WorldWideScience

Sample records for axis vegf-flt-1 fms-like

  1. Gamma-linolenic acid inhibits both tumour cell cycle progression and angiogenesis in the orthotopic C6 glioma model through changes in VEGF, Flt1, ERK1/2, MMP2, cyclin D1, pRb, p53 and p27 protein expression

    Directory of Open Access Journals (Sweden)

    Colquhoun Alison

    2009-03-01

    expression of VEGF, Flt1, ERK1, ERK2, MMP2, Cyclin D1, pRb, p53 and p27. Combination therapy using drugs with other, complementary targets and GLA could lead to gains in treatment efficacy in this notoriously difficult to treat tumour.

  2. Removal of Soluble Fms-Like Tyrosine Kinase-1 by Dextran Sulfate Apheresis in Preeclampsia.

    Science.gov (United States)

    Thadhani, Ravi; Hagmann, Henning; Schaarschmidt, Wiebke; Roth, Bernhard; Cingoez, Tuelay; Karumanchi, S Ananth; Wenger, Julia; Lucchesi, Kathryn J; Tamez, Hector; Lindner, Tom; Fridman, Alexander; Thome, Ulrich; Kribs, Angela; Danner, Marco; Hamacher, Stefanie; Mallmann, Peter; Stepan, Holger; Benzing, Thomas

    2016-03-01

    Preeclampsia is a devastating complication of pregnancy. Soluble Fms-like tyrosine kinase-1 (sFlt-1) is an antiangiogenic protein believed to mediate the signs and symptoms of preeclampsia. We conducted an open pilot study to evaluate the safety and potential efficacy of therapeutic apheresis with a plasma-specific dextran sulfate column to remove circulating sFlt-1 in 11 pregnant women (20-38 years of age) with very preterm preeclampsia (23-32 weeks of gestation, systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg, new onset protein/creatinine ratio >0.30 g/g, and sFlt-1/placental growth factor ratio >85). We evaluated the extent of sFlt-1 removal, proteinuria reduction, pregnancy continuation, and neonatal and fetal safety of apheresis after one (n=6), two (n=4), or three (n=1) apheresis treatments. Mean sFlt-1 levels were reduced by 18% (range 7%-28%) with concomitant reductions of 44% in protein/creatinine ratios. Pregnancy continued for 8 days (range 2-11) and 15 days (range 11-21) in women treated once and multiple times, respectively, compared with 3 days (range 0-14) in untreated contemporaneous preeclampsia controls (n=22). Transient maternal BP reduction during apheresis was managed by withholding pre-apheresis antihypertensive therapy, saline prehydration, and reducing blood flow through the apheresis column. Compared with infants born prematurely to untreated women with and without preeclampsia (n=22 per group), no adverse effects of apheresis were observed. In conclusion, therapeutic apheresis reduced circulating sFlt-1 and proteinuria in women with very preterm preeclampsia and appeared to prolong pregnancy without major adverse maternal or fetal consequences. A controlled trial is warranted to confirm these findings.

  3. Alteration and potential role of soluble fms-like tyrosine kinase receptor 1 in preeclampsia

    Institute of Scientific and Technical Information of China (English)

    LI Yi; LI Dong-hong; YAO Yuan-qing; ZHAO Hong-xi; ZHANG Chun-li; HUANG Liang

    2005-01-01

    Objective:To investigate the alteration of serum soluble fms-like tyrosine kinase receptor 1 (sFlt-1), the possible cause in preeclampsia, the relationship between altered sFlt-1 and the development of pregnancy. Methods: Semi-quantitative RT-PCR was carried out to detect the level of sFlt-1 mRNA in placental tissue of 10 preeclampsia (study group) and 10 normotensive pregnancies (control group); ELISA was used to detect the serum level of sFlt-1 in peripheral venous blood and uterine venous blood in control group (n=35) and study group (n=35), and furthermore to detect the volume of peripheral venous blood sFlt-1 in early, middle and later pregnancies. Results: sFlt-1 mRNA of placental tissue was significantly higher in preeclampsia than that in normal pregnancy. The serum level of sFlt-1 of peripheral vein in preeclampsia was higher than that in normal pregnancy ([ 5639.6±3190.5] pg/ml vs[ 2194.4±635.8 ] pg/ml, P<0.01) , so did the serum sFlt-1 of uterine vein in preeclampsia and control group ([7673.3±2295.8] pg/ml vs[ 3056.6±784.6] pg/ml, P<0.01), indicating that the volume of sFlt-1 of uterine vein blood was significantly higher than that of peripheral venous blood (P<0.01). The serum level of sFlt-1 in early, middle and later pregnancy were (31.7±19.6) pg/ml (n=10), (994.0±302.1) pg/ml (n=10), (2194.4±635.8) pg/ml (n=35), respectively, showing that the level of sFlt-1 in peripheral venous blood increasingly elevated with the development of pregnancy (P<0.01). Conclusion: Preeclampsia is associated with increased level of sFlt-1 which might be largely from placenta during pregnancy.

  4. Clonal evolution of AML on novel FMS-like tyrosine kinase-3 (FLT3 inhibitor therapy with evolving actionable targets

    Directory of Open Access Journals (Sweden)

    Pashtoon M. Kasi

    2016-01-01

    Full Text Available For acute myeloid leukemia (AML, identification of activating mutations in the FMS-like tyrosine kinase-3 (FLT3 has led to the development of several FLT3-inhibitors. Here we present clinical and next generation sequencing data at the time of progression of a patient on a novel FLT3-inhibitor clinical trial (ASP2215 to show that employing therapeutic interventions with these novel targeted therapies can lead to consequences secondary to selective pressure and clonal evolution of cancer. We describe novel findings alongside data on treatment directed towards actionable aberrations acquired during the process. (Clinical Trial: NCT02014558; registered at: 〈https://clinicaltrials.gov/ct2/show/NCT02014558〉

  5. Case of soluble fms-like tyrosine kinase 1 apheresis in severe pre-eclampsia developed at 15 weeks' gestation.

    Science.gov (United States)

    Nakakita, Baku; Mogami, Haruta; Kondoh, Eiji; Tsukamoto, Tatsuo; Yanagita, Motoko; Konishi, Ikuo

    2015-10-01

    Soluble fms-like tyrosine kinase-1 (sFlt1), a circulating vascular endothelial growth factor receptor 1 antagonist, is associated with the pathogenesis of pre-eclampsia. Extracorporeal removal of sFlt1 (sFlt1 apheresis) is emerging as a treatment for pre-eclampsia. We performed sFlt1 apheresis for a patient with very early onset pre-eclampsia, beginning at 15 weeks' gestation. She underwent sFlt1 apheresis 13 times from 19 to 23 weeks' gestation. The series of treatments lowered circulating sFlt1, stabilized blood pressure, reduced urinary protein, and preserved renal function, which contributed to a successful prolongation of pregnancy for 4 weeks and a live birth at 23(+3) weeks' gestation. Further studies are necessary for clinical application of sFlt1 apheresis as sFlt1 might have a protective function for the placenta and fetus in pre-eclampsia.

  6. Increased serum levels of anti-angiogenic factors soluble fms-like tyrosine kinase and soluble endoglin in sickle cell disease

    NARCIS (Netherlands)

    Landburg, P.P.; Elsenga, H.; Schnog, J.B.; Duits, A.J.

    2008-01-01

    The anti-angiogenic factors soluble fms-like tyrosine kinase (sFlt)-1 and soluble endoglin (sEng) have been shown to be of importance in angiogenesis by sequestering and inhibiting vascular endothelial growth factor, placenta-like growth factor and transforming growth factor-beta(1) signaling. Given

  7. Serum Soluble Fms-Like Tyrosine Kinase 1 (sFlt-1) Predicts the Severity of Acute Pancreatitis

    Science.gov (United States)

    Dumnicka, Paulina; Sporek, Mateusz; Mazur-Laskowska, Małgorzata; Ceranowicz, Piotr; Kuźniewski, Marek; Drożdż, Ryszard; Ambroży, Tadeusz; Olszanecki, Rafał; Kuśnierz-Cabala, Beata

    2016-01-01

    Organ failure is the most important determinant of the severity of acute pancreatitis (AP). Soluble fms-like tyrosine kinase 1 (sFlt-1) is positively associated with organ failure in sepsis. Our aim was to evaluate the diagnostic utility of automated sFlt-1 measurements for early prediction of AP severity. Adult patients (66) with AP were recruited, including 46 with mild (MAP), 15 with moderately-severe (MSAP) and 5 with severe AP (SAP). Serum and urine samples were collected twice. Serum sFlt-1 was measured with automated electrochemiluminescence immunoassay. Serum concentrations of sFlt-1 were significantly higher in patients with MSAP and SAP as compared to MAP. SAP patients had the highest concentrations. At 24 and 48 h, sFlt-1 positively correlated with inflammatory markers (leukocyte count, C-reactive protein), kidney function (creatinine, urea, cystatin C, serum and urine neutrophil gelatinase-associated lipocalin, urine albumin/creatinine ratio), D-dimer and angiopoietin-2. sFlt-1 positively correlated with the bedside index of severity in AP (BISAP) score and the duration of hospital stay. Serum sFlt-1 above 139 pg/mL predicted more severe AP (MSAP + SAP). In the early phase of AP, sFlt-1 is positively associated with the severity of AP and predicts organ failure, in particular kidney failure. Serum sFlt-1 may be a practical way to improve early assessment of AP severity. PMID:27929426

  8. Evaluation of placental growth factor and soluble Fms-like tyrosine kinase 1 as predictors of all-cause and cardiovascular mortality in patients with Type 1 diabetes with and without diabetic nephropathy

    DEFF Research Database (Denmark)

    Theilade, S; Lajer, Maria Stenkil; Jorsal, Anders;

    2012-01-01

    Placental growth factor is a vascular endothelial growth factor involved in angiogenesis, vascular inflammation and plaque formation. Soluble Fms-like tyrosine kinase 1 is a decoy receptor for placental growth factor, reducing its activity. The aim of this study is to evaluate the predictive valu...... of placental growth factor and soluble Fms-like tyrosine kinase 1 in relation to all-cause and cardiovascular mortality and decline in kidney function in Type 1 diabetes....

  9. Murine germinal center B cells require functional Fms-like tyrosine kinase 3 signaling for IgG1 class-switch recombination.

    Science.gov (United States)

    Svensson, Mattias N D; Andersson, Karin M E; Wasén, Caroline; Erlandsson, Malin C; Nurkkala-Karlsson, Merja; Jonsson, Ing-Marie; Brisslert, Mikael; Bemark, Mats; Bokarewa, Maria I

    2015-12-01

    Switched antibody classes are important for efficient immune responses. Aberrant antibody production to otherwise harmless antigens may result in autoimmunity. The protein kinase fms-like tyrosine kinase 3 receptor (Flt3) has an important role during early B-cell development, but the role of Flt3 in peripheral B cells has not been assessed before. Herein we describe a previously unappreciated role for Flt3 in IgG1 class-switch recombination (CSR) and production. We show that Flt3 is reexpressed on B-cell lymphoma 6(+) germinal center B cells in vivo and following LPS activation of peripheral B cells in vitro. Absence of Flt3 signaling in Flt3 ligand-deficient mice results in impaired IgG1 CSR and accumulation of IgM-secreting plasma cells. On activated B cells, Flt3 is coexpressed and functions in synergy with the common-gamma chain receptor family. B cells from Flt3 ligand-deficient mice have impaired IL-4R signaling, with reduced phosphorylation of signal transducer and activator of transcription (Stat) 6, and demonstrate a failure to initiate CSR to IgG1 with low expression of γ1 germ-line transcripts, resulting in impaired IgG1 production. Thus, functional synergy between Flt3 and IL-4R signaling is critical for Stat-mediated regulation of sterile γ1 germ-line transcripts and CSR to IgG1.

  10. Perbedaan Rerata Kadar Soluble Fms-Like Tyrosine Kinase-1 (Sflt-1 Serum pada Penderita Early Onset, Late Onset Preeklampsia Berat / Eklampsia dan Kehamilan Normal

    Directory of Open Access Journals (Sweden)

    Laila Rahmi

    2016-01-01

    Full Text Available AbstrakPreeklampsia merupakan sumber utama morbiditas dan mortalitas ibu di seluruh dunia. Kegagalan pengaturan dan ketidakseimbangan agen vasoaktif proangiogenik dan antiangiogenik plasenta, soluble fms-like tyrosine kinase-1 (sFlt-1, vascular endothelial growth factor (VEGF dan placental growth factor (PlGF memainkan peran penting dalam patogenesis preeklampsia. Tujuan penelitian ini adalah menentukan perbedaan rerata kadar sFlt-1 serum pada penderita early onset, late onset preeklampsia berat/ eklampsia dan kehamilan normal. Penelitian dilakukan di RSUP Dr. M. Djamil, RS TK. III dr. Reksodiwiryo dan Laboratorium Biologi Molekuler Fakultas Kedokteran Universitas Andalas Padang dari Februari sampai  Desember 2014 dengan desain cross sectional. Subjek berjumlah 84 orang, terdiri dari tiga kelompok, yaitu kelompok early onset preeklampsia berat/ eklampsia, late onset preeklampsia berat/ eklampsia, dan kehamilan normal sebagai kelompok kontrol yang diambil dengan teknik consecutive sampling. Darah dikumpulkan dari subjek penelitian dengan cara intravena kemudian diukur dengan metode ELISA. Rerata kadar sFlt-1 pada kelompok early onset, late onset preeklampsia berat/ eklampsia dan kehamilan normal secara berturut-turut adalah 4,69±0,96 ng/ml, 2,39±0,57 ng/ml, dan 1,23±0,42 ng/ml. Perbedaan ini sangat signifikan dengan uji statistik ANOVA (p<0,05 dan uji Post Hoc Test Multiple Comparisons. Kesimpulan penelitian adalah terdapat perbedaan yang sangat signifikan antara kadar sFlt-1 serum pada kelompok early onset preeklampsia berat/ eklampsia, late onset preeklampsia berat/ eklampsia dan kehamilan normal.Kata kunci: sFlt-1, antiangiogenik, preeklampsia berat/ eklampsia, kehamilan normal AbstractPreeclampsia is a major cause maternal morbidity and mortality in the world. Failure regulation and imbalance of vasoactive agents and antiangiogenic proangiogenik placenta, soluble fms-like tyrosine kinase-1 (sFlt-1, vascular endothelial growth factor

  11. Soluble fms-like tyrosine kinase-1 and vascular endothelial growth factor:Novel markers for unexplained early recurrent pregnancy loss

    Institute of Scientific and Technical Information of China (English)

    Mahmoud Fathy; Hassan

    2014-01-01

    Objective:To evaluate the role of soluble fms-like tyrosine kinase-1(sFlt-1) and vascular endothelial growth factor(VEGF) for prediction of pregnancy loss in patients with history of unexplained early recurrent pregnancy loss(RPL).Methods:A prospective case control study was conducted in42 women with history of unexplained earlyRPL, and170 pregnant controls with history of uncomplicated pregnancy.We measured maternal serum sFlt-1 andVEGF at gestational age6-9 weeks as predictor for pregnancy loss.Results:Mean serum levels of sFlt-1 andVEGF were significantly higher inRPL group than controls(10439.7±385.4vs3304.5±104.8;P<0.0001, for sFlt-1, and1885.0±98.3 vs709.8±24.8;P<0.0001, forVEGF).Receiver operating characteristic(ROC) curves analyses established that sFlt-1 andVEGF were able to discriminate women at risk of developing pregnancy loss with area underROC curve0.970 for sFlt-1 and0.953 forVEGF.Cutoff value of5159.5 pg/mL for sFlt-1 was predictor for early pregnancy loss with 95.2% sensitivity,91.2% specificity, and odds ratio(OR)206 [95%confidence interval(CI),45.4-941].Cutoff value of915.5 pg/mL forVEGF was predictor for early pregnancy loss with92.9% sensitivity,90.6% specificity, andOR125 [95%CI:34.7-451].Conclusion:These data advocate a relationship between sFlt-1,VEGF, andRPL suggesting that the high levels of sFlt-1 andVEGF might be associated with the pathogenesis ofRPL.

  12. Combination of plasma-soluble fms-like tyrosine kinase 1 and uterine artery Doppler for the prediction of preeclampsia in cases of elderly gravida.

    Science.gov (United States)

    Kulmala, Lalita; Phupong, Vorapong

    2014-06-01

    The aim of this study was to determine the predictive value of the combination of plasma-soluble fms-like tyrosine kinase 1 (sFlt-1) and uterine artery Doppler for the detection of preeclampsia in women of advanced age at 16-18 weeks of gestation and to identify associations between other pregnancy complications and abnormalities of these combined tests. The maternal plasma sFlt-1 level was measured, and uterine artery Doppler was performed at 16-18 weeks of gestation in 314 cases of elderly gravida. The main outcome was preeclampsia. Fourteen women (4.46%) developed preeclampsia. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of uterine artery Doppler combined with plasma sFlt-1 for preeclampsia prediction were 28.6, 95.7, 23.5 and 96.6%, respectively. For the prediction of early-onset preeclampsia, the sensitivity, specificity, PPV and NPV were 80, 95.8, 23.5 and 99.7%, respectively. Patients with abnormal uterine artery Doppler findings and an abnormal plasma s Flt-1 level (greater than 1724.5 pg ml(-1)) had a higher risk of preterm delivery (relative risk (RR)=3.38, 95% confidence interval (CI) 1.47-7.59), neonatal respiratory distress syndrome (RR=52.06, 95% CI 5.71-474.45) and perinatal death (RR=17.35, 95% CI 1.13-265.64). Our findings indicate that the combination of uterine artery Doppler and sFlt-1 level at 16-18 weeks of gestation in cases of elderly gravida has a high predictive value for early-onset preeclampsia, but not for overall preeclampsia. This combination test may be a useful early second trimester screening test for the prediction of early-onset preeclampsia in cases of elderly gravida.

  13. Altered Level of Soluble fms-like Tyrosine Kinase 1 (sFlt1 and Hypoxia Inducible Factor-1alpha (HIF-1alpha in Normotensive Pregnancy and Preeclampsia

    Directory of Open Access Journals (Sweden)

    John Wantania

    2013-08-01

    Full Text Available BACKGROUND: Preeclampsia is still a significant problem worldwide. Of the many suggested mechanisms of its pathogenesis, the latest one is the balance of angiogenic factor and its relationship with hypoxia factors. The objective of this study was to observe changes or dynamic process of soluble fms-like tyrosine kinase 1 (sFlt1 as anti-angiogenic factor and hypoxia inducible factor 1-alpha (HIF-1α as hypoxia marker in normotensive pregnancy and preeclampsia in mid-term and full-term pregnancies. METHODS: A cohort study was conducted on 36 normotensive subjects, first examination was conducted at 20-28 weeks of gestation. Then second examination was conducted at the time of preeclampsia diagnosed or full-term pregnancy. Preeclampsia was characterized by hypertension of systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, with two readings separated in 4-6 hours period, and/or proteinuria with urine dipstick of ≥1+ or ≥300 mg per 24 hours. Examinations of sFlt-1 and HIF-1α were done by enzyme-linked immunosorbent assay method. Statistical analysis was done using a significance level of p<0.05. RESULTS: Concentration of sFlt-1 was elevated in normotensive pregnancy and preeclampsia. Higher sFlt-1 concentration elevation was seen in preeclamptic group comparing to normotensive group, although not significant. This finding was related to the fact that investigated subjects were mostly developing mild preeclampsia merely. Comparing to normotensive group, preeclamptic group had higher HIF-1α concentration-per-week elevation, but not significant. There was a positive correlation between concentrations of sFlt-1 and HIF-1α, but not significant. CONCLUSIONS: sFlt-1 concentration elevation was correlated with preeclampsia. Therefore comparing to averages, changes of sFlt-1 concentrations were more important. Concentrations of HIF-1α and sFlt-1 were positively correlated. KEYWORDS: sFlt-1, HIF-1α, preeclampsia, normotension.

  14. Restoring placental growth factor-soluble fms-like tyrosine kinase-1 balance reverses vascular hyper-reactivity and hypertension in pregnancy.

    Science.gov (United States)

    Zhu, Minglin; Ren, Zongli; Possomato-Vieira, José S; Khalil, Raouf A

    2016-09-01

    Preeclampsia (PE) is a pregnancy-related hypertensive disorder (HTN-Preg) with unclear mechanism. An imbalance between antiangiogenic soluble fms-like tyrosine kinase-1 (sFlt-1) and angiogenic placental growth factor (PlGF) has been observed in PE, but the vascular targets and signaling pathways involved are unclear. We assessed the extent of sFlt-1/PlGF imbalance and vascular dysfunction in a rat model of HTN-Preg produced by reduction of uteroplacental perfusion pressure (RUPP), and tested whether inducing a comparable sFlt-1/PlGF imbalance by infusing sFlt-1 (10 μg·kg(-1)·day(-1)) in day 14 pregnant (Preg) rats cause similar increases in blood pressure (BP) and vascular reactivity. Using these guiding measurements, we then tested whether restoring sFlt-1/PlGF balance by infusing PIGF (20 μg·kg(-1)·day(-1)) in RUPP rats would improve BP and vascular function. On gestational day 19, BP was in Preg+sFlt-1 and RUPP > Preg, and in RUPP+PlGF Preg, and in RUPP+PlGF RUPP, and was blocked by N(ω)-nitro-l-arginine methyl ester (l-NAME) or ODQ treatment or endothelium removal. Western blots revealed that aortic total endothelial NOS (eNOS) and activated phosphorylated-eNOS were in Preg+sFlt-1 and RUPP RUPP. ACh-induced vascular nitrate/nitrite production was in Preg+sFlt-1 and RUPP RUPP. Vascular relaxation to the exogenous NO donor sodium nitroprusside was not different among groups. Thus, a tilt in the angiogenic balance toward anti-angiogenic sFlt-1 is associated with decreased vascular relaxation and increased vasoconstriction and BP. Restoring the angiogenic/antiangiogenic balance using PlGF enhances endothelial NO-cGMP vascular relaxation and decreases vasoconstriction and BP in HTN-Preg rats and could offer a new approach in the management of PE.

  15. Drug Discovery against Psoriasis: Identification of a New Potent FMS-like Tyrosine Kinase 3 (FLT3) Inhibitor, 1-(4-((1H-Pyrazolo[3,4-d]pyrimidin-4-yl)oxy)-3-fluorophenyl)-3-(5-(tert-butyl)isoxazol-3-yl)urea, That Showed Potent Activity in a Psoriatic Animal Model.

    Science.gov (United States)

    Li, Guo-Bo; Ma, Shuang; Yang, Ling-Ling; Ji, Sen; Fang, Zhen; Zhang, Guo; Wang, Li-Jiao; Zhong, Jie-Min; Xiong, Yu; Wang, Jiang-Hong; Huang, Shen-Zhen; Li, Lin-Li; Xiang, Rong; Niu, Dawen; Chen, Ying-Chun; Yang, Sheng-Yong

    2016-09-22

    Psoriasis is a chronic T-cell-mediated autoimmune disease, and FMS-like tyrosine kinase 3 (FLT3) has been considered as a potential molecular target for the treatment of psoriasis. In this investigation, structural optimization was performed on a lead compound, 1-(4-(1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)phenyl)-3-(4-chloro-3-(trifluoromethyl)phenyl)urea (1), which showed a moderate inhibitory activity againt FLT3. A series of pyrazolo[3,4-d]pyrimidine derivatives were synthesized, and structure-activity relationship analysis led to the discovery of a number of potent FLT3 inhibitors. One of the most active compounds, 1-(4-(1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)-3-fluorophenyl)-3-(5-tert-butylisoxazol-3-yl)urea (18b), was then chosen for in-depth antipsoriasis studies because this compound displayed the highest potency in a preliminary antipsoriasis test. Compound 18b exhibited significant antipsoriatic effects in the K14-VEGF transgenic mouse model of psoriasis, and no recurrence was found 15 days later after the last administration. Detailed mechanisms of action of compound 18b were also investigated. Collectively, compound 18b could be a potential drug candidate for psoriasis treatment.

  16. 白血病患者Flt-3基因突变及其与白血病发生、预后的关系%Association of Fms-like tyrosine kinase-3 mutation with the occurrence and prognosis of leukemia in patients with leukemia

    Institute of Scientific and Technical Information of China (English)

    王彤; 王杰

    2007-01-01

    后判断的重要标志.%BACKGROUND: Fms-like tyrosine kinase-3 (FLT3) gene is one of the receptors for growth factors in early hematogenesis. By binding to its ligand (FL), FLT3 regulates the proliferation and differentiation of hematopoietic stem/pregenitor cells via cell signal transduction pathway. FLT3 juxtamembrane internal tandem duplication (ITD)mutation is correlated with leukemia onset, development and act as an independent factor for poor prognosis.OBJECTIVE: To explore the relationship between Flt-3/ITD mutation and acute leukemia (AL), and analyze its clinical implication.DESIGN: A repetitive measurement.SETTING: Department of Biochemistry and Molecular Biology, Shenyang Medical College.PARTICIPANTS: Totally 147 samples of leukemia patients were diagnosed by morphological bone marrow biopsy in Shenyang Central Hospitals affiliated to Shenyang Medical College from January 1999 to October 2004. They were 95 males and 52 females with the mean age of 14.5 years old (5-23 years old). According to FAB standard, there were 62 patients with acute leukemia [including 33 cases of acute myelocytic leukemia (AMLs, M1, M2), 3 cases of acute myelo-monocytic leukemia (AMMOLs, M4), 18 cases of acute monocytic leukemia (AMOLs, M5), 8 cases of acute megakaryocytic leukemia (AMKLs, M7)], 43 patients with acute lymphoblastic leukemia (ALLs), 13 patietns with juvenile chronic myelocytic leukemia (JCMLs) and 29 patients with myelodysplastic syndrome (MDSs). Informed contents were obtained from all the participants.METHOD: Flt-3/ITD was detected with polymerase chain reaction (PCR) sequence in the 147 leukemia patients.MArN OUTCOME MEASURES: The clinical manifestations and prognosis were observed in the ALL patients with Flt-3/ITD;The Flt-3 gene expression, Flt-3/ITD positive rate, duplication region and length were detected in all kinds of leukemia.to Flt-3 gene products, including 3 cases of AMLs (M1, M2), 1 case of AMMOL (M4), and 1 case of AMOL (M5). DNA sequencing and blast alignment revealed that ITDs

  17. 补肾安胎冲剂对复发性流产患者血清血管内皮生长因子及其可溶性受体-1的影响%Effects of Granules for Tonifying Kidney and Preventing Miscarriage on Serum Levels of Vascular Endothelial Growth Factor and Soluble Fms-like Tyrosine Kinase-1 in Patients with Recurrent Spontaneous Abortion

    Institute of Scientific and Technical Information of China (English)

    李伟莉; 胡瑞华

    2013-01-01

    目的 探讨补肾安胎冲剂治疗复发性流产(recurrent spontaneous abortion,RSA)的机制.方法 采用酶联免疫吸附法检测30例RSA患者治疗前后及30例正常早孕妇女血清血管内皮生长因子(vascular endothelial growth factor,VEGF)及其受体--可溶性fms样酪氨酸激酶-1(soluble fms-like tyrosine kinase-1,sFlt-1)的水平.结果 治疗组妊娠成功率为80.0%;与对照组比较,治疗组治疗前血清VEGF显著降低(P<0.01),sFlt-1显著增高(P<0.01);治疗组治疗后与治疗前比较,VEGF显著升高(P<0.01),sFlt-1显著降低(P<0.01);保胎治疗无效者与保胎治疗成功者比较,血清VEGF水平显著降低(P<0.01),血清sFlt-1水平显著增高(P<0.05).结论 补肾安胎冲剂治疗RSA的机制可能与提高血清VEGF水平,降低血清sFlt-1水平,从而促进胎盘绒毛血管的形成有关.%Objective To investigate the mechanism by -which Granules for tonifying the kidney and preventing miscarriage exert therapeutic effect in patients with recurrent spontaneous abortion (RSA). Methods Thirty RSA patients (as treatment group) and 30 women with normal early pregnancy (as control group) were included in this study. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum levels of vascular endothelial growth factor (VEGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) before and after treatment with the granules for tonifying the kidney and preventing miscarriage. Results The success rate of pregnancy was 80. 00% in the treatment group. Before treatment, the treatment group had significantly lower serum VEGF level and significantly higher serum sFlt-1 level than the control group (P

  18. Diagnosis of preeclampsia with soluble Fms-like tyrosine kinase 1/placental growth factor ratio

    DEFF Research Database (Denmark)

    Andersen, Louise Bjørkholt; Frederiksen-Møller, Britta; Work Havelund, Kathrine;

    2015-01-01

    The angiogenic factor ratio soluble Fms-kinase 1 (sFlt-1)/placental growth factor (PlGF) is a novel diagnostic tool for preeclampsia. We compared the efficacy of the KRYPTOR (BRAHMS) automated assays for sFlt-1 and PlGF with the Elecsys (Roche) assays in a routine clinical setting. Preeclamptic...... = .047). For early-onset preeclampsia, KRYPTOR area under the curve increased to 0.929 with a 100% specificity for preeclampsia at cut-off 85 and an 88.9% sensitivity for preeclampsia at cut-off 33. For women with preeclampsia and preterm delivery or Hemolysis, Elevated Liver enzymes, Low Platelet count...... (HELLP) syndrome, the KRYPTOR sFlt-1/PlGF ratio was manifold increased (P preeclampsia, preeclampsia with preterm delivery or HELLP, and among non-obese women....

  19. 急性髓系白血病患者骨髓涂片FMS样酪氨酸激酶3、NPM1和c-kit基因检测及临床研究%Detection and clinical research of FMS-like tyrosine kinase-3, NPM1 and c-kit genes in bone marrow slides of patients with acute myeloid leukemia

    Institute of Scientific and Technical Information of China (English)

    潘莹; 龚五星; 梁翠微; 杜均祥; 彭东旭; 谢云; 郑礼平; 张楠; 黄思超

    2016-01-01

    Objective To study the FMS-like tyrosine kinase-3 (FLT3) gene, NPM1 gene and c-kit gene mutations in acute myeloid leukemia (AML) by extracting DNA from the storage of bone marrow slides, and to investigate the relationship between the three gene mutations and clinical features in AML. Methods The bone marrow slides of 55 patients diagnosed with AML were enrolled in this study. The PCR, DNA sequencing and molecular cloning were used to detect and analyse the FLT3-ITD, NPM1 and c-kit gene mutations. Patients' remission, progression and survival time were also recorded. Results The DNA was successfully extracted from the bone marrow slides with -20 ℃ frozen storage without Wright stained, chemically fixed, and room temperature storage Wright stained discoloured by phenol ∶ chloroform ∶ isoamyl alcohol method, which can be used in PCR, direct sequencing and molecular cloning sequencing analysis. 10 of the 55 cases (18.2 %) were FLT3-ITD positive, including 9 cases with heterozygous mutations and 1 case with homozygous mutation. FLT3-ITD positive group had lower complete remission (CR) rate, shorter event-free survival (EFS) time and overall survival (OS) time than the negative group (P< 0.05). 9 of the 55 cases (16.4 %) had NPM1 heterozygous gene mutations, all belonging to type A. The EFS rate of the patients with NPM1 mutation was higher in 10 months and the OS rate was higher in 19 months (P< 0.05). 3 of 9 NPM1 mutations patients were FLT3-ITD positive. The CR rates of the four groups after initial remission induction therapy in order were NPM1+FLT3-ITD-, NPM1-FLT3-ITD-, NPM1-FLT3-ITD+, NPM1+FLT3-ITD+(P<0.05). Besides, NPM1-FLT3-ITD+was a risk factor affecting the OS (RR=1.250, P=0.005). 2 of the 55 cases (3.6 %) had c-kit gene mutations, namely mutant D816H and mutant D816V. The c-kit gene mutations were not found in patients with FLT3-ITD and NPM1 mutations. Conclusions The FLT3-ITD mutation is a poor prognosis molecular marker in AML, and NPM1 mutation is

  20. Single-Axis Accelerometer

    Science.gov (United States)

    Tucker, Dennis Stephen (Inventor); Capo-Lugo, Pedro A. (Inventor)

    2016-01-01

    A single-axis accelerometer includes a housing defining a sleeve. An object/mass is disposed in the sleeve for sliding movement therein in a direction aligned with the sleeve's longitudinal axis. A first piezoelectric strip, attached to a first side of the object and to the housing, is longitudinally aligned with the sleeve's longitudinal axis. The first piezoelectric strip includes a first strip of a piezoelectric material with carbon nanotubes substantially aligned along a length thereof. A second piezoelectric strip, attached to a second side of the object and to the housing, is longitudinally aligned with the sleeve's longitudinal axis. The second piezoelectric strip includes a second strip of the piezoelectric material with carbon nanotubes substantially aligned along a length thereof. A voltage sensor is electrically coupled to at least one of the first and second piezoelectric strips.

  1. Oblique Axis Body Fracture

    DEFF Research Database (Denmark)

    Takai, Hirokazu; Konstantinidis, Lukas; Schmal, Hagen;

    2016-01-01

    was uneventful. Conclusions. Oblique type axis body fractures resemble a highly unstable subtype of Anderson type III fractures with the potential of severe secondary deformity following conservative treatment, irrespective of initial grade of displacement. The authors therefore warrant a high index of suspicion......Purpose. Anderson type III odontoid fractures have traditionally been considered stable and treated conservatively. However, unstable cases with unfavorable results following conservative treatment have been reported. Methods. We present the cases of two patients who sustained minimally displaced...

  2. Vertical axis wind turbines

    Science.gov (United States)

    Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij

    2011-03-08

    A vertical axis wind turbine is described. The wind turbine can include a top ring, a middle ring and a lower ring, wherein a plurality of vertical airfoils are disposed between the rings. For example, three vertical airfoils can be attached between the upper ring and the middle ring. In addition, three more vertical airfoils can be attached between the lower ring and the middle ring. When wind contacts the vertically arranged airfoils the rings begin to spin. By connecting the rings to a center pole which spins an alternator, electricity can be generated from wind.

  3. Diagnosis of preeclampsia with soluble Fms-like tyrosine kinase 1/placental growth factor ratio: an inter-assay comparison.

    Science.gov (United States)

    Andersen, Louise Bjørkholt; Frederiksen-Møller, Britta; Work Havelund, Kathrine; Dechend, Ralf; Jørgensen, Jan Stener; Jensen, Boye L; Nielsen, Jan; Lykkedegn, Sine; Barington, Torben; Christesen, Henrik Thybo

    2015-02-01

    The angiogenic factor ratio soluble Fms-kinase 1 (sFlt-1)/placental growth factor (PlGF) is a novel diagnostic tool for preeclampsia. We compared the efficacy of the KRYPTOR (BRAHMS) automated assays for sFlt-1 and PlGF with the Elecsys (Roche) assays in a routine clinical setting. Preeclamptic women (n = 39) were included shortly after the time of diagnosis. Normotensive control pregnancies were matched by gestational age (n = 76). The KRYPTOR assays performed comparably or superior to Elecsys (sFlt-1/PlGF area under the curve 0.746 versus 0.735; P = .09; for non-obese 0.820 versus 0.805, P = .047). For early-onset preeclampsia, KRYPTOR area under the curve increased to 0.929 with a 100% specificity for preeclampsia at cut-off 85 and an 88.9% sensitivity for preeclampsia at cut-off 33. For women with preeclampsia and preterm delivery or Hemolysis, Elevated Liver enzymes, Low Platelet count (HELLP) syndrome, the KRYPTOR sFlt-1/PlGF ratio was manifold increased (P < .01). The sFlt-1/PlGF ratio proved especially useful in early-onset preeclampsia, preeclampsia with preterm delivery or HELLP, and among non-obese women.

  4. The axis of evil

    CERN Document Server

    Land, K; Land, Kate; Magueijo, Joao

    2005-01-01

    We examine previous claims for a preferred axis at $(b,l)\\approx (60,-100)$ in the cosmic radiation anisotropy, by generalizing the concept of multipole planarity to any shape preference (a concept we define mathematically). Contrary to earlier claims, we find that the amount of power concentrated in planar modes for $\\ell=2,3$ is not inconsistent with isotropy and Gaussianity. The multipoles' alignment, however, is indeed anomalous, and extends up to $\\ell=5$ rejecting statistical isotropy with a probability in excess of 99.9%. There is also an uncanny correlation of azimuthal phases between $\\ell=3$ and $\\ell=5$. We are unable to blame these effects on foreground contamination or large-scale systematic errors. We show how this reappraisal may be crucial in identifying the theoretical model behind the anomaly.

  5. Preferred axis in cosmology

    CERN Document Server

    Zhao, Wen

    2016-01-01

    The foundation of modern cosmology relies on the so-called cosmological principle which states an homogeneous and isotropic distribution of matter in the universe on large scales. However, recent observations, such as the temperature anisotropy of the cosmic microwave background (CMB) radiation, the motion of galaxies in the universe, the polarization of quasars and the acceleration of the cosmic expansion, indicate preferred directions in the sky. If these directions have a cosmological origin, the cosmological principle would be violated, and modern cosmology should be reconsidered. In this paper, by considering the preferred axis in the CMB parity violation, we find that it coincides with the preferred axes in CMB quadrupole and CMB octopole, and they all align with the direction of the CMB kinematic dipole. In addition, the preferred directions in the velocity flows, quasar alignment, anisotropy of the cosmic acceleration, the handedness of spiral galaxies, and the angular distribution of the fine-structu...

  6. Effect of oxygen and glucose deprivation on VEGF and its receptors in microvascular endothelial cells co-cultured with mast cells.

    Science.gov (United States)

    Wang, Zhihua; Tao, Jianping; Zhang, Qingyong; Wei, Meng

    2015-09-01

    The aim of this study was to determine the correlation between angiogenesis and the differential expression of vascular endothelial growth factor (VEGF) and its receptors in myocardial microvascular endothelial cells (MMVECs) co-cultured with mast cells (MCs) or mast cell granules (MCGs) under oxygen and glucose deprivation (OGD). MMVECs and MCs were isolated from Wistar rats. MCs spontaneously degranulated in OGD. The expression of VEGF peaked at 8 h and decreased from 16 h in OGD. However, the expression of its receptor, fms-like tyrosine kinase-1 (Flt-1), and fetal liver kinase-1 (Flk-1), decreased significantly, and angiogenic potential of MMVECs decreased in OGD. Expression of VEGF, Flt-1, and Flk-1 increased significantly when MMVECs were co-cultured with MCGs or active MCs, but MCs had only a limited ability to induce angiogenesis in OGD. The angiogenic potential of MMVECs cultured in OGD (even with MCGs) was inferior to that of MMVECs cultured under normoxic conditions. OGD have a profound effect on angiogenesis, which is more pronounced than the effect of MCs on angiogenesis.

  7. Gut Microbiota-brain Axis

    OpenAIRE

    2016-01-01

    Objective: To systematically review the updated information about the gut microbiota-brain axis. Data Sources: All articles about gut microbiota-brain axis published up to July 18, 2016, were identified through a literature search on PubMed, ScienceDirect, and Web of Science, with the keywords of “gut microbiota”, “gut-brain axis”, and “neuroscience”. Study Selection: All relevant articles on gut microbiota and gut-brain axis were included and carefully reviewed, with no limitation of s...

  8. Gut Microbiota-brain Axis

    Institute of Scientific and Technical Information of China (English)

    Hong-Xing Wang; Yu-Ping Wang

    2016-01-01

    Objective:To systematically review the updated information about the gut microbiota-brain axis.Data Sources:All articles about gut microbiota-brain axis published up to July 18,2016,were identified through a literature search on PubMed,ScienceDirect,and Web of Science,with the keywords of"gut microbiota","gut-brain axis",and "neuroscience".Study Selection:All relevant articles on gut microbiota and gut-brain axis were included and carefully reviewed,with no limitation of study design.Results:It is well-recognized that gut microbiota affects the brain's physiological,behavioral,and cognitive functions although its precise mechanism has not yet been fully understood.Gut microbiota-brain axis may include gut microbiota and their metabolic products,enteric nervous system,sympathetic and parasympathetic branches within the autonomic nervous system,neural-immune system,neuroendocrine system,and central nervous system.Moreover,there may be five communication routes between gut microbiota and brain,including the gut-brain's neural network,neuroendocrine-hypothalamic-pituitary-adrenal axis,gut immune system,some neurotransmitters and neural regulators synthesized by gut bacteria,and barrier paths including intestinal mucosal barrier and blood-brain barrier.The microbiome is used to define the composition and functional characteristics of gut microbiota,and metagenomics is an appropriate technique to characterize gut microbiota.Conclusions:Gut microbiota-brain axis refers to a bidirectional information network between the gut microbiota and the brain,which may provide a new way to protect the brain in the near future.

  9. Vertical axis wind turbine airfoil

    Science.gov (United States)

    Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij Vasiljevich

    2012-12-18

    A vertical axis wind turbine airfoil is described. The wind turbine airfoil can include a leading edge, a trailing edge, an upper curved surface, a lower curved surface, and a centerline running between the upper surface and the lower surface and from the leading edge to the trailing edge. The airfoil can be configured so that the distance between the centerline and the upper surface is the same as the distance between the centerline and the lower surface at all points along the length of the airfoil. A plurality of such airfoils can be included in a vertical axis wind turbine. These airfoils can be vertically disposed and can rotate about a vertical axis.

  10. Gut Microbiota-brain Axis

    Science.gov (United States)

    Wang, Hong-Xing; Wang, Yu-Ping

    2016-01-01

    Objective: To systematically review the updated information about the gut microbiota-brain axis. Data Sources: All articles about gut microbiota-brain axis published up to July 18, 2016, were identified through a literature search on PubMed, ScienceDirect, and Web of Science, with the keywords of “gut microbiota”, “gut-brain axis”, and “neuroscience”. Study Selection: All relevant articles on gut microbiota and gut-brain axis were included and carefully reviewed, with no limitation of study design. Results: It is well-recognized that gut microbiota affects the brain's physiological, behavioral, and cognitive functions although its precise mechanism has not yet been fully understood. Gut microbiota-brain axis may include gut microbiota and their metabolic products, enteric nervous system, sympathetic and parasympathetic branches within the autonomic nervous system, neural-immune system, neuroendocrine system, and central nervous system. Moreover, there may be five communication routes between gut microbiota and brain, including the gut-brain's neural network, neuroendocrine-hypothalamic-pituitary-adrenal axis, gut immune system, some neurotransmitters and neural regulators synthesized by gut bacteria, and barrier paths including intestinal mucosal barrier and blood-brain barrier. The microbiome is used to define the composition and functional characteristics of gut microbiota, and metagenomics is an appropriate technique to characterize gut microbiota. Conclusions: Gut microbiota-brain axis refers to a bidirectional information network between the gut microbiota and the brain, which may provide a new way to protect the brain in the near future. PMID:27647198

  11. Two-axis angular effector

    Energy Technology Data Exchange (ETDEWEB)

    Vaughn, Mark R. (Albuquerque, NM); Robinett, III, Rush D. (Tijeras, NM); Phelan, John R. (Albuquerque, NM); Van Zuiden, Don M. (Albuquerque, NM)

    1997-01-21

    A new class of coplanar two-axis angular effectors. These effectors combine a two-axis rotational joint analogous to a Cardan joint with linear actuators in a manner to produce a wider range of rotational motion about both axes defined by the joint. This new class of effectors also allows design of robotic manipulators having very high strength and efficiency. These effectors are particularly suited for remote operation in unknown surroundings, because of their extraordinary versatility. An immediate application is to the problems which arise in nuclear waste remediation.

  12. Two-axis angular effector

    Energy Technology Data Exchange (ETDEWEB)

    Vaughn, M.R.; Robinett, R.D. III; Phelan, J.R.; Zuiden, D.M. Van

    1997-01-21

    A new class of coplanar two-axis angular effectors is described. These effectors combine a two-axis rotational joint analogous to a Cardan joint with linear actuators in a manner to produce a wider range of rotational motion about both axes defined by the joint. This new class of effectors also allows design of robotic manipulators having very high strength and efficiency. These effectors are particularly suited for remote operation in unknown surroundings, because of their extraordinary versatility. An immediate application is to the problems which arise in nuclear waste remediation. 11 figs.

  13. Fetal and Neonatal HPA Axis.

    Science.gov (United States)

    Wood, Charles E; Walker, Claire-Dominique

    2015-12-15

    Stress is an integral part of life. Activation of the hypothalamus-pituitary-adrenal (HPA) axis in the adult can be viewed as mostly adaptive to restore homeostasis in the short term. When stress occurs during development, and specifically during periods of vulnerability in maturing systems, it can significantly reprogram function, leading to pathologies in the adult. Thus, it is critical to understand how the HPA axis is regulated during developmental periods and what are the factors contributing to shape its activity and reactivity to environmental stressors. The HPA axis is not a passive system. It can actively participate in critical physiological regulation, inducing parturition in the sheep for instance or being a center stage actor in the preparation of the fetus to aerobic life (lung maturation). It is also a major player in orchestrating mental function, metabolic, and cardiovascular function often reprogrammed by stressors even prior to conception through epigenetic modifications of gametes. In this review, we review the ontogeny of the HPA axis with an emphasis on two species that have been widely studied-sheep and rodents-because they each share many similar regulatory mechanism applicable to our understanding of the human HPA axis. The studies discussed in this review should ultimately inform us about windows of susceptibility in the developing brain and the crucial importance of early preconception, prenatal, and postnatal interventions designed to improve parental competence and offspring outcome. Only through informed studies will our public health system be able to curb the expansion of many stress-related or stress-induced pathologies and forge a better future for upcoming generations.

  14. Neospora caninum is a cause of perinatal mortality in axis deer (Axis axis).

    Science.gov (United States)

    Basso, Walter; Moré, Gastón; Quiroga, Maria Alejandra; Balducchi, Diego; Schares, Gereon; Venturini, Maria Cecilia

    2014-01-31

    Neospora caninum is a worldwide distributed protozoan that may cause neuromuscular disease in dogs and reproductive failure in domestic and wild ruminants. One axis fawn (Axis axis) and four neonates from the same deer herd died at a zoo in Argentina within a four-month period. The fawn presented with dilatation of the anal sphincter at birth and incontinence, developed weakness and ataxia and died at 14 days of age. At necropsy, a mega formation of the distal large intestine was observed. Microscopically, non-suppurative encephalitis, suppurative bronchopneumonia, fibrin necrotic enteritis and degenerative changes in the liver were observed in hematoxilin and eosin-stained tissue sections, and thick-walled N. caninum-like cysts were observed in fresh brain samples. Serologic studies for N. caninum revealed an IFAT titer of 1:6400 in the fawn and 1:25, 1:400, 1:3200 and 1:6400 in the neonates. N. caninum DNA was detected in brain samples from the fawn and from one neonate by PCR, and the parasite was isolated in vitro from the fawn' brain after passage through gerbils (Meriones unguiculatus) and gamma-interferon knock-out mice. N. caninum DNA obtained from the fawn, neonate and isolated parasites showed the same microsatellite pattern. This suggests a common infection source for both animals. The diagnosis of N. caninum infection was confirmed, suggesting its association with perinatal mortality in captive axis deer. To the best of our knowledge, this is the first report of clinical disease associated to N. caninum infection in axis deer and of isolation of the parasite from this wild ruminant species.

  15. The Axis of Evil revisited

    CERN Document Server

    Land, K; Land, Kate; Magueijo, Joao

    2006-01-01

    In light of the three-year data release from WMAP we re-examine the evidence for the ``Axis of Evil''. We discover that previous frequentist methods are not robust with respect to the data-sets available and different treatments of the galactic plane. We identify the cause of the instability and show that this result is not a weakness of the data. This is further confirmed by exhibiting an alternative approach, Bayesian in flavour, and based on a likelihood method and the information criteria. We find strong (and sometimes decisive) evidence for the ``Axis of Evil'' in almost all renditions of the WMAP data. However some significant differences between data-sets remain, and the quantitative aspects of the result depend on the particular information criteria used.

  16. Antenna Axis Offset Estimation from VLBI

    Science.gov (United States)

    Kurdubov, Sergey; Skurikhina, Elena

    2010-01-01

    The antenna axis offsets were estimated from global solutions and single sessions. We have built a set of global solutions from R1 and R4 sessions and from the sets of sessions between SVETLOE repairs. We compared our estimates with local survey data for the stations of the QUASAR network. Svetloe station axis offset values have changed after repairs. For non-global networks, the axis offset value of a single station can significantly affect the EOP estimations.

  17. A numerical method of tracing a vortical axis along local topological axis line

    Science.gov (United States)

    Nakayama, Katsuyuki; Hasegawa, Hideki

    2016-06-01

    A new numerical method is presented to trace or identify a vortical axis in flow, which is based on Galilean invariant flow topology. We focus on the local flow topology specified by the eigenvalues and eigenvectors of the velocity gradient tensor, and extract the axis component from its flow trajectory. Eigen-vortical-axis line is defined from the eigenvector of the real eigenvalue of the velocity gradient tensor where the tensor has the conjugate complex eigenvalues. This numerical method integrates the eigen-vortical-axis line and traces a vortical axis in terms of the invariant flow topology, which enables to investigate the feature of the topology-based vortical axis.

  18. Principles of the prolactin/vasoinhibin axis.

    Science.gov (United States)

    Triebel, Jakob; Bertsch, Thomas; Bollheimer, Cornelius; Rios-Barrera, Daniel; Pearce, Christy F; Hüfner, Michael; Martínez de la Escalera, Gonzalo; Clapp, Carmen

    2015-11-15

    The hormonal family of vasoinhibins, which derive from the anterior pituitary hormone prolactin, are known for their inhibiting effects on blood vessel growth, vasopermeability, and vasodilation. As pleiotropic hormones, vasoinhibins act in multiple target organs and tissues. The generation, secretion, and regulation of vasoinhibins are embedded into the organizational principle of an axis, which integrates the hypothalamus, the pituitary, and the target tissue microenvironment. This axis is designated as the prolactin/vasoinhibin axis. Disturbances of the prolactin/vasoinhibin axis are associated with the pathogenesis of retinal and cardiac diseases and with diseases occurring during pregnancy. New phylogenetical, physiological, and clinical implications are discussed.

  19. Acute injuries of the axis vertebra

    Energy Technology Data Exchange (ETDEWEB)

    Burke, J.T. (United General Hospital, Sedro Woolley, WA (USA)); Harris, J.H. (Texas Univ., Houston, TX (USA). Dept. of Radiology)

    1989-08-01

    A retrospective analysis of 165 patients admitted to Hermann Hospital with acute injuries of the axis vertebra revealed 68 (41%) dens fractures, 62 (38%) cases of traumatic spondylolisthesis ('hangman's' fracture), 21 (13%) extension teardrop fractures, 10 (6%) hyperextension dislocations, and 2 (1.0%) fractures each of the laminae and spinous processes. Of the axis injuries 31 (18%) were limited to the axis body alone. Of these, 21 (61%) were hyperextension teardrop fractures and 10 (32%) were hyperextension dislocations. Axis injuries were associated with acute injuries of other cervical vertebrae in 14 (8%) of the patients. (orig./GDG).

  20. Discovery and Rational Design of Pteridin-7(8H)-one-Based Inhibitors Targeting FMS-like Tyrosine Kinase 3 (FLT3) and Its Mutants.

    Science.gov (United States)

    Sun, Deheng; Yang, Yu; Lyu, Jiankun; Zhou, Wei; Song, Wenlin; Zhao, Zhenjiang; Chen, Zhuo; Xu, Yufang; Li, Honglin

    2016-07-14

    FLT3 has been validated as a therapeutic target for the treatment of acute myeloid leukemia (AML). In this paper, we describe for the first time, pteridin-7(8H)-one as a scaffold for potent FLT3 inhibitors derived from structural optimizations on irreversible EGFR inhibitors. The representative inhibitor (31) demonstrates single-digit nanomolar inhibition against FLT3 and subnanomolar KD for drug-resistance FLT3 mutants. In profiling of the in vitro tumor cell lines, it shows good selectivity against AML cells harboring FLT3-ITD mutations over other leukemia and solid tumor cell lines. The mechanism of action study illustrates that pteridin-7(8H)-one derivatives suppress the phosphorylation of FLT3 and its downstream pathways, thereby inducing G0/G1 cell cycle arrest and apoptosis in AML cells. In in vivo studies, 31 significantly suppresses the tumor growth in MV4-11 xenograft model. Overall, we provide a structurally distinct chemical scaffold with which to develop FLT3 mutants-selective inhibitors for AML treatment.

  1. Placental Growth Factor, Soluble fms-Like Tyrosine Kinase 1, Soluble Endoglin, IL-6, and IL-16 as Biomarkers in Preeclampsia

    Science.gov (United States)

    Rădulescu, Carmen; Huțanu, Adina; Gabor, Rozalia; Dobreanu, Minodora

    2016-01-01

    Preeclampsia (PE), an important cause of maternal and perinatal morbidity and mortality worldwide, is a pregnancy-related disease characterized by hypertension and proteinuria after 20 weeks of gestation. The aim of our study was to find a practical panel of biomarkers useful in early diagnosis of PE. This study was carried out at the Obstetrics and Gynecology Department in Tîrgu Mureș University Hospital, Romania, between January 2014 and July 2015 and included 68 pregnant women (47 preeclamptic women and 21 controls) with gestational age between 16 and 20 weeks at enrollment. The biomarkers PlGF, sFlt-1, sEng, IL-6, and IL-16 were determined by ELISA test. We compared the serum levels of soluble markers analysed in preeclamptic women and controls during the second and third trimesters of pregnancy and we found that the best predictor for PE was PlGF with a sensitivity of 100% at a concentration threshold of 120.16 pg/mL, a diagnosis accuracy of 70.8%, and AUC of 0.684 (p = 0.005). We also estimated the risk for PE according to BMI and we found that pregnant women with weight >90 kg had 7 times higher risk for PE. Second-trimester PlGF serum level may serve as an early biomarker for the diagnosis of PE.

  2. An Elevated Maternal Plasma Soluble fms-Like Tyrosine Kinase-1 to Placental Growth Factor Ratio at Midtrimester Is a Useful Predictor for Preeclampsia

    Directory of Open Access Journals (Sweden)

    Mahmoud Fathy Hassan

    2013-01-01

    Full Text Available Background. To assess the ability of mid-trimester sFlt-1/PlGF ratio for prediction of preeclampsia in two different Arabic populations. Methods. This study measured levels of sFlt-1, PlGF, and sFlt-1/PlGF ratio at midtrimester in 83 patients who developed preeclampsia with contemporary 250 matched controls. Results. Women subsequently developed preeclampsia had significantly lower PlGF levels and higher sFlt-1 and sFlt-1/PlGF ratio levels than women with normal pregnancies (P<0.0001 for all. Women who with preterm preeclampsia had significantly higher sFlt-1 and sFlt-1/PlGF ratio than term preeclamptic women (P=0.01, 0.003, resp.. A cutoff value of 3198 pg/mL for sFlt-1 was able to predict preeclampsia with sensitivity, specificity, and accuracy of 88%, 83.6%, and 84.7%, respectively, with odds ratio (OR 37.2 [95% confidence interval (CI 17.7–78.1]. PIGF at cutoff value of 138 pg/mL was able to predict preeclampsia with sensitivity, specificity, and accuracy of 85.5%, 77.2%, and 79.3%, respectively, with OR 20 [95% CI, 10.2–39.5]. The sFlt-1/PIGF ratio at cutoff value of 24.5 was able to predict preeclampsia with sensitivity, specificity, and accuracy of 91.6%, 86.4%, and 87.7%, respectively with OR 67 [95% CI, 29.3–162.1]. Conclusion. Midtrimester sFlt-1/PlGF ratio displayed the highest sensitivity, specificity, accuracy, and OR for prediction of preeclampsia, demonstrating that it may stipulate more effective prediction of preeclampsia development than individual factor assay.

  3. Innovative Design of Vertical Axis Wind Turbine

    DEFF Research Database (Denmark)

    Chougule, Prasad

    2013-01-01

    The wind turbines can be classified as: i) Horizontal axis wind turbines (HAWT), and ii) Vertical axis wind turbines (VAWT). The HAWT is fully developed and the size is growing higher. Whereas, the VAWT is not developed because of the less efficiency and vibration issues of big structure. However...

  4. Identification of Kinematic Errors of Five-axis Machine Tool Trunnion Axis from Finished Test Piece

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ya; FU Jianzhong; CHEN Zichen

    2014-01-01

    Compared with the traditional non-cutting measurement, machining tests can more accurately reflect the kinematic errors of five-axis machine tools in the actual machining process for the users. However, measurement and calculation of the machining tests in the literature are quite difficult and time-consuming. A new method of the machining tests for the trunnion axis of five-axis machine tool is proposed. Firstly, a simple mathematical model of the cradle-type five-axis machine tool was established by optimizing the coordinate system settings based on robot kinematics. Then, the machining tests based on error-sensitive directions were proposed to identify the kinematic errors of the trunnion axis of cradle-type five-axis machine tool. By adopting the error-sensitive vectors in the matrix calculation, the functional relationship equations between the machining errors of the test piece in the error-sensitive directions and the kinematic errors of C-axis and A-axis of five-axis machine tool rotary table was established based on the model of the kinematic errors. According to our previous work, the kinematic errors of C-axis can be treated as the known quantities, and the kinematic errors of A-axis can be obtained from the equations. This method was tested in Mikron UCP600 vertical machining center. The machining errors in the error-sensitive directions can be obtained by CMM inspection from the finished test piece to identify the kinematic errors of five-axis machine tool trunnion axis. Experimental results demonstrated that the proposed method can reduce the complexity, cost, and the time consumed substantially, and has a wider applicability. This paper proposes a new method of the machining tests for the trunnion axis of five-axis machine tool.

  5. Dual Axis Light Sensor for Tracking Sun

    Science.gov (United States)

    Shibata, Miki; Tambo, Toyokazu

    We have developed convenient light sensors to control a platform of solar cell panel. Dual axis light sensor in the present paper has structure of 5 PD (photodiode) light sensor which is composed of 5 photodiodes attached on a frustum of pyramid(1). Light source can be captured in front of the sensor by rotating the X and Y axis as decreasing the output deviation between two pairs of outside photodiodes. We here report the mechanism of sun tacking using the dual axis 5 PD light sensor and the fundamental results performed in the dark room.

  6. Axis of Zodiacal light Near Tropic Cancer

    CERN Document Server

    Nawar, S; Mikhail, J S; Morcos, A B; Ibrahim, Alhassan I

    2014-01-01

    The axis of zodiacal lights have been obtained in blue and yellow colors using photoelectric observations of zodiacal light. These observations have been carried out at Abu Simbel Site in Egypt, in October 1975. This site lies too near to the tropic of Cancer, at which the axis of the zodiacal light cone perpendiculars to the horizon. The results show that the plane of the zodiacal light is inclined to the normal by 1.59 degrees in blue color and 1.18 degrees in yellow color. This means that there is a slight variation in zodiacal light axis with wavelength, and the axis almost coincide with the ecliptic. The present results for blue color can be considered as the first one in the world near the tropic of Cancer.

  7. Electrical-Discharge Machining With Additional Axis

    Science.gov (United States)

    Malinzak, Roger M.; Booth, Gary N.

    1991-01-01

    Proposed electrical-discharge-machining (EDM) apparatus uses moveable vertical wire as electrode. Wire positionable horizontally along one axis as it slides vertically past workpiece. Workpiece indexed in rotation about horizontal axis. Because of symmetry of parts, process used to make two such parts at a time by defining boundary between them. Advantages: cost of material reduced, imparts less residual stress to workpiece, and less time spent machining each part when parts produced in such symmetrical pairs.

  8. Sex differences in the HPA axis.

    Science.gov (United States)

    Goel, Nirupa; Workman, Joanna L; Lee, Tiffany T; Innala, Leyla; Viau, Victor

    2014-07-01

    The hypothalamic-pituitary-adrenal (HPA) axis is a major component of the systems that respond to stress, by coordinating the neuroendocrine and autonomic responses. Tightly controlled regulation of HPA responses is critical for maintaining mental and physical health, as hyper- and hypo-activity have been linked to disease states. A long history of research has revealed sex differences in numerous components of the HPA stress system and its responses, which may partially form the basis for sex disparities in disease development. Despite this, many studies use male subjects exclusively, while fewer reports involve females or provide direct sex comparisons. The purpose of this article is to present sex comparisons in the functional and molecular aspects of the HPA axis, through various phases of activity, including basal, acute stress, and chronic stress conditions. The HPA axis in females initiates more rapidly and produces a greater output of stress hormones. This review focuses on the interactions between the gonadal hormone system and the HPA axis as the key mediators of these sex differences, whereby androgens increase and estrogens decrease HPA activity in adulthood. In addition to the effects of gonadal hormones on the adult response, morphological impacts of hormone exposure during development are also involved in mediating sex differences. Additional systems impinging on the HPA axis that contribute to sex differences include the monoamine neurotransmitters norepinephrine and serotonin. Diverse signals originating from the brain and periphery are integrated to determine the level of HPA axis activity, and these signals are, in many cases, sex-specific.

  9. UMAPRM: Uniformly sampling the medial axis

    KAUST Repository

    Yeh, Hsin-Yi Cindy

    2014-05-01

    © 2014 IEEE. Maintaining clearance, or distance from obstacles, is a vital component of successful motion planning algorithms. Maintaining high clearance often creates safer paths for robots. Contemporary sampling-based planning algorithms That utilize The medial axis, or The set of all points equidistant To Two or more obstacles, produce higher clearance paths. However, They are biased heavily Toward certain portions of The medial axis, sometimes ignoring parts critical To planning, e.g., specific Types of narrow passages. We introduce Uniform Medial Axis Probabilistic RoadMap (UMAPRM), a novel planning variant That generates samples uniformly on The medial axis of The free portion of Cspace. We Theoretically analyze The distribution generated by UMAPRM and show its uniformity. Our results show That UMAPRM\\'s distribution of samples along The medial axis is not only uniform but also preferable To other medial axis samplers in certain planning problems. We demonstrate That UMAPRM has negligible computational overhead over other sampling Techniques and can solve problems The others could not, e.g., a bug Trap. Finally, we demonstrate UMAPRM successfully generates higher clearance paths in The examples.

  10. POGAL B-Axis Motor Test

    Energy Technology Data Exchange (ETDEWEB)

    Hale, L C; Wulff, T A

    2004-06-28

    The Aerotech model S-180-69-A, a brushless DC motor of slotless design, was selected as the B-axis drive for the Precision Optical Grinder and Lathe (POGAL). It is common knowledge that a slotless motor will have effectively no magnetic cogging and much less torque ripple than a traditional slot-type motor. It is logical to believe that the radial and axial forces generated between the rotor and stator would also be smaller for a slotless design. This is important when a frameless motor is directly coupled to the axis, as these forces directly influence the axis and affect its error motion. It is the purpose of this test to determine the radial and axial forces generated by the Aerotech motor and to estimate their effect on the error motion of the axis using a mathematical model of the hydrostatic bearing being designed for POGAL. The test results combined with a mathematical model of the POGAL B axis indicate that the directly coupled Aerotech motor will be quite acceptable. In the radial direction, the residual motor force, after subtracting out the one-cycle force, could cause sub nanometer level error motion at the tool point. The axial direction is not in a sensitive direction for turning.

  11. Aeroelastically coupled blades for vertical axis wind turbines

    Science.gov (United States)

    Paquette, Joshua; Barone, Matthew F.

    2016-02-23

    Various technologies described herein pertain to a vertical axis wind turbine blade configured to rotate about a rotation axis. The vertical axis wind turbine blade includes at least an attachment segment, a rear swept segment, and optionally, a forward swept segment. The attachment segment is contiguous with the forward swept segment, and the forward swept segment is contiguous with the rear swept segment. The attachment segment includes a first portion of a centroid axis, the forward swept segment includes a second portion of the centroid axis, and the rear swept segment includes a third portion of the centroid axis. The second portion of the centroid axis is angularly displaced ahead of the first portion of the centroid axis and the third portion of the centroid axis is angularly displaced behind the first portion of the centroid axis in the direction of rotation about the rotation axis.

