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Sample records for peripheral primitive neuroectodermal

  1. Peripheral facial palsy, the only presentation of a primitive neuroectodermal tumor of the skull base

    PubMed Central

    Kim, Hyung Jin; Kang, Ben; Joo, Eun Young; Kim, Eun Young; Kwon, Young Se

    2015-01-01

    Introduction Peripheral facial palsy is rarely caused by primary neoplasms, which are mostly constituted of tumors of the central nervous system, head and neck, and leukemia. Presentation of case A 2-month-old male infant presented with asymmetric facial expression for 3 weeks. Physical examination revealed suspicious findings of right peripheral facial palsy. Computed tomography of the temporal bone revealed a suspicious bone tumor centered in the right petrous bone involving surrounding bones with extension into the middle ear cavity and inner ear. Subtotal resection of the tumor was performed due to crucial structures adjacent the mass. Histopathology and immunohistochemistry of the resected tumor was consistent with primitive neuroectodermal tumor. Conclusion We report a rare case of a primitive neuroectodermal tumor located at the skull base presenting with only peripheral facial palsy. PMID:26710328

  2. A peripheral primitive neuroectodermal tumor in the larynx: A case report and literature review

    PubMed Central

    IJICHI, KEI; TSUZUKI, TOYONORI; ADACHI, MAKOTO; MURAKAMI, SHINGO

    2016-01-01

    Primitive neuroectodermal tumors (PNETs) are malignant tumors comprised of small round cells of neuroectodermal origin. Current evidence indicates that peripheral PNETs (pPNETs), which arise in the non-central nervous system, possess histological similarity to Ewing's sarcoma. Though the occurrence of pPNETs in the head and neck region is rare, these are aggressive malignant tumors, and long-term survival rates following diagnosis remain poor. The current report presents a case of pPNET and evaluates its significance with regard to previous studies. In the present case, a tumor was located in the larynx of the patient, and was diagnosed as pPNET. Immunohistochemical analysis indicated that tumor cells were positive for cluster of differentiation 99. The patient was treated with surgery, multiagent chemotherapy and radiotherapy. Five years subsequent to treatment, the patient had survived and demonstrated no evidence of disease recurrence. In existing literature concerning pPNET located outside the head and neck region, it is recommended that patients are treated with a combination of resection with a wide surgical margin, multiagent chemotherapy and radiotherapy. The present case report concluded that the combination of surgery, systematic chemotherapy and radiotherapy, offers an improved outcome for pPNET localized to the head and neck region, compared with any of these therapies alone. PMID:26893703

  3. Peripheral primitive neuroectodermal tumor/Ewing's sarcoma of the craniospinal vault: case reports and review.

    PubMed

    Mobley, Bret C; Roulston, Diane; Shah, Gaurang V; Bijwaard, Karen E; McKeever, Paul E

    2006-07-01

    The peripheral primitive neuroectodermal tumor/Ewing's sarcoma family tumor (pPNET/ESFT) group includes small round cell tumors of the bone, soft tissue, and nerve with morphological attributes of the germinal neuroepithelium. Peripheral PNETs/ESFTs also occur within the craniospinal vault, a region including the central nervous system, the meninges, and the cranial and spinal nerve roots. Gene rearrangements between the EWS gene on chromosome 22q12 and members of the ETS gene family are common in and specific to pPNETs/ESFTs. Another defining characteristic of pPNETs/ESFTs is their membranous expression of the MIC2 gene product. We describe 2 cases of pPNETs within the craniospinal vault. An intradural tumor arising from the nerve roots of the cauda equina was discovered in a 32-year-old man presenting with radiculopathic back pain and lower-extremity weakness. An intracranial pPNET that mimicked a meningioma was found in a 21-year-old man presenting with headache and visual disturbances. MIC2 gene product expression and EWS/ETS gene rearrangement were detected in both case patients. The literature with regard to pPNETs/ESFTs arising within the craniospinal vault is reviewed.

  4. Synthetic treatment of intracranial peripheral primitive neuroectodermal tumor with multiple metastasis: a case report

    PubMed Central

    Zhang, Yang; Li, Hongsheng; Li, Zongjuan; Liu, Ming; Yang, Linke; Fan, Liyuan; Huang, Chengsuo; Li, Baosheng

    2016-01-01

    Ewing sarcomas (ES) and peripheral primitive neuroectodermal tumors (pPNET) are now thought to belong to the same tumor family. Ewing sarcoma family tumor (ESFT) members commonly originate in bones and soft tissues. However, a few published articles describe ESFT arising from cranial cavities. Pathologically, ES/pPNET are composed of small round cells. Unambiguous distinction between pPNET and other small round cell tumors, in particular central PNET, is of clinical significance. Definitive diagnoses of pPNET can be obtained through CD99 (MIC2 gene product) membrane positivities and molecular identifications of chromosomal rearrangements between EWS and ETS family genes. Multimodal approaches comprising surgical resections, radiotherapies, and chemotherapies are required for the treatment of ESFT. Decompressive medical measures are preferentially performed when epidural masses are compressing spinal cords. In cases of ES-induced brain herniations, emergent radiotherapies may serve as effective tools. We report a case of multiple disseminated intracranial ES/pPNET for which synthetic treatments were used. PMID:27330312

  5. [A case report of Ewing's sarcoma with a peripheral primitive neuroectodermal tumor (ES/pPNET) in the abdominal cavity].

    PubMed

    Takahashi, Hiroki; Chida, Nobuyuki; Kimura, Kenji; Yamao, Yoko; Shiotuka, Kaori; Ritsuno, Hideaki; Awabuchi, Satoshi; Akoshima, Hiromichi; Sugimura, Mikako; Noguchi, Kenji; Tanabe, Nobukazu; Iwabuchi, Masahiro; Mano, Yutaka; Tadokoro, Keiichi; Suzuki, Hiroyoshi

    2009-10-01

    In this report, we present a rare case of Ewing's sarcoma with a peripheral primitive neuroectodermal tumor (ES/pPNET) arising from the abdominal cavity in a 20-year-old woman. The patient complained of upper abdominal pain. Radiological imaging showed a 15-cm mass penetrating to the proxymal jejunum in the upper abdominal cavity and peritoneal disseminations. Immunohistochemical studies revealed that the tumor was ES/pPNET. Although the patient underwent radiation therapy, she died of the disease two months after diagnosis. ES/pPNET in the abdominal cavity is extremely rare and our case showed aggressive behavior and an unfortunate outcome.

  6. Huge peripheral primitive neuroectodermal tumor of the small bowel mesentery at nonage: A case report and review of the literature.

    PubMed

    Liu, Zhe; Xu, Yuan-Hong; Ge, Chun-Lin; Long, Jin; Du, Rui-Xia; Guo, Ke-Jian

    2016-09-16

    Extraskeletal Ewing's sarcoma/peripheral primitive neuroectodermal tumor (E-EWS/pPNET) is a rare aggressive malignant small round cell tumor. In this report, we present the case of a 15-year-old boy who suffered from acute abdominal pain accompanied by hematemesis and melena, and was eventually diagnosed with E-EWS/pPNET. To date, there have been only five reported cases of E-EWS/pPNET of the small bowel including the patient in this report. To the best of our knowledge, this is the first documentation of a pPNET of the small bowel mesentery at nonage. All these have made this report rare and significant. PMID:27672649

  7. Cervicomedullary intramedullary peripheral primitive neuroectodermal tumor with intratumoral bleed: Report of one case and review of literature

    PubMed Central

    Sharma, Pradeep; Das, Kuntal K; Mehrotra, Anant; Srivastava, Arun K; Sahu, Rabi N; Jaiswal, Awadhesh; Pandey, Rakesh; Behari, Sanjay; Bhaisora, Kamlesh S; Sardhara, Jayesh

    2016-01-01

    Primitive neuroectodermal tumors (PNET) are highly malignant, yet relatively uncommon neoplasms of the central nervous system. Although a host of different parts of the nervous system can be affected, intramedullary location of PNET is extremely rare. Most reports on intramedullary PNET have reported central PNET (cPNET); peripheral PNET (pPNET) affecting intramedullary spinal location is extremely rare. Till now, seven such cases of intramedullary pPNET have been described in medical literature in English. Here, we report an 11-year-old boy with cervicomedullary junction intramedullary pPNET who presented with intratumoral bleed, wherein the clinical presentation and radiological features gave us no clue preoperatively about the underlying diagnosis. In this report, we additionally review certain salient aspects of this dreaded disease in light of the existing evidence. PMID:27217659

  8. Huge peripheral primitive neuroectodermal tumor of the small bowel mesentery at nonage: A case report and review of the literature

    PubMed Central

    Liu, Zhe; Xu, Yuan-Hong; Ge, Chun-Lin; Long, Jin; Du, Rui-Xia; Guo, Ke-Jian

    2016-01-01

    Extraskeletal Ewing’s sarcoma/peripheral primitive neuroectodermal tumor (E-EWS/pPNET) is a rare aggressive malignant small round cell tumor. In this report, we present the case of a 15-year-old boy who suffered from acute abdominal pain accompanied by hematemesis and melena, and was eventually diagnosed with E-EWS/pPNET. To date, there have been only five reported cases of E-EWS/pPNET of the small bowel including the patient in this report. To the best of our knowledge, this is the first documentation of a pPNET of the small bowel mesentery at nonage. All these have made this report rare and significant. PMID:27672649

  9. Peripheral primitive neuroectodermal tumor: Dynamic CT, MRI and clinicopathological characteristics - analysis of 36 cases and review of the literature

    PubMed Central

    Tan, Yan; Zhang, Hui; Ma, Guo-lin; Xiao, En-hua; Wang, Xiao-chun

    2014-01-01

    Background The peripheral primitive neuroectodermal tumor (pPNET) is a rare malignant tumor originating from neuroectoderm. The accurate diagnosis is essential for the treatment of pPNET. Methods we performed the largest cases of retrospective analysis thus far to review the unique computed tomography (CT), magnetic resonance imaging (MRI), and clinicopathological features of pPNET. The tumor location, morphological features, signal intensity, contrast enhancement characteristics, and involvement of local soft tissues of 36 pPNETs were assessed. Results Our results showed that there were more men (25/36) than women pPNETs patients. Unenhanced MRI (16 cases) showed that 14 cases were isointense and 2 cases were hypointense on T1WI. Nine cases were isointense and 7 were hyperintense on T2WI. Most pPNETs had heterogeneous signal intensity with small necrosis (CT: 31/36; MRI: 14/16) as well as heterogeneous enhancement (CT: 34/30; MRI: 15/16). The tumors usually had ill-defined borders and irregular shapes (CT: 30/36; MRI: 15/16). Pathologic exam showed small areas of necrosis in all tumors. Conclusions The diagnosis of pPNET should be suggested in young men when the imaging depicts a single large ill-defined solid mass with small area of necrosis, especially for those whose images show iso-intense on T1WI and T2WI and have heterogeneous enhancement. PMID:25587032

  10. Primary spinal primitive neuroectodermal tumor on MR imaging.

    PubMed

    Thoriya, Prashant J; Watal, Pankaj; Bahri, Nandini U; Rathod, Ketan

    2015-01-01

    Neoplasms in the region of filum terminale are not uncommon. Myxopapillary ependymoma is the commonest tumor at this location. The differentials reported for this entity are nerve sheath tumor, meningioma, paraganglioma, intradural metastases, lymphoma, other varieties of ependymoma, subependymoma, astrocytoma, ganglioglioma, hemangioblastoma, and primitive neuroectodermal tumor (PNET). PNET may very rarely present as an intradural thoracolumbar mass. We present pre- and post-therapy magnetic resonance imaging (MRI) features of a patient with proven primary spinal primitive neuroectodermal tumor (PSPNET) of peripheral subtype. PMID:26752826

  11. Primary spinal primitive neuroectodermal tumor on MR imaging

    PubMed Central

    Thoriya, Prashant J; Watal, Pankaj; Bahri, Nandini U; Rathod, Ketan

    2015-01-01

    Neoplasms in the region of filum terminale are not uncommon. Myxopapillary ependymoma is the commonest tumor at this location. The differentials reported for this entity are nerve sheath tumor, meningioma, paraganglioma, intradural metastases, lymphoma, other varieties of ependymoma, subependymoma, astrocytoma, ganglioglioma, hemangioblastoma, and primitive neuroectodermal tumor (PNET). PNET may very rarely present as an intradural thoracolumbar mass. We present pre- and post-therapy magnetic resonance imaging (MRI) features of a patient with proven primary spinal primitive neuroectodermal tumor (PSPNET) of peripheral subtype. PMID:26752826

  12. Cerebellopontine angle primitive neuroectodermal tumor mimicking trigeminal schwannoma

    PubMed Central

    Khan, Saad Akhtar; Ujjan, Badar Uddin; Salim, Adnan; Shamim, Shahzad

    2016-01-01

    Background: Primitive neuroectodermal tumors (PNETs) comprise a group of aggressive, poorly differentiated embryonal tumors occurring in central nervous system as well as in peripheral locations. Primary cerebellopontine angle (CPA) PNET is an extremely rare entity. It is important to have knowledge of this pathology and to be able to differentiate it from other commonly occurring CPA tumors, such as vestibular and trigeminal schwannomas. This distinction is essential because of the difference in the overall treatment plan and prognosis. Case Description: This report describes a case of a young male presenting with diplopia and numbness of face; magnetic resonance imaging showed a CPA mass. With a provisional diagnosis of trigeminal schwannoma, the patient underwent surgery. Histopathology provided a diagnosis of PNET. Conclusion: We discuss the importance of recognizing this rare condition and how this entity differs from the commonly occurring tumors. PMID:26862446

  13. Primary extraskeletal Ewing's sarcoma/primitive neuroectodermal tumor of breast

    PubMed Central

    Srivastava, Smita; Arora, Jyoti; Parakh, Anushri; Goel, Ruchika Kumar

    2016-01-01

    Extraskeletal Ewing's sarcoma (EES) is a rare soft tissue tumor that is morphologically indistinguishable from skeletal ES. We report a case of a 25-year-old female with recurrent EES/primitive neuroectodermal tumor of right breast with imaging findings on mammogram, ultrasound, magnetic resonance imaging breast, and positron emission tomography–computed tomography. PMID:27413270

  14. Primitive neuroectodermal tumor originating from the lung: A case report

    PubMed Central

    Jin, Xin; Cao, Jianfeng; Liu, Yong; Bian, Fang; Zhao, Qingqing; Wang, Yan; Lv, Xu; Huang, Yayong

    2016-01-01

    Primitive neuroectodermal tumors (PNETs) are small, round cell tumors that may be classified as peripheral or central, based on their site of origin. PNETs often arise in the soft tissue or bone of young adults. Although not common, PNETs have been described in other organs, including the gonads, kidneys, myocardium and pancreas, but rarely in the lungs without chest wall or pleural involvement. The present study reports a rare case of peripheral PNET (pPNET), which originated in the lung. A 37-year-old female patient presented at Xuzhou Central Hospital (Xuzhou, China) with a history of a dry cough, mild dyspnea and slight pain in the left chest. Histopathological and immunohistochemical analyses permitted the diagnosis of a pPNET. The patient was treated with surgical resection, followed by chemotherapy (including cyclophosphamide, cisplatin and vincristine), radiotherapy and traditional Chinese medicine (including Kanglaite and Shenqi Fuzheng injections). At the time of writing, the patient was alive with no sign of recurrence and under regular follow-ups at the Outpatient Clinic of Xuzhou Central Hospital.

  15. Primitive neuroectodermal tumor of the uterine cervix diagnosed during pregnancy: a rare case with review of literature.

    PubMed

    Khosla, Divya; Rai, Bhavana; Patel, Firuza D; Sreedharanunni, Sreejesh; Dey, Pranab; Sharma, Suresh C

    2014-03-01

    Primitive neuroectodermal tumors of the cervix are very rare. A 28-year-old pregnant woman presented with a cervical mass. The tumor was staged as IB2. The biopsy from tumor was suggestive of malignant small round cell tumor. She then underwent termination of pregnancy followed by radical hysterectomy. Based on morphologic and immunohistochemical profile, a diagnosis of peripheral primitive neuroectodermal tumor of the cervix was made. The patient received adjuvant chemotherapy and radiotherapy. The patient is alive and disease-free 33 months post-surgery. The present case highlights the importance of keeping primitive neuroectodermal tumors in the differential diagnosis of small cell neoplasms of the uterine cervix. Pregnancy should not be a barrier to early detection and treatment of this potentially aggressive tumor. The optimal treatment methods have not yet been established because of the rarity of the tumor.

  16. Primitive Neuroectodermal Tumor of the Stomach: A Case Report.

    PubMed

    Song, Min Jeong; An, Soyeon; Lee, Seung Soo; Kim, Beom Su; Kim, Jihun

    2016-09-01

    Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET) is a highly aggressive small round cell tumor that mainly occurs in the bone or soft tissue of children or young adults but is extremely rare in the stomach. A 55-year-old man presented with melena and anemia. On endoscopy, an ulcerofungating mass was observed in the high body and total gastrectomy was performed. Histologically, the mass consisted of small round cells with scanty cytoplasm and inconspicuous nucleoli. They often formed perivascular pseudorosettes and multinucleated giant cells were frequently observed. The tumor cells strongly expressed CD99, FLI1, and chromogranin and weakly expressed synaptophysin and CD56. EWS-FLI1 fusion transcript was confirmed by reverse transcription-polymerase chain reaction. ES/PNET is frequently misdiagnosed because of its similarity with small cell carcinoma. Although gastric ES/PNET is very rare, it should be included in differential diagnoses of small round cell tumor in the stomach. PMID:27006299

  17. Multiple Ewing Sarcoma/Primitive Neuroectodermal Tumors in the Mediastinum

    PubMed Central

    Bae, Sung Hwan; Hwang, Jung Hwa; Da Nam, Bo; Kim, Hyun Jo; Kim, Ki-Up; Kim, Dong Won; Choi, In Ho

    2016-01-01

    Abstract Ewing sarcoma/primitive neuroectodermal tumors (ES/PNET) are high-grade malignant neoplasms. These malignancies present very rare tumors of thoracopulmonary area and even rarer in the mediastinum. In our knowledge, ES/PNET presented with multiple mediastinal masses has not been reported previously. We experienced a case of a 42-year-old man presented with gradual onset of left-side pleuritic chest pain. A contrast-enhanced chest computed tomography (CT) scan showed separate 2 large heterogeneously enhancing masses in each anterior and middle mediastinum of the left hemithorax. Positron emission tomography-computed tomography (PET-CT) scan revealed high fluorodeoxyglucose (FDG) uptake in the mediastinal masses. After surgical excision for the mediastinal masses, both of the masses were diagnosed as the ES/PNET group of tumors on the histopathologic examination. The patient refused postoperative adjuvant chemotherapy and came back with local tumor recurrence and distant metastasis on 4-month follow-up after surgical resection. We report this uncommon form of ES/PNET. We are to raise awareness that this rare malignancy should be considered as a differential diagnosis of the malignant mediastinal tumors and which can be manifested as multiple masses in a patient. Understanding this rare entity of extra-skeletal ES/PNET and characteristic imaging findings can help radiologists and clinicians to approach proper diagnosis and better management for this highly malignant tumor. PMID:26886614

  18. CT and MRI Findings in a Rare Case of Renal Primitive Neuroectodermal Tumor

    PubMed Central

    Akkaya, Zehra; Peker, Elif; Gulpinar, Basak; Karadag, Hale; Erden, Ayse

    2016-01-01

    Summary Background Primary renal primitive neuroectodermal tumor/extraskeletal Ewing’s sarcoma (PNET/EES) is a very rare renal tumor. Case Report We report a case of primary renal PNET/EES of the kidney in an adult patient and describe its computed tomography and magnetic resonance imaging findings, including diffusion weighted images along with a review of the current medical literature. Conclusions Although very rare, a relatively large renal mass which shows very infiltrative growth pattern on CT and MR imaging and striking diffusion restriction should raise the suspicion of a renal primitive neuroectodermal tumor, in a young adult. PMID:27635170

  19. A rare case of extraskeletal Ewing's sarcoma/primitive neuroectodermal tumor developing in maxillary sinus of an old patient.

    PubMed

    Kulkarni, Maithili Mandar; Khandeparkar, Siddhi Gaurish Sinai; Joshi, Avinash R; Barpande, Chitrangi

    2016-01-01

    Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) family of tumors is an uncommon group of malignant neoplasms that may present in both skeletal and extraskeletal sites. PNET outside the central nervous system is called peripheral PNET (pPNET) developing from migrating embryonal cells of the neural crest. Very few cases of pPNET of the maxilla are reported in English literature. These tumors may be difficult to diagnose due to their primitive morphology. These tumors occur predominantly in infancy or early childhood. The occurrence of extraskeletal ES/PNET in the maxillary sinus in an old age is very rare. We report a case of extraskeletal ES/PNET developing in maxillary sinus in a 60-year-old woman. The ES/PNET should be included in the differential diagnosis of a small round cell tumor and immunohistochemical analysis with a panel of immunomarkers should be done for correct diagnosis and proper treatment. PMID:27601837

  20. A rare case of extraskeletal Ewing's sarcoma/primitive neuroectodermal tumor developing in maxillary sinus of an old patient

    PubMed Central

    Kulkarni, Maithili Mandar; Khandeparkar, Siddhi Gaurish Sinai; Joshi, Avinash R; Barpande, Chitrangi

    2016-01-01

    Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) family of tumors is an uncommon group of malignant neoplasms that may present in both skeletal and extraskeletal sites. PNET outside the central nervous system is called peripheral PNET (pPNET) developing from migrating embryonal cells of the neural crest. Very few cases of pPNET of the maxilla are reported in English literature. These tumors may be difficult to diagnose due to their primitive morphology. These tumors occur predominantly in infancy or early childhood. The occurrence of extraskeletal ES/PNET in the maxillary sinus in an old age is very rare. We report a case of extraskeletal ES/PNET developing in maxillary sinus in a 60-year-old woman. The ES/PNET should be included in the differential diagnosis of a small round cell tumor and immunohistochemical analysis with a panel of immunomarkers should be done for correct diagnosis and proper treatment. PMID:27601837

  1. Ewing Sarcoma/Primitive Neuroectodermal Tumor of the Kidney: A Rare and Lethal Entity.

    PubMed

    Celli, Romulo; Cai, Guoping

    2016-03-01

    Ewing sarcoma/primitive neuroectodermal tumor represents a spectrum of undifferentiated tumors with similar biology that together represent the second most common sarcoma in the pediatric-young adult age range. Very rarely, this tumor presents as a primary neoplasm of the kidney. The clinical presentation of this tumor is not specific, and other renal tumors may present with a similar histologic appearance. Establishing the correct diagnosis is critical because renal Ewing sarcoma/primitive neuroectodermal tumor carries a strikingly dismal prognosis and thus dictates a specific treatment strategy. A low threshold for the use of ancillary molecular tests is recommended, particularly in diagnostically problematic cases. Important considerations with regards to morphology, immunohistochemistry, and molecular alterations will be reviewed here and should be taken into account before rendering this rare and lethal diagnosis.

  2. Primary vaginal Ewing's sarcoma or primitive neuroectodermal tumor in a 17-year-old woman: a case report

    PubMed Central

    2010-01-01

    Introduction Primary Ewing's sarcoma or primitive neuroectodermal tumor of the genital tract of women is uncommon. Rarer still is its occurrence in the vagina, with only five cases described so far. Out of these, only one case was confirmed using molecular analysis. Case presentation We present an extremely rare case of Ewing's sarcoma or primitive neuroectodermal tumor in a 17-year-old Indian girl. She presented with a vaginal mass that was initially diagnosed as a malignant round cell tumor. Immunohistochemistry showed diffuse positivity for vimentin, membranous positivity for MIC2, and positivity for BCL2 and FLI-1. On the other hand, she was negative for cytokeratin, epithelial membrane antigen, desmin, Myo D-1, myogenin and smooth muscle actin. A diagnosis of primitive neuroectodermal tumor was thus offered. Furthermore, a molecular analysis of our patient using reverse transcription-polymerase chain reaction technique showed positivity for t(11; 22) (q24; q12) (EWSR1-FLI1), thus confirming the diagnosis of a Ewing's sarcoma/primitive neuroectodermal tumor. Our patient was offered chemotherapy on Institutional protocol EFT 2001. Conclusion This is a rare case of primary vaginal Ewing's sarcoma or primitive neuroectodermal tumor, which was confirmed with molecular analysis, in the youngest patient known so far. This study reinforces the value of integrating morphological features with membranous MIC2 positivity, along with application of molecular techniques in objective identification of an Ewing's sarcoma or primitive neuroectodermal tumor at uncommon sites. PMID:20233457

  3. Heavy Metal Bioaccumulation in an Atypical Primitive Neuroectodermal Tumor of the Abdominal Wall.

    PubMed

    Roncati, Luca; Gatti, Antonietta Morena; Capitani, Federico; Barbolini, Giuseppe; Maiorana, Antonio; Palmieri, Beniamino

    2015-01-01

    Heavy metals are able to interfere with the function of vital cellular components. Besides in trace heavy metals, which are essential at low concentration for humans, there are heavy metals with a well-known toxic and oncogenic potential. In this study, for the first time in literature, we report the unique adulthood case of an atypical primitive neuroectodermal tumor of the abdominal wall, diagnosed by histology and immunohistochemistry, with the molecular hybridization support. The neoplasia occurred in a patient chronically exposed to a transdermal delivery of heavy metal salts (aluminum and bismuth), whose intracellular bioaccumulation has been revealed by elemental microanalysis.

  4. The imaging findings of infratentorial primitive neuroectodermal tumour: A case report.

    PubMed

    Nekitsing, Indima; Wu, Xing; Tang, Guangyu

    2015-12-01

    Central primitive neuroectodermal tumour (cPNET), a rare malignant neoplasm of embryonal origin, often occurs in children younger than 15 years. This is the first case report of the imaging findings of an infratentorial cPNET to be reported in a patient. Here, is reported the case of a 6-year-old boy presenting with symptoms of diplopia for 14 days. Magnetic resonance imaging revealed a solid mass in the fourth ventricle. The postoperative pathological diagnosis was cPNET. To conclude, whenever a child is diagnosed to have an infratentorial solid tumour in the fourth ventricle, cPNET should always be considered despite its rarity.

