Science.gov

Sample records for jejunal rotation caused

  1. Primarily Proximal Jejunal Stone Causing Enterolith Ileus in a Patient without Evidence of Cholecystoenteric Fistula or Jejunal Diverticulosis

    PubMed Central

    Mneimneh, Mostapha; Hammoud, Mazen M.; Zaaroura, Ahmed; Papas, Yasmina S.

    2016-01-01

    Stone formation within the intestinal lumen is called enterolith. This stone can encroach into the lumen causing obstruction and surgical emergency. Jejunal obstruction by an enterolith is a very rare entity and often missed preoperatively. To our knowledge, most cases of jejunal obstruction, secondary to stone, were associated with biliary disease (cholecystoenteric fistula), bezoar, jejunal diverticulosis, or foreign body. Hereby we present a rare case report of small bowel obstruction in an elderly man who was diagnosed lately to have primary proximal jejunal obstruction by an enterolith without evidence of a cholecystoenteric fistula or jejunal diverticulosis. This patient underwent laparotomy, enterotomy with stone extraction, and subsequent primary repair of the bowel. PMID:27803836

  2. Primarily Proximal Jejunal Stone Causing Enterolith Ileus in a Patient without Evidence of Cholecystoenteric Fistula or Jejunal Diverticulosis.

    PubMed

    Abtar, Houssam Khodor; Mneimneh, Mostapha; Hammoud, Mazen M; Zaaroura, Ahmed; Papas, Yasmina S

    2016-01-01

    Stone formation within the intestinal lumen is called enterolith. This stone can encroach into the lumen causing obstruction and surgical emergency. Jejunal obstruction by an enterolith is a very rare entity and often missed preoperatively. To our knowledge, most cases of jejunal obstruction, secondary to stone, were associated with biliary disease (cholecystoenteric fistula), bezoar, jejunal diverticulosis, or foreign body. Hereby we present a rare case report of small bowel obstruction in an elderly man who was diagnosed lately to have primary proximal jejunal obstruction by an enterolith without evidence of a cholecystoenteric fistula or jejunal diverticulosis. This patient underwent laparotomy, enterotomy with stone extraction, and subsequent primary repair of the bowel.

  3. Phytobezoar in a jejunal diverticulum as a cause of small bowel obstruction: a case report

    PubMed Central

    2011-01-01

    Introduction Phytobezoars are concretions of poorly digested fruit and vegetable fibers found in the alimentary tract. Previous gastric resection, gastrojejunostomy, or pyloroplasty predispose people to bezoar formation. Small-bowel bezoars normally come from the stomach, and primary small-bowel bezoars are very rare. They are seen only in patients with underlying small-bowel diseases such as diverticula, strictures, or tumors. Primary small-bowel bezoars almost always present as intestinal obstructions, although it is a very rare cause, being responsible for less than 3% of all small-bowel obstructions in one series. Jejunal diverticula are rare, with an incidence of less than 0.5%. They are usually asymptomatic pseudodiverticula of pulsion type, and complications are reported in 10% to 30% of patients. A phytobezoar in a jejunal diverticulum is an extremely rare presentation. Case presentation A 78-year-old Pakistani man presented to our clinic with small-bowel obstruction. Upon exploration, we found a primary small-bowel bezoar originating in a jejunal diverticulum and causing jejunal obstruction. Resection and anastomosis of the jejunal segment harboring the diverticulum was performed, and our patient had an uneventful recovery. Conclusion Primary small-bowel bezoars are very rare but must be kept in mind as a possible cause of small-bowel obstruction. PMID:21951579

  4. Jejunal choristoma: a very rare cause of abdominal pain in children.

    PubMed

    Olajide, T A; Agodirin, S O; Ojewola, R W; Akanbi, O O; Solaja, T O; Odesanya, Johnson Oluremi; Ariyibi, O O

    2014-01-01

    Choristoma is development of a normal tissue in an aberrant location. This report describes jejunal salivary choristoma (JSC) causing recurring episodes of abdominal discomfort in a 5-year-old girl. Exploratory laporatomy revealed a pale yellow subserosal jejunal lesion. Wedge resection of the lesion and repair of the bowel were performed. The child did well postoperatively and has since that time been free of pain at follow-up. Histopathological examination of the resected lesion revealed salivary gland choriostoma. Literature review (PUBMED search engine) revealed no previous report of this rare clinicopathologic entity. We conclude that choriostoma should be considered a possible differential when evaluating abdominal complaint in children.

  5. One of the Rare Causes of Acute Abdomen Leading to Subileus: Jejunal Diverticulitis

    PubMed Central

    Aydın, Elçin; Yerli, Hasan; Avcı, Tevfik; Yılmaz, Tuğbahan; Gülay, Hüseyin

    2016-01-01

    Background: Jejunal diverticulitis is one of the rare causes of acute abdomen generally seen in the elderly. Jejunal diverticulosis was defined as the herniation of the mucosa and the submucosa from the inside of the muscular layer of the bowel wall on the mesenteric side of the intestine. Case Report: We presented the intraoperative and pathological findings of a 69-year-old male patient who had presented with complaints about abdominal pain, nausea, and vomiting and been operated upon due to subileus and peritonitis induced by large-sized jejunal diverticulitis, along with his computed tomography (CT) findings. Conclusion: Jejunal diverticulitis is uncommon and may be a disease which might be difficult to diagnose when it develops on the basis of the large-sized diverticula resembling intestinal ansae. To the best of our knowledge, the computed tomography and intraoperative findings of a case in which partial resection is applied to the jejunum due to subileus have not been previously presented in the literature. PMID:27308082

  6. Jejunal intussusception caused by a huge Vanek's tumor: a case report

    PubMed Central

    Neishaboori, Hassan; Emadian, Omid

    2013-01-01

    Inflammatory fibroid polyp (known also as Vanek's tumor) is a type of localized, non-neoplastic inflammatory pseudotumor or inflammatory myofibroblastic tumor that occurs most commonly in the stomach but also in the small and large bowel. It is a documented cause of intussusception in adults. We report a case of a 40-year-old woman who presented with severe, postprandial abdominal pain followed by projectile vomiting over a period of three days. Ultrasonography demonstrated a solid and echogenic mass surrounded by the typical mural layers of an invaginated jejunum. She underwent urgent laparotomy and resection of an 18 cm tumor from the distal jejunum. The immuno-histopathological diagnosis after segmental jejunal resection was a jejunal inflammatory fibroid polyp. Although inflammatory fibroid polyps are seen very rarely in adults, they are among the probable diagnoses that should be considered in obstructive tumors of the small bowel causing intussusceptions. PMID:24834274

  7. Jejunal Diverticulitis Ascending to the Duodenum as a Rare Cause of Acute Abdomen

    PubMed Central

    Fresow, Robert; Kamusella, Peter; Talanow, Roland; Andresen, Reimer

    2014-01-01

    We present the case of a 73 year-old Caucasian male with acute abdominal pain, peritonism and vomiting. Due to the severity of symptoms a CT examination of the abdomen was performed. The scans revealed multiple jejunal diverticula, wall thickening of the duodenum and jejunum, and free peritoneal fluid. No clear signs of mesenteric infarction, free abdominal air or abscess formation were seen. An additional exploratory laparotomy was conducted to confirm the CT findings and rule out the need for resection of small bowel. Since the results were matching, conservative therapy was scheduled and the patient recovered well. Jejunal diverticulitis is a rare cause of acute abdomen, however has to be considered as a differential diagnosis to more common entities. It usually stays localized, while in our case the inflammation ascended to the duodenum. CT is the modality of choice to diagnose and rule out potentially life threatening complications. PMID:25302248

  8. Toxoplasma gondii causes death and plastic alteration in the jejunal myenteric plexus

    PubMed Central

    Araújo, Eduardo José de Almeida; Zaniolo, Larissa Marchi; Vicentino, Suellen Laís; Góis, Marcelo Biondaro; Zanoni, Jacqueline Nelisis; da Silva, Aristeu Vieira; Sant’Ana, Débora de Mello Gonçales

    2015-01-01

    AIM: To assess the effects of ME-49 Toxoplasma gondii (T. gondii) strain infection on the myenteric plexus and external muscle of the jejunum in rats. METHODS: Thirty rats were distributed into two groups: the control group (CG) (n = 15) received 1 mL of saline solution orally, and the infected group (IG) (n = 15) inoculated with 1 mL of saline solution containing 500 oocysts of M-49 T. gondii strain orally. After 36 d of infection, the rats were euthanized. Infection with T. gondii was confirmed by blood samples collected from all rats at the beginning and end of the experiment. The jejunum of five animals was removed and submitted to routine histological processing (paraffin) for analysis of external muscle thickness. The remaining jejunum from the others animals was used to analyze the general population and the NADH-diaphorase, VIPergic and nitrergic subpopulations of myenteric neurons; and the enteric glial cells (S100-IR). RESULTS: Serological analysis showed that animals from the IG were infected with the parasite. Hypertrophy affecting jejunal muscle thickness was observed in the IG rats (77.02 ± 42.71) in relation to the CG (51.40 ± 12.34), P < 0.05. In addition, 31.2% of the total number of myenteric neurons died (CG: 39839.3 ± 5362.3; IG: 26766.6 ± 2177.6; P < 0.05); hyperplasia of nitrergic myenteric neurons was observed (CG: 7959.0 ± 1290.4; IG: 10893.0 ± 1156.3; P < 0.05); general hypertrophy of the cell body in the remaining myenteric neurons was noted [CG: 232.5 (187.2-286.0); IG: 248.2 (204.4-293.0); P < 0.05]; hypertrophy of the smallest varicosities containing VIP neurotransmitter was seen (CG: 0.46 ± 0.10; IG: 0.80 ± 0.16; P < 0.05) and a reduction of 25.3% in enteric glia cells (CG: 12.64 ± 1.27; IG: 10.09 ± 2.10; P < 0.05) was observed in the infected rats. CONCLUSION: It was concluded that infection with oocysts of ME-49 T. gondii strain caused quantitative and plastic alterations in the myenteric plexus of the jejunum in rats. PMID

  9. Foreign Body Penetration through Jejunal Loops Causing Renal Artery Thrombosis and Renal Infarct

    PubMed Central

    El-Charabaty, Elie; Nasr, Patricia; Barakat, Iskandar; Andrawes, Sherif

    2017-01-01

    Foreign body ingestion is common, although perforation after ingestion is rare. We report a case of an ingested sharp wooden stick that perforated the proximal jejunum toward the renal vasculature, causing segmental renal artery thrombosis and renal infarct. The patient presented with severe abdominal pain and vomiting. A computed tomography scan revealed a linear opacity corresponding to the foreign body. The wooden stick was removed endoscopically through deep-push enteroscopy with a rat-tooth forceps. We report this unique case of perforation by a foreign body through the proximal jejunum to the left kidney, which was managed endoscopically. PMID:28144617

  10. Ruptured jejunal artery aneurysm

    PubMed Central

    Costa, Sílvia; Costa, Alexandre; Pereira, Tiago; Maciel, Jorge

    2013-01-01

    Visceral artery aneurysms (VAAs), unlike aortic aneurysms, are very rare, but are also a potentially lethal vascular disease. Jejunal artery aneurysms only account for less than 3% of VAAs, but have a 30% risk of rupture, with 20% death rate, presenting with only few and vague symptoms. We report the case of a 76-year-old man presenting at the emergency department (ED) with a crampy epigastric pain and vomiting. An ultrasound performed diagnosed free abdominal fluid and immediate CT scan diagnosed jejunal artery aneurysm spontaneously rupturing, followed by hypovolaemic shock. Emergent surgery was undertaken, and aneurysmectomy, followed by partial enterectomy with primary anastomosis were performed, because of segmentary jejunal ischaemia. The patient's recovery was unremarkable. High level of suspicion, rapid diagnosis capability and prompt surgical or endovascular intervention, as well as an effective teamwork in the ED are critical to avoid the devastating consequences of ruptured VAAs. PMID:23771962

  11. Rare Jejunal Diverticular Bleeding

    PubMed Central

    Christman, Emily; Hassell, Lewis A.; Kastens, Donald

    2016-01-01

    Severe gastrointestinal bleeding (GIB) secondary to jejunal diverticulosis (JD) is very rare. Delay in establishing a diagnosis is common and GIB from JD is associated with significant morbidity and mortality. We report an illustrative case diagnosed by push enteroscopy and managed with surgery. PMID:27800518

  12. Perforation of jejunal diverticulum with ectopic pancreas.

    PubMed

    Shiratori, Hiroshi; Nishikawa, Takeshi; Shintani, Yukako; Murono, Koji; Sasaki, Kazuhito; Yasuda, Koji; Otani, Kensuke; Tanaka, Toshiaki; Kiyomatsu, Tomomichi; Hata, Keisuke; Kawai, Kazushige; Nozawa, Hiroaki; Ishihara, Soichiro; Fukayama, Masashi; Watanabe, Toshiaki

    2017-04-01

    Perforation of jejunal diverticulum is a rare complication. Here, we report a case of jejunal diverticulum penetration with surrounding ectopic pancreas. An 83-year-old female patient was admitted to our department with acute onset of severe abdominal pain lasting for half a day. Abdominal computed tomography showed outpouching of the small intestine that contained air/fluid, with multiple surrounding air bubbles in the mesentery of the small intestine. She was diagnosed with penetration of the small intestine, and an emergency laparotomy was indicated. The penetrated jejunal diverticulum was identified ~20-cm distal to the ligament of Treitz. Partial resection of the jejunum was performed, and her postoperative course was uneventful. The pathological findings confirmed diverticulum penetration into the mesentery and severe inflammation at the site, with surrounding ectopic pancreas. Furthermore, the pancreatic ducts were opened through the penetrated diverticulum. This rare case shows that the ectopic pancreas might have caused penetration of jejunal diverticulum owing to the pancreatic duct opening through the diverticulum.

  13. Rotator Cuff Damage: Reexamining the Causes and Treatments.

    ERIC Educational Resources Information Center

    Nash, Heyward L.

    1988-01-01

    Sports medicine specialists are beginning to reexamine the causes and treatments of rotator cuff problems, questioning the role of primary impingement in a deficient or torn cuff and trying new surgical procedures as alternatives to the traditional open acromioplasty. (Author/CB)

  14. Free jejunal flaps can be monitored by use of microdialysis.

    PubMed

    Sorensen, Hanne Birke

    2008-08-01

    When new combinations of preoperative treatments of carcinoma of the esophagus are implemented, surgical morbidity and mortality become even more important risk factors. This study investigated whether the risk of postoperative complications caused by ischemia in the reconstructed esophagus can be reduced using microdialysis as monitoring method. This is a retrospective study of 14 patients undergoing resection of carcinoma in the upper part of the esophagus and reconstruction with a free jejunal flap. The metabolism in all 14 jejunal transfers was monitored by use of microdialysis. The data were analyzed looking for reliable parameters detecting critical ischemia. Critical ischemia was suspected in two cases. Both of these cases were surgically revised, ischemia in the jejunal flap was verified, and the jejunal flaps were revascularized. All 14 jejunal flaps survived. Using the concentration of glucose in the microdialysate, it was possible to detect the two cases of critical ischemia. Yet, the most reliable parameter seemed to be the retrospectively calculated lactate:glucose ratio; in both the ischemic flaps, the lactate:glucose ratio exceeded more than 1000% the maximum values found in all the nonischemic flaps. Microdialysis is a promising monitoring method for surveillance of free jejunal flaps.

  15. Differential Rotation and Angular Momentum Transport Caused by Thermal Convection in a Rotating Spherical Shell

    NASA Astrophysics Data System (ADS)

    Takehiro, S.; Sasaki, Y.; Hayashi, Y.-Y.; Yamada, M.

    2013-12-01

    We investigate generation mechanisms of differential rotation and angular momentum transport caused by Boussinesq thermal convection in a rotating spherical shell based on weakly nonlinear numerical calculations for various values of the Prandtl and Ekman numbers under a setup similar to the solar convection layer. When the Prandtl number is of order unity or less and the rotation rate of the system is small (the Ekman number is larger than O(10-2)), the structure of thermal convection is not governed by the Taylor-Proudman theorem; banana-type convection cells emerge which follow the spherical shell boundaries rather than the rotation axis. Due to the Coriolis effect, the velocity field associated with those types of convection cells accompanies the Reynolds stress which transports angular momentum from high-latitudes to the equatorial region horizontally, and equatorial prograde flows are produced. The surface and internal distributions of differential rotation realized in this regime are quite similar to those observed in the Sun with helioseismology. These results may suggest that we should apply larger values of the eddy diffusivities than those believed so far when we use a low resolution numerical model for thermal convection in the solar interior.

  16. A Rare Case of Jejunal Atresia Due to Intrauterine Intussusception

    PubMed Central

    Kinhal, Vidyadhar; Desai, Mahesh; Tilak; Choudhari, Fazal UR Rehman

    2015-01-01

    Intestinal atresia is generally caused by intrauterine vascular obstructions involving mesenteric vessels. Intrauterine intussusceptions (IUI) are one of these disruptive events. Intestinal intussusceptions affects children commonly between 3 months and 3 years of age, but it rarely affects in intrauterine life. The relationship between intrauterine intussusception and intestinal atresia has been demonstrated by few cases in literature, suggesting intrauterine intussusception as a rare cause of intestinal atresia. We report a 7-day-old full term neonate presenting with intrauterine intussusceptions (jejuno-jejunal) resulting in jejunal atresia. PMID:26500958

  17. A Rare Case of Jejunal Atresia Due to Intrauterine Intussusception.

    PubMed

    Joshi, Sanjeev B; Kinhal, Vidyadhar; Desai, Mahesh; Tilak; Choudhari, Fazal Ur Rehman

    2015-09-01

    Intestinal atresia is generally caused by intrauterine vascular obstructions involving mesenteric vessels. Intrauterine intussusceptions (IUI) are one of these disruptive events. Intestinal intussusceptions affects children commonly between 3 months and 3 years of age, but it rarely affects in intrauterine life. The relationship between intrauterine intussusception and intestinal atresia has been demonstrated by few cases in literature, suggesting intrauterine intussusception as a rare cause of intestinal atresia. We report a 7-day-old full term neonate presenting with intrauterine intussusceptions (jejuno-jejunal) resulting in jejunal atresia.

  18. Eagle Syndrome Causing Vascular Compression with Cervical Rotation: Case Report

    PubMed Central

    Demirtaş, Hakan; Kayan, Mustafa; Koyuncuoğlu, Hasan Rıfat; Çelik, Ahmet Orhan; Kara, Mustafa; Şengeze, Nihat

    2016-01-01

    Summary Background Eagle syndrome is a condition caused by an elongated styloid process. Unilateral face, neck and ear pain, stinging pain, foreign body sensation and dysphagia can be observed with this syndrome. Rarely, the elongated styloid process may cause pain by compressing the cervical segment of the internal carotid and the surrounding sympathetic plexus, and that pain spreading along the artery can cause neurological symptoms such as vertigo and syncope. Case Report In this case report we presented a very rare eagle syndrome with neurological symptoms that occurred suddenly with cervical rotation. The symptoms disappeared as suddenly as they occurred, with the release of pressure in neutral position. We also discussed CT angiographic findings of this case. Conclusions Radiological diagnosis of the Eagle syndrome that is manifested with a wide variety of symptoms and causes diagnostic difficulties when it is not considered in the differential diagnosis is easy in patients with specific findings. CT angiography is a fast and effective examination in terms of showing compression in patients with the Eagle syndrome that is considered to be atypical and causes vascular compression. PMID:27354882

  19. Non-occlusive mesenteric ischaemia of a free jejunal flap.

    PubMed

    Onoda, Satoshi; Kimata, Yoshihiro; Yamada, Kiyoshi; Koshimune, Seijiro; Onoda, Tomoo; Shirakawa, Yasuhiro

    2013-05-01

    Free jejunal transfer using microsurgery after oesophageal or pharyngeal cancer resection is a useful operative approach. However, the disadvantage of free tissue transfer is the risk of necrosis of the transferred tissue due to impaired blood supply. In addition, jejunal flaps are more prone to blood-flow disorders such as ischaemia and congestion compared with other types of flaps. The causes of local blood supply disorders after microsurgery are divided broadly into two classes: one is thrombosis of an artery and/or vein in the anastomotic region and the other consists of local physical factors such as compressive pressure derived from haematoma formation and the effect of infection of the vascular pedicle. In this report, two rare cases of blood-flow disorder of the transferred free jejunum are described. In both cases, no signs of significant infection or occlusion of the vascular pedicles were present and late necrosis progressed gradually. The patients showed remarkable weight loss and a poor nutritional state due to inadequate preoperative nutritional intake. The necrosis was considered to be a result of non-occlusive mesenteric ischaemia of a free jejunal flap, and the factors contributing to free jejunal necrosis were reviewed.

  20. Jejunal Epiphany: Diverticulae, Enteroliths and Strictures

    PubMed Central

    Rehmani, Babar; Kumar, Navin

    2016-01-01

    Multiple jejunal diverticulae represent a rare entity and are usually asymptomatic. This case report is about one such jejunal diverticulae along with multiple enteroliths and jejunal strictures. All these three different findings in a short segment of jejunum is a very rare finding with all three variants seen in a segment of jejunum. We herein present a case of a 45-year-old male, who presented with vague abdominal pain for one and half years associated with nausea and vomiting and altered bowel habits. Laparotomy revealed multiple large jejunal diverticulae compressing the bowel with multiple enteroliths and two strictures in a short segment of jejunum leading to intestinal obstruction. Patient underwent resection of the involved jejunal segment and then repair by anastomosis. Post-operative period was uneventful. PMID:28208925

  1. Stacking transition in bilayer graphene caused by thermally activated rotation

    NASA Astrophysics Data System (ADS)

    Zhu, Mengjian; Ghazaryan, Davit; Son, Seok-Kyun; Woods, Colin R.; Misra, Abhishek; He, Lin; Taniguchi, Takashi; Watanabe, Kenji; Novoselov, Kostya S.; Cao, Yang; Mishchenko, Artem

    2017-03-01

    Crystallographic alignment between two-dimensional crystals in van der Waals heterostructures brought a number of profound physical phenomena, including observation of Hofstadter butterfly and topological currents, and promising novel applications, such as resonant tunnelling transistors. Here, by probing the electronic density of states in graphene using graphene-hexagonal boron nitride-graphene tunnelling transistors, we demonstrate a structural transition of bilayer graphene from incommensurate twisted stacking state into a commensurate AB stacking due to a macroscopic graphene self-rotation. This structural transition is accompanied by a topological transition in the reciprocal space and by pseudospin texturing. The stacking transition is driven by van der Waals interaction energy of the two graphene layers and is thermally activated by unpinning the microscopic chemical adsorbents which are then removed by the self-cleaning of graphene.

  2. [A case of jejunal perforation in gallstone ileus].

    PubMed

    Taira, Akiko; Yamada, Masami; Takehira, Yasunori; Kageyama, Fujito; Yoshii, Shigeto; Murohisa, Gou; Yoshida, Kenichi; Iwaoka, Yasushi; Terai, Tomohiro; Uotani, Takahiro; Watanabe, Shinya; Noritake, Hidenao; Ikematu, Yoshito; Kanai, Toshikazu

    2008-04-01

    Gallstone ileus is a rare but important cause of small bowel obstruction in the geriatric population. A 65-year-old man with a twenty year history of cholecystolithiasis was admitted to our hospital with abdominal pain and vomiting. Physical exams showed abdominal defence and rebound tenderness. A plain abdominal X-ray suggested a small bowel obstruction and pneumobilia. CT scan revealed a 2.5-cm gallstone at the jejunum and air in the biliary tree. The patient underwent a emergency laparotomy based on a diagnosis of panperitonitis with a perforation associated with gallstone ileus. Operative findings revealed a jejunal perforation and a impacted stone on the anal side of perforation. Enterolithotomy and jejunal resection were performed with cholecystectomy and repairment of the cholecystoduodenal fistula.

  3. Modulatory effects of taurine on jejunal contractility.

    PubMed

    Yao, Q Y; Chen, D P; Ye, D M; Diao, Y P; Lin, Y

    2014-12-01

    Taurine (2-aminoethanesulfonic acid) is widely distributed in animal tissues and has diverse pharmacological effects. However, the role of taurine in modulating smooth muscle contractility is still controversial. We propose that taurine (5-80 mM) can exert bidirectional modulation on the contractility of isolated rat jejunal segments. Different low and high contractile states were induced in isolated jejunal segments of rats to observe the effects of taurine and the associated mechanisms. Taurine induced stimulatory effects on the contractility of isolated rat jejunal segments at 3 different low contractile states, and inhibitory effects at 3 different high contractile states. Bidirectional modulation was not observed in the presence of verapamil or tetrodotoxin, suggesting that taurine-induced bidirectional modulation is Ca(2+) dependent and requires the presence of the enteric nervous system. The stimulatory effects of taurine on the contractility of isolated jejunal segments was blocked by atropine but not by diphenhydramine or by cimetidine, suggesting that muscarinic-linked activation was involved in the stimulatory effects when isolated jejunal segments were in a low contractile state. The inhibitory effects of taurine on the contractility of isolated jejunal segments were blocked by propranolol and L-NG-nitroarginine but not by phentolamine, suggesting that adrenergic β receptors and a nitric oxide relaxing mechanism were involved when isolated jejunal segments were in high contractile states. No bidirectional effects of taurine on myosin phosphorylation were observed. The contractile states of jejunal segments determine taurine-induced stimulatory or inhibitory effects, which are associated with muscarinic receptors and adrenergic β receptors, and a nitric oxide associated relaxing mechanism.

  4. Complicated Jejunal Diverticulosis: Small Bowel Volvulus with Obstruction

    PubMed Central

    Mohi, Rommel Singh; Moudgil, Ashish; Bhatia, Suresh Kumar; Seth, Kaushal; Kaur, Tajinder

    2016-01-01

    The incidence of the diverticulum of the small bowel varies from 0.2-1.3% in autopsy studies to 2.3% when assessed on enteroclysis. It occurs mostly in patients in the 6th decade of their life. Of all the small bowel diverticuli, jejunal diverticulum is the most common type. This rare entity is usually asymptomatic. However, they may cause chronic non-specific symptoms for a long period of time like dyspepsia, chronic postprandial pain, nausea, vomiting, borborgymi, alternating diarrhoea and constipation, weight loss, anaemia, steatorrhea or rarely lead to complications like haemorrhage, obstruction, perforation. Obstruction can be due to enterolith, adhesions, intussusception, and volvulus. The condition is difficult to diagnose because patients are generally presented with symptoms that mimic other diseases. It is important for clinicians to have awareness of this entity. Here, we present a case of multiple jejunal diverticuli with a history of repeated attacks of diverticulitis over past 20 years, which were misdiagnosed and now presented with intestinal obstruction due to volvulus of the involved segment along with mesentery around its axis. Resection of the diverticuli segment of jejunum was done with end-to-end jejuno-jejunal anastomosis. The patient is asymptomatic since 10 months of follow-up. PMID:27853337

  5. Spontaneous Intra-Abdominal Hemorrhage Due to Rupture of Jejunal Artery Aneurysm in Behcet Disease

    PubMed Central

    Wu, Xiao-yan; Wei, Jiang-peng; Zhao, Xiu-yuan; Wang, Yue; Wu, Huan-huan; Shi, Tao; Liu, Tong; Liu, Gang

    2015-01-01

    Abstract Rupture of jejunal artery aneurysm is a very rare event resulting in life-threatening hemorrhage in Behcet disease (BD). We report a case of ruptured jejunal artery aneurysm in a 35-year-old patient with BD. The patient had a 1-year history of intermittent abdominal pain caused by superior mesenteric artery aneurysm with thrombosis. Anticoagulation treatment showed a good response. Past surgical history included stenting for aortic pseudoaneurysm. On admission, the patient underwent an urgent operation due to sudden hemorrhagic shock. Resection was performed for jejunal artery aneurysm and partial ischemia of intestine. The patient was diagnosed with BD, based on a history of recurrent oral and skin lesions over the past 6 years. Treatment with anti-inflammatory medications showed a good response during the 8-month follow-up. An increased awareness of BD and its vascular complications is essential. Aneurysms in BD involving jejunal artery are rare, neglected and require proper management to prevent rupture and death. To our knowledge, this is the first reported case of jejunal artery aneurysm caused by BD. PMID:26559278

  6. Anthropogenic versus Seismogenic Causes of the Rotation of a Lycian Sarcophagus in Pinara, SW-Turkey

    NASA Astrophysics Data System (ADS)

    Hinzen, Klaus-G.; Schreiber, Stephan; Yerli, Baris

    2010-05-01

    A Lycian sarcophagus located in the ancient city of Pınara, southwest Turkey, shows a clockwise rotation of 5.37° with respect to its North-South oriented foundation. The city of Pınara was occupied from the Lycian period, through Roman times to the Byzantine era. Considering the seismotectonic potential of the area and numerous other indications of earthquake related damages in the archaeological site, this rotation has also been attributed to earthquake ground motion before. We present a 3D model of the sarcophagus constructed out of 12 million points from a 3D laser scan. The sarcophagus has a foundation block directly worked out of the outcropping rock. On top of this is a 2.46 x 1.67 m and 0.91 m high base block on which the 1.64 m high coffin and lid of the same height are resting. The sarcophagus shows a crater in the eastern side of the coffin, which was most probably caused by the detonation of an explosive charge during a looting attempt. The direction of the rotation agrees with the sense expected from the blast. Therefore the question arises whether the rotation has a natural, seismogenic, or an anthropogenic cause. A rigid block model of the sarcophagus with a total weight of 26.5 t was derived from the laser scan with application of CAD. With the rigid block model we studied the feasibility of two alternative sources as the cause for the rotation of the coffin: an explosion and earthquake ground motion. Scaled recorded ground motions from local earthquakes and a strong motion record from the recent L'Aquila, Italy, earthquake were used to study the sarcophagus dynamic reactions to earthquake motions. The geometry of the structure requires large ground motion amplitudes to initiate rocking. However, rocking is necessary to produce rotation around the vertical axis by translational movements. The size of the explosion is back calculated from the crater size and compared to the duration and amplitude of an impulse necessary to rotate the coffin. All

  7. Demanding response time requirements on coherent receivers due to fast polarization rotations caused by lightning events.

    PubMed

    Krummrich, Peter M; Ronnenberg, David; Schairer, Wolfgang; Wienold, Daniel; Jenau, Frank; Herrmann, Maximilian

    2016-05-30

    Lightning events can cause fast polarization rotations and phase changes in optical transmission fibers due to strong electrical currents and magnetic fields. Whereas these are unlikely to affect legacy transmission systems with direct detection, different mechanisms have to be considered in systems with local oscillator based coherent receivers and digital signal processing. A theoretical analysis reveals that lightning events can result in polarization rotations with speeds as fast as a few hundred kRad/s. We discuss possible mechanisms how such lightning events can affect coherent receivers with digital signal processing. In experimental investigations with a high current pulse generator and transponder prototypes, we observed post FEC errors after polarization rotation events which can be expected from lightning strikes.

  8. Causes of variability in plasmasphere rotation rate: IMAGE EUV observations (Invited)

    NASA Astrophysics Data System (ADS)

    Galvan, D. A.; Moldwin, M.; Sandel, B. R.; Crowley, G.

    2010-12-01

    IMAGE EUV observations demonstrate that the plasmasphere usually does not corotate as assumed in simple convection models, even at low L shells. The prevailing hypothesis states that plasmaspheric subcorotation is due to enhanced auroral zone Joule heating which drives equatorward thermospheric winds. As the neutral thermospheric material moves to lower latitudes, it grows farther from the Earth’s spin axis and turns westward to conserve angular momentum. This induces a westward motion in the ionosphere (a subcorotation), which produces a change in the corotation electric field that maps out to the plasmasphere, causing a subcorotation there as well. We test this hypothesis by searching for a correlation between plasmaspheric rotation rates and several geomagnetic indices (used as proxies for enhanced Joule heating in the auroral zone). We carry out a statistical survey of plasmaspheric rotation rates over several months of IMAGE EUV data in 2001, using two different measurement techniques. Azimuthal features such as “notches” are tracked in local time over a single pass of the IMAGE satellite, both visually and using an automated cross-correlation routine. Each technique provides an estimate of the plasmasphere’s rotation rate. We find a weak correlation between rotation rate and Dst, Kp, AE, the midnight boundary index (MBI), and Joule heating estimates from assimilative mapping of ionospheric electrodynamics (AMIE) at L = 2.5, but not at L = 3.5. In general, lower rotation rates correspond to higher auroral and geomagnetic activity. We also make the first direct observation of plasmaspheric superrotation. The rotation rate is found to be highly variable on multi-day timescales, but the typical state of the plasmasphere is subcorotation, with inferred mean values ranging from 88% to 95% of corotation, depending on L shell. In addition, a statistical analysis shows that rotation rates near dusk are generally lower than those at dawn, suggesting that local

  9. On the Cause of Solar Differential Rotations in the Solar Interior and Near the Solar Surface

    NASA Astrophysics Data System (ADS)

    Lyu, L.

    2012-12-01

    A theoretical model is proposed to explain the cause of solar differential rotations observed in the solar interior and near the solar surface. We propose that the latitudinal differential rotation in the solar convection zone is a manifestation of an easterly wind in the mid latitude. The speed of the easterly wind is controlled by the magnitude of the poleward temperature gradient in the lower part of the solar convection zone. The poleward temperature gradient depends on the orientation and strength of the magnetic fields at different latitudes in the solar convection zone. The north-south asymmetry in the wind speed can lead to north-south asymmetry in the evolution of the solar cycle. The easterly wind is known to be unstable for a west-to-east rotating star or planet. Based on the observed differential rotations in the solar convection zone, we can estimate the easterly wind speed at about 60-degree latitude and determine the azimuthal wave number of the unstable wave modes along the zonal flow. The lowest azimuthal wave number is about m=7~8. This result is consistent with the average width of the elephant-trunk coronal hole shown in the solar X-ray images. The nonlinear evolution of the unstable easterly wind can lead to transpolar migration of coronal holes and can change the poloidal magnetic field in a very efficient way. In the study of radial differential rotation near the solar surface, we propose that the radial differential rotation depends on the radial temperature gradient. The radial temperature gradient depends on the magnetic field structure above the solar surface. The non-uniform magnetic field distribution above the solar surface can lead to non-uniform radial convections and formation of magnetic flux rope at different spatial scales. The possible cause of continuous formation and eruption of prominences near an active region will also be discussed.

  10. Crystal settling and crystal growth caused by Ostwald Ripening in a terrestrial magma ocean under rotation

    NASA Astrophysics Data System (ADS)

    Maas, C.; Moeller, A.; Hansen, U.

    2013-12-01

    About 4.5 billion years ago the earth was covered by a heavily convecting and rotating global magma ocean which was caused by an impact of a mars-sized impactor in a later stage of the earth's accretion. After the separation of metal and silicate (see A. Möller, U. Hansen (2013)) and the formation of the earth's core it began to crystallize. Small silicate crystals emerge and grow by Ostwald Ripening when the fluid is supersaturated. This process results in shrinking of small crystals and growing of large crystals on behalf of the smaller ones. This leads to an altering of the crystal settling time. One question which is still under great debate is whether fractional or equilibrium crystallization occurred in the magma ocean. Fractional crystallization means that different mineral fractions settle one after the other which would lead to a strongly differentiated mantle after solidification of the magma ocean. In contrast to that equilibrium crystallization would result in a well mixed mantle. Whether fractional or equilibrium crystallization occurred is for example important for the starting model of plate tectonics or the understanding of the mantle development until today. To study the change of crystal radius in a convecting and rotating magma ocean we employed a 3D numerical model. Due to the low viscosity and strong rotation the influence of rotation on the early magma Ocean cannot be neglected. In the model the crystals are able to influence each other and the fluid flow. They are able to grow, shrink, vanish and form and gravitational, Coriolis and drag forces due to the fluid act on them. In our present work we study the crystal settling depending on different rotation rates and rotation axes with two configurations. For the polar setting the rotation axis is parallel, at the equator it is perpendicular to gravity. Low rotation at the pole leads to a large fraction of suspended crystals. With increasing rotation the crystals settle and form a thick layer

  11. Calcium mediation of the pig jejunal secretory response.

    PubMed Central

    Forsyth, G W; Wong, P H; Maenz, D D

    1985-01-01

    The involvement of Ca++ ions as secretory mediators in pig jejunal epithelia has been investigated with an in vitro system. Omission of Ca++ from the Ringer-HCO3 bathing media on both sides of the tissue had minor effects on the basal electrical activity of pig jejunal mucosa. There were only slight decreases in transepithelial potential difference and increases in conductance with Ca++ free media. Low EGTA concentrations which reversibly blocked potential difference responses to secretory agents also had minimal effects on basal electrical activity. The in vitro secretory responses to A23187, to theophylline, and to Escherichia coli heat-stable enterotoxin were all eliminated by Ca++ depletion and restored by replacing normal Ca++ concentrations in the bathing media. Dantrolene prevented the secretory response but not the potential difference increases caused by heat-stable enterotoxin and A23187, suggesting that intracellular Ca++ stores may be reservoirs of secretory signal agent. Verapamil only blocked the secretory response to heat-stable enterotoxin. Chlorpromazine had negligible effects on basal conditions, but totally blocked both the secretory response and the Ca++-dependent effects of A23187 and heat-stable enterotoxin on potential difference. The response to theophylline was only partially inhibited by chlorpromazine, implying some involvement of both cAMP and Ca++ as secretory signals for theophylline. Cytoplasmic Ca++ concentrations appear to be at least as important as cyclic nucleotides in regulating the secretory effects of pig jejunum. PMID:2410089

  12. Jejunal water and electrolyte secretion induced by L-arginine in man.

    PubMed Central

    Hegarty, J E; Fairclough, P D; Clark, M L; Dawson, A M

    1981-01-01

    In this study a perfusion technique has been used to investigate jejunal secretion in response to the dibasic amino acid L-arginine. L-arginine at 5, 15, and 40 mmol/l in isotonic saline solutions induced net intestinal secretion of water and Na+. The structurally similar dibasic amino acid L-lysine caused net absorption at 5 and 15 mmol/l, and only modest net secretion of water and Na+ at 40 mmol/l, although absorption rates of the two amino acids were similar. D-arginine (15 mmol/l) was without effect on net water and Na+ absorption. L-arginine 15 mmol/l inhibited glucose-stimulated water and Na+ absorption when perfused in the same intestinal segment, but was without effect when perfused in separate jejunal or ileal segments. Parenteral chlorpromazine inhibited L-arginine induced jejunal water and Na+ secretion. Jejunal secretion induced by L-arginine thus appears not to be due to passive osmotic water flow, nor to release of circulating secretagogues. Stimulation of a mucosal secretory process is most likely to be the mechanism. PMID:6783480

  13. On the experimental prediction of the stability threshold speed caused by rotating damping

    NASA Astrophysics Data System (ADS)

    Vervisch, B.; Derammelaere, S.; Stockman, K.; De Baets, P.; Loccufier, M.

    2016-08-01

    An ever increasing demand for lighter rotating machinery and higher operating speeds results in a raised probability of instabilities. Rotating damping is one of the reasons, instability occurs. Rotating damping, or rotor internal damping, is the damping related to all rotating parts while non-rotating damping appearing in the non-rotating parts. The present study describes a rotating setup, designed to investigate rotating damping experimentally. An efficient experimental procedure is presented to predict the stability threshold of a rotating machine. The setup consists of a long thin shaft with a disk in the middle and clamped boundary conditions. The goal is to extract the system poles as a function of the rotating speed. The real parts of these poles are used to construct the decay rate plot, which is an indication for the stability. The efficiency of the experimental procedure relies on the model chosen for the rotating shaft. It is shown that the shaft behavior can be approximated by a single degree of freedom model that incorporates a speed dependent damping. As such low measurement effort and only one randomly chosen measurement location are needed to construct the decay rate plot. As an excitation, an automated impact hammer is used and the response is measured by eddy current probes. The proposed method yields a reliable prediction of the stability threshold speed which is validated through measurements.

  14. Delayed jejunal perforation after laparoscopic cholecystectomy

    PubMed Central

    Browne, Ikennah L.; Dixon, Elijah

    2016-01-01

    Bowel perforation is a rare complication of laparoscopic cholecystectomy, which if left undiagnosed can have fatal consequences. In addition, isolated small bowel perforation is extremely rare and should be considered in patients presenting with sudden onset abdominal pain in the postoperative period. A 57-year-old male with symptomatic gallstones underwent urgent laparoscopic cholecystectomy and was discharged home on postoperative day (POD) 1 without complications. He presented to the emergency department on POD 11 complaining of sudden onset abdominal pain. A CT scan did not confirm a diagnosis and he was admitted for observation. On post admission day 2, he became significantly peritonitic and laparotomy revealed jejunal perforation. Bowel resection with hand-sewn anastomosis was completed and he was discharged on POD 10. Follow-up at 6 weeks revealed no further issues. We review the literature on small bowel perforation post laparoscopic cholecystectomy. PMID:26908534

  15. Exposure to a Rotating Virtual Environment During Treadmill Locomotion Causes Adaptation in Heading Direction

    NASA Technical Reports Server (NTRS)

    Mulavara, A. P.; Richards, J. T.; Marshburn, A.; Nomura, Y.; Bloomberg, J. J.

    2005-01-01

    The goal of the present study was to investigate the adaptive effects of variation in the direction of optic flow, experienced during linear treadmill walking, on modifying locomotor trajectory. Subjects (n = 30) walked on a motorized linear treadmill at 4.0 km/h for 24 minutes while viewing the interior of a 3D virtual scene projected onto a screen 1.5 m in front of them. The virtual scene depicted constant self-motion equivalent to either 1) walking around the perimeter of a room to one s left (Rotating Room group) 2) walking down the center of a hallway (Infinite Hallway group). The scene was static for the first 4 minutes, and then constant rate self-motion was simulated for the remaining 20 minutes. Before and after the treadmill locomotion adaptation period, subjects performed five stepping trials where in each trial they marched in place to the beat of a metronome at 90 steps/min while blindfolded in a quiet room. The subject s final heading direction (deg), final X (for-aft, cm) and final Y (medio-lateral, cm) positions were measured for each trial. During the treadmill locomotion adaptation period subject s 3D torso position was measured. We found that subjects in the Rotating Room group as compared to the Infinite Hallway group: 1) showed significantly greater deviation during post exposure testing in the heading direction and Y position opposite to the direction of optic flow experienced during treadmill walking 2) showed a significant monotonically increasing torso yaw angular rotation bias in the direction of optic flow during the treadmill adaptation exposure period. Subjects in both groups showed greater forward translation (in the +X direction) during the post treadmill stepping task that differed significantly from their pre exposure performance. Subjects in both groups reported no perceptual deviation in position during the stepping tasks. We infer that 3 viewing simulated rotary self-motion during treadmill locomotion causes adaptive modification

  16. Exposure to a Rotating Virtual Environment During Treadmill Locomotion Causes Adaptation in Heading Direction

    NASA Technical Reports Server (NTRS)

    Ruttley, T; Marshburn, A.; Bloomberg, J. J.; Mulavara, A. P.; Richards, J. T.; Nomura, Y.

    2005-01-01

    The goal of the present study was to investigate the adaptive effects of variation in the direction of optic flow, experienced during linear treadmill walking, on modifying locomotor trajectory. Subjects (n = 30) walked on a motorized linear treadmill at 4.0 kilometers per hour for 24 minutes while viewing the interior of a 3D virtual scene projected onto a screen 1.5 in in front of them. The virtual scene depicted constant self-motion equivalent to either 1) walking around the perimeter of a room to one s left (Rotating Room group) 2) walking down the center of a hallway (Infinite Hallway group). The scene was static for the first 4 minutes, and then constant rate self-motion was simulated for the remaining 20 minutes. Before and after the treadmill locomotion adaptation period, subjects performed five stepping trials where in each trial they marched in place to the beat of a metronome at 90 steps/min while blindfolded in a quiet room. The subject's final heading direction (deg), final X (for-aft, cm) and final Y (medio-lateral, cm) positions were measured for each trial. During the treadmill locomotion adaptation period subject's 3D torso position was measured. We found that subjects in the Rotating Room group as compared to the Infinite Hallway group: 1) showed significantly greater deviation during post exposure testing in the heading direction and Y position opposite to the direction of optic flow experienced during treadmill walking 2) showed a significant monotonically increasing torso yaw angular rotation bias in the direction of optic flow during the treadmill adaptation exposure period. Subjects in both groups showed greater forward translation (in the +X direction) during the post treadmill stepping task that differed significantly from their pre exposure performance. Subjects in both groups reported no perceptual deviation in position during the stepping tasks. We infer that viewing simulated rotary self-motion during treadmill locomotion causes

  17. Jejunal Diverticulosis Presented with Acute Abdomen and Diverticulitis Complication: A Case Report

    PubMed Central

    Fidan, Nurdan; Mermi, Esra Ummuhan; Acay, Mehtap Beker; Murat, Muammer; Zobaci, Ethem

    2015-01-01

    Summary Background Jejunal diverticulosis is a rare, usually asymptomatic disease. Its incidence increases with age. If symptomatic, diverticulosis may cause life-threatening acute complications such as diverticulitis, perforation, intestinal hemorrhage and obstruction. In this report, we aimed to present a 67-year-old male patient with jejunal diverticulitis accompanying with abdominal pain and vomiting. Case Report A 67-year-old male patient complaining of epigastric pain for a week and nausea and fever for a day presented to our emergency department. Ultrasonographic examination in our clinic revealed diverticulum-like images with thickened walls adjacent to the small intestine loops, and increase in the echogenicity of the surrounding mesenteric fat tissue. Contrast-enhanced abdominal computed tomography showed multiple diverticula, thickened walls with showing contrast enhancement and adjacent jejunum in the left middle quadrant, increased density of the surrounding mesenteric fat tissue, and mesenteric lymph nodes. The patient was hospitalized by general surgery department with the diagnosis of jejunal diverticulitis. Conservative intravenous fluid administration and antibiotic therapy were initiated. Clinical symptoms regressed and the patient was discharged from hospital after 2 weeks. Conclusions In cases of diverticulitis it should be kept in mind that in patients with advanced age and pain in the left quadrant of the abdomen, diverticular disease causing mortality and morbidity does not always originate from the colon but might also originate from the jejunum. PMID:26715947

  18. Dual effect of chronic nicotine administration: augmentation of jejunitis and amelioration of colitis induced by iodoacetamide in rats.

    PubMed

    Eliakim, R; Karmeli, F; Cohen, P; Heyman, S N; Rachmilewitz, D

    2001-02-01

    Smoking has a dichotomous effect on inflammatory bowel disease, ameliorating disease activity in ulcerative colitis but having a deleterious effect on Crohn's disease. This effect is thought to be due to nicotine. We investigated the effect of chronic nicotine administration on the small and large bowel in iodoacetamide-induced jejunitis and colitis. Jejunitis was induced in Sprague-Dawley rats by intrajejunal administration of 0.1 ml 2% iodoacetamide and colitis by intrarectal administration of 0.1 ml 3% iodoacetamide. Nicotine was dissolved in drinking water (12.5 or 250 micrograms/ml), rats drinking ad libitum. Nicotine administration started 10 days prior to damage induction and throughout the experiment and had no effect on weight gain or daily food intake of rats. Rats were killed 5 days after iodoacetamide-induced colitis and 7 days after induction of jejunitis. The jejunum and colon were resected, rinsed, weighed, damage assessed macroscopically and microscopically and tissue processed for myeloperoxidase and nitric oxide synthase (NOS) activities and prostaglandin E2 (PGE2) generation. Effects of nicotine on gut microcirculation were also assessed. Nicotine by itself caused no damage to the colon. Nicotine had a dichotomous effect on jejunitis and colitis. At a dose of 12.5 micrograms/ml nicotine improved the macroscopic damage of colitis from 252 +/- 66 to 70 +/- 31 mm2, and segmental weight also declined significantly in the colon (from 1.7 +/- 0.2 to 1.2 +/- 0.1 g/10 cm). In contrast, the same dose of nicotine had a deleterious effect on iodoacetamide-induced jejunitis, increasing the macroscopic damage from 368 +/- 38 to 460 +/- 97 mm2 in rats treated with injury escalating to 970 +/- 147 in rats treated with 250 micrograms/ml nicotine. Nicotine treatment also significantly increased jejunal segmental weight. By itself nicotine did not change NOS activity or PGE2 generation compared to control rats, but it enhanced microcirculation in the colon

  19. Effect of ethanol on jejunal regional blood flow in the rabbit.

    PubMed

    Buell, M G; Beck, I T

    1983-01-01

    The effects of intraluminal ethanol perfusion (3.0% and 6.0% vt/vol) on mucosal morphology, water transport, and regional blood flow were examined in in vivo jejunal segments of pentobarbital-anesthetized rabbits. Compared with control segments, ethanol-perfused segments exhibited morphological alterations of the mucosa consisting of subepithelial fluid accumulation (bleb formation), exfoliation of enterocytes, and vascular congestion. The prevalence of epithelial damage was significantly increased in the segments perfused with 6% ethanol. Net water transport was significant (p less than 0.025) depressed in segments perfused with 3.0% and 6.0% wt/vol ethanol. In animals in which the control segment was absorbing water, ethanol led to a depression in net water absorption or to the reversal of absorption to net secretion. In animals in which the control segment exhibited secretion, ethanol led to an enhanced net secretion. Blood flow through the total jejunal wall and through the luminal layer (consisting of mucosa plus submucosa) was significantly (p less than 0.05) increased by the presence of 3.0% and 6.0% wt/vol ethanol in the intestinal lumen. Blood flow in the external layer of the jejunum (consisting of muscularis plus serosa) did not change significantly. It therefore appears that the ethanol-induced alterations in jejunal mucosal morphology and water transport are accompanied by a localized mucosal or submucosal hyperemia, or both. However, a direct cause and effect relationship between these remains to be established.

  20. Portal vein stent placement with or without varix embolization of jejunal variceal bleeding after hepatopancreatobiliary surgery.

    PubMed

    Shim, Dong Jae; Shin, Ji Hoon; Ko, Gi-Young; Kim, Yook; Han, Kichang; Gwon, Dong-Il; Ko, Heung-Kyu

    2017-04-01

    Background Extrahepatic portal hypertension after surgery involving the duodenum or jejunum might result in massive ectopic variceal bleeding. Purpose To report the results of portal vein stent placement with the addition of variceal embolization. Material and Methods Between January 2000 and June 2015, portal vein stent placement was attempted in 477 patients. Of these, 22 patients (age, 63 ± 10 years) with jejunal variceal bleeding caused by portal vein obstruction after surgery were included in this study. Computed tomography (CT) findings before and after treatment and the rates of technical and clinical success, complications, and clinical outcomes were retrospectively evaluated. Results Stent placement was successful in 19 of 22 patients. Additional variceal embolization was performed in five cases. Clinical success, defined as the cessation of bleeding without recurrence within 1 month, was achieved in 18 of 19 patients with technical success. One patient developed recurrent bleeding 4 days after stent placement and was successfully treated with additional variceal embolization. There were no procedure-related complications. A regression of the jejunal varices was noted in 14 of 19 patients on follow-up CT scans. During the follow-up period (258 days; range, 7-1196 days), stent occlusion and recurrent bleeding occurred in six and four patients, respectively, of the 19 patients who achieved technical success. Statistical analyses revealed no significant differences regarding stent patency between benign and malignant strictures. Conclusion Percutaneous, transhepatic, portal vein stent placement with or without jejunal variceal embolization appears to be a safe and effective treatment for jejunal variceal bleeding after surgery.

  1. Contact binaries: II. The importance of deformation caused by rotation and tides to the light curve of a contact binary

    NASA Astrophysics Data System (ADS)

    Luo, ChangQing; Huang, RunQian

    2012-05-01

    The theoretical light curves of contact binaries are calculated with and without putting in the contact binary evolution model. Firstly, we do not use the contact binary evolution model. A comparison of the light curve is performed with and without the deformation caused by rotation and tides. It shows that the light curve presents many differences, especially on the bottom and top. Secondly, we adopt the contact binary model [Huang R Q, et al. Chin J Astron Astrophys, 2007, 7: 235-244; Song H F, et al. Chin J Astron Astrophys, 2007, 7: 539-550] and compute the theoretical light curve with and without rotational and tidal effects by studying three binary systems (with low-, intermediate- and high-mass components). The bottom and top of the theoretical light curves are discussed and compared to observations. The results show that taking into account the rotational effect has a better agreement with observations than without it. Therefore, the deformation of the light curve of contact binaries caused by rotation and tides is very important. Meanwhile, the rotational and tidal effect can advance the start of the semi-detached, contact phase and the time of mass-reversal.

  2. Sidelobes in the response of arrayed waveguide gratings caused by polarization rotation.

    PubMed

    Kleijn, Emil; Williams, Peter J; Whitbread, Neil D; Wale, Michael J; Smit, Meint K; Leijtens, Xaveer J M

    2012-09-24

    Earlier it was observed that polarization rotation in an AWG built from birefringent waveguides can result in sidelobes in its response. This effect was measured in a polarization sensitive AWG with an orthogonal layout. Now we investigate through detailed simulation whether this effect also exists in polarization desensitised AWGs. It is shown that a dispersion compensated AWG does not suffer from a polarization sidelobe. Alternatively, the AWG can be designed to minimize polarization rotation to suppress the sidelobe.

  3. Line Shifts in Rotational Spectra of Polyatomic Chiral Molecules Caused by the Parity Violating Electroweak Interaction

    NASA Astrophysics Data System (ADS)

    Stohner, J.; Quack, M.

    2009-06-01

    Are findings in high-energy physics of any importance in molecular spectroscopy ? The answer is clearly `yes'. Energies of enantiomers were considered as exactly equal in an achiral environment, e.g. the gas phase. Today, however, it is well known that this is not valid. The violation of mirror-image symmetry (suggested theoretically and confirmed experimentally in 1956/57) was established in the field of nuclear, high-energy, and atomic physics since then, and it is also the cause for a non-zero energy difference between enantiomers. We expect today that the violation of mirror-image symmetry (parity violation) influences chemistry of chiral molecules as well as their spectroscopy. Progress has been made in the quantitative theoretical prediction of possible spectroscopic signatures of molecular parity violation. The experimental confirmation of parity violation in chiral molecules is, however, still open. Theoretical studies are helpful for the planning and important for a detailed analysis of rovibrational and tunneling spectra of chiral molecules. We report results on frequency shifts in rotational, vibrational and tunneling spectra of some selected chiral molecules which are studied in our group. If time permits, we shall also discuss critically some recent claims of experimental observations of molecular parity violation in condensed phase systems. T. D. Lee, C. N. Yang, Phys. Rev., 104, 254 (1956) C. S. Wu, E. Ambler, R. W. Hayward, D. D. Hoppes, R. P. Hudson, Phys. Rev., 105, 1413 (1957) M. Quack, Angew. Chem. Intl. Ed., 28, 571 (1989) Angew. Chem. Intl. Ed., 41, 4618 (2002) M. Quack, J. Stohner, Chimia, 59, 530 (2005) M. Quack, J. Stohner, M. Willeke, Ann Rev. Phys. Chem. 59, 741 (2008) M. Quack, J. Stohner, Phys. Rev. Lett., 84, 3807 (2000) M. Quack, J. Stohner, J. Chem. Phys., 119, 11228 (2003) J. Stohner, Int. J. Mass Spectrometry 233, 385 (2004) M. Gottselig, M. Quack, J. Stohner, M. Willeke, Int. J. Mass Spectrometry 233, 373 (2004) R. Berger, G

  4. Perforated jejunal diverticulum: a rare case of acute abdomen

    PubMed Central

    Sehgal, Rishabh; Cheung, Cherry X.; Hills, Tristram; Waris, Aqueel; Healy, Donagh; Khan, Tahir

    2016-01-01

    Jejunal pseudo-diverticulosis is a rare acquired herniation of the mucosa and submucosa through weakened areas of the muscularis mucosa of the mesenteric aspect of the bowel. They are asymptomatic in the majority of cases; however, they can present with a wide spectrum of non-specific symptoms such as chronic abdominal discomfort, postprandial flatulence, diarrhoea, malabsorption and steattorhoea. In up to 15% of cases, more serious acute complications may arise such as the development of intestinal obstruction, haemorrhage or as in our case, localized peritonitis secondary to perforation. Perforation carries an overall mortality rate of up to 40% and exploratory laparotomy followed by copious lavage with segmental resection and primary anastomosis remains the mainstay of managing such sequalae of jejunal pseudo-diverticulosis. Our case report highlights the importance of maintaining a high clinical suspicion of a perforated jejunal diverticulum in an elderly patient presenting with an acute abdomen. PMID:27765806

  5. Symbolic dynamics of jejunal motility in the irritable bowel

    NASA Astrophysics Data System (ADS)

    Wackerbauer, Renate; Schmidt, Thomas

    1999-09-01

    Different studies of the irritable bowel syndrome (IBS) by conventional analysis of jejunal motility report conflicting results. Therefore, our aim is to quantify the jejunal contraction activity by symbolic dynamics in order to discriminate between IBS and control subjects. Contraction amplitudes during fasting motility (phase II) are analyzed for 30 IBS and 30 healthy subjects. On the basis of a particular scale-independent discretization of the contraction amplitudes with respect to the median, IBS patients are characterized by increased block entropy as well as increased mean contraction amplitude. In a further more elementary level of analysis these differences can be reduced to specific contraction patterns within the time series, namely the fact that successive large contraction amplitudes are less ordered in IBS than in controls. These significant differences in jejunal motility may point to an altered control of the gut in IBS, although further studies on a representative number of patients have to be done for a validation of these findings.

  6. An approach for online evaluations of dose consequences caused by small rotational setup errors in intracranial stereotactic radiation therapy

    SciTech Connect

    Lu Bo; Li, Jonathan; Kahler, Darren; Yan Guanghua; Mittauer, Kathryn; Shi Wenyin; Okunieff, Paul; Liu, Chihray

    2011-11-15

    Purpose: The purpose of this work is to investigate the impact of small rotational errors on the magnitudes and distributions of spatial dose variations for intracranial stereotactic radiotherapy (SRT) treatment setups, and to assess the feasibility of using the original dose map overlaid with rotated contours (ODMORC) method as a fast, online evaluation tool to estimate dose changes (using DVHs) to clinical target volumes (CTVs) and organs-at-risks (OARs) caused by small rotational setup errors. Methods: Fifteen intracranial SRT cases treated with either three-dimensional conformal radiation therapy (3DCRT) or intensity-modulated radiation therapy (IMRT) techniques were chosen for the study. Selected cases have a variety of anatomical dimensions and pathologies. Angles of {+-}3 deg. and {+-}5 deg. in all directions were selected to simulate the rotational errors. Dose variations in different regions of the brain, CTVs, and OARs were evaluated to illustrate the various spatial effects of dose differences before and after rotations. DVHs accounting for rotations that were recomputed by the treatment planning system (TPS) and those generated by the ODMORC method were compared. A framework of a fast algorithm for multicontour rotation implemented by ODMORC is introduced as well. Results: The average values of relative dose variations between original dose and recomputed dose accounting for rotations were greater than 4.0% and 10.0% in absolute mean and in standard deviation, respectively, at the skull and adjacent regions for all cases. They were less than 1.0% and 2.5% in absolute mean and in standard deviation, respectively, for dose points 3 mm away from the skull. The results indicated that spatial dose to any part of the brain organs or tumors separated from the skull or head surface would be relatively stable before and after rotations. Statistical data of CTVs and OARs indicate the lens and cochleas have the large dose variations before and after rotations

  7. Jejunal perforation due to porcupine quill ingestion in a horse

    PubMed Central

    Anderson, Stacy L.; Panizzi, Luca; Bracamonte, Jose

    2014-01-01

    An 8-month-old Andalusian filly was treated for jejunal perforations due to ingestion of a porcupine quill. During exploratory laparotomy, 2 separate stapled side-to-side jejunojejunal resection and anastomoses were performed. Post-operative complications after 2 years follow-up included mild incisional herniation following incisional infection and chronic intermittent colic. PMID:24489394

  8. Jejunal perforation due to porcupine quill ingestion in a horse.

    PubMed

    Anderson, Stacy L; Panizzi, Luca; Bracamonte, Jose

    2014-02-01

    An 8-month-old Andalusian filly was treated for jejunal perforations due to ingestion of a porcupine quill. During exploratory laparotomy, 2 separate stapled side-to-side jejunojejunal resection and anastomoses were performed. Post-operative complications after 2 years follow-up included mild incisional herniation following incisional infection and chronic intermittent colic.

  9. Rotational Spin-up Caused CO2 Outgassing on Comet 103P/Hartley 2

    NASA Astrophysics Data System (ADS)

    Steckloff, Jordan; Graves, Kevin; Hirabayashi, Masatoshi; Richardson, James

    2015-11-01

    The Deep Impact spacecraft’s flyby of comet 103P/Hartley 2 on November 4, 2010 revealed its nucleus to be a small, bilobate, and highly active world [1] [2]. The bulk of this activity is driven by CO2 sublimation, which is enigmatically restricted to the tip of the small lobe [1]. Because Hartley 2's CO2 production responds to the diurnal cycle of the nucleus [1], CO2 ice must be no deeper than a few centimeters below the surface of the small lobe. However the high volatility of CO2 would suggest that its sublimation front should recede deep below the surface, such that diurnal volatile production is dominated by more refractory species such as water ice, as was observed at comet Tempel 1 [3].Here we show that both the near surface CO2 ice and its geographic restriction to the tip of the small lobe suggest that Hartley 2 recently experienced an episode of fast rotation. We use the GRAVMAP code to compute the stability of slopes on the surface of Hartley 2 as a function of spin period. We determine that the surface of the active region of Hartley 2’s small lobe becomes unstable at a rotation period of ~10-12 hours (as opposed to its current spin period of ~ 18 hours [1]), and will flow toward the tip of the lobe, excavating buried CO2 ice and activating CO2-driven activity. However, the rest of the surface of the nucleus is stable at these spin rates, and will therefore not exhibit CO2 activity. We additionally use Finite Element Model (FEM) analysis to demonstrate that the interior of Hartley 2’s nucleus is structurally stable (assuming a cohesive strength of at least 5 Pa) at these spin rates.The uncommonly high angular acceleration of Hartley 2, which has changed the nucleus spin period by two hours in three months [4], suggests that this episode of fast rotation may have existed only a few years or decades ago. Thus, Hartley 2 may provide an excellent case study into the reactivation of quiescent comet nuclei via rotational spin up, as would result from

  10. Annoyance caused by advanced turboprop aircraft flyover noise: Counter-rotating-propeller configuration

    NASA Technical Reports Server (NTRS)

    Mccurdy, David A.

    1990-01-01

    Two experiments were conducted to quantify the annoyance of people to flyover noise of advanced turboprop aircraft with counter rotating propellers. The first experiment examined configurations having an equal number of blades on each rotor and the second experiment examined configurations having an unequal number of blades on each rotor. The objectives were to determine the effects on annoyance of various tonal characteristics, and to compare annoyance to advanced turboprops with annoyance to conventional turboprops and turbofans. A computer was used to synthesize realistic, time-varying simulations of advanced turboprop aircraft takeoff noise. The simulations represented different combinations fundamental frequency and tone-to-broadband noise ratio. Also included in each experiment were recordings of 10 conventional turboprop and turbofan takeoffs. Each noise was presented at three sound pressure levels in an anechoic chamber. In each experiment, 64 subjects judged the annoyance of each noise stimulus. Analyses indicated that annoyance was significantly affected by the interaction of fundamental frequency with tone-to-broadband noise ratio. No significant differences in annoyance between the advanced turboprop aircraft and the conventional turbofans were found. The use of a duration correction and a modified tone correction improved the annoyance prediction for the stimuli.

  11. Geomechanical simulation of the stress tensor rotation caused by injection of cold water in a deep geothermal reservoir

    NASA Astrophysics Data System (ADS)

    Jeanne, Pierre; Rutqvist, Jonny; Dobson, Patrick F.; Garcia, Julio; Walters, Mark; Hartline, Craig; Borgia, Andrea

    2015-12-01

    We present a three-dimensional thermohydromechanical numerical study of the evolution and distribution of the stress tensor within the northwest part of The Geysers geothermal reservoir (in California), including a detailed study of the region around one injection well from 2003 to 2012. Initially, after imposing a normal faulting stress regime, we calculated local changes in the stress regime around injection wells. Our results were compared with previously published studies in which the stress state was inferred from inverting the focal plane mechanism of seismic events. Our main finding is that changes in stress tensor orientation are caused by injection-induced progressive cooling of the reservoir, as well as by the seasonal variations in injection rate. Because of the gravity flow and cooling around a liquid zone formed by the injection, the vertical stress reduction is larger and propagates far below the injection well. At the same time, the horizontal stress increases, mostly because of stress redistribution below and above the cooling area. These two phenomena cause the rotation of the stress tensor and the appearance of a strike-slip regime above, inside, and below the cooling area. The cooling and the associated rotation of the stress regime can play a significant role in the observed long-term deepening of the microseismicity below active injection wells.