  12. ELONGATED ODONTOID PROCESS OF AXIS VERTEBRA

    Directory of Open Access Journals (Sweden)

    Prathap Kumar J,

    2014-09-01

    Full Text Available Introduction: Odontoid process is a bony projection of axis around which the atlas rotates. It measures 1 to 1.25 cms in length and projects upwards from the body of Axis. An elongated odontoid process may narrow the foramen magnum causing compressive neurological symptoms. It can cause cervical stiffness, serious restrictions of neck movement, and even a bone-derived torticollis. Observation: During routine osteology classes, we encountered an Axis vertebra with an elongated odontoid process. The measurements of the elongated odontoid process were taken using digital Vernier slide calipers. Conclusion: Elongated odontoid process can be mistaken for fracture of dens in radiological images; hence the knowledge of elongated odontoid process is useful for the radiologists, neurosurgeons and orthopaedicians for accurate diagnosis and treatment involving cranio-vertebral junctions.

  13. Oxytocin and hypothalamo-pituitary- adrenal axis

    Directory of Open Access Journals (Sweden)

    Berrak Ç. Yeğen

    2010-05-01

    Full Text Available BSTRACT: Upon exposure to different types of stressors, neuroendocrine and behavioral responses that include the activation of the hypothalamus-pituitary-adrenal (HPA axis are given to allow the individuals to cope with stress conditions. It was proven that oxytocin, anonapeptide released from the posterior pituitary, has behavioral and stress-attenuating effects by dampening HPA activity. On the other hand, the neuropeptide was also shown to exert anti-inflammatory effects through the modulation of immune and inflammatory processes in several experimental models of tissue injury. The findings of recent studies suggest that the anti-inflammatory effect of oxytocin depends on its role on HPA axis activity and subsequent release of cortisol. Thus, oxytocin seems to restrain the activity within the HPA-axis, which becomes overactive during many inflammatory processes

  14. Diffuser Augmented Horizontal Axis Tidal Current Turbines

    Directory of Open Access Journals (Sweden)

    Nasir Mehmood

    2012-09-01

    Full Text Available The renewal energy technologies are increasingly popular to ensure future energy sustenance and address environmental issues. The tides are enormous and consistent untapped resource of renewable energy. The growing interest in exploring tidal energy has compelling reasons such as security and diversity of supply, intermittent but predictable and limited social and environmental impacts. The tidal energy industry is undergoing an increasing shift towards diffuser augmented turbines. The reason is the higher power output of diffuser augmented turbines compared to conventional open turbines. The purpose of this study is to present a comprehensive review of diffuser augmented horizontal axis tidal current turbines. The components, relative advantages, limitations and design parameters of diffuser augmented horizontal axis tidal current turbines are presented in detail. CFD simulation of NACA 0016 airfoil is carried out to explore its potential for designing a diffuser. The core issues associated with diffuser augmented horizontal axis tidal current turbines are also discussed.

  15. Modular off-axis solar concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Plesniak, Adam P; Hall, John C

    2015-01-27

    A solar concentrator including a housing defining a vertical axis and including a receiving wall connected to a reflecting wall to define an internal volume and an opening into the internal volume, wherein the reflecting wall defines at least one primary optical element, and wherein at least a portion of the reflecting wall includes a layer of reflective material, the housing further including a cover connected to the receiving wall and the reflecting wall to seal the opening, and at least one receiver mounted on the receiving wall such that a vertical axis of the receiver is disposed at a non-zero angle relative to the vertical axis of the housing, the receiver including at least one photovoltaic cell.

  16. A users guide to HPA axis research.

    Science.gov (United States)

    Spencer, Robert L; Deak, Terrence

    2016-11-18

    Glucocorticoid hormones (cortisol and corticosterone - CORT) are the effector hormones of the hypothalamic-pituitary-adrenal (HPA) axis neuroendocrine system. CORT is a systemic intercellular signal whose level predictably varies with time of day and dynamically increases with environmental and psychological stressors. This hormonal signal is utilized by virtually every cell and physiological system of the body to optimize performance according to circadian, environmental and physiological demands. Disturbances in normal HPA axis activity profiles are associated with a wide variety of physiological and mental health disorders. Despite numerous studies to date that have identified molecular, cellular and systems-level glucocorticoid actions, new glucocorticoid actions and clinical status associations continue to be revealed at a brisk pace in the scientific literature. However, the breadth of investigators working in this area poses distinct challenges in ensuring common practices across investigators, and a full appreciation for the complexity of a system that is often reduced to a single dependent measure. This Users Guide is intended to provide a fundamental overview of conceptual, technical and practical knowledge that will assist individuals who engage in and evaluate HPA axis research. We begin with examination of the anatomical and hormonal components of the HPA axis and their physiological range of operation. We then examine strategies and best practices for systematic manipulation and accurate measurement of HPA axis activity. We feature use of experimental methods that will assist with better understanding of CORT's physiological actions, especially as those actions impact subsequent brain function. This research approach is instrumental for determining the mechanisms by which alterations of HPA axis function may contribute to pathophysiology.

  17. DRIVE AND CONTROL OF VIRTUAL-AXIS NC MACHINE TOOLS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The structure features and driving modes of virtual-axis NC machine tools are studied.Accor- ding to different application requirements,the three-axis control method,the five-axis control method and the six-freedom control method are put forward.These results lay a foundation for the product development of the virtual-axis NC machine tools.

  18. Triple-axis spectrometer DruechaL

    Energy Technology Data Exchange (ETDEWEB)

    Buehrer, W.; Keller, P. [Lab. for Neutron Scattering ETH Zurich, Zurich (Switzerland) and Paul Scherrer Institute, Villigen (Switzerland)

    1996-11-01

    DruechaL is a triple-axis spectrometer located at a cold guide. The characteristics of guide and instrument allow the use of a broad spectral range of neutrons. The resolution in momentum and energy transfer can be tuned to match the experimental requirements by using either collimators or focusing systems (monochromator, antitrumpet, analyser). (author) figs., tabs., refs.

  19. Resolution of a triple axis spectrometer

    DEFF Research Database (Denmark)

    Nielsen, Mourits; Bjerrum Møller, Hans

    1969-01-01

    A new method for obtaining the resolution function for a triple-axis neutron spectrometer is described, involving a combination of direct measurement and analytical calculation. All factors which contribute to the finite resolution of the instrument may be taken into account, and Gaussian...

  20. Tennis Rackets and the Parallel Axis Theorem

    Science.gov (United States)

    Christie, Derek

    2014-01-01

    This simple experiment uses an unusual graph straightening exercise to confirm the parallel axis theorem for an irregular object. Along the way, it estimates experimental values for g and the moment of inertia of a tennis racket. We use Excel to find a 95% confidence interval for the true values.

  1. The Trading Axis in Irkutsk Downtown

    Directory of Open Access Journals (Sweden)

    Elena Grigoryeva

    2016-10-01

    Full Text Available The article reveals a linear concentration of the trading function in the historical center of Irkutsk. It features historical prerequisites and continuation of the tradition in the post-Soviet period, given the conversion of plants and factories. The article analyses the current state and prospects of modernization of the trading axis with its transformation into a modern public space.

  2. Mortality of a captive axis deer (Axis axis) and a llama (Lama glama) due to ingestion of Wedelia glauca.

    Science.gov (United States)

    Giannitti, Federico; Margineda, Carlos A; Cid, María S; Diab, Santiago S; Weber, Natalia; Rodríguez, Alejandro; Campero, Carlos M; Odriozola, Ernesto R

    2012-11-01

    The current study describes a naturally occurring cluster of cases of Wedelia glauca intoxication. Seven of 14 axis deer (Axis axis) and 1 of 8 llamas (Lama glama) in a zoo of Buenos Aires province, Argentina, died suddenly after ingestion of a new batch of alfalfa (Medicago sativa) hay bales contaminated with the hepatotoxic plant W. glauca. Necropsies of 1 deer and 1 llama were performed. Pathological findings in both animals included severe diffuse acute centrilobular hepatocellular necrosis and hemorrhage, and clear yellowish translucent gelatinous edema on the wall of the gall bladder and the serosa of the choledochoduodenal junction. Fragments of W. glauca plants were identified in the hay based on the botanical characteristics of the leaves. Samples of gastric contents were examined by microhistological analysis, which identified epidermal fragments of W. glauca based on the presence of characteristic uniseriate glandular hairs (trichomes), confirming recent ingestion of W. glauca in both cases. The fragments were quantified and represented 5% of all examined vegetal fragments in the deer and 10% in the llama.

  3. Two-axis joint assembly and method

    Science.gov (United States)

    Le, Thang D. (Inventor); Lewis, James L. (Inventor); Carroll, Monty B. (Inventor)

    2010-01-01

    In an embodiment, a two-axis joint that utilizes planar reactions to handle moments applied to the side of the joint thereby allowing the device to remain low profile and compact with minimal intrusion to the mounting surface of the two-axis joint. To handle larger moments, the diameter of the planar member can be increased without increasing the overall height of the joint assembly thereby retaining the low profile thereof. Upper and lower antifriction bearings may be positioned within a housing engage the planar member to reduce rotational friction. The upper and lower bearings and a hub which supports the planar member transfer forces produced by moments applied to the side of the joint so as to spread the forces over the area of the housing.

  4. Determining the Stellar Spin Axis Orientation

    Science.gov (United States)

    Lesage, Anna-Lea; Wiedemann, Gunter

    2015-01-01

    We present an observing method that permits the determination of the absolute stellar spin axis position angle based on spectro-astrometric observations for slowly-rotating late-type stars. This method is complementary to current interferometric observations that determine the orientation of stellar spin axis for early-type fast-rotating stars. Spectro-astrometry enables us to study phenomena below the diffraction limit, at the milli-arcsecond scale. It relies on the wavelength dependent variations of the centroid position of a structured source in a long-slit spectrum. A rotating star has a slight tilt in its spectral lines, which induces a displacement of the photocentre's position. By monitoring the amplitude of the displacement for varying slit orientations, we can infer the absolute position angle of the stellar spin axis. Finally, we present first observational results on Aldebaran obtained with the Thüringer Landesternwarte high resolution spectrograph. We were able to retrieve Aldebaran's position angle with less than 10° errors.

  5. Neuroanatomy and physiology of the avian hypothalamic/pituitary axis: clinical aspects.

    Science.gov (United States)

    Ritchie, Midge

    2014-01-01

    This article describes the anatomy of the avian hypothalamic/pituitary axis, the hypothalamic-pituitary-thyroid axis, the hypothalamic-pituitary-adrenal axis, the hypothalamic-pituitary-gonadal axis, the somatotrophic axis, and neurohypophysis.

  6. Cross-axis adaptation of torsional components in the yaw-axis vestibulo-ocular reflex

    Science.gov (United States)

    Trillenberg, P.; Shelhamer, M.; Roberts, D. C.; Zee, D. S.

    2003-01-01

    The three pairs of semicircular canals within the labyrinth are not perfectly aligned with the pulling directions of the six extraocular muscles. Therefore, for a given head movement, the vestibulo-ocular reflex (VOR) depends upon central neural mechanisms that couple the canals to the muscles with the appropriate functional gains in order to generate a response that rotates the eye the correct amount and around the correct axis. A consequence of these neural connections is a cross-axis adaptive capability, which can be stimulated experimentally when head rotation is around one axis and visual motion about another. From this visual-vestibular conflict the brain infers that the slow-phase eye movement is rotating around the wrong axis. We explored the capability of human cross-axis adaptation, using a short-term training paradigm, to determine if torsional eye movements could be elicited by yaw (horizontal) head rotation (where torsion is normally inappropriate). We applied yaw sinusoidal head rotation (+/-10 degrees, 0.33 Hz) and measured eye movement responses in the dark, and before and after adaptation. The adaptation paradigm lasted 45-60 min, and consisted of the identical head motion, coupled with a moving visual scene that required one of several types of eye movements: (1) torsion alone (-Roll); (2) horizontal/torsional, head right/CW torsion (Yaw-Roll); (3) horizontal/torsional, head right/CCW torsion (Yaw+Roll); (4) horizontal, vertical, torsional combined (Yaw+Pitch-Roll); and (5) horizontal and vertical together (Yaw+Pitch). The largest and most significant changes in torsional amplitude occurred in the Yaw-Roll and Yaw+Roll conditions. We conclude that short-term, cross-axis adaptation of torsion is possible but constrained by the complexity of the adaptation task: smaller torsional components are produced if more than one cross-coupling component is required. In contrast, vertical cross-axis components can be easily trained to occur with yaw head

  7. The optical axis optimization in measurement of decentration of lens

    Science.gov (United States)

    Wang, Yajing; Yang, Lin; Wang, Chunyu

    2013-09-01

    Measure of optical decentration plays an important role in inspection, installation and adjustment of optical system. This article describes optical measurement principle of decentration, analyzes the reason of the decentration measurement accuracy, and indicates the necessity of optimizing the optical axis. Finally, because of the error of the decentration optical axis fitting. A new method of optical axis optimization is put forward here. A mathematical model to find the best optical axis is established, which improved the optical performance of the system.

  8. Micromachined dual input axis rate gyroscope

    Science.gov (United States)

    Juneau, Thor Nelson

    The need for inexpensive yet reliable angular rate sensors in fields ranging from automotive to consumer electronics has motivated prolific micromachined rate gyroscope research. The vast majority of research has focused on single input axis rate gyroscopes based upon either translational resonance, such as tuning forks, or structural mode resonance, such as vibrating rings. However, this work presents a novel, contrasting approach based on angular resonance of a rotating rigid rotor suspended by torsional springs. The inherent symmetry of the circular design allows angular rate measurement about two axes simultaneously, hence the name micromachined dual-axis rate gyroscope. The underlying theory of operation, mechanical structure design optimization, electrical interface circuitry, and signal processing are described in detail. Several operational versions were fabricated using two different fully integrated surface micromachining processes as proof of concept. The heart of the dual-axis rate gyroscope is a ˜2 mum thick polysilicon disk or rotor suspended above the substrate by a four beam suspension. When this rotor in driven into angular oscillation about the axis perpendicular to the substrate, a rotation rate about the two axes parallel to the substrate invokes an out of plane rotor tilting motion due to Coriolis acceleration. This tilting motion is capacitively measured and on board integrated signal processing provides two output voltages proportional to angular rate input about the two axes parallel to the substrate. The design process begins with the derivation of gyroscopic dynamics. The equations suggest that tuning sense mode frequencies to the drive oscillation frequency can vastly increase mechanical sensitivity. Hence the supporting four beam suspension is designed such that electrostatic tuning can match modes despite process variations. The electrostatic tuning range is limited only by rotor collapse to the substrate when tuning-voltage induced

  9. Segmental patterning of the vertebrate embryonic axis.

    Science.gov (United States)

    Dequéant, Mary-Lee; Pourquié, Olivier

    2008-05-01

    The body axis of vertebrates is composed of a serial repetition of similar anatomical modules that are called segments or metameres. This particular mode of organization is especially conspicuous at the level of the periodic arrangement of vertebrae in the spine. The segmental pattern is established during embryogenesis when the somites--the embryonic segments of vertebrates--are rhythmically produced from the paraxial mesoderm. This process involves the segmentation clock, which is a travelling oscillator that interacts with a maturation wave called the wavefront to produce the periodic series of somites. Here, we review our current understanding of the segmentation process in vertebrates.

  10. VERITAS: Versatile Triple-Axis Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Il

    2006-04-15

    Korea Atomic Energy Research Institute is planning to build a cold neutron triple-axis spectrometer at HANARO, the 30 MW research reactor. The spectrometer is expected to be completed in 2008 with the following configuration from the upstream to the downstream. Guide Supermirror m = 2, In-pile Straight Section, {approx} 5 m Curved Guide, {approx} 26 m w/ R 1500 m Straight Guide before the Instrument, {approx} 40 m Filters PG and Be Neutron Velocity Selector (Future) Monochromators Vertically Focusing Monochromators PG(002) and Heusler(111) Doubly Focusing Monochromators (Future) Monochromator-Sample Distance 2 m Collimation C1 Soller Collimators, 20', 40' 80'Beam Height at the Sample Table 1.5 m Sample-Analyzer Distance 1.0 m Collimation C2 Soller Collimators, 20', 40', 80' Radial Collimator Analyzers Horizontally Focusing Analyzers w/ Fixed Vertical Focusing PG(002) and Heusler(111) Analyzer-Detector Distance 0.5 m Detectors 5 cm Tube Detector 25 cm wide Position Sensitive Detector Once completed, the neutron flux at sample is expected to surpass that of SPINS at NCNR, making this instrument one of the most powerful 2nd generation cold neutron triple-axis spectrometers in the world.

  11. Rapid 2-axis scanning lidar prototype

    Science.gov (United States)

    Hartsell, Daryl; LaRocque, Paul E.; Tripp, Jeffrey

    2016-10-01

    The rapid 2-axis scanning lidar prototype was developed to demonstrate high-precision single-pixel linear-mode lidar performance. The lidar system is a combined integration of components from various commercial products allowing for future customization and performance enhancements. The intent of the prototype scanner is to demonstrate current stateof- the-art high-speed linear scanning technologies. The system consists of two pieces: the sensor head and control unit. The senor head can be installed up to 4 m from the control box and houses the lidar scanning components and a small RGB camera. The control unit houses the power supplies and ranging electronics necessary for operating the electronics housed inside the sensor head. This paper will discuss the benefits of a 2-axis scanning linear-mode lidar system, such as range performance and a userselectable FOV. Other features include real-time processing of 3D image frames consisting of up to 200,000 points per frame.

  12. Model for performance prediction in multi-axis machining

    CERN Document Server

    Lavernhe, Sylvain; Lartigue, Claire; 10.1007/s00170-007-1001-4

    2009-01-01

    This paper deals with a predictive model of kinematical performance in 5-axis milling within the context of High Speed Machining. Indeed, 5-axis high speed milling makes it possible to improve quality and productivity thanks to the degrees of freedom brought by the tool axis orientation. The tool axis orientation can be set efficiently in terms of productivity by considering kinematical constraints resulting from the set machine-tool/NC unit. Capacities of each axis as well as some NC unit functions can be expressed as limiting constraints. The proposed model relies on each axis displacement in the joint space of the machine-tool and predicts the most limiting axis for each trajectory segment. Thus, the calculation of the tool feedrate can be performed highlighting zones for which the programmed feedrate is not reached. This constitutes an indicator for trajectory optimization. The efficiency of the model is illustrated through examples. Finally, the model could be used for optimizing process planning.

  13. Comparison of 4 cm Z-axis and 16 cm Z-axis multidetector CT perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Page, Mark; Nandurkar, Dee; Crossett, Marcus Peter; Stuckey, Stephen L.; Lau, Kenneth P.; Kenning, Nicholas; Troupis, John M. [Monash Medical Centre, Department of Diagnostic Imaging, Southern Health Network, Clayton, Victoria (Australia)

    2010-06-15

    The aim of the study was to compare 4 cm with 16 cm Z-axis coverage in the assessment of brain CT perfusion (CTP) using. 320 slice multidetector CT A retrospective non-randomised review of CTP performed on MD320 CT between September 2008 and January 2009 was undertaken. Two experienced readers reviewed the studies along with the 4 cm and 16 cm Z-axis CTP image data set. The outcome parameters assessed were the extent of the original finding, any additional findings and a change of diagnosis. 14 out of 27 patients were found to have abnormal CTP (mean age 58.1 years, 9 male). The 16 cm Z-axis increased the accuracy of the infarct core in 78% and ischaemic penumbra quantification in 100% of the cases. It also diagnosed additional infarcts in the same vascular territory in 28% of cases and in a different vascular territory in 14%. The increased field of view with MD320 better defines the true extent of the infarct core and ischaemic penumbra. It also identified other areas of infarction that were not identified on the 4 cm Z-axis. (orig.)

  14. Polarized triple-axis spectrometer TASP

    Energy Technology Data Exchange (ETDEWEB)

    Boeni, P.; Keller, P. [Lab. for Neutron Scattering ETH Zurich, Zurich (Switzerland) and Paul Scherrer Institute, Villigen (Switzerland)

    1996-11-01

    The polarized triple-axis spectrometer TASP at SINQ has been optimized for measuring magnetic cross sections in condensed matter. The neutrons are polarized or analyzed either by means of benders or Heusler monochromators. The beam divergence, i.e. the intensity, and the spectral range of the neutrons is rather large because of the supermirror coatings of the feeding neutron guide. The intensity can be further increased at the sample position by means of a focussing monochromator and a focussing anti-trumpet. The end position of TASP allows the tailoring of the neutron beam already before the monochromator and to scatter neutrons over very wide ranges of angles. (author) 6 figs., 1 tab., 8 refs.

  15. A Portable Single Axis Magnetic Gradiometer

    DEFF Research Database (Denmark)

    Merayo, José M.G.; Petersen, Jan Raagaard; Nielsen, Otto V

    2001-01-01

    The single axis magnetic gradiometer based on two compact detector compensation (CDC) fluxgate ringcore sensors separated 20 cm is described. Despite its high stability and precision better than 1 nT, the calibration procedures are not straightforward. Firstly, the mono-axial measurement does...... not provide vector information about the magnetic field. Secondly, one of the sensors measures the ambient magnetic field and is used to compensate for the main field at both sensors. Several methods have been developed for characterization of the 2 gradiometer, and the calibration of the gradient...... measurements is achieved by using a magnetic dipole of strength 2 mAm(2). In a coil facility, the gradient can be determined with an accuracy of 0.3 nT/m(RMS)....

  16. Five-axis rough machining for impellers

    Institute of Scientific and Technical Information of China (English)

    Ruolong QI; Weijun LIU; Hongyou BIAN; Lun LI

    2009-01-01

    The most important components used in aero-space, ships, and automobiles are designed with free form surfaces. An impeller is one of the most important components that is difficult to machine because of its twisted blades. Rough machining is recognized as the most crucial procedure influencing machining efficiency and is critical for the finishing process. An integrated rough machining course with detailed algorithms is presented in this paper. An algorithm for determining the minimum distance between two surfaces is applied to estimate the tool size. The space between two blades that will be cleared from the roughcast is divided to generate CC points. The tool axis vector is confirmed based on flank milling using a simple method that could eliminate global interference between the tool and the blades. The result proves that the machining methodology presented in this paper is useful and successful.

  17. A comparison of on-axis and off-axis heliostat alignment strategies

    Energy Technology Data Exchange (ETDEWEB)

    Jones, S.A.

    1996-03-01

    Heliostat installation and alignment costs will be an important element in future solar power tower projects. The predicted annual performances of on- and-off axis strategies are compared for 95 m{sup 2} flat-glass heliostats and an external, molten-salt receiver. Actual approaches to heliostat alignment that have been used in the past are briefly discussed, and relative strengths and limitations are noted. The optimal approach can vary with the application.

  18. Growth Hormone-Insulin-Like Growth Factor Axis, Thyroid Axis, Prolactin, and Exercise.

    Science.gov (United States)

    Hackney, Anthony C; Davis, Hope C; Lane, Amy R

    2016-01-01

    This chapter addresses what is known about the endocrine system components growth hormone (GH)-insulin-like growth factor (IGF) axis, thyroid axis, and prolactin relative to exercise and exercise training. Each one of these hormone axes contributes to the maintenance of homeostasis in the body through impact on a multitude of physiological systems. The homeostatic disruption of exercise causes differing responses in each hormone axis. GH levels increase with sufficient stimulation, and IGFs are released in response to GH from the anterior pituitary providing multiple roles including anabolic properties. Changes in the thyroid hormones T3 and T4 vary greatly with exercise, from increases/decreases to no change in levels across different exercise types, intensities and durations. These ambiguous findings could be due to numerous confounding factors (e.g. nutrition status) within the research. Prolactin increases proportionally to the intensity of the exercise. The magnitude may be augmented with extended durations; conflicting findings have been reported with resistance training. While the responses to exercise vary, it appears there may be overall adaptive and regenerative impacts on the body into recovery by these hormones through immune and tissue inflammatory responses/mediations. Nonetheless, well-designed exercise research studies are still needed on each of these hormones, especially thyroid hormones and prolactin.

  19. Rotation Axis Variation Due To Spin Orbit Resonance

    CERN Document Server

    Gallavotti, G

    1993-01-01

    Abstract: rotation axis variation due to spin orbit resonance: conference report; keywords: planetary precession, rigid body, chaos, KAM, Arnold diffusion, averaging, celestial mechanics, classical mechanics, large deviations

  20. Creating a Multi-axis Machining Postprocessor

    Directory of Open Access Journals (Sweden)

    Petr Vavruška

    2012-01-01

    Full Text Available This paper focuses on the postprocessor creation process. When using standard commercially available postprocessors it is often very difficult to modify its internal source code, and it is a very complex process, in many cases even impossible, to implement the newly-developed functions. It is therefore very important to have a method for creating a postprocessor for any CAM system, which allows CL data (Cutter Location data to be generated to a separate text file. The goal of our work is to verify the proposed method for creating a postprocessor. Postprocessor functions for multi-axis machiningare dealt with in this work. A file with CL data must be translated by the postprocessor into an NC program that has been customized for a specific production machine and its control system. The postprocessor is therefore verified by applications for machining free-form surfaces of complex parts, and by executing the NC programs that are generated on real machine tools. This is also presented here.

  1. Effective solidity in vertical axis wind turbines

    Science.gov (United States)

    Parker, Colin M.; Leftwich, Megan C.

    2016-11-01

    The flow surrounding vertical axis wind turbines (VAWTs) is investigated using particle imaging velocimetry (PIV). This is done in a low-speed wind tunnel with a scale model that closely matches geometric and dynamic properties tip-speed ratio and Reynolds number of a full size turbine. Previous results have shown a strong dependance on the tip-speed ratio on the wake structure of the spinning turbine. However, it is not clear whether this is a speed or solidity effect. To determine this, we have measured the wakes of three turbines with different chord-to-diameter ratios, and a solid cylinder. The flow is visualized at the horizontal mid-plane as well as the vertical mid-plane behind the turbine. The results are both ensemble averaged and phase averaged by syncing the PIV system with the rotation of the turbine. By keeping the Reynolds number constant with both chord and diameter, we can determine how each effects the wake structure. As these parameters are varied there are distinct changes in the mean flow of the wake. Additionally, by looking at the vorticity in the phase averaged profiles we can see structural changes to the overall wake pattern.

  2. Gut/brain axis and the microbiota.

    Science.gov (United States)

    Mayer, Emeran A; Tillisch, Kirsten; Gupta, Arpana

    2015-03-02

    Tremendous progress has been made in characterizing the bidirectional interactions between the central nervous system, the enteric nervous system, and the gastrointestinal tract. A series of provocative preclinical studies have suggested a prominent role for the gut microbiota in these gut-brain interactions. Based on studies using rodents raised in a germ-free environment, the gut microbiota appears to influence the development of emotional behavior, stress- and pain-modulation systems, and brain neurotransmitter systems. Additionally, microbiota perturbations by probiotics and antibiotics exert modulatory effects on some of these measures in adult animals. Current evidence suggests that multiple mechanisms, including endocrine and neurocrine pathways, may be involved in gut microbiota-to-brain signaling and that the brain can in turn alter microbial composition and behavior via the autonomic nervous system. Limited information is available on how these findings may translate to healthy humans or to disease states involving the brain or the gut/brain axis. Future research needs to focus on confirming that the rodent findings are translatable to human physiology and to diseases such as irritable bowel syndrome, autism, anxiety, depression, and Parkinson's disease.

  3. Yaw dynamics of horizontal axis wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, A.C. (Utah Univ., Salt Lake City, UT (United States))

    1992-05-01

    Designers of a horizontal axis wind turbine yaw mechanism are faced with a difficult decision. They know that if they elect to use a yaw- controlled rotor then the system will suffer increased initial cost and increased inherent maintenance and reliability problems. On the other hand, if they elect to allow the rotor to freely yaw they known they will have to account for unknown and random, though bounded, yaw rates. They will have a higher-risk design to trade-off against the potential for cost savings and reliability improvement. The risk of a yaw-free system could be minimized if methods were available for analyzing and understanding yaw behavior. The complexity of yaw behavior has, until recently, discouraged engineers from developing a complete yaw analysis method. The objectives of this work are to (1) provide a fundamental understanding of free-yaw mechanics and the design concepts most effective at eliminating yaw problems, and (2) provide tested design tools and guidelines for use by free-yaw wind systems manufacturers. The emphasis is on developing practical and sufficiently accurate design methods.

  4. Circadian genes, the stress axis, and alcoholism.

    Science.gov (United States)

    Sarkar, Dipak K

    2012-01-01

    The body's internal system to control the daily rhythm of the body's functions (i.e., the circadian system), the body's stress response, and the body's neurobiology are highly interconnected. Thus, the rhythm of the circadian system impacts alcohol use patterns; at the same time, alcohol drinking also can alter circadian functions. The sensitivity of the circadian system to alcohol may result from alcohol's effects on the expression of several of the clock genes that regulate circadian function. The stress response system involves the hypothalamus and pituitary gland in the brain and the adrenal glands, as well as the hormones they secrete, including corticotrophin-releasing hormone, adrenocorticotrophic hormone, and glucocorticoids. It is controlled by brain-signaling molecules, including endogenous opioids such as β-endorphin. Alcohol consumption influences the activity of this system and vice versa. Finally, interactions exist between the circadian system, the hypothalamic-pituitary-adrenal axis, and alcohol consumption. Thus, it seems that certain clock genes may control functions of the stress response system and that these interactions are affected by alcohol.

  5. On-Axis Digital Moire Optoelectronic Telemetrology

    Science.gov (United States)

    Meilan, Pablo F.; Laquidara, Aníbal P.; Bava, José A.; Garavaglia, Mario

    2008-04-01

    In previous papers [2,3,4,5] we introduced an operation based on digital moiré pattern processing to measure the distance to an object and its size. The method uses a sequence of digital photographic operations to capture two pictures of the scene with the CCD camera placed at two near and well defined positions along the optical axis of the camera. The distance ΔL between both camera positions is of the order of 1-10% of the distance L from the camera to the selected object in the scene. The teleoperation process algoritm requires to introduce ΔL to determine the distance L. Now we will report a simple and powerful optical system: an optical delay line with an optical path equal to 1.5 m, introduced in the line of sight from the camera to the selected object in the scene. With this optical system it is possible to capture the observed object at distances L and L+ΔL simultaneously in the same picture. The uncertainty in measuring L is of the order of 1%.

  6. Six axis force feedback input device

    Science.gov (United States)

    Ohm, Timothy (Inventor)

    1998-01-01

    The present invention is a low friction, low inertia, six-axis force feedback input device comprising an arm with double-jointed, tendon-driven revolute joints, a decoupled tendon-driven wrist, and a base with encoders and motors. The input device functions as a master robot manipulator of a microsurgical teleoperated robot system including a slave robot manipulator coupled to an amplifier chassis, which is coupled to a control chassis, which is coupled to a workstation with a graphical user interface. The amplifier chassis is coupled to the motors of the master robot manipulator and the control chassis is coupled to the encoders of the master robot manipulator. A force feedback can be applied to the input device and can be generated from the slave robot to enable a user to operate the slave robot via the input device without physically viewing the slave robot. Also, the force feedback can be generated from the workstation to represent fictitious forces to constrain the input device's control of the slave robot to be within imaginary predetermined boundaries.

  7. Axis: Generating Explanations at Scale with Learnersourcing and Machine Learning

    Science.gov (United States)

    Williams, Joseph Jay; Kim, Juho; Rafferty, Anna; Heffernan, Neil; Maldonado, Samuel; Gajos, Krzysztof Z.; Lasecki, Walter S.; Heffernan, Neil

    2016-01-01

    While explanations may help people learn by providing information about why an answer is correct, many problems on online platforms lack high-quality explanations. This paper presents AXIS (Adaptive eXplanation Improvement System), a system for obtaining explanations. AXIS asks learners to generate, revise, and evaluate explanations as they solve…

  8. Wind rotor with vertical axis. Vindrotor med vertikal axel

    Energy Technology Data Exchange (ETDEWEB)

    Colling, J.; Sjoenell, B.

    1987-06-15

    This rotor is of dual type i.e. a paddle wheel shaped rotor close to the vertical axis and a second rotor consisting of vertical blades with wing profile and attached to radial spokes which are fixed to the axis together with the paddle wheel rotor. (L.F.).

  9. Verticality Perception During Off-Vertical Axis Rotation

    NARCIS (Netherlands)

    Vingerhoets, R.A.A.; Gisbergen, J.A.M. van; Medendorp, W.P.

    2007-01-01

    During prolonged rotation about a tilted yaw axis, often referred to as off-vertical axis rotation (OVAR), a percept of being translated along a conical path slowly emerges as the sense of rotation subsides. Recently, we found that these perceptual changes are consistent with a canal-otolith interac

  10. Verticality perception during off-vertical axis rotation

    NARCIS (Netherlands)

    Vingerhoets, R.A.A.; Gisbergen, J.A.M. van; Medendorp, W.P.

    2007-01-01

    During prolonged rotation about a tilted yaw axis, often referred to as off-vertical axis rotation (OVAR), a percept of being translated along a conical path slowly emerges as the sense of rotation subsides. Recently, we found that these perceptual changes are consistent with a canal-otolith interac

  11. Angular momentum projection of tilted axis rotating states

    Energy Technology Data Exchange (ETDEWEB)

    Oi, M.; Onishi, N.; Tajima, N. [Tokyo Univ. (Japan); Horibata, T.

    1998-03-01

    We applied an exact angular momentum projection to three dimensional cranked HFB (3d-CHFB) states. Tilted axis rotating states (TAR) and principal axis rotating states (PAR) are compared. It is shown that TAR is more adequate than PAR for description of the back bending phenomena driven by tilted rotation or wobbling motion. (author)

  12. Effect of low-energy extracorporeal shock wave on vascular regeneration after spinal cord injury and the recovery of motor function

    Directory of Open Access Journals (Sweden)

    Wang L

    2016-08-01

    .05.Conclusion: Low-energy ESWT promotes expression of VEGF, decreases secondary damage of nerve tissue, and improves recovery of motor function. It can be regarded as one mode of clinical routine adjunctive therapy for spinal injury. Keywords: spinal injury, impact wave, VEGF, Flt-1, nerve protection

  13. Turbulence in vertical axis wind turbine canopies

    Science.gov (United States)

    Kinzel, Matthias; Araya, Daniel B.; Dabiri, John O.

    2015-11-01

    Experimental results from three different full scale arrays of vertical-axis wind turbines (VAWTs) under natural wind conditions are presented. The wind velocities throughout the turbine arrays are measured using a portable meteorological tower with seven, vertically staggered, three-component ultrasonic anemometers. The power output of each turbine is recorded simultaneously. The comparison between the horizontal and vertical energy transport for the different turbine array sizes shows the importance of vertical transport for large array configurations. Quadrant-hole analysis is employed to gain a better understanding of the vertical energy transport at the top of the VAWT arrays. The results show a striking similarity between the flows in the VAWT arrays and the adjustment region of canopies. Namely, an increase in ejections and sweeps and decrease in inward and outward interactions occur inside the turbine array. Ejections are the strongest contributor, which is in agreement with the literature on evolving and sparse canopy flows. The influence of the turbine array size on the power output of the downstream turbines is examined by comparing a streamwise row of four single turbines with square arrays of nine turbine pairs. The results suggest that a new boundary layer forms on top of the larger turbine arrays as the flow adjusts to the new roughness length. This increases the turbulent energy transport over the whole planform area of the turbine array. By contrast, for the four single turbines, the vertical energy transport due to turbulent fluctuations is only increased in the near wake of the turbines. These findings add to the knowledge of energy transport in turbine arrays and therefore the optimization of the turbine spacing in wind farms.

  14. DARHT status and preparations for dual-axis hydrotesting (u)

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, David W [Los Alamos National Laboratory

    2010-01-01

    The status of the DARHT facility, including a history of events that have taken place since the end of the DARHT Second Axis Refurbishment Project, is discussed. Technical and operational enhancements that have been made will be addressed, and recent technical challenges, such as the RF noise in the kicker region, are discussed. Historical data on reliability of the second axis is discussed, as well as operational changes made to enhance reliability. In addition, the path forward for integrating the second axis into overall DARHT operations in preparation for a hydrotest is addressed. Timing integration tests are accompanied by a series of tests to evaluate neutron contamination and cross-axis scatter, with attempts being made to provide adequate shielding to minimize the effects of neutrons and cross-beam scatter. The discussion includes results of the testing performed to-date, and concludes with a discussion of the path forward for dual-axis hydrotesting at DARHT.

  15. ACCURATE MEASUREMENT OF ROTA-RY MACHINE AXIS CENTER TRACE

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Four methods aiming at measuring rotary machine axis center trace are discussed in detail.The comparative analysis is made on some aspects such as measurement accuracy, on-machine characteristics, feasibility, practical operation convenience and the integrity of measurement information.In order to simplify measurement, the axis profile error is ignored in traditional condition, while the measurement accuracy will be reduced.The 3-point method that the axis profile error is firstly separated has better real time character, at the same time, not only the axis motion error but also the axis profile error can be measured.All of those information can be used to diagnose the fault origin.The analysis result is proved to be correct by the experiment.

  16. AxiSketcher: Interactive Nonlinear Axis Mapping of Visualizations through User Drawings.

    Science.gov (United States)

    Kwon, Bum Chul; Kim, Hannah; Wall, Emily; Choo, Jaegul; Park, Haesun; Endert, Alex

    2017-01-01

    Visual analytics techniques help users explore high-dimensional data. However, it is often challenging for users to express their domain knowledge in order to steer the underlying data model, especially when they have little attribute-level knowledge. Furthermore, users' complex, high-level domain knowledge, compared to low-level attributes, posits even greater challenges. To overcome these challenges, we introduce a technique to interpret a user's drawings with an interactive, nonlinear axis mapping approach called AxiSketcher. This technique enables users to impose their domain knowledge on a visualization by allowing interaction with data entries rather than with data attributes. The proposed interaction is performed through directly sketching lines over the visualization. Using this technique, users can draw lines over selected data points, and the system forms the axes that represent a nonlinear, weighted combination of multidimensional attributes. In this paper, we describe our techniques in three areas: 1) the design space of sketching methods for eliciting users' nonlinear domain knowledge; 2) the underlying model that translates users' input, extracts patterns behind the selected data points, and results in nonlinear axes reflecting users' complex intent; and 3) the interactive visualization for viewing, assessing, and reconstructing the newly formed, nonlinear axes.

  17. Childhood stressful events, HPA axis and anxiety disorders.

    Science.gov (United States)

    Faravelli, Carlo; Lo Sauro, Carolina; Godini, Lucia; Lelli, Lorenzo; Benni, Laura; Pietrini, Francesco; Lazzeretti, Lisa; Talamba, Gabriela Alina; Fioravanti, Giulia; Ricca, Valdo

    2012-02-22

    Anxiety disorders are among the most common of all mental disorders and their pathogenesis is a major topic in psychiatry, both for prevention and treatment. Early stressful life events and alterations of hypothalamic pituitary adrenal (HPA) axis function seem to have a significant role in the onset of anxiety. Existing data appear to support the mediating effect of the HPA axis between childhood traumata and posttraumatic stress disorder. Findings on the HPA axis activity at baseline and after stimuli in panic disordered patients are inconclusive, even if stressful life events may have a triggering function in the development of this disorder. Data on the relationship between stress, HPA axis functioning and obsessive-compulsive disorder (OCD) are scarce and discordant, but an increased activity of the HPA axis is reported in OCD patients. Moreover, normal basal cortisol levels and hyper-responsiveness of the adrenal cortex during a psychosocial stressor are observed in social phobics. Finally, abnormal HPA axis activity has also been observed in generalized anxiety disordered patients. While several hypothesis have attempted to explain these findings over time, currently the most widely accepted theory is that early stressful life events may provoke alterations of the stress response and thus of the HPA axis, that can endure during adulthood, predisposing individuals to develop psychopathology. All theories are reviewed and the authors conclude that childhood life events and HPA abnormalities may be specifically and transnosographically related to all anxiety disorders, as well as, more broadly, to all psychiatric disorders.

  18. On the problems of describing joint axis alignment.

    Science.gov (United States)

    Ball, Kevin A; Greiner, Thomas M

    2008-01-01

    Each three-dimensional joint possesses at least one potentially oblique axis of rotation. Several systems are used to express joint axis alignment. One system, designated the plane projection (PP) method, describes angles based on orthogonal projections onto two, of the three, anatomical planes. Alternatively, a joint axis may be described in two different ways using two sequential Cardan angle rotations. These expression systems all lay claim to similar descriptive labels, such as deviation and elevation. Difficulties arise as researchers use these various methods to compare their own data to the results of others. A joint axis alignment, described as 27 degrees deviation and 41 degrees elevation in PP, differs by as much as 6 degrees when expressed as Cardan angles. Differences among expression systems increase as the joint axis alignment becomes more oblique -- eventually differing by as much as 75 degrees . This paper explores implications for this lack of congruence among the joint axis expression systems. Effective steps in dealing with these issues begin with recognizing the existence and extent of the problem. The paper provides a common set of algorithms to illustrate and alleviate the possible problems associated with the exchange of joint axis alignment data.

  19. Off-axis illumination direct-to-digital holography

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Clarence E.; Price, Jeffery R.; Voelkl, Edgar; Hanson, Gregory R.

    2004-06-08

    Systems and methods are described for off-axis illumination direct-to-digital holography. A method of recording an off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis, includes: reflecting a reference beam from a reference mirror at a non-normal angle; reflecting an object beam from an object at an angle with respect to an optical axis defined by a focusing lens; focusing the reference beam and the object beam at a focal plane of a digital recorder to form the off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis; digitally recording the off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis; Fourier analyzing the recorded off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes by transforming axes of the recorded off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes in Fourier space to sit on top of a heterodyne carrier frequency defined as an angle between the reference beam and the object beam; applying a digital filter to cut off signals around an original origin; and then performing an inverse Fourier transform.

  20. Thoughts on the so-called radius-capitellum axis

    Energy Technology Data Exchange (ETDEWEB)

    Schild, H.; Mueller, H.A.; Wagner, H.; Baetz, W.

    1982-02-01

    We have studied 438 patients radiologically in order to observe the so-called 'radius-capitellum axis'. In about a quarter of people with normal elbows the axis passes lateral to the middle portion of the capitellum, so that even when there is marked deviation, there is no certainty that the humero-radial joint is abnormal. Deviation of the axis can be caused by changes in the shape of the capitellum or of the radius, or by distension of the capsule of the elbow joint, or by various changes in muscular pull.

  1. Research of the micromechanical three-axis accelerometer

    Science.gov (United States)

    Konoplev, B.; Lysenko, I.; Ryndin, E.; Ezhova, O.; Bondarev, F.

    2016-12-01

    In the report the linear acceleration sensor design with three axis of sensitivity is researched. Parameterized geometry and finite element model for modal analysis are developed in the ANSYS program. Behavioral description of the study design is developed with language VHDL-AMS to simulate the sensor operation under the influence of linear acceleration along three axis of sensitivity. On the basis of research results three-axis device sensitivity, cross-sensitivity, duration transients are specified. As part of the work the experimental sensor prototypes are fabricated.

  2. Kinematic and Dynamic Analyses of the Orthoglide 5-axis

    CERN Document Server

    Ur-Rehman, Raza; Chablat, Damien; Wenger, Philippe

    2008-01-01

    This paper deals with the kinematic and dynamic analyses of the Orthoglide 5-axis, a five-degree-of-freedom manipulator. It is derived from two manipulators: i) the Orthoglide 3-axis; a three dof translational manipulator and ii) the Agile eye; a parallel spherical wrist. First, the kinematic and dynamic models of the Orthoglide 5-axis are developed. The geometric and inertial parameters of the manipulator are determined by means of a CAD software. Then, the required motors performances are evaluated for some test trajectories. Finally, the motors are selected in the catalogue from the previous results.

  3. Asteroid spin-axis longitudes from the Lowell Observatory database

    CERN Document Server

    Bowell, E; Wasserman, L H; Muinonen, K; Penttilä, A; Trilling, D E

    2013-01-01

    By analyzing brightness variation with ecliptic longitude and using the Lowell Observatory photometric database, we estimate spin-axis longitudes for more than 350 000 asteroids. Hitherto, spin-axis longitude estimates have been made for fewer than 200 asteroids. We investigate longitude distributions in different dynamical groups and asteroid families. We show that asteroid spin-axis longitudes are not isotropically distributed as previously considered. We find that the spin-axis longitude distribution for main-belt asteroids is clearly non-random, with an excess of longitudes from the interval 30{\\deg}-110{\\deg} and a paucity between 120{\\deg}-180{\\deg}. The explanation of the non-isotropic distribution is unknown at this point. Further studies have to be conducted to determine if the shape of the distribution can be explained by observational bias, selection effects, a real physical process or other mechanism.

  4. Circular Interpolation Algorithms of 5-Axis Simultaneous CNC System

    Institute of Scientific and Technical Information of China (English)

    ZHENG Kuijing; SHANG Bo

    2006-01-01

    Spatial circular arc can be machined conveniently by a 5-axis NC machine tool. Based on the data sampling method, circular interpolation in two-dimensional plane is discussed briefly. The key is to solve the problem of circular center expressed in the workpiece coordinate system by means of the transformation matrix. Circular interpolation in three-dimensional space is analyzed in detail. The method of undetermined coefficient is used to solve the center of the spatial circle and the method of coordinate transformation is used to transform the spatial circle into the XY_plane. Circular arc in three-dimensional space can be machined by the positional 5-axis machining and the conical surface can be machined by the continuous 5-axis machining. The velocity control is presented to avoid the feedrate fluctuation. The interpolation algorithms are tested by a simulation example and the interpolation algorithms are proved feasible. The algorithms are applied to the 5-axis CNC system software.

  5. Space/Flight Operable Miniature Six Axis Transducer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — FUTEK will fully design and manufacture a sensor capable of measuring forces in and about each axis. The unit will measure forces up to 300 Newton's in the principle...

  6. Determination of Elastic Twist in Horizontal Axis Wind Turbines (HAWTs)

    Energy Technology Data Exchange (ETDEWEB)

    Stoddard, F.; Nelson, V.; Starcher, K.; Andrews, B.

    2006-06-01

    This report presents the results of a project at the Alternative Energy Institute (AEI) which measured and calculated the elastic twist of three representative composite horizontal-axis blades: Carter 300, Gougeon ESI 54, and UTRC 8 kW.

  7. The effects of lateral head tilt on ocular astigmatic axis

    Directory of Open Access Journals (Sweden)

    Hamid Fesharaki

    2014-01-01

    Conclusion: Any minimal angle of head tilt may cause erroneous measurement of astigmatic axis and should be avoided during refraction. One cannot rely on the compensatory function of ocular counter-torsion during the refraction.

  8. A Method for Modeling of Floating Vertical Axis Wind Turbine

    DEFF Research Database (Denmark)

    Wang, Kai; Hansen, Martin Otto Laver; Moan, Torgeir

    2013-01-01

    . In order to assess the technical and economic feasibility of this novel concept, a comprehensive simulation tool for modeling of the floating vertical axis wind turbine is needed. This work presents the development of a coupled method for modeling of the dynamics of a floating vertical axis wind turbine......It is of interest to investigate the potential advantages of floating vertical axis wind turbine (FVAWT) due to its economical installation and maintenance. A novel 5MW vertical axis wind turbine concept with a Darrieus rotor mounted on a semi-submersible support structure is proposed in this paper....... This integrated dynamic model takes into account the wind inflow, aerodynamics, hydrodynamics, structural dynamics (wind turbine, floating platform and the mooring lines) and a generator control. This approach calculates dynamic equilibrium at each time step and takes account of the interaction between the rotor...

  9. Early programming of the IGF-I axis

    DEFF Research Database (Denmark)

    Larnkjær, Anni; Ingstrup, Helga Kristensen; Schack-Nielsen, Lene

    2009-01-01

    -I production. Conversely, studies suggest that later in childhood, those breastfed are taller and have higher IGF-I levels. Therefore, it has been suggested that the IGF-I axis may be programmed by diet during infancy. The association between IGF-I in infancy and later life is not known. OBJECTIVE: To examine......=-0.26, P=0.043, and n=109). CONCLUSION: The results support the hypothesis that the IGF-I axis can be programmed early in life....

  10. The reno-pineal axis: A novel role for melatonin

    Directory of Open Access Journals (Sweden)

    Sanjay Kalra

    2012-01-01

    Full Text Available The pineal gland is a tiny endocrine gland whose physiologic role has been the focus of much research and much more speculation over the past century. This mini-review discusses recent findings which correlate melatonin and renal physiology, and postulates the presence of a "reno-pineal axis." Drawing lessons from comparative endocrinology, while quoting human data, it advocates the need to study the "reno-pineal axis" in greater detail.

  11. DARHT Axis-I Diode Simulations II: Geometric Scaling

    OpenAIRE

    Ekdahl, Carl

    2017-01-01

    The dual-axis radiography for hydrodynamic testing (DARHT) facility at Los Alamos National Laboratory uses two electron linear-induction accelerators (LIA) to produce the source spots for perpendicular flash radiographs of a dynamic experiment.Manipulating the beam current is a means for adjusting the dose, and one way to do this is to change the size of the cathode. This article describes simulations undertaken to develop scaling laws for use as design tools in changing the Axis-1 beam curre...

  12. Improved Controller for a Three-Axis Piezoelectric Stage

    Science.gov (United States)

    Rao, Shanti; Palmer, Dean

    2009-01-01

    An improved closed-loop controller has been built for a three-axis piezoelectric positioning stage. The stage can be any of a number of commercially available or custom-made units that are used for precise three-axis positioning of optics in astronomical instruments and could be used for precise positioning in diverse fields of endeavor that include adaptive optics, fabrication of semiconductors, and nanotechnology.

  13. Traumatic Spondylolisthesis of the Axis Vertebra in Adults

    OpenAIRE

    Schleicher, Philipp; Scholz, Matti; Pingel, Andreas; Kandziora, Frank

    2015-01-01

    Study Design Narrative review. Objective To elucidate the current concepts in diagnosis and treatment of traumatic spondylolisthesis of the axis. Methods Literature review using PubMed, Google Scholar, and Cochrane databases. Results The traumatic spondylolisthesis of the axis accounts to 5% of all cervical spine injuries and is defined by a bilateral separation of the C2 vertebral body from the neural arch. The precise location of the fracture line may vary widely. For understanding the path...

  14. Off-Axis Aspheric Surfacing Using Sub-Aperture Tools

    Science.gov (United States)

    Feng, Yunpeng; Qiao, Xiaoyan; Cheng, Haobo; Tam, Hon-Yuen

    2013-10-01

    The off-axis aspheric surface used in modern optical systems widely can obtain nearly perfect quality, realize both small packet-size and low-mass, and avoid the central obscuration. But it is difficult to fabricate because of asymmetry. There are some key technologies during the testing and fabrication of off-axis asphere. In this article, we proposed a method of the best fit sphere based on non-negative minimized removal criterion. And a measured data fitting algorithm was presented to estimate the geometry parameters of off-axis aspheric surface. Then an off-axis mirror was fabricated, and the interferometrically measured data was corrected to eliminate the distortion introduced by null compensator in every run. Finally, the surface error of off-axis mirror reduced to pv = 0.372λ, rms = 0.046λ, the surface roughness reached 0.72 nm. These methods mentioned in the article are suitable for off-axis aspheric optics.

  15. Optic axis-driven new horizons for hyperbolic metamaterials

    Directory of Open Access Journals (Sweden)

    Boardman Allan D.

    2015-01-01

    Full Text Available The broad assertion here is that the current hyperbolic metamaterial world is only partially served by investigations that incorporate only some limited version of anisotropy. Even modest deviations of the optic axis from the main propagation axis lead to new phase shifts, which not only compete with those created by absorption but end up dominating them. Some progress has been attempted in the literature by introducing the terms “asymmetric hyperbolic media”, but it appears that this kind of asymmetry only involves an optic axis at an angle to the interface of a uniaxial crystal. From a device point of view, many new prospects should appear and the outcomes of the investigations presented here yield a new general theory. It is emphasised that the orientation of the optic axis is a significant determinant in the resulting optical properties. Whereas for conventional anisotropic waveguides homogeneous propagating waves occur over a limited range of angular dispositions of the optic axis it is shown that for a hyperbolic guide a critical angular setting exists, above which the guided waves are always homogeneous. This has significant implications for metawaveguide designs. The resulting structures are more tolerant to optic axis misalignment.

  16. Space camera optical axis pointing precision measurement system

    Science.gov (United States)

    Chen, Gang; Meng, Fanbo; Yang, Zijun; Guo, Yubo; Ye, Dong

    2016-01-01

    In order to realize the space camera which on satellite optical axis pointing precision measurement, a monocular vision measurement system based on object-image conjugate is established. In this system the algorithms such as object-image conjugate vision models and point by point calibration method are applied and have been verified. First, the space camera axis controller projects a laser beam to the standard screen for simulating the space camera's optical axis. The laser beam form a target point and has been captured by monocular vision camera. Then the two-dimensional coordinates of the target points on the screen are calculated by a new vision measurement model which based on a looking-up and matching table, the table has been generated by object-image conjugate algorithm through point by point calibration. Finally, compare the calculation of coordinates offered by measurement system with the theory of coordinate offered by optical axis controller, the optical axis pointing precision can be evaluated. Experimental results indicate that the absolute precision of measurement system up to 0.15mm in 2m×2m FOV. This measurement system overcome the nonlinear distortion near the edge of the FOV and can meet the requirement of space camera's optical axis high precision measurement and evaluation.

  17. Energy Efficient Hybrid Dual Axis Solar Tracking System

    Directory of Open Access Journals (Sweden)

    Rashid Ahammed Ferdaus

    2014-01-01

    Full Text Available This paper describes the design and implementation of an energy efficient solar tracking system from a normal mechanical single axis to a hybrid dual axis. For optimizing the solar tracking mechanism electromechanical systems were evolved through implementation of different evolutional algorithms and methodologies. To present the tracker, a hybrid dual-axis solar tracking system is designed, built, and tested based on both the solar map and light sensor based continuous tracking mechanism. These light sensors also compare the darkness and cloudy and sunny conditions assisting daily tracking. The designed tracker can track sun’s apparent position at different months and seasons; thereby the electrical controlling device requires a real time clock device for guiding the tracking system in seeking solar position for the seasonal motion. So the combination of both of these tracking mechanisms made the designed tracker a hybrid one. The power gain and system power consumption are compared with a static and continuous dual axis solar tracking system. It is found that power gain of hybrid dual axis solar tracking system is almost equal to continuous dual axis solar tracking system, whereas the power saved in system operation by the hybrid tracker is 44.44% compared to the continuous tracking system.

  18. The equivalents of human blood and spleen dendritic cell subtypes can be generated in vitro from human CD34+ stem cells in the presence of fms-like tyrosine kinase 3 ligand and thrombopoietin

    OpenAIRE

    Proietto, AI; Mittag, D; Roberts, AW; Sprigg, N; L. Wu

    2012-01-01

    Dendritic cells (DCs) are immune cells specialized to capture, process and present antigen to T cells in order to initiate an appropriate adaptive immune response. The study of mouse DC has revealed a heterogeneous population of cells that differ in their development, surface phenotype and function. The study of human blood and spleen has shown the presence of two subsets of conventional DC including the CD1b/c+ and CD141+CLEC9A+ conventional DC (cDC) and a plasmacytoid DC (pDC) that is CD304...

  19. Ultrasound-guided internal jugular vein access: Comparison between short axis and long axis techniques

    Directory of Open Access Journals (Sweden)

    Tarek F Tammam

    2013-01-01

    Full Text Available The use of real-time ultrasound (US is advantageous in the insertion of central venous catheters (CVCs in adults, especially in whom difficulties are anticipated for various reasons. The aim of the present study was to compare two different real-time 2-dimensional US-guided techniques [short axis view/out-of-plane approach (SAX OOP approach versus long axis view/in-plane approach (LAX IP approach] for internal jugular vein (IJV cannulation. In this prospective study, 90 critical care and hemodialysis patients were assigned for insertion of CVCs using either the real-time US-guided (SAX OOP approach or LAX IP approach or landmark technique (control group. Failed catheter placement, risk of complications from placement, failure on first attempt at placement, number of attempts until successful catheterization, time to successful catheterization, incidence of central line-associated blood stream infection (CLA-BSI and demographics of each patient were recorded. There were no significant differences in patient′s demographic characteristics, side of cannulation (right or left or presence of risk factors for difficult venous cannulation between the three groups of patients. Cannulation of the IJV was achieved in all patients by using US (SAX OOP and LAX IP approaches and in 27 of the patients (90% by using the landmark technique (P = 0.045. Average access time (skin to vein and number of attempts were comparable between the SAX OOP and the LAX IP approaches while significantly reduced in both US groups of patients compared with the landmark group (P <0.001. In the landmark group, puncture of the carotid artery occurred in 16.7% of the patients, hematoma in 23.3% of the patients, pneumothorax in 3.3% of the patients and CLA-BSI in 20% of the patients, which were all significantly increased compared with the US group (P <0.05. The findings of this study suggest that the SAX OOP and LAX IP approaches were comparable for cannulation of IJV in critical

  20. Magnetic axis alignment and the Poisson alignment reference system

    Science.gov (United States)

    Griffith, Lee V.; Schenz, Richard F.; Sommargren, Gary E.

    1989-01-01

    Three distinct metrological operations are necessary to align a free-electron laser (FEL): the magnetic axis must be located, a straight line reference (SLR) must be generated, and the magnetic axis must be related to the SLR. This paper begins with a review of the motivation for developing an alignment system that will assure better than 100 micrometer accuracy in the alignment of the magnetic axis throughout an FEL. The paper describes techniques for identifying the magnetic axis of solenoids, quadrupoles, and wiggler poles. Propagation of a laser beam is described to the extent of revealing sources of nonlinearity in the beam. Development and use of the Poisson line, a diffraction effect, is described in detail. Spheres in a large-diameter laser beam create Poisson lines and thus provide a necessary mechanism for gauging between the magnetic axis and the SLR. Procedures for installing FEL components and calibrating alignment fiducials to the magnetic axes of the components are also described. An error budget shows that the Poisson alignment reference system will make it possible to meet the alignment tolerances for an FEL.

  1. Mifepristone Accelerates HPA Axis Recovery in Secondary Adrenal Insufficiency.

    Science.gov (United States)

    Cohan, Pejman

    2016-01-01

    Context. Transient secondary adrenal insufficiency (SAI) is an expected complication following successful adenomectomy of ACTH-secreting pituitary adenomas or unilateral adrenalectomy for cortisol-secreting adrenal adenomas. To date, no pharmacological therapy has been shown to hasten recovery of the hypothalamic-pituitary-adrenal (HPA) axis in this clinical scenario. Case Description. A 33-year-old woman underwent uncomplicated unilateral adrenalectomy for a 3.7 cm cortisol-secreting adrenal adenoma. Postoperatively, she developed SAI and was placed on hydrocortisone 15 mg/day, given in divided doses. In the ensuing six years, the patient's HPA axis failed to recover and she remained corticosteroid-dependent. Quarterly biochemical testing (after withholding hydrocortisone for 18 hours) consistently yielded undetectable serum cortisol and subnormal plasma ACTH levels. While she was on hydrocortisone 15 mg/day, mifepristone was initiated and gradually titrated to a maintenance dose of 600 mg/day after 5 months. Rapid recovery of the HPA axis was subsequently noted with ACTH rising into the supranormal range at 4 months followed by a subsequent rise in cortisol levels into the normal range. After 6 months, the dose of hydrocortisone and mifepristone was lowered and both were ultimately stopped after 8 months. The HPA axis remains normal after an additional 16 months of follow-up. Conclusion. Mifepristone successfully restored the HPA axis in a woman with prolonged secondary adrenal insufficiency (SAI) after adrenalectomy for Cushing's syndrome (CS).

  2. Measurement Axis Searching Model for Terrestrial Laser Scans Registration

    Directory of Open Access Journals (Sweden)

    Shaoxing Hu

    2016-01-01

    Full Text Available Nowadays, terrestrial Lidar scans can cover rather a large area; the point densities are strongly varied because of the line-of-sight measurement principle in potential overlaps with scans taken from different viewpoints. Most of the traditional methods focus on registration algorithm and ignore searching model. Sometimes the traditional methods are directly used to align two point clouds; a large critically unsolved problem of the large biases will be created in areas distant from the overlaps while the local overlaps are often aligned well. So a novel measurement axis searching model (MASM has been proposed in this paper. The method includes four steps: (1 the principal axis fitting, (2 the measurement axis generation, (3 low-high-precision search, and (4 result generation. The principal axis gives an orientation to the point cloud; the search scope is limited by the measurement axis. The point cloud orientation can be adjusted gradually until the achievement of the global optimum using low- and high-precision search. We perform some experiments with simulated point clouds and real terrestrial laser scans. The results of simulated point clouds have shown the processing steps of our method, and the results of real terrestrial laser scans have shown the sensitivity of the approach with respect to the indoor and outdoor scenes.

  3. Alignment method of off-axis RC reflective optical system

    Science.gov (United States)

    Xue-min, Zhang; Xing, Song; Zhi-jun, Zhang; Hou, Xiao-hua

    2016-10-01

    Off-axis optical system has a wide application in space optics and remote detective area. The high surface shape accuracy can be ensured with the development of advanced manufacture technique. So the only condition which limits the wide application of off-axis optical system is how to realize the precise alignment of it. Based on a RC reflective optical system whose diameter is 400mm, the alignment method which combines the high resolution initial placement and computer-aided alignment is introduced. By designing a system which can measure the off-axis fabrication and off-axis angle precisely, the high resolution initial placement of off-axis mirror can be ensured with a measurement accuracy of +/-0.05mm and +/-10". The good initial placement can give a good initial state, so the computer-aided model can be converged well. The experiment shows that a system which has a good initial placement could have a good wave aberration of 0.04λ after three times iteration adjustment.

  4. An FGF3-BMP Signaling Axis Regulates Caudal Neural Tube Closure, Neural Crest Specification and Anterior-Posterior Axis Extension.

    Science.gov (United States)

    Anderson, Matthew J; Schimmang, Thomas; Lewandoski, Mark

    2016-05-01

    During vertebrate axis extension, adjacent tissue layers undergo profound morphological changes: within the neuroepithelium, neural tube closure and neural crest formation are occurring, while within the paraxial mesoderm somites are segmenting from the presomitic mesoderm (PSM). Little is known about the signals between these tissues that regulate their coordinated morphogenesis. Here, we analyze the posterior axis truncation of mouse Fgf3 null homozygotes and demonstrate that the earliest role of PSM-derived FGF3 is to regulate BMP signals in the adjacent neuroepithelium. FGF3 loss causes elevated BMP signals leading to increased neuroepithelium proliferation, delay in neural tube closure and premature neural crest specification. We demonstrate that elevated BMP4 depletes PSM progenitors in vitro, phenocopying the Fgf3 mutant, suggesting that excessive BMP signals cause the Fgf3 axis defect. To test this in vivo we increased BMP signaling in Fgf3 mutants by removing one copy of Noggin, which encodes a BMP antagonist. In such mutants, all parameters of the Fgf3 phenotype were exacerbated: neural tube closure delay, premature neural crest specification, and premature axis termination. Conversely, genetically decreasing BMP signaling in Fgf3 mutants, via loss of BMP receptor activity, alleviates morphological defects. Aberrant apoptosis is observed in the Fgf3 mutant tailbud. However, we demonstrate that cell death does not cause the Fgf3 phenotype: blocking apoptosis via deletion of pro-apoptotic genes surprisingly increases all Fgf3 defects including causing spina bifida. We demonstrate that this counterintuitive consequence of blocking apoptosis is caused by the increased survival of BMP-producing cells in the neuroepithelium. Thus, we show that FGF3 in the caudal vertebrate embryo regulates BMP signaling in the neuroepithelium, which in turn regulates neural tube closure, neural crest specification and axis termination. Uncovering this FGF3-BMP signaling axis is

  5. An FGF3-BMP Signaling Axis Regulates Caudal Neural Tube Closure, Neural Crest Specification and Anterior-Posterior Axis Extension.

