis. Before treatment begins, associated malignancies should be investigated. Surgical excision and micrographic surgery are the best treatment options, although recurrences are frequent. PMID:25830993

Pondering the procephalon: the segmental origin of the labrum.

PubMed

Haas, M S; Brown, S J; Beeman, R W

2001-02-01

With accumulating evidence for the appendicular nature of the labrum, the question of its actual segmental origin remains. Two existing insect head segmentation models, the linear and S-models, are reviewed, and a new model introduced. The L-/Bent-Y model proposes that the labrum is a fusion of the appendage endites of the intercalary segment and that the stomodeum is tightly integrated into this segment. This model appears to explain a wider variety of insect head segmentation phenomena. Embryological, histological, neurological and molecular evidence supporting the new model is reviewed.

Graduate engineering research participation in aeronautics

NASA Technical Reports Server (NTRS)

Roberts, A. S., Jr.

1984-01-01

Graduate student engineering research in aeronautics at Old Dominion University is surveyed. Student participation was facilitated through a NASA sponsored university program which enabled the students to complete degrees. Research summaries are provided and plans for the termination of the grant program are outlined. Project topics include: Failure modes for mechanically fastened joints in composite materials; The dynamic stability of an earth orbiting satellite deploying hinged appendages; The analysis of the Losipescu shear test for composite materials; and the effect of boundary layer structure on wing tip vortex formation and decay.

Equations of motion of a space station with emphasis on the effects of the gravity gradient

NASA Technical Reports Server (NTRS)

Tuell, L. P.

1987-01-01

The derivation of the equations of motion is based upon the principle of virtual work. As developed, these equations apply only to a space vehicle whose physical model consists of a rigid central carrier supporting several flexible appendages (not interconnected), smaller rigid bodies, and point masses. Clearly evident in the equations is the respect paid to the influence of the Earth's gravity field, considerably more than has been the custom in simulating vehicle motion. The effect of unpredictable crew motion is ignored.

Bacterial flagellin—a potent immunomodulatory agent

PubMed Central

Hajam, Irshad A; Dar, Pervaiz A; Shahnawaz, Imam; Jaume, Juan Carlos; Lee, John Hwa

2017-01-01

Flagellin is a subunit protein of the flagellum, a whip-like appendage that enables bacterial motility. Traditionally, flagellin was viewed as a virulence factor that contributes to the adhesion and invasion of host cells, but now it has emerged as a potent immune activator, shaping both the innate and adaptive arms of immunity during microbial infections. In this review, we summarize our understanding of bacterial flagellin and host immune system interactions and the role flagellin as an adjuvant, anti-tumor and radioprotective agent, and we address important areas of future research interests. PMID:28860663

Remote chance of recontact

NASA Technical Reports Server (NTRS)

Elkin, D.; Abeyagunawardene, S.; Defazio, R.

1988-01-01

The ejection of appendages with uncertain drag characteristics presents a concern for eventual recontact. Recontact shortly after release can be prevented by avoiding ejection in a plane perpendicular to the velocity. For ejection tangential to the orbit, the likelihood of recontact within a year is high in the absence of drag and oblateness. The optimum direction of ejection of the thermal shield cable and an overestimate of the recontact probability are determined for the Cosmic Background Explorer (COBE) mission when drag, oblateness, and solar/lunar perturbations are present. The probability is small but possibly significant.

Lessons from America? Commercialization and growth of private medicine in Britain.

PubMed

Rayner, G

1987-01-01

This article examines the transition of the private medical sector in Britain from a mere appendage to the National Health Service to a significant business sector involving multinational enterprise. The author argues that private medicine continues to be in a state of flux because its degree of independence is limited by its links to the dominant public sector, particularly with regard to staffing, and is still vulnerable to attacks from the opposition parties. Private medicine, despite rapid growth in the late 1970s, is beset by mounting costs and intense competition.

Syntheses and Biological Studies of Marine Terpenoids Derived from Inorganic Cyanide

PubMed Central

Schnermann, Martin J.; Shenvi, Ryan A.

2015-01-01

Isocyanoterpenes (ICTs) are marine natural products biosynthesized through an unusual pathway that adorns terpene scaffolds with nitrogenous functionality derived from cyanide. The appendage of nitrogen functional groups–isonitriles in particular–onto stereochemically-rich carbocyclic ring systems provides enigmatic, bioactive molecules that have required innovative chemical syntheses. This review discusses the challenges inherent to the synthesis of this diverse family and details the development of the field. We also present recent progress in isolation and discuss key aspects of the remarkable biological activity of these compounds. PMID:25514696

Infrared detector Dewars - Increased LN2 hold time and vacuum jacket life spans

NASA Technical Reports Server (NTRS)

Jennings, D. E.; Boyd, W. J.; Blass, W. E.