  5. Infradiaphragmatic bronchogenic cyst with high CT numbers in a boy with primitive neuroectodermal tumor.

    PubMed

    Fischbach, R; Benz-Bohm, G; Berthold, F; Eidt, S; Schmidt, R

    1994-01-01

    Abdominal bronchogenic cysts are very rare with less than 20 published cases. We report the case of a retroperitoneal bronchogenic cyst in a 12-year-old boy, who initially presented with a primitive neuroectodermal tumor of the pelvis. Computed tomography (CT) showed a small, hyperdense nonenhancing mass adjacent to the right crus of the diaphragm. Follow-up CT after chemotherapy showed a decrease in CT attenuation of this mass, but a slight increase in size. At surgery the mass was loosely attached to the diaphragm and final pathology confirmed the diagnosis of a bronchogenic cyst.

  6. Oral Teratoma with a Primitive Neuroectodermal Tumor Component: A Case Report

    PubMed Central

    Tayaar, Amsavardani; Adirajaiah, Sahana; Kulandswamy, Gopalkrishnan

    2011-01-01

    Teratomas are tumors of germ cell derivation consist of tissues derived from all the three germ cell layers. They comprise the most common extragonadal germ cell tumors (EGCT) in childhood. EGCTs of head and neck region account for only 5% of all benign and malignant germ cell tumors and for 6% of all teratomas. Primitive neuroectodermal tumor (PNET) arising from germ cell tumor is a distinct entity. It develops from the malignant transformation of teratomas along ectodermal lines. This paper presents a rare case of oral teratoma in a 6-year-old male who reported with pain and swelling in the right upper back teeth region of jaw. Under light microscopy, mature and immature structures representatives of trilineage derivatives were appreciated. Sheets of small round cells showing vague rosette and membranous positivity to CD-99 directed us to consider the above diagnosis.

  7. Therapeutic Difficulty in a Case of Supratentorial Primitive Neuroectodermal Tumor Diagnosed during Pregnancy

    PubMed Central

    Sarica, Feyzi Birol; Sen, Orhan; Erdogan, Bulent

    2009-01-01

    We report a supratentorial primitive neuroectodermal tumor (sPNET) in 17-year-old primipara in the second trimester her pregnancy. Magnetic resonance imaging revealed a left frontoparietal mass with solid and cystic component. Gross-total resection was achieved via a left frontoparietal craniotomy. It was decided to suspend the radiotherapy and chemotherapy until the 30 weeks of gestation. But, a sudden uncal herniation was developed due to the reccurrence of the tumor and bleeding into the tumor at the 25 weeks of gestation and the patient died after urgent decompressive surgery. sPNETs is an extremely rare brain tumor in pregnancy and only two cases were reported in the literature to date. There is no universally agreed treatment protocol for sPNETs during pregnancy and a multidisciplinary approach is required in treatment. In the present study, the clinical, histopathological features and therapeutical difficulties of sPNETs diagnosed during pregnancy was discussed with the literature review. PMID:19242570

  8. Management of Primitive Neuroectodermal Tumor of the Kidney with Inferior Vena Cava Thrombus

    PubMed Central

    Gupta, Sahil; Majumder, Kaustav; Chahal, Anurag; Saini, Ashish K.; Gupta, Arjun

    2016-01-01

    Primitive neuroectodermal tumors (PNET) are an aggressive group of small round cell tumors usually arising in the nervous system and affecting children. They have a tendency for local invasion, distant spread and formation of tumor thrombi. The kidney is a rare primary location for these tumors. Outcomes are frequently poor due to late diagnosis (Wilms tumor is a more common tumor in this population) and early spread. Immunohistochemistry is invaluable in making the diagnosis of PNET. We report a case of a primary renal PNET with extensive tumor thrombus into the inferior vena cava, and lung metastasis in a pediatric patient, and its successful management. Our 14-year-old patient with renal PNET was managed with radical nephrectomy, thrombectomy and chemotherapy and remains disease free to date. The diagnosis of renal PNETs should be considered in young adult patients who present with aggressive renal masses at initial presentations. Despite its aggressive nature, good outcomes can be achieved by a multimodality therapeutic strategy. PMID:26989372

  9. Ewing's sarcoma/primitive neuroectodermal tumour occurring in the maxillary sinus.

    PubMed

    Kawabata, Masaki; Yoshifuku, Kosuke; Sagara, Yukari; Kurono, Yuichi

    2008-03-01

    A 12-year-old boy complained of swelling of the left cheek. Fiberscopic examination revealed the presence of a soft reddish mass in the middle meatus of the left nostril. CT scan showed a large mass completely filling the left maxillary sinus. The lesion originated from the maxillary sinus and extended to the middle nasal meatus; bone destruction and invasion of the subcutaneous tissue of the cheek were noted. T2-weighted MRI images revealed a heterogeneous signal in the left maxillary sinus. Under general anaesthesia, biopsies were obtained through an intraoral incision. On pathology, atypical cells containing irregular nuclei with scanty cytoplasm were noted. The tumour cells were strongly positive for CD99 and reacted weakly with NSE however the cells were negative for synaptophysin, LCA and cytokeratin on immunohistochemical examination. Based on these findings, the tumour was diagnosed as a Ewing's sarcoma/primitive neuroectodermal tumour. The patient was treated with radiotherapy and combination chemotherapy; subsequently, the tumour's size decreased markedly. After 20 months of follow-up, the patient showed no evidence of local tumour growth or metastasis. PMID:18444498

  10. Clinicopathological analysis of nine consecutive central nervous system primitive neuroectodermal tumors in a single institute.

    PubMed

    Aizawa-Kohama, Misaki; Kumabe, Toshihiro; Saito, Ryuta; Kanamori, Masayuki; Yamashita, Yoji; Sonoda, Yukihiko; Watanabe, Mika; Tominaga, Teiji

    2013-01-01

    The objective of this study was to determine the outcome of central nervous system primitive neuroectodermal tumors (CNS PNETs) and to clarify the histopathological findings as prognostic factors. We performed a retrospective analysis of nine consecutive patients with CNS PNETs who underwent treatment at our institute between 1993 and 2011. All patients were treated by surgical resection followed by chemoradiotherapy. Additional treatment, including surgical resection, was performed at relapse. Expression of immunohistochemical markers was examined for neuronal, astrocytic, mesenchymal, and epithelial differentiation, and also for TP53, O(6)-methylguanine-DNA methyltransferase, and Ki-67. Five-year progression-free survival was 18.2 % and the overall survival was 52.5 %. Five the 9 patients had recurrence and 4 patients died during the median follow-up period of 41.1 months. All 4 patients died of dissemination not local recurrence. After relapses, the extent of differentiation was different in each case and TP53 changed to positive or negative, but the Ki-67 labeling index did not reveal any differences between primary and recurrent tumors. A treatment procedure to prevent and treat dissemination of CNS PNETs should be established. Because the pathological change after relapse was different in each case, definitive histopathological prognostic factors for CNS PNETs are still difficult to propose.

  11. p53 protein overexpression identifies a group of central primitive neuroectodermal tumours with poor prognosis.

    PubMed

    Jaros, E; Lunec, J; Perry, R H; Kelly, P J; Pearson, A D

    1993-10-01

    Primitive neuroectodermal tumours (PNET's) or medulloblastomas are common primary brain tumours of childhood. Current treatment protocols achieve 50-60% cures. However, it has proved difficult to develop better treatment for the remaining patients because prognostic factors are not established. We have investigated the prognostic value of p53 protein expression in 87 PNET's using immunohistochemistry with DO-7 and CM-1 antibodies on biopsy paraffin sections. Eight patients (9%) had intensely reactive tumour cell nuclei, and a significantly reduced survival (P = 0.002); only one survives and this with a recurrent tumour 50 months following diagnosis. Sixty eight per cent of patients had faintly reactive tumour cell nuclei, a reduced survival up to 4 years but a long term survival not significantly different (P = 0.41) from 23% of patients with p53 negative PNET's; the 10 year survival rates were 37% and 40%, respectively. Males had a reduced survival (P = 0.04) with a 2-fold relative risk of death compared to females. Multivariate analysis showed that intense overexpression of p53 protein identifies a group of PNET patients with a 7-fold relative risk of death compared to all other cases, irrespective of sex. This marked difference suggests the involvement of p53 in the pathogenesis of PNET's which have a particularly poor response to treatment, and should help to develop new therapies for this group of patients.

  12. Pediatric Primitive Neuroectodermal Tumors of the Central Nervous System Differentially Express Granzyme Inhibitors

    PubMed Central

    Vermeulen, Jeroen F.; van Hecke, Wim; Spliet, Wim G. M.; Villacorta Hidalgo, José; Fisch, Paul; Broekhuizen, Roel; Bovenschen, Niels

    2016-01-01

    Background Central nervous system (CNS) primitive neuroectodermal tumors (PNETs) are malignant primary brain tumors that occur in young infants. Using current standard therapy, up to 80% of the children still dies from recurrent disease. Cellular immunotherapy might be key to improve overall survival. To achieve efficient killing of tumor cells, however, immunotherapy has to overcome cancer-associated strategies to evade the cytotoxic immune response. Whether CNS-PNETs can evade the immune response remains unknown. Methods We examined by immunohistochemistry the immune response and immune evasion strategies in pediatric CNS-PNETs. Results Here, we show that CD4+, CD8+, γδ-T-cells, and Tregs can infiltrate pediatric CNS-PNETs, although the activation status of cytotoxic cells is variable. Pediatric CNS-PNETs evade immune recognition by downregulating cell surface MHC-I and CD1d expression. Intriguingly, expression of SERPINB9, SERPINB1, and SERPINB4 is acquired during tumorigenesis in 29%, 29%, and 57% of the tumors, respectively. Conclusion We show for the first time that brain tumors express direct granzyme inhibitors (serpins) as a potential mechanism to overcome cellular cytotoxicity, which may have consequences for cellular immunotherapy. PMID:26963506

  13. Ewing's sarcoma/primitive neuroectodermal tumor of the proximal humeral epiphysis.

    PubMed

    Morris, Parisa; Dickman, Paul S; Seidel, Matthew J

    2013-01-01

    Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) of bone is a rare childhood tumor most commonly located in the metadiaphysis. In skeletally immature patients, lesions of the epiphysis are rarely malignant, with the most common diagnosis being chondroblastoma. This article presents a case of ES/PNET of the proximal humeral epiphysis in a 12-year-old boy. To the authors' knowledge, this is the first reported case of epiphyseal ES/PNET confirmed with molecular testing. Radiographs of the patient's painful shoulder showed a well-defined lytic lesion within the humeral epiphysis. Magnetic resonance imaging suggested a chondroid tumor with surrounding edema. Based on the imaging characteristics, the patient's age, and the lesion's location, a preliminary diagnosis of chondroblastoma was made. A trochar biopsy of the lesion demonstrated a small, round, blue cell tumor on frozen section. Subsequently, immunohistochemical staining was uniformly positive in a membrane pattern for CD99, and molecular diagnostic testing demonstrated a EWSR1/FLI1 fusion transcript, confirming the pathologic diagnosis of ES/PNET. Although metadiaphyseal locations for ES/PNET are most common, this case adds to previously reported cases of epiphyseal ES/PNET, suggesting that the diagnosis be considered for pediatric epiphyseal tumors. This case also demonstrates why following rigorous oncologic treatment algorithms by obtaining a limited trochar biopsy, even in the case of a confident radiographic diagnosis, is critically important; the biopsy results can lead to a major change in treatment and avoid contamination of a larger area of soft tissue and bone. PMID:23276342

  14. Primary primitive neuroectodermal tumor of the conus medullaris in an elderly patient: a case report and review of the literature.

    PubMed

    Shimosawa, H; Matsumoto, M; Yabe, H; Mukai, M; Toyama, Y; Morioka, H

    2011-05-01

    Primary spinal primitive neuroectodermal tumors (PNETs) are very rare conditions. Most of these tumors occur in children and young adults. A 63-year-old man with a primary spinal PNET in the conus medullaris from the L1 to L2 level is presented in this report. The optimal treatment of primary spinal PNETs is yet unknown. Surgical resection, radiation therapy, and chemotherapy have been advocated for the treatment of spinal PNET based on PNETs at other sites. However, the outcome is very poor. There are a few reports of cases with long-term survival and no recurrence. In these patients, en bloc resections were performed.

  15. Primitive neuroectodermal tumor of the central nervous system with glial differentiation: a FISH study of an adult case.

    PubMed

    Alameda, F; Lloreta, J; Ariza, A; Salido, M; Espinet, B; Baro, T; Garcia-Fructoso, G; Galito, E; Munne, A; Cruz Sanchez, F F; Sole, F; Serrano, S

    2007-01-01

    Primitive neuroectodermal tumors (PNETs) of the central nervous system (CNS), a rare occurrence in adults, may show glial differentiation and can be misinterpreted as pure astrocytic neoplasms. Few fluorescence in situ hybridization (FISH) studies have been carried out on these tumors; isochromosome 17q was found to be the major chromosomal abnormality. We present the case of an adult in which we performed a FISH study of both the glial and neuronal components. A complex array of FISH changes, not including an isochromosome 17q were identified.

  16. Genome-wide molecular characterization of central nervous system primitive neuroectodermal tumor and pineoblastoma

    PubMed Central

    Miller, Suzanne; Rogers, Hazel A.; Lyon, Paul; Rand, Vikki; Adamowicz-Brice, Martyna; Clifford, Steven C.; Hayden, James T.; Dyer, Sara; Pfister, Stefan; Korshunov, Andrey; Brundler, Marie-Anne; Lowe, James; Coyle, Beth; Grundy, Richard G.

    2011-01-01

    Central nervous system primitive neuroectodermal tumor (CNS PNET) and pineoblastoma are highly malignant embryonal brain tumors with poor prognoses. Current therapies are based on the treatment of pediatric medulloblastoma, even though these tumors are distinct at both the anatomical and molecular level. CNS PNET and pineoblastoma have a worse clinical outcome than medulloblastoma; thus, improved therapies based on an understanding of the underlying biology of CNS PNET and pineoblastoma are needed. To this end, we characterized the genomic alterations of 36 pediatric CNS PNETs and 8 pineoblastomas using Affymetrix single nucleotide polymorphism arrays. Overall, the majority of CNS PNETs contained a greater degree of genomic imbalance than pineoblastomas, with gain of 19p (8 [27.6%] of 29), 2p (7 [24.1%] of 29), and 1q (6 [20.7%] of 29) common events in primary CNS PNETs. Novel gene copy number alterations were identified and corroborated by Genomic Identification of Significant Targets In Cancer (GISTIC) analysis: gain of PCDHGA3, 5q31.3 in 62.1% of primary CNS PNETs and all primary pineoblastomas and FAM129A, 1q25 in 55.2% of primary CNS PNETs and 50% of primary pineoblastomas. Comparison of our GISTIC data with publically available data for medulloblastoma confirmed these CNS PNET–specific copy number alterations. With use of the collection of 5 primary and recurrent CNS PNET pairs, we found that gain of 2p21 was maintained at relapse in 80% of cases. Novel gene copy number losses included OR4C12, 11p11.12 in 48.2% of primary CNS PNETs and 50% of primary pineoblastomas. Loss of CDKN2A/B (9p21.3) was identified in 14% of primary CNS PNETs and was significantly associated with older age among children (P = .05). CADPS, 3p14.2 was lost in 27.6% of primary CNS PNETs and was associated with poor prognosis (P = .043). This genome-wide analysis revealed the marked molecular heterogeneity of CNS PNETs and enabled the identification of novel genes and clinical

  17. Renal primitive neuroectodermal tumor as a second malignancy after chemotherapy and radiation for Non-Hodgkin's Lymphoma--treatment-related or just poor old bad luck?: A case report.

    PubMed

    de Menezes, Jean-Louis; Patil, Hitendra M; Kannan, R; Pradhan, Sultan A

    2015-01-01

    Peripheral primitive neuroectodermal tumor (PNET) is a rare histology to be found in primary tumors of the kidney. There are less than a hundred cases reported in the English literature. Most of these have been diagnosed after surgery for a renal neoplasm diagnosed on imaging. PNET has rarely been reported as a second malignancy, and has never been reported as a second malignancy after non-Hodgkin's lymphoma (NHL). Herein, we present our case of a 38-year-old female who developed a second malignancy in the kidney after the treatment for NHL. PMID:26458616

  18. Thyroid-Stimulating Hormone Suppression for Protection Against Hypothyroidism Due to Craniospinal Irradiation for Childhood Medulloblastoma/Primitive Neuroectodermal Tumor

    SciTech Connect

    Massimino, Maura Gandola, Lorenza; Collini, Paola; Seregni, Ettore; Marchiano, Alfonso; Serra, Annalisa; Pignoli, Emanuele Ph.D.; Spreafico, Filippo; Pallotti, Federica; Terenziani, Monica; Biassoni, Veronica; Bombardieri, Emilio; Fossati-Bellani, Franca

    2007-10-01

    Purpose: Hypothyroidism is one of the earliest endocrine effects of craniospinal irradiation (CSI). The effects of radiation also depend on circulating thyroid-stimulating hormone (TSH), which acts as an indicator of thyrocyte function and is the most sensitive marker of thyroid damage. Hence, our study was launched in 1998 to evaluate the protective effect of TSH suppression during CSI for medulloblastoma/primitive neuroectodermal tumor. Patients and Methods: From Jan 1998 to Feb 2001, a total of 37 euthyroid children scheduled for CSI for medulloblastoma/primitive neuroectodermal tumor underwent thyroid ultrasound and free triiodothyronine (FT3), free thyroxine (FT4), and TSH evaluation at the beginning and end of CSI. From 14 days before and up to the end of CSI, patients were administered L-thyroxine at suppressive doses; every 3 days, TSH suppression was checked to ensure a value <0.3 {mu}M/ml. During follow-up, blood tests and ultrasound were repeated after 1 year; primary hypothyroidism was considered an increased TSH level greater than normal range. CSI was done using a hyperfractionated accelerated technique with total doses ranging from 20.8-39 Gy; models were used to evaluate doses received by the thyroid bed. Results: Of 37 patients, 25 were alive a median 7 years after CSI. They were well matched for all clinical features, except that eight children underwent adequate TSH suppression during CSI, whereas 17 did not. Hypothyroidism-free survival rates were 70% for the 'adequately TSH-suppressed' group and 20% for the 'inadequately TSH-suppressed' group (p = 0.02). Conclusions: Thyroid-stimulating hormone suppression with L-thyroxine had a protective effect on thyroid function at long-term follow-up. This is the first demonstration that transient endocrine suppression of thyroid activity may protect against radiation-induced functional damage.

  19. Primitive neuroectodermal tumour in a striped dolphin (Stenella coeruleoalba) with features of ependymoma and neural tube differentiation (Medulloepithelioma).

    PubMed

    Baily, J L; Morrison, L R; Patterson, I A; Underwood, C; Dagleish, M P

    2013-11-01

    Primary brain tumours in cetaceans are rare with only four reported cases of intracranial tumours in the scientific literature. A juvenile female, striped dolphin live-stranded at Whitepark Bay, Co Antrim, Northern Ireland, UK, and died after an unsuccessful attempt at refloatation. Necropsy examination revealed a large, soft, non-encapsulated friable mass, which expanded and replaced the frontal lobes, corpus callosum and caudate nucleus of the brain and extended into the lateral ventricles, displacing the thalamus caudally. Microscopically, this comprised moderately pleomorphic neoplastic cells arranged variably in dense monotonous sheets, irregular streams, ependymal rosettes, 'ependymoblastomatous rosettes' and multilayered to pseudostratified tubules. Liquefactive necrosis, palisading glial cells, haemorrhage and mineralization were also observed. Immunohistochemically, the neoplastic cells expressed vimentin but not S100, glial fibrillary acidic protein, cytokeratin, neuron-specific enolase or synaptophysin. Based on these findings a diagnosis of primitive neuroectodermal tumour was made. Monitoring and recording such cases is crucial as neoplasia may be related to viral, carcinogenic or immunosuppressive chemical exposure and can ultimately contribute to assessing the ocean health. PMID:24011906

  20. Primitive neuroectodermal tumour in a striped dolphin (Stenella coeruleoalba) with features of ependymoma and neural tube differentiation (Medulloepithelioma).

    PubMed

    Baily, J L; Morrison, L R; Patterson, I A; Underwood, C; Dagleish, M P

    2013-11-01

    Primary brain tumours in cetaceans are rare with only four reported cases of intracranial tumours in the scientific literature. A juvenile female, striped dolphin live-stranded at Whitepark Bay, Co Antrim, Northern Ireland, UK, and died after an unsuccessful attempt at refloatation. Necropsy examination revealed a large, soft, non-encapsulated friable mass, which expanded and replaced the frontal lobes, corpus callosum and caudate nucleus of the brain and extended into the lateral ventricles, displacing the thalamus caudally. Microscopically, this comprised moderately pleomorphic neoplastic cells arranged variably in dense monotonous sheets, irregular streams, ependymal rosettes, 'ependymoblastomatous rosettes' and multilayered to pseudostratified tubules. Liquefactive necrosis, palisading glial cells, haemorrhage and mineralization were also observed. Immunohistochemically, the neoplastic cells expressed vimentin but not S100, glial fibrillary acidic protein, cytokeratin, neuron-specific enolase or synaptophysin. Based on these findings a diagnosis of primitive neuroectodermal tumour was made. Monitoring and recording such cases is crucial as neoplasia may be related to viral, carcinogenic or immunosuppressive chemical exposure and can ultimately contribute to assessing the ocean health.

  1. Systematic comparison of MRI findings in pediatric ependymoblastoma with ependymoma and CNS primitive neuroectodermal tumor not otherwise specified

    PubMed Central

    Nowak, Johannes; Seidel, Carolin; Pietsch, Torsten; Alkonyi, Balint; Fuss, Taylor Laura; Friedrich, Carsten; von Hoff, Katja; Rutkowski, Stefan; Warmuth-Metz, Monika

    2015-01-01

    Background Ependymoblastoma (EBL), ependymoma (EP), and primitive neuroectodermal tumors of the central nervous system not otherwise specified (CNS-PNET NOS) are pediatric brain tumors that can be differentiated by histopathology in the clinical setting. Recently, we described specific MRI features of EBL. In this study, we compare standardized MRI characteristics of EBL with EP and CNS-PNET NOS in a series comprising 22 patients in each group. Methods All 66 centrally reviewed cases were obtained from the database of the German multicenter HIT trials. We systematically analyzed the initial MRI scans at diagnosis according to standardized criteria, and paired comparison was performed for EBL and EP, as well as for EBL and CNS-PNET NOS. Results We found differences between EBL and EP regarding age at diagnosis, MR signal intensity, tumor margin and surrounding edema, presence and size of cysts, and contrast enhancement pattern. Although MRI appearance of EBL shares many features with CNS-PNET NOS, we revealed significant differences in terms of age at diagnosis, tumor volume and localization, tumor margins, edema, and contrast enhancement. Conclusion This is the first study that systematically compares multiple parameters of MRI in pediatric EBL with findings in EP and CNS-PNET NOS. Although a definite differentiation by means of MRI alone might not be feasible in the individual case, we identify significant differences between these tumor entities. PMID:25916887

  2. Supratentorial primitive neuroectodermal tumors (S-PNET) in children: A prospective experience with adjuvant intensive chemotherapy and hyperfractionated accelerated radiotherapy

    SciTech Connect

    Massimino, Maura . E-mail: maura.massimino@istitutotumori.mi.it; Gandola, Lorenza; Spreafico, Filippo; Luksch, Roberto; Collini, Paola; Giangaspero, Felice; Simonetti, Fabio; Casanova, Michela; Cefalo, Graziella; Pignoli, Emanuele; Ferrari, Andrea; Terenziani, Monica; Podda, Marta; Meazza, Cristina; Polastri, Daniela; Poggi, Geraldina; Ravagnani, Fernando; Fossati-Bellani, Franca

    2006-03-15

    Purpose: Supratentorial primitive neuroectodermal tumors (S-PNET) are rare and have a grim prognosis, frequently taking an aggressive course with local relapse and metastatic spread. We report the results of a mono-institutional therapeutic trial. Methods and Materials: We enrolled 15 consecutive patients to preradiation chemotherapy (CT) consisting of high-dose methotrexate, high-dose etoposide, high-dose cyclophosphamide, and high-dose carboplatin, craniospinal irradiation (CSI) with hyperfractionated accelerated radiotherapy (HART) plus focal boost, maintenance with vincristine/lomustine or consolidation with high-dose thiotepa followed by autologous stem-cell rescue. Results: Median age was 9 years; 7 were male, 8 female. Site of disease was pineal in 3, elsewhere in 12. Six patients were had no evidence of disease after surgery (NED). Of those with evidence of disease after surgery (ED), 2 had central nervous system spread. Of the 9 ED patients, 2 had complete response (CR) and 2 partial response (PR) after CT, 4 stable disease, and 1 progressive disease. Of the 7 ED patients before radiotherapy, 1 had CR, 4 PR, and 2 minor response, thus obtaining a 44% CR + PR after CT and 71% after HART. Because of rapid progression in 2 of the first 5 patients, high-dose thiotepa was systematically adopted after HART in the subsequent 10 patients. Six of 15 patients relapsed (4 locally, 1 locally with dissemination, 1 with dissemination) a mean of 6 months after starting CT, 2 developed second tumors; 5 of 6 relapsers died at a median of 13 months. Three-year progression-free survival, event-free survival, and overall survival were 54%, 34%, and 61%, respectively. Conclusion: Hyperfractionated accelerated RT was the main tool in obtaining responses in S-PNET; introducing the myeloablative phase improved the prognosis (3/10 vs. 3/5 relapses), though the outcome remained unsatisfactory despite the adoption of this intensive treatment.

  3. Proton Radiation Therapy for Pediatric Medulloblastoma and Supratentorial Primitive Neuroectodermal Tumors: Outcomes for Very Young Children Treated With Upfront Chemotherapy

    SciTech Connect

    Jimenez, Rachel B.; Sethi, Roshan; Depauw, Nicolas; Pulsifer, Margaret B.; Adams, Judith; McBride, Sean M.; Ebb, David; Fullerton, Barbara C.; Tarbell, Nancy J.; Yock, Torunn I.; MacDonald, Shannon M.