    Directory of Open Access Journals (Sweden)

    Matthew J Anderson

    2016-05-01

    Full Text Available During vertebrate axis extension, adjacent tissue layers undergo profound morphological changes: within the neuroepithelium, neural tube closure and neural crest formation are occurring, while within the paraxial mesoderm somites are segmenting from the presomitic mesoderm (PSM. Little is known about the signals between these tissues that regulate their coordinated morphogenesis. Here, we analyze the posterior axis truncation of mouse Fgf3 null homozygotes and demonstrate that the earliest role of PSM-derived FGF3 is to regulate BMP signals in the adjacent neuroepithelium. FGF3 loss causes elevated BMP signals leading to increased neuroepithelium proliferation, delay in neural tube closure and premature neural crest specification. We demonstrate that elevated BMP4 depletes PSM progenitors in vitro, phenocopying the Fgf3 mutant, suggesting that excessive BMP signals cause the Fgf3 axis defect. To test this in vivo we increased BMP signaling in Fgf3 mutants by removing one copy of Noggin, which encodes a BMP antagonist. In such mutants, all parameters of the Fgf3 phenotype were exacerbated: neural tube closure delay, premature neural crest specification, and premature axis termination. Conversely, genetically decreasing BMP signaling in Fgf3 mutants, via loss of BMP receptor activity, alleviates morphological defects. Aberrant apoptosis is observed in the Fgf3 mutant tailbud. However, we demonstrate that cell death does not cause the Fgf3 phenotype: blocking apoptosis via deletion of pro-apoptotic genes surprisingly increases all Fgf3 defects including causing spina bifida. We demonstrate that this counterintuitive consequence of blocking apoptosis is caused by the increased survival of BMP-producing cells in the neuroepithelium. Thus, we show that FGF3 in the caudal vertebrate embryo regulates BMP signaling in the neuroepithelium, which in turn regulates neural tube closure, neural crest specification and axis termination. Uncovering this FGF3

  6. Dual axis operation of a micromachined rate gyroscope

    Energy Technology Data Exchange (ETDEWEB)

    Juneau, T. [BSAC, Berkeley, CA (United States); Pisano, A.P. [Univ. California, Berkeley, CA (United States). Dept. of Mechanical Engineering; Smith, J. [Sandia National Lab., Albuquerque, NM (United States)

    1997-04-01

    Since micromachining technology has raised the prospect of fabricating high performance sensors without the associated high cost and large size, many researchers have investigated micromachined rate gyroscopes. The vast majority of research has focused on single input axis rate gyroscopes, but this paper presents work on a dual input axis micromachined rate gyroscope. The key to successful simultaneous dual axis operation is the quad symmetry of the circular oscillating rotor design. Untuned gyroscopes with mismatched modes yielded random walk as low as 10{degrees}/{radical}hour with cross sensitivity ranging from 6% to 16%. Mode frequency matching via electrostatic tuning allowed performance better than 2{degrees}/{radical}hour, but at the expense of excessive cross sensitivity.

  7. The microbiota-gut-brain axis in functional gastrointestinal disorders.

    Science.gov (United States)

    De Palma, Giada; Collins, Stephen M; Bercik, Premysl

    2014-01-01

    Functional gastrointestinal disorders (FGIDs) are highly prevalent and pose a significant burden on health care and society, and impact patients' quality of life. FGIDs comprise a heterogeneous group of disorders, with unclear underlying pathophysiology. They are considered to result from the interaction of altered gut physiology and psychological factors via the gut-brain axis, where brain and gut symptoms are reciprocally influencing each other's expression. Intestinal microbiota, as a part of the gut-brain axis, plays a central role in FGIDs. Patients with Irritable Bowel Syndrome, a prototype of FGIDs, display altered composition of the gut microbiota compared with healthy controls and benefit, at the gastrointestinal and psychological levels, from the use of probiotics and antibiotics. This review aims to recapitulate the available literature on FGIDs and microbiota-gut-brain axis.

  8. Chronic Lyme disease and the 'Axis of Evil'.

    Science.gov (United States)

    Stricker, Raphael B; Johnson, Lorraine

    2008-12-01

    Lyme disease is a controversial illness, and the existence of chronic Lyme disease induced by persistent infection with the Lyme spirochete, Borrelia burgdorferi, is the subject of continued debate. A recent publication defined the 'Axis of Evil' in this controversy as physicians who treat patients with needlessly prolonged courses of antibiotics, 'specialty laboratories' that perform 'inaccurate' Lyme testing and the internet, which promotes 'Lyme hysteria'. We examine the 'Axis of Evil' components in the context of diagnostic and therapeutic challenges for Lyme disease patients and their physicians, and we present an evidence-based refutation to this misguided view. Despite its virulent nature, the 'Axis of Evil' perspective is a useful starting point to resolve the controversy over Lyme disease.

  9. Targeting the HER-kinase axis in cancer.

    Science.gov (United States)

    Gross, Mitchell E; Shazer, Ronald L; Agus, David B

    2004-02-01

    The human epidermal growth factor receptor (HER) family of receptor tyrosine kinases controls critical pathways involved in the differentiation, growth, division, and motility of normal epithelial cells. Most human solid tumors are of epithelial origin. The process of malignant transformation and progression in many cancers may depend on activation of ligands and receptors that function as part of the HER-kinase pathway. This signaling axis has earned increased attention because of the development of antibodies and small-molecule tyrosine kinase inhibitors that specifically target components of the HER-kinase axis for cancer therapy. This review focuses on the basic biology underlying HER-kinase pathway activation and the current state of development for agents that target this axis. In particular, the importance of pan-HER inhibitors is discussed.

  10. Helly-type Theorems for Hollow Axis-aligned Boxes

    CERN Document Server

    Swanepoel, Konrad J

    2009-01-01

    A hollow axis-aligned box is the boundary of the cartesian product of $d$ compact intervals in R^d. We show that for d\\geq 3, if any 2^d of a collection of hollow axis-aligned boxes have non-empty intersection, then the whole collection has non-empty intersection; and if any 5 of a collection of hollow axis-aligned rectangles in R^2 have non-empty intersection, then the whole collection has non-empty intersection. The values 2^d for d\\geq 3 and 5 for d=2 are the best possible in general. We also characterize the collections of hollow boxes which would be counterexamples if 2^d were lowered to 2^d-1, and 5 to 4, respectively.

  11. Microscope system with on axis programmable Fourier transform filtering

    Science.gov (United States)

    Martínez, José Luis; García-Martínez, Pascuala; Moreno, Ignacio

    2017-02-01

    We propose an on-axis microscope optical system to implement programmable optical Fourier transform image processing operations, taking advantage of phase and polarization modulation of a liquid crystal on silicon (LCOS) display. We use a Hamamatsu spatial light modulator (SLM), free of flickering, which therefore can be tuned to fully eliminate the zero order component of the encoded diffractive filter. This allows the realization of filtering operation on axis (as opposed to other systems in the literature that require operating off axis), therefore making use of the full space bandwidth provided by the SLM. The system is first demonstrated by implementing different optical processing operations based on phase-only blazed gratings such as phase contrast, band-pass filtering, or additive and substractive imaging. Then, a simple Differential interference contrast (DIC) imaging is obtained changing to a polarization modulation scheme, achieved simply by selecting a different incident state of polarization on the incident beam.

  12. Chandra X-ray Observatory Optical Axis and Aimpoint

    Science.gov (United States)

    Zhao, Ping

    2016-01-01

    Chandra X-ray Observatory revolutionized the X-ray astronomy as being the first, and so far the only, X-ray telescope achieving sub-arcsecond resolution. Chandra comprises of three principal elements: the High Resolution Mirror Assembly (HRMA), Pointing Control and Aspect Determination (PCAD) system, and the Science Instrument Module (SIM). To achieve and retain the unprecedented imaging quality, it is critical that these three principal elements stay rigid and stable for the entire life time of the Chandra operation. Tracking the Chandra optical axis and aimpoint with respect to detector positions is the most relevant measurement for understanding telescope stability. The study shows that both the optical axis and the aimpoint has been drifting since Chandra launch. I will discuss the telescope focal-point, optical axis, aimpoint, their positiondrifts during the mission, the impact to Chandra operations, and the permanent default aimpoint, to be implemented in Chandra cycle 18.

  13. A three-axis ultrasensitive accelerometer for space

    Science.gov (United States)

    Bernard, A.

    A three-axis ultrasensitive accelerometer ASTRE (Accelerometre Spatial Triaxial Electrostatique) is a simplified version of the GRADIO accelerometer designed for the ARISTOTELES mission, which operates by measuring the force provided by a three-axis electrostatic suspension of the proof-mass. It covers the g-spectrum from 10 exp -8 to 10 exp -4 in the frequency range dc to 5 Hz. A dedicated test bench was developed in order to preserve the accelerometer from the seismic noise. The paper presents the performance parameters of the ASTRE accelerometer and some of the design schemes.

  14. Development of methodology for horizontal axis wind turbine dynamic analysis

    Science.gov (United States)

    Dugundji, J.

    1982-01-01

    Horizontal axis wind turbine dynamics were studied. The following findings are summarized: (1) review of the MOSTAS computer programs for dynamic analysis of horizontal axis wind turbines; (2) review of various analysis methods for rotating systems with periodic coefficients; (3) review of structural dynamics analysis tools for large wind turbine; (4) experiments for yaw characteristics of a rotating rotor; (5) development of a finite element model for rotors; (6) development of simple models for aeroelastics; and (7) development of simple models for stability and response of wind turbines on flexible towers.

  15. Computer Controlled Polishing of the Off-axis Aspheric Mirrors

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, the manufacturing and testing procedures to make large off-axis aspherical mirrors are presented. The difficulties in polishing and testing for both circular-aperture and rectangular-aperture mirrors are previewed, and a possible solution is given. The two mirrors have been polished by means of CCOS, and the final accuracy is 25nm rms for 770mm×210mm rectangular mirror and 20nm rms for φ600mm circular mirror. These results just meet the optical tolerances specified by the designer, and the manufacturing and testing procedures presented here show good ability to make the large off-axis aspherical mirrors.

  16. Efficient Path Query and Reasoning Method Based on Rare Axis

    Institute of Scientific and Technical Information of China (English)

    姜洋; 冯志勇; 王鑫马晓宁

    2015-01-01

    A new concept of rare axis based on statistical facts is proposed, and an evaluation algorithm is designed thereafter. For the nested regular expressions containing rare axes, the proposed algorithm can reduce its evaluation complexity from polynomial time to nearly linear time. The distributed technique is also employed to construct the navigation axis indexes for resource description framework (RDF) graph data. Experiment results in DrugBank and BioGRID show that this method can improve the query efficiency significantly while ensuring the accuracy and meet the query requirements on Web-scale RDF graph data.

  17. Three axis vector atomic magnetometer utilizing polarimetric technique.

    Science.gov (United States)

    Pradhan, Swarupananda

    2016-09-01

    The three axis vector magnetic field measurement based on the interaction of a single elliptically polarized light beam with an atomic system is described. The magnetic field direction dependent atomic responses are extracted by the polarimetric detection in combination with laser frequency modulation and magnetic field modulation techniques. The magnetometer geometry offers additional critical requirements like compact size and large dynamic range for space application. Further, the three axis magnetic field is measured using only the reflected signal (one polarization component) from the polarimeter and thus can be easily expanded to make spatial array of detectors and/or high sensitivity field gradient measurement as required for biomedical application.

  18. Three axis vector atomic magnetometer utilizing polarimetric technique

    CERN Document Server

    Pradhan, Swarupananda

    2016-01-01

    The three axis magnetic field measurement based on the interaction of a single elliptically polarized light beam with an atomic system is described. The magnetic field direction dependent atomic responses are extracted by the polarimetric detection in combination with laser frequency modulation and magnetic field modulation techniques. The magnetometer offers additional critical requirements like compact size and large dynamic range for space application. Further, the three axis magnetic field is measured using only reflected signal from the polarimeter, thus can be easily expanded to make spatial array of detectors or / and high sensitivity field gradient measurement as required for biomedical application.

  19. Fast satellite prediction for four-axis telescopes

    Institute of Scientific and Technical Information of China (English)

    林钦畅

    1996-01-01

    The features of the method are as follows: Adopting an optimum average small arc to four-axis prediction,the azimuth and altitude of the tracking axis need not be adjusted during the same observation procedure.The prediction has been used for three different types of telescopes for many years and all demands of users have been satisfied.In this method,the prediction contents were more than others.Separating the unknowns,the actual equations for operation were concise,and the needed machine time was much less,even for the prediction of multistation.

  20. Fast and accurate measurement of on-axis gain and on-axis polarization at a finite distance

    DEFF Research Database (Denmark)

    Pivnenko, S.; Breinbjerg, O.

    2013-01-01

    In this paper, a technique for fast and accurate measurement of on-axis gain and on-axis polarization characteristics of antennas, such as Standard Gain Horns, compact range feed horns, and near-field probes, is described. The proposed gain determination procedure is a modification of the far-field...... orientations versus a polarization calibrated probe. A complete set of measurements for one AUT takes less than two hours. The measurement uncertainty for the gain is comparable to the one obtained with the near-field substitution technique and typically does not exceed 0.1 dB (1 sigma)....

  1. Alfven eigenmode structure during off-axis neutral beam injection

    NARCIS (Netherlands)

    Tobias, B.; Bass, E. M.; Classen, I.G.J.; Domier, C.W.; Grierson, B. A.; Heidbrink, W. W.; N C Luhmann Jr.,; Nazikian, R.; Park, H. K.; Spong, D. A.; VanZeeland, M. A.

    2012-01-01

    The spatial structure of Alfven eigenmodes on the DIII-D tokamak is compared for contrasting fast ion deposition profiles resulting from on- and off-axis neutral beam injection (NBI). In both cases, poloidal mode rotation and eigenmode twist, or radial phase variation, are correlated with the direct

  2. On lifting line analysis of horizontal axis windturbines

    Science.gov (United States)

    Politis, G. K.; Loukakis, T. A.

    A convergent iteration scheme for lifting line performance analysis of horizontal axis windturbines is presented. Lifting line correction factors are introduced and compared with those of Prandtl and Goldstein. Lifting line and strip theory formulations are applied for the calculation of performance for two windturbines. Differences of engineering importance are shown to exist in the prediction of the Power coefficient.

  3. Thermally induced reversible easy axis rotations in permalloy thin films

    NARCIS (Netherlands)

    Horsthuis, Winfried H.G.; Eijkel, Kees J.M.; Ridder, de René M.; Leeuwis, Henk

    1988-01-01

    The thermal stability of the easy axis orientation in thin Permalloy films was studied. This orientation was measured by two methods, i.e. the magneto-optic Kerr effect and a novel measurement scheme based on magnetoresistive effects. It appeared that even for small temperature changes rotations of

  4. Microbiota regulation of the Mammalian gut-brain axis.

    Science.gov (United States)

    Burokas, Aurelijus; Moloney, Rachel D; Dinan, Timothy G; Cryan, John F

    2015-01-01

    The realization that the microbiota-gut-brain axis plays a critical role in health and disease has emerged over the past decade. The brain-gut axis is a bidirectional communication system between the central nervous system (CNS) and the gastrointestinal tract. Regulation of the microbiota-brain-gut axis is essential for maintaining homeostasis, including that of the CNS. The routes of this communication are not fully elucidated but include neural, humoral, immune, and metabolic pathways. A number of approaches have been used to interrogate this axis including the use of germ-free animals, probiotic agents, antibiotics, or animals exposed to pathogenic bacterial infections. Together, it is clear that the gut microbiota can be a key regulator of mood, cognition, pain, and obesity. Understanding microbiota-brain interactions is an exciting area of research which may contribute new insights into individual variations in cognition, personality, mood, sleep, and eating behavior, and how they contribute to a range of neuropsychiatric diseases ranging from affective disorders to autism and schizophrenia. Finally, the concept of psychobiotics, bacterial-based interventions with mental health benefit, is also emerging.

  5. Transport Phenomena of Off-Axis Sputtering Deposition

    Science.gov (United States)

    Zhu, S.; Su, C. H.; Lehoczky, S. L.; Zhang, S.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Various high quality epitaxial films, especially oxides, have been synthesized using off-axis sputtering deposition. In this presentation, we report the experiment results of ZnO films grown by the off-axis sputtering deposition. Films were synthesized in temperatures ranged from room temperature to 600 C, and pressures from 5 mTorr to 150 mTorr. Film growth rate was measured by surface profilometer, ellipsometer, and wavelength dispersive spectrometry. Due to the collisions between the sputtered species and the residue gases, the kinetic energy of species was reduced and the transport of depositing species changed from a ballistic movement for low pressure to a diffuse drift for high pressure in which the transport species were almost thermalized. The measurements show an increase of growth rates along the gravity vector when the Knodson (Knudsen??) number of transport species is less than 0.05, which suggests that gravity affected the transport characterization in off-axis sputtering deposition. Because the product of pressure (p) and travel distance (d) of sputtered species, p exceeds several mTorr-cm during film deposition, the classical simulations for sputtering process in high vacuum system may not be applied. Based on these experimental measurements, a transport process of the off-axis sputtering deposition is proposed. Several methods including the Monte Carlo method and gravity-driven flow dynamics simulation will be discussed.

  6. A novel dual-axis reconstruction algorithm for electron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Jenna; Midgley, Paul [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom)

    2006-02-22

    A new algorithm for computing electron microscopy tomograms which combines iterative methods with dual-axis geometry is presented. Initial modelling using test data shows several improvements over both the weighted back-projection (WBP) and Simultaneous Iterative Reconstruction Technique (SIRT) method, and, with increased stability and tomogram fidelity under high-noise conditions.

  7. Targeting the gut-liver axis in cirrhosis

    DEFF Research Database (Denmark)

    Madsen, Bjørn S; Havelund, Troels; Krag, Aleksander

    2013-01-01

    The gut-liver axis in cirrhosis and portal hypertension is gaining increasing attention as a key pathophysiological mechanism responsible for progression of liver failure and development of complications such as spontaneous infections and hepatocellular carcinoma. Antibiotics and non-selective β-...

  8. On the Turbulent Mixing in Horizontal Axis Wind Turbine Wakes

    NARCIS (Netherlands)

    Lignarolo, L.E.M.

    2016-01-01

    The wake flow of a horizontal axis wind turbine is characterised by lower wind speed and higher turbulence than the free-stream conditions. When clustered in large wind farms, wind turbines regularly operate inside the wake of one or more upstream machines. This is a major cause of energy production

  9. All-optical, Three-axis Fiber Laser Magnetometer

    Science.gov (United States)

    2012-04-16

    E-1 1.  INTRODUCTION ...achieved with other magnetic field sensing technologies such as those based on flux gates and fiber optic magnetostrictive sensors. The deployed...ALL-OPTICAL, THREE-AXIS FIBER LASER MAGNETOMETER 1. INTRODUCTION This report describes the development of an undersea fiber optic magnetometer

  10. The gut microbiome, probiotics, bile acids axis, and human health.

    Science.gov (United States)

    Jones, Mitchell Lawrence; Tomaro-Duchesneau, Catherine; Prakash, Satya

    2014-06-01

    The human gut microbiome produces potent ligands to bile acid receptors, and probiotics could act as therapeutics of bile acid dysmetabolism. A recent study in Cell Reports demonstrates that probiotic VSL#3 affects bile acid deconjugation and excretion, as well as the gut-liver FXR-FGF15 axis.

  11. Brain-gut-microbiota axis in Parkinson's disease.

    Science.gov (United States)

    Mulak, Agata; Bonaz, Bruno

    2015-10-07

    Parkinson's disease (PD) is characterized by alpha-synucleinopathy that affects all levels of the brain-gut axis including the central, autonomic, and enteric nervous systems. Recently, it has been recognized that the brain-gut axis interactions are significantly modulated by the gut microbiota via immunological, neuroendocrine, and direct neural mechanisms. Dysregulation of the brain-gut-microbiota axis in PD may be associated with gastrointestinal manifestations frequently preceding motor symptoms, as well as with the pathogenesis of PD itself, supporting the hypothesis that the pathological process is spread from the gut to the brain. Excessive stimulation of the innate immune system resulting from gut dysbiosis and/or small intestinal bacterial overgrowth and increased intestinal permeability may induce systemic inflammation, while activation of enteric neurons and enteric glial cells may contribute to the initiation of alpha-synuclein misfolding. Additionally, the adaptive immune system may be disturbed by bacterial proteins cross-reacting with human antigens. A better understanding of the brain-gut-microbiota axis interactions should bring a new insight in the pathophysiology of PD and permit an earlier diagnosis with a focus on peripheral biomarkers within the enteric nervous system. Novel therapeutic options aimed at modifying the gut microbiota composition and enhancing the intestinal epithelial barrier integrity in PD patients could influence the initial step of the following cascade of neurodegeneration in PD.

  12. Comparison of aerodynamic models for Vertical Axis Wind Turbines

    NARCIS (Netherlands)

    Simao Ferreira, C.J.; Aagaard Madsen, H.; Barone, M.; Roscher, B.; Deglaire, P.; Arduin, I.

    2014-01-01

    Multi-megawatt Vertical Axis Wind Turbines (VAWTs) are experiencing an increased interest for floating offshore applications. However, VAWT development is hindered by the lack of fast, accurate and validated simulation models. This work compares six different numerical models for VAWTS: a multiple s

  13. Tilted axis rotation in odd-odd {sup 164}Tm

    Energy Technology Data Exchange (ETDEWEB)

    Reviol, W.; Riedinger, L.L.; Wang, X.Z.; Zhang, J.Y. [Univ. of Tennessee, Knoxville, TN (United States)] [and others

    1996-12-31

    Ten band structures are observed in {sup 164}Tm, among them sets of parallel and anti-parallel couplings of the proton and neutron spins. The Tilted Axis Cranking scheme is applied for the first time to an odd-odd nucleus in a prominent region of nuclear deformation.

  14. Genetic disorders in the growth hormone - IGF-I Axis

    NARCIS (Netherlands)

    Walenkamp, Maria Josephina Elisabeth

    2007-01-01

    Growth is a complex process, regulated by multiple external and internal factors. Deviation from the normal growth pattern can be one of the first manifestations of an underlying disorder, disrupting the normal growth process. The growth hormone – IGF-I axis plays a key role in regulating this growt

  15. Serotonergic stimulation of the rat hypothalamo-pituitary-adrenal axis

    DEFF Research Database (Denmark)

    Mikkelsen, Jens D; Hay-Schmidt, Anders; Kiss, Alexander

    2004-01-01

    Acute stimulation of the hypothalamo-pituitary-adrenal (HPA) axis by selective serotonin reuptake inhibitors (SSRIs) is mediated by several postsynaptic 5-HT receptor subtypes. Activation of 5-HT(1A) and 5-HT(2A) receptors increases plasma corticosterone levels, and it is likely that these recept...

  16. Stereo PIV Experiments on Horizontal Axis Wind Turbine Rotor Model

    NARCIS (Netherlands)

    Akay, B.; Micallef, D.; Ferreira, C.S.; Van Bussel, G.J.W.

    2011-01-01

    This paper sets out to describe the measurements and computations to construct three components of velocity field around the blade. The primary aim of the measurements was to gain insight into the physics of the flow field produced by a horizontal axis wind turbine-HAWT blade. Stereo Particle Image

  17. Comparative transcriptomic analysis of developing cotton cotyledons and embryo axis.

    Directory of Open Access Journals (Sweden)

    Xiaoming Jiao

    Full Text Available BACKGROUND: As a by product of higher value cotton fibre, cotton seed has been increasingly recognised to have excellent potential as a source of additional food, feed, biofuel stock and even a renewable platform for the production of many diverse biological molecules for agriculture and industrial enterprises. The large size difference between cotyledon and embryo axis that make up a cotton seed results in the under-representation of embryo axis gene transcript levels in whole seed embryo samples. Therefore, the determination of gene transcript levels in the cotyledons and embryo axes separately should lead to a better understanding of metabolism in these two developmentally diverse tissues. RESULTS: A comparative study of transcriptome changes between cotton developing cotyledon and embryo axis has been carried out. 17,384 unigenes (20.74% of all the unigenes were differentially expressed in the two adjacent embryo tissues, and among them, 7,727 unigenes (44.45% were down-regulated and 9,657 unigenes (55.55% were up-regulated in cotyledon. CONCLUSIONS: Our study has provided a comprehensive dataset that documents the dynamics of the transcriptome at the mid-maturity of cotton seed development and in discrete seed tissues, including embryo axis and cotyledon tissues. The results showed that cotton seed is subject to many transcriptome variations in these two tissue types and the differential gene expression between cotton embryo axis and cotyledon uncovered in our study should provide an important starting point for understanding how gene activity is coordinated during seed development to make a seed. Further, the identification of genes involved in rapid metabolite accumulation stage of seed development will extend our understanding of the complex molecular and cellular events in these developmental processes and provide a foundation for future studies on the metabolism, embryo differentiation of cotton and other dicot oilseed crops.

  18. The manufacturing and metrology of off-axis mirrors

    Science.gov (United States)

    Penzkofer, Karlheinz; Rascher, Rolf; Küpper, Lutz; Liebl, Johannes

    2015-10-01

    Especially in the area of the large mirror manufacturing only a few manufacturers are capable to produce optical surfaces of high quality. Therefore a deterministic process should be developed in the project IFasO. In the field of telescope optics off-axis optical systems are becoming increasingly important. These systems try to avoid an obstructing of the incoming light by moving the secondary mirror out of the primary mirror's optical axis. This advantage leads to an increasing market for this type of optical surface. Until now off-axis mirrors were difficult or almost impossible to produce. With the processes developed in IFasO, high quality mirrors become possible. For this reason, this paper describes the manufacturing of off-axis surfaces and its problems. The mirror production used in the project IFasO is based on the specific design of the CNC center developed by the company Optotech. This center UPG2000 is capable of grinding, polishing, sagitta measurement and interferometric measurement in one mounting of the specimen. Usually a large optics has to be transported during their manufacturing after every individual process step. There is always a risk of damage of the specimen. The exact orientation of the surface relatively to the tool position is also required. This takes a huge amount of time and makes up most of the production time. In this presentation the use of UPG2000 and the next steps within the process development are described. In the current status the manufacturing of large off-axis elements with a PV < λ/10 rms is reproducible.

  19. DARHT Axis-I Diode Simulations II: Geometrical Scaling

    Energy Technology Data Exchange (ETDEWEB)

    Ekdahl, Carl A. Jr. [Los Alamos National Laboratory

    2012-06-14

    Flash radiography of large hydrodynamic experiments driven by high explosives is a venerable diagnostic technique in use at many laboratories. Many of the largest hydrodynamic experiments study mockups of nuclear weapons, and are often called hydrotests for short. The dual-axis radiography for hydrodynamic testing (DARHT) facility uses two electron linear-induction accelerators (LIA) to produce the radiographic source spots for perpendicular views of a hydrotest. The first of these LIAs produces a single pulse, with a fixed {approx}60-ns pulsewidth. The second axis LIA produces as many as four pulses within 1.6-{micro}s, with variable pulsewidths and separation. There are a wide variety of hydrotest geometries, each with a unique radiographic requirement, so there is a need to adjust the radiographic dose for the best images. This can be accomplished on the second axis by simply adjusting the pulsewidths, but is more problematic on the first axis. Changing the beam energy or introducing radiation attenuation also changes the spectrum, which is undesirable. Moreover, using radiation attenuation introduces significant blur, increasing the effective spot size. The dose can also be adjusted by changing the beam kinetic energy. This is a very sensitive method, because the dose scales as the {approx}2.8 power of the energy, but it would require retuning the accelerator. This leaves manipulating the beam current as the best means for adjusting the dose, and one way to do this is to change the size of the cathode. This method has been proposed, and is being tested. This article describes simulations undertaken to develop scaling laws for use as design tools in changing the Axis-1 beam current by changing the cathode size.

  20. Velocity measurement of model vertical axis wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.A.; McWilliam, M. [Waterloo Univ., ON (Canada). Dept. of Mechanical Engineering

    2006-07-01

    An increasingly popular solution to future energy demand is wind energy. Wind turbine designs can be grouped according to their axis of rotation, either horizontal or vertical. Horizontal axis wind turbines have higher power output in a good wind regime than vertical axis turbines and are used in most commercial class designs. Vertical axis Savonius-based wind turbine designs are still widely used in some applications because of their simplistic design and low wind speed performance. There are many design variables that must be considered in order to optimize the power output in a given wind regime in a typical wind turbine design. Using particle image velocimetry, a study of the air flow around five different model vertical axis wind turbines was conducted in a closed loop wind tunnel. A standard Savonius design with two semi-circular blades overlapping, and two variations of this design, a deep blade and a shallow blade design were among the turbine models included in this study. It also evaluated alternate designs that attempt to increase the performance of the standard design by allowing compound blade curvature. Measurements were collected at a constant phase angle and also at random rotor orientations. It was found that evaluation of the flow patterns and measured velocities revealed consistent and stable flow patterns at any given phase angle. Large scale flow structures are evident in all designs such as vortices shed from blade surfaces. An important performance parameter was considered to be the ability of the flow to remain attached to the forward blade and redirect and reorient the flow to the following blade. 6 refs., 18 figs.

  1. Symmetry axis based object recognition under translation, rotation and scaling.

    Science.gov (United States)

    Hyder, Mashud; Islam, Md Monirul; Akhand, M A H; Murase, Kazuyuki

    2009-02-01

    This paper presents a new approach, known as symmetry axis based feature extraction and recognition (SAFER), for recognizing objects under translation, rotation and scaling. Unlike most previous invariant object recognition (IOR) systems, SAFER puts emphasis on both simplicity and accuracy of the recognition system. To achieve simplicity, it uses simple formulae for extracting invariant features from an object. The scheme used in feature extraction is based on the axis of symmetry and angles of concentric circles drawn around the object. SAFER divides the extracted features into a number of groups based on their similarity. To improve the recognition performance, SAFER uses a number of neural networks (NNs) instead of single NN are used for training and recognition of extracted features. The new approach, SAFER, has been tested on two of real world problems i.e., English characters with two different fonts and images of different shapes. The experimental results show that SAFER can produce good recognition performance in comparison with other algorithms.

  2. Tuning the DARHT Axis-II linear induction accelerator focusing

    Energy Technology Data Exchange (ETDEWEB)

    Ekdahl, Carl A. [Los Alamos National Laboratory

    2012-04-24

    Flash radiography of large hydrodynamic experiments driven by high explosives is a well-known diagnostic technique in use at many laboratories, and the Dual-Axis Radiography for Hydrodynamic Testing (DARHT) facility at Los Alamos produces flash radiographs of large hydrodynamic experiments. Two linear induction accelerators (LIAs) make the bremsstrahlung radiographic source spots for orthogonal views of each test. The 2-kA, 20-MeV Axis-I LIA creates a single 60-ns radiography pulse. The 1.7-kA, 16.5-MeV Axis-II LIA creates up to four radiography pulses by kicking them out of a longer pulse that has a 1.6-{mu}s flattop. The Axis-II injector, LIA, kicker, and downstream transport (DST) to the bremsstrahlung converter are described. Adjusting the magnetic focusing and steering elements to optimize the electron-beam transport through an LIA is often called 'tuning.' As in all high-current LIAs, the focusing field is designed to be as close to that of the ideal continuous solenoid as physically possible. In ideal continuous solenoidal transport a smoothly varying beam size can easily be found for which radial forces balance, and the beam is said to be 'matched' to the focusing field. A 'mismatched' beam exhibits unwanted oscillations in size, which are a source of free energy that contributes to emittance growth. This is undesirable, because in the absence of beam-target effects, the radiographic spot size is proportional to the emittance. Tuning the Axis-II LIA is done in two steps. First, the solenoidal focusing elements are set to values designed to provide a matched beam with little or no envelope oscillations, and little or no beam-breakup (BBU) instability growth. Then, steering elements are adjusted to minimize the motion of the centroid of a well-centered beam at the LIA exit. This article only describes the design of the tune for the focusing solenoids. The DARHT Axis-II LIA was required to be re-tuned after installing an

  3. Locating an axis-parallel rectangle on a Manhattan plane

    DEFF Research Database (Denmark)

    Brimberg, Jack; Juel, Henrik; Körner, Mark-Christoph

    2014-01-01

    In this paper we consider the problem of locating an axis-parallel rectangle in the plane such that the sum of distances between the rectangle and a finite point set is minimized, where the distance is measured by the Manhattan norm 1. In this way we solve an extension of the Weber problem to ext...... to extensive facility location. As......In this paper we consider the problem of locating an axis-parallel rectangle in the plane such that the sum of distances between the rectangle and a finite point set is minimized, where the distance is measured by the Manhattan norm 1. In this way we solve an extension of the Weber problem...

  4. Effects of structure flexibility on horizontal axis wind turbine performances

    Science.gov (United States)

    Coiro, D. P.; Daniele, E.; Scherillo, F.

    2013-10-01

    This work illustrates the effects of flexibility of rotor blades and turbine tower on the performances of an horizontal axis wind turbine (HAWT) designed by our ADAG research group, by means of several example applied on a recent project for a active pitch controlled upwind 60 kW HAWT. The influence of structural flexibility for blade only, tower only and blade coupled with tower configuration is investigated using an aero-elastic computer-aided engineering (CAE) tool for horizontal axis wind turbines named FAST developed at National Renewable Energy Laboratory (NREL) of USA. For unsteady inflow conditions in front of the isolated HAWT the performances in rigid and flexible operation mode are computed and compared in order to illustrate the limitation included within a classical rigid body approach to wind turbine simulation.

  5. Psychiatric Axis I Comorbidities among Patients with Gender Dysphoria

    Directory of Open Access Journals (Sweden)

    Azadeh Mazaheri Meybodi

    2014-01-01

    Full Text Available Objectives. Cooccurring psychiatric disorders influence the outcome and prognosis of gender dysphoria. The aim of this study is to assess psychiatric comorbidities in a group of patients. Methods. Eighty-three patients requesting sex reassignment surgery (SRS were recruited and assessed through the Persian Structured Clinical Interview for DSM-IV Axis I disorders (SCID-I. Results. Fifty-seven (62.7% patients had at least one psychiatric comorbidity. Major depressive disorder (33.7%, specific phobia (20.5%, and adjustment disorder (15.7% were the three most prevalent disorders. Conclusion. Consistent with most earlier researches, the majority of patients with gender dysphoria had psychiatric Axis I comorbidity.

  6. Development of the adrenal axis in the neonatal rat

    Energy Technology Data Exchange (ETDEWEB)

    Guillet, Ronnie

    1977-01-01

    Plasma corticosterone and ACTH concentrations were determined in neonatal rats 1, 7, 14, and 21 days old, under a variety of experimental conditions, to obtain more information on the postnatal development of the rat hypothalamo-adrenal (HHA) axis. The results indicate that: (1) there is a diminution followed by an increase in responsiveness of the adrenal gland, but the pituitary response to direct hormonal stimulation is unchanged during the first three postnatal weeks; (2) continued stimulation of the adrenal by ACTH or of the central nervous system (CNS) or hypothalamus by corticosterone is necessary during early postnatal development to allow normal maturation of the HHA axis; and (3) feedback inhibition is operative by birth, at least to a moderate degree. Taken together, the studies suggest that both the adrenal and pituitary glands are potentially functional at birth, but that the hypothalamic and CNS mediators of the stress response are not mature until at least the second or third postnatal week. (ERB)

  7. Electrostatic levitation under the single-axis feedback control condition

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    An electrostatic levitator with a single-axis feedback control system was developed on the basis of electric field analysis and optimum design for levitation electrodes. In order to realize the stable levitation of various types of materials such as metals, inorganic materials and polymers, we made both experimental and theoretical investigations to solve the four key problems of electric field optimization, sample position detecting, sample charging control and levitation voltage minimization. Under the capacitive induction charging condition, a sample with the size of 2.6–4.5 mm usually bears positive charges amounting to 10-9 Coulomb. Because the single-axis feedback control system responds quickly, it takes the levitated sample only 0.1 s from leaving the bottom electrode until attaining a stable levitation in the upright direction. The levitated sample displays satisfactory levitation stability in both the upright and the horizontal directions owing to the constraining force produced by spherical electrodes.

  8. Plasma Transport at Magnetic Axis in Toroidal Confinement System

    Institute of Scientific and Technical Information of China (English)

    WANGZhongtian

    2001-01-01

    The particle orbits which intersect the magnetic axis behave differently from banana ones, referred to as potato orbits. The potential importance on tokamak transport is emphasized by Politzer, Lin, Tang, and Lee,and Shaing, Hazeltine, and Zarnstoff. However, there are many problems in the lasttwo papers. For example, the Eq. (48) in Ref. [5] should satisfy the orbit constraint which guarantees single value of the function go, that is, solubility condition, and Eq. (8) in Ref. [6] has the same problem.

  9. Three-Axis Motion Compensated Crane Head Control

    OpenAIRE

    Henriksen, Vegard Wie; Røine, Audun Gerhardsen

    2016-01-01

    Offshore operations can be harsh and demanding and set personnel and equipment at risk. Ships will be exposed to the environmental forces of wind, waves and current, which will influence offshore crane operations considerably. This thesis addresses the use of a crane head, a Three Axis Compensator (TAC), constructed as a Delta parallel robot, to compensate for the motions of the ship in three axes. This type of robot has a rigid and accurate structure, and because of its highly nonlinear natu...

  10. Neuropeptides and the microbiota-gut-brain axis.

    Science.gov (United States)

    Holzer, Peter; Farzi, Aitak

    2014-01-01

    Neuropeptides are important mediators both within the nervous system and between neurons and other cell types. Neuropeptides such as substance P, calcitonin gene-related peptide and neuropeptide Y (NPY), vasoactive intestinal polypeptide, somatostatin and corticotropin-releasing factor are also likely to play a role in the bidirectional gut-brain communication. In this capacity they may influence the activity of the gastrointestinal microbiota and its interaction with the gut-brain axis. Current efforts in elucidating the implication of neuropeptides in the microbiota-gut-brain axis address four information carriers from the gut to the brain (vagal and spinal afferent neurons; immune mediators such as cytokines; gut hormones; gut microbiota-derived signalling molecules) and four information carriers from the central nervous system to the gut (sympathetic efferent neurons; parasympathetic efferent neurons; neuroendocrine factors involving the adrenal medulla; neuroendocrine factors involving the adrenal cortex). Apart from operating as neurotransmitters, many biologically active peptides also function as gut hormones. Given that neuropeptides and gut hormones target the same cell membrane receptors (typically G protein-coupled receptors), the two messenger roles often converge in the same or similar biological implications. This is exemplified by NPY and peptide YY (PYY), two members of the PP-fold peptide family. While PYY is almost exclusively expressed by enteroendocrine cells, NPY is found at all levels of the gut-brain and brain-gut axis. The function of PYY-releasing enteroendocrine cells is directly influenced by short chain fatty acids generated by the intestinal microbiota from indigestible fibre, while NPY may control the impact of the gut microbiota on inflammatory processes, pain, brain function and behaviour. Although the impact of neuropeptides on the interaction between the gut microbiota and brain awaits to be analysed, biologically active peptides

  11. Spherical polarimetry on the three-axis spectrometer IN22

    Energy Technology Data Exchange (ETDEWEB)

    Regnault, L.P.; Geffray, B.; Fouilloux, P.; Longuet, B.; Mantegezza, F.; Tasset, F.; Lelievre-Berna, E.; Bourgeat-Lami, E.; Thomas, M.; Gibert, Y

    2003-07-01

    The existence at the ILL of three-axis spectrometers (TAS) offering high flux of polarized neutrons in the thermal range ('CRG' IN22 and IN20B) has open a new field of investigation of magnetic and lattice excitation spectra. In this paper, we will show recent technical developments concerning the installation and the optimization of the spherical neutron polarization analysis on TAS IN22.

  12. Intestinal barrier function and the brain-gut axis.

    Science.gov (United States)

    Alonso, Carmen; Vicario, María; Pigrau, Marc; Lobo, Beatriz; Santos, Javier

    2014-01-01

    The luminal-mucosal interface of the intestinal tract is the first relevant location where microorganism-derived antigens and all other potentially immunogenic particles face the scrutiny of the powerful mammalian immune system. Upon regular functioning conditions, the intestinal barrier is able to effectively prevent most environmental and external antigens to interact openly with the numerous and versatile elements that compose the mucosal-associated immune system. This evolutionary super system is capable of processing an astonishing amount of antigens and non-immunogenic particles, approximately 100 tons in one individual lifetime, only considering food-derived components. Most important, to develop oral tolerance and proper active immune responses needed to prevent disease and inflammation, this giant immunogenic load has to be managed in a way that physiological inflammatory balance is constantly preserved. Adequate functioning of the intestinal barrier involves local and distant regulatory networks integrating the so-called brain-gut axis. Along this complex axis both brain and gut structures participate in the processing and execution of response signals to external and internal changes coming from the digestive tract, using multidirectional pathways to communicate. Dysfunction of brain-gut axis facilitates malfunctioning of the intestinal barrier, and vice versa, increasing the risk of uncontrolled immunological reactions that may trigger mucosal and brain low-grade inflammation, a putative first step to the initiation of more permanent gut disorders. In this chapter, we describe the structure, function and interactions of intestinal barrier, microbiota and brain-gut axis in both healthy and pathological conditions.

  13. Discrete Scale Axis Representations for 3D Geometry

    OpenAIRE

    Miklos, Balint; Giesen, Joachim; Pauly, Mark

    2010-01-01

    This paper addresses the fundamental problem of computing stable medial representations of 3D shapes. We propose a spatially adaptive classification of geometric features that yields a robust algorithm for generating medial representations at different levels of abstraction. The recently introduced continuous scale axis transform serves as the mathematical foundation of our algorithm. We show how geometric and topological properties of the continuous setting carry over to discrete shape repre...

  14. Shape and Spin Axis Model for 53 Kalypso

    Science.gov (United States)

    Franco, Lorenzo; Pilcher, Frederick; Pray, Donald P.; Maurice, Andejean

    2016-07-01

    We present shape and spin axis model for main-belt asteroid 53 Kalypso. The model was achieved with the lightcurve inversion process, using combined dense photometric data acquired from six apparitions between 1979-2012 and sparse data from USNO Flagstaff. Analysis of the resulting data found a sidereal period P = 9.035058 ± 0.000008 hours and two mirrored pole solutions at (168°, 12°) and (349°, 8°), with an error of ± 5 degrees.

  15. Super Earth Explorer: Coronagraphic Off-Axis Space Telescope

    CERN Document Server

    Schneider, J; Mawet, D; Baudoz, P; Beuzit, J L; Doyon, R; Marley, M; Stam, D; Tinetti, G; Traub, W; Trauger, J; Aylward, A; Cho, J Y K; Keller, C U; Udry, S

    2008-01-01

    The Super-Earth Explorer is an Off-Axis Space Telescope (SEE-COAST) designed for high contrast imaging. Its scientific objective is to make the physico-chemical characterization of exoplanets possibly down to 2 Earth radii >. For that purpose it will analyze the spectral and polarimetric properties of the parent starlight reflected by the planets, in the wavelength range 400-1250 nm

  16. A Two-Axis Goniometric Sensor for Tracking Finger Motion.

    Science.gov (United States)

    Wang, Lefan; Meydan, Turgut; Williams, Paul Ieuan

    2017-04-05

    The study of finger kinematics has developed into an important research area. Various hand tracking systems are currently available; however, they all have limited functionality. Generally, the most commonly adopted sensors are limited to measurements with one degree of freedom, i.e., flexion/extension of fingers. More advanced measurements including finger abduction, adduction, and circumduction are much more difficult to achieve. To overcome these limitations, we propose a two-axis 3D printed optical sensor with a compact configuration for tracking finger motion. Based on Malus' law, this sensor detects the angular changes by analyzing the attenuation of light transmitted through polarizing film. The sensor consists of two orthogonal axes each containing two pathways. The two readings from each axis are fused using a weighted average approach, enabling a measurement range up to 180 ∘ and an improvement in sensitivity. The sensor demonstrates high accuracy (±0.3 ∘ ), high repeatability, and low hysteresis error. Attaching the sensor to the index finger's metacarpophalangeal joint, real-time movements consisting of flexion/extension, abduction/adduction and circumduction have been successfully recorded. The proposed two-axis sensor has demonstrated its capability for measuring finger movements with two degrees of freedom and can be potentially used to monitor other types of body motion.

  17. A New, Adaptable, Optical High-Resolution 3-Axis Sensor.

    Science.gov (United States)

    Buchhold, Niels; Baumgartner, Christian

    2017-01-27

    This article presents a new optical, multi-functional, high-resolution 3-axis sensor which serves to navigate and can, for example, replace standard joysticks in medical devices such as electric wheelchairs, surgical robots or medical diagnosis devices. A light source, e.g., a laser diode, is affixed to a movable axis and projects a random geometric shape on an image sensor (CMOS or CCD). The downstream microcontroller's software identifies the geometric shape's center, distortion and size, and then calculates x, y, and z coordinates, which can be processed in attached devices. Depending on the image sensor in use (e.g., 6.41 megapixels), the 3-axis sensor features a resolution of 1544 digits from right to left and 1038 digits up and down. Through interpolation, these values rise by a factor of 100. A unique feature is the exact reproducibility (deflection to coordinates) and its precise ability to return to its neutral position. Moreover, optical signal processing provides a high level of protection against electromagnetic and radio frequency interference. The sensor is adaptive and adjustable to fit a user's range of motion (stroke and force). This recommendation aims to optimize sensor systems such as joysticks in medical devices in terms of safety, ease of use, and adaptability.

  18. A New, Adaptable, Optical High-Resolution 3-Axis Sensor

    Science.gov (United States)

    Buchhold, Niels; Baumgartner, Christian

    2017-01-01

    This article presents a new optical, multi-functional, high-resolution 3-axis sensor which serves to navigate and can, for example, replace standard joysticks in medical devices such as electric wheelchairs, surgical robots or medical diagnosis devices. A light source, e.g., a laser diode, is affixed to a movable axis and projects a random geometric shape on an image sensor (CMOS or CCD). The downstream microcontroller’s software identifies the geometric shape’s center, distortion and size, and then calculates x, y, and z coordinates, which can be processed in attached devices. Depending on the image sensor in use (e.g., 6.41 megapixels), the 3-axis sensor features a resolution of 1544 digits from right to left and 1038 digits up and down. Through interpolation, these values rise by a factor of 100. A unique feature is the exact reproducibility (deflection to coordinates) and its precise ability to return to its neutral position. Moreover, optical signal processing provides a high level of protection against electromagnetic and radio frequency interference. The sensor is adaptive and adjustable to fit a user’s range of motion (stroke and force). This recommendation aims to optimize sensor systems such as joysticks in medical devices in terms of safety, ease of use, and adaptability. PMID:28134824

  19. A Dual-Axis Electrostatically Driven MEMS Microgripper

    Directory of Open Access Journals (Sweden)

    Yukun Jia

    2014-11-01

    Full Text Available This paper presents the design of a new monolithic two- axis electrostatically actuated MEMS microgripper with integrated capacitive position and force sensors working at the micro-scale level. Each of the two jaws of the micro‐ gripper possesses two degrees-of-freedom (DOF and is capable of positioning in both x-and y-axes. Unlike existing works, where one gripper arm is actuated and other one is sensed, both arms of the proposed microgripper are actuated and sensed independently. A sensing scheme is constructed to provide the position and force signals in the noncontact and contact phases, respectively. By applying a 120V driving voltage, the jaw can provide 70 μm x-axis and 18 μm y-axis displacements with the force of 190 μN. By this design, the real-time position and grasping force information can be obtained in the dual sensing mode. Both analytical calculation and finite-element analysis (FEA were performed to verify the performance of the proposed design. A scaled-up prototype is designed, fabricated and tested through the experiment to verify the structure design of the microgripper.

  20. A New, Adaptable, Optical High-Resolution 3-Axis Sensor

    Directory of Open Access Journals (Sweden)

    Niels Buchhold

    2017-01-01

    Full Text Available This article presents a new optical, multi-functional, high-resolution 3-axis sensor which serves to navigate and can, for example, replace standard joysticks in medical devices such as electric wheelchairs, surgical robots or medical diagnosis devices. A light source, e.g., a laser diode, is affixed to a movable axis and projects a random geometric shape on an image sensor (CMOS or CCD. The downstream microcontroller’s software identifies the geometric shape’s center, distortion and size, and then calculates x, y, and z coordinates, which can be processed in attached devices. Depending on the image sensor in use (e.g., 6.41 megapixels, the 3-axis sensor features a resolution of 1544 digits from right to left and 1038 digits up and down. Through interpolation, these values rise by a factor of 100. A unique feature is the exact reproducibility (deflection to coordinates and its precise ability to return to its neutral position. Moreover, optical signal processing provides a high level of protection against electromagnetic and radio frequency interference. The sensor is adaptive and adjustable to fit a user’s range of motion (stroke and force. This recommendation aims to optimize sensor systems such as joysticks in medical devices in terms of safety, ease of use, and adaptability.

  1. Noise estimation for off-axis electron holography

    Energy Technology Data Exchange (ETDEWEB)

    Röder, Falk, E-mail: Falk.Roeder@Triebenberg.de [Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Lubk, Axel; Wolf, Daniel [Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Niermann, Tore [Institut für Optik und Atomare Physik, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin (Germany)

    2014-09-15

    Off-axis electron holography provides access to the phase of the elastically scattered wave in a transmission electron microscope at scales ranging from several hundreds of nanometres down to 0.1 nm. In many cases the reconstructed phase shift is directly proportional to projected electric and magnetic potentials rendering electron holography a useful and established characterisation method for materials science. However, quantitative interpretation of experimental phase shifts requires quantitative knowledge about the noise, which has been previously established for some limiting cases only. Here, we present a general noise transfer formalism for off-axis electron holography allowing to compute the covariance (noise) of reconstructed amplitude and phase from characteristic detector functions and general properties of the reconstruction process. Experimentally, we verify the presented noise transfer formulas for two different cameras with and without objects within the errors given by the experimental noise determination. - Highlights: • We derive a general noise transfer for the off-axis holographic reconstruction. • Noise transfer formulas given by F. Lenz are included as a special case. • We estimate the covariance of a hologram using the noise spread function. • We experimentally verify the derived noise transfer formulas.

  2. Automated segmentation of the human hippocampus along its longitudinal axis.

    Science.gov (United States)

    Lerma-Usabiaga, Garikoitz; Iglesias, Juan Eugenio; Insausti, Ricardo; Greve, Douglas N; Paz-Alonso, Pedro M

    2016-09-01

    The human hippocampal formation is a crucial brain structure for memory and cognitive function that is closely related to other subcortical and cortical brain regions. Recent neuroimaging studies have revealed differences along the hippocampal longitudinal axis in terms of structure, connectivity, and function, stressing the importance of improving the reliability of the available segmentation methods that are typically used to divide the hippocampus into its anterior and posterior parts. However, current segmentation conventions present two main sources of variability related to manual operations intended to correct in-scanner head position across subjects and the selection of dividing planes along the longitudinal axis. Here, our aim was twofold: (1) to characterize inter- and intra-rater variability associated with these manual operations and compare manual (landmark based) and automatic (percentage based) hippocampal anterior-posterior segmentation procedures; and (2) to propose and test automated rotation methods based on approximating the hippocampal longitudinal axis to a straight line (estimated with principal component analysis, PCA) or a quadratic Bézier curve (fitted with numerical methods); as well as an automated anterior-posterior hippocampal segmentation procedure based on the percentage-based method. Our results reveal that automated rotation and segmentation procedures, used in combination or independently, minimize inconsistencies generated by the accumulation of manual operations while providing higher statistical power to detect well-known effects. A Matlab-based implementation of these procedures is made publicly available to the research community. Hum Brain Mapp 37:3353-3367, 2016. © 2016 Wiley Periodicals, Inc.

  3. Vasoactive intestinal peptide signaling axis in human leukemia

    Institute of Scientific and Technical Information of China (English)

    Glenn; Paul; Dorsam; Keith; Benton; Jarrett; Failing; Sandeep; Batra

    2011-01-01

    The vasoactive intestinal peptide (VIP) signaling axis constitutes a master "communication coordinator" between cells of the nervous and immune systems.To date,VIP and its two main receptors expressed in T lymphocytes,vasoactive intestinal peptide receptor (VPAC)1 and VPAC2,mediate critical cellular functions regulating adaptive immunity,including arresting CD4 T cells in G 1 of the cell cycle,protection from apoptosis and a potent chemotactic recruiter of T cells to the mucosa associated lymphoid compartment of the gastrointestinal tissues.Since the discovery of VIP in 1970,followed by the cloning of VPAC1 and VPAC2 in the early 1990s,this signaling axis has been associated with common human cancers,including leukemia.This review highlights the present day knowledge of the VIP ligand and its receptor expression profile in T cell leukemia and cell lines.Also,there will be a discussion describing how the anti-leukemic DNA binding transcription factor,Ikaros,regulates VIP receptor expression in primary human CD4 T lymphocytes and T cell lymphoblastic cell lines (e.g.Hut-78).Lastly,future goals will be mentioned that are expected to uncover the role of how the VIP signaling axis contributes to human leukemogenesis,and to establish whether the VIP receptor signature expressed by leukemic blasts can provide therapeutic and/or diagnostic information.

  4. MARRT: Medial Axis biased rapidly-exploring random trees

    KAUST Repository

    Denny, Jory

    2014-05-01

    © 2014 IEEE. Motion planning is a difficult and widely studied problem in robotics. Current research aims not only to find feasible paths, but to ensure paths have certain properties, e.g., shortest or safest paths. This is difficult for current state-of-the-art sampling-based techniques as they typically focus on simply finding any path. Despite this difficulty, sampling-based techniques have shown great success in planning for a wide range of applications. Among such planners, Rapidly-Exploring Random Trees (RRTs) search the planning space by biasing exploration toward unexplored regions. This paper introduces a novel RRT variant, Medial Axis RRT (MARRT), which biases tree exploration to the medial axis of free space by pushing all configurations from expansion steps towards the medial axis. We prove that this biasing increases the tree\\'s clearance from obstacles. Improving obstacle clearance is useful where path safety is important, e.g., path planning for robots performing tasks in close proximity to the elderly. Finally, we experimentally analyze MARRT, emphasizing its ability to effectively map difficult passages while increasing obstacle clearance, and compare it to contemporary RRT techniques.

  5. CMB Maximum Temperature Asymmetry Axis: Alignment with Other Cosmic Asymmetries

    CERN Document Server

    Mariano, Antonio

    2012-01-01

    We use a global pixel based estimator to identify the axis of the residual Maximum Temperature Asymmetry (MTA) (after the dipole subtraction) of the WMAP 7 year Internal Linear Combination (ILC) CMB temperature sky map. The estimator is based on considering the temperature differences between opposite pixels in the sky at various angular resolutions (4 degrees-15 degrees and selecting the axis that maximizes this difference. We consider three large scale Healpix resolutions (N_{side}=16 (3.7 degrees), N_{side}=8 (7.3 degrees) and N_{side}=4 (14.7 degrees)). We compare the direction and magnitude of this asymmetry with three other cosmic asymmetry axes (\\alpha dipole, Dark Energy Dipole and Dark Flow) and find that the four asymmetry axes are abnormally close to each other. We compare the observed MTA axis with the corresponding MTA axes of 10^4 Gaussian isotropic simulated ILC maps (based on LCDM). The fraction of simulated ILC maps that reproduces the observed magnitude of the MTA asymmetry and alignment wit...

  6. Endomorphins and activation of the hypothalamo-pituitary-adrenal axis.

    Science.gov (United States)

    Coventry, T L; Jessop, D S; Finn, D P; Crabb, M D; Kinoshita, H; Harbuz, M S

    2001-04-01

    Endomorphin (EM)-1 and EM-2 are opioid tetrapeptides recently located in the central nervous system and immune tissues with high selectivity and affinity for the mu-opioid receptor. Intracerebroventricular (i.c.v.) administration of morphine stimulates the hypothalamo-pituitary-adrenal (HPA) axis. The present study investigated the effect of centrally administered EM-1 and EM-2 on HPA axis activation. Rats received a single i.c.v. injection of either EM-1 (0.1, 1.0, 10 microg), EM-2 (10 microg), morphine (10 microg), or vehicle (0.9% saline). Blood samples for plasma corticosterone determinations were taken immediately prior to i.c.v. administration and at various time points up to 4 h post-injection. Trunk blood, brains and pituitaries were collected at 4 h. Intracerebroventricular morphine increased plasma corticosterone levels within 30 min, whereas EM-1 and EM-2 were without effect. In addition, pre-treatment of i.c.v. EM-1 did not block the rise in corticosterone after morphine. Corticotrophin-releasing factor (CRF) mRNA and arginine vasopressin (AVP) mRNA in the paraventricular nucleus (PVN) and POMC mRNA in the anterior pituitary were found to be unaffected by either morphine or endomorphins. Since release of other opioids are elevated in response to acute stress, we exposed rats to a range of stressors to determine whether plasma EM-1 and EM-2 can be stimulated by HPA axis activation. Plasma corticosterone, ACTH and beta-endorphin were elevated following acute restraint stress, but concentrations of plasma EM-1-immunoreactivity (ir) and EM-2-ir did not change significantly. Corticosterone, ACTH and beta-endorphin were further elevated in adjuvant-induced arthritis (AA) rats by a single injection of lipopolysaccharide (LPS), but not by restraint stress. In conclusion, neither EM-1 or EM-2 appear to influence the regulation of the HPA axis. These data suggest that endomorphins may be acting on a different subset of the mu-opioid receptor than morphine. The

  7. Drop Axis Ratio Distributions in Stratiform and Convective Rain

    Science.gov (United States)

    Thurai, M.; Bringi, V. N.; Petersen, W. A.; Schultz, C.

    2010-01-01

    A fully calibrated low profile 2D video disdrometer (2DVD) has been recording many different rainfall events in Northern Alabama (USA) since June 2007. An earlier publication reported drop shapes and axis ratio distributions determined for some of the events. For one of the cases examined, a noticeable shift in the 3.5 - 3.75 mm drop axis ratio distribution was noted. In this paper, we extend the earlier work by separating the 2DVD measurements into stratiform and convective rain. The separation is made possible by using the minute-by-minute drop size distribution (DSD) measured by the 2DVD. The 1-minute DSDs are fitted to a gamma distribution, and using a simple indexing technique which involves two of the fitted parameters, periods of convective and stratiform rain are separated for a given event. The output of the DSD indexing technique is qualitatively confirmed by comparing with simultaneous time series observations from a co-located UHF profiler which continuously records height profiles of reflectivity, Doppler mean and spectral width, all of which enable the identification of bright-band periods and, furthermore, periods of moderate and deep convection. Excellent consistency is found between the output of the DSD-based separation method and the profiler observations. Next, we utilize the output of DSD index-based separation method to flag the periods of severe convection for a given event. Drop axis ratios during the flagged periods are derived and compared with those during stratiform rain periods. Five cases have been considered. Axis ratio distributions do not show appreciable differences between stratiform and convective periods for four of the cases. The fifth case (the same case as reported earlier) shows a shift in the 3.5 - 3.75 mm drop axis ratios during a prolonged period of convection. The contoured shapes for these drops determined from the 2DVD camera data indicate the possibility of non-axisymmetric oscillations, compared with the contoured

  8. Disector Z-axis mechanical method for stereology

    Directory of Open Access Journals (Sweden)

    Ricardo Xavier-Vidal

    2010-06-01

    Full Text Available The purpose of this work is to calibrate a not expensive microscope to be applied in Optical Disector estimation. The evaluation of "Z-axis" bias and the "Z-axis" calibration were made utilizing a cover slip and a "manual digimatic outside micrometer scale" (Mitutoyo, Japan. Calibrating the cover slip we performed the calibration of the "Z-axis" of a microscope. In the cover slip two lines were painted with different colors using a pen glass. A blue line was painted on the up surface and another line (red on the bottom surface of the cover slip forming a cross. Two metal rings with one palette welded in each were adapted in the microscope. Other palette was welded in the gross focuses in order to restrict the route of the fine focuses (Z-axis study using the two palettes fixed in both rings. Results show that 10 micrometers in "Z-axis" were equal to 3.2 micrometers in the scale of its fine focuses of the microscope. Then, a Disector of 10μm (10μm in Z-axis is equal to 3.2 micrometers in the fine focuses of this microscope. In conclusion, "Z-axis" calibration is crucial to assure enough precision for Disector Method since the equipment can be manufactured without the ideal precision or its precision can be lost after use.O propósito deste trabalho é a Calibração de um microscópio comum de baixo custo de forma a usá-lo para estimativas do Método Disector Óptico. A avaliação do viés e a calibração do "eixo-Z" foram feitas usando uma lamínula e um "micrômetro manual digital" (Mitutoyo, Japan. Com a cali-bração da lamínula, calibramos o "eixo-Z" de um microscópio. Foram pintadas duas linhas com diferentes cores utilizando canetas para vidro. Uma linha (azul foi pintada na superfície superior da lamínula e outra linha (vermelha foi pintada na superfície inferior da lamínula, formando uma cruz. Dois anéis de metal com uma paleta de metal soldada a cada um deles foram adaptados ao micrométrico do microscópio. Outra paleta foi

  9. Manufacturing progress of production of high aspherical axis and off-axis astronomical and space optics for the last decade

    Science.gov (United States)

    Semenov, Aleksandr P.; Abdulkadyrov, Magomed A.; Belousov, Sergey P.; Ignatov, Aleksandr N.; Patrikeev, Vladimir E.

    2016-10-01

    The article describes the technology of production of astronomical and space mirrors from Astrositall CO-115M including its properties and stability of these properties over time and presents the results of material long-term testing. The article also describes computer-controlled methods of large-scaled optics production and testing, including high aspherical, off-axis and thin mirrors, using the examples of production of mirrors at JSC LZOS.

  10. Effect of Relative Marker Movement on the Calculation of the Foot Torsion Axis Using a Combined Cardan Angle and Helical Axis Approach

    Directory of Open Access Journals (Sweden)

    Eveline S. Graf

    2012-01-01

    Full Text Available The two main movements occurring between the forefoot and rearfoot segment of a human foot are flexion at the metatarsophalangeal joints and torsion in the midfoot. The location of the torsion axis within the foot is currently unknown. The purpose of this study was to develop a method based on Cardan angles and the finite helical axis approach to calculate the torsion axis without the effect of flexion. As the finite helical axis method is susceptible to error due to noise with small helical rotations, a minimal amount of rotation was defined in order to accurately determine the torsion axis location. Using simulation, the location of the axis based on data containing noise was compared to the axis location of data without noise with a one-sample t-test and Fisher's combined probability score. When using only data with helical rotation of seven degrees or more, the location of the torsion axis based on the data with noise was within 0.2 mm of the reference location. Therefore, the proposed method allowed an accurate calculation of the foot torsion axis location.

  11. Effect of relative marker movement on the calculation of the foot torsion axis using a combined Cardan angle and helical axis approach.

    Science.gov (United States)

    Graf, Eveline S; Wright, Ian C; Stefanyshyn, Darren J

    2012-01-01

    The two main movements occurring between the forefoot and rearfoot segment of a human foot are flexion at the metatarsophalangeal joints and torsion in the midfoot. The location of the torsion axis within the foot is currently unknown. The purpose of this study was to develop a method based on Cardan angles and the finite helical axis approach to calculate the torsion axis without the effect of flexion. As the finite helical axis method is susceptible to error due to noise with small helical rotations, a minimal amount of rotation was defined in order to accurately determine the torsion axis location. Using simulation, the location of the axis based on data containing noise was compared to the axis location of data without noise with a one-sample t-test and Fisher's combined probability score. When using only data with helical rotation of seven degrees or more, the location of the torsion axis based on the data with noise was within 0.2 mm of the reference location. Therefore, the proposed method allowed an accurate calculation of the foot torsion axis location.

  12. Research on identifying the dynamic error model of strapdown gyro on 3-axis turntable

    Institute of Scientific and Technical Information of China (English)

    WANG Hai; REN Shun-qing; WANG Chang-hong

    2005-01-01

    The dynamic errors of gyros are the important error sources of a strapdown inertial navigation system.In order to identify the dynamic error model coefficients accurately, the static erTor model coefficients which lay a foundation for compensating while identifying the dynamic error model are identified in the gravity acceleration fields by using angular position function of the three-axis turntable. The angular acceleration and angular velocity are excited on the input, output and spin axis of the gyros when the outer axis and the middle axis of a threeaxis turntable are in the uniform angular velocity state simultaneously, while the inner axis of the turntable is in different static angular positions. 8 groups of data are sampled when the inner axis is in 8 different angular positions. These data are the function of the middle axis positions and the inner axis positions. For these data, harmonic analysis method is applied two times versus the middle axis positions and inner axis positions respectively so that the dynamic error model coefficients are finally identified through the least square method. In the meantime the optimal angular velocity of the outer axis and the middle axis are selected by computing the determination value of the information matrix.