1976-01-01

IR detector Dewars commonly suffer from shorter than desired LN2 hold times and insulation jacket vacuum corruption over relatively short time periods. In an attempt to solve this problem for a 9144 detector Dewar, small 1 liter/s appendage ion pumps were selected for continuous pumping of the vacuum jackets. This procedure extended LN2 hold times from 20 to 60 h and virtually eliminated vacuum jacket corruption. Thus the detector systems are usable continuously over periods of 6 months or more.

A study of the dynamics of rotating space stations with elastically connected counterweight and attached flexible appendages. Volume 1: Theory

NASA Technical Reports Server (NTRS)

Austin, F.; Markowitz, J.; Goldenberg, S.; Zetkov, G. A.

1973-01-01

The formulation of a mathematical model for predicting the dynamic behavior of rotating flexible space station configurations was conducted. The overall objectives of the study were: (1) to develop the theoretical techniques for determining the behavior of a realistically modeled rotating space station, (2) to provide a versatile computer program for the numerical analysis, and (3) to present practical concepts for experimental verification of the analytical results. The mathematical model and its associated computer program are described.

Inertia-Wheel Vibration-Damping System

NASA Technical Reports Server (NTRS)

Fedor, Joseph V.

1990-01-01

Proposed electromechanical system would damp vibrations in large, flexible structure. In active vibration-damping system motors and reaction wheels at tips of appendages apply reaction torques in response to signals from accelerometers. Velocity signal for vibrations about one axis processes into control signal to oppose each of n vibrational modes. Various modes suppressed one at a time. Intended primarily for use in spacecraft that has large, flexible solar panels and science-instrument truss assembly, embodies principle of control interesting in its own right and adaptable to terrestrial structures, vehicles, and instrument platforms.

STS-31 Hubble Space Telescope (HST) solar array (SA) deploy aboard OV-103

NASA Image and Video Library

1990-04-25

During STS-31, the Hubble Space Telescope (HST) is held in appendage deploy position by Discovery's, Orbiter Vehicle (OV) 103's, remote manipulator system (RMS) above the payload bay (PLB) and crew compartment cabin. While in this position the solar array (SA) wing bistem cassette (HST center) is deployed from its stowed location along side the Support System Module (SSM) forward shell. A high gain antenna (HGA) remains stowed along the SSM. The Earth's surface and the Earth limb creates a dramatic backdrop.

The synaptic terminations of certain midbrain-olivary fibers in the opossum.

PubMed

King, J S; Hamos, J E; Maley, B E

1978-11-15

The nuclear origin and distribution of midbrain-olivary fibers has been described in a previous study utilizing axonal transport techniques (Linauts and Martin, '78a). The present report extends their results to the electron microscopic level and details the postsynaptic distribution of such fibers. Lesions within the ventral periaqueductal grey and adjacent tegmentum, the red nucleus or the nucleus subparafascicularis result in electron dense axon terminals within the olive at survival times of 48, 72 and 96 hours. At 72 hours, many degenerating presynaptic profiles shrink, become irregular in shape and are totally or partially surrounded by glial processes. The principal olivary nucleus contains the majority of these profiles. However, the subparafascicular terminals are more abundant in the rostral and intermediate parts of the medial accessory nucleus and the rubral terminals are concentrated within the dorsal lamella of the principal nucleus. The nuclear location of the degenerating terminals was determined by examination of 1 micrometer plastic sections cut in the transverse plane from each block face prior to thin sectioning. Degenerating terminals were counted in three cases, one from each of the three lesion sites described above. When taken together these cases show that just over 50% of the degenerating terminals are presynaptic to spiny appendages and are located within the synaptic clusters (glomeruli) described previously (King, '76). The percentage of degenerating terminals in the glomeruli increases to 70% when the lesion is in the ventral periaqueductal grey and adjacent tegmentum. The remaining degenerating terminals contact dendritic shafts outside the astrocytic boundaries of the synaptic clusters. The synpatic vesicle populations within the degenerating terminals vary with the location of the lesion. Lesions in the ventral periaqueductal grey and the adjacent tegmentum result in the degeneration of terminals with either clear spherical vesicles or endings with both clear spherical vesicles and a variable number of large dense core vesicles. In contrast, the primary degenerative changes that occur after destruction of the red nucleus or the nucleus subparafascicularis are in terminals with clear spherical vesicles. When the synaptic complex was present in the plane of section, regardless of the site of the lesion, the degenerating terminals could be classified as Gray's type I. Thus, we have demonstrated that afferents from the mesencephalon terminate within synpatic clusters located in the principal and medial accessory (part A) subnuclei of the inferior olive. Although the mesencephalic afferents have multiple origins (Linauts and Martin, '78a), many of their synaptic terminals contact spiny appendages within the synaptic clusters. This postsynaptic site also receives cerebellar terminals (King et al., '76). The origin of presynaptic profiles within the synaptic clusters that contain clear pleomorphlic vesicles is yet to be determined.