  12. Life-threating upper gastrointestinal bleeding due to a primary aorto-jejunal fistula

    PubMed Central

    Fernández de Sevilla, Elena; Echeverri, Juan Andrés; Boqué, Miriam; Valverde, Silvia; Ortega, Nuria; Gené, Anna; Rodríguez, Nivardo; Balibrea, José María; Armengol, Manel

    2015-01-01

    Introduction Primary aorto-enteric fistula (AEF) is an uncommon life-threating condition. Only 4% of them involve the jejunum or ileum and its mortality ranges from 33 to 85%. Presentation of case A 54-year-old female was admitted to the Emergency Department with syncope and hematemesis. The esophagogastroduodenoscopy found a pulsatile vessel in the second portion of the duodenum. A computed tomography scan showed an AEF with an infrarenal aortic aneurysm and iliac artery thrombosis. During surgery, an infrarenal aortic aneurysm complicated with an aorto-jejunal fistula was found. An axilo-bifemoral bypass, open repair of the aneurysm and segmental small bowel resection with primary suture of the jejunal defect were performed. Discussion Depending on previous aortic grafting, AEF can be classified as primary or secondary. Primary AEF is usually caused by an untreated abdominal aortic aneurysm, commonly presenting an infectious etiology. The main clinical sign is a “herald” hemorrhage. The EGD is considered as the first step in diagnosing AEF. The treatment of choice for AEF is emergent surgery. Use of broad-spectrum antibiotics is mandatory in the postoperative period to avoid fistula recurrence. Conclusion AEF is a rare entity with a high mortality. High clinical suspicion is essential to make a correct diagnosis, which is crucial for the prognosis of these patients, such is the case of our patient. If hemodynamic stability is achieved, it allows to employ surgical strategies in which extra-abdominal bypass is performed before fistula is treated. PMID:25616071

  13. The complex arrangement of an "aorto-jejunal paraduodenal" fossa, as revealed by dissection of human posterior parietal peritoneum.

    PubMed

    Barberini, Fabrizio; Zani, Augusto; Ripani, Maurizio; Di Nitto, Valentina; Brunone, Francesca

    2007-01-01

    Peritoneal fossae derive from normal or anomalous coalescence of the peritoneum during fetal development, or from the course of retroperitoneal vessels. Clinically, internal abdominal hernias may be housed inside these fossae. In this report from an autopsy, a singular peritoneal fossa was delimited superiorly by an arcuate serous fold, raised up by the inferior mesenteric vein, and infero-posteriorly by two (right and left) avascular folds, extending from the abdominal aorta to the jejunum. The right fold reached the duodeno-jejunal flexure, which was located on the right side of the aorta. The left fold subdivided into two, anterior and posterior, secondary folds. The anterior fold reached the superior edge of the first jejunal loop, and the posterior fold turned medially to connect with the inferior edge of the proximal limb of the same loop. This fossa consisted of three recesses: superior, Located behind the subserous vascular arch, antero-inferior and postero-inferior, separated by interposition of the left posterior secondary fold, between the jejunum and aorta. The complex arrangement of this fossa suggests that it might have originated from a coalescence arising beyond the duodeno-jejunal flexure and including the first jejunal loop, and from the subserous course of the inferior mesenteric vein. Because of displacement to the right of the flexure, processes of coalescence in a location normally occupied by the ascending duodenum might have occurred in a similar pattern for the jejunum, involving the mesoduodenum and the proximal part of the mesentery. Labyrinthine fossae like this might cause strangulation of internal abdominal hernias and hinder intraoperative maneuvers.

  14. An Atypical Presentation of Sporadic Jejunal Burkitt's Lymphoma

    PubMed Central

    2016-01-01

    Burkitt's lymphoma is a very aggressive type of B-cell NHL with replication approaching 100%. Primary gastrointestinal lymphoma is rare. In our case, a 24-year-old male initially presented with symptomatic anemia. He was initially evaluated with colonoscopy and EGD, both of which were unremarkable. A capsule endoscopy was then performed to further evaluate his significant anemia which revealed friable inflamed ulcerated mass in the jejunum. A push enteroscopy was then performed to obtain tissue from the jejunal mass. Biopsy results and immunohistochemical stains were consistent with Burkitt's lymphoma. PET/CT scan revealed only jejunal involvement. Treatment consisted of bowel resection prior to chemotherapy due to concern for perforation with chemotherapy. Patient achieved complete remission after the treatment. PMID:27672459

  15. A new tube for simultaneous gastric decompression and jejunal alimentation.

    PubMed

    Nelson, R; Nyhus, L M

    1985-04-01

    A new tube has been devised for simultaneous gastric decompression and jejunal enteral alimentation. The tube is inserted by the nasogastric route intraoperatively. What differentiates this from earlier tubes is the addition of two inflatable balloons that facilitate passage of the tip of the tube through the retroperitoneal duodenum and into the proximal jejunum. Such a device is needed because the advantages of enteral alimentation in the postoperative patient include safety, low cost and significant metabolic benefits.

  16. Replaceable Jejunal Feeding Tubes in Severely Ill Children

    PubMed Central

    Pang, Tabea; Holland-Cunz, Stefan

    2017-01-01

    Long-term enteral nutrition in chronically ill, malnourished children represents a clinical challenge if adequate feeding via nasogastric or gastrostomy tubes fails. We evaluated the usefulness and complications of a new type of surgical jejunostomy that allows for easier positioning and replacement of the jejunal feeding tube in children. We surgically inserted replaceable jejunal feeding tubes (RJFT) connected to a guide thread which exited through a separate tiny opening of the abdominal wall. In a retrospective case series, we assessed the effectiveness and complications of this technique in severely ill children suffering from malnutrition and complex disorders. Three surgical complications occurred, and these were addressed by reoperation. Four children died from their severe chronic disorders within the study period. The RJFT permitted continuous enteral feeding and facilitated easy replacement of the tube. After the postoperative period, jejunal feeding by RJFT resulted in adequate weight gain. This feeding access represents an option for children in whom sufficient enteral nutrition by nasogastric tubes or gastrostomy proved impossible. Further studies are required to investigate the safety and effectiveness of this surgical technique in a larger case series. PMID:28232847

  17. GASTRIC AND JEJUNAL HISTOPATHOLOGICAL CHANGES IN PATIENTS UNDERGOING BARIATRIC SURGERY

    PubMed Central

    RODRIGUES, Rosemary Simões Nomelini; ALMEIDA, Élia Cláudia de Souza; CAMILO, Silvia Maria Perrone; TERRA-JÚNIOR, Júverson Alves; GUIMARÃES, Lucinda Calheiros; DUQUE, Ana Cristina da Rocha; ETCHEBEHERE, Renata Margarida

    2016-01-01

    ABSTRACT Background: Morbid obesity is a multifactorial disease that increasingly is being treated by surgery. Aim: To evaluate gastric histopathological changes in obese, and to compare with patients who underwent gastrojejunal bypass and the jejunal mucosa after the surgery. Methods: This is an observational study performed at a tertiary public hospital, evaluating endoscopic biopsies from 36 preoperative patients and 35 postoperative. Results: In the preoperative group, 80.6% had chronic gastritis, which was active in 38.9% (77.1% and 20.1%, respectively, in the postoperative). The postoperative group had a significant reduction in H. pylori infection (p=0.0001). A longer length of the gastric stump and a time since surgery of more than two years were associated with Helicobacter pylori infection. The jejunal mucosa was normal in 91.4% and showed slight nonspecific chronic inflammation in 8.6%. Conclusion: There was a reduction in the incidence of Helicobacter pylori infection in the postoperative group. A longer length of the gastric stump and longer time elapsed since surgery were associated with Helicobacter pylori infection. The jejunal mucosa was considered normal in an absolute majority of patients. PMID:27683773

  18. [Surgical Removal of Migrated Coil after Embolization of Jejunal Variceal Bleeding: A Case Report].

    PubMed

    Kim, Junhwan; Lee, Danbi; Oh, Kyunghwan; Lee, Mingee; So, Seol; Yang, Dong Hoon; Kim, Chan Wook; Gwon, Dong Il; Chung, Young Hwa

    2017-01-25

    Jejunal variceal bleeding is less common compared with esophagogastric varices in patients with portal hypertension. However, jejunal variceal bleeding can be fatal without treatment. Treatments include surgery, transjugular intrahepatic porto-systemic shunt (TIPS), endoscopic sclerotherapy, percutaneous coil embolization, and balloon-occluded retrograde transvenous obliteration (BRTO). Percutaneous coil embolization can be considered as an alternative treatment option for those where endoscopic sclerotherapy, surgery, TIPS or BRTO are not possible. Complications of percutaneous coil embolization have been reported, including coil migration. Herein, we report a case of migration of the coil into the jejunal lumen after percutaneous coil embolization for jejunal variceal bleeding. The migrated coil was successfully removed using surgery.

  19. Ileal impaction and jejunal enterotomy in a 4-month-old Arabian filly.

    PubMed

    Davis, Heather A; Munsterman, Amelia

    2012-01-01

    A 4-month-old Arabian filly was treated by surgical correction of an ileal impaction. The impaction was resolved through a distal jejunal enterotomy. One-year follow-up showed no post-operative complications secondary to the enterotomy. Jejunal enterotomy may be a surgical option for resolution of an ileal impaction.

  20. Ileal impaction and jejunal enterotomy in a 4-month-old Arabian filly

    PubMed Central

    Davis, Heather A.; Munsterman, Amelia

    2012-01-01

    A 4-month-old Arabian filly was treated by surgical correction of an ileal impaction. The impaction was resolved through a distal jejunal enterotomy. One-year follow-up showed no post-operative complications secondary to the enterotomy. Jejunal enterotomy may be a surgical option for resolution of an ileal impaction. PMID:22753967

  1. Chagas' achalasia treated by a jejunal interposed segment.

    PubMed

    Dantas, A N; Carvalho, J L; Coelho, F K; Teixeira, A M; Lyra, L G; Rebouças, G; Didier, F V

    1975-01-01

    Resection of the achalasic area and replacement by a segment of jejunal loop, associated with vagotomy and pyloroplasty, has been performed in 21 patients. The majority of these patients had Chagas' disease, with a dilated esophagus wider than 7 cm. This surgical procedure offered symptomatic relief in 20 of our 21 cases. One patient died, but the death was not necessarily related to the operation. Although disphagia and regurgitation did not disappear entirely in all cases the decrease in severity of these symptoms was such to allow the few symptomatic patients to lead an entirely normal life after the operation.

  2. Transient ischemic jejunitis due to symptomatic isolated superior mesenteric artery dissection: case report and review of literature

    PubMed Central

    MOCAN, MIHAELA; JEICAN, IONUŢ ISAIA; MOALE, MIHAI; CHIRA, ROMEO

    2017-01-01

    Acute abdominal pain is one of the most common conditions encountered in the emergency department. The differential diagnosis of acute abdominal pain is extensive and identifying the underlying etiology can be challenging. We report a case of acute transient ischemic jejunitis due to symptomatic isolated superior mesenteric artery dissection in a patient with no cardiovascular risk factors or autoimmune diseases. Symptomatic isolated superior mesenteric artery dissection is a rare cause of acute abdominal pain usually treated in the surgical department. The patient had criteria for conservative treatment and rapidly recovered. We highlight a rare condition which should be taken into account for the differential diagnosis of acute abdominal pain. PMID:28246505

  3. Jejunal and ileal absorption of oxprenolol in man: influence of nutrients and digestive secretions on jejunal absorption and systemic availability.

    PubMed Central

    Godbillon, J; Vidon, N; Palma, R; Pfeiffer, A; Franchisseur, C; Bovet, M; Gosset, G; Bernier, J J; Hirtz, J

    1987-01-01

    1 Study I evaluated the absorption of oxprenolol in the ileum, compared to jejunum, in healthy volunteers by an intestinal perfusion technique. Around 80 mg of drug were delivered as a saline solution directly in the small bowel. 2 Samples taken 30 cm distally to the site of perfusion showed that 63% of perfused oxprenolol was absorbed in the jejunum and 48% in the ileum; the differences were significant. 3 The plasma concentration-time profiles were similar for the two perfusions. The AUC and Cmax values of free and conjugated oxprenolol for the jejunal perfusion were significantly lower than those of ileum. They showed large but consistent intersubject variations in the two treatments. 4 Study II investigated, using the same technique, the influence of nutrients and digestive secretions on jejunal absorption and systemic availability of this drug. A saline (in treatments A and B) or a nutrient (in treatment C) solution containing oxprenolol was perfused into the jejunum below a balloon either inflated (A) or deflated (B and C). 5 The disappearance rate of oxprenolol from the jejunum was unaffected by endogenous secretions. The mean amount of drug absorbed along a 30-cm jejunal segment accounted for 52 (A) and 57% (B) of the total amount perfused. The intestinal absorption rate was markedly increased in the presence of nutrients (mean amount absorbed 96% for C). 6 The change in the rate of disappearance from the intestine had no effect on the systemic availability of oxprenolol (mean AUC values 8740, 8250 and 8020 nmol l-1 h for A, B and C, respectively) or its elimination from plasma.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3663450

  4. Effects of scapula-upward taping using kinesiology tape in a patient with shoulder pain caused by scapular downward rotation

    PubMed Central

    Kim, Byeong-Jo; Lee, Jung-Hoon

    2015-01-01

    [Purpose] The aim of this study was to evaluate the effects of scapula-upward taping (SUT) in a patient with shoulder pain caused by scapular downward rotation (SDR). [Subject] A 26-year-old male with SDR experienced severe pain in the left shoulder when he lifted his left upper extremity to hold the handle in a bus and during and after push-up exercise. [Methods] The patient underwent SUT for a period of 1 month, 5 times per week, for an average of 9 h/d. [Results] The patient’s radiographs showed that the degree of SDR had decreased; the left shoulder pain also decreased in the resting state and during and after push-up exercise. The manual muscle strength test grades of the upper trapezius, lower trapezius, and serratus anterior had increased. The patient was able to lift the left upper extremity to hold the handle in a bus and perform the push-up exercise without experiencing any pain. [Conclusion] Repeated SUT application may be a beneficial treatment method for alleviating the degree of SDR and shoulder pain in SDR patients. PMID:25729213

  5. Analysis and calibration of the gyro bias caused by geomagnetic field in a dual-axis rotational inertial navigation system

    NASA Astrophysics Data System (ADS)

    Cai, Qingzhong; Yang, Gongliu; Song, Ningfang; Yin, Hongliang; Liu, Yiliang

    2016-10-01

    A rotational inertial navigation system (RINS) has been wildly used in long term marine navigation. In a dual-axis RINS, with all constant biases averaged out, the errors which can not be averaged out become the main error source. In this paper, the gyro geomagnetic biases of a dual-axis RINS are modelled, analysed and calibrated. The gyro geomagnetic biases are proved unable to be averaged out, but can be modulated to be a constant value in the navigation frame. A slope error term of longitude error is found to be caused by gyro geomagnetic biases in north and upward directions, which increases linearly with time and is remarkable in long term navigation. Thus, a calibration method based on least square regression is proposed to compensate the slope error term. Laboratory and sailing experimental results show that the divergence speed of longitude error can be effectively slowed down by the compensation of gyro geomagnetic biases. In long term independent navigation, the position accuracy of dual-axis RINS is improved about 50% by the calibration method proposed in this paper.

  6. Can Rotational Atherectomy Cause Thermal Tissue Damage? A Study of the Potential Heating and Thermal Tissue Effects of a Rotational Atherectomy Device

    SciTech Connect

    Gehani, Abdurrazzak A.; Rees, Michael R.

    1998-11-15

    Purpose: Thermal tissue damage (TTD) is customarily associated with some lasers. The thermal potential of rotational atherectomy (RA) devices is unknown. We investigated the temperature profile and potential TTD as well as the value of fluid flushing of an RA device. Methods: We used a high-resolution infrared imaging system that can detect changes as small as 0.1 deg. C to measure the temperature changes at the tip of a fast RA device with and without fluid flushing. To assess TTD, segments of porcine aorta were subjected to the rotating tip under controlled conditions, stained by a special histochemical stain (picrisirius red) and examined under normal and polarized light microscopy. Results: There was significant heating of the rotating cam. The mean 'peak' temperature rise was 52.8 {+-} 16.9 deg. C. This was related to rotational speed; thus the 'peak' temperature rise was 88.3 {+-} 12.6 deg. C at 80,000 rpm and 17.3 {+-} 3.8 deg. C at 20,000 rpm (p < 0.001, t-test). Fluid flushing at 18 ml/min reduced, but did not abolish, heating of the device (11.8 {+-} 2.9 deg. C). A crater was observed in all segments exposed to the rotating tip. The following features were most notable: (i) A zone of 'thermal' tissue damage extended radially from the crater reaching adventitia in some sections, especially at high speeds. This zone showed markedly reduced or absent birefringence. (ii) Fluid flushing of the catheter reduced the above changes but increased the incidence and extent of dissections in the media, especially when combined with high atherectomy speeds. (iii) These changes were observed in five of six specimens exposed to RA without flushing, but in only one of six with flushing (p < 0.05). (iv) None of the above changes was seen in control segments. Conclusion: RA is capable of generating significant heat and potential TTD. Fluid flushing reduced heating and TTD. These findings warrant further studies in vivo, and may influence the design of atherectomy devices.

  7. Jejunal access loop cholangiogram and intervention using image guided access.

    PubMed

    Amitha Vikrama, K S; Keshava, S N; Surendrababu, N R S; Moses, V; Joseph, P; Vyas, F; Sitaram, V

    2010-02-01

    Jejunal access loop is fashioned in patients who undergo Roux en Y hepaticojejunostomy and biliary intervention is anticipated on follow up. Post-operative study of the biliary tree through the access loop is usually done under fluoroscopic guidance. We present a series of 20 access loop cholangiograms performed in our institution between August 2004 and November 2008. We aimed to evaluate the safety and efficacy of the procedure and to highlight the role of CT guidance in procuring access. Access loop was accessed using CT (n = 13), ultrasound (n = 3) or fluoroscopic guidance (n = 4). Fluoroscopy was used for performing cholangiograms and interventions. Twelve studies had balloon plasty of the stricture at anastomotic site or high up in the hepatic ducts. Seven studies showed normal cholangiogram. Plasty was unsuccessful in one study. Technical success in accessing the jejunal access loop was 100%; in cannulation of anastomotic site and balloon plasty it was 95%. One case required two attempts. Procedure-related complications were not seen. All patients who underwent balloon plasty of the stricture were doing well for variable lengths of time. Access loop cholangiogram and interventions are safe and effective. CT guidance in locating/procuring the access loop is a good technique.

  8. Effects of spaceflight on the proliferation of jejunal mucosal cells

    NASA Technical Reports Server (NTRS)

    Phillips, Robert W.; Moeller, C. L.; Sawyer, Heywood R.; Smirnov, K. L.

    1991-01-01

    The purpose of this project was to test the hypothesis that the generalized, whole body decrease in synthetic activity due to microgravity conditions encountered during spaceflight would be demonstrable in cells and tissues characterized by a rapid rate of turnover. Jejunal mucosal cells were chosen as a model since these cells are among the most rapidly proliferating in the body. Accordingly, the percentage of mitotic cells present in the crypts of Lieberkuhn in each of 5 rats flown on the COSMOS 2044 mission were compared to the percentage of mitotic cells present in the crypts in rats included in each of 3 ground control groups (i.e., vivarium, synchronous and caudal-elevated). No significant difference (p greater than .05) was detected in mitotic indices between the flight and vivarium group. Although the ability of jejunal mucosal cells to divide by mitosis was not impaired in flight group, there was, however, a reduction in the length of villi and depth of crypts. The concommitant reduction in villus length and crypth depth in the flight group probably reflects changes in connective tissue components within the core of villi.

  9. Improved Cell Line IPEC-J2, Characterized as a Model for Porcine Jejunal Epithelium

    PubMed Central

    Zakrzewski, Silke S.; Richter, Jan F.; Krug, Susanne M.; Jebautzke, Britta; Lee, In-Fah M.; Rieger, Juliane; Sachtleben, Monika; Bondzio, Angelika; Schulzke, Jörg D.; Fromm, Michael; Günzel, Dorothee

    2013-01-01

    Cell lines matching the source epithelium are indispensable for investigating porcine intestinal transport and barrier properties on a subcellular or molecular level and furthermore help to reduce animal usage. The porcine jejunal cell line IPEC-J2 is established as an in vitro model for porcine infection studies but exhibits atypically high transepithelial resistances (TER) and only low active transport rates so that the effect of nutritional factors cannot be reliably investigated. This study aimed to properly remodel IPEC-J2 and then to re-characterize these cells regarding epithelial architecture, expression of barrier-relevant tight junction (TJ) proteins, adequate TER and transport function, and reaction to secretagogues. For this, IPEC-J2 monolayers were cultured on permeable supports, either under conventional (fetal bovine serum, FBS) or species-specific (porcine serum, PS) conditions. Porcine jejunal mucosa was analyzed for comparison. Main results were that under PS conditions (IPEC-J2/PS), compared to conventional FBS culture (IPEC-J2/FBS), the cell height increased 6-fold while the cell diameter was reduced by 50%. The apical cell membrane of IPEC-J2/PS exhibited typical microvilli. Most importantly, PS caused a one order of magnitude reduction of TER and of trans- and paracellular resistance, and a 2-fold increase in secretory response to forskolin when compared to FBS condition. TJ ultrastructure and appearance of TJ proteins changed dramatically in IPEC-J2/PS. Most parameters measured under PS conditions were much closer to those of typical pig jejunocytes than ever reported since the cell line’s initial establishment in 1989. In conclusion, IPEC-J2, if cultured under defined species-specific conditions, forms a suitable model for investigating porcine paracellular intestinal barrier function. PMID:24260272

  10. The effects of progressive anemia on jejunal mucosal and serosal tissue oxygenation in pigs.

    PubMed

    Haisjackl, M; Luz, G; Sparr, H; Germann, R; Salak, N; Friesenecker, B; Deusch, E; Meusburger, S; Hasibeder, W

    1997-03-01

    Anemia may promote intestinal hypoxia. We studied the effects of progressive isovolemic hemodilution on jejunal mucosal (Po2muc), and serosal tissue oxygen tension (Po2ser, Clark-type surface electrodes), mucosal microvascular hemoglobin oxygen saturation (Hbo2muc), and hematocrit (Hctmuc; tissue reflectance spectophotometry) in a jejunal segment. Twelve domestic pigs were anesthetized, paralyzed, and mechanically ventilated. Laparatomy was performed, arterial supply of a jejunal segment isolated, and constant pressure pump perfused. Seven animals were progressively hemodiluted to systemic hematocrits (Hctsys) of 20%, 15%, 10%, and 6%. Baseline for Po2muc, Po2ser and Hbo2muc was 23.5 +/- 2.1 mm Hg, 57.5 +/- 4 mm Hg, and 47.0% +/- 6.4% which were not different from the five controls. Despite a significant increase in jejunal blood flow, jejunal oxygen delivery decreased and oxygen extraction ratio increased significantly at Hctsys 10% and 6%. Po2ser decreased significantly below or at Hctsys of 15%, whereas Po2muc and Hbo2muc were maintained to Hctsys of 10%, but less than 10% Hbo2muc and mesenteric venous pH decreased significantly, implying that physiological limits of jejunal microvascular adaptation to severe anemia were reached. Decrease of Hctmuc was less pronounced than Hctsys. In conclusion, redistribution of jejunal blood flow and an increase in the ratio of mucosal to systemic hematocrit are the main mechanisms maintaining mucosal oxygen supply during progressive anemia.

  11. Reconstruction of esophageal defects with microsurgically revascularized jejunal segments: a report of 13 cases.

    PubMed

    Chang, T S; Hwang, O L; Wang-Wei

    1980-12-01

    Experimental free transfer of a jejunal segment to a recipient bed in the neck was successfully performed in 5 mongrel dogs. This was followed by clinical application of 2 different microvascular procedures in 13 patients for repair of esophageal defects. In 7 of these patients a free jejunal transfer was used; in 6 of these patients a pedicled jejunal graft with revascularization of its distal end by microvascular anastomosis was used. The esophageal defects were located in the cervical portion in 7 cases, the cervicothoracic portion in 5 cases, and the thoracic portion in 1 case. Ten (77%) of the 13 procedures were successful.

  12. Late metastatic colon cancer masquerading as primary jejunal carcinoma

    PubMed Central

    Meshikhes, A-WN; Joudeh, AA

    2016-01-01

    Metastasis to the small bowel from a previously resected colorectal cancer is rare and may erroneously be diagnosed as a primary small bowel carcinoma. It usually occurs several years after the primary resection. We present the case of a 67-year-old man who had undergone left hemicolectomy for colon cancer 3 years earlier and returned with subacute small bowel obstruction. This was initially thought, based on preoperative radiological findings and normal colonoscopic examination, to be due a primary jejunal cancer. Even at surgery, the lesion convincingly appeared as an obstructing primary small bowel carcinoma. However, the histology of the resected small bowel revealed metastatic colon cancer. This rare and an unusual metastatic occurrence some years after the primary resection is described and reviewed. PMID:26890851

  13. Duodeno-Jejunal Varicosities Following Extrahepatic Portal Vein Thrombosis

    PubMed Central

    Varsamidakis, Nick; Hobbs, Kenneth

    1992-01-01

    A 31 year old man, under investigation for melena, was found at endoscopy to have varicosities at the site of a duodeno-jejunostomy which had been performed for duodenal atresia when he was three days old. Angiography revealed an occluded portal vein with an extensive collateral circulation. At laparotomy some of the collateral vessels were found to pass through the anastomotic site and directly into the left lobe of the liver. The portal pressure was found to be minimally elevated. Resection of the anastomotic segment was performed with reconstruction using a Roux en Y jejunal loop. Bleeding from collateral vessels passing through an anastomosis site in a patient with extrahepatic portal vein thrombosis has not previously been reported. PMID:1610726

  14. Percutaneous Retrograde Sclerotherapy for Refractory Bleeding of Jejunal Varices: Direct Injection via Superficial Epigastric Vein

    SciTech Connect

    Nakata, Manabu Nakata, Waka; Isoda, Norio Yoshizawa, Mitsuyo; Sugimoto, Hideharu

    2012-02-15

    Small-bowel varices are rare and almost always occur in cases with portal hypertension. We encountered a patient with bleeding jejunal varices due to liver cirrhosis. Percutaneous retrograde sclerotherapy was performed via the superficial epigastric vein. Melena disappeared immediately after treatment. Disappearance of jejunal varices was confirmed by contrast-enhanced computed tomography. After 24 months of follow-up, no recurrent melena was observed.

  15. Preduodenal portal vein, malrotation, and high jejunal atresia: a case report.

    PubMed

    Baglaj, Maciej; Gerus, Sylwester

    2012-01-01

    Preduodenal portal vein (PDPV) is a rare congenital anomaly. In most patients, it is associated with other congenital defects including situs inversus, malrotation, and biliary atresia or occurs as part of the heterotaxia syndrome or polysplenia syndrome. We describe a newborn affected by high jejunal atresia, malrotation, and a complex cardiac anomaly, in whom PDPV was diagnosed at early relaparotomy because of stenosis of the jejunal anastomosis. Occurrence of PDPV with intestinal atresia has not been previously reported in the literature.

  16. [Usefulness of endoscopically guided nasogastric-jejunal feeding tube placement in a case of aspiration pneumonia due to postgastrectomy].

    PubMed

    Tamura, Kosei; Totsuka, Osamu; Tamura, Jun'ichi

    2015-01-01

    A 79-year-old man with a history of gastrectomy with Billroth II reconstruction 27 years previously was admitted to our hospital due to recurrent pneumonia. Because he had dysphagia and had frequently developed pneumonia over the course of a year, enteral nutrition via nasogastric tube was initiated approximately six months before admission. The clinical and computed tomography findings showed that the cause of pneumonia was aspiration of tube feeding nutrients due to gastroesophageal reflux. To prevent gastroesophageal reflux, he was continuously kept in a 30-degree or greater reclining position. However, gastroesophageal reflux was seen at an injection rate of 50 ml/h or greater. After we inserted a nasogastric-jejunal feeding tube guided by endoscopy, gastroesophageal reflux, dumping syndrome and diarrhea were not seen up to an injection rate of 300 ml/h. Endoscopically guided nasogastric-jejunal feeding tube placement is a simple method and may be useful for patients with aspiration pneumonia due to postgastrectomy. Moreover, long-term postgastrectomy patients appear to tolerate the postopyloric injection of enteral nutrition. Because the number of elderly patients who have dysphagia with postgastrectomy is increasing, these findings provide a basis for treatment in elderly medical settings.

  17. A ``WET Dog" Tunneling Motion as the Cause for the Doubled Rotational Spectrum of 1-IodononaFluorobutane

    NASA Astrophysics Data System (ADS)

    Bailey, W. C.; Bohn, R. K.; Grubbs, G. S. Grubbs, Ii; Kisiel, Z.; Cooke, S. A.

    2013-06-01

    A chirped pulse Fourier transform microwave spectrometer has been used to record the rotational spectra of 1-iodononafluorobutane between 8 GHz and 12 GHz. The target compound was spectroscopically examined as it participated in a supersonic expansion of argon. The spectra recorded are dense owing in part to the small rotational constants, B + C ≈ 480 MHz, but also to hyperfine structure generated by the coupling of angular momenta of the iodine nucleus and the rotating molecular frame, e.g. mid χ_{ab} mid ≈ 1200 MHz. Notably all of the hyperfine components were observed as doublets. It is postulated that this doubling effect is the result of a low barrier, double minimum potential between two mirror image transoid structures. The tunneling motion between these structures resembles that of a ``wet dog" shaking itself dry. Numerous transitions are shifted in frequency and it is proposed that the density of rotational energy levels from the two interacting states results in numerous perturbations to the energy levels involved. A preliminary spectral analysis of over 400 transitions will be presented, along with the results of supporting quantum mechanical calculations.

  18. The visceromotor responses to colorectal distension and skin pinch are inhibited by simultaneous jejunal distension.

    PubMed

    Shafton, Anthony D; Furness, John B; Ferens, Dorota; Bogeski, Goce; Koh, Shir Lin; Lean, Nicholas P; Kitchener, Peter D

    2006-07-01

    Noxious stimuli that are applied to different somatic sites interact; often one stimulus diminishes the sensation elicited from another site. By contrast, inhibitory interactions between visceral stimuli are not well documented. We investigated the interaction between the effects of noxious distension of the colorectum and noxious stimuli applied to the jejunum, in the rat. Colorectal distension elicited a visceromotor reflex, which was quantified using electromyographic (EMG) recordings from the external oblique muscle of the upper abdomen. The same motor units were activated when a strong pinch was applied to the flank skin. Distension of the jejunum did not provoke an EMG response at this site, but when it was applied during colorectal distension it blocked the EMG response. Jejunal distension also inhibited the response to noxious skin pinch. The inhibition of the visceromotor response to colorectal distension was prevented by local application of tetrodotoxin to the jejunum, and was markedly reduced when nicardipine was infused into the local jejunal circulation. Chronic sub-diaphragmatic vagotomy had no effect on the colorectal distension-induced EMG activity or its inhibition by jejunal distension. The nicotinic antagonist hexamethonium suppressed phasic contractile activity in the jejunum, had only a small effect on the inhibition of visceromotor response by jejunal distension. It is concluded that signals that arise from skin pinch and colorectal distension converge in the central nervous system with pathways that are activated by jejunal spinal afferents; the jejunal signals strongly inhibit the abdominal motor activity evoked by noxious stimuli.

  19. Anemia and jejunal intussusception: An unusual presentation for a metastatic phyllodes breast tumor

    PubMed Central

    Schechet, Sidney A.; Askenasy, Erik P.; Dhamne, Sagar; Scott, Bradford G.

    2011-01-01

    INTRODUCTION Phyllodes tumor of the breast is a rare cause of breast cancer, accounting for less than 0.5% of breast cancers. These tumors are classified as benign, borderline, or malignant, with malignant tumors compromising nearly 25% of cases. Metastases occur in 20% of malignant tumors, lungs, bones, liver and brain being the frequent sites of metastases. PRESENTATION OF CASE We present a case of a metastatic phyllodes tumor to the small bowel causing jejunal intussusception, symptomatic anemia, and small bowel obstruction. DISCUSSION Patients with phyllodes tumor of the breast can develop disease recurrence even years after initial treatment. Phyllodes tumor metastasizing to the small bowel is extremely rare, with only three known previously described case reports in the literature. CONCLUSION High risk patients, with a past medical history of phyllodes breast cancer, should be monitored closely. Even years after breast cancer treatment, these patients may present with gastrointestinal complaints such as obstruction or bleeding, and therefore metastatic disease to the small bowel should be considered on the differential with subsequent abdominal imaging obtained. PMID:22288047

  20. Nicotinic acid inhibits enterotoxin-induced jejunal secretion in the pig.

    PubMed Central

    Forsyth, G W; Kapitany, R A; Scoot, A

    1981-01-01

    The use of nicotinic acid for preventing intestinal secretion caused by cholera toxin and by the heat-stable enterotoxin of Escherichia coli has been investigated in the weanling pig. Secretory effects were measured in ligated jejunal loops of halothane-anesthetized pigs by dilution of a nonabsorbable marker added to the loop fluid. Different routes of administration and different initial pH values for nicotinate solutions were studied to determine optimal conditions for secretory inhibition. The neutral sodium salt of nicotinic acid had no significant antisecretory activity under any conditions used in these trials. Inhibition of secretion was most effective with partly neutralized nicotinic acid at pH 4.5 added directly to loops containing enterotoxin. Net fluid secretion induced by cholera toxin or heat-stable enterotoxin of E. coli was prevented by this treatment. Reversal of secretion was not accompanied by any measurable changes in cyclic nucleotide concentration in intestinal mucosa. Nicotinic acid antagonism of a secretory step common to cholera toxin and heat-stable enterotoxin of E. coli but subsequent to cyclic nucleotide involvement is indicated by these data. PMID:7020893

  1. Pharyngoesophageal stricture and fistula. Treatment by free jejunal graft.

    PubMed Central

    Hester, T R; McConnel, F; Nahai, F; Cunningham, S J; Jurkiewicz, M J

    1984-01-01

    Fifty-five patients with disorders of the pharynx or cervical esophagus requiring extensive ablative therapy were reconstructed by heterotopic autotransplantation of a segment of jejunum. Of these 55 patients, the overwhelming majority were treated for squamous cell carcinoma or the complications of combined radiation and operative therapy. There were six graft failures in the entire group of 55 patients for a transfer reliability of 90%. Three patients died in the perioperative period (5%). The purpose of this paper is to report on the treatment of a subset of these patients in whom fixed cicatricial stenosis of the gullet was the problem or in whom a radionecrotic cutaneous fistula existed. Fourteen such patients were treated, ten with stricture and four with fistula. Both patch grafts of on-lay segments and more routine circumferentially intact tubed segments of jejunum were used depending upon the nature of the defect. The youngest patient in this group was a 3-year-old juvenile diabetic with caustic stricture and the oldest was a 75-year-old man with fixed stricture following operation and radiation for cancer. Nine of ten and four of four anatomic reconstructions were successful in the stricture and fistula patients, respectively. All of these 13 patients with a neo- gullet of jejunum were able to handle secretions and liquids satisfactorily. Eleven patients were on a regular diet and had no discernible physiological impairment in alimentation. One patient had mild dysphagia and used a blenderized diet. One patient was able to swallow liquids only. In this patient the resection for tumor was so high and so extensive that the physiologic act of deglutition itself was impaired. There were no perioperative deaths, although one patient has succumbed to recurrent and metastatic carcinoma. When conventional treatment for stricture or fistula in the cervical alimentary tract has failed, reconstruction can be accomplished safely by free revascularized jejunal graft

  2. Effects of Salmonella on spatial-temporal processes of jejunal development in chickens.

    PubMed

    Schokker, Dirkjan; Smits, Mari A; Hoekman, Arjan J W; Parmentier, Henk K; Rebel, Johanna M J

    2010-10-01

    To study effects of Salmonella enteritidis on morphological and functional changes in chicken jejunal development, we analysed gene expression profiles at seven points post-infection in 1-21 day-old broiler chickens. Nine clusters with different gene expression patterns were identified, and the genes in each cluster were further analyzed by a functional annotation clustering method (DAVID). Functional and morphological developmental processes dominated in all the nine clusters. Salmonella infection caused delays in several intestinal-morphological processes, whereas functional metabolic processes occurred in a similar spatial-temporal frame compared to normal jejunum development. A clear difference between normal developing- and Salmonella disturbed jejunum was the higher expression of genes involved in cell turn-over at early stages in the infected jejunum. Surprisingly, we found no clustered immune related processes in the infected birds. To compare the immunological processes between control and Salmonella infected chickens, the gene expression data was superimposed on known immunological KEGG pathways. Furthermore an in-depth analysis on the immune gene level was performed. As expected, we did find immunological processes in the Salmonella infected jejunum. Several of these processes could be verified by immunohistochemistry measurements of different immunological cell types. However, the well-ordered spatial-temporal development of the immune system, as observed in control non-infected animals, was completely abolished in the infected animals. Several immunological processes started much earlier in time, whereas other processes are disorganised. These data indicate that normal morphological and immunological development of jejunum is changed dramatically by a disturbance due to Salmonella infection. Due to the disturbance, the well-organized spatial-temporal development of morphological processes are delayed, those of the immunological development are

  3. Jejunal Perforation: A Rare Presentation of Burkitt's Lymphoma—Successful Management

    PubMed Central

    Nayak, Samir Ranjan; Rao, Ganni Bhaskara; Yerraguntla, Subramanya Sarma; Bodepudi, Sisir

    2014-01-01

    Malignant tumors of the small bowel presenting as acute abdomen are a rare occurrence. Burkitt's lymphoma presenting as a surgical emergency needing emergency laparotomy is an uncommon presentation of this tumor. We present an interesting case of jejunal perforation as a first manifestation of Burkitt's lymphoma which was successfully managed with surgical resection, high dose chemotherapy, and good supportive care. PMID:24995139

  4. Effect of jejunal infusion of nutrients on gastrointestinal transit and hormonal response in man.

    PubMed

    Vidon, N; Pfeiffer, A; Chayvialle, J A; Merite, F; Maurel, M; Franchisseur, C; Huchet, B; Bernier, J J

    1989-12-01

    The effects of jejunal infusion of nutrients on gastric emptying and secretion, intestinal transit and hormone release were studied in human volunteers. Two caloric loads, 1.3 and 3.3 kcal/min, of a nutrient solution consisting of 18 percent protein, 27 percent lipids, and 55 percent carbohydrates were tested. These were first used in random order in 6 subjects to assess the effects on intestinal transit. For the study of gastric emptying, jejunal infusion was started 1 h after intragastric instillation of a 490 kcal, 400 ml, homogenized meal. Intestinal transit time and gastric emptying half-time increased with the rate of nutrient infusion into the jejunum. Postprandial gastric secretion was reduced. The two caloric loads induced significant rises of plasma cholecystokinin and gastric inhibitory polypeptide concentrations. Plasma motilin decreased in relation to the jejunal caloric load. The other peptides were essentially not affected by jejunal nutrient infusion in fasting subjects. We conclude that in man, gastric emptying rate, gastric secretion, and intestinal transit are regulated by the presence of nutrients in the jejunum.

  5. The TRPA1 Activator Allyl Isothiocyanate (AITC) Contracts Human Jejunal Muscle: Pharmacological Analysis.

    PubMed

    Sandor, Zsolt; Dekany, Andras; Kelemen, Dezsö; Bencsik, Timea; Papp, Robert; Bartho, Lorand

    2016-09-01

    The contractile effect of AITC (300 μM) on human jejunal longitudinal strips was inhibited by the TRPA1 antagonist HC 030031 and atropine or scopolamine, but was insensitive to tetrodotoxin, purinoceptor antagonists or capsaicin desensitization. It is concluded that TRPA1 activation stimulates a cholinergic mechanism in a tetrodotoxin-resistant manner.

  6. Differences in transcriptomic profile and IgA repertoire between jejunal and ileal Peyer's patches.

    PubMed

    Levast, Benoît; De Monte, Michèle; Melo, Sandrine; Chevaleyre, Claire; Berri, Mustapha; Salmon, Henri; Meurens, François

    2010-02-01

    In many species such as sheep and pig, there are two types of Peyer's patches (PP): several discrete patches in the jejunum and a long and continuous patch in the ileum. Most of the immunoglobulin A in the gut is generated by B-cells in the PP germinal centers. Moreover, swine like ovine ileal PP might be important for antigen independent B-cell repertoire diversification. We examined, by quantitative real-time PCR, the expression of 36 transcripts of antimicrobial peptides, chemokines, interleukines, Toll-like receptors and transcription factors from both PP and we highlighted the differences by a principal component analysis. Ileal PP was characterized by a higher mRNA expression of CCL28, IL5, IL10, TLR2 and TLR4 while jejunal PP showed higher mRNA expression of antimicrobial peptides, CCL25, FOXP3, IL4, T-Bet, TSLP and SOCS2. Then, we analyzed some VDJ rearrangements to assess immunoglobulin repertoire diversity in jejunal and ileal PP from weaned piglets. The IgA and IgM repertoires were more diverse in ileal than in jejunal piglet PP. All these results could be related to the rarefaction of interfollicular T-cell zone and the presence in ileal versus jejunal lumen of a more diversified microflora. These findings shed a light on the functional differences between both PP.

  7. Electrophysiological response of chicken's jejunal epithelium to increasing levels of T-2 toxin.

    PubMed

    Yunus, Agha Waqar; Kröger, Susan; Tichy, Alexander; Zentek, Jürgen; Böhm, Josef

    2013-02-01

    The present investigations were conducted to test the effects of T-2 toxin on electrophysiological variables of jejunal epithelium of chicken. Jejunal segments of broilers were monitored in Ussing chambers in the presence of T-2 toxin at the levels of 0 (negative control), 0 (methanol/vehicle control), 0.1, 1, 5, and 10 μg/ml of buffer. T-2 toxin did not affect basal values of short circuit current (I(sc)), transmural potential difference, or tissue conductivity in the jejunal epithelium. T-2 toxin also did not statistically affect glucose-induced electrophysiological variables during the first 3 min of glucose induction. Compared to the vehicle control, the ouabain-sensitive I(sc) was negatively affected (P = 0.008) only under 5 μg of T-2 toxin/ml. Increasing levels of T-2 toxin negatively affected the ouabain-sensitive I(sc) in a cubic (P = 0.007) fashion. These data indicate that acute exposure to moderate levels of T-2 toxin may progressively impair the cation gradient across the jejunal epithelium.

  8. Electroacupuncture at ST37 Enhances Jejunal Motility via Excitation of the Parasympathetic System in Rats and Mice

    PubMed Central

    Yuan, Mengqian; Li, Yuqin; Wang, Yidan; Zhang, Na; Hu, XuanMing; Yin, Yin; Zhu, Bing

    2016-01-01

    Background. The roles of the sympathetic and parasympathetic systems in mediating the effect of electroacupuncture (EA) at ST37 on jejunal motility have yet to be demonstrated. Aim. We used rats and mice to investigate the effect and mechanism of action of EA at ST37 on jejunal motility. Methods. Jejunal motility was recorded by a balloon placed in the jejunum and connected to a biological signal collection system through a transducer. The effects of EA (3 mA) at ST37 were evaluated in Sprague-Dawley rats without drugs and with the administration of clenbuterol, propranolol, acetylcholine, and atropine. Further, the efficacy of EA at different intensities (1/2/4/6/8 mA) was measured in wild-type mice and β1β2−/− mice and M2M3−/− mice. Results. In Sprague-Dawley rats, the excitatory effect of EA at ST37 on jejunal motility disappeared in the presence of the muscarinic receptor antagonist atropine. EA at ST37 was less effective in M2M3−/− mice than in wild-type mice. Furthermore, to a certain extent, there existed “intensity-response” relationship between jejunal motility and EA. Conclusions. EA at ST37 can enhance jejunal motility in rats and mice mainly via excitation of the parasympathetic pathway. There is an “intensity-response” relationship between EA and effect on jejunal motility. PMID:27818700

  9. Interference fringes of m=0 spin states under the Majorana transition caused by rapid half-rotation of a magnetic field

    NASA Astrophysics Data System (ADS)

    Takahashi, Atsushi; Morinaga, Atsuo

    2010-04-01

    The phase shift and visibility of fringes in the Ramsey atom interferometer composed of the |F=1,mF=0> and |F=2,mF=0> states were examined systematically for rapid half-rotation of the magnetic field. It was verified that the phase shifts by π rad in the adiabatic regime, but it does not shift from the original one in the nonadiabatic regime. These results support Robbins and Berry’s claim [J. M. Robbins and M. V. Berry, J. Phys. A 27, L435 (1994)]. The fact that the interference fringes disappear in the intermediate regime and reappear in the nonadiabatic regime can be explained by the Majorana transition caused by a rapid reverse of the magnetic field.

  10. Disruption of the jejunal migrating motor complex by gastric distension and feeding in the dog.

    PubMed Central

    Bull, J S; Grundy, D; Scratcherd, T

    1987-01-01

    1. The jejunal motor response to gastric distension has been quantified in the conscious dog and compared with that of feeding in order to determine the role of the physical bulk of a meal in the conversion from fasted to fed motor activity. 2. In six dogs gastric distension abolished the cyclical migrating motor complex (m.m.c.) and evoked a pattern of continuous irregular jejunal motility similar to that seen postprandially, but only after a latency of 21.5 +/- 2.7 min compared to that of 7.1 +/- 1.2 min for the response to feeding. Computer analysis of distension and fed jejunal motility revealed similar distributions of intervals between contractions and contraction amplitudes with comparable mean values for both. 3. In two dogs with antrum and corpus surgically divided distension of the corpus had a similar effect on jejunal motility although the latency to both distension and feeding were considerably less. 4. By varying the period of distension it has been possible to control accurately the duration of the jejunal motor response and so assess its effectiveness in disrupting the timing of the m.m.c. The return to m.m.c. cycling following deflation was independent of preceding complexes. The occurrence of the post-distension activity front was closely related to the act of deflation itself (R = 0.94) following a latency of 26.2 +/- 2.1 min (n = 39). 5. It is concluded that the bulk of a meal contributes significantly to the early part of postprandial motility and is capable of disrupting the timing of subsequent migrating motor complexes. PMID:3443971

  11. Oncological outcome after free jejunal flap reconstruction for carcinoma of the hypopharynx.

    PubMed

    Chan, Jimmy Yu Wai; Chow, Velda Ling Yu; Chan, Richie Chiu Lung; Lau, Gregory Ian Siu Kee

    2012-07-01

    It has been a common practice among the oncologist to reduce the dosage of adjuvant radiotherapy for patients after free jejunal flap reconstruction. The current aims to study potential risk of radiation to the visceral flap and the subsequent oncological outcome. Between 1996 and 2010, consecutive patients with carcinoma of the hypopharynx requiring laryngectomy, circumferential pharyngectomy and post-operative irradiation were recruited. Ninety-six patients were recruited. TNM tumor staging at presentation was: stage II (40.6%), stage III (34.4%) and stage IV (25.0%). Median follow-up period after surgery was 68 months. After tumor ablation, reconstruction was performed using free jejunal flap (60.4%), pectoralis major myocutaneous (PM) flap (31.3%) and free anterolateral thigh (ALT) flap (8.3%). All patients underwent adjuvant radiotherapy within 6.4 weeks after surgery. The mean total dose of radiation given to those receiving cutaneous and jejunal flap reconstruction was 62.2 Gy and 54.8 Gy, respectively. There was no secondary ischaemia or necrosis of the flaps after radiotherapy. The 5-year actuarial loco-regional tumor control for the cutaneous flap and jejunal flap group was: stage II (61 vs. 69%, p = 0.9), stage III (36 vs. 46%, p = 0.2) and stage IV (32 vs. 14%, p = 0.04), respectively. Reduction of radiation dosage in free jejunal group adversely affects the oncological control in stage IV hypopharyngeal carcinoma. In such circumstances, tubed cutaneous flaps are the preferred reconstructive option, so that full-dose radiotherapy can be given.

  12. The ileal brake--inhibition of jejunal motility after ileal fat perfusion in man.

    PubMed Central

    Spiller, R C; Trotman, I F; Higgins, B E; Ghatei, M A; Grimble, G K; Lee, Y C; Bloom, S R; Misiewicz, J J; Silk, D B

    1984-01-01

    The possibility that malabsorbed fat passing through the human ileum exerts an inhibitory feedback control on jejunal motility has been investigated in 24 normal subjects by perfusing the ileum with a fat containing solution designed to produce ileal luminal fat concentrations similar to those in steatorrhoea (30-40 mg/ml). Mean transit times through a 30 cm saline perfused jejunal segment were measured by a dye dilution technique. Thirty minutes after ileal fat perfusion, mean transit times rose markedly to 18.9 +/- 2.5 minutes from a control value of 7.5 +/- 0.9 minutes (n = 5; p less than 0.05). This was associated with an increase in volume of the perfused segment which rose to 175.1 +/- 22.9 ml (control 97.6 +/- 10.3 ml, n = 5; p less than 0.05). Transit times and segmental volumes had returned towards basal values 90 minutes after completing the fat perfusion. Further studies showed that ileal fat perfusion produced a pronounced inhibition of jejunal pressure wave activity, percentage duration of activity falling from a control level of 40.3 +/- 5.0% to 14.9 +/- 2.8% in the hour after ileal perfusion (p less than 0.01). Ileal fat perfusion was associated with marked rises in plasma enteroglucagon and neurotensin, the peak values (218 +/- 37 and 68 +/- 13.1 pmol/l) being comparable with those observed postprandially in coeliac disease. These observations show the existence in man of an inhibitory intestinal control mechanism, whereby ileal fat perfusion inhibits jejunal motility and delays caudal transit of jejunal contents. PMID:6706215

  13. Did clockwise rotation of Antarctica cause the break-up of Gondwanaland? An investigation in the 'deep-keeled cratons' frame for global dynamics

    NASA Astrophysics Data System (ADS)

    Osmaston, M. F.

    2012-04-01

    Introduction. The 'deep-keeled cratons' frame for global dynamics is the result of seeking Earth-behaviour answers to the following outside-the-box proposition:- "If cratons have tectospheric keels that reach or approach the 660 km discontinuity, AND the 660 level is an effective barrier to mantle circulation, then obviously (i) when two cratons separate, the upper mantle to put under the nascent ocean must arrive by a circuitous route and, conversely, (ii) if they approach one another, the mantle volume that was in between them must get extruded sideways." Surprisingly it has turned out [1 - 4] that Earth dynamical behaviour for at least the past 150 Ma provides persuasive affirmation of both these expectations and that there is a rational petrological explanation for the otherwise-unexpected immobility of subcratonic material to such depths [5 - 7]. Clockwise rotation of Antarctica? This contribution greatly amplifies my original plate dynamical arguments for suggesting [8] that such rotation is ongoing. Convection is unsuited to causing rotation about a pole within the plate so, as noted then, a gearwheel-like linkage to Africa at the SWIR would provide its clearly CCW (Biscay-Caucasus) relationship to the Mediterranean belt for the past 100 Ma, also seen in its separation from South America. Gearwheel-like linkage of motion requires the presence of some kind of E-W restraint further north. In that case it was the N Africa/Arabia involvement in the Alpide belt, but the earlier opening of the central Atlantic by the eastward motion of Africa, suggests its rigid Gondwanan attachment to Antarctica rotation at that time, with little constraint in the north. Further east, the seafloor data show that Australia-Antarctica separation involved no such opposite rotational linkage, so, with no E-W mechanical constraint in the north by Indonesia, they must have rotated together, as is recorded by Australia's eastward motion to generate the Mesozoic seafloor at its western

  14. Jejunal intussusception caused by metastasis of a giant cell carcinoma of the lung

    PubMed Central

    Fujii, Yuki; Homma, Shigenori; Yoshida, Tadashi; Taketomi, Akinobu

    2016-01-01

    A 55-year-old woman was admitted to our hospital reporting of nausea, vomiting and anorexia. One month before admission, she had been diagnosed with lung cancer with intestinal metastasis. A CT scan confirmed intussusception due to intestinal metastasis and she underwent emergency laparoscopic surgery followed by resection of the primary lung cancer. Histopathological findings of the intestinal specimen suggested the metastasis was from a giant cell carcinoma of the lung, which had extensive necrosis. She was still alive without recurrence 11 months after the first surgery. Giant cell carcinoma of the lung is a rare type of non-small cell carcinoma and intestinal metastasis is one of the unique features. This type of tumour has such aggressive characteristics that oncological prognosis is reported to be extremely poor. In our case, however, complete surgical resection of both primary and metastatic tumours might result in a better outcome than has been reported. PMID:27485876

  15. Free jejunal flap for pharyngoesophageal reconstruction in head and neck cancer patients: An evaluation of donor site complications

    PubMed Central

    Razdan, Shantanu N.; Albornoz, Claudia R.; Matros, Evan; Paty, Philip B.; Cordeiro, Peter G.

    2016-01-01

    Background Free jejunal transfer for pharyngoesophageal reconstruction has often been criticized for its associated donor site morbidity. Conversely, the same argument has been invoked to support use of fasciocutaneous flaps, given their low incidence of donor site complications. The purpose of the current study was to document donor site complication rate with free jejunal flaps for pharyngoesophageal reconstruction, in the hands of an experienced surgeon. Methods A retrospective chart review was performed of consecutive patients who underwent free jejunal transfer between 1992 and 2012 by the senior author. Demographic data, abdominal complications, surgical characteristics of small bowel anastomoses and postoperative bowel function were specifically noted. Results Ninety-two jejunal flap reconstructions were performed in 90 patients. Mean follow up time was 29 months. Twelve (13%) patients had prior abdominal surgery. Donor site complications included ileus (n=2), wound cellulitis (n=1), wound dehiscence (n=1) and small bowel obstruction (n=1). Mean time to initiation of tube feeds after reconstruction was 5 days. Seventy-seven (86.5%) patients were discharged on an oral diet. The perioperative mortality rate of 2% was not associated with any donor site complication. Conclusion Free jejunal transfer is associated with minimal and acceptable donor site complication rates. The choice of flap for pharyngoesophageal reconstruction should be determined by the type of defect, potential recipient site complications and the surgeon’s familiarity with the flap. Potential donor site complications should not be a deterrent for free jejunal flaps given the low rate described in this study. PMID:26220434

  16. Jejunal ultrastructural changes induced by kidney bean (Phaseolus vulgaris) lectins in rats.

    PubMed

    Rossi, M A; Mancini Filho, J; Lajolo, F M

    1984-02-01

    Rats maintained for a period of 5 days on a diet containing purified lectins extracted from a Brazilian variety (called 'Jalo') of white kidney beans (Phaseolus vulgaris) developed marked ultrastructural changes in the epithelium of the proximal jejunum, while both pair-fed and ad-libitum-fed controls did not. The jejunal absorptive cells of rats fed a diet containing lectins exhibited conspicuous abnormalities of the microvilli. They were shorter, slightly thicker, irregular and more sparse; some were bi- or tri-furcated, sharing a common base of implantation. A slightly disorganized terminal web was present below the brush border. The supranuclear cytoplasm of a great number of cells exhibited large cytolysosomes. Comparison with the results of pair-feeding suggests that purified bean lectins have a direct causative role in the pathogenesis of absorptive cell changes in the jejunal villi of rats. The possible pathogenic mechanism of these lesions is discussed.

  17. Jejunal ultrastructural changes induced by kidney bean (Phaseolus vulgaris) lectins in rats.

    PubMed Central

    Rossi, M. A.; Mancini Filho, J.; Lajolo, F. M.

    1984-01-01

    Rats maintained for a period of 5 days on a diet containing purified lectins extracted from a Brazilian variety (called 'Jalo') of white kidney beans (Phaseolus vulgaris) developed marked ultrastructural changes in the epithelium of the proximal jejunum, while both pair-fed and ad-libitum-fed controls did not. The jejunal absorptive cells of rats fed a diet containing lectins exhibited conspicuous abnormalities of the microvilli. They were shorter, slightly thicker, irregular and more sparse; some were bi- or tri-furcated, sharing a common base of implantation. A slightly disorganized terminal web was present below the brush border. The supranuclear cytoplasm of a great number of cells exhibited large cytolysosomes. Comparison with the results of pair-feeding suggests that purified bean lectins have a direct causative role in the pathogenesis of absorptive cell changes in the jejunal villi of rats. The possible pathogenic mechanism of these lesions is discussed. Images Fig. 1 Fig. 2 Fig. 3 PMID:6696828

  18. The Combination of Gastroschisis, Jejunal Atresia, and Colonic Atresia in a Newborn

    PubMed Central

    Bauman, Zachary; Nanagas, Victor

    2015-01-01

    We encountered a rare case of gastroschisis associated with jejunal atresia and colonic atresia. In our case, the jejunal atresia was not discovered for 27 days after the initial abdominal wall closure. The colonic atresia was not discovered for 48 days after initial repair of the gastroschisis secondary to the rarity of the disorder. Both types of atresia were repaired with primary hand-sewn anastomoses. Other than the prolonged parenteral nutrition and hyperbilirubinemia, our patient did very well throughout his hospital course. Based on our case presentation, small bowel atresia and colonic atresia must be considered in patients who undergo abdominal wall closure for gastroschisis with prolonged symptoms suggestive of bowel obstruction. Our case report also demonstrates primary enteric anastomosis as a safe, well-tolerated surgical option for patients with types of intestinal atresia. PMID:26180651

  19. Lanreotide inhibits human jejunal secretion induced by prostaglandin E1 in healthy volunteers.

    PubMed

    Sobhani, I; René, E; Ramdani, A; Bayod, F; Sabbagh, L C; Thomas, F; Mignon, M

    1996-02-01

    1. Somatostatin inhibits hormonal secretions in the gastrointestinal tract. Somatostatin analogues are used in the treatment of VIPome-related watery diarrhoea. In addition, more than 10% of patients with AIDS suffer from diarrhoea likely due to the increased intestinal secretion of water and ions. However, the direct effect of somatostatin on the flux of water and ions in the intestine has not been, so far, analyzed in vivo. The aim of the present study was to evaluate the effect of lanreotide, a somatostatin analogue, on the movements of water and ions in the jejunum in man. 2. Accordingly, 10 healthy volunteers (age 18-35 years, mean 27) and two patients with AIDS (26 and 33 years) suffering from water diarrhoea (> 800 ml day-1) underwent intestinal perfusion using a four lumen tube with proximal occluding balloon. The segment tested was 25 cm long. The jejunum was infused by an isotonic control saline solution containing polyethylene glycol (PEG) as nonabsorbable marker. Basal jejunal secretions were measured in all subjects. Prostaglandin E1 (PGE1) was administered intraluminally to stimulate jejunal secretion in healthy volunteers. The effect of intravenous lanreotide on the jejunal PGE1-induced secretions of water and electrolytes was analysed in healthy subjects and on the basal secretions in AIDS patients. Each period was analyzed on the basis of three (10 min) successive intestinal juice collections after 20-30 min equilibration time. The antisecretory effect of lanreotide was evaluated in each subject as the difference between fluxes compared to the control period. 3. In healthy volunteers, PGE1 induced secretion of H2O, Na+, K+ and Cl- in the jejunum and lanreotide reduced significantly PGE1-induced response. In both AIDS patients basal fluxes of water and ions were reduced by lanreotide in a dose-dependent manner. 4. Somatostatin can reduce stimulated-jejunal secretion of ions and water in normal subjects and may improve water diarrhoea in AIDS

  20. Chloride ion transport into pig jejunal brush-border membrane vesicles.

    PubMed Central

    Forsyth, G W; Gabriel, S E

    1988-01-01

    1. This study was carried out to determine the types and activities of carrier proteins which transport the chloride ion in pig jejunal brush-border membranes, with an emphasis on studying the properties of chloride conductance activity in vesicles prepared from these membranes. 2. Sodium-chloride co-transport activity was not detected in this tissue. A sodium-proton antiport with typical amiloride sensitivity was present. An anion exchanger linking chloride to hydroxyl or bicarbonate ions was also found in the pig jejunal brush-border membrane vesicles. 3. Chloride conductance activity in this system was specifically dependent on the buffering agents used for vesicle preparation. Conductance activity could not be demonstrated in vesicles prepared in imidazolium acetate or in HEPES-Tris buffers. HEPES-tetramethylammonium buffering of vesicles in the chloride uptake system produced a significant conductance response to a potassium gradient plus valinomycin. 4. Chloride conductance showed saturable kinetics with respect to substrate concentration, with a Michaelis-Menten constant (Km) of approximately 116 mM and a maximum velocity (Vmax) of 132 nmol (mg protein)-1 min-1. 5. Preliminary screening of potential inhibitors of chloride conductance showed only minimal inhibitor effects of SITS (4-acetamido-4'-isothiocyanostilbene-2,2'-sulphonic acid), anthracene-9-carboxylate, N-phenylanthranilate and piretanide. 6. The conductance activity in pig jejunal vesicles appears to have stringent buffer requirements, and to be relatively insensitive to the effects of reported conductance inhibitors. PMID:2466986

  1. Intestinal absorptive capacity, intestinal permeability and jejunal histology in HIV and their relation to diarrhoea.

    PubMed Central

    Keating, J; Bjarnason, I; Somasundaram, S; Macpherson, A; Francis, N; Price, A B; Sharpstone, D; Smithson, J; Menzies, I S; Gazzard, B G

    1995-01-01

    Intestinal function is poorly defined in patients with HIV infection. Absorptive capacity and intestinal permeability were assessed using 3-O-methyl-D-glucose, D-xylose, L-rhamnose, and lactulose in 88 HIV infected patients and the findings were correlated with the degree of immunosuppression (CD4 counts), diarrhoea, wasting, intestinal pathogen status, and histomorphometric analysis of jejunal biopsy samples. Malabsorption of 3-O-methyl-D-glucose and D-xylose was prevalent in all groups of patients with AIDS but not in asymptomatic, well patients with HIV. Malabsorption correlated significantly (r = 0.34-0.56, p < 0.005) with the degree of immune suppression and with body mass index. Increased intestinal permeability was found in all subgroups of patients. The changes in absorption-permeability were of comparable severity to those found in patients with untreated coeliac disease. Jejunal histology, however, showed only mild changes in the villus height/crypt depth ratio as compared with subtotal villus atrophy in coeliac disease. Malabsorption and increased intestinal permeability are common in AIDS patients. Malabsorption, which has nutritional implications, relates more to immune suppression than jejunal morphological changes. PMID:8549936

  2. Jejunal bypass stimulation of pancreatic growth and cholecystokinin secretion in rats: importance of luminal nutrients.

    PubMed Central

    Levan, V H; Liddle, R A; Green, G M

    1987-01-01

    The effect of jejunal bypass on pancreatic growth and plasma cholecystokinin (CCK) was investigated in rats. Rats underwent bypass of jejunum or sham operation. Rats with jejunal bypass were further divided into three groups; one group received a continuous infusion of a partially hydrolysed liquid diet (Vital) into the bypassed jejunum; a second group received the nutrient solution mixed with trypsin and infused into the bypassed jejunum; the third bypass group did not receive infusion of nutrient or trypsin into the jejunum. Jejunal bypass alone did not significantly stimulate pancreatic growth or DNA content at one or two weeks postoperative. Infusion of nutrient solution into the bypassed jejunum stimulated pancreatic growth and DNA content, with maximal increases of 185% and 181% for pancreatic weight and DNA content, respectively, at two weeks. This coincided with significant increases in postabsorptive plasma CCK concentrations. Infusion of pancreatic proteases into the bypassed jejunum partially reversed the effects of nutrient infusion. These results suggest that exclusion of bile-pancreatic juice or pancreatic proteases from the jejunum does not lead to maximal release of CCK unless the jejunum receives luminal nutrients. It is proposed that CCK release from rat jejunum occurs spontaneously in the absence of pancreatic proteases, and that luminal nutrients in bypassed jejunum increase plasma CCK and stimulate pancreatic growth by maintaining synthesis of CCK. PMID:3692314

  3. Microvascular Reconstruction of Free Jejunal Graft in Larynx-preserving Esophagectomy for Cervical Esophageal Carcinoma

    PubMed Central

    Natori, Yuhei; Komoto, Masakazu; Matsumura, Takashi; Horiguchi, Masatoshi; Yoshizawa, Hidekazu; Iwanuma, Yoshimi; Tsurumaru, Masahioko; Kajiyama, Yoshiaki; Mizuno, Hiroshi

    2016-01-01

    Background: Losing the ability to speak severely affects the quality of life, and patients who have undergone laryngectomy tend to become depressed, which may lead to social withdrawal. Recently, with advancements in chemoradiotherapy and with alternative perspectives on postoperative quality of life, larynx preservation has been pursued; however, the selection of candidates and the optimal reconstructive procedure remain controversial. In this study, we retrospectively reviewed our experience with free jejunal graft for larynx-preserving cervical esophagectomy (LPCE), focusing on microvascular reconstruction. Methods: Seven patients underwent LPCE for cervical esophageal carcinoma, and defects were reconstructed by free jejunal transfer subsequently. We collected preoperative and postoperative data of the patients and assessed the importance of the procedure. Results: We mostly used the transverse cervical artery as the recipient, and a longer operative time was required, particularly for the regrowth cases. The operative field for microvascular anastomosis was more limited and deeper than those in the laryngectomy cases. Two graft necrosis cases were confirmed at postoperative day 9 or 15, and vessels contralateral from the graft were chosen as recipients in both patients. Conclusions: Microvascular reconstruction for free jejunal graft in LPCE differed in several ways from the procedure combined with laryngectomy. Compression from the tracheal cartilage to the pedicle was suspected as the reason of the necrosis clinically and pathologically. Therefore, we should select recipient vessels from the ipsilateral side of the graft, and careful and extended monitoring of the flap should be considered to make this procedure successful. PMID:27257562

  4. Abnormal leukotriene C4 released by unaffected jejunal mucosa in patients with inactive Crohn's disease.

    PubMed Central

    Casellas, F; Guarner, F; Antolín, M; Rodríguez, R; Salas, A; Malagelada, J R

    1994-01-01

    The mucosal release of inflammatory mediators is enhanced in active inflammatory bowel disease. This study examines whether leukotriene C4 production occurs in apparently unaffected segments of the gut. The intraluminal release of leukotriene C4 was determined by jejunal perfusion in seven healthy controls, in nine patients with chronic ulcerative colitis, and in 13 patients with Crohn's disease (six with ileal disease, and seven with only colonic). All patients were in clinical remission and none of them had evidence of jejunal involvement. Mild intraluminal irritation with a 2.5 mmol/l deoxycholic acid solution was induced to stimulate local inflammatory mechanisms. The release of DNA (a marker of mucosal desquamation) and prostaglandin E2 (PGE2) was simultaneously measured. Jejunal release of DNA was higher in Crohn's disease patients than in ulcerative colitis or healthy controls. Basal release of PGE2 was similar in the three groups of patients. Basal release of leukotriene C4 was considerably enhanced, however, in Crohn's disease patients compared with healthy controls. In ulcerative colitis patients, basal leukotriene C4 release was non-significantly different from controls. Bile acid perfusion stimulated PGE2, leukotriene C4, and DNA release in all groups studied, but leukotriene C4 release was significantly higher in Crohn's disease patients. It is concluded that in inactive Crohn's disease there is an enhanced intraluminal release of leukotriene C4 in apparently unaffected segments of proximal small bowel, which may reflect fundamental changes in the function of the gut mucosal barrier. PMID:8174991

  5. Jejunal wall triglyceride concentration of morbidly obese persons is lower in those with type 2 diabetes mellitus.

    PubMed

    Soriguer, F; García-Serrano, S; Garrido-Sánchez, L; Gutierrez-Repiso, C; Rojo-Martínez, G; Garcia-Escobar, E; García-Arnés, J; Gallego-Perales, J L; Delgado, V; García-Fuentes, Eduardo

    2010-12-01

    The overproduction of intestinal lipoproteins may contribute to the dyslipidemia found in diabetes. We studied the influence of diabetes on the fasting jejunal lipid content and its association with plasma lipids and the expression of genes involved in the synthesis and secretion of these lipoproteins. The study was undertaken in 27 morbidly obese persons, 12 of whom had type 2 diabetes mellitus (T2DM). The morbidly obese persons with diabetes had higher levels of chylomicron (CM) triglycerides (P < 0.001) and apolipoprotein (apo)B48 (P = 0.012). The jejunum samples obtained from the subjects with diabetes had a lower jejunal triglyceride content (P = 0.012) and angiopoietin-like protein 4 (ANGPTL4) mRNA expression (P = 0.043). However, the apoA-IV mRNA expression was significantly greater (P = 0.036). The jejunal triglyceride content correlated negatively with apoA-IV mRNA expression (r = -0.587, P = 0.027). The variables that explained the jejunal triglyceride content in a multiple linear regression model were the insulin resistance state and the apoA-IV mRNA expression. Our results show that the morbidly obese subjects with diabetes had lower jejunal lipid content and that this correlated negatively with apoA-IV mRNA expression. These findings show that the jejunum appears to play an active role in lipid homeostasis in the fasting state.