  13. Hypothalamic-pituitary-adrenal axis activity in older persons with and without a depressive disorder

    NARCIS (Netherlands)

    Rhebergen, D.; Korten, N. C. M.; Penninx, B. W. J. H.; Stek, M. L.; van der Mast, R. C.; Voshaar, R. Oude; Comijs, H. C.

    2015-01-01

    Background: Altered functioning of the hypothalamic-pituitary-adrenal axis (HPA-axis) has been associated with depression, but findings have been inconsistent. Among older depressed persons, both hyperactivity and hypo-activity of the HPA-axis were demonstrated. However, most studies were population

  14. Kynurenine pathway metabolism and the microbiota-gut-brain axis.

    Science.gov (United States)

    Kennedy, P J; Cryan, J F; Dinan, T G; Clarke, G

    2017-01-01

    It has become increasingly clear that the gut microbiota influences not only gastrointestinal physiology but also central nervous system (CNS) function by modulating signalling pathways of the microbiota-gut-brain axis. Understanding the neurobiological mechanisms underpinning the influence exerted by the gut microbiota on brain function and behaviour has become a key research priority. Microbial regulation of tryptophan metabolism has become a focal point in this regard, with dual emphasis on the regulation of serotonin synthesis and the control of kynurenine pathway metabolism. Here, we focus in detail on the latter pathway and begin by outlining the structural and functional dynamics of the gut microbiota and the signalling pathways of the brain-gut axis. We summarise preclinical and clinical investigations demonstrating that the gut microbiota influences CNS physiology, anxiety, depression, social behaviour, cognition and visceral pain. Pertinent studies are drawn from neurogastroenterology demonstrating the importance of tryptophan and its metabolites in CNS and gastrointestinal function. We outline how kynurenine pathway metabolism may be regulated by microbial control of neuroendocrine function and components of the immune system. Finally, preclinical evidence demonstrating direct and indirect mechanisms by which the gut microbiota can regulate tryptophan availability for kynurenine pathway metabolism, with downstream effects on CNS function, is reviewed. Targeting the gut microbiota represents a tractable target to modulate kynurenine pathway metabolism. Efforts to develop this approach will markedly increase our understanding of how the gut microbiota shapes brain and behaviour and provide new insights towards successful translation of microbiota-gut-brain axis research from bench to bedside. This article is part of the Special Issue entitled 'The Kynurenine Pathway in Health and Disease'.

  15. Mechanical Coupling between Endoderm Invagination and Axis Extension in Drosophila.

    Directory of Open Access Journals (Sweden)

    Claire M Lye

    Full Text Available How genetic programs generate cell-intrinsic forces to shape embryos is actively studied, but less so how tissue-scale physical forces impact morphogenesis. Here we address the role of the latter during axis extension, using Drosophila germband extension (GBE as a model. We found previously that cells elongate in the anteroposterior (AP axis in the extending germband, suggesting that an extrinsic tensile force contributed to body axis extension. Here we further characterized the AP cell elongation patterns during GBE, by tracking cells and quantifying their apical cell deformation over time. AP cell elongation forms a gradient culminating at the posterior of the embryo, consistent with an AP-oriented tensile force propagating from there. To identify the morphogenetic movements that could be the source of this extrinsic force, we mapped gastrulation movements temporally using light sheet microscopy to image whole Drosophila embryos. We found that both mesoderm and endoderm invaginations are synchronous with the onset of GBE. The AP cell elongation gradient remains when mesoderm invagination is blocked but is abolished in the absence of endoderm invagination. This suggested that endoderm invagination is the source of the tensile force. We next looked for evidence of this force in a simplified system without polarized cell intercalation, in acellular embryos. Using Particle Image Velocimetry, we identify posteriorwards Myosin II flows towards the presumptive posterior endoderm, which still undergoes apical constriction in acellular embryos as in wildtype. We probed this posterior region using laser ablation and showed that tension is increased in the AP orientation, compared to dorsoventral orientation or to either orientations more anteriorly in the embryo. We propose that apical constriction leading to endoderm invagination is the source of the extrinsic force contributing to germband extension. This highlights the importance of physical

  16. HPA axis dysregulation in men with hypersexual disorder.

    Science.gov (United States)

    Chatzittofis, Andreas; Arver, Stefan; Öberg, Katarina; Hallberg, Jonas; Nordström, Peter; Jokinen, Jussi

    2016-01-01

    Hypersexual disorder integrating pathophysiological aspects such as sexual desire deregulation, sexual addiction, impulsivity and compulsivity was suggested as a diagnosis for the DSM-5. However, little is known about the neurobiology behind this disorder. A dysregulation of the hypothalamic pituitary adrenal (HPA) axis has been shown in psychiatric disorders but has not been investigated in hypersexual disorder. The aim of this study was to investigate the function of the HPA axis in hypersexual disorder. The study includes 67 male patients with hypersexual disorder and 39 healthy male volunteers. Basal morning plasma levels of cortisol and ACTH were assessed and low dose (0.5mg) dexamethasone suppression test was performed with cortisol and ACTH measured post dexamethasone administration. Non-suppression status was defined with DST-cortisol levels ≥ 138 nmol/l. The Sexual Compulsive scale (SCS), Hypersexual disorder current assessment scale (HD:CAS), Montgomery-Åsberg Depression Scale-self rating (MADRS-S) and Childhood trauma questionnaire (CTQ), were used for assessing hypersexual behavior, depression severity and early life adversity. Patients with hypersexual disorder were significantly more often DST non-suppressors and had significantly higher DST-ACTH levels compared to healthy volunteers. The patients reported significantly more childhood trauma and depression symptoms compared to healthy volunteers. CTQ scores showed a significant negative correlation with DST-ACTH whereas SCS and HD:CAS scores showed a negative correlation with baseline cortisol in patients. The diagnosis of hypersexual disorder was significantly associated DST non-suppression and higher plasma DST-ACTH even when adjusted for childhood trauma. The results suggest HPA axis dysregulation in male patients with hypersexual disorder.

  17. Multiscale mathematical modeling of the hypothalamo-pituitary-gonadal axis.

    Science.gov (United States)

    Clément, Frédérique

    2016-07-01

    Although the fields of systems and integrative biology are in full expansion, few teams are involved worldwide into the study of reproductive function from the mathematical modeling viewpoint. This may be due to the fact that the reproductive function is not compulsory for individual organism survival, even if it is for species survival. Alternatively, the complexity of reproductive physiology may be discouraging. Indeed, the hypothalamo-pituitary-gonadal (HPG) axis involves not only several organs and tissues but also intricate time (from the neuronal millisecond timescale to circannual rhythmicity) and space (from molecules to organs) scales. Yet, mathematical modeling, and especially multiscale modeling, can renew our approaches of the molecular, cellular, and physiological processes underlying the control of reproductive functions. In turn, the remarkable dynamic features exhibited by the HPG axis raise intriguing and challenging questions to modelers and applied mathematicians. In this article, we draw a panoramic review of some mathematical models designed in the framework of the female HPG, with a special focus on the gonadal and central control of follicular development. On the gonadal side, the modeling of follicular development calls to the generic formalism of structured cell populations, that allows one to make mechanistic links between the control of cell fate (proliferation, differentiation, or apoptosis) and that of the follicle fate (ovulation or degeneration) or to investigate how the functional interactions between the oocyte and its surrounding cells shape the follicle morphogenesis. On the central, mainly hypothalamic side, models based on dynamical systems with multiple timescales allow one to represent within a single framework both the pulsatile and surge patterns of the neurohormone GnRH. Beyond their interest in basic research investigations, mathematical models can also be at the source of useful tools to study the encoding and decoding of

  18. Design of Five-Axis Ultrasonic Assistant Compound Machine Tool

    Institute of Scientific and Technical Information of China (English)

    Liu Bing刘冰; Fang Fengzhou房丰洲; Xu Zongwei徐宗伟; Zhang Xiaofeng张晓峰

    2015-01-01

    A compound machine tool was designed, which combined rotary ultrasonic assisted grinding, electrical discharge machining (EDM) and multi-axis milling. Experimental results indicated that its positioning accuracy was less than 5.6μm and its repetitive positioning accuracy was less than 1.8μm;the vibration amplitude of ultrasonic grinding system was uniform and stable, and the EDM system worked well and stably.A smooth surface of K9 optical glass component was achieved by the grinding method.

  19. Multi-axis analog adaptive feedforward cancellation of cryocooler vibration

    Science.gov (United States)

    Collins, Simon Andrew

    1994-01-01

    The vibration produced by Stirling cryocoolers is incompatible with spacecraft-borne precision-pointing imaging instruments. Thermal considerations prevent the addition of sufficient mechanical isolation to eliminate the effects of this vibration. The objective of this research is the design, analysis, and experimental verification of a multi-axis vibration cancellation system for the expander of a split Stirling cryocooler. Cancellation of the periodic cryocooler vibration is achieved with a set of load cells, a custom three-axis electrodynamic actuator, and a narrowband adaptive feedforward controller. In order to size the actuator, a simple model of the cryocooler's vibration is combined with a first-order analysis of a four-magnet two-return-plate forcing element. While the resulting actuator has sufficient force capability, it exhibits significant nonlinearity. A nonlinear actuator model is developed that accounts for in-plane flexure restraint due to both large-amplitude static deflections and large-amplitude vibrations. Numerical solutions of the nonlinear model accurately reflect jump phenomena and higher harmonics observed in the actuator's response. The adaptive feedforward controller employs the filtered-x least-mean-square (FXLMS) algorithm to update an adaptive filter. Rather than implementing this filter with a digital signal processor (DSP), for which there is little flight heritage, a continuous-time analog realization of the FXLMS filter is selected. Theoretically, the FXLMS filter may be represented by an equivalent linear transfer function. However a comprehensive treatment of factors associated with the actual implementation reveals the limitations of the transfer function representation. Factors such as harmonic distortion of the reference signal and imperfect quadrature are shown to result in frequency-shifted terms in the filter's output. The presence of these output components is confirmed experimentally, and their effect on performance is

  20. Error Model and Accuracy Calibration of 5-Axis Machine Tool

    Directory of Open Access Journals (Sweden)

    Fangyu Pan

    2013-08-01

    Full Text Available To improve the machining precision and reduce the geometric errors for 5-axis machinetool, error model and calibration are presented in this paper. Error model is realized by the theory of multi-body system and characteristic matrixes, which can establish the relationship between the cutting tool and the workpiece in theory. The accuracy calibration was difficult to achieve, but by a laser approach-laser interferometer and laser tracker, the errors can be displayed accurately which is benefit for later compensation.

  1. Design of tracking photovoltaic systems with a single vertical axis

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzo, E. [Ciudad Universitaria, Madrid (Spain). Instituto de Energeia Solar; Perez, M. [Pol Industrial La Nava, Naavarrsa (Spain). Alternativas Energeticas Solares; Ezpeleta, A. [Energia Hidroelectrica Navarra, Pamplona (Spain); Acedo, J. [Ingeteam SA, Pamplona (Spain)

    2002-07-01

    Solar tracking is used in large grid-connected photovoltaic plants to maximise solar radiation collection and, hence, to reduce the cost of delivered electricity. In particular, single vertical axis tracking, also called azimuth tracking, allows for energy gains up to 40%, compared with optimally tilted fully static arrays. This paper examines the theoretical aspects associated with the design of azimuth tracking, taking into account shadowing between different trackers and back-tracking features. Then, the practical design of the trackers installed at the 1.4 MW Tudela PV plant is presented and discussed. Finally, this tracking alternative is compared with the more conventional fully stationary approach. (author)

  2. Design and Analysis of Vertical Axis Savonius Wind Turbine

    OpenAIRE

    2016-01-01

    This paper presents the design and analysis of vertical axis Savonius wind turbine to generate electrical energy from wind energy. The Savonius rotor was designed with the rotor diameter of 2 m and the rotor height of 4 m. The 3D model of Savonius rotor blade was made by utilizing SolidWorks software. Computational Fluid Dynamics (CFD)analysis and structural Finite Element Analysis are presented in this paper. CFD analysis was done to obtain the pressure difference between concave and conv...

  3. Three-axis atomic magnetometer based on spin precession modulation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H. C.; Dong, H. F., E-mail: hfdong@buaa.edu.cn; Hu, X. Y.; Chen, L.; Gao, Y. [School of Instrumentation Science and Opto-Electronics Engineering, Beihang University, Beijing 100191 (China)

    2015-11-02

    We demonstrate a three-axis atomic magnetometer with one intensity-modulated pump beam and one orthogonal probe beam. The main field component is measured using the resonance of the pumping light, while the transverse field components are measured simultaneously using the optical rotation of the probe beam modulated by the spin precession. It is an all-optical magnetometer without using any modulation field or radio frequency field. Magnetic field sensitivity of 0.8 pT/Hz{sup 1∕2} is achieved under a bias field of 2 μT.

  4. The cathode test stand for the DARHT second-axis

    Energy Technology Data Exchange (ETDEWEB)

    Fortgang, C.; Monroe, M.; Prono, D. [Los Alamos National Lab., NM (United States); Hudson, C.; Macy, D.; Moy, K. [Bechtel Nevada, Santa Barbara, CA (United States)

    1998-12-31

    The injector for the DARHT second-axis injector will use an 8-in. thermionic dispenser cathode. Because the cathode is relatively large and requires a large amount of heat (5 kW) there are certain engineering issues that need to be addressed, before the DARHT injector reaches the final design stage. The Cathode Test Stand (CTS) will be used to address those concerns. The CTS is a new facility, presently under construction. The CTS will consist of a high-voltage pulse modulator, a high-vacuum diode test-chamber, and a short beam-transport section with diagnostics. This paper discusses the status of the project.

  5. Two-axis solar tracking accomplished through small lateral translations.

    Science.gov (United States)

    Hallas, Justin M; Baker, Katherine A; Karp, Jason H; Tremblay, Eric J; Ford, Joseph E

    2012-09-01

    High-concentration solar-power optics require precise two-axis tracking. The planar micro-optic solar concentrator uses a lenslet array over a planar waveguide with small reflective facets at the focal point of each lenslet to couple incident light into the waveguide. The concentrator can use conventional tracking, tilting the entire assembly, but the system geometry also allows tracking by small lateral translation of the lenslet relative to the waveguide. Here, we experimentally demonstrate such microtracking with the existing concentrator optics and present optimized optical designs for systems with higher efficiency and angle range.

  6. Local charge measurement using off-axis electron holography

    DEFF Research Database (Denmark)

    Beleggia, Marco; Gontard, L.C.; Dunin-Borkowski, R.0E.

    2016-01-01

    A model-independent approach based on Gauss’ theorem for measuring the local charge in a specimen from an electron-optical phase image recorded using off-axis electron holography was recently proposed. Here, we show that such a charge measurement is reliable when it is applied to determine...... the total charge enclosed within an object. However, the situation is more complicated for a partial charge measurement when the integration domain encloses only part of the object. We analyze in detail the effects on charge measurement of the mean inner potential of the object, of the presence of induced...

  7. Design and Analysis of Vertical Axis Savonius Wind Turbine

    Directory of Open Access Journals (Sweden)

    S. Jagadish Venkata Sai

    2016-04-01

    Full Text Available This paper presents the design and analysis of vertical axis Savonius wind turbine to generate electrical energy from wind energy. The Savonius rotor was designed with the rotor diameter of 2 m and the rotor height of 4 m. The 3D model of Savonius rotor blade was made by utilizing SolidWorks software. Computational Fluid Dynamics (CFDanalysis and structural Finite Element Analysis are presented in this paper. CFD analysis was done to obtain the pressure difference between concave and convex surface of the rotor blade and structural FEA was done to obtain the structural response of blade.

  8. Impedances and power losses for an off-axis beam

    CERN Document Server

    Kurennoy, S S

    1996-01-01

    A method for calculating coupling impedances and power losses for off-axis beams is developed. It is applied to calculate impedances of small localized discontinuities like holes and slots, as well as the impedance due to a finite resistivity of chamber walls, in homogeneous chambers with an arbitrary shape of the chamber cross section. The approach requires to solve a two-dimensional electrostatic problem, which can be easily done numerically in the general case, while for some particular cases analytical solutions are obtained.

  9. Smart phone orientation estimation comparisons using three axis gimbal

    Science.gov (United States)

    Gaquin, Kevin G.; Fields, MaryAnne

    2016-05-01

    Smartphones have put powerful sensor arrays in nearly everyone's pockets. Fusing the data from these sensors it is possible to estimate the phone's current orientation. In this study we utilize a 3 axis gimbal to compare the performance of multiple orientation estimation algorithms. Controlling the position of the gimbal allows us to compare the known device orientation to the estimated orientation. Using this same method we determine where each algorithm's faults lie, and where they begin to break down. Then repeating these movements we are able to compare each algorithm to each other.

  10. Eight Pulse Performance of DARHT Axis II - Preliminary Results

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, Martin E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-12-08

    The DARHT-II accelerator produces a 1.65-kA, 17-MeV beam in a 1600-ns pulse. Standard operation of the DARHT Axis II accelerator involves extracting four short pulses from the 1.6 us long macro-pulse produced by the LIA. The four short pulses are extracted using a fast kicker in combination with a quadrupole septum magnet and then transported for several meters to a high-Z material target for conversion to x-rays for radiography. The ability of the DARHT Axis 2 kicker to produce more than the standard four pulse format has been previously demonstrated. This capability was developed to study potential risks associated with beam transport during an initial commissioning phase at low energy (8 MeV) and low current (1.0 kA).The ability of the kicker to deliver more than four pulses to the target has been realized for many years. This note describes the initial results demonstrating this capability.

  11. Off-Axis Neutrino Scattering in GRB Central Engines

    CERN Document Server

    George, N D; McGhee, J M; Miller, W A; George, Nathan D.; Kheyfets, Arkady; Ghee, John M. Mc; Miller, Warner A.

    2003-01-01

    The search for an understanding of an energy source great enough to explain the gamma-ray burst (GRB) phenomena has attracted much attention from the astrophysical community since its discovery. In this paper we extend the work of K. Asano and T. Fukuyama, and J. D. Salmonson and J. R. Wilson, and analyze the off-axis contributions to the energy-momentum deposition rate (MDR) from the neutrino anti-neutrino collisions above a rotating black hole/thin accretion disk system. Our calculations are performed by imaging the accretion disk at a specified observer using the full geodesic equations, and calculating the cumulative MDR from the scattering of all pairs of neutrinos and anti-neutrinos arriving at the observer. Our results shed light on the beaming efficiency of GRB models of this kind. Although we confirm Asano and Fukuyama's conjecture as to the constancy of the beaming for small angles away from the axis; nevertheless, we find the dominant contribution to the MDR comes from near the surface of the disk ...

  12. Modeling the brain-pituitary-gonad axis in salmon

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jonghan; Hayton, William L.; Schultz, Irv R.

    2006-08-24

    To better understand the complexity of the brain-pituitary-gonad axis (BPG) in fish, we developed a biologically based pharmacodynamic model capable of accurately predicting the normal functioning of the BPG axis in salmon. This first-generation model consisted of a set of 13 equations whose formulation was guided by published values for plasma concentrations of pituitary- (FSH, LH) and ovary- (estradiol, 17a,20b-dihydroxy-4-pregnene-3-one) derived hormones measured in Coho salmon over an annual spawning period. In addition, the model incorporated pertinent features of previously published mammalian models and indirect response pharmacodynamic models. Model-based equations include a description of gonadotropin releasing hormone (GnRH) synthesis and release from the hypothalamus, which is controlled by environmental variables such as photoperiod and water temperature. GnRH stimulated the biosynthesis of mRNA for FSH and LH, which were also influenced by estradiol concentration in plasma. The level of estradiol in the plasma was regulated by the oocytes, which moved along a maturation progression. Estradiol was synthesized at a basal rate and as oocytes matured, stimulation of its biosynthesis occurred. The BPG model can be integrated with toxico-genomic, -proteomic data, allowing linkage between molecular based biomarkers and reproduction in fish.

  13. Early calibration of the HPA axis by maternal psychopathology.

    Science.gov (United States)

    Laurent, Heidemarie

    2017-02-01

    Given the central role of stress-responsive neurophysiology in mental and physical health, it is important to understand how particular patterns of stress responsivity may become entrained by the early caregiving environment. In this study we investigated links between maternal depression and anxiety symptom profiles and within-infant development of hypothalamic-pituitary-adrenal (HPA) axis responses from 6 to 18 months of life. Associations with infant cognitive and social-emotional development were also tested to gauge the adjustment implications of HPA response trajectories. Mothers from a low-income community sample reported their symptoms at 3, 6, 12, and 18 months postnatal, and infants engaged in interpersonal stress tasks at 6, 12, and 18 months. Four saliva samples were taken at each time to assess cortisol responses, and a developmental screener at 18 months provided an index of infant adjustment. Multilevel modeling results revealed an association between maternal symptoms and infant HPA axis sensitization-i.e., a higher cortisol reactivity slope that increased over time. In particular, early (3-month) depression symptoms among mothers who had crossed a diagnostic threshold for major depressive disorder predicted this pattern of response, which in turn related to poorer infant developmental outcomes. Results are considered in terms of adaptive calibration of stress response systems, which may come at a cost to individual psychosocial functioning.

  14. CFD Simulation of Twin Vertical Axis Tidal Turbines System

    Directory of Open Access Journals (Sweden)

    Syed Shah Khalid

    2013-01-01

    Full Text Available As concerns about rising fossil-fuel prices, energy security and climate-change increase, renewable energy can play a vital role in producing local, clean and inexhaustible energy to supply world rising demand for electricity. In this study, hydrodynamic analysis of vertical axis tidal turbine operating side-by-side is numerically analyzed. Two-dimensional numerical modeling of the unsteady flow through the blades of the turbine is performed using ANSYS CFX, hereafter CFX; this is based on a Reynolds-Averaged Navier-Stokes (RANS model. The purpose is to find an optimal distance between the turbines where interaction effect is minimal and constructive, where the turbines operate more efficiently than stand alone turbine. A transient simulation is done on Vertical Axis Tidal Turbine (VATT using the Shear Stress Transport Turbulence (SST model. Main hydrodynamic parameters like torque T, coefficients of performance CP and coefficient of torque CT are investigated. The gap spacing between the turbines has an important role in performance improvement and also in vortex shedding suppression for the flows around two counters rotating systems. The simulation results are validated with Ye and Calisal data. The results of this study prove that the total power output of a twin-turbine system with an optimal layout can be about 24% higher than two times that of a stand-alone turbine. We conclude that the optimally configured counter-rotating twin turbines should be a side-by-side arrangement.

  15. Shock margin testing of a one-axis MEMS accelerometer.

    Energy Technology Data Exchange (ETDEWEB)

    Parson, Ted Blair; Tanner, Danelle Mary; Buchheit, Thomas Edward

    2008-07-01

    Shock testing was performed on a selected commercial-off-the-shelf - MicroElectroMechanical System (COTS-MEMS) accelerometer to determine the margin between the published absolute maximum rating for shock and the 'measured' level where failures are observed. The purpose of this testing is to provide baseline data for isolating failure mechanisms under shock and environmental loading in a representative device used or under consideration for use within systems and assemblies of the DOD/DOE weapons complex. The specific device chosen for this study was the AD22280 model of the ADXL78 MEMS Accelerometer manufactured by Analog Devices Inc. This study focuses only on the shock loading response of the device and provides the necessary data for adding influence of environmental exposure to the reliability of this class of devices. The published absolute maximum rating for acceleration in any axis was 4000 G for this device powered or unpowered. Results from this study showed first failures at 8000 G indicating a margin of error of two. Higher shock level testing indicated that an in-plane, but off-axis acceleration was more damaging than one in the sense direction.

  16. Related Axis: The Extension to XPath Towards Effective XML Search

    Institute of Scientific and Technical Information of China (English)

    Jun-Feng Zhou; Tok Wang Ling; Zhi-Feng Bao; Xiao-Feng Meng

    2012-01-01

    We investigate the limitations of existing XML search methods and propose a new semantics,related relationship,to effectively capture meaningful relationships of data elements from XML data in the absence of structural constraints.Then we make an extension to XPath by introducing a new axis,related axis,to specify the related relationship between query nodes so as to enhance the flexibility of XPath.We propose to reduce the cost of computing the related relationship by a new schema summary that summarizes the related relationship from the original schema without any loss.Based on this schema summary,we introduce two indices to improve the performance of query processing.Our algorithm shows that the evaluation of most queries can be equivalently transformed into just a few selection and value join operations,thus avoids the costly structural join operations.The experimental results show that our method is effective and efficient in terms of comparing the effectiveness of the related relationship with existing keyword search semantics and comparing the efficiency of our evaluation methods with existing query engines.

  17. Pituitary-Adrenal Axis in Prader Willi Syndrome

    Directory of Open Access Journals (Sweden)

    Olivia S. Edgar

    2016-01-01

    Full Text Available Purpose: Prader Willi syndrome (PWS is a rare genetic condition that has concurrent endocrinological insufficiencies. The presence of growth hormone deficiency has been well documented, but adrenal insufficiency (AI is not widely reported. A review was conducted to investigate its prevalence and relevance in PWS in both adults and children. Methodology: A literature review was performed with the search terms “Prader-Willi syndrome” and “adrenal insufficiency”. Results: The review found studies disagree on the prevalence and method of investigation of AI in PWS. Case studies demonstrate that patients with PWS are at risk of premature death, often secondary to respiratory infections. The possibility that this may be the result of the inability to mount an effective cortisol response has been studied, with some evidence confirming AI in PWS patients. Most reports agreed AI is present in PWS, however, Farholt et al. showed no HPA axis dysfunction in adults, suggesting that perhaps it is rare in adults, and children should be the focus of further studies. Conclusion: AI is present in some patients with PWS. Further research is required to ensure optimal treatment can be implemented and to prevent premature deaths related to adrenal insufficiency. Clinicians should have a low threshold for testing the adrenal axis and considering treatment for adrenal insufficiency in PWS patients.

  18. Actuator line modeling of vertical-axis turbines

    CERN Document Server

    Bachant, Peter; Wosnik, Martin

    2016-01-01

    To bridge the gap between high and low fidelity numerical modeling tools for vertical-axis (or cross-flow) turbines (VATs or CFTs), an actuator line model (ALM) was developed and validated for both a high and a medium solidity vertical-axis turbine at rotor diameter Reynolds numbers $Re_D \\sim 10^6$. The ALM is a hybridization of classical blade element theory with Navier--Stokes based flow models, and in this study both $k$--$\\epsilon$ Reynolds-averaged Navier--Stokes (RANS) and Smagorinsky large eddy simulation (LES) turbulence models were tested. The RANS models were able to be run on coarse grids while still providing good convergence behavior in terms of the mean power coefficient, and also approximately four orders of magnitude reduction in computational expense compared with 3-D blade-resolved RANS simulations. Submodels for dynamic stall, end effects, added mass, and flow curvature were implemented, resulting in reasonable performance predictions for the high solidity rotor, more discrepancies for the...

  19. Searching for Cosmological Preferred Axis using cosmographic approach

    CERN Document Server

    Salehi, Amin

    2016-01-01

    Recent released Planck data and other astronomical observations show that the universe may be anisotropic on large scales. This hints a cosmological privileged axis in our anisotropic expanding universe. This paper proceeds a modified redshift in anisotropic cosmological model as $ 1+\\tilde{z}(t,\\hat{\\textbf{p}})=\\frac{a(t_{0)}}{a(t)}(1-A(\\hat{\\textbf{n}}.\\hat{\\textbf{p}}))$ (where $A$ is the magnitude of anisotropy ,$\\hat{\\textbf{n}}$ is the direction of privileged axis, and $\\hat{\\textbf{p}}$ is the direction of each SNe Ia sample to galactic coordinates) along with anisotropic parameter $\\delta=\\frac{A(\\hat{\\textbf{n}}.\\hat{\\textbf{p}})}{1+A(\\hat{\\textbf{n}}.\\hat{\\textbf{p}})}$. The luminosity distance is expanded with model-independent cosmographic parameters as a function of modified redshift $\\tilde{z}$. As the transformation matrix $M(n\\times n)$ is obtained to convert the Taylor series coefficients of isotropic luminosity distance to corresponding anisotropic parameters. These results culminate the ma...

  20. Physics design of the DARHT 2nd axis accelerator cell

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y J; Houck, T L; Reginato, L J; Shang, C C; Yu, S S

    1999-08-19

    The next generation of radiographic machines based on induction accelerators require very high brightness electron beams to realize the desired x-ray spot size and intensity. This high brightness must be maintained throughout the beam transport, from source to x-ray converter target. The accelerator for the second-axis of the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility is being designed to accelerate a 4-kA, 2-{micro}s pulse of electrons to 20 MeV. After acceleration, the 2-{micro}s pulse will be chopped into a train of four 50-ns pulses with variable temporal spacing by rapidly deflecting the beam between a beam stop and the final transport section. The short beam pulses will be focused onto an x-ray converter target generating four radiographic pulses within the 2-{micro}s window. Beam instability due to interaction with the accelerator cells can very adversely effect the beam brightness and radiographic pulse quality. This paper describes the various issues considered in the design of the accelerator cell with emphasis on transverse impedance and minimizing beam instabilities.

  1. Reframing the Teenage Wasteland: Adolescent Microbiota-Gut-Brain Axis.

    Science.gov (United States)

    McVey Neufeld, Karen-Anne; Luczynski, Pauline; Dinan, Timothy G; Cryan, John F

    2016-04-01

    Human adolescence is arguably one of the most challenging periods of development. The young adult is exposed to a variety of stressors and environmental stimuli on a backdrop of significant physiological change and development, which is especially apparent in the brain. It is therefore unsurprising that many psychiatric disorders are first observable during this time. The human intestine is inhabited by trillions of microorganisms, and evidence from both preclinical and clinical research focusing on the established microbiota-gut-brain axis suggests that the etiology and pathophysiology of psychiatric disorders may be influenced by intestinal dysbiosis. Provocatively, many if not all of the challenges faced by the developing teen have a documented impact on these intestinal commensal microbiota. In this review, we briefly summarize what is known about the developing adolescent brain and intestinal microbiota, discuss recent research investigating the microbiota-gut-brain axis during puberty, and propose that pre- and probiotics may prove useful in both the prevention and treatment of psychiatric disorders specifically benefitting the young adult.

  2. Two Axis Pointing System (TAPS) attitude acquisition, determination, and control

    Science.gov (United States)

    Azzolini, John D.; McGlew, David E.

    1990-12-01

    The Two Axis Pointing System (TAPS) is a 2 axis gimbal system designed to provide fine pointing of Space Transportation System (STS) borne instruments. It features center-of-mass instrument mounting and will accommodate instruments of up to 1134 kg (2500 pounds) which fit within a 1.0 by 1.0 by 4.2 meter (40 by 40 by 166 inch) envelope. The TAPS system is controlled by a microcomputer based Control Electronics Assembly (CEA), a Power Distribution Unit (PDU), and a Servo Control Unit (SCU). A DRIRU-II inertial reference unit is used to provide incremental angles for attitude propagation. A Ball Brothers STRAP star tracker is used for attitude acquisition and update. The theory of the TAPS attitude determination and error computation for the Broad Band X-ray Telescope (BBXRT) are described. The attitude acquisition is based upon a 2 star geometric solution. The acquisition theory and quaternion algebra are presented. The attitude control combines classical position, integral and derivative (PID) control with techniques to compensate for coulomb friction (bias torque) and the cable harness crossing the gimbals (spring torque). Also presented is a technique for an adaptive bias torque compensation which adjusts to an ever changing frictional torque environment. The control stability margins are detailed, with the predicted pointing performance, based upon simulation studies. The TAPS user interface, which provides high level operations commands to facilitate science observations, is outlined.

  3. Optimization of Blade Motion of Vertical Axis Turbine

    Institute of Scientific and Technical Information of China (English)

    马勇; 张亮; 张之阳; 韩端锋

    2016-01-01

    In this paper, a method is proposed to improve the energy efficiency of the vertical axis turbine. First of all, a single disk multiple stream-tube model is used to calculate individual fitness. Genetic algorithm is adopted to optimize blade pitch motion of vertical axis turbine with the maximum energy efficiency being selected as the optimization objective. Then, a particular data processing method is proposed, fitting the result data into a cosine-like curve. After that, a general formula calculating the blade motion is developed. Finally, CFD simulation is used to validate the blade pitch motion formula. The results show that the turbine’s energy efficiency becomes higher after the optimization of blade pitch motion; compared with the fixed pitch turbine, the efficiency of variable-pitch turbine is significantly improved by the active blade pitch control; the energy efficiency declines gradually with the growth of speed ratio; besides, compactness has lager effect on the blade motion while the number of blades has little effect on it.

  4. Computational analysis of vertical axis wind turbine arrays

    Science.gov (United States)

    Bremseth, J.; Duraisamy, K.

    2016-10-01

    Canonical problems involving single, pairs, and arrays of vertical axis wind turbines (VAWTs) are investigated numerically with the objective of understanding the underlying flow structures and their implications on energy production. Experimental studies by Dabiri (J Renew Sustain Energy 3, 2011) suggest that VAWTs demand less stringent spacing requirements than their horizontal axis counterparts and additional benefits may be obtained by optimizing the placement and rotational direction of VAWTs. The flowfield of pairs of co-/counter-rotating VAWTs shows some similarities with pairs of cylinders in terms of wake structure and vortex shedding. When multiple VAWTs are placed in a column, the extent of the wake is seen to spread further downstream, irrespective of the direction of rotation of individual turbines. However, the aerodynamic interference between turbines gives rise to regions of excess momentum between the turbines which lead to significant power augmentations. Studies of VAWTs arranged in multiple columns show that the downstream columns can actually be more efficient than the leading column, a proposition that could lead to radical improvements in wind farm productivity.

  5. Determining the axis orientation of cylindrical magnetic flux rope

    Science.gov (United States)

    Rong, Zhaojin; Wan, Weixing; Shen, Chao; Zhang, Tielong; Lui, Anthony; Wang, Yuming; Dunlop, malcolm; Zhang, Yongcun; Zong, Qiugang

    2013-04-01

    We develop a new simple method for inferring the orientation of a magnetic flux rope, which is assumed to be a time-independent cylindrically symmetric structure via the direct single-point analysis of magnetic field structure. The model tests demonstrate that, for the cylindrical flux rope regardless of whether it is force-free or not, the method can consistently yield the axis orientation of the flux rope with higher accuracy and stability than the minimum variance analysis of the magnetic field and the Grad-Shafranov reconstruction technique. Moreover, the radial distance to the axis center and the current density can also be estimated consistently. Application to two actual flux transfer events observed by the four satellites of the Cluster mission demonstrates that the method is more appropriate to be used for the inner part of flux rope, which might be closer to the cylindrical structure, showing good agreement with the results obtained from the optimal Grad-Shafranov reconstruction and the least squares technique of Faraday's law, but fails to produce such agreement for the outer satellite that grazes the flux rope. Therefore, the method must be used with caution.

  6. Application of Circulation Controlled Blades for Vertical Axis Wind Turbines

    Directory of Open Access Journals (Sweden)

    Velissarios Kourkoulis

    2013-07-01

    Full Text Available The blades of a vertical axis wind turbine (VAWT rotor see an inconsistent angle of attack through its rotation. Consequently, VAWT blades generally use symmetrical aerofoils with a lower lift-to-drag ratio than cambered aerofoils tailored to maximise horizontal axis wind turbine rotor performance. This paper considers the feasibility of circulation controlled (CC VAWT blades, using a tangential air jet to provide lift and therefore power augmentation. However CC blade sections require a higher trailing-edge thickness than conventional sections giving rise to additional base drag. The choice of design parameters is a compromise between lift augmentation, additional base drag as well as the power required to pump the air jet. Although CC technology has been investigated for many years, particularly for aerospace applications, few researchers have considered VAWT applications. This paper considers the feasibility of the technology, using Computational Fluid Dynamics to evaluate a baseline CC aerofoil with different trailing-edge ellipse shapes. Lift and drag increments due to CC are considered within a momentum based turbine model to determine net power production. The study found that for modest momentum coefficients significant net power augmentation can be achieved with a relatively simple aerofoil geometry if blowing is controlled through the blades rotation.

  7. Harnessing Tidal Energy Using Vertical Axis Tidal Turbine

    Directory of Open Access Journals (Sweden)

    Syed Shah Khalid

    2013-01-01

    Full Text Available An overview of the current design practices in the field of Renewable Energy (RE is presented; also paper delineates the background to the development of unique and novel techniques for power generation using the kinetic energy of tidal streams and other marine currents. Also this study focuses only on vertical axis tidal turbine. Tidal stream devices have been developed as an alternative method of extracting the energy from the tides. This form of tidal power technology poses less threat to the environment and does not face the same limiting factors associated with tidal barrage schemes, therefore making it a more feasible method of electricity production. Large companies are taking interest in this new source of power. There is a rush to research and work with this new energy source. Marine scientists are looking into how much these will affect the environment, while engineers are developing turbines that are harmless for the environment. In addition, the progression of technological advancements tracing several decades of R & D efforts on vertical axis turbines is highlighted.

  8. PRIGo: a new multi-axis goniometer for macromolecular crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Waltersperger, Sandro; Olieric, Vincent, E-mail: vincent.olieric@psi.ch; Pradervand, Claude [Paul Scherrer Institute, Villigen PSI (Switzerland); Glettig, Wayne [Centre Suisse d’Electronique et Microtechnique SA, Neuchâtel 2002 (Switzerland); Salathe, Marco; Fuchs, Martin R.; Curtin, Adrian; Wang, Xiaoqiang; Ebner, Simon; Panepucci, Ezequiel; Weinert, Tobias [Paul Scherrer Institute, Villigen PSI (Switzerland); Schulze-Briese, Clemens [Dectris Ltd, Baden 5400 (Switzerland); Wang, Meitian, E-mail: vincent.olieric@psi.ch [Paul Scherrer Institute, Villigen PSI (Switzerland)

    2015-05-09

    The design and performance of the new multi-axis goniometer PRIGo developed at the Swiss Light Source at Paul Scherrer Institute is described. The Parallel Robotics Inspired Goniometer (PRIGo) is a novel compact and high-precision goniometer providing an alternative to (mini-)kappa, traditional three-circle goniometers and Eulerian cradles used for sample reorientation in macromolecular crystallography. Based on a combination of serial and parallel kinematics, PRIGo emulates an arc. It is mounted on an air-bearing stage for rotation around ω and consists of four linear positioners working synchronously to achieve x, y, z translations and χ rotation (0–90°), followed by a ϕ stage (0–360°) for rotation around the sample holder axis. Owing to the use of piezo linear positioners and active correction, PRIGo features spheres of confusion of <1 µm, <7 µm and <10 µm for ω, χ and ϕ, respectively, and is therefore very well suited for micro-crystallography. PRIGo enables optimal strategies for both native and experimental phasing crystallographic data collection. Herein, PRIGo hardware and software, its calibration, as well as applications in macromolecular crystallography are described.

  9. Off-Axis Undulator Radiation for CLIC Drive Beam Diagnostics

    CERN Document Server

    Jeff, A; Welsch, CP

    2013-01-01

    The Compact LInear Collider (CLIC) will use a novel acceleration scheme in which energy extracted from a very intense beam of relatively low-energy electrons (the Drive Beam) is used to accelerate a lower intensity Main Beam to very high energy. The high intensity of the Drive Beam, with pulses of more than 1015 electrons, poses a challenge for conventional profile measurements such as wire scanners. Thus, new non-invasive profile measurements are being investigated. In this paper we propose the use of relatively inexpensive permanent-magnet undulators to generate off-axis visible Synchrotron Radiation from the CLIC Drive Beam. The field strength and period length of the undulator should be designed such that the on-axis undulator wavelength is in the ultra-violet. A smaller but still useable amount of visible light is then generated in a hollow cone. This light can be reflected out of the beam pipe by a ring-shaped mirror placed downstream and imaged on a camera. In this contribution, results of SRW and ZEMA...

  10. Optimization of blade motion of vertical axis turbine

    Science.gov (United States)

    Ma, Yong; Zhang, Liang; Zhang, Zhi-yang; Han, Duan-feng

    2016-04-01

    In this paper, a method is proposed to improve the energy efficiency of the vertical axis turbine. First of all, a single disk multiple stream-tube model is used to calculate individual fitness. Genetic algorithm is adopted to optimize blade pitch motion of vertical axis turbine with the maximum energy efficiency being selected as the optimization objective. Then, a particular data processing method is proposed, fitting the result data into a cosine-like curve. After that, a general formula calculating the blade motion is developed. Finally, CFD simulation is used to validate the blade pitch motion formula. The results show that the turbine's energy efficiency becomes higher after the optimization of blade pitch motion; compared with the fixed pitch turbine, the efficiency of variable-pitch turbine is significantly improved by the active blade pitch control; the energy efficiency declines gradually with the growth of speed ratio; besides, compactness has lager effect on the blade motion while the number of blades has little effect on it.

  11. On the spin-axis dynamics of a Moonless Earth

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gongjie; Batygin, Konstantin, E-mail: gli@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, The Institute for Theory and Computation, 60 Garden Street, Cambridge, MA 02138 (United States)

    2014-07-20

    The variation of a planet's obliquity is influenced by the existence of satellites with a high mass ratio. For instance, Earth's obliquity is stabilized by the Moon and would undergo chaotic variations in the Moon's absence. In turn, such variations can lead to large-scale changes in the atmospheric circulation, rendering spin-axis dynamics a central issue for understanding climate. The relevant quantity for dynamically forced climate change is the rate of chaotic diffusion. Accordingly, here we re-examine the spin-axis evolution of a Moonless Earth within the context of a simplified perturbative framework. We present analytical estimates of the characteristic Lyapunov coefficient as well as the chaotic diffusion rate and demonstrate that even in absence of the Moon, the stochastic change in Earth's obliquity is sufficiently slow to not preclude long-term habitability. Our calculations are consistent with published numerical experiments and illustrate the putative system's underlying dynamical structure in a simple and intuitive manner.

  12. Evaluation of Methods to Increase Beam Pulse Width on the DARHT Axis-II Accelerator

    Science.gov (United States)

    2013-06-01

    lanl.gov Abstract The second axis (Axis II) of the Dual-Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory ( LANL ...of the cell pulses are of less importance than 665U.S. Government work not protected by U.S. copyright Report Documentation Page Form ApprovedOMB No...19th). Held in San Francisco, CA on 16-21 June 2013., The original document contains color images. 14. ABSTRACT The second axis (Axis II) of the Dual

  13. Mechanical strain determines the axis of planar polarity in ciliated epithelia

    OpenAIRE

    2015-01-01

    Epithelia containing multiciliated cells align beating cilia along a common planar axis specified by the conserved planar cell polarity (PCP) pathway. Specification of the planar axis is also thought to require a long-range cue to align the axis globally, but the nature of this cue in ciliated and other epithelia remains poorly understood. We examined this issue using the Xenopus larval skin where ciliary flow aligns to the anterior-posterior (A-P) axis. We first show that a planar axis initi...

  14. Fracture fixation of the Odontoid process of the axis through an osseous-axis pin in Cuba. A case report.

    Directory of Open Access Journals (Sweden)

    José Ramón Tejera del Valle

    2005-11-01

    Full Text Available The fractures of the odontoid process of the Axis has been a polemic topic for many years. The alternative technique of placing a fixation screw directly across the fracture site, reattaching the odontoid to the body of C2 had been gained defensors in the actuality in the world. The topic was reviewed, and the seventh case knowned was been operated in Cuba by this technique was presented. This intervention was realized in the Department of Neurosurgery of Cienfuegos. Current considerations are emitted.

  15. The Mechanical Axis of the First Ray: A Radiographic Assessment in Hallux Abducto Valgus Evaluation.

    Science.gov (United States)

    LaPorta, Guido A; Nasser, Ellianne M; Mulhern, Jennifer L; Malay, D Scot

    2016-01-01

    The present report describes a new method of hallux abducto valgus deformity correction planning using the mechanical axis of the medial column (mechanical axis planning). This method of radiographic evaluation identifies an ideal position for the first metatarsal after correction and is useful regardless of the surgical procedure chosen. We retrospectively reviewed 200 radiographs to identify a "normal" value for the mechanical axis angle. We reviewed 100 radiographs of patients with hallux abducto valgus deformity (deformity group) and 100 radiographs of patients without hallux abducto valgus deformity (control group). The deformity group revealed an M1-M2 anatomic axis angle of 13.5° ± 2.83° and an M1-M2 mechanical axis angle of 11.58° ± 1°. The control group revealed an M1-M2 anatomic axis angle of 7.5° ± 1.76° and an M1-M2 mechanical axis angle of 11.19° ± 0.9°. The differences in the M1-M2 anatomic axis angle and M1-M2 mechanical axis angle were statistically significant between the control and deformity groups. We sought to provide a reliable method for planning hallux abducto valgus deformity correction by aligning the mechanical axis of the medial column and the mechanical axis of the first ray to the "normal" value of 11° to reduce the deformity.

  16. Dual axis translation apparatus and system for translating an optical beam and related method

    Science.gov (United States)

    Cassidy, Kelly

    1991-01-01

    A dual axis translation device and system in accordance with this invention, for translating an optical beam along both an x-axis and a y-axis which are perpendicular to one another, has a beam directing means acting on said optical beam for directing the beam along a particular path transverse to said x and y axes. An arrangement supporting said beam directing means for movement in the x and y direction within a given plane is provided. The arrangement includes a first means for translating said beam directing means along the x-axis in said given plane in order to translate the beam along said x-axis. The arrangement comprises a second means for translating said beam directing means along the y-axis in said given plane in order to translate the beam along said y-axis.

  17. Comparison of Efficiencies of Solar Tracker systems with static panel Single- Axis Tracking System and Dual-Axis Tracking System with Fixed Mount

    Directory of Open Access Journals (Sweden)

    Dhanabal.R

    2013-04-01

    Full Text Available Electricity plays a key role now in our daily lives but the energy sources to electric power has been used in abundance and so researchers were compelled to find an alternate source of power leading to the discovery of solar energy. Solar energy is inexhaustible and eco-friendly and can be converted into electricityusing photovoltaic panels. These panels can be used in a fixed form or used in a solar tracking system for single axis as well as for dual axis. In a fixed form their efficiency is low since the panels will be tilted in a particular angle whereas in a tracking system the panel is made to move either in single axis or dual axis. In a single axis system the panel is moved in an east to west direction with respect to the sun and it has better efficiency than panels in fixed form. But in a dual axis system the panel is made to rotate in all four directions in accordance with the sun. And dual axis has proved to have more efficiency than both fixed panels and single axis system.

  18. On steady rotations of a rigid body bearing a single-axis powered gyroscope whose precession axis is parallel to a principal plane of inertia

    NARCIS (Netherlands)

    Amel'kin, N. I.

    2009-01-01

    The set of steady motions of the system named in the title is represented parametrically via the gyro gimbal rotation angle for an arbitrary position of the gimbal axis. We study the set of steady motions for a system in which the gyro gimbal axis is parallel to a principal plane of inertia as well

  19. Optimization model for rotor blades of horizontal axis wind turbines

    Institute of Scientific and Technical Information of China (English)

    LIU Xiong; CHEN Yan; YE Zhiquan

    2007-01-01

    This paper presents an optimization model for rotor blades of horizontal axis wind turbines. The model refers to the wind speed distribution function on the specific wind site, with an objective to satisfy the maximum annual energy output. To speed up the search process and guarantee a global optimal result, the extended compact genetic algorithm (ECGA) is used to carry out the search process.Compared with the simple genetic algorithm, ECGA runs much faster and can get more accurate results with a much smaller population size and fewer function evaluations. Using the developed optimization program, blades of a 1.3 MW stall-regulated wind turbine are designed. Compared with the existing blades, the designed blades have obviously better aerodynamic performance.

  20. Dynamic behavior analysis for a six axis industrial machining robot

    CERN Document Server

    Bisu, Claudiu-Florinel; Gérard, Alain; K'Nevez, Jean-Yves

    2012-01-01

    The six axis robots are widely used in automotive industry for their good repeatability (as defined in the ISO92983) (painting, welding, mastic deposition, handling etc.). In the aerospace industry, robot starts to be used for complex applications such as drilling, riveting, fiber placement, NDT, etc. Given the positioning performance of serial robots, precision applications require usually external measurement device with complexes calibration procedure in order to reach the precision needed. New applications in the machining field of composite material (aerospace, naval, or wind turbine for example) intend to use off line programming of serial robot without the use of calibration or external measurement device. For those applications, the position, orientation and path trajectory precision of the tool center point of the robot are needed to generate the machining operation. This article presents the different conditions that currently limit the development of robots in robotic machining applications. We ana...

  1. Heterogeneity of extraparenchymal primitive neuroectodermal tumors within the craniospinal axis.

    Directory of Open Access Journals (Sweden)

    M Debiec-Rychter

    2005-02-01

    Full Text Available Four cases of primitive neuroectodermal tumors (PNETs with unusual localization (three intraspinal extramedullary and one pontocerebellar are reviewed. Histologically, they were small round blue cell tumors with diverse patterns. Immunohistochemically, all tumors were positive for at least two neuronal markers, two cases were Mic-2 positive and one showed glial differentiation. The paraffin-embedded tumor specimens were examined by interphase FISH using dual-color probes specific for EWS, HER-2 and BCR loci. Molecular cytogenetic study revealed the presence of EWS rearrangement in two cases and the presence of i(17q in one tumor. Three tumors exhibited 22 disomy and one was 22 polyploid. Extraparenchymal PNETs within craniospinal axis are heterogeneous from the clinical, histological, immunohistochemical and molecular point of view. These PNETs can be of a central or peripheral type. Multidisciplinary approach is of a basic importance in differential diagnosis of such cases.

  2. Optical voice recorder by off-axis digital holography.

    Science.gov (United States)

    Matoba, Osamu; Inokuchi, Hiroki; Nitta, Kouichi; Awatsuji, Yasuhiro

    2014-11-15

    An optical voice recorder capable of recording and reproducing propagating sound waves by using off-axis digital holography, as well as quantitative visualization, is presented. Propagating sound waves temporally modulate the phase distribution of an impinging light wave via refractive index changes. This temporally modulated phase distribution is recorded in the form of digital holograms by a high-speed image sensor. After inverse propagation using Fresnel diffraction of a series of the recorded holograms, the temporal phase profile of the reconstructed object wave at each three-dimensional position can be used to reproduce the original sound wave. Experimental results using a tuning fork vibrating at 440 Hz and a human voice are presented to show the feasibility of the proposed method.

  3. The plasma boundary in Single Helical Axis RFP plasmas

    CERN Document Server

    Martines, E; Momo, B; Munaretto, S; Innocente, P; Spolaore, M

    2009-01-01

    Single Helical Axis (SHAx) states obtained in high current reversed field pinch (RFP) plasmas display, aside from a dominant mode in the m=1 spectrum, also a dominant m=0 mode, with the same toroidal mode number as the m=1 one. The two modes have a fixed phase relationship. The island chain created by the m=0 mode across the reversal surface gives rise, at shallow reversal of the toroidal field, to an X-point structure which separates the last closed flux surface from the first wall, creating a divertor-like configuration. The plasma-wall interaction is found to be related to the connection length of the field lines intercepting the wall, which displays a pattern modulated by the dominant mode toroidal periodicity. This configuration, which occurs only for shallow toroidal field reversal, could be exploited to realize an island divertor in analogy to stellarators.

  4. The Minimal Model of the Hypothalamic-Pituitary-Adrenal Axis

    DEFF Research Database (Denmark)

    Vinther, Frank; Andersen, Morten; Ottesen, Johnny T.

    2011-01-01

    thereof. The second part of the paper concerns a specific realization of the minimal model in which feedback functions are built explicitly using receptor dynamics. Using physiologically reasonable parameter values, along with the results of the general case, it is demonstrated that un...... that influence the dynamics of the HPA axis, i.e. a negative feedback from cortisol on CRH and ACTH. Therefore we term our model the minimal model. The minimal model, encompasses a wide class of different realizations, obeying only a few physiologically reasonable demands. The results include the existence...... emerge from the model. Sufficient criteria for local stability of the fixed point, and an easily applicable sufficient criteria guaranteeing global stability of the fixed point, is formulated. If the latter is fulfilled, ultradian rhythm is an impossible outcome of the minimal model and all realizations...

  5. Equilibrium reconstruction for Single Helical Axis reversed field pinch plasmas

    CERN Document Server

    Martines, Emilio; Momo, Barbara; Terranova, David; Zanca, Paolo; Alfier, Alberto; Bonomo, Federica; Canton, Alessandra; Fassina, Alessandro; Franz, Paolo; Innocente, Paolo

    2011-01-01

    Single Helical Axis (SHAx) configurations are emerging as the natural state for high current reversed field pinch (RFP) plasmas. These states feature the presence of transport barriers in the core plasma. Here we present a method for computing the equilibrium magnetic surfaces for these states in the force-free approximation, which has been implemented in the SHEq code. The method is based on the superposition of a zeroth order axisymmetric equilibrium and of a first order helical perturbation computed according to Newcomb's equation supplemented with edge magnetic field measurements. The mapping of the measured electron temperature profiles, soft X-ray emission and interferometric density measurements on the computed magnetic surfaces demonstrates the quality of the equilibrium reconstruction. The procedure for computing flux surface averages is illustrated, and applied to the evaluation of the thermal conductivity profile. The consistency of the evaluated equilibria with Ohm's law is also discussed.

  6. Equilibrium reconstruction for single helical axis reversed field pinch plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Martines, E; Lorenzini, R; Momo, B; Terranova, D; Zanca, P; Alfier, A; Bonomo, F; Canton, A; Fassina, A; Franz, P; Innocente, P, E-mail: emilio.martines@igi.cnr.it [Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, corso Stati Uniti 4, 35127 Padova (Italy)

    2011-03-15

    Single helical axis configurations are emerging as the natural state for high-current reversed field pinch plasmas. These states feature the presence of transport barriers in the core plasma. Here we present a method for computing the equilibrium magnetic surfaces for these states in the force-free approximation, which has been implemented in the SHEq code. The method is based on the superposition of a zeroth-order axisymmetric equilibrium and of a first-order helical perturbation computed according to Newcomb's equation supplemented with edge magnetic field measurements. The mapping of the measured electron temperature profiles, soft x-ray emission and interferometric density measurements on the computed magnetic surfaces demonstrates the quality of the equilibrium reconstruction. The procedure for computing flux surface averages is illustrated, and applied to the evaluation of the thermal conductivity profile. The consistency of the evaluated equilibria with Ohm's law is also discussed.

  7. A multi-fork z-axis quartz micromachined gyroscope.

    Science.gov (United States)

    Feng, Lihui; Zhao, Ke; Sun, Yunan; Cui, Jianmin; Cui, Fang; Yang, Aiying

    2013-01-01

    A novel multi-fork z-axis gyroscope is presented in this paper. Different from traditional quartz gyroscopes, the lateral electrodes of the sense beam can be arranged in simple patterns; as a result, the fabrication is simplified. High sensitivity is achieved by the multi-fork design. The working principles are introduced, while the finite element method (FEM) is used to simulate the modal and sensitivity. A quartz fork is fabricated, and a prototype is assembled. Impedance testing shows that the drive frequency and sense frequency are similar to the simulations, and the quality factor is approximately 10,000 in air. The scale factor is measured to be 18.134 mV/(°/s) and the nonlinearity is 0.40% in a full-scale input range of ±250 °/s.

  8. Comparison of aerodynamic models for Vertical Axis Wind Turbines

    DEFF Research Database (Denmark)

    Ferreira, C. Simão; Aagaard Madsen, Helge; Barone, M.

    2014-01-01

    Multi-megawatt Vertical Axis Wind Turbines (VAWTs) are experiencing an increased interest for floating offshore applications. However, VAWT development is hindered by the lack of fast, accurate and validated simulation models. This work compares six different numerical models for VAWTS: a multiple...... streamtube model, a double-multiple streamtube model, the actuator cylinder model, a 2D potential flow panel model, a 3D unsteady lifting line model, and a 2D conformal mapping unsteady vortex model. The comparison covers rotor configurations with two NACA0015 blades, for several tip speed ratios, rotor...... solidity and fixed pitch angle, included heavily loaded rotors, in inviscid flow. The results show that the streamtube models are inaccurate, and that correct predictions of rotor power and rotor thrust are an effect of error cancellation which only occurs at specific configurations. The other four models...

  9. Software tool for horizontal-axis wind turbine simulation

    Energy Technology Data Exchange (ETDEWEB)

    Vitale, A.J. [Instituto Argentino de Oceanografia, Camino La Carrindanga Km. 7, 5 CC 804, B8000FWB Bahia Blanca (Argentina); Universidad Tecnologica Nacional Facultad Regional Bahia Blanca, GESE, 11 de Abril 461, B8000LMI Bahia Blanca (Argentina); Dpto. de Ing. Electrica y de Computadoras, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina); Rossi, A.P. [Universidad Tecnologica Nacional Facultad Regional Bahia Blanca, GESE, 11 de Abril 461, B8000LMI Bahia Blanca (Argentina); Dpto. de Ing. Electrica y de Computadoras, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina)

    2008-07-15

    The main problem of a wind turbine generator design project is the design of the right blades capable of satisfying the specific energy requirement of an electric system with optimum performance. Once the blade has been designed for optimum operation at a particular rotor angular speed, it is necessary to determine the overall performance of the rotor under the range of wind speed that it will encounter. A software tool that simulates low-power, horizontal-axis wind turbines was developed for this purpose. With this program, the user can calculate the rotor power output for any combination of wind and rotor speeds, with definite blade shape and airfoil characteristics. The software also provides information about distribution of forces along the blade span, for different operational conditions. (author)

  10. METHODOLOGY FOR CROSS-CURRICULAR THEME OF THE ENVIRONMENTAL AXIS

    Directory of Open Access Journals (Sweden)

    José Luis Aparicio López

    2015-04-01

    Full Text Available This article introduces a methodology to identify the presence of the environmental axis in educational programs in Bachelors in the Universidad Autónoma de Guerrero, Mexico. It is sustained on competency-based education and constructionism, due to they appeal to humanism to deal current problems. It is composed of four phases: committee conformation, theoretical and conceptual concerning analysis, construction and application of instruments on a PE, and identification of the cross-curricular theme level. Even though the proposed methodology is applied to the environment, it is feasible to adapt to other axes, such as human rights, multiculturalism, and poverty, relevant to the educational context of the state of Guerrero.

  11. Performance Characteristics of a Vertical Axis Hydrokinetic Turbine

    Science.gov (United States)

    Bailin, Benjamin; Flack, Karen; Lust, Ethan

    2016-11-01

    Performance characteristics are presented for a vertical axis hydrokinetic turbine designed for use in a riverine environment. The test turbine is a 1:6 scale model of a three-bladed device (9.5 m span, 6.5 m diameter) that has been proposed by the Department of Energy. Experiments are conducted in the large towing tank (116 m long, 7.9 m wide, 5 m deep) at the United States Naval Academy. The large scale facility allows for scale independent results. The turbine is towed beneath a moving carriage at a constant speed in combination with a shaft brake to achieve the desired tip speed ratio (TSR) range. The measured quantities of turbine thrust, torque and RPM result in power and thrust coefficients for a range of TSR. Results will be presented for cases with quiescent flow and flow with mild surface waves, representative of riverine environments.

  12. A three-axis SQUID-based absolute vector magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Schönau, T.; Schmelz, M.; Stolz, R.; Anders, S.; Linzen, S.; Meyer, H.-G. [Department of Quantum Detection, Leibniz Institute of Photonic Technology, Jena 07745 (Germany); Zakosarenko, V.; Meyer, M. [Supracon AG, An der Lehmgrube 11, Jena 07751 (Germany)

    2015-10-15

    We report on the development of a three-axis absolute vector magnetometer suited for mobile operation in the Earth’s magnetic field. It is based on low critical temperature dc superconducting quantum interference devices (LTS dc SQUIDs) with sub-micrometer sized cross-type Josephson junctions and exhibits a white noise level of about 10 fT/Hz{sup 1/2}. The width of superconducting strip lines is restricted to less than 6 μm in order to avoid flux trapping during cool-down in magnetically unshielded environment. The long-term stability of the flux-to-voltage transfer coefficients of the SQUID electronics is investigated in detail and a method is presented to significantly increase their reproducibility. We further demonstrate the long-term operation of the setup in a magnetic field varying by about 200 μT amplitude without the need for recalibration.

  13. A three-axis SQUID-based absolute vector magnetometer.

    Science.gov (United States)

    Schönau, T; Zakosarenko, V; Schmelz, M; Stolz, R; Anders, S; Linzen, S; Meyer, M; Meyer, H-G

    2015-10-01

    We report on the development of a three-axis absolute vector magnetometer suited for mobile operation in the Earth's magnetic field. It is based on low critical temperature dc superconducting quantum interference devices (LTS dc SQUIDs) with sub-micrometer sized cross-type Josephson junctions and exhibits a white noise level of about 10 fT/Hz(1/2). The width of superconducting strip lines is restricted to less than 6 μm in order to avoid flux trapping during cool-down in magnetically unshielded environment. The long-term stability of the flux-to-voltage transfer coefficients of the SQUID electronics is investigated in detail and a method is presented to significantly increase their reproducibility. We further demonstrate the long-term operation of the setup in a magnetic field varying by about 200 μT amplitude without the need for recalibration.

  14. Development and demonstration of a vertical axis wind turbine POWERHOUSE

    Science.gov (United States)

    Vosburgh, P. N.

    1984-06-01

    A performance of reliable lower cost base assembly and controls was designed for the electricity generating wind energy conversion system of the VAWTPOWER 185 wind turbine. The base assembly includes low speed shaft and couplings, disc or drum brake, hydraulic or pneumatic brake control systems, speed increasing gear box, high speed shaft and couplings, induction motor/generator, bottom rotor bearings, lightning and ground fault protection, support structure, and environmental protection. VAWTPOWER 185 is a 200 kW capacity Vertical Axis Wind Turbine rated 185 kW at 37 mph. After system analysis, subsystem definition, detailed design and engineering, and development of a test plan, two versions of the powerhouse were fabricated and tested. Both appear ready for commercial production.

  15. Strain measurements in ferromagnetic martensitic Heuslers and magnetization easy axis

    Energy Technology Data Exchange (ETDEWEB)

    Aksoy, Seda; Acet, Mehmet; Wassermann, Eberhard F. [Experimentalphysik, Universitaet Duisburg-Essen, Duisburg (Germany)

    2008-07-01

    The temperature-dependence of strain under constant magnetic-fields is studied in Ni-Mn-X (X:Ga,In,Sn,Sb) and Ni-Mn-In-X (X:Ga,Sn,Sb) polycrystalline ferromagnetic Heusler alloys which undergo a martensitic transformation close to room-temperature. The applied magnetic-field influences the nucleation of martensite so that decreasing the temperature under a magnetic field leads to large length changes between the austenite and martensite states. The length-change within the martensitic state varies with the magnitude of the cooling-field. This is related to the variant-orientation during martensite nucleation. These strain-data provide information on the easy axis of magnetization.

  16. Nonlinear characterization of a single-axis acoustic levitator

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Marco A. B. [Institute of Physics, University of São Paulo, São Paulo (Brazil); Ramos, Tiago S.; Okina, Fábio T. A.; Adamowski, Julio C. [Department of Mechatronics and Mechanical Systems Engineering, Escola Politécnica, University of São Paulo, São Paulo (Brazil)

    2014-04-15

    The nonlinear behavior of a 20.3 kHz single-axis acoustic levitator formed by a Langevin transducer with a concave radiating surface and a concave reflector is experimentally investigated. In this study, a laser Doppler vibrometer is applied to measure the nonlinear sound field in the air gap between the transducer and the reflector. Additionally, an electronic balance is used in the measurement of the acoustic radiation force on the reflector as a function of the distance between the transducer and the reflector. The experimental results show some effects that cannot be described by the linear acoustic theory, such as the jump phenomenon, harmonic generation, and the hysteresis effect. The influence of these nonlinear effects on the acoustic levitation of small particles is discussed.