    2013-09-01

    Purpose: To report the early outcomes for very young children with medulloblastoma or supratentorial primitive neuroectodermal tumor (SPNET) treated with upfront chemotherapy followed by 3-dimensional proton radiation therapy (3D-CPT). Methods and Materials: All patients aged <60 months with medulloblastoma or SPNET treated with chemotherapy before 3D-CPT from 2002 to 2010 at our institution were included. All patients underwent maximal surgical resection, chemotherapy, and adjuvant 3D-CPT with either craniospinal irradiation followed by involved-field radiation therapy or involved-field radiation therapy alone. Results: Fifteen patients (median age at diagnosis, 35 months) were treated with high-dose chemotherapy and 3D-CPT. Twelve of 15 patients had medulloblastoma; 3 of 15 patients had SPNET. Median time from surgery to initiation of radiation was 219 days. Median craniospinal irradiation dose was 21.6 Gy (relative biologic effectiveness); median boost dose was 54.0 Gy (relative biologic effectiveness). At a median of 39 months from completion of radiation, 1 of 15 was deceased after a local failure, 1 of 15 had died from a non-disease-related cause, and the remaining 13 of 15 patients were alive without evidence of disease recurrence. Ototoxicity and endocrinopathies were the most common long-term toxicities, with 2 of 15 children requiring hearing aids and 3 of 15 requiring exogenous hormones. Conclusions: Proton radiation after chemotherapy resulted in good disease outcomes for a small cohort of very young patients with medulloblastoma and SPNET. Longer follow-up and larger numbers of patients are needed to assess long-term outcomes and late toxicity.

  4. Neurotrophin and neurotrophin receptor proteins in medulloblastomas and other primitive neuroectodermal tumors of the pediatric central nervous system.

    PubMed Central

    Washiyama, K.; Muragaki, Y.; Rorke, L. B.; Lee, V. M.; Feinstein, S. C.; Radeke, M. J.; Blumberg, D.; Kaplan, D. R.; Trojanowski, J. Q.

    1996-01-01

    Primitive neuroectodermal tumors (PNETs) of the central nervous system (CNS) are poorly understood childhood neoplasms, and medulloblastomas are the most common pediatric PNETs. Neoplastic cells in medulloblastomas and other PNETs resemble progenitor cells of the developing central nervous system, but they also may exhibit the molecular phenotype of immature neurons or glia. As neurotrophins play a role in regulating differentiation, proliferation, and cell death in the normal developing central nervous system, and recent evidence suggests that neurotrophins may influence the behavior of medulloblastomas, we studied 29 PNET biopsy samples (27 of which were posterior fossa medulloblastomas) by immunobistochemistry using antibodies specific for each of the major high affinity neurotrophin receptor proteins, ie, TrkA, TrkB, and TrkC. A subset of these tumors also was examined by Western blot. Immunoreactive TrkA, TrkB, and TrkC were observed in neoplastic cells in 8 (27%), 18 (62%), and 14 (48%) of these PNETs, respectively. Additional immunohistochemical studies of a subset of these PNETs using antibodies to neurotrophins that primarily activate TrkB and TrkC, ie, brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4/5, showed that immunoreactive brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4/5 were detected in 22, 9, and 19% of these PNET biopsies, respectively. Finally, 19 pediatric brain tumors other than these PNETs also were studied here, and they expressed these neurotrophins and their receptors to a variable extent. The demonstration here that neurotrophins and their cognate receptor proteins are expressed in PNETs as well as in other pediatric brain tumors may imply that signal transduction pathways mediated by neurotrophins and/or their receptors influence the induction or progression of these common childhood neoplasms. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:8774147

  5. [CNS primitive neuroectodermal tumor suspected as a secondary recurrence after radiation therapy for medulloblastoma:a case report].

    PubMed

    Sato, Hiroyuki; Shibuya, Kouhei; Koizumi, Takayuki; Kato, Shunichi; Endo, Shin

    2014-07-01

    We report a case of a suspected secondary central nervous system(CNS)primitive neuroectodermal tumor(PNET)that developed 25 years after radiation therapy for a medulloblastoma of the cerebellum. At 5 years of age, the patient underwent craniotomy and subsequent radiation therapy of the whole brain(39Gy), whole spinal cord(9Gy), and posterior fossa(49Gy)for the treatment of a medulloblastoma of the cerebellum;the patient did not receive chemotherapy. After radiation therapy, the medulloblastoma completely receded and did not recur. Twenty-five years later, at 30 years of age, the patient visited our institution experiencing right-sided hemiparesis and aphasia that had arisen approximately 1 month prior and had gradually worsened. The patient was subsequently hospitalized after experiencing disturbed consciousness and a generalized convulsion seizure. Gadolinium-enhanced magnetic resonance imaging(MRI)revealed a mass accompanied by a large cyst in the left frontal lobe. Complete tumor resection was achieved via macroscopic surgery, and the histopathological findings were indicative of CNS PNET. Considering the tumor occurred in the same site where radiation therapy had been previously administered to treat a medulloblastoma, additional radiotherapy was avoided in favor of combination chemotherapy with ifosfamide, cisplatin, and etoposide. Tumor recurrence was not observed in a follow-up MRI after 6 courses of ICE therapy, and the patient has resumed a normal life. The present case, a CNS PNET, is suspected as a secondary brain tumor induced by radiation therapy previously used to treat a medulloblastoma, and it represents a rare late-onset complication of radiation therapy. For the treatment of PNET, we believe that maximal safe surgical resection of the tumor and post-operative radiation therapy are typically necessary for long-term survival. However, taking into account the risks of repeated exposure to radiation, we did not perform post-operative radiation therapy

  6. Primary Renal Primitive Neuroectodermal Tumor/Ewing’s Sarcoma Imaging and Pathologic Findings of a Patient with a Nine Year, Eight Month Disease Free Period: Case Report and Review of Literature

    PubMed Central

    Zokalj, Ivan; Igrec, Jasminka; Plesnar, Antonio

    2016-01-01

    Introduction Primitive neuroectodermal tumor (PNET)/Ewing’s sarcoma (EWS) belongs to a family of neoplasms that are presumed to originate from the neuroectodermal crest. PNET/EWSs are highly aggressive malignancies that usually present in the form of bone or soft tissue masses and usually affect adolescents and young adults. Primary PNET/EWS of the kidney is very rare. Case Presentation We present the case of a 32-year-old female patient with primary renal PNET/EWS diagnosed nine years and eight months earlier. The patient presented with acute flank pain in the left lumbar region, hematuria, and episodes of high body temperature of 40°C. Abdominal ultrasound (US) and subsequently performed computed tomography (CT) revealed a large renal mass of heterogenous structure. The kidney tumor had central necrotic hypodense areas and strongly peripherally enhanced solid parts on postcontrast CT images. Immunohistochemistry revealed positivity for CD99 and neuron-specific enolase (NSE). Tumor cells were negative for CD3, CD 20, chromogranin, synaptophysin, vimentin, and neurofilament. Reverse transcription polymerase change reaction (RT-PCR) revealed EWS/FL1 translocation type 2. The patient underwent nephrectomy and polychemotherapy. The follow-up nine years and eight months after the diagnosis showed no evidence of tumor. Conclusions PNET/EWS should be included in the differential diagnosis of renal tumors in symptomatic young adults. Patients with localised PNET/EWS treated with a combination of surgery and chemotherapy have an excellent chance of long-term survival, as in the case we have presented.

  7. Peripheral primitive neuroectodermal tumor of seminal vesicles: is there a role for relatively aggressive treatment modalities?

    PubMed

    Crestani, Alessandro; Guttilla, Andrea; Gardi, Mario; Gardiman, Marina; Dal Moro, Fabrizio; Valotto, Claudio; Zattoni, Filiberto

    2014-12-30

    A 50 year old white man received an incidental ultrasound diagnosis of hypoechoic mass interesting the right seminal vesicle. A CT scan showed the presence of a 7.8 cm roundish cyst, originating from the right seminal vesicle. He had been followed by the removal of the right seminal vesicle and both the cystic lesion. The histological findings of the specimen documented the presence of small round cells compatible with Ewing's sarcoma/PPNET. The patient received also adjuvant chemotherapy and radiation treatment. After 10 years, the follow-up is still negative.

  8. H3.3 G34R mutations in pediatric primitive neuroectodermal tumors of central nervous system (CNS-PNET) and pediatric glioblastomas: possible diagnostic and therapeutic implications?

    PubMed

    Gessi, Marco; Gielen, Gerrit H; Hammes, Jennifer; Dörner, Evelyn; Mühlen, Anja Zur; Waha, Andreas; Pietsch, Torsten

    2013-03-01

    Pediatric glioblastomas recently have been exon sequenced with evidence that approximately 30 % of cases harbour mutations of the histone H3.3 gene. Although studies to determinate their role in risk stratification are on-going, it remains to be determined whether H3.3 mutations could be found in other tumors such as pediatric primitive neuroectodermal tumors of the central nervous system (CNS-PNETs) and whether the presence of H3.3 mutations in glioblastomas could be used as diagnostic tool in their differential diagnosis with CNS-PNETs. We performed a large mutational pyrosequencing-based screening on 123 pediatric glioblastomas and 33 CNS-PNET. The analysis revealed that 39/123 (31.7 %) glioblastomas carry H3.3 mutations. The K27M (AAG → ATG, lysine → methionine) mutation was found in 33 glioblastomas (26 %); the G34R (GGG → AGG, glycine → arginine) was observed in 6 glioblastomas (5.5 %). However, we also identified 4 of 33 cases (11 %) of CNS-PNETs harbouring a H3.3 G34R mutation. Multiplex ligation-dependent probe amplification analysis revealed PDGFR-alpha amplification and EGFR gain in two cases and N-Myc amplification in one case of H3.3 G34R mutated CNS-PNET. None of H3.3 mutated tumors presented a CDKN2A loss. In conclusion, because pediatric patients with glioblastoma and CNS-PNET are treated according to different therapeutic protocols, these findings may raise further concerns about the reliability of the histological diagnosis in the case of an undifferentiated brain tumor harbouring G34R H3.3 mutation. In this view, additional studies are needed to determine whether H3.3 G34 mutated CNS-PNET/glioblastomas may represent a defined tumor subtype. PMID:23354654

  9. INSM1 promoter-driven adenoviral herpes simplex virus thymidine kinase cancer gene therapy for the treatment of primitive neuroectodermal tumors.

    PubMed

    Wang, Hong-Wei; Breslin, Mary B; Chen, Chiachen; Akerstrom, Victoria; Zhong, Qiu; Lan, Michael S

    2009-11-01

    The INSM1 gene encodes a developmentally regulated zinc finger transcription factor. INSM1 expression is normally absent in adult tissues, but is reactivated in neuroendocrine tumor cells. In the present study, we analyzed the therapeutic potential of an adenoviral INSM1 promoter-driven herpes simplex virus thymidine kinase (HSV-tk) construct in primitive neuroectodermal tumors (PNETs). We constructed an adenoviral INSM1 promoter-driven HSV-tk gene for therapy in PNETs. The PNET-specific adeno-INSM1 promoter HSV-tk construct was tested both in vitro and in vivo in a nude mouse tumor model. Northern blot analysis and transient transfection of an INSM1 promoter-driven luciferase reporter gene indicated that the INSM1 promoter was active in neuroblastoma (IMR-32), retinoblastoma (Y79), and medulloblastoma (D283 Med) cells, but not in glioblastoma (U-87 MG) cells. After Ad-INSM1p-HSV-tk infection, the levels of HSV-tk protein expression were consistent with INSM1 promoter activities. Furthermore, in vitro multiplicity of infection and ganciclovir (GCV) sensitivity studies indicated that the INSM1 promoter could mediate specific expression of the HSV-tk gene and selective killing of INSM1-positive PNETs. In vivo intratumoral adenoviral delivery demonstrated that the INSM1 promoter could direct HSV-tk gene expression in a nude mouse tumor model and effectively repressed tumor growth in response to GCV treatment. Taken together, our data show that the INSM1 promoter is specific and effective for targeted cancer gene therapy in PNETs. PMID:19604042

  10. Effects of all-trans retinoic acid and interferon alpha in peripheral neuroectodermal tumor cell cultures and xenografts.

    PubMed

    Rosolen, A; Favaretto, G; Masarotto, G; Cavazzana, A; Zanesco, L; Frascella, E

    1998-11-01

    Peripheral neuroectodermal tumors (PNET) have an unsatisfactory outcome when treated with standard approaches. Among novel treatments, the use of biological response modifiers has rarely been reported in this group of malignancies. We have previously demonstrated that both all-trans retinoic acid (ATRA) and interferon á (IFNá) can inhibit proliferation of human PNET cells and that ATRA can up-regulate IFNá receptor expression in vitro. In this study we evaluated the anti-tumor effects of ATRA and IFNá in PNET cells in vitro and in a human PNET xenograft model, using CHP100 cells. A synergistic inhibitory effect of ATRA and IFNá was observed on CHP100 cells in vitro. On the contrary, a significant inhibition of tumor growth was observed in mice treated with ATRA alone, whereas neither IFNá nor the combination of ATRA and IFNá, reached a statistically significant anti-tumor effect. Histologic examination of tumors revealed the presence of necrosis upon treatment with IFNá, whereas almost no necrosis, but a more differentiated morphology, confirmed by electron microscopy analysis, was associated with the ATRA containing treatments. Taken together these data show an in vitro and in vivo anti-tumor activity of ATRA in human PNET cells, although no synergism of ATRA and IFNá was observed in our xenograft model.

  11. Treatment of Children With Central Nervous System Primitive Neuroectodermal Tumors/Pinealoblastomas in the Prospective Multicentric Trial HIT 2000 Using Hyperfractionated Radiation Therapy Followed by Maintenance Chemotherapy

    SciTech Connect

    Gerber, Nicolas U.; Hoff, Katja von; Resch, Anika; Ottensmeier, Holger; Kwiecien, Robert; Faldum, Andreas; Matuschek, Christiane; Hornung, Dagmar; Bremer, Michael; Benesch, Martin; Pietsch, Torsten; Warmuth-Metz, Monika; Kuehl, Joachim; Rutkowski, Stefan; Kortmann, Rolf D.

    2014-07-15

    Purpose: The prognosis for children with central nervous system primitive neuroectodermal tumor (CNS-PNET) or pinealoblastoma is still unsatisfactory. Here we report the results of patients between 4 and 21 years of age with nonmetastatic CNS-PNET or pinealoblastoma diagnosed from January 2001 to December 2005 and treated in the prospective GPOH-trial P-HIT 2000-AB4. Methods and Materials: After surgery, children received hyperfractionated radiation therapy (36 Gy to the craniospinal axis, 68 Gy to the tumor region, and 72 Gy to any residual tumor, fractionated at 2 × 1 Gy per day 5 days per week) accompanied by weekly intravenous administration of vincristine and followed by 8 cycles of maintenance chemotherapy (lomustine, cisplatin, and vincristine). Results: Twenty-six patients (15 with CNS-PNET; 11 with pinealoblastoma) were included. Median age at diagnosis was 11.5 years old (range, 4.0-20.7 years). Gross total tumor resection was achieved in 6 and partial resection in 16 patients (indistinct, 4 patients). Median follow-up of the 15 surviving patients was 7.0 years (range, 5.2-10.0 years). The combined response rate to postoperative therapy was 17 of 20 (85%). Eleven of 26 patients (42%; 7 of 15 with CNS-PNET; 4 of 11 with pinealoblastoma) showed tumor progression or relapse at a median time of 1.3 years (range, 0.5-1.9 years). Five-year progression-free and overall survival rates (±standard error [SE]) were each 58% (±10%) for the entire cohort: CNS-PNET was 53% (±13); pinealoblastoma was 64% (±15%; P=.524 and P=.627, respectively). Conclusions: Postoperative hyperfractionated radiation therapy with local dose escalation followed by maintenance chemotherapy was feasible without major acute toxicity. Survival rates are comparable to those of a few other recent studies but superior to those of most other series, including the previous trial, HIT 1991.

  12. Diagnostic Study of Tumor Characteristics in Patients With Ewing's Sarcoma

    ClinicalTrials.gov

    2013-06-20

    Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor

  13. Collecting and Storing Biological Samples From Patients With Ewing Sarcoma

    ClinicalTrials.gov

    2016-05-16

    Askin Tumor; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor

  14. 18F-FLT Positron Emission Tomography and Diffusion-Weighted Magnetic Resonance Imaging in Planning Surgery and Radiation Therapy and Measuring Response in Patients With Newly Diagnosed Ewing Sarcoma

    ClinicalTrials.gov

    2016-03-15

    Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Ewing Sarcoma of Bone; Extraosseous Ewing Sarcoma; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Untreated Childhood Supratentorial Primitive Neuroectodermal Tumor

  15. Combination Chemotherapy in Treating Patients With Non-Metastatic Extracranial Ewing Sarcoma

    ClinicalTrials.gov

    2016-02-19

    Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Childhood Supratentorial Primitive Neuroectodermal Tumor; Ewing Sarcoma of Bone; Extraosseous Ewing Sarcoma; Extraosseous Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Peripheral Primitive Neuroectodermal Tumor of the Kidney; Untreated Childhood Supratentorial Primitive Neuroectodermal Tumor

  16. Chlorotoxin, a scorpion-derived peptide, specifically binds to gliomas and tumors of neuroectodermal origin.

    PubMed

    Lyons, Susan A; O'Neal, Jeffrey; Sontheimer, Harald

    2002-08-01

    Highly migratory neuroectodermal cells share a common embryonic origin with cells of the central nervous system (CNS). They include enteric, parasympathetic, sympathoadrenal, and sensory neurons of the peripheral nervous system, Schwann cells, melanocytes, endocrine cells, and cells forming connective tissue of the face and neck. Because of their common embryologic origin, these cells and the tumors that derive from them can share genetic and antigenic phenotypes with gliomas, tumors derived from CNS glia. We recently discovered that chlorotoxin (ClTx), a 4-kD peptide purified from Leiurus quinquestriatus scorpion, is a highly specific marker for glioma cells in biopsy tissues (Soroceanu et al. Cancer Res 58:4871-4879, 1998) that can target tumors in animal models. We report on the specificity of ClTx as a marker for tumors of neuroectodermal origin that include peripheral neuroectodermal tumors (PNET) and gliomas. Specifically, we histochemically stained frozen and paraffin tissue sections of human biopsy tissues from 262 patients with a synthetically manufactured and biologically active ClTx bearing an N-terminal biotin. The vast majority (74 of 79) of primary human brain tumors investigated showed abundant binding of ClTx with greater than 90% ClTx-positive cells in each section. By comparison, 32 biopsies of uninvolved brain used for comparison were largely ClTx-negative, with only a few isolated reactive astrocytes showing some ClTx binding. However, as with gliomas, the vast majority of PNETs examined showed specific ClTx binding (31 of 34). These include medulloblastomas (4 of 4), neuroblastomas (6 of 7), ganglioneuromas (4 of 4), melanomas (7 of 7), adrenal pheochromocytomas (5 of 6), primitive PNET (1), small cell lung carcinoma (2 of 3), and Ewing's sarcoma (2 of 2). Under identical staining conditions, normal tissues from brain, skin, kidney, and lung were consistently negative for ClTx. These results suggest that chlorotoxin is a reliable and specific

  17. Therapeutic Trial for Patients With Ewing Sarcoma Family of Tumor and Desmoplastic Small Round Cell Tumors

    ClinicalTrials.gov

    2015-12-01

    Desmoplastic Small Round Cell Tumor; Ewing Sarcoma of Bone or Soft Tissue; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor

  18. Whole-Body Radiation Therapy, Systemic Chemotherapy, and High-Dose Chemotherapy Followed By Stem Cell Rescue in Treating Patients With Poor-Risk Ewing Sarcoma

    ClinicalTrials.gov

    2015-01-07

    Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Ewing Sarcoma of Bone; Extraosseous Ewing Sarcoma; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Untreated Childhood Supratentorial Primitive Neuroectodermal Tumor

  19. Monoclonal antibodies to a rat nestin fusion protein recognize a 220-kDa polypeptide in subsets of fetal and adult human central nervous system neurons and in primitive neuroectodermal tumor cells.

    PubMed Central

    Tohyama, T.; Lee, V. M.; Rorke, L. B.; Marvin, M.; McKay, R. D.; Trojanowski, J. Q.

    1993-01-01

    Nestin is the major intermediate filament protein of embryonic central nervous system (CNS) progenitor cells. To identify proteins involved in early stages of lineage commitment in the developing human CNS we generated monoclonal antibodies to a TrpE-rat nestin fusion protein. This resulted in a monoclonal antibody (designated NST11) that did not recognize authentic human nestin, but did recognize a novel neuron-specific human polypeptide expressed in a subset of embryonic and adult CNS neurons as well as in medulloblastomas. NST11 immunoreactivity was abundant in developing spinal cord motor neurons, but was extinguished in these neurons by 17 weeks gestation. NST11 also labeled Purkinje cells at 17 weeks gestation, but Purkinje cells continued to express the NST11 antigen throughout gestation as well as in the adult cerebellum, and NST11 immunoreactivity was more abundant in Purkinje cells than in any other human CNS neurons. No NST11 immunoreactivity was detected in cells of the adult human peripheral nervous system or in a variety of adult non-neural human tissues. Further, NST11 almost exclusively stained cerebellar medulloblastomas. In Western blots of immature and mature human cerebral and cerebellar extracts, NST11 did not bind human nestin, but did detect an immunoband with a molecular weight of 220 kd. A similar immunoband was detected in medulloblastoma-derived cell lines with a neuron-like phenotype. These findings suggest that the NST11 monoclonal antibody recognizes a novel protein expressed by a subpopulation of immature and mature human CNS neurons, medulloblastomas, and medulloblastoma-derived cell lines. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:7686344

  20. Treatment Options for Medulloblastoma and CNS Primitive Neuroectodermal Tumor (PNET)

    PubMed Central

    Packer, Roger J.

    2016-01-01

    The amount of residual disease after surgery better correlates with survival for medulloblastomas than for CNS PNETs. Maximal surgical resection of tumor should be done, only if additional permanent, neurologic deficits can be spared. Patients should have a staging work-up to assess the extent of disease. This includes postoperative magnetic resonance imaging (MRI) of the brain, MRI of the entire spine and lumbar cerebrospinal fluid (CSF) sampling for cytological examination, if deemed safe. Radiation therapy to the entire CNS axis is required, with a greater dose (boost) given to the region of the primary site or any bulky residual disease for older children. Adjuvant chemotherapy must be given even if no evidence of disease after radiation therapy exists, as the risk of relapse is substantial after radiation alone. Subsets of younger children with medulloblastoma, arbitrarily defined as those younger than 3 years of age in some studies and 4 or even 5 years in other studies, can be effectively treated with chemotherapy alone. Recent genomic studies have revealed further subtypes of disease than previously recognized. Clinical trials to exploit these biologic differences are required to assess potential efficacy of targeted agents. The treatment of medulloblastoma and CNS PNET can cause significant impairment in neurologic function. Evaluations by physical therapy, occupational therapy, speech therapy and neurocognitive assessments should be obtained, as needed. After therapy is completed, survivors need follow-up of endocrine function, surveillance scans and psychosocial support. PMID:23979905

  1. A module of human peripheral blood mononuclear cell transcriptional network containing primitive and differentiation markers is related to specific cardiovascular health variables.

    PubMed

    Moldovan, Leni; Anghelina, Mirela; Kantor, Taylor; Jones, Desiree; Ramadan, Enass; Xiang, Yang; Huang, Kun; Kolipaka, Arunark; Malarkey, William; Ghasemzadeh, Nima; Mohler, Peter J; Quyyumi, Arshed; Moldovan, Nicanor I

    2014-01-01

    Peripheral blood mononuclear cells (PBMCs), including rare circulating stem and progenitor cells (CSPCs), have important yet poorly understood roles in the maintenance and repair of blood vessels and perfused organs. Our hypothesis was that the identities and functions of CSPCs in cardiovascular health could be ascertained by analyzing the patterns of their co-expressed markers in unselected PBMC samples. Because gene microarrays had failed to detect many stem cell-associated genes, we performed quantitative real-time PCR to measure the expression of 45 primitive and tissue differentiation markers in PBMCs from healthy and hypertensive human subjects. We compared these expression levels to the subjects' demographic and cardiovascular risk factors, including vascular stiffness. The tested marker genes were expressed in all of samples and organized in hierarchical transcriptional network modules, constructed by a bottom-up approach. An index of gene expression in one of these modules (metagene), defined as the average standardized relative copy numbers of 15 pluripotency and cardiovascular differentiation markers, was negatively correlated (all p<0.03) with age (R2 = -0.23), vascular stiffness (R2 = -0.24), and central aortic pressure (R2 = -0.19) and positively correlated with body mass index (R2 = 0.72, in women). The co-expression of three neovascular markers was validated at the single-cell level using mRNA in situ hybridization and immunocytochemistry. The overall gene expression in this cardiovascular module was reduced by 72±22% in the patients compared with controls. However, the compactness of both modules was increased in the patients' samples, which was reflected in reduced dispersion of their nodes' degrees of connectivity, suggesting a more primitive character of the patients' CSPCs. In conclusion, our results show that the relationship between CSPCs and vascular function is encoded in modules of the PBMCs transcriptional network

  2. Primitive Clay.

    ERIC Educational Resources Information Center

    Chorches, Joan

    A five-week unit providing first hand experience with primitive ceramic techniques is described in this curriculum guide, which includes course goals and objectives, a daily schedule of class activities, and handouts for students. The unit features construction of a sawdust kiln as a group problem-solving activity; students work in groups…

  3. Combination Chemotherapy With or Without Ganitumab in Treating Patients With Newly Diagnosed Metastatic Ewing Sarcoma

    ClinicalTrials.gov

    2016-11-02

    Metastatic Ewing Sarcoma; Metastatic Malignant Neoplasm in the Bone; Metastatic Malignant Neoplasm in the Bone Marrow; Metastatic Malignant Neoplasm in the Lung; Metastatic Peripheral Primitive Neuroectodermal Tumor of Bone; Peripheral Primitive Neuroectodermal Tumor of Soft Tissues

  4. The evolution of the diagnosis and understanding of primitive and embryonic neoplasms in children: living through an epoch.