  6. Fractionated low doses of abdominal irradiation alters jejunal uptake of nutrients

    SciTech Connect

    Thomson, A.B.; Keelan, M.; Cheeseman, C.I.; Walker, K.

    1986-06-01

    Abdominal radiation is associated with changes in intestinal uptake of nutrients that begins within three days and persist for over 33 weeks. Clinically, fractionated doses of radiation (FDR) are used in an attempt to minimize the complications of this therapy, but the effects of fractionated doses of radiation on intestinal transport have not been defined. An in vitro technique was used to assess the jejunal and ileal uptake of varying concentrations of glucose and leucine, as well as the uptake of single concentrations of fatty acids and decanol in rats exposed 3, 7, and 14 days previously to a course of 200 cGy given on each of five consecutive days. FDR was associated with an increase in the uptake of decanol, and therefore a decrease in the effective resistance of the unstirred water layer. FDR had a variable effect on the uptake of glucose and leucine, with a decline in the value of the Michaelis constant (Km) and the passive permeability coefficient for glucose (Pd), whereas the Km for leucine was unchanged and the Pd for leucine was variably affected by FDR. The maximal transport rate (Jdm) for leucine progressively rose following FDR, whereas the Jdm for glucose initially rose, then fell. The uptake of galactose and medium chain-length fatty acids was unchanged by FDR, whereas the jejunal uptake of myristic acid rose, and the uptake of cholic acid declined, then returned to normal. FDR was associated with greater body weight gain and jejunal and ileal weight. The changes in nutrient uptake following FDR differed from the absorption changes occurring after a single dose of radiation. Thus, fractionated doses of abdominal radiation produce complex changes in the intestinal uptake of actively and passively transported nutrients, and these variable changes are influenced by the time following radiation exposure and by the solute studied.

  7. Cystic jejunal duplication with Heinrich’s type I ectopic pancreas, incidentally discovered in a patient with pancreatic tail neoplasm

    PubMed Central

    Gurzu, Simona; Bara Jr, Tivadar; Bara, Tivadar; Fetyko, Annamaria; Jung, Ioan

    2016-01-01

    The aim of this study was to present a case of enteric duplication cyst and criteria for a proper differential diagnosis. A 51-year-old male was hospitalized for pancreatic tail neoplasm and distal pancreatectomy with splenectomy was performed. During surgery, a jejunal cystic lesion was incidentally detected and jejunectomy was performed. Microscopically, the cyst was observed to be covered by Keratin 7/Keratin 20 positive intestinal type epithelium and the muscularis layer was shared by the cyst and adjacent jejunum, without a cleavage plane between the cyst wall and jejunal muscularis propria. In the deep muscularis propria, a Heinrich’s type I ectopic pancreas was also noted. In the pancreatic tail, a low grade intraepithelial lesion (panIN-1a) was diagnosed. This case highlights the necessity for a correct differential diagnosis of such rare lesions. Roughly 30 cases of jejunal duplication cysts have been reported to date in the PubMed database. PMID:27672644

  8. Multiple jejunal cancers resulting from combination of germline APC and MLH1 mutations.

    PubMed

    Lindor, Noralane M; Smyrk, Tom C; Buehler, Sheila; Gunawardena, Shanaka R; Thomas, Brittany C; Limburg, Paul; Kirmani, Salman; Thibodeau, Stephen N

    2012-12-01

    Double heterozygotes for mutations in APC and a DNA mismatch repair gene are extremely rare. We report on an individual who had truncating mutations in APC and MLH1 whose clinical presentation initially resembled Familial Adenomatous Polyposis but then emerged as a novel phenotype with multiple jejunal carcinomas. We have reviewed the relevant literature on double heterozygotes and based on what has been reported to date, this phenotype was not anticipated. It may be useful for clinicians to be aware of this observation as clinical screening guidelines are proposed for such individuals.

  9. Rotating Vesta

    NASA Video Gallery

    Astronomers combined 146 exposures taken by NASA's Hubble SpaceTelescope to make this 73-frame movie of the asteroid Vesta's rotation.Vesta completes a rotation every 5.34 hours.› Asteroid and...

  10. Four-photon spectroscopy of rotational transitions in liquid: recording of changes in the chemical composition of water caused by cavitation

    SciTech Connect

    Bunkin, Aleksei F; Pershin, S M

    2010-05-26

    It is shown for the first time by the method of four-photon coherent scattering by rotational molecular resonances that the cavitation action on water changes its chemical composition, resulting in the formation of hydrogen peroxide. It is found that the concentration of hydrogen peroxide during cavitation grows by several times and depends on the cavitation process technology.

  11. A case of lymphocytic-plasmacytic jejunitis diagnosed by double-balloon enteroscopy in a dog.

    PubMed

    Ayala, Ignacio; Latorre, Rafael; Soria, Federico; Carballo, Fernando; Lopez-Albors, Octavio; Buendia, Antonio J; Perez-Cuadrado, Enrique

    2011-01-01

    A 3 yr old male English setter dog was presented for evaluation of a 6-wk history of intermittent diarrhea. After standard gastroduodenoscopy and colonoscopy showed normal mucosa, double-balloon endoscopy (DBE) was used via both oral and anal approaches. Gross changes consistent with inflammation in the jejunum were seen, and biopsy specimens were obtained. Histologic analysis confirmed a diagnosis of lymphocytic-plasmacytic jejunitis. Clinical remission of the disease occurred after 3 mo of therapy with prednisone, metronidazole, and a novel protein diet. Use of DBE has not been previously reported in dogs with inflammatory bowel disease, and isolated lymphocytic-plasmacytic jejunitis has not been described. The described cases of intestinal inflammatory disease diagnosed by conventional endoscopy were related to pathologic changes in the duodenum, ileum or colon, but not the jejunum. The main advantage of the DBE technique allowed examination of portions of the small intestine (jejunum) that were not commonly accessible by standard endoscopic techniques, and permitted a minimally invasive collection of biopsy samples compared with surgical biopsy. This case highlights the need to consider using DBE in animals with gastrointestinal disorders, whose symptoms are not readily explained by routine tests, conventional endoscopy, and dietary or therapeutic trials.

  12. Experiment K-7-17: Effects of Spaceflight on the Proliferation of Jejunal Mucosal Cells

    NASA Technical Reports Server (NTRS)

    Phillips, R. W.; Moeller, C. L.; Sawyer, H. R.; Smirnov, K. L.

    1994-01-01

    The purpose of this project was to test the hypothesis that the generalized, whole body decrease in synthetic activity due to microgravity conditions encountered during spaceflight would be demonstrable in cells and tissues characterized by a rapid rate of turnover. Jejunal mucosal cells were chosen as a model since these cells are among the most rapidly proliferating in the body. Accordingly, the percentage of mitotic cells present in the crypts of Lieberkuhn in each of 5 rats flown on the COSMOS 2044 mission were compared to the percentage of mitotic cells present in the crypts in rats included in each of 3 ground control groups (i.e., vivarium, synchronous and caudal-elevated). No significant difference (p greater than .05) was detected in mitotic indices between the flight and vivarium group. Although the ability of jejunal mucosal cells to divide by mitosis was not impaired in flight group, there was, however, a reduction in the length of villi and depth of crypts. The concommitant reduction in villus length and crypth depth in the flight group probably reflects changes in connective tissue components within the core of villi.

  13. Vagal influences on the jejunal 'minute rhythm' in the anaesthetized ferret.

    PubMed Central

    Collman, P I; Grundy, D; Scratcherd, T

    1983-01-01

    Spontaneous jejunal motility in the urethane-anaesthetized ferret shows a cyclical pattern of contraction bursts alternating with quiescent periods described as 'minute rhythm' in conscious animals. Cooling the cervical vagi to below 4 degrees C or acute vagotomy abolished this pattern of motility. On re-warming the vagi there was a return to cyclical motility after a latency which depended upon the contractile state at the time vagal conduction was restored. Electrical vagal stimulation produced bursts of contractions at the same frequency as the spontaneous motility. Longer periods of stimulation gave rise to bursts of contractions interrupted by periods of relative quiescence, mimicking the spontaneous motility, despite the continuous stimulation. Following atropinization all spontaneous motility was abolished, but electrical stimulation of the vagi revealed a non-cholinergic, non-adrenergic response whose characteristics differed from that of the cholinergic response. It is concluded that the vagus plays a permissive role in regulating the jejunal 'minute rhythm' via a cholinergic pathway and that there is a second excitatory vagal pathway which innervates non-cholinergic post-ganglionic neurones whose functional significance and transmitter mechanism is unknown. PMID:6663513

  14. An unusual presentation of a malignant jejunal tumor and a different management strategy.

    PubMed

    Samaiya, Atul; Deo, Sv Suryanarayana; Thulkar, Sanjay; Hazarika, Sidhartha; Kumar, Sunil; Parida, Dillip K; Shukla, Nootan K

    2005-01-09

    BACKGROUND: Malignant small bowel tumors are very rare and leiomyosarcoma accounts for less than 15% of the cases. Management of these tumors is challenging in view of nonspecific symptoms, unusual presentation and high incidence of metastasis. In this case report, an unusual presentation of jejunal sarcoma and management of liver metastasis with radiofrequency ablation (RFA) is discussed. CASE PRESENTATION: A 45-year-old male presented with anemia and features of small bowel obstruction. Operative findings revealed a mass lesion in jejunum with intussusception of proximal loop. Resection of bowel mass was performed. Histopathological findings were suggestive of leiomyosarcoma. After 3-years of follow-up, the patient developed recurrence in infracolic omentum and a liver metastasis. The omental mass was resected and liver lesion was managed with radiofrequency ablation. CONCLUSION: Jejunal leiomyosarcoma is a rare variety of malignant small bowel tumor and a clinical presentation with intussusception is unusual. We suggest that an aggressive management approach using a combination of surgery and a newer technique like RFA can be attempted in patients with limited metastatic spread to liver to prolong the long-term survival in a subset of patients.

  15. [Anastomotic false-diverticulum causing an atypical dumping syndrome. A case report].

    PubMed

    Covarelli, P; Esperti, L; Fratto, A; Cerroni, M; Marianeschi, P; Cristofani, R

    2003-02-01

    Aim of the study is to evaluate the causes of dumping syndromes following partial gastrectomies, and to report an unusual feature of dumping. A case of early dumping due to diverticular-like dilation of gastro-jejunal anastomosis is described with preoperative imaging and intraoperative picture. The surgical correction led to complete clinical remission; the common causes and physiopathological bases of dumping are reviewed and the role of en-Y gastro-jejunal reconstruction is underlined in order to reduce the risk of developing the syndrome.

  16. Rotational testing.

    PubMed

    Furman, J M

    2016-01-01

    The natural stimulus for the semicircular canals is rotation of the head, which also might stimulate the otolith organs. Vestibular stimulation usually induces eye movements via the vestibulo-ocular reflex (VOR). The orientation of the subject with respect to the axis of rotation and the orientation of the axis of rotation with respect to gravity together determine which labyrinthine receptors are stimulated for particular motion trajectories. Rotational testing usually includes the measurement of eye movements via a video system but might use a subject's perception of motion. The most common types of rotational testing are whole-body computer-controlled sinusoidal or trapezoidal stimuli during earth-vertical axis rotation (EVAR), which stimulates primarily the horizontal semicircular canals bilaterally. Recently, manual impulsive rotations, known as head impulse testing (HIT), have been developed to assess individual horizontal semicircular canals. Most types of rotational stimuli are not used routinely in the clinical setting but may be used in selected research environments. This chapter will discuss clinically relevant rotational stimuli and several types of rotational testing that are used primarily in research settings.

  17. Dietary Leucine Supplementation Improves the Mucin Production in the Jejunal Mucosa of the Weaned Pigs Challenged by Porcine Rotavirus.

    PubMed

    Mao, Xiangbing; Liu, Minghui; Tang, Jun; Chen, Hao; Chen, Daiwen; Yu, Bing; He, Jun; Yu, Jie; Zheng, Ping

    2015-01-01

    The present study was mainly conducted to determine whether dietary leucine supplementation could attenuate the decrease of the mucin production in the jejunal mucosa of weaned pigs infected by porcine rotavirus (PRV). A total of 24 crossbred barrows weaned at 21 d of age were assigned randomly to 1 of 2 diets supplemented with 1.00% L-leucine or 0.68% L-alanine (isonitrogenous control) for 17 d. On day 11, all pigs were orally infused PRV or the sterile essential medium. During the first 10 d of trial, dietary leucine supplementation could improve the feed efficiency (P = 0.09). The ADG and feed efficiency were impaired by PRV infusion (P<0.05). PRV infusion also increased mean cumulative score of diarrhea, serum rotavirus antibody concentration and crypt depth of the jejunal mucosa (P<0.05), and decreased villus height: crypt depth (P = 0.07), goblet cell numbers (P<0.05), mucin 1 and 2 concentrations (P<0.05) and phosphorylated mTOR level (P<0.05) of the jejunal mucosa in weaned pigs. Dietary leucine supplementation could attenuate the effects of PRV infusion on feed efficiency (P = 0.09) and mean cumulative score of diarrhea (P = 0.09), and improve the effects of PRV infusion on villus height: crypt depth (P = 0.06), goblet cell numbers (P<0.05), mucin 1 (P = 0.08) and 2 (P = 0.07) concentrations and phosphorylated mTOR level (P = 0.08) of the jejunal mucosa in weaned pigs. These results suggest that dietary 1% leucine supplementation alleviated the decrease of mucin production and goblet cell numbers in the jejunal mucosa of weaned pigs challenged by PRV possibly via activation of the mTOR signaling.

  18. Spatial variability of soil total and DTPA-extractable cadmium caused by long-term application of phosphate fertilizers, crop rotation, and soil characteristics.

    PubMed

    Jafarnejadi, A R; Sayyad, Gh; Homaee, M; Davamei, A H

    2013-05-01

    Increasing cadmium (Cd) accumulation in agricultural soils is undesirable due to its hazardous influences on human health. Thus, having more information on spatial variability of Cd and factors effective to increase its content on the cultivated soils is very important. Phosphate fertilizers are main contamination source of cadmium (Cd) in cultivated soils. Also, crop rotation is a critical management practice which can alter soil Cd content. This study was conducted to evaluate the effects of long-term consumption of the phosphate fertilizers, crop rotations, and soil characteristics on spatial variability of two soil Cd species (i.e., total and diethylene triamine pentaacetic acid (DTPA) extractable) in agricultural soils. The study was conducted in wheat farms of Khuzestan Province, Iran. Long-term (27-year period (1980 to 2006)) data including the rate and the type of phosphate fertilizers application, the respective area, and the rotation type of different regions were used. Afterwards, soil Cd content (total or DTPA extractable) and its spatial variability in study area (400,000 ha) were determined by sampling from soils of 255 fields. The results showed that the consumption rate of di-ammonium phosphate fertilizer have been varied enormously in the period study. The application rate of phosphorus fertilizers was very high in some subregions with have extensive agricultural activities (more than 95 kg/ha). The average and maximum contents of total Cd in the study region were obtained as 1.47 and 2.19 mg/kg and DTPA-extractable Cd as 0.084 and 0.35 mg/kg, respectively. The spatial variability of Cd indicated that total and DTPA-extractable Cd contents were over 0.8 and 0.1 mg/kg in 95 and 25 % of samples, respectively. The spherical model enjoys the best fitting and lowest error rate to appraise the Cd content. Comparing the phosphate fertilizer consumption rate with spatial variability of the soil cadmium (both total and DTPA extractable) revealed the high

  19. Intussusception and volvulus secondary to jejunal adenocarcinoma in an adult Nigerian male: a case report.

    PubMed

    Okolo, C A; Afolabi, A O; Sahabi, S M

    2010-12-01

    A 31 year-old Nigerian man with jejuno-jejunal intussusception with the lead point being an adenocarcinoma complicated by small intestinal volvulus is presented. The subtle clinical features of an underlying small bowel malignancy were masked by the overwhelming clinical and radiological features of intussusception. rare case is reported to remind clinicians to have an increased index of suspicion of malignancy in patients who present with the usual features of chronic anemia, weight loss and loss of appetite with an intra-abdominal mass. The presentation of acute intestinal obstruction, with mesenteric vein thrombosis probably due to intussusception or volvulus should not however lower the suspicion. Histological evaluation of surgical biopsies is of immense importance.

  20. Kinetics of changes in the crypts of the jejunal mucosa of dimethylhydrazine-treated rats.

    PubMed Central

    Sunter, J. P.; Appleton, D. R.; Wright, N. A.; Watson, A. J.

    1978-01-01

    When symmetrical 1,2 dimethylhydrazine was administered to rats by weekly s.c. injection, 37% of the animals had developed small intestinal carcinomas after 21-27 weeks. These lesions were largely localized to duodenum and upper jejunum. At the same time there was a diffuse crypt hyperplasia in the jejunum which affected all the treated animals, not just those with neoplasms. This marked hyperplasia was preceded by a modest sustained crypt elongation which was seen soon after DMH injections began. In these hyperplastic jejunal crypts the absolute size of the proliferative compartment was increased, but the growth fraction calculated from labelling studies appeared to fall, probably by reduction in relative size of the proliferating population within the proliferative compartment. No convincing alteration in actual cell-cycle time was observed in the abnormal crypts. There was a slight (25%) increase in cell-production rate in the abnormal crypts. Images Fig. 1 PMID:656298

  1. Effect of genetically modified corn on the jejunal mucosa of adult male albino rat.

    PubMed

    Ibrahim, Marwa A A; Okasha, Ebtsam F

    2016-11-01

    Genetically modified (GM) plants expressing insecticidal traits offer a new strategy for crop protection. GM-corn contains Bacillus thuringiensis (Bt) genes producing delta endotoxins in the whole plant. Diet can influence the characteristics of the gastrointestinal tract altering its function and structure. The aim of this study was to evaluate the effect of GM-corn on the histological structure of jejunal mucosa of adult male albino rat using different histological, immunohistochemical and morphometrical methods. Twenty adult male albino rats were divided into two equal groups; control and GM-corn fed group administered with 30% GM-corn for 90days. Specimens from the jejunum were processed for light and electron microscopy. Immunohistochemical study was carried out using antibody against proliferating cell nuclear antigen (PCNA). Different morphometrical parameters were assessed. Specimens from GM-corn fed group showed different forms of structural changes. Focal destruction and loss of the villi leaving denuded mucosal surface alternating with stratified areas were observed, while some crypts appeared totally disrupted. Congested blood capillaries and focal infiltration with mononuclear cells were detected. Significant upregulation of PCNA expression, increase in number of goblet cells and a significant increase in both villous height and crypt depth were detected. Marked ultrastructural changes of some enterocytes with focal loss of the microvillous border were observed. Some enterocytes had vacuolated cytoplasm, swollen mitochondria with disrupted cristae and dilated rough endoplasmic reticulum (rER). Some cells had dark irregular nuclei with abnormally clumped chromatin. It could be concluded that consumption of GM-corn profoundly alters the jejunal histological structure.

  2. Effects of chronic 137Cs ingestion on barrier properties of jejunal epithelium in rats.

    PubMed

    Dublineau, I; Grison, S; Grandcolas, L; Baudelin, C; Paquet, F; Voisin, P; Aigueperse, J; Gourmelon, P

    2007-05-15

    Environmental contamination by 137Cs is of particular public health interest because of the various sources of fallout originating from nuclear weapons, radiological source disruptions, and the Chernobyl disaster. This dispersion may lead to a chronic ecosystem contamination and subsequent ingestion of contaminated foodstuffs. The aim of this study was to thus determine the impact of a chronic ingestion of low-dose 137Cs on small intestine functions in rats. The animals received 150 Bq per day in drinking water over 3 mo. At these environmental doses, 137Cs contamination did not modify the crypt and villus architecture. In addition, epithelial integrity was maintained following the chronic ingestion of 137Cs, as demonstrated by histological analyses (no breakdown of the surface mucosa) and electrical transepithelial parameters (no change in potential difference and tissue conductance). Furthermore, cesium contamination seemed to induce contradictory effects on the apoptosis pathway, with an increase in the gene expression of Fas/FasL and a decrease in the apoptotic cell number present in intestinal mucosa. No marked inflammation was observed following chronic ingestion of 137Cs, as indicated by neutrophil infiltration and gene expression of cytokines and chemokines. Results indicated no imbalance in the Th1/Th2 response induced by cesium at low doses. Finally, evaluation of the functionality of the jejunal epithelium in rats contaminated chronically with 137Cs did not demonstrate changes in the maximal response to carbachol, nor in the cholinergic sensitivity of rat jejunal epithelium. In conclusion, this study shows that chronic ingestion of 137Cs over 3 mo at postaccidental doses exerts few biological effects on the epithelium of rat jejunum with regard to morphology, inflammation status, apoptosis/proliferation processes, and secretory functions.

  3. ASSESSMENT OF THE GASTRO-JEJUNO-DUODENAL TRANSIT AFTER JEJUNAL POUCH INTERPOSITION

    PubMed Central

    da SILVA, Alcino Lázaro; GOMES, Célio Geraldo de Oliveira

    2015-01-01

    Background : The jejunal pouch interposition between the gastric body and the duodenum after the gastrectomy, although not frequent in the surgical practice today, has been successfully employed for the prevention and treatment of the postgastrectomy syndromes. In the latter, it is included the dumping syndrome, which affects 13-58% of the patients who undergo gastrectomy. Aim : Retrospective assessment of the results of this procedure for the prevention of the dumping syndrome. Methods : Fourty patients were selected and treatetd surgically for peptic ulcer, between 1965 and 1970. Of these, 29 underwent vagotomy, antrectomy, gastrojejunalduodenostomy at the lesser curvature level, and the 11 remaining were submitted to vagotomy, antrectomy, gastrojejunal-duodenostomy at the greater curvature level. The gastro-jejuno-duodenal transit was assessed in the immediate or late postoperative with the contrasted study of the esophagus, stomach and duodenum. The clinical evolution was assessed according to the Visick grade. Results : Of the 40 patients, 28 were followed with the contrast evaluation in the late postoperative. Among those who were followed until the first month (n=22), 20 (90%) had slow gastro-jejuno-duodenal transit and in two (10%) the transit was normal. Among those who were followed after the first month (n=16), three (19%) and 13 (81%) had slow and normal gastric emptying, respectively. None had the contrasted exam compatible with the dumping syndrome. Among the 40 patients, 22 underwent postoperative clinical evaluation. Of these, 19 (86,5%) had excellent and good results (Visick 1 and 2, respectively). Conclusions : The jejunal pouch interposition showed to be a very effective surgical procedure for the prevention of the dumping syndrome in gastrectomized patients. PMID:26734789

  4. Rotating Wavepackets

    ERIC Educational Resources Information Center

    Lekner, John

    2008-01-01

    Any free-particle wavepacket solution of Schrodinger's equation can be converted by differentiations to wavepackets rotating about the original direction of motion. The angular momentum component along the motion associated with this rotation is an integral multiple of [h-bar]. It is an "intrinsic" angular momentum: independent of origin and…

  5. Supergranulation rotation

    NASA Astrophysics Data System (ADS)

    Schou, Jesper; Beck, John G.

    2001-01-01

    Simple convection models estimate the depth of supergranulation at approximately 15,000 km which suggests that supergranules should rotate at the rate of the plasma in the outer 2% of the Sun by radius. Previous measurements (Snodgrass & Ulrich, 1990; Beck & Schou, 2000) found that supergranules rotate significantly faster than this, with a size-dependent rotation rate. We expand on previous work and show that the torsional oscillation signal seen in the supergranules tracks that obtained for normal modes. We also find that the amplitudes and lifetimes of the supergranulation are size dependent.

  6. Rotational Energy.

    ERIC Educational Resources Information Center

    Lockett, Keith

    1988-01-01

    Demonstrates several objects rolling down a slope to explain the energy transition among potential energy, translational kinetic energy, and rotational kinetic energy. Contains a problem from Galileo's rolling ball experiment. (YP)

  7. Solar rotation.

    NASA Astrophysics Data System (ADS)

    Dziembowski, W.

    Sunspot observations made by Johannes Hevelius in 1642 - 1644 are the first ones providing significant information about the solar differential rotation. In modern astronomy the determination of the rotation rate is done in a routine way by measuring positions of various structures on the solar surface as well as by studying the Doppler shifts of spectral lines. In recent years a progress in helioseismology enabled determination of the rotation rate in the layers inaccessible for direct observations. There are still uncertainties concerning, especially, the temporal variations of the rotation rate and its behaviour in the radiative interior. We are far from understanding the observations. Theoretical works have not yet resulted in a satisfactory model for the angular momentum transport in the convective zone.

  8. Isolation of Cokeromyces recurvatus, initially misidentified as Coccidioides immitis, from peritoneal fluid in a cat with jejunal perforation.

    PubMed

    Nielsen, Cheri; Sutton, Deanna A; Matise, Ilze; Kirchhof, Nicole; Libal, Melissa C

    2005-07-01

    Cokeromyces recurvatus, a zygomycete, was isolated by fungal culture from the peritoneal fluid of a cat with jejunal perforation secondary to intestinal lymphosarcoma. This organism has not been recovered previously from a veterinary patient. The tissue form of C. recurvatus is morphologically similar to those of Coccidioides immitis and Paracoccidioides brasiliensis and may be misdiagnosed as 1 of these organisms on the basis of cytologic or histopathologic specimens, particularly in geographic regions where these organisms are not endemic.

  9. Enhanced jejunal production of antibodies to Klebsiella and other Enterobacteria in patients with ankylosing spondylitis and rheumatoid arthritis

    PubMed Central

    Maki-Ikola, O.; Hallgren, R.; Kanerud, L.; Feltelius, N.; Knutsson, L.; Granfors, K.

    1997-01-01

    OBJECTIVE—To measure gut immunity directly in jejunal fluid in patients with ankylosing spondylitis (AS) and rheumatoid arthritis (RA).
METHODS—Antibodies against three different Enterobacterias were measured in jejunal perfusion fluids (collected by a double balloon perfusion device) of 19 patients with AS, 14 patients with RA, and 22 healthy controls using enzyme linked immunosorbent assay.
RESULTS—The AS patients had significantly increased jejunal fluid concentrations of IgM, IgG, and IgA class antibodies against Klebsiella pneumoniae, and IgM and IgA class antibodies against Escherichia coli and Proteus mirabilis compared with healthy controls. When compared with the patients with RA, the AS patients had higher concentrations of IgA and IgG class antibodies only against K pneumoniae. The RA patients had higher IgM class antibody concentrations against all three studied Enterobacterias, when compared with the healthy controls, suggesting an enhanced mucosal immune response in these patients. A three month treatment with sulphasalazine did not decrease enterobacterial antibody concentrations in the 10 patients with AS.
CONCLUSION—There is strong direct evidence for an abnormal mucosal humoral immune response particularly to K pneumoniae in patients with AS.

 PMID:9486004

  10. Type 2 diabetes mellitus control and atherosclerosis prevention in a non-obese rat model using duodenal-jejunal bypass.

    PubMed

    Chen, Xuan; Huang, Zhen; Ran, Wenhua; Liao, Gang; Zha, Lang; Wang, Ziwei

    2014-09-01

    Type 2 diabetes mellitus (T2DM) is a prevalent disease worldwide and during its conventional treatment, vascular complications remain unavoidable. Roux-en-Y gastric bypass (GBP) is able to induce the remission of T2DM. However, studies of duodenal-jejunal bypass (DJB), a modified procedure of GBP, are being carried out to investigate its ability to induce the remission of T2DM and protect the aorta from atherosclerosis. The present study aimed to investigate the effect of DJB on the rate of T2DM remission and the prevention of atherosclerosis in the aorta in rats with streptozotocin-induced diabetes without obesity, and to explore the mechanism of DJB in protecting the aorta from atherosclerosis. A T2DM rat model was established with a high-fat diet and low-dose streptozotocin. Surgery was performed to analyze its effects on glucose homeostasis, lipid metabolism, inflammation and pathological changes. Furthermore, changes in c-jun NH2-terminal kinase 1 (JNK1) and inhibitor of κB kinase (IKKβ) genes in the aorta following DJB surgery were examined. Levels of blood glucose, lipids, insulin and tumor necrosis factor (TNF)-α were significantly elevated in the T2DM diabetic model compared with the non-diabetic control. A gradual recovery was observed in the DJB group following surgery. Foam cells and atherosclerotic plaques appeared in the ascending aortic tissue in the sham-surgery and T2DM groups, whereas only slight lesions were observed in the DJB group. The expression levels of JNK1 and IKKβ genes in the aorta were significantly increased in the sham-operated and T2DM groups compared with those in the DJB and normal control groups. The present study demonstrated that DJB caused remission of T2DM without weight loss in non-obese rats. Thus, DJB may delay or prevent the occurrence and development of atherosclerosis in the aorta and this may occur through the JNK1 and nuclear factor κB (NF-κB) signaling pathways.

  11. Effect of dietary fiber on absorption of B-6 vitamers in a rat jejunal perfusion study.

    PubMed

    Nguyen, L B; Gregory, J F; Cerda, J J

    1983-09-01

    Previous research has indicated that dietary fiber may affect the absorption and utilization of certain nutrients. To determine the effect of certain fiber materials on the absorption of B-6 vitamers, jejunal segments from young male adult rats were perfused in situ with a control solution containing 0.02 mM pyridoxine (PN), 0.02 mM pyridoxal (PL), and 0.02 mM pyridoxamine (PM), followed by a test solution containing the same vitamin B-6 mixture and one of five fiber-rich test materials (cellulose, pectin, lignin, homogenized fresh carrot, or carrot homogenized after 10 min boiling) added at a concentration of 1-3%. The mean absorption rates of PL, PN, and PM from the control solution were, respectively, 3.66 +/- 0.23, 2.06 +/- 0.23, and 1.74 +/- 0.37 nmole/min/20 cm jejunal segment. There were no significant differences between the absorption rates of B-6 vitamers from control and test solutions containing cellulose, pectin, and lignin. The absorption rates of PM and PL were significantly depressed (P less than 0.05 and P less than 0.01, respectively) by the presence of fresh or cooked carrot. The absorption rate of PN in presence of cooked carrot was also decreased relative to the control value but the difference was only marginally significant (P less than 0.10). When the concentration of fresh carrot in the test solution was increased to 10% by weight and the perfusion rate was decreased from 1.91 to 0.49 ml/min in a second perfusion experiment, there was a significant increase in variability and the differences between absorption rates of the B-6 vitamers in control and test solutions were not statistically significant. The limited evidence of adverse effect of carrot on absorption of vitamin B-6 suggested the need for further clarification of the influence of dietary fiber in an unrefined state on the bioavailability of vitamin B-6.

  12. Sixth-grade Indonesian student explanations of directions on flat maps and globes, of the Earth's rotation to cause night and day, and of the relative positions of the Earth, Moon, and Sun during an eclipse

    NASA Astrophysics Data System (ADS)

    Dimyati, Surachman

    The purpose of the study was to elicit and analyze sixth grade students' explanations concerning concepts taught in the national Indonesian sixth grade science curriculum. In this study, students were asked to identify the cardinal directions on flat maps and a globe, to describe what causes night and day on the earth, to identify the direction of the earth's rotation, and to identify the relative positions of the earth, sun, and moon during either a solar or lunar eclipse. The findings in the study can be summarized as follows (1) Eighty out of 88 students (91%) were able to explain what causes night and day. (2) Approximately 50% could identify the direction the earth rotates to cause night and day. (3) Using a solar system model, about 64% of the students could describe the relative position of the earth, sun, and moon during an eclipse. (4) Cultural differences affect student thinking. One student thought that Mecca had to be west of everywhere, not just west of Indonesia. (5) The way teachers teach seems to influence student thinking. It is easy for students to form the misconception that up is north. Most maps in classrooms are hung vertically. (6) Some students were confused by the globe. Teachers need to explain why the globe is tilted. Also, they need to help students understand how to determine the cardinal directions on a globe. More research is needed to determine what is needed to help students truly understand these concepts and to determine whether these concepts are best taught at the elementary level.

  13. Formation of independently revascularized bowel segments using the rectus abdominis muscle flap: a rat model for jejunal prefabrication.

    PubMed

    Tan, Bien-Keem; Chen, Hung-Chi; Wei, Fu-Chan; Ma, Shwu-Fan; Lan, Chyn-Tair; See, Lai-Chu; Wan, Yung-Liang

    2002-02-01

    Reconstruction of the pharyngoesophagus with free jejunal transfer is a major challenge when recipient neck vessels are absent because of previous surgery or irradiation. In such instances, jejunal transfer using a muscle flap as a "vascular carrier" may be a problem-solving alternative. Pretransfer vascularization of the jejunum is achieved by wrapping the muscle flap around the small bowel segment. After a short staging period, the mesenteric pedicle is divided and the bowel segment is transferred up to the neck based on its new blood supply. The objectives of this study were to develop an animal model for prefabricating independently revascularized jejunal segments using the rectus abdominis muscle flap and to determine the minimal time required for independent bowel survival. Twenty-four mature (500-g to 700-g) rats were divided into six experimental groups of four animals each. In each animal, a 1.5-cm segment of proximal jejunum was isolated on two jejunal arteries and wrapped with a superior pedicled rectus abdominis muscle flap. To determine the time of neovascular takeover, the mesenteric pedicles were ligated on postoperative day 2 (group I), day 3 (group II), day 4 (group III), day 5 (group IV), day 6 (group V), and day 7 (group VI). At the time of pedicle ligation, the composite flap was transposed to a new subcutaneous position. Viability of bowel was assessed according to gross appearance and histologic examination 48 hours after transfer. Complete survival of revascularized jejunum in 11 of 12 animals was obtained after pedicle ligation on postoperative day 5 and beyond (p < 0.0001, Fisher's exact test). These bowel segments demonstrated luminal patency, intact pink mucosa, mucus production, and visible peristalsis. Histologic examination showed healthy intestinal epithelium and tissue integration along the serosa-muscle interphase. In contrast, pedicle ligation on day 4 and earlier resulted in varying degrees of bowel necrosis characterized by

  14. Earth Rotation

    NASA Technical Reports Server (NTRS)

    Dickey, Jean O.

    1995-01-01

    The study of the Earth's rotation in space (encompassing Universal Time (UT1), length of day, polar motion, and the phenomena of precession and nutation) addresses the complex nature of Earth orientation changes, the mechanisms of excitation of these changes and their geophysical implications in a broad variety of areas. In the absence of internal sources of energy or interactions with astronomical objects, the Earth would move as a rigid body with its various parts (the crust, mantle, inner and outer cores, atmosphere and oceans) rotating together at a constant fixed rate. In reality, the world is considerably more complicated, as is schematically illustrated. The rotation rate of the Earth's crust is not constant, but exhibits complicated fluctuations in speed amounting to several parts in 10(exp 8) [corresponding to a variation of several milliseconds (ms) in the Length Of the Day (LOD) and about one part in 10(exp 6) in the orientation of the rotation axis relative to the solid Earth's axis of figure (polar motion). These changes occur over a broad spectrum of time scales, ranging from hours to centuries and longer, reflecting the fact that they are produced by a wide variety of geophysical and astronomical processes. Geodetic observations of Earth rotation changes thus provide insights into the geophysical processes illustrated, which are often difficult to obtain by other means. In addition, these measurements are required for engineering purposes. Theoretical studies of Earth rotation variations are based on the application of Euler's dynamical equations to the problem of finding the response of slightly deformable solid Earth to variety of surface and internal stresses.

  15. Stress and strain analysis of contractions during ramp distension in partially obstructed guinea pig jejunal segments.

    PubMed

    Zhao, Jingbo; Liao, Donghua; Yang, Jian; Gregersen, Hans

    2011-07-28

    Previous studies have demonstrated morphological and biomechanical remodeling in the intestine proximal to an obstruction. The present study aimed to obtain stress and strain thresholds to initiate contraction and the maximal contraction stress and strain in partially obstructed guinea pig jejunal segments. Partial obstruction and sham operations were surgically created in mid-jejunum of male guinea pigs. The animals survived 2, 4, 7 and 14 days. Animals not being operated on served as normal controls. The segments were used for no-load state, zero-stress state and distension analyses. The segment was inflated to 10 cmH(2)O pressure in an organ bath containing 37°C Krebs solution and the outer diameter change was monitored. The stress and strain at the contraction threshold and at maximum contraction were computed from the diameter, pressure and the zero-stress state data. Young's modulus was determined at the contraction threshold. The muscle layer thickness in obstructed intestinal segments increased up to 300%. Compared with sham-obstructed and normal groups, the contraction stress threshold, the maximum contraction stress and the Young's modulus at the contraction threshold increased whereas the strain threshold and maximum contraction strain decreased after 7 days obstruction (P<0.05 and 0.01). In conclusion, in the partially obstructed intestinal segments, a larger distension force was needed to evoke contraction likely due to tissue remodeling. Higher contraction stresses were produced and the contraction deformation (strain) became smaller.

  16. Stress and strain analysis of contractions during ramp distension in partially obstructed guinea pig jejunal segments

    PubMed Central

    Zhao, Jingbo; Liao, Donghua; Yang, Jian; Gregersen, Hans

    2011-01-01

    Previous studies have demonstrated morphological and biomechanical remodeling in the intestine proximal to an obstruction. The present study aimed to obtain stress and strain thresholds to initiate contraction and the maximal contraction stress and strain in partially obstructed guinea pig jejunal segments. Partial obstruction and sham operations were surgically created in mid-jejunum of male guinea pigs. The animals survived 2, 4, 7, and 14 days, respectively. Animals not being operated on served as normal controls. The segments were used for no-load state, zero-stress state and distension analyses. The segment was inflated to 10 cmH2O pressure in an organ bath containing 37°C Krebs solution and the outer diameter change was monitored. The stress and strain at the contraction threshold and at maximum contraction were computed from the diameter, pressure and the zero-stress state data. Young’s modulus was determined at the contraction threshold. The muscle layer thickness in obstructed intestinal segments increased up to 300%. Compared with sham-obstructed and normal groups, the contraction stress threshold, the maximum contraction stress and the Young’s modulus at the contraction threshold increased whereas the strain threshold and maximum contraction strain decreased after 7 days obstruction (P<0.05 and 0.01). In conclusion, in the partially obstructed intestinal segments, a larger distension force was needed to evoke contraction likely due to tissue remodeling. Higher contraction stresses were produced and the contraction deformation (strain) became smaller. PMID:21632056

  17. Morphometric study of the jejunal mucosa in various childhood enteropathies with special reference to intraepithelial lymphocytes.

    PubMed

    Kuitunen, P; Kosnai, I; Savilahti, E

    1982-01-01

    A morphometric study of intraepithelial (IE) lymphocytes per 100 epithelial cells, villous heights (VH), crypt depths (CrD), and epithelial cell heights (ECH) was made on jejunal specimens of 17 patients with cow's-milk allergy (CMA), 52 with celiac disease (CD), seven with congenital lactase deficiency (CLD), four with acrodermatitis enteropathica (AE), four with giardiasis, and four with dermatitis herpetiformis (DH). The aim of this study was to investigate how the morphometric parameters correlate with each other. All cases with CMA, CD, and DH had villous atrophy with hyperplasia of the crypts, both signs being more severe in cases with CD and DH than with CMA. IE lymphocyte infiltration was more intense in specimens of patients with CD and DH (mean 76.0), than those with CMA (mean 62.5). The ECH were equally reduced in patients with CD and CMA. In a follow-up specimen at 1 year and 10 months for CD patients and 11 months for CMA patients the inflammation was reduced, and the VH were increased but still differed from the controls. In CLD cases the morphology of the villi and crypts of the jejunum was quite normal, with no IE lymphocyte infiltration; ECH were reduced. Minor morphological changes were seen in the specimens of patients with AE and giardiasis. In the whole study group there was a significant linear correlation, either positive or negative, between all variables measured (IE lymphocytes, VH, CrD, and ECH).

  18. The lack of protective effects of tea supplementation on liver and jejunal epithelium in adult rats exposed to cadmium and lead.

    PubMed

    Tomaszewska, Ewa; Winiarska-Mieczan, Anna; Dobrowolski, Piotr

    2015-11-01

    Adult rats at the age of 12 weeks were divided into the control group and groups supplemented with green (GT), black (BT), red (RT), or white (WT) tea extracts. The diet (except that for the control) was mixed with 7 mg Cd/kg and 50 mg Pb/kg. The experiment lasted 12 weeks. Basal haematology and plasma biochemical parameters as well as the histomorphometrical parameters of jejunal epithelium and liver were determined. The lowest body mass was found in the RT and WT groups. Some functional (increased plasma ALT and AST, and the de Ritis coefficient) and structural changes in the liver (slight fatty degenerative changes, an increase in the intercellular space) were evident irrespective of the type of tea in the Cd and Pb poisoned rats. This toxic effect was visible especially in rats drinking black or red tea. However, the rats had no elevated LDH and ALT activities. The highest content of Cd and Pb in the liver and blood plasma was found in rats drinking red tea. Based on the results obtained, it is clear that long-term exposure of adult rats with a mature intestinal barrier to Cd and Pb contamination, under higher exposure conditions than the current estimates of weekly exposure of the general population to Cd and Pb through diet, causes a toxic effect, especially in the liver, and can change the structure of intestinal mucosa, irrespective of tea administration.

  19. A Rare Case of Jejunal Arterio-Venous Fistula: Treatment with Superselective Catheter Embolization with a Tracker-18 Catheter and Microcoils

    SciTech Connect

    Sonnenschein, Martin J. Anderson, Suzanne E.; Lourens, Steven; Triller, Juergen

    2004-11-15

    Arterio-venous fistulas may develop spontaneously, following trauma or infection, or be iatrogenic in nature. We present a rare case of a jejunal arterio- venous fistula in a 35-year-old man with a history of pancreatic head resection that had been performed two years previously because of chronic pancreatitis. The patient was admitted with acute upper abdominal pain, vomiting and an abdominal machinery-type bruit. The diagnosis of a jejunal arterio-venous fistula was established by MR imaging. Transfemoral angiography was performed to assess the possibility of catheter embolization. The angiographic study revealed a small aneurysm of the third jejunal artery, abnormal early filling of dilated jejunal veins and marked filling of the slightly dilated portal vein (13-14 mm). We considered the presence of segmental portal hypertension. The patient was treated with coil embolization in the same angiographic session. This case report demonstrates the importance of auscultation of the abdomen in the initial clinical examination. MR imaging and color Doppler ultrasound are excellent noninvasive tools in establishing the diagnosis. The role of interventional radiological techniques in the treatment of early portal hypertension secondary to jejunal arterio-venous fistula is discussed at a time when this condition is still asymptomatic. A review of the current literature is included.

  20. Indomethacin decreases jejunal fluid secretion in addition to luminal release of prostaglandin E2 in patients with acute cholera.

    PubMed Central

    Van Loon, F P; Rabbani, G H; Bukhave, K; Rask-Madsen, J

    1992-01-01

    Human cholera is associated with an increased luminal release of prostaglandin E2 (PGE2), but whether inhibition of increased PGE2 synthesis will reduce or control intestinal secretion is uncertain. 'Steady state' perfusions (10 ml/minute) in 12 patients with acute cholera, and repeat perfusions in nine of these patients during the convalescent phase were therefore performed using the triple lumen technique. The proximal jejunum was perfused with isotonic saline containing sodium-sulphobromophthalein as a non-absorbable marker. After intravenous administration of indomethacin (1.0 mg/kg) the jejunal net transfer of fluid and the jejunal flow rate of PGE2 were determined in 30 minute periods for 120 minutes after a 120 minute control period. Indomethacin decreased net fluid secretion (2.1 (0.3-4.2) v 4.5 (2.5-8.4) ml/hour x cm; medians, Q50 ranges, p less than 0.01) and the jejunal flow rate of PGE2 (1.5 (1.2-2.7) v 2.2 (1.4-4.9) ng/minute, p less than 0.05). The results of similar perfusion studies in 22 patients with acute cholera, used to establish the spontaneous time related change in fluid secretion, showed no significant change in net fluid transfer (3.5 (2.2-6.2) to 3.5 (2.6-11.6) ml/hour x cm, p greater than 0.25) over 240 minutes. These data provide further evidence in favour of the hypothesis that prostaglandins have a role in the cholera toxin induced intestinal fluid secretion in man. PMID:1612480

  1. Jejunal free flap for reconstruction of pharyngeal defects in patients with head and neck cancer-the Birmingham experience.

    PubMed

    Walker, Rachel J; Parmar, Satyesh; Praveen, Prav; Martin, Tim; Pracy, Paul; Jennings, Chris; Simms, Malcolm

    2014-02-01

    We retrospectively audited operative complications, success of flaps, and speech and swallowing outcomes in patients with head and neck cancer who had reconstruction with jejunal free tissue transfer to the pharynx. A total of 104 patients had jejunal free flaps between 1987 and 2009 at University Hospital, Birmingham. Management was by a multidisciplinary team, and the same vascular surgeon did all the anastomoses. We investigated the relations between patients, operative factors, and postoperative complications, and noted the ischaemic time of the flaps and coexisting conditions of the patients. Outcomes measured included initial and final survival rates of flaps, donor and recipient site complications, and speech and swallowing outcomes on discharge and up to 2 years postoperatively. Of the 104 patients, 14 (13%) had initial flap complications but overall flap survival was 97%. A total of 11 (11%) patients developed a fistula at a mean of 15 days postoperatively and 11 (11%) had minor donor site complications. A total of 95 (91%) were able to resume oral diet on discharge. Of the 44 who were followed up on discharge, 32 (73%) were able to maintain oral intake at 2 years and 31 (70%) could use their voice in everyday situations. The jejunal free flap enables the tumour to be removed, and reconstruction and restoration of function to be done in a single operation using tissue that is versatile. The operation is associated with low morbidity at the donor and recipient sites, and results in good speech and swallowing outcomes. The flap can also be used to reconstruct pharyngolaryngeal defects.

  2. Structural and functional evolution of jejunal allograft rejection in rats and the ameliorating effects of cyclosporine therapy.

    PubMed Central

    Madara, J L; Kirkman, R L

    1985-01-01

    We assessed the structural and functional evolution of small intestinal transplant rejection in a rat model by use of 1-micron section, electron microscopic, and in vitro electrophysiologic techniques to study jejunal mucosa 3, 6, and 9 d posttransplantation. The earliest structural abnormalities detected in jejunal loops transplanted from Lewis X Brown Norway F1 hybrids into Lewis rats occurred within 3 d posttransplantation and consisted of focal endothelial cell injury of the microvasculature and focal injury of crypt epithelial cells. Both alterations were associated with adjacent infiltration of large lymphoid cells, and both markedly progressed and became rather diffuse over the following 6 d. In contrast, villus absorptive cells were not markedly altered in structure until the 9th postoperative day. As compared with host jejuna, allograft jejunal epithelium demonstrated multiple functional abnormalities. Transepithelial resistance declined progressively by days 6 and 9 (both P less than 0.05), although baseline transepithelial spontaneous potential difference was only affected at day 9 (P less than 0.01). Stimulated absorption by allograft jejuna, as assessed by measuring electrical response to mucosal glucose, was not significantly diminished until day 9 (P less than 0.05). In contrast, stimulated secretion assessed by measurement of electrical response to serosal theophylline was diminished by day 6 (P less than .01). These data suggest that the earliest epithelial injury during rejection, as judged both structurally and functionally, occurs in the crypt and is paralleled by endothelial injury at the level of the microvasculature. Thus, the primary targets for rejection are most likely endothelial cells and crypt epithelial cells. In contrast, structural and functional impairment of villus epithelium is detectable only at substantially later times during rejection and are most likely secondary processes related to either ischemia produced by microvascular

  3. Individual and combined effects of Fusarium toxins on the mRNA expression of pro-inflammatory cytokines in swine jejunal epithelial cells.

    PubMed

    Wan, Lam-Yim Murphy; Woo, Chit-Shing Jackson; Turner, Paul C; Wan, Jennifer Man-Fan; El-Nezami, Hani

    2013-07-18

    Fusarium toxins have been arousing public interest in recent years because of their potential health hazards for humans and agricultural livestock. It was hypothesized that selected pro-inflammatory cytokines might serve as sensitive biomarkers of the predicted adverse effects of Fusarium toxins on the basis of their potential ability to induce immune and intestinal alterations comparable to those in human chronic inflammatory infection. Consequently, the aim of this study was to elucidate individual and combined effects of four common Fusarium toxins, deoxynivalenol (DON), nivalenol (NIV), zearalenone (ZEA) and fumonisin B1 (FB1) on the mRNA expression of pro-inflammatory cytokines (IL1α, IL1β, IL6, IL8, TNFα and MCP-1) using a porcine jejunal epithelial cell line, IPEC-J2. Based on a dose-response relationship between individual mycotoxins and cell viability (MTT assay) that was previously established, cytotoxic and non-cytotoxic concentrations were selected to investigate combinations of two, three and all four of the mycotoxins. In general, up-regulation of pro-inflammatory cytokine mRNA expression occurred for both individual and mixtures of Fusarium toxins at cytotoxic concentrations, whereas significant up-regulation of pro-inflammatory cytokine mRNA mostly obtained when the toxins existed in mixtures at non-cytotoxic concentrations and these mixtures were found to cause cytotoxicity from MTT assay determined previously. Therefore, it may be concluded that some of the changes in the mRNA expression of IL1α, IL1β, IL6, IL8, TNFα and MCP-1 could be cytotoxicity-related. It was also noted that additive effects were not always observed for the mixtures. These data suggest that individual or mixtures of Fusarium toxins could cause or exacerbate intestinal inflammation. These also provide a better understanding of the possible effects of Fusarium toxins, alone or in combinations on the immunological defense mechanisms of IECs, which would contribute to the

  4. Keplerian Rotation of Our Galaxy?

    NASA Astrophysics Data System (ADS)

    Gnaciński, P.; Młynik, T.

    2017-04-01

    It is common to attribute a flat rotation curve to our Galaxy. However, in a recent paper, Galazutdinov et al. obtained a Keplerian rotation curve for interstellar clouds in the outer parts of the Galaxy. They calculated the distances from equivalent widths of interstellar CaII lines. The radial velocity was also measured on the interstellar CaII absorption line. We verify the results of Galazutdinov et al. based on observations of old open clusters. We propose that the observations of flat and Keplerian rotation curves may be caused by the assumption of circular orbits. The application of formulas derived with the assumption of circular orbits to elliptical ones may mimics the flat rotation curve. The interstellar clouds with cross-sections larger than stars may have almost circular orbits, and the derived rotation curve will be Keplerian.

  5. Claudin-4 Undergoes Age-Dependent Change in Cellular Localization on Pig Jejunal Villous Epithelial Cells, Independent of Bacterial Colonization

    PubMed Central

    Van Kessel, Andrew G.; Wilson, Heather L.

    2015-01-01

    Newborn piglets are immunologically naïve and must receive passive immunity via colostrum within 24 hours to survive. Mechanisms by which the newborn piglet gut facilitates uptake of colostral cells, antibodies, and proteins may include FcRn and pIgR receptor-mediated endocytosis and paracellular transport between tight junctions (TJs). In the present study, FcRn gene (FCGRT) was minimally expressed in 6-week-old gut and newborn jejunum but it was expressed at significantly higher levels in the ileum of newborn piglets. pIgR was highly expressed in the jejunum and ileum of 6-week-old animals but only minimally in neonatal gut. Immunohistochemical analysis showed that Claudin-5 localized to blood vessel endothelial cells. Claudin-4 was strongly localized to the apical aspect of jejunal epithelial cells for the first 2 days of life after which it was redistributed to the lateral surface between adjacent enterocytes. Claudin-4 was localized to ileal lateral surfaces within 24 hours after birth indicating regional and temporal differences. Tissue from gnotobiotic piglets showed that commensal microbiota did not influence Claudin-4 surface localization on jejunal or ileal enterocytes. Regulation of TJs by Claudin-4 surface localization requires further investigation. Understanding the factors that regulate gut barrier maturation may yield protective strategies against infectious diseases. PMID:25948883

  6. The inside mystery of jejunal gastrointestinal stromal tumor: a rare case report and review of the literature.

    PubMed

    Dhull, A K; Kaushal, V; Dhankhar, R; Atri, R; Singh, H; Marwah, N

    2011-01-01

    Gastrointestinal stromal tumors (GISTs) are malignant and rare form of soft tissue sarcoma of the digestive tract. The incidence of gastrointestinal stromal tumors is very low Kramer et al. 2005 Jejunal GISTs are extremely rare. Here we present a rare case of jejunal GIST with unusually large size at presentation. The patient presented with severe abdomen pain, exophytic growth, and dimorphic anemia. Surgical resection of the tumor was carried out, and operative findings revealed a 15 × 10 cm growth, arising from serosal surface of jejunum, at the antimesenteric surface. Diagnosis in this case was made by subjecting the resected specimen to immunohistochemical analysis. In view of large size of the resected tumor, and high-risk histopathological features, imatinib mesylate 400 mg once daily was given as adjuvant chemotherapy. Patient is asymptomatic without any evidence of tumor recurrence after six months of postoperative followup. Imatinib as such is recommended in metastatic, residual or recurrent cases of GISTs or which are surgically not removable; however, recent recommendations suggests the use of imatinib mesylate after radical surgery in high-risk cases, because it has shown a significant decrease in the recurrence rate, and the Food and Drug Administration (FDA) has also approved the use of imatinib as adjuvant therapy after complete resection of localized, primary GIST.

  7. Claudin-4 undergoes age-dependent change in cellular localization on pig jejunal villous epithelial cells, independent of bacterial colonization.

    PubMed

    Pasternak, J Alex; Kent-Dennis, Coral; Van Kessel, Andrew G; Wilson, Heather L

    2015-01-01

    Newborn piglets are immunologically naïve and must receive passive immunity via colostrum within 24 hours to survive. Mechanisms by which the newborn piglet gut facilitates uptake of colostral cells, antibodies, and proteins may include FcRn and pIgR receptor-mediated endocytosis and paracellular transport between tight junctions (TJs). In the present study, FcRn gene (FCGRT) was minimally expressed in 6-week-old gut and newborn jejunum but it was expressed at significantly higher levels in the ileum of newborn piglets. pIgR was highly expressed in the jejunum and ileum of 6-week-old animals but only minimally in neonatal gut. Immunohistochemical analysis showed that Claudin-5 localized to blood vessel endothelial cells. Claudin-4 was strongly localized to the apical aspect of jejunal epithelial cells for the first 2 days of life after which it was redistributed to the lateral surface between adjacent enterocytes. Claudin-4 was localized to ileal lateral surfaces within 24 hours after birth indicating regional and temporal differences. Tissue from gnotobiotic piglets showed that commensal microbiota did not influence Claudin-4 surface localization on jejunal or ileal enterocytes. Regulation of TJs by Claudin-4 surface localization requires further investigation. Understanding the factors that regulate gut barrier maturation may yield protective strategies against infectious diseases.

  8. Dose-dependent increase and decrease in active glucose uptake in jejunal epithelium of broilers after acute exposure to ethanol.

    PubMed

    Yunus, Agha Waqar; Awad, Wageha A; Kröger, Susan; Zentek, Jürgen; Böhm, Josef

    2011-06-01

    Little is known about the effects of ethanol on gastrointestinal tract of chicken. In this study, we investigated the effects of low levels of ethanol on electrophysiological variables of jejunal epithelium of commercial broilers. Jejunal tissues from 35- to 39-day-old broilers were exposed to either 0 or 0.1% ethanol in Ussing chambers, and electrophysiological variables were monitored for 40 min. After 40 and 60 min of incubation, glucose (20 mM) and carbamoylcholine (200 μM), respectively, were introduced into the chambers. The absolute and percent increase in short-circuit current (Isc) and potential difference (Vt) induced by glucose were increased significantly with 0.1% ethanol. There was no significant effect of 0.1% ethanol on carbamoylcholine-induced electrophysiological variables. To investigate if higher levels of ethanol have similar effects, we tested the effects of 0, 0.33, and 0.66% ethanol under similar experimental conditions until the glucose-addition step. Contrary to 0.1% ethanol, both the 0.33 and 0.66% ethanol levels significantly decreased the basal and glucose-induced Isc and Vt. Tissue conductivity remained unaffected in all cases. These results indicate that intestinal epithelia of chicken may be more sensitive to the effects of ethanol as compared with other species. This is the first report indicating dose-dependent increase and decrease in active glucose absorption in intestinal epithelia in the presence of ethanol.

  9. Rotating Bioreactor

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues currently being cultured in rotating bioreactors by investigators.

  10. Conservative treatment of rotator cuff injuries.

    PubMed

    Bytomski, Jeffrey R; Black, Douglass

    2006-01-01

    Across all ages and activity levels, rotator cuff injuries are one of the most common causes of shoulder pain. The anatomy and biomechanics of the shoulder guide the history and physical exam toward the appropriate treatment of rotator cuff injuries. Rotator cuff tears are rare under the age of 40 unless accompanied by acute trauma. Throwing athletes are prone to rotator cuff injury from various causes of impingement (subacromial, internal, or secondary) and flexibility deficits, strength deficits, or both along the kinetic chain. Most rotator cuff injuries may be treated conservatively by using regimens of nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroid injections, and functional rehabilitation therapy. Injury prevention programs are essential for the long-term care of patients with rotator cuff disease, for primary prevention, and for prevention of recurrent injuries, unless a traumatically torn rotator cuff is present. Surgical management is reserved for refractory cases that have exhausted conservative measures.

  11. Influence of dietary supplementation with flaxseed and lactobacilli on the mucosal morphology and proliferative cell rate in the jejunal mucosa of piglets after weaning

    PubMed Central

    Jonecova, Zuzana; Toth, Stefan; Ciccocioppo, Rachele; Rodrigo, Luis; Kruzliak, Peter; Nemcova, Radomira

    2015-01-01

    The aim of the study was to investigate the influence of flaxseed and lactobacilli supplementation to the diet of piglets during the time period between 10 days before and 21 days after weaning. The morphometry of the jejunal mucosa and proliferative ratio of both epithelial and lamina propria cells were compared with those found in a group of piglets fed with the usual diet added with sunflower oil during the same time period. The addition of flaxseed oil to the diet significantly increased the crypt depth in comparison with both groups supplemented with sunflower (P < 0.05 and 0.001 respectively) on the weaning day. Moreover, the flaxseed addition caused a significant decrease in villus height (P < 0.01) and crypt depth (P < 0.01) 21 days postweaning in comparison with the sunflower group. The proliferative ratio of the epithelial cells in the sunflower group on the weaning day was significantly higher than in both flaxseed groups (P < 0.01). Paradoxically, significantly higher proliferative activity in the mucosal connective tissue in the group with flaxseed supplementation in comparison with the sunflower group was observed on the day of weaning, as well as 3 days later (P < 0.05 both). A combination of flaxseed with lactobacilli showed significantly lower proliferative activity in the connective tissue cells from weaning up to 7 days after weaning (P < 0.05 all) in comparison with the flaxseed group. PMID:25929724

  12. Influence of dietary supplementation with flaxseed and lactobacilli on the mucosal morphology and proliferative cell rate in the jejunal mucosa of piglets after weaning.

    PubMed

    Jonecova, Zuzana; Toth, Stefan; Ciccocioppo, Rachele; Rodrigo, Luis; Kruzliak, Peter; Nemcova, Radomira

    2015-06-01

    The aim of the study was to investigate the influence of flaxseed and lactobacilli supplementation to the diet of piglets during the time period between 10 days before and 21 days after weaning. The morphometry of the jejunal mucosa and proliferative ratio of both epithelial and lamina propria cells were compared with those found in a group of piglets fed with the usual diet added with sunflower oil during the same time period. The addition of flaxseed oil to the diet significantly increased the crypt depth in comparison with both groups supplemented with sunflower (P < 0.05 and 0.001 respectively) on the weaning day. Moreover, the flaxseed addition caused a significant decrease in villus height (P < 0.01) and crypt depth (P < 0.01) 21 days postweaning in comparison with the sunflower group. The proliferative ratio of the epithelial cells in the sunflower group on the weaning day was significantly higher than in both flaxseed groups (P < 0.01). Paradoxically, significantly higher proliferative activity in the mucosal connective tissue in the group with flaxseed supplementation in comparison with the sunflower group was observed on the day of weaning, as well as 3 days later (P < 0.05 both). A combination of flaxseed with lactobacilli showed significantly lower proliferative activity in the connective tissue cells from weaning up to 7 days after weaning (P < 0.05 all) in comparison with the flaxseed group.

  13. Toxin-associated and other genes in Clostridium perfringens type A isolates from bovine clostridial abomasitis (BCA) and jejunal hemorrhage syndrome (JHS).

    PubMed

    Schlegel, Benjamin J; Nowell, Victoria J; Parreira, Valeria R; Soltes, Glenn; Prescott, John F

    2012-10-01

    This study examined known or possible virulence-associated genes in type A Clostridium perfringens from cases of both bovine clostridial abomasitis (BCA) and jejunal hemorrhage syndrome (JHS) and compared these to isolates from calves that were healthy or had undifferentiated diarrheal illness. A real-time polymerase chain reaction (PCR) assay was used to genotype the 218 C. perfringens isolates. Isolates were sourced from healthy and diarrheic young and mature cattle (n = 191), from calves with confirmed or suspected BCA (n = 22), and from mature cattle with JHS (n = 5). Of 216 isolates (96%), 208 were positive for the cpa gene and 13% (29/218) were positive for atypical cpb2. Three of 8 (37.5%) confirmed BCA isolates, 2 of 13 (15.4%) suspected BCA isolates, and no JHS isolates tested positive for atypical cpb2. As all isolates were negative for cpb, cpb2, cpe, etx, netB, and tpeL, the results of the present study do not support a role for these genes in BCA or JHS. A subset of unique genes identified in 1 bovine clostridial abomasitis isolate (F262), for which a genome sequence is available, was searched for in 8 BCA isolates by PCR. None of the 10 genes was consistently present in all or even in a majority of BCA isolates. Many of these genes were also variably and inconsistently present in type A isolates from calves that did not have BCA. Although a virulence signature to aid in the diagnosis of BCA caused by C. perfringens type A was not identified, further work may discover a gene or group of genes that would constitute such a signature.

  14. Changes in α-glucosidase activities along the jejunal-ileal axis of normal rats by the α-glucosidase inhibitor miglitol.

    PubMed

    Mochizuki, Kazuki; Hanai, Emiko; Suruga, Kazuhito; Kuranuki, Sachi; Goda, Toshinao

    2010-10-01

    Miglitol, an α-glucosidase inhibitor that inhibits postprandial hyperglycemia by delaying carbohydrate digestion and absorption along the jejunal-ileal axis, has recently been approved for use in patients with type 2 diabetes mellitus. Miglitol treatment may lead to increased α-glucosidase activities toward the ileum because carbohydrate flow toward the ileum increases. However, it is not yet known if miglitol treatment alters the α-glucosidase activities along the jejunal-ileal axis. In this study, we examined the effects of miglitol supplementation for 3 or 7 days on α-glucosidase activities along the jejunal-ileal axis of Wistar rats. Supplementation with miglitol for 3 or 7 days in rats increased tissue weights of the lower jejunum and ileum, but did not alter tissue weights of the upper jejunum and cecum or the contents of the cecum. Furthermore, supplementation with miglitol for 7 days reduced the activities of isomaltase and maltase in the upper jejunum and increased the activities of sucrase, isomaltase, and maltase in the lower jejunum and ileum. These results suggest that the delay in carbohydrate digestion and absorption along the jejunal-ileal axis by miglitol supplementation in rats is associated with increased α-glucosidase activities toward the ileum.