  17. IDENTIFICATION OF GYRO DRIFTS UNDER THREE AXIS ATTITUDE COUPLING

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Optical gyros and star sensors are primary measurement hardware in an attitude control system with high accuracy.The drifts of the optical gyros, however, make an unfavorable impact on the accuracy of the attitude control system.In order for compensations to be provided, this paper presents a least-square method to identify the optical gyro drifts by using flight attitude data from the star sensors and the optical gyros.Equations for identification are formulated by quaternion.Integration of the identification equations and the data from the star sensors are utilized to form a least-square index, in which lower sampling frequency of the star sensors than that of the optical gyros is dealt with effectively.An iterative identification algorithm is presented to minimize the index.Identification procedure under three-axis attitude coupling is illustrated .Simulation results show the effectiveness of the method presented.Proper sample size and sampling frequency are also recommended.

  18. A Multi-Fork Z-Axis Quartz Micromachined Gyroscope

    Directory of Open Access Journals (Sweden)

    Aiying Yang

    2013-09-01

    Full Text Available A novel multi-fork z-axis gyroscope is presented in this paper. Different from traditional quartz gyroscopes, the lateral electrodes of the sense beam can be arranged in simple patterns; as a result, the fabrication is simplified. High sensitivity is achieved by the multi-fork design. The working principles are introduced, while the finite element method (FEM is used to simulate the modal and sensitivity. A quartz fork is fabricated, and a prototype is assembled. Impedance testing shows that the drive frequency and sense frequency are similar to the simulations, and the quality factor is approximately 10,000 in air. The scale factor is measured to be 18.134 mV/(°/s and the nonlinearity is 0.40% in a full-scale input range of ±250 °/s.

  19. The Gut-Lung Axis in Respiratory Disease.

    Science.gov (United States)

    Marsland, Benjamin J; Trompette, Aurélien; Gollwitzer, Eva S

    2015-11-01

    Host-microorganism interactions shape local cell functionality, immune responses, and can influence disease development. Evidence indicates that the impact of host-microbe interactions reaches far beyond the local environment, thus influencing responses in peripheral tissues. There is a vital cross-talk between the mucosal tissues of our body, as exemplified by intestinal complications during respiratory disease and vice versa. Although, mechanistically, this phenomenon remains poorly defined, the existence of the gut-lung axis and its implications in both health and disease could be profoundly important for both disease etiology and treatment. In this review, we highlight how changes in the intestinal microenvironment, with a particular focus on the intestinal microbiota, impact upon respiratory disease.

  20. Development of Rotary Axis For Wire Electrical Discharge Machining (WEDM

    Directory of Open Access Journals (Sweden)

    M. Parthiban, C. Manigandan, G. Muthu Venkadesh, M. Ranjith Kumar

    2013-08-01

    Full Text Available This paper gives an overview of setting up a rotary axis to the existing WEDM machine to investigate the machining parameters in WEDG of harder materials. There are a number of hybrid machining processes (HMPs seeking the combined advantage of EDM and other machining techniques. One such combination is wire electrical discharge grinding (WEDG, which is commonly used for micro-machining of fine and hard rods. WEDG employs a single wire guide to confine the wire tension within the discharge area between the rod and the front edge of the wire and also to minimize the wire vibration. Other advantages of WEDG include the ability to machine hard- to- machine materials with large aspect ratio.

  1. New airfoils for small horizontal axis wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Giguere, P.; Selig, M.S. [Univ. of Illinois, Urbana, IL (United States)

    1997-12-31

    In a continuing effort to enhance the performance of small energy systems, one root airfoil and three primary airfoils were specifically designed for small horizontal axis wind turbines. These airfoils are intended primarily for 1-10 kW variable-speed wind turbines for both conventional (tapered/twisted) or pultruded blades. The four airfoils were wind-tunnel tested at Reynolds numbers between 100,000 and 500,000. Tests with simulated leading-edge roughness were also conducted. The results indicate that small variable-speed wind turbines should benefit from the use of the new airfoils which provide enhanced lift-to-drag ratio performance as compared with previously existing airfoils.

  2. Thyroid axis activity and suicidal behavior in depressed patients.

    Science.gov (United States)

    Duval, Fabrice; Mokrani, Marie-Claude; Lopera, Felix Gonzalez; Diep, Thanh Son; Rabia, Hassen; Fattah, Saïd

    2010-08-01

    The aim of this study was to investigate the relationship between suicidal behavior and hypothalamic-pituitary thyroid (HPT) axis activity in depressed patients. The serum levels of thyrotropin (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) were evaluated before and after 0800 and 2300 h thyrotropin-releasing hormone (TRH) challenges, on the same day, in 95 medication-free DSM-IV euthyroid major depressed inpatients and 44 healthy hospitalized controls. Compared to controls: (1) patients with a positive suicide history (PSH; n=53) showed lower basal FT4 (at 0800 h: p<0.005; at 2300 h: p<0.03), but normal FT3 levels, while patients with a negative suicide history (NSH; n=42) showed normal FT4 and FT3 levels; (2) TSH responses to TRH (DeltaTSH) were blunted in NSHs (at 0800 h: p<0.03; at 2300 h: p<0.00001), but not in PSHs; (3) both NSHs and PSHs showed lower DeltaDeltaTSH values (differences between 2300 h-DeltaTSH and 0800 h-DeltaTSH) (p<0.000001 and p<0.003, respectively). Compared to NSHs, basal FT4 levels were reduced in PSHs (at 0800 h: p<0.002; at 2300h: p<0.006). HPT parameters were not significantly different between recent suicide attempters (n=32) and past suicide attempters (n=21). However, compared to controls, recent suicide attempters showed lower 2300 h-DeltaTSH (p<0.04) and DeltaDeltaTSH (p<0.002) values, and lower basal FT4 values (at 0800 h: p<0.006; at 2300 h: p<0.02). Our results, obtained in a large sample of depressed inpatients, indicate that various degrees of HPT axis dysregulation are associated with the history of suicide.

  3. Brain-Pituitary Axis Development In The CEBAS Minimodule

    Science.gov (United States)

    Schreibman, Martin P.; Magliulo-Cepriano, Lucia

    2001-01-01

    The CEBAS minimodule system is a man-made aquatic ecological system that incorporates animals, plants, snails, and microorganisms. It has been proposed that CEBAS will lead to a multigenerational experimental facility for utilization in a space station as well as for the development of an aquatic CELSS to produce animal and plant biomass for human nutrition. In this context, research on the reproductive biology of the organisms within the system should receive the highest priority. 1bus, the goals of our proposal were to provide information on space-flight-induced changes in the brain-pituitary axis and in the organs that receive information from the environment in the vertebrate selected for the CEBAS Minimodule program, the freshwater teleost Xiphophorus helleri (the swordtail). We studied the development of the brain- pituitary axis in neonates, immature and mature swordtails using histology, cytology, immunohistochemistry, morphometry, and in situ histochemistry to evaluate the synthesis, storage, and release of neurotransmitters, neuroregulatory peptides, neurohormones, and pituitary hormones as well as the structure of the organs and cells that produce, store, or are the target organs for these substances. We flew experiments in the CEBAS-minimodule on two shuttle missions, STS-89 and STS-90. In both flights four gravid females and about 200 juvenile (7 days old) swordtails (Xiphophorus helleri) constituted the aquatic vertebrates to be studied, in addition to the plants and snails that were studied by other team members. In a sample sharing agreement developed with Dr. Volker Bluem, organizer of the CEBAS research program, we received a small number of the juveniles and shared the brains of two adult females.

  4. Suppression of the HPA axis during extrahepatic biliary obstruction induces cholangiocyte proliferation in the rat.

    Science.gov (United States)

    Quinn, Matthew; Ueno, Yoshiyuki; Pae, Hae Yong; Huang, Li; Frampton, Gabriel; Galindo, Cheryl; Francis, Heather; Horvat, Darijana; McMillin, Matthew; Demorrow, Sharon

    2012-01-01

    Cholestatic patients often present with clinical features suggestive of adrenal insufficiency. In the bile duct-ligated (BDL) model of cholestasis, the hypothalamic-pituitary-adrenal (HPA) axis is suppressed. The consequences of this suppression on cholangiocyte proliferation are unknown. We evaluated 1) HPA axis activity in various rat models of cholestasis and 2) effects of HPA axis modulation on cholangiocyte proliferation. Expression of regulatory molecules of the HPA axis was determined after BDL, partial BDL, and α-naphthylisothiocyanate (ANIT) intoxication. The HPA axis was suppressed by inhibition of hypothalamic corticotropin-releasing hormone (CRH) expression by central administration of CRH-specific Vivo-morpholinos or by adrenalectomy. After BDL, the HPA axis was reactivated by 1) central administration of CRH, 2) systemic ACTH treatment, or 3) treatment with cortisol or corticosterone for 7 days postsurgery. There was decreased expression of 1) hypothalamic CRH, 2) pituitary ACTH, and 3) key glucocorticoid synthesis enzymes in the adrenal glands. Serum corticosterone and cortisol remained low after BDL (but not partial BDL) compared with sham surgery and after 2 wk of ANIT feeding. Experimental suppression of the HPA axis increased cholangiocyte proliferation, shown by increased cytokeratin-19- and proliferating cell nuclear antigen-positive cholangiocytes. Conversely, restoration of HPA axis activity inhibited BDL-induced cholangiocyte proliferation. Suppression of the HPA axis is an early event following BDL and induces cholangiocyte proliferation. Knowledge of the role of the HPA axis during cholestasis may lead to development of innovative treatment paradigms for chronic liver disease.

  5. Short-axis epicardial volume change is a measure of cardiac left ventricular short-axis function, which is independent of myocardial wall thickness.

    Science.gov (United States)

    Ugander, Martin; Carlsson, Marcus; Arheden, Håkan

    2010-02-01

    Fractional shortening (FS) by echocardiography is considered to represent the short-axis contribution to the stroke volume (SV), also called short-axis function. However, FS is mathematically coupled to the amount of myocardium, since it rearranges during atrioventricular plane displacement (AVPD). The SV is the sum of the volumes generated by 1) reduction in outer volume of the heart, and 2) inner AVPD. The long-axis contribution to the SV is generated by AVPD, and thus the short-axis contribution is the remaining outer volume change of the heart, which should be unrelated to myocardial wall thickness. We hypothesized that both endocardial and midwall shortening indexed to SV are dependent on myocardial wall thickness, whereas epicardial volume change (EVC) indexed to SV is not. Twelve healthy volunteers (normals), 12 athletes, and 12 patients with dilated cardiomyopathy (ejection fraction EVC was defined as SV minus long-axis function. Endocardial and midwall shortening were measured in a midventricular short-axis slice. Endocardial shortening/SV and midwall shortening/SV both varied in relation to end-diastolic myocardial wall thickness (R(2) = 0.16, P = 0.008 and R(2) = 0.14, P = 0.012, respectively), whereas EVC/SV did not (R(2) = 0.00, P = 0.37). FS is dependent on myocardial wall thickness, whereas EVC is not and therefore represents true short-axis function. This is not surprising considering that FS is mainly caused by rearrangement of myocardium secondary to long-axis function. FS is therefore not synonymous with short-axis function.

  6. Modal Parameter Identification of New Design of Vertical Axis Wind Turbine

    DEFF Research Database (Denmark)

    Chougule, Prasad; Nielsen, Søren R.K.

    2013-01-01

    Vertical axis wind turbines have lower power efficiency than the horizontal axis wind turbines. However vertical axis wind turbines are proven to be economical and noise free on smaller scale. A new design of three bladed vertical axis wind turbine by using two airfoils in construction of each...... blade has been proposed to improve power efficiency. The purpose of two airfoils in blade design of vertical axis wind turbine is to create high lift which in turns gives higher power output. In such case the structural parameter identification is important to understand the system behavior due to its...... first kind of design before experimental analysis. Therefore a study is carried out to determine the natural frequency to avoid unstable state of the system due to rotational frequency of rotor. The present paper outlines a conceptual design of vertical axis wind turbine and a modal analysis by using...

  7. Deflecting Easy-axis of Fe304 Single Crystal Nanowires by Magnetic-field-induced Method

    Institute of Scientific and Technical Information of China (English)

    W. Wang; S. Y. Wang

    2012-01-01

    In order to control the orientation of easy-axis of magnetic nanowires, FesO4 single crystal nanowires with easy-axis perpendicular to wire-axis were prepared successfully by means of a magnetic-field-induced method. Analysis of X-ray diffraction and electron diffraction pattern showed that there was a wide-angle deflection of easy-axis in the prepared Fe304 nanowires. A high saturation magnetization (82 emu/g) of the FesO4 nanowires was achieved at room temperature. The benefits and mechanism of the deflection of easy-axis from its wire-axis in FesO4 single crystal nanowires were discussed. The results are expected to broaden the magnetic properties of traditional ferrite nanowires.

  8. Research on pattern recognition for marine steam turbine rotor axis orbit

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yan; YANG Zhi-da; XIA Hong

    2003-01-01

    The structure,function and recognition method of an axis orbit auto-recognizing system are presented in this paper.In order to make the best use of information of format and dynamic characteristics of marine steam turbine axis orbit,the structure and functions or neural network are applied to this system,which can be used to auto-recognize axis orbit of the system turbine rotor using BP neural network.

  9. Charged current disappearance measurements in the NuMI off-axis beam

    Energy Technology Data Exchange (ETDEWEB)

    R. H. Bernstein

    2003-09-25

    This article studies the potential of combining charged-current disappearance measurements of {nu}{sub {mu}} {yields} {nu}{sub {tau}} from MINOS and an off-axis beam. The author finds that the error on {Delta}m{sup 2} from a 100 kt-yr off-axis measurement is a few percent of itself. Further, the author found little improvement to an off-axis measurement by combining it with MINOS.

  10. Using the axis of elongation to align shapes: Developmental changes between 18 and 24 months

    OpenAIRE

    Smith, Linda B.; Street, Sandra; Jones, Susan S.; James, Karin H.

    2014-01-01

    An object’s axis of elongation serves as an important frame of reference for forming 3-dimensional representations of object shape. By several recent accounts, the formation of these representations is also related to experiences of acting on objects. Four experiments examined 18- to 24-month-old (N = 103) infants’ sensitivity to the elongated axis in action tasks that required extracting, comparing and physically rotating an object so that its major axis was aligned with that of a visual sta...

  11. Kinematical analysis of 5-axis corner smoothing for transitions between linear (G1) blocks

    OpenAIRE

    Beudaert, Xavier; Lavernhe, Sylvain; Tournier, Christophe

    2012-01-01

    5-axis high speed machine tools are widely used in industry. The axis movements are generated by the Computer Numerical Controller (CNC) which has to transform the part program into a sequence of axis setpoints. Most of the time, the tool path is described with linear segments (G1) which lead to tangency discontinuities between blocks. With acceleration and jerk limitations, these discontinuities will induce a zero feedrate and thus surface marks and an increase in machining time. The aim of ...

  12. The role of Toll signaling in dorsoventral axis formation in the milkweed bug Oncopeltus fasciatus

    OpenAIRE

    Chen, Yen-Ta

    2015-01-01

    The establishment of dorsoventral (DV) axis in the Drosophila embryo relies on the Toll/Dorsal signaling pathway. The transcription factor Dorsal acts downstream of Toll forming a nuclear gradient that determines different cell fates along the DV axis. The formation of the DV axis has been studied in two other holometabolous insects, the bee- tle Tribolium and the wasp Nasonia. However, the role of Toll signaling has not been addressed in the more basally branching hemimetabolous insects. Her...

  13. The determination of the direction of the optic axis of uniaxial crystalline materials

    Science.gov (United States)

    Lock, J. A.; Schock, H. J.; Regan, C. A.

    1986-01-01

    The birefringence of crystalline substances in general, and of sapphire in particular, is described. A test is described whose purpose is to determine the direction of the optic axis of a cylindrically machined single crystal of sapphire. This test was performed on the NASA Lewis sapphire cylinder and it was found that the optic axis made an angle of 18 deg with the axis of symmetry of the cylinder.

  14. Intracerebroventricular leptin injection affects neuroendocrine reproductive axis in ovariectomized rats

    Institute of Scientific and Technical Information of China (English)

    Yuebing Qiao; Huixian Cui

    2008-01-01

    BACKGROUND: Leptin regulates neuroendocrine function of the hypothalamus-pituitary-ovary axis in humans.OBJECTIVE: To verify effects of intracerebroventricular leptin injection on neuroendocrine function of the hypothalamus-pituitary-ovary axis in nvariectomized rats.DESIGN, TIME AND SETTING: A randomized, controlled experiment was performed at the Basic Medical Institute, Chengde Medical College between June and October 2007.MATERIALS: Thirty healthy, female, Wistar rats were included in this study. The following compounds were used: leptin; gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) enzyme-linked immunosorbent assay kits.METHODS: Rats were randomly divided into 3 groups at 1, 2, and 4 hours after injection. Each group was subdivided into control and experimental groups (n = 5 animals per group and time point). All rats were subjected to bilateral ovariectomy and, beginning on day 7 after surgery, animals received daily subcutaneous injections of estradiol benzoate (2 μ g) for 7 consecutive days. The experimental groups were injected with 5 μ L leptin (1 g/L) into the lateral cerebral ventricle, and control groups received an equal volume of physiological saline.MAIN OUTCOME MEASURES: GnRH and LH secretion were examined 1, 2, and 4 hours after injection using GnRH and LH ELISA kits, respectively.RESULTS: In the experimental groups, GnRH secretion significantly increased (P < 0.01), followed by LH secretion (P < 0.01), compared with the control groups. GnRH secretion significantly increased l hour after leptin injection (P < 0.01). The LH increase was less pronounced, but still significant (P < 0.01); however,the most prominent LH increase occurred between 1 and 2 hours. Both GnRH and LH secretion reached peak levels at 2 hours after leptin injection. Thereafter, both GnRH and LH secretion decreased, but still maintained very high levels, compared with the control group (P < 0.01).CONCLUSION: lntracerebroventricular leptin injection

  15. Analisis Semiotika Makna Pesan pada Iklan Axis Versi “Iritologi – Menatap Masa Depan”

    Directory of Open Access Journals (Sweden)

    Puri Sulistiyawati

    2016-02-01

    Full Text Available Abstrak Tujuan dari penelitian ini adalah untuk mengetahui dan menganalisis makna pesan dalam iklan Axis versi “Iritologi – Menatap masa depan” di televisi dengan menggunakan pendekatan semiotika Roland Barthes. Dari analisis yang telah dilakukan berdasarkan makna denotasi, konotasi dan mitos dalam iklan Axis versi “iritologi – Menatap masa depan”, dapat diketahui bahwa iklan Axis memiliki konsep yang sangat sederhana, dengan mengusung tema tentang kebiasaan remaja dalam memanfaatkan media sosial. Dari visual iklan yang ditampilkan menguatkan pesan bahwa produk Axis ini menyasar remaja sebagai target audience, remaja atau pelajar adalah konsumen yang mendambakan produk dengan kalitas baik namun dengan harga yang terjangkau. Meski menyasar remaja, namun dalam target marketnya Axis tetap menyasar semua kalangan. Setting tempat atau latar pada iklan yang ditampilkan pun sebagai representasi bahwa Axis dapat dijangkau oleh semua kalangan ekonomi khususnya masyarakat menengah kebawah. Makna Mitos dalam iklan Axis ini tersirat pada scene tertentu. Secara umum iklan ini menyampaikan bahwa selfie dan media sosial sebagai bagian dari kehidupan masyaraka khususnya generasi muda, sebagai sarana untuk berinteraksi dan menunjukan eksistensinya kepada komunitas. Melalui foto yang diunggah pada media sosial, khalayak merepresentasikan perasaan maupun kegiatan yang sedang di lakukannya. Sehingga hal tersebut memicu kebutuhan akan jaringan komunikasi yang lancar dan ekonomis. Kata Kunci: iklan, axis, semiotika, mitos  Abstract The purpose of this research was to determine and analyze the meaning of message in Axis advertisement version “Iritologi – Menatap masa depan” on television using Roland Barthes semiotic approach. Analysis has been done based on the meaning of denotation, connotation and myth in Axis advertisement version “Iritologi – Menatap masa depan”, it can be seen that Axis advertisement has a simple concept, with a theme of

  16. Influence of temperature on the optical system with large diameter off-axis parabolic lenses

    Science.gov (United States)

    Su, Yaru; Ruan, Hao; Liu, Jie

    2016-10-01

    In this work, an optical system with large diameter off-axis parabolic lenses was adopted to achieve diffraction gratings by laser interference exposure. The diffraction wavefront aberration caused by temperature variations was simulated using ZEMAX. Through theoretical analysis and optical simulation, it is proved that the diffraction wavefront aberration of holographic grating caused by the pinhole's location errors (it is assumed that when the displacement of pinhole exists along one axis, the locations of the pinhole along the other two orthogonal axes are in a state of precise adjustment ) is much larger when the displacement occurs along z axis than along the other two axes, and the diffraction wavefront aberration is the smallest when the displacement occurs along x axis. If the ambient temperature changes by 1 degree, the PV value is 0.0631λ when the location of the pinhole changes by 0.121mm along z axis, 0.0034λor 0.0672λ when the location of the pinhole changes by 0.002mm along x axis or 0.03mm along y axis. To reach the diffraction limit (that means the PV value is 0.25λ), the decentering value of the pinhole along z axis should be less than 0.0341mm. In conclusion, the position error along z axis is an important factor to influence the PV value of diffraction grating, and the effect of temperature on the PV value of diffraction grating can be neglected.

  17. Initial Test Results from a 3-axis Vibrating Ring Gyroscope

    Energy Technology Data Exchange (ETDEWEB)

    Gallacher, B J; Neasham, J A; Burdess, J S; Harris, A J [INSAT University of Newcastle upon Tyne NE1 7RU (United Kingdom)

    2006-04-01

    There are several application areas where the simultaneous measurement of rates of rotation about three mutually orthogonal axes is required. In this paper the principle features of a 3-axis vibrating ring gyroscope are described. The fabrication process for the gyroscope is presented and employs standard MEMS techniques. The modal properties for the ring are measured experimentally using laser vibrometry and electrostatic sensing and compared with the design predictions. In operation as a rate gyroscope it is necessary to excite the primary motion of the gyroscope and control is amplitude. As Q-factors of vibratory gyroscope are typically of the order 10{sup 3}-10{sup 4} slight variations in environmental conditions will perturb the natural frequency of the primary mode significantly. To ensure the primary motion of the gyroscope is maintained with constant amplitude a control scheme employing both frequency tracking and amplitude control is required. An electronic control system using digital signal processing (DSP) has been developed to ensure excitation of the primary motion occurs at resonance with controlled amplitude. The control scheme employs an embedded processor to generate the drive frequency (via a D/A converter) and to monitor the primary vibration (via an A/D converter). Experimental results from the control scheme highlighting its effectiveness over conventional PLL approaches are presented.

  18. NEAR WAKE OF A MODEL HORIZONTAL-AXIS WIND TURBINE

    Institute of Scientific and Technical Information of China (English)

    HU Dan-mei; DU Zhao-hui

    2009-01-01

    An experimental investigation on the properties of the near wake behind the rotor of a Horizontal-Axis Wind Turbine (HAWT) was carried out at model scale. Measurements were made with a stationary slanted hot-wire anemometer using the technique of phase-locked averaging. The primary aim is to study the formation and development of the three-dimensional wake. Five axial locations were chosen within four chord lengths of the blades over a range of tip speed ratios. The results show that during the downstream development of the wake, the wake centre traces a helical curve with its rotation direction opposite to that of the rotor. The distribution of mean velocity behind the HAWT rotor reveals an expansion and a decay of the three-dimensional wake. The shapes of the mean velocity distribution are similar along the blades span at the same downstream axial location. It is shown that the turbulence levels in the wake are higher than those in the non-wake region. The circumferential component and the radial component of the turbulence intensity are higher than the axial component. Our study offers some food of thought for better understanding of the physical features of the flow field as well as the performance of HAWT.

  19. Five-Axis Ultrasonic Additive Manufacturing for Nuclear Component Manufacture

    Science.gov (United States)

    Hehr, Adam; Wenning, Justin; Terrani, Kurt; Babu, Sudarsanam Suresh; Norfolk, Mark

    2017-03-01

    Ultrasonic additive manufacturing (UAM) is a three-dimensional metal printing technology which uses high-frequency vibrations to scrub and weld together both similar and dissimilar metal foils. There is no melting in the process and no special atmosphere requirements are needed. Consequently, dissimilar metals can be joined with little to no intermetallic compound formation, and large components can be manufactured. These attributes have the potential to transform manufacturing of nuclear reactor core components such as control elements for the High Flux Isotope Reactor at Oak Ridge National Laboratory. These components are hybrid structures consisting of an outer cladding layer in contact with the coolant with neutron-absorbing materials inside, such as neutron poisons for reactor control purposes. UAM systems are built into a computer numerical control (CNC) framework to utilize intermittent subtractive processes. These subtractive processes are used to introduce internal features as the component is being built and for net shaping. The CNC framework is also used for controlling the motion of the welding operation. It is demonstrated here that curved components with embedded features can be produced using a five-axis code for the welder for the first time.

  20. Hydroelastic dynamic characteristics of a slender axis-symmetric body

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The slender axis-symmetric submarine body moving in the vertical plane is the object of our investigation.A coupling model is developed where displacements of a solid body as a Euler beam(consisting of rigid motions and elastic deformations) and fluid pressures are employed as basic independent variables,including the interaction between hydrodynamic forces and structure dynamic forces.Firstly the hydrodynamic forces,depending on and conversely influencing body motions,are taken into account as the governing equations.The expressions of fluid pressure are derived based on the potential theory.The characteristics of fluid pressure,including its components,distribution and effect on structure dynamics,are analyzed.Then the coupling model is solved numerically by means of a finite element method(FEM).This avoids the complicacy,combining CFD(fluid) and FEM(structure),of direct numerical simulation,and allows the body with a non-strict ideal shape so as to be more suitable for practical engineering.An illustrative example is given in which the hydroelastic dynamic characteristics,natural frequencies and modes of a submarine body are analyzed and compared with experimental results.Satisfactory agreement is observed and the model presented in this paper is shown to be valid.

  1. Numerical study on small scale vertical axis wind turbine

    Directory of Open Access Journals (Sweden)

    Parra-Santos Teresa

    2016-01-01

    Full Text Available The performance of a Vertical Axis Wind Turbine (VAWT is numerically analyzed. The set-up is Hdarrieus with three straight blades airfoils NACA attached to a rotating vertical shaft. The wind turbine has solidity equals to the unity operating with wind velocity of 7 m/s. Influence of pitch angle is tested to get design tendencies. 2D, transient, Navier Stokes equations are solved using the code Ansys-Fluent. Conservation equations were solved with a Third-Order MUSCL scheme using SIMPLE to couple pressure and velocity. More than six revolutions must be simulated to get the periodic behavior. Two models of turbulence have been contrasted Realizable k-epsilon and Transition SST concluding the last one show more realistic flow features. Pitch angles of 0º, -6º and -10º have been tested with Tip Speed Ratios ranging from 0.7 and 1.6. The no null pitch angles improve the performance of the wind turbine. Instantaneous and averaged power coefficients as well as detailed flow field around the airfoils are showed.

  2. Optical axis jitter rejection for double overlapped adaptive optics systems

    Science.gov (United States)

    Luo, Qi; Luo, Xi; Li, Xinyang

    2016-04-01

    Optical axis jitters, or vibrations, which arise from wind shaking and structural oscillations of optical platforms, etc., cause a deleterious impact on the performance of adaptive optics systems. When conventional integrators are utilized to reject such high frequency and narrow-band disturbance, the benefits are quite small despite their acceptable capabilities to reject atmospheric turbulence. In our case, two suits of complete adaptive optics systems called double overlapped adaptive optics systems (DOAOS) are used to counteract both optical jitters and atmospheric turbulence. A novel algorithm aiming to remove vibrations is proposed by resorting to combine the Smith predictor and notch filer. With the help of loop shaping method, the algorithm will lead to an effective and stable controller, which makes the characteristics of error transfer function close to notch filters. On the basis of the spectral analysis of observed data, the peak frequency and bandwidth of vibrations can be identified in advance. Afterwards, the number of notch filters and their parameters will be determined using coordination descending method. The relationship between controller parameters and filtering features is discussed, and the robustness of the controller against varying parameters of the control object is investigated. Preliminary experiments are carried out to validate the proposed algorithms. The overall control performance of DOAOS is simulated. Results show that time delays are a limit of the performance, but the algorithm can be successfully implemented on our systems, which indicate that it has a great potential to reject jitters.

  3. Weighted simultaneous iterative reconstruction technique for single-axis tomography

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, D., E-mail: Daniel.Wolf@Triebenberg.de; Lubk, A.; Lichte, H.

    2014-01-15

    Tomographic techniques play a crucial role in imaging methods such as transmission electron microscopy (TEM) due to their unique capabilities to reconstruct three-dimensional object information. However, the accuracy of the two standard tomographic reconstruction techniques, the weighted back-projection (W-BP) and the simultaneous iterative reconstruction technique (SIRT) is reduced under common experimental restrictions, such as limited tilt range or noise. We demonstrate that the combination of W-BP and SIRT leads to an improved tomographic reconstruction technique: the weighted SIRT. Convergence, resolution and reconstruction error of the W-SIRT are analyzed by a detailed analytical, numerical, and experimental comparison with established methods. Our reconstruction technique is not restricted to TEM tomography but can be applied to all problems sharing single axis imaging geometry. - Highlights: • A new tomographic reconstruction technique W-SIRT was developed. • W-SIRT provides better convergence, higher resolution and smaller reconstruction error compared to established tomographic techniques. • This is demonstrated by a detailed analytical, numerical, and experimental comparison.

  4. Hydroelastic dynamic characteristics of a slender axis-symmetric body

    Science.gov (United States)

    Chen, Weimin; Li, Min; Zheng, Zhongqin; Zhang, Liwu

    2010-07-01

    The slender axis-symmetric submarine body moving in the vertical plane is the object of our investigation. A coupling model is developed where displacements of a solid body as a Euler beam (consisting of rigid motions and elastic deformations) and fluid pressures are employed as basic independent variables, including the interaction between hydrodynamic forces and structure dynamic forces. Firstly the hydrodynamic forces, depending on and conversely influencing body motions, are taken into account as the governing equations. The expressions of fluid pressure are derived based on the potential theory. The characteristics of fluid pressure, including its components, distribution and effect on structure dynamics, are analyzed. Then the coupling model is solved numerically by means of a finite element method (FEM). This avoids the complicacy, combining CFD (fluid) and FEM (structure), of direct numerical simulation, and allows the body with a non-strict ideal shape so as to be more suitable for practical engineering. An illustrative example is given in which the hydroelastic dynamic characteristics, natural frequencies and modes of a submarine body are analyzed and compared with experimental results. Satisfactory agreement is observed and the model presented in this paper is shown to be valid.

  5. The Gut-Brain Axis: The Missing Link in Depression.

    Science.gov (United States)

    Evrensel, Alper; Ceylan, Mehmet Emin

    2015-12-31

    The gut microbiota is essential to human health and the immune system and plays a major role in the bidirectional communication between the gut and the brain. Based on evidence, the gut microbiota is associated with metabolic disorders such as obesity, diabetes mellitus and neuropsychiatric disorders such as schizophrenia, autistic disorders, anxiety disorders and major depressive disorders. In the past few years, neuroscientific research has shown the importance of the microbiota in the development of brain systems. Recent studies showed that the microbiota could activate the immune and central nervous systems, including commensal and pathogenic microorganisms in the gastrointestinal tract. Gut microorganisms are capable of producing and delivering neuroactive substances such as serotonin and gamma-aminobutyric acid, which act on the gut-brain axis. Preclinical research in rodents suggested that certain probiotics have antidepressant and anxiolytic activities. Effects may be mediated via the immune system or neuroendocrine systems. Herein, we present the latest literature examining the effects of the gut microbiota on depression.

  6. Off-axis electron holography of ferromagnetic multilayer nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Akhtari-Zavareh, Azadeh; Kavanagh, K. L. [Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A1S6 (Canada); Carignan, L. P. [Apollo Microwaves, 1650 Trans-Canada Highway, Dorval, Quebec H9P 1H7 (Canada); Department of Engineering Physics, École Polytechnique de Montréal, Montréal, Quebec, H3C 3A7 Canada (Canada); Department of Electrical Engineering, École Polytechnique de Montréal, Montréal, Quebec, H3C 3A7 Canada (Canada); Yelon, A.; Ménard, D. [Department of Engineering Physics, École Polytechnique de Montréal, Montréal, Quebec, H3C 3A7 Canada (Canada); Kasama, T. [Center for Electron Nanoscopy, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark); Herring, R. [Department of Mechanical Engineering, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Dunin-Borkowski, R. E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Institute for Microstructure Research, D-52425 Jülich (Germany); McCartney, M. R. [Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States)

    2014-07-14

    We have used electron holography to investigate the local magnetic behavior of isolated ferromagnetic nanowires (NWs) in their remanent states. The NWs consisted of periodic magnetic layers of soft, high-saturation magnetization CoFeB alloys, and non-magnetic layers of Cu. All NWs were fabricated by pulsed-potential electrodeposition in nanoporous alumina membranes. The NW composition and layer thicknesses were measured using scanning transmission electron microscopy and energy dispersive spectroscopy. The magnetization of individual NWs depended upon the thicknesses of the layers and the direction of an external magnetic field, which had been applied in situ. When the CoFeB was thicker than the diameter (50 nm), magnetization was axial for all external field directions, while thinner layers could be randomized via a perpendicular field. In some cases, magnetization inside the wire was detected at an angle with respect to the axis of the wires. In thinner Cu/CoFeB (<10 nm each) multilayer, magnetic field vortices were detected, associated with opposing magnetization in neighbouring layers. The measured crystallinity, compositions, and layer thicknesses of individual NWs were found to be significantly different from those predicted from calibration growths based on uniform composition NWs. In particular, a significant fraction of Cu (up to 50 at. %) was present in the CoFeB layers such that the measured magnetic induction was lower than expected. These results will be used to better understand previously measured effective anisotropy fields of similar NW arrays.

  7. A broadband two axis flux-gate magnetometer

    Directory of Open Access Journals (Sweden)

    P. Palangio

    1998-06-01

    Full Text Available A broadband two axis flux-gate magnetometer was developed to obtain high sensitivity in magnetotelluric measurements. In magnetotelluric sounding, natural low frequency electromagnetic fields are used to estimate the conductivity of the Earth's interior. Because variations in the natural magnetic field have small amplitude(10-100 pT in the frequency range 1 Hz to 100 Hz, highly sensitive magnetic sensors are required. In magnetotelluric measurements two long and heavy solenoids, which must be installed, in the field station, perpendicular to each other (north-south and east-west and levelled in the horizontal plane are used. The coil is a critical component in magnetotelluric measurements because very slight motions create noise voltages, particularly troublesome in wooded areas; generally the installation takes place in a shallow trench. Moreover the coil records the derivative of the variations rather than the magnetic field variations, consequently the transfer function (amplitude and phase of this sensor is not constant throughout the frequency range 0.001-100 Hz. The instrument, developed at L'Aquila Geomagnetic Observatory, has a flat response in both amplitude and phase in the frequency band DC-100 Hz, in addition it has low weight, low power, small volume and it is easier to install in the field than induction magnetometers. The sensivity of this magnetometer is 10 pT rms.

  8. Morping blade design for vertical axis wind turbines

    Science.gov (United States)

    Macphee, David; Beyene, Asfaw

    2015-11-01

    Wind turbines operate at peak efficiency at a certain set of operational conditions. Away from these conditions, conversion efficiency drops significantly, requiring pitch and yaw control schemes to mitigate these losses. These efforts are an example of geometric variability, allowing for increased power production but with an unfortunate increase in investment cost to the energy conversion system. In Vertical-Axis Wind Turbines (VAWTs), the concept of pitch control is especially complicated due to a dependence of attack angle on armature azimuth. As a result, VAWT pitch control schemes, both active and passive, are as of yet unfeasible. This study investigates a low-cost, passive pitch control system, in which VAWT blades are constructed of a flexible material, allowing for continuous shape-morphing in response to local aerodynamic loading. This design is analyzed computationally using a finite-volume fluid-structure interaction routine and compared to a geometrically identical rigid rotor. The results indicate that the flexible blade increases conversion efficiency by reducing the severity of vortex shedding, allowing for greater average torque over a complete revolution.

  9. Design of h-Darrieus vertical axis wind turbine

    Science.gov (United States)

    Parra, Teresa; Vega, Carmen; Gallegos, A.; Uzarraga, N. C.; Castro, F.

    2015-05-01

    Numerical simulation is used to predict the performance of a Vertical Axis Wind Turbine (VAWT) H-Darrieus. The rotor consists of three straight blades with shape of aerofoil of the NACA family attached to a rotating vertical shaft. The influence of the solidity is tested to get design tendencies. The mesh has two fluid volumes: one sliding mesh for the rotor where the rotation velocity is established while the other is the environment of the rotor. Bearing in mind the overall flow is characterized by important secondary flows, the turbulence model selected was realizable k-epsilon with non-equilibrium wall functions. Conservation equations were solved with a Third-Order Muscl scheme using SIMPLE to couple pressure and velocity. During VAWT operation, the performance depends mainly on the relative motion of the rotating blade and has a fundamental period which depends both on the rate of rotation and the number of blades. The transient study is necessary to characterise the hysteresis phenomenon. Hence, more than six revolutions get the periodic behaviour. Instantaneous flows provide insight about wake structure interaction. Time averaged parameters let obtain the characteristic curves of power coefficient.

  10. Design of h-Darrieus vertical axis wind turbine

    Directory of Open Access Journals (Sweden)

    Parra Teresa

    2015-01-01

    Full Text Available Numerical simulation is used to predict the performance of a Vertical Axis Wind Turbine (VAWT H-Darrieus. The rotor consists of three straight blades with shape of aerofoil of the NACA family attached to a rotating vertical shaft. The influence of the solidity is tested to get design tendencies. The mesh has two fluid volumes: one sliding mesh for the rotor where the rotation velocity is established while the other is the environment of the rotor. Bearing in mind the overall flow is characterized by important secondary flows, the turbulence model selected was realizable k-epsilon with non-equilibrium wall functions. Conservation equations were solved with a Third-Order Muscl scheme using SIMPLE to couple pressure and velocity. During VAWT operation, the performance depends mainly on the relative motion of the rotating blade and has a fundamental period which depends both on the rate of rotation and the number of blades. The transient study is necessary to characterise the hysteresis phenomenon. Hence, more than six revolutions get the periodic behaviour. Instantaneous flows provide insight about wake structure interaction. Time averaged parameters let obtain the characteristic curves of power coefficient.

  11. The Parameters Affect on Power Coefficient Vertical Axis Wind Turbine

    Directory of Open Access Journals (Sweden)

    Ahmed Y. Qasim

    2012-04-01

    Full Text Available ABSTRACT: This study describes the design of a special type of vertical axis rotor wind turbine with moveable vertically positioned vanes. The novel design increases the torque in the left side of the wind turbine by increasing the drag coefficient. It also reduces the negative torque of the frame which rotates contrary to the wind in the other side. Two different types of models, having different vane shapes (flat vane and cavity shaped vane, were fabricated. Each type consisted of two models with varying number of frames (three and four frames. The models were tested in a wind tunnel with variable wind speed in order to understand the effect of shape, weight, and number of frames on the power coefficient of the wind turbine. ABSTRAK: Di dalam kajian ini, rotor turbin angin berpaksi vertikel sebagai rangka khusus telah direkabentuk dengan lokasi vertikel mudahalih oleh bilah kipas. Rekabentuk ini meningkatkan tork di bahagian kiri turbin angin dengan meningkatkan pekali seretan dan mengurangkan tork negatif rangka yang berputar berlawanan dengan angin pada bahagian lain. Dua jenis model berbentuk berlainan telah difabrikasi (bilah kipas rata dan bilah kipas berbentuk kaviti, dengan setiap jenis mempunyai dua model dengan bilangan rangka yang berlainan (berangka tiga dan berangka empat. Model-model telah diuji di dalam terowong angin dengan kelajuan angin yang berbeza bagi mendapatkan kesan rekabentuk, berat dan bilangan rangka ke atas pekali kuasa.KEYWORDS: design; wind turbine; drag coefficient; vane

  12. 3D CFD Analysis of a Vertical Axis Wind Turbine

    Directory of Open Access Journals (Sweden)

    Andrea Alaimo

    2015-04-01

    Full Text Available To analyze the complex and unsteady aerodynamic flow associated with wind turbine functioning, computational fluid dynamics (CFD is an attractive and powerful method. In this work, the influence of different numerical aspects on the accuracy of simulating a rotating wind turbine is studied. In particular, the effects of mesh size and structure, time step and rotational velocity have been taken into account for simulation of different wind turbine geometries. The applicative goal of this study is the comparison of the performance between a straight blade vertical axis wind turbine and a helical blade one. Analyses are carried out through the use of computational fluid dynamic ANSYS® Fluent® software, solving the Reynolds averaged Navier–Stokes (RANS equations. At first, two-dimensional simulations are used in a preliminary setup of the numerical procedure and to compute approximated performance parameters, namely the torque, power, lift and drag coefficients. Then, three-dimensional simulations are carried out with the aim of an accurate determination of the differences in the complex aerodynamic flow associated with the straight and the helical blade turbines. Static and dynamic results are then reported for different values of rotational speed.

  13. MRI of the hypothalamic-pituitary axis in children

    Energy Technology Data Exchange (ETDEWEB)

    Argyropoulou, Maria I. [University of Ioannina, Department of Radiology, Medical School, Ioannina (Greece); Kiortsis, Dimitrios Nikiforos [University of Ioannina, Department of Physiology, Medical School, Ioannina (Greece)

    2005-11-01

    In childhood, the MR characteristics of the normal pituitary gland are well established. During the first 2 months of life the adenohypophysis demonstrates high signal. Pituitary gland height (PGH) decreases during the 1st year of life and then increases, reaching a plateau after puberty. The magnetization transfer ratio (MTR) increases in both sexes up to the age of 20 years. On dynamic contrast-enhanced studies, the posterior pituitary lobe enhances simultaneously with the straight sinus, and the adenohypophysis later, but within 30 s. In genetically determined dysfunctional states, the adenohypophysis may be normal, hypoplastic, or enlarged. Pituitary enlargement, observed in Prop 1 gene mutations, is characterized by a mass interposed between the anterior and posterior lobes. An ectopic posterior lobe (EPP), associated with a hypoplastic or absent pituitary stalk, may be observed in patients with hypopituitarism. Tumors of the hypothalamic-pituitary (HP) axis may be the origin of adenohypophyseal deficiencies. A small hypointense adenohypophysis is found in iron overload states and is often associated with hypogonadotrophic hypogonadism. Absence of the posterior lobe bright signal, with or without a thick pituitary stalk or a mass at any site from the median eminence to the posterior pituitary lobe, may be found in diabetes insipidus. Hydrocephalus, suprasellar arachnoid cysts, hypothalamic hamartomas and craniopharyngiomas may result in central precocious puberty (CPP). Increased PGH in girls with idiopathic CPP is useful for its differential diagnosis from premature thelarche (PT). Pituitary adenomas, observed mainly in adolescents, present the same MR characteristics as those in adults. (orig.)

  14. Real-Time Attitude Independent Three Axis Magnetometer Calibration

    Science.gov (United States)

    Crassidis, John L.; Lai, Kok-Lam; Harman, Richard R.

    2003-01-01

    In this paper new real-time approaches for three-axis magnetometer sensor calibration are derived. These approaches rely on a conversion of the magnetometer-body and geomagnetic-reference vectors into an attitude independent observation by using scalar checking. The goal of the full calibration problem involves the determination of the magnetometer bias vector, scale factors and non-orthogonality corrections. Although the actual solution to this full calibration problem involves the minimization of a quartic loss function, the problem can be converted into a quadratic loss function by a centering approximation. This leads to a simple batch linear least squares solution. In this paper we develop alternative real-time algorithms based on both the extended Kalman filter and Unscented filter. With these real-time algorithms, a full magnetometer calibration can now be performed on-orbit during typical spacecraft mission-mode operations. Simulation results indicate that both algorithms provide accurate integer resolution in real time, but the Unscented filter is more robust to large initial condition errors than the extended Kalman filter. The algorithms are also tested using actual data from the Transition Region and Coronal Explorer (TRACE).

  15. Investigation of implementation of stators on vertical axis wind turbines

    Science.gov (United States)

    Alexander, Aaron; Santhanakrishnan, Arvind

    2014-11-01

    Vertical Axis Wind Turbines (VAWT) have historically suffered from an inability to self-start and, especially on Savonius rotors, low efficiencies due to drag on the returning blade. A few VAWT studies have examined the use of stators to direct the flow onto the power producing side of the rotor thus preventing drag on the returning side, yet all of the designs studied allow the air to exit on the downstream side of the entering flow. This study investigates an alternative stator design for extracting more wind energy by trapping the incoming flow into a rising vortex within the stator enclosure. The flow is then allowed to exit above the stator. The current study compared the performance of a generic Savonius rotor in a 7 m/s free stream flow with the same rotor in two different stator designs. The first stator design allows the flow to escape in the downstream direction. The second stator design utilizes the same stator shape, but forces the air to remain trapped until it can exit above the stators. The initial evaluation of the results was conducted using Computational Fluid Dynamics (CFD) package Star-CCM + set up with an unsteady k- ɛ model at a Reynolds number of about 1,400,000. Experimental comparisons with scale models will be presented.

  16. Propagation of angular errors in two-axis rotation systems

    Science.gov (United States)

    Torrington, Geoffrey K.

    2003-10-01

    Two-Axis Rotation Systems, or "goniometers," are used in diverse applications including telescope pointing, automotive headlamp testing, and display testing. There are three basic configurations in which a goniometer can be built depending on the orientation and order of the stages. Each configuration has a governing set of equations which convert motion between the system "native" coordinates to other base systems, such as direction cosines, optical field angles, or spherical-polar coordinates. In their simplest form, these equations neglect errors present in real systems. In this paper, a statistical treatment of error source propagation is developed which uses only tolerance data, such as can be obtained from the system mechanical drawings prior to fabrication. It is shown that certain error sources are fully correctable, partially correctable, or uncorrectable, depending upon the goniometer configuration and zeroing technique. The system error budget can be described by a root-sum-of-squares technique with weighting factors describing the sensitivity of each error source. This paper tabulates weighting factors at 67% (k=1) and 95% (k=2) confidence for various levels of maximum travel for each goniometer configuration. As a practical example, this paper works through an error budget used for the procurement of a system at Sandia National Laboratories.

  17. Five-Axis Ultrasonic Additive Manufacturing for Nuclear Component Manufacture

    Science.gov (United States)

    Hehr, Adam; Wenning, Justin; Terrani, Kurt; Babu, Sudarsanam Suresh; Norfolk, Mark

    2016-12-01

    Ultrasonic additive manufacturing (UAM) is a three-dimensional metal printing technology which uses high-frequency vibrations to scrub and weld together both similar and dissimilar metal foils. There is no melting in the process and no special atmosphere requirements are needed. Consequently, dissimilar metals can be joined with little to no intermetallic compound formation, and large components can be manufactured. These attributes have the potential to transform manufacturing of nuclear reactor core components such as control elements for the High Flux Isotope Reactor at Oak Ridge National Laboratory. These components are hybrid structures consisting of an outer cladding layer in contact with the coolant with neutron-absorbing materials inside, such as neutron poisons for reactor control purposes. UAM systems are built into a computer numerical control (CNC) framework to utilize intermittent subtractive processes. These subtractive processes are used to introduce internal features as the component is being built and for net shaping. The CNC framework is also used for controlling the motion of the welding operation. It is demonstrated here that curved components with embedded features can be produced using a five-axis code for the welder for the first time.

  18. Bifurcation magnetic resonance in films magnetized along hard magnetization axis

    Energy Technology Data Exchange (ETDEWEB)

    Vasilevskaya, Tatiana M., E-mail: t_vasilevs@mail.ru [Ulyanovsk State University, Leo Tolstoy 42, 432017 Ulyanovsk (Russian Federation); Sementsov, Dmitriy I.; Shutyi, Anatoliy M. [Ulyanovsk State University, Leo Tolstoy 42, 432017 Ulyanovsk (Russian Federation)

    2012-09-15

    We study low-frequency ferromagnetic resonance in a thin film magnetized along the hard magnetization axis performing an analysis of magnetization precession dynamics equations and numerical simulation. Two types of films are considered: polycrystalline uniaxial films and single-crystal films with cubic magnetic anisotropy. An additional (bifurcation) resonance initiated by the bistability, i.e. appearance of two closely spaced equilibrium magnetization states is registered. The modification of dynamic modes provoked by variation of the frequency, amplitude, and magnetic bias value of the ac field is studied. Both steady and chaotic magnetization precession modes are registered in the bifurcation resonance range. - Highlights: Black-Right-Pointing-Pointer An additional bifurcation resonance arises in a case of a thin film magnetized along HMA. Black-Right-Pointing-Pointer Bifurcation resonance occurs due to the presence of two closely spaced equilibrium magnetization states. Black-Right-Pointing-Pointer Both regular and chaotic precession modes are realized within bifurcation resonance range. Black-Right-Pointing-Pointer Appearance of dynamic bistability is typical for bifurcation resonance.

  19. Techniques for measuring small changes in the orientation of the easy axis in permalloy films

    NARCIS (Netherlands)

    Eijkel, Kees J.M.; Haan, de Poul; Ridder, de René M.

    1988-01-01

    It is well known that the orientation of the easy axis in permalloy can be affected by annealing. The need in our research for detailed information of the behavior of the easy‐axis orientation in the temperature range from room temperature to 100 °C and the absence of measurement techniques to deriv

  20. Hypothalamic Pituitary Adrenal Axis Functioning in Reactive and Proactive Aggression in Children

    Science.gov (United States)

    Lopez-Duran, Nestor L.; Olson, Sheryl L.; Hajal, Nastassia J.; Felt, Barbara T.; Vazquez, Delia M.

    2009-01-01

    The purpose of this study was to examine the association between hypothalamic-pituitary-adrenal axis (HPA-axis) reactivity and proactive and reactive aggression in pre-pubertal children. After a 30-min controlled base line period, 73 7-year-old children (40 males and 33 females) were randomly assigned to one of two experimental tasks designed to…

  1. Modular design and development methodology for robotic multi-axis F/M sensors

    Science.gov (United States)

    Liang, Qiao-Kang; Zhang, Dan; Coppola, Gianmarc; Wu, Wan-Neng; Zou, Kun-Lin; Wang, Yao-Nan; Sun, Wei; Ge, Yun-Jian; Ge, Yu

    2016-04-01

    Accurate Force/Moment (F/M) measurements are required in many applications, and multi-axis F/M sensors have been utilized a wide variety of robotic systems since 1970s. A multi-axis F/M sensor is capable of measuring multiple components of force terms along x-, y-, z-axis (Fx, Fy, Fz), and the moments terms about x-, y- and z-axis (Mx, My and Mz) simultaneously. In this manuscript, we describe experimental and theoretical approaches for using modular Elastic Elements (EE) to efficiently achieve multi-axis, high-performance F/M sensors. Specifically, the proposed approach employs combinations of simple modular elements (e.g. lamella and diaphragm) in monolithic constructions to develop various multi-axis F/M sensors. Models of multi-axis F/M sensors are established, and the experimental results indicate that the new approach could be widely used for development of multi-axis F/M sensors for many other different applications.

  2. Effortful Control and Parenting: Associations with HPA Axis Reactivity in Early Childhood

    Science.gov (United States)

    Kryski, Katie R.; Dougherty, Lea R.; Dyson, Margaret W.; Olino, Thomas M.; Laptook, Rebecca S.; Klein, Daniel N.; Hayden, Elizabeth P.

    2013-01-01

    While activation of the hypothalamic-pituitary-adrenal (HPA) axis is an adaptive response to stress, excessive HPA axis reactivity may be an important marker of childhood vulnerability to psychopathology. Parenting, including parent affect during parent-child interactions, may play an important role in shaping the developing HPA system; however,…

  3. Bouncing back - trauma and the HPA-axis in healthy adults

    Directory of Open Access Journals (Sweden)

    Ellen Renée Klaassens

    2010-12-01

    Full Text Available Dysregulation of the hypothalamic–pituitary–adrenal (HPA-axis is thought to underlie stress-related psychiatric disorders such as posttraumatic stress disorder (PTSD. Some studies have reported HPA-axis dysregulation in trauma-exposed (TE adults in the absence of psychiatric morbidity. In this dissertation we set out to unravel part of the mechanism that underlies the complex relations between trauma exposure, stress regulation, and psychopathology. Mentally healthy TE subjects were compared with non-trauma-exposed (NE healthy controls. To distinguish between the potential effects of childhood trauma and adulthood trauma, we included women exposed to childhood trauma as well as men who were exposed to trauma during adulthood. Basal HPA-axis functioning was assessed with salivary cortisol samples. HPA-axis reactivity was assessed with the dexamethasone/corticotropin-releasing hormone (Dex/CRH test. The results show that childhood trauma exposure is associated with an attenuated cortisol response after the Dex/CRH challenge test in women. In contrast, trauma exposure during adulthood was not associated with alterations in HPA-axis regulation after the Dex/CRH test. Neither childhood trauma nor adulthood trauma were associated with basal HPA-axis functioning. Childhood trauma rather than adulthood trauma may chronically affect HPA-axis functioning. Since the association between adulthood trauma and resilience to psychopathology cannot be explained by HPA-axis functioning alone, other factors must play a role.

  4. Characterization of the hypothalamic-pituitary-adrenal-axis in familial longevity under resting conditions

    NARCIS (Netherlands)

    Jansen, S.W.; Roelfsema, F.; Akintola, A.A.; Oei, N.Y.; Cobbaert, C.M.; Ballieux, B.E.; van der Grond, J.; Westendorp, R.G.; Pijl, H.; van Heemst, D.

    2015-01-01

    Objective: The hypothalamic-pituitary-adrenal (HPA)-axis is the most important neuro-endocrine stress response system of our body which is of critical importance for survival. Disturbances in HPA-axis activity have been associated with adverse metabolic and cognitive changes. Humans enriched for lon

  5. Modular design and development methodology for robotic multi-axis F/M sensors.

    Science.gov (United States)

    Liang, Qiao-Kang; Zhang, Dan; Coppola, Gianmarc; Wu, Wan-Neng; Zou, Kun-Lin; Wang, Yao-Nan; Sun, Wei; Ge, Yun-Jian; Ge, Yu

    2016-04-22

    Accurate Force/Moment (F/M) measurements are required in many applications, and multi-axis F/M sensors have been utilized a wide variety of robotic systems since 1970s. A multi-axis F/M sensor is capable of measuring multiple components of force terms along x-, y-, z-axis (Fx, Fy, Fz), and the moments terms about x-, y- and z-axis (Mx, My and Mz) simultaneously. In this manuscript, we describe experimental and theoretical approaches for using modular Elastic Elements (EE) to efficiently achieve multi-axis, high-performance F/M sensors. Specifically, the proposed approach employs combinations of simple modular elements (e.g. lamella and diaphragm) in monolithic constructions to develop various multi-axis F/M sensors. Models of multi-axis F/M sensors are established, and the experimental results indicate that the new approach could be widely used for development of multi-axis F/M sensors for many other different applications.

  6. Relationship between the hypothalamic-pituitary-adrenal-axis and fatty acid metabolism in recurrent depression

    NARCIS (Netherlands)

    Mocking, Roel J T; Ruhe, Eric; Assies, Johanna; Lok, Anja; Koeter, Maarten W J; Visser, Ieke; Bockting, Claudi L H; Schene, Aart H

    2013-01-01

    Alterations in hypothalamic-pituitary-adrenal (HPA)-axis activity and fatty acid (FA)-metabolism have been observed in (recurrent) major depressive disorder (MDD). Through the pathophysiological roles of FAs in the brain and cardiovascular system, a hypothesized relationship between HPA-axis activit

  7. Evaluation of the P Wave Axis in Patients With Systemic Lupus Erythematosus

    Directory of Open Access Journals (Sweden)

    Rezzan Deniz Acar

    2015-12-01

    Conclusion: P wave axis was found significantly increased in patients with SLE and positively correlated with SELENA-SLEDAI score. As the risk score increases in patients with SLE, P wave axis changes which may predict the risk of all-cause and cardiovascular mortality.

  8. Combined Structural Optimization and Aeroelastic Analysis of a Vertical Axis Wind Turbine

    DEFF Research Database (Denmark)

    Roscher, Björn; Ferreira, Carlos Simao; Bernhammer, Lars O.;

    2015-01-01

    Floating offshore wind energy poses challenges on the turbine design. A possible solution is vertical axis wind turbines, which are possibly easier to scale-up and require less components (lower maintenance) and a smaller floating structure than horizontal axis wind turbines. This paper presents...

  9. Questions Students Ask: Why Does a Football Keep its Axis Pointing Along its Trajectory?

    Science.gov (United States)

    Physics Teacher, 1985

    1985-01-01

    Why does a football thrown with a spin keep its axis pointing along its trajectory? (It's most obvious in a long, soft pass. Even with a wobbly pass the ball's axis wobbles around the line of its trajectory). The answer to this question is provided. (JN)

  10. Association analyses of depression and genes in the hypothalamus-pituitary-adrenal axis

    DEFF Research Database (Denmark)

    Buttenschøn, Henrietta Nørmølle; Krogh, Jesper; Nielsen, Marit Nyholm;

    2016-01-01

    OBJECTIVE: Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been reported in depression. The aim was to investigate the potential association between depression and seven genes regulating or interfering with the HPA axis, including the gene encoding angiotensin converting enzyme...

  11. HPA-axis activity as a predictor of future disruptive behaviors in young adolescents

    NARCIS (Netherlands)

    Sondeijker, Frouke E. P. L.; Ferdinand, Robert F.; Oldehinkel, Albertine J.; Tiemeier, Henning; Ormel, Johan; Verhulst, Frank C.

    2008-01-01

    Low HPA-axis activity has been proposed as a risk factor for disruptive behaviors. However longitudinal data on this topic are practically lacking. In the present study we investigated if low HPA-axis activity predicted future disruptive behaviors. We included 1,399 boys and girls from the Dutch gen

  12. Local Auxin Sources Orient the Apical-Basal Axis in Arabidopsis Embryos

    NARCIS (Netherlands)

    Robert, H.S.; Grones, P.; Stepanova, A.N.; Robles, L.M.; Lokerse, A.S.; Alonso, J.M.; Weijers, D.; Friml, J.

    2013-01-01

    Establishment of the embryonic axis foreshadows the main body axis of adults both in plants and in animals, but underlying mechanisms are considered distinct. Plants utilize directional, cell-to-cell transport of the growth hormone auxin [1 and 2] to generate an asymmetric auxin response that specif

  13. Patient specific modeling of the HPA axis related to clinical diagnosis of depression

    DEFF Research Database (Denmark)

    Bangsgaard, Elisabeth; Ottesen, Johnny T.

    2016-01-01

    A novel model of the hypothalamic-pituitary-adrenal axis is presented. The axis is an endocrine system responsible for coping with stress and it is likely to be involved in depression. The dynamics of the system is studied and existence, uniqueness and positivity of the solution and the existence...

  14. Co-occurring manic symptomatology influences HPA axis alterations in depression

    NARCIS (Netherlands)

    Jabben, Nienke; Nolen, Willem A.; Smit, Johannes H.; Vreeburg, Sophie A.; Beekman, Aartjan T. F.; Penninx, Brenda

    2011-01-01

    Although dysfunctioning of the HPA axis is considered to be a core pathophysiological process in mood disorders, the evidence with regard to depression remains conflicting. This could partly be due to the large heterogeneity within mood disorders, since HPA axis abnormalities may also be associated

  15. Kinematic equations to grind a helical drill point on a virtual axis drill sharpener

    Institute of Scientific and Technical Information of China (English)

    陈五一; 陈鼎昌

    2000-01-01

    The basic structure of a virtual axis drill grinder is presented in terms of the spatial vectors and thegrinding parameters calculated according to the geometry of a helical drill point. The kinematic equations for sharpening the drills on the virtual axis grinder are deduced using the grinding parameters via vector-matrix txansformation.

  16. A MORPHOMETRIC STUDY OF ATLAS & AXIS VERTEBRAE IN RAJASTHAN POPULATION

    Directory of Open Access Journals (Sweden)

    Rekha

    2014-12-01

    Full Text Available Knowing the dimensions of the vertebral elements is very important for the development of instrumentation related to cervical spine. Ethnic variations have been reported in these dimensions. Aim of the present study was to evaluate the metrical details of first and second cervical vertebrae to correct the instability of atlantoaxial joint, and to analyze the morphological features to understand the ergonomics of the craniovertebral joints. This study was conducted in the Department of Anatomy S. M. S. Medical college jaipur. Total 150 (75 atlas and 75 axis cervical vertebrae were evaluated. All the measurements were taken in bilateral manner using Digital Vernier Calipers with .01 precision. Calculated mean value for width of atlas in our study was 69.03 mm. In present study the observed mean value for anterioposterior diameter of vertebral canal of atlas was 25.52 mm. and transverse diameter was observed as 21.98 mm. Mean value for height of anterior arch of atlas was 7.42 mm and for posterior arch height was calculated 5.3 mm. The mean value of Anterioposterior diameter of Rt. and Lt. Superior articular facet was calculated 17.99 and18.29 mm and transverse diameter was observed as 7.81±1.28 and 8.33±1.54 mm. In our present study anterioposterior diameter of inferior articular facet of atlas was calculated as 13.35±1.50mm and 13.38±1.65 respectively for right and left side and transverse diameter was observed as 6.86±1.32 mm and 6.92±1.44 mm for right and left side. Calculated mean value for width of dens was observed 6.64±0.992mm and mean value of dens length was 12.95 mm. Calculated mean value for A-P diameter of vertebral canal was observed 16.48±1.12 mm and transverse diameter of vertebral canal was calculated as 19.81±1.18 mm. Calculated A-P diameter of Rt. Superior articular facet of axis was 14.65±1.44 mm and for Lt. It was calculated 14.65±1.44 mm and transverse diameter was calculated as 13.38 ±1.65. For inferior articular

  17. Hereditary hypophosphatemias: new genes in the bone-kidney axis.

    Science.gov (United States)

    Negri, Armando L

    2007-08-01

    Hypophosphatemia due to isolated renal phosphate wasting is a genetically heterogeneous disease. Two new genes linked to two different forms of hereditary hypophosphatemias have recently been described. Autosomal recessive form of hypophosphatemic rickets was mapped to chromosome 4q21 and identified homozygous mutations in dentin matrix protein 1 (DMP1) gene, which encodes a non-collagenous bone matrix protein. Intact plasma levels of the phosphaturic protein FGF23 (fibroblast growth factor 23) were clearly elevated in some of the affected individuals, providing a possible explanation for the phosphaturia and inappropriately normal 1,25(OH)2D levels, and suggesting that DMP1 may regulate FGF23 expression. Hereditary hypophosphatemic rickets with hypercalciuria is another rare disorder of autosomal recessive inheritance. Affected individuals present with hypercalciuria due to increased serum 1,25-dihydroxyvitamin D levels and increased intestinal calcium absorption. The disease was mapped to a 1.6 Mbp region on chromosome 9q34, which contains SLC34A3, the gene encoding the renal sodium-phosphate cotransporter NaPi-IIc. This was the first demonstration that NaPi-IIc has a key role in the regulation of phosphate homeostasis. Thus, DMP1 and NaPi-IIc add two new members to the bone-kidney axis proposed since it was discovered that the first phosphatonin, FGF23, was of osteoblastic/osteocyte origin. This provides a mechanism for the skeleton to communicate with the kidney to coordinate the mineralization of extracelular matrix and the renal handling of phosphate.