    PubMed

    Dehner, L P

    1998-07-01

    Approximately 30% of malignant neoplasms in children are dysontogenetic tumors whose pathologic features resemble or recapitulate those of the developing organ or tissue of origin. Archetypes include classic neuroblastoma, Wilms' tumor, and embryonal rhabdomyosarcoma. This review traces the history of the principal types of dysontogenetic neoplasms and the primitive round cell tumors, Ewing's sarcoma, and peripheral primitive neuroectodermal tumor. Retinoblastoma, neuroblastoma, and Wilms' tumor were first described in the 19th century but with several different appellations than those we use today. Although some progress was made in the surgical management of Wilms' tumor during the 1940s and 1950s, most of these unique solid neoplasms of childhood were seen as essentially untreatable and inevitably fatal; surgery and perhaps irradiation were the principal therapeutic offerings. The folic acid analogue, aminopterin, was reported in 1948 as inducing the first complete but temporary remission in acute childhood leukemia. The chemotherapeutic era began shortly thereafter with effective chemotherapy in the management of Wilms' tumor with the introduction of dactinomycin. Pathologists were no longer restricted to being purveyors of the death sentence; they were now responsible for differentiating one type of primitive and embryonic neoplasm from another by using a variety of ancillary techniques, including tissue culture, electron microscopy, immunohistochemistry, and cytogenetics. Favorable or unfavorable morphologic types and subtypes of tumors were defined and, together with the pathologic staging, became incorporated into the therapeutic plan and prognostic assessment. During the past 40 years, these tumors progressed from being virtually treatment resistant to having an overall 5-year survival of 70% or greater. Through the cooperative efforts of pediatric hematologists/oncologists, pediatric surgeons, radiation therapists, and pathologists, the primitive and

  5. Extensive Melanotic Neuroectodermal Tumor of Infancy.

    PubMed

    Albuquerque, Assis Filipe Medeiros; Cunha, José Ferreira; Avelar, Rafael Linard; Juca, Eduardo; Costa, Fabio Wildson Gurgel; Macedo, Mario Sérgio

    2016-09-01

    The melanotic neuroectodermal tumor of infancy (MNTI) is a rare childhood neoplasm with an alarming but classical clinical presentation. We present the case of a 2-month-old male infant treated with surgery for an aggressive MNTI on the alveolar process of the maxilla. Radiographic examination showed a diffuse osteolytic radiolucent lesion in the right maxilla, and displacement and dysmorphic changes in the developing primary tooth buds. The patient remained well without evidence of recurrence for 6 months after surgery. We discussed clinicopathological features, management alternatives, and outcome.

  6. Mutational analysis of the NF1 GAP-related domain in neuroectodermal tumors

    SciTech Connect

    Vinanzi, C.; Basso, G.; Perilongo, G.

    1994-09-01

    To try to contribute to the more precise characterization of the function of the NF1 gene in tumorigenesis we have analyzed the most conserved region of its coding sequence, the GAP-related domain (NF1 GRD), which is attributed with tumor suppressor function. The rationale for the study was based on the likelihood of finding structural alterations resulting in loss of function of this region, in situations such as tumors of neuroepithelial tissues. In these situations, the activity of the NF1 gene product, neurofibromis, a GTPase activating protein, seems to be crucial in regulating the mechanisms of signal transduction mediated by p21 ras. We have studied the NF1 GRD region by PCR amplification of each exon (exons 21-27a) followed by subsequent PAGE and SSCP analysis of the amplification products in 60 primary sporadic neuroectodermal tumors. Our sample included: 14 neuroblastoma, 11 glioblastoma, 8 medulloblastoma, 7 ependimoma, 6 peripheral PNET, 1 ganglioneuroma, 1 glioma, 1 Ewing sarcoma, 1 meningioma and 1 schwannoma. We have not identified structural alterations of the NF1 GRD region in the tumors analysed, with one possible exception now in the process of being characterized. We can conclude that the loss of the NF1 gene tumor suppressor function that might lead or contribute to the development of malignancies in tissues of neuroectodermal origin is not due to structural abnormalities of the region of the gene interacting with p21 ras, either as a negative regulator or as a downstream effector of it. These data, together with the observation that the oncogene ras 21 is not typically mutated in neuroectodermal tumors, and that GTP-ras has been found normally regulated in neurofibromis-deficient melanoma and neuroblastoma cell lines, seem to support the hypothesis that the antioncogene activity of the NF1 gene could be totally independent from its interaction with ras.

  7. Chromosomal translocations highlighted in Primitive Neuroectodermal Tumors (PNET) and Ewing sarcoma

    PubMed Central

    Trancău, IO

    2014-01-01

    Almost 200 molecular markers in oncology, very important in the diagnosis, prognostic and treatment were identified. The cell and tissue markers and also the circulating (sanguine) ones are genetic markers of the hereditary and non-hereditary tumors. Also extremely important are the regulatory ways of cell growth and differentiation, of the cell “senescence” and cell death (apoptosis). The term of “tumor marker” concerns a variety of molecules or processes that are different in the normal cell compared with the malign cell. The tumor markers may include modifications to the genetic level (mutations, deletions or genes amplifications) to the transcription level (super expression or sub-expression), to the translation level (high or low quantities of proteins, abnormal glycosylation of proteins) and/or to the functional level (the level of cell differentiation or presence of neo-vascularisation). Cancer is a genetic disease. There is a deregulation at the genes level that controls the cell division and withdrawal from the cell cycle or there is a genetic susceptibility. In other words, cancer is an end point for several phases in which the oncogenes and stimulatory signals and inhibitors produced and controlled by the products of these oncogenes are involved. PMID:25870694

  8. Generalized compliant motion primitive

    NASA Technical Reports Server (NTRS)

    Backes, Paul G. (Inventor)

    1994-01-01

    This invention relates to a general primitive for controlling a telerobot with a set of input parameters. The primitive includes a trajectory generator; a teleoperation sensor; a joint limit generator; a force setpoint generator; a dither function generator, which produces telerobot motion inputs in a common coordinate frame for simultaneous combination in sensor summers. Virtual return spring motion input is provided by a restoration spring subsystem. The novel features of this invention include use of a single general motion primitive at a remote site to permit the shared and supervisory control of the robot manipulator to perform tasks via a remotely transferred input parameter set.

  9. Workshop: Teaching Primitive Arts.

    ERIC Educational Resources Information Center

    Jordison, Jerry

    1999-01-01

    Discusses the concrete and spiritual aspects of teaching workshops on survival skills or primitive arts. Gives details on lostproofing, or ways to teach a child not to get lost in the outdoors; building a survival shelter; and wilderness cooking. (CDS)

  10. Imetelstat Sodium in Treating Younger Patients With Relapsed or Refractory Solid Tumors

    ClinicalTrials.gov

    2014-06-03

    Childhood Hepatoblastoma; Previously Treated Childhood Rhabdomyosarcoma; Recurrent Childhood Liver Cancer; Recurrent Childhood Rhabdomyosarcoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Neuroblastoma; Recurrent Osteosarcoma

  11. Melanotic neuroectodermal tumor of infancy arising in the temporal bone.

    PubMed

    Zhang, Jian-guo; Zhao, Rui-jiao; Kong, Ling-fei

    2015-04-01

    Melanotic neuroectodermal tumor of infancy is a rare melanin-containing neoplasm with locally aggressive and rapid expansile growth, usually involving the maxilla, skull, and mandible of early infancy. Radical surgery is critical for a long-term outcome. We present a case of 14-month-old girl with rapid-growing subcutaneous mass arising in the right temporal bone and extending intracranially on computed tomographic scan. Radical surgery was performed. A brownish-black tumor composed of large pigmented epithelioid cells, positive for cytokeratins and HMB-45, and nests of small neuroblast-like cells positive for neuron-specific enolase and synaptophysin, was diagnosed as melanotic neuroectodermal tumor of infancy. The patient remained well without evidence of recurrence for 1 year after surgery. Clinicopathological features, management alternatives and outcome were discussed.

  12. [Jaws of primitive mammals].

    PubMed

    Tsubamoto, Takehisa

    2005-06-01

    Some of main osteological differences between mammals and reptiles are seen in the number of bones that constitute lower jaw and in jaw articulation. A lower jaw of mammals consists of only one bone, while in reptiles it consists of several bones (e.g., four to six in lizards and five in crocodiles). The jaw articulation in mammals is performed by squamosal of the skull and the mandible ( = dentary), while in reptiles it is done by quadrate of the skull and articular of the lower jaw. When mammals first appeared about 200 million years ago in the Mesozoic Era, the jaws of primitive mammals were morphologically intermediate between those of reptiles and typical mammals. Here, I briefly introduce the evolution of lower jaw morphology from the reptilian one to the mammalian one, showing lower jaw features of some mammal-like reptiles and primitive mammals.

  13. Primitive Solar System Objects

    NASA Astrophysics Data System (ADS)

    Jewitt, David

    1999-10-01

    Some of the most fundamental and topical questions in astronomy concern the origin and evolution of planetary systems. In the solar system, these questions are most directly addressed through observations of chemically and physically primitive bodies in which a record of the initial conditions may be preserved. The most primitive materials in the solar system reside near its outer edge, in a trans-Neptunian ring known as the Kuiper Belt and in a surrounding spherical cloud first postulated by Oort. These regions supply comets to the inner solar system and, in the case of the Kuiper Belt, preserve evidence of dynamical processes operative in the first 100 million years after formation. The Kuiper Belt is also a source of collisionally produced dust and may be analogous to the dusty rings observed encircling a number of nearby main-sequence stars. I will review the currently known properties of these primitive objects, and discuss how ALMA can contribute to our understanding of the early solar system.

  14. Tanespimycin in Treating Young Patients With Recurrent or Refractory Leukemia or Solid Tumors

    ClinicalTrials.gov

    2013-06-03

    Childhood Chronic Myelogenous Leukemia; Childhood Desmoplastic Small Round Cell Tumor; Disseminated Neuroblastoma; Metastatic Childhood Soft Tissue Sarcoma; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Osteosarcoma; Previously Treated Childhood Rhabdomyosarcoma; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Neuroblastoma; Recurrent Osteosarcoma

  15. Sorafenib in Treating Patients With Soft Tissue Sarcomas (Extremity Sarcoma Closed to Entry as of 5/30/07)

    ClinicalTrials.gov

    2014-04-01

    Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Osteosarcoma; Recurrent Adult Soft Tissue Sarcoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Osteosarcoma; Stage I Adult Soft Tissue Sarcoma; Stage II Adult Soft Tissue Sarcoma; Stage III Adult Soft Tissue Sarcoma; Stage IV Adult Soft Tissue Sarcoma

  16. Carbon in primitive meteorites

    NASA Technical Reports Server (NTRS)

    Kerridge, John F.

    1990-01-01

    No meteorites are truly primitive, in the sense of being pristine collections of interstellar grains or solar-nebular condensates. Nonetheless, some chrondritic meteorites have been so little altered by secondary processing that they are commonly termed primitive and it is almost a definition of such chondrites that they contain significant quantities of carbon. Most of that carbon is of apparently local, i.e., solar-system, origin but a proportion that ranges from trace, in some cases, to minor, in others, is believed to be exotic, i.e., of circumstellar or interstellar origin, and it is upon such material that researchers focus here. The nature of the meteoritic samples and the techniques used to analyse them are briefly discussed and the observational record is surveyed. Clearly, the study of exotic carbon preserved in meteorites has been informative about sites of nucleosynthesis, processes of nucleation and growth of grains in stellar outflows, grain survival in the interstellar medium, and many other topics of astrophysical significance. Much more work, particularly of an interdisciplinary nature remains to be done, however.

  17. A Structure behind Primitive Chaos

    NASA Astrophysics Data System (ADS)

    Ogasawara, Yoshihito

    2015-06-01

    Recently, a new concept, primitive chaos, has been proposed as a concept closely related to the fundamental problems of physics itself such as determinism, causality, free will, predictability, and irreversibility [J. Phys. Soc. Jpn. 79, 015002 (2010)]. This paper reveals a structure hidden behind the primitive chaos; under some conditions, a new primitive chaos is constructed from the original primitive chaos, this procedure can be repeated, and the hierarchical structure of the primitive chaos is obtained. This implies such a picture that new events and causality are constructed from the old ones, with the aid of the concept of a coarse graining. As an application of this structure, interesting facts are revealed for the essential condition of the primitive chaos and for chaotic behaviors.

  18. Dynamic Primitives of Motor Behavior

    PubMed Central

    Hogan, Neville; Sternad, Dagmar

    2013-01-01

    We present in outline a theory of sensorimotor control based on dynamic primitives, which we define as attractors. To account for the broad class of human interactive behaviors—especially tool use—we propose three distinct primitives: submovements, oscillations and mechanical impedances, the latter necessary for interaction with objects. Due to fundamental features of the neuromuscular system, most notably its slow response, we argue that encoding in terms of parameterized primitives may be an essential simplification required for learning, performance, and retention of complex skills. Primitives may simultaneously and sequentially be combined to produce observable forces and motions. This may be achieved by defining a virtual trajectory composed of submovements and/or oscillations interacting with impedances. Identifying primitives requires care: in principle, overlapping submovements would be sufficient to compose all observed movements but biological evidence shows that oscillations are a distinct primitive. Conversely, we suggest that kinematic synergies, frequently discussed as primitives of complex actions, may be an emergent consequence of neuromuscular impedance. To illustrate how these dynamic primitives may account for complex actions, we briefly review three types of interactive behaviors: constrained motion, impact tasks, and manipulation of dynamic objects. PMID:23124919

  19. Density of Primitive Pythagorean Triples

    ERIC Educational Resources Information Center

    Killen, Duncan A.

    2004-01-01

    Based on the properties of a Primitive Pythagorean Triple (PPT), a computer program was written to generate, print, and count all PPTs greater than or equal to I[subscript x], where I[subscript x] is an arbitrarily chosen integer. The Density of Primitive Pythagorean Triples may be defined as the ratio of the number of PPTs whose hypotenuse is…

  20. Scans as primitive parallel operations

    SciTech Connect

    Blelloch, G.E. . Dept. of Computer Science)

    1989-11-01

    In most parallel random access machine (PRAM) models, memory references are assumed to take unit time. In practice, and in theory, certain scan operations, also known as prefix computations, can execute in no more time than these parallel memory references. This paper outlines an extensive study of the effect of including, in the PRAM models, such scan operations as unit-time primitives. The study concludes that the primitives improve the asymptotic running time of many algorithms by an O(log n) factor greatly simplify the description of many algorithms, and are significantly easier to implement than memory references. The authors argue that the algorithm designer should feel free to use these operations as if they were as cheap as a memory reference. This paper describes five algorithms that clearly illustrate how the scan primitives can be used in algorithm design. These all run on an EREW PRAM with the addition of two scan primitives.

  1. Pax6 is a human neuroectoderm cell fate determinant

    PubMed Central

    Zhang, Xiaoqing; Huang, Cindy T.; Chen, Jing; Pankratz, Matthew T.; Xi, Jiajie; Li, Jin; Yang, Ying; LaVaute, Timothy M.; Li, Xue-Jun; Ayala, Melvin; Bondarenko, Gennadiy I.; Du, Zhong-Wei; Jin, Ying; Golos, Thaddeus G.; Zhang, Su-Chun

    2010-01-01

    SUMMARY The transcriptional regulation of neuroectoderm (NE) specification is unknown. Here we show that Pax6 is uniformly expressed in early NE cells of human fetuses and those differentiated from human embryonic stem cells (hESCs). This contrasts the later expression of Pax6 in restricted mouse brain regions. Knockdown of Pax6 blocks NE specification from hESCs. Overexpression of either Pax6a or Pax6b, but not Pax6 PD, triggers hESC differentiation. However, only Pax6a converts hESCs to NE. In contrast, neither loss nor gain of function of Pax6 affects mouse NE specification. Both Pax6a and Pax6b bind to pluripotent gene promoters but only Pax6a binds to NE genes during human NE specification. These findings indicate that Pax6 is a transcriptional determinant of the human NE and suggest that Pax6a and Pax6b coordinate with each other in determining the transition from pluripotency to the NE fate in human by differentially targeting pluripotent and NE genes. PMID:20621053

  2. Primitive Terrestrial Atmospheres

    NASA Astrophysics Data System (ADS)

    Zahnle, Kevin John

    1985-12-01

    A 23.3 year periodicity preserved in a 2500 million year old banded iron-formation is interpreted as reflecting the climatic influence of the lunar nodal tide, the signature of which has been detected in the modern climate. The lunar distance is deduced to have been 52 Earth radii. The influence of the lunar nodal tide is also detected in varves dating to 680 million years B.P. The implied history of Precambrian tidal friction is in excellent agreement with both more recent paleontological evidence and the long -term stability of the lunar orbit. The solar semidiurnal thermal tide was resonant with the natural period of the atmosphere when the day was (TURN)21.3 hours. This took place at the end of the Precambrian. The resonant atmospheric tide would have been large enough (.01 bar at the surface) to have influenced the weather. In contrast to lunar oceanic tides, the gravitational torque on the thermal tide accelerates the Earth's rotation rate; near resonance the opposing torques were comparable, so that the day may have been stabilized near 21.3 hours for much of the Precambrian. A sustained resonance does not conflict with the available evidence. Methane photochemistry in the primitive terrestrial atmosphere is studied using a detailed numerical model. Methane is oxidized cleanly and efficiently provided CO(,2) is more abundant than CH(,4). If CH(,4) and CO(,2) abundances are comparable, a large fraction of the methane present is polymerized, forming alkanes in the troposphere and polyacetylenes and nitriles in the upper atmosphere. Production of HCN from CH(,4) and N(,2) in the anaerobic atmosphere and its subsequent removal in rainwater could have been efficient; net production varying from .01% to 10% of the methane consumed. In the absence of a magnetic field, high ancient solar EUV and X-ray fluxes would have permitted an ocean of hydrogen to escape as a transsonic wind from a primordial accretionary greenhouse atmosphere in as little as 25 million years

  3. Cooperative Wnt-Nodal Signals Regulate the Patterning of Anterior Neuroectoderm

    PubMed Central

    Yaguchi, Junko; Takeda, Noriyo; Inaba, Kazuo; Yaguchi, Shunsuke

    2016-01-01

    When early canonical Wnt is experimentally inhibited, sea urchin embryos embody the concept of a Default Model in vivo because most of the ectodermal cell fates are specified as anterior neuroectoderm. Using this model, we describe here how the combination of orthogonally functioning anteroposterior Wnt and dorsoventral Nodal signals and their targeting transcription factors, FoxQ2 and Homeobrain, regulates the precise patterning of normal neuroectoderm, of which serotonergic neurons are differentiated only at the dorsal/lateral edge. Loss-of-function experiments revealed that ventral Nodal is required for suppressing the serotonergic neural fate in the ventral side of the neuroectoderm through the maintenance of foxQ2 and the repression of homeobrain expression. In addition, non-canonical Wnt suppressed homeobrain in the anterior end of the neuroectoderm, where serotonergic neurons are not differentiated. Canonical Wnt, however, suppresses foxQ2 to promote neural differentiation. Therefore, the three-dimensionally complex patterning of the neuroectoderm is created by cooperative signals, which are essential for the formation of primary and secondary body axes during embryogenesis. PMID:27101101

  4. Cooperative Wnt-Nodal Signals Regulate the Patterning of Anterior Neuroectoderm.

    PubMed

    Yaguchi, Junko; Takeda, Noriyo; Inaba, Kazuo; Yaguchi, Shunsuke

    2016-04-01

    When early canonical Wnt is experimentally inhibited, sea urchin embryos embody the concept of a Default Model in vivo because most of the ectodermal cell fates are specified as anterior neuroectoderm. Using this model, we describe here how the combination of orthogonally functioning anteroposterior Wnt and dorsoventral Nodal signals and their targeting transcription factors, FoxQ2 and Homeobrain, regulates the precise patterning of normal neuroectoderm, of which serotonergic neurons are differentiated only at the dorsal/lateral edge. Loss-of-function experiments revealed that ventral Nodal is required for suppressing the serotonergic neural fate in the ventral side of the neuroectoderm through the maintenance of foxQ2 and the repression of homeobrain expression. In addition, non-canonical Wnt suppressed homeobrain in the anterior end of the neuroectoderm, where serotonergic neurons are not differentiated. Canonical Wnt, however, suppresses foxQ2 to promote neural differentiation. Therefore, the three-dimensionally complex patterning of the neuroectoderm is created by cooperative signals, which are essential for the formation of primary and secondary body axes during embryogenesis. PMID:27101101

  5. Dysembryoplastic neuroectodermal tumor: an ultrastructural study of six cases.

    PubMed

    Biernat, W; Liberski, P P; Kordek, R; Zakrzewski, K; Polis, L; Budka, H

    2001-01-01

    Dysembryoplastic neuroectodermal tumor (DNT) is a rare brain neoplasm. Although the tumor pathology is relatively well charactererized, its full clinicopathological spectrum is still discussed, and ultrastructural data on it are very limited. Here, the authors describe detailed ultrastructural pathology of 7 cases of DNT. Each tumor consisted of 3 major elements: neoplastic cells (oligodendroglial-like cells, OLC), elongated processes forming neuropil-like structure, and expanded "mucoid" extracellular space, the latter giving an impression of cellular elements floating within it. Neoplastic cells had round, oval, or elongated nuclei, no discernible nucleoli, and a relatively narrow rim of cytoplasm. Some nuclei were irregular and invaginated, and pseudoinclusions (invaginations of cytoplasm penetrated into toroid-like nuclear formations) were observed. Part of the cytoplasm sequestrated within pseudoinclusions often appeared degenerated with large blebs and electron-lucent vesicles, and some of these contained, in turn, semicircular profiles of unknown significance. Chromatin was clustered below the nuclear membrane. The cytoplasm contained a few mitochondria, round rather than elongated, a few stacks of rough endoplasmic reticulum, and scanty microtubules and clear vesicles. The second element consisted of innumerable cellular processes. Some of these were elongated and formed stacks connected by symmetric or asymetric adhesive plaque junctions. Others had shorter "neck" containing microtubules extending into bulbous extensions. Dense-cored vesicles were occasionally observed, both in the cytoplasm of neoplastic cells and within processes. In one cell, cross-sectioned annulate lamellae were found. In the cytoplasm of a few cells, unusual inclusions reminiscent of ribosome-lamellae resembled "laboratory tubes" with cone-like endings. At higher power, walls of the "tubes" resolved into layered structures composed of several laminae; between these, ribosome

  6. Ganglioside conjugate vaccines. Immunotherapy against tumors of neuroectodermal origin.

    PubMed

    Helling, F; Livingston, P O

    1994-01-01

    Gangliosides are known to be suitable targets for immune attack against cancer but they are poorly immunogenic. Active immunization with ganglioside/BCG or liposome vaccines results in moderate titer IgM antibody responses of short duration. Covalent attachment of poorly immunogenic antigens to immunogenic proteins is a potent method for inducing an IgG antibody response. GD3, a dominant ganglioside on malignant melanoma, was modified by ozone cleavage of the double bond in the ceramide backbone, an aldehyde group introduced and used for coupling via reductive amination to epsilon-amino-lysyl groups of proteins. Utilizing this method, GD3 conjugates were constructed with: 1. Synthetic multiple antigenic peptide (MAP) constructs expressing 4 repeats of a malaria T-cell epitope; 2. Outer membrane proteins (OMP) of Neisseria meningitidis; 3. Cationized bovine serum albumin; 4. Keyhole limpet hemocyanin (KLH); and 5. Polylysine. In addition, conjugates containing only the GD3 oligosaccharide were synthesized. All constructs were tested for antigenicity using anti-GD3 antibody R24, and for immunogenicity in mice. Serum antibody levels were analyzed by ELISA and immune thin-layer chromatography. Results in the mouse show a significant improvement in the IgM antibody response and a consistent IgG response against GD3 using GD3-KLH conjugates. Other carrier proteins and the use of GD3 oligosaccharide were significantly less effective. If improved immunogenicity and clinical benefit with conjugate vaccines can be demonstrated in patients with melanoma, this approach may be applicable to patients with other tumors of neuroectodermal origin, including gliomas, glioblastomas, astrocytomas, and neuroblastomas.

  7. Peripheral Neuropathy

    MedlinePlus

    ... Enhancing Diversity Find People About NINDS NINDS Peripheral Neuropathy Information Page Condensed from Peripheral Neuropathy Fact Sheet ... Español Additional resources from MedlinePlus What is Peripheral Neuropathy? Peripheral neuropathy describes damage to the peripheral nervous ...

  8. Super VGA Primitives Graphics System.

    1992-05-14

    Version 00 These primitives are the lowest level routines needed to perform super VGA graphics on a PC. A sample main program is included that exercises the primitives. Both Lahey and Microsoft FORTRAN's have graphics libraries. However, the libraries do not support 256 color graphics at resolutions greater than 320x200. The primitives bypass these libraries while still conforming to standard usage of BIOS. The supported graphics modes depend upon the PC graphics card and itsmore » memory. Super VGA resolutions of 640x480 and 800x600 have been tested on an ATI VGA Wonder card with 512K memory and on several 80486 PC's (unknown manufacturers) at retail stores.« less

  9. AGUA TIBIA PRIMITIVE AREA, CALIFORNIA.

    USGS Publications Warehouse

    Irwin, William P.; Thurber, Horace K.

    1984-01-01

    The Agua Tibia Primitive Area in southwestern California is underlain by igneous and metamorphic rocks that are siilar to those widely exposed throughout much of the Peninsular Ranges. To detect the presence of any concealed mineral deposits, samples of stream sediments were collected along the various creeks that head in the mountain. As an additional aid in evaluating the mineral potential, an aeromagnetic survey was made and interpreted. A search for records of past or existing mining claims within the primitive area was made but none was found. Evidence of deposits of metallic or nonmetallic minerals was not seen during the study.

  10. Peripheral neuropathy

    MedlinePlus

    Peripheral neuritis; Neuropathy - peripheral; Neuritis - peripheral; Nerve disease; Polyneuropathy ... Neuropathy is very common. There are many types and causes. Often, no cause can be found. Some ...

  11. Image recovery from edge primitives

    NASA Technical Reports Server (NTRS)

    Alter-Gartenberg, Rachel; Huck, Friedrich O.; Narayanswamy, Ramkumar

    1990-01-01

    A method for extracting edge primitives from Mach-band patterns is presented together with a method for recovering image representations of features outlined by the edge boundaries. The accuracy, stability, and resolution of these representations are assessed. Since these representations are most commonly used in characterizing targets, this method of low-level processing offers new opportunities for computer vision and high data-compressing coding. Two bandpass filters are considered, the spatially invariant Laplacian of Gaussian filter and spatially variant intensity-dependent spatial (IDS) summation. It is shown that the recovery from the IDS bandpass data is particularly advantageous in applications for which robustness to local and temporal variations in illumination is important. It is concluded that the edge primitives extracted from bandpassed images can be an efficient way to store, transmit, and represent images.

  12. SPANISH PEAKS PRIMITIVE AREA, MONTANA.

    USGS Publications Warehouse

    Calkins, James A.; Pattee, Eldon C.