  15. Proximal Biceps Tendon and Rotator Cuff Tears.

    PubMed

    Virk, Mandeep S; Cole, Brian J

    2016-01-01

    The long head of biceps tendon (LHBT) is frequently involved in rotator cuff tears and can cause anterior shoulder pain. Tendon hypertrophy, hourglass contracture, delamination, tears, and tendon instability in the bicipital groove are common macroscopic pathologic findings affecting the LHBT in the presence of rotator cuff tears. Failure to address LHBT disorders in the setting of rotator cuff tear can result in persistent shoulder pain and poor satisfaction after rotator cuff repair. Tenotomy or tenodesis of the LHBT are effective options for relieving pain arising from the LHBT in the setting of reparable and selected irreparable rotator cuff tears.

  16. Dietary Zinc Oxide Modulates Antioxidant Capacity, Small Intestine Development, and Jejunal Gene Expression in Weaned Piglets.

    PubMed

    Zhu, Cui; Lv, Hang; Chen, Zhuang; Wang, Li; Wu, Xiuju; Chen, Zhongjian; Zhang, Weina; Liang, Rui; Jiang, Zongyong

    2017-02-01

    The current study was conducted to investigate the effects of dietary zinc oxide (ZnO) on the antioxidant capacity, small intestine development, and jejunal gene expression in weaned piglets. Ninety-six 21-day-old piglets were randomly assigned to three dietary treatments. Each treatment had eight replicates with four piglets per replicate. The piglets were fed either control diet (control) or control diet supplemented with in-feed antibiotics (300 mg/kg chlortetracycline and 60 mg/kg colistin sulfate) or pharmacological doses of ZnO (3000 mg/kg). The experiment lasted 4 weeks. Blood samples were collected at days 14 and 28, while intestinal samples were harvested at day 28 of the experiment. Dietary high doses of ZnO supplementation significantly increased the body weight (BW) at day 14 and average daily gain (ADG) of days 1 to 14 in weaned piglets, when compared to control group (P < 0.05). The incidence of diarrhea of piglets fed ZnO-supplemented diets, at either days 1 to 14, days 14 to 28, or the overall experimental period, was significantly decreased in comparison with those in other groups (P < 0.05). Supplementation with ZnO increased the villus height of the duodenum and ileum in weaned piglets and decreased the crypt depth of the duodenum, when compared to the other groups (P < 0.05). Dietary ZnO supplementation decreased the malondialdehyde (MDA) concentration at either day 14 or day 28, but increased total superoxide dismutase (T-SOD) at day 14, when compared to that in the control (P < 0.05). ZnO supplementation upregulated the messenger RNA (mRNA) expression of zonula occludens-1 (ZO-1) and occludin in the jejunum mucosa of weaned piglets, compared to those in the control (P < 0.05). The pro-inflammatory cytokine interleukin-lβ (IL-1β) mRNA expression in the jejunum mucosa was downregulated in the ZnO-supplemented group, compared with the control (P < 0.05). Both in-feed antibiotics and ZnO supplementation decreased the m

  17. Effects of vertical rotation on Arabidopsis development

    NASA Technical Reports Server (NTRS)

    Brown, A. H.; Chapman, D. K.; Dahl, A. O.

    1975-01-01

    Various gross morphological end points of Arabidopsis development are examined in an attempt to separate the effects of growth on the horizontal clinostat into a component caused by rotation alone and another component caused by the altered position with respect to the direction of the g-vector. In a series of tests which involved comparisons between vertical stationary plants, vertical rotated plants, and plants rotated on clinostats, certain characters were consistently influenced by vertical rotation alone. The characters for which this effect was statistically significant were petiole length and leaf blade width.

  18. Rotational ratchets with dipolar interactions.

    PubMed

    Jäger, Sebastian; Klapp, Sabine H L

    2012-12-01

    We report results from a computer simulation study on the rotational ratchet effect in systems of magnetic particles interacting via dipolar interactions. The ratchet effect consists of directed rotations of the particles in an oscillating magnetic field, which lacks a net rotating component. Our investigations are based on Brownian dynamics simulations of such many-particle systems. We investigate the influence of both the random and deterministic contributions to the equations of motion on the ratchet effect. As a main result, we show that dipolar interactions can have an enhancing as well as a dampening effect on the ratchet behavior depending on the dipolar coupling strength of the system under consideration. The enhancement is shown to be caused by an increase in the effective field on a particle generated by neighboring magnetic particles, while the dampening is due to restricted rotational motion in the effective field. Moreover, we find a nontrivial influence of the short-range, repulsive interaction between the particles.

  19. Rotating Apparatus for Isoelectric Focusing

    NASA Technical Reports Server (NTRS)

    Bier, M.

    1986-01-01

    Remixing of separated fractions prevented. Improved isoelectric focusing apparatus helps to prevent electro-osmosis and convection, both of which cause remixing of separated fractions. Fractionating column segmented and rotated about horizontal axis: Only combined effects of both features fully effective in making good separations. Improved apparatus slowly rotated continuously or rocked (at rotational amplitude of at least 180 degrees) about its horizontal axis so average gravitational vector experienced by fluid is zero and convection is therefore suppressed. Electro-osmosis suppressed and convection further suppressed by separating column into disklike compartments along its length with filters. Experiments have shown dimensions of apparatus not critical. Typical compartment and column volumes are 2 and 40 ml, respectively. Rotation speeds lie between 3 and 30 rpm.

  20. Is laparoscopic resection the appropriate management of a jejunal gastrointestinal stromal tumor (GIST)? Report of a case.

    PubMed

    Pitiakoudis, Michail; Zezos, Petros; Courcoutsakis, Nikos; Papanas, Nikolaos; Giatromanolaki, Alexandra; Sivridis, Efthimios; Kouklakis, Georgios; Simopoulos, Constantinos

    2010-10-01

    A 51-year-old female patient presented with iron deficiency anemia. Upper and lower gastrointestinal endoscopy were unremarkable. Computed tomography enteroclysis showed an ovoid 3×4-cm jejunal tumor with intraluminal protrusion and exophytic growth pattern, without lymphadenopathy or metastatic disease. Laparoscopic resection of the tumor was successfully carried out. Histologically, a mesenchymal tumor composed of spindle cells with an interlacing bundle pattern and high-mitotic activity greater than 10 mitoses/50 high-power fields were observed. The immunohistochemistry showed that the tumor was KIT (CD117)-, vimentin-, smooth muscle actin-, and S-100-positive, whereas it was CD34-negative. These findings were consistent with the features of a gastrointestinal stromal tumor. The patient had an uneventful postoperative course, and after 10 months of follow-up, she is well without any evidence of tumor recurrence.

  1. Food deprivation increases alpha(2)-adrenoceptor-mediated modulation of jejunal epithelial transport in young and adult rats.

    PubMed

    Lucas-Teixeira, V; Vieira-Coelho, M A; Serrão, M P; Soares-da-Silva, P

    2000-10-01

    This study examined the effect of food deprivation on the jejunal response to alpha(2)-adrenoceptor activation in young (20-d-old) and adult (60-d-old) rats, using short-circuit (I(sc)) measurements in the absence or presence of furosemide (1 mmol/L). The effect of alpha(2)-adrenoceptor stimulation by 5-bromo-N:-(4, 5-dihydro-1H-imidazol-2-yl)-6-quinoxalinamine (UK 14,304; 0.3-3000 nmol/L) was a concentration-dependent decrease in I(sc) with similar half-maximal effective concentration (EC(50); 12.3 +/- 1.1 vs. 9.6 +/- 1.1 nmol/L) and maximal effect (E(max); 70.6 +/- 6.9 vs. 80.6 +/- 4.5% of reduction) values in adult food-deprived and fed rats. The effect of UK 14,304 on I(sc) in fed and food-deprived rats was markedly (P: < 0.05) attenuated by furosemide (1 mmol/L). E(max) values for UK 14,304 in 20-d-old food-deprived rats were higher (P: < 0.05) than those observed in fed rats (93.3 +/- 3.3 vs. 67.0 +/- 11.3% of reduction), without differences in EC(50) values. The effect of UK 14,304 on I(sc) in 20-d-old fed rats was completely abolished by furosemide (1 mmol/L). In food-deprived young rats, the effect of UK 14,304 was also markedly (P: < 0.05) antagonized by furosemide, but not completely abolished. Specific [(3)H]-rauwolscine binding in membranes from jejunal epithelial cells revealed the presence of a single class of binding sites, with an apparent K:(D) in the low nmol/L range. In 20-d-old food-deprived rats, specific [(3)H]-rauwolscine binding was markedly increased, and this was reversed by refeeding. Na(+),K(+)-ATPase activity in isolated jejunal epithelial cells from 60-d-old fed rats was twice that in 20-d-old fed rats [117 +/- 14 vs. 52 +/- 5 nmol free inorganic phosphorus/(mg protein.min)]. Food deprivation in adult rats, but not in 20-d-old rats, was accompanied by a significant decrease in Na(+),K(+)-ATPase activity. In both young and adult rats (fed and food-deprived), UK 14,304 did not affect Na(+),K(+)-ATPase activity. In conclusion, food

  2. Locomotion gaits of a rotating cylinder pair

    NASA Astrophysics Data System (ADS)

    van Rees, Wim M.; Novati, Guido; Koumoutsakos, Petros; Mahadevan, L.

    2015-11-01

    Using 2D numerical simulations of the Navier-Stokes equations, we demonstrate that a simple pair of rotating cylinders can display a range of locomotion patterns of biological and engineering interest. Steadily counter-rotating the cylinders causes the pair to move akin to a vortex dipole for low rotation rates, but as the rotational velocity is increased the direction of motion reverses. Unsteady rotations lead to different locomotion gaits that resemble jellyfish (for in-phase rotations) and undulating swimmers (for out-of-phase rotations). The small number of parameters for this simple system allows us to systematically map the phase space of these gaits, and allows us to understand the underlying physical mechanisms using a minimal model with implications for biological locomotion and engineered analogs.

  3. Bleeding peptic ulcer caused by ectopic gastric mucosa in a duplicated segment of jejunum

    SciTech Connect

    Newmark, H.; Ching, G.; Halls, J.; Levy, I.J.

    1981-02-01

    The authors present a case in which a patient suffered a bleeding jejunal ulcer caused by heterotopic gastric mucosa in a congenital duplication of a segment of jejunum. This is the first case diagnosed preoperatively by two different radiographic means. These lesions were shown by both pertechnetate flow and barium small bowel studies. The rarity of these entities and the modalities used for diagnosis are described.

  4. DEVICE FOR CONVEYING AND ROTATING OBJECTS

    DOEpatents

    Frantz, C.E.; Roslund, J.

    1958-01-21

    A device is described for conveying cylindrical material with a combined rotary and axial motion. The material rides on a series of balls which are retained in a guide plate and rotated by bearing against a rotating drum. The drum has a series of conical sections or grooves cut in its outer surface on which the balls ride. The grooves and balls match in such a way that all the balls are caused to rotate about an axis at an angle to the drum axis. This skewed rotation of the ball imparts a longitudinal as well as a rotary motion to the cylinders being conveyed.

  5. Effect of diet and age on jejunal and circulating lymphocyte subsets in children with coeliac disease: persistence of CD4-8-intraepithelial T cells through treatment.

    PubMed

    Verkasalo, M A; Arató, A; Savilahti, E; Tainio, V M

    1990-04-01

    Monoclonal antibodies were used to determine the relative numbers of T lymphocyte subsets in 61 jejunal biopsies and in peripheral blood of 35 children with coeliac disease, and of 13 healthy controls. The T cell numbers in the lamina propria were unaffected by a change from gluten-free to gluten containing diet in the patients. The number of intraepithelial lymphocytes (where the CD8 cells predominated) were significantly raised in patients taking gluten. Ten to 20% of the patients' intraepithelial CD3 (mature T) cells expressed neither CD8 nor CD4 surface antigens. This CD4 8 T cell population persisted through gluten elimination and challenge. The circulating lymphocyte subsets showed little variation with the diet although there was a marked increase in the proportion (14.9%) of CD4 8 T cells in patients during gluten elimination. In the histologically normal jejunal mucosa from control subjects, the age of the subject showed a positive correlation with villus intraepithelial CD3+ and CD8+ cells, and crypt intraepithelial CD4+ cells. No clear cut effect of age was observed on lamina propria lymphocyte counts of the controls, or on the lymphocyte counts in jejunal mucosa of the coeliac patients. The observed CD3+4-8- lymphocytes may represent activated cells unable to present their surface antigens, or they may be gamma delta-receptor bearing T cells, which could have a significant role in the pathogenesis of coeliac disease.

  6. Effects of different levels of sanguinarine on antioxidant indices, immunological responses, ileal microbial counts and jejunal morphology of laying hens fed diets with different levels of crude protein.

    PubMed

    Bavarsadi, M; Mahdavi, A H; Ansari-Mahyari, S; Jahanian, E

    2016-06-08

    This study was carried out to assess the effects of different levels of sanguinarine on antioxidant indices, immunological responses, serum biochemical parameters, ileal microbial counts and jejunal morphology of laying hens fed on diets with different levels of crude protein (CP). A total of 180 laying hens were subjected into nine dietary treatments with four cages of five birds each. Experimental treatments consisted of three levels of CP (85.0, 92.5 and 100% of Hy-Line W36 manual recommendation) and three levels of sanguinarine (0.00, 3.75 and 7.50 mg/kg) as a 3 × 3 factorial arrangement of laying hens which fed during a 70-day feeding trial. The in vitro study showed that sanguinarine exhibited sevenfold and threefold decreased antioxidant activities to inhibit 2-2-diphenyl-1-picric hydrazyl free radical as well as ferric ion reducing rather than butylated hydroxyl toluene. Although using the decremental levels of CP caused the increase in heterophil-to-lymphocyte ratio (p < 0.01), dietary administration of sanguinarine could suppress the serum cholesterol and malondialdehyde concentrations as well as heterophil-to-lymphocyte ratio (p < 0.05). Additionally, decreasing CP content resulted in the decreased percentage of albumin (p < 0.05); however, it had no negative effects on humoral immunity. Nonetheless, feeding of at least 3.75 mg/kg sanguinarine led to the remarkable increases in serum gamma globulin concentration (p < 0.01) and secondary (p < 0.05) antibody titres against sheep red blood cells. Moreover, a decline in dietary CP content led to higher villi height and crypt depth (p < 0.05; p < 0.001) and consequently decreased villi height-to-crypt depth ratio (p < 0.001) than the optimum level (100% CP). In spite of the effects of sanguinarine on the suppression of Escherichia coli and Salmonella counts (p < 0.05), it markedly enhanced villi height-to-crypt depth ratio as well as lamina propria lymphatic follicles extent

  7. Effects of different sulphur amino acids and dietary electrolyte balance levels on performance, jejunal morphology, and immunocompetence of broiler chicks.

    PubMed

    Nikoofard, V; Mahdavi, A H; Samie, A H; Jahanian, E

    2016-02-01

    As alterations of dietary electrolyte balance (DEB) can influence amino acid metabolism via changes the ions incur in their configurations, performance and immunological responses of broiler chicks might be affected. So, the current study was carried out to investigate the effects of different levels of sulphur amino acids (SAA) and DEB on performance, jejunal morphology and immunocompetence of broiler chicks. A total of 360 1-day-old male Ross 308 broiler chicks were randomly assigned to nine experimental treatments with four replicates of 10 birds each. Experimental treatments consisted of three levels of SAA (100, 110, and 120% of NRC recommendation, provided by methionine supplementation in diets with the same cysteine level) and three levels of DEB (150, 250, and 350 mEq/kg) that were fed during the entire of trial in a 3 × 3 factorial arrangement. Results showed that the relative weights of intestine and abdominal fat were decreased markedly (p < 0.001) with increasing levels of SAA and DEB respectively. Antibody titre against sheep red blood cell was neither individually nor in combination influenced by supplementation of SAA or DEB. Nevertheless, a decrease in DEB level led to a suppression in heterophile (p < 0.05) and an increase in lymphocyte counts (p = 0.06); consequently, heterophile to lymphocyte ratio was significantly decreased (p < 0.05) by decremental levels of DEB. Albumin to globulin ratio was increased after inclusion of at least 10% SAA (p < 0.001) and 150 mEq DEB/kg in the diet (p = 0.11). Although feeding high-DEB level led to a remarkable decrease in villus height (p < 0.01) and goblet cell numbers (p < 0.001), supplementing the highest level of SAA improved the height of jejunal villus. During the entire trial period, average daily feed intake (ADFI) was increased by incremental SAA levels (p < 0.05). However, inclusion of 150 mEq/kg led to not only a remarkable increase (p < 0.0001) in both ADFI and average daily weight gain (ADWG) but

  8. The expression of genes involved in jejunal lipogenesis and lipoprotein synthesis is altered in morbidly obese subjects with insulin resistance.

    PubMed

    Gutierrez-Repiso, Carolina; Rodriguez-Pacheco, Francisca; Garcia-Arnes, Juan; Valdes, Sergio; Gonzalo, Montserrat; Soriguer, Federico; Moreno-Ruiz, Francisco J; Rodriguez-Cañete, Alberto; Gallego-Perales, Jose L; Alcain-Martinez, Guillermo; Vazquez-Pedreño, Luis; Lopez-Enriquez, Soledad; Garcia-Serrano, Sara; Garrido-Sanchez, Lourdes; Garcia-Fuentes, Eduardo

    2015-12-01

    The dyslipidemia associated with type 2 diabetes mellitus (T2DM) is an important risk factor for atherosclerotic cardiovascular disease. However, until now little attention has been paid to the role that the intestine might have. The aim of this research was to determine the relation between insulin resistance and intestinal de novo lipogenesis/lipoprotein synthesis in morbidly obese subjects and to study the effect of insulin on these processes. Jejunal mRNA expression of the different genes involved in the intestinal de novo lipogenesis/lipoprotein synthesis was analyzed in three groups of morbidly obese subjects: Group 1 with low insulin resistance (MO-low-IR), group 2 with high insulin resistance (MO-high-IR), and group 3 with T2DM and treatment with metformin (MO-metf-T2DM). In addition, intestinal epithelial cells (IECs) from MO-low-IR were incubated with different doses of insulin/glucose. In Group 2 (MO-high-IR), the jejunal mRNA expression levels of apo A-IV, ATP-citrate lyase (ACLY), pyruvate dehydrogenase (lipoamide) beta (PDHB), and sterol regulatory element-binding protein-1c (SREBP-1c) were significantly higher and acetyl-CoA carboxylase alpha (ACC1) and fatty-acid synthase lower than in Group 1 (MO-low-IR). In Group 3 (MO-metf-T2DM), only the ACLY and PDHB mRNA expressions were significantly higher than in Group 1 (MO-low-IR). The mRNA expression of most of the genes studied was significantly linked to insulin and glucose levels. The incubation of IEC with different doses of insulin and glucose produced a higher expression of diacylglycerol acyltransferase 2, microsomal triglyceride transfer protein, apo A-IV, SREBP-1c, and ACC1 when both, glucose and insulin, were at a high concentration. However, with only high insulin levels, there were higher apo A-IV, PDHB and SREBP-1c expressions, and a lower ACLY expression. In conclusion, the jejunum of MO-high-IR has a decreased mRNA expression of genes involved in de novo fatty-acid synthesis and an

  9. The Maximum Mass of Rotating Strange Stars

    NASA Astrophysics Data System (ADS)

    Szkudlarek, M.; Gondek-Rosiń; ska, D.; Villain, L.; Ansorg, M.

    2012-12-01

    Strange quark stars are considered as a possible alternative to neutron stars as compact objects (e.g. Weber 2003). A hot compact star (a proto-neutron star or a strange star) born in a supernova explosion or a remnant of neutron stars binary merger are expected to rotate differentially and be important sources of gravitational waves. We present results of the first relativistic calculations of differentially rotating strange quark stars for broad ranges of degree of differential rotation and maximum densities. Using a highly accurate, relativistic code we show that rotation may cause a significant increase of maximum allowed mass of strange stars, much larger than in the case of neutron stars with the same degree of differential rotation. Depending on the maximum allowed mass a massive neutron star (strange star) can be temporarily stabilized by differential rotation or collapse to a black hole.

  10. PLT rotating pumped limiter

    SciTech Connect

    Cohen, S.A.; Budny, R.V.; Corso, V.; Boychuck, J.; Grisham, L.; Heifetz, D.; Hosea, J.; Luyber, S.; Loprest, P.; Manos, D.

    1984-07-01

    A limiter with a specially contoured front face and the ability to rotate during tokamak discharges has been installed in a PLT pump duct. These features have been selected to handle the unique particle removal and heat load requirements of ICRF heating and lower-hybrid current-drive experiments. The limiter has been conditioned and commissioned in an ion-beam test stand by irradiation with 1 MW power, 200 ms duration beams of 40 keV hydrogen ions. Operation in PLT during ohmic discharges has proven the ability of the limiter to reduce localized heating caused by energetic electron bombardment and to remove about 2% of the ions lost to the PLT walls and limiters.

  11. Rotating colloids in rotating magnetic fields: Dipolar relaxation and hydrodynamic coupling

    NASA Astrophysics Data System (ADS)

    Coughlan, Anna C. H.; Bevan, Michael A.

    2016-10-01

    Video microscopy (VM) experiments and Brownian dynamics (BD) simulations were used to measure and model superparamagnetic colloidal particles in rotating magnetic fields for interaction energies on the order of the thermal energy, kT . Results from experiments and simulations were compared for isolated particle rotation, particle rotation within doublets, doublet rotation, and separation within doublets vs field rotation frequency. Agreement between VM and BD results was obtained at all frequencies and amplitudes only by including exact two-body hydrodynamic interactions and relevant relaxation times of magnetic dipoles. Frequency-dependent particle forces and torques cause doublets to rotate at low frequencies via dipolar interactions and at high frequencies via hydrodynamic translation-rotation coupling. By matching measurements and simulations for a range of conditions, our findings unambiguously demonstrate the quantitative forms of dipolar and hydrodynamic interactions necessary to capture nonequilibrium, steady-state dynamics of Brownian colloids in magnetic fields.

  12. Mental object rotation and the planning of hand movements.

    PubMed

    Wohlschläger, A

    2001-05-01

    Recently, we showed that the simultaneous execution of rotational hand movements interferes with mental object rotation, provided that the axes of rotation coincide in space. We hypothesized that mental object rotation and the programming of rotational hand movements share a common process presumably involved in action planning. Two experiments are reported here that show that the mere planning of a rotational hand movement is sufficient to cause interference with mental object rotation. Subjects had to plan different spatially directed hand movements that they were asked to execute only after they had solved a mental object rotation task. Experiment 1 showed that mental object rotation was slower if hand movements were planned in a direction opposite to the presumed mental rotation direction, but only if the axes of hand rotation and mental object rotation were parallel in space. Experiment 2 showed that this interference occurred independent of the preparatory hand movements observed in Experiment 1. Thus, it is the planning of hand movements and not their preparation or execution that interferes with mental object rotation. This finding underlines the idea that mental object rotation is an imagined (covert) action, rather than a pure visual-spatial imagery task, and that the interference between mental object rotation and rotational hand movements is an interference between goals of actions.

  13. Raised number of jejunal IgG2-producing cells in untreated adult coeliac disease compared with food allergy.

    PubMed Central

    Rognum, T O; Kett, K; Fausa, O; Bengtsson, U; Kilander, A; Scott, H; Gaarder, P I; Brandtzaeg, P

    1989-01-01

    The subclass distribution of IgG-producing immunocytes was studied by two colour immunohistochemistry with monoclonal antibodies in jejunal biopsy specimens from 10 adults with untreated coeliac disease, 11 coeliac disease patients on a gluten free diet, and seven patients with established food allergy. Paired immunofluorescence staining was performed with subclass specific murine monoclonal antibodies in combination with polyclonal rabbit antibody reagent to total IgG; the proportion of cells belonging to each subclass could thereby be determined. The ratio of IgG2 immunocytes was significantly higher (p less than 0.05) in untreated coeliac disease patients (median, 35.2%; range, 26.7-65.2%) than in those on a gluten free diet (median, 7.3%; range, 0-31.9%) or those having food allergy (median, 12.5%; range, 0-36.5%). The disparity in the local IgG2 response between patients with untreated coeliac disease and those with food allergy might be due to differences in the nature of the antigenic stimuli, dissimilar genetic 'make-up' of the subjects, or both. Images Fig. 2 PMID:2599444

  14. Studies of intestinal lymphoid tissue. VII. The secondary nature of lymphoid cell "activation" in the jejunal lesion of tropical sprue.

    PubMed Central

    Marsh, M. N.; Mathan, M.; Mathan, V. I.

    1983-01-01

    Morphometric techniques were used in the evaluation of lymphocyte morphology and activity in tropical sprue. jejunal biopsies from control subjects (8), patients with epidemic disease (7), patients with endemic disease (11), and subjects who had recovered from sprue (4) were analyzed blindly. In patients with sprue, lymphocytes were increased significantly within crypt (but not surface) epithelium. Immunoblasts (greater than 6 mu in diameter) were increased by 5% over control subjects. Group means for lymphocytic mitotic indexes were also significantly raised, while flux ratios only differed significantly between endemic sprue patients and control subjects. The lymphocytic infiltration was distributed focally in the upper crypt and crypt-villus interzones. Analysis of epidemic cases (presenting within 4-28 days) revealed detectable changes in lymphocyte behavior only after 3 weeks' illness, whereas mucosal lesions and malabsorption were already established during the first week. These data indicate that lymphocyte activation, suggestive of a local cell-mediated immune reaction, does occur in tropical sprue but is secondary to damage already inflicted on enterocytes and their function. Images Figure 3 Figure 4 Figure 5 PMID:6614143

  15. Absence of Role of Dietary Protein Sensing in the Metabolic Benefits of Duodenal-Jejunal Bypass in the Mouse

    PubMed Central

    Barataud, Aude; Goncalves, Daisy; Vinera, Jennifer; Zitoun, Carine; Duchampt, Adeline; Gautier-Stein, Amandine; Mithieux, Gilles

    2017-01-01

    Roux-en-Y gastric bypass (RYGB) induces remission or substantial improvement of type 2 diabetes mellitus (T2D) but underlying mechanisms are still unclear. The beneficial effects of dietary proteins on energy and glucose homeostasis are mediated by the antagonist effects of peptides toward mu-opioid receptors (MORs), which are highly expressed in the distal gut. We hypothesized that the beneficial effects of RYGB could depend at least in part on the interaction of peptides from food with intestinal MORs. Duodenal-jejunal bypass (DJB) was performed in obese and lean wild-type (WT) or MOR deficient (MOR−/−) mice. Food intake and body weight was monitored daily during 3 weeks. Glucose homeostasis was assessed from glucose and insulin tolerance tests. In obese WT and MOR−/− mice, DJB induced a rapid and sustained weight loss partly independent of food intake, and a rapid improvement in glycaemic parameters. Weight loss was a major determinant of the improvements observed. In lean WT and MOR−/− mice, DJB had no effect on weight loss but significantly enhanced glucose tolerance. We found that MORs are not essential in the metabolic beneficial effects of DJB, suggesting that protein sensing in the distal gut is not a link in the metabolic benefits of gastric surgery. PMID:28332577

  16. Shear rotation numbers

    NASA Astrophysics Data System (ADS)

    Doeff, E.; Misiurewicz, M.

    1997-11-01

    This paper presents results on rotation numbers for orientation-preserving torus homeomorphisms homotopic to a Dehn twist. Rotation numbers and the rotation set for such homeomorphisms have been defined and initially investigated by the first author in a previous paper. Here we prove that each rotation number 0951-7715/10/6/017/img5 in the interior of the rotation set is realized by some compact invariant set, and that there is an ergodic measure on that set with mean rotation number 0951-7715/10/6/017/img5. It is also proved that the function which assigns its rotation set to such a homeomorphism is continuous. Finally, a counterexample is presented that shows that rational extremal points of the shear rotation set do not necessarily correspond to any periodic orbits.

  17. Power Harvesting from Rotation?

    ERIC Educational Resources Information Center

    Chicone, Carmen; Feng, Z. C.

    2008-01-01

    We show the impossibility of harvesting power from rotational motions by devices attached to the rotating object. The presentation is suitable for students who have studied Lagrangian mechanics. (Contains 2 figures.)

  18. Rotator cuff exercises

    MedlinePlus

    ... to these tendons may result in: Rotator cuff tendinitis, which is irritation and swelling of these tendons ... Brien MJ, Leggin BG, Williams GR. Rotator cuff tendinopathies and tears: surgery and therapy. In: Skirven TM, ...

  19. Shaft-Rotation Detector

    NASA Technical Reports Server (NTRS)

    Randall, Richard L.

    1990-01-01

    Signal-processing subsystem generates signal indicative of rotation of shaft from output of accelerometer mounted on housing of bearing supporting shaft. Output of subsystem binary signal at frequency of rotation of shaft. Part of assembly of electronic equipment measuring vibrations in rotating machinery. Accelerometer mounted in such way sensitive to vibrations of shaft perpendicular to axis. Output of accelerometer includes noise and components of vibration at frequencies higher than rotational frequency of shaft.

  20. Rotations with Rodrigues' Vector

    ERIC Educational Resources Information Center

    Pina, E.

    2011-01-01

    The rotational dynamics was studied from the point of view of Rodrigues' vector. This vector is defined here by its connection with other forms of parametrization of the rotation matrix. The rotation matrix was expressed in terms of this vector. The angular velocity was computed using the components of Rodrigues' vector as coordinates. It appears…

  1. Ex vivo absorption of thymol and thymol-beta-D-glucopyranoside in piglet everted jejunal segments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Food-producing animals can be reservoirs of Campylobacter, a leading bacterial cause of human foodborne illness. The natural product thymol can reduce the growth rate, survivability, and ammonia production of Campylobacter jejuni and Campylobacter coli. Thymol-ß-D-glucopyranoside may be used to tr...

  2. A typical presentation of a rare cause of obscure gastrointestinal bleeding

    PubMed Central

    Reuter, Stefan; Bettenworth, Dominik; Mees, Sören Torge; Neumann, Jörg; Beyna, Torsten; Domschke, Wolfram; Wessling, Johannes; Ullerich, Hansjörg

    2011-01-01

    A 52-year-old white woman had suffered from intermittent gastrointestinal (GI) bleeding for one year. Upper GI endoscopy, colonoscopy and peroral double-balloon enteroscopy (DBE) did not detect any bleeding source, suggesting obscure GI bleeding. However, in videocapsule endoscopy a jejunal ulceration without bleeding signs was suspected and this was endoscopically confirmed by another peroral DBE. After transfusion of packed red blood cells, the patient was discharged from our hospital in good general condition. Two weeks later she was readmitted because of another episode of acute bleeding. Multi-detector row computed tomography with 3D reconstruction was performed revealing a jejunal tumor causing lower gastrointestinal bleeding. The patient underwent exploratory laparotomy with partial jejunal resection and end-to-end jejunostomy for reconstruction. Histological examination of the specimen confirmed the diagnosis of a low risk gastrointestinal stromal tumor (GIST). Nine days after surgery the patient was discharged in good health. No signs of gastrointestinal rebleeding occurred in a follow-up of eight months. We herein describe the complex presentation and course of this patient with GIST and also review the current approach to treatment. PMID:21403816

  3. Galaxy cluster's rotation

    NASA Astrophysics Data System (ADS)

    Manolopoulou, M.; Plionis, M.

    2017-03-01

    We study the possible rotation of cluster galaxies, developing, testing, and applying a novel algorithm which identifies rotation, if such does exist, as well as its rotational centre, its axis orientation, rotational velocity amplitude, and, finally, the clockwise or counterclockwise direction of rotation on the plane of the sky. To validate our algorithms we construct realistic Monte Carlo mock rotating clusters and confirm that our method provides robust indications of rotation. We then apply our methodology on a sample of Abell clusters with z ≲ 0.1 with member galaxies selected from the Sloan Digital Sky Survey DR10 spectroscopic data base. After excluding a number of substructured clusters, which could provide erroneous indications of rotation, and taking into account the expected fraction of misidentified coherent substructure velocities for rotation, provided by our Monte Carlo simulation analysis, we find that ∼23 per cent of our clusters are rotating under a set of strict criteria. Loosening the strictness of the criteria, on the expense of introducing spurious rotation indications, we find this fraction increasing to ∼28 per cent. We correlate our rotation indicators with the cluster dynamical state, provided either by their Bautz-Morgan type or by their X-ray isophotal shape and find for those clusters showing rotation within 1.5 h^{-1}_{70} Mpc that the significance of their rotation is related to the dynamically younger phases of cluster formation but after the initial anisotropic accretion and merging has been completed. Finally, finding rotational modes in galaxy clusters could lead to the necessity of correcting the dynamical cluster mass calculations.

  4. Rotational studies of late-type stars. III - Rotation among BY Draconis stars

    NASA Astrophysics Data System (ADS)

    Vogt, S. S.; Penrod, G. D.; Soderblom, D. R.

    1983-06-01

    High-resolution line profiles have been obtained and v sin i's measured for 17 K and M dwarfs. All BY Draconis stars (whether single or in binaries) rotate more rapidly than other K and M dwarfs, reinforcing previous suggestions that rapid rotation (≥5 km s-1) is the underlying cause of the BY Draconis syndrome.

  5. SEAL FOR ROTATING SHAFT

    DOEpatents

    Coffman, R.T.

    1957-12-10

    A seal is described for a rotatable shaft that must highly effective when the shaft is not rotating but may be less effective while the shaft is rotating. Weights distributed about a sealing disk secured to the shaft press the sealing disk against a tubular section into which the shiilt extends, and whem the shaft rotates, the centrifugal forces on the weights relieve the pressurc of the sealing disk against the tubular section. This action has the very desirible result of minimizing the wear of the rotating disk due to contact with the tubular section, while affording maximum sealing action when it is needed.

  6. Visualizing molecular unidirectional rotation

    NASA Astrophysics Data System (ADS)

    Lin, Kang; Song, Qiying; Gong, Xiaochun; Ji, Qinying; Pan, Haifeng; Ding, Jingxin; Zeng, Heping; Wu, Jian

    2015-07-01

    We directly visualize the spatiotemporal evolution of a unidirectional rotating molecular rotational wave packet. Excited by two time-delayed polarization-skewed ultrashort laser pulses, the cigar- or disk-shaped rotational wave packet is impulsively kicked to unidirectionally rotate as a quantum rotor which afterwards disperses and exhibits field-free revivals. The rich dynamics can be coherently controlled by varying the timing or polarization of the excitation laser pulses. The numerical simulations very well reproduce the experimental observations and intuitively revivify the thoroughgoing evolution of the molecular rotational wave packet of unidirectional spin.

  7. Progress in geophysical aspects of the rotation of the earth

    NASA Technical Reports Server (NTRS)

    Lambeck, K.

    1978-01-01

    The geophysical causes and consequences of the Earth's rotation are reviewed. Specific topics covered include: (1) the motion of the rotation axis in space, precession and nutation; (2) the motion of the rotation axis relative to the Earth, polar motion; and (3) the rate of rotation about this axis, or changes in the length of day. Secular decrease in obliquity and evolution of the Earth-Moon system are also discussed.

  8. Predictors of human rotation.

    PubMed

    Stochl, Jan; Croudace, Tim

    2013-01-01

    Why some humans prefer to rotate clockwise rather than anticlockwise is not well understood. This study aims to identify the predictors of the preferred rotation direction in humans. The variables hypothesised to influence rotation preference include handedness, footedness, sex, brain hemisphere lateralisation, and the Coriolis effect (which results from geospatial location on the Earth). An online questionnaire allowed us to analyse data from 1526 respondents in 97 countries. Factor analysis showed that the direction of rotation should be studied separately for local and global movements. Handedness, footedness, and the item hypothesised to measure brain hemisphere lateralisation are predictors of rotation direction for both global and local movements. Sex is a predictor of the direction of global rotation movements but not local ones, and both sexes tend to rotate clockwise. Geospatial location does not predict the preferred direction of rotation. Our study confirms previous findings concerning the influence of handedness, footedness, and sex on human rotation; our study also provides new insight into the underlying structure of human rotation movements and excludes the Coriolis effect as a predictor of rotation.

  9. Rotated balance in humans due to repetitive rotational movement

    NASA Astrophysics Data System (ADS)

    Zakynthinaki, M. S.; Madera Milla, J.; López Diaz De Durana, A.; Cordente Martínez, C. A.; Rodríguez Romo, G.; Sillero Quintana, M.; Sampedro Molinuevo, J.

    2010-03-01

    We show how asymmetries in the movement patterns during the process of regaining balance after perturbation from quiet stance can be modeled by a set of coupled vector fields for the derivative with respect to time of the angles between the resultant ground reaction forces and the vertical in the anteroposterior and mediolateral directions. In our model, which is an adaption of the model of Stirling and Zakynthinaki (2004), the critical curve, defining the set of maximum angles one can lean to and still correct to regain balance, can be rotated and skewed so as to model the effects of a repetitive training of a rotational movement pattern. For the purposes of our study a rotation and a skew matrix is applied to the critical curve of the model. We present here a linear stability analysis of the modified model, as well as a fit of the model to experimental data of two characteristic "asymmetric" elite athletes and to a "symmetric" elite athlete for comparison. The new adapted model has many uses not just in sport but also in rehabilitation, as many work place injuries are caused by excessive repetition of unaligned and rotational movement patterns.

  10. Rotated balance in humans due to repetitive rotational movement.

    PubMed

    Zakynthinaki, M S; Milla, J Madera; De Durana, A López Diaz; Martínez, C A Cordente; Romo, G Rodríguez; Quintana, M Sillero; Molinuevo, J Sampedro

    2010-03-01

    We show how asymmetries in the movement patterns during the process of regaining balance after perturbation from quiet stance can be modeled by a set of coupled vector fields for the derivative with respect to time of the angles between the resultant ground reaction forces and the vertical in the anteroposterior and mediolateral directions. In our model, which is an adaption of the model of Stirling and Zakynthinaki (2004), the critical curve, defining the set of maximum angles one can lean to and still correct to regain balance, can be rotated and skewed so as to model the effects of a repetitive training of a rotational movement pattern. For the purposes of our study a rotation and a skew matrix is applied to the critical curve of the model. We present here a linear stability analysis of the modified model, as well as a fit of the model to experimental data of two characteristic "asymmetric" elite athletes and to a "symmetric" elite athlete for comparison. The new adapted model has many uses not just in sport but also in rehabilitation, as many work place injuries are caused by excessive repetition of unaligned and rotational movement patterns.

  11. Partial Thickness Rotator Cuff Tears: Current Concepts

    PubMed Central

    Matthewson, Graeme; Beach, Cara J.; Nelson, Atiba A.; Woodmass, Jarret M.; Ono, Yohei; Boorman, Richard S.; Lo, Ian K. Y.; Thornton, Gail M.

    2015-01-01

    Partial thickness rotator cuff tears are a common cause of pain in the adult shoulder. Despite their high prevalence, the diagnosis and treatment of partial thickness rotator cuff tears remains controversial. While recent studies have helped to elucidate the anatomy and natural history of disease progression, the optimal treatment, both nonoperative and operative, is unclear. Although the advent of arthroscopy has improved the accuracy of the diagnosis of partial thickness rotator cuff tears, the number of surgical techniques used to repair these tears has also increased. While multiple repair techniques have been described, there is currently no significant clinical evidence supporting more complex surgical techniques over standard rotator cuff repair. Further research is required to determine the clinical indications for surgical and nonsurgical management, when formal rotator cuff repair is specifically indicated and when biologic adjunctive therapy may be utilized. PMID:26171251

  12. Effects of sleeve gastrectomy with jejuno-jejunal or jejuno-ileal loop on glycolipid metabolism in diabetic rats

    PubMed Central

    Zhong, Ming-Wei; Liu, Shao-Zhuang; Zhang, Guang-Yong; Zhang, Xiang; Hu, San-Yuan

    2016-01-01

    AIM To explore the effect of sleeve gastrectomy (SG) with jejuno-jejunal or jejuno-ileal loop on glycolipid metabolism in diabetic rats. METHODS Diabetic rats, which were induced by high-fat diet (HFD), nicotinamide and low-dose streptozotocin, underwent sham operations, SG, SG with jejuno-ileal loop (SG-JI) and SG with jejuno-jejunal loop (SG-JJ) followed by postoperative HFD. Then, at the time points of baseline and 2, 12 and 24 wk postoperatively, we determined and compared several variables, including the area under the curve for the results of oral glucose tolerance test (AUCOGTT), serum levels of triglyceride, cholesterol and ghrelin in fasting state, homeostasis model assessment of insulin resistance (HOMA-IR), body weight, calorie intake, glucagon-like peptide (GLP)-1 and insulin secretions after glucose gavage at dose of 1 g/kg. RESULTS At 2 wk postoperatively, rats that underwent SG, SG-JJ and SG-JI, compared with sham-operated (SHAM) rats, demonstrated lower body weight, calorie intake and ghrelin (P < 0.05 vs SHAM), enhanced secretion of insulin and GLP-1 after glucose gavage (P < 0.05 vs SHAM), improved AUCOGTT, HOMA-IR, fasting serum triglyceride and cholesterol (AUCOGTT: 1616.9 ± 83.2, 837.4 ± 83.7, 874.9 ± 97.2 and 812.6 ± 81.9, P < 0.05 vs SHAM; HOMA-IR: 4.31 ± 0.54, 2.94 ± 0.22, 3.17 ± 0.37 and 3.41 ± 0.22, P < 0.05 vs SHAM; Triglyceride: 2.35 ± 0.17, 1.87 ± 0.23, 1.98 ± 0.30 and 2.04 ± 0.21 mmol/L, P < 0.05 vs SHAM; Cholesterol: 1.84 ± 0.21, 1.53 ± 0.20, 1.52 ± 0.20 and 1.46 ± 0.23 mmol/L). At 12 wk postoperatively, rats receiving SG-JJ and SG-JI had lower body weight, reduced levels of triglyceride and cholesterol and elevated level of GLP-1 compared to those receiving SG (P < 0.05 vs SG). At 24 wk after surgery, compared with SG, the advantage of SG-JJ and SG-JI for glucolipid metabolism was still evident (P < 0.05 vs SG). SG-JI had a better performance in lipid metabolism and GLP-1 secretion of rats than did SG-JJ. CONCLUSION

  13. Duodenal-jejunal bypass normalizes pancreatic islet proliferation rate and function but not hepatic steatosis in hypothalamic obese rats.

    PubMed

    Cantelli, K R; Soares, G M; Ribeiro, R A; Balbo, S L; Lubaczeuski, C; Boschero, A C; Araújo, A C F; Bonfleur, M L

    2017-03-30

    Modifications in life-style and/or pharmacotherapies contribute to weight loss and ameliorate the metabolic profile of diet-induced obese humans and rodents. Since these strategies fail to treat hypothalamic obesity, we have assessed the possible mechanisms by which duodenal-jejunal bypass (DJB) surgery regulates hepatic lipid metabolism and the morphophysiology of pancreatic islets, in hypothalamic obese (HyO) rats. During the first 5 days of life, male Wistar rats received subcutaneous injections of monosodium glutamate (4 g/kg body weight, HyO group), or saline (CTL). At 90 days of age, HyO rats were randomly subjected to DJB (HyO DJB group) or sham surgery (HyO Sham group). HyO Sham rats were morbidly obese, insulin resistant, hypertriglyceridemic and displayed higher serum concentrations of non-esterified fatty acids (NEFA) and hepatic triglyceride (TG). These effects were associated with higher expressions of the lipogenic genes and fatty acid synthase (FASN) protein content in the liver. Furthermore, hepatic genes involved in β-oxidation and TG export were down-regulated in HyO rats. In addition, these rats exhibited hyperinsulinemia, β-cell hypersecretion, a higher percentage of islets and β-cell area/pancreas section, and enhanced nuclear content of Ki67 protein in islet-cells. At 2 months after DJB surgery, serum concentrations of TG and NEFA, but not hepatic TG accumulation and gene and protein expressions, were normalized in HyO rats. Insulin release and Ki67 positive cells were also normalized in HyO DJB islets. In conclusion, DJB decreased islet-cell proliferation, normalized insulinemia, and ameliorated insulin sensitivity and plasma lipid profile, independently of changes in hepatic metabolism.

  14. HLA-DR expression, natural killer cells and IgE containing cells in the jejunal mucosa of coeliac children.

    PubMed Central

    Arato, A; Savilahti, E; Tainio, V M; Verkasalo, M; Klemola, T

    1987-01-01

    The expression of HLA-DR by surface and crypt epithelium and the numbers of cells of natural killer (NK) phenotype and of IgE containing cells were studied with monoclonal antisera using the peroxidase technique. We examined 48 jejunal biopsy specimens taken from 35 coeliac children before treatment (11), during gluten free diet (20) and after gluten challenge (17), and 13 control specimens. The luminal surface of the epithelial cells stained with HLA-DR antiserum in all specimens, but the cytoplasm of the surface epithelial cells took up the stain more frequently in the specimens from the controls (5/13) than those from the coeliacs (2/48) (p less than 0.01). In 21/28 specimens taken from coeliacs when on a gluten containing diet the crypt epithelium showed strong HLA-DR expression, while only 4/20 (p less than 0.01) specimens of coeliacs on a gluten free diet and 1/13 specimens of controls had similar staining. Among the intraepithelial lymphocytes no cells of NK phenotype were found in specimens from patients or controls. As compared with control specimens biopsy specimens from untreated coeliac patients showed smaller numbers of NK cells in the lamina propria. No difference was found in the numbers of IgE containing cells between the patients and controls. The strong expression of HLA-DR by the crypt epithelial cells in coeliac children on a normal diet suggest that these cells are involved in the presentation of the antigen. Images Fig. 1 Fig. 2 Fig. 3 PMID:3311907

  15. Lactobacillus fermentum BR11 and fructo-oligosaccharide partially reduce jejunal inflammation in a model of intestinal mucositis in rats.

    PubMed

    Smith, Cassie L; Geier, Mark S; Yazbeck, Roger; Torres, Diana M; Butler, Ross N; Howarth, Gordon S

    2008-01-01

    Although probiotics are beginning to enter mainstream medicine for disorders of the colon, their effects on the small bowel remain largely unexplored. We investigated the recently identified probiotic, Lactobacillus fermentum (L. fermentum) BR11 (BR11) and the prebiotic, fructo-oligosaccharide (FOS), both individually and in synbiotic combination, for their potential to alleviate intestinal mucositis. From Days 0-9, rats consumed skim milk (SM; saline + SM), low dose (LD-BR11; 1 x 10(6)cfu/ml), high dose (HD-BR11; 1 x 10(9)cfu/ml), LD-FOS (3%), HD-FOS (6%), or synbiotic (HD-BR11/FOS). On Day 7, rats were injected with 5-fluorouracil (5-FU; 150 mg/kg). All rats were sacrificed on Day 10. Intestinal tissues were collected for quantitative histology, sucrase, and myeloperoxidase (MPO) determinations. 5-FU decreased sucrase activity, villus height, crypt depth, and crypt cell proliferation compared to controls. Compared to 5-FU + SM, histological damage severity scores were increased for all treatments, although all were effective at reducing jejunal inflammation, indicated by reduced MPO activity (P < 0.05). The combination of BR11 and FOS did not provide additional protection. Moreover, HD-FOS and the synbiotic actually increased clinical mucositis severity (P < 0.05). We conclude that L. fermentum BR11 has the potential to reduce inflammation of the upper small intestine. However, its combination with FOS does not appear to confer any further therapeutic benefit for the alleviation of mucositis.

  16. Effect of dietary fatty acids on jejunal and ileal oleic acid uptake by rat brush border membrane vesicles.

    PubMed

    Prieto, R M; Stremmel, W; Sales, C; Tur, J A

    1996-04-18

    To test the effect of dietary fatty acids on fatty acid uptake, the influx kinetics of a representative long-chain fatty acid, 3H-oleic acid, in both the jejunum and ileum of rats has been studied using brush border membrane vesicles (BBMV). Animals were fed with semipurified diets containing 5 g fat/100 g diet, as corn oil (control group), safflower oil (unsaturated group) and coconut oil hydrogenated (saturated group). With increasing unbound oleate concentration in the medium, the three dietary groups showed saturable kinetics in both jejunal and ileal BBMV (controls: Vmax = 0.15 +/- 0.01 nmol x mg protein-1 x 5 min-1 and Km = 136 +/- 29.1 nmol for jejunum, and Vmax = 0.23 +/- 0.03 nmol x mg protein-1 x 5 min-1 and Km = 196 +/- 50.3 nmol for ileum; unsaturated: Vmax = 0.28 +/- 0.05 nmol x mg protein-1 x 5 min-1 and Km = 242.7 +/- 91.8 nmol for jejunum, and Vmax = 1.29 +/- 0.06 nmol x mg protein-1 x 5 min-1 and Km = 509.8 +/- 97.5 nmol for ileum; saturated: Vmax = 0.03 +/- 0.01 nmol x mg protein-1 x 5 min-1 and Km = 124.5 +/- 72.6 nmol for jejunum, and Vmax = 0.04 +/- 0.01 nmol x mg protein -1.5 min-1 and Km = 205.6 +/- 85.3 nmol for ileum). These results support the theory that feeding an isocaloric diet containing only unsaturated fatty acids enhanced oleic acid uptake, and feeding an isocaloric diet containing only saturated fatty acids decreased oleic acid uptake. The results obtained in the present work also show the adaptative ability of jejunum and ileum to the type of dietary fat.

  17. Cylindrical rotating triboelectric nanogenerator.

    PubMed

    Bai, Peng; Zhu, Guang; Liu, Ying; Chen, Jun; Jing, Qingshen; Yang, Weiqing; Ma, Jusheng; Zhang, Gong; Wang, Zhong Lin

    2013-07-23

    We demonstrate a cylindrical rotating triboelectric nanogenerator (TENG) based on sliding electrification for harvesting mechanical energy from rotational motion. The rotating TENG is based on a core-shell structure that is made of distinctly different triboelectric materials with alternative strip structures on the surface. The charge transfer is strengthened with the formation of polymer nanoparticles on surfaces. During coaxial rotation, a contact-induced electrification and the relative sliding between the contact surfaces of the core and the shell result in an "in-plane" lateral polarization, which drives the flow of electrons in the external load. A power density of 36.9 W/m(2) (short-circuit current of 90 μA and open-circuit voltage of 410 V) has been achieved by a rotating TENG with 8 strip units at a linear rotational velocity of 1.33 m/s (a rotation rate of 1000 r/min). The output can be further enhanced by integrating more strip units and/or applying larger linear rotational velocity. This rotating TENG can be used as a direct power source to drive small electronics, such as LED bulbs. This study proves the possibility to harvest mechanical energy by TENGs from rotational motion, demonstrating its potential for harvesting the flow energy of air or water for applications such as self-powered environmental sensors and wildlife tracking devices.

  18. The differential rotation of G dwarfs

    NASA Astrophysics Data System (ADS)

    Küker, M.; Rüdiger, G.; Kitchatinov, L. L.

    2011-06-01

    A series of stellar models of spectral type G is computed to study the rotation laws resulting from mean-field equations. The rotation laws of the slowly rotating Sun, the rapidly rotating MOST stars ɛ Eri and κ1 Cet, and the rapid rotators R58 and LQ Lup can be easily reproduced. We also find that differences in the depth of the convection zone cause large differences in the surface rotation law and that the extreme surface shear of HD 171488 can only be explained with an artificially shallow convection layer. We verify the thermal wind equilibrium in rapidly rotating G dwarfs and find that the polar subrotation (dΩ/dz < 0) is due to the baroclinic effect and the equatorial superrotation (dΩ/dr > 0) is caused by the Reynolds stresses. In the bulk of the convection zones where the meridional flow is slow and smooth, the thermal wind equilibrium holds between the centrifugal and the pressure forces. It does not hold, however, in the bounding shear layers including the equatorial region where the Reynolds stresses dominate.

  19. Rotating saddle trap as Foucault's pendulum

    NASA Astrophysics Data System (ADS)

    Kirillov, Oleg N.; Levi, Mark

    2016-01-01

    One of the many surprising results found in the mechanics of rotating systems is the stabilization of a particle in a rapidly rotating planar saddle potential. Besides the counterintuitive stabilization, an unexpected precessional motion is observed. In this note, we show that this precession is due to a Coriolis-like force caused by the rotation of the potential. To our knowledge, this is the first example where such a force arises in an inertial reference frame. We also propose a simple mechanical demonstration of this effect.

  20. CENTRAL ROTATIONS OF MILKY WAY GLOBULAR CLUSTERS

    SciTech Connect

    Fabricius, Maximilian H.; Rukdee, Surangkhana; Saglia, Roberto P.; Bender, Ralf; Hopp, Ulrich; Thomas, Jens; Williams, Michael J.; Noyola, Eva; Opitsch, Michael

    2014-06-01

    Most Milky Way globular clusters (GCs) exhibit measurable flattening, even if on a very low level. Both cluster rotation and tidal fields are thought to cause this flattening. Nevertheless, rotation has only been confirmed in a handful of GCs, based mostly on individual radial velocities at large radii. We are conducting a survey of the central kinematics of Galactic GCs using the new Integral Field Unit instrument VIRUS-W. We detect rotation in all 11 GCs that we have observed so far, rendering it likely that a large majority of the Milky Way GCs rotate. We use published catalogs of GCs to derive central ellipticities and position angles. We show that in all cases where the central ellipticity permits an accurate measurement of the position angle, those angles are in excellent agreement with the kinematic position angles that we derive from the VIRUS-W velocity fields. We find an unexpected tight correlation between central rotation and outer ellipticity, indicating that rotation drives flattening for the objects in our sample. We also find a tight correlation between central rotation and published values for the central velocity dispersion, most likely due to rotation impacting the old dispersion measurements.

  1. Central Rotations of Milky Way Globular Clusters

    NASA Astrophysics Data System (ADS)

    Fabricius, Maximilian H.; Noyola, Eva; Rukdee, Surangkhana; Saglia, Roberto P.; Bender, Ralf; Hopp, Ulrich; Thomas, Jens; Opitsch, Michael; Williams, Michael J.

    2014-06-01

    Most Milky Way globular clusters (GCs) exhibit measurable flattening, even if on a very low level. Both cluster rotation and tidal fields are thought to cause this flattening. Nevertheless, rotation has only been confirmed in a handful of GCs, based mostly on individual radial velocities at large radii. We are conducting a survey of the central kinematics of Galactic GCs using the new Integral Field Unit instrument VIRUS-W. We detect rotation in all 11 GCs that we have observed so far, rendering it likely that a large majority of the Milky Way GCs rotate. We use published catalogs of GCs to derive central ellipticities and position angles. We show that in all cases where the central ellipticity permits an accurate measurement of the position angle, those angles are in excellent agreement with the kinematic position angles that we derive from the VIRUS-W velocity fields. We find an unexpected tight correlation between central rotation and outer ellipticity, indicating that rotation drives flattening for the objects in our sample. We also find a tight correlation between central rotation and published values for the central velocity dispersion, most likely due to rotation impacting the old dispersion measurements. This Letter includes data taken at The McDonald Observatory of The University of Texas at Austin.

  2. Experimental and analytical study of rotating cavitation

    SciTech Connect

    Kamijo, Kenjiro; Shimura, Takashi; Tsujimoto, Yoshinobu

    1994-12-31

    This paper describes experimental and analytical results of rotating cavitation. There are four major sections in this paper. The first section presents the main characteristics of rotating cavitation which was found in the inducer test using a water tunnel. The second section describes the rotating cavitation which occurred in the development test of an LE-7 liquid oxygen pump for the H-II rocket. Also described in this section is how the rotating cavitation was suppressed. The rotating cavitation was the cause of both super synchronous shaft vibration and an unstable head coefficient curve. The third section presents how the theory of rotating cavitation was developed. The final section shows the measured cavitation compliance and mass flow gain factor of the LE-7 pump inducer for comparison of the experimental and analytical results of the rotating cavitation of the LE-7 pump inducer. Almost all the information presented in this paper has already been reported by Kamijo et al. (1977, 1980, 1993, 1993) and by Shimura (1993). In the present paper, the authors attempt to combine and give a clear overview of the experimental and analytical results described in the previous papers to systematically show their experience and findings on rotating cavitation.

  3. Rotating cooloing flows

    NASA Technical Reports Server (NTRS)

    Kley, Wilhelm; Mathews, William G.

    1995-01-01

    We describe the evolution of the hot interstellar medium in a large, slowly rotating elliptical galaxy. Although the rotation assumed is a small fraction of the circular velocity, in accordance with recent observations, it is sufficient to have a profound influence on the X-ray emission and cooling geometry of the interstellar gas. The hot gas cools into a disk that extends out to approximately 10 kpc. The cool, dusty disks observed in the majority of elliptical galaxies may arise naturally from internal cooling rather than from mergers with gas-rich companions. As a result of angular momentum conservation in the cooling flow, the soft X-ray isophotes are quite noticeably flatter than those of the stellar image. The gas temperature is higer along the rotation axis. The rotational velocity of the gas several kiloparcsecs above the central disk far exceeds the local stellar rotation and approaches the local circular velocity as it flows toward the galactic core. The detailed appearance of the X-ray image and velocity field of the X-ray gas provide information about the global rotational properties of giant ellipticals at radii too distant for optical observations. The overall pattern of rotation in these galaxies retains information about the origin of ellipticals, particularly of their merging history. In ellipticals having radio jets, if the jets are aligned with the rotation axis of the inner cooling flow, rotation within the jet could be sustained by the rotating environment. Since most large ellipticals have modest rotation, the X-ray observations at low spatial resolution, when interpreted with spherical theoretical models, give the impression that hot gas undergoes localized cooling to very low temperatures many kiloparcsecs from the galactic core. We suggest that such apparent cooling can result in a natural way as gas cools onto a rotating disk.

  4. Rotational effects on impingement cooling

    NASA Technical Reports Server (NTRS)

    Epstein, A. H.; Kerrebrock, J. L.; Koo, J. J.; Preiser, U. Z.

    1987-01-01

    The present consideration of rotation effects on heat transfer in a radially exhausted, impingement-cooled turbine blade model gives attention to experimental results for Reynolds and Rossby numbers and blade/coolant temperature ratio values that are representative of small gas turbine engines. On the basis of a model that encompasses the effects of Coriolis force and buoyancy on heat transfer, bouyancy is identified as the cause of an average Nusselt number that is 20-30 percent lower than expected from previous nonrotating data. A heuristic model is proposed which predicts that the impingement jets nearest the blade roots should deflect inward, due to a centripetal force generated by their tangential velocity counter to the blade motion. Potentially serious thermal stresses must be anticipated from rotation effects in the course of blade design.

  5. Centrifugally activated bearing for high-speed rotating machinery

    DOEpatents

    Post, R.F.

    1994-02-15

    A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation. 4 figures.

  6. Centrifugally activated bearing for high-speed rotating machinery

    DOEpatents

    Post, Richard F.

    1994-01-01

    A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation.

  7. Diamagnetism of rotating plasma

    SciTech Connect

    Young, W. C.; Hassam, A. B.; Romero-Talamas, C. A.; Ellis, R. F.; Teodorescu, C.

    2011-11-15

    Diamagnetism and magnetic measurements of a supersonically rotating plasma in a shaped magnetic field demonstrate confinement of plasma pressure along the magnetic field resulting from centrifugal force. The Grad-Shafranov equation of ideal magnetohydrodynamic force balance, including supersonic rotation, is solved to confirm that the predicted angular velocity is in agreement with spectroscopic measurements of the Doppler shifts.

  8. Wideband rotating junctions

    NASA Astrophysics Data System (ADS)

    Pochernyaev, V. N.

    1993-06-01

    Rotating junctions of coaxial-waveguide and waveguide type with a traveling wave coefficient exceeding 0.8 in a wide frequency range are considered. The design of these junctions is based on a method of the theory of electrodynamic circuits. Numerical results are obtained for rotating junctions of partially filled rectangular waveguide type and their particular cases.

  9. The Weighted Oblimin Rotation.

    ERIC Educational Resources Information Center

    Lorenzo-Seva, Urbano

    2000-01-01

    Demonstrates that the weighting procedure proposed by E. Cureton and S. Mulaik (1975) can be applied to the Direct Oblimin approach of D. Clarkson and R. Jennrich (1988) to provide good results. The rotation method obtained is called Weighted Oblimin. Compared this method to other rotation methods with favorable results. (SLD)

  10. SMAP Faraday Rotation

    NASA Technical Reports Server (NTRS)

    Le Vine, David

    2016-01-01

    Faraday rotation is a change in the polarization as signal propagates through the ionosphere. At L-band it is necessary to correct for this change and measurements are made on the spacecraft of the rotation angle. These figures show that there is good agreement between the SMAP measurements (blue) and predictions based on models (red).

  11. Rotatable shear plate interferometer

    DOEpatents

    Duffus, Richard C.

    1988-01-01

    A rotatable shear plate interferometer comprises a transparent shear plate mounted obliquely in a tubular supporting member at 45.degree. with respect to its horizontal center axis. This tubular supporting member is supported rotatably around its center axis and a collimated laser beam is made incident on the shear plate along this center axis such that defocus in different directions can be easily measured.

  12. Rotation sensor switch

    DOEpatents

    Sevec, John B.

    1978-01-01

    A protective device to provide a warning if a piece of rotating machinery slows or stops comprises a pair of hinged weights disposed to rotate on a rotating shaft of the equipment. When the equipment is rotating, the weights remain in a plane essentially perpendicular to the shaft and constitute part of an electrical circuit that is open. When the shaft slows or stops, the weights are attracted to a pair of concentric electrically conducting disks disposed in a plane perpendicular to the shaft and parallel to the plane of the weights when rotating. A disk magnet attracts the weights to the electrically conducting plates and maintains the electrical contact at the plates to complete an electrical circuit that can then provide an alarm signal.

  13. Effect of genistein on basal jejunal chloride secretion in R117H CF mice is sex and route specific

    PubMed Central

    Rayyan, Esa; Polito, Sarah; Leung, Lana; Bhakta, Ashesh; Kang, Jonathan; Willey, Justin; Mansour, Wasim; Drumm, Mitchell L; Al-Nakkash, Layla

    2015-01-01

    Cystic fibrosis (CF) results from the loss or reduction in function of the CFTR (cystic fibrosis transmembrane conductance regulatory protein) chloride channel. The third most common CFTR mutation seen clinically is R117H. Genistein, a naturally occurring phytoestrogen, is known to stimulate CFTR function in vitro. We aimed to determine whether route of administration of genistein could mediate differential effects in R117H male and female CF mice. Mice were fed (4 weeks) or injected subcutaneously (1 week) with the following: genistein 600 mg/kg diet (600Gd); genistein-free diet (0Gd); genistein injection 600 mg/kg body weight (600Gi); dimethyl sulfoxide control (0Gi). In male R117H mice fed 600Gd, basal short circuit current (Isc) was unchanged. In 600Gd-fed female mice, there was a subgroup that demonstrated a significant increase in basal Isc (53.14±7.92 μA/cm2, n=6, P<0.05) and a subgroup of nonresponders (12.05±6.59 μA/cm2, n=4), compared to 0Gd controls (29.3±6.5 μA/cm2, n=7). In R117H mice injected with 600Gi, basal Isc was unchanged in both male and female mice compared to 0Gi controls. Isc was measured in response to the following: the adenylate cyclase activator forskolin (10 μM, bilateral), bumetanide (100 μM, basolateral) to indicate the Cl− secretory component, and acetazolamide (100 μM, bilateral) to indicate the HCO3− secretory component; however, there was no effect of genistein (diet or injection) on any of these parameters. Jejunal morphology (ie, villi length, number of goblet cells per villus, crypt depth, and number of goblet cells per crypt) in R117H mice suggested no genistein-mediated difference among the groups. Serum levels of genistein were significantly elevated, compared to respective controls, by either 600Gd (equally elevated in males and females) or 600Gi (elevated more in females versus males). These data suggest a sex-dependent increase in basal Isc of R117H mice and that the increase is also specific for route of

  14. Stress field rotation or block rotation: An example from the Lake Mead fault system

    NASA Technical Reports Server (NTRS)

    Ron, Hagai; Nur, Amos; Aydin, Atilla

    1990-01-01

    The Coulomb criterion, as applied by Anderson (1951), has been widely used as the basis for inferring paleostresses from in situ fault slip data, assuming that faults are optimally oriented relative to the tectonic stress direction. Consequently if stress direction is fixed during deformation so must be the faults. Freund (1974) has shown that faults, when arranged in sets, must generally rotate as they slip. Nur et al., (1986) showed how sufficiently large rotations require the development of new sets of faults which are more favorably oriented to the principal direction of stress. This leads to the appearance of multiple fault sets in which older faults are offset by younger ones, both having the same sense of slip. Consequently correct paleostress analysis must include the possible effect of fault and material rotation, in addition to stress field rotation. The combined effects of stress field rotation and material rotation were investigated in the Lake Meade Fault System (LMFS) especially in the Hoover Dam area. Fault inversion results imply an apparent 60 degrees clockwise (CW) rotation of the stress field since mid-Miocene time. In contrast structural data from the rest of the Great Basin suggest only a 30 degrees CW stress field rotation. By incorporating paleomagnetic and seismic evidence, the 30 degrees discrepancy can be neatly resolved. Based on paleomagnetic declination anomalies, it is inferred that slip on NW trending right lateral faults caused a local 30 degrees counter-clockwise (CCW) rotation of blocks and faults in the Lake Mead area. Consequently the inferred 60 degrees CW rotation of the stress field in the LMFS consists of an actual 30 degrees CW rotation of the stress field (as for the entire Great Basin) plus a local 30 degrees CCW material rotation of the LMFS fault blocks.

  15. Podokinetic After-Rotation in Parkinson Disease

    PubMed Central

    Hong, Minna; Perlmutter, Joel S.; Earhart, Gammon M.