  18. The Gut-Brain Axis, BDNF, NMDA and CNS Disorders.

    Science.gov (United States)

    Maqsood, Raeesah; Stone, Trevor W

    2016-11-01

    Gastro-intestinal (GI) microbiota and the 'gut-brain axis' are proving to be increasingly relevant to early brain development and the emergence of psychiatric disorders. This review focuses on the influence of the GI tract on Brain-Derived Neurotrophic Factor (BDNF) and its relationship with receptors for N-methyl-D-aspartate (NMDAR), as these are believed to be involved in synaptic plasticity and cognitive function. NMDAR may be associated with the development of schizophrenia and a range of other psychopathologies including neurodegenerative disorders, depression and dementias. An analysis of the routes and mechanisms by which the GI microbiota contribute to the pathophysiology of BDNF-induced NMDAR dysfunction could yield new insights relevant to developing novel therapeutics for schizophrenia and related disorders. In the absence of GI microbes, central BDNF levels are reduced and this inhibits the maintenance of NMDAR production. A reduction of NMDAR input onto GABA inhibitory interneurons causes disinhibition of glutamatergic output which disrupts the central signal-to-noise ratio and leads to aberrant synaptic behaviour and cognitive deficits. Gut microbiota can modulate BDNF function in the CNS, via changes in neurotransmitter function by affecting modulatory mechanisms such as the kynurenine pathway, or by changes in the availability and actions of short chain fatty acids (SCFAs) in the brain. Interrupting these cycles by inducing changes in the gut microbiota using probiotics, prebiotics or antimicrobial drugs has been found promising as a preventative or therapeutic measure to counteract behavioural deficits and these may be useful to supplement the actions of drugs in the treatment of CNS disorders.

  19. 60 YEARS OF NEUROENDOCRINOLOGY: The hypothalamo-prolactin axis.

    Science.gov (United States)

    Grattan, David R

    2015-08-01

    The hypothalamic control of prolactin secretion is different from other anterior pituitary hormones, in that it is predominantly inhibitory, by means of dopamine from the tuberoinfundibular dopamine neurons. In addition, prolactin does not have an endocrine target tissue, and therefore lacks the classical feedback pathway to regulate its secretion. Instead, it is regulated by short loop feedback, whereby prolactin itself acts in the brain to stimulate production of dopamine and thereby inhibit its own secretion. Finally, despite its relatively simple name, prolactin has a broad range of functions in the body, in addition to its defining role in promoting lactation. As such, the hypothalamo-prolactin axis has many characteristics that are quite distinct from other hypothalamo-pituitary systems. This review will provide a brief overview of our current understanding of the neuroendocrine control of prolactin secretion, in particular focusing on the plasticity evident in this system, which keeps prolactin secretion at low levels most of the time, but enables extended periods of hyperprolactinemia when necessary for lactation. Key prolactin functions beyond milk production will be discussed, particularly focusing on the role of prolactin in inducing adaptive responses in multiple different systems to facilitate lactation, and the consequences if prolactin action is impaired. A feature of this pleiotropic activity is that functions that may be adaptive in the lactating state might be maladaptive if prolactin levels are elevated inappropriately. Overall, my goal is to give a flavour of both the history and current state of the field of prolactin neuroendocrinology, and identify some exciting new areas of research development.

  20. Endocrine disruptors and estrogenic effects on male reproductive axis

    Institute of Scientific and Technical Information of China (English)

    Suresh C. Sikka; Run Wang

    2008-01-01

    Endocrine disruptors (e.g., polychlorinated biphenyls [PCBs], dichlorodiphenyl-trichloroethane [DDT], dioxin,and some pesticides) are estrogen-like and anti-androgenic chemicals in the environment. They mimic natural hormones,inhibit the action of hormones, or alter the normal regulatory function of the endocrine system and have potential hazardous effects on male reproductive axis causing infertility. Although testicular and prostate cancers, abnormal sexual development, undescended testis, chronic inflammation, Sertoli-cell-only pattern, hypospadias, altered pituitary and thyroid gland functions are also observed, the available data are insufficient to deduce worldwide conclusions.The development of intra-cytoplasmic sperm injection (ICSI) is beyond doubt the most important recent breakthrough in the treatment of male infertility, but it does not necessarily treat the cause and may inadvertently pass on adverse genetic consequences. Many well-controlled clinical studies and basic scientific discoveries in the physiology,biochemistry, and molecular and cellular biology of the male reproductive system have helped in the identification of greater numbers of men with male factor problems. Newer tools for the detection of Y-chromosome deletions have further strengthened the hypothesis that the decline in male reproductive health and fertility may be related to the presence of certain toxic chemicals in the environment. Thus the etiology, diagnosis, and treatment of male factor infertility remain a real challenge. Clinicians should always attempt to identify the etiology of a possible testicular toxicity, assess the degree of risk to the patient being evaluated for infertility, and initiate a plan to control and prevent exposure to others once an association between occupation/toxicant and infertility has been established.

  1. Novel calibration algorithm for a three-axis strapdown magnetometer.

    Science.gov (United States)

    Liu, Yan Xia; Li, Xi Sheng; Zhang, Xiao Juan; Feng, Yi Bo

    2014-05-14

    A complete error calibration model with 12 independent parameters is established by analyzing the three-axis magnetometer error mechanism. The said model conforms to an ellipsoid restriction, the parameters of the ellipsoid equation are estimated, and the ellipsoid coefficient matrix is derived. However, the calibration matrix cannot be determined completely, as there are fewer ellipsoid parameters than calibration model parameters. Mathematically, the calibration matrix derived from the ellipsoid coefficient matrix by a different matrix decomposition method is not unique, and there exists an unknown rotation matrix R between them. This paper puts forward a constant intersection angle method (angles between the geomagnetic field and gravitational field are fixed) to estimate R. The Tikhonov method is adopted to solve the problem that rounding errors or other errors may seriously affect the calculation results of R when the condition number of the matrix is very large. The geomagnetic field vector and heading error are further corrected by R. The constant intersection angle method is convenient and practical, as it is free from any additional calibration procedure or coordinate transformation. In addition, the simulation experiment indicates that the heading error declines from ±1° calibrated by classical ellipsoid fitting to ±0.2° calibrated by a constant intersection angle method, and the signal-to-noise ratio is 50 dB. The actual experiment exhibits that the heading error is further corrected from ±0.8° calibrated by the classical ellipsoid fitting to ±0.3° calibrated by a constant intersection angle method.

  2. Clinical science workshop: targeting the gut-liver-brain axis.

    Science.gov (United States)

    Patel, Vishal C; White, Helen; Støy, Sidsel; Bajaj, Jasmohan S; Shawcross, Debbie L

    2016-12-01

    A clinical science workshop was held at the ISHEN meeting in London on Friday 11th September 2014 with the aim of thrashing out how we might translate what we know about the central role of the gut-liver-brain axis into targets which we can use in the treatment of hepatic encephalopathy (HE). This review summarises the integral role that inter-organ ammonia metabolism plays in the pathogenesis of HE with specific discussion of the roles that the small and large intestine, liver, brain, kidney and muscle assume in ammonia and glutamine metabolism. Most recently, the salivary and gut microbiome have been shown to underpin the pathophysiological changes which culminate in HE and patients with advanced cirrhosis present with enteric dysbiosis with small bowel bacterial overgrowth and translocation of bacteria and their products across a leaky gut epithelial barrier. Resident macrophages within the liver are able to sense bacterial degradation products initiating a pro-inflammatory response within the hepatic parenchyma and release of cytokines such as tumour necrosis factor alpha (TNF-α) and interleukin-8 into the systemic circulation. The endotoxemia and systemic inflammatory response that are generated predispose both to the development of infection as well as the manifestation of covert and overt HE. Co-morbidities such as diabetes and insulin resistance, which commonly accompany cirrhosis, may promote slow gut transit, promote bacterial overgrowth and increase glutaminase activity and may need to be acknowledged in HE risk stratification assessments and therapeutic regimens. Therapies are discussed which target ammonia production, utilisation or excretion at an individual organ level, or which reduce systemic inflammation and endotoxemia which are known to exacerbate the cerebral effects of ammonia in HE. The ideal therapeutic strategy would be to use an agent that can reduce hyperammonemia and reduce systemic inflammation or perhaps to adopt a combination of

  3. Large Eddy Simulation of Vertical Axis Wind Turbine Wakes

    Directory of Open Access Journals (Sweden)

    Sina Shamsoddin

    2014-02-01

    Full Text Available In this study, large eddy simulation (LES is combined with a turbine model to investigate the wake behind a vertical-axis wind turbine (VAWT in a three-dimensional turbulent flow. Two methods are used to model the subgrid-scale (SGS stresses: (a the Smagorinsky model; and (b the modulated gradient model. To parameterize the effects of the VAWT on the flow, two VAWT models are developed: (a the actuator swept-surface model (ASSM, in which the time-averaged turbine-induced forces are distributed on a surface swept by the turbine blades, i.e., the actuator swept surface; and (b the actuator line model (ALM, in which the instantaneous blade forces are only spatially distributed on lines representing the blades, i.e., the actuator lines. This is the first time that LES has been applied and validated for the simulation of VAWT wakes by using either the ASSM or the ALM techniques. In both models, blade-element theory is used to calculate the lift and drag forces on the blades. The results are compared with flow measurements in the wake of a model straight-bladed VAWT, carried out in the Institute de Méchanique et Statistique de la Turbulence (IMST water channel. Different combinations of SGS models with VAWT models are studied, and a fairly good overall agreement between simulation results and measurement data is observed. In general, the ALM is found to better capture the unsteady-periodic nature of the wake and shows a better agreement with the experimental data compared with the ASSM. The modulated gradient model is also found to be a more reliable SGS stress modeling technique, compared with the Smagorinsky model, and it yields reasonable predictions of the mean flow and turbulence characteristics of a VAWT wake using its theoretically-determined model coefficient.

  4. Equine hyperinsulinemia: investigation of the enteroinsular axis during insulin dysregulation.

    Science.gov (United States)

    de Laat, M A; McGree, J M; Sillence, M N

    2016-01-01

    Compared with some other species, insulin dysregulation in equids is poorly understood. However, hyperinsulinemia causes laminitis, a significant and often lethal disease affecting the pedal bone/hoof wall attachment site. Until recently, hyperinsulinemia has been considered a counterregulatory response to insulin resistance (IR), but there is growing evidence to support a gastrointestinal etiology. Incretin hormones released from the proximal intestine, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide, augment insulin secretion in several species but require investigation in horses. This study investigated peripheral and gut-derived factors impacting insulin secretion by comparing the response to intravenous (iv) and oral d-glucose. Oral and iv tests were performed in 22 ponies previously shown to be insulin dysregulated, of which only 15 were classified as IR (iv test). In a more detailed study, nine different ponies received four treatments: d-glucose orally, d-glucose iv, oats, and commercial grain mix. Insulin, glucose, and incretin concentrations were measured before and after each treatment. All nine ponies showed similar iv responses, but five were markedly hyperresponsive to oral d-glucose and four were not. Insulin responsiveness to oral d-glucose was strongly associated with blood glucose concentrations and oral glucose bioavailability, presumably driven by glucose absorption/distribution, as there was no difference in glucose clearance rates. Insulin was also positively associated with the active amide of GLP-1 following d-glucose and grain. This study has confirmed a functional enteroinsular axis in ponies that likely contributes to insulin dysregulation that may predispose them to laminitis. Moreover, iv tests for IR are not reliable predictors of the oral response to dietary nonstructural carbohydrate.

  5. Note: A compact three-axis optical force/torque sensor using photo-interrupters.

    Science.gov (United States)

    Kim, Ji-Chul; Kim, Kyung-Soo; Kim, Soohyun

    2013-12-01

    By integrating four photo-interrupters in a cross-shaped structure, we developed a compact three-axis optical force/torque (F/T) sensor. The developed sensor has a diameter of 28 mm and a thickness of 7 mm. Despite simplicity and compactness, the experiments with a prototype of the proposed sensor demonstrate notably high accuracy. The RMS errors are 0.5% ± 0.1% of the maximum vertical force in z-axis, 1.9% ± 0.2% of the maximum torque in x-axis, and 2.0% ± 0.3% of the maximum torque in y-axis. It is expected that the proposed sensor allows cost-effective integration of robot systems requiring compact and multi-axis F/T sensors such as a walking assist robot.

  6. Concentration of off-axis radiation by solar concentrators for space power

    Science.gov (United States)

    Jefferies, Kent S.

    1989-01-01

    Four types of off-axis radiation are discussed. These are: (1) small off-axis angles during walk-off, (2) large off-axis angles, (3) an extended off-axis source such as Earth albedo, and (4) miscellaneous off-axis sources including radio frequency sources and local point sources. A code named OFFSET has been developed to represent the solar concentrator being developed for Space Station Freedom. It is a detailed, ray-tracing model which represents 50 ray originating points on the Sun and reflections from 10 points on each of the 456 concentrator facets. Results of this code are generally similar to the PIXEL results although there are small differences due to the more detailed representations of the Sun and concentrator that were used in the OFFSET code.

  7. Role of Nonclassical Renin-angiotensin system Axis In Renal Fibrosis

    Directory of Open Access Journals (Sweden)

    Linli eLv

    2015-04-01

    Full Text Available The renin–angiotensin system (RAS is a major regulator of renal fibrosis. Besides the classical renin/Angiotensin-converting enzyme 2 (ACE2/angiotensin II (Ang II/AT1 and AT2 axis, multiple new axes have been recently described. The new members have added new dimensions to RAS, including the ACE2/ANG (1–7/Mas receptor axis, the prorenin/(prorenin receptor(PRR/intracelluar pathway axis, and the Angiotensin A (Ang A, alamandine-Mas-related G protein coupled receptor D(MrgD axis. This review summarized recent studies regarding role of the non-classical RAS axis in renal fibrosis, and its possible implications to the intervention of progression of chronic kidney disease.

  8. 2002–2012: 10 Years of Research Progress in Horizontal-Axis Marine Current Turbines

    Directory of Open Access Journals (Sweden)

    Kai-Wern Ng

    2013-03-01

    Full Text Available Research in marine current energy, including tidal and ocean currents, has undergone significant growth in the past decade. The horizontal-axis marine current turbine is one of the machines used to harness marine current energy, which appears to be the most technologically and economically viable one at this stage. A number of large-scale marine current turbines rated at more than 1 MW have been deployed around the World. Parallel to the development of industry, academic research on horizontal-axis marine current turbines has also shown positive growth. This paper reviews previous research on horizontal-axis marine current turbines and provides a concise overview for future researchers who might be interested in horizontal-axis marine current turbines. The review covers several main aspects, such as: energy assessment, turbine design, wakes, generators, novel modifications and environmental impact. Future trends for research on horizontal-axis marine current turbines are also discussed.

  9. Improvement of strategies and parameters for multi-axis laser cladding operations

    Science.gov (United States)

    Calleja, A.; Tabernero, I.; Fernández, A.; Celaya, A.; Lamikiz, A.; López de Lacalle, L. N.

    2014-05-01

    The application of laser cladding technology is nowadays widely extended in several industrial sectors due to its advantages for high added value parts direct manufacturing and repairing. At the moment, the process is mainly applied to 3 axis or 3+2 axis strategies, being numerous works focused on the obtainment of process parameters. Some industrial application imposes the use of 5 continuous axis kinematics to perform complex parts. This fact requires new processes design and new strategies for this type of operations. The presented work evaluates the steps to be followed before accomplishing 5 axis laser cladding operations. First, the design of a test part for the experimental tests is carried out, taking into account the machine kinematics. Afterwards, both, the process control parameters and the tool path strategies are analyzed. Finally, the optimization of process parameter and strategies is presented. Therefore, the work represents a useful tool for the industrial application of 5 axis laser cladding.

  10. Research on the aerodynamic characteristics of a lift drag hybrid vertical axis wind turbine

    Directory of Open Access Journals (Sweden)

    Xiaojing Sun

    2016-01-01

    Full Text Available Compared with a drag-type vertical axis wind turbines, one of the greatest advantages for a lift-type vertical axis wind turbines is its higher power coefficient (Cp. However, the lift-type vertical axis wind turbines is not a self-starting turbine as its starting torque is very low. In order to combine the advantage of both the drag-type and the lift-type vertical axis wind turbines, a lift drag hybrid vertical axis wind turbines was designed in this article and its aerodynamics and starting performance was studied in detail with the aid of computational fluid dynamics simulations. Numerical results indicate that the power coefficient of this lift drag hybrid vertical axis wind turbines declines when the distance between its drag-type blades and the center of rotation of the turbine rotor increases, whereas its starting torque can be significantly improved. Studies also show that unlike the lift-type vertical axis wind turbines, this lift drag hybrid-type vertical axis wind turbines could be able to solve the problem of low start-up torque. However, the installation position of the drag blade is very important. If the drag blade is mounted very close to the spindle, the starting torque of the lift drag hybrid-type vertical axis wind turbines may not be improved at all. In addition, it has been found that the power coefficient of the studied vertical axis wind turbines is not as good as expected and possible reasons have been provided in this article after the pressure distribution along the surfaces of the airfoil-shaped blades of the hybrid turbine was analyzed.

  11. Dynamic Stall on Vertical Axis Wind Turbine Blades

    Science.gov (United States)

    Dunne, Reeve

    In this study the dynamics of flow over the blades of vertical axis wind turbines was investigated using a simplified periodic motion to uncover the fundamental flow physics and provide insight into the design of more efficient turbines. Time-resolved, two-dimensional velocity measurements were made with particle image velocimetry on a wing undergoing pitching and surging motion to mimic the flow on a turbine blade in a non-rotating frame. Dynamic stall prior to maximum angle of attack and a leading edge vortex development were identified in the phase-averaged flow field and captured by a simple model with five modes, including the first two harmonics of the pitch/surge frequency identified using the dynamic mode decomposition. Analysis of these modes identified vortical structures corresponding to both frequencies that led the separation and reattachment processes, while their phase relationship determined the evolution of the flow. Detailed analysis of the leading edge vortex found multiple regimes of vortex development coupled to the time-varying flow field on the airfoil. The vortex was shown to grow on the airfoil for four convection times, before shedding and causing dynamic stall in agreement with 'optimal' vortex formation theory. Vortex shedding from the trailing edge was identified from instantaneous velocity fields prior to separation. This shedding was found to be in agreement with classical Strouhal frequency scaling and was removed by phase averaging, which indicates that it is not exactly coupled to the phase of the airfoil motion. The flow field over an airfoil undergoing solely pitch motion was shown to develop similarly to the pitch/surge motion; however, flow separation took place earlier, corresponding to the earlier formation of the leading edge vortex. A similar reduced-order model to the pitch/surge case was developed, with similar vortical structures leading separation and reattachment; however, the relative phase lead of the separation mode

  12. Age of Trauma Onset and HPA Axis Dysregulation Among Trauma-Exposed Youth.

    Science.gov (United States)

    Kuhlman, Kate Ryan; Vargas, Ivan; Geiss, Elisa G; Lopez-Duran, Nestor L

    2015-12-01

    The hypothalamic-pituitary-adrenal axis (HPA axis) is a pathway through which childhood trauma may increase risk for negative health outcomes. The HPA axis is sensitive to stress throughout development; however, few studies have examined whether timing of exposure to childhood trauma is related to differences in later HPA axis functioning. Therefore, we examined the association between age of first trauma and HPA axis functioning among adolescents, and whether these associations varied by sex. Parents of 97 youth (aged 9-16 years) completed the Early Trauma Inventory (ETI), and youth completed the Socially-Evaluated Cold-Pressor Task (SECPT). We measured salivary cortisol response to the SECPT, the cortisol awakening response, and diurnal regulation at home across 2 consecutive weekdays. Exposure to trauma during infancy related to delayed cortisol recovery from peak responses to acute stress, d = 0.23 to 0.42. Timing of trauma exposure related to diverging patterns of diurnal cortisol regulation for males, d = 0.55, and females, d = 0.57. Therefore, the HPA axis may be susceptible to developing acute stress dysregulation when exposed to trauma during infancy, whereas the consequences within circadian cortisol regulation may occur in the context of later trauma exposure and vary by sex. Further investigations are warranted to characterize HPA axis sensitivity to exposure to childhood trauma across child development.

  13. Analysis of nodal aberration properties in off-axis freeform system design.

    Science.gov (United States)

    Shi, Haodong; Jiang, Huilin; Zhang, Xin; Wang, Chao; Liu, Tao

    2016-08-20

    Freeform surfaces have the advantage of balancing off-axis aberration. In this paper, based on the framework of nodal aberration theory (NAT) applied to the coaxial system, the third-order astigmatism and coma wave aberration expressions of an off-axis system with Zernike polynomial surfaces are derived. The relationship between the off-axis and surface shape acting on the nodal distributions is revealed. The nodal aberration properties of the off-axis freeform system are analyzed and validated by using full-field displays (FFDs). It has been demonstrated that adding Zernike terms, up to nine, to the off-axis system modifies the nodal locations, but the field dependence of the third-order aberration does not change. On this basis, an off-axis two-mirror freeform system with 500 mm effective focal length (EFL) and 300 mm entrance pupil diameter (EPD) working in long-wave infrared is designed. The field constant aberrations induced by surface tilting are corrected by selecting specific Zernike terms. The design results show that the nodes of third-order astigmatism and coma move back into the field of view (FOV). The modulation transfer function (MTF) curves are above 0.4 at 20 line pairs per millimeter (lp/mm) which meets the infrared reconnaissance requirement. This work provides essential insight and guidance for aberration correction in off-axis freeform system design.

  14. Dynamic transitions in a model of the hypothalamic-pituitary-adrenal axis

    Science.gov (United States)

    Čupić, Željko; Marković, Vladimir M.; Maćešić, Stevan; Stanojević, Ana; Damjanović, Svetozar; Vukojević, Vladana; Kolar-Anić, Ljiljana

    2016-03-01

    Dynamic properties of a nonlinear five-dimensional stoichiometric model of the hypothalamic-pituitary-adrenal (HPA) axis were systematically investigated. Conditions under which qualitative transitions between dynamic states occur are determined by independently varying the rate constants of all reactions that constitute the model. Bifurcation types were further characterized using continuation algorithms and scale factor methods. Regions of bistability and transitions through supercritical Andronov-Hopf and saddle loop bifurcations were identified. Dynamic state analysis predicts that the HPA axis operates under basal (healthy) physiological conditions close to an Andronov-Hopf bifurcation. Dynamic properties of the stress-control axis have not been characterized experimentally, but modelling suggests that the proximity to a supercritical Andronov-Hopf bifurcation can give the HPA axis both, flexibility to respond to external stimuli and adjust to new conditions and stability, i.e., the capacity to return to the original dynamic state afterwards, which is essential for maintaining homeostasis. The analysis presented here reflects the properties of a low-dimensional model that succinctly describes neurochemical transformations underlying the HPA axis. However, the model accounts correctly for a number of experimentally observed properties of the stress-response axis. We therefore regard that the presented analysis is meaningful, showing how in silico investigations can be used to guide the experimentalists in understanding how the HPA axis activity changes under chronic disease and/or specific pharmacological manipulations.

  15. Axis IV--psychosocial and environmental problems--in the DSM-IV.

    Science.gov (United States)

    Ramirez, A; Ekselius, L; Ramklint, M

    2013-11-01

    The aim of this study was to further explore the properties of axis IV in the Diagnostic and statistical manual of mental disorders, 4th edition (DSM-IV). In a naturalistic cross-sectional design, a group (n = 163) of young (18-25 years old) Swedish psychiatric outpatients was assessed according to DSM-IV. Psychosocial and environmental problems/axis IV were evaluated through structured interviewing by a social worker and by self-assessment on a questionnaire. Reliability between professional assessment and self-assessment of axis IV was examined. Concurrent validity of axis IV was also examined. Reliability between professional and self-assessed axis IV was fair to almost perfect, 0.31-0.83, according to prevalence and bias-adjusted kappa. Categories of psychosocial stress and environmental problems were related to the presence of axis I disorders, co-morbidity, personality disorders and decreasing Global Assessment of Functioning (GAF) values. The revised axis IV according to DSM-IV seems to have concurrent validity, but is still hampered by limited reliability.

  16. 基于Rampart模块的Axis2 Web服务安全研究%ON AXIS2 WEB SERVICE SECURITY BASED ON RAMPART MODULE

    Institute of Scientific and Technical Information of China (English)

    马安峰; 赵逢禹

    2009-01-01

    随着Web Service技术与应用的发展,Web Service 安全问题日益突出.Axis2 作为新一代的Web服务开发平台,具有模块化和可扩展的新特性.首先介绍Axis2 和Rampart 的工作原理,然后通过一个应用场景具体说明Rampart 作为Axis2的一个安全模块,在客户端与服务端安全配置方法和回调函数的设计,以及模块是如何实现WS-Security 规范中的XML加密来保证Web服务的安全.

  17. The Role of Anti-Phase Domains in InSb-Based Structures Grown on On-Axis and Off-Axis Ge Substrates

    Energy Technology Data Exchange (ETDEWEB)

    Debnath, M. C.; Mishima, T. D.; Santos, M. B. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Hossain, K.; Holland, O. W. [Amethyst Research, Inc., 1405 4th Ave NW, Ardmore, OK 73401 (United States)

    2011-12-26

    Anti-phase domains form in InSb epilayers and InSb/Al{sub 0.20}In{sub 0.80}Sb single quantum wells when grown upon on-axis (001) Ge substrates by molecular beam epitaxy. Domain formation is partially suppressed through growth on Ge substrates with surfaces that are several degrees off the (001) or (211) axis. By using off-axis Ge substrates, room-temperature electron mobilities increased to {approx}60,000 cm{sup 2}/V-s and {approx}14,000 cm{sup 2}/V-s for a 4.0-{mu}m-thick InSb epilayer and a 25-nm InSb quantum well, respectively.

  18. Identification and characterization of HPA-axis reactivity endophenotypes in a cohort of female PTSD patients.

    Science.gov (United States)

    Zaba, Monika; Kirmeier, Thomas; Ionescu, Irina A; Wollweber, Bastian; Buell, Dominik R; Gall-Kleebach, Dominique J; Schubert, Christine F; Novak, Bozidar; Huber, Christine; Köhler, Katharina; Holsboer, Florian; Pütz, Benno; Müller-Myhsok, Bertram; Höhne, Nina; Uhr, Manfred; Ising, Marcus; Herrmann, Leonie; Schmidt, Ulrike

    2015-05-01

    Analysis of the function of the hypothalamic-pituitary-adrenal (HPA)-axis in patients suffering from posttraumatic stress disorder (PTSD) has hitherto produced inconsistent findings, inter alia in the Trier Social Stress Test (TSST). To address these inconsistencies, we compared a sample of 23 female PTSD patients with either early life trauma (ELT) or adult trauma (AT) or combined ELT and AT to 18 age-matched non-traumatized female healthy controls in the TSST which was preceded by intensive baseline assessments. During the TSST, we determined a variety of clinical, psychological, endocrine and cardiovascular parameters as well as expression levels of four HPA-axis related genes. Using a previously reported definition of HPA-axis responsive versus non-responsive phenotypes, we identified for the first time two clinically and biologically distinct HPA-axis reactivity subgroups of PTSD. One subgroup ("non-responders") showed a blunted HPA-axis response and distinct clinical and biological characteristics such as a higher prevalence of trauma-related dissociative symptoms and of combined AT and ELT as well as alterations in the expression kinetics of the genes encoding for the mineralocorticoid receptor (MR) and for FK506 binding protein 51 (FKBP51). Interestingly, this non-responder subgroup largely drove the relatively diminished HPA axis response of the total cohort of PTSD patients. These findings are limited by the facts that the majority of patients was medicated, by the lack of traumatized controls and by the relatively small sample size. The here for the first time identified and characterized HPA-axis reactivity endophenotypes offer an explanation for the inconsistent reports on HPA-axis function in PTSD and, moreover, suggest that most likely other factors than HPA-axis reactivity play a decisive role in determination of PTSD core symptom severity.

  19. Effects of Temperature on Weak Principal Axis of Twisted Fiber Loop

    Institute of Scientific and Technical Information of China (English)

    XU Ling; YAO Shou-quan

    2004-01-01

    Theoretically and experimentally, the effects of temperature on the weak principal axis of twisted optical fiber loop are analyzed, and the results show that the location of the pair of weak principal axis will drift with temperature change, which will deteriorate the stability of system when applied to sensor system. In this paper, the influence of phase drift of weak principal axis on the performance of optical fiber current sensor is mainly predicted theoretically. Our research results will provide a beneficial reference for improving optical fiber sensor system.

  20. An effective correction algorithm for off-axis portal dosimetry errors

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, Daniel W.; Kumaraswamy, Lalith; Podgorsak, Matthew B. [Department of Physics, State University of New York at Buffalo, Buffalo, New York 14260 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States)

    2009-09-15

    Portal dosimetric images acquired for IMRT pretreatment verification show dose errors of up to 15% near the detector edges as compared to dose predictions calculated by a treatment planning system for these off-axis regions. A method is proposed to account for these off-axis effects by precisely correcting the off-axis output factors, which calibrate the imager for absolute dose. Using this method, agreement between the predicted and the measured doses improves by up to 15% for fields near the detector edges, resulting in passing rate improvements of as much as 60% for gamma evaluation of 3 mm, 3% within the collimator jaws.

  1. An effective correction algorithm for off-axis portal dosimetry errors.

    Science.gov (United States)

    Bailey, Daniel W; Kumaraswamy, Lalith; Podgorsak, Matthew B

    2009-09-01

    Portal dosimetric images acquired for IMRT pretreatment verification show dose errors of up to 15% near the detector edges as compared to dose predictions calculated by a treatment planning system for these off-axis regions. A method is proposed to account for these off-axis effects by precisely correcting the off-axis output factors, which calibrate the imager for absolute dose. Using this method, agreement between the predicted and the measured doses improves by up to 15% for fields near the detector edges, resulting in passing rate improvements of as much as 60% for gamma evaluation of 3 mm, 3% within the collimator jaws.

  2. FSH and TSH in the Regulation of Bone Mass: The Pituitary/Immune/Bone Axis

    Directory of Open Access Journals (Sweden)

    Graziana Colaianni

    2013-01-01

    Full Text Available Recent evidences have highlighted that the pituitary hormones have profound effects on bone, so that the pituitary-bone axis is now becoming an important issue in the skeletal biology. Here, we discuss the topical evidence about the dysfunction of the pituitary-bone axis that leads to osteoporotic bone loss. We will explore the context of FSH and TSH hormones arguing their direct or indirect role in bone loss. In addition, we will focus on the knowledge that both FSH and TSH have influence on proinflammatory and proosteoclastogenic cytokine expression, such as TNFα and IL-1, underlining the correlation of pituitary-bone axis to the immune system.

  3. Comparison of Efficiencies of Solar Tracker systems with static panel Single- Axis Tracking System and Dual-Axis Tracking System with Fixed Mount

    OpenAIRE

    Dhanabal R; Bharathi.V; Ranjitha.R; Ponni.A; Deepthi S; Mageshkannan.P

    2013-01-01

    Electricity plays a key role now in our daily lives but the energy sources to electric power has been used in abundance and so researchers were compelled to find an alternate source of power leading to the discovery of solar energy. Solar energy is inexhaustible and eco-friendly and can be converted into electricityusing photovoltaic panels. These panels can be used in a fixed form or used in a solar tracking system for single axis as well as for dual axis. In a fixed form their efficiency is...

  4. Design Of Rotor Blade For Vertical Axis Wind Turbine Using Double Aerofoil

    DEFF Research Database (Denmark)

    Chougule, Prasad; Ratkovich, Nicolas Rios; Kirkegaard, Poul Henning;

    Nowadays, small vertical axis wind turbines are receiving more attention compared to horizontal wind turbines due to their suitability in urban use because they generate less noise, have bird free turbines and lower cost. There is few vertical axis wind turbines design with good power curve....... However, the efficiency of power extraction has not been improved. Therefore, an attempt has been made to utilize high lift technology in practice for vertical axis wind turbines in order to improve power efficiency. High lift is obtained by double aerofoil elements mainly used in aeroplane wing design....... In this current work two aerofoils are used to design a rotor blade for a vertical axis wind turbine to improve the power efficiency on the rotor. Double aerofoil blade design consists of a main aerofoil and a slat aerofoil. The parameters related to position and orientation of the slat aerofoil with respect...

  5. Assessment of movement distribution in the lumbar spine using the instantaneous axis of rotation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ki Won [Trine University, Angola (Indonesia)

    2014-12-15

    The position of the torso and the magnitude of exertion are thought to influence the distribution pattern of intervertebral movements within the lumbar spine. Abnormal intervertebral movements have been correlated with the risk of spine injuries. Since the capability to measure movement distribution within the lumbar spine noninvasively is limited, a convenient method to diagnose joint motion function was proposed. The goal of this research was to test the efficacy of the instantaneous axis of rotation for assessment of the distribution of movement within the lumbar spine. The proposed method was evaluated in the bio mechanical model. The results showed that the location of instantaneous axis of rotation lowered with increased trunk exertion force, and slightly moved higher with increased trunk angle. Recognizing that abnormal location of the instantaneous axis of rotation correlated with spinal pain, these results suggest potential the location of the instantaneous axis of rotation relates to the risk of low back pain on distributed spinal kinematics.

  6. Indications of c-axis Charge Transport in Hole Doped Triangular Antiferromagnets

    Institute of Scientific and Technical Information of China (English)

    LIANG Ying; LIU Bin; FENG Shi-Ping

    2004-01-01

    The c-axis charge transport of the hole doped triangular antiferromagnet is investigated within the tJ model by considering the incoherent interlayer hopping.It is shown that the c-axis charge transport of the hole doped triangular antiferromagnet is essentially determined by the scattering from the in-plane fluctuation.The c-axis conductivity spectrum shows a lov-energy peak and the unusual high-energy broad band,while the c-axis resistivity is characterized by a crossover from the high temperature metallic-like behavior to the Iow temperature insulating-like behavior,which is qualitatively consistent with those of the hole doped square lattice antiferromagnet.

  7. Transient stability of synchronous generators with two-axis slip frequency excitation

    Energy Technology Data Exchange (ETDEWEB)

    Morsy, M.S.; Amer, H.H.; Badr, M.A.; El-Serafi, A.M.

    1983-04-01

    Investigations have indicated the possibility of operating two-axis synchronous generators (a machine which has two identical field windings: one on the d-axis and the other on the q-axis) asynchronously when the field windings are excited by slip frequency alternating currents. Such generators are free from the conventional steady-state stability limitations of the conventional synchronous machines and retain the advantage of reactive power control. This paper presents a study of the transient stability characteristics of such generators as affected by its excitation control and input governing systems when they operate synchronously before the occurrence of the disturbance. The results show that such unregulated two-axis synchronous generators with slip frequency excitation have superior transient stability limits compared with conventional alternators. These generators, when properly controlled, can have also improved transient stability characteristics compared with regulated conventional synchronous generators. The improvement realized depends on the optimal choice of the control system and parameters.

  8. Rapid fabrication of miniature lens arrays by four-axis single point diamond machining.

    Science.gov (United States)

    McCall, Brian; Tkaczyk, Tomasz S

    2013-02-11

    A novel method for fabricating lens arrays and other non-rotationally symmetric free-form optics is presented. This is a diamond machining technique using 4 controlled axes of motion - X, Y, Z, and C. As in 3-axis diamond micro-milling, a diamond ball endmill is mounted to the work spindle of a 4-axis ultra-precision computer numerical control (CNC) machine. Unlike 3-axis micro-milling, the C-axis is used to hold the cutting edge of the tool in contact with the lens surface for the entire cut. This allows the feed rates to be doubled compared to the current state of the art of micro-milling while producing an optically smooth surface with very low surface form error and exceptionally low radius error.

  9. Photographic simulation of off-axis blurring due to chromatic aberration in spectacle lenses.

    Science.gov (United States)

    Doroslovački, Pavle; Guyton, David L

    2015-02-01

    Spectacle lens materials of high refractive index (nd) tend to have high chromatic dispersion (low Abbé number [V]), which may contribute to visual blurring with oblique viewing. A patient who noted off-axis blurring with new high-refractive-index spectacle lenses prompted us to do a photographic simulation of the off-axis aberrations in 3 readily available spectacle lens materials, CR-39 (nd = 1.50), polyurethane (nd = 1.60), and polycarbonate (nd = 1.59). Both chromatic and monochromatic aberrations were found to cause off-axis image degradation. Chromatic aberration was more prominent in the higher-index materials (especially polycarbonate), whereas the lower-index CR-39 had more astigmatism of oblique incidence. It is important to consider off-axis aberrations when a patient complains of otherwise unexplained blurred vision with a new pair of spectacle lenses, especially given the increasing promotion of high-refractive-index materials with high chromatic dispersion.

  10. [Growth Hormone-Insulin Growth Factor I (GH-IGF-I) axis and growth].

    Science.gov (United States)

    Castell, A-L; Sadoul, J-L; Bouvattier, C

    2013-10-01

    Normal human linear growth results from an evolutionary process expressing the sum effect of multiple genes. The growth hormone (GH) - insulin like growth factor (IGF)-I axis is one of the main actors in the growth process. Defects in this axis can be responsible for short or tall stature. Short stature is defined as smaller than - 2 standard deviations (SD). It is a very common reason for consultation in pediatrics; indeed, 2.5 % of children are concerned. Multiple causes make diagnosis difficult. In this article, we detail the most common constitutional causes of small size, including those related to a defect in the GH-IGF-I axis. Then, we report, the first results of the clinical and genetic study conducted on 213 patients with gigantism. Tall stature is defined by a height superior to 2 SD. Finally, recent work linking epigenetics and growth - via signaling pathways of GH-IGF-I axis - will be presented.

  11. Lagrangian neoclassical transport theory applied to the region near the magnetic axis

    Energy Technology Data Exchange (ETDEWEB)

    Satake, Shinsuke [The Graduate Univ. for Advanced Studies, Dept. of Fusion Science, Toki, Gifu (Japan); Okamoto, Masao; Sugama, Hideo [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2002-06-01

    Neoclassical transport theory around the magnetic axis of a tokamak is studied, in which relatively wide ''potato'' orbits play an important role in transport. Lagrangian formulation of transport theory, which has been investigated to reflect finiteness of guiding-center orbit widths to transport equations, is developed in order to analyze neoclassical transport near the axis for a low-collisionality plasma. The treatment of self-collision term in Lagrangian formulation is revised to retain momentum conservation property of it. With directly reflecting the orbital properties of all the types of orbits in calculation, the ion thermal conductivity around the axis is found to decrease than from that predicted by conventional neoclassical theory. This result supports recent numerical simulations which show the reduction of thermal conductivity near the magnetic axis. (author)

  12. Characterization of reactively sputtered c-axis aligned nanocrystalline InGaZnO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, David M.; Zhu, Bin; Ast, Dieter G.; Thompson, Michael O. [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States); Levin, Barnaby D. A. [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States); Muller, David A. [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States); Kavli Institute for Nanoscale Science, Cornell University, Ithaca, New York 14853 (United States); Greene, Raymond G. [Corning Incorporated, Corning, New York 14831 (United States)

    2014-12-29

    Crystallinity and texturing of RF sputtered c-axis aligned crystal InGaZnO{sub 4} (CAAC IGZO) thin films were quantified using X-ray diffraction techniques. Above 190 °C, nanocrystalline films with an X-ray peak at 2θ = 30° (009 planes) developed with increasing c-axis normal texturing up to 310 °C. Under optimal conditions (310 °C, 10% O{sub 2}), films exhibited a c-axis texture full-width half-maximum of 20°. Cross-sectional high-resolution transmission electron microscopy confirmed these results, showing alignment variation of ±9° over a 15 × 15 nm field of view and indicating formation of much larger aligned domains than previously reported. At higher deposition temperatures, c-axis alignment was gradually lost as polycrystalline films developed.

  13. Family environment is associated with HPA-axis activity in adolescents : The TRAILS study

    NARCIS (Netherlands)

    Marsman, R.; Nederhof, E.; Rosmalen, J.G.; Oldehinkel, A.J.; Ormel, J.; Buitelaar, J.K.

    2012-01-01

    The purpose of the present study was to investigate the developmental programming part of the theory of biological sensitivity to context using family environmental factors and hypothalamus-pituitary-adrenal (HPA) axis functioning. Specifically, we investigated whether perceived parenting (Rejection

  14. Six-Axis Force-Torque Transducer for Mars 2018 Mission Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A transducer element that is hearty enough for a Mars lander mission needs to be developed so that a six-axis force and torque transducer is possible. The technical...

  15. Ontogenetic studies of tolerance development: effects of chronic morphine on the hypothalamic-pituitary-adrenal axis.

    Science.gov (United States)

    Little, P J; Kuhn, C M

    1995-11-01

    Endogenous opiates are important regulators of the hypothalamic-pituitary-adrenal (HPA) axis in rats. Tolerance clearly develops to morphine-induced stimulation of the HPA axis in adult rats (Ignar and Kuhn 1990). The goal of the present study was to determine whether tolerance to morphine-induced stimulation of the HPA axis developed in neonatal and weanling rats treated chronically with morphine. Rats were injected with morphine or saline between days 4-8 postnatal (pups) or days 21-25 (weanlings) and tolerance assessed by determining dose-response curves for ACTH and corticosterone secretion following an acute morphine challenge. Weanlings displayed marked tolerance to the stimulation of ACTH and corticosterone secretion by morphine. Tolerance was also observed in pups to morphine-stimulated ACTH and corticosterone release. These findings suggest that the relative adaptability of the HPA axis to chronic morphine in neonatal and weanling rats is similar.

  16. Update on stress and depression: the role of the hypothalamic-pituitary-adrenal (HPA axis

    Directory of Open Access Journals (Sweden)

    Mello Andrea de Abreu Feijó de

    2003-01-01

    Full Text Available Over the past 50 years, relationships between stress and the neurobiological changes seen in psychiatric disorders have been well-documented. A major focus of investigations in this area has been the role of the hypothalamic-pituitary-adrenal (HPA axis, both as a marker of stress response and as a mediator of additional downstream pathophysiologic changes. This review examines the emerging literature concerning the relationship between stress, HPA axis function, and depression, as well as the role of early life stress as an important risk factor for HPA axis dysregulation. The more recent studies reviewed suggest that the prominence of HPA axis hyperactivity in adults with depressive and anxiety disorders may constitute a link between the occurrence of adversity in childhood and the development of adult psychopathology

  17. Magnetostructural transition in NdCu{sub 2}. Evidence for an axis conversion like behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Kramp, S.; Doerr, M.; Rotter, M.; Loewenhaupt, M. [Technische Univ. Dresden (Germany). Inst. fuer Angewandte Physik und Didaktik der Physik; Kamp, R. v.d. [Hahn-Meitner-Institut Berlin GmbH (Germany)

    2000-12-01

    The magnetic (H,T)-phase diagram of the orthorhombic compound NdCu{sub 2} was investigated for external magnetic fields up to 15 T parallel to the crystallographic c-direction. Magnetization and magnetostriction measurements reveal an anomalous change of the magnetic properties as well as giant magnetostriction (GMS) and large hysteretic effects. This behaviour is similar to that observed in some other RCu{sub 2} compounds where it has been interpreted as a conversion of the magnetic Ising axis. In contrast to these other RCu{sub 2} compounds, however, the easy axis of magnetization in NdCu{sub 2} is the b-axis. The macroscopic measurements are compared with neutron diffraction experiments which reveal GMS along the b-axis and a new magnetic phase with propagation vector {tau}=(0.7 0 0) in the converted crystal. (orig.)

  18. From Malthus to motive: how the HPA axis engineers the phenotype, yoking needs to wants.

    Science.gov (United States)

    Pecoraro, Norman; Dallman, Mary F; Warne, James P; Ginsberg, Abigail B; Laugero, Kevin D; la Fleur, Susanne E; Houshyar, Hani; Gomez, Francisca; Bhargava, Aditi; Akana, Susan F

    2006-08-01

    The hypothalamo-pituitary-adrenal (HPA) axis is the critical mediator of the vertebrate stress response system, responding to environmental stressors by maintaining internal homeostasis and coupling the needs of the body to the wants of the mind. The HPA axis has numerous complex drivers and highly flexible operating characterisitics. Major drivers include two circadian drivers, two extra-hypothalamic networks controlling top-down (psychogenic) and bottom-up (systemic) threats, and two intra-hypothalamic networks coordinating behavioral, autonomic, and neuroendocrine outflows. These various networks jointly and flexibly control HPA axis output of periodic (oscillatory) functions and a range of adventitious systemic or psychological threats, including predictable daily cycles of energy flow, actual metabolic deficits over many time scales, predicted metabolic deficits, and the state-dependent management of post-prandial responses to feeding. Evidence is provided that reparation of metabolic derangement by either food or glucocorticoids results in a metabolic signal that inhibits HPA activity. In short, the HPA axis is intimately involved in managing and remodeling peripheral energy fluxes, which appear to provide an unidentified metabolic inhibitory feedback signal to the HPA axis via glucocorticoids. In a complementary and perhaps a less appreciated role, adrenocortical hormones also act on brain to provide not only feedback, but feedforward control over the HPA axis itself and its various drivers, as well as coordinating behavioral and autonomic outflows, and mounting central incentive and memorial networks that are adaptive in both appetitive and aversive motivational modes. By centrally remodeling the phenotype, the HPA axis provides ballistic and predictive control over motor outflows relevant to the type of stressor. Evidence is examined concerning the global hypothesis that the HPA axis comprehensively induces integrative phenotypic plasticity, thus

  19. Population pharmacokinetic/pharmacodynamic modelling of the hypothalamic-pituitary-gonadal axis

    OpenAIRE

    2005-01-01

    The present thesis deals with different aspects of population pharmacokinetic/ pharmacodynamic (PK/PD) modelling of the male hypothalamic-pituitary-go-nadal (HPG) axis. The thesis consists of a summary report and five scientific research papers. An overview of the main topics covered in the thesis is provided in the summary report including PK/PD modelling in drug development, the pathological, physiological, and pharmacological aspects of the male HPG axis, and a detailed description of the ...

  20. On global regular solutions to magnetohydrodynamics in axi-symmetric domains

    Science.gov (United States)

    Nowakowski, Bernard; Zajączkowski, Wojciech M.

    2016-12-01

    We consider mhd equations in three-dimensional axially symmetric domains under the Navier boundary conditions for both velocity and magnetic fields. We prove the existence of global, regular axi-symmetric solutions and examine their stability in the class of general solutions to the mhd system. As a consequence, we show the existence of global, regular solutions to the mhd system which are close in suitable norms to axi-symmetric solutions.

  1. System Identification and Automatic Mass Balancing of Ground-Based Three-Axis Spacecraft Simulator

    Science.gov (United States)

    2006-08-01

    System Identification and Automatic Mass Balancing of Ground-Based Three-Axis Spacecraft Simulator Jae-Jun Kim∗ and Brij N. Agrawal † Department of...TITLE AND SUBTITLE System Identification and Automatic Mass Balancing of Ground-Based Three-Axis Spacecraft Simulator 5a. CONTRACT NUMBER 5b...and Dynamics, Vol. 20, No. 4, July-August 1997, pp. 625-632. 6Schwartz, J. L. and Hall, C. D., “ System Identification of a Spherical Air-Bearing

  2. Design and dynamic analysis of single-axis integrated inertia measurement device

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The structure and measurement theory of a single-axis integrated inertia measurement device are discussed in this paper.The acceleration and angle velocity can be detected by the proposed sensor at the same time.The kinetic model of the device is also established.In addition,the signal generation of the single-axis integrated inertiameasurement device is analyzed and simulated.The results of the model are consistent with simulation result.

  3. Spherical neutron polarization analysis on the three-axis spectrometer IN22

    Energy Technology Data Exchange (ETDEWEB)

    Regnault, L.P.; Geffray, B.; Fouilloux, P.; Longuet, B.; Mantegazza, F.; Tasset, F.; Lelievre-Berna, E.; Pujol, S.; Bourgeat-Lami, E.; Kernavanois, N.; Thomas, M.; Gibert, Y

    2004-07-15

    The recent availability at the ILL of two three-axis spectrometers, IN20B and IN22, offering high flux of polarized neutrons in the thermal-energy range has opened a new field of investigation of magnetic and lattice excitations. In this short article, we will show recent technical developments concerning the installation and the optimization of the spherical neutron polarimetry (SNP) on the three-axis spectrometer IN22.

  4. Does the GH/IGF-1 axis contribute to skeletal sexual dimorphism? Evidence from mouse studies.

    Science.gov (United States)

    Liu, Zhongbo; Mohan, Subburaman; Yakar, Shoshana

    2016-04-01

    The contribution of the gonadotropic axis to skeletal sexual dimorphism (SSD) was clarified in recent years. Studies with animal models of estrogen receptor (ER) or androgen receptor (AR) null mice, as well as mice with bone cell-specific ablation of ER or AR, revealed that both hormones play major roles in skeletal acquisition, and that estrogen regulates skeletal accrual in both sexes. The growth hormone (GH) and its downstream effector, the insulin-like growth factor-1 (IGF-1) are also major determinants of peak bone mass during puberty and young adulthood, and play important roles in maintaining bone integrity during aging. A few studies in both humans and animal models suggest that in addition to the differences in sex steroid actions on bone, sex-specific effects of GH and IGF-1 play essential roles in SSD. However, the contributions of the somatotropic (GH/IGF-1) axis to SSD are controversial and data is difficult to interpret. GH/IGF-1 are pleotropic hormones that act in an endocrine and autocrine/paracrine fashion on multiple tissues, affecting body composition as well as metabolism. Thus, understanding the contribution of the somatotropic axis to SSD requires the use of mouse models that will differentiate between these two modes of action. Elucidation of the relative contribution of GH/IGF-1 axis to SSD is significant because GH is approved for the treatment of normal children with short stature and children with congenital growth disorders. Thus, if the GH/IGF-1 axis determines SSD, treatment with GH may be tailored according to sex. In the following review, we give an overview of the roles of sex steroids in determining SSD and how they may interact with the GH/IGF-1 axis in bone. We summarize several mouse models with impaired somatotropic axis and speculate on the possible contribution of that axis to SSD.

  5. The somatotropic axis may not modulate ageing and longevity in humans.

    Science.gov (United States)

    Le Bourg, Éric

    2016-04-01

    Studies in nematodes and mice have shown that the somatotropic axis can modulate their longevity and it has been argued that it could also modulate human longevity. Thus, like nematodes and mice, human beings should live longer when facing starvation and genetic variation of the somatotropic axis should be linked to longevity. This article argues that, because the life-history strategies of humans are very different from those of mice, these hypotheses are not warranted.

  6. Functions and Imaging of Mast Cell and Neural Axis of the Gut

    OpenAIRE

    2013-01-01

    Close association between nerves and mast cells in the gut wall provides the microanatomic basis for functional interactions between these elements, supporting the hypothesis that a mast cell–nerve axis influences gut functions in health and disease. Advanced morphology and imaging techniques are now available to assess structural and functional relationships of the mast cell–nerve axis in human gut tissues. Morphologic techniques including co-labeling of mast cells and nerv...

  7. 如何用Axis2开发Web Service服务

    Institute of Scientific and Technical Information of China (English)

    唐青

    2007-01-01

    Web Service是一种新的web应用程序分支.Apache Axis是较受欢迎的web service开发平台之一.主要介绍如果利用Axis2.1.0开发Web服务以及如何利用Axis2所提供的客户端API进行Web服务的调用.

  8. Advanced numerical study of the three-axis magnetic attitude control and determination with uncertainties

    Science.gov (United States)

    Ivanov, D. S.; Ovchinnikov, M. Yu.; Penkov, V. I.; Roldugin, D. S.; Doronin, D. M.; Ovchinnikov, A. V.

    2017-03-01

    Attitude motion of a satellite equipped with magnetic control system is considered. System comprises of three magnetorquers and one three-axis magnetometer. Satellite is stabilized in orbital reference frame using PD controller and extended Kalman filter. Three-axis attitude is analyzed numerically with advanced assumptions: inertia tensor uncertainty, disturbances of unknown nature, magnetometer errors are taken into account. Stabilization and determination accuracy dependence on orbit inclination is studied.

  9. Application of Artificial Neural Networks in the Heart Electrical Axis Position Conclusion Modeling

    Science.gov (United States)

    Bakanovskaya, L. N.

    2016-08-01

    The article touches upon building of a heart electrical axis position conclusion model using an artificial neural network. The input signals of the neural network are the values of deflections Q, R and S; and the output signal is the value of the heart electrical axis position. Training of the network is carried out by the error propagation method. The test results allow concluding that the created neural network makes a conclusion with a high degree of accuracy.

  10. Three-dimensional finite element analysis of critical pre-twist strain angle for torsional axis

    Institute of Scientific and Technical Information of China (English)

    ZHOU Guo-feng; LI Xiao-yan; SHI Yao-wu; XU Bin-shi

    2005-01-01

    A three-dimensional elasto-plastic finite element analysis of pre-twist process for a torsional axis made of 45GrNiMoVA steel, was carried out using a commercial finite element analysis code, MSC MARC 2001. The results show that the critical pre-twist strain angle is 0. 027 rad and the maximum elastic shear stress after pre-twist is 1 694 MPa for the torsional axis.

  11. Electron Traps in GaAs Grown by Molecular Beam Epitaxy on On-axis (100 and Off-axis Substrates

    Directory of Open Access Journals (Sweden)

    R. Sarmiento

    2003-06-01

    Full Text Available Deep level transient spectroscopy (DLTS was used to characterize the electron traps present in the bulkGaAs grown by molecular beam epitaxy (MBE on on-axis (100 and off-axis (4° towards the (111 Adirection substrates. Two electron traps were obtained for each sample having identical correspondingpeak locations in the DLTS spectra. The layer grown on the on-axis substrate has electron traps withactivation energies of EC–0.454 eV and EC–0.643 eV and capture cross-sections of 1.205 x 10-14 cm2 and3.88 x 10-15 cm2, respectively. The layer grown on the off-axis substrate has traps with activation energiesof EC–0.454 eV and EC–0.723 eV and capture cross-sections of 2.060 x 10-14 cm2 and 4.40 x 10-14 cm2.The electron traps are possibly the M4 (or EL3 and EL2 (or EB4 traps commonly found in GaAs layers.Due to the high trap concentrations obtained and to the non-uniform trap concentration profile, Asdesorption may be considerable during growth.

  12. Goldstone radar evidence for short-axis mode non-principal-axis rotation of near-Earth asteroid (214869) 2007 PA8

    Science.gov (United States)

    Brozović, Marina; Benner, Lance A. M.; Magri, Christopher; Scheeres, Daniel J.; Busch, Michael W.; Giorgini, Jon D.; Nolan, Michael C.; Jao, Joseph S.; Lee, Clement G.; Snedeker, Lawrence G.; Silva, Marc A.; Lawrence, Kenneth J.; Slade, Martin A.; Hicks, Michael D.; Howell, Ellen S.; Taylor, Patrick A.; Sanchez, Juan A.; Reddy, Vishnu; Dykhuis, Melissa; Corre, Lucille Le

    2017-04-01

    We report radar and optical photometric observations of near-Earth asteroid (214869) 2007 PA8 obtained during October 2-November 13, 2012. We observed 2007 PA8 on sixteen days with Goldstone (8560 MHz, 3.5 cm) and on five days with the 0.6 m telescope at Table Mountain Observatory. Closest approach was on November 5 at a distance of 0.043 au. Images obtained with Goldstone's new chirp system achieved range resolutions as fine as 3.75 m, placing thousands of pixels on the asteroid's surface, and revealing that 2007 PA8 is an elongated, asymmetric object. Surface features include angularities, facets, and a concavity approximately 400 m in diameter. We used the Shape software to estimate the asteroid's 3D shape and spin state. 2007 PA8 has a broad, rounded end and a tapered, angular end with sharp-crested ridges. The asteroid's effective diameter is 1.35 ± 0.07 km, which in combination with the absolute magnitude of 16.30 ± 0.52 gives an optical albedo of pV = 0.29 ± 0.14. The shape modeling of the radar data revealed that 2007 PA8 is a non-principal axis (NPA) rotator in the short-axis mode with an average period of precession by the long axis around the angular momentum vector of 4.26 ± 0.02 days and an oscillatory period around the long axis of 20.55 ± 3.75 days. The amplitude of rolling around the long axis is 42 ± 7° . The angular momentum vector points toward ecliptic longitude and latitude of 273.6 ± 10°, +16.9 ± 5°. 2007 PA8 is only the second confirmed short-axis mode NPA rotator known in the near-Earth asteroid population after (99942) Apophis (Pravec et al., 2014). 2007 PA8 has a geopotential high at the equator, where the equator is defined as the plane that contains the long and intermediate axis. This geopotential extreme could be interpreted as a large, hidden surface depression, or as evidence that 2007 PA8 is a multi-component body.

  13. Seizure-induced disinhibition of the HPA axis increases seizure susceptibility.

    Science.gov (United States)

    O'Toole, Kate K; Hooper, Andrew; Wakefield, Seth; Maguire, Jamie

    2014-01-01

    Stress is the most commonly reported precipitating factor for seizures. The proconvulsant actions of stress hormones are thought to mediate the effects of stress on seizure susceptibility. Interestingly, epileptic patients have increased basal levels of stress hormones, including corticotropin-releasing hormone (CRH) and corticosterone, which are further increased following seizures. Given the proconvulsant actions of stress hormones, we proposed that seizure-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis may contribute to future seizure susceptibility. Consistent with this hypothesis, our data demonstrate that pharmacological induction of seizures in mice with kainic acid or pilocarpine increases circulating levels of the stress hormone, corticosterone, and exogenous corticosterone administration is sufficient to increase seizure susceptibility. However, the mechanism(s) whereby seizures activate the HPA axis remain unknown. Here we demonstrate that seizure-induced activation of the HPA axis involves compromised GABAergic control of CRH neurons, which govern HPA axis function. Following seizure activity, there is a collapse of the chloride gradient due to changes in NKCC1 and KCC2 expression, resulting in reduced amplitude of sIPSPs and even depolarizing effects of GABA on CRH neurons. Seizure-induced activation of the HPA axis results in future seizure susceptibility which can be blocked by treatment with an NKCC1 inhibitor, bumetanide, or blocking the CRH signaling with Antalarmin. These data suggest that compromised GABAergic control of CRH neurons following an initial seizure event may cause hyperexcitability of the HPA axis and increase future seizure susceptibility.

  14. Stressing diabetes? The hidden links between insulinotropic peptides and the HPA axis.

    Science.gov (United States)

    Diz-Chaves, Yolanda; Gil-Lozano, Manuel; Toba, Laura; Fandiño, Juan; Ogando, Hugo; González-Matías, Lucas C; Mallo, Federico

    2016-08-01

    Diabetes mellitus exerts metabolic stress on cells and it provokes a chronic increase in the long-term activity of the hypothalamus-pituitary-adrenocortical (HPA) axis, perhaps thereby contributing to insulin resistance. GLP-1 receptor (GLP-1R) agonists are pleiotropic hormones that not only affect glycaemic and metabolic control, but they also produce many other effects including activation of the HPA axis. In fact, several of the most relevant effects of GLP-1 might involve, at least in part, the modulation of the HPA axis. Thus, the anorectic activity of GLP-1 could be mediated by increasing CRF at the hypothalamic level, while its lipolytic effects could imply a local increase in glucocorticoids and glucocorticoid receptor (GC-R) expression in adipose tissue. Indeed, the potent activation of the HPA axis by GLP-1R agonists occurs within the range of therapeutic doses and with a short latency. Interestingly, the interactions of GLP-1 with the HPA axis may underlie most of the effects of GLP-1 on food intake control, glycaemic metabolism, adipose tissue biology and the responses to stress. Moreover, such activity has been observed in animal models (mice and rats), as well as in normal humans and in type I or type II diabetic patients. Accordingly, better understanding of how GLP-1R agonists modulate the activity of the HPA axis in diabetic subjects, especially obese individuals, will be crucial to design new and more efficient therapies for these patients.

  15. The HPA axis and ethanol: a synthesis of mathematical modelling and experimental observations.

    Science.gov (United States)

    Čupić, Željko; Stanojević, Ana; Marković, Vladimir M; Kolar-Anić, Ljiljana; Terenius, Lars; Vukojević, Vladana

    2016-05-18

    Stress and alcohol use are interrelated-stress contributes to the initiation and upholding of alcohol use and alcohol use alters the way we perceive and respond to stress. Intricate mechanisms through which ethanol alters the organism's response to stress remain elusive. We have developed a stoichiometric network model to succinctly describe neurochemical transformations underlying the stress response axis and use numerical simulations to model ethanol effects on complex daily changes of blood levels of cholesterol, 6 peptide and 8 steroid hormones. Modelling suggests that ethanol alters the dynamical regulation of hypothalamic-pituitary-adrenal (HPA) axis activity by affecting the amplitude of ultradian oscillations of HPA axis hormones, which defines the threshold with respect to which the response to stress is being set. These effects are complex-low/moderate acute ethanol challenge (8 mM) increases instantaneous CORT levels and the amplitude of ultradian CORT oscillations in a dose-dependent manner, affecting the HPA axis activity also during the following day(s). Chronic exposure to ethanol qualitatively changes the HPA axis dynamics, whereas ethanol at intoxicating levels shuts down this dynamic regulation mechanism. Mathematical modelling gives a quantitative biology-based framework that can be used for predicting how the integral HPA axis response is perturbed by alcohol.

  16. Proto-Model of an Infrared Wide-Field Off-Axis Telescope

    CERN Document Server

    Kim, Sanghyuk; Chang, Seunghyuk; Kim, Geon Hee; Yang, Sun Choel; Kim, Myung Sang; Lee, Sungho; Lee, Hanshin; 10.5303/JKAS.2010.43.5.169

    2010-01-01

    We develop a proto-model of an off-axis reflective telescope for infrared wide-field observations based on the design of Schwarzschild-Chang type telescope. With only two mirrors, this design achieves an entrance pupil diameter of 50 mm and an effective focal length of 100 mm. We can apply this design to a mid-infrared telescope with a field of view of 8 deg X 8 deg. In spite of the substantial advantages of off-axis telescopes in the infrared compared to refractive or on-axis reflective telescopes, it is known to be difficult to align the mirrors in off-axis systems because of their asymmetric structures. Off-axis mirrors of our telescope are manufactured at the Korea Basic Science Institute (KBSI). We analyze the fabricated mirror surfaces by fitting polynomial functions to the measured data. We accomplish alignment of this two-mirror off-axis system using a ray tracing method. A simple imaging test is performed to compare a pinhole image with a simulated prediction.

  17. GRB off-axis afterglows and the emission from the accompanying supernovae

    CERN Document Server

    Kathirgamaraju, Adithan; Giannios, Dimitrios

    2016-01-01

    Gamma-Ray Burst (GRB) afterglows are likely produced in the shock that is driven as the GRB jet interacts with the external medium. Long duration GRBs are also associated with powerful supernovae (SN). We consider the optical and radio afterglows of long GRBs for both blasts viewed along the jet axis ("on-axis" afterglows) and misaligned observes ("off-axis" afterglows). Comparing the optical emission from the afterglow with that of the accompanying SN, using SN 1998bw as an archetype, we find that only a few percent of afterglows viewed off-axis are brighter than the SN. For observable optical off-axis afterglows the viewing angle is at most twice the half-opening angle of the GRB jet. Radio off-axis afterglows should be detected with upcoming radio surveys within a few hundred Mpc. We propose that these surveys will act as "radio triggers," and that dedicated radio facilities should follow-up these sources. Follow-ups can unveil the presence of the radio supernova remnant, if present. In addition, they can ...

  18. GRB off-axis afterglows and the emission from the accompanying supernovae

    Science.gov (United States)

    Kathirgamaraju, Adithan; Barniol Duran, Rodolfo; Giannios, Dimitrios

    2016-09-01

    Gamma-ray burst (GRB) afterglows are likely produced in the shock that is driven as the GRB jet interacts with the external medium. Long-duration GRBs are also associated with powerful supernovae (SNe). We consider the optical and radio afterglows of long GRBs for both blasts viewed along the jet axis (`on-axis' afterglows) and misaligned observes (`off-axis' afterglows). Comparing the optical emission from the afterglow with that of the accompanying SN, using SN 1998bw as an archetype, we find that only a few per cent of afterglows viewed off-axis are brighter than the SN. For observable optical off-axis afterglows, the viewing angle is at most twice the half-opening angle of the GRB jet. Radio off-axis afterglows should be detected with upcoming radio surveys within a few hundred Mpc. We propose that these surveys will act as `radio triggers', and that dedicated radio facilities should follow-up these sources. Follow-ups can unveil the presence of the radio SN remnant, if present. In addition, they can probe the presence of a mildly relativistic component, either associated with the GRB jet or the SN ejecta, expected in these sources.