    1984-01-01

    A mineral survey of the Spanish Peaks Primitive Area, Montana, disclosed a small low-grade deposit of demonstrated chromite and asbestos resources. The chances for discovery of additional chrome resources are uncertain and the area has little promise for the occurrence of other mineral or energy resources. A reevaluation, sampling at depth, and testing for possible extensions of the Table Mountain asbestos and chromium deposit should be undertaken in the light of recent interpretations regarding its geologic setting.

  13. HIGH SIERRA PRIMITIVE AREA, CALIFORNIA.

    USGS Publications Warehouse

    Moore, James G.; Marks, Lawrence Y.

    1984-01-01

    On the basis of a mineral-resource survey, the High Sierra Primitive Area, California was found to have an area of probable mineral-resource potential for tungsten. A small demonstrated tungsten resource is present on the Obelisk claims near the contact of limy metasedimentary rock and granitic rock in the northwest part of the area, and additional small deposits may be expected to occur to the south, in a similar geologic setting.

  14. SYCAMORE CANYON PRIMITIVE AREA, ARIZONA.

    USGS Publications Warehouse

    Huff, Lyman C.; Raabe, R.C.

    1984-01-01

    The Sycamore Canyon Primitive Area, which occupies about 74 sq mi, lies about 24 mi southwest of Flagstaff, Arizona. To help evaluate the area for mineral resources, sediment samples were collected along Sycamore Creek and its tributaries. These were analyzed for traces of the ore metals without finding any local concentrations. In addition, a scintillometer was used to test rocks in the area without finding any abnormal radioactivity.

  15. A role of melatonin in neuroectodermal-mesodermal interactions: the hair follicle synthesizes melatonin and expresses functional melatonin receptors.

    PubMed

    Kobayashi, Hiromi; Kromminga, Arno; Dunlop, Thomas W; Tychsen, Birte; Conrad, Franziska; Suzuki, Naoto; Memezawa, Ai; Bettermann, Albrecht; Aiba, Setsuya; Carlberg, Carsten; Paus, Ralf

    2005-10-01

    Since mammalian skin expresses the enzymatic apparatus for melatonin synthesis, it may be an extrapineal site of melatonin synthesis. However, evidence is still lacking that this is really the case in situ. Here, we demonstrate melatonin-like immunoreactivity (IR) in the outer root sheath (ORS) of mouse and human hair follicles (HFs), which corresponds to melatonin, as shown by radioimmunoassay and liquid chromatography/tandem mass spectrometry (LC/MS/MS). The melatonin concentration in organ-cultured mouse skin, mouse vibrissae follicles, and human scalp HFs far exceeds the respective melatonin serum level and is significantly increased ex vivo by stimulation with norepinephrine (NE), the key stimulus for pineal melatonin synthesis. By real-time PCR, transcripts for the melatonin membrane receptor MT2 and for the nuclear mediator of melatonin signaling, retinoid orphan receptor alpha (ROR)alpha, are detectable in murine back skin. Transcript levels for these receptors fluctuate in a hair cycle-dependent manner, and are maximal during apoptosis-driven HF regression (catagen). Melatonin may play a role in hair cycle regulation, since its receptors (MT2 and RORalpha) are expressed in murine skin in a hair cycle-dependent manner, and because it inhibits keratinocyte apoptosis and down-regulates ERalpha expression. Therefore, the HF is both, a prominent extrapineal melatonin source, and an important peripheral melatonin target tissue. Regulated intrafollicular melatonin synthesis and signaling may play a previously unrecognized role in the endogenous controls of hair growth, for example, by modulating keratinocyte apoptosis during catagen and by desensitizing the HF to estrogen signaling. As a prototypic neuroectodermal-mesodermal interaction model, the HF can be exploited for dissecting the obscure role of melatonin in such interactions in peripheral tissues. PMID:16030176

  16. Stardust silicates from primitive meteorites.

    PubMed

    Nagashima, Kazuhide; Krot, Alexander N; Yurimoto, Hisayoshi

    2004-04-29

    Primitive chondritic meteorites contain material (presolar grains), at the level of a few parts per million, that predates the formation of our Solar System. Astronomical observations and the chemical composition of the Sun both suggest that silicates must have been the dominant solids in the protoplanetary disk from which the planets of the Solar System formed, but no presolar silicates have been identified in chondrites. Here we report the in situ discovery of presolar silicate grains 0.1-1 microm in size in the matrices of two primitive carbonaceous chondrites. These grains are highly enriched in 17O (delta17O(SMOW) > 100-400 per thousand ), but have solar silicon isotopic compositions within analytical uncertainties, suggesting an origin in an oxygen-rich red giant or an asymptotic giant branch star. The estimated abundance of these presolar silicates (3-30 parts per million) is higher than reported for other types of presolar grains in meteorites, consistent with their ubiquity in the early Solar System, but is about two orders of magnitude lower than their abundance in anhydrous interplanetary dust particles. This result is best explained by the destruction of silicates during high-temperature processing in the solar nebula.

  17. Primitive reflexes in Parkinson's disease.

    PubMed Central

    Vreeling, F W; Verhey, F R; Houx, P J; Jolles, J

    1993-01-01

    A standardised protocol for the examination of 15 primitive reflexes in which the amplitude and the persistence were scored separately, was applied to 25 patients with Parkinson's disease and an equal number of healthy matched control subjects. Most reflexes were found considerably more often in the patients than in the control subjects, especially the snout, the glabellar tap, and its variant, the nasopalpebral reflex. Only the mouth open finger spread reflex was present more often in the control subjects. For all reflexes except this last, the scores for amplitude and persistence of the reflexes for the control group never exceeded the scores for the patient group. Reflexes persisted more often in the patients than in the control subjects. Parkinsonism alone can explain a large number of primitive reflexes, irrespective of the severity or duration of the disease. In contrast, the number of reflexes was related more closely to cognitive scales. It is concluded that such reflexes may be helpful in diagnosing Parkinson's disease. In addition, a standardised protocol for eliciting and scoring is essential for the study of these reflexes in parkinsonism and other neuropsychiatric conditions. PMID:8270937

  18. Stardust silicates from primitive meteorites.

    PubMed

    Nagashima, Kazuhide; Krot, Alexander N; Yurimoto, Hisayoshi

    2004-04-29

    Primitive chondritic meteorites contain material (presolar grains), at the level of a few parts per million, that predates the formation of our Solar System. Astronomical observations and the chemical composition of the Sun both suggest that silicates must have been the dominant solids in the protoplanetary disk from which the planets of the Solar System formed, but no presolar silicates have been identified in chondrites. Here we report the in situ discovery of presolar silicate grains 0.1-1 microm in size in the matrices of two primitive carbonaceous chondrites. These grains are highly enriched in 17O (delta17O(SMOW) > 100-400 per thousand ), but have solar silicon isotopic compositions within analytical uncertainties, suggesting an origin in an oxygen-rich red giant or an asymptotic giant branch star. The estimated abundance of these presolar silicates (3-30 parts per million) is higher than reported for other types of presolar grains in meteorites, consistent with their ubiquity in the early Solar System, but is about two orders of magnitude lower than their abundance in anhydrous interplanetary dust particles. This result is best explained by the destruction of silicates during high-temperature processing in the solar nebula. PMID:15118720

  19. Talazoparib and Temozolomide in Treating Younger Patients With Refractory or Recurrent Malignancies

    ClinicalTrials.gov

    2016-10-10

    Adult Solid Neoplasm; Childhood Solid Neoplasm; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Central Nervous System Neoplasm; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Refractory Central Nervous System Neoplasm

  20. Evaluating Dactinomycin and Vincristine in Young Patients With Cancer

    ClinicalTrials.gov

    2016-09-23

    Childhood Acute Lymphoblastic Leukemia; Childhood Rhabdomyosarcoma; Childhood Soft Tissue Sarcoma; Ewing Sarcoma; Ewing Sarcoma of Bone; Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor (PNET); Unspecified Childhood Solid Tumor, Protocol Specific; Wilms Tumor and Other Childhood Kidney Tumors

  1. Origin of Ameloblastoma From Basal Cells of the Oral Epithelium- Establishing the Relation Using Neuroectodermal Markers

    PubMed Central

    Suneela, S; Narayan, T V; Shreedhar, Balasundari; Mohanty, Leeky; Shenoy, Sadhana; Swaminathan, Uma

    2014-01-01

    Background and Objectives: Basal cell layer of the oral epithelium has been rightfully regarded as a potential source of odontogenic tumours and cysts, but, without substantial evidence. Also, whether the basal cell layer retains within it, some properties of ectomesenchyme, which was imbibed during the early embryogenesis and hence its neuroectodermal relation, is not known. Here, an attempt is made to establish the hidden neuroectodermal potential of the oral epithelium, especially the basal layer, by observing the expression of known neuroectodermal markers, NSE (Neuron Specific Enolase), Synaptophysin and CD99. The expression of the same markers has also been studied in Ameloblastoma, connecting it with oral epithelium, in turn establishing basal cell layer as a potential source of Ameloblastoma. Materials and Methods: Sections of formalin fixed, paraffin embedded tissue samples of 20 cases of Ameloblastoma and 10 cases of Normal Retromolar mucosa, were stained immunohistochemically with NSE, Synaptophysin, CD99 and also with CK-19 and evaluated for positive expression. Results: Positive reaction was obtained in all the cases of Ameloblastoma and NRM (Normal Retromolar mucosa) with NSE, all the cases of Ameloblastoma and eight cases of NRM with Synaptophysin and in six cases of Ameloblastoma and NRM with CD99. The staining was diffuse and more marked in case of NSE than Synaptophysin and CD99. CK19 staining done to assure that the tissue antigenicity was maintained was positive in all the samples. Interpretation and Conclusion: A strong relationship between the neuroectoderm, Ameloblastoma and the basal layer of the oral epithelium is established by the study. It favours the hypothesis that the basal cell layer of oral mucosa may be the sought out culprit in most cases of the Ameloblastomas, especially those occurring in the non-tooth bearing area. This would call for the need to incorporate additional therapy in the form of mucosal striping along with the

  2. Primitive pleasure as the basic human state.

    PubMed

    Norris, C M

    1985-10-01

    Physiological homeostasis as a goal for much of nursing practice is put into question. The goal of primitive pleasure is substituted as a goal of nursing in that nurses assist people in returning to a basic state of pleasure. This basic human state is further specified as primitive pleasure, primitive in that it is sensory, sensual, and carnal as compared to cognitive or esthetic in nature. Propositions related to primitive pleasure as the basic human state are identified, described, illustrated, and discussed. This beginning conceptualization of an ideal human state was developed without examination of or relation to existing theories such as arousal, stimulation response, Freud's pleasure principle, or developmental theories.

  3. Depsipeptide (Romidepsin) in Treating Patients With Metastatic or Unresectable Soft Tissue Sarcoma

    ClinicalTrials.gov

    2016-09-12

    Adult Alveolar Soft-part Sarcoma; Adult Angiosarcoma; Adult Epithelioid Sarcoma; Adult Extraskeletal Chondrosarcoma; Adult Extraskeletal Osteosarcoma; Adult Fibrosarcoma; Adult Leiomyosarcoma; Adult Liposarcoma; Adult Malignant Fibrous Histiocytoma; Adult Malignant Hemangiopericytoma; Adult Malignant Mesenchymoma; Adult Neurofibrosarcoma; Adult Rhabdomyosarcoma; Adult Synovial Sarcoma; Gastrointestinal Stromal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Adult Soft Tissue Sarcoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Stage III Adult Soft Tissue Sarcoma; Stage IV Adult Soft Tissue Sarcoma

  4. Intensity-Modulated Radiation Therapy in Treating Younger Patients With Lung Metastases

    ClinicalTrials.gov

    2013-09-23

    Adult Rhabdomyosarcoma; Lung Metastases; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Previously Treated Childhood Rhabdomyosarcoma; Recurrent Adult Soft Tissue Sarcoma; Recurrent Childhood Rhabdomyosarcoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Wilms Tumor and Other Childhood Kidney Tumors; Stage IV Adult Soft Tissue Sarcoma; Stage IV Wilms Tumor; Stage V Wilms Tumor; Unspecified Adult Solid Tumor, Protocol Specific; Unspecified Childhood Solid Tumor, Protocol Specific

  5. Reflectance spectra of primitive chondrites

    NASA Astrophysics Data System (ADS)

    Trigo-Rodríguez, J. M.; Moyano-Cambero, C. E.; Llorca, J.

    2013-05-01

    We are studying a wide sample of pristine carbonaceous chondrites from the NASA Antarctic collection in order to get clues on the physico-chemical processes occurred in the parent bodies of these meteorites. We are obtaining laboratory reflectance spectra of different groups of carbonaceous chondrites, but here we focus in CM and CI chondrites. We discuss the main spectral features that can be used to identify primitive carbonaceous asteroids by remote sensing techniques. Two different spectrometers were used covering the entire 0.3 to 30 μm electromagnetic window. Only a handful of Near Earth Objects (NEOs) exhibit bands or features clearly associated with aqueous alteration. Among them are the target asteroids of Osiris Rex and Marco Polo-R missions.

  6. Filamentation as primitive growth mode?

    NASA Astrophysics Data System (ADS)

    Bigan, Erwan; Steyaert, Jean-Marc; Douady, Stéphane

    2015-12-01

    Osmotic pressure influences cellular shape. In a growing cell, chemical reactions and dilution induce changes in osmolarity, which in turn influence the cellular shape. Using a protocell model relying upon random conservative chemical reaction networks with arbitrary stoichiometry, we find that when the membrane is so flexible that its shape adjusts itself quasi-instantaneously to balance the osmotic pressure, the protocell either grows filamentous or fails to grow. This behavior is consistent with a mathematical proof. This suggests that filamentation may be a primitive growth mode resulting from the simple physical property of balanced osmotic pressure. We also find that growth is favored if some chemical species are only present inside the protocell, but not in the outside growth medium. Such an insulation requires specific chemical schemes. Modern evolved cells such as E. coli meet these requirements through active transport mechanisms such as the phosphotransferase system.

  7. Filamentation as primitive growth mode?

    PubMed

    Bigan, Erwan; Steyaert, Jean-Marc; Douady, Stéphane

    2015-12-01

    Osmotic pressure influences cellular shape. In a growing cell, chemical reactions and dilution induce changes in osmolarity, which in turn influence the cellular shape. Using a protocell model relying upon random conservative chemical reaction networks with arbitrary stoichiometry, we find that when the membrane is so flexible that its shape adjusts itself quasi-instantaneously to balance the osmotic pressure, the protocell either grows filamentous or fails to grow. This behavior is consistent with a mathematical proof. This suggests that filamentation may be a primitive growth mode resulting from the simple physical property of balanced osmotic pressure. We also find that growth is favored if some chemical species are only present inside the protocell, but not in the outside growth medium. Such an insulation requires specific chemical schemes. Modern evolved cells such as E. coli meet these requirements through active transport mechanisms such as the phosphotransferase system. PMID:26718101

  8. Advanced missions to primitive bodies

    NASA Technical Reports Server (NTRS)

    Yeomans, D. K.

    1985-01-01

    Six interplanetary spacecraft, three earth orbital experiments, and one spacecraft orbiting Venus will observe comets Halley and Giacobini-Zinner in 1985-86. At comet Halley, attempts will be made to image the nucleus, remote sensing will be made by spectrometers in wavelength ranges from the IR to the UV, and in-situ observations will be made with neutral, ion and dust mass spectrometers. Plasma measurements will be made at both comets and at comet Halley the upstream solar wind flux will be simultaneously monitored by nearby spacecraft. In the post-Halley era, there are several missions being planned for the continued exploration of the solar system's most primitive bodies - comets and asteroids.

  9. A manual for PARTI runtime primitives

    NASA Technical Reports Server (NTRS)

    Berryman, Harry; Saltz, Joel

    1990-01-01

    Primitives are presented that are designed to help users efficiently program irregular problems (e.g., unstructured mesh sweeps, sparse matrix codes, adaptive mesh partial differential equations solvers) on distributed memory machines. These primitives are also designed for use in compilers for distributed memory multiprocessors. Communications patterns are captured at runtime, and the appropriate send and receive messages are automatically generated.

  10. Primitive Societies, Social Studies: 6478.02.

    ERIC Educational Resources Information Center

    Friedman, Harrabey

    Junior high students examine selected primitive societies in this quinmester course. The concept of culture is defined and studied to expose similarities and differences between primitive and contemporary man and civilizations, not simply for greater understanding but also to permit further insight into American civilization. Both types of…

  11. Apes, Primitives, Children and...Translators.

    ERIC Educational Resources Information Center

    Kozulin, Alex

    1993-01-01

    Reviews two books by L. S. Vygotsky and A. R. Luria: (1) "Studies on the History of Behavior: Ape, Primitive, and Child"; and (2) "Ape, Primitive Man and Child: Essays in the History of Behavior." Both books are based on a book published in 1930 that examined the phylogenetic, historical, and ontogenetic development of human behavior and…

  12. Pharmacodynamics of tandem high-dose melphalan with peripheral blood stem cell transplantation in children with neuroblastoma and medulloblastoma.

    PubMed

    Vassal, G; Tranchand, B; Valteau-Couanet, D; Mahé, C; Couanet, D; Schoeppfer, C; Grill, J; Kalifa, C; Hill, C; Ardiet, C; Hartmann, O

    2001-03-01

    Repeated high-dose (HD) chemotherapy with peripheral blood stem cell (PBSC) transplantation is a new modality aimed at increasing both the dose and its intensity in the treatment of chemosensitive tumours. The aim of this study was to evaluate the tolerance, pharmacokinetics (PK) and pharmacodynamics (PD) of HD single-agent melphalan administered over two consecutive courses (C1 and C2) in children. Twenty-one patients (10 girls) with a median age of 4.1 years (range 8 months-14 years) were entered into this study. Five had metastatic neuroblastoma (NB) and 16 a cerebral primitive neuroectodermal tumour (PNET). Melphalan was given at a dose of 100 mg/m(2) every 21 days. PBSCs were infused at a median number of 2.98 x 10(6) CD34(+) cells/kg. Forty courses, ie 21 C1 and 19 C2, were administered. Both courses were well tolerated. The median duration of ANC < 500/microl was 7 and 6 days after C1 and C2, respectively. Platelet recovery (not mandatory to continue the HD strategy) was achieved in 52% of courses. GI toxicity was mild to moderate. The melphalan AUC ranged from 177 to 475 microg small middle dotmin/ml (no difference between C1 and C2). Prolonged neutropenia was associated with a young age (P < 0.001) and a low amount of CFU-GM (P = 0.002). A long time to platelet recovery was associated with a high AUC (P = 0.004) and a young age (P = 0.02). Grade 1 or 2 GI toxicity was associated with a high AUC (P = 0.015). Partial remission was observed in 11/14 patients with measurable cerebral PNET. In conclusion, tandem HD melphalan is feasible and safe in children, and achieved a high response rate in cerebral PNET. The observed PK-PD relationships may help us design PK-guided outpatient treatment.

  13. Dynamic primitives in the control of locomotion

    PubMed Central

    Hogan, Neville; Sternad, Dagmar

    2013-01-01

    Humans achieve locomotor dexterity that far exceeds the capability of modern robots, yet this is achieved despite slower actuators, imprecise sensors, and vastly slower communication. We propose that this spectacular performance arises from encoding motor commands in terms of dynamic primitives. We propose three primitives as a foundation for a comprehensive theoretical framework that can embrace a wide range of upper- and lower-limb behaviors. Building on previous work that suggested discrete and rhythmic movements as elementary dynamic behaviors, we define submovements and oscillations: as discrete movements cannot be combined with sufficient flexibility, we argue that suitably-defined submovements are primitives. As the term “rhythmic” may be ambiguous, we define oscillations as the corresponding class of primitives. We further propose mechanical impedances as a third class of dynamic primitives, necessary for interaction with the physical environment. Combination of these three classes of primitive requires care. One approach is through a generalized equivalent network: a virtual trajectory composed of simultaneous and/or sequential submovements and/or oscillations that interacts with mechanical impedances to produce observable forces and motions. Reliable experimental identification of these dynamic primitives presents challenges: identification of mechanical impedances is exquisitely sensitive to assumptions about their dynamic structure; identification of submovements and oscillations is sensitive to their assumed form and to details of the algorithm used to extract them. Some methods to address these challenges are presented. Some implications of this theoretical framework for locomotor rehabilitation are considered. PMID:23801959

  14. Melanotic neuroectodermal tumor of infancy in the soft tissue of the forearm: report of a case.

    PubMed

    Ma, Yangyang; Zheng, Jicui; Yang, Shaobao; Zhu, Haitao; Dong, Kuiran; Xiao, Xianmin; Chen, Lian

    2015-01-01

    Melanotic neuroectodermal tumor of infancy is rare. Only 3 cases have been reported in the soft tissue of the extremities up to date. It has a typically biphasic feature in morphology. Epithelial and melanotic markers are positive in the epitheliod cells and neuron-specific enolase or synaptophysin is positive in the small blue round cells in immunohistochemistry. Radical resection and close follow-up is the treatment strategy in general situation. Here we report one case of MNTI in the upper extremity with review of the literature. This is the first case of MNTI in the forearm.

  15. Melanotic neuroectodermal tumor of infancy in the soft tissue of the forearm: report of a case

    PubMed Central

    Ma, Yangyang; Zheng, Jicui; Yang, Shaobao; Zhu, Haitao; Dong, Kuiran; Xiao, Xianmin; Chen, Lian

    2015-01-01

    Melanotic neuroectodermal tumor of infancy is rare. Only 3 cases have been reported in the soft tissue of the extremities up to date. It has a typically biphasic feature in morphology. Epithelial and melanotic markers are positive in the epitheliod cells and neuron-specific enolase or synaptophysin is positive in the small blue round cells in immunohistochemistry. Radical resection and close follow-up is the treatment strategy in general situation. Here we report one case of MNTI in the upper extremity with review of the literature. This is the first case of MNTI in the forearm. PMID:26722579

  16. Basic primitives for molecular diagram sketching

    PubMed Central

    2010-01-01

    A collection of primitive operations for molecular diagram sketching has been developed. These primitives compose a concise set of operations which can be used to construct publication-quality 2 D coordinates for molecular structures using a bare minimum of input bandwidth. The input requirements for each primitive consist of a small number of discrete choices, which means that these primitives can be used to form the basis of a user interface which does not require an accurate pointing device. This is particularly relevant to software designed for contemporary mobile platforms. The reduction of input bandwidth is accomplished by using algorithmic methods for anticipating probable geometries during the sketching process, and by intelligent use of template grafting. The algorithms and their uses are described in detail. PMID:20923555

  17. Mesenchymal Stem Cells from Human Extra Ocular Muscle Harbor Neuroectodermal Differentiation Potential

    PubMed Central

    Magdalene, Damaris; Bhattacharyya, Jina; Jaganathan, Bithiah Grace

    2016-01-01

    Mesenchymal stem cells (MSC) have been proposed as suitable candidates for cell therapy for neurological disorderssince they exhibit good neuronal differentiation capacity. However, for better therapeutic outcomes, it is necessary to isolate MSC from a suitable tissue sourcethat posses high neuronal differentiation. In this context, we isolated MSC from extra ocular muscle (EOM) tissue and tested the in vitro neuronal differentiation potential. In the current study, EOM tissue derived MSC were characterized and compared with bone marrow derived MSC. We found that EOM derived MSC proliferated as a monolayer and showed similarities in morphology, growth properties and cell surface marker expression with bone marrow derived MSC and expressed high levels of NES, OCT4, NANOG and SOX2 in its undifferentiated state. They also expressed embryonic cell surface marker SSEA4 and their intracellular mitochondrial distribution pattern was similar to that of multipotent stem cells. Although EOM derived MSC differentiated readily into adipocytes, osteocytes and chondrocytes, they differentiated more efficiently into neuroectodermal cells. The differentiation into neuroectodermal cellswas confirmed by the expression of neuronal markers NGFR and MAP2B. Thus, EOM derived MSC might be good candidates for stem cell based therapies for treating neurodegenerative diseases. PMID:27248788

  18. A method of plane geometry primitive presentation

    NASA Astrophysics Data System (ADS)

    Jiao, Anbo; Luo, Haibo; Chang, Zheng; Hui, Bin

    2014-11-01

    Point feature and line feature are basic elements in object feature sets, and they play an important role in object matching and recognition. On one hand, point feature is sensitive to noise; on the other hand, there are usually a huge number of point features in an image, which makes it complex for matching. Line feature includes straight line segment and curve. One difficulty in straight line segment matching is the uncertainty of endpoint location, the other is straight line segment fracture problem or short straight line segments joined to form long straight line segment. While for the curve, in addition to the above problems, there is another difficulty in how to quantitatively describe the shape difference between curves. Due to the problems of point feature and line feature, the robustness and accuracy of target description will be affected; in this case, a method of plane geometry primitive presentation is proposed to describe the significant structure of an object. Firstly, two types of primitives are constructed, they are intersecting line primitive and blob primitive. Secondly, a line segment detector (LSD) is applied to detect line segment, and then intersecting line primitive is extracted. Finally, robustness and accuracy of the plane geometry primitive presentation method is studied. This method has a good ability to obtain structural information of the object, even if there is rotation or scale change of the object in the image. Experimental results verify the robustness and accuracy of this method.

  19. MACOP modular architecture with control primitives.

    PubMed

    Waegeman, Tim; Hermans, Michiel; Schrauwen, Benjamin

    2013-01-01

    Walking, catching a ball and reaching are all tasks in which humans and animals exhibit advanced motor skills. Findings in biological research concerning motor control suggest a modular control hierarchy which combines movement/motor primitives into complex and natural movements. Engineers inspire their research on these findings in the quest for adaptive and skillful control for robots. In this work we propose a modular architecture with control primitives (MACOP) which uses a set of controllers, where each controller becomes specialized in a subregion of its joint and task-space. Instead of having a single controller being used in this subregion [such as MOSAIC (modular selection and identification for control) on which MACOP is inspired], MACOP relates more to the idea of continuously mixing a limited set of primitive controllers. By enforcing a set of desired properties on the mixing mechanism, a mixture of primitives emerges unsupervised which successfully solves the control task. We evaluate MACOP on a numerical model of a robot arm by training it to generate desired trajectories. We investigate how the tracking performance is affected by the number of controllers in MACOP and examine how the individual controllers and their generated control primitives contribute to solving the task. Furthermore, we show how MACOP compensates for the dynamic effects caused by a fixed control rate and the inertia of the robot.