    2007-01-01

    Walking on a rotating platform for 15 minutes causes healthy subjects to involuntarily turn when walking without vision. This adaptive response, called podokinetic after-rotation (PKAR), uses the same kinematic patterns as voluntary turning suggesting that PKAR and voluntary turning share common mechanisms. The purpose of this study is to determine whether people with Parkinson disease (PD), a condition that produces substantial disability from turning difficulties, can adapt to the rotating platform. Initial testing of people with PD revealed that most were unable to step on the rotating platform for 15 continuous minutes. We thus tested a less intense version of the paradigm in eight healthy people. On one day, subjects walked on the platform for 15 continuous minutes; on another day, they walked on the platform for three 5 minutes intervals separated by 5 minute rests. After both sessions, subjects rested for 5 min. then walked in place for 30 min. without vision, while we recorded rotational velocity of PKAR. Continuous and interval protocols effectively elicited robust PKAR. We then tested eight subjects with PD and matched controls using the 5 min. interval protocol and recorded PKAR responses for 10 min. There were no significant differences between the PD and control groups. We conclude that PD subjects can adapt to the rotating platform and develop PKAR from interval training. Future studies are needed to determine whether the rotating platform may act as a rehabilitative tool to reinforce motor patterns for turning and alleviate turning difficulties in people with PD. PMID:17140549

  16. ROTATIONAL DOPPLER BEAMING IN ECLIPSING BINARIES

    SciTech Connect

    Groot, Paul J.

    2012-01-20

    In eclipsing binaries the stellar rotation of the two components will cause a rotational Doppler beaming during eclipse ingress and egress when only part of the eclipsed component is covered. For eclipsing binaries with fast spinning components this photometric analog of the well-known spectroscopic Rossiter-McLaughlin effect can exceed the strength of the orbital effect. Example light curves are shown for a detached double white dwarf binary, a massive O-star binary and a transiting exoplanet case, similar to WASP-33b. Inclusion of the rotational Doppler beaming in eclipsing systems is a prerequisite for deriving the correct stellar parameters from fitting high-quality photometric light curves and can be used to determine stellar obliquities as well as, e.g., an independent measure of the rotational velocity in those systems that may be expected to be fully synchronized.

  17. Optical angular momentum in a rotating frame.

    PubMed

    Speirits, Fiona C; Lavery, Martin P J; Padgett, Miles J; Barnett, Stephen M

    2014-05-15

    It is well established that light carrying orbital angular momentum (OAM) can be used to induce a mechanical torque causing an object to spin. We consider the complementary scenario: will an observer spinning relative to the beam axis measure a change in OAM as a result of their rotational velocity? Remarkably, although a linear Doppler shift changes the linear momentum of a photon, the angular Doppler shift induces no change in the angular momentum. Further, we examine the rotational Doppler shift in frequency imparted to the incident light due to the relative motion of the beam with respect to the observer and consider what must happen to the measured wavelength if the speed of light c is to remain constant. We show specifically that the OAM of the incident beam is not affected by the rotating observer and that the measured wavelength is shifted by a factor equal and opposite to that of the frequency shift induced by the rotational Doppler effect.

  18. Rotatable seal assembly. [Patent application; rotating targets

    DOEpatents

    Logan, C.M.; Garibaldi, J.L.

    1980-11-12

    An assembly is provided for rotatably supporting a rotor on a stator so that vacuum chambers in the rotor and stator remain in communication while the chambers are sealed from ambient air, which enables the use of a ball bearing or the like to support most of the weight of the rotor. The apparatus includes a seal device mounted on the rotor to rotate therewith, but shiftable in position on the rotor while being sealed to the rotor as by an O-ring. The seal device has a flat face that is biased towards a flat face on the stator, and pressurized air is pumped between the faces to prevent contact between them while spacing them a small distance apart to avoid the inflow of large amounts of air between the faces and into the vacuum chambers.

  19. Rotating reactor studies

    NASA Technical Reports Server (NTRS)

    Roberts, Glyn O.

    1991-01-01

    Undesired gravitational effects such as convection or sedimentation in a fluid can sometimes be avoided or decreased by the use of a closed chamber uniformly rotated about a horizontal axis. In a previous study, the spiral orbits of a heavy or buoyant particle in a uniformly rotating fluid were determined. The particles move in circles, and spiral in or out under the combined effects of the centrifugal force and centrifugal buoyancy. A optimization problem for the rotation rate of a cylindrical reactor rotated about its axis and containing distributed particles was formulated and solved. Related studies in several areas are addressed. A computer program based on the analysis was upgraded by correcting some minor errors, adding a sophisticated screen-and-printer graphics capability and other output options, and by improving the automation. The design, performance, and analysis of a series of experiments with monodisperse polystyrene latex microspheres in water were supported to test the theory and its limitations. The theory was amply confirmed at high rotation rates. However, at low rotation rates (1 rpm or less) the assumption of uniform solid-body rotation of the fluid became invalid, and there were increasingly strong secondary motions driven by variations in the mean fluid density due to variations in the particle concentration. In these tests the increase in the mean fluid density due to the particles was of order 0.015 percent. To a first approximation, these flows are driven by the buoyancy in a thin crescent-shaped depleted layer on the descending side of the rotating reactor. This buoyancy distribution is balanced by viscosity near the walls, and by the Coriolis force in the interior. A full analysis is beyond the scope of this study. Secondary flows are likely to be stronger for buoyant particles, which spiral in towards the neutral point near the rotation axis under the influence of their centrifugal buoyancy. This is because the depleted layer is

  20. Chaotic rotation of Hyperion?

    NASA Technical Reports Server (NTRS)

    Binzel, R. P.; Green, J. R.; Opal, C. B.

    1986-01-01

    Thomas et al. (1984) analyzed 14 Voyager 2 images of Saturn's satellite Hyperion and interpreted them to be consistent with a coherent (nonchaotic) rotation period of 13.1 days. This interpretation was criticized by Peale and Wisdom (1984), who argued that the low sampling frequency of Voyager data does not allow chaotic or nonchaotic rotation to be distinguished. New observations obtained with a higher sampling frequency are reported here which conclusively show that the 13.1 day period found by Thomas et al. was not due to coherent rotation.

  1. Method for Design Rotation

    DTIC Science & Technology

    1993-08-01

    desirability of a rotation as a function of the set of planar angles. Criteria for the symmetry of the design (such as the same set of factor levels for...P is -1. Hence there is no theoretical problem in obtaining rotations of a design; there are only the practical questions Why rotate a design? And...star points, which can be represented in a shorthand notation by the permutations of (±1,0, "’" , 0), and (c) factorial points, which are a two- level

  2. Hematological and serum biochemical parameters of blood in adolescent rats and histomorphological changes in the jejunal epithelium and liver after chronic exposure to cadmium and lead in the case of supplementation with green tea vs black, red or white tea.

    PubMed

    Tomaszewska, Ewa; Winiarska-Mieczan, Anna; Dobrowolski, Piotr

    2015-01-01

    Rats were used to check whether regular consumption of black, red, or white tea would have a protective effect similar to the action of green tea on the intestine and liver in the case of exposure to Cd and Pb within the limits of human environmental exposure to these elements. Rats at the age of 6 weeks were divided into the control and four groups supplemented with green (GT), black (BT), red (RT), or white (WT) tea extracts. Their diet (except the control) was mixed with 7 mg Cd/kg and 50mg Pb/kg. The experiment lasted 12 weeks. The effects of administration of tea in Cd- and Pb-poisoned rats on plasma biochemical parameters and the jejunal epithelium and liver were determined. The highest body mass was found in the GT group. The highest hemoglobin and Fe concentrations were in the control and GT groups. The highest activity of AST was in groups poisoned with Cd and Pb independently on supplementation. The highest ALT activity was in BT and RT groups with lower content of polifenoles. Pb and Cd disturbed the liver leading to necrosis and fatty degenerative changes, and a loss of normal architecture of the hepatocytes. Rats from the GT group had the highest cell proliferation rate in intestinal glands and the largest absorptive surface. Black, red, and white tea exerted a varied impact on the histological structure and innervation of the small intestine wall as well as on the absorptive function of small intestine mucosa in rats poisoned with Pb and Cd than green tea. On the other hand, taking into account the number of apoptotic cells, the effect of the teas was the same. Moreover, it is clear that long term exposure to Cd and Pb contamination causes toxic effect in the liver.

  3. Exciting Molecules Close to the Rotational Quantum Resonance: Anderson Wall and Rotational Bloch Oscillations.

    PubMed

    Floß, Johannes; Averbukh, Ilya Sh

    2016-05-19

    We describe a universal behavior of linear molecules excited by a periodic train of short laser pulses under conditions close to the quantum resonance. The quantum resonance effect causes an unlimited ballistic growth of the angular momentum. We show that a disturbance of the quantum resonance, either by the centrifugal distortion of the rotating molecules or a controlled detuning of the pulse train period from the so-called rotational revival time, eventually halts the growth by causing Anderson localization beyond a critical value of the angular momentum, the Anderson wall. Below the wall, the rotational excitation oscillates with the number of pulses due to a mechanism similar to Bloch oscillations in crystalline solids. We suggest optical experiments capable of observing the rotational Anderson wall and Bloch oscillations at near-ambient conditions with the help of existing laser technology.

  4. Rotating mobile launcher

    NASA Technical Reports Server (NTRS)

    Gregory, T. J.

    1977-01-01

    Apparatus holds remotely piloted arm that accelerates until launching speed is reached. Then vehicle and counterweight at other end of arm are released simultaneously to avoid structural damage from unbalanced rotating forces.

  5. The Rotating Mirror.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    1981-01-01

    Discusses theory of the rotating mirror, its use in measuring the velocity of the electrical signal in wires, and the velocity of light. Concludes with a description of the manometric flame apparatus developed for analyzing sound waves. (SK)

  6. Rotator Cuff Injuries

    MedlinePlus

    ... cuff are common. They include tendinitis, bursitis, and injuries such as tears. Rotator cuff tendons can become ... cuff depends on age, health, how severe the injury is, and how long you've had the ...

  7. Rotator cuff problems

    MedlinePlus

    Miller RH III, Azar FM, Throckmorton TW. Shoulder and elbow injuries. In: Canale ST, Beaty JH, eds. ... Krishnan SG. Rotator cuff and impingement lesions. In: Miller MD, Thompson SR, eds. DeLee and Drez's Orthopaedic ...

  8. Rotator cuff repair - slideshow

    MedlinePlus

    ... presentations/100229.htm Rotator cuff repair - series—Normal anatomy To use the sharing features on this page, ... Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health Page last updated: ...

  9. Rotator cuff injuries.

    PubMed

    Crusher, R H

    2000-07-01

    Different types of rotator cuff injuries frequently present to Accident and Emergency departments and minor injury units but can be difficult to differentiate clinically. This brief case study describes the examination and diagnosis of related shoulder injuries, specifically rotator cuff tears/disruption and calcifying supraspinatus tendinitis. The relevant anatomy and current therapies for these injuries is also discussed to enable the emergency nurse practitioner to have a greater understanding of the theory surrounding their diagnosis and treatments.

  10. Rotational rate sensor

    DOEpatents

    Hunter, Steven L.

    2002-01-01

    A rate sensor for angular/rotational acceleration includes a housing defining a fluid cavity essentially completely filled with an electrolyte fluid. Within the housing, such as a toroid, ions in the fluid are swept during movement from an excitation electrode toward one of two output electrodes to provide a signal for directional rotation. One or more ground electrodes within the housing serve to neutralize ions, thus preventing any effect at the other output electrode.

  11. Rotational spectrum of phenylglycinol

    NASA Astrophysics Data System (ADS)

    Simão, Alcides; Peña, Isabel; Cabezas, Carlos; Alonso, José L.

    2014-11-01

    Solid samples of phenylglycinol were vaporized by laser ablation and investigated through rotational spectroscopy in a supersonic expansion using two different techniques: chirped pulse Fourier transform microwave spectroscopy and narrow band molecular beam Fourier transform microwave spectroscopy. One conformer, bearing an O-H···N and an N-H···π intramolecular hydrogen bonds, could be successfully identified by comparison of the experimental rotational and 14N nuclear quadruple coupling constants with those predicted theoretically.

  12. Rotating arc spark plug

    DOEpatents

    Whealton, John H.; Tsai, Chin-Chi

    2003-05-27

    A spark plug device includes a structure for modification of an arc, the modification including arc rotation. The spark plug can be used in a combustion engine to reduce emissions and/or improve fuel economy. A method for operating a spark plug and a combustion engine having the spark plug device includes the step of modifying an arc, the modifying including rotating the arc.

  13. Instability in Rotating Machinery

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The proceedings contain 45 papers on a wide range of subjects including flow generated instabilities in fluid flow machines, cracked shaft detection, case histories of instability phenomena in compressors, turbines, and pumps, vibration control in turbomachinery (including antiswirl techniques), and the simulation and estimation of destabilizing forces in rotating machines. The symposium was held to serve as an update on the understanding and control of rotating machinery instability problems.

  14. Electromagnetic rotational actuation.

    SciTech Connect

    Hogan, Alexander Lee

    2010-08-01

    There are many applications that need a meso-scale rotational actuator. These applications have been left by the wayside because of the lack of actuation at this scale. Sandia National Laboratories has many unique fabrication technologies that could be used to create an electromagnetic actuator at this scale. There are also many designs to be explored. In this internship exploration of the designs and fabrications technologies to find an inexpensive design that can be used for prototyping the electromagnetic rotational actuator.

  15. Pumping of water through carbon nanotubes by rotating electric field and rotating magnetic field

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Peng; Kong, Gao-Pan; Zhang, Xing; He, Guo-Wei

    2013-09-01

    Using molecular dynamics simulations, we demonstrate pumping of water through a carbon nanotube by applying the combination of a rotating electric field and a rotating magnetic field. The driving force is a Lorentz force generated from the motion of charges in the magnetic field, and the motion is caused by the rotation of the electric field. We find that there exits a linear relationship between the average pumping velocity v and magnetic field strength B, which can be used to control the flux of the continuous unidirectional water flow. This approach is expected to be used in liquid circulation without a pressure gradient.

  16. Rotational Spectrum of Sarin

    NASA Astrophysics Data System (ADS)

    Walker, A. R. Hight; Suenram, R. D.; Samuels, Alan; Jensen, James; Ellzy, Michael W.; Lochner, J. Michael; Zeroka, Daniel

    2001-05-01

    As part of an effort to examine the possibility of using molecular-beam Fourier-transform microwave spectroscopy to unambiguously detect and monitor chemical warfare agents, we report the first observation and assignment of the rotational spectrum of the nerve agent Sarin (GB) (Methylphosphonofluoridic acid 1-methyl-ethyl ester, CAS #107-44-8) at frequencies between 10 and 22 GHz. Only one of the two low-energy conformers of this organophosphorus compound (C4H10FO2P) was observed in the rotationally cold (Trot<2 K) molecular beam. The experimental asymmetric-rotor ground-state rotational constants of this conformer are A=2874.0710(9) MHz, B=1168.5776(4) MHz, C=1056.3363(4) MHz (Type A standard uncertainties are given, i.e., 1σ), as obtained from a least-squares analysis of 74 a-, b-, and c-type rotational transitions. Several of the transitions are split into doublets due to the internal rotation of the methyl group attached to the phosphorus. The three-fold-symmetry barrier to internal rotation estimated from these splittings is 677.0(4) cm-1. Ab initio electronic structure calculations using Hartree-Fock, density functional, and Moller-Plesset perturbation theories have also been made. The structure of the lowest-energy conformer determined from a structural optimization at the MP2/6-311G** level of theory is consistent with our experimental findings.

  17. Nanoselenium Supplementation of Heat-Stressed Broilers: Effects on Performance, Carcass Characteristics, Blood Metabolites, Immune Response, Antioxidant Status, and Jejunal Morphology.

    PubMed

    Safdari-Rostamabad, Morteza; Hosseini-Vashan, Seyyed Javad; Perai, Ali Hossein; Sarir, Hadi

    2016-11-22

    An experiment was conducted to investigate the effects of dietary nanoselenium supplementation at 0, 0.6 and 1.2 mg/kg of diet on growth performance, serum biochemical parameters, immune response, antioxidant capacity, and jejunal morphology of 29-d-old male broilers subjected to heat stress at 37 ± 1°C for 14 d. Broilers were fed for 42 d on the experimental diets. The results showed that nanoselenium supplementation had no effect on growth performance, but it supplementation at the rate of 1.2 mg/kg diet decreased the serum concentration of cholesterol prior to the heat exposure. Further, dietary nanoselenium supplementation linearly increased the high-density lipoprotein cholesterol concentration, while linearly decreased those of low-density lipoprotein cholesterol and aspartate aminotransferase in the serum before applying heat stress. Compared with thermoneutral temperature, heat stress reduced body mass gain, feed intake, percentages of carcass, breast, leg, abdominal fat, bursa of Fabricius, thymus, antibody response against sheep red blood cells, serum concentration of protein, erythrocyte activities of glutathione peroxidase and superoxide dismutase, jejunal villus height, and villus height to crypt depth ratio, while increased feed conversion ratio, percentages of liver, gizzard, pancreas, gallbladder, heart, and the concentrations of aspartate aminotransferase and malondialdehyde. Dietary supplementation of nanoselenium linearly reduced the abdominal fat and liver percentages, while linearly increased the activity of glutathione peroxidase and villus height in heat-stressed broilers. Furthermore, the lower level of nanoselenium decreased the percentages of gizzard and heart in broilers under heat stress. The diet supplemented with 1.2 mg/kg nanoselenium improved feed conversion ratio and increased antibody response against sheep red blood cells, activity of superoxide dismutase, and villus height to crypt depth ratio, but decreased the serum

  18. D-Glucose Acts via SGLTI to Increase NHE3 in Mouse Jejunal Brush Border by a NHERF2-Dependent Process

    PubMed Central

    Lin, Rong; Murtazina, Rakhilya; Cha, Boyoung; Chakraborty, Molee; Sarker, Rafiquel; Chen, Tian-e; Lin, Zhihong; Hogema, Boris M.; de Jonge, Hugo R.; Seidler, Ursula; Turner, Jerrold R.; Li, Xuhang; Kovbasnjuk, Olga; Donowitz, Mark

    2010-01-01

    Background & Aims Oral rehydration solutions (ORS) reduce diarrhea-associated mortality by unclear mechanisms. Sodium absorption is mediated by the Na+/H+ hydrogen exchanger NHE3 and is increased by Na+-glucose co-transport in vitro, but the mechanisms of this process are only partially understood and its in vivo relevance has not been determined. Methods Intracellular pH was measured in jejunal enterocytes of wild-type mice and mice with disrupted Na+/H+ exchange regulatory co-factor 2 (NHERF2−/− mice) by multi-photon microscopy. Diarrhea was induced by cholera toxin. Caco-2BBe cells that express NHE3 and the sodium/glucose cotransporter (SGLT)1 were studied by fluorometery, before and after siRNA-mediated knockdown of NHERF1 or NHERF2. NHE3 distribution was assessed by cell-surface biotinylation and confocal microscopy. Brush border mobility was determined by fluorescence recovery after photobleaching and confocal microscopy. Results The non-metabolized SGLT1 substrate α-methyl-D-Glu (α-MD-G) activated jejunal NHE3; this process required Akt and NHERF2. α-MD-G normalized NHE3 activity after cholera toxin-induced diarrhea. α-MD-G–stimulated jejunal NHE3 activity was: defective in NHERF2−/− mice and cells with NHERF2 knockdown, but occurred normally with NHERF1 knockdown; associated with increased NHE3 surface expression in Caco-2 cells, which was also NHERF2-dependent; associated with dissociation of NHE3 from NHERF2 and an increase in the NHE3 mobile fraction from the brush border; and accompanied by a NHERF2 ezrin-radixin-moesin–binding domain-dependent increase in co-precipitation of ezrin with NHE3. Conclusions SGLT1-mediated Na-glucose co-transport stimulates NHE3 activity in vivo by an Akt- and NHERF2-dependent signaling pathway. It is associated with increased brush border NHE3 and association between ezrin and NHE3. Activation of NHE3 corrects cholera toxin-induced defects in Na absorption and might mediate efficacy of ORS. PMID:20977906

  19. Oral Morphine Pharmacokinetic in Obesity: The Role of P-Glycoprotein, MRP2, MRP3, UGT2B7, and CYP3A4 Jejunal Contents and Obesity-Associated Biomarkers.

    PubMed

    Lloret-Linares, Célia; Miyauchi, Eisuke; Luo, Huilong; Labat, Laurence; Bouillot, Jean-Luc; Poitou, Christine; Oppert, Jean-Michel; Laplanche, Jean-Louis; Mouly, Stéphane; Scherrmann, Jean-Michel; Uchida, Yasuo; Tachikawa, Masanori; Terasaki, Tetsuya; Bergmann, Jean-François; Declèves, Xavier

    2016-03-07

    The objective of our work was to study the association between the jejunal expression levels of P-gp, MRP2, MRP3, UGT2B7, CYP3A4, the ABCB1 c.3435C > T polymorphism, and several obesity-associated biomarkers, as well as oral morphine and glucuronides pharmacokinetics in a population of morbidly obese subjects. The pharmacokinetics of oral morphine (30 mg) and its glucuronides was performed in obese patients candidate to bariatric surgery. A fragment of jejunal mucosa was preserved during surgery. Subjects were genotyped for the ABCB1 single nucleotide polymorphism (SNP) c.3435C > T. The subjects were 6 males and 23 females, with a mean body mass index of 44.8 (35.4-61.9) kg/m(2). The metabolic ratios AUC0-inf M3G/morphine and AUC0-inf M6G/morphine were highly correlated (rs = 0.8, p < 0.0001) and were 73.2 ± 24.6 (34.7-137.7) and 10.9 ± 4.1 (3.8-20.6). The pharmacokinetic parameters of morphine and its glucuronides were not associated with the jejunal contents of P-gp, CYP3A4, MRP2, and MRP3. The jejunal content of UGT2B7 was positively associated with morphine AUC0-inf (rs = 0.4, p = 0.03). Adiponectin was inversely correlated with morphine Cmax (rs = -0.44, p = 0.03). None of the factors studied was associated with morphine metabolic ratios. The interindividual variability in the jejunal content of drug transporters and metabolizing enzymes, the ABCB1 gene polymorphism, and the low-grade inflammation did not explain the variability in morphine and glucuronide exposure. High morphine metabolic ratio argued for an increased morphine glucuronidation in morbidly obese patients.

  20. Rotating superconductor magnet for producing rotating lobed magnetic field lines

    DOEpatents

    Hilal, Sadek K.; Sampson, William B.; Leonard, Edward F.

    1978-01-01

    This invention provides a rotating superconductor magnet for producing a rotating lobed magnetic field, comprising a cryostat; a superconducting magnet in the cryostat having a collar for producing a lobed magnetic field having oppositely directed adjacent field lines; rotatable support means for selectively rotating the superconductor magnet; and means for energizing the superconductor magnet.

  1. Automated shell theory for rotating structures (ASTROS)

    NASA Technical Reports Server (NTRS)

    Foster, B. J.; Thomas, J. M.

    1971-01-01

    A computer program for analyzing axisymmetric shells with inertial forces caused by rotation about the shell axis is developed by revising the STARS II shell program. The basic capabilities of the STARS II shell program, such as the treatment of the branched shells, stiffened wall construction, and thermal gradients, are retained.

  2. Effect of different levels of black cumin (Nigella sativa L.) on performance, intestinal Escherichia coli colonization and jejunal morphology in laying hens.

    PubMed

    Boka, J; Mahdavi, A H; Samie, A H; Jahanian, R

    2014-04-01

    This study was conducted to investigate the effects of different levels of black cumin seeds (Nigella sativa L.) on performance, intestinal Escherichia coli count and morphology of jejunal epithelial cells in laying hens. A total of 100 Leghorn laying hens (Hy-Line W-36) of 49 weeks old were randomly distributed among five cage replicates of five birds each. Experimental diets consisted of different levels (0%, 1%, 2% and 3% of diet) of dietary black cumin inclusion. The experimental period lasted for a total of 10 weeks, and egg quality indexes and laying hens' performance were measured as two 35-day trial periods. At the final day, two hens per replicate were slaughtered to investigate the influence of dietary treatments on intestinal E. coli colonization and morphology of jejunal cells. Although dietary black cumin in all supplementation levels decreased (p < 0.05) the enumeration of ileal E. coli, the morphological and histological alterations in small intestine such as enhancement of villus height to crypt depth ratio, increased goblet cell numbers and proliferation of lamina propria lymphatic follicles were observed after dietary supplementation with at least 2% black cumin. Dietary treatments decreased (p < 0.05) the concentration of serum cholesterol and triglycerides and increased (p < 0.05) serum HDL concentration and relative weight of pancreas; however, the egg yolk cholesterol was not influenced by dietary treatments. In addition, dietary supplementation with black cumin improved (p < 0.05) eggshell quality and Haugh unit. The best feed conversion ratio was obtained when diets were supplemented with 2% black cumin. This improvement was due to the increase (p < 0.05) in egg mass and contemporaneous decrease (p < 0.01) in feed consumption. The present results indicated that regardless of supplementation level, dietary inclusion of black cumin decreased E. coli enumeration in ileal digesta and improved serum lipid profile and eggshell quality, whereas the

  3. Jejunal microvilli atrophy and reduced nutrient transport in rats with advanced liver cirrhosis: improvement by Insulin-like Growth Factor I

    PubMed Central

    Castilla-Cortázar, Inma; Pascual, María; Urdaneta, Elena; Pardo, Javier; Puche, Juan Enrique; Vivas, Bárbara; Díaz-Casares, Amelia; García, María; Díaz-Sánchez, Matías; Varela-Nieto, Isabel; Castilla, Alberto; González-Barón, Salvador

    2004-01-01

    Background Previous results have shown that in rats with non-ascitic cirrhosis there is an altered transport of sugars and amino acids associated with elongated microvilli. These alterations returned to normal with the administration of Insulin-Like Growth Factor-I (IGF-I). The aims of this study were to explore the evolution of these alterations and analyse the effect of IGF-I in rats with advanced cirrhosis and ascites. Thus, jejunal structure and nutrient transport (D-galactose, L-leucine, L-proline, L-glutamic acid and L-cystine) were studied in rats with ascitic cirrhosis. Methods Advanced cirrhosis was induced by CCl4 inhalation and Phenobarbital administration for 30 weeks. Cirrhotic animals were divided into two groups which received IGF-I or saline during two weeks. Control group was studied in parallel. Jejunal microvilli were studied by electron microscopy. Nutrient transport was assessed in brush border membrane vesicles using 14C or 35S-labelled subtracts in the three experimental groups. Results Intestinal active Na+-dependent transport was significantly reduced in untreated cirrhotic rats. Kinetic studies showed a decreased Vmax and a reduced affinity for sugar and four amino acids transporters (expressed as an increased Kt) in the brush border membrane vesicles from untreated cirrhotic rats as compared with controls. Both parameters were normalised in the IGF-I-treated cirrhotic group. Electron microscopy showed elongation and fusion of microvilli with degenerative membrane lesions and/or notable atrophy. Conclusions The initial microvilli elongation reported in non ascitic cirrhosis develops into atrophy in rats with advanced cirrhosis and nutrient transports (monosaccharides and amino acids) are progressively reduced. Both morphological and functional alterations improved significantly with low doses of IGF-I. PMID:15196310

  4. Activity and Rotation of Kepler-17

    NASA Astrophysics Data System (ADS)

    Valio, Adriana; Estrela, Raissa; Netto, Yuri; Bravo, J. P.; de Medeiros, J. R.

    2017-02-01

    Magnetic activity on stars manifests itself in the form of dark spots on the stellar surface, which cause modulations of a few percent in the light curve of the star as it rotates. When a planet eclipses its host star, it might cross in front of one of these spots, creating a “bump” in the transit light curve. By modeling these spot signatures, it is possible to determine the physical properties of the spots such as size, temperature, and location. In turn, monitoring of the spots’ longitude provides estimates of the stellar rotation and differential rotation. This technique was applied to the star Kepler-17, a solar–type star orbited by a hot Jupiter. The model yields the following spot characteristics: average radius of 49 ± 10 Mm, temperatures of 5100 ± 300 K, and surface area coverage of 6 ± 4%. The rotation period at the transit latitude, -5^\\circ , occulted by the planet was found to be 11.92 ± 0.05 day, slightly smaller than the out-of-transit average period of 12.4 ± 0.1 day. Adopting a solar-like differential rotation, we estimated the differential rotation of Kepler-17 to be {{Δ }}{{Ω }}=0.041+/- 0.005 rd day‑1, which is close to the solar value of 0.050 rd day‑1, and a relative differential rotation of {{Δ }}{{Ω }}/{{Ω }}=8.0+/- 0.9 % . Because Kepler-17 is much more active than our Sun, it appears that, for this star, larger rotation rate is more effective in the generation of magnetic fields than shear.

  5. High-Aspect-Ratio Rotating Cell-Culture Vessel

    NASA Technical Reports Server (NTRS)

    Wolf, David A.; Sams, Clarence; Schwarz, Ray P.

    1992-01-01

    Cylindrical rotating cell-culture vessel with thin culture-medium layer of large surface area provides exchange of nutrients and products of metabolism with minimal agitation. Rotation causes averaging of buoyant forces otherwise separating components of different densities. Vessel enables growth of cells in homogeneous distribution with little agitation and little shear stress.

  6. STRUCTURE OF UNIFORMLY ROTATING STARS

    SciTech Connect

    Deupree, Robert G.

    2011-07-10

    Zero-age main-sequence models of uniformly rotating stars have been computed for 10 masses between 1.625 and 8 M{sub sun} and for 21 rotation rates from zero to nearly critical rotation. The surface shape is used to distinguish rotation rather than the surface equatorial velocity or the rotation rate. Using the surface shape is close, but not quite equivalent, to using the ratio of the rotation rate to the critical rotation rate. Using constant shape as the rotation variable means that it and the mass are separable, something that is not true for either the rotation rate or surface equatorial velocity. Thus, a number of properties, including the ratio of the effective temperature anywhere on the surface to the equatorial temperature, are nearly independent of the mass of the model, as long as the rotation rate changes in such a way as to keep the surface shape constant.

  7. IO Rotation Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    During its 1979 flyby, Voyager 2 observed Io only from a distance. However, the volcanic activity discovered by Voyager 1 months earlier was readily visible. This sequence of nine color images was collected using the Blue, Green and Orange filters from about 1.2 million kilometers. A 2.5 hour period is covered during which Io rotates 7 degrees.

    Rotating into view over the limb of Io are the plumes of the volcanoes Amirani (top) and Maui (lower). These plumes are very distinct against the black sky because they are being illuminated from behind. Notice that as Io rotates, the proportion of Io which is sunlit decreases greatly. This changing phase angle is because Io is moving between the spacecraft and the Sun.

    This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1985.

  8. Rotating Aperture System

    DOEpatents

    Rusnak, Brian; Hall, James M.; Shen, Stewart; Wood, Richard L.

    2005-01-18

    A rotating aperture system includes a low-pressure vacuum pumping stage with apertures for passage of a deuterium beam. A stator assembly includes holes for passage of the beam. The rotor assembly includes a shaft connected to a deuterium gas cell or a crossflow venturi that has a single aperture on each side that together align with holes every rotation. The rotating apertures are synchronized with the firing of the deuterium beam such that the beam fires through a clear aperture and passes into the Xe gas beam stop. Portions of the rotor are lapped into the stator to improve the sealing surfaces, to prevent rapid escape of the deuterium gas from the gas cell.

  9. Chiral rotational spectroscopy

    NASA Astrophysics Data System (ADS)

    Cameron, Robert P.; Götte, Jörg B.; Barnett, Stephen M.

    2016-09-01

    We introduce chiral rotational spectroscopy, a technique that enables the determination of the orientated optical activity pseudotensor components BX X, BY Y, and BZ Z of chiral molecules, in a manner that reveals the enantiomeric constitution of a sample and provides an incisive signal even for a racemate. Chiral rotational spectroscopy could find particular use in the analysis of molecules that are chiral solely by virtue of their isotopic constitution and molecules with multiple chiral centers. A basic design for a chiral rotational spectrometer together with a model of its functionality is given. Our proposed technique offers the more familiar polarizability components αX X, αY Y, and αZ Z as by-products, which could see it find use even for achiral molecules.

  10. Lattice QCD in rotating frames.

    PubMed

    Yamamoto, Arata; Hirono, Yuji

    2013-08-23

    We formulate lattice QCD in rotating frames to study the physics of QCD matter under rotation. We construct the lattice QCD action with the rotational metric and apply it to the Monte Carlo simulation. As the first application, we calculate the angular momenta of gluons and quarks in the rotating QCD vacuum. This new framework is useful to analyze various rotation-related phenomena in QCD.

  11. Rotating bubble membrane radiator

    DOEpatents

    Webb, Brent J.; Coomes, Edmund P.

    1988-12-06

    A heat radiator useful for expelling waste heat from a power generating system aboard a space vehicle is disclosed. Liquid to be cooled is passed to the interior of a rotating bubble membrane radiator, where it is sprayed into the interior of the bubble. Liquid impacting upon the interior surface of the bubble is cooled and the heat radiated from the outer surface of the membrane. Cooled liquid is collected by the action of centrifical force about the equator of the rotating membrane and returned to the power system. Details regarding a complete space power system employing the radiator are given.

  12. Rotating flexible drag mill

    DOEpatents

    Pepper, W.B.

    1984-05-09

    A rotating parachute for decelerating objects travelling through atmosphere at subsonic or supersonic deployment speeds includes a circular canopy having a plurality of circumferentially arranged flexible panels projecting radially from a solid central disk. A slot extends radially between adjacent panels to the outer periphery of the canopy. Upon deployment, the solid disk diverts air radially to rapidly inflate the panels into a position of maximum diameter. Air impinging on the panels adjacent the panel slots rotates the parachute during its descent. Centrifugal force flattens the canopy into a constant maximum diameter during terminal descent for maximum drag and deceleration.

  13. Bound Motion of Bodies and Paticles in the Rotating Systems

    NASA Astrophysics Data System (ADS)

    Pardy, Miroslav

    2007-04-01

    The Lagrange theory of particle motion in the noninertial systems is applied to the Foucault pendulum, isosceles triangle pendulum and the general triangle pendulum swinging on the rotating Earth. As an analogue, planet orbiting in the rotating galaxy is considered as the giant galactic gyroscope. The Lorentz equation and the Bargmann-Michel-Telegdi equations are generalized for the rotation system. The knowledge of these equations is inevitable for the construction of LHC where each orbital proton “feels” the Coriolis force caused by the rotation of the Earth.

  14. Effect of rotation on a rotating hot-wire sensor

    NASA Technical Reports Server (NTRS)

    Hah, C.; Lakshminarayana, B.

    1978-01-01

    An investigation was conducted to discern the effects of centrifugal and Coriolis forces on a rotating hot-wire. The probe was calibrated in a wind tunnel as well as in a rotating mode. The effect of rotation was found to be negligibly small. A small change in cold resistance (1.5%) was observed in the rotating wire. The rotation seems to have a negligible effect on the fluid mechanics, heat transfer and material characteristics of the wire. This is a significant conclusion in view of the potential application of the hot-wire probe in a rotating passage (such as turbomachinery).

  15. Compact rotating cup anemometer

    NASA Technical Reports Server (NTRS)

    Wellman, J. B.

    1968-01-01

    Compact, collapsible rotating cup anemometer is used in remote locations where portability and durability are factors in the choice of equipment. This lightweight instrument has a low wind-velocity threshold, is capable of withstanding large mechanical shocks while in its stowed configuration, and has fast response to wind fluctuations.

  16. Rotationally Actuated Prosthetic Hand

    NASA Technical Reports Server (NTRS)

    Norton, William E.; Belcher, Jewell G., Jr.; Carden, James R.; Vest, Thomas W.

    1991-01-01

    Prosthetic hand attached to end of remaining part of forearm and to upper arm just above elbow. Pincerlike fingers pushed apart to degree depending on rotation of forearm. Simpler in design, simpler to operate, weighs less, and takes up less space.

  17. Rotating Science Classrooms.

    ERIC Educational Resources Information Center

    Hogg, Loretta A.

    1980-01-01

    Described is a science classroom program with centralized materials, and assistance and workshops for teachers. Classroom materials on one of five topics rotate every six weeks among five schools. Teachers plan specific units to match the arrival of the materials in their schools. (Author/DS)

  18. Rotational Dynamics with Tracker

    ERIC Educational Resources Information Center

    Eadkhong, T.; Rajsadorn, R.; Jannual, P.; Danworaphong, S.

    2012-01-01

    We propose the use of Tracker, freeware for video analysis, to analyse the moment of inertia ("I") of a cylindrical plate. Three experiments are performed to validate the proposed method. The first experiment is dedicated to find the linear coefficient of rotational friction ("b") for our system. By omitting the effect of such friction, we derive…

  19. Concepts in crop rotations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop rotations have been a part of civilization since the Middle Ages. With colonization of what would become the United States came new crops of tobacco, cotton, and corn, the first two of which would play significant roles in both the economic beginnings and social fabric of the new country, how ...

  20. Anisotropy in rotating drums

    NASA Astrophysics Data System (ADS)

    Povall, Timothy; McBride, Andrew; Govender, Indresan

    2015-11-01

    An anisotropic relationship between the stress and the strain rate has been observed in two-dimensional simulations of rotating drums. The objective of this work is to investigate the structure of the constitutive relation using three-dimensional discrete-element-method simulations of a rotating drum containing identical rigid spheres for a range of rotational speeds. Anisotropy is quantified from the alignment of the stress and strain rate tensors, with the strain rate computed using a least-squares fit. It is shown that in certain regions there is a strong anisotropic relationship, regardless of the speed of rotation. The effective friction coefficient is examined in order to determine the phase space in which the μ (I) rheology is valid. Lastly, a depth-averaged approach through the flowing layer is employed to determine the relationship between the velocity tangential to the equilibrium surface and the height of the flowing layer. A power-law relationship that approaches linear at high speeds is observed. Supported by NRF/DST Scarce Skills (South Africa).

  1. Rotating Saddle Paul Trap.

    ERIC Educational Resources Information Center

    Rueckner, Wolfgang; And Others

    1995-01-01

    Describes a demonstration in which a ball is placed in an unstable position on a saddle shape. The ball becomes stable when it is rotated above some threshold angular velocity. The demonstration is a mechanical analog of confining a particle in a "Paul Trap". (DDR)

  2. Rotatable stem and lock

    DOEpatents

    Deveney, Joseph E.; Sanderson, Stephen N.

    1984-01-01

    A valve stem and lock include a housing surrounding a valve stem, a solenoid affixed to an interior wall of the housing, an armature affixed to the valve stem and a locking device for coupling the armature to the housing body. When the solenoid is energized, the solenoid moves away from the housing body, permitting rotation of the valve stem.

  3. Rotatable stem and lock

    DOEpatents

    Deveney, J.E.; Sanderson, S.N.

    1981-10-27

    A valve stem and lock is disclosed which includes a housing surrounding a valve stem, a solenoid affixed to an interior wall of the housing, an armature affixed to the valve stem and a locking device for coupling the armature to the housing body. When the solenoid is energized, the solenoid moves away from the housing body, permitting rotation of the valve stem.

  4. Rotator Cuff Injuries.

    ERIC Educational Resources Information Center

    Connors, G. Patrick

    Many baseball players suffer from shoulder injuries related to the rotator cuff muscles. These injuries may be classified as muscular strain, tendonitis or tenosynovitis, and impingement syndrome. Treatment varies from simple rest to surgery, so it is important to be seen by a physician as soon as possible. In order to prevent these injuries, the…

  5. NEA rotations and binaries

    NASA Astrophysics Data System (ADS)

    Pravec, Petr; Harris, A. W.; Warner, B. D.

    2007-05-01

    Of nearly 3900 near-Earth asteroids known in June 2006, 325 have got estimated rotation periods. NEAs with sizes down to 10 meters have been sampled. Observed spin distribution shows a major changing point around D=200 m. Larger NEAs show a barrier against spin rates >11 d-1 (period P~2.2 h) that shifts to slower rates with increasing equatorial elongation. The spin barrier is interpreted as a critical spin rate for bodies held together by self-gravitation only, suggesting that NEAs larger than 200 m are mostly strenghtless bodies (i.e., with zero tensile strength), so called `rubble piles'. The barrier disappears at D<200 m where most objects rotate too fast to be held together by self-gravitation only, so a non-zero cohesion is implied in the smaller NEAs. The distribution of NEA spin rates in the `rubble pile' range (D>0.2 km) is non-Maxwellian, suggesting that other mechanisms than just collisions worked there. There is a pile up in front of the barrier (P of 2-3 h). It may be related to a spin up mechanism crowding asteroids to the barrier. An excess of slow rotators is seen at P>30 h. The spin-down mechanism has no clear lower limit on spin rate; periods as long as tens of days occur. Most NEAs appear to be in basic spin states with rotation around the principal axis. Excited rotations are present among and actually dominate in slow rotators with damping timescales >4.5 byr. A few tumblers observed among fast rotating coherent objects consistently appear to be more rigid or younger than the larger, rubble-pile tumblers. An abundant population of binary systems among NEAs has been found. The fraction of binaries among NEAs larger than 0.3 km has been estimated to be 15 +/-4%. Primaries of the binary systems concentrate at fast spin rates (periods 2-3 h) and low amplitudes, i.e., they lie just below the spin barrier. The total angular momentum content in the binary systems suggests that they formed at the critical spin rate, and that little or no angular

  6. Instability of a rotating liquid ring

    NASA Astrophysics Data System (ADS)

    Zhao, Sicheng; Tao, Jianjun

    2013-09-01

    It is shown numerically that a rotating inviscid liquid ring has a temporally oscillating state, where the radius of the ring varies periodically because of the competition between the centrifugal force and the centripetal force caused by the surface tension. Stability analysis reveals that an enlarging or shrinking ring is unstable to a varicose-type mode, which is affected by both the radial velocity and the radius ratio between the cross section and the ring. Furthermore, uniform rotation of a ring leads to a traveling unstable mode, whose frequency is determined by a simple sinuous mode, while the surface shape is modulated by the varicose mode and twisted by the rotation-induced Coriolis force.

  7. Earth Rotation Dynamics: Review and Prospects

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    2004-01-01

    Modem space geodetic measurement of Earth rotation variations, particularly by means of the VLBI technique, has over the years allowed studies of Earth rotation dynamics to advance in ever-increasing precision, accuracy, and temporal resolution. A review will be presented on our understanding of the geophysical and climatic causes, or "excitations", for length-of-day change, polar motion, and nutations. These excitations sources come from mass transports that constantly take place in the Earth system comprised of the atmosphere, hydrosphere, cryosphere, lithosphere, mantle, and the cores. In this sense, together with other space geodetic measurements of time-variable gravity and geocenter motion, Earth rotation variations become a remote-sensing tool for the integral of all mass transports, providing valuable information about the latter on a wide range of spatial and temporal scales. Future prospects with respect to geophysical studies with even higher accuracy and resolution will be discussed.

  8. Earth Rotational Variations Excited by Geophysical Fluids

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    2004-01-01

    Modern space geodetic measurement of Earth rotation variations, particularly by means of the VLBI technique, has over the years allowed studies of Earth rotation dynamics to advance in ever-increasing precision, accuracy, and temporal resolution. A review will be presented on our understanding of the geophysical and climatic causes, or "excitations". for length-of-day change, polar motion, and nutations. These excitations sources come from mass transports that constantly take place in the Earth system comprised of the atmosphere, hydrosphere, cryosphere, lithosphere, mantle, and the cores. In this sense, together with other space geodetic measurements of time-variable gravity and geocenter motion, Earth rotation variations become a remote-sensing tool for the integral of all mass transports, providing valuable information about the latter on a wide range of spatial and temporal scales. Future prospects with respect to geophysical studies with even higher accuracy and resolution will be discussed.

  9. The Rotational and Gravitational Effect of Earthquakes

    NASA Technical Reports Server (NTRS)

    Gross, Richard

    2000-01-01

    The static displacement field generated by an earthquake has the effect of rearranging the Earth's mass distribution and will consequently cause the Earth's rotation and gravitational field to change. Although the coseismic effect of earthquakes on the Earth's rotation and gravitational field have been modeled in the past, no unambiguous observations of this effect have yet been made. However, the Gravity Recovery And Climate Experiment (GRACE) satellite, which is scheduled to be launched in 2001, will measure time variations of the Earth's gravitational field to high degree and order with unprecedented accuracy. In this presentation, the modeled coseismic effect of earthquakes upon the Earth's gravitational field to degree and order 100 will be computed and compared to the expected accuracy of the GRACE measurements. In addition, the modeled second degree changes, corresponding to changes in the Earth's rotation, will be compared to length-of-day and polar motion excitation observations.

  10. Stellar Rotation Effects in Polarimetric Microlensing

    NASA Astrophysics Data System (ADS)

    Sajadian, Sedighe

    2016-07-01

    It is well known that the polarization signal in microlensing events of hot stars is larger than that of main-sequence stars. Most hot stars rotate rapidly around their stellar axes. The stellar rotation creates ellipticity and gravity-darkening effects that break the spherical symmetry of the source's shape and the circular symmetry of the source's surface brightness respectively. Hence, it causes a net polarization signal for the source star. This polarization signal should be considered in polarimetric microlensing of fast rotating stars. For moderately rotating stars, lensing can magnify or even characterize small polarization signals due to the stellar rotation through polarimetric observations. The gravity-darkening effect due to a rotating source star creates asymmetric perturbations in polarimetric and photometric microlensing curves whose maximum occurs when the lens trajectory crosses the projected position of the rotation pole on the sky plane. The stellar ellipticity creates a time shift (i) in the position of the second peak of the polarimetric curves in transit microlensing events and (ii) in the peak position of the polarimetric curves with respect to the photometric peak position in bypass microlensing events. By measuring this time shift via polarimetric observations of microlensing events, we can evaluate the ellipticity of the projected source surface on the sky plane. Given the characterizations of the FOcal Reducer and low dispersion Spectrograph (FORS2) polarimeter at the Very Large Telescope, the probability of observing this time shift is very small. The more accurate polarimeters of the next generation may well measure these time shifts and evaluate the ellipticity of microlensing source stars.

  11. Adaptation in a rotating artificial gravity environment

    NASA Technical Reports Server (NTRS)

    Lackner, J. R.; DiZio, P.

    1998-01-01

    The centripetal force generated by a rotating space vehicle is a potential source of artificial gravity. Minimizing the cost of such a vehicle dictates using the smallest radius and highest rotation rate possible, but head movements made at high rotation rates generate disorienting, nauseogenic cross-coupled semicircular canal stimulation. Early studies suggested 3 or 4 rpm as the highest rate at which humans could adapt to this vestibular stimulus. These studies neglected the concomitant Coriolis force actions on the head/neck system. We assessed non-vestibular Coriolis effects by measuring arm and leg movements made in the center of a rotating room turning at 10 rpm and found that movement endpoints and trajectories are initially deviated; however, subjects readily adapt with 10-20 additional movements, even without seeing their errors. Equilibrium point theories of motor control errantly predict that Coriolis forces will not cause movement endpoint errors so that subjects will not have to adapt their reaching movements during rotation. Adaptation of movement trajectory acquired during Coriolis force perturbations of one arm transfers to the unexposed arm but there is no intermanual transfer of endpoint adaptation indicating that neuromotor representations of movement endpoint and trajectory are separable and can adapt independently, also contradictory to equilibrium point theories. Touching a surface at the end of reaching movements is required for complete endpoint adaptation in darkness but trajectory adapts completely with or without terminal contact. We have also made the first kinematic measurements of unconstrained head movements during rotation, these movements show rapid adaptation to Coriolis force perturbations. Our results point to methods for achieving full compensation for rotation up to 10 rpm. Copyright 1998 Published by Elsevier Science B.V.

  12. The rotation of Titan and Ganymede

    NASA Astrophysics Data System (ADS)

    Van Hoolst, Tim; Coyette, Alexis; Baland, Rose-Marie; Trinh, Antony

    2016-10-01

    The rotation rates of Titan and Ganymede, the largest satellites of Saturn and Jupiter, are on average equal to their orbital mean motion. Here we discuss small deviations from the average rotation for both satellites and evaluate the polar motion of Titan induced by its surface fluid layers. We examine different causes at various time scales and assess possible consequences and the potential of using librations and polar motion as probes of the interior structure of the satellites.The rotation rate of Titan and Ganymede cannot be constant on the orbital time scale as a result of the gravitational torque of the central planet acting on the satellites. Titan is moreover expected to show significant polar motion and additional variations in the rotation rate due to angular momentum exchange with the atmosphere, mainly at seasonal periods. Observational evidence for deviations from the synchronous state has been reported several times for Titan but is unfortunately inconclusive. The measurements of the rotation variations are based on determinations of the shift in position of Cassini radar images taken during different flybys. The ESA JUICE (JUpiter ICy moons Explorer) mission will measure the rotation variations of Ganymede during its orbital phase around the satellite starting in 2032.We report on different theoretical aspects of the librations and polar motion. We consider the influence of the rheology of the ice shell and take into account Cassini measurements of the external gravitational field and of the topography of Titan and similar Galileo data about Ganymede. We also evaluate the librations and polar motion induced by Titan's hydrocarbon seas and use the most recent results of Titan's atmosphere dynamics. We finally evaluate the potential of rotation variations to constrain the satellite's interior structure, in particular its ice shell and ocean.

  13. COUNTER-ROTATION IN RELATIVISTIC MAGNETOHYDRODYNAMIC JETS

    SciTech Connect

    Cayatte, V.; Sauty, C.; Vlahakis, N.; Tsinganos, K.; Matsakos, T.; Lima, J. J. G.

    2014-06-10

    Young stellar object observations suggest that some jets rotate in the opposite direction with respect to their disk. In a recent study, Sauty et al. showed that this does not contradict the magnetocentrifugal mechanism that is believed to launch such outflows. Motion signatures that are transverse to the jet axis, in two opposite directions, have recently been measured in M87. One possible interpretation of this motion is that of counter-rotating knots. Here, we extend our previous analytical derivation of counter-rotation to relativistic jets, demonstrating that counter-rotation can indeed take place under rather general conditions. We show that both the magnetic field and a non-negligible enthalpy are necessary at the origin of counter-rotating outflows, and that the effect is associated with a transfer of energy flux from the matter to the electromagnetic field. This can be realized in three cases: if a decreasing enthalpy causes an increase of the Poynting flux, if the flow decelerates, or if strong gradients of the magnetic field are present. An illustration of the involved mechanism is given by an example of a relativistic magnetohydrodynamic jet simulation.

  14. Position, rotation, and intensity invariant recognizing method

    DOEpatents

    Ochoa, E.; Schils, G.F.; Sweeney, D.W.

    1987-09-15

    A method for recognizing the presence of a particular target in a field of view which is target position, rotation, and intensity invariant includes the preparing of a target-specific invariant filter from a combination of all eigen-modes of a pattern of the particular target. Coherent radiation from the field of view is then imaged into an optical correlator in which the invariant filter is located. The invariant filter is rotated in the frequency plane of the optical correlator in order to produce a constant-amplitude rotational response in a correlation output plane when the particular target is present in the field of view. Any constant response is thus detected in the output plane to determine whether a particular target is present in the field of view. Preferably, a temporal pattern is imaged in the output plane with a optical detector having a plurality of pixels and a correlation coefficient for each pixel is determined by accumulating the intensity and intensity-square of each pixel. The orbiting of the constant response caused by the filter rotation is also preferably eliminated either by the use of two orthogonal mirrors pivoted correspondingly to the rotation of the filter or the attaching of a refracting wedge to the filter to remove the offset angle. Detection is preferably performed of the temporal pattern in the output plane at a plurality of different angles with angular separation sufficient to decorrelate successive frames. 1 fig.

  15. Wave-driven Rotation in Supersonically Rotating Mirrors

    SciTech Connect

    A. Fetterman and N.J. Fisch

    2010-02-15

    Supersonic rotation in mirrors may be produced by radio frequency waves. The waves produce coupled diffusion in ion kinetic and potential energy. A population inversion along the diffusion path then produces rotation. Waves may be designed to exploit a natural kinetic energy source or may provide the rotation energy on their own. Centrifugal traps for fusion and isotope separation may benefit from this wave-driven rotation.

  16. Optimized dynamic rotation with wedges.

    PubMed

    Rosen, I I; Morrill, S M; Lane, R G

    1992-01-01

    Dynamic rotation is a computer-controlled therapy technique utilizing an automated multileaf collimator in which the radiation beam shape changes dynamically as the treatment machine rotates about the patient so that at each instant the beam shape matches the projected shape of the target volume. In simple dynamic rotation, the dose rate remains constant during rotation. For optimized dynamic rotation, the dose rate is varied as a function of gantry angle. Optimum dose rate at each gantry angle is computed by linear programming. Wedges can be included in the optimized dynamic rotation therapy by using additional rotations. Simple and optimized dynamic rotation treatment plans, with and without wedges, for a pancreatic tumor have been compared using optimization cost function values, normal tissue complication probabilities, and positive difference statistic values. For planning purposes, a continuous rotation is approximated by static beams at a number of gantry angles equally spaced about the patient. In theory, the quality of optimized treatment planning solutions should improve as the number of static beams increases. The addition of wedges should further improve dose distributions. For the case studied, no significant improvements were seen for more than 36 beam angles. Open and wedged optimized dynamic rotations were better than simple dynamic rotation, but wedged optimized dynamic rotation showed no definitive improvement over open beam optimized dynamic rotation.

  17. Rotating bacteria aggregate into active crystals

    NASA Astrophysics Data System (ADS)

    Petroff, Alexander; Wu, Xiao-Lun; Libchaber, Albert

    2014-11-01

    The dynamics of many microbial ecosystems are determined not only by the response of individual bacteria to their chemical and physical environments but also the dynamics that emerge from interactions between cells. Here we investigate the collective dynamics displayed by communities of Thiovulum majus, one of the fastest known bacteria. We observe that when these bacteria swim close to a microscope cover slip, the cells spontaneously aggregate into a visually-striking two-dimensional hexagonal lattice of rotating cells. Each cell in an aggregate rotates its flagella, exerting a force that pushes the cell into the cover slip and a torque that causes the cell to rotate. As cells rotate against their neighbors, they exert forces and torques on the aggregate that cause the crystal to move and cells to hop to new positions in the lattice. We show how these dynamics arises from hydrodynamic and surface forces between cells. We derive the equations of motion for an aggregate, show that this model reproduces many aspects of the observed dynamics, and discuss the stability of these and similar active crystals. Finally, we discuss the ecological significance of this behavior to understand how the ability to aggregate into these communities may have evolved.

  18. Rotating Bacteria Aggregate into Active Crystals

    NASA Astrophysics Data System (ADS)

    Petroff, A. P.; Wu, X. L.; Libchaber, A.

    2014-12-01

    The dynamics of many microbial ecosystems are determined not only by the response of individual bacteria to their chemical and physical environments but also the dynamics that emerge from interactions between cells. Here we investigate collective dynamics displayed by communities of Thiovulum majus, one of the fastest known bacteria. We observe that when these bacteria swim close to a microscope cover slip, the cells spontaneously aggregate into a visually-striking, two-dimensional hexagonal lattice of rotating cells. Each cell in an aggregate rotates its flagella, exerting a force that pushes the cell into the cover slip and a torque that causes the cell to rotate. As cells rotate against their neighbors, they exert forces and torques on the aggregate that cause the crystal to move and cells to hop to new positions in the lattice. We show how these dynamics arise from hydrodynamic and surface forces between cells. We derive the equations of motion for an aggregate, show that this model reproduces many aspects of the observed dynamics, and discuss the stability of these and similar active crystals. Finally, we discuss the ecological significance of this behavior to understand how the ability to aggregate into these communities may have evolved.

  19. A Translational Polarization Rotator

    NASA Technical Reports Server (NTRS)

    Chuss, David T.; Wollack, Edward J.; Pisano, Giampaolo; Ackiss, Sheridan; U-Yen, Kongpop; Ng, Ming wah

    2012-01-01

    We explore a free-space polarization modulator in which a variable phase introduction between right- and left-handed circular polarization components is used to rotate the linear polarization of the outgoing beam relative to that of the incoming beam. In this device, the polarization states are separated by a circular polarizer that consists of a quarter-wave plate in combination with a wire grid. A movable mirror is positioned behind and parallel to the circular polarizer. As the polarizer-mirror distance is separated, an incident liear polarization will be rotated through an angle that is proportional to the introduced phase delay. We demonstrate a prototype device that modulates Stokes Q and U over a 20% bandwidth.

  20. A call for rotators

    NASA Astrophysics Data System (ADS)

    Mountain, Gregory

    “Needed: highly motivated geoscientists willing to slow the pace of their research for 1-2 years while managing federal government support of their discipline. Assured: change of perspective; no change in pay. Contact your National Science Foundation Program Director for details.—No, this isn't an NSF job announcement; this is an open letter to members of the Earth science community from a recently “retired” NSF rotator concerned by the small number of researchers interested in a Washington tour. I learned firsthand the extent to which an individual in this position is entrusted with decision-making powers, and as a result, I believe that each of us in the research community should feel responsible for ensuring that highly qualified people serve as rotators.

  1. Rotatable seal assembly

    DOEpatents

    Logan, Clinton M.; Garibaldi, Jack L.

    1982-01-01

    An assembly is provided for rotatably supporting a rotor on a stator so that vacuum chambers in the rotor and stator remain in communication while the chambers are sealed from ambient air, which enables the use of a ball bearing or the like to support most of the weight of the rotor. The apparatus includes a seal device mounted on the rotor to rotate therewith, but shiftable in position on the rotor while being sealed to the rotor as by an O-ring. The seal device has a flat face that is biased towards a flat face on the stator, and pressurized air is pumped between the faces to prevent contact between them while spacing them a small distance apart to avoid the inflow of large amounts of air between the faces and into the vacuum chambers.

  2. Rotational spectrum of tryptophan

    NASA Astrophysics Data System (ADS)

    Sanz, M. Eugenia; Cabezas, Carlos; Mata, Santiago; Alonso, Josè L.

    2014-05-01

    The rotational spectrum of the natural amino acid tryptophan has been observed for the first time using a combination of laser ablation, molecular beams, and Fourier transform microwave spectroscopy. Independent analysis of the rotational spectra of individual conformers has conducted to a definitive identification of two different conformers of tryptophan, with one of the observed conformers never reported before. The analysis of the 14N nuclear quadrupole coupling constants is of particular significance since it allows discrimination between structures, thus providing structural information on the orientation of the amino group. Both observed conformers are stabilized by an O-H...N hydrogen bond in the side chain and a N-H...π interaction forming a chain that reinforce the strength of hydrogen bonds through cooperative effects.

  3. Rotational spectrum of tryptophan

    SciTech Connect

    Sanz, M. Eugenia Cabezas, Carlos Mata, Santiago Alonso, Josè L.

    2014-05-28

    The rotational spectrum of the natural amino acid tryptophan has been observed for the first time using a combination of laser ablation, molecular beams, and Fourier transform microwave spectroscopy. Independent analysis of the rotational spectra of individual conformers has conducted to a definitive identification of two different conformers of tryptophan, with one of the observed conformers never reported before. The analysis of the {sup 14}N nuclear quadrupole coupling constants is of particular significance since it allows discrimination between structures, thus providing structural information on the orientation of the amino group. Both observed conformers are stabilized by an O–H···N hydrogen bond in the side chain and a N–H···π interaction forming a chain that reinforce the strength of hydrogen bonds through cooperative effects.

  4. Broadband Rotational Spectroscopy

    NASA Astrophysics Data System (ADS)

    Pate, Brooks

    2014-06-01

    The past decade has seen several major technology advances in electronics operating at microwave frequencies making it possible to develop a new generation of spectrometers for molecular rotational spectroscopy. High-speed digital electronics, both arbitrary waveform generators and digitizers, continue on a Moore's Law-like development cycle that started around 1993 with device bandwidth doubling about every 36 months. These enabling technologies were the key to designing chirped-pulse Fourier transform microwave (CP-FTMW) spectrometers which offer significant sensitivity enhancements for broadband spectrum acquisition in molecular rotational spectroscopy. A special feature of the chirped-pulse spectrometer design is that it is easily implemented at low frequency (below 8 GHz) where Balle-Flygare type spectrometers with Fabry-Perot cavity designs become technologically challenging due to the mirror size requirements. The capabilities of CP-FTMW spectrometers for studies of molecular structure will be illustrated by the collaborative research effort we have been a part of to determine the structures of water clusters - a project which has identified clusters up to the pentadecamer. A second technology trend that impacts molecular rotational spectroscopy is the development of high power, solid state sources in the mm-wave/THz regions. Results from the field of mm-wave chirped-pulse Fourier transform spectroscopy will be described with an emphasis on new problems in chemical dynamics and analytical chemistry that these methods can tackle. The third (and potentially most important) technological trend is the reduction of microwave components to chip level using monolithic microwave integrated circuits (MMIC) - a technology driven by an enormous mass market in communications. Some recent advances in rotational spectrometer designs that incorporate low-cost components will be highlighted. The challenge to the high-resolution spectroscopy community - as posed by Frank De

  5. On rotational conical flow

    NASA Technical Reports Server (NTRS)

    Ferrari, Carlo

    1952-01-01

    Some general properties of isoenergetic rotational conical fields are determined. For such fields, provided the physical parameters of the fluid flow are known on a conical reference surface, it being understood that they satisfy certain imposed conditions, it is shown how to construct the hodographs in the various meridional semiplanes, as the envelope of either the tangents to the hodographs or of the osculatory circles.

  6. Rotating housing turbine

    DOEpatents

    Allouche, Erez; Jaganathan, Arun P.

    2016-10-11

    The invention is a new turbine structure having a housing that rotates. The housing has a sidewall, and turbine blades are attached to a sidewall portion. The turbine may be completely open in the center, allowing space for solids and debris to be directed out of the turbine without jamming the spinning blades/sidewall. The turbine may be placed in a generator for generation of electrical current.

  7. Rotating Connection for Electrical Cables

    NASA Technical Reports Server (NTRS)

    Manges, D. R.

    1986-01-01

    Cable reel provides electrical connections between fixed structure and rotating one. Reel carries power and signal lines while allowing rotating structure to turn up to 360 degrees with respect to fixed structure. Reel replaces sliprings. Can be used to electrically connect arm of robot with body. Reel releases cable to rotating part as it turns and takes up cable as rotating part comes back to its starting position, without tangling, twisting, or kinking.

  8. Rotating black hole hair

    NASA Astrophysics Data System (ADS)

    Gregory, Ruth; Kubizňák, David; Wills, Danielle

    2013-06-01

    A Kerr black hole sporting cosmic string hair is studied in the context of the abelian Higgs model vortex. It is shown that such a system displays much richer phenomenology than its static Schwarzschild or Reissner-Nordstrom cousins, for example, the rotation generates a near horizon `electric' field. In the case of an extremal rotating black hole, two phases of the Higgs hair are possible: large black holes exhibit standard hair, with the vortex piercing the event horizon. Small black holes on the other hand, exhibit a flux-expelled solution, with the gauge and scalar field remaining identically in their false vacuum state on the event horizon. This solution however is extremely sensitive to confirm numerically, and we conjecture that it is unstable due to a supperradiant mechanism similar to the Kerr-adS instability. Finally, we compute the gravitational back reaction of the vortex, which turns out to be far more nuanced than a simple conical deficit. While the string produces a conical effect, it is conical with respect to a local co-rotating frame, not with respect to the static frame at infinity.

  9. Bioreactor rotating wall vessel

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Cell constructs grown in a rotating bioreactor on Earth (left) eventually become too large to stay suspended in the nutrient media. In the microgravity of orbit, the cells stay suspended. Rotation then is needed for gentle stirring to replenish the media around the cells.

  10. Snakes and spin rotators

    SciTech Connect

    Lee, S.Y.

    1990-06-18

    The generalized snake configuration offers advantages of either shorter total snake length and smaller orbit displacement in the compact configuration or the multi-functions in the split configuration. We found that the compact configuration can save about 10% of the total length of a snake. On other hand, the spilt snake configuration can be used both as a snake and as a spin rotator for the helicity state. Using the orbit compensation dipoles, the spilt snake configuration can be located at any distance on both sides of the interaction point of a collider provided that there is no net dipole rotation between two halves of the snake. The generalized configuration is then applied to the partial snake excitation. Simple formula have been obtained to understand the behavior of the partial snake. Similar principle can also be applied to the spin rotators. We also estimate the possible snake imperfections are due to various construction errors of the dipole magnets. Accuracy of field error of better than 10{sup {minus}4} will be significant. 2 refs., 5 figs.

  11. OH "Rotational" Temperatures

    NASA Astrophysics Data System (ADS)

    Slanger, T. G.; Matsiev, D.

    2015-12-01

    It is customary to determine temperatures in the mesosphere and MLT by using Boltzmann plots based on the distributions of the lowest rotational levels in the bands of the OH Meinel system, assuming that populations in these levels are in LTE with the kinetic temperature. The higher rotational levels are clearly not in LTE, and using sky spectra from the large telescopes (Keck, VLT) has now shown that this assumption is invalid even for low rotational levels [Cosby and Slanger, 2007; Noll et al. 2014]. The apparent temperatures derived from such Boltzmann plots show an upward trend with increasing OH vibrational level, from v = 2 to v = 9, with reproducible structure such that there is always a peak at v = 8. Over this range of vibrational levels, the "temperature" increase with increasing altitude is on the order of 15-20 K. At the same time, the modeled kinetic temperature is decreasing, as the OH layer lies below the mesopause, and rocket/satellite measurements indicate that the highest levels have the highest altitude. Since this technique of kinetic temperature assessment has been in use for many years, it is important to realize that the procedure is flawed, most likely due to the details of the relaxation processes of OH(v).

  12. Suppressing Permutations or Rigid Planar Rotations: A Remedy against Nonoptimal Varimax Rotations.

    ERIC Educational Resources Information Center

    Berge, Jos M. F. ten

    1995-01-01

    In Varimax rotation, permutations and reflections can give rise to the phenomenon that certain pairs of columns are consistently skipped in the iterative process, causing Varimax to terminate at a nonstationary point. This skipping phenomenon is demonstrated, and how to prevent it is described. (SLD)

  13. System for automatically aligning a support roller system under a rotating body

    DOEpatents

    Singletary, B.H.