  19. Space cutter compensation method for five-axis nonuniform rational basis spline machining

    Directory of Open Access Journals (Sweden)

    Yanyu Ding

    2015-07-01

    Full Text Available In view of the good machining performance of traditional three-axis nonuniform rational basis spline interpolation and the space cutter compensation issue in multi-axis machining, this article presents a triple nonuniform rational basis spline five-axis interpolation method, which uses three nonuniform rational basis spline curves to describe cutter center location, cutter axis vector, and cutter contact point trajectory, respectively. The relative position of the cutter and workpiece is calculated under the workpiece coordinate system, and the cutter machining trajectory can be described precisely and smoothly using this method. The three nonuniform rational basis spline curves are transformed into a 12-dimentional Bézier curve to carry out discretization during the discrete process. With the cutter contact point trajectory as the precision control condition, the discretization is fast. As for different cutters and corners, the complete description method of space cutter compensation vector is presented in this article. Finally, the five-axis nonuniform rational basis spline machining method is further verified in a two-turntable five-axis machine.

  20. Design and implementation of five-axis transformation function in CNC system

    Directory of Open Access Journals (Sweden)

    Wang Feng

    2014-04-01

    Full Text Available To implement five-axis functions in CNC system, based on domestic system Lan Tian series, an improved design method for the system software structure is proposed in this paper. The numerical control kernel of CNC system is divided into the task layer and the motion layer. A five-axis transformation unit is integrated into the motion layer. After classifying five-axis machines into different types and analyzing their geometry information, the five-axis kinematic library is designed according to the abstract factory pattern. Furthermore, by taking CA spindle-tilting machine as an example, the forward and the inverse kinematic transformations are deduced. Based on the new software architecture and the five-axis kinematic library, algorithms of RTCP (rotation tool center point control and 3D radius compensation for end-milling are designed and realized. The milling results show that, with five-axis functions based on such software structure, the instructions with respect to the cutter’s position and orientation can be directly carried out in the CNC system.

  1. Food and the circadian activity of the hypothalamic-pituitary-adrenal axis

    Directory of Open Access Journals (Sweden)

    A.M.O. Leal

    1997-12-01

    Full Text Available Temporal organization is an important feature of biological systems and its main function is to facilitate adaptation of the organism to the environment. The daily variation of biological variables arises from an internal time-keeping system. The major action of the environment is to synchronize the internal clock to a period of exactly 24 h. The light-dark cycle, food ingestion, barometric pressure, acoustic stimuli, scents and social cues have been mentioned as synchronizers or" zeitgebers". The circadian rhythmicity of plasma corticosteroids has been well characterized in man and in rats and evidence has been accumulated showing daily rhythmicity at every level of the hypothalamic-pituitary-adrenal (HPA axis. Studies of restricted feeding in rats are of considerable importance because they reveal feeding as a major synchronizer of rhythms in HPA axis activity. The daily variation of the HPA axis stress response appears to be closely related to food intake as well as to basal activity. In humans, the association of feeding and HPA axis activity has been studied under physiological and pathological conditions such as anorexia nervosa, bulimia, malnutrition, obesity, diabetes mellitus and Cushing's syndrome. Complex neuroanatomical pathways and neurochemical circuitry are involved in feeding-associated HPA axis modulation. In the present review we focus on the interaction among HPA axis rhythmicity, food ingestion, and different nutritional and endocrine states

  2. Geometrical principium of fewer-axis grinding for large complex optical mirrors

    Institute of Scientific and Technical Information of China (English)

    JIANG; ZhenHua; YIN; YueHong

    2013-01-01

    Ultraprecision grinding is an important approach to efficiently fabricate large complex optical mirrors, and five-axis grinding method is commonly used for ultraprecision grinding. However, this method can hardly meet the high stiffness requirement for grinding large mirror, especially with a diameter over 2 m. Meanwhile, the use of fewer-axis grinding solves this problem, as it reduces the number of the grinder’s axes to improve the rigidity of the system and minimize deformation for hard and brittle materials. But its characteristic of unfixed grinding point which changes with workpiece surface curvature increases geometric complexity and requires a higher geometric shape accuracy of grinding wheel. This paper parameterizes grinding wheel’s geometric shape, reveals the relationship between fewer-axis and five-axis grinding methods from the point of view of the differential geometry, and establishes virtual-axis equivalence principium of feweraxis grinding. A quantitative method to determine grinding wheel’s geometric parameters and its shaft inclination angle is proposed based on the requirements of geometric properties of optical mirror, grinder features and grinding process. Moreover, according to the properties of Gauss curvature of curved surface, the wear law of the toric grinding wheel is found and the surface geometric error distribution due to wear is achieved for fewer-axis grinding. The correctness of the principium and method above are verified through simulations.

  3. Local auxin sources orient the apical-basal axis in Arabidopsis embryos.

    Science.gov (United States)

    Robert, Hélène S; Grones, Peter; Stepanova, Anna N; Robles, Linda M; Lokerse, Annemarie S; Alonso, Jose M; Weijers, Dolf; Friml, Jiří

    2013-12-16

    Establishment of the embryonic axis foreshadows the main body axis of adults both in plants and in animals, but underlying mechanisms are considered distinct. Plants utilize directional, cell-to-cell transport of the growth hormone auxin to generate an asymmetric auxin response that specifies the embryonic apical-basal axis. The auxin flow directionality depends on the polarized subcellular localization of PIN-FORMED (PIN) auxin transporters. It remains unknown which mechanisms and spatial cues guide cell polarization and axis orientation in early embryos. Herein, we provide conceptually novel insights into the formation of embryonic axis in Arabidopsis by identifying a crucial role of localized tryptophan-dependent auxin biosynthesis. Local auxin production at the base of young embryos and the accompanying PIN7-mediated auxin flow toward the proembryo are required for the apical auxin response maximum and the specification of apical embryonic structures. Later in embryogenesis, the precisely timed onset of localized apical auxin biosynthesis mediates PIN1 polarization, basal auxin response maximum, and specification of the root pole. Thus, the tight spatiotemporal control of distinct local auxin sources provides a necessary, non-cell-autonomous trigger for the coordinated cell polarization and subsequent apical-basal axis orientation during embryogenesis and, presumably, also for other polarization events during postembryonic plant life.

  4. The A/P axis in echinoderm ontogeny and evolution: evidence from fossils and molecules

    Science.gov (United States)

    Peterson, K. J.; Arenas-Mena, C.; Davidson, E. H.

    2000-01-01

    Even though echinoderms are members of the Bilateria, the location of their anterior/posterior axis has remained enigmatic. Here we propose a novel solution to the problem employing three lines of evidence: the expression of a posterior class Hox gene in the coeloms of the nascent adult body plan within the larva; the anatomy of certain early fossil echinoderms; and finally the relation between endoskeletal plate morphology and the associated coelomic tissues. All three lines of evidence converge on the same answer, namely that the location of the adult mouth is anterior, and the anterior/posterior axis runs from the mouth through the adult coelomic compartments. This axis then orients the animal such that there is but a single plane of symmetry dividing the animal into left and right halves. We tentatively hypothesize that this plane of symmetry is positioned along the dorsal/ventral axis. These axis identifications lead to the conclusion that the five ambulacra are not primary body axes, but instead are outgrowths from the central anterior/posterior axis. These identifications also shed insight into several other evolutionary mysteries of various echinoderm clades such as the independent evolution of bilateral symmetry in irregular echinoids, but do not elucidate the underlying mechanisms of the adult coelomic architecture.

  5. Nanoscratch Characterization of GaN Epilayers on c- and a-Axis Sapphire Substrates

    Directory of Open Access Journals (Sweden)

    Wen Hua-Chiang

    2010-01-01

    Full Text Available Abstract In this study, we used metal organic chemical vapor deposition to form gallium nitride (GaN epilayers on c- and a-axis sapphire substrates and then used the nanoscratch technique and atomic force microscopy (AFM to determine the nanotribological behavior and deformation characteristics of the GaN epilayers, respectively. The AFM morphological studies revealed that pile-up phenomena occurred on both sides of the scratches formed on the GaN epilayers. It is suggested that cracking dominates in the case of GaN epilayers while ploughing during the process of scratching; the appearances of the scratched surfaces were significantly different for the GaN epilayers on the c- and a-axis sapphire substrates. In addition, compared to the c-axis substrate, we obtained higher values of the coefficient of friction (μ and deeper penetration of the scratches on the GaN a-axis sapphire sample when we set the ramped force at 4,000 μN. This discrepancy suggests that GaN epilayers grown on c-axis sapphire have higher shear resistances than those formed on a-axis sapphire. The occurrence of pile-up events indicates that the generation and motion of individual dislocation, which we measured under the sites of critical brittle transitions of the scratch track, resulted in ductile and/or brittle properties as a result of the deformed and strain-hardened lattice structure.

  6. ANALYSIS OF THE MAGNETIC FIELD MEASURED BY A ROTATING HALL PROBE IN A SOLENOID TO LOCATE ITS MAGNETIC AXIS.

    Energy Technology Data Exchange (ETDEWEB)

    KPONOU,A.; PIKIN,A.; BEEBE,E.; ALESSI,J.

    2000-11-06

    We have analyzed the motion of a Hall probe, which is rotated about an axis that is arbitrarily displaced and oriented with respect to the magnetic axis of a solenoid. We outline how the magnetic field measured by the rotating Hall probe can be calculated. We show how to compare theoretical results with actual measurements, to determine the displacement and orientation of the axis of rotation of the probe from the magnetic axis. If the center of rotation of the probe is known by surveying, the corresponding point on the magnetic axis of the solenoid can be located. This is applied to a solenoid that was built for BNL by Oxford Instruments.

  7. The different roles of glucocorticoids in the hippocampus and hypothalamus in chronic stress-induced HPA axis hyperactivity.

    Science.gov (United States)

    Zhu, Li-Juan; Liu, Meng-Ying; Li, Huan; Liu, Xiao; Chen, Chen; Han, Zhou; Wu, Hai-Yin; Jing, Xing; Zhou, Hai-Hui; Suh, Hoonkyo; Zhu, Dong-Ya; Zhou, Qi-Gang

    2014-01-01

    Hypothalamus-pituitary-adrenal (HPA) hyperactivity is observed in many patients suffering from depression and the mechanism underling the dysfunction of HPA axis is not well understood. Chronic stress has a causal relationship with the hyperactivity of HPA axis. Stress induces the over-synthesis of glucocorticoids, which will arrive at all the body containing the brain. It is still complicated whether glucocorticoids account for chronic stress-induced HPA axis hyperactivity and in which part of the brain the glucocorticoids account for chronic stress-induced HPA axis hyperactivity. Here, we demonstrated that glucocorticoids were indispensable and sufficient for chronic stress-induced hyperactivity of HPA axis. Although acute glucocorticoids elevation in the hippocampus and hypothalamus exerted a negative regulation of HPA axis, we found that chronic glucocorticoids elevation in the hippocampus but not in the hypothalamus accounted for chronic stress-induced hyperactivity of HPA axis. Chronic glucocorticoids exposure in the hypothalamus still exerted a negative regulation of HPA axis activity. More importantly, we found mineralocorticoid receptor (MR) - neuronal nitric oxide synthesis enzyme (nNOS) - nitric oxide (NO) pathway mediated the different roles of glucocorticoids in the hippocampus and hypothalamus in regulating HPA axis activity. This study suggests that the glucocorticoids in the hippocampus play an important role in the development of HPA axis hyperactivity and the glucocorticoids in the hypothalamus can't induce hyperactivity of HPA axis, revealing new insights into understanding the mechanism of depression.

  8. The different roles of glucocorticoids in the hippocampus and hypothalamus in chronic stress-induced HPA axis hyperactivity.

    Directory of Open Access Journals (Sweden)

    Li-Juan Zhu

    Full Text Available Hypothalamus-pituitary-adrenal (HPA hyperactivity is observed in many patients suffering from depression and the mechanism underling the dysfunction of HPA axis is not well understood. Chronic stress has a causal relationship with the hyperactivity of HPA axis. Stress induces the over-synthesis of glucocorticoids, which will arrive at all the body containing the brain. It is still complicated whether glucocorticoids account for chronic stress-induced HPA axis hyperactivity and in which part of the brain the glucocorticoids account for chronic stress-induced HPA axis hyperactivity. Here, we demonstrated that glucocorticoids were indispensable and sufficient for chronic stress-induced hyperactivity of HPA axis. Although acute glucocorticoids elevation in the hippocampus and hypothalamus exerted a negative regulation of HPA axis, we found that chronic glucocorticoids elevation in the hippocampus but not in the hypothalamus accounted for chronic stress-induced hyperactivity of HPA axis. Chronic glucocorticoids exposure in the hypothalamus still exerted a negative regulation of HPA axis activity. More importantly, we found mineralocorticoid receptor (MR - neuronal nitric oxide synthesis enzyme (nNOS - nitric oxide (NO pathway mediated the different roles of glucocorticoids in the hippocampus and hypothalamus in regulating HPA axis activity. This study suggests that the glucocorticoids in the hippocampus play an important role in the development of HPA axis hyperactivity and the glucocorticoids in the hypothalamus can't induce hyperactivity of HPA axis, revealing new insights into understanding the mechanism of depression.

  9. Light curves and spectra from off-axis gamma-ray bursts

    Science.gov (United States)

    Salafia, O. S.; Ghisellini, G.; Pescalli, A.; Ghirlanda, G.; Nappo, F.

    2016-10-01

    If gamma-ray burst prompt emission originates at a typical radius, and if material producing the emission moves at relativistic speed, then the variability of the resulting light curve depends on the viewing angle. This is due to the fact that the pulse evolution time-scale is Doppler contracted, while the pulse separation is not. For off-axis viewing angles θview ≳ θjet + Γ-1, the pulse broadening significantly smears out the light-curve variability. This is largely independent of geometry and emission processes. To explore a specific case, we set up a simple model of a single pulse under the assumption that the pulse rise and decay are dominated by the shell curvature effect. We show that such a pulse observed off-axis is (i) broader, (ii) softer and (iii) displays a different hardness-intensity correlation with respect to the same pulse seen on-axis. For each of these effects, we provide an intuitive physical explanation. We then show how a synthetic light curve made by a superposition of pulses changes with increasing viewing angle. We find that a highly variable light curve (as seen on-axis) becomes smooth and apparently single-pulsed (when seen off-axis) because of pulse overlap. To test the relevance of this fact, we estimate the fraction of off-axis gamma-ray bursts detectable by Swift as a function of redshift, finding that a sizeable fraction (between 10 per cent and 80 per cent) of nearby (z < 0.1) bursts are observed with θview ≳ θjet + Γ-1. Based on these results, we argue that low-luminosity gamma-ray bursts are consistent with being ordinary bursts seen off-axis.

  10. Binocular Coordination of the Human Vestibulo-Ocular Reflex during Off-axis Pitch Rotation

    Science.gov (United States)

    Wood, S. J.; Reschke, M. F.; Kaufman, G. D.; Black, F. O.; Paloski, W. H.

    2006-01-01

    Head movements in the sagittal pitch plane typically involve off-axis rotation requiring both vertical and horizontal vergence ocular reflexes to compensate for angular and translational motion relative to visual targets of interest. The purpose of this study was to compare passive pitch VOR responses during rotation about an Earth-vertical axis (canal only cues) with off-axis rotation (canal and otolith cues). Methods. Eleven human subjects were oscillated sinusoidally at 0.13, 0.3 and 0.56 Hz while lying left-side down with the interaural axis either aligned with the axis of rotation or offset by 50 cm. In a second set of measurements, twelve subjects were also tested during sinusoidally varying centrifugation over the same frequency range. The modulation of vertical and horizontal vergence ocular responses was measured with a binocular videography system. Results. Off-axis pitch rotation enhanced the vertical VOR at lower frequencies and enhanced the vergence VOR at higher frequencies. During sinusoidally varying centrifugation, the opposite trend was observed for vergence, with both vertical and vergence vestibulo-ocular reflexes being suppressed at the highest frequency. Discussion. These differential effects of off-axis rotation over the 0.13 to 0.56 Hz range are consistent with the hypothesis that otolith-ocular reflexes are segregated in part on the basis of stimulus frequency. At the lower frequencies, tilt otolith-ocular responses compensate for declining canal input. At higher frequencies, translational otolith-ocular reflexes compensate for declining visual contributions to the kinematic demands required for fixating near targets.

  11. Improvement of the insertion axis for cochlear implantation with a robot-based system.

    Science.gov (United States)

    Torres, Renato; Kazmitcheff, Guillaume; De Seta, Daniele; Ferrary, Evelyne; Sterkers, Olivier; Nguyen, Yann

    2017-02-01

    It has previously reported that alignment of the insertion axis along the basal turn of the cochlea was depending on surgeon' experience. In this experimental study, we assessed technological assistances, such as navigation or a robot-based system, to improve the insertion axis during cochlear implantation. A preoperative cone beam CT and a mastoidectomy with a posterior tympanotomy were performed on four temporal bones. The optimal insertion axis was defined as the closest axis to the scala tympani centerline avoiding the facial nerve. A neuronavigation system, a robot assistance prototype, and software allowing a semi-automated alignment of the robot were used to align an insertion tool with an optimal insertion axis. Four procedures were performed and repeated three times in each temporal bone: manual, manual navigation-assisted, robot-based navigation-assisted, and robot-based semi-automated. The angle between the optimal and the insertion tool axis was measured in the four procedures. The error was 8.3° ± 2.82° for the manual procedure (n = 24), 8.6° ± 2.83° for the manual navigation-assisted procedure (n = 24), 5.4° ± 3.91° for the robot-based navigation-assisted procedure (n = 24), and 3.4° ± 1.56° for the robot-based semi-automated procedure (n = 12). A higher accuracy was observed with the semi-automated robot-based technique than manual and manual navigation-assisted (p robot-based system reduces both the error and the variability of the alignment with a defined optimal axis.

  12. Evaluation of the P Wave Axis in Patients With Systemic Lupus Erythematosus

    Science.gov (United States)

    Acar, Rezzan Deniz; Bulut, Mustafa; Acar, Şencan; Izci, Servet; Fidan, Serdar; Yesin, Mahmut; Efe, Suleyman Cagan

    2015-01-01

    Introduction: P wave axis is one of the most practical clinical tool for evaluation of cardiovascular disease. The aim of our study was to evaluate the P wave axis in electrocardiogram (ECG), left atrial function and association between the disease activity score in patients with systemic lupus erythematosus (SLE). Methods: Standard 12-lead surface ECGs were recorded by at a paper speed of 25 m/s and an amplifier gain of 10 mm/mV. The heart rate (HR), the duration of PR, QRS, QTd (dispersion), the axis of P wave were measured by ECG machine automatically. Results: The P wave axis was significantly increased in patients with SLE (49 ± 20 vs. 40 ± 18, P = 0.037) and the disease activity score was found positively correlated with P wave axis (r: 0.382, P = 0.011). The LA volume and the peak systolic strain of the left atrium (LA) were statistically different between the groups (P = 0.024 and P = 0.000). The parameters of the diastolic function; E/A and E/e’ were better in the control group than the patients with SLE (1.1 ± 0.3 vs. 1.3 ± 0.3, P = 0.041 and 6.6 ± 2.8 vs. 5.4 ± 1.4, P = 0.036, respectively). Conclusion: P wave axis was found significantly increased in patients with SLE and positively correlated with SELENA-SLEDAI score. As the risk score increases in patients with SLE, P wave axis changes which may predict the risk of all-cause and cardiovascular mortality. PMID:26702344

  13. Metabotropic glutamate receptor-mediated signaling dampens the HPA axis response to restraint stress.

    Science.gov (United States)

    Evanson, Nathan K; Herman, James P

    2015-10-15

    Glutamate is an important neurotransmitter in the regulation of the neural portion of hypothalamus-pituitary-adrenal (HPA) axis activity, and signals through ionotropic and metabotropic receptors. In the current studies we investigated the role of hypothalamic paraventricular group I metabotropic glutamate receptors in the regulation of the HPA axis response to restraint stress in rats. Direct injection of the group I metabotropic glutamate receptor agonist 3,5-dihydroxyphenylglycine (DHPG) into the PVN prior to restraint leads to blunting of the HPA axis response in awake animals. Consistent with this result, infusion of the group I receptor antagonist hexyl-homoibotenic acid (HIBO) potentiates the HPA axis response to restraint. The excitatory effect of blocking paraventricular group I metabotropic glutamate signaling is blocked by co-administration of dexamethasone into the PVN. However, the inhibitory effect of DHPG is not affected by co-administration of the cannabinoid CB1 receptor antagonist AM-251 into the PVN. Together, these results suggest that paraventricular group I metabotropic glutamate receptor signaling acts to dampen HPA axis reactivity. This effect appears to be similar to the rapid inhibitory effect of glucocorticoids at the PVN, but is not mediated by endocannabinoid signaling.

  14. Time-of-day-dependent adaptation of the HPA axis to predictable social defeat stress.

    Science.gov (United States)

    Koch, C E; Bartlang, M S; Kiehn, J T; Lucke, L; Naujokat, N; Helfrich-Förster, C; Reber, S O; Oster, H

    2016-12-01

    In modern societies, the risk of developing a whole array of affective and somatic disorders is associated with the prevalence of frequent psychosocial stress. Therefore, a better understanding of adaptive stress responses and their underlying molecular mechanisms is of high clinical interest. In response to an acute stressor, each organism can either show passive freezing or active fight-or-flight behaviour, with activation of sympathetic nervous system and the hypothalamus-pituitary-adrenal (HPA) axis providing the necessary energy for the latter by releasing catecholamines and glucocorticoids (GC). Recent data suggest that stress responses are also regulated by the endogenous circadian clock. In consequence, the timing of stress may critically affect adaptive responses to and/or pathological effects of repetitive stressor exposure. In this article, we characterize the impact of predictable social defeat stress during daytime versus nighttime on bodyweight development and HPA axis activity in mice. While 19 days of social daytime stress led to a transient reduction in bodyweight without altering HPA axis activity at the predicted time of stressor exposure, more detrimental effects were seen in anticipation of nighttime stress. Repeated nighttime stressor exposure led to alterations in food metabolization and reduced HPA axis activity with lower circulating adrenocorticotropic hormone (ACTH) and GC concentrations at the time of predicted stressor exposure. Our data reveal a circadian gating of stress adaptation to predictable social defeat stress at the level of the HPA axis with impact on metabolic homeostasis underpinning the importance of timing for the body's adaptability to repetitive stress.

  15. Role of Paraventricular Nucleus Glutamate Signaling in Regulation of HPA Axis Stress Responses.

    Science.gov (United States)

    Evanson, Nathan K; Herman, James P

    The hypothalamus-pituitary-adrenal (HPA) axis is the main neuroendocrine arm of the stress response, activation of which leads to the production of glucocorticoid hormones. Glucocorticoids are steroid hormones that are secreted from the adrenal cortex, and have a variety of effects on the body, including modulation of the immune system, suppression of reproductive hormones maintenance of blood glucose levels, and maintenance of blood pressure. Glutamate plays an important role in coordination of HPA axis output. There is strong evidence that glutamate drives HPA axis stress responses through excitatory signaling via ionotropic glutamate receptor signaling. However, glutamate signaling via kainate receptors and group I metabotropic receptors inhibit HPA drive, probably via presynaptic inhibitory mechanisms. Notably, kainate receptors are also localized in the median eminence, and appear to play an excitatory role in control of CRH release at the nerve terminals. Finally, glutamate innervation of the PVN undergoes neuroplastic changes under conditions of chronic stress, and may be involved in sensitization of HPA axis responses. Altogether, the data suggest that glutamate plays a complex role in excitation of CRH neurons, acting at multiple levels to both drive HPA axis responses and limit over-activation.

  16. Osmoregulatory actions of the GH/IGF axis in non-salmonid teleosts

    Science.gov (United States)

    Mancera, J.M.; McCormick, S.D.

    1998-01-01

    Salmonid fishes provided the first findings on the influence of the growth hormone (GH)/insulin-like growth factor I (IGF-I) axis on osmoregulation in teleost fishes. Recent studies on non-salmonid species, however, indicate that this physiological action of the GH/IGF-I axis is not restricted to salmonids or anadromous fishes. GH-producing cells in the pituitary of fish acclimated to different salinities show different degrees of activation depending on the species studied. Plasma GH levels either increase or do not change after transfer of fish from freshwater to seawater. Treatment with GH or IGF-I increases salinity tolerance and/or increases gill Na+,K+-ATPase activity of killifish (Fundulus heteroclitus), tilapia (Oreochromis mossambicus and Oreochromis niloticus) and striped bass (Morone saxatilis). As in salmonids, a positive interaction between GH and cortisol for improving hypoosmoregulatory capacity has been described in tilapia (O. mossambicus). Research on the osmoregulatory role of the GH/IGF-I axis is derived from a small number of teleost species. The study of more species with different osmoregulary patterns will be necessary to fully clarify the osmoregulatory role of GH/IGF-I axis in fish. The available data does suggest, however, that the influence of the GH/IGF-I axis on osmoregulation may be a common feature of euryhalinity in teleosts. Copyright (C) 1998 Elsevier Science Inc.

  17. HPA-axis stress reactivity in youth depression: evidence of impaired regulatory processes in depressed boys.

    Science.gov (United States)

    Lopez-Duran, Nestor L; McGinnis, Ellen; Kuhlman, Kate; Geiss, Elisa; Vargas, Ivan; Mayer, Stefanie

    2015-01-01

    Given the link between youth depression and stress exposure, efforts to identify related biomarkers have involved examinations of stress regulation systems, including the hypothalamic-pituitary-adrenal (HPA) axis. Despite these vast efforts, the underlying mechanisms at play, as well as factors that may explain heterogeneity of past findings, are not well understood. In this study, we simultaneously examined separate components of the HPA-axis response (e.g. activation intensity, peak levels, recovery) to the Socially Evaluated Cold-Pressor Test in a targeted sample of 115 youth (age 9-16), recruited to overrepresent youth with elevated symptoms of depression. Among youth who displayed a cortisol response to the task, depression symptoms were associated with higher peak responses but not greater rate of activation or recovery in boys only. Among those who did not respond to the task, depression symptoms were associated with greater cortisol levels throughout the visit in boys and girls. Results suggest that depression symptoms are associated with a more prolonged activation of the axis and impaired recovery to psychosocial stressors primarily in boys. We discussed two potential mechanistic explanations of the link between depression symptoms and the duration of activation: (1) inhibitory shift (i.e. point at which the ratio of inhibitory and excitatory input into the axis shifts from greater excitatory to greater inhibitory input) or (2) inhibitory threshold (i.e. level of cortisol exposure required to activate the axis' feedback inhibition system).

  18. Spontaneous transfer of chirality in an atropisomerically enriched two-axis system.

    Science.gov (United States)

    Barrett, Kimberly T; Metrano, Anthony J; Rablen, Paul R; Miller, Scott J

    2014-05-01

    One of the most well-recognized stereogenic elements in a chiral molecule is an sp(3)-hybridized carbon atom that is connected to four different substituents. Axes of chirality can also exist about bonds with hindered barriers of rotation; molecules containing such axes are known as atropisomers. Understanding the dynamics of these systems can be useful, for example, in the design of single-atropisomer drugs or molecular switches and motors. For molecules that exhibit a single axis of chirality, rotation about that axis leads to racemization as the system reaches equilibrium. Here we report a two-axis system for which an enantioselective reaction produces four stereoisomers (two enantiomeric pairs): following a catalytic asymmetric transformation, we observe a kinetically controlled product distribution that is perturbed from the system's equilibrium position. As the system undergoes isomerization, one of the diastereomeric pairs drifts spontaneously to a higher enantiomeric ratio. In a compensatory manner, the enantiomeric ratio of the other diastereomeric pair decreases. These observations are made for a class of unsymmetrical amides that exhibits two asymmetric axes--one axis is defined through a benzamide substructure, and the other axis is associated with differentially N,N-disubstituted amides. The stereodynamics of these substrates provides an opportunity to observe a curious interplay of kinetics and thermodynamics intrinsic to a system of stereoisomers that is constrained to a situation of partial equilibrium.

  19. The critical importance of the fetal hypothalamus-pituitary-adrenal axis [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Charles E. Wood

    2016-01-01

    Full Text Available The fetal hypothalamus-pituitary-adrenal (HPA axis is at the center of mechanisms controlling fetal readiness for birth, survival after birth and, in several species, determination of the timing of birth. Stereotypical increases in fetal HPA axis activity at the end of gestation are critical for preparing the fetus for successful transition to postnatal life. The fundamental importance in fetal development of the endogenous activation of this endocrine axis at the end of gestation has led to the use of glucocorticoids for reducing neonatal morbidity in premature infants. However, the choice of dose and repetition of treatments has been controversial, raising the possibility that excess glucocorticoid might program an increased incidence of adult disease (e.g., coronary artery disease and diabetes. We make the argument that because of the critical importance of the fetal HPA axis and its interaction with the maternal HPA axis, dysregulation of cortisol plasma concentrations or inappropriate manipulation pharmacologically can have negative consequences at the beginning of extrauterine life and for decades thereafter.

  20. A Wavelet Bicoherence-Based Quadratic Nonlinearity Feature for Translational Axis Condition Monitoring

    Directory of Open Access Journals (Sweden)

    Yong Li

    2014-01-01

    Full Text Available The translational axis is one of the most important subsystems in modern machine tools, as its degradation may result in the loss of the product qualification and lower the control precision. Condition-based maintenance (CBM has been considered as one of the advanced maintenance schemes to achieve effective, reliable and cost-effective operation of machine systems, however, current vibration-based maintenance schemes cannot be employed directly in the translational axis system, due to its complex structure and the inefficiency of commonly used condition monitoring features. In this paper, a wavelet bicoherence-based quadratic nonlinearity feature is proposed for translational axis condition monitoring by using the torque signature of the drive servomotor. Firstly, the quadratic nonlinearity of the servomotor torque signature is discussed, and then, a biphase randomization wavelet bicoherence is introduced for its quadratic nonlinear detection. On this basis, a quadratic nonlinearity feature is proposed for condition monitoring of the translational axis. The properties of the proposed quadratic nonlinearity feature are investigated by simulations. Subsequently, this feature is applied to the real-world servomotor torque data collected from the X-axis on a high precision vertical machining centre. All the results show that the performance of the proposed feature is much better than that of original condition monitoring features.

  1. A wavelet bicoherence-based quadratic nonlinearity feature for translational axis condition monitoring.

    Science.gov (United States)

    Li, Yong; Wang, Xiufeng; Lin, Jing; Shi, Shengyu

    2014-01-27

    The translational axis is one of the most important subsystems in modern machine tools, as its degradation may result in the loss of the product qualification and lower the control precision. Condition-based maintenance (CBM) has been considered as one of the advanced maintenance schemes to achieve effective, reliable and cost-effective operation of machine systems, however, current vibration-based maintenance schemes cannot be employed directly in the translational axis system, due to its complex structure and the inefficiency of commonly used condition monitoring features. In this paper, a wavelet bicoherence-based quadratic nonlinearity feature is proposed for translational axis condition monitoring by using the torque signature of the drive servomotor. Firstly, the quadratic nonlinearity of the servomotor torque signature is discussed, and then, a biphase randomization wavelet bicoherence is introduced for its quadratic nonlinear detection. On this basis, a quadratic nonlinearity feature is proposed for condition monitoring of the translational axis. The properties of the proposed quadratic nonlinearity feature are investigated by simulations. Subsequently, this feature is applied to the real-world servomotor torque data collected from the X-axis on a high precision vertical machining centre. All the results show that the performance of the proposed feature is much better than that of original condition monitoring features.

  2. Retrieving the surface axis of the Kuroshio off southern coast of Japan from SST data

    Institute of Scientific and Technical Information of China (English)

    SHAO Quanqin; CHEN Zhuoqi; MA Weiwei

    2007-01-01

    One thousand and forty-nine sea surface isotherm maps during 1990~2000 were used to detect the Kuroshio axis off the coast of Japan. The current axis on the surface cannot be identified by just one indicative isotherm as is commonly done in deep water, but still there are complicated isotherms indicatives of the Kuroshio axis.Three types of isotherms indicatives of the surface axis of the Kuroshio are identified, which are nesting-warm-tongue-indicator, warm-tongue-isotherm-indicator, and isotherm-indicator. The occurrence frequency of NWTI-type is 72%, that of WTII-type is 19.1% and that of Ⅱ-type is 8.9%. The vector-based and raster-based methods were introduced and used to retrieve automatically the Kuroshio paths from SST data. The total retrieving percentage is 74% by the three methods, 52.3% by the vector method, 56.8% by one raster method and 49.6% by another raster method. For the NWTI-type, the total retrieving percentage is 91.3% by the three methods, 64.4% by the vector method, 75.9% by one raster method and 65% by another raster method. Using retrieving results of the Kuroshio axis from SST data,the Kuroshio path detour is analyzed during 1990~2000.

  3. AXIS: an instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF.

    Science.gov (United States)

    Hall, G N; Izumi, N; Tommasini, R; Carpenter, A C; Palmer, N E; Zacharias, R; Felker, B; Holder, J P; Allen, F V; Bell, P M; Bradley, D; Montesanti, R; Landen, O L

    2014-11-01

    Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV-200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.

  4. Hypothalamic-Pituitary-Adrenal Axis Programming after Recurrent Hypoglycemia during Development

    Directory of Open Access Journals (Sweden)

    Raghavendra Rao

    2015-08-01

    Full Text Available Permanent brain injury is a complication of recurrent hypoglycemia during development. Recurrent hypoglycemia also has adverse consequences on the neuroendocrine system. Hypoglycemia-associated autonomic failure, characterized by ineffective glucose counterregulation during hypoglycemia, is well described in children and adults on insulin therapy for diabetes mellitus. Whether recurrent hypoglycemia also has a programming effect on the hypothalamus-pituitary-adrenal cortex (HPA axis has not been well studied. Hypoglycemia is a potent stress that leads to increased glucocorticoid secretion in all age groups, including the perinatal period. Other conditions associated with exposure to excess glucocorticoid in the perinatal period have a programming effect on the HPA axis activity. Limited animal data suggest the possibility of similar programming effect after recurrent hypoglycemia in the postnatal period. The age at exposure to hypoglycemia likely determines the HPA axis response in adulthood. Recurrent hypoglycemia in the early postnatal period likely leads to a hyperresponsive HPA axis, whereas recurrent hypoglycemia in the late postnatal period lead to a hyporesponsive HPA axis in adulthood. The age-specific programming effects may determine the neuroendocrine response during hypoglycemia and other stressful events in individuals with history of recurrent hypoglycemia during development.

  5. Post-stress rumination predicts HPA axis responses to repeated acute stress.

    Science.gov (United States)

    Gianferante, Danielle; Thoma, Myriam V; Hanlin, Luke; Chen, Xuejie; Breines, Juliana G; Zoccola, Peggy M; Rohleder, Nicolas

    2014-11-01

    Failure of the hypothalamus-pituitary-adrenal (HPA) axis to habituate to repeated stress exposure is related with adverse health outcomes, but our knowledge of predictors of non-habituation is limited. Rumination, defined as repetitive and unwanted past-centered negative thinking, is related with exaggerated HPA axis stress responses and poor health outcomes. The aim of this study was to test whether post-stress rumination was related with non-habituation of cortisol to repeated stress exposure. Twenty-seven participants (n=13 females) were exposed to the Trier Social Stress Test (TSST) twice on consecutive afternoons. Post-stress rumination was measured after the first TSST, and HPA axis responses were assessed by measuring salivary cortisol 1 min before, and 1, 10, 20, 60, and 120 min after both TSSTs. Stress exposure induced HPA axis activation on both days, and this activation showed habituation indicated by lower responses to the second TSST (F=3.7, p=0.015). Post-stress rumination after the first TSST was associated with greater cortisol reactivity after the initial stress test (r=0.45, pHPA axis responses. This finding implicates rumination as one possible mechanism mediating maladaptive stress response patterns, and it might also offer a pathway through which rumination might lead to negative health outcomes.

  6. Measurement of z-axis deviation angle of electro-optic crystal by conoscopic interference

    Science.gov (United States)

    Li, Dong; Liu, Yong; Liu, Xu; Jiang, Hongzhen; Zheng, Fanglan

    2016-09-01

    Properties of plasma electrode pockels cell is directly affected by the Z-axis deviation angle of the electro-optic crystal. Therefore, high precision measurement of the Z-axis deviation angle is indispensable. By using conoscopic interference technique, a measurement system for Z-axis deviation angle of electro-optic crystal is introduced. The principle of conoscopic interference method is described in detail, and a series of techniques are implied in this measurement system to improve the accuracy. High-precision positioning method of the crystal based on Michelson interference is proposed to determine the normal consistency of crystal, which can ensure the high positioning repeatability of crystal in the measurement process. The positioning comparison experiment of the crystal shows that the standard deviation of our method is less than 1pixel, which is much better than the traditional method (nearly 4pixels). Moreover, melatope extraction algorithm of optical axis based on image matching technique is proposed to ensure the melatope can be extracted in high precision. Calibration method of the normal of transmission surface of crystal is also proposed. The experiment results show that the PV and rms of Z-axis deviation angle is less than 0.05mrad and 0.02mrad, respectively. The repeatability accuracy is less than 0.01mrad.

  7. Recognition Method of Aircraft Axis Direction Based on Morphological Skeleton and Hough Transform

    Institute of Scientific and Technical Information of China (English)

    WANG Hong-bo; ZHUANG Zhi-hong; ZHENG Hua-li; ZHANG Qing-tai; HE Hong-jun

    2008-01-01

    Because of the limit of angle of view(AOV) of IR imaging seeker during the approach of missile and target, the detector can only get the partial image sequence of aircraft nose after "lose point". Recognizing the axis direction on the basis of partial IR image sequence is a key issue of the advanced IR imaging guide air-to-air missile faced. In this paper, a recognition method was proposed based on the morphological skeleton and modified Hough transform, and this method can recognize correctly the axis direction of aircraft nose in different poses during missile-target encounter. Firstly, the morphological skeleton transform was used for the extraction of skeleton features. Secondly, the modified Hough transform was used for the straight-lines detection. Finally, According to the relations between aircraft nose and axis and invariant of nose features in high-speed IR image sequence, the axis direction can be detected and calculated. Experimental results indicate that the method is feasible and effective, and the precision of axis direction recognized can meet the requirement of accurate burst control of GIF fuze.

  8. The complex interaction between obesity, metabolic syndrome and reproductive axis: a narrative review.

    Science.gov (United States)

    Michalakis, Konstantinos; Mintziori, Gesthimani; Kaprara, Athina; Tarlatzis, Basil C; Goulis, Dimitrios G

    2013-04-01

    The aim of this narrative review is to provide current evidence for the interaction between obesity, metabolic syndrome (MS) and reproductive axis. Gonadotropin-releasing hormone (GnRH) pulses and, consequently, normal function of reproductive (hypothalamus-pituitary-gonadal) axis depend on normal energy balance, which presupposes sufficient food intake, reasonable energy consumption and average thermoregulatory costs. In case of an energy imbalance, reproductive dysfunction may occur. In young women, excessive leanness is accompanied by puberty delay, whereas premature puberty might be a manifestation of obesity. In a similar way, obesity in men affects fertility. Excess adipose tissue results in increased conversion of testosterone to estradiol, which may lead to secondary hypogonadism through reproductive axis suppression. Moreover, oxidative stress at the level of the testicular micro-environment may result in decreased spermatogenesis and sperm damage. Products of the adipocyte, such as leptin, adiponectin and resistin, and gut peptides, such as ghrelin, are considered to be crucial in the interaction between energy balance and reproduction. Finally, an indirect evidence for the interplay between MS and reproductive axis is the fact that when treating components of one, parameters of the other can be improved as well. These therapeutic interventions include lifestyle modifications, pharmacological agents, such as sex hormone replacement therapy, and surgical procedures. Although many issues remain unclear, the elucidation of the complex interaction between MS and reproductive axis will have obvious clinical implications in the therapeutic approach of both entities.

  9. Comparative radiographic analysis on the anatomical axis in knee osteoarthritis cases: inter and intraobserver evaluation

    Directory of Open Access Journals (Sweden)

    Luiz Felipe Matos

    2015-06-01

    Full Text Available OBJECTIVE: To make a comparative inter and intraobserver analysis on measurements of the anatomical axis between panoramic radiographs of the lower limbs in anteroposterior (AP view with bipedal weight-bearing, on short film.METHODS: An accuracy study comparing radiographic measurements on 47 knees of patients attending the knee surgery outpatient clinic due to osteoarthritis. The radiographic evaluation used was as standardized for the total knee arthroplasty program, including panoramic AP views of the lower limbs and short radiographs of the knees in AP and lateral views, all with bipedal weight-bearing. Following this, the anatomical axis of the lower limbs or the femorotibial angle was measured by five independent examiners on the panoramic and short AP radiographs; three of the examiners were considered to be more experienced and two, less experienced. All the measurements were made again by the same examiners after an interval of not less than 15 days. The statistical analysis was performed using the intraclass correlation coefficient, in order to evaluate the inter and intraobserver concordance of the anatomical axis measurements.RESULTS: From the statistical analysis, it was observed that there was strongly significant concordance between the anatomical axis measurements on the panoramic and short radiographs, for all the five examiners and for both measurements.CONCLUSIONS: Under the conditions studied, short radiographs were equivalent to panoramic radiographs for evaluating the anatomical axis of the lower limbs in patients with advanced osteoarthritis. The measurements used also showed high rates of inter and intraobserver concordance and reproducibility.

  10. Chronic Stress and Limbic-Hypothalamopituitary-Adrenal Axis (LHPA Response in Female Reproductive system

    Directory of Open Access Journals (Sweden)

    Farideh Zafari Zangeneh

    2009-12-01

    Full Text Available The hypothalamo-pituitary-adrenocortical (HPA axis is a critical adaptive system that maximizes survival potential in the face of physical or psychological challenge. The principal end products of the HPA axis, glucocorticoid hormones, act on multiple organ systems, including the brain, to maintain homeostatic balance. The brain is a target of stress, and the hippocampus is the first brain region, besides the hypothalamus, to be recognized as a target of glucocorticoids. These anatomical areas in brain are limbic system, and in particular the hippocampus, medial prefrontal cortex (mPFC and amigdal that have multiple control points in regulation of the hypothalamic–pituitary–adrenal (HPA axis. The studies show the prefrontal cortex (PFC plays an important role in the regulation of stress-induced hypothalamic–pituitary–adrenal (HPA activity and regulation of gonadal function in men and women is under the control of the HPA. This regulation is complex and sex steroids are important regulators of GnRH and gonadotropin release through classic feedback mechanisms in the hypothalamus and pituitary gland. Chronic stress can have a deleterious effect on the reproductive axis that, for females, is manifested in reduced pulsatile gonadotropin secretion and increased incidence of ovulatory abnormalities and infertility. The limbic–hypothalamic–pituitary–adrenal (LHPA axis suggests a functional role for gonadal steroids in the regulation of a female’s response to stress.

  11. Comparison of Hensen's node and retinoic acid in secondary axis induction in the early chick embryo.

    Science.gov (United States)

    Chen, Y; Solursh, M

    1992-10-01

    Retinoic acid (RA) and Hensen's node, the organizer center in the chick embryo, have been shown to have polarizing activity when applied or grafted into the chick limb bud. Here we investigate and compare the effects of RA and grafted Hensen's node on the early chick embryo. Anion exchange beads soaked with RA at concentrations ranging from 5 to 100 ng/ml and implanted on the anterior side or on the left side of the host anteroposterior axis of a stage 4 chick embryo in ovo have the ability to induce secondary axis formation, while beads soaked with RA of the same concentration and implanted on the right side or on the posterior side of the host axis are unable to induce the secondary axis. All of the induced axes contain trunk-tail structures. Hensen's node from quail embryos implanted into the early chick blastoderm could also cause the formation of secondary axes in addition to self-differentiation of the graft into a secondary axis. Both RA and grafted Hensen's node caused the inhibition of forebrain development with an increase in hindbrain development and the host heart to loop in an abnormal direction. The results support the hypothesis that Hensen's node is a source of RA which is involved in early embryogenesis. Alternatively, RA might stimulate the formation of Hensen's nodal properties in adjacent tissue.

  12. Adaptive sliding mode control of the A-axis used for blisk manufacturing

    Institute of Scientific and Technical Information of China (English)

    Zhao Pengbing; Shi Yaoyao

    2014-01-01

    As a key assembly in the 5-axis CNC machine tools, positioning precision of the A-axis directly affects the machining accuracy and surface quality of the parts. First of all, mechanical structure and control system of the A-axis are designed. Then, considering the influence of nonlin-ear friction, backlash, unmodeled dynamics, uncertain cutting force and other external disturbance on the control precision of the A-axis, an adaptive sliding mode control (ASMC) based on extended state observer (ESO) is proposed. ESO is employed to estimate the state variables of the unknown system and an adaptive law is adopted to compensate for the input dead-zone caused by friction, backlash and other nonlinear characteristics. Finally, stability of the closed-loop system is guaran-teed by the Lyapunov theory. Positioning experiments illustrate the perfect estimation of ESO and the stronger anti-interference and robustness of ASMC, which can improve the control precision of the A-axis by about 40 times. Processing experiments show that the ASMC can reduce the waviness, average error and roughness of the processed surface by 35.63%, 31.31%and 30.35%, respectively.

  13. Expression of NMS and NMU2R in the pig reproductive axis during the estrus cycle and the effect of NMS on the reproductive axis in vitro.

    Science.gov (United States)

    Yang, Guihong; Su, Juan; Li, Xun; Yao, Yuan; Lei, Zhihai; Yang, Xizhi; Kou, Rui; Liu, Yanpeng

    2009-12-01

    Evidence has revealed that neuromedin S (NMS) and neuromedin U-receptor type-2 (NMU2R) mRNAs are expressed in the central nervous system and reproductive organs. Previous data indicated that variation of NMS and NMU2R was due to the phases of the adult rat hypothalamus estrus cycle. However, the expression and function of NMS in the pig reproductive axis remains unexplored. In this study, 16 virginal gilts were classified into four groups: proestrus, estrus, diestrus 1, and diestrus 2; the expression of NMS and NMU2R in the cyclic pig hypothalamus-pituitary-ovary axis was studied by reverse transcriptaion-polymerase chain reaction (RT-PCR), and the effect of NMS on the reproductive axis in vitro was detected by radioimmunoassay (RIA). The cloned pig NMS and NMU2R sequences were 82% and 90.2% identical to those of the corresponding human homologues, respectively. RT-PCR showed that NMS and NMU2R mRNA expression in the hypothalamus and pituitary changed with the estrus cycle, i.e., with the highest level in the proestrus group and the lowest in the estrus group. In the ovary, NMS and NMU2R expression was highest in the diestrus 2 group and the lowest in the proestrus group. In the in vitro study, different concentrations of NMS induced the release of gonadotropin-releasing hormone, luteinizing hormone, and estradiol at different levels of the reproductive axis. Taken together, the expression pattern of NMS during the estrus cycle and its role in reproductive hormones in vitro provide novel evidences of the potential roles of NMS in the regulation of pig reproduction.

  14. Active Blade Pitch Control for Straight Bladed Darrieus Vertical Axis Wind Turbine of New Design

    DEFF Research Database (Denmark)

    Chougule, Prasad; Nielsen, Søren R.K.; Basu, Biswajit

    2013-01-01

    As Development of small vertical axis wind turbines (VAWT) for urban use is becoming an interesting topic both within industry and academia. However, there are few new designs of vertical axis turbines which are customized for building integration. These are getting importance because they operate...... at low rotational speed producing very less noise during operation, although these are less efficient than Horizontal Axis Wind Turbines (HAWT). The efficiency of a VAWT has been significantly improved by H-Darrieus VAWT design based on double airfoil technology as demonstrated by the authors...... multiple stream tube method is used to determine the performance of the H-Darrieus VAWT. The power coefficient is compared with that of a fixed pitch and a variable pitch double airfoil blade VAWT. It is demonstrated that an improvement in power coefficient by 20% is achieved and the turbine could start...

  15. Ghrelin axis genes, peptides and receptors: recent findings and future challenges.

    Science.gov (United States)

    Seim, Inge; Josh, Peter; Cunningham, Peter; Herington, Adrian; Chopin, Lisa

    2011-06-20

    The ghrelin axis consists of the gene products of the ghrelin gene (GHRL), and their receptors, including the classical ghrelin receptor GHSR. While it is well-known that the ghrelin gene encodes the 28 amino acid ghrelin peptide hormone, it is now also clear that the locus encodes a range of other bioactive molecules, including novel peptides and non-coding RNAs. For many of these molecules, the physiological functions and cognate receptor(s) remain to be determined. Emerging research techniques, including proteogenomics, are likely to reveal further ghrelin axis-derived molecules. Studies of the role of ghrelin axis genes, peptides and receptors, therefore, promises to be a fruitful area of basic and clinical research in years to come.

  16. Intermittent changing axis deviation with intermittent left anterior hemiblock during atrial flutter with subclinical hyperthyroidism.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo

    2009-06-26

    Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that subclinical hyperthyroidism is not associated with CHD or mortality from cardiovascular causes but it is usually associated with a higher heart rate and a higher risk of supraventricular arrhythmias including atrial fibrillation and atrial flutter. Intermittent changing axis deviation during atrial fibrillation has also rarely been reported. We present a case of intermittent changing axis deviation with intermittent left anterior hemiblock in a 59-year-old Italian man with atrial flutter and subclinical hyperthyroidism. To our knowledge, this is the first report of intermittent changing axis deviation with intermittent left anterior hemiblock in a patient with atrial flutter.

  17. Off-vertical axis rotation: a test of the otolith-ocular reflex

    Science.gov (United States)

    Furman, J. M.; Schor, R. H.; Schumann, T. L.

    1992-01-01

    The vestibulo-ocular reflex was studied via off-vertical axis rotation (OVAR) in the dark. The axis of the turntable could be tilted from vertical by up to 30 degrees. Eye movements were measured with electro-oculography. Results from healthy asymptomatic subjects indicated that 1) a reliable otolith-induced response could be obtained during constant velocity OVAR using a velocity of 60 degrees/s with a tilt of 30 degrees; 2) constant velocity OVAR rotation was nausea-producing and, especially if subjects were rotated in the dark about an earth-vertical axis prior to being tilted, disorienting; and 3) sinusoidal OVAR produced minimal nausea; the eye movement response appeared to be the result of a combination of semicircular canal and otolith components. We conclude that OVAR has the potential of becoming a useful method for clinically assessing both the otolith-ocular reflex and semicircular canal-otolith interaction.

  18. Modulation of Gut Microbiota-Brain Axis by Probiotics, Prebiotics, and Diet.

    Science.gov (United States)

    Liu, Xiaofei; Cao, Shangqing; Zhang, Xuewu

    2015-09-16

    There exists a bidirectional communication system between the gastrointestinal tract and the brain. Increasing evidence shows that gut microbiota can play a critical role in this communication; thus, the concept of a gut microbiota and brain axis is emerging. Here, we review recent findings in the relationship between intestinal microbes and brain function, such as anxiety, depression, stress, autism, learning, and memory. We highlight the advances in modulating brain development and behavior by probiotics, prebiotics, and diet through the gut microbiota-brain axis. A variety of mechanisms including immune, neural, and metabolic pathways may be involved in modulation of the gut microbiota-brain axis. We also discuss some future challenges. A deeper understanding of the relationship between the gut bacteria and their hosts is implicated in developing microbial-based therapeutic strategies for brain disorders.

  19. Realization Methodology of a 5-axis Spline Interpolator in an Open CNC System

    Institute of Scientific and Technical Information of China (English)

    Wang Yongzhang; Ma Xiongbo; Chen Liangji; Han Zhenyu

    2007-01-01

    By making use of the advantages of non-uniform rational B-spline (NURBS) curves to represent spatial curves, an instruction format with double NURBS curves suitable for 5-axis coordinated real-time interpolation is presented to replace the current 5-axis coordinated linear interpolation method defective in low-speed, low-accuracy and enormous numerical control (NC) files in sculptured surface machining. A generation procedure of the NC files with the presented format is introduced and the method to realize the interpolation in an open computer numerical control (CNC) system is developed by ourselves. These illustrated the feasibility of the proposed method and its capability of avoiding all the shortages of 5-axis linear interpolation method.

  20. The energy-redox axis in aging and age-related neurodegeneration.

    Science.gov (United States)

    Yap, Li-Peng; Garcia, Jerome V; Han, Derick; Cadenas, Enrique

    2009-11-30

    Decrease in mitochondrial energy-transducing capacity is a feature of the aging process that accompanies redox alterations, such as increased generation of mitochondrial oxidants, altered GSH status, and increased protein oxidation. The decrease in mitochondrial energy-transducing capacity and altered redox status should be viewed as a concerted process that embodies the mitochondrial energy-redox axis and is linked through various mechanisms including: (a) an inter-convertible reducing equivalents pool (i.e., NAD(P)(+)/NAD(P)H) and (b) redox-mediated protein post-translational modifications involved in energy metabolism. The energy-redox axis provides the rationale for therapeutic approaches targeted to each or both component(s) of the axis that effectively preserves or improve mitochondrial function and that have implications for aging and age-related neurodegenerative disorders.

  1. Characterization of the Hypothalamic-Pituitary-Adrenal-Axis in Familial Longevity under Resting Conditions

    DEFF Research Database (Denmark)

    Jansen, Steffy W; Roelfsema, Ferdinand; Akintola, Abimbola A;

    2015-01-01

    of the HPA-axis in offspring from long-lived siblings, who are enriched for familial longevity and age-matched controls. DESIGN: Case-control study within the Leiden Longevity study cohort consisting of 20 middle-aged offspring of nonagenarian siblings (offspring) together with 18 partners (controls...... for longevity have less metabolic and cognitive disturbances and therefore diminished activity of the HPA axis may be a potential candidate mechanism underlying healthy familial longevity. Here, we compared 24-h plasma ACTH and serum cortisol concentration profiles and different aspects of the regulation...... not differ between offspring and controls. In addition, no significant differences in feedforward and feedback synchrony and adrenal gland ACTH responsivity were observed between groups. CONCLUSIONS: These results suggest that familial longevity is not associated with major differences in HPA-axis activity...

  2. Irritable bowel syndrome, the microbiota and the gut-brain axis

    DEFF Research Database (Denmark)

    Raskov, Hans; Burcharth, Jakob; Pommergaard, Hans-Christian

    2016-01-01

    Irritable bowel syndrome is a common functional gastrointestinal disorder and it is now evident that irritable bowel syndrome is a multi-factorial complex of changes in microbiota and immunology. The bidirectional neurohumoral integrated communication between the microbiota and the autonomous...... nervous system is called the gut-brain-axis, which integrates brain and GI functions, such as gut motility, appetite and weight. The gut-brain-axis has a central function in the perpetuation of irritable bowel syndrome and the microbiota plays a critical role. The purpose of this article is to review...... recent research concerning the epidemiology of irritable bowel syndrome, influence of microbiota, probiota, gut-brain-axis, and possible treatment modalities on irritable bowel syndrome....

  3. Creation of multiple on-axis foci and ultra-long focal depth for SPPs.

    Science.gov (United States)

    Wang, Jiayuan; Chen, Cuiyun; Sun, Zhijun

    2017-01-23

    We present the design of a plasmonic lens (PL) which is composed of pixelated nano-grooves on a gold film for the coupling and focusing of surface plasmon polaritons (SPPs) into multiple focal spots on the optical axis. The pixelated grooves are arranged along the y-axis and the x-position of each groove is optimized by the simulated annealing algorithm. PLs that implement two and three on-axis foci are presented and the designed structures have been validated with FDTD simulations. We also successfully constructed a long-focal-depth PL with a longitudinal FWHM of the focus that reached 25 plasmonic wavelengths, while its transverse field profile is maintained over 15 µm distance. The presented design method constitutes a new basis for plasmonic beam engineering, and the proposed particular SPP focal fields have potential applications in multiple imaging, particle manipulating, and plasmonic on-chip signal transmission.

  4. ANALYSIS OF METHOD FOR DETERMINING AZIMUTH OF PRINCIPAL AXIS OF INERTIA BASED ON DYNAMIC BALANCE MEASUREMENT

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jun; GUAN Yingzi; QI Naiming

    2006-01-01

    The dynamic balance quality of a rotating object is an important factor to maintain the stability and accuracy for motion. The azimuth of the principal axis of inertia is a major sign of dynamic balance. A usual method is measuring moment of inertia matrix relative to some base coordinates on a rotary inertia machine so as to calculate the azimuth of principal axis of inertia. By using the measured unbalance results on the two trimmed planes on a vertical hard bearing double-plane dynamic balancing machine, the dimension and direction of couple unbalance can be found. An azimuth angle formula for the principal axis of inertia is derived and is solved by using unbalance quantities. The experiments indicate that method based on dynamic balancing measurement is proved rational and effective and has a fine precision.

  5. Modelling cholesterol effects on the dynamics of the hypothalamic-pituitary-adrenal (HPA) axis.

    Science.gov (United States)

    Marković, Vladimir M; Čupić, Željko; Maćešić, Stevan; Stanojević, Ana; Vukojević, Vladana; Kolar-Anić, Ljiljana

    2016-03-01

    A mathematical model of the hypothalamic-pituitary-adrenal (HPA) axis with cholesterol as a dynamical variable was derived to investigate the effects of cholesterol, the primary precursor of all steroid hormones, on the ultradian and circadian HPA axis activity. To develop the model, the parameter space was systematically examined by stoichiometric network analysis to identify conditions for ultradian oscillations, determine conditions under which dynamic transitions, i.e. bifurcations occur and identify bifurcation types. The bifurcations were further characterized using numerical simulations. Model predictions agree well with empirical findings reported in the literature, indicating that cholesterol levels may critically affect the global dynamics of the HPA axis. The proposed model provides a base for better understanding of experimental observations, it may be used as a tool for designing experiments and offers useful insights into the characteristics of basic dynamic regulatory mechanisms that, when impaired, may lead to the development of some modern-lifestyle-associated diseases.

  6. Inter-relation between autonomic and HPA axis activity in children and adolescents.

    Science.gov (United States)

    Rotenberg, Sivan; McGrath, Jennifer J

    2016-05-01

    Stress research in youth typically considers either the autonomic nervous system or HPA axis. However, these systems are highly coordinated and physically interconnected. We examined whether the inter-relation between cardio-autonomic and HPA axis measures was better associated with perceived stress than their singular associations. Children and adolescents (N=201) collected saliva samples to measure cortisol (AUCAG, AUCI, maximum), wore an electrocardiogram monitor for 24h to derive heart rate variability (HRV; LF, HF, LF/HF ratio), and completed the Perceived Stress Scale. The interaction between sympathovagal modulation (LF, LF/HF ratio) and cortisol awakening response (AUCAG, AUCI, maximum) explained significantly greater variance in perceived stress than either stress system alone. Higher sympathovagal modulation combined with higher cortisol awakening response was associated with greater perceived stress. Findings suggest that the inter-relation between cardio-autonomic and HPA axis activity may advance our understanding of how stress impacts health.

  7. Spatial re-orienting of visual attention along the horizontal or the vertical axis.

    Science.gov (United States)

    Macaluso, E; Patria, F

    2007-06-01

    Neuroimaging data indicate functional segregation between voluntary and stimulus-driven control of spatial attention in dorsal and ventral fronto-parietal regions, respectively. While recent evidences demonstrated location-specific attentional effects in dorsal regions, little is known about any location or direction selectivity within the ventral network. Here, we used a spatial cueing paradigm to investigate stimulus-driven spatial re-orienting along different axes (horizontal or vertical). We found that re-orienting of attention activated the ventral attentional network, irrespective of axis-orientation. Statistical comparisons between homologous regions in the two hemispheres revealed significant main effects of attention re-orienting (common activation for the two hemispheres), irrespective of leftward or rightward re-orienting along the horizontal axis, or re-orienting along the vertical axis. We conclude that in healthy volunteers, a bilateral ventral network controls spatial covert re-orienting, and that this system is multidirectional.

  8. Neuromedins U and S involvement in the regulation of the hypothalamo - pituitary - adrenal axis.

    Directory of Open Access Journals (Sweden)

    Ludwik K. Malendowicz

    2012-12-01

    Full Text Available Abstract: We reviewed neuromedin U (NMU and neuromedin S (NMS involvement in the regulation of the hypothalamo - pituitary - adrenal (HPA axis function. NMU and NMS are structurally related and highly conserved neuropeptides. They exert biological effects via two GPCR receptors designated as NMUR1 and NMUR2 which show differential expression. NMUR1 is expressed predominantly at the periphery, while NMUR2 in the central nervous system. Elements of the NMU/NMS and their receptors network are also expressed in the HPA axis and progress in molecular biology techniques provided new information on their actions within this system. Several lines of evidence suggest that within the HPA axis NMU and NMS act at both hypothalamic and adrenal levels. Moreover, new data suggest that NMU and NMS are involved in central and peripheral control of the stress response.

  9. Dynamic Analysis of a Floating Vertical Axis Wind Turbine Under Emergency Shutdown Using Hydrodynamic Brake

    DEFF Research Database (Denmark)

    Wang, K.; Hansen, Martin Otto Laver; Moan, T.

    2014-01-01

    axis wind turbine were carried out for emergency shutdown cases over a range of environmental conditions based on correlated wind and wave data. When generator failure happens, a brake should be applied to stop the acceleration of the rotor to prevent the rotor from overspeeding and subsequent disaster....... In addition to the traditional mechanical brake, a novel hydrodynamic brake was presented to apply to the shutdown case. The effects of the hydrodynamic brake on the platform motions and structural loads under normal operating conditions and during the emergency shutdown events were evaluated. The use of both......Emergency shutdown is always a challenge for an operating vertical axis wind turbine. A 5-MW vertical axis wind turbine with a Darrieus rotor mounted on a semi-submersible support structure was examined in this study. Coupled non-linear aero-hydro-servo-elastic simulations of the floating vertical...

  10. Frequency-domain characteristics of aerodynamic loads of offshore floating vertical axis wind turbines

    DEFF Research Database (Denmark)

    Borg, Michael; Collu, M.

    2015-01-01

    The re-emerging interest in vertical axis wind turbines for floating offshore applications has led to a need to investigate the relatively complex dynamics of such floating offshore structures. Through the use of a coupled model of dynamics this article investigates the frequency-domain character......The re-emerging interest in vertical axis wind turbines for floating offshore applications has led to a need to investigate the relatively complex dynamics of such floating offshore structures. Through the use of a coupled model of dynamics this article investigates the frequency-domain...... characteristics of floating vertical axis wind turbine aerodynamic loads. The impact of platform induced motion on aerodynamic loads is discussed in detail, with results indicating an increase in aerodynamic loads of several orders of magnitude over the range of frequencies usually containing significant wave...

  11. Anatomy of an eradication effort: Removing Hawaii's illegally introduced axis deer

    Science.gov (United States)

    Hess, Steven C.; Muise, Jake; Schipper, Jan

    2015-01-01

    In February 2011, a rancher in the rural southern part of Hawaii Island reported a large mammal on her land. Her call mobilized several agencies led by the Big Island Invasive Species Committee (BIISC), a partnership to prevent, detect, and control the establishment and spread of invasive species, to sit up and take notice. Agency biologists installed camera traps to identify the animal, and a few months later verified the diagnostic field marks of a chervid with spots. The animal in questions was a chital, or axis deer (Axis axis)--a species native to tropical and subtropical India. Although the deer are abundant on the islands of Molokai, Lānai, and Maui, officials knew they weren't capable of swimming across the notoriously treacherous ʻAlenuihāhā channel, and subsequently suspected human intervention.