  20. Primitive African Medical Lore and Witchcraft *

    PubMed Central

    Thompson, Ethel E.

    1965-01-01

    This article presents a comprehensive study of the methods, practices, equipment, and paraphernalia of African witch doctors in carrying out primitive medical practices. The chief tribes studied are the Azandes of the Sudan, the Manos of Liberia, the Congo tribes, the Bundas of Angola, and the Zulus and other Bantu tribes of South Africa. Primitive beliefs and customs are discussed only insofar as they have a direct bearing on medical practices. The medical practices considered deal mainly with the application of general remedies for ailments and diseases, but certain specialized fields such as obstetrics, surgery, treatment for fractures, and dentistry are also included. Primitive medicaments are presented with reference to their application for various illnesses. An alphabetical list of these medicaments is given at the end of the article. PMID:14223742

  1. PRIMitive Asteroids Spectroscopic Survey - PRIMASS: First Results

    NASA Astrophysics Data System (ADS)

    de Leon, Julia; Pinilla-Alonso, Noemi; Campins, Humberto; Lorenzi, Vania; Licandro, Javier; Morate, David; Tanga, Paolo; Cellino, Alberto; Delbo, Marco

    2015-11-01

    NASA OSIRIS-REx and JAXA Hayabusa 2 sample-return missions have targeted two near-Earth asteroids: (101955) Bennu and (162173) 1999 JU3, respectively. These are primitive asteroids that are believed to originate in the inner belt, where five distinct sources have been identified: four primitive collisional families (Polana, Erigone, Sulamitis, and Clarissa), and a population of low-albedo and low-inclination background asteroids. Identifying and characterizing the populations from which these two NEAs might originate will enchance the science return of the two missions.With this main objective in mind, we initiated in 2010 a spectroscopic survey in the visible and the near-infrared to characterize the primitive collisional families in the inner belt and the low-albedo background population. This is the PRIMitive Asteroids Spectroscopic Survey - PRIMASS. So far we have obtained more than 200 spectra using telescopes located at different observatories. PRIMASS uses a variety of ground based facilities. Most of the spectra have been obtained using the 10.4m Gran Telescopio Canarias (GTC), and the 3.6m Telescopio Nazionale Galileo (TNG), both located at the El Roque de los Muchachos Observatory (La Palma, Spain), and the 3.0m NASA Infrared Telescope Facility on Mauna Kea (Hawai, USA).We present the first results from our on-going survey (de Leon et al. 2015; Pinilla-Alonso et al. 2015; Morate et al. 2015), focused on the Polana and the Erigone primitive families, with visible and near-infrared spectra of more than 200 objects, most of them with no previous spectroscopic data. Our survey is already the largest database of primitive asteroids spectra, and we keep obtaining data on the Sulamitis and the Clarissa families, as well as on the background low-albedo population.

  2. Human monoclonal antibody to a neuroectodermal tumor antigen (OFA-I-2).

    PubMed

    Katano, M; Sidell, N; Irie, R F

    1983-01-01

    Human IgM kappa monoclonal antibody to human tumors of neuroectodermal origin was produced in the spent medium of an Epstein-Barr virus-transformed B-lymphoblastoid cell line, L72. Chemically, the antigen was identified as ganglioside GD2 [Gal NAc beta 1----4 (Neu Ac alpha 2----8 Neu Ac alpha 2---3) Gal beta 1----4 Glc----ceramide]. Twenty-seven mg of pure human IgM were obtained from 10 liters of L72 spent medium using salt and hypotonic precipitation, ultracentrifugation, and Sephacryl-S 300 superfine gel filtration. The monoclonal origin of the antibody was determined by agarose isoelectrofocusing. This human monoclonal antibody may be a particularly useful reagent for immunotherapy trials in cancer patients.

  3. The melanotic neuroectodermal tumor of infancy. Report of two cases and review of the literature.

    PubMed

    Hupp, J R; Topazian, R G; Krutchkoff, D J

    1981-12-01

    The melanotic neuroectodermal tumor of infancy (MNTI) is a rare childhood neoplasm with an alarming but classical clinical presentation. It appears as a rapidly enlarging mass in the jaws of skull of infants and unless MNTI is considered in the differential diagnosis, the lesion can easily be mistaken for a malignant neoplasm. Although possessing an aggressive growth rate and radiographic appearance, the MNTI almost always behaves in a benign fashion and can be treated with local excision. However, recent reports of malignant behavior as well as of occasional recurrences make close follow-up important. Approximately 139 cases of the MNTI have been reviewed and tabulated with respect to age at discovery, sex, tumor location, length of follow-up, and whether recurrence occurred, 2 additional cases, 1 of which was in the mandible, are presented along with theories of origin and recommended therapy.

  4. Chemical evolution of primitive solar system bodies

    NASA Technical Reports Server (NTRS)

    Oro, J.; Mills, T.

    1989-01-01

    Observations on organic molecules and compounds containing biogenic elements in the interstellar medium and in the primitive bodies of the solar system are reviewed. The discovery of phosphorus molecular species in dense interstellar clouds, the existence of organic ions in the dust and gas phase of the comas of Comet Halley, and the presence of presolar, deuterium-hydrogen ratios in the amino acids of carbonaceous chondrites are discussed. The relationships between comets, dark asteroids, and carbonaceous chondrites are examined. Also, consideration is given to the chemical evolution of Titan, the primitive earth, and early Mars.

  5. Melville and the Tradition of Primitive Utopia.

    ERIC Educational Resources Information Center

    Beauchamp, Gorman

    1981-01-01

    Discusses the relationships among the myth of the Golden Age, the concept of the Noble Savage, and the dream of Utopia. Uses Lewis Mumford's division of utopias into two basic types, i.e., reconstruction and escape utopias, to examine Herman Melville's "Typee" as an example of the primitive escapist utopia. (Editor/DMM)

  6. Peripheral Neuropathy

    MedlinePlus

    ... can be associated with peripheral neuropathy. Metabolic and endocrine disorders impair the body’s ability to transform nutrients into ... to neuropathies as a result of chemical imbalances. Endocrine disorders that lead to hormonal imbalances can disturb normal ...

  7. Persistent Primitive Trigeminal Artery That Mimics Persistent Primitive Otic Artery on Cerebral Angiography

    PubMed Central

    Lee, Kwangho; Park, Insung; Han, Jongwoo

    2016-01-01

    Persistent primitive trigeminal artery (PPTA) is the most common carotid-basilar anastomosis; on the other hand, persistent primitive otic artery (PPOA) is extremely rare. PPTA is often misdiagnosed as PPOA on cerebral angiography. We present a case of PPTA that mimicked PPOA on cerebral angiography. We further describe the utility of brain computed tomography angiography for differential diagnosis of PPTA from PPOA, together with a review of previous literature. PMID:27790403

  8. 36 CFR 293.17 - National Forest Primitive Areas.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false National Forest Primitive Areas. 293.17 Section 293.17 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE WILDERNESS-PRIMITIVE AREAS § 293.17 National Forest Primitive Areas. (a) Within those areas...

  9. 36 CFR 293.17 - National Forest Primitive Areas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false National Forest Primitive Areas. 293.17 Section 293.17 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE WILDERNESS-PRIMITIVE AREAS § 293.17 National Forest Primitive Areas. (a) Within those areas...

  10. 36 CFR 293.17 - National Forest Primitive Areas.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false National Forest Primitive Areas. 293.17 Section 293.17 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE WILDERNESS-PRIMITIVE AREAS § 293.17 National Forest Primitive Areas. (a) Within those areas...

  11. 36 CFR 293.17 - National Forest Primitive Areas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false National Forest Primitive Areas. 293.17 Section 293.17 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE WILDERNESS-PRIMITIVE AREAS § 293.17 National Forest Primitive Areas. (a) Within those areas...

  12. 36 CFR 293.17 - National Forest Primitive Areas.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false National Forest Primitive Areas. 293.17 Section 293.17 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE WILDERNESS-PRIMITIVE AREAS § 293.17 National Forest Primitive Areas. (a) Within those areas...

  13. Chemical evolution of primitive solar system bodies.

    PubMed

    Oró, J; Mills, T

    1989-01-01

    In this paper we summarize some of the most salient observations made recently on the organic molecules and other compounds of the biogenic elements present in the interstellar medium and in the primitive bodies of the solar system. They include the discovery of the first phosphorus molecular species in dense interstellar clouds, the presence of complex organic ions in the dust and gas phase of Halley's coma, the finding of unusual, probably presolar, deuterium-hydrogen ratios in the amino acids of carbonaceous chondrites, and new developments on the chemical evolution of Titan, the primitive Earth, and early Mars. Some of the outstanding problems concerning the synthesis of organic molecules on different cosmic bodies are also discussed from an exobiological perspective.

  14. Deictic primitives for general purpose navigation

    NASA Technical Reports Server (NTRS)

    Crismann, Jill D.

    1994-01-01

    A visually-based deictic primative used as an elementary command set for general purpose navigation was investigated. It was shown that a simple 'follow your eyes' scenario is sufficient for tracking a moving target. Limitations of velocity, acceleration, and modeling of the response of the mechanical systems were enforced. Realistic paths of the robots were produced during the simulation. Scientists could remotely command a planetary rover to go to a particular rock formation that may be interesting. Similarly an expert at plant maintenance could obtain diagnostic information remotely by using deictic primitives on a mobile are used in the deictic primitives, we could imagine that the exact same control software could be used for all of these applications.

  15. Dimensional Analysis Using Toric Ideals: Primitive Invariants

    PubMed Central

    Atherton, Mark A.; Bates, Ronald A.; Wynn, Henry P.

    2014-01-01

    Classical dimensional analysis in its original form starts by expressing the units for derived quantities, such as force, in terms of power products of basic units etc. This suggests the use of toric ideal theory from algebraic geometry. Within this the Graver basis provides a unique primitive basis in a well-defined sense, which typically has more terms than the standard Buckingham approach. Some textbook examples are revisited and the full set of primitive invariants found. First, a worked example based on convection is introduced to recall the Buckingham method, but using computer algebra to obtain an integer matrix from the initial integer matrix holding the exponents for the derived quantities. The matrix defines the dimensionless variables. But, rather than this integer linear algebra approach it is shown how, by staying with the power product representation, the full set of invariants (dimensionless groups) is obtained directly from the toric ideal defined by . One candidate for the set of invariants is a simple basis of the toric ideal. This, although larger than the rank of , is typically not unique. However, the alternative Graver basis is unique and defines a maximal set of invariants, which are primitive in a simple sense. In addition to the running example four examples are taken from: a windmill, convection, electrodynamics and the hydrogen atom. The method reveals some named invariants. A selection of computer algebra packages is used to show the considerable ease with which both a simple basis and a Graver basis can be found. PMID:25436774

  16. TWO BEYOND-PRIMITIVE EXTRASOLAR PLANETESIMALS

    SciTech Connect

    Xu, S.; Jura, M.; Klein, B.; Zuckerman, B.; Koester, D. E-mail: jura@astro.ucla.edu E-mail: ben@astro.ucla.edu

    2013-04-01

    Using the Cosmic Origins Spectrograph on board the Hubble Space Telescope, we have obtained high-resolution ultraviolet observations of GD 362 and PG 1225-079, two helium-dominated, externally polluted white dwarfs. We determined or placed useful upper limits on the abundances of two key volatile elements, carbon and sulfur, in both stars; we also constrained the zinc abundance in PG 1225-079. In combination with previous optical data, we find strong evidence that each of these two white dwarfs has accreted a parent body that has evolved beyond primitive nebular condensation. The planetesimal that accreted onto GD 362 had a bulk composition roughly similar to that of a mesosiderite meteorite based on a reduced chi-squared comparison with solar system objects; however, additional material is required to fully reproduce the observed mid-infrared spectrum for GD 362. No single meteorite can reproduce the unique abundance pattern observed in PG 1225-079; the best fit model requires a blend of ureilite and mesosiderite material. From a compiled sample of nine well-studied polluted white dwarfs, we find evidence for both primitive planetesimals, which are a direct product from nebular condensation, as well as beyond-primitive planetesimals, whose final compositions were mainly determined by post-nebular processing.

  17. Clinicopathological features of melanotic neuroectodermal tumor of infancy: Report of two cases.

    PubMed

    Higashi, Kenjiro; Ogawa, Takenori; Onuma, Masaei; Usubuchi, Hajime; Imai, Yoshimichi; Takata, Iori; Hidaka, Hiroshi; Watanabe, Mika; Sasahara, Yoji; Koyama, Shigeto; Kure, Shigeo; Katori, Yukio

    2016-08-01

    Melanotic neuroectodermal tumor of infancy (MNTI) is an extremely rare, pigmented neoplastic entity of neural crest origin. Histological and immunohistochemical profiles indicate the presence of two components, small rounded neuroblast-like cellular areas and areas with large melanin-containing cells which consist of combination of neural, melanocytic, and epithelial cell types. Here we present two interesting cases of infants with MNTI which have different clinicopathological features. The first case is a 3-month-old female with rapidly growing MNTI involving the lacrimal sac and inferior wall of the orbital cavity, treated with total maxillectomy without orbital exenteration followed by chemotherapy. The second case is a 7-month-old male with slow-growing maxillary MNTI treated with complete surgical excision. In the female patient, histological findings revealed a predominance of neuroblast-like cellular areas and a high Ki67 index indicating rapid cellular proliferation. In the male patient however, large melanin-containing cells were dominant in this slow-growing tumor. These findings support the presence of two different types of MNTI, rapid-growing and slow-growing types, determined by the component of neuroblast-like cellular areas.

  18. Melanotic neuroectodermal tumor of the brain recurring 12 years after complete remission: case report.

    PubMed

    Omodaka, Shunsuke; Saito, Ryuta; Kumabe, Toshihiro; Kawagishi, Jun; Jokura, Hidefumi; Sonoda, Yukihiko; Watanabe, Mika; Kayama, Takamasa; Tominaga, Teiji

    2010-04-01

    We describe a rare case of melanotic neuroectodermal tumor (MNT) of the brain recurring 12 years after complete remission. An 11-year-old girl initially presented with exotropia and bilateral papilledema. Magnetic resonance (MR) imaging revealed an intracranial extraaxial large tumor at the midfrontal region. T(1)-weighted MR imaging showed the tumor to be well delineated with homogeneous enhancement by gadolinium. The tumor was subtotally removed, and the histological diagnosis was MNT. The residual tumor became enlarged, so gamma knife radiosurgery was performed 5 months after initial surgery. The enhanced lesion disappeared, but another lesion emerged 3 years later. A second gamma knife radiosurgery was performed for this local recurrence. The enhanced lesion disappeared once again. Twelve years after the second gamma knife radiosurgery, another local recurrence was detected. This tumor was subtotally removed. Histological examination confirmed the same diagnosis of MNT. This case suggests that MNTs not completely resected need long-term follow up, even if complete remission was achieved after adjuvant therapy.

  19. Ex vivo organ culture of human hair follicles: a model epithelial-neuroectodermal-mesenchymal interaction system.

    PubMed

    Tobin, Desmond J

    2011-01-01

    The development of hair follicle organ culture techniques is a significant milestone in cutaneous biology research. The hair follicle, or more accurately the "pilo-sebaceous unit", encapsulates all the important physiologic processes found in the human body; controlled cell growth/death, interactions between cells of different histologic type, cell differentiation and migration, and hormone responsitivity to name a few. Thus, the value of the hair follicle as a model for biological scientific research goes way beyond its scope for cutaneous biology or dermatology alone. Indeed, the recent and dramatic upturn in interest in hair follicle biology has focused principally on the pursuit of two of biology's holy grails; post-embryonic morphogenesis and control of cyclical tissue activity. The hair follicle organ culture model, pioneered by Philpott and colleagues, ushered in an exceptionally accessible way to assess how cells of epithelial (e.g., keratinocytes), mesenchymal (e.g., fibroblasts), and neuroectodermal (e.g., melanocytes) origin interact in a three-dimensional manner. Moreover, this assay system allows us to assess how various natural and pharmacologic agents affect complex tissues for growth modulation. In this article, I focus on the culture of the human hair follicle mini-organ, discussing both the practical issues involved and some possible research applications of this assay.

  20. BRAFV600E Mutation in Melanotic Neuroectodermal Tumor of Infancy: Toward Personalized Medicine?

    PubMed

    Gomes, Carolina C; Diniz, Marina G; de Menezes, Grazielle Helena F; Castro, Wagner H; Gomez, Ricardo S

    2015-07-01

    The melanotic neuroectodermal tumor of infancy (MNTI) is a rare neoplasm that primarily affects the maxilla of infants during their first year of life. Complete resection is the conventional treatment and recurrence rates vary from 10% to 60%. The recurrent tumors grow more aggressively and can invade other anatomic structures, such as the nasal cavity, the orbit, and the skull base. The aggressive behavior of MNTIs may require radical resection, which may not be possible in some cases because of its rapid and invading growth together with invasion of vital structures. In these situations, adjunct radiotherapy or chemotherapy has been used. However, as there are no conclusive data regarding the molecular profile of this tumor, currently there is no targeted therapy that may be used in the treatment of selected aggressive cases. On the basis of MNTI similarities with melanomas, such as derivation from the neural crest cells and presence of large melanin-containing cells, we hypothesized that MNTIs also may harbor the BRAFV600E oncogenic mutation. We show for the first time that this important pediatric tumor may harbor the oncogenic BRAFV600E mutation, providing the first insights to their personalized treatment. PMID:26122804

  1. Transcription factor KLF7 regulates differentiation of neuroectodermal and mesodermal cell lineages

    SciTech Connect

    Caiazzo, Massimiliano; Colucci-D'Amato, Luca; Esposito, Maria T.; Parisi, Silvia; Stifani, Stefano; Ramirez, Francesco; Porzio, Umberto di

    2010-08-15

    Previous gene targeting studies in mice have implicated the nuclear protein Krueppel-like factor 7 (KLF7) in nervous system development while cell culture assays have documented its involvement in cell cycle regulation. By employing short hairpin RNA (shRNA)-mediated gene silencing, here we demonstrate that murine Klf7 gene expression is required for in vitro differentiation of neuroectodermal and mesodermal cells. Specifically, we show a correlation of Klf7 silencing with down-regulation of the neuronal marker microtubule-associated protein 2 (Map2) and the nerve growth factor (NGF) tyrosine kinase receptor A (TrkA) using the PC12 neuronal cell line. Similarly, KLF7 inactivation in Klf7-null mice decreases the expression of the neurogenic marker brain lipid-binding protein/fatty acid-binding protein 7 (BLBP/FABP7) in neural stem cells (NSCs). We also report that Klf7 silencing is detrimental to neuronal and cardiomyocytic differentiation of embryonic stem cells (ESCs), in addition to altering the adipogenic and osteogenic potential of mouse embryonic fibroblasts (MEFs). Finally, our results suggest that genes that are key for self-renewal of undifferentiated ESCs repress Klf7 expression in ESCs. Together with previous findings, these results provide evidence that KLF7 has a broad spectrum of regulatory functions, which reflect the discrete cellular and molecular contexts in which this transcription factor operates.

  2. Deterministic HOX Patterning in Human Pluripotent Stem Cell-Derived Neuroectoderm

    PubMed Central

    Lippmann, Ethan S.; Williams, Clay E.; Ruhl, David A.; Estevez-Silva, Maria C.; Chapman, Edwin R.; Coon, Joshua J.; Ashton, Randolph S.

    2015-01-01

    Summary Colinear HOX expression during hindbrain and spinal cord development diversifies and assigns regional neural phenotypes to discrete rhombomeric and vertebral domains. Despite the precision of HOX patterning in vivo, in vitro approaches for differentiating human pluripotent stem cells (hPSCs) to posterior neural fates coarsely pattern HOX expression thereby generating cultures broadly specified to hindbrain or spinal cord regions. Here, we demonstrate that successive activation of fibroblast growth factor, Wnt/β-catenin, and growth differentiation factor signaling during hPSC differentiation generates stable, homogenous SOX2+/Brachyury+ neuromesoderm that exhibits progressive, full colinear HOX activation over 7 days. Switching to retinoic acid treatment at any point during this process halts colinear HOX activation and transitions the neuromesoderm into SOX2+/PAX6+ neuroectoderm with predictable, discrete HOX gene/protein profiles that can be further differentiated into region-specific cells, e.g., motor neurons. This fully defined approach significantly expands capabilities to derive regional neural phenotypes from diverse hindbrain and spinal cord domains. PMID:25843047

  3. Protective and detrimental effects of neuroectodermal cell–derived tissue factor in mouse models of stroke

    PubMed Central

    Wang, Shaobin; Reeves, Brandi; Sparkenbaugh, Erica M.; Russell, Janice; Soltys, Zbigniew; Zhang, Hua; Faber, James E.; Key, Nigel S.; Kirchhofer, Daniel; Granger, D. Neil; Mackman, Nigel

    2016-01-01

    Within the CNS, a dysregulated hemostatic response contributes to both hemorrhagic and ischemic strokes. Tissue factor (TF), the primary initiator of the extrinsic coagulation cascade, plays an essential role in hemostasis and also contributes to thrombosis. Using both genetic and pharmacologic approaches, we characterized the contribution of neuroectodermal (NE) cell TF to the pathophysiology of stroke. We used mice with various levels of TF expression and found that astrocyte TF activity reduced to ~5% of WT levels was still sufficient to maintain hemostasis after hemorrhagic stroke but was also low enough to attenuate inflammation, reduce damage to the blood-brain barrier, and improve outcomes following ischemic stroke. Pharmacologic inhibition of TF during the reperfusion phase of ischemic stroke attenuated neuronal damage, improved behavioral deficit, and prevented mortality of mice. Our data demonstrate that NE cell TF limits bleeding complications associated with the transition from ischemic to hemorrhagic stroke and also contributes to the reperfusion injury after ischemic stroke. The high level of TF expression in the CNS is likely the result of selective pressure to limit intracerebral hemorrhage (ICH) after traumatic brain injury but, in the modern era, poses the additional risk of increased ischemia-reperfusion injury after ischemic stroke. PMID:27489885

  4. Peripheral neuropathies.

    PubMed

    Hanewinckel, R; Ikram, M A; Van Doorn, P A

    2016-01-01

    Peripheral neuropathies are diseases of the peripheral nervous system that can be divided into mononeuropathies, multifocal neuropathies, and polyneuropathies. Symptoms usually include numbness and paresthesia. These symptoms are often accompanied by weakness and can be painful. Polyneuropathies can be divided into axonal and demyelinating forms, which is important for diagnostic reasons. Most peripheral neuropathies develop over months or years, but some are rapidly progressive. Some patients only suffer from mild, unilateral, slowly progressive tingling in the fingers due to median nerve compression in the wrist (carpal tunnel syndrome), while other patients can be tetraplegic, with respiratory insufficiency within 1-2 days due to Guillain-Barré syndrome. Carpal tunnel syndrome, with a prevalence of 5% and incidence of 1-2 per 1000 person-years, is the most common mononeuropathy. Population-based data for chronic polyneuropathy are relatively scarce. Prevalence is estimated at 1% and increases to 7% in persons over 65 years of age. Incidence is approximately 1 per 1000 person-years. Immune-mediated polyneuropathies like Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy are rare diseases, with an annual incidence of approximately 1-2 and 0.2-0.5 per 100 000 persons respectively. Most peripheral neuropathies are more prevalent in older adults and in men, except for carpal tunnel syndrome, which is more common in women. Diabetes is a common cause of peripheral neuropathy and is associated with both mono- and polyneuropathies. Among the group of chronic polyneuropathies, in about 20-25% no direct cause can be found. These are slowly progressive axonal polyneuropathies. PMID:27637963

  5. Dimensional analysis using toric ideals: primitive invariants.

    PubMed

    Atherton, Mark A; Bates, Ronald A; Wynn, Henry P

    2014-01-01

    Classical dimensional analysis in its original form starts by expressing the units for derived quantities, such as force, in terms of power products of basic units [Formula: see text] etc. This suggests the use of toric ideal theory from algebraic geometry. Within this the Graver basis provides a unique primitive basis in a well-defined sense, which typically has more terms than the standard Buckingham approach. Some textbook examples are revisited and the full set of primitive invariants found. First, a worked example based on convection is introduced to recall the Buckingham method, but using computer algebra to obtain an integer [Formula: see text] matrix from the initial integer [Formula: see text] matrix holding the exponents for the derived quantities. The [Formula: see text] matrix defines the dimensionless variables. But, rather than this integer linear algebra approach it is shown how, by staying with the power product representation, the full set of invariants (dimensionless groups) is obtained directly from the toric ideal defined by [Formula: see text]. One candidate for the set of invariants is a simple basis of the toric ideal. This, although larger than the rank of [Formula: see text], is typically not unique. However, the alternative Graver basis is unique and defines a maximal set of invariants, which are primitive in a simple sense. In addition to the running example four examples are taken from: a windmill, convection, electrodynamics and the hydrogen atom. The method reveals some named invariants. A selection of computer algebra packages is used to show the considerable ease with which both a simple basis and a Graver basis can be found. PMID:25436774

  6. Self assembly properties of primitive organic compounds

    NASA Technical Reports Server (NTRS)

    Deamer, D. W.