    1982-07-21

    Two support rings on a rotatable drum respectively engage conically tapered end surfaces of support rollers mounted on pivot universally relative to its axis of rotation and translate therealong. Rotation of the drum on differential conical support roller diameters causes pivotal steering and axial translation of support roller until roller is centered on support rings.

  14. System for automatically aligning a support roller system under a rotating body

    DOEpatents

    Singletary, B. Huston

    1983-01-01

    Two support rings on a rotatable drum respectively engage conically tapered nd surfaces of support rollers mounted on pivot universally relative to its axis of rotation and translate therealong. Rotation of the drum on differential conical support roller diameters causes pivotal steering and axial translation of support roller until roller is centered on support rings.

  15. Rotating Vessels for Growing Protein Crystals

    NASA Technical Reports Server (NTRS)

    Cottingham, Paul

    2005-01-01

    Rotating vessels have been proposed as means of growing larger, more nearly uniform protein crystals than would otherwise be possible in the presence of normal Earth gravitation. Heretofore, nonrotating vessels have been used. It is difficult to grow high-quality protein crystals in the terrestrial gravitational field because of convection plumes created by the interaction between gravitation and density gradients in protein-solution depletion layers around growing crystals. The density gradients and the associated convection plumes cause the surfaces of growing crystals to be exposed to nonuniform solution densities, thereby causing the crystals to form in irregular shapes. The microgravitational environment of outer space has been utilized to eliminate gravitation-induced convection, but this approach is generally not favorable because of the high cost and limited availability of space flight. The use of a rotating vessel according to the proposal is intended to ameliorate the effects of gravitation and the resultant convection, relative to the corresponding effects in a non-rotating vessel. The rotation would exert an averaging effect over time, distributing the convective force on the depletion layer. Therefore, the depletion layer would be more nearly uniform and, as a result, the growing crystal would be more nearly perfect. The proposal admits of variations (see figure), including the following: The growing crystal could be rotated about its own central axis or an external axis. The crystal-growth vessel could be of any of various shapes, including cylindrical, hemispherical, conical, and combinations thereof. The crystal-growth vessel could be suspended in a viscous fluid in an outer vessel to isolate the growing crystal from both ambient vibrations and vibrations induced by a mechanism that drives the rotation. The rotation could be coupled to the crystal-growth vessel by viscous or magnetic means. The crystal-growth vessel could be supported within the

  16. Rotating plug bearing and seal

    DOEpatents

    Wade, Elman E.

    1977-01-01

    A bearing and seal structure for nuclear reactors utilizing rotating plugs above the nuclear reactor vessel. The structure permits lubrication of bearings and seals of the rotating plugs without risk of the lubricant draining into the reactor vessel below. The structure permits lubrication by utilizing a rotating outer race bearing.

  17. The rotation of the earth

    NASA Technical Reports Server (NTRS)

    Herring, Thomas A.

    1991-01-01

    Earth rotation studies are reviewed for the 1987-1990 time period. It is noted that the emphasis in these studies has shifted from improvements in the observational techniques to interpreting and gaining greater understanding of the variations of the earth rotations. There have been progressive improvements in the accuracy and the temporal resolution of earth rotation measurements.

  18. Doppler observations of solar rotation

    NASA Technical Reports Server (NTRS)

    Scherrer, P. H.

    1980-01-01

    Daily observations of the photospheric equatorial rotation rate using the Doppler effect mode at the Sanford Solar Observatory are presented. These observations show no variations in the rotation rate that exceed the observational error of about one percent. The average rotation rate is indistinguishable from that of sunspots and large scale magnetic field structures.

  19. Doppler observations of solar rotation

    NASA Technical Reports Server (NTRS)

    Scherrer, P. H.; Wilcox, J. M.

    1980-01-01

    Daily observations of the photospheric equatorial rotation rate using the Doppler effect are made at the Stanford Solar Observatory. These observations show no variations in the rotation rate that exceed the observational error of about 1%. The average rotation rate is indistinguishable from that of sunspots and large-scale magnetic field structures.

  20. On the Product of Rotations

    ERIC Educational Resources Information Center

    Trenkler, G.; Trenkler, D.

    2008-01-01

    Using the elementary tools of matrix theory, we show that the product of two rotations in the three-dimensional Euclidean space is a rotation again. For this purpose, three types of rotation matrices are identified which are of simple structure. One of them is the identity matrix, and each of the other two types can be uniquely characterized by…

  1. Rotational drift of mandibular third molar teeth: a series of four cases.

    PubMed

    Hughes, A J; Vudiniabola, S T; McMillan, B D; Smith, A C

    2009-03-01

    Rotational drift of mandibular third molar teeth is a challenge for clinicians to predict and manage. Evidence on the incidence and degree of rotation is sparse. As the factors influencing rotation are not defined, prediction is impossible. A series of four cases with lower third molar rotation are presented and discussed. Significant rotation can alter the degree of difficulty for an extraction. A lack of well-documented cases has hindered investigation of this phenomenon. Further research is required to identify the aetiology, incidence and increase in risk factors caused by such rotational drift.

  2. Differentially Rotating White Dwarfs I: Regimes of Internal Rotation

    NASA Astrophysics Data System (ADS)

    Ghosh, Pranab; Wheeler, J. Craig

    2017-01-01

    Most viable models of Type Ia supernovae (SNe Ia) require the thermonuclear explosion of a carbon/oxygen white dwarf that has evolved in a binary system. Rotation could be an important aspect of any model for SNe Ia, whether single or double degenerate, with the white dwarf mass at, below, or above the Chandrasekhar limit. Differential rotation is specifically invoked in attempts to account for the apparent excess mass in the super-Chandrasekhar events. Some earlier work has suggested that only uniform rotation is consistent with the expected mechanisms of angular momentum transport in white dwarfs, while others have found pronounced differential rotation. We show that if the baroclinic instability is active in degenerate matter and the effects of magnetic fields are neglected, both nearly uniform rotation and strongly differential rotation are possible. We classify rotation regimes in terms of the Richardson number, Ri. At small values of Ri ≤slant 0.1, we find both the low-viscosity Zahn regime with a nonmonotonic angular velocity profile and a new differential rotation regime for which the viscosity is high and scales linearly with the shear, σ. Employment of Kelvin–Helmholtz viscosity alone yields differential rotation. Large values of Ri ≫ 1 produce a regime of nearly uniform rotation for which the baroclinic viscosity is of intermediate value and scales as {σ }3. We discuss the gap in understanding of the behavior at intermediate values of Ri and how observations may constrain the rotation regimes attained by nature.

  3. Rotation curve for the Milky Way galaxy in conformal gravity

    NASA Astrophysics Data System (ADS)

    O'Brien, James G.; Moss, Robert J.

    2015-05-01

    Galactic rotation curves have proven to be the testing ground for dark matter bounds in galaxies, and our own Milky Way is one of many large spiral galaxies that must follow the same models. Over the last decade, the rotation of the Milky Way galaxy has been studied and extended by many authors. Since the work of conformal gravity has now successfully fit the rotation curves of almost 140 galaxies, we present here the fit to our own Milky Way. However, the Milky Way is not just an ordinary galaxy to append to our list, but instead provides a robust test of a fundamental difference of conformal gravity rotation curves versus standard cold dark matter models. It was shown by Mannheim and O'Brien that in conformal gravity, the presence of a quadratic potential causes the rotation curve to eventually fall off after its flat portion. This effect can currently be seen in only a select few galaxies whose rotation curve is studied well beyond a few multiples of the optical galactic scale length. Due to the recent work of Sofue et al and Kundu et al, the rotation curve of the Milky Way has now been studied to a degree where we can test the predicted fall off in the conformal gravity rotation curve. We find that - like the other galaxies already studied in conformal gravity - we obtain amazing agreement with rotational data and the prediction includes the eventual fall off at large distances from the galactic center.

  4. Is rotating between static and dynamic work beneficial for our fatigue state?

    PubMed

    Luger, Tessy; Bosch, Tim; Hoozemans, Marco J M; Veeger, DirkJan H E J; de Looze, Michiel P

    2016-06-01

    Shoulder disorders comprise a large part of work-related musculoskeletal disorders. Risk factors, such as repetitiveness and monotony, may cause muscle fatigue and be attenuated by task rotation. We investigated rotation between a dynamic box-lifting task and a relatively static pick-and-place task and aimed to determine whether (1) a high rotation frequency leads to less fatigue development than a low rotation frequency, and (2) a self-selected rotation frequency leads to less fatigue development than imposed rotation frequencies. Ten participants performed four one-hour rotation schedules: two low frequency rotation schedules rotating at 30min, one high frequency rotation schedule rotating every sixth minute, and a self-selected rotation schedule. Borg, SOFI and electromyography of Trapezius and Deltoid subparts served as fatigue indicators. We found significant signs of fatigue for most schedules regarding the Borg and SOFI ratings and the M. Trapezius pars Descendens. Task rotation frequency had no significant effect on any of the outcome parameters, whereas the self-selected rotation schedule clearly resulted in less development of perceived fatigue than imposed schedules. In conclusion, we think that freedom of rotation has the greatest potential to attenuate potential development of musculoskeletal disorders and we require due caution with the use and interpretation of EMG indicators of fatigue.

  5. Rotator cuff tear arthropathy: evaluation, diagnosis, and treatment: AAOS exhibit selection.

    PubMed

    Nam, Denis; Maak, Travis G; Raphael, Bradley S; Kepler, Christopher K; Cross, Michael B; Warren, Russell F

    2012-03-21

    Rotator cuff tear arthropathy encompasses a broad spectrum of pathology, but it involves at least three critical features: rotator cuff insufficiency, degenerative changes of the glenohumeral joint, and superior migration of the humeral head. Although many patients possess altered biomechanics of the glenohumeral joint secondary to rotator cuff pathology, not all patients develop rotator cuff tear arthropathy, and thus the exact etiology of rotator cuff tear arthropathy remains unclear. The objectives of this manuscript are to (1) review the biomechanical properties of the rotator cuff and the glenohumeral joint, (2) discuss the proposed causes of rotator cuff tear arthropathy, (3) provide a brief review of the historically used surgical options to treat rotator cuff tear arthropathy, and (4) present a treatment algorithm for rotator cuff tear arthropathy based on a patient's clinical presentation, functional goals, and anatomic integrity.

  6. Rotating Rayleigh-Taylor instability

    NASA Astrophysics Data System (ADS)

    Scase, M. M.; Baldwin, K. A.; Hill, R. J. A.

    2017-02-01

    The effect of rotation upon the classical Rayleigh-Taylor instability is investigated. We consider a two-layer system with an axis of rotation that is perpendicular to the interface between the layers. In general, we find that a wave mode's growth rate may be reduced by rotation. We further show that in some cases, unstable axisymmetric wave modes may be stabilized by rotating the system above a critical rotation rate associated with the mode's wavelength, the Atwood number, and the flow's aspect ratio.

  7. Observation of dust torus with poloidal rotation in direct current glow discharge plasma

    SciTech Connect

    Kaur, Manjit Bose, Sayak; Chattopadhyay, P. K. Sharma, Devendra; Ghosh, J.; Saxena, Y. C.

    2015-03-15

    Observation of dust cloud rotation in parallel-plate DC glow discharge plasma is reported here. The experiments are carried out at high pressures (∼130 Pa) with a metallic ring placed on the lower electrode (cathode). The dust cloud rotates poloidally in the vertical plane near the cathode surface. This structure is continuous toroidally. Absence of magnetic field rules out the possibility of E × B induced ion flow as the cause of dust rotation. The dust rotational structures exist even with water cooled cathode. Therefore, temperature gradient driven mechanisms, such as thermophoretic force, thermal creep flow, and free convection cannot be causing the observed dust rotation. Langmuir probe measurement reveals the existence of a sharp density gradient near the location of the rotating dust cloud. The gradient in the density, giving rise to a gradient in the ion drag force, has been identified as the principal cause behind the rotation of dust particles.

  8. Regimes of Internal Rotation in Differentially Rotating White Dwarfs

    NASA Astrophysics Data System (ADS)

    Wheeler, J. Craig; Ghosh, Pranab

    2017-01-01

    Most viable models of Type Ia supernovae (SN Ia) require the thermonuclear explosion of a carbon/oxygen white dwarf that has evolved in a binary system. Rotation could be an important aspect of any model for SN Ia, whether single or double degenerate, with the white dwarf mass at, below, or above the Chandrasekhar limit. Differential rotation is specifically invoked in attempts to account for the apparent excess mass in the super--Chandrasekhar events. Some earlier work has suggested that only uniform rotation is consistent with the expected mechanisms of angular momentum transport in white dwarfs, while others have found pronounced differential rotation. We show that if the baroclinic instability is active in degenerate matter and the effects of magnetic fields are neglected, both nearly-uniform and strongly-differential rotation are possible. We classify rotation regimes in terms of the Richardson number, Ri. At small values of Ri < 0.1, we find both the low-viscosity Zahn regime with a non-monotonic angular velocity profile and a new differential rotation regime for which the viscosity is high and scales linearly with the shear, σ. Employment of Kelvin-Helmholtz viscosity alone yields differential rotation. Large values of Ri >> 1 produce a regime of nearly-uniform rotation for which the baroclinic viscosity is of intermediate value and scales as σ3. We discuss the gap in understanding of the behavior at intermediate values of Ri and how observations may constrain the rotation regimes attained by nature.

  9. Isorotation and differential rotation in a magnetic mirror with imposed E Multiplication-Sign B rotation

    SciTech Connect

    Romero-Talamas, C. A.; Elton, R. C.; Young, W. C.; Reid, R.; Ellis, R. F.

    2012-07-15

    Doppler spectroscopy of helium impurities in the Maryland Centrifugal Experiment reveals the simultaneous existence of isorotating and differentially rotating magnetic surfaces. Differential rotation occurs at the innermost surfaces and is conjectured to cause plasma voltage oscillations of hundreds of kilohertz by periodically changing the current path inductance. High-speed images show the periodic expulsion of plasma near the mirror ends at the same frequencies. In spite of this, the critical ionization velocity limit is exceeded, with respect to the vacuum field definition, for at least 0.5 ms.

  10. ROTATING PLASMA DEVICE

    DOEpatents

    Boyer, K.; Hammel, J.E.; Longmire, C.L.; Nagle, D.E.; Ribe, F.L.; Tuck, J.L.

    1961-10-24

    ABS>A method and device are described for obtaining fusion reactions. The basic concept is that of using crossed electric and magnetic fields to induce a plasma rotation in which the ionized particles follow a circumferential drift orbit on wldch a cyclotron mode of motion is superimposed, the net result being a cycloidal motion about the axis of symmetry. The discharge tube has a radial electric field and a longitudinal magnetic field. Mirror machine geometry is utilized. The device avoids reliance on the pinch effect and its associated instability problems. (AEC)

  11. Rotational isomerism of vinylmethyltelluride

    SciTech Connect

    Keiko, V.V.; Sinegovskaya, L.M.; Gusarova, N.K.; Tatarinova, A.A.; Kalinina, N.A.; Trofimov, B.A.

    1987-08-10

    In the IR spectrum of solutions of vinylmethyltelluride in n-heptane the doublet form of the valence oscillation band of the double bond is due to rotational isomerism. By analyzing the temperature dependence of the doublet shape, the low-frequency component of the doublet was identified as the s-cis-rotamer. The differences in the enthalpies (4.6 +/- 0.2 kJ/mole) and entropies (-11.1 +/- 0.3 e.u.) of the vinylmethyltelluride rotamers have been calculated and it has been shown that the p,..pi..-conjugation in its molecule is weaker by a factor of 2 than in vinylmethylsulfide.

  12. Management of a Septic Open Abdomen Patient with Spontaneous Jejunal Perforation after Emergent C/S with Confounding Factor of Mild Acute Pancreatitis

    PubMed Central

    Yetisir, Fahri; Sarer, Akgün Ebru; Acar, Hasan Zafer; Osmanoglu, Gokhan; Özer, Mehmet; Yaylak, Faik

    2016-01-01

    Introduction. We report the management of a septic Open Abdomen (OA) patient by the help of negative pressure therapy (NPT) and abdominal reapproximation anchor (ABRA) system in pregnant woman with spontaneous jejunal perforation after emergent cesarean section (C/S) with confounding factor of mild acute pancreatitis (AP). Presentation of Case. A 29-year-old and 34-week pregnant woman with AP underwent C/S. She was arrested after anesthesia induction and responded to cardiopulmonary resuscitation (CPR). There were only ash-colored serosanguinous fluid within abdomen during C/S. After C/S, she was transferred to intensive care unit (ICU) with vasopressor support. On postoperative 1st day, she underwent reoperation due to fecal fluid coming near the drainage. Leakage point could not be identified exactly and operation had to be deliberately abbreviated due to hemodynamic instability. NPT was applied. Two days later source control was provided by conversion of enteroatmospheric fistula (EAF) to jejunostomy. ABRA was added and OA was closed. No hernia developed at 10-month follow-up period. Conclusion. NPT application in septic OA patient may gain time to patient until adequate source control could be achieved. Using ABRA in conjunction with NPT increases the fascial closure rate in infected OA patient. PMID:27006853

  13. Rotational Doppler effect in x-ray photoionization

    SciTech Connect

    Sun Yuping; Wang Chuankui; Gel'mukhanov, Faris

    2010-11-15

    The energy of the photoelectron experiences a red or blue Doppler shift when the molecule recedes from the detector or approaches him. This results in a broadening of the photoelectron line due to the translational thermal motion. However, the molecules also have rotational degrees of freedom and we show that the translational Doppler effect has its rotational counterpart. This rotational Doppler effect leads to an additional broadening of the spectral line of the same magnitude as the Doppler broadening caused by translational thermal motion. The rotational Doppler broadening as well as the rotational recoil broadening is sensitive to the molecular orbital from which the photoelectron is ejected. This broadening should be taken into account in analysis of x-ray photoemission spectra of super-high resolution and it can be directly observed using x-ray pump-probe spectroscopy.

  14. Unusual Slowly Rotating Brown Dwarfs Discovered through Precision Spitzer Photometry

    NASA Astrophysics Data System (ADS)

    Heinze, Aren; Metchev, S.

    2014-01-01

    Many brown dwarfs exhibit low-amplitude rotationally modulated variability due to photospheric inhomogeneities caused by condensate clouds in their atmospheres. The Spitzer Space Telescope 'Weather on Other Worlds' (WoW) project has monitored 44 brown dwarfs at unprecedented photometric precision from space. We present one of several important new results from WoW: the discovery of brown dwarfs with unexpectedly slow rotation periods. While most brown dwarfs have periods of 2-12 hours, we have identified two with well-constrained periods of 13±1 and >20 hours, respectively, and 2 others that show more tentative evidence of longer than 20-hour periods. By serving as almost non-rotating standards, these objects will allow more accurate calibration of spectroscopic measurements of brown dwarfs' projected rotational velocities. The existence of such slowly-rotating objects also constrains models of brown dwarf formation and angular momentum evolution.

  15. Rotational manipulation of single cells and organisms using acoustic waves

    PubMed Central

    Ahmed, Daniel; Ozcelik, Adem; Bojanala, Nagagireesh; Nama, Nitesh; Upadhyay, Awani; Chen, Yuchao; Hanna-Rose, Wendy; Huang, Tony Jun

    2016-01-01

    The precise rotational manipulation of single cells or organisms is invaluable to many applications in biology, chemistry, physics and medicine. In this article, we describe an acoustic-based, on-chip manipulation method that can rotate single microparticles, cells and organisms. To achieve this, we trapped microbubbles within predefined sidewall microcavities inside a microchannel. In an acoustic field, trapped microbubbles were driven into oscillatory motion generating steady microvortices which were utilized to precisely rotate colloids, cells and entire organisms (that is, C. elegans). We have tested the capabilities of our method by analysing reproductive system pathologies and nervous system morphology in C. elegans. Using our device, we revealed the underlying abnormal cell fusion causing defective vulval morphology in mutant worms. Our acoustofluidic rotational manipulation (ARM) technique is an easy-to-use, compact, and biocompatible method, permitting rotation regardless of optical, magnetic or electrical properties of the sample under investigation. PMID:27004764

  16. Management of irreparable rotator cuff tears and glenohumeral arthritis.

    PubMed

    Laudicina, Laurence; D'Ambrosia, Robert

    2005-04-01

    Glenohumeral arthritis with irreparable rotator cuff tears remain a difficult entity to treat. Varied causes include rotator cuff tear arthropathy, osteoarthritis, or rheumatoid arthritis with irreparable cuff tear. Common symptoms are progressive pain and dysfunction. Physical examination may reveal pain, crepitance, rotator cuff weakness, and loss of motion and function. Radiographs may reveal varying degrees of osteophyte formation, sclerotic bone, superior humeral head migration, and bony erosion. Additional imaging modalities may reveal cuff tear size, retraction, atrophy, and fatty infiltration. Failure of nonoperative management may lead to operative intervention. Rotator cuff repair or reconstruction may help prevent progression of tears and future arthritic changes. In patients with moderate to severe glenohumeral arthritis and irreparable rotator cuff tears, hemiarthroplasty is currently the procedure of choice. For patients with severe cuff dysfunction or loss of coracoacromial arch, or for patients who require revision, the reverse shoulder prosthesis may offer a treatment option. Future management continues to be defined with additional study.

  17. Asteroid rotation control via a tethered solar sail

    NASA Astrophysics Data System (ADS)

    Gao, Youtao; Wu, Jingyun

    2016-12-01

    The rotation of asteroids causes difficulties in the exploration of asteroids or prevention of asteroids impact on the Earth. We propose to use a solar sail to control, i.e., slow down or stop the rotational motion of an asteroid. First, the dynamic model of a tethered solar sail in the rotating gravitational field of an asteroid is presented. An optimal control method is employed to determine the control law of the tethered solar sail. The optimal control problem is converted into a nonlinear programming problem with the Gauss pseudospectral method. Simulation results show that this method can effectively slow down or even stop the rotation of an asteroid. A solar sail of 105 m2 can stop the rotation of the asteroid Apophis in 1000 days.

  18. Rotating drum filter

    DOEpatents

    Anson, Donald

    1990-01-01

    A perforated drum (10) rotates in a coaxial cylindrical housing (18) having three circumferential ports (19,22,23), and an axial outlet (24) at one end. The axis (11) is horizontal. A fibrous filter medium (20) is fed through a port (19) on or near the top of the housing (81) by a distributing mechanism (36) which lays a uniform mat (26) of the desired thickness onto the rotating drum (10). This mat (26) is carried by the drum (10) to a second port (23) through which dirty fluid (13) enters. The fluid (13) passes through the filter (26) and the cleaned stream (16) exits through the open end (15) of the drum (10) and the axial port (24) in the housing (18). The dirty filter material (20) is carried on to a third port (22) near the bottom of the housing (18) and drops into a receiver (31) from which it is continuously removed, cleaned (30), and returned (32) to the charging port (36) at the top. To support the filter mat, the perforated cylinder may carry a series of tines (40), shaped blades (41), or pockets, so that the mat (26) will not fall from the drum (10) prematurely. To minimize risk of mat failure, the fluid inlet port (23) may be located above the horizontal centerline (11).

  19. Optical rotation sensors

    NASA Astrophysics Data System (ADS)

    Rotge, J. R.; Simmons, B. J.; Kroncke, G. T.; Stech, D. J.

    1986-05-01

    Research efforts were concentrated on passive ring laser rotation sensor technology. Initial efforts were performed on supportive projects, e.g., laser stabilization, followed by a 0.62 sq m passive resonant ring laser gyro (PRRLG), leading to the development of a 60 sq m system mounted on the pneumatically supported isolation test platform (Iso-Pad) at FJSRL. Numerous sub-system tasks and a feasibility 0.62 sq m PRRLG were completed, supporting projections of very high resolution performance by a large 60 sq m PRRLG. The expected performance of the large PRRLG, on the order of 10 to the minus 10th power ERU (earth rate units), would provide an accurate error model applicable to Air Force operational ring laser gyros, a new source of geophysical data, e.g., earth wobble and variations in earth rotation, a proven design concept applicable to Air Force sensor needs as reference to MX instruments tests, and relativity experiments. This report documents the many accomplishments leading to, and the status of the large PRRLG at the date of the PRRLG stop order, November 1985.

  20. Digital rotation measurement unit

    DOEpatents

    Sanderson, S.N.

    1983-09-30

    A digital rotation indicator is disclosed for monitoring the position of a valve member having a movable actuator. The indicator utilizes mercury switches adapted to move in cooperation with the actuator. Each of the switches produces an output as it changes state when the actuator moves. A direction detection circuit is connected to the switches to produce a first digital signal indicative of the direction of rotation of the actuator. A count pulse generating circuit is also connected to the switches to produce a second digital pulse signal having count pulses corresponding to a change of state of any of the mercury switches. A reset pulse generating circuit is provided to generate a reset pulse each time a count pulse is generated. An up/down counter is connected to receive the first digital pulse signal and the second digital pulse signal and to count the pulses of the second digital pulse signal either up or down depending upon the instantaneous digital value of the first digital signal whereby a running count indicative of the movement of the actuator is maintained.

  1. Rotating Wheel Wake

    NASA Astrophysics Data System (ADS)

    Lombard, Jean-Eloi; Xu, Hui; Moxey, Dave; Sherwin, Spencer

    2016-11-01

    For open wheel race-cars, such as Formula One, or IndyCar, the wheels are responsible for 40 % of the total drag. For road cars, drag associated to the wheels and under-carriage can represent 20 - 60 % of total drag at highway cruise speeds. Experimental observations have reported two, three or more pairs of counter rotating vortices, the relative strength of which still remains an open question. The near wake of an unsteady rotating wheel. The numerical investigation by means of direct numerical simulation at ReD =400-1000 is presented here to further the understanding of bifurcations the flow undergoes as the Reynolds number is increased. Direct numerical simulation is performed using Nektar++, the results of which are compared to those of Pirozzoli et al. (2012). Both proper orthogonal decomposition and dynamic mode decomposition, as well as spectral analysis are leveraged to gain unprecedented insight into the bifurcations and subsequent topological differences of the wake as the Reynolds number is increased.

  2. Sample rotating turntable kit for infrared spectrometers

    DOEpatents

    Eckels, Joel Del; Klunder, Gregory L.

    2008-03-04

    An infrared spectrometer sample rotating turntable kit has a rotatable sample cup containing the sample. The infrared spectrometer has an infrared spectrometer probe for analyzing the sample and the rotatable sample cup is adapted to receive the infrared spectrometer probe. A reflectance standard is located in the rotatable sample cup. A sleeve is positioned proximate the sample cup and adapted to receive the probe. A rotator rotates the rotatable sample cup. A battery is connected to the rotator.

  3. Biological strategies to enhance rotator cuff healing.

    PubMed

    Longo, Umile Giuseppe; Rizzello, Giacomo; Berton, Alessandra; Maltese, Ludovica; Fumo, Caterina; Khan, Wasim S; Denaro, Vincenzo

    2013-11-01

    Rotator cuff tear causes a high rate of morbidity. After surgical repair, the presence of a scar tissue reduces tendon biomechanical properties. Emerging strategies for enhancing tendon healing are growth factors, cytokines, gene therapy and tissue engineering. However their efficacy has to be proved. Growth factors help the process of tendon healing by aiding cells chemotaxis, differentiation and proliferation. Numerous growth factors, including the bone morphogenetic proteins and platelet-derived growth factor can be found during the early healing process of a rotator cuff repair. Growth factors are delivered to the repair site using tissue-engineered scaffolding, coated sutures, or dissolved in a fibrin sealant. Platelet-rich plasma is an autologous concentration of platelets and contains an high density of growth factors. There is some evidence that platelet-rich plasma may improve pain and recovery of function in a short time period, but it does not improve healing rates in rotator cuff. Thus the routine use of platelet-rich plasma in rotator cuff repair is not recommended. The addition of mesenchymal stem cells to scaffolds can lead to the production of a better quality healing tissue. Gene therapy is a gene transfer from a cell into another, in order to over-express the gene required. In this way, cultures of stem cells can over-express growth factors. Better understanding of the mechanisms of physiological tendon healing can promote the correct use of these new biological therapies for a better healing tissue.

  4. Rotational Dynamics of Optically Trapped Human Spermatozoa

    PubMed Central

    Basu, Himanish; Thangaraju, Shyam; Mathur, Deepak

    2014-01-01

    Introduction. Optical trapping is a laser-based method for probing the physiological and mechanical properties of cells in a noninvasive manner. As sperm motility is an important criterion for assessing the male fertility potential, this technique is used to study sperm cell motility behavior and rotational dynamics. Methods and Patients. An integrated optical system with near-infrared laser beam has been used to analyze rotational dynamics of live sperm cells from oligozoospermic and asthenozoospermic cases and compared with controls. Results. The linear, translational motion of the sperm is converted into rotational motion on being optically trapped, without causing any adverse effect on spermatozoa. The rotational speed of sperm cells from infertile men is observed to be significantly less as compared to controls. Conclusions. Distinguishing normal and abnormal sperm cells on the basis of beat frequency above 5.6 Hz may be an important step in modern reproductive biology to sort and select good quality spermatozoa. The application of laser-assisted technique in biology has the potential to be a valuable tool for assessment of sperm fertilization capacity for improving assisted reproductive technology. PMID:24600321

  5. Bifurcations of rotating waves in rotating spherical shell convection.

    PubMed

    Feudel, F; Tuckerman, L S; Gellert, M; Seehafer, N

    2015-11-01

    The dynamics and bifurcations of convective waves in rotating and buoyancy-driven spherical Rayleigh-Bénard convection are investigated numerically. The solution branches that arise as rotating waves (RWs) are traced by means of path-following methods, by varying the Rayleigh number as a control parameter for different rotation rates. The dependence of the azimuthal drift frequency of the RWs on the Ekman and Rayleigh numbers is determined and discussed. The influence of the rotation rate on the generation and stability of secondary branches is demonstrated. Multistability is typical in the parameter range considered.

  6. Visualizing rotations and composition of rotations with the Rodrigues vector

    NASA Astrophysics Data System (ADS)

    Valdenebro, Angel G.

    2016-11-01

    The purpose of this paper is to show that the mathematical treatment of three-dimensional rotations can be simplified, and its geometrical understanding improved, using the Rodrigues vector representation. We present a novel geometrical interpretation of the Rodrigues vector. Based on this interpretation and simple geometrical considerations, we derive the Euler-Rodrigues formula, Cayley’s rotation formula and the composition law for finite rotations. The level of this discussion should be suitable for undergraduate physics or engineering courses where rotations are discussed.

  7. MEMS IMU Error Mitigation Using Rotation Modulation Technique.

    PubMed

    Du, Shuang; Sun, Wei; Gao, Yang

    2016-11-29

    Micro-electro-mechanical-systems (MEMS) inertial measurement unit (IMU) outputs are corrupted by significant sensor errors. The navigation errors of a MEMS-based inertial navigation system will therefore accumulate very quickly over time. This requires aiding from other sensors such as Global Navigation Satellite Systems (GNSS). However, it will still remain a significant challenge in the presence of GNSS outages, which are typically in urban canopies. This paper proposed a rotary inertial navigation system (INS) to mitigate navigation errors caused by MEMS inertial sensor errors when external aiding information is not available. A rotary INS is an inertial navigator in which the IMU is installed on a rotation platform. Application of proper rotation schemes can effectively cancel and reduce sensor errors. A rotary INS has the potential to significantly increase the time period that INS can bridge GNSS outages and make MEMS IMU possible to maintain longer autonomous navigation performance when there is no external aiding. In this research, several IMU rotation schemes (rotation about X-, Y- and Z-axes) are analyzed to mitigate the navigation errors caused by MEMS IMU sensor errors. As the IMU rotation induces additional sensor errors, a calibration process is proposed to remove the induced errors. Tests are further conducted with two MEMS IMUs installed on a tri-axial rotation table to verify the error mitigation by IMU rotations.

  8. MEMS IMU Error Mitigation Using Rotation Modulation Technique

    PubMed Central

    Du, Shuang; Sun, Wei; Gao, Yang

    2016-01-01

    Micro-electro-mechanical-systems (MEMS) inertial measurement unit (IMU) outputs are corrupted by significant sensor errors. The navigation errors of a MEMS-based inertial navigation system will therefore accumulate very quickly over time. This requires aiding from other sensors such as Global Navigation Satellite Systems (GNSS). However, it will still remain a significant challenge in the presence of GNSS outages, which are typically in urban canopies. This paper proposed a rotary inertial navigation system (INS) to mitigate navigation errors caused by MEMS inertial sensor errors when external aiding information is not available. A rotary INS is an inertial navigator in which the IMU is installed on a rotation platform. Application of proper rotation schemes can effectively cancel and reduce sensor errors. A rotary INS has the potential to significantly increase the time period that INS can bridge GNSS outages and make MEMS IMU possible to maintain longer autonomous navigation performance when there is no external aiding. In this research, several IMU rotation schemes (rotation about X-, Y- and Z-axes) are analyzed to mitigate the navigation errors caused by MEMS IMU sensor errors. As the IMU rotation induces additional sensor errors, a calibration process is proposed to remove the induced errors. Tests are further conducted with two MEMS IMUs installed on a tri-axial rotation table to verify the error mitigation by IMU rotations. PMID:27916852

  9. Geometry of tracer trajectories in turbulent rotating convection

    NASA Astrophysics Data System (ADS)

    Alards, Kim; Rajaei, Hadi; Kunnen, Rudie; Toschi, Federico; Clercx, Herman

    2016-11-01

    In Rayleigh-Bénard convection rotation is known to cause transitions in flow structures and to change the level of anisotropy close to the horizontal plates. To analyze this effect of rotation, we collect curvature and torsion statistics of passive tracer trajectories in rotating Rayleigh-Bénard convection, using both experiments and direct numerical simulations. In previous studies, focusing on homogeneous isotropic turbulence (HIT), curvature and torsion PDFs are found to reveal pronounced power laws. In the center of the convection cell, where the flow is closest to HIT, we recover these power laws, regardless of the rotation rate. However, near the top plate, where we expect the flow to be anisotropic, the scaling of the PDFs deviates from the HIT prediction for lower rotation rates. This indicates that anisotropy clearly affects the geometry of tracer trajectories. Another effect of rotation is observed as a shift of curvature and torsion PDFs towards higher values. We expect this shift to be related to the length scale of typical flow structures. Using curvature and torsion statistics, we can characterize how these typical length scales evolve under rotation and moreover analyze the effect of rotation on more complicated flow characteristics, such as anisotropy.

  10. Rotating Shaft Tilt Angle Measurement Using an Inclinometer

    NASA Astrophysics Data System (ADS)

    Luo, Jun; Wang, Zhiqian; Shen, Chengwu; Wen, Zhuoman; Liu, Shaojin; Cai, Sheng; Li, Jianrong

    2015-10-01

    This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.

  11. Galvano-rotational effect induced by electroweak interactions in pulsars

    SciTech Connect

    Dvornikov, Maxim

    2015-05-21

    We study electroweakly interacting particles in rotating matter. The existence of the electric current along the axis of the matter rotation is predicted in this system. This new galvano-rotational effect is caused by the parity violating interaction between massless charged particles in the rotating matter. We start with the exact solution of the Dirac equation for a fermion involved in the electroweak interaction in the rotating frame. This equation includes the noninertial effects. Then, using the obtained solution, we derive the induced electric current which turns out to flow along the rotation axis. We study the possibility of the appearance of the galvano-rotational effect in dense matter of compact astrophysical objects. The particular example of neutron and hypothetical quark stars is discussed. It is shown that, using this effect, one can expect the generation of toroidal magnetic fields comparable with poloidal ones in old millisecond pulsars. We also briefly discuss the generation of the magnetic helicity in these stars. Finally we analyze the possibility to apply the galvano-rotational effect for the description of the asymmetric neutrino emission from a neutron star to explain pulsars kicks.

  12. Galvano-rotational effect induced by electroweak interactions in pulsars

    SciTech Connect

    Dvornikov, Maxim

    2015-05-01

    We study electroweakly interacting particles in rotating matter. The existence of the electric current along the axis of the matter rotation is predicted in this system. This new galvano-rotational effect is caused by the parity violating interaction between massless charged particles in the rotating matter. We start with the exact solution of the Dirac equation for a fermion involved in the electroweak interaction in the rotating frame. This equation includes the noninertial effects. Then, using the obtained solution, we derive the induced electric current which turns out to flow along the rotation axis. We study the possibility of the appearance of the galvano-rotational effect in dense matter of compact astrophysical objects. The particular example of neutron and hypothetical quark stars is discussed. It is shown that, using this effect, one can expect the generation of toroidal magnetic fields comparable with poloidal ones in old millisecond pulsars. We also briefly discuss the generation of the magnetic helicity in these stars. Finally we analyze the possibility to apply the galvano-rotational effect for the description of the asymmetric neutrino emission from a neutron star to explain pulsars kicks.

  13. Simultaneous measurement of bacterial flagellar rotation rate and swimming speed.

    PubMed Central

    Magariyama, Y; Sugiyama, S; Muramoto, K; Kawagishi, I; Imae, Y; Kudo, S

    1995-01-01

    Swimming speeds and flagellar rotation rates of individual free-swimming Vibrio alginolyticus cells were measured simultaneously by laser dark-field microscopy at 25, 30, and 35 degrees C. A roughly linear relation between swimming speed and flagellar rotation rate was observed. The ratio of swimming speed to flagellar rotation rate was 0.113 microns, which indicated that a cell progressed by 7% of pitch of flagellar helix during one flagellar rotation. At each temperature, however, swimming speed had a tendency to saturate at high flagellar rotation rate. That is, the cell with a faster-rotating flagellum did not always swim faster. To analyze the bacterial motion, we proposed a model in which the torque characteristics of the flagellar motor were considered. The model could be analytically solved, and it qualitatively explained the experimental results. The discrepancy between the experimental and the calculated ratios of swimming speed to flagellar rotation rate was about 20%. The apparent saturation in swimming speed was considered to be caused by shorter flagella that rotated faster but produced less propelling force. Images FIGURE 1 FIGURE 4 PMID:8580359

  14. Rotational scanning atomic force microscopy.

    PubMed

    Ulčinas, A; Vaitekonis, Š

    2017-03-10

    A non-raster scanning technique for atomic force microscopy (AFM) imaging which combines rotational and translational motion is presented. The use of rotational motion for the fast scan axis allows us to significantly increase the scanning speed while imaging a large area (diameter > 30 μm). An image reconstruction algorithm and the factors influencing the resolution of the technique are discussed. The experimental results show the potential of the rotational scanning technique for high-throughput large area AFM investigation.

  15. Torque Simulator for Rotating Systems

    NASA Technical Reports Server (NTRS)

    Davis, W. T.

    1982-01-01

    New torque brake simulates varying levels of friction in bearings of rotating body. Rolling-tail torque brake uses magnetic force to produce friction between rotating part and stationary part. Simulator electronics produce positive or negative feedback signal, depending on direction of rotation. New system allows for first time in-depth study of effects of tail-fin spin rates on pitch-, yaw-, and roll-control characteristics.

  16. Internal rotation of the sun

    NASA Technical Reports Server (NTRS)

    Duvall, T. L., Jr.; Dziembowski, W. A.; Goode, P. R.; Gough, D. O.; Harvey, J. W.; Leibacher, J. W.

    1984-01-01

    The frequency difference between prograde and retrograde sectoral solar oscillations is analyzed to determine the rotation rate of the solar interior, assuming no latitudinal dependence. Much of the solar interior rotates slightly less rapidly than the surface, while the innermost part apparently rotates more rapidly. The resulting solar gravitational quadrupole moment is J2 = (1.7 + or - 0.4) x 10 to the -7th and provides a negligible contribution to current planetary tests of Einstein's theory of general relativity.

  17. Rotational scanning atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Ulčinas, A.; Vaitekonis, Š.

    2017-03-01

    A non-raster scanning technique for atomic force microscopy (AFM) imaging which combines rotational and translational motion is presented. The use of rotational motion for the fast scan axis allows us to significantly increase the scanning speed while imaging a large area (diameter > 30 μm). An image reconstruction algorithm and the factors influencing the resolution of the technique are discussed. The experimental results show the potential of the rotational scanning technique for high-throughput large area AFM investigation.

  18. Rotating Detonation Engine Operation (Preprint)

    DTIC Science & Technology

    2012-01-01

    MdotH2 = mass flow of hydrogen MdotAir = mass flow of air PCB = Piezoelectric Pressure Sensor PDE = Pulsed Detonation Engine RDE = Rotating ...and unsteady thrust output of PDEs . One of the new designs was the Rotating Detonation Engine (RDE). An RDE operates by exhausting an initial...AFRL-RZ-WP-TP-2012-0003 ROTATING DETONATION ENGINE OPERATION (PREPRINT) James A. Suchocki and Sheng-Tao John Yu The Ohio State

  19. Uniformly Rotating Single Substance Bodies

    NASA Astrophysics Data System (ADS)

    Leonard, Charles Michael Leo

    This dissertation explicitly and in detail solves the extended rotator problem in the uncharged relativistic classical cases of most physical interest. It shows that no plausible relativistic solutions exist in the literature of the extended rotator and that the point rotator solutions sometimes ballyhooed are not to be taken seriously. Explicit energy speedratio functions, angular momentum speedratio functions, Hamiltonian, Lagrangian, and other important characteristic functions of the state of uniform rotation of the extended body are detailed. This dissertation does not retreat to an 'analysis' of just the point rotator --which so many others have done and done incorrectly, or at best misleadingly, by hiding implausible assumptions in manifestly covariant formats. Assumptions in the model are not hidden but are brought out and analyzed as to their relevance for highlighting the core of the uniform rotation physics. Neither does the author hide any ignorance of the internal holding field for the rotator. Formulae for the characteristic Minimum Holding Field are explicitly given and their relativistic relevance is shown. The demonstration that such fields can be ignored in the energy and angular momentum expressions is completely detailed. The explicit Stress-Energy Tensor for the entire closed rotator system is given with all that entails as to the inescapability of the results from out of that mathematics. The generality of the finiteness of the extreme relativistic rotational limit is detailed and explained with its stark essential contrast to the infinite limit in the case of extreme relativistic translation of a body. The rotator is shown to possess a rich mathematical structure. Many elegant interconnection formulae are found as well as new Hamiltonian formulae --sometimes of considerable complexity. Exact rotator formulae as well as graphs, tables, and even interesting approximations are provided. New nonlinear differential equations are discovered and

  20. The rotation of Uranus

    NASA Technical Reports Server (NTRS)

    Goody, R. M.

    1981-01-01

    A historical review of the use of three independent techniques for measuring the rotational rate is presented. The approaches examined are: (1) using theoretical interior models together with observations of the oblateness and the gravitational moment; (2) studying periodic fluctuations in the brightness; and (3) spectrographically measuring the Doppler shifts (line tilts). Measurements of line tilts obtained using the Kitt Peak National Observation 4 meter telescope with a Cassegrain echelle to high obtain high spectral dispersion and large image are discussed and compared with results obtained by Muench and Hipplelein (1980) and by Hayes and Belton (1977). The possibility of using speckel imaging techniques to detect the motion of features across the disc in the 6091 methane band, and with more suitable image intensifiers, in the 7261 band is considered.

  1. Asteroid Ida Rotation Sequence

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This montage of 14 images (the time order is right to left, bottom to top) shows Ida as it appeared in the field of view of Galileo's camera on August 28, 1993. Asteroid Ida rotates once every 4 hours, 39 minutes and clockwise when viewed from above the north pole; these images cover about one Ida 'day.' This sequence has been used to create a 3-D model that shows Ida to be almost croissant shaped. The earliest view (lower right) was taken from a range of 240,000 kilometers (150,000 miles), 5.4 hours before closest approach. The asteroid Ida draws its name from mythology, in which the Greek god Zeus was raised by the nymph Ida.

  2. The Rapidly Rotating Sun

    NASA Technical Reports Server (NTRS)

    Hanasoge, Shravan M.; Duvall, Thomas L., Jr.; Sreenivasan, Katepalli R.

    2012-01-01

    Convection in the solar interior is thought to comprise structures at a continuum of scales, from large to small. This conclusion emerges from phenomenological studies and numerical simulations though neither covers the proper range of dynamical parameters of solar convection. In the present work, imaging techniques of time-distance helioseismology applied to observational data reveal no long-range order in the convective motion. We conservatively bound the associated velocity magnitudes, as a function of depth and the spherical-harmonic degree l to be 20-100 times weaker than prevailing estimates within the wavenumber band l < 60. The observationally constrained kinetic energy is approximately a thousandth of the theoretical prediction, suggesting the prevalence of an intrinsically different paradigm of turbulence. A fundamental question arises: what mechanism of turbulence transports the heat ux of a solar luminosity outwards? The Sun is seemingly a much faster rotator than previously thought, with advection dominated by Coriolis forces at scales l < 60.

  3. Rotating Gravity Gradiometer Study

    NASA Technical Reports Server (NTRS)

    Forward, R. L.

    1976-01-01

    The application of a Rotating Gravity Gradiometer (RGG) system on board a Lunar Polar Orbiter (LPO) for the measurement of the Lunar gravity field was investigated. A data collection simulation study shows that a gradiometer will give significantly better gravity data than a doppler tracking system for the altitudes under consideration for the LOP, that the present demonstrated sensitivity of the RGG is adequate for measurement of the Lunar gravity gradient field, and that a single RGG instrument will provide almost as much data for geophysical interpretation as an orthogonal three axis RGG system. An engineering study of the RGG sensor/LPO spacecraft interface characteristics shows that the RGG systems under consideration are compatible with the present models of the LPO spacecraft.

  4. Rotating gravity gradiometer study

    NASA Technical Reports Server (NTRS)

    Forward, R. L.

    1982-01-01

    Two rotating gravity gradiometer (RGG) sensors, along with all the external electronics needed to operate them, and the fixtures and special test equipment needed to fill and align the bearings, were assembled in a laboratory, and inspected. The thermal noise threshold of the RGG can be lowered by replacing a damping resistor in the first stage electronics by an active artificial resistor that generates less random voltage noise per unit bandwidth than the Johnson noise from the resistor it replaces. The artificial resistor circuit consists of an operational amplifier, three resistors, and a small DC to DC floating power supply. These are small enough to be retrofitted to the present circuit boards inside the RGG rotor in place of the 3 Megohm resistor. Using the artificial resistor, the thermal noise of the RGG-2 sensor can be lowered from 0.3 Eotvos to 0.15 Eotvos for a 10 sec integration time.

  5. Rotation Curves of Galaxies

    NASA Astrophysics Data System (ADS)

    Kalnajs, Agris J.

    One can obtain a fairly good understanding of the relation between axially symmetric mass distributions and the rotation curves they produce without resorting to calculations. However it does require a break with tradition. The first step consists of replacing quantities such as surface density, volume density, and circular velocity with the mass in a ring, mass in a spherical shell, and the square of the circular velocity, or more precisely with 2 pi G r mu(r), 4 pi G r^2 rho(r), and Vc^2 (r). These three quantities all have the same dimensions, and are related to each other by scale-free linear operators. The second step consists of introducing ln(r) as the coordinate. On the log scale the scale-free operators becomes the more familiar convolution operations. Convolutions are easily handled by Fourier techniques and a surface density can be converted into a rotation curve or volume density in a small fraction of a second. A simple plot of 2 pi G r mu(r) as a function of ln(r) reveals the relative contributions of different radii to Vc^2(r). Such a plot also constitutes a sanity test for the fitting of various laws to photometric data. There are numerous examples in the literature of excellent fits to the tails that lack data or are poor fits around the maximum of 2 pi G r mu(r). I will discuss some exact relations between the above three quantities as well as some empirical observations such as the near equality of the maxima of 2 pi G r mu(r) and Vc^2 (r) curves for flat mass distributions.

  6. Plasma rotation induced by RF

    SciTech Connect

    Chan, V. S.; Chiu, S. C.; Lin-Liu, Y. R. [General Atomics, P.O. Box 85608, San Diego, California 92186-5698; Omelchenko, Y. A. [General Atomics, P.O. Box 85608, San Diego, California 92186-5698

    1999-09-20

    Plasma rotation has many beneficial effects on tokamak operation including stabilization of MHD and microturbulence to improve the beta limit and confinement. Contrary to present-day tokamaks, neutral beams may not be effective in driving rotation in fusion reactors; hence the investigation of radiofrequency (RF) induced plasma rotation is of great interest and potential importance. This paper reviews the experimental results of RF induced rotation and possible physical mechanisms, suggested by theories, to explain the observations. This subject is only in the infancy of its research and many challenging issues remained to be understood and resolved. (c) 1999 American Institute of Physics.

  7. Rotation and particle loss in Tore Supra

    SciTech Connect

    R.B. White; F.W. Perkins; X. Garbet; C. Bourdelle; et al

    2000-06-13

    Although plasma heating with ICRF imparts negligible angular momentum to a tokamak plasma, the high energy particles give significant torque to the plasma through diamagnetic effects. This effect has been directly modeled through guiding center simulations. It is found that heating in Tore Supra, with the location of the resonance surface on the high field side of the magnetic axis, can produce negative central rotation of up to 40 km/sec. Particle loss also contributes to negative rotation, but this is not the dominant effect in most discharges. In this work the authors examine the effect of collisions and strong plasma rotation on the loss of high energy particles. Magnetic field strength variation due to discrete toroidal field coils, or ripple, produces two important loss channels in tokamaks. The trapping of particles in local ripple wells produces super banana orbits and, in the case of strong ripple, direct loss orbits leading to the plasma edge. These particles leave the device in the direction of vertical drift, and are characterized by small values of parallel velocity, or pitch. Ripple also causes high energy particles in banana orbits to diffuse stochastically, leading to banana orbits which impact the wall near the outer midplane. Both these loss processes are modified by the magnitude of the collision rate, and by plasma rotation. In Tore Supra the magnitude of the ripple makes ripple trapping a dominant loss mechanism for the background plasma as well as for ICRF produced non Maxwellian high energy tails. The authors have examined the loss as a function of collisionality and rotation using the Hamiltonian guiding center code ORBIT.

  8. Subdaily Earth rotation model and GPS solutions

    NASA Astrophysics Data System (ADS)

    Panafidina, Natalia; Hugentobler, Urs; Seitz, Manuela

    2014-05-01

    In this contribution we study the influence of the subdaily Earth rotation model on the GPS solution including station coordinates, satellite orbits and daily Earth rotation parameters (ERPs). The approach used is based on the transformation of GPS normal equation systems: free daily normal equations containing ERPs with 1-hour resolution are used as input data, in this case the high-frequency ERPs can be transformed into tidal terms which then can be fixed to new a priori values, thus changing implicitly the underlying subdaily Earth rotation model. To study the influence of individual tidal terms on the solution we successively changed a priori values for one tidal term in polar motion and compared the resulting solutions for GPS orbits, station coordinates and daily ERPs for a time interval of 13 years. The comparison reveals periodic changes in all estimated parameters with periods depending on the periods of the changed tidal terms. The dynamical reference frame realized by the GPS orbits is also affected: the whole satellite constellation shows periodic orientation variations, and each individual satellite shows periodic changes in the position of the orbit origin. We present a mechanism showing how errors in the subdaily Earth rotation model are propagated into the dynamical reference frame and the estimated parameters. Our model represents a change in one tidal term over one day as the sum of a prograde diurnal wave, a retrograde diurnal wave and an offset and linear drift in x- and y-pole. We demonstrate that this simple model, in conjunction with appropriate constraints, can explain well the observed variations in a one day GPS solution as well as in daily pole rates caused by changes in the subdaily Earth rotation model.

  9. Image Rotation Does Not Rotate Smooth Eye Movements

    NASA Technical Reports Server (NTRS)

    Mulligan, Jeffrey B.; Stone, Leland S. (Technical Monitor)

    1997-01-01

    Subjects viewing a drifting noise pattern make reflexive smooth eye movements in the direction of motion, which follow rapid changes in movement direction. These responses are unaffected by rotations of the pattern, suggesting that there is no coupling between visually sensed rotation and the direction of ocular following.

  10. Modeling rigid magnetically rotated microswimmers: Rotation axes, bistability, and controllability

    NASA Astrophysics Data System (ADS)

    Meshkati, Farshad; Fu, Henry Chien

    2014-12-01

    Magnetically actuated microswimmers have recently attracted attention due to many possible biomedical applications. In this study we investigate the dynamics of rigid magnetically rotated microswimmers with permanent magnetic dipoles. Our approach uses a boundary element method to calculate a mobility matrix, accurate for arbitrary geometries, which is then used to identify the steady periodically rotating orbits in a co-rotating body-fixed frame. We evaluate the stability of each of these orbits. We map the magnetoviscous behavior as a function of dimensionless Mason number and as a function of the angle that the magnetic field makes with its rotation axis. We describe the wobbling motion of these swimmers by investigating how the rotation axis changes as a function of experimental parameters. We show that for a given magnetic field strength and rotation frequency, swimmers can have more than one stable periodic orbit with different rotation axes. Finally, we demonstrate that one can improve the controllability of these types of microswimmers by adjusting the relative angle between the magnetic field and its axis of rotation.

  11. Surface dimpling on rotating work piece using rotation cutting tool

    DOEpatents

    Bhapkar, Rohit Arun; Larsen, Eric Richard

    2015-03-31

    A combined method of machining and applying a surface texture to a work piece and a tool assembly that is capable of machining and applying a surface texture to a work piece are disclosed. The disclosed method includes machining portions of an outer or inner surface of a work piece. The method also includes rotating the work piece in front of a rotating cutting tool and engaging the outer surface of the work piece with the rotating cutting tool to cut dimples in the outer surface of the work piece. The disclosed tool assembly includes a rotating cutting tool coupled to an end of a rotational machining device, such as a lathe. The same tool assembly can be used to both machine the work piece and apply a surface texture to the work piece without unloading the work piece from the tool assembly.

  12. Rotational period of GQ Lupi

    NASA Astrophysics Data System (ADS)

    Broeg, C.; Schmidt, T. O. B.; Guenther, E.; Gaedke, A.; Bedalov, A.; Neuhäuser, R.; Walter, F. M.

    2007-06-01

    Aims: We wanted to determine the rotation parameters of GQ Lup A, thereby constraining the evolutionary history of the GQ Lup system. Methods: We have undertaken a photometric monitoring campaign on GQ Lup A consisting of two epochs spaced one year apart. We also searched the photometric archives to enlarge the data set. Results: We were able to determine the photometric period (8.45±0.2 days) in both epochs in several photometric bands. This periodicity could also be found in some of the archival data. The combined false-alarm probability is 0.015. The variation is most likely caused by hot spots on the surface of GQ Lup A. This, combined with high-resolution spectra (v sin i) allows calculation of GQ Lup A's inclination (i=27±5°). Radial velocity data also contains this period but is inconclusive. Nevertheless, the RV data supports the interpretation that hot spots cause the photometric variation. We use the known K-band variability, amplitude, and phase of GQ Lup A together with a new image of GQ Lup A+b, taken quasi-simultaneously with our monitoring of the star, to confirm the magnitude and, hence, luminosity of the companion. Based on observations obtained on Cerro Paranal, Chile, in ESO program 075.C-0710(C) and on La Silla, Chile, in ESO programs 074.C-0034(A),075.C-0710(E), 075.C-0710(F), 075.C-0202(A), 076.C-0010(A) as well as with ANDICAM of the SMARTS consortium. Photometry data of epochs I and II are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/468/1039

  13. Giant Fecaloma Causing Small Bowel Obstruction: Case Report and Review of the Literature.

    PubMed

    Mushtaq, Mosin; Shah, Mubashir A; Malik, Aijaz A; Wani, Khurshid A; Thakur, Natasha; Q Parray, Fazl

    2015-04-01

    Fecaloma is a mass of hardened feces being impacted mostly in rectum and sigmoid. The most common sites of the fecaloma is the sigmoid colon and the rectum. There are several causes of fecaloma and have been described in association with Hirschsprung's disease, psychiatric patients, Chagas disease, both inflammatory and neoplastic, and in patients suffering with chronic constipation. Up to now several cases of giant fecaloma has been reported in the literature most of them presenting with megacolon or urinary retention. We herein report a case of giant fecaloma leading to bowel obstruction who was successfully treated by surgery. A 30-yrar-old man presented with sign and symptoms of acute bowel obstruction. He underwent exploratory laparotomy and enterotomy. He was found to have a giant fecaloma causing bowel obstruction in the jejunum. He was discharged after the operation with good condition. Jejunal fecaloma is extremely rare condition.

  14. Beneficial Metabolic Effects of Duodenal Jejunal Bypass Liner for the Treatment of Adipose Patients with Type 2 Diabetes Mellitus: Analysis of Responders and Non-Responders.

    PubMed

    Stratmann, B; Krepak, Y; Schiffer, E; Jarick, I; Hauber, M; Lee-Barkey, Y H; Fischer, M; Tschoepe, D

    2016-09-01

    Implantation of a duodenal-jejunal endoluminal bypass liner (DJBL) has shown to induce weight loss and to improve metabolic parameters. DJBL is a reversible endoduodenal sleeve mimicking duodenal bypass while lacking risks and limitations of bariatric surgery.Effects on metabolic control, body mass parameters, appetite regulation, glucose tolerance, organ health, and lipid profile were determined in 16 morbidly overweight patients with type 2 diabetes mellitus. In addition, relevant hormones (leptin, ghrelin, gastric inhibitory peptide, glucagon-like peptide, and insulin) were measured by enzyme-linked immunosorbent assay (ELISA) and chemiluminescent microparticle immunoassay (CMIA) at 0, 1, 32, and 52 weeks post-implant following a mixed meal tolerance test. Lipoprotein subclasses were analysed by proton nuclear magnetic resonance ((1)H NMR) spectrometry. DJBL provoked weight loss, a decrease in fat mass, and an improvement in insulin resistance and hepatic function in most but not all of the patients, but in the long term did not increase gut hormone fasting levels pointing to a combined effect of more than gut parameters alone. Lipidome analysis was done in 10 patients, allowing classification to responders and non-responders by reduction of sLDL-p subfraction; and to further analyse the atherogenic profile. Responders showed an overall more pronounced effect regarding improvement of HbA1c, BMI, and HOMA index.Implantation of a DJBL in obese type 2 diabetes patients does not per se lead to an improvement of the metabolic situation. Further analyses including larger cohorts have to be performed to identify responding patients, to better treat non-responders and to analyse the key effectors.

  15. Effects and mechanism of duodenal-jejunal bypass and sleeve gastrectomy on GLUT2 and glucokinase in diabetic Goto–Kakizaki rats

    PubMed Central

    2012-01-01

    Background The study investigated the effects and mechanism of duodenal-jejunal bypass (DJB) and sleeve gastrectomy (SG) on the expression of liver GLUT2 and glucokinase (GCK) in diabetic rats. Methods Animal models of Goto–Kakizaki (GK) rats were established for the investigation of DJB and SG. Results of weight, food intake, fasting plasma glucose level, oral glucose tolerance test and insulin were compared. Liver tissues were harvested 8 weeks postoperatively. Reverse transcription-PCR and western blot were used to detect liver GLUT2 and GCK mRNA and protein expression after operation. Results Fasting plasma glucose levels of DJB group and SG group in GK rats were markedly declined at 3 days and l, 2, 4, 6, and 8 weeks postoperatively (P <0.01), whereas the levels of the sham-operated group only dropped at 3 days and 1 week postoperatively, and there were no significant differences 2 weeks postoperatively (P >0.05). In the liver of GK rats, GLUT2 mRNA level and protein expression after DJB were higher than those in sham-operated group and control group. GLUT2 mRNA level and protein expression after SG were significantly lower than those in control group (P <0.01). GCK mRNA and protein experienced similar expression change. Conclusions Both DJB and SG can decrease the plasma glucose levels of GK rats, whereas they have different effects on the expression of liver GLUT2 and GCK. PMID:22686706

  16. Colonic GLP-2 is not Sufficient to Promote Jejunal Adaptation in a PN-Dependent Rat Model of Human Short Bowel Syndrome

    PubMed Central

    Koopmann, Matthew C.; Liu, Xiaowen; Boehler, Christopher J.; Murali, Sangita G.; Holst, Jens J.; Ney, Denise M.

    2013-01-01

    Background Bowel resection may lead to short bowel syndrome (SBS), which often requires parenteral nutrition (PN) due to inadequate intestinal adaptation. The objective of this study was to determine the time course of adaptation and proglucagon system responses after bowel resection in a PN-dependent rat model of SBS. Methods Rats underwent jugular catheter placement and a 60% jejunoileal resection + cecectomy with jejunoileal anastomosis or transection control surgery. Rats were maintained exclusively with PN and killed at 4 hours to 12 days. A nonsurgical group served as baseline. Bowel growth and digestive capacity were assessed by mucosal mass, protein, DNA, histology, and sucrase activity. Plasma insulin-like growth factor I (IGF-I) and bioactive glucagon-like peptide 2 (GLP-2) were measured by radioimmunoassay. Results Jejunum cellularity changed significantly over time with resection but not transection, peaking at days 3–4 and declining by day 12. Jejunum sucrase-specific activity decreased significantly with time after resection and transection. Colon crypt depth increased over time with resection but not transection, peaking at days 7–12. Plasma bioactive GLP-2 and colon proglucagon levels peaked from days 4–7 after resection and then approached baseline. Plasma IGF-I increased with resection through day 12. Jejunum and colon GLP-2 receptor RNAs peaked by day 1 and then declined below baseline. Conclusions After bowel resection resulting in SBS in the rat, peak proglucagon, plasma GLP-2, and GLP-2 receptor levels are insufficient to promote jejunal adaptation. The colon adapts with resection, expresses proglucagon, and should be preserved when possible in massive intestinal resection. PMID:19644131

  17. Spatially homogeneous rotating world models.

    NASA Technical Reports Server (NTRS)

    Ozsvath, I.

    1971-01-01

    The mathematical problem encountered when looking for the simplest expanding and rotating model of the universe without the compactness condition for the space sections is formulated. The Lagrangian function is derived for four different rotating universes simultaneously. These models correspond in a certain sense to Godel's (1950) ?symmetric case.'

  18. KEPLER RAPIDLY ROTATING GIANT STARS

    SciTech Connect

    Costa, A. D.; Martins, B. L. Canto; Bravo, J. P.; Paz-Chinchón, F.; Chagas, M. L. das; Leão, I. C.; Oliveira, G. Pereira de; Silva, R. Rodrigues da; Roque, S.; Oliveira, L. L. A. de; Silva, D. Freire da; De Medeiros, J. R.

    2015-07-10

    Rapidly rotating giant stars are relatively rare and may represent important stages of stellar evolution, resulting from stellar coalescence of close binary systems or accretion of substellar companions by their hosting stars. In the present Letter, we report 17 giant stars observed in the scope of the Kepler space mission exhibiting rapid rotation behavior. For the first time, the abnormal rotational behavior for this puzzling family of stars is revealed by direct measurements of rotation, namely from photometric rotation period, exhibiting a very short rotation period with values ranging from 13 to 55 days. This finding points to remarkable surface rotation rates, up to 18 times the rotation of the Sun. These giants are combined with six others recently listed in the literature for mid-infrared (IR) diagnostics based on Wide-field Infrared Survey Explorer information, from which a trend for an IR excess is revealed for at least one-half of the stars, but at a level far lower than the dust excess emission shown by planet-bearing main-sequence stars.

  19. Rotation of the planet mercury.

    PubMed

    Jefferys, W H

    1966-04-08

    The equations of motion for the rotation of Mercury are solved for the general case by an asymptotic expansion. The findings of Liu and O'Keefe, obtained by numerical integration of a special case, that it is possible for Mercury's rotation to be locked into a 2:3 resonance with its revolution, are confirmed in detail. The general solution has further applications.

  20. Rotational joint for prosthetic leg

    NASA Technical Reports Server (NTRS)

    Jones, W. C.; Owens, L. J.

    1977-01-01

    Device is installed in standard 30 millimeter tubing used for lower leg prosthetics. Unit allows proper rotation (about 3 degrees) of foot relative to the hip, during normal walking or running. Limited rotational movement with restoring force results in a more natural gait.

  1. Advances in Rotational Seismic Measurements

    SciTech Connect

    Pierson, Robert; Laughlin, Darren; Brune, Robert

    2016-10-19

    Rotational motion is increasingly understood to be a significant part of seismic wave motion. Rotations can be important in earthquake strong motion and in Induced Seismicity Monitoring. Rotational seismic data can also enable shear selectivity and improve wavefield sampling for vertical geophones in 3D surveys, among other applications. However, sensor technology has been a limiting factor to date. The US Department of Energy (DOE) and Applied Technology Associates (ATA) are funding a multi-year project that is now entering Phase 2 to develop and deploy a new generation of rotational sensors for validation of rotational seismic applications. Initial focus is on induced seismicity monitoring, particularly for Enhanced Geothermal Systems (EGS) with fracturing. The sensors employ Magnetohydrodynamic (MHD) principles with broadband response, improved noise floors, robustness, and repeatability. This paper presents a summary of Phase 1 results and Phase 2 status.

  2. Optomechanics for absolute rotation detection

    NASA Astrophysics Data System (ADS)

    Davuluri, Sankar

    2016-07-01

    In this article, we present an application of optomechanical cavity for the absolute rotation detection. The optomechanical cavity is arranged in a Michelson interferometer in such a way that the classical centrifugal force due to rotation changes the length of the optomechanical cavity. The change in the cavity length induces a shift in the frequency of the cavity mode. The phase shift corresponding to the frequency shift in the cavity mode is measured at the interferometer output to estimate the angular velocity of absolute rotation. We derived an analytic expression to estimate the minimum detectable rotation rate in our scheme for a given optomechanical cavity. Temperature dependence of the rotation detection sensitivity is studied.