  12. HPA axis in major depression: cortisol, clinical symptomatology and genetic variation predict cognition.

    Science.gov (United States)

    Keller, J; Gomez, R; Williams, G; Lembke, A; Lazzeroni, L; Murphy, G M; Schatzberg, A F

    2016-08-16

    The hypothalamic-pituitary-adrenal (HPA) axis has been implicated in the pathophysiology of a variety of mood and cognitive disorders. Neuroendocrine studies have demonstrated HPA axis overactivity in major depression, a relationship of HPA axis activity to cognitive performance and a potential role of HPA axis genetic variation in cognition. The present study investigated the simultaneous roles HPA axis activity, clinical symptomatology and HPA genetic variation play in cognitive performance. Patients with major depression with psychotic major depression (PMD) and with nonpsychotic major depression (NPMD) and healthy controls (HC) were studied. All participants underwent a diagnostic interview and psychiatric ratings, a comprehensive neuropsychological battery, overnight hourly blood sampling for cortisol and genetic assessment. Cognitive performance differed as a function of depression subtype. Across all subjects, cognitive performance was negatively correlated with higher cortisol, and PMD patients had higher cortisol than did NPMDs and HCs. Cortisol, clinical symptoms and variation in genes, NR3C1 (glucocorticoid receptor; GR) and NR3C2 (mineralocorticoid receptor; MR) that encode for GRs and MRs, predicted cognitive performance. Beyond the effects of cortisol, demographics and clinical symptoms, NR3C1 variation predicted attention and working memory, whereas NR3C2 polymorphisms predicted memory performance. These findings parallel the distribution of GR and MR in primate brain and their putative roles in specific cognitive tasks. HPA axis genetic variation and activity were important predictors of cognition across the entire sample of depressed subjects and HR. GR and MR genetic variation predicted unique cognitive functions, beyond the influence of cortisol and clinical symptoms. GR genetic variation was implicated in attention and working memory, whereas MR was implicated in verbal memory.Molecular Psychiatry advance online publication, 16 August 2016; doi

  13. Two-axis water-immersible microscanning mirror for scanning optics and acoustic microscopy

    Science.gov (United States)

    Xu, Song; Zou, Jun

    2016-10-01

    Fast multiaxis scanning is useful for not only optical but also acoustic microscopic imaging. Although they have been used for optical scanning, the application of (MEMS) scanning mirrors in acoustic microscopy is still very limited due to their small mirror plate size, and more importantly, inability to operate in liquids (as ultrasound coupling media). A microfabricated two-axis water-immersible scanning mirror for optical and acoustic microscopy is reported. It has an optical and acoustically reflective mirror plate (6 mm×4 mm) to provide numerical aperture for ultrasound beam steering. Electromagnetic and mechanical analysis and simulation were conducted to estimate the mechanical tilting angle and resonance frequency of both fast and slow axes, which matches well with the measurement results. The fast axis has a resonant frequency of 320 Hz in air and 220 Hz in water, which is more than 10 times higher than that of the slow axis (24 Hz in air and 14 Hz in water). Under a 100-mA driving current, the scanning angles of the fast axis reached ±9.5 deg in both air and water at the resonance frequency, respectively. The scanning angles of the slow axis reached ±15 deg in air and ±12.5 deg in water at resonant frequencies, respectively. Raster scanning of a collimated laser beam was achieved by driving both axes simultaneously close to their own resonance frequencies. The feasibility of using the two-axis water-immersible scanning mirror in scanning acoustic microscopy was also demonstrated.

  14. Flexible Piezoelectric Tactile Sensor Array for Dynamic Three-Axis Force Measurement.

    Science.gov (United States)

    Yu, Ping; Liu, Weiting; Gu, Chunxin; Cheng, Xiaoying; Fu, Xin

    2016-06-03

    A new flexible piezoelectric tactile sensor array based on polyvinylidene fluoride (PVDF) film is proposed for measuring three-axis dynamic contact force distribution. The array consists of six tactile units arranged as a 3 × 2 matrix with spacing 8 mm between neighbor units. In each unit, a PVDF film is sandwiched between four square-shaped upper electrodes and one square-shaped lower electrode, forming four piezoelectric capacitors. A truncated pyramid bump is located above the four piezoelectric capacitors to improve force transmission. A three-axis contact force transmitted from the top of the bump will lead to the four piezoelectric capacitors underneath undergoing different charge changes, from which the normal and shear components of the force can be calculated. A series of dynamic tests have been carried out by exerting sinusoidal forces with amplitudes ranging from 0 to 0.5 N in the x-axis, 0 to 0.5 N in the y-axis, and 0 to 1.5 N in the z-axis, separately. The tactile units show good sensitivities with 14.93, 14.92, and 6.62 pC/N in the x-, y-, and z-axes, respectively. They can work with good linearity, relatively low coupling effect, high repeatability, and acceptable frequency response in the range of 5-400 Hz to both normal and shear load. In addition, dynamic three-axis force measurement has been conducted for all of the tactile units. The average errors between the applied and calculated forces are 10.68% ± 6.84%. Furthermore, the sensor array can be easily integrated onto a curved surface, such as robotic and prosthetic hands, due to its excellent flexibility.

  15. HPA Axis in Major Depression: Cortisol, Clinical Symptomatology, and Genetic Variation Predict Cognition

    Science.gov (United States)

    Keller, Jennifer; Gomez, Rowena; Williams, Gordon; Lembke, Anna; Lazzeroni, Laura; Murphy, Greer M.; Schatzberg, Alan F.

    2016-01-01

    The Hypothalamic Pituitary Adrenal (HPA) axis has been implicated in the pathophysiology of a variety of mood and cognitive disorders. Neuroendocrine studies have demonstrated HPA axis overactivity in major depression, a relationship of HPA axis activity to cognitive performance, and a potential role of HPA axis genetic variation in cognition. The present study investigated the simultaneous roles HPA axis activity, clinical symptomatology, and HPA genetic variation play in cognitive performance. Patients with major depression with psychosis (PMD) and without psychosis (NPMD) and healthy controls (HC) were studied. All participants underwent a diagnostic interview and psychiatric ratings, a comprehensive neuropsychological battery, overnight hourly blood sampling for cortisol, and genetic assessment. Cognitive performance differed as a function of depression subtype. Across all subjects, cognitive performance was negatively correlated with higher cortisol, and PMD patients had higher cortisol than did NPMDs and HCs. Cortisol, clinical symptoms, and variation in genes, NR3C1 (glucocorticoid receptor - GR) and NR3C2 (minercorticoid receptor – MR) that encode for glucocorticoid and mineralcorticoid receptors, predicted cognitive performance. Beyond the effects of cortisol, demographics, and clinical symptoms, NR3C1 variation predicted attention and working memory, whereas NR3C2 polymorphisms predicted memory performance. These findings parallel the distribution of GR and MR in primate brain and their putative roles in specific cognitive tasks. HPA axis genetic variation and activity were important predictors of cognition across the entire sample of depressed subjects and healthy controls. GR and MR genetic variation predicted unique cognitive functions, beyond the influence of cortisol and clinical symptoms. GR genetic variation was implicated in attention and working memory, whereas MR was implicated in verbal memory. PMID:27528460

  16. Accurate Compensation of Attitude Angle Error in a Dual-Axis Rotation Inertial Navigation System

    Science.gov (United States)

    Jiang, Rui; Yang, Gongliu; Zou, Rui; Wang, Jing; Li, Jing

    2017-01-01

    In the dual-axis rotation inertial navigation system (INS), besides the gyro error, accelerometer error, rolling misalignment angle error, and the gimbal angle error, the shaft swing angle and the axis non-orthogonal angle also affect the attitude accuracy. Through the analysis of the structure, we can see that the shaft swing angle and axis non-orthogonal angle will produce coning errors which cause the fluctuation of the attitude. According to the analysis of the rotation vector, it can be seen that the coning error will generate additional drift velocity along the rotating shaft, which can reduce the navigation precision of the system. In this paper, based on the establishment of the modulation average frame, the vector projection is carried out, and then the attitude conversion matrix and the attitude error matrix mainly including the shaft swing angle and axis non-orthogonal are obtained. Because the attitude angles are given under the static condition, the shaft swing angle and the axis non-orthogonal angle are estimated by the static Kalman filter (KF). This kind of KF method has been widely recognized as the standard optimal estimation tool for estimating the parameters such as coning angles (α1 , α2), initial phase angles (ϕ1,ϕ2), and the non-perpendicular angle (η). In order to carry out the system level verification, a dual axis rotation INS is designed. Through simulation and experiments, the results show that the amplitudes of the attitude angles’ variation are reduced by about 20%–30% when the shaft rotates. The attitude error equation is reasonably simplified and the calibration method is accurate enough. The attitude accuracy is further improved. PMID:28304354

  17. Evaluation of the prototype dual-axis wall attitude measurement sensor

    Science.gov (United States)

    Wong, Douglas T.

    1994-01-01

    A prototype dual-axis electrolytic tilt sensor package for angular position measurements was built and evaluated in a laboratory environment. The objective was to investigate the use of this package for making wind tunnel wall attitude measurements for the National Transonic Facility (NTF) at NASA Langley Research Center (LaRC). The instrumentation may replace an existing, more costly, and less rugged servo accelerometer package (angle-of-attack package) currently in use. The dual-axis electrolytic tilt sensor package contains two commercial electrolytic tilt sensors thermally insulated with NTF foam, all housed within a stainless steel package. The package is actively heated and maintained at 160 F using foil heating elements. The laboratory evaluation consisted of a series of tests to characterize the linearity, repeatability, cross-axis interaction, lead wire effect, step response, thermal time constant, and rectification errors. Tests revealed that the total RMS errors for the x-axis sensor is 0.084 degree, and 0.182 degree for the y-axis sensor. The RMS errors are greater than the 0.01 degree specification required for NTF wall attitude measurements. It is therefore not a viable replacement for the angle-of-attack package in the NTF application. However, with some physical modifications, it can be used as an inexpensive 5-degree range dual-axis inclinometer with overall accuracy approaching 0.01 degree under less harsh environments. Also, the data obtained from the tests can be valuable for wind tunnel applications of most types of electrolytic tilt sensors.

  18. An empirical method for calculating melt compositions produced beneath mid-ocean ridges: Application for axis and off-axis (seamounts) melting

    Science.gov (United States)

    Niu, Yaoling; Batiza, Rodey

    1991-12-01

    We present a new method for calculating the major element compositions of primary melts parental to mid-ocean ridge basalt (MORB). This model is based on the experimental data of Jaques and Green (1980), Falloon et al. (1988), and Falloon and Green (1987, 1988) which are ideal for this purpose. Our method is empirical and employs solid-liquid partition coefficients (Di) from the experiments. We empirically determine Di = ƒ(P,F) and use this to calculate melt compositions produced by decompression-induced melting along an adiabat (column melting). Results indicate that most MORBs can be generated by 10-20% partial melting at initial pressures (P0) of 12-21 kbar. Our primary MORB melts have MgO = 10-12 wt %. We fractionate these at low pressure to an MgO content of 8.0 wt % in order to interpret natural MORB liquids. This model allows us to calculate Po, Pƒ, To, Tƒ, and F for natural MORB melts. We apply the model to interpret MORB compositions and mantle upwelling patterns beneath a fast ridge (East Pacific Rise (EPR)8°N to 14°N), a slow ridge (mid-Atlantic Ridge (MAR) at 26°S), and seamounts near the EPR (Lament seamount chain). We find mantle temperature differences of up to 50°-60°C over distances of 30-50 km both across axis and along axis at the EPR. We propose that these are due to upward mantle flow in a weakly conductive (versus adiabatic) temperature gradient. We suggest that the EPR is fed by a wide (-100 km) zone of upwelling due to plate separation but has a central core of faster buoyant flow. An along-axis thermal dome between the Siqueiros transform and the 11°45' Overlapping Spreading center (OSC) may represent such an upwelling; however, in general there is a poor correlation between mantle temperature, topography, and the segmentation pattern at the EPR. For the Lament seamounts we find regular across-axis changes in Po and F suggesting that the melt zone pinches out off axis. This observation supports the idea that the EPR is fed by a

  19. An empirical method for calculating melt compositions produced beneath mid-ocean ridges: for axis and off-axis (seamounts) melting application

    Science.gov (United States)

    Batiza, Rodey

    1991-12-01

    We present a new method for calculating the major element compositions of primary melts parental to mid-ocean ridge basalt (MORB). This model is based on the experimental data of Jaques and Green (1980), Falloon et al. (1988), and Falloon and Green (1987, 1988) which are ideal for this purpose. Our method is empirical and employs solid-liquid partition coefficients (Di) from the experiments. We empirically determine Di=f(P,F) and use this to calculate melt compositions produced by decompression-induced melting along an adiabat (column melting). Results indicate that most MORBs can be generated by 10-20% partial melting at initial pressures (P0) of 12-21 kbar. Our primary MORB melts have MgO=10-12 wt %. We fractionate these at low pressure to an MgO content of 8.0 wt% in order to interpret natural MORB liquids. This model allows us to calculate Po, Pf, To, Tf, and F for natural MORB melts. We apply the model to interpret MORB compositions and mantle upwelling patterns beneath a fast ridge (East Pacific Rise (EPR) 8°N to 14°N), a slow ridge (mid-Atlantic Ridge (MAR) at 26°S), and seamounts near the EPR (Lamont seamount chain). We find mantle temperature differences of up to 50°-60°C over distances of 30-50 km both across axis and along axis at the EPR. We propose that these are due to upward mantle flow in a weakly conductive (versus adiabatic) temperature gradient. We suggest that the EPR is fed by a wide (~100 km) zone of upwelling due to plate separation but has a central core of faster buoyant flow. An along-axis thermal dome between the Siqueiros transform and the 11°45' Overlapping Spreading Center (OSC) may represent such an upwelling; however, in general there is a poor correlation between mantle temperature, topography, and the segmentation pattern at the EPR. For the Lamont seamounts we find regular across-axis changes in Po and F suggesting that the melt zone pinches out off axis. This observation supports the idea that the EPR is fed by a broad

  20. Automatic Identification of Axis Orbit Based on Both Wavelet Moment Invariants and Neural Network

    Institute of Scientific and Technical Information of China (English)

    FuXiang-qian; LiuGuang-lin; JiangJing; LiYou-ping

    2003-01-01

    Axis orbit is an important characteristic to be used in the condition monitoring and diagnosis system of rotating machine. The wavelet moment has the invariant to the translation, scaling and rotation. A method, which uses a neural network based on Radial Basis Function (RBF) and wavelet moment invariants to identify the orbit of shaft centerline of rotating machine is discussed in this paper. The principle and its application procedure of the method are introduced in detail. It gives simulation results of automatic identification for three typical axis orbits. It is proved that the method is effective and practicable.

  1. Automatic Identification of Axis Orbit Based on Both Wavelet Moment Invariants and Neural Network

    Institute of Scientific and Technical Information of China (English)

    Fu Xiang-qian; Liu Guang-lin; Jiang Jing; Li You-ping

    2003-01-01

    Axis orbit is an important characteristic to be used in the condition monitoring and diagnosis system of rota-ting machine. The wavelet moment has the invariant to the translation, scaling and rotation. A method, which uses a neural network based on Radial Basis Function (RBF) and wavelet moment invariants to identify the orbit of shaft centerline of rotating machine is discussed in this paper. The principle and its application procedure of the method are intro-duced in detail. It gives simulation results of automatic identi-fication for three typical axis orbits. It is proved that the method is effective and practicable.

  2. Micromechanical Analysis of Interfacial Debonding in Metal Matrix Composites Subjected to off-axis Loading

    Institute of Scientific and Technical Information of China (English)

    Xiaojun Zhu; Xuefeng Chen; Zhi Zhai; Qiang Chen; Shaohua Tian; Zhengjia He

    2013-01-01

    This study aims to investigate the effects of interfacial debonding and fiber volume fraction on the stress -strain behavior of the fiber reinforced metal matrix composites subjected to off -axis loading .The generalized method of cells ( GMC) is used to analyze a representative element whose fiber shape is circular .The constant compliant interface model (CCI) is also adopted to study the response of composites with imperfect interfacial bonding .Results show that for the com-posites subjected to off-axis loading ,the mechanical behaviors are affected appreciably by the interfacial debonding and the fiber volume fraction .

  3. Attitude determination for three-axis stabilized geostationary meteorological satellite image navigation

    Science.gov (United States)

    Wu, Yaguang; Wang, Zhigang

    2005-11-01

    To achieve the high accuracy of attitude determination for three-axis stabilized geostationary meteorological satellite image navigation, a new approach combined gyro with star trackers is proposed, and a real-time algorithm for attitude estimation is designed. This algorithm begins with a prediction for angular rate model errors induced by gyro drifting error, and ends with the extended Kalman filtering (EKF) for attitude estimation of three-axis. A Matlab-based time domain simulation model is developed to evaluate the attitude determination performance. Simulation results demonstrate that the proposed algorithm has characteristics of high accuracy, rapid convergence and strong robustness.

  4. Activation of the hypothalamic-pituitary-adrenal stress axis induces cellular oxidative stress

    Directory of Open Access Journals (Sweden)

    Jereme G. Spiers

    2015-01-01

    Full Text Available Glucocorticoids released from the adrenal gland in response to stress-induced activation of the hypothalamic-pituitary-adrenal (HPA axis induce activity in the cellular reduction-oxidation (redox system. The redox system is a ubiquitous chemical mechanism allowing the transfer of electrons between donor/acceptors and target molecules during oxidative phosphorylation while simultaneously maintaining the overall cellular environment in a reduced state. The objective of this review is to present an overview of the current literature discussing the link between HPA axis-derived glucocorticoids and increased oxidative stress, particularly focussing on the redox changes observed in the hippocampus following glucocorticoid exposure.

  5. A Singular Limit Problem for Rotating Capillary Fluids with Variable Rotation Axis

    Science.gov (United States)

    Fanelli, Francesco

    2016-12-01

    In the present paper we study a singular perturbation problem for a Navier-Stokes-Korteweg model with Coriolis force. Namely, we perform the incompressible and fast rotation asymptotics simultaneously, while we keep the capillarity coefficient constant in order to capture surface tension effects in the limit. We consider here the case of variable rotation axis: we prove the convergence to a linear parabolic-type equation with variable coefficients. The proof of the result relies on compensated compactness arguments. Besides, we look for minimal regularity assumptions on the variations of the axis.

  6. Reconstruction of the Electron Density of Molecules with Single-Axis Alignment

    Energy Technology Data Exchange (ETDEWEB)

    Starodub, Dmitri

    2011-08-12

    Diffraction from the individual molecules of a molecular beam, aligned parallel to a single axis by a strong electric field or other means, has been proposed as a means of structure determination of individual molecules. As in fiber diffraction, all the information extractable is contained in a diffraction pattern from incidence of the diffracting beam normal to the molecular alignment axis. We present two methods of structure solution for this case. One is based on the iterative projection algorithms for phase retrieval applied to the coefficients of the cylindrical harmonic expansion of the molecular electron density. Another is the holographic approach utilizing presence of the strongly scattering reference atom for a specific molecule.

  7. A two-dimensional matrix correction for off-axis portal dose prediction errors

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, Daniel W. [Department of Physics, State University of New York at Buffalo, Buffalo, New York 14260 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Kumaraswamy, Lalith; Bakhtiari, Mohammad [Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Podgorsak, Matthew B. [Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 and Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14214 (United States)

    2013-05-15

    Purpose: This study presents a follow-up to a modified calibration procedure for portal dosimetry published by Bailey et al. ['An effective correction algorithm for off-axis portal dosimetry errors,' Med. Phys. 36, 4089-4094 (2009)]. A commercial portal dose prediction system exhibits disagreement of up to 15% (calibrated units) between measured and predicted images as off-axis distance increases. The previous modified calibration procedure accounts for these off-axis effects in most regions of the detecting surface, but is limited by the simplistic assumption of radial symmetry. Methods: We find that a two-dimensional (2D) matrix correction, applied to each calibrated image, accounts for off-axis prediction errors in all regions of the detecting surface, including those still problematic after the radial correction is performed. The correction matrix is calculated by quantitative comparison of predicted and measured images that span the entire detecting surface. The correction matrix was verified for dose-linearity, and its effectiveness was verified on a number of test fields. The 2D correction was employed to retrospectively examine 22 off-axis, asymmetric electronic-compensation breast fields, five intensity-modulated brain fields (moderate-high modulation) manipulated for far off-axis delivery, and 29 intensity-modulated clinical fields of varying complexity in the central portion of the detecting surface. Results: Employing the matrix correction to the off-axis test fields and clinical fields, predicted vs measured portal dose agreement improves by up to 15%, producing up to 10% better agreement than the radial correction in some areas of the detecting surface. Gamma evaluation analyses (3 mm, 3% global, 10% dose threshold) of predicted vs measured portal dose images demonstrate pass rate improvement of up to 75% with the matrix correction, producing pass rates that are up to 30% higher than those resulting from the radial correction technique alone

  8. Optical Design for the Off-axis Reflective Optics with Wide Field

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Reflective optics with wide field of view has been applied more and more widely in EUVL or space optics, and also plays an important role in promoting scientific and technological research. Among the reflective optics, the off-axis reflective optics is the most hopeful solution to the ever-highest demands of these applications. This paper gives the requirements of both the above mentioned applications and the similarities and differences between these two kinds of optical systems. Finally, a design example of off-axis reflective optics with wide field of view is presented and described.

  9. Electron gun with off-axis beam injection for a race-track microtron

    Energy Technology Data Exchange (ETDEWEB)

    Aloev, A.V. [Institute of Nuclear Physics, Moscow State University, 119991 Moscow (Russian Federation); Carrillo, D. [CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Kubyshin, Yu.A., E-mail: iouri.koubychine@upc.ed [Institute of Energy Technologies, Technical University of Catalonia, Campus Sud, Av. Diagonal 647, 08028 Barcelona (Spain); Pakhomov, N.I.; Shvedunov, V.I. [Institute of Nuclear Physics, Moscow State University, 119991 Moscow (Russian Federation)

    2010-12-01

    A miniature 12 MeV race-track microtron for medical applications is under construction at the Technical University of Catalonia in collaboration with several Spanish centers and companies and the Skobeltsyn Institute of Nuclear Physics of the Moscow State University. As a source of electrons a compact 3D on-axis electron gun with an off-axis cathode has been designed to allow a direct and efficient injection into the accelerating structure. Its prototype has been built and successfully tested. Results of the electron gun design simulations and of the prototype performance are herein described.

  10. Static/dynamic Analysis and Optimization of Z-axis Stand of PCB CNC Drilling Machine*

    Directory of Open Access Journals (Sweden)

    Zhou Yanjun

    2016-01-01

    Full Text Available The finite element analysis is used for the static and dynamic analysis of the Z axis brace of PCB CNC drilling machine. With its results of maximum displacement deformation and von Mises stress and modal frequency, the defect of original design was found out. On such bases, a variety of optimization scheme is put forward and the best size of the Z axis brace is obtained by the performance comparison of the schemes. This method offers bases for the design and renovation of other machine tool components.

  11. Off-Axis Astigmatic Gaussian Beam Combination Beyond the Paraxial Approximation

    Institute of Scientific and Technical Information of China (English)

    GAO Zeng-Hui; L(U) Bai-Da

    2007-01-01

    Taking the off-axis astigmatic Gaussian beam combination as an example, the beam-combination concept is extended to the nonparaxial regime. The closed-form propagation expressions for coherent and incoherent combinations of nonparaxial off-axis astigmatic Gaussian beams with rectangular geometry are derived and illustrated with numerical examples. It is shown that the intensity distributions of the resulting beam depend on the combination scheme and beam parameters in general, and in the paraxial approximation (i.e., for the small f-parameter)our results reduce to the paraxial ones.

  12. Mathematical modeling of the hypothalamic–pituitary–adrenal gland (HPA) axis, including hippocampal mechanisms

    DEFF Research Database (Denmark)

    Andersen, Morten; Vinther, Frank; Ottesen, Johnny T.

    2013-01-01

    non-negative and bounded, which can be interpreted as a mathematical formulation of homeostasis. No oscillating solutions are present when using physiologically reasonable parameter values. This indicates that the ultradian rhythm originate from different mechanisms.Using physiologically reasonable......This paper presents a mathematical model of the HPA axis. The HPA axis consists of the hypothalamus, the pituitary and the adrenal glands in which the three hormones CRH, ACTH and cortisol interact through receptor dynamics. Furthermore, it has been suggested that receptors in the hippocampus have...

  13. OPTIMAL DESIGN OF A 6-AXIS FORCE TRANSDUCER BASED ON STEWART PLATFORM RELATED TO SENSITIVITY ISOTROPY

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The design method of a 6-axis force robot's transducer based on the Stewart platform is detailed.For this purpose, the sensitivity isotropy evaluation criteria of the transducer are defined, and by the aid of computer, the relationships between the criteria and the parameters of all the transducers based on the Stewart platform are investigated within the geometric model of the solution space, which can provide the theoretical background for the optimal construction design of the 6-axis force transducer related to the sensitivity isotropy.

  14. Uniaxial ferromagnetic film in magnetic field perpendicular to the easy axis

    Science.gov (United States)

    Korneta, W.; Pytel, Z.

    1987-08-01

    The spin model of single domain ferromagnetic film is considered. Only the nearest-neighbor interactions are taken into account. The interactions depend on distances from surfaces. The external magnetic field is applied perpendicular to the easy axis lying in the plane of the film. The thermodynamic behaviour of the model is studied near the second-order ferro-paramagnetic phase transition for the component of the magnetization in the direction of the easy axis. The molecular-field theory is used. The phase diagram and profiles of the order parameter are obtained. Different feasible investigations of the phase transition are compared.

  15. Comprehensive Calibration of Strap-Down Tri-Axis Accelerometer Unit

    Directory of Open Access Journals (Sweden)

    Xi Zhang

    2017-02-01

    Full Text Available This paper proposes a comprehensive calibration method to improve the precision of a strap-down tri-axis accelerometer unit, in which parameters are divided into static and dynamic ones. The contribution of the manuscript is that it solves the problem of inappropriate installation and the size effect error for tri-axis accelerometer unit at high speed by using static and dynamic calibration method, respectively. The experiment results show the measuring accuracy of accelerometers is increased by more than one order of magnitude, and the navigation precision is increased by more than two orders of magnitude.

  16. Contact lens intolerance: refitting with dual axis lens for corneal refractive therapy

    Science.gov (United States)

    López-López, María; Pelegrín-Sánchez, José Miguel; Sobrado-Calvo, Paloma; García-Ayuso, Diego

    2011-01-01

    Corneal refractive therapy is a non-surgical procedure whose main purpose is to improve uncorrected visual acuity during the day, without spectacles or contact lenses. We report an adult woman who shows contact lens intolerance and does not want to wear eyeglasses. We used dual axis contact lens to improve lens centration. We demonstrate a maintained unaided visual acuity during one year of treatment. In conclusion, we can consider refitting with dual axis lens for corneal refractive therapy as a non-surgical option for patients who show contact lens intolerance.

  17. The Accuracy of Screw Axis Analysis Using Position Data from Anatomical Motion Studies.

    Science.gov (United States)

    1980-05-05

    Hip Motion ........ . 57 7-2 Screw Axis Analysis for the Sacro -iliac Joint. 57 viii " LIST OF FIGURES Figure Title Page 2-1 Systems Anthropometry Data...The piercing point selected for this test was an arbitrary point. The screw axis direction was selected so that there would be equal components in all...analyzed are the hip, and the sacro -iliac joint. The bone movements analyzed are the femur moving relative to the left inominate for hip motion, and the

  18. Design and implementation of a multi-axis precision movement machine based on MAS theory

    Institute of Scientific and Technical Information of China (English)

    Li MA; Linlin CI; Genyan GE

    2009-01-01

    A model construction of a multi-agent system (MAS) and the basic function of the agent are described.The precision control method using the multi-CPU of a programmable logic controller (PLC) is introduced,and a distributed method using multiple CPUs to control different motion machines is given.The test results indicate that in industrial control fields,the combination of using the credible PLC to control the motion machine and multi-CPU task distributing methods can solve multi-axis machine linkage and implication,providing a more credible method for multi-axis motion units.

  19. Orbital Angular Momentum in Noncollinear Second Harmonic Generation by off-axis vortex beams

    CERN Document Server

    Bovino, Fabio Antonio; Giardina, Maurizio; Sibilia, Concita

    2011-01-01

    We experimentally study the behavior of orbital angular momentum (OAM) of light in a noncollinear second harmonic generation (SHG) process. The experiment is performed by using a type I BBO crystal under phase matching conditions with femtosecond pumping fields at 830 nm. Two specular off-axis vortex beams carrying fractional orbital angular momentum at the fundamental frequency (FF) are used. We analyze the behavior of the OAM of the SH signal when the optical vortex of each input field at the FF is displaced from the beam's axis. We obtain different spatial configurations of the SH field, always carrying the same zero angular momentum.

  20. Separated at Birth: Jet Maximization, Axis Minimization, and Stable Cone Finding

    OpenAIRE

    Thaler, Jesse

    2015-01-01

    Jet finding is a type of optimization problem, where hadrons from a high-energy collision event are grouped into jets based on a clustering criterion. As three interesting examples, one can form a jet cluster that (1) optimizes the overall jet four-vector, (2) optimizes the jet axis, or (3) aligns the jet axis with the jet four-vector. In this paper, we show that these three approaches to jet finding, despite being philosophically quite different, can be regarded as descendants of a mother op...

  1. SIKA—the multiplexing cold-neutron triple-axis spectrometer at ANSTO

    Science.gov (United States)

    Wu, C.-M.; Deng, G.; Gardner, J. S.; Vorderwisch, P.; Li, W.-H.; Yano, S.; Peng, J.-C.; Imamovic, E.

    2016-10-01

    SIKA is a new cold-neutron triple-axis spectrometer receiving neutrons from the cold source CG4 of the 20MW Open Pool Australian Light-water reactor. As a state-of-the-art triple-axis spectrometer, SIKA is equipped with a large double-focusing pyrolytic graphite monochromator, a multiblade pyrolytic graphite analyser and a multi-detector system. In this paper, we present the design, functions, and capabilities of SIKA, and discuss commissioning experimental results from powder and single-crystal samples to demonstrate its performance.

  2. Design verification and performance analysis of Serial AXI Links in Broadcom System-on-Chip

    OpenAIRE

    Sarai, Simran Kaur

    2014-01-01

    Design verification is an essential step in the development of any product. Also referred to as qualification testing, design verification ensures that the product as designed is the same as the product as intended. In this project, design verification and performance analysis of Thin Advanced Extensible Interface Links (T-AXI) is conducted on a Broadcom’s SoC (System on Chip). T-AXI is a Broadcom’s proprietary bus that interfaces all the subsystems on the System-onchip (SoC) to the system me...

  3. Increasing Plant Availability by Mechanical Checking of the Cement Rotary Kiln Axis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A periodic check of the cement rotary kiln axis is needed within the framework of preventive maintenance for maintaining high plant availability. The fourth generation “KAS-4” measuring system was developed by Wuhan University of Technology in 1999. The system can be carried out with rotating or stationary kiln plant. The same is true of the measurement of tire and supporting roller diameters, the clearance of tires, the position of rollers, the machining of tires and rollers, the slopes of roller surfaces, the deflection of gear, the axis of kiln. The system has been applied to the measurement for 10 sets of cement rotary kiln in China.

  4. MODELING AND COMPENSATION TECHNIQUE FOR THE GEOMETRIC ERRORS OF FIVE-AXIS CNC MACHINE TOOLS

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    One of the important trends in precision machining is the development of real-time error compensation technique.The error compensation for multi-axis CNC machine tools is very difficult and attractive.The modeling for the geometric error of five-axis CNC machine tools based on multi-body systems is proposed.And the key technique of the compensation-identifying geometric error parameters-is developed.The simulation of cutting workpiece to verify the modeling based on the multi-body systems is also considered.

  5. Research on the Unsteady Hydrodynamic Characteristics of Vertical Axis Tidal Turbine

    Institute of Scientific and Technical Information of China (English)

    张学伟; 张亮; 王峰; 赵东亚; 庞程燕

    2014-01-01

    The unsteady hydrodynamic characteristics of vertical axis tidal turbine are investigated by numerical simulation based on viscous CFD method. The starting mechanism of the turbine is revealed through analyzing the interaction of its motion and dynamics during starting process. The operating hydrodynamic characteristics of the turbine in wave-current condition are also explored by combining with the linear wave theory. According to possible magnification of the cyclic loads in the maximum power tracking control of vertical axis turbine, a novel torque control strategy is put forward, which can improve the structural characteristics significantly without effecting energy efficiency.

  6. [Application of story stems to the diagnosis of the axis "structure" of OPD-CA].

    Science.gov (United States)

    Weber, Matthias; Stadelmann, Stephanie

    2011-01-01

    The continued play of story stems, introduced by a diagnostician, can add to the diagnostic of the axis "structure" of the OPD-CA in a useful way. Story stems (e.g., the MacArthur Story Stem Battery (MSSB) or the Attachment Story Completion Task (ASCT)) are already used in different research fields and in the clinical context. In this article we propose the administration of story stems, which are supposed to represent certain mental skills. A case study will demonstrate the possibility to complement the evaluation of the axis "structure" by symbolic play with story stems.

  7. A Singular Limit Problem for Rotating Capillary Fluids with Variable Rotation Axis

    Science.gov (United States)

    Fanelli, Francesco

    2016-04-01

    In the present paper we study a singular perturbation problem for a Navier-Stokes-Korteweg model with Coriolis force. Namely, we perform the incompressible and fast rotation asymptotics simultaneously, while we keep the capillarity coefficient constant in order to capture surface tension effects in the limit. We consider here the case of variable rotation axis: we prove the convergence to a linear parabolic-type equation with variable coefficients. The proof of the result relies on compensated compactness arguments. Besides, we look for minimal regularity assumptions on the variations of the axis.

  8. Prenatal undernutrition and postnatal overnutrition alter thyroid hormone axis function in sheep

    DEFF Research Database (Denmark)

    Johnsen, Lærke; Kongsted, Anna Hauntoft; Nielsen, Mette Olaf

    2013-01-01

    -bearing sheep were fed one of two diets during late gestation: NORM (fulfilling energy and protein requirements) or LOW (50% of NORM). From day-3 to 6-months after birth (around puberty) the twin lambs were assigned to each their diet: conventional (CONV) or high-carbohydrate-high-fat (HCHF), where after half......Mounting evidence led us to hypothesize that: 1) function of the thyroid hormone (TH) axis can be programmed by late-gestation undernutrition (LG-UN), and 2) early-postnatal-life overnutrition (EL-ON) exacerbates the fetal impacts on TH-axis function. In a 2×2 factorial experiment, 21 twin...

  9. Cognition and HPA axis reactivity in mildly to moderately depressed outpatients. A case-control study

    DEFF Research Database (Denmark)

    Krogh, Jesper; Videbech, Poul; Renvillard, Signe Groth

    2012-01-01

    Background: Patients with depression display neurobiological changes of the hypothalamic-pituitary axis as well as cognitive disturbances. Aims: To assess any association between hypothalamus-pituitary-adrenal (HPA) axis reactivity and memory-related cognitive functions. Methods: Depressed......, a positive association between post-DST cortisol and Rey's Complex figure test (1.3; 95% CI 0.3-3.6; P =¿0.02) was found. We found no significant associations between other memory functions and cortisol measures. Conclusions: Contrary to our hypothesis, we found a positive association between cortisol levels...

  10. Overview and Design of self-acting pitch control mechanism for vertical axis wind turbine using multi body simulation approach

    DEFF Research Database (Denmark)

    Chougule, Prasad; Nielsen, Søren R.K.

    2014-01-01

    problem of self-start inability and has low power coefficient as compare to the horizontal axis wind turbine. These two problems can be eliminated by incorporating the blade pitching mechanism. So, in this paper overview of various pitch control systems is discussed and design of self-acting pitch...... wind turbines are suitable for high wind speed whereas vertical axis wind turbines operate relatively low wind speed area. Vertical axis wind turbines are cost effective and simple in construction as compared to the horizontal axis wind turbine. However, vertical axis wind turbines have inherent...... mechanism is given. A pitch control linkage mechanism for vertical axis wind turbine is modeled by multi-body approach using MSC Software. Aerodynamic loads are predicted from a mathematical model based on double multiple stream tube method. An appropriate airfoil which works at low Reynolds number...

  11. A Miniature Magnetic-Force-Based Three-Axis AC Magnetic Sensor with Piezoelectric/Vibrational Energy-Harvesting Functions

    Science.gov (United States)

    Hung, Chiao-Fang; Yeh, Po-Chen; Chung, Tien-Kan

    2017-01-01

    In this paper, we demonstrate a miniature magnetic-force-based, three-axis, AC magnetic sensor with piezoelectric/vibrational energy-harvesting functions. For magnetic sensing, the sensor employs a magnetic–mechanical–piezoelectric configuration (which uses magnetic force and torque, a compact, single, mechanical mechanism, and the piezoelectric effect) to convert x-axis and y-axis in-plane and z-axis magnetic fields into piezoelectric voltage outputs. Under the x-axis magnetic field (sine-wave, 100 Hz, 0.2–3.2 gauss) and the z-axis magnetic field (sine-wave, 142 Hz, 0.2–3.2 gauss), the voltage output with the sensitivity of the sensor are 1.13–26.15 mV with 8.79 mV/gauss and 1.31–8.92 mV with 2.63 mV/gauss, respectively. In addition, through this configuration, the sensor can harness ambient vibrational energy, i.e., possessing piezoelectric/vibrational energy-harvesting functions. Under x-axis vibration (sine-wave, 100 Hz, 3.5 g) and z-axis vibration (sine-wave, 142 Hz, 3.8 g), the root-mean-square voltage output with power output of the sensor is 439 mV with 0.333 μW and 138 mV with 0.051 μW, respectively. These results show that the sensor, using this configuration, successfully achieves three-axis magnetic field sensing and three-axis vibration energy-harvesting. Due to these features, the three-axis AC magnetic sensor could be an important design reference in order to develop future three-axis AC magnetic sensors, which possess energy-harvesting functions, for practical industrial applications, such as intelligent vehicle/traffic monitoring, processes monitoring, security systems, and so on. PMID:28208693

  12. A Miniature Magnetic-Force-Based Three-Axis AC Magnetic Sensor with Piezoelectric/Vibrational Energy-Harvesting Functions.

    Science.gov (United States)

    Hung, Chiao-Fang; Yeh, Po-Chen; Chung, Tien-Kan

    2017-02-08

    In this paper, we demonstrate a miniature magnetic-force-based, three-axis, AC magnetic sensor with piezoelectric/vibrational energy-harvesting functions. For magnetic sensing, the sensor employs a magnetic-mechanical-piezoelectric configuration (which uses magnetic force and torque, a compact, single, mechanical mechanism, and the piezoelectric effect) to convert x-axis and y-axis in-plane and z-axis magnetic fields into piezoelectric voltage outputs. Under the x-axis magnetic field (sine-wave, 100 Hz, 0.2-3.2 gauss) and the z-axis magnetic field (sine-wave, 142 Hz, 0.2-3.2 gauss), the voltage output with the sensitivity of the sensor are 1.13-26.15 mV with 8.79 mV/gauss and 1.31-8.92 mV with 2.63 mV/gauss, respectively. In addition, through this configuration, the sensor can harness ambient vibrational energy, i.e., possessing piezoelectric/vibrational energy-harvesting functions. Under x-axis vibration (sine-wave, 100 Hz, 3.5 g) and z-axis vibration (sine-wave, 142 Hz, 3.8 g), the root-mean-square voltage output with power output of the sensor is 439 mV with 0.333 μW and 138 mV with 0.051 μW, respectively. These results show that the sensor, using this configuration, successfully achieves three-axis magnetic field sensing and three-axis vibration energy-harvesting. Due to these features, the three-axis AC magnetic sensor could be an important design reference in order to develop future three-axis AC magnetic sensors, which possess energy-harvesting functions, for practical industrial applications, such as intelligent vehicle/traffic monitoring, processes monitoring, security systems, and so on.

  13. 3Dwheel: 3-axis low-noise, high-bandwidth attitude actuation from a single momentum wheel using magnetic bearings.

    OpenAIRE

    Seddon, Jon; Pechev, Alexandre

    2009-01-01

    This paper proposes a new concept for attitude actuation for small satellites that uses active magnetic bearings to support and tilt a spinning rotor to provide 3-axis attitude control of the satellite using a single actuator. A controlled 3D motion in the spinning rotor provides a conventional torque output about the momentum axis and a gyroscopic torque output about any direction in the plane normal to the spinning axis. Therefore, a single tilting momentum-wheel can generate torque along t...

  14. INTERFERENCE-FREE TOOL POSTURE GENERATION FOR 5-AXIS NC MILLING FREE-FORM SURFACES WITH CYLINDRICAL MILL

    Institute of Scientific and Technical Information of China (English)

    Chen Liping; Chen Yan; Hu Dejin

    2004-01-01

    The 5-axis NC machining offers the potential of efficient and accurate machining. However, the present CAM system for 5-axis control is still an unsolved problem due to interference between tool and surrounding objects. A new method is presented. There are two steps in this procedure. First, it detects the interference by calculating the shortest distance between the tool-axis and the surrounding surfaces. Then upon the maximum gouging, the interference-free tool posture for 5-axis NC cylindrical milling free-form surfaces is obtained by adjusting tool. The validity of the proposed method has been confirmed by machining an impeller.

  15. Impact of Sleep and Its Disturbances on Hypothalamo-Pituitary-Adrenal Axis Activity

    Directory of Open Access Journals (Sweden)

    Marcella Balbo

    2010-01-01

    Full Text Available The daily rhythm of cortisol secretion is relatively stable and primarily under the influence of the circadian clock. Nevertheless, several other factors affect hypothalamo-pituitary-adrenal (HPA axis activity. Sleep has modest but clearly detectable modulatory effects on HPA axis activity. Sleep onset exerts an inhibitory effect on cortisol secretion while awakenings and sleep offset are accompanied by cortisol stimulation. During waking, an association between cortisol secretory bursts and indices of central arousal has also been detected. Abrupt shifts of the sleep period induce a profound disruption in the daily cortisol rhythm, while sleep deprivation and/or reduced sleep quality seem to result in a modest but functionally important activation of the axis. HPA hyperactivity is clearly associated with metabolic, cognitive and psychiatric disorders and could be involved in the well-documented associations between sleep disturbances and the risk of obesity, diabetes and cognitive dysfunction. Several clinical syndromes, such as insomnia, depression, Cushing's syndrome, sleep disordered breathing (SDB display HPA hyperactivity, disturbed sleep, psychiatric and metabolic impairments. Further research to delineate the functional links between sleep and HPA axis activity is needed to fully understand the pathophysiology of these syndromes and to develop adequate strategies of prevention and treatment.

  16. Euclidean skeletons of 3D data sets in linear time by the integer medial axis transform

    NARCIS (Netherlands)

    Hesselink, Wim H.; Visser, Menno; Roerdink, Jos B.T.M.; Ronse, C; Najman, L; Decenciere, E

    2005-01-01

    A general algorithm for computing Euclidean skeletons of 3D data sets in linear time is presented. These skeletons are defined in terms of a new concept, called the integer medial axis (IMA) transform. The algorithm is based upon the computation of 3D feature transforms, using a modification of an a

  17. Use of a Two-Axis Joystick for Control of Externally Powered, Shoulder Disarticulation Prostheses

    Science.gov (United States)

    Lipschutz, Robert D.; Lock, Blair; Sensinger, Jonathon; Schultz, Aimee E.; Kuiken, Todd A.

    2015-01-01

    We explored a new method for simple and accurate control of shoulder movement for externally powered shoulder disarticulation prostheses using a two-axis joystick. Ten subjects with intact shoulders and arms were tested to determine the average amount of shoulder motion and force available for control of an electronic input device. This information was then applied to two different input strategies in order to examine their effectiveness: (1) a traditional strategy implemented with a rocker potentiometer and a pair of force-sensing resistors (FSRs), and (2) a strategy implemented with a two-axis joystick. Three able-bodied subjects and two subjects with shoulder disarticulation amputations attempted to control an experimental powered shoulder using both control strategies. Two powered arms were tested, one with powered flexion/extension and humeral rotation, and one with powered flexion/extension and adduction/abduction. Overwhelmingly, the subjects preferred the joystick control, as it was more intuitively linked with their shoulder movement. Additionally, two motions (one in each axis) could be controlled simultaneously. This pilot study provides valuable insight into an effective means of controlling high-level, externally powered prostheses via a two-axis joystick. PMID:21938653

  18. Role of the insulin-like growth factor 1 axis and visceral adiposity in oesophageal adenocarcinoma.

    LENUS (Irish Health Repository)

    Donohoe, C L

    2012-03-01

    Epidemiological studies have linked obesity with many cancers. The insulin-like growth factor (IGF) 1 axis may be an important mediator in obesity-associated cancer. This study examined the relationship between IGF-1 and its receptor (IGF-1R) in oesophageal adenocarcinoma, a cancer strongly linked to obesity.

  19. Glucocorticoid receptor gene methylation and HPA-axis regulation in adolescents. The TRAILS study.

    Science.gov (United States)

    van der Knaap, Lisette J; Oldehinkel, Albertine J; Verhulst, Frank C; van Oort, Floor V A; Riese, Harriëtte

    2015-08-01

    Early life adversity and psychopathology are thought to be linked through HPA-axis deregulation. Changes in methylation levels of stress reactivity genes such as the glucocorticoid receptor gene (NR3C1) can be induced by adversity. Higher NR3C1 methylation levels have been associated with a reduced NR3C1 expression, possibly leading to impaired negative feedback regulation of the HPA-axis. In this study we tested whether methylation levels of NR3C1 were associated with HPA-axis regulation, operationalized as cortisol responses. In 361 adolescents (mean age 16.1, SD=0.6), salivary cortisol samples were collected before, during, and after a social stress task, from which response measures (cortisol activation and recovery) were calculated. Higher NR3C1 methylation levels were associated with a flattened cortisol recovery slope, indicating a delayed recovery time. Cortisol response activation was not associated with NR3C1 methylation. These results suggest that methylation of NR3C1 may impair negative feedback of the HPA-axis in adolescents.

  20. HPA-Axis Activation as a Key Moderator of Childhood Trauma Exposure and Adolescent Mental Health.

    Science.gov (United States)

    Kuhlman, Kate R; Geiss, Elisa G; Vargas, Ivan; Lopez-Duran, Nestor

    2017-02-18

    Individual differences in a child's sensitivity to stress may influence whether youth exposed to trauma develop symptoms of psychopathology. We examined the interaction between HPA-axis reactivity to an acute stressor and exposure to different types of childhood trauma as predictors of mental health symptoms in a sample of youth. Youth (n = 121, ages 9-16; 47% female) completed a standardized stress task, including 5 post-stress salivary cortisol samples. Parents also completed the Child Behavior Checklist as a measure of child internalizing and externalizing symptoms in the past month, and completed the Early Trauma Inventory (ETI) as a measure of their child's trauma exposure. More emotional abuse and non-intentional trauma were associated with greater internalizing symptoms. Youth exposed to physical abuse who demonstrated slower HPA-axis reactivity had elevated internalizing and externalizing symptoms. Youth exposed to emotional abuse or non-intentional traumatic events who demonstrated faster HPA-axis reactivity had elevated internalizing and externalizing symptoms. Profiles of exaggerated or attenuated HPA-axis reactivity to acute stress may be risk factors for psychopathology in children facing different stressful social environments.

  1. In Search of HPA Axis Dysregulation in Child and Adolescent Depression

    Science.gov (United States)

    Guerry, John D.; Hastings, Paul D.

    2011-01-01

    Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis in adults with major depressive disorder is among the most consistent and robust biological findings in psychiatry. Given the importance of the adolescent transition to the development and recurrence of depressive phenomena over the lifespan, it is important to have an integrative…

  2. Dynamics of the HPA axis and inflammatory cytokines: Insights from mathematical modeling.

    Science.gov (United States)

    Malek, Hamed; Ebadzadeh, Mohammad Mehdi; Safabakhsh, Reza; Razavi, Alireza; Zaringhalam, Jalal

    2015-12-01

    In the work presented here, a novel mathematical model was developed to explore the bi-directional communication between the hypothalamic-pituitary-adrenal (HPA) axis and inflammatory cytokines in acute inflammation. The dynamic model consists of five delay differential equations 5D for two main pro-inflammatory cytokines (TNF-α and IL-6) and two hormones of the HPA axis (ACTH and cortisol) and LPS endotoxin. The model is an attempt to increase the understanding of the role of primary hormones and cytokines in this complex relationship by demonstrating the influence of different organs and hormones in the regulation of the inflammatory response. The model captures the main qualitative features of cytokine and hormone dynamics when a toxic challenge is introduced. Moreover, in this work a new simple delayed model of the HPA axis is introduced which supports the understanding of the ultradian rhythm of HPA hormones both in normal and infection conditions. Through simulations using the model, the role of key inflammatory cytokines and cortisol in transition from acute to persistent inflammation through stability analysis is investigated. Also, by employing a Markov chain Monte Carlo (MCMC) method, parameter uncertainty and the effects of parameter variations on each other are analyzed. This model confirms the important role of the HPA axis in acute and prolonged inflammation and can be a useful tool in further investigation of the role of stress on the immune response to infectious diseases.

  3. Activation of the Hypothalamic-Pituitary-Adrenal (HPA) Axis Following Extended Exposure to Atrazine (ATR)###

    Science.gov (United States)

    While it is known that adrenal steroids impact reproduction and a variety of other physiological and behavioral functions, disruption of the HPA-axis is not typically considered in toxicological studies. Here we characterize changes in basal corticosterone (CORT) and progesterone...

  4. Activation of the Hypothalamic-Pituitary-Adrenal (HPA) Axis Following Extended Exposure to Atrazine (ATR)

    Science.gov (United States)

    While it is known that adrenal steroids impact reproduction and a variety of other physiological and behavioral fimctions, disruption of the HPA-axis is not typically considered in toxicological studies. Here we characterize changes in basal corticosterone (CORT) and progesterone...

  5. Kalman filter based data fusion for neutral axis tracking in wind turbine towers

    DEFF Research Database (Denmark)

    Soman, Rohan; Malinowski, Pawel; Ostachowicz, Wieslaw;

    2015-01-01

    downtime, hence increasing the availability of the system. The present work is based on the use of neutral axis (NA) for SHM of the structure. The NA is tracked by data fusion of measured yaw angle and strain through the use of Extended Kalman Filter (EKF). The EKF allows accurate tracking even...

  6. Analysis of soybean embryonic axis proteins by two-dimensional gel electrophoresis and mass spectrometry

    Science.gov (United States)

    A proteomic approach based on two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) for protein separation and subsequent mass spectrometry (MS) for protein identification was applied to establish a proteomic reference map for the soybean embryonic axis. Proteins were extracted from dissecte...

  7. Theta variation and spatiotemporal scaling along the septotemporal axis of the hippocampus

    Directory of Open Access Journals (Sweden)

    Lauren L Long

    2015-03-01

    Full Text Available Hippocampal theta has been related to locomotor speed, attention, anxiety, sensorimotor integration and memory among other emergent phenomena. One difficulty in understanding the function of theta is that the hippocampus (HPC modulates voluntary behavior at the same time that it processes sensory input. Both functions are correlated with characteristic changes in theta indices. The current review highlights a series of studies examining theta local field potential (LFP signals across the septotemporal or longitudinal axis of the HPC. While the theta signal is coherent throughout the entirety of the HPC, the amplitude, but not the frequency, of theta varies significantly across its three-dimensional expanse. We suggest that the theta signal offers a rich vein of information about how distributed neuronal ensembles support emergent function. Further, we speculate that emergent function across the long axis varies with respect to spatiotemporal scale. Thus, septal hippocampus processes details of the proximal spatiotemporal environment while more temporal aspects process larger spaces and wider time-scales. The degree to which emergent functions are supported by the synchronization of theta across the septotemporal axis is an open question. Our working model is that theta synchrony serves to bind ensembles representing varying resolutions of spatiotemporal information at interdependent septotemporal areas of the HPC. Such synchrony and cooperative interactions along the septotemporal axis likely support memory formation and subsequent consolidation and retrieval.

  8. Paleomagnetic investigation of late Neogene vertical axis rotation and remagnetization in central coastal California

    Science.gov (United States)

    Horns, Daniel M.; Verosub, Kenneth L.

    1995-03-01

    Outcrops of shallow marine sedimentary rocks of the Neogene Purisima Formation and Santa Cruz Mudstone occur throughout the Santa Cruz Mountains and along the coast of Santa Cruz and San Mateo counties in California. Within the Santa Cruz Mountains, the Purisima Formation has been extensively folded and offset by reverse faults. Along the coast, the Purisima Formation and Santa Cruz Mudstone are only gently folded although the Purisima Formation is cut by the San Gregorio Fault Zone. Previous paleomagnetic studies have shown that vertical axis rotation has occurred within some parts of the San Gregorio Fault Zone. As part of a kinematic study of the San Gregorio Fault Zone, this paleomagnetic investigation of the Purisima Formation and Santa Cruz Mudstone was conducted to determine the extent of the vertical axis rotation. The characteristic paleomagnetic directions of the Purisima Formation and Santa Cruz Mudstone, which we interpret as the primary directions, indicate that a clockwise vertical axis rotation of 35 deg to 60 deg has occurred throughout the San Gregorio Zone, whereas no rotation has occurred away from the fault zone. This result suggests that vertical axis rotation is fundamentally related to shear across the San Gregorio Fault Zone. Our work also indicates that while the Purisima Formation and Santa Cruz Mudstone along the coast have retained their primary magnetizations, the Purisima Formation within the Santa Cruz Mountains has been remagnetized after folding.

  9. Light curves and spectra from off-axis gamma-ray burst single pulses

    CERN Document Server

    Salafia, Om S; Pescalli, Alessio; Ghirlanda, Giancarlo; Nappo, Francesco

    2016-01-01

    We set up a simple model to compute the bolometric light curve and time dependent spectrum of a single pulse of a Gamma-Ray Burst under the assumption that the pulse rise and decay are dominated by the shell curvature effect. For the first time, our model includes the effect of an arbitrary off-axis viewing angle. We show that a pulse observed off-axis is (i) longer, (ii) softer and (iii) displays a different hardness-intensity correlation with respect to the same pulse seen on-axis. For each of these effects, we provide an intuitive physical explanation. We then show how a synthetic light curve made by a superposition of pulses changes with increasing viewing angle. We find that many observed properties found in time-resolved spectral analysis of Gamma-Ray Burst light curves are reproduced in curves with a slightly off-axis viewing angle. Such properties include the fact that the spectral peak energy evolution tracks the variations in flux, leading them slightly. Based on these results, we argue that low lum...

  10. Creating a benchmark of vertical axis wind turbines in dynamic stall for validating numerical models

    DEFF Research Database (Denmark)

    Castelein, D.; Ragni, D.; Tescione, G.;

    2015-01-01

    An experimental campaign using Particle Image Velocimetry (2C-PIV) technique has been conducted on a H-type Vertical Axis Wind Turbine (VAWT) to create a benchmark for validating and comparing numerical models. The turbine is operated at tip speed ratios (TSR) of 4.5 and 2, at an average chord-ba...

  11. Polymorphisms in the insulin-like growth factor axis are associated with gastrointestinal cancer

    NARCIS (Netherlands)

    Ong, J.; Salomon, J.; Morsche, R.H.M. te; Roelofs, H.M.J.; Witteman, B.J.; Dura, P.; Lacko, M.; Peters, W.H.M.

    2014-01-01

    INTRODUCTION: Numerous factors influence the development of gastrointestinal (GI) cancer. The insulin-like growth factor (IGF) axis plays a role in embryonic and postnatal growth and tissue repair. Elevated levels of IGFs, low levels of IGF binding proteins (IGFBPs) and over-expression of IGF recept

  12. Traveltime approximations for inhomogeneous transversely isotropic media with a horizontal symmetry axis

    KAUST Repository

    Alkhalifah, Tariq Ali

    2012-04-30

    Traveltime information is crucial for parameter estimation, especially if the medium is described by a set of anisotropy parameters. We can efficiently estimate these parameters if we are able to relate them analytically to traveltimes, which is generally hard to do in inhomogeneous media. I develop traveltime approximations for transversely isotropic media with a horizontal symmetry axis (HTI) as simplified and even linear functions of the anisotropy parameters. This is accomplished by perturbing the solution of the HTI eikonal equation with respect to the anellipticity parameter, η and the azimuth of the symmetry axis (typically associated with the fracture direction) from a generally inhomogeneous, elliptically anisotropic background medium. Such a perturbation is convenient since the elliptically anisotropic information might be obtained from well velocities in HTI media. Thus, we scan for only η and the symmetry-axis azimuth. The resulting approximations can provide a reasonably accurate analytical description of the traveltime in a homogenous background compared to other published moveout equations. They also help extend the inhomogenous background isotropic or elliptically anisotropic models to an HTI one with a smoothly variable η and symmetry-axis azimuth. © 2012 European Association of Geoscientists & Engineers.

  13. Design galvanometer position detection unit based on single detector compound axis tracking system

    Science.gov (United States)

    Liu, Yang; Tong, Shoufeng; Song, Yansong; Chang, Shuai; Gao, Yinan; Zhao, Kewei

    2016-10-01

    The fine tracking unit of composite axis of acquisition, pointing and tracking(APT) is a key component of space laser communication system. In order to prevent the principal axis in open-loop without proper input of control after started the tracking of auxiliary axis, which led to the target out of field. In a single detector composite shaft structure, we need to provide the accurate position of PZT volume feedback for the principle axis to control. This article has made an galvanometer position detective method of the single detector composite shaft structure. It provided the theory of circuit design and optimization plan. Researchers conducted a multiple sets of experiments. The experimental result shows that the galvanometer 1 "per deflection Angle, the detection circuit can retrieve 13 mV voltage change. At the same time, compared with the traditional camera calibration, we put forward a new calibration method which using optical autocollimator that the maximum error control within 1 ". Finally, the control formula is given and the error should be within 0.01mrad. So that the calibration precision of the detecting plate is improved.

  14. VOLUMETRIC ERROR COMPENSATION IN FIVE-AXIS CNC MACHINING CENTER THROUGH KINEMATICS MODELING OF GEOMETRIC ERROR

    Directory of Open Access Journals (Sweden)

    Pooyan Vahidi Pashsaki

    2016-06-01

    Full Text Available Accuracy of a five-axis CNC machine tool is affected by a vast number of error sources. This paper investigates volumetric error modeling and its compensation to the basis for creation of new tool path for improvement of work pieces accuracy. The volumetric error model of a five-axis machine tool with the configuration RTTTR (tilting head B-axis and rotary table in work piece side A΄ was set up taking into consideration rigid body kinematics and homogeneous transformation matrix, in which 43 error components are included. Volumetric error comprises 43 error components that can separately reduce geometrical and dimensional accuracy of work pieces. The machining accuracy of work piece is guaranteed due to the position of the cutting tool center point (TCP relative to the work piece. The cutting tool is deviated from its ideal position relative to the work piece and machining error is experienced. For compensation process detection of the present tool path and analysis of the RTTTR five-axis CNC machine tools geometrical error, translating current position of component to compensated positions using the Kinematics error model, converting newly created component to new tool paths using the compensation algorithms and finally editing old G-codes using G-code generator algorithm have been employed.

  15. High Resolution Triple Axis X-Ray Diffraction Analysis of II-VI Semiconductor Crystals

    Science.gov (United States)

    Volz, H. M.; Matyi, R. J.

    1999-01-01

    The objective of this research program is to develop methods of structural analysis based on high resolution triple axis X-ray diffractometry (HRTXD) and to carry out detailed studies of defect distributions in crystals grown in both microgravity and ground-based environments. HRTXD represents a modification of the widely used double axis X-ray rocking curve method for the characterization of grown-in defects in nearly perfect crystals. In a double axis rocking curve experiment, the sample is illuminated by a monochromatic X-ray beam and the diffracted intensity is recorded by a fixed, wide-open detector. The intensity diffracted by the sample is then monitored as the sample is rotated through the Bragg reflection condition. The breadth of the peak, which is often reported as the full angular width at half the maximum intensity (FWHM), is used as an indicator of the amount of defects in the sample. This work has shown that high resolution triple axis X-ray diffraction is an effective tool for characterizing the defect structure in semiconductor crystals, particularly at high defect densities. Additionally, the technique is complimentary to X-ray topography for defect characterization in crystals.

  16. Bile acids modulate glucocorticoid metabolism and the hypothalamic-pituitary-adrenal axis in obstructive jaundice

    DEFF Research Database (Denmark)

    McNeilly, Alison D; Macfarlane, David P; O'Flaherty, Emmett

    2010-01-01

    Suppression of the hypothalamic-pituitary-adrenal axis occurs in cirrhosis and cholestasis and is associated with increased concentrations of bile acids. We investigated whether this was mediated through bile acids acting to impair steroid clearance by inhibiting glucocorticoid metabolism by 5beta-reductase....

  17. The microbiota-gut-brain axis and its potential therapeutic role in autism spectrum disorder.

    Science.gov (United States)

    Li, Q; Zhou, J-M

    2016-06-02

    Autism spectrum disorder (ASD) is a series of neurodevelopmental disorders that are characterized by deficits in both social and cognitive functions. Although the exact etiology and pathology of ASD remain unclear, a disorder of the microbiota-gut-brain axis is emerging as a prominent factor in the generation of autistic behaviors. Clinical studies have shown that gastrointestinal symptoms and compositional changes in the gut microbiota frequently accompany cerebral disorders in patients with ASD. A disturbance in the gut microbiota, which is usually induced by a bacterial infection or chronic antibiotic exposure, has been implicated as a potential contributor to ASD. The bidirectional microbiota-gut-brain axis acts mainly through neuroendocrine, neuroimmune, and autonomic nervous mechanisms. Application of modulators of the microbiota-gut-brain axis, such as probiotics, helminthes and certain special diets, may be a promising strategy for the treatment of ASD. This review mainly discusses the salient observations of the disruptions of the microbiota-gut-brain axis in the pathogenesis of ASD and reveals its potential therapeutic role in autistic deficits.

  18. Fast phase processing in off-axis holography by CUDA including parallel phase unwrapping.

    Science.gov (United States)

    Backoach, Ohad; Kariv, Saar; Girshovitz, Pinhas; Shaked, Natan T

    2016-02-22

    We present parallel processing implementation for rapid extraction of the quantitative phase maps from off-axis holograms on the Graphics Processing Unit (GPU) of the computer using computer unified device architecture (CUDA) programming. To obtain efficient implementation, we parallelized both the wrapped phase map extraction algorithm and the two-dimensional phase unwrapping algorithm. In contrast to previous implementations, we utilized unweighted least squares phase unwrapping algorithm that better suits parallelism. We compared the proposed algorithm run times on the CPU and the GPU of the computer for various sizes of off-axis holograms. Using the GPU implementation, we extracted the unwrapped phase maps from the recorded off-axis holograms at 35 frames per second (fps) for 4 mega pixel holograms, and at 129 fps for 1 mega pixel holograms, which presents the fastest processing framerates obtained so far, to the best of our knowledge. We then used common-path off-axis interferometric imaging to quantitatively capture the phase maps of a micro-organism with rapid flagellum movements.

  19. Rotation Angle for the Optimum Tracking of One-Axis Trackers

    Energy Technology Data Exchange (ETDEWEB)

    Marion, W. F.; Dobos, A. P.

    2013-07-01

    An equation for the rotation angle for optimum tracking of one-axis trackers is derived along with equations giving the relationships between the rotation angle and the surface tilt and azimuth angles. These equations are useful for improved modeling of the solar radiation available to a collector with tracking constraints and for determining the appropriate motor revolutions for optimum tracking.

  20. Two-axis hydraulic joint for high speed, heavy lift robotic operations

    Energy Technology Data Exchange (ETDEWEB)

    Vaughn, M.R.; Robinett, R.D.; Phelan, J.R.; VanZuiden, D.M.

    1994-04-01

    A hydraulically driven universal joint was developed for a heavy lift, high speed nuclear waste remediation application. Each axis is driven by a simple hydraulic cylinder controlled by a jet pipe servovalve. Servovalve behavior is controlled by a force feedback control system, which damps the hydraulic resonance. A prototype single joint robot was built and tested. A two joint robot is under construction.