    1991-01-01

    A central event in the origin of life was the self-assembly of amphiphilic, lipid-like compounds into closed microenvironments. If a primitive macromolecular replicating system could be encapsulated within a vesicular membrane, the components of the system would share the same microenvironment, and the result would be a step toward true cellular function. The goal of our research has been to determine what amphiphilic molecules might plausibly have been available on the early Earth to participate in the formation of such boundary structures. To this end, we have investigated primitive organic mixtures present in carbonaceous meteorites such as the Murchison meteorite, which contains 1-2 percent of its mass in the form of organic carbon compounds. It is likely that such compounds contributed to the inventory of organic carbon on the prebiotic earth, and were available to participate in chemical evolution leading to the emergence of the first cellular life forms. We found that Murchison components extracted into non-polar solvent systems are surface active, a clear indication of amphiphilic character. One acidic fraction self-assembles into vesicular membranes that provide permeability barriers to polar solutes. Other evidence indicates that the membranes are bimolecular layers similar to those formed by contemporary membrane lipids. We conclude that bilayer membrane formation by primitive amphiphiles on the early Earth is feasible. However, only a minor fraction of acidic amphiphiles assembles into bilayers, and the resulting membranes require narrowly defined conditions of pH and ionic composition to be stable. It seems unlikely, therefore, that meteoritic infall was a direct source of membrane amphiphiles. Instead, the hydrocarbon components and their derivatives more probably would provide an organic stock available for chemical evolution. Our current research is directed at possible reactions which would generate substantial quantities of membranogenic

  7. An anterior signaling center patterns and sizes the anterior neuroectoderm of the sea urchin embryo.

    PubMed

    Range, Ryan C; Wei, Zheng

    2016-05-01

    Anterior signaling centers help specify and pattern the early anterior neuroectoderm (ANE) in many deuterostomes. In sea urchin the ANE is restricted to the anterior of the late blastula stage embryo, where it forms a simple neural territory comprising several types of neurons as well as the apical tuft. Here, we show that during early development, the sea urchin ANE territory separates into inner and outer regulatory domains that express the cardinal ANE transcriptional regulators FoxQ2 and Six3, respectively. FoxQ2 drives this patterning process, which is required to eliminate six3 expression from the inner domain and activate the expression of Dkk3 and sFRP1/5, two secreted Wnt modulators. Dkk3 and low expression levels of sFRP1/5 act additively to potentiate the Wnt/JNK signaling pathway governing the positioning of the ANE territory around the anterior pole, whereas high expression levels of sFRP1/5 antagonize Wnt/JNK signaling. sFRP1/5 and Dkk3 levels are rigidly maintained via autorepressive and cross-repressive interactions with Wnt signaling components and additional ANE transcription factors. Together, these data support a model in which FoxQ2 initiates an anterior patterning center that implements correct size and positions of ANE structures. Comparisons of functional and expression studies in sea urchin, hemichordate and chordate embryos reveal striking similarities among deuterostome ANE regulatory networks and the molecular mechanism that positions and defines ANE borders. These data strongly support the idea that the sea urchin embryo uses an ancient anterior patterning system that was present in the common ambulacrarian/chordate ancestor.

  8. An anterior signaling center patterns and sizes the anterior neuroectoderm of the sea urchin embryo.

    PubMed

    Range, Ryan C; Wei, Zheng

    2016-05-01

    Anterior signaling centers help specify and pattern the early anterior neuroectoderm (ANE) in many deuterostomes. In sea urchin the ANE is restricted to the anterior of the late blastula stage embryo, where it forms a simple neural territory comprising several types of neurons as well as the apical tuft. Here, we show that during early development, the sea urchin ANE territory separates into inner and outer regulatory domains that express the cardinal ANE transcriptional regulators FoxQ2 and Six3, respectively. FoxQ2 drives this patterning process, which is required to eliminate six3 expression from the inner domain and activate the expression of Dkk3 and sFRP1/5, two secreted Wnt modulators. Dkk3 and low expression levels of sFRP1/5 act additively to potentiate the Wnt/JNK signaling pathway governing the positioning of the ANE territory around the anterior pole, whereas high expression levels of sFRP1/5 antagonize Wnt/JNK signaling. sFRP1/5 and Dkk3 levels are rigidly maintained via autorepressive and cross-repressive interactions with Wnt signaling components and additional ANE transcription factors. Together, these data support a model in which FoxQ2 initiates an anterior patterning center that implements correct size and positions of ANE structures. Comparisons of functional and expression studies in sea urchin, hemichordate and chordate embryos reveal striking similarities among deuterostome ANE regulatory networks and the molecular mechanism that positions and defines ANE borders. These data strongly support the idea that the sea urchin embryo uses an ancient anterior patterning system that was present in the common ambulacrarian/chordate ancestor. PMID:26952978

  9. Primitive agriculture in a social amoeba.

    PubMed

    Brock, Debra A; Douglas, Tracy E; Queller, David C; Strassmann, Joan E

    2011-01-20

    Agriculture has been a large part of the ecological success of humans. A handful of animals, notably the fungus-growing ants, termites and ambrosia beetles, have advanced agriculture that involves dispersal and seeding of food propagules, cultivation of the crop and sustainable harvesting. More primitive examples, which could be called husbandry because they involve fewer adaptations, include marine snails farming intertidal fungi and damselfish farming algae. Recent work has shown that microorganisms are surprisingly like animals in having sophisticated behaviours such as cooperation, communication and recognition, as well as many kinds of symbiosis. Here we show that the social amoeba Dictyostelium discoideum has a primitive farming symbiosis that includes dispersal and prudent harvesting of the crop. About one-third of wild-collected clones engage in husbandry of bacteria. Instead of consuming all bacteria in their patch, they stop feeding early and incorporate bacteria into their fruiting bodies. They then carry bacteria during spore dispersal and can seed a new food crop, which is a major advantage if edible bacteria are lacking at the new site. However, if they arrive at sites already containing appropriate bacteria, the costs of early feeding cessation are not compensated for, which may account for the dichotomous nature of this farming symbiosis. The striking convergent evolution between bacterial husbandry in social amoebas and fungus farming in social insects makes sense because multigenerational benefits of farming go to already established kin groups. PMID:21248849

  10. The organic inventory of primitive meteorites

    NASA Astrophysics Data System (ADS)

    Martins, Zita

    Carbonaceous meteorites are primitive samples that provide crucial information about the solar system genesis and evolution. This class of meteorites has also a rich organic inventory, which may have contributed the first prebiotic building blocks of life to the early Earth. We have studied the soluble organic inventory of several CR and CM meteorites, using high performance liquid chromatography with UV fluorescence detection (HPLC-FD), gas chromatography-mass spectrometry (GC-MS) and gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Our target organic molecules include amino acids, nucleobases and polycyclic aromatic hydrocarbons (PAHs), among others. CR chondrites contain the highest amino acids concentration ever detected in a meteorite. The degree of aqueous alteration amongst this class of meteorites seems to be responsible for the amino acid distribution. Pioneering compound-specific carbon isotope measurements of nucleobases present in carbonaceous chondrites show that these compounds have a non-terrestrial origin. This suggests that components of the ge-netic code may have had a crucial role in life's origin. Investigating the abundances, distribution and isotopic composition of organic molecules in primitive meteorites significantly improves our knowledge of the chemistry of the early solar system, and the resources available for the first living organisms on Earth.

  11. The Spemann organizer meets the anterior-most neuroectoderm at the equator of early gastrulae in amphibian species

    PubMed Central

    Yanagi, Takanori; Ito, Kenta; Nishihara, Akiha; Minamino, Reika; Mori, Shoko; Sumida, Masayuki; Hashimoto, Chikara

    2015-01-01

    The dorsal blastopore lip (known as the Spemann organizer) is important for making the body plan in amphibian gastrulation. The organizer is believed to involute inward and migrate animally to make physical contact with the prospective head neuroectoderm at the blastocoel roof of mid- to late-gastrula. However, we found that this physical contact was already established at the equatorial region of very early gastrula in a wide variety of amphibian species. Here we propose a unified model of amphibian gastrulation movement. In the model, the organizer is present at the blastocoel roof of blastulae, moves vegetally to locate at the region that lies from the blastocoel floor to the dorsal lip at the onset of gastrulation. The organizer located at the blastocoel floor contributes to the anterior axial mesoderm including the prechordal plate, and the organizer at the dorsal lip ends up as the posterior axial mesoderm. During the early step of gastrulation, the anterior organizer moves to establish the physical contact with the prospective neuroectoderm through the “subduction and zippering” movements. Subduction makes a trench between the anterior organizer and the prospective neuroectoderm, and the tissues face each other via the trench. Zippering movement, with forming Brachet's cleft, gradually closes the gap to establish the contact between them. The contact is completed at the equator of early gastrulae and it continues throughout the gastrulation. After the contact is established, the dorsal axis is formed posteriorly, but not anteriorly. The model also implies the possibility of constructing a common model of gastrulation among chordate species. PMID:25754292

  12. The Spemann organizer meets the anterior-most neuroectoderm at the equator of early gastrulae in amphibian species.

    PubMed

    Yanagi, Takanori; Ito, Kenta; Nishihara, Akiha; Minamino, Reika; Mori, Shoko; Sumida, Masayuki; Hashimoto, Chikara

    2015-04-01

    The dorsal blastopore lip (known as the Spemann organizer) is important for making the body plan in amphibian gastrulation. The organizer is believed to involute inward and migrate animally to make physical contact with the prospective head neuroectoderm at the blastocoel roof of mid- to late-gastrula. However, we found that this physical contact was already established at the equatorial region of very early gastrula in a wide variety of amphibian species. Here we propose a unified model of amphibian gastrulation movement. In the model, the organizer is present at the blastocoel roof of blastulae, moves vegetally to locate at the region that lies from the blastocoel floor to the dorsal lip at the onset of gastrulation. The organizer located at the blastocoel floor contributes to the anterior axial mesoderm including the prechordal plate, and the organizer at the dorsal lip ends up as the posterior axial mesoderm. During the early step of gastrulation, the anterior organizer moves to establish the physical contact with the prospective neuroectoderm through the "subduction and zippering" movements. Subduction makes a trench between the anterior organizer and the prospective neuroectoderm, and the tissues face each other via the trench. Zippering movement, with forming Brachet's cleft, gradually closes the gap to establish the contact between them. The contact is completed at the equator of early gastrulae and it continues throughout the gastrulation. After the contact is established, the dorsal axis is formed posteriorly, but not anteriorly. The model also implies the possibility of constructing a common model of gastrulation among chordate species.

  13. Peripheral intravenous line - infants

    MedlinePlus

    PIV - infants; Peripheral IV - infants; Peripheral line - infants; Peripheral line - neonatal ... A peripheral intravenous line (PIV) is a small, short, plastic tube, called a catheter. A health care provider puts ...

  14. Reconstruction of anterior maxillary defect with buccal pad fat after excision of melanotic neuroectodermal tumor of infancy

    PubMed Central

    Kumar, Dinesh; Rattan, Vidya; Rai, Sachin; Yadav, Shikha; Sahu, Gyana Ranjan

    2015-01-01

    This paper highlights a rare case of melanotic neuroectodermal tumor of infancy involving the anterior maxilla in a 3-month-old infant. The tumor was excised completely, and the defect was reconstructed with a bilateral buccal pad of fat. The patient has been followed for 2 years without any evidence of recurrence. We propose that for similar anterior maxillary defects in infants and children, a buccal pad of fat can be utilized as an appropriate pedicled flap for coverage after tumor resection. PMID:26981478

  15. Primitive material surviving in chondrites - Matrix

    NASA Technical Reports Server (NTRS)

    Scott, E. R. D.; Barber, D. J.; Alexander, C. M.; Hutchinson, R.; Peck, J. A.

    1988-01-01

    A logical place to search for surviving pristine nebular material is in the fine-grained matrices of ordinary and carbonaceous chondrites of petrographic type 3. Unfortunately, many of these chondrites have experienced brecciation, thermal metamorphism, and aqueous alteration, so that interpreting individual features in terms of specific nebular conditions and/or processes is difficult. It follows that the origin and evolutionary history of such matrix phases are controversial, and a consensus is difficult to define. In this chapter, therefore, after summarizing the salient mineralogical, petrographic, chemical, and isotopic features of matrix in apparently primitive chondrites, an attempt is made to provide an overview both of areas of agreement and of topics that are currently in dispute.

  16. Nitrogen isotope anomalies in primitive ordinary chondrites

    NASA Astrophysics Data System (ADS)

    Sugiura, Naoji; Hashizume, Ko

    1992-07-01

    Large anomalies in nitrogen isotopic composition were found in two type-L3 ordinary chondrites. One of them is isotopically heavy, and the other is isotopically light. The carriers of anomalous nitrogen are partly soluble in HCl. Thus, the anomalies are probably due to new types of presolar grains, although they have not been identified yet. Trapped Ar-36 in these chondrites seems to be associated with this anomalous nitrogen, and may be presolar in origin. The presence of two different nitrogen isotopic anomalies suggests that the parent body of L chondrites, and also the primitive solar nebula, were not homogeneous. Nitrogen isotope anomalies seem to be useful in detecting subdivisions of chemical groups of chondrites.

  17. Primitive defenses: cognitive aspects and therapeutic handling.

    PubMed

    Groh, L S

    In this paper the primitive defenses first described by Melanie Klein under the label of "schizoid mechanisms" are examined. The defenses considered are splitting the pathological uses of identification and projective identification, and the psychotic forms of denial. This examination is twofold: (1) the cognitive aspects of these defenses as described in terms of concepts developed by Jean Piaget; (2) concrete examples of the operation of these defenses during the treatment of schizophrenic patients are given and the effects of interventions based on the cognitive analysis are described. It is stressed that at times interventions, such as interpretation and confrontation, based on cognitive analysis, can temporarily and in some instances even permanently stop the operation of these defenses, allowing emotionally meaningful material to emerge which expedites the therapeutic process.

  18. Giant impacts on a primitive Uranus

    NASA Technical Reports Server (NTRS)

    Slattery, Wayne L.; Benz, Willy; Cameron, A. G. W.

    1992-01-01

    Simulations of collisions are conducted between a model of the primitive Uranus and 1-3 earth-mass impactors, using smooth-particle hydrodynamics. A series of collisions was simulated for each impactor while varying the total angular momentum of the system. Most of the simulation runs left ices in orbit; a subset of the runs also left rock or iron (from the impactor). It is concluded on the basis of these results that there is a wide range of giant impacts which could have produced the current period and inclination of the spin axis relative to the plane of the ecliptic. A subset of these could have deposited the material in orbit from which the regular satellites of Uranus were assembled.

  19. Primitive defenses: cognitive aspects and therapeutic handling.

    PubMed

    Groh, L S

    In this paper the primitive defenses first described by Melanie Klein under the label of "schizoid mechanisms" are examined. The defenses considered are splitting the pathological uses of identification and projective identification, and the psychotic forms of denial. This examination is twofold: (1) the cognitive aspects of these defenses as described in terms of concepts developed by Jean Piaget; (2) concrete examples of the operation of these defenses during the treatment of schizophrenic patients are given and the effects of interventions based on the cognitive analysis are described. It is stressed that at times interventions, such as interpretation and confrontation, based on cognitive analysis, can temporarily and in some instances even permanently stop the operation of these defenses, allowing emotionally meaningful material to emerge which expedites the therapeutic process. PMID:7429737

  20. Peripheral circulation.

    PubMed

    Laughlin, M Harold; Davis, Michael J; Secher, Niels H; van Lieshout, Johannes J; Arce-Esquivel, Arturo A; Simmons, Grant H; Bender, Shawn B; Padilla, Jaume; Bache, Robert J; Merkus, Daphne; Duncker, Dirk J

    2012-01-01

    Blood flow (BF) increases with increasing exercise intensity in skeletal, respiratory, and cardiac muscle. In humans during maximal exercise intensities, 85% to 90% of total cardiac output is distributed to skeletal and cardiac muscle. During exercise BF increases modestly and heterogeneously to brain and decreases in gastrointestinal, reproductive, and renal tissues and shows little to no change in skin. If the duration of exercise is sufficient to increase body/core temperature, skin BF is also increased in humans. Because blood pressure changes little during exercise, changes in distribution of BF with incremental exercise result from changes in vascular conductance. These changes in distribution of BF throughout the body contribute to decreases in mixed venous oxygen content, serve to supply adequate oxygen to the active skeletal muscles, and support metabolism of other tissues while maintaining homeostasis. This review discusses the response of the peripheral circulation of humans to acute and chronic dynamic exercise and mechanisms responsible for these responses. This is accomplished in the context of leading the reader on a tour through the peripheral circulation during dynamic exercise. During this tour, we consider what is known about how each vascular bed controls BF during exercise and how these control mechanisms are modified by chronic physical activity/exercise training. The tour ends by comparing responses of the systemic circulation to those of the pulmonary circulation relative to the effects of exercise on the regional distribution of BF and mechanisms responsible for control of resistance/conductance in the systemic and pulmonary circulations.

  1. Motor learning through the combination of primitives.

    PubMed Central

    Mussa-Ivaldi, F A; Bizzi, E

    2000-01-01

    In this paper we discuss a new perspective on how the central nervous system (CNS) represents and solves some of the most fundamental computational problems of motor control. In particular, we consider the task of transforming a planned limb movement into an adequate set of motor commands. To carry out this task the CNS must solve a complex inverse dynamic problem. This problem involves the transformation from a desired motion to the forces that are needed to drive the limb. The inverse dynamic problem is a hard computational challenge because of the need to coordinate multiple limb segments and because of the continuous changes in the mechanical properties of the limbs and of the environment with which they come in contact. A number of studies of motor learning have provided support for the idea that the CNS creates, updates and exploits internal representations of limb dynamics in order to deal with the complexity of inverse dynamics. Here we discuss how such internal representations are likely to be built by combining the modular primitives in the spinal cord as well as other building blocks found in higher brain structures. Experimental studies on spinalized frogs and rats have led to the conclusion that the premotor circuits within the spinal cord are organized into a set of discrete modules. Each module, when activated, induces a specific force field and the simultaneous activation of multiple modules leads to the vectorial combination of the corresponding fields. We regard these force fields as computational primitives that are used by the CNS for generating a rich grammar of motor behaviours. PMID:11205339

  2. Primary Cilium-Autophagy-Nrf2 (PAN) Axis Activation Commits Human Embryonic Stem Cells to a Neuroectoderm Fate.

    PubMed

    Jang, Jiwon; Wang, Yidi; Lalli, Matthew A; Guzman, Elmer; Godshalk, Sirie E; Zhou, Hongjun; Kosik, Kenneth S

    2016-04-01

    Under defined differentiation conditions, human embryonic stem cells (hESCs) can be directed toward a mesendoderm (ME) or neuroectoderm (NE) fate, the first decision during hESC differentiation. Coupled with lineage-specific G1 lengthening, a divergent ciliation pattern emerged within the first 24 hr of induced lineage specification, and these changes heralded a neuroectoderm decision before any neural precursor markers were expressed. By day 2, increased ciliation in NE precursors induced autophagy that resulted in the inactivation of Nrf2 and thereby relieved transcriptional activation of OCT4 and NANOG. Nrf2 binds directly to upstream regions of these pluripotency genes to promote their expression and repress NE derivation. Nrf2 suppression was sufficient to rescue poorly neurogenic iPSC lines. Only after these events had been initiated did neural precursor markers get expressed at day 4. Thus, we have identified a primary cilium-autophagy-Nrf2 (PAN) control axis coupled to cell-cycle progression that directs hESCs toward NE. PMID:27020754

  3. 36 CFR 261.21 - National Forest primitive areas.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false National Forest primitive areas. 261.21 Section 261.21 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PROHIBITIONS General Prohibitions § 261.21 National Forest primitive areas. The following...

  4. 36 CFR 261.21 - National Forest primitive areas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false National Forest primitive areas. 261.21 Section 261.21 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PROHIBITIONS General Prohibitions § 261.21 National Forest primitive areas. The following...

  5. 36 CFR 261.21 - National Forest primitive areas.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false National Forest primitive areas. 261.21 Section 261.21 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PROHIBITIONS General Prohibitions § 261.21 National Forest primitive areas. The following...

  6. 36 CFR 261.21 - National Forest primitive areas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false National Forest primitive areas. 261.21 Section 261.21 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PROHIBITIONS General Prohibitions § 261.21 National Forest primitive areas. The following...

  7. 36 CFR 261.21 - National Forest primitive areas.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false National Forest primitive areas. 261.21 Section 261.21 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PROHIBITIONS General Prohibitions § 261.21 National Forest primitive areas. The following...

  8. A manual for PARTI runtime primitives, revision 1

    NASA Technical Reports Server (NTRS)

    Das, Raja; Saltz, Joel; Berryman, Harry

    1991-01-01

    Primitives are presented that are designed to help users efficiently program irregular problems (e.g., unstructured mesh sweeps, sparse matrix codes, adaptive mesh partial differential equations solvers) on distributed memory machines. These primitives are also designed for use in compilers for distributed memory multiprocessors. Communications patterns are captured at runtime, and the appropriate send and receive messages are automatically generated.

  9. Sperm Cells of a Primitive Strepsipteran.

    PubMed

    Nardi, James B; Delgado, Juan A; Collantes, Francisco; Miller, Lou Ann; Bee, Charles M; Kathirithamby, Jeyaraney

    2013-09-04

    The unusual life style of Strepsiptera has presented a long-standing puzzle in establishing its affinity to other insects. Although Strepsiptera share few structural similarities with other insect orders, all members of this order share a parasitic life style with members of two distinctive families in the Coleoptera-the order now considered the most closely related to Strepsiptera based on recent genomic evidence. Among the structural features of several strepsipteran families and other insect families that have been surveyed are the organization of testes and ultrastructure of sperm cells. For comparison with existing information on insect sperm structure, this manuscript presents a description of testes and sperm of a representative of the most primitive extant strepsipteran family Mengenillidae, Eoxenos laboulbenei. We compare sperm structure of E. laboulbenei from this family with that of the three other families of Strepsiptera in the other strepsipteran suborder Stylopidia that have been studied as well as with members of the beetle families Meloidae and Rhipiphoridae that share similar life histories with Strepsiptera. Meloids, Rhipiphorids and Strepsipterans all begin larval life as active and viviparous first instar larvae. This study examines global features of these insects' sperm cells along with specific ultrastructural features of their organelles.

  10. Sperm Cells of a Primitive Strepsipteran

    PubMed Central

    Nardi, James B.; Delgado, Juan A.; Collantes, Francisco; Miller, Lou Ann; Bee, Charles M.; Kathirithamby, Jeyaraney

    2013-01-01

    The unusual life style of Strepsiptera has presented a long-standing puzzle in establishing its affinity to other insects. Although Strepsiptera share few structural similarities with other insect orders, all members of this order share a parasitic life style with members of two distinctive families in the Coleoptera—the order now considered the most closely related to Strepsiptera based on recent genomic evidence. Among the structural features of several strepsipteran families and other insect families that have been surveyed are the organization of testes and ultrastructure of sperm cells. For comparison with existing information on insect sperm structure, this manuscript presents a description of testes and sperm of a representative of the most primitive extant strepsipteran family Mengenillidae, Eoxenos laboulbenei. We compare sperm structure of E. laboulbenei from this family with that of the three other families of Strepsiptera in the other strepsipteran suborder Stylopidia that have been studied as well as with members of the beetle families Meloidae and Rhipiphoridae that share similar life histories with Strepsiptera. Meloids, Rhipiphorids and Strepsipterans all begin larval life as active and viviparous first instar larvae. This study examines global features of these insects’ sperm cells along with specific ultrastructural features of their organelles. PMID:26462430

  11. From Titan to the primitive Earth

    NASA Astrophysics Data System (ADS)

    Raulin, F.; Gpcos Team

    Our knowledge of the conditions prevailing in the environment of the primitive Earth is still very limited, due to the lack of geological data. Fortunately, there are a few planetary objects in the solar system which present similarities with our planet, including during its early history. Titan is one of these. With a diameter of more than 5100 km, Titan, the largest moon of Saturn, is also the only one to have a dense atmosphere. This atmosphere, clearly evidenced by the presence of haze layers, extends to approximately 1500 km. Like the Earth, Titan's atmosphere is mainly composed of dinitrogen, N2 . The other main constituents are methane, CH4 , about 1.6% to 2.0% in the stratosphere, as measured by CIRS on Cassini and GC-MS on Huygens and dihydrogen (H2 , approximate 0.1%). With surface temperatures of approximately 94 K, and an average surface pressure of 1.5 bar, Titan's atmosphere is nearly five times denser than the Earth's. Despite of these differences between Titan and the Earth there are several analogies that can be drawn between the two planetary bodies. The first resemblances concern the vertical atmospheric structure. Although Titan is much colder, with a troposphere (˜94-˜70 K), a tropopause (70.4 K) and a stratosphere (˜70-175 K) its atmosphere presents a similar complex structure to that of the Earth. These analogies are linked to the presence in both atmospheres of greenhouse gases: CH4 and H2 on Titan, equivalent respectively to terrestrial condensable H2 O and non-condensable CO2 . In addition the haze particles and clouds in Titan's atmosphere play an antigreenhouse effect similar to that of the terrestrial atmospheric aerosols and clouds. Indeed, methane on Titan seems to play the role of water on the Earth, with a complex cycle, which still has to be understood. The possibility that Titan is covered with hydrocarbon oceans is now ruled out, but it is still possible that Titan's surface include lakes of methane and ethane. Moreover, the

  12. Sperm Cells of a Primitive Strepsipteran.

    PubMed

    Nardi, James B; Delgado, Juan A; Collantes, Francisco; Miller, Lou Ann; Bee, Charles M; Kathirithamby, Jeyaraney

    2013-01-01

    The unusual life style of Strepsiptera has presented a long-standing puzzle in establishing its affinity to other insects. Although Strepsiptera share few structural similarities with other insect orders, all members of this order share a parasitic life style with members of two distinctive families in the Coleoptera-the order now considered the most closely related to Strepsiptera based on recent genomic evidence. Among the structural features of several strepsipteran families and other insect families that have been surveyed are the organization of testes and ultrastructure of sperm cells. For comparison with existing information on insect sperm structure, this manuscript presents a description of testes and sperm of a representative of the most primitive extant strepsipteran family Mengenillidae, Eoxenos laboulbenei. We compare sperm structure of E. laboulbenei from this family with that of the three other families of Strepsiptera in the other strepsipteran suborder Stylopidia that have been studied as well as with members of the beetle families Meloidae and Rhipiphoridae that share similar life histories with Strepsiptera. Meloids, Rhipiphorids and Strepsipterans all begin larval life as active and viviparous first instar larvae. This study examines global features of these insects' sperm cells along with specific ultrastructural features of their organelles. PMID:26462430

  13. Likelihood reinstates Archaeopteryx as a primitive bird

    PubMed Central

    Lee, Michael S. Y.; Worthy, Trevor H.