  3. Rotating Stars Can Help Planets Become Habitable

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-12-01

    What characteristics must a terrestrial planet exhibit to have the potential to host life? Orbiting within the habitable zone of its host star is certainly a good start, but theres another important aspect: the planet has to have the right atmosphere. A recent study has determined how host stars can help their planets to lose initial, enormous gaseous envelopes and become more Earth-like.Collecting An EnvelopeWhen a terrestrial planet forms inside a gaseous protoplanetary disk, it can accumulate a significant envelope of hydrogen gas causing the planet to bear more similarity to a mini-Neptune than to Earth. Before the planet can become habitable, it must shed this enormous, primordial hydrogen envelope, so that an appropriate secondary atmosphere can form.So what determines whether a planet can get rid of its protoatmosphere? The dominant process for shedding a hydrogen atmosphere is thermal mass loss: as the planets upper atmosphere is heated by X-ray and extreme-ultraviolet (XUV) radiation from the host star, the envelope evaporates.A Critical DependenceIn a recent study led by Colin Johnstone (University of Vienna), a team of scientists has developed models of this evaporation process for hydrogen planetary atmospheres. In particular, Johnstone and collaborators examine how the host stars initial rotation rate which strongly impacts the stars level of XUV activity affects the degree to which the planets hydrogen atmosphere is evaporated, and the rate at which the evaporation occurs.The authors findings can be illustrated with the example of an Earth-mass planet located in the habitable zone of a solar-mass star. In this case, the authors find four interesting regimes (shown in the plot to the right):Evolution of the hydrogen protoatmosphere of an Earth-mass planet in the habitable zone of a solar-mass star. The four lettered cases describe different initial atmospheric masses. The three curves for each case describe the stellar rotation rate: slow (red

  4. Magnetostrophic Rotating Magnetoconvection

    NASA Astrophysics Data System (ADS)

    King, Eric; Aurnou, Jonathan

    2016-11-01

    Planetary magnetic fields are generated by turbulent convection within their vast interior liquid metal cores. Although direct observation is not possible, this liquid metal circulation is thought to be dominated by the controlling influences of Coriolis and Lorentz forces. Theory famously predicts that local-scale convection naturally settles into the so-called magnetostrophic state, where the Coriolis and Lorentz forces partially cancel, and convection is optimally efficient. To date, no laboratory experiments have reached the magnetostrophic regime in turbulent liquid metal convection. Furthermore, computational dynamo simulations have as yet failed to produce a globally magnetostrophic dynamo, which has led some to question the existence of the magnetostrophic state. Here, we present results from the first turbulent magnetostrophic rotating magnetoconvection experiments using the liquid metal gallium. We find that turbulent convection in the magnetostrophic regime is, in fact, maximally efficient. The experimental results clarify these previously disparate results, suggesting that the fluid dynamics saturate in magnetostrophic balance within turbulent liquid metal, planetary cores. The authors thank the NSF Geophysics Program for financial support.

  5. Simulating rotational grazing management.

    PubMed

    Cros, M J; Duru, M; Garcia, F; Martin-Clouaire, R

    2001-09-01

    Dairy systems predominantly based on rotational grazing are notoriously hard to manage. In order to ensure profitability, this type of production requires quite good organisation, planning, and operating capability on the part of the farmer. A simulation-based decision support system, called SEPATOU, has been developed for this purpose. At the core of the decision support approach lies an explicit and rigorous modelling of the management strategy that underlies a dairy farmer's decision-making behaviour (real or hypothetical). The SEPATOU system is a discrete-event simulator that reproduces the day-to-day dynamics of the farmer's decision process and the response of the controlled biophysical system for which models of grass growth, animal consumption, and milk production are used. SEPATOU provides the means to evaluate and compare tentative strategies by simulating their application throughout the production season under different hypothetical weather conditions. The relative worth of a strategy can be assessed by analysing the effects on the biophysical system and their variability across the representative range of possible conditions that is considered. The activities to be managed concern the type and amount of conserved feed, where to fertilise and how much, the choice of fields to harvest, and most importantly, which field to graze next. Typically, SEPATOU is designed to be used by extension services and farming system scientists. It is implemented in C++ and is currently undergoing a validation process with the intended users.

  6. Differential rotation in rapidly rotating F-stars

    NASA Astrophysics Data System (ADS)

    Reiners, A.; Schmitt, J. H. M. M.

    2003-12-01

    We obtained high quality spectra of 135 stars of spectral types F and later and derived ``overall'' broadening functions in selected wavelength regions utilizing a Least Squares Deconvolution (LSD) procedure. Precision values of the projected rotational velocity v \\sini were derived from the first zero of the Fourier transformed profiles and the shapes of the profiles were analyzed for effects of differential rotation. The broadening profiles of 70 stars rotating faster than v \\sini = 45 km s-1 show no indications of multiplicity nor of spottedness. In those profiles we used the ratio of the first two zeros of the Fourier transform q_2/q_1 to search for deviations from rigid rotation. In the vast majority the profiles were found to be consistent with rigid rotation. Five stars were found to have flat profiles probably due to cool polar caps, in three stars cuspy profiles were found. Two out of those three cases may be due to extremely rapid rotation seen pole on, only in one case (v \\sini = 52 km s-1) is solar-like differential rotation the most plausible explanation for the observed profile. These results indicate that the strength of differential rotation diminishes in stars rotating as rapidly as v \\sini >~ 50 km s-1. Table A.1 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.125.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/412/813 Based on observations collected at the European Southern Observatory, La Silla, 69.D-0015(B).

  7. Generalized investigation of the rotation-activity relation: favoring rotation period instead of Rossby number

    SciTech Connect

    Reiners, A.; Passegger, V. M.; Schüssler, M.

    2014-10-20

    Magnetic activity in Sun-like and low-mass stars causes X-ray coronal emission which is stronger for more rapidly rotating stars. This relation is often interpreted in terms of the Rossby number, i.e., the ratio of rotation period to convective overturn time. We reconsider this interpretation on the basis of the observed X-ray emission and rotation periods of 821 stars with masses below 1.4 M {sub ☉}. A generalized analysis of the relation between X-ray luminosity normalized by bolometric luminosity, L {sub X}/L {sub bol}, and combinations of rotational period, P, and stellar radius, R, shows that the Rossby formulation does not provide the solution with minimal scatter. Instead, we find that the relation L {sub X}/L {sub bol}∝P {sup –2} R {sup –4} optimally describes the non-saturated fraction of the stars. This relation is equivalent to L {sub X}∝P {sup –2}, indicating that the rotation period alone determines the total X-ray emission. Since L {sub X} is directly related to the magnetic flux at the stellar surface, this means that the surface flux is determined solely by the star's rotation and is independent of other stellar parameters. While a formulation in terms of a Rossby number would be consistent with these results if the convective overturn time scales exactly as L{sub bol}{sup −1/2}, our generalized approach emphasizes the need to test a broader range of mechanisms for dynamo action in cool stars.

  8. General-relativistic rotation laws in rotating fluid bodies

    NASA Astrophysics Data System (ADS)

    Mach, Patryk; Malec, Edward

    2015-06-01

    We formulate new general-relativistic extensions of Newtonian rotation laws for self-gravitating stationary fluids. They have been used to rederive, in the first post-Newtonian approximation, the well-known geometric dragging of frames. We derive two other general-relativistic weak-field effects within rotating tori: the recently discovered dynamic antidragging and a new effect that measures the deviation from the Keplerian motion and/or the contribution of the fluids self-gravity. One can use the rotation laws to study the uniqueness and the convergence of the post-Newtonian approximations as well as the existence of the post-Newtonian limits.

  9. Rotator Cuff Tears

    MedlinePlus

    ... protect your shoulder and keep it still. • Activity modification. Avoid activities that cause shoulder pain. • Non-steroidal ... improve flexibility and range of motion. Strengthening the muscles that support your shoulder can relieve pain and ...

  10. Rotational polarities of sudden impulses in the magnetotail lobe

    NASA Technical Reports Server (NTRS)

    Kawano, H.; Yamamoto, T.; Kokubun, S.; Lepping, R. P.

    1992-01-01

    A sudden impulse (SI) is a sudden change in the magnetic field strength which is caused by a change in the solar wind pressure and is observed throughout the magnetosphere. In this report we have examined the rotations of the magnetic field vectors at times of SIs in the magnetotail lobe, by using IMP 6, 7, and 8 magnetometer data. The following properties have been found: (1) at the time of SI the arrowhead of the magnetic vector tends to rotate in one plane; (2) the plane of rotation tends to include the unperturbed magnetic field vector; (3) the plane of rotation tends to be aligned with the radial direction from the magnetotail axis; and (4) the magnetic vectors have a particular rotational polarity: when the plane of rotation is viewed so that the Sun is to the right of the viewed plane and the magnetotail axis is to the bottom, the arrowhead of the vector tends to rotate counterclockwise in this plane. These magnetic vector properties are consistent with those expected when part of an increase in solar wind lateral pressure squeezes the magnetotail axisymmetrically while moving tailward.

  11. Improved apparatus for predictive diagnosis of rotator cuff disease

    NASA Astrophysics Data System (ADS)

    Pillai, Anup; Hall, Brittany N.; Thigpen, Charles A.; Kwartowitz, David M.

    2014-03-01

    Rotator cuff disease impacts over 50% of the population over 60, with reports of incidence being as high as 90% within this population, causing pain and possible loss of function. The rotator cuff is composed of muscles and tendons that work in tandem to support the shoulder. Heavy use of these muscles can lead to rotator cuff tear, with the most common causes is age-related degeneration or sport injuries, both being a function of overuse. Tears ranges in severity from partial thickness tear to total rupture. Diagnostic techniques are based on physical assessment, detailed patient history, and medical imaging; primarily X-ray, MRI and ultrasonography are the chosen modalities for assessment. The final treatment technique and imaging modality; however, is chosen by the clinician is at their discretion. Ultrasound has been shown to have good accuracy for identification and measurement of full-thickness and partial-thickness rotator cuff tears. In this study, we report on the progress and improvement of our method of transduction and analysis of in situ measurement of rotator cuff biomechanics. We have improved the ability of the clinician to apply a uniform force to the underlying musculotendentious tissues while simultaneously obtaining the ultrasound image. This measurement protocol combined with region of interest (ROI) based image processing will help in developing a predictive diagnostic model for treatment of rotator cuff disease and help the clinicians choose the best treatment technique.

  12. Toroidal rotation studies in KSTAR

    NASA Astrophysics Data System (ADS)

    Lee, S. G.; Lee, H. H.; Yoo, J. W.; Kim, Y. S.; Ko, W. H.; Terzolo, L.; Bitter, M.; Hill, K.; KSTAR Team

    2014-10-01

    Investigation of the toroidal rotation is one of the most important topics for the magnetically confined fusion plasma researches since it is essential for the stabilization of resistive wall modes and its shear plays an important role to improve plasma confinement by suppressing turbulent transport. The most advantage of KSTAR tokamak for toroidal rotation studies is that it equips two main diagnostics including the high-resolution X-ray imaging crystal spectrometer (XICS) and charge exchange spectroscopy (CES). Simultaneous core toroidal rotation and ion temperature measurements of different impurity species from the XICS and CES have shown in reasonable agreement with various plasma discharges in KSTAR. It has been observed that the toroidal rotation in KSTAR is faster than that of other tokamak devices with similar machine size and momentum input. This may due to an intrinsically low toroidal field ripple and error field of the KSTAR device. A strong braking of the toroidal rotation by the n = 1 non-resonant magnetic perturbations (NRMPs) also indicates these low toroidal field ripple and error field. Recently, it has been found that n = 2 NRMPs can also damp the toroidal rotation in KSTAR. The detail toroidal rotation studies will be presented. Work supported by the Korea Ministry of Science, ICT and Future Planning under the KSTAR project.

  13. Rotational motion of Vesta

    NASA Astrophysics Data System (ADS)

    Rambaux, N.; Asmar, S. W.; Konopliv, A. S.

    2012-09-01

    Vesta is the second most massive body of the asteroid belt and contains a giant impact and a differentiated interior. Constraints on internal structure can be inferred from various observations such as gravity field measurements [1]. Especially, detailed knowledge of the rotational motion can help constrain the mass distribution inside the body, which in turn can lead to information on its history. Here, we compute the polar motion, precession-nutation, and length-of-day variations of Vesta. The Vesta's Pole position in space has been obtained by Dawn mission [1] and the orbital pole of Vesta at J2000 can be obtained from the Horizons ephemerides [2]. The obliquity, defined as the angle between the normal to the orbital plane and the figure axis, brings information on the moment of inertia if it has reached its equilibrium position [3], the present value from observations is around 27 degrees. That is far from the ˜ 0.03 deg expected for the equilibrium position. In addition, the required timescale to fully damped the obliquity appears to be very long following the same approach developed in [4]. Thus, it appears that the obliquity of Vesta has not yet relaxed in its Cassini state. The figure of Vesta appears to be triaxial and the Sun exerts a non-zero torque. By following the approach developed for the Earth [e.g. 5] and Ceres [4], we compute the nutation of Vesta. The nutational motion of Vesta is dominated by the semi-annual nutation (996 milli-arcseconds or 1.26 m surface displacement) related to the large obliquity of Vesta, and then terms related to harmonics and also to the planet's mean longitude. The detection of such small displacement requires tracking of Vesta's surface with high precision. The precession time of the axis of Vesta is very long, about 179,000 years.

  14. Rotational bursting of interplanetary dust particles

    NASA Technical Reports Server (NTRS)

    Paddack, S. J.; Rhee, J. W.

    1974-01-01

    Solar radiation pressure is discussed as a cause of rotational bursting, and of eventual elimination of asymmetric dust particles from the solar system, by a windmill effect. The predicted life span with this process for metallic particles with radii of 0.00001 to 0.01 cm ranges from 10 to 10,000 years. The effects of magnetic spin damping were considered. This depletion mechanism works faster than the traditional Poynting-Robertson effect by approximately one order of magnitude for metallic particles and about two orders of magnitude for nonmetallic particles.

  15. Electric-field-induced rotation of Brownian metal nanowires.

    PubMed

    Arcenegui, Juan J; García-Sánchez, Pablo; Morgan, Hywel; Ramos, Antonio

    2013-09-01

    We describe the physical mechanism responsible for the rotation of Brownian metal nanowires suspended in an electrolyte exposed to a rotating electric field. The electric field interacts with the induced charge in the electrical double layer at the metal-electrolyte interface, causing rotation due to the torque on the induced dipole and to the induced-charge electro-osmotic flow around the particle. Experiments demonstrate that the primary driving mechanism is the former of these two. Our analysis contrasts with previous work describing the electrical manipulation of metallic particles with electric fields, which neglected the electrical double layer. Theoretical values for the rotation speed are calculated and good agreement with experiments is found.

  16. The influence of clinostat rotation on the fertilized amphibian egg.

    NASA Technical Reports Server (NTRS)

    Tremor, J. W.; Souza, K. A.

    1972-01-01

    Study in which unrestrained, fertilized eggs of Rana pipiens and Xenopus laevis were rotated in a plane parallel to the normal gravity vector. In R. pipiens rotation at 1/4 rpm for five days at 18 C produced a significantly increased number of commonly occurring abnormalities. Rotation at 1/15, 1/8, 1, 2, 5 and 10 rpm did not significantly affect normal development. X. laevis eggs reacted similarly. R. pipiens eggs were most sensitive to rotation at 1/4 rpm when exposure was initiated before first cleavage. Mixing of intracellular constituents apparently occurred only at 1/4 rpm in R. pipiens (of the clinostat speeds studied), and may have been the cause of the increased abnormality observed at this rate.

  17. The Rotational Excitation Temperature of the 6614 DIB Carrier

    NASA Technical Reports Server (NTRS)

    Cami, J.; Salama, F.; Jimenez-Vicente, J.; Galazutdinov, G.; Krelowski, J.

    2004-01-01

    Analysis of high spectral resolution observations of the lambda6614 DIB line profile show systematic variations in the positions of the peaks in the substructure of the profile. These variations can only be understood in the framework of rotational contours of large molecules, where the variations are caused by changes in the rotational excitation temperature. We show that the rotational excitation temperature for the DIB carrier is of the order 10-40 K - much lower than the gas kinetic temperature - indicating that for this particular DIB carrier angular momentum buildup is not very efficient. The rotational constant indicates that the carrier of this DIB is smaller than previously assumed:7-22 C atoms, depending on the geometry.

  18. Rotating pigment cells exhibit an intrinsic chirality.

    PubMed

    Yamanaka, Hiroaki; Kondo, Shigeru

    2015-01-01

    In multicellular organisms, cell properties, such as shape, size and function are important in morphogenesis and physiological functions. Recently, 'cellular chirality' has attracted attention as a cellular property because it can cause asymmetry in the bodies of animals. In recent in vitro studies, the left-right bias of cellular migration and of autonomous arrangement of cells under some specific culture conditions were discovered. However, it is difficult to identify the molecular mechanism underlying their intrinsic chirality because the left-right bias observed to date is subtle or is manifested in the stable orientation of cells. Here, we report that zebrafish (Danio rerio) melanophores exhibit clear cellular chirality by unidirectional counterclockwise rotational movement under isolated conditions without any special settings. The chirality is intrinsic to melanophores because the direction of the cellular rotation was not affected by the type of extracellular matrix. We further found that the cellular rotation was generated as a counter action of the clockwise movement of actin cytoskeleton. It suggested that the mechanism that directs actin cytoskeleton in the clockwise direction is pivotal for determining cellular chirality.

  19. Flare differentially rotates sunspot on Sun's surface

    NASA Astrophysics Data System (ADS)

    Liu, Chang; Xu, Yan; Cao, Wenda; Deng, Na; Lee, Jeongwoo; Hudson, Hugh S.; Gary, Dale E.; Wang, Jiasheng; Jing, Ju; Wang, Haimin

    2016-10-01

    Sunspots are concentrations of magnetic field visible on the solar surface (photosphere). It was considered implausible that solar flares, as resulted from magnetic reconnection in the tenuous corona, would cause a direct perturbation of the dense photosphere involving bulk motion. Here we report the sudden flare-induced rotation of a sunspot using the unprecedented spatiotemporal resolution of the 1.6 m New Solar Telescope, supplemented by magnetic data from the Solar Dynamics Observatory. It is clearly observed that the rotation is non-uniform over the sunspot: as the flare ribbon sweeps across, its different portions accelerate (up to ~50° h-1) at different times corresponding to peaks of flare hard X-ray emission. The rotation may be driven by the surface Lorentz-force change due to the back reaction of coronal magnetic restructuring and is accompanied by a downward Poynting flux. These results have direct consequences for our understanding of energy and momentum transportation in the flare-related phenomena.

  20. A low frequency rotational energy harvesting system

    NASA Astrophysics Data System (ADS)

    Febbo, M.; Machado, S. P.; Ramirez, J. M.; Gatti, C. D.

    2016-11-01

    This paper presents a rotary power scavenging unit comprised of two systems of flexible beams connected by two masses which are joined by means of a spring, considering a PZT (QP16N, Midé Corporation) piezoelectric sheet mounted on one of the beams. The energy harvesting (EH) system is mounted rigidly on a rotating hub. The gravitational force on the masses causes sustained oscillatory motion in the flexible beams as long as there is rotary motion. The intention is to use the EH system in the wireless autonomous monitoring of wind turbines under different wind conditions. Specifically, the development is oriented to monitor the dynamic state of the blades of a wind generator of 30 KW which rotates between 50 and 150 rpm. The paper shows a complete set of experimental results on three devices, modifying the amount of beams in the frame supporting the system. The results show an acceptable sustained voltage generation for the expected range, in the three proposed cases. Therefore, it is possible to use this system for generating energy in a low-frequency rotating environment. As an alternative, the system can be easily adapted to include an array of piezoelectric sheets to each of the beams, to provide more power generation.

  1. Correcting ionospheric Faraday rotation for ASKAP

    NASA Astrophysics Data System (ADS)

    O'Sullivan, Shane; Gaensler, Bryan; Landecker, Tom L.; Willis, Tony

    2012-10-01

    Next-generation polarisation surveys, such as the POSSUM survey on ASKAP, aim to measure weak, statistical, cosmological effects associated with weak magnetic fields, and so will require unprecedented accuracy and stability for measuring polarisation vectors and their Faraday rotation measures (RMs). Ionospheric Faraday rotation (IFR) corrupts polarization observations and cannot be ignored at mid to low frequencies. In aperture-synthesis polarimetry IFR rotates individual visibilities and leads to a loss of coherence and accuracy of polarization angle determination. Through the POSSUM survey science team we have been involved in developing detailed ionospheric prediction software (POSSUM memos #10a,b) that will be used to correct the observed visibilities on ASKAP before imaging to obtain sufficiently accurate polarization and RM data. To provide a stringent test of this software, we propose a continuous 24 hr observing block using the 1.1-3.1 GHz band to monitor the variations caused by the time-variable ionosphere in the polarization angle and RM of a strongly polarized calibrator source, PKS B1903-802. We request a total of 96 hrs (4 x 24 hrs) to monitor the changes in the ionosphere every 3 to 6 months until BETA/ASKAP-12 is taking reliable polarization data.

  2. Compact, Precise Inertial Rotation Sensors for Spacecraft

    NASA Technical Reports Server (NTRS)

    Rosing, David; Oseas, Jeffrey; Korechoff, Robert

    2006-01-01

    A document describes a concept for an inertial sensor for measuring the rotation of an inertially stable spacecraft around its center of gravity to within 100 microarcseconds or possibly even higher precision. Whereas a current proposal for a spacecraft-rotation sensor of this accuracy requires one spacecraft dimension on the order of ten meters, a sensor according to this proposal could fit within a package smaller than 1 meter and would have less than a tenth of the mass. According to the concept, an inertial mass and an apparatus for monitoring the mass would be placed at some known distance from the center of gravity so that any rotation of the spacecraft would cause relative motion between the mass and the spacecraft. The relative motion would be measured and, once the displacement of the mass exceeded a prescribed range, a precisely monitored restoring force would be applied to return the mass to a predetermined position. Measurements of the relative motion and restoring force would provide information on changes in the attitude of the spacecraft. A history of relative motion and restoring-force measurements could be kept, enabling determination of the cumulative change in attitude during the observation time.

  3. Flare differentially rotates sunspot on Sun's surface.

    PubMed

    Liu, Chang; Xu, Yan; Cao, Wenda; Deng, Na; Lee, Jeongwoo; Hudson, Hugh S; Gary, Dale E; Wang, Jiasheng; Jing, Ju; Wang, Haimin

    2016-10-10

    Sunspots are concentrations of magnetic field visible on the solar surface (photosphere). It was considered implausible that solar flares, as resulted from magnetic reconnection in the tenuous corona, would cause a direct perturbation of the dense photosphere involving bulk motion. Here we report the sudden flare-induced rotation of a sunspot using the unprecedented spatiotemporal resolution of the 1.6 m New Solar Telescope, supplemented by magnetic data from the Solar Dynamics Observatory. It is clearly observed that the rotation is non-uniform over the sunspot: as the flare ribbon sweeps across, its different portions accelerate (up to ∼50° h(-1)) at different times corresponding to peaks of flare hard X-ray emission. The rotation may be driven by the surface Lorentz-force change due to the back reaction of coronal magnetic restructuring and is accompanied by a downward Poynting flux. These results have direct consequences for our understanding of energy and momentum transportation in the flare-related phenomena.

  4. Flare differentially rotates sunspot on Sun's surface

    PubMed Central

    Liu, Chang; Xu, Yan; Cao, Wenda; Deng, Na; Lee, Jeongwoo; Hudson, Hugh S.; Gary, Dale E.; Wang, Jiasheng; Jing, Ju; Wang, Haimin

    2016-01-01

    Sunspots are concentrations of magnetic field visible on the solar surface (photosphere). It was considered implausible that solar flares, as resulted from magnetic reconnection in the tenuous corona, would cause a direct perturbation of the dense photosphere involving bulk motion. Here we report the sudden flare-induced rotation of a sunspot using the unprecedented spatiotemporal resolution of the 1.6 m New Solar Telescope, supplemented by magnetic data from the Solar Dynamics Observatory. It is clearly observed that the rotation is non-uniform over the sunspot: as the flare ribbon sweeps across, its different portions accelerate (up to ∼50° h−1) at different times corresponding to peaks of flare hard X-ray emission. The rotation may be driven by the surface Lorentz-force change due to the back reaction of coronal magnetic restructuring and is accompanied by a downward Poynting flux. These results have direct consequences for our understanding of energy and momentum transportation in the flare-related phenomena. PMID:27721463

  5. A slowly rotating impeller in a rapidly rotating fluid

    NASA Astrophysics Data System (ADS)

    Machicoane, Nathanael; Moisy, Frederic; Cortet, Pierre-Philippe; Instability, waves; turbulence Team

    2016-11-01

    We characterize the two-dimensionalization process in the turbulent flow produced by an impeller rotating at a rate ω in a fluid rotating at a rate Ω around the same axis for Rossby number Ro = ω / Ω down to 0.01. The flow can be described as the superposition of a large-scale vertically invariant global rotation and small-scale shear layers detached from the impeller blades. As Ro decreases, the large-scale flow is subjected to azimuthal modulations. In this regime, the shear layers can be described in terms of wakes of inertial waves traveling with the blades, originating from the velocity difference between the non-axisymmetric large-scale flow and the blade rotation. The wakes are well defined and stable at low Rossby number, but they become disordered and interact nonlinearly at Ro of order of 1.

  6. Torsion-rotation intensities in methanol

    NASA Astrophysics Data System (ADS)

    Pearson, John

    Methanol exists in numerous kinds of astronomical objects featuring a wide range of local conditions. The light nature of the molecule coupled with the internal rotation of the methyl group with respect to the hydroxyl group results in a rich, strong spectrum that spans the entire far-infrared region. As a result, any modest size observational window will have a number of strong methanol transitions. This has made it the gas of choice for testing THz receivers and to extract the local physical conditions from observations covering small frequency windows. The latter has caused methanol to be dubbed the Swiss army knife of astrophysics. Methanol has been increasingly used in this capacity and will be used even more for subsequent investigations into the Herschel archive, and with SOFIA and ALMA. Interpreting physical conditions on the basis of a few methanol lines requires that the molecular data, line positions, intensities, and collision rates, be complete, consistent and accurate to a much higher level than previously required for astrophysics. The need for highly reliable data is even more critical for modeling the two classes of widespread maser action and many examples of optical pumping through the torsional bands. Observation of the torsional bands in the infrared will be a unique opportunity to directly connect JWST observations with those of Herschel, SOFIA, and ALMA. The theory for the intensities of torsion-rotation transitions in a molecule featuring a single internally rotating methyl group is well developed after 70 years of research. However, other than a recent very preliminary and not completely satisfactory investigation of a few CH3OH torsional bands, this theory has never been experimentally tested for any C3V internal rotor. More alarming is a set of recent intensity calibrated microwave measurements that showed deviations relative to calculations of up to 50% in some ground state rotational transitions commonly used by astronomers to extract

  7. Cooling system for rotating machine

    DOEpatents

    Gerstler, William Dwight; El-Refaie, Ayman Mohamed Fawzi; Lokhandwalla, Murtuza; Alexander, James Pellegrino; Quirion, Owen Scott; Palafox, Pepe; Shen, Xiaochun; Salasoo, Lembit

    2011-08-09

    An electrical machine comprising a rotor is presented. The electrical machine includes the rotor disposed on a rotatable shaft and defining a plurality of radial protrusions extending from the shaft up to a periphery of the rotor. The radial protrusions having cavities define a fluid path. A stationary shaft is disposed concentrically within the rotatable shaft wherein an annular space is formed between the stationary and rotatable shaft. A plurality of magnetic segments is disposed on the radial protrusions and the fluid path from within the stationary shaft into the annular space and extending through the cavities within the radial protrusions.

  8. Orbital, Rotational, and Climatic Interactions

    NASA Technical Reports Server (NTRS)

    Bills, Bruce G. (Editor)

    1992-01-01

    The report of an international meeting on the topic of Orbital, Rotational, and Climatic Interactions, which was held 9-11 Jul. 1991 at the Johns Hopkins University is presented. The meeting was attended by 22 researchers working on various aspects of orbital and rotational dynamics, paleoclimate data analysis and modeling, solid-Earth deformation studies, and paleomagnetic analyses. The primary objective of the workshop was to arrive at a better understanding of the interactions between the orbital, rotational, and climatic variations of the Earth. This report contains a brief introduction and 14 contributed papers which cover most of the topics discussed at the meeting.

  9. Antimagnetic rotation in 104Pd

    NASA Astrophysics Data System (ADS)

    Rather, N.; Roy, S.; Datta, P.; Chattopadhyay, S.; Goswami, A.; Nag, S.; Palit, R.; Pal, S.; Saha, S.; Sethi, J.; Trivedi, T.; Jain, H. C.

    2014-06-01

    The electric quadrupole transition rates for the high-spin yrast states of 104Pd have been measured by using the Doppler-shift attenuation method. These values decrease with the increase of angular momentum, which can be associated with the phenomenon of antimagnetic rotation. In the present work, a numerical calculation based on the semiclassical particle plus rotor model for antimagnetic rotation has been employed, giving a good description of the experimental Routhian and the transition rates and providing conclusive evidence of antimagnetic rotation in a nucleus other than cadmium.

  10. Venus' rotation and atmospheric tides

    NASA Technical Reports Server (NTRS)

    Ingersoll, A. P.; Dobrovolskis, A. R.

    1978-01-01

    On the basis of a presented theory, it is suggested that Venus' current rotation is a stable balance between atmospheric and solar body tides. The theory is concerned with Venus' atmospheric tides, driven by solar heating, and how these tides could serve as a third torque to balance the effects of solar body torque and to maintain a stable equilibrium resonance with regard to the earth's gravitational effects. In the absence of the atmospheric tidal torque, or some other torque, it would be expected that Venus would be despun until synchronous rotation (one side always facing the sun) is attained, rather than retain the retrograde rotation period of 243 days.

  11. Axial gap rotating electrical machine

    DOEpatents

    None

    2016-02-23

    Direct drive rotating electrical machines with axial air gaps are disclosed. In these machines, a rotor ring and stator ring define an axial air gap between them. Sets of gap-maintaining rolling supports bear between the rotor ring and the stator ring at their peripheries to maintain the axial air gap. Also disclosed are wind turbines using these generators, and structures and methods for mounting direct drive rotating electrical generators to the hubs of wind turbines. In particular, the rotor ring of the generator may be carried directly by the hub of a wind turbine to rotate relative to a shaft without being mounted directly to the shaft.

  12. On regular rotating black holes

    NASA Astrophysics Data System (ADS)

    Torres, R.; Fayos, F.

    2017-01-01

    Different proposals for regular rotating black hole spacetimes have appeared recently in the literature. However, a rigorous analysis and proof of the regularity of this kind of spacetimes is still lacking. In this note we analyze rotating Kerr-like black hole spacetimes and find the necessary and sufficient conditions for the regularity of all their second order scalar invariants polynomial in the Riemann tensor. We also show that the regularity is linked to a violation of the weak energy conditions around the core of the rotating black hole.

  13. Rotating regular black hole solution

    NASA Astrophysics Data System (ADS)

    Abdujabbarov, Ahmadjon

    2016-07-01

    Based on the Newman-Janis algorithm, the Ayón-Beato-García spacetime metric [Phys. Rev. Lett. 80, 5056 (1998)] of the regular spherically symmetric, static, and charged black hole has been converted into rotational form. It is shown that the derived solution for rotating a regular black hole is regular and the critical value of the electric charge for which two horizons merge into one sufficiently decreases in the presence of the nonvanishing rotation parameter a of the black hole.

  14. The automated rotating shadowband spectroradiometer

    SciTech Connect

    Harrison, L.; Beik, M.A.; Michalsky, J.J.

    1993-11-01

    We are developing a photodiode array rotating shadowband spectroradiometer (RSS) as part of the Instrument Development Program (IDP) of the Atmospheric Radiation Measurement (ARM) Program of the United States Department of Energy (DOE). This instrument uses the automated rotating shadowband technique to separate and measure the spectrally resolved direct-normal, total horizontal, and diffuse horizontal irradiances in the 360 to 1060 nm wavelength region. It is intended as an instrument for the central facility of each of the cloud and radiation testbed (CART) sites, and will complement the array of multi-filter rotating shadowband radiometers (MFRSR) currently being deployed by ARM and other research programs including TOGA/COARE.

  15. Rotating apparatus for isoelectric focusing

    NASA Technical Reports Server (NTRS)

    Bier, Milan (Inventor)

    1986-01-01

    This disclosure is directed to an isoelectric focusing apparatus, wherein stabilization of the fluid containing the isolated proteins is achieved by carrying out the separation in a rotating cylinder with the separation cavity of the cylinder being segmented by means of filter elements. The filter elements are constituted of a material offering some degree of resistance to fluid convection, but allowing relatively free and unhindered passage of current and transport of proteins. The combined effect of segmentation and rotation has been found to be superior to either segmentation or rotation alone in maintaining the stability of the migrated fractions.

  16. Catastrophic rotational braking among Sun-like stars. A model of the Sun's rotation evolution

    NASA Astrophysics Data System (ADS)

    Gondoin, P.

    2017-03-01

    Context. Observations of young open clusters show a bimodal distribution of stellar rotation. In those clusters, Sun-like stars group into two main populations of fast and slow rotators. Beyond an age of approximately 600 Myr, the two populations converge towards a single sequence of slow rotators. Aims: The present study addresses the origin of this bimodal distribution and the cause of its observed evolution. Methods: New prescriptions of mass-loss rate and Alfven radius dependences on Rossby number suggested by observations are implemented in a phenomenological model of angular-momentum loss and redistribution. The obtained model is used to calculate the time evolution of a rotation-period distribution of solar-mass stars similar to that observed in the 5 Myr-old NGC 2362 open cluster. The simulated distributions at subsequent ages are compared with those of h Per, the Pleiades, M 50, M 35, and M 37. Results: The model is able to reproduce the appearance and disappearance of a bimodal rotation-period distribution in open clusters providing that a brief episode of large-angular-momentum loss is included in the early evolution of Sun-like stars. Conclusions: I argue that a transitory episode of large-angular-momentum loss occurs on Sun-like stars with Rossby numbers between 0.13 and 0.3. This phenomenon of enhanced magnetic braking by stellar wind would be mainly driven by a rapid increase of mass loss at a critical rotation rate. This scenario accounts for the bimodal distribution of stellar rotation in open clusters with ages between 20-30 Myr and approximately 600 Myr. The mass-loss rate increase could account for a significant fraction of the X-ray luminosity decay of Sun-like stars in the 0.13-0.3 Rossby number range where a transition from the saturated to the non-saturated regime of X-ray emission is observed. Observed correlations between Li abundance and rotation sequences in the Pleiades and M 34 clusters support this scenario.

  17. STELLAR ROTATION PERIODS OF THE KEPLER OBJECTS OF INTEREST: A DEARTH OF CLOSE-IN PLANETS AROUND FAST ROTATORS

    SciTech Connect

    McQuillan, A.; Mazeh, T.; Aigrain, S.

    2013-09-20

    We present a large sample of stellar rotation periods for Kepler Objects of Interest, based on three years of public Kepler data. These were measured by detecting periodic photometric modulation caused by star spots, using an algorithm based on the autocorrelation function of the light curve, developed recently by McQuillan, Aigrain and Mazeh (2013). Of the 1919 main-sequence exoplanet hosts analyzed, robust rotation periods were detected for 737. Comparing the detected stellar periods to the orbital periods of the innermost planet in each system reveals a notable lack of close-in planets around rapid rotators. It appears that only slowly spinning stars with rotation periods longer than 5-10 days host planets on orbits shorter than 2 or 3 days, although the mechanism(s) that lead(s) to this is not clear.

  18. Optical wheel-rotation sensor

    SciTech Connect

    Veeser, L.; Rodriguez, P.; Forman, P.; Deeter, M.

    1994-05-01

    We describe a fiber-optic rotation sensor based on diffraction of light in a magneto-optic crystal (BIG). Exploitation of this effect permits the construction of a sensor requiring no polarization elements or lenses.

  19. Rotation Velocities of White Dwarfs

    NASA Astrophysics Data System (ADS)

    Karl, C.; Napiwotzki, R.; Heber, U.; Dreizler, S.; Koester, D.; Reid, I. N.

    White dwarfs are the compact remnants of low and intermediate mass stars (M < 8Msolar). Due to the conservation of angular momentum white dwarfs should be very fast rotators, if a significant fraction of the angular momentum of the progenitor stars were preserved. The existence of sharp NLTE cores of the hydrogen Hα line in high resolution spectra (obtained at the Keck observatory) of DA white dwarfs allowed us to determine (projected) rotational velocities v sin i for white dwarfs. Among those of our targets lying close to the ZZ Ceti instability many show evidence for extra broadening similar to rotation, whereas stars at higher temperatures (and therefore younger ones) rotate more slowly or not at all. Our result based on a large sample is in accordance with previous results presented by Koester et al. (1998). We discuss possible explanations for this astonishing result.

  20. High performance rotational vibration isolator

    NASA Astrophysics Data System (ADS)

    Sunderland, Andrew; Blair, David G.; Ju, Li; Golden, Howard; Torres, Francis; Chen, Xu; Lockwood, Ray; Wolfgram, Peter

    2013-10-01

    We present a new rotational vibration isolator with an extremely low resonant frequency of 0.055 ± 0.002 Hz. The isolator consists of two concentric spheres separated by a layer of water and joined by very soft silicone springs. The isolator reduces rotation noise at all frequencies above its resonance which is very important for airborne mineral detection. We show that more than 40 dB of isolation is achieved in a helicopter survey for rotations at frequencies between 2 Hz and 20 Hz. Issues affecting performance such as translation to rotation coupling and temperature are discussed. The isolator contains almost no metal, making it particularly suitable for electromagnetic sensors.

  1. High performance rotational vibration isolator.

    PubMed

    Sunderland, Andrew; Blair, David G; Ju, Li; Golden, Howard; Torres, Francis; Chen, Xu; Lockwood, Ray; Wolfgram, Peter

    2013-10-01

    We present a new rotational vibration isolator with an extremely low resonant frequency of 0.055 ± 0.002 Hz. The isolator consists of two concentric spheres separated by a layer of water and joined by very soft silicone springs. The isolator reduces rotation noise at all frequencies above its resonance which is very important for airborne mineral detection. We show that more than 40 dB of isolation is achieved in a helicopter survey for rotations at frequencies between 2 Hz and 20 Hz. Issues affecting performance such as translation to rotation coupling and temperature are discussed. The isolator contains almost no metal, making it particularly suitable for electromagnetic sensors.

  2. Fission of rotating fermium isotopes

    NASA Astrophysics Data System (ADS)

    Baran, A.; Staszczak, A.

    2014-05-01

    In this paper we discuss the process of fission of even fermium isotopes, on the basis of their rotational states. The nuclear intrinsic vorticity and its coupling to the global rotation of the nucleus are used to simulate the interaction between the rotational motion and the pairing field, and lead to pairing quenching in the case of higher angular momentum states. The rotation leads to a decreasing of the fission barrier heights. The ingredients of the model—ground state fission barriers, pairing correlation energies and the cranking moments of inertia—are obtained within the self-consistent Hartree-Fock-Bogoliubov framework using the Skyrme \\text{Sk}{{\\text{M}}^{*}} energy density functional. Fission barriers and half-lives are estimated for spins I up to I = 16ℏ.

  3. An Exercise in Rotational Motion.

    ERIC Educational Resources Information Center

    Mahoney, Brother James

    1980-01-01

    Describes an advanced high school physics experiment demonstrating rotational kinematics and dynamics, using simple equipment such as empty coffee cans, inclined planes, meter sticks, and a large 10-second demonstration timer. (CS)

  4. Rotation, differential rotation, and gyrochronology of active Kepler stars

    NASA Astrophysics Data System (ADS)

    Reinhold, Timo; Gizon, Laurent

    2015-11-01

    Context. In addition to the discovery of hundreds of exoplanets, the high-precision photometry from the CoRoT and Kepler satellites has led to measurements of surface rotation periods for tens of thousands of stars, which can potentially be used to infer stellar ages via gyrochronology. Aims: Our main goal is to derive ages of thousands of field stars using consistent rotation period measurements derived by different methods. Multiple rotation periods are interpreted as surface differential rotation (DR). We study the dependence of DR with rotation period and effective temperature. Methods: We reanalyze a previously studied sample of 24 124 Kepler stars using different approaches based on the Lomb-Scargle periodogram. Each quarter (Q1-Q14) is treated individually using a prewhitening approach. Additionally, the full time series and their different segments are analyzed. Results: For more than 18 500 stars our results are consistent with the rotation periods from McQuillan et al. (2014, ApJS, 211, 24). Of these, more than 12 300 stars show multiple significant peaks, which we interpret as DR. Dependencies of the DR with rotation period and effective temperature could be confirmed, e.g., the relative DR increases with rotation period. Gyrochronology ages between 100 Myr and 10 Gyr were derived for more than 17 000 stars using different gyrochronology relations, most of them with uncertainties dominated by period variations. We find a bimodal age distribution for Teff between 3200-4700 K. The derived ages reveal an empirical activity-age relation using photometric variability as stellar activity proxy. Additionally, we found 1079 stars with extremely stable (mostly short) periods. Half of these periods may be associated with rotation stabilized by non-eclipsing companions, the other half might be due to pulsations. Conclusions: The derived gyrochronology ages are well constrained since more than ~93.0% of the stars seem to be younger than the Sun where calibration is

  5. The deconjugation ability of bacteria isolated from the jejunal fluids in the blind loop syndrome with high sup 14 CO sub 2 excretion. Using the breath analysis technique and thin-layer chromatography

    SciTech Connect

    Shindo, K.; Yamazaki, R.; Mizuno, T.; Shionoiri, H.; Sugiyama, M. )

    1989-01-01

    Five patients with blind loop syndrome (Billroth II) were examined by measuring {sup 14}CO{sub 2} specific activity of expired breath samples taken at intervals after a meal containing glycine-1-{sup 14}C cholate. The 5 patients tested showed a marked increase of {sup 14}CO{sub 2} specific activity. Furthermore, the ability of deconjugation of bacteria isolated from the jejunal fluids in the efferent loop of these patients was tested by thin-layer chromatography. The bacterial species identified from the samples were as follows: enterococcus, Lactobacillus buchneri, L. bifidus, L. brevis, Eubacterium lentum, Bacteroides vulgaricus, B. filamentosum, Corynebacterium granulosum, Escherichia coli, Staphylococcus epidermidis, and Aerobacter aerogenes. These species of bacteria, except E. coli and A. aerogenes, showed the deconjugation ability by which conjugated bile acids in ox gall was hydrolyzed. Administration of chloramphenicol to the 5 patients reduced {sup 14}CO{sub 2} specific activity significantly. On the other hand, 9 healthy men who were tested showed a flat curve, and 8 of the 9 had no growth of bacteria isolated from the jejunal fluids. The remaining healthy man showed an over growth of E. coli and Pseudomonas aeruginosa, but the species did not have the ability of deconjugation.

  6. Histological alterations in the intestinal epithelium caused by the inclusion of full-fat sunflower kernels in broiler chicken diets.

    PubMed

    Arija, I; Viveros, A; Brenes, A; Canales, R; Pizarro, M; Castaño, M

    2000-09-01

    Changes in small intestinal morphology (jejunum) were examined at 28 d of age in chicks fed with full-fat sunflower kernels (FFSK)-based diets. Jejunal mucosa of chicks (six chicks per treatment) were embedded in Epon-812 for examination by a conventional electron microscope procedure. A portion of the tissues was also sectioned and embedded in paraffin for examination by light microscopy. Brush border, goblet cells, and intraepithelial lymphocytes, on the one hand, and fibroblast and mononuclear cells (lymphocytes, plasma cells, macrophages) were observed in the enterocytes and lamina propria, respectively. The results showed that the birds fed 150 g kg(-1) of FFSK showed a shortening and thickening of the villi, hyperplasia and vacuolar degeneration of enterocytes, and hypertrophy and hyperplasia of goblet cells. Likewise, an increment of intraepithelial lymphoid cells and hypercellularity of the lamina propria was observed. In addition, electron microscopy showed large vacuoles in the enterocytes, which could be dilations of agranular and granular endoplasmic reticulum or Golgi. There were many dark granules within the vacuoles that could be triglyceride-rich lipoproteins (portomicrons). These lesions could have been due to the presence of chlorogenic acid or to the greater concentration of oil in the FFSK diet. Our observations demonstrated that addition of 150 g kg(-1) FFSK to broiler chicken diets caused alterations in jejunal mucosa that could explain the decrease in fat digestibility observed in a previous experiment in which we incorporated FFSK into broiler diets.

  7. Rotation of Hyperion. I - Observations

    NASA Technical Reports Server (NTRS)

    Klavetter, James Jay

    1989-01-01

    Precise and well sampled observations of Hyperion over a long period of time have been performed to test the prediction of Wisdom et al. (1984) that the satellite is in a state of chaotic rotation. CCD data for a 13-week period were obtained in Chile and in Arizona. A phase-dispersion-minimization analysis of the light curve indicates that Hyperion is not in a periodic rotational state, thus suggesting that it is chaotic.

  8. Relativity on Rotated Graph Paper

    NASA Astrophysics Data System (ADS)

    Salgado, Roberto

    2011-11-01

    We present visual calculations in special relativity using spacetime diagrams drawn on graph paper that has been rotated by 45 degrees. The rotated lines represent lightlike directions in Minkowski spacetime, and the boxes in the grid (called light-clock diamonds) represent ticks of an inertial observer's lightclock. We show that many quantitative results can be read off a spacetime diagram by counting boxes, using a minimal amount of algebra.

  9. Rotating thin-shell wormhole

    NASA Astrophysics Data System (ADS)

    Ovgun, A.

    2016-11-01

    We construct a rotating thin-shell wormhole using a Myers-Perry black hole in five dimensions, using the Darmois-Israel junction conditions. The stability of the wormhole is analyzed under perturbations. We find that exotic matter is required at the throat of the wormhole to keep it stable. Our analysis shows that stability of the rotating thin-shell wormhole is possible if suitable parameter values are chosen.

  10. Doubly Rotated Cut SAW Devices.

    DTIC Science & Technology

    1981-04-01

    locating promising angular ranges with properties superior to the singly rotated cuts now in existence. More detailed calculations follow to refinethe...superior to the singly rotated cuts now in existence. More detailed calculations followed to refine the angular coordinates in order to specify cuts...correlation between theory and experiment, all procedures followed as well as equipment used are discussed in paragraph 4. Paragraph 5 presents experimental

  11. Rotating Shadowband Spectroradiometer (RSS) Handbook

    SciTech Connect

    Kiedron, P; Schlemmer, J; Klassen, M

    2005-01-01

    The rotating shawdowband spectroradiometer (RSS) implements the same automated shadowbanding technique used by the multifilter rotating shadowband radiometer (MFRSR), and so it too provides spectrally-resolved, direct-normal, diffuse-horizontal, and total-horizontal irradiances, and can be calibrated in situ via Langley regression. The irradiance spectra are measured simultaneously at all spectral elements (pixels) in 360-nm to 1050-nm range.

  12. Nonaxisymmetric oscillations of differentially rotating relativistic stars

    SciTech Connect

    Passamonti, Andrea; Stavridis, Adamantios; Kokkotas, Kostas D.

    2008-01-15

    Nonaxisymmetric oscillations of differentially rotating stars are studied using both slow rotation and Cowling approximation. The equilibrium stellar models are relativistic polytropes where differential rotation is described by the relativistic j-constant rotation law. The oscillation spectrum is studied versus three main parameters: the stellar compactness M/R, the degree of differential rotation A, and the number of maximum couplings l{sub max}. It is shown that the rotational splitting of the nonaxisymmetric modes are strongly enhanced by increasing the compactness of the star and the degree of differential rotation. Finally, we investigate the relation between the fundamental quadrupole mode and the corotation band of differentially rotating stars.

  13. SOLiD SAGE sequencing shows differential gene expression in jejunal lymph node samples of resistant and susceptible red deer (Cervus elaphus) challenged with Mycobacterium avium subsp. paratuberculosis.

    PubMed

    Mackintosh, C G; Griffin, J F T; Scott, I C; O'Brien, R; Stanton, J L; MacLean, P; Brauning, R

    2016-01-01

    and higher MAP numbers in lymph nodes of S animals. By week 50 the number of upregulated genes declined in both groups. A number of genes upregulated in R animals appear to be associated with host resistance and regulation of adaptive immunity, especially CEACAM8. Genes upregulated in S animals involve antigen presentation (ENDOD1) and gut associated immune pathology (HSH2D). In conclusion, gene expression in jejunal lymph nodes of resistant and susceptible deer infer that the resistant phenotype is associated with pathways of adaptive immunity, while susceptibility is linked with upregulated non-protective pro-inflammatory responses, following experimental MAP infection.

  14. The Rotation of Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    Tovmassian, H. M.

    2015-09-01

    The method for detection of the galaxy cluster rotation based on the study of distribution of member galaxies with velocities lower and higher than the cluster mean velocity over the cluster image is proposed. The search for rotation is made for flat clusters with a/b > 1.8 and BMI type clusters which are expected to be rotating. For comparison there were studied also round clusters and clusters of NBMI type, the second by brightness galaxy, which does not differ significantly from the cluster cD galaxy. Seventeen out of studied 65 clusters are found to be rotating. It was found that the detection rate is sufficiently high for flat clusters, over 60%, and clusters of BMI type with dominant cD galaxy, ≈ 35% . The obtained results show that clusters were formed from the huge primordial gas clouds and preserved the rotation of the primordial clouds, unless they did not experience mergings with other clusters and groups of galaxies, as a result of which the rotation was prevented.

  15. The rotation of magnetic grains

    NASA Astrophysics Data System (ADS)

    Borradaile, Graham J.

    1993-05-01

    It has been questioned whether magnetic remanence rotates as a rigid marker or as a passive marker (with no material properties) during tectonic strain. The remanence of a rock is actually the sum of the moments of individual grains, so we must first understand their rotation. Simple shear provides a simple strain history which may be used to distinguish between the two extreme possibilities. A passive marker cannot rotate through the shear plane but a rigid marker can: this is a useful criterion to distinguish between the two extreme models. However, for reasonable strains ( γ < 4 orRs < 18), it is only possible to distinguish between rigid marker and passive marker behaviour for grains of low aspect ratio ( R < 5), preferably making a low initial angle with the shear direction. For these conditions, rigid grains would rotate through the shear plane. Because natural hematite usually has high aspect ratios ( R > 10) the passive model is successful in explaining the rotation of these grains, even though their behaviour is mechanistically closer to that of a rigid marker. This explains the success of field studies in which the remanence of redbeds has been de-strained using the hypothesis of passive behaviour, notwithstanding the reality that the natural iron oxide grains do not rotate in that manner.

  16. Effects of Clinostat Rotation on Aurelia Statolith Synthesis

    NASA Technical Reports Server (NTRS)

    Spangenberg, Dorothy B.; Davis, S.; Ross-Clunis, H., III

    1991-01-01

    Aurelia ephyrae develop eight graviceptors (rhopalia) during their metamorphosis from polyps, which are used for positional orientation with respect to gravity. In three experiments for each speed of 1/15, 1/8, 1/2, 1, and 24 rpm, groups of six polyps were rotated in the horizontal or vertical plane (control) using clinostats. Other controls were kept stationary in the two planes. Ten ephyrae from each group were collected after 5 to 6 days at 27 C in iodine and the number of statoliths per rhopalium were counted. Statistical analyses of statolith numbers revealed that horizontal clinostat rotation at 1/4 and 1/2 rpm caused the formation of significantly fewer statoliths per rhopalium than were found in controls. The finding that these slow rates of rotation reduces statolith numbers suggests that the developing ephyrae were disoriented with respect to gravity at these speeds, causing fewer statocytes to differentiate or to mineralize.

  17. Effects of clinostat rotation on Aurelia statolith synthesis

    NASA Technical Reports Server (NTRS)

    Spangenberg, D.; Davis, S.; Ross-Clunis, H., III

    1985-01-01

    Aurelia ephyrae develop eight graviceptors (rhopalia) during their metamorphosis from polyps, which are used for positional orientation with respect to gravity. In three experiments for each speed of 1/15, 1/8, 1/4, 1/2, 1, and 24 rpm, groups of six polyps were rotated in the horizontal or vertical plane (control) using clinostats. Other controls were kept stationary in the two planes. Ten ephyrae from each group were collected after 5-6 days at 27 C in iodine and the number of statoliths per rhopalium were counted. Statistical analyses of statolith numbers revealed that horizontal clinostat rotation at 1/4 and 1/2 rpm caused the formation of significantly fewer statoliths per rhopalium than were found in controls. The finding that these slow rates of rotation reduces statolith numbers suggests that the developing ephyrae were disoriented with respect to gravity at these speeds, causing fewer statocytes to differentiate or to mineralize.

  18. On the influence of the rotation of a corner cube reflector in absolute gravimetry

    NASA Astrophysics Data System (ADS)

    Rothleitner, Ch; Francis, O.

    2010-10-01

    Test masses of absolute gravimeters contain prism or hollow retroreflectors. A rotation of such a retroreflector during free-fall can cause a bias in the measured g-value. In particular, prism retroreflectors produce phase shifts, which cannot be eliminated. Such an error is small if the rotation occurs about the optical centre of the retroreflector; however, under certain initial conditions the error can reach the microgal level. The contribution from these rotation-induced accelerations is calculated.

  19. Mental rotation and motor performance in children with developmental dyslexia.

    PubMed

    Kaltner, Sandra; Jansen, Petra

    2014-03-01

    . However, since the impairment of dyslexics regarding mental rotation performance is letter-specific and motor results show no differences between dyslexic and non-dyslexic children, further approaches next to the cerebellar deficit hypothesis must be taken into account, especially in consideration of the fact that there are a number of causes for the failure in reading.

  20. Fork rotation and DNA precatenation are restricted during DNA replication to prevent chromosomal instability.

    PubMed

    Schalbetter, Stephanie A; Mansoubi, Sahar; Chambers, Anna L; Downs, Jessica A; Baxter, Jonathan

    2015-08-18

    Faithful genome duplication and inheritance require the complete resolution of all intertwines within the parental DNA duplex. This is achieved by topoisomerase action ahead of the replication fork or by fork rotation and subsequent resolution of the DNA precatenation formed. Although fork rotation predominates at replication termination, in vitro studies have suggested that it also occurs frequently during elongation. However, the factors that influence fork rotation and how rotation and precatenation may influence other replication-associated processes are unknown. Here we analyze the causes and consequences of fork rotation in budding yeast. We find that fork rotation and precatenation preferentially occur in contexts that inhibit topoisomerase action ahead of the fork, including stable protein-DNA fragile sites and termination. However, generally, fork rotation and precatenation are actively inhibited by Timeless/Tof1 and Tipin/Csm3. In the absence of Tof1/Timeless, excessive fork rotation and precatenation cause extensive DNA damage following DNA replication. With Tof1, damage related to precatenation is focused on the fragile protein-DNA sites where fork rotation is induced. We conclude that although fork rotation and precatenation facilitate unwinding in hard-to-replicate contexts, they intrinsically disrupt normal chromosome duplication and are therefore restricted by Timeless/Tipin.

  1. Long-Period Tidal Variations of the Earth's Rotation Rate

    NASA Technical Reports Server (NTRS)

    Desai, S.; Gross, R.; Wahr, J.

    1999-01-01

    Long-period tidal variations of the Earth's rotation rate are caused by the redistribution of mass associated with the respective elastic solid Earth tides, the ocean tide heights, and the anelasticity of the Earth's mantle, and by the relative angular momentum associated with the long-period ocean tide currents.

  2. Rehabilitation after Rotator Cuff Repair

    PubMed Central

    Nikolaidou, Ourania; Migkou, Stefania; Karampalis, Christos

    2017-01-01

    Background: Rotator cuff tears are a very common condition that is often incapacitating. Whether non-surgical or surgical, successful management of rotator cuff disease is dependent on appropriate rehabilitation. If conservative management is insufficient, surgical repair is often indicated. Postsurgical outcomes for patients having had rotator cuff repair can be quite good. A successful outcome is much dependent on surgical technique as it is on rehabilitation. Numerous rehabilitation protocols for the management of rotator cuff disease are based primarily on clinical experience and expert opinion. This article describes the different rehabilitation protocols that aim to protect the repair in the immediate postoperative period, minimize postoperative stiffness and muscle atrophy. Methods: A review of currently available literature on rehabilitation after arthroscopic rotator cuff tear repair was performed to illustrate the available evidence behind various postoperative treatment modalities. Results: There were no statistically significant differences between a conservative and an accelerated rehabilitation protocol . Early passive range of motion (ROM) following arthroscopic cuff repair is thought to decrease postoperative stiffness and improve functionality. However, early aggressive rehabilitation may compromise repair integrity. Conclusion: The currently available literature did not identify any significant differences in functional outcomes and relative risks of re-tears between delayed and early motion in patients undergoing arthroscopic rotator cuff repairs. A gentle rehabilitation protocol with limits in range of motion and exercise times after arthroscopic rotator cuff repair would be better for tendon healing without taking any substantial risks. A close communication between the surgeon, the patient and the physical therapy team is important and should continue throughout the whole recovery process.

  3. A study of rotational velocity distribution of Be stars

    NASA Astrophysics Data System (ADS)

    Sitko, C.; Janot-Pacheco, E.; Emilio, M.

    2014-10-01

    Classical Be stars are rapid rotators of spectral type late O to early A and luminosity class V-III, which exhibit Balmer emission lines and often a near infrared excess originating in an equatorially concentrated circumstellar envelope, both produced by sporadic mass ejection episodes. The causes of the abnormal mass loss (the so-called Be phenomenon) are as yet unknown. In spite of their high vsin i, rapid rotation alone cannot explain the ejection episodes as most Be stars do not rotate at their critical rotation rates. In this work we present the distribution of vsin i of 261 Be's stars from BeSS (Be Star Spectra) database. We used two techniques, the Fourier method and the FWHM (Full Width at Half Maximum) method. For the analysis we made use of three absorption lines of Helium (4026r A, 4388 Å and 4471 Å). Stars with projected rotational velocities up to 300 km s^{-1} agree with the ones already published in the literature. 84 of our stars do not have the values of rotational velocity published. The majority of our sample are B1/B2 spectral type, whose have the greatest velocities.

  4. Rotational evolution of pre-main sequence stars in Lupus

    NASA Astrophysics Data System (ADS)

    Wichmann, R.; Bouvier, J.; Allain, S.; Krautter, J.

    1998-02-01

    We present results of a study of the rotational periods of Post-TTauri stars (PTTSs) in the Lupus star forming region. These stars have been discovered by spectroscopic follow-up observations of ROSAT x-ray sources. Photometric observations have allowed to determine their luminosity, and by comparison with theoretical evolutionary tracks they were found to be significantly older on average than typical TTauri stars. 46 stars have been monitored photometrically, and for 34 of them photometric variations were found that are consistent with rotational brightness modulations caused by starspots. The large number of data on rotational periods of pre-main-sequence (PMS) / zero-age main-sequence (ZAMS) stars available by now allows us to study the impact of stellar mass on the evolution of angular momentum. For several different mass bins, we compare the available data on rotational periods with theoretical models, and find good agreement between theory and observations for the mass-dependency of the pre-main-sequence evolution of angular momentum. We also study the relation between activity, rotation, mass, and age of low mass stars, and demonstrate that activity is driven by rotation mainly, while it seems to be rather independent of mass and age. Based on observations collected at European Southern Observatory, La Silla, Chile (observing proposals ESO No. 55.E-0575, 57.E-0250).

  5. Rotation and differential rotation of active Kepler stars

    NASA Astrophysics Data System (ADS)

    Reinhold, Timo; Reiners, Ansgar; Basri, Gibor

    2013-12-01

    Context. The Kepler space telescope monitors more than 160 000 stars with an unprecedented precision providing the opportunity to study the rotation of thousands of stars. Aims: We present rotation periods for thousands of active stars in the Kepler field derived from Q3 data. In most cases a second period close to the rotation period was detected that we interpreted as surface differential rotation (DR). We show how the absolute and relative shear (ΔΩ and α = ΔΩ/Ω, respectively) correlate with rotation period and effective temperature. Methods: Active stars were selected from the whole sample using the range of the variability amplitude. To detect different periods in the light curves we used the Lomb-Scargle periodogram in a pre-whitening approach to achieve parameters for a global sine fit. The most dominant periods from the fit were associated to different surface rotation periods. Our purely mathematical approach is capable of detecting different periods but cannot distinguish between the physical origins of periodicity. We ascribe the existence of different periods to DR, but spot evolution could also play a role. Because of the large number of stars the period errors are estimated statistically. We thus cannot exclude the existence of false positives among our periods. Results: In our sample of 40 661 active stars we found 24 124 rotation periods P1 between 0.5 and 45 days, with a mean of ⟨P1⟩ = 16.3 days. The distribution of stars with 0.5 < B - V < 1.0 and ages derived from angular momentum evolution that are younger than 300 Myr is consistent with a constant star-formation rate; the detection among older stars is incomplete probably because of our active sample selection. A second period P2 within ±30% of the rotation period P1 was found in 18 616 stars (77.2%). Attributing these two periods to DR we found that for active stars other than the Sun the relative shear α increases with rotation period, and slightly decreases with effective

  6. Submillimeter-Wave Rotational Spectra of DNC

    NASA Astrophysics Data System (ADS)

    Amano, T.

    2011-06-01

    Spectroscopic investigations of DNC have been less extensive than those for HNC. See Brünken et al. and Bechtel et al. for relevant references. In the present investigation, rotational transitions of DNC have been observed in the submillimeter-wave region in an extended negative glow discharge in a gas mixture of CD_4 and N_2. The dissociative recombination reaction of DCND^+ with electrons is thought to be a dominant channel to produce DNC in highly excited vibrational states; the rotational lines in levels up to (008) are observed. The rotational and centrifugal distortion constants are determined for these states along with those for the (100) state. The measurement accuracy is high enough to determine some higher order vibration-rotation interaction constants. The least-squares fits were straightforward except for (004), (006), and (008), where very small but significant perturbations were found. A striking isotope effect was observed on the vibrational temperature in this investigation. The vibrational temperature for the ν_3 mode for DNC is as high as 4000 K and the rotational transitions are observable in states up to (008), while the corresponding temperature is about 1500 K for HNC. The vibrational temperature for the ν_1 mode is about 1000 K for DNC and about 1300 K for HNC. The bending vibrational mode is not excited, and the vibrational temperature for the ν_2 mode is only about 400 K. The origin of this conspicuous excitation of the ν_3 mode of DNC is not obvious. However, it should be closely related to mechanism of the dissociation of HCNH and DCND. Apparently the difference in the masses of the departing H/D is a factor causing this difference, but the vibrational temperature for ν_3 of DCN is not particularly high, about 1000 K. When the D atom departs from the D-C side, apparently the C-N vibration is highly excited. On the other hand, when the D-N bond is broken, not much excitation of the C-N vibration occurs. S. Brünken, H. S. P. M

  7. The Dosimetric Impact of Prostate Rotations During Electromagnetically Guided External-Beam Radiation Therapy

    SciTech Connect

    Amro, Hanan; Hamstra, Daniel A.; Mcshan, Daniel L.; Sandler, Howard; Vineberg, Karen; Hadley, Scott; Litzenberg, Dale

    2013-01-01

    Purpose: To study the impact of daily rotations and translations of the prostate on dosimetric coverage during radiation therapy (RT). Methods and Materials: Real-time tracking data for 26 patients were obtained during RT. Intensity modulated radiation therapy plans meeting RTOG 0126 dosimetric criteria were created with 0-, 2-, 3-, and 5-mm planning target volume (PTV) margins. Daily translations and rotations were used to reconstruct prostate delivered dose from the planned dose. D{sub 95} and V{sub 79} were computed from the delivered dose to evaluate target coverage and the adequacy of PTV margins. Prostate equivalent rotation is a new metric introduced in this study to quantify prostate rotations by accounting for prostate shape and length of rotational lever arm. Results: Large variations in prostate delivered dose were seen among patients. Adequate target coverage was met in 39%, 65%, and 84% of the patients for plans with 2-, 3-, and 5-mm PTV margins, respectively. Although no correlations between prostate delivered dose and daily rotations were seen, the data showed a clear correlation with prostate equivalent rotation. Conclusions: Prostate rotations during RT could cause significant underdosing even if daily translations were managed. These rotations should be managed with rotational tolerances based on prostate equivalent rotations.

  8. Rapidly rotating neutron star progenitors

    NASA Astrophysics Data System (ADS)

    Postnov, K. A.; Kuranov, A. G.; Kolesnikov, D. A.; Popov, S. B.; Porayko, N. K.

    2016-12-01

    Rotating proto-neutron stars can be important sources of gravitational waves to be searched for by present-day and future interferometric detectors. It was demonstrated by Imshennik that in extreme cases the rapid rotation of a collapsing stellar core may lead to fission and formation of a binary proto-neutron star which subsequently merges due to gravitational wave emission. In this paper, we show that such dynamically unstable collapsing stellar cores may be the product of a former merger process of two stellar cores in a common envelope. We applied population synthesis calculations to assess the expected fraction of such rapidly rotating stellar cores which may lead to fission and formation of a pair of proto-neutron stars. We have used the BSE (Binary Star Evolution) population synthesis code supplemented with a new treatment of stellar core rotation during the evolution via effective core-envelope coupling, characterized by the coupling time, τc. The validity of this approach is checked by direct MESA calculations of the evolution of a rotating 15 M⊙ star. From comparison of the calculated spin distribution of young neutron stars with the observed one, reported by Popov and Turolla, we infer the value τc ≃ 5 × 105 yr. We show that merging of stellar cores in common envelopes can lead to collapses with dynamically unstable proto-neutron stars, with their formation rate being ˜0.1-1 per cent of the total core collapses, depending on the common envelope efficiency.