Steady-state MRA techniques with a blood pool contrast agent improve visualization of pulmonary venous anatomy and left atrial patency compared with time-resolved MRA pre- and postcatheter ablation in atrial fibrillation.

PubMed

Rustogi, Rahul; Galizia, Mauricio; Thakrar, Darshit; Merritt, Bryce; Bi, Xiaoming; Collins, Jeremy; Carr, James C

2015-11-01

To compare steady-state magnetic resonance angiography (SS-MRA), using a blood pool contrast agent, with the established technique of time-resolved MRA (TR-MRA), in pulmonary vein mapping and left atrial patency. Twenty-one patients (12 males, age 58.3 ± 8.4 years; 9 females; 57 ± 10 years) undergoing pulmonary vein mapping were evaluated with TR-MRA (TWIST) and SS-MRA. Orthogonal measurements and areas for four veins per patient per technique were assessed by Friedman's test. Overall intertechnique mean difference for any pulmonary vein orthogonal measurement and area was 0.02 ± 0.34 cm (P = 0.705), and 0.2 ± 0.08 cm(2) (P < 0.001). Interobserver correlation was strong for diameter and area measurements using the three methods with a range of 0.72-0.94, and 0.87-0.97, respectively. Left atrial appendage image quality score for TR-MRA was significantly lower than the other two methods (P < 0.001). Both observers detected more stenosis on inversion recovery (IR)-True FISP compared to TR-MRA and IR-FLASH. SS-MRA with a blood pool agent compared favorably to the established technique of TR-MRA for quantitative assessment of pulmonary venous anatomy. SS-MRA offers greater spatial resolution than TR-MRA with increased confidence for ruling out left atrial appendage filling defect. © 2015 Wiley Periodicals, Inc.

Twisting cracks in Bouligand structures.

PubMed

Suksangpanya, Nobphadon; Yaraghi, Nicholas A; Kisailus, David; Zavattieri, Pablo

2017-12-01

The Bouligand structure, which is found in many biological materials, is a hierarchical architecture that features uniaxial fiber layers assembled periodically into a helicoidal pattern. Many studies have highlighted the high damage-resistant performance of natural and biomimetic Bouligand structures. One particular species that utilizes the Bouligand structure to achieve outstanding mechanical performance is the smashing Mantis Shrimp, Odontodactylus Scyllarus (or stomatopod). The mantis shrimp generates high speed, high acceleration blows using its raptorial appendage to defeat highly armored preys. The load-bearing part of this appendage, the dactyl club, contains an interior region [16] that consists of a Bouligand structure. This region is capable of developing a significant amount of nested twisting microcracks without exhibiting catastrophic failure. The development and propagation of these microcracks are a source of energy dissipation and stress relaxation that ultimately contributes to the remarkable damage tolerance properties of the dactyl club. We develop a theoretical model to provide additional insights into the local stress intensity factors at the crack front of twisting cracks formed within the Bouligand structure. Our results reveal that changes in the local fracture mode at the crack front leads to a reduction of the local strain energy release rate, hence, increasing the necessary applied energy release rate to propagate the crack, which is quantified by the local toughening factor. Ancillary 3D simulations of the asymptotic crack front field were carried out using a J-integral to validate the theoretical values of the energy release rate and the local stress intensity factors. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Recent and upcoming randomized trials for left atrial appendage occlusion : Need for a definite assessment of the situation].

PubMed

Skurk, Carsten; Hartung, Johannes Jakob; Landmesser, Ulf

2017-12-01

Atrial fibrillation (AF) is the most common arrhythmia affecting more than 1.6 million patients in Germany. Based on demographic developments, an the number is expected to increase. Embolic strokes in AF patients are particularly severe, and individualized new oral anticoagulant (NOAC) therapy reduces the incidence of stroke in these patients by approximately 70%. Besides vitamin K antagonists, the NOACs rivaroxaban, dabigatran, apixaban, and edoxaban have been introduced into clinical practice; however, major bleeding still occurs at a rate of 2-3% per year. Moreover, randomized studies and real-life registries suggest that >20% of patients with AF and an indication for anticoagulation cannot tolerate chronic oral anticoagulant therapy. Therefore, an alternative method for stroke prevention in AF patients has been developed, i. e., catheter-based exclusion of the left atrial appendage (LAA), a location that is prone for thrombus formation in these patients. The randomized trials of catheter-based LAA occlusion have compared this interventional therapy with vitamin K antagonists. In the future, however, LAA exclusion needs to be compared with NOAC therapy. Moreover, percutaneous LAA exclusion in clinical practice is mostly offered to patients ineligible for long-term oral anticoagulation or with high bleeding risk. However, no controlled, randomized trial data exist for this patient population. These data are needed for appropriate clinical judgment and optimal clinical management. Ongoing studies and scientific questions that are important to define the future for catheter-based LAA closure are discussed in this review.