  9. Spline screw multiple rotations mechanism

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1993-01-01

    A system for coupling two bodies together and for transmitting torque from one body to another with mechanical timing and sequencing is reported. The mechanical timing and sequencing is handled so that the following criteria are met: (1) the bodies are handled in a safe manner and nothing floats loose in space, (2) electrical connectors are engaged as long as possible so that the internal processes can be monitored throughout by sensors, and (3) electrical and mechanical power and signals are coupled. The first body has a splined driver for providing the input torque. The second body has a threaded drive member capable of rotation and limited translation. The embedded drive member will mate with and fasten to the splined driver. The second body has an embedded bevel gear member capable of rotation and limited translation. This bevel gear member is coaxial with the threaded drive member. A compression spring provides a preload on the rotating threaded member, and a thrust bearing is used for limiting the translation of the bevel gear member so that when the bevel gear member reaches the upward limit of its translation the two bodies are fully coupled and the bevel gear member then rotates due to the input torque transmitted from the splined driver through the threaded drive member to the bevel gear member. An output bevel gear with an attached output drive shaft is embedded in the second body and meshes with the threaded rotating bevel gear member to transmit the input torque to the output drive shaft.

  10. Rotationally Molded Liquid Crystalline Polymers

    NASA Technical Reports Server (NTRS)

    Rogers, Martin; Scribben, Eric; Baird, Donald; Hulcher, Bruce

    2002-01-01

    Rotational molding is a unique process for producing hollow plastic parts. Rotational molding offers low cost tooling and can produce very large parts with complicated shapes. Products made by rotational molding include water tanks with capacities up to 20,000 gallons, truck bed liners, playground equipment, air ducts, Nylon fuel tanks, pipes, toys, stretchers, kayaks, pallets, and many others. Thermotropic liquid crystalline polymers are an important class of engineering resins employed in a wide variety of applications. Thermotropic liquid crystalline polymers resins are composed of semirigid, nearly linear polymeric chains resulting in an ordered mesomorphic phase between the crystalline solid and the isotropic liquid. Ordering of the rigid rod-like polymers in the melt phase yields microfibrous, self-reinforcing polymer structures with outstanding mechanical and thermal properties. Rotational molding of liquid crystalline polymer resins results in high strength and high temperature hollow structures useful in a variety of applications. Various fillers and reinforcements can potentially be added to improve properties of the hollow structures. This paper focuses on the process and properties of rotationally molded liquid crystalline polymers. This paper will also highlight the interactions between academia and small businesses in developing new products and processes.

  11. Rotationally Molded Liquid Crystalline Polymers

    NASA Technical Reports Server (NTRS)

    Rogers, Martin; Stevenson, Paige; Scribben, Eric; Baird, Donald; Hulcher, Bruce

    2002-01-01

    Rotational molding is a unique process for producing hollow plastic parts. Rotational molding offers advantages of low cost tooling and can produce very large parts with complicated shapes. Products made by rotational molding include water tanks with capacities up to 20,000 gallons, truck bed liners, playground equipment, air ducts, Nylon fuel tanks, pipes, toys, stretchers, kayaks, pallets, and many others. Thermotropic liquid crystalline polymers are an important class of engineering resins employed in a wide variety of applications. Thermotropic liquid crystalline polymers resins are composed of semi-rigid, nearly linear polymeric chains resulting in an ordered mesomorphic phase between the crystalline solid and the isotropic liquid. Ordering of the rigid rod-like polymers in the melt phase yields microfibrous, self-reinforcing polymer structures with outstanding mechanical and thermal properties. Rotational molding of liquid crystalline polymer resins results in high strength and high temperature hollow structures useful in a variety of applications. Various fillers and reinforcements can potentially be added to improve properties of the hollow structures. This paper focuses on the process and properties of rotationally molded liquid crystalline polymers.

  12. Rotationally Invariant Holographic Tracking System

    NASA Astrophysics Data System (ADS)

    Lambert, James L.; Chao, Tien-Hsin; Gheen, Gregory; Johnston, Alan R.; Liu, Hua-Kuang

    1989-06-01

    A multi-channel holographic correlator has been constructed which can identify and track objects of a given shape across the input field independent of their in-plane rotation. This system, derived from the classic Vander Lugt correlator, incorporates a hololens to store an array of matched spatial filters (MSFs) on thermoplastic film. Each member of the MSF array is generated from a different incrementally rotated version of the training object. Rotational invariant tracking is achieved through superposition of the corresponding array of the correlations in the output plane. Real time tracking is accomplished by utilizing a liquid crystal light valve (LCLV) illuminated with a CRT to process video input signals. The system can be programmed to recognize different objects by recording the MSF array on re-usable thermoplastic film. Discussion of the system architecture and laboratory results are presented.

  13. Wormhole shadows in rotating dust

    NASA Astrophysics Data System (ADS)

    Ohgami, Takayuki; Sakai, Nobuyuki

    2016-09-01

    As an extension of our previous work, which investigated the shadows of the Ellis wormhole surrounded by nonrotating dust, in this paper we study wormhole shadows in a rotating dust flow. First, we derive steady-state solutions of slowly rotating dust surrounding the wormhole by solving relativistic Euler equations. Solving null geodesic equations and radiation transfer equations, we investigate the images of the wormhole surrounded by dust for the above steady-state solutions. Because the Ellis wormhole spacetime possesses unstable circular orbits of photons, a bright ring appears in the image, just as in Schwarzschild spacetime. The bright ring looks distorted due to rotation. Aside from the bright ring, there appear weakly luminous complex patterns by the emission from the other side of the throat. These structure could be detected by high-resolution very-long-baseline-interferometry observations in the near future.

  14. Rotating Rayleigh-Taylor turbulence

    NASA Astrophysics Data System (ADS)

    Boffetta, G.; Mazzino, A.; Musacchio, S.

    2016-09-01

    The turbulent Rayleigh-Taylor system in a rotating reference frame is investigated by direct numerical simulations within the Oberbeck-Boussinesq approximation. On the basis of theoretical arguments, supported by our simulations, we show that the Rossby number decreases in time, and therefore the Coriolis force becomes more important as the system evolves and produces many effects on Rayleigh-Taylor turbulence. We find that rotation reduces the intensity of turbulent velocity fluctuations and therefore the growth rate of the temperature mixing layer. Moreover, in the presence of rotation the conversion of potential energy into turbulent kinetic energy is found to be less effective, and the efficiency of the heat transfer is reduced. Finally, during the evolution of the mixing layer we observe the development of a cyclone-anticyclone asymmetry.

  15. The rotational spectrum of tyrosine.

    PubMed

    Pérez, Cristóbal; Mata, Santiago; Cabezas, Carlos; López, Juan C; Alonso, José L

    2015-04-23

    In this work neutral tyrosine has been generated in the gas phase by laser ablation of solid samples, and its most abundant conformers characterized through their rotational spectra. Their identification has been made by comparison between the experimental and ab initio values of the rotational and quadrupole coupling constants. Both conformers are stabilized by an O-H•••N hydrogen bond established within the amino acid skeleton chain and an additional weak N-H•••π hydrogen bond. The observed conformers differ in the orientation of the phenolic -OH group.

  16. Vacuum Friction in Rotating Particles

    SciTech Connect

    Manjavacas, A.; Garcia de Abajo, F. J.

    2010-09-10

    We study the frictional torque acting on particles rotating in empty space. At zero temperature, vacuum friction transforms mechanical energy into light emission and produces particle heating. However, particle cooling relative to the environment occurs at finite temperatures and low rotation velocities. Radiation emission is boosted and its spectrum significantly departed from a hot-body emission profile as the velocity increases. Stopping times ranging from hours to billions of years are predicted for materials, particle sizes, and temperatures accessible to experiment. Implications for the behavior of cosmic dust are discussed.

  17. Butterflies with rotation and charge

    NASA Astrophysics Data System (ADS)

    Reynolds, Alan P.; Ross, Simon F.

    2016-11-01

    We explore the butterfly effect for black holes with rotation or charge. We perturb rotating BTZ and charged black holes in 2 + 1 dimensions by adding a small perturbation on one asymptotic region, described by a shock wave in the spacetime, and explore the effect of this shock wave on the length of geodesics through the wormhole and hence on correlation functions. We find the effect of the perturbation grows exponentially at a rate controlled by the temperature; dependence on the angular momentum or charge does not appear explicitly. We comment on issues affecting the extension to higher-dimensional charged black holes.

  18. Rotationally actuated prosthetic helping hand

    NASA Technical Reports Server (NTRS)

    Norton, William E. (Inventor); Belcher, Jewell G., Jr. (Inventor); Carden, James R. (Inventor); West, Thomas W. (Inventor)

    1991-01-01

    A prosthetic device has been developed for below-the-elbow amputees. The device consists of a cuff, a stem, a housing, two hook-like fingers, an elastic band for holding the fingers together, and a brace. The fingers are pivotally mounted on a housing that is secured to the amputee's upper arm with the brace. The stem, which also contains a cam, is rotationally mounted within the housing and is secured to the cuff, which fits over the amputee's stump. By rotating the cammed stem between the fingers with the lower arm, the amputee can open and close the fingers.

  19. Energy Transfer in Rotating Turbulence

    NASA Technical Reports Server (NTRS)

    Cambon, Claude; Mansour, Nagi N.; Godeferd, Fabien S.; Rai, Man Mohan (Technical Monitor)

    1995-01-01

    The influence or rotation on the spectral energy transfer of homogeneous turbulence is investigated in this paper. Given the fact that linear dynamics, e.g. the inertial waves regime tackled in an RDT (Rapid Distortion Theory) fashion, cannot Affect st homogeneous isotropic turbulent flow, the study of nonlinear dynamics is of prime importance in the case of rotating flows. Previous theoretical (including both weakly nonlinear and EDQNM theories), experimental and DNS (Direct Numerical Simulation) results are gathered here and compared in order to give a self-consistent picture of the nonlinear effects of rotation on tile turbulence. The inhibition of the energy cascade, which is linked to a reduction of the dissipation rate, is shown to be related to a damping due to rotation of the energy transfer. A model for this effect is quantified by a model equation for the derivative-skewness factor, which only involves a micro-Rossby number Ro(sup omega) = omega'/(2(OMEGA))-ratio of rms vorticity and background vorticity as the relevant rotation parameter, in accordance with DNS and EDQNM results fit addition, anisotropy is shown also to develop through nonlinear interactions modified by rotation, in an intermediate range of Rossby numbers (Ro(omega) = (omega)' and Ro(omega)w greater than 1), which is characterized by a marco-Rossby number Ro(sup L) less than 1 and Ro(omega) greater than 1 which is characterized by a macro-Rossby number based on an integral lengthscale L and the micro-Rossby number previously defined. This anisotropy is mainly an angular drain of spectral energy which tends to concentrate energy in tile wave-plane normal to the rotation axis, which is exactly both the slow and the two-dimensional manifold. In Addition, a polarization of the energy distribution in this slow 2D manifold enhances horizontal (normal to the rotation axis) velocity components, and underlies the anisotropic structure of the integral lengthscales. Finally is demonstrated the

  20. Vibration Problems of Rotating Machinery due to Coupling Misalignments

    DTIC Science & Technology

    1988-05-01

    These configurations can be seen in figures 2-4a and 2-4b. A rotor can be bowed for a variety of reasons. In steam turbines Improper heating or cooling of... rotor outside its design orbit can cause collision of close tolerance components as in the vanes of steam and gas turbines leading to total destruction...shaft bent such that the centroid of mass of the rotor does not lie on the axis of rotation is analytically the same as an unbalanced rotating disk

  1. Experimental and numerical investigation of energy dissipation in elastomeric rotational joint under harmonic loading

    NASA Astrophysics Data System (ADS)

    Jrad, Hanen; Dion, Jean Luc; Renaud, Franck; Tawfiq, Imad; Haddar, Mohamed

    2016-10-01

    This paper focuses on energy losses caused by inner damping and friction in an elastomeric rotational joint. A description of the design of a new experimental device intended to characterize dynamic stiffness in rotational elastomeric joint is presented. An original method based on Lagrange's equations, which allows accurately measuring forces and torques only with accelerometers, is proposed in order to identify dissipated energy in the rotational elastomeric joint. A rheological model developed taking into account dependence of the torque and the angular displacement (rotation). Experimental results and simulations used to quantify the dissipated energy in order to evaluate the damping ratio are presented and discussed.

  2. Rotational dynamics with geometric algebra

    NASA Technical Reports Server (NTRS)

    Hestenes, D.

    1983-01-01

    A new spinor formulation of rotational dynamics is developed. A general theorem is established reducing the theory of the symmetric top to that of the spherical top. The classical problems of Lagrange and Poinsot are treated in detail, along with a modern application to the theory of magnetic resonance.

  3. Hydrogen rotation-vibration oscillator

    DOEpatents

    Rhodes, C.K.

    1974-01-29

    A laser system is described wherein molecular species of hydrogen and hydrogen isotopes are induced to oscillate on rotational-vibrational levels by subjecting the hydrogen to a transverse beam of electrons of a narrowly defined energy between about 1 and 5 eV, thereby producing high intensity and high energy output. (Official Gazette)

  4. Rotating Cylinder Treatment System Demonstration

    EPA Science Inventory

    In August 2008, a rotating cylinder treatment system (RCTSTM) demonstration was conducted near Gladstone, CO. The RCTSTM is a novel technology developed to replace the aeration/oxidation and mixing components of a conventional lime precipitation treatment s...

  5. Repetition Blindness for Rotated Objects

    ERIC Educational Resources Information Center

    Hayward, William G.; Zhou, Guomei; Man, Wai-Fung; Harris, Irina M.

    2010-01-01

    Repetition blindness (RB) is the finding that observers often miss the repetition of an item within a rapid stream of words or objects. Recent studies have shown that RB for objects is largely unaffected by variations in viewpoint between the repeated items. In 5 experiments, we tested RB under different axes of rotation, with different types of…

  6. Rotations in a Vertebrate Setting

    NASA Astrophysics Data System (ADS)

    McCollum, Gin

    2003-05-01

    Rotational movements of the head are often considered to be measured in a single three dimensional coordinate system implemented by the semicircular canals of the vestibular system of the inner ear. However, the vertebrate body -- including the nervous system -- obeys rectangular symmetries alien to rotation groups. At best, nervous systems mimic the physical rotation group in a fragmented way, only partially reintegrating physical movements in whole organism responses. The vestibular canal reference frame is widely used in nervous systems, for example by eye movements. It is used to some extent even in the cerebrum, as evidenced by the remission of hemineglect -- in which half of space is ignored -- when the vestibular system is stimulated. However, reintegration of space by the organism remains incomplete. For example, compensatory eye movements (which in most cases aid visual fixation) may disagree with conscious self-motion perception. In addition, movement-induced nausea, illusions, and cue-free perceptions demonstrate symmetry breaking or incomplete spatial symmetries. As part of a long-term project to investigate rotation groups in nervous systems, we have analyzed the symmetry group of a primary vestibulo-spinal projection.

  7. An Assigned Teaching Resident Rotation

    ERIC Educational Resources Information Center

    Daniels-Brady, Catherine; Rieder, Ronald

    2010-01-01

    Objective: The authors' adult psychiatry residency training program identified several educational needs for residents at their institution. Junior residents needed enhanced learning of clinical interviewing skills and learning connected to the inpatient psychiatry ward rotations, and senior residents needed opportunities to prepare for the…

  8. Meniscus Stability in Rotating Systems

    NASA Astrophysics Data System (ADS)

    Reichel, Yvonne; Dreyer, Michael

    2013-11-01

    In this study, the stability of free surfaces of fluid between two rotating coaxial, circular disks is examined. Radially mounted baffles are used to form menisci of equal size. To the center of the upper disk, a tube is connected in which a separate meniscus is formed. Assuming solid-body rotation and ignoring dynamic effects, it is observed that the free surfaces between the disks fail to remain stable once the rotation speed exceeds a critical value. In other words, Rayleigh-Taylor instability ensues when the capillary forces fail to balance centrifugal forces. Dimensionless critical rotation speeds are studied by means of the Surface Evolver via SE-FIT for varied number of baffles, the normalized distance between the disks, and the normalized central tube radius. Drop tower tests are performed to confirm some of the numerical results. The computation also reveals that there are different modes of instability as a function of the relevant parameters. This study was funded by the space agency of the German Aerospace Center with resources of the Federal Ministry of Economics and Technology on the basis of a resolution of the German Bundestag under grant number 50 RL 1320.

  9. Holder for rotating glass body

    DOEpatents

    Kolleck, Floyd W.

    1978-04-04

    A device is provided for holding and centering a rotating glass body such as a rod or tube. The device includes a tubular tip holder which may be held in a lathe chuck. The device can utilize a variety of centering tips each adapted for a particular configuration, such as a glass O-ring joint or semi-ball joint.

  10. Rotating drum variable depth sampler

    DOEpatents

    Nance, Thomas A.; Steeper, Timothy J.

    2008-07-01

    A sampling device for collecting depth-specific samples in silt, sludge and granular media has three chambers separated by a pair of iris valves. Rotation of the middle chamber closes the valves and isolates a sample in a middle chamber.

  11. Rotation and inversion in nitrosamines

    NASA Astrophysics Data System (ADS)

    Kirste, Karl; Rademacher, Paul

    1981-04-01

    Geometry optimizations of the ground states as well as of the transition states for internal rotation and inversion have been performed by the semiempirical MNDO method for dimethyl nitrosamine (1), perfluordimethyl nitrosamine (2), N-nitroso aziridine (3), and N-nitroso azetidine (4). It was found that the potential barrier to internal rotation about the N-N bond is always of lower energy than that to inversion on the nitroso nitrogen. While the ground states tend to adopt structures which enable mesomerism, the lowest transition state is characterized by a pyramidal sp3-hybridized amino nitrogen. In accordance with experimental results the low barriers to rotation of 2 (7.96 kcal mol -1), 3 (3.38 kcal mol -1) and 4 (9.97 kcal mol -1) in comparison with 1 (12.54 kcal mol -1) indicate that in donor-acceptor molecules the transfer of charge can be limited by electronic and stereochemical effects. In particular, the equivalence of the α-methylene hydrogens which was observed in the NMR-spectrum of 3 is due to unhindered rotation and ring inveirsion.

  12. Turbulent Flow Between Rotating Cylinders

    NASA Technical Reports Server (NTRS)

    Shih-I, Pai

    1943-01-01

    The turbulent air flow between rotating cylinders was investigated. The distributions of mean speed and of turbulence were measured in the gap between a rotating inner and a stationary outer cylinder. The measurements led to the conclusion that the turbulent flow in the gap cannot be considered two dimensional, but that a particular type of secondary motion takes place. It is shown that the experimentally found velocity distribution can be fully understood under the assumption that this secondary motion consists of three-dimensional ring-shape vortices. The vortices occur only in pairs, and their number and size depend on the speed of the rotating cylinder; the number was found to decrease with increasing speed. The secondary motion has an essential part in the transmission of the moment of momentum. In regions where the secondary motion is negligible, the momentum transfer follows the laws known for homologous turbulence. Ring-shape vortices are known to occur in the laminar flow between rotating cylinders, but it was hitherto unknown that they exist even at speeds that are several hundred times the critical limit.

  13. Polarization Properties of Rotation Powered Pulsars

    NASA Technical Reports Server (NTRS)

    Harding Alice K.

    2009-01-01

    Polarization measurements of rotation-powered pulsars and their nebulae have unique diagnostic potential. The polarization position angle of the pulsar wind nebula, as is know for the Crab pulsar, can tell us the orientation of the spin axis. Phase-resolved polarimetry of pulsars has had enormous diagnostic capability at radio and optical wavelengths and could also be a powerful diagnostic in the X-ray range. Measurement of the polarization properties as a function of pulse phase can therefore provide a multidimensional mapping of the pulsar emission. In the 'rotating vector' model, radiation originating near a magnetic pole is expected to show a characteristic S-shaped swing of the position angle vs. pulse phase. In this case it is possible to determine the magnetic inclination and viewing angles. Radiation originating further from the poles or further above the neutron star surface will have a more complex polarization signature, as a result of relativistic effects of aberration and time-of-flight delays and may also cause depolarization of the signal. I will discuss predicted polarization properties of pulsed emission in polar cap models, where radiation originates near the neutron star surface at the magnetic poles, and in slot gap and outer gap models, where radiation originates over a range of altitudes out to the speed-of-light cylinder.

  14. Optimal rotation sequences for active perception

    NASA Astrophysics Data System (ADS)

    Nakath, David; Rachuy, Carsten; Clemens, Joachim; Schill, Kerstin

    2016-05-01

    One major objective of autonomous systems navigating in dynamic environments is gathering information needed for self localization, decision making, and path planning. To account for this, such systems are usually equipped with multiple types of sensors. As these sensors often have a limited field of view and a fixed orientation, the task of active perception breaks down to the problem of calculating alignment sequences which maximize the information gain regarding expected measurements. Action sequences that rotate the system according to the calculated optimal patterns then have to be generated. In this paper we present an approach for calculating these sequences for an autonomous system equipped with multiple sensors. We use a particle filter for multi- sensor fusion and state estimation. The planning task is modeled as a Markov decision process (MDP), where the system decides in each step, what actions to perform next. The optimal control policy, which provides the best action depending on the current estimated state, maximizes the expected cumulative reward. The latter is computed from the expected information gain of all sensors over time using value iteration. The algorithm is applied to a manifold representation of the joint space of rotation and time. We show the performance of the approach in a spacecraft navigation scenario where the information gain is changing over time, caused by the dynamic environment and the continuous movement of the spacecraft

  15. Climate model studies of synchronously rotating planets.

    PubMed

    Joshi, Manoj

    2003-01-01

    M stars constitute 75% of main sequence stars though, until recently, their star systems have not been considered suitable places for habitable planets to exist. In this study the climate of a synchronously rotating planet around an M dwarf star is evaluated using a three-dimensional global atmospheric circulation model. The presence of clouds and evaporative cooling at the surface of the planet result in a cooler surface temperature at the subsolar point. Water ice forms at the polar regions and on the dark side, where the minimum temperature lies between -30 degrees C and 0 degrees C. As expected, rainfall is extremely high on the starlit side and extremely low on the dark side. The presence of a dry continent causes higher temperatures on the dayside, and allows accumulation of snow on the nightside. The absence of any oceans leads to higher day-night temperature differences, consistent with previous work. The present study reinforces recent conclusions that synchronously rotating planets within the circumstellar habitable zones of M dwarf stars should be habitable, and therefore M dwarf systems should not be excluded in future searches for exoplanets.

  16. Effect of rotating earth for AOTV analysis

    NASA Astrophysics Data System (ADS)

    Ikawa, H.

    The Aeroassisted Orbit Transfer Vehicle (AOTV) operates in the endo/exoatmosphere. Exoatmospheric flight phase is dictated only by the inertial properties. In endoatmospheric flight phase, the trajectory is also shaped by the inertial velocity. However, the aerodynamic maneuver that causes the trajectory perturbation is controlled by the relative velocity. For example, along the equatorial flight path: (1) the velocity difference between the inertial and the relative reference frames represents 5 to 7 percent of the entry velocity; (2) the dynamic pressure difference becomes 10 to 14 percent, which is significant in evaluating the proper atmospheric flight maneuver; (3) in consequence, exit errors that are induced at the edge of the sensible atmosphere produce significant deviation in the final orbit transfer. The possible errors affecting AOTV analyses conducted by neglecting the earth's rotation are discussed. The control laws using the shallow glide path ascent and the constant altitude glide trajectories in the atmosphere, with the required pull-up maneuver, are also demonstrated. Conclusions are: (1) AOTV analyses using the stationary earth assumption tend to underpredict the final LEO altitude and to overpredict the orbital inclination change, and (2) effects of the rotating earth cannot be ignored for realistic AOTV simulations.

  17. Intramolecular electron arrangement with a rotative trigger.

    PubMed

    Kume, Shoko; Nomoto, Kuniharu; Kusamoto, Tetsuro; Nishihara, Hiroshi

    2009-10-14

    We have constructed a single molecule system, consisting of a ferrocene-tethered copper complex, in which electron transfer between redox centers is triggered by molecular rotational motion. In the compound, an asymmetric methyl-substituted 2,2'-pyridylpyrimidine ligand, tethered to the ferrocene moiety, has two isomeric ring-inversion coordination conformations around the copper center. Both isomeric structures were characterized by X-ray crystallography. (1)H NMR and electrochemical measurements revealed that these isomers interconvert through rotation of the pyrimidine at room temperature, but the process is frozen below 233 K in the solution state. The two isomers undergo different redox processes, and the identity of the first oxidation center alternates between the copper center and ferrocene, as confirmed by chemical oxidation monitored by EPR and UV-vis absorption spectroscopy. Oxidation of the compound causes spontaneous isomerization of the pyrimidine due to the different relative stabilities of the isomers in the monovalent and divalent states. Oxidation in the motionless state at low temperatures extracts the first electron from the ferrocene center. When molecular motion is released by warming, the electron moves from the copper center to the ferrocene, leading to an enhancement of the copper(II) signal in the EPR spectrum. The synchronized motion/electron migration process was observed as a one-step UV-vis absorption spectral conversion.

  18. On possible interconnections between Climate Change and Earth rotation

    NASA Astrophysics Data System (ADS)

    Zotov, Leonid; Christian, Bizouard; Sidorenkov, Nikolay

    The question of interconnections between rotation of the Earth and Climate Change raised more, then 30 years ago. In Lambeck’s, Sidorenkov’s and others books the correlation between the secular changes of temperature and rotation velocity of the Earth was found. Since Climate Change brings to the redistribution of water and ice mass, ocean currents and atmospheric circulation, it also influences the angular momentum and moment of inertia of the Earth system, what causes variations in its rotation. We present the results of analysis of global temperature, sea level, Chandler wobble, atmospheric winds, and length of day (LOD) changes with arguments testifying possible interrelations between these processes and their dependence on space factors.

  19. Effect of Spacecraft Rotation on Fluid Convection Under Microgravity

    NASA Technical Reports Server (NTRS)

    Yuferev, Valentin S.; Kolesnikova, Elvira N.; Polovko, Yuri A.; Zhmakin, Alexander I.

    1996-01-01

    The influence of the rotational effects on two-dimensional fluid convection in a rectangular enclosure with rigid walls during the orbital flight is considered. It is shown that the Coriolis force influence both on steady and oscillatory convection becomes significant at Ekman numbers which are quite attainable in the space orbital conditions. In the case of harmonic oscillations of the gravity force appearance of the resonance phenomena is demonstrated. Dependence of the height and shape of the resonance peak on aspect ratio of a rectangular domain and orientation of vectors of the gravity force and the angular rotation velocity is studied. Special attention is given to non-linear effects caused by convective terms of Navier-Stokes equations. The convection produced by variations of the angular rotation velocity of a spacecraft is also discussed. It is shown that in some cases the latter convection can be comparable with another kinds of convection.

  20. Rotational motion of traveling spots in dissipative systems.

    PubMed

    Teramoto, Takashi; Suzuki, Katsuya; Nishiura, Yasumasa

    2009-10-01

    What is the origin of rotational motion? An answer is presented through the study of the dynamics for spatially localized spots near codimension 2 singularity consisting of drift and peanut instabilities. The drift instability causes a head-tail asymmetry in spot shape, and the peanut one implies a deformation from circular to peanut shape. Rotational motion of spots can be produced by combining these instabilities in a class of three-component reaction-diffusion systems. Partial differential equations dynamics can be reduced to a finite-dimensional one by projecting it to slow modes. Such a reduction clarifies the bifurcational origin of rotational motion of traveling spots in two dimensions in close analogy to the normal form of 1:2 mode interactions.

  1. Rapid rotation and mixing in active OB stars - Physical processes

    NASA Astrophysics Data System (ADS)

    Zahn, Jean-Paul

    2011-07-01

    In the standard description of stellar interiors, O and B stars possess a thoroughly mixed convective core surrounded by a stable radiative envelope in which no mixing occurs. But as is well known, this model disagrees strongly with the spectroscopic diagnostic of these stars, which reveals the presence at their surface of chemical elements that have been synthesized in the core. Hence the radiation zone must be the seat of some mild mixing mechanisms. The most likely to operate there are linked with the rotation: these are the shear instabilites triggered by the differential rotation, and the meridional circulation caused by the changes in the rotation profile accompanying the non-homologous evolution of the star. In addition to these hydrodynamical processes, magnetic stresses may play an important role in active stars, which host a magnetic field. These physical processes will be critically examined, together with some others that have been suggested.

  2. Modeling brain injury response for rotational velocities of varying directions and magnitudes.

    PubMed

    Weaver, Ashley A; Danelson, Kerry A; Stitzel, Joel D

    2012-09-01

    An estimated 1.7 million people in the United States sustain a traumatic brain injury (TBI) annually. To investigate the effects of rotational motions on TBI risk and location, this study modeled rotational velocities of five magnitudes and 26 directions of rotation using the Simulated Injury Monitor finite element brain model. The volume fraction of the total brain exceeding a predetermined strain threshold, the Cumulative Strain Damage Measure (CSDM), was investigated to evaluate global model response. To evaluate regional response, this metric was computed relative to individual brain structures and termed the Structure Cumulative Strain Damage Measure (SCSDM). CSDM increased as input magnitude increased and varied with the direction of rotation. CSDM was 0.55-1.7 times larger in simulations with transverse plane rotation compared to those without transverse plane rotation. The largest SCSDM in the cerebrum and brainstem occurred with rotations in the transverse and sagittal planes, respectively. Velocities causing medial rotation of the cerebellum resulted in the largest SCSDM in this structure. For velocities of the same magnitude, injury risk calculated from CSDM varied from 0 to 97% with variations in the direction of rotation. These findings demonstrate injury risk, as estimated by CSDM and SCSDM, is affected by the direction of rotation and input magnitude, and these may be important considerations for injury prediction.

  3. Effects of electron-cyclotron-resonance-heating-induced internal kink mode on the toroidal rotation in the KSTAR Tokamak.

    PubMed

    Seol, J; Lee, S G; Park, B H; Lee, H H; Terzolo, L; Shaing, K C; You, K I; Yun, G S; Kim, C C; Lee, K D; Ko, W H; Kwak, J G; Kim, W C; Oh, Y K; Kim, J Y; Kim, S S; Ida, K

    2012-11-09

    It is observed that the magnitude of the toroidal rotation speed is reduced by the central electron cyclotron resonance heating (ECRH) regardless of the direction of the toroidal rotation. The magnetohydrodynamics activities generally appear with the rotation change due to ECRH. It is shown that the internal kink mode is induced by the central ECRH and breaks the toroidal symmetry. When the magnetohydrodynamics activities are present, the toroidal plasma viscosity is not negligible. The observed effects of ECRH on the toroidal plasma rotation are explained by the neoclassical toroidal viscosity in this Letter. It is found that the neoclassical toroidal viscosity torque caused by the internal kink mode damps the toroidal rotation.

  4. Particle motion and Penrose processes around rotating regular black hole

    NASA Astrophysics Data System (ADS)

    Abdujabbarov, Ahmadjon

    2016-07-01

    The neutral particle motion around rotating regular black hole that was derived from the Ayón-Beato-García (ABG) black hole solution by the Newman-Janis algorithm in the preceding paper (Toshmatov et al., Phys. Rev. D, 89:104017, 2014) has been studied. The dependencies of the ISCO (innermost stable circular orbits along geodesics) and unstable orbits on the value of the electric charge of the rotating regular black hole have been shown. Energy extraction from the rotating regular black hole through various processes has been examined. We have found expression of the center of mass energy for the colliding neutral particles coming from infinity, based on the BSW (Baňados-Silk-West) mechanism. The electric charge Q of rotating regular black hole decreases the potential of the gravitational field as compared to the Kerr black hole and the particles demonstrate less bound energy at the circular geodesics. This causes an increase of efficiency of the energy extraction through BSW process in the presence of the electric charge Q from rotating regular black hole. Furthermore, we have studied the particle emission due to the BSW effect assuming that two neutral particles collide near the horizon of the rotating regular extremal black hole and produce another two particles. We have shown that efficiency of the energy extraction is less than the value 146.6 % being valid for the Kerr black hole. It has been also demonstrated that the efficiency of the energy extraction from the rotating regular black hole via the Penrose process decreases with the increase of the electric charge Q and is smaller in comparison to 20.7 % which is the value for the extreme Kerr black hole with the specific angular momentum a= M.

  5. The effect of shoulder manipulation on rotator cuff integrity.

    PubMed

    Atoun, Ehud; Funk, Lennard; Copland, Stephen A; Even, Tirtza; Levy, Ofer; Rath, Ehud

    2013-06-01

    The use of shoulder manipulation in the treatment of frozen shoulder remains controversial. Humeral fractures and neurological damage are the risks associated with the procedure. A concern of causing a rotator cuff tear exists but the incidence of iatrogenic rotator cuff tears is not reported. The purpose of this study was to assess the effect of shoulder manipulation for frozen shoulder on the integrity of the rotator cuff. In a prospective study, 32 consecutive patients (33 shoulders) with the diagnosis of frozen shoulder underwent manipulation of the shoulder under anaesthesia (MUA), 18 female and 15 males with mean age at manipulation of 503 years (range: 42-63). The average duration of symptoms before treatment was 6.2 months (range: 2-18 months). The patients were examined prior to the manipulation and at follow-up for combined shoulder range of motion, external and internal rotation and strength. All patients had an ultrasound assessment of the rotator cuff before and at 3 weeks after manipulation of the shoulder. Mean time between manipulation and last follow-up was 133 weeks. None of the patients had ultrasound findings of a rotator cuff tear, prior to the manipulation. In all patients the rotator cuff remained undamaged on ultrasound examination at 3 weeks after the procedure. The mean improvement in motion was 81.2 degrees (from 933 degrees pre-op to 174.5 degrees at last follow-up) for forward flexion; 102.6 degrees (from 68.8 degrees pre-op to 171.4 degrees at last follow-up) for abduction, 49.4 degrees (from 8.8 degrees pre-op to 58.2 degrees at last follow-up) for external rotation and 3.5 levels of internal rotation (range: 2 to 5 levels). These gains in motion were all highly significant (p < 0.0001). No fractures, dislocations or nerve palsies were observed. In this study, manipulation of the shoulder has not been associated with rotator cuff tears. If done properly the procedure appeared to be safe and to result in a marked improvement of range

  6. Physiological and Pathological Responses to Head Rotations in Toddler Piglets

    PubMed Central

    Ibrahim, Nicole G.; Ralston, Jill; Smith, Colin

    2010-01-01

    Abstract Closed head injury is the leading cause of death in children less than 4 years of age, and is thought to be caused in part by rotational inertial motion of the brain. Injury patterns associated with inertial rotations are not well understood in the pediatric population. To characterize the physiological and pathological responses of the immature brain to inertial forces and their relationship to neurological development, toddler-age (4-week-old) piglets were subjected to a single non-impact head rotation at either low (31.6 ± 4.7 rad/sec2, n = 4) or moderate (61.0 ± 7.5 rad/sec2, n = 6) angular acceleration in the axial direction. Graded outcomes were observed for both physiological and histopathological responses such that increasing angular acceleration and velocity produced more severe responses. Unlike low-acceleration rotations, moderate-acceleration rotations produced marked EEG amplitude suppression immediately post-injury, which remained suppressed for the 6-h survival period. In addition, significantly more severe subarachnoid hemorrhage, ischemia, and axonal injury by β-amyloid precursor protein (β-APP) were observed in moderate-acceleration animals than low-acceleration animals. When compared to infant-age (5-day-old) animals subjected to similar (54.1 ± 9.6 rad/sec2) acceleration rotations, 4-week-old moderate-acceleration animals sustained similar severities of subarachnoid hemorrhage and axonal injury at 6 h post-injury, despite the larger, softer brain in the older piglets. We conclude that the traditional mechanical engineering approach of scaling by brain mass and stiffness cannot explain the vulnerability of the infant brain to acceleration-deceleration movements, compared with the toddler. PMID:20560753

  7. Wave-Driven Rotation In Centrifugal Mirrors

    SciTech Connect

    Abraham J. Fetterman and Nathaniel J. Fisch

    2011-03-28

    Centrifugal mirrors use supersonic rotation to provide axial confinement and enhanced stability. Usually the rotation is produced using electrodes, but these electrodes have limited the rotation to the Alfven critical ionization velocity, which is too slow to be useful for fusion. Instead, the rotation could be produced using radio frequency waves. A fixed azimuthal ripple is a simple and efficient wave that could produce rotation by harnessing alpha particle energy. This is an extension of the alpha channeling effect. The alpha particle power and efficiency in a simulated devices is sufficient to produce rotation without external energy input. By eliminating the need for electrodes, this opens new opportunities for centrifugal traps.

  8. Rotatable non-circular forebody flow controller

    NASA Technical Reports Server (NTRS)

    Moskovitz, Cary A. (Inventor)

    1991-01-01

    The invention is a rotatable, non-circular forebody flow controller. The apparatus comprises a small geometric device located at a nose of a forebody of an aircraft and a non-circular cross-sectional area that extends toward the apex of the aircraft. The device is symmetrical about a reference plane and preferably attaches to an axle which in turn attaches to a rotating motor. The motor rotates the device about an axis of rotation. Preferably, a control unit connected to an aircraft flight control computer signals to the rotating motor the proper rotational positioning of the geometric device.

  9. Torque requirement of rotating rods in airflow

    NASA Technical Reports Server (NTRS)

    Barna, P. S.; Crossman, G. R.

    1979-01-01

    Experiments were performed to determine the torque required for rotating a rotor disk fitted with a number of radially arranged rods placed into a ducted airflow. An array of stationary rods, also radially arranged, was placed upstream close to the rotor with a small gap between the rods to cause wake interference. The results show that torque generally increased with airflow and the rate of increase varied considerably. At lower values of airflow, the rate of increase was larger than at higher airflow, and definite torque peaks occurred at certain airflow rates, where the torque attained a maximum within the test airflow range. During the test, a maximum blade passage frequency of 2037 Hz was attained. The results also show that the torque peaks occurred at the same Strouhal number for all speeds.

  10. Rapidly rotating polytropes in general relativity

    NASA Technical Reports Server (NTRS)

    Cook, Gregory B.; Shapiro, Stuart L.; Teukolsky, Saul A.

    1994-01-01

    We construct an extensive set of equilibrium sequences of rotating polytropes in general relativity. We determine a number of important physical parameters of such stars, including maximum mass and maximum spin rate. The stability of the configurations against quasi-radial perturbations is diagnosed. Two classes of evolutionary sequences of fixed rest mass and entropy are explored: normal sequences which behave very much like Newtonian evolutionary sequences, and supramassive sequences which exist solely because of relativistic effects. Dissipation leading to loss of angular momentum causes a star to evolve in a quasi-stationary fashion along an evolutionary sequence. Supramassive sequences evolve towards eventual catastrophic collapse to a black hole. Prior to collapse, the star must spin up as it loses angular momentum, an effect which may provide an observational precursor to gravitational collapse to a black hole.

  11. Adiabatic rotation of effective spin. II. Spin-rotational relaxation

    NASA Astrophysics Data System (ADS)

    Serebrennikov, Yu. A.; Steiner, U. E.

    1994-05-01

    The theory of electron spin-rotational (SR) relaxation in systems with an effective spin Seff=1/2 is formulated in terms of the adiabatic rotation of effective spin (ARES) approach. It is shown that SR relaxation results from the orientational random walk of the axes of the intramolecular electric field potential (ligand field) to which a spin-bearing atomic center is exposed. The validity of the stochastic treatment presented here is not limited by the Redfield conditions. The general expression obtained for the time constant of electron spin relaxation in liquid phase reproduces the well-known result of Hubbard-Atkins-Kivelson theory if it is specialized to the case of systems with weak spin-orbit coupling.

  12. Piezoelectric Vibration Damping Study for Rotating Composite Fan Blades

    NASA Technical Reports Server (NTRS)

    Min, James B.; Duffy, Kirsten P.; Choi, Benjamin B.; Provenza, Andrew J.; Kray, Nicholas

    2012-01-01

    Resonant vibrations of aircraft engine blades cause blade fatigue problems in engines, which can lead to thicker and aerodynamically lower performing blade designs, increasing engine weight, fuel burn, and maintenance costs. In order to mitigate undesirable blade vibration levels, active piezoelectric vibration control has been investigated, potentially enabling thinner blade designs for higher performing blades and minimizing blade fatigue problems. While the piezoelectric damping idea has been investigated by other researchers over the years, very little study has been done including rotational effects. The present study attempts to fill this void. The particular objectives of this study were: (a) to develop and analyze a multiphysics piezoelectric finite element composite blade model for harmonic forced vibration response analysis coupled with a tuned RLC circuit for rotating engine blade conditions, (b) to validate a numerical model with experimental test data, and (c) to achieve a cost-effective numerical modeling capability which enables simulation of rotating blades within the NASA Glenn Research Center (GRC) Dynamic Spin Rig Facility. A numerical and experimental study for rotating piezoelectric composite subscale fan blades was performed. It was also proved that the proposed numerical method is feasible and effective when applied to the rotating blade base excitation model. The experimental test and multiphysics finite element modeling technique described in this paper show that piezoelectric vibration damping can significantly reduce vibrations of aircraft engine composite fan blades.

  13. Passive stiffness of coupled wrist and forearm rotations.

    PubMed

    Drake, Will B; Charles, Steven K

    2014-09-01

    Coordinated movement requires that the neuromuscular system account and compensate for movement dynamics. One particularly complex aspect of movement dynamics is the interaction that occurs between degrees of freedom (DOF), which may be caused by inertia, damping, and/or stiffness. During wrist rotations, the two DOF of the wrist (flexion-extension and radial-ulnar deviation, FE and RUD) are coupled through interaction torques arising from passive joint stiffness. One important unanswered question is whether the DOF of the forearm (pronation-supination, PS) is coupled to the two DOF of the wrist. Answering this question, and understanding the dynamics of wrist and forearm rotations in general, requires knowledge of the stiffness encountered during rotations involving all three DOF (PS, FE, and RUD). Here we present the first-ever measurement of the passive stiffness encountered during simultaneous wrist and forearm rotations. Using a wrist and forearm robot, we measured coupled wrist and forearm stiffness in 10 subjects and present it as a 3-by-3 stiffness matrix. This measurement of passive wrist and forearm stiffness will enable future studies investigating the dynamics of wrist and forearm rotations, exposing the dynamics for which the neuromuscular system must plan and compensate during movements involving the wrist and forearm.

  14. Rotational viscometer for high-pressure, high-temperature fluids

    DOEpatents

    Carr, K.R.

    1983-06-06

    The invention is a novel rotational viscometer which is well adapted for use with fluids at high temperatures and/or pressures. In one embodiment, the viscometer include a substantially non-magnetic tube having a closed end and having an open end in communication with a fluid whose viscosity is to be determined. An annular drive magnet is mounted for rotation about the tube. The tube encompasses and supports a rotatable shaft assembly which carries a rotor, or bob, for insertion in the fluid. Affixed to the shaft are (a) a second magnet which is magnetically coupled to the drive magnet and (b) a third magnet. In a typical operation, the drive magnet is rotated to turn the shaft assembly while the shaft rotor is immersed in the fluid. The viscous drag on the rotor causes the shaft assembly to lag the rotation of the drive magnet by an amount which is a function of the amount of viscous drag. A first magnetic pickup generates a waveform whose phase is a function of the angular position of the drive magnet. A second magnetic pickup generates a waveform whose phase is a function of the angular position of the third magnet. Means are provided to generate an output indicative of the phase difference between the two waveforms. The viscometer is comparatively simple, inexpensive, rugged, and does not require shaft seals.

  15. Radial velocity planet detection biases at the stellar rotational period

    NASA Astrophysics Data System (ADS)

    Vanderburg, Andrew; Plavchan, Peter; Johnson, John Asher; Ciardi, David R.; Swift, Jonathan; Kane, Stephen R.

    2016-07-01

    Future generations of precise radial velocity (RV) surveys aim to achieve sensitivity sufficient to detect Earth mass planets orbiting in their stars' habitable zones. A major obstacle to this goal is astrophysical RV noise caused by active areas moving across the stellar limb as a star rotates. In this paper, we quantify how stellar activity impacts exoplanet detection with radial velocities as a function of orbital and stellar rotational periods. We perform data-driven simulations of how stellar rotation affects planet detectability and compile and present relations for the typical time-scale and amplitude of stellar RV noise as a function of stellar mass. We show that the characteristic time-scales of quasi-periodic RV jitter from stellar rotational modulations coincides with the orbital period of habitable-zone exoplanets around early M-dwarfs. These coincident periods underscore the importance of monitoring the targets of RV habitable-zone planet surveys through simultaneous photometric measurements for determining rotation periods and activity signals, and mitigating activity signals using spectroscopic indicators and/or RV measurements at different wavelengths.

  16. JET ROTATION DRIVEN BY MAGNETOHYDRODYNAMIC SHOCKS IN HELICAL MAGNETIC FIELDS

    SciTech Connect

    Fendt, Christian

    2011-08-10

    In this paper, we present a detailed numerical investigation of the hypothesis that a rotation of astrophysical jets can be caused by magnetohydrodynamic (MHD) shocks in a helical magnetic field. Shock compression of the helical magnetic field results in a toroidal Lorentz force component that will accelerate the jet material in the toroidal direction. This process transforms magnetic angular momentum (magnetic stress) carried along the jet into kinetic angular momentum (rotation). The mechanism proposed here only works in a helical magnetic field configuration. We demonstrate the feasibility of this mechanism by axisymmetric MHD simulations in 1.5 and 2.5 dimensions using the PLUTO code. In our setup, the jet is injected into the ambient gas with zero kinetic angular momentum (no rotation). We apply different dynamical parameters for jet propagation such as the jet internal Alfven Mach number and fast magnetosonic Mach number, the density contrast of the jet to the ambient medium, and the external sonic Mach number of the jet. The mechanism we suggest should work for a variety of jet applications, e.g., protostellar or extragalactic jets, and internal jet shocks (jet knots) or external shocks between the jet and the ambient gas (entrainment). For typical parameter values for protostellar jets, the numerically derived rotation feature looks consistent with the observations, i.e., rotational velocities of 0.1%-1% of the jet bulk velocity.

  17. Anomalous Faraday rotation in the ISM/ICM

    NASA Astrophysics Data System (ADS)

    Medvedev, Mikhail V.

    2016-10-01

    Faraday effect is a common and useful way to deduce cosmic magnetic fields in the interstellar and intracluster media (ISM and ICM). Faraday rotation is the result of magnetically-induced birefringence in a dielectric medium causing a linearly polarized wave to suffer a rotation of its polarization axis as it traverses such a medium. However, the standard λ2-law of the rotation angle may not hold in strongly turbulent plasmas. Electromagnetic high-frequency and/or small-scale fluctuations may lead to effective collisionality with the pitch-angle diffusion coefficient being an effective ``quasi-collision'' frequency. Recently, we showed that quasi-collisionality may radically alter radiative transport properties of plasmas, such as absorption, transmission and reflection and other effects, which can be very important in laboratory and astrophysical plasmas. Here we briefly discuss the quasi-collisional generalization of the classical Faraday effect, which is drastically modified and can even become negative. Furthermore, we explore the origin of the long-known anomaly of Faraday rotation in a famous Cygnus regions. We argue that the anomaly can be due to the anomalous Faraday rotation in a thin ``blanket'' of turbulent plasma at the front of an interstellar bubble/shock. Supported by KU CLAS and DOE Grant ID0000225143 (07/01/16).

  18. Conversion of rotational output to linear force-a transmission

    SciTech Connect

    Montalbano, P.J.

    1991-08-27

    This patent describes a transmission device for converting rotational torque into linear force. It comprises a combination large internally toothed annular gear and large flywheel rotatable within a housing by bearing means, in operative interconnection with a small externally toothed circular gear mounted within it annulus and provided with a source of variable rotary motion for driving the annular gear, a second large internally toothed annular gear, located above the first the annular gear, rotatable within a housing by bearing means and provided with a clutch connection to first annular gear, is in operative connection with three small externally toothed circular gears driven by the second annular gear, a member pivotably supported along the axis of the annular gear and rockable on the axis, the member having an upper and a lower arm, the upper arm in interconnection with two of the respective gears and the lower arm in interconnection with one of the respective gears, the gears driven by the second annular gear, in upper arm the gears causing the rocker element to move two off- centered weights, the first weight rotatable with one of the gears, the second weight rotatable in the opposite direction and mounted within the rocker element driven by an additional small externally toothed circular gear in mesh with one of the small gears, the weights generating centrifugal forces.

  19. Convection in the tanks of a rotating spacecraft

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A general study of convection and mixing of a stratified fluid in a rotating container is described, with application to the special problem of fluid heating and convection in a spacecraft tank. The analysis was based on a set of approximate equations for the Navier-Stokes description of fluid convection with small density variations in a rotating system, including effects of body forces due to temperature stratification (caused by a heater) and arbitrary time-dependent rotation of the tank about a noncentral axis. An efficient numerical finite difference scheme and computational method are described for the convection of vorticity and energy in a two-dimensional tank. Special procedures were developed for analysis of the thermodynamic states resulting from the approximate flow equations derived for small density variations. Results of the numerical simulation are presented for studying the effectiveness of rotation maneuvers in mixing stratified oxygen in the tanks of an Apollo spacecraft. Significant effects of the rotation maneuvers are discussed, including the reduction of the potential for pressure collapse.

  20. Rotational viscometer for high-pressure high-temperature fluids

    DOEpatents

    Carr, Kenneth R.

    1985-01-01

    The invention is a novel rotational viscometer which is well adapted for use with fluids at high temperatures and/or pressures. In one embodiment, the viscometer includes a substantially non-magnetic tube having a closed end and having an open end in communication with a fluid whose viscosity is to be determined. An annular drive magnet is mounted for rotation about the tube. The tube encompasses and supports a rotatable shaft assembly which carries a rotor, or bob, for insertion in the fluid. Affixed to the shaft are (a) a second magnet which is magnetically coupled to the drive magnet and (b) a third magnet. In a typical operation, the drive magnet is rotated to turn the shaft assembly while the shaft rotor is immersed in the fluid. The viscous drag on the rotor causes the shaft assembly to lag the rotation of the drive magnet by an amount which is a function of the amount of viscous drag. A first magnetic pickup generates a waveform whose phase is a function of the angular position of the drive magnet. A second magnetic pickup generates a waveform whose phase is a function of the angular position of the third magnet. An output is generated indicative of the phase difference between the two waveforms.

  1. Reduction of Sample Rotation in Electrostatic Levitation

    NASA Technical Reports Server (NTRS)

    Hyers, R. W; Johnson, W. L.; Savage, L.; Rogers, J. R.

    2000-01-01

    In many containerless processing systems, control of sample rotation is an important issue. Sample rotation is even more important for microgravity containerless processing systems, where the centrifugal acceleration can approach 1 g for even a small rotation rate. Prior work on rotation control by Rhim focused on driving the sample rotation at a controlled rate for droplet dynamics experiments and measurement of electrical conductivity. His technique allows controlled, fast rotation, but for many microgravity experiments the goal is zero rotation. To minimize sample rotation, two approaches are apparent: first, to identify and balance or eliminate the driving forces for undesired sample rotation, or second, implement a feedback-based rotation control loop in parallel with the position control loop. In this work, we have taken the first approach. To minimize sample rotation, the simplest approach is to identify and balance or eliminate the driving forces for undesired sample rotation. Our experiments show that the dominant driving force for rotation of machined Zr spheres in the MSFC ESL is photon pressure from the heating laser. Experimental results showing the correlation between heating power and torque are compared to theoretical predictions, and a strategy for minimizing the torque due to photon pressure is presented.

  2. [Sources of error in sonographic diagnosis of the rotator cuff].

    PubMed

    Casser, H R; Sulimma, H; Straub, A; Paus, R

    1991-12-01

    Sonography of the shoulder joint has developed into an established examination technique in the diagnosis of periarticular lesions of the shoulder. Sonographic diagnosis of the rotator cuff in particular contains a multitude of possible errors, which are gone into by this study by means of 149 clinically, radiologically and sonographically examined shoulder patients with an average age of 50.5 years. Besides errors made by wrong examination technique such of the transducer as incorrect adjustment of the equipment, insufficient contact of the transducer with the skin and unsuitable choice of the examination plane, there are sources of errors in the interpretation of the sonogram caused by lack of knowledge about physically caused artifacts and sonoanatomical qualities of the shoulder joint. Calcification inside the rotator cuff and the so-called "sonographic inhomogeneity of the rotator cuff" are numbered among the sources of error particular to the shoulder joint. Most errors in sonographic diagnosis of the rotator cuff can be avoided by careful examination of both shoulder joints with an exactly tuned ultrasound device, taking into account the sonoanatomical and ultrasonic qualities. Radiological examination of the affected shoulder joint cannot be replaced by ultrasound.

  3. Determination Method of Bridge Rotation Angle Response Using MEMS IMU.

    PubMed

    Sekiya, Hidehiko; Kinomoto, Takeshi; Miki, Chitoshi

    2016-11-09

    To implement steel bridge maintenance, especially that related to fatigue damage, it is important to monitor bridge deformations under traffic conditions. Bridges deform and rotate differently under traffic load conditions because their structures differ in terms of length and flexibility. Such monitoring enables the identification of the cause of stress concentrations that cause fatigue damage and the proposal of appropriate countermeasures. However, although bridge deformation monitoring requires observations of bridge angle response as well as the bridge displacement response, measuring the rotation angle response of a bridge subject to traffic loads is difficult. Theoretically, the rotation angle response can be calculated by integrating the angular velocity, but for field measurements of actual in-service bridges, estimating the necessary boundary conditions would be difficult due to traffic-induced vibration. To solve the problem, this paper proposes a method for determining the rotation angle response of an in-service bridge from its angular velocity, as measured by a inertial measurement unit (IMU). To verify our proposed method, field measurements were conducted using nine micro-electrical mechanical systems (MEMS) IMUs and two contact displacement gauges. The results showed that our proposed method provided high accuracy when compared to the reference responses calculated by the contact displacement gauges.

  4. Determination Method of Bridge Rotation Angle Response Using MEMS IMU

    PubMed Central

    Sekiya, Hidehiko; Kinomoto, Takeshi; Miki, Chitoshi

    2016-01-01

    To implement steel bridge maintenance, especially that related to fatigue damage, it is important to monitor bridge deformations under traffic conditions. Bridges deform and rotate differently under traffic load conditions because their structures differ in terms of length and flexibility. Such monitoring enables the identification of the cause of stress concentrations that cause fatigue damage and the proposal of appropriate countermeasures. However, although bridge deformation monitoring requires observations of bridge angle response as well as the bridge displacement response, measuring the rotation angle response of a bridge subject to traffic loads is difficult. Theoretically, the rotation angle response can be calculated by integrating the angular velocity, but for field measurements of actual in-service bridges, estimating the necessary boundary conditions would be difficult due to traffic-induced vibration. To solve the problem, this paper proposes a method for determining the rotation angle response of an in-service bridge from its angular velocity, as measured by a inertial measurement unit (IMU). To verify our proposed method, field measurements were conducted using nine micro-electrical mechanical systems (MEMS) IMUs and two contact displacement gauges. The results showed that our proposed method provided high accuracy when compared to the reference responses calculated by the contact displacement gauges. PMID:27834871

  5. Characterization of the rotating display.

    PubMed

    Keyes, J W; Fahey, F H; Harkness, B A; Eggli, D F; Balseiro, J; Ziessman, H A

    1988-09-01

    The rotating display is a useful method for reviewing single photon emission computed tomography (SPECT) data. This study evaluated the requirements for a subjectively pleasing and useful implementation of this technique. Twelve SPECT data sets were modified and viewed by several observers who recorded the minimum framing rates for apparent smooth rotation, 3D effect, effects of image size, and other parameters. The results showed that a minimum of 16 frames was needed for a useful display. Smaller image sizes and more frames were preferred. The recommended minimal framing rate for a 64-frame study is 16-17 frames per second and for a 32-frame study, 12-13 frames per second. Other enhancements also were useful.

  6. Tidal variations of earth rotation

    NASA Technical Reports Server (NTRS)

    Yoder, C. F.; Williams, J. G.; Parke, M. E.

    1981-01-01

    The periodic variations of the earths' rotation resulting from the tidal deformation of the earth by the sun and moon were rederived including terms with amplitudes of 0.002 millisec and greater. The series applies to the mantle, crust, and oceans which rotate together for characteristic tidal periods; the scaling parameter is the ratio of the fraction of the Love number producing tidal variations in the moment of inertia of the coupled mantle and oceans (k) to the dimensionless polar moment of inertia of the coupled moments (C). The lunar laser ranging data shows that k/C at monthly and fortnightly frequencies equals 0.99 + or - 0.15 and 0.99 + or - 0.20 as compared to the theoretical value of 0.94 + or - 0.04.

  7. Slowly rotating homogeneous masses revisited

    NASA Astrophysics Data System (ADS)

    Reina, Borja

    2016-02-01

    Hartle's model for slowly rotating stars has been extensively used to compute equilibrium configurations of slowly rotating stars to second order in perturbation theory in general relativity, given a barotropic equation of state. A recent study based on the modern theory of perturbed matchings concludes that the functions in the (first and second order) perturbation tensors can always be taken as continuous at the surface of the star, except for the second-order function m0. This function presents a jump at the surface of the star proportional to the discontinuity of the energy density there. This concerns only a particular outcome of the model: the change in mass δM. In this paper, the amended change in mass is calculated for the case of constant density stars.

  8. Faraday rotation system. Topical report

    SciTech Connect

    Bauman, L.E.; Wang, W.

    1994-07-01

    The Faraday Rotation System (FRS) is one of the advanced laser-based diagnostics developed at DIAL to provide support for the demonstration of prototype-scale coal-fired combustion magnetohydrodynamic (MHD) electrical power generation. Intended for application in the MHD channel, the system directly measures electron density through a measurement of the induced rotation in the polarization of a far infrared laser beam after passing through the MHD flow along the magnetic field lines. A measurement of the induced polarization ellipticity provides a measure of the electron collision frequency which together with the electron density gives the electron conductivity, a crucial parameter for MHD channel performance. The theory of the measurements, a description of the system, its capabilities, laboratory demonstration measurements on seeded flames with comparison to emission absorption measurements, and the current status of the system are presented in this final report.

  9. The chaotic rotation of Hyperion

    NASA Technical Reports Server (NTRS)

    Wisdom, J.; Peale, S. J.; Mignard, F.

    1984-01-01

    Under the assumption that the satellite is rotating about a principal axis that is normal to its orbit plane, a plot of spin rate-versus-orientation for Hyperion at the pericenter of its orbit has revealed a large, chaotic zone surrounding Hyperion's synchronous spin-orbit state. The chaotic zone is so large that it surrounds the 1/2 and 2 states, and libration in the 3/2 state is not possible. Rotation in the chaotic zone is also attitude-unstable. As tidal dissipation drives Hyperion's spin toward a nearly synchronous value, Hyperion necessarily enters the large chaotic zone, becoming attitude-unstable and tumbling. It is therefore predicted that Hyperion will be found to be tumbling chaotically.

  10. Rotation sensing with trapped ions

    NASA Astrophysics Data System (ADS)

    Campbell, W. C.; Hamilton, P.

    2017-03-01

    We present a protocol for rotation measurement via matter-wave Sagnac interferometry using trapped ions. The ion trap based interferometer encloses a large area in a compact apparatus through repeated round-trips in a Sagnac geometry. We show how a uniform magnetic field can be used to close the interferometer over a large dynamic range in rotation speed and measurement bandwidth without contrast loss. Since this technique does not require the ions to be confined in the Lamb–Dicke regime, Doppler laser cooling should be sufficient to reach a sensitivity of { S }=1.4× {10}-6 {{rad}} {{{s}}}-1 {{{H}}{{z}}}-1/2. , which features invited work from the best early-career researchers working within the scope of J. Phys. B. This project is part of the Journal of Physics series’ 50th anniversary celebrations in 2017. Wes Campbell was selected by the Editorial Board of J. Phys. B as an Emerging Leader.

  11. Charged rotating dilaton black strings

    SciTech Connect

    Dehghani, M.H.; Farhangkhah, N.

    2005-02-15

    In this paper we, first, present a class of charged rotating solutions in four-dimensional Einstein-Maxwell-dilaton gravity with zero and Liouville-type potentials. We find that these solutions can present a black hole/string with two regular horizons, an extreme black hole or a naked singularity provided the parameters of the solutions are chosen suitable. We also compute the conserved and thermodynamic quantities, and show that they satisfy the first law of thermodynamics. Second, we obtain the (n+1)-dimensional rotating solutions in Einstein-dilaton gravity with Liouville-type potential. We find that these solutions can present black branes, naked singularities or spacetimes with cosmological horizon if one chooses the parameters of the solutions correctly. Again, we find that the thermodynamic quantities of these solutions satisfy the first law of thermodynamics.

  12. Translation and rotation positioning motor

    DOEpatents

    Schmid, Andreas; Schaff, Oliver

    2006-07-04

    A positioning device provides the capability of moving an object in both a linear and a rotational direction. The positioning device includes a first piezo stack with plural piezo plates that are capable of movement in orthogonal directions with respect to each other. The positioning device further includes a second piezo stack with plural piezo plates that are capable of movement in orthogonal directions with respect to each other. The positioning device also includes a first bearing that is disposed against the first piezo stack. The positioning device further includes a second bearing that is disposed against the second piezo stack. The positioning device also includes a spring element and a fifth bearing that is disposed against the spring element. The first through fifth bearings are disposed around and against the object to be positioned, to provide for positioning of the object in at least one of a linear direction and a rotational direction.

  13. Translation and rotation positioning motor

    DOEpatents

    Schmid, Andreas; Schaff, Oliver

    2005-02-01

    A positioning device provides the capability of moving an object in both a linear and a rotational direction. The positioning device includes a first piezo stack with plural piezo plates that are capable of movement in orthogonal directions with respect to each other. The positioning device further includes a second piezo stack with plural piezo plates that are capable of movement in orthogonal directions with respect to each other. The positioning device also includes a first bearing that is disposed against the first piezo stack. The positioning device further includes a second bearing that is disposed against the second piezo stack. The positioning device also includes a spring element and a fifth bearing that is disposed against the spring element. The first through fifth bearings are disposed around and against the object to be positioned, to provide for positioning of the object in at least one of a linear direction and a rotational direction.

  14. Rotating concave eddy current probe

    DOEpatents

    Roach, Dennis P.; Walkington, Phil; Rackow, Kirk A.; Hohman, Ed

    2008-04-01

    A rotating concave eddy current probe for detecting fatigue cracks hidden from view underneath the head of a raised head fastener, such as a buttonhead-type rivet, used to join together structural skins, such as aluminum aircraft skins. The probe has a recessed concave dimple in its bottom surface that closely conforms to the shape of the raised head. The concave dimple holds the probe in good alignment on top of the rivet while the probe is rotated around the rivet's centerline. One or more magnetic coils are rigidly embedded within the probe's cylindrical body, which is made of a non-conducting material. This design overcomes the inspection impediment associated with widely varying conductivity in fastened joints.

  15. SEG Advances in Rotational Seismic Measurements

    SciTech Connect

    Pierson, Robert; Laughlin, Darren; Brune, Bob

    2016-10-17

    Significant advancements in the development of sensors to enable rotational seismic measurements have been achieved. Prototypes are available now to support experiments that help validate the utility of rotational seismic measurements.

  16. Earth Rotation Parameters from DSN VLBI: 1994

    NASA Technical Reports Server (NTRS)

    Steppe, J. A.; Oliveau, S. H.; Sovers, O. J.

    1994-01-01

    In this report, Earth Rotation Parameter (ERP) estimates ahve been obtained from an analysis of Deep Space Network (DSN) VLBI data that directly aligns its celestial and terrestrial reference frames with those of the International Earth Rotation Service (IERS).

  17. On the Addition of Planar Rotations

    ERIC Educational Resources Information Center

    Maor, Eli

    1974-01-01

    An interpretation of the transformation formulas for rotations in a plane in terms of the exponential function is given. Addition of two rotations is shown to correspond to the multiplication of the two corresponding matrices. (Author/LS)

  18. Operating characteristics of rotating beds

    SciTech Connect

    Keyvani, M.; Gardner, N.C.

    1988-01-01

    Vapor-liquid contacting in high gravitational fields offers prospects for significant reductions in the physical size, capital, and operating costs of packed towers. Pressure drops, power requirements, mass transfer coefficients and liquid residence time distributions are reported for a rotating bed separator. The beds studied were rigid, foamed aluminum, with specific surface areas ranging from 650 to 3000 m{sup 2}/m{sup 2}. Gravitational fields were varied from 50 to 300g.

  19. Muon spin rotation in solids

    NASA Technical Reports Server (NTRS)

    Stronach, C. E.

    1983-01-01

    The muon spin rotation (MuSR) technique is used to probe the microscopic electron density in materials. High temperature MuSR and magnetization measurements in nickel are in progress to allow an unambiguous determination of the muon impurity interaction and the impurity induced change in local spin density. The first results on uniaxial stress induced frequency shifts in an Fe single crystal are also reported.

  20. Rotation of a Moonless Earth

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Barnes, Jason W.; Chambers, John E.

    2013-01-01

    We numerically explore the obliquity (axial tilt) variations of a hypothetical moonless Earth. Previous work has shown that the Earth's Moon stabilizes Earth's obliquity such that it remains within a narrow range, between 22.1 deg and 24.5 deg. Without lunar influence, a frequency-map analysis by Laskar et al. showed that the obliquity could vary between 0 deg. and 85 deg. This has left an impression in the astrobiology community that a large moon is necessary to maintain a habitable climate on an Earth-like planet. Using a modified version of the orbital integrator mercury, we calculate the obliquity evolution for moonless Earths with various initial conditions for up to 4 Gyr. We find that while obliquity varies significantly more than that of the actual Earth over 100,000 year timescales, the obliquity remains within a constrained range, typically 20-25 deg. in extent, for timescales of hundreds of millions of years. None of our Solar System integrations in which planetary orbits behave in a typical manner show obliquity accessing more than 65% of the full range allowed by frequency-map analysis. The obliquities of moonless Earths that rotate in the retrograde direction are more stable than those of pro-grade rotators. The total obliquity range explored for moonless Earths with rotation periods shorter than 12 h is much less than that for slower-rotating moonless Earths. A large moon thus does not seem to be needed to stabilize the obliquity of an Earth-like planet on timescales relevant to the development of advanced life.