    2012-01-01

    The widespread view that Archaeopteryx was a primitive (basal) bird has been recently challenged by a comprehensive phylogenetic analysis that placed Archaeopteryx with deinonychosaurian theropods. The new phylogeny suggested that typical bird flight (powered by the front limbs only) either evolved at least twice, or was lost/modified in some deinonychosaurs. However, this parsimony-based result was acknowledged to be weakly supported. Maximum-likelihood and related Bayesian methods applied to the same dataset yield a different and more orthodox result: Archaeopteryx is restored as a basal bird with bootstrap frequency of 73 per cent and posterior probability of 1. These results are consistent with a single origin of typical (forelimb-powered) bird flight. The Archaeopteryx–deinonychosaur clade retrieved by parsimony is supported by more characters (which are on average more homoplasious), whereas the Archaeopteryx–bird clade retrieved by likelihood-based methods is supported by fewer characters (but on average less homoplasious). Both positions for Archaeopteryx remain plausible, highlighting the hazy boundary between birds and advanced theropods. These results also suggest that likelihood-based methods (in addition to parsimony) can be useful in morphological phylogenetics. PMID:22031726

  14. Busulfan, Melphalan, Topotecan Hydrochloride, and a Stem Cell Transplant in Treating Patients With Newly Diagnosed or Relapsed Solid Tumor

    ClinicalTrials.gov

    2016-05-04

    Solid Tumor; Adult Central Nervous System Germ Cell Tumor; Adult Rhabdomyosarcoma; Childhood Central Nervous System Germ Cell Tumor; Childhood Soft Tissue Sarcoma; Ewing Sarcoma; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Ovarian Mixed Germ Cell Tumor; Previously Untreated Childhood Rhabdomyosarcoma; Recurrent Adult Brain Tumor; Recurrent Adult Soft Tissue Sarcoma; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Medulloblastoma; Recurrent Childhood Pineoblastoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma; Recurrent Childhood Visual Pathway Glioma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Extragonadal Germ Cell Tumor; Recurrent Extragonadal Non-seminomatous Germ Cell Tumor; Recurrent Malignant Testicular Germ Cell Tumor; Recurrent Neuroblastoma; Recurrent Ovarian Germ Cell Tumor; Recurrent Wilms Tumor and Other Childhood Kidney Tumors; Unspecified Adult Solid Tumor, Protocol Specific; Unspecified Childhood Solid Tumor, Protocol Specific

  15. The ``primitive'' wave function in the theory of intermolecular interactions

    NASA Astrophysics Data System (ADS)

    Kutzelnigg, Werner

    1980-07-01

    The concept of the primitive wave function for a supermolecule consisting of interacting subsystems is critically analyzed. The distinction between formal and genuine primitive functions is stressed. The concept of uniformly complete basis sets as contrasted to simply complete basis is introduced. Primitive basis sets are defined and shown not to be uniformly complete for the expansion of the supersystem wave function while 'full supersystem basis sets' are. The conditions are specified under which a supersystem wave function can be decomposed into its 'primitive components' corresponding to different partitions of the electrons among the subsystems. These primitive components satisfy the Schrödinger equation asymptotically. The matrix representation of the Hamiltonian (both the full supersystem Hamiltonian H and the zeroth order Hamiltonian Ho) in terms of these partitions is analyzed. It is shown that in the standard application of RS-perturbation theory to intermolecular forces (the polarization approximation) the limiting processes λ→1 and R→∞ do not commute, that the λ-series is not uniformly convergent with respect to R and that the wave function to any finite order in λ is genuinely primitive. The symmetrized polarization approximation is justified for the 'coasymptotic ground state' in certain cases and a 'symmetrized polarization approximation with shifted eigenvalues' is proposed that connects the lowest eigenvalue of Ho with the physical ground state. A justification of simplified schemes in the region of 'small exchange' is given and alternative perturbation schemes are discussed. Finally the use of the primitive function in variational treatments is outlined. One advantage is that a genuinely (not a formally) primitive function is uniformly expandable in a primitive basis set.

  16. Ideals and primitive elements of some relatively free Lie algebras.

    PubMed

    Ekici, Naime; Esmerligil, Zerrin; Ersalan, Dilek

    2016-01-01

    Let F be a free Lie algebra of finite rank over a field K. We prove that if an ideal [Formula: see text] of the algebra [Formula: see text] contains a primitive element [Formula: see text] then the element [Formula: see text] is primitive. We also show that, in the Lie algebra [Formula: see text] there exists an element [Formula: see text] such that the ideal [Formula: see text] contains a primitive element [Formula: see text] but, [Formula: see text] and [Formula: see text] are not conjugate by means of an inner automorphism.

  17. Ideals and primitive elements of some relatively free Lie algebras.

    PubMed

    Ekici, Naime; Esmerligil, Zerrin; Ersalan, Dilek

    2016-01-01

    Let F be a free Lie algebra of finite rank over a field K. We prove that if an ideal [Formula: see text] of the algebra [Formula: see text] contains a primitive element [Formula: see text] then the element [Formula: see text] is primitive. We also show that, in the Lie algebra [Formula: see text] there exists an element [Formula: see text] such that the ideal [Formula: see text] contains a primitive element [Formula: see text] but, [Formula: see text] and [Formula: see text] are not conjugate by means of an inner automorphism. PMID:27386282

  18. Hf-W chronometry of primitive achondrites

    NASA Astrophysics Data System (ADS)

    Schulz, T.; Münker, C.; Mezger, K.; Palme, H.

    2010-03-01

    Metal segregation and silicate melting on asteroids are the most incisive differentiation events in the early evolution of planetary bodies. The timing of these events can be constrained using the short-lived 182Hf- 182W radionuclide system. Here we present new 182Hf- 182W data for major types of primitive achondrites including acapulcoites, winonaites and one lodranite. These meteorites are of particular interest because they show only limited evidence for partial melting of silicates and are therefore intermediate between chondrites and achondrites. For acapulcoites we derived a 182Hf- 182W age of Δ tCAI = 4.1 +1.2/ -1.1 Ma. A model age for winonaite separates calculated from the intercept of the isochron defines an age of Δ tCAI = 4.8 +3.1/ -2.6 Ma (assuming a bulk Hf/W ratio of ˜1.2). Both ages most likely define primary magmatic events on the respective parent bodies, such as melting of metal, although metal stayed in place and did not segregate to form a core. A later thermal event is responsible for resetting of the winonaite isochron, yielding an age of Δ tCAI = 14.3 +2.7/ -2.2 Ma, significantly younger than the model age. Assuming a co-genetic relationship between winonaites and silicates present in IAB iron meteorites (based on oxygen isotope composition) and including data by Schulz et al. (2009), a common parent body chronology can be established. Magmatic activity occurred between ˜1.5 and 5 Ma after CAIs. More than 5 Ma later, intensive thermal metamorphism has redistributed Hf-W. Average cooling rates calculated for the winonaite/IAB parent asteroid range between ˜35 and ˜4 K/Ma, most likely reflecting different burial depths. Cooling rates obtained for acapulcoites were ˜40 K/Ma to ˜720 K and then ˜3 K/Ma to ˜550 K. Accretion and subsequent magmatism on the acapulcoite parent body occurred slightly later if compared to most achondrite parent bodies (e.g., angrites, ureilites and eucrites), in this case supporting the concept of an inverse

  19. Clinically effective monoclonal antibody 3F8 mediates nonoxidative lysis of human neuroectodermal tumor cells by polymorphonuclear leukocytes.

    PubMed

    Kushner, B H; Cheung, N K

    1991-09-15

    Most studies of antibody-dependent cellular cytotoxicity (ADCC) by polymorphonuclear leukocytes (PMN) have supported oxidative lytic processes. This may be because the studies used nonhuman or nonneoplastic cells that were highly sensitive to reactive oxygen species or were small enough to be phagocytosed by PMN. We therefore investigated whether oxygen radicals participate in PMN cytotoxicity toward human neuroectodermal solid tumor cells sensitized by 3F8, which is an anti-ganglioside GD2 murine IgG3 monoclonal antibody with documented anticancer activity in humans. A 4-h 51Cr release assay was used to assess tumor cell lysis by hydrogen peroxide, superoxide, and hypochlorite. Nine of 11 GD2(+) human melanoma and neuroblastoma cell lines had equal or greater resistance to these oxidants as compared to a GD2(-) human carcinoma line (SKBr1-III) found by others (and confirmed by us) to be significantly more resistant to oxidative lysis than a murine cell line (P388D1) representative of those commonly used in cytotoxicity assays. To facilitate detection of oxidant-mediated lysis, subsequent studies of 3F8-mediated ADCC used GD2(+) targets that were relatively sensitive and others that were relatively resistant to oxygen radicals. Normal PMN and PMN obtained from children with chronic granulomatous disease, which do not generate reactive oxygen species, were equally effective in ADCC. Granulocyte-macrophage colony-stimulating factor, which primes oxidative responses of normal but not of chronic granulomatous disease PMN, enhanced ADCC by both kinds of PMN. During ADCC of 3F8-sensitized targets, with or without granulocyte-macrophage colony-stimulating factor, GD2(-) "innocent bystander" tumor cells (including P388D1) were not lysed, a finding consistent with unimportant extracellular release of cytotoxic mediators. Finally, antioxidant and antimyeloperoxidase moieties did not block ADCC. We conclude that oxidants are not key factors in 3F8-mediated lysis by PMN of

  20. Incidence and survival of children with central nervous system primitive tumors in the French National Registry of Childhood Solid Tumors

    PubMed Central

    Desandes, Emmanuel; Guissou, Sandra; Chastagner, Pascal; Lacour, Brigitte

    2014-01-01

    Background Central nervous system (CNS) tumors are the second most common childhood malignancy. The French National Registry of Childhood Solid Tumors (NRCST) makes it possible to describe this variety of distinct tumor types and to provide incidence and survival data in France on a nationwide basis. Methods All children aged 0–14 years, who were registered with a primary CNS tumor in the NRCST of France between 2000 and 2008, were identified. Tumors were classified according to the International Classification of Childhood Cancer, third edition. Results Approximately 57% of pediatric CNS tumors were gliomas, with astrocytomas of the pilocytic type predominating. Distributions of subtypes by age showed that primitive neuroectodermal tumors and ependymomas mainly occurred in children aged <5 years. The mean annual incidence rate of CNS tumors was 39 per million. No statistically significant change in time trends of incidence rate was observed during 2000–2008. For all tumors combined, overall survival was 84.8% (95% CI, 83.7%–85.9%) at 1 year and 72.9% (95% CI, 71.5%–74.3%) at 5 years. Survival time trends were studied in a multivariate analysis observing a reduction in the risk of death in periods of diagnosis 2003–2005 (HR = 0.8; 95% CI, 0.7–0.9) and 2006–2008 (HR = 0.7; 95% CI, 0.6–0.9) compared with 2000–2002. Conclusions The stable incidence rates during the last 10 years could indicate that major changes in environmental risk factors are unlikely, but the ongoing need for population-based surveillance remains relevant. Results indicate a positive trend in the survival probability still persistent in the 2000s. PMID:24470548

  1. The Artist/Craftsman/Teacher: And Primitive Pottery.

    ERIC Educational Resources Information Center

    Verbalaitis, Victor

    1978-01-01

    In two related articles, the author describes (1) a field trip during which his high school ceramics club collected clay from the outdoors and (2) the process he used to create primitive pottery pieces from such material. (SJL)

  2. A comment on methanogenic bacteria and the primitive ecology

    NASA Technical Reports Server (NTRS)

    Woese, C. R.

    1977-01-01

    As the phenotype of methanogenic bacteria is suggested to have been one of the major factors creating a dynamic balance between CO2 and CH4 in the primitive atmosphere, these organisms are thought to be very ancient. Their antiquity may be further postulated by comparative characterization of their ribosomal RNA. Accepting this antiquity, it is concluded that a carbon-dioxide-methane cycle, driven by photosynthesis, was the major carbon cycle in primitive ecology, and that photosynthesis and methanogens were thus contemporaneous.

  3. Zero Viscosity Limit for Analytic Solutions of the Primitive Equations

    NASA Astrophysics Data System (ADS)

    Kukavica, Igor; Lombardo, Maria Carmela; Sammartino, Marco

    2016-10-01

    The aim of this paper is to prove that the solutions of the primitive equations converge, in the zero viscosity limit, to the solutions of the hydrostatic Euler equations. We construct the solution of the primitive equations through a matched asymptotic expansion involving the solution of the hydrostatic Euler equation and boundary layer correctors as the first order term, and an error that we show to be {O(√{ν})}. The main assumption is spatial analyticity of the initial datum.

  4. Neuropilin-2 genomic elements drive cre recombinase expression in primitive blood, vascular and neuronal lineages.

    PubMed

    Wiszniak, Sophie; Scherer, Michaela; Ramshaw, Hayley; Schwarz, Quenten

    2015-11-01

    We have established a novel Cre mouse line, using genomic elements encompassing the Nrp2 locus, present within a bacterial artificial chromosome clone. By crossing this Cre driver line to R26R LacZ reporter mice, we have documented the temporal expression and lineage traced tissues in which Cre is expressed. Nrp2-Cre drives expression in primitive blood cells arising from the yolk sac, venous and lymphatic endothelial cells, peripheral sensory ganglia, and the lung bud. This mouse line will provide a new tool to researchers wishing to study the development of various tissues and organs in which this Cre driver is expressed, as well as allow tissue-specific knockout of genes of interest to study protein function. This work also presents the first evidence for expression of Nrp2 protein in a mesodermal progenitor with restricted hematopoietic potential, which will significantly advance the study of primitive erythropoiesis. genesis 53:709-717, 2015. © 2015 Wiley Periodicals, Inc. PMID:26454009

  5. Comet Dust: The Diversity of "Primitive" Particles and Implications

    NASA Technical Reports Server (NTRS)

    Wooden, Diane H.; Ishii, Hope A.; Bradley, John P.; Zolensky, Michael E.

    2016-01-01

    Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive particles has expanded significantly through microscale investigations of cosmic dust samples ( IDP's(Interplanetary Dust Particles) and AMM's (Antarctic Micrometeorites)) and of comet dust samples (Stardust and Rosetta's COSIMA), as well as through remote sensing (spectroscopy and imaging) via Spitzer and via spacecraft encounters with 103P/Hartley 2 and 67P/Churyumov-Gerasimenko. Microscale investigations show that comet dust and cosmic dust are particles of unequilibrated materials, including aggregates of materials unequilibrated at submicron scales. We call unequilibrated materials "primitive" and we deduce they were incorporated into ice-rich (H2O-, CO2-, and CO-ice) parent bodies that remained cold, i.e., into comets, because of the lack of aqueous or thermal alteration since particle aggregation; yet some Stardust olivines suggest mild thermal metamorphism. Primitive particles exhibit a diverse range of: structure and typology; size and size distribution of constituents; concentration and form of carbonaceous and organic matter; D-, N-, and O- isotopic enhancements over solar; Mg-, Fe-contents of the silicate minerals; the compositions and concentrations of sulfides, and of less abundant mineral species such as chondrules, CAIs and carbonates. The uniformity within a group of samples points to: aerodynamic sorting of particles and/or particle constituents; the inclusion of a limited range of oxygen fugacities; the inclusion or exclusion of chondrules; a selection of organics. The properties of primitive particles imply there were disk processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disk present at the time and in the region where the comets formed.

  6. Detection of N-glycolyl GM3 ganglioside in neuroectodermal tumors by immunohistochemistry: an attractive vaccine target for aggressive pediatric cancer.

    PubMed

    Scursoni, Alejandra M; Galluzzo, Laura; Camarero, Sandra; Lopez, Jessica; Lubieniecki, Fabiana; Sampor, Claudia; Segatori, Valeria I; Gabri, Mariano R; Alonso, Daniel F; Chantada, Guillermo; de Dávila, María Teresa G

    2011-01-01

    The N-glycolylated ganglioside NeuGc-GM3 has been described in solid tumors such as breast carcinoma, nonsmall cell lung cancer, and melanoma, but is usually not detected in normal human cells. Our aim was to evaluate the presence of NeuGc-GM3 in pediatric neuroectodermal tumors by immunohistochemistry. Twenty-seven archival cases of neuroblastoma and Ewing sarcoma family of tumors (ESFT) were analyzed. Formalin-fixed, paraffin-embedded tumor samples were cut into 5 μm sections. The monoclonal antibody 14F7, a mouse IgG1 that specifically recognizes NeuGc-GM3, and a peroxidase-labeled polymer conjugated to secondary antibodies were used. Presence of NeuGc-GM3 was evident in 23 of 27 cases (85%), with an average of about 70% of positive tumors cells. Immunoreactivity was moderate to intense in most tumors, showing a diffuse cytoplasmic and membranous staining, although cases of ESFT demonstrated a fine granular cytoplasmic pattern. No significant differences were observed between neuroblastoma with and without NMYC oncogene amplification, suggesting that expression of NeuGc-GM3 is preserved in more aggressive cancers. Until now, the expression of N-glycolylated gangliosides in pediatric neuroectodermal tumors has not been investigated. The present study evidenced the expression of NeuGc-GM3 in a high proportion of neuroectodermal tumors, suggesting its potential utility as a specific target of immunotherapy.

  7. Nonaffine chain and primitive path deformation in crosslinked polymers

    NASA Astrophysics Data System (ADS)

    Davidson, J. D.; Goulbourne, N. C.

    2016-08-01

    Chains in a polymer network deform nonaffinely at small length scales due to the ability for extensive microscopic rearrangement. Classically, the conformations of an individual chain can be described solely by an end-to-end length. This picture neglects interchain interactions and therefore does not represent the behavior of a real polymer network. The primitive path concept provides the additional detail to represent interchain entanglements, and techniques have recently been developed to identify the network of primitive paths in a polymer simulation. We use coarse-grained molecular dynamics (MD) to track both chain end-to-end and primitive path deformation in crosslinked polymer networks. The range of simulated materials includes short chain unentangled networks to long, entangled chain networks. Both chain end-to-end and primitive path length are found to be linear functions of the applied deformation, and a simple relationship describes the behavior of a network in response to large stretch uniaxial, pure shear, and equi-biaxial deformations. As expected, end-to-end chain length deformation is nonaffine for short chain networks, and becomes closer to affine for networks of long, entangled chains. However, primitive path deformation is found to always be nonaffine, even for long, entangled chains. We demonstrate how the microscopic constraints of crosslinks and entanglements affect nonaffine chain deformation as well as the simulated elastic behavior of the different networks.

  8. JMJD2A attenuation affects cell cycle and tumourigenic inflammatory gene regulation in lipopolysaccharide stimulated neuroectodermal stem cells

    SciTech Connect

    Das, Amitabh; Chai, Jin Choul; Jung, Kyoung Hwa; Das, Nando Dulal; Kang, Sung Chul; Lee, Young Seek; Seo, Hyemyung; Chai, Young Gyu

    2014-11-01

    JMJD2A is a lysine trimethyl-specific histone demethylase that is highly expressed in a variety of tumours. The role of JMJD2A in tumour progression remains unclear. The objectives of this study were to identify JMJD2A-regulated genes and understand the function of JMJD2A in p53-null neuroectodermal stem cells (p53{sup −/−} NE-4Cs). We determined the effect of LPS as a model of inflammation in p53{sup −/−} NE-4Cs and investigated whether the epigenetic modifier JMJD2A alter the expression of tumourigenic inflammatory genes. Global gene expression was measured in JMJD2A knockdown (kd) p53{sup −/−} NE-4Cs and in LPS-stimulated JMJD2A-kd p53{sup −/−} NE-4C cells. JMJD2A attenuation significantly down-regulated genes were Cdca2, Ccnd2, Ccnd1, Crebbp, IL6rα, and Stat3 related with cell cycle, proliferation, and inflammatory-disease responses. Importantly, some tumour-suppressor genes including Dapk3, Timp2 and TFPI were significantly up-regulated but were not affected by silencing of the JMJD2B. Furthermore, we confirmed the attenuation of JMJD2A also down-regulated Cdca2, Ccnd2, Crebbp, and Rest in primary NSCs isolated from the forebrains of E15 embryos of C57/BL6J mice with effective p53 inhibitor pifithrin-α (PFT-α). Transcription factor (TF) motif analysis revealed known binding patterns for CDC5, MYC, and CREB, as well as three novel motifs in JMJD2A-regulated genes. IPA established molecular networks. The molecular network signatures and functional gene-expression profiling data from this study warrants further investigation as an effective therapeutic target, and studies to elucidate the molecular mechanism of JMJD2A-kd-dependent effects in neuroectodermal stem cells should be performed. - Highlights: • Significant up-regulation of epigenetic modifier JMJD2A mRNA upon LPS treatment. • Inhibition of JMJD2A attenuated key inflammatory and tumourigenic genes. • Establishing IPA based functional genomics in JMJD2A-attenuated p53{sup

  9. Flavopiridol in Treating Children With Relapsed or Refractory Solid Tumors or Lymphomas

    ClinicalTrials.gov

    2013-07-01

    Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Large Cell Lymphoma; Recurrent Childhood Liver Cancer; Recurrent Childhood Lymphoblastic Lymphoma; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Medulloblastoma; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Small Noncleaved Cell Lymphoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma; Recurrent Childhood Visual Pathway Glioma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Neuroblastoma; Recurrent Osteosarcoma; Recurrent Retinoblastoma; Recurrent Wilms Tumor and Other Childhood Kidney Tumors; Recurrent/Refractory Childhood Hodgkin Lymphoma; Unspecified Childhood Solid Tumor, Protocol Specific

  10. Peripheral intravenous line (image)

    MedlinePlus

    A peripheral intravenous line is a small, short plastic catheter that is placed through the skin into a vein, ... or foot, but occasionally in the head. A peripheral intravenous line is used to give fluids and ...

  11. Peripheral arterial line (image)

    MedlinePlus

    A peripheral arterial line is a small, short plastic catheter placed through the skin into an artery of the arm or leg. The purpose of a peripheral arterial line is to allow continuous monitoring of ...

  12. Peripheral Nerve Disorders

    MedlinePlus

    ... spinal cord. Like static on a telephone line, peripheral nerve disorders distort or interrupt the messages between the brain ... body. There are more than 100 kinds of peripheral nerve disorders. They can affect one nerve or many nerves. ...

  13. Insights to primitive replication derived from structures of small oligonucleotides

    NASA Technical Reports Server (NTRS)

    Smith, G. K.; Fox, G. E.

    1995-01-01

    Available information on the structure of small oligonucleotides is surveyed. It is observed that even small oligomers typically exhibit defined structures over a wide range of pH and temperature. These structures rely on a plethora of non-standard base-base interactions in addition to the traditional Watson-Crick pairings. Stable duplexes, though typically antiparallel, can be parallel or staggered and perfect complementarity is not essential. These results imply that primitive template directed reactions do not require high fidelity. Hence, the extensive use of Watson-Crick complementarity in genes rather than being a direct consequence of the primitive condensation process, may instead reflect subsequent selection based on the advantage of accuracy in maintaining the primitive genetic machinery once it arose.

  14. Polycyclic aromatic hydrocarbons - Primitive pigment systems in the prebiotic environment

    NASA Technical Reports Server (NTRS)

    Deamer, D. W.

    1992-01-01

    The chemical evolution of meteoritic organics in the primitive earth is examined experimentally with attention given to the photochemical effects of hydrocarbon/water mixtures. Also addressed are the generation of amphiphilic products by photochemical reactions and the transduction of light energy into potentially useful forms. Polycyclic aromatic hydrocarbons (PAHs) absorb light and exist in carbonaceous chondrites; PAHs are therefore examined as primitive pigments by means of salt solutions with pyrene, fluoranthene, and pyrene derivatives with hexadecane. The hexadecane undergoes photochemical oxidation and yields long-chain amphiphiles with oxygen supplied by water, and acid pH shifts also occur. PAHs are also tested in lipid bilayer membranes to examine light-energy transduction. Protons are found to accumulate within the membrane-bounded volume to form proton gradients, and this reaction is theorized to be a good model of primitive photochemical reactions that related to the transduction of light energy into useable forms.

  15. Clay minerals in primitive meteorites and interplanetary dust 1

    NASA Technical Reports Server (NTRS)

    Zolensky, M. E.; Keller, L. P.

    1991-01-01

    Many meteorites and interplanetary dust particles (IDPs) with primitive compositions contain significant amounts of phyllosilicate minerals, which are generally interpreted as evidence of protoplanetary aqueous alteration at an early period of the solar system. These meteorites are chondrites (near solar composition) of the carbonaceous and ordinary varieties. The former are subdivided (according to bulk composition and petrology) into CI, CM, CV, CO, CR, and ungrouped classes. IDPs are extraterrestrial particulates, collected in stratosphere, which have chemical compositions indicative of a primitive origin; they are typically distinct from the primitive meteorites. Characterization of phyllosilicates in these materials is a high priority because of the important physico-chemical information they hold. The most common phyllosilicates present in chondritic extraterrestrial materials are serpentine-group minerals, smectites, and micas. We discuss these phyllosilicates and describe the interpretation of their occurrence in meteorites and IDPs and what this indicates about history of their parent bodies, which are probably the hydrous asteroids.

  16. Concepts for robot motion primitives required for space station teleoperations

    NASA Technical Reports Server (NTRS)

    Grover, Jeffrey L.; Suchting, Steven A. E.

    1988-01-01

    Ground controlled teleoperations are expected to be used to augment Space Station manned extravehicular activities (EVA) and Intravehicular activities (IVA). However, ground controlled teleoperations will encounter communications time delays of from 3 to 8 secs. Time delays greater than 1 sec have been shown to be detrimental to safe and efficient teleoperations. Therefore, concepts must be developed to overcome the hazards and limitations of time delays when performing teleoperations using robots. The concept for robot motion primitives incorporate force/torque and tactile sensor feedback to implement the degree of autonomy required for interactive, ground controlled telerobotics. Several primitives are studied that augment human initiated actions by providing rapid response interaction with the physical environment of a telerobot. These primitives are detailed. They constitute a level of intelligent sensing and reaction required to augment human actions through autonomous interaction with the physical environment.

  17. Primitive Xe in the atmospheres of Earth and mars

    NASA Technical Reports Server (NTRS)

    Igarashi, G.

    1994-01-01

    Published data on Xe isotope compositions in primitive carbonaceous meteorites are examined using multidimensional correlation analysis. Distribution of the Xe data in multidimensional data space, except for (129)Xe, can be characterized by a single component, whose isotope composition is identical to 'H plus L minus Xe'. Additional small contributions to the data variations, less than 1 percent of total variations, can be attributed to 'S minus Xe' as well as atmospheric contamination. Isotopic composition of primitive Xe common to the Earth's atmosphere and carbonaceous meteorites are determined with the same assumption as adopted by Pepin and Phinney: primitive Xe is precisely related to fission-free Xe in the Earth's atmosphere by mass fractionation. The determined isotopic composition of primitive Xe is closer to Solar-type Xe, rather than U-Xe (and the primitive Xe estimated from chondrite-achondrite correlation. Hence, the present published data on Xe isotope compositions in meteorites do not seem to require any special component for the primitive Xe common to the Earth's atmosphere and carbonaceous meteorites. Thus Earth's accreting planetesimals would have trapped Xe from the surrounding nebula gases where Xe isotope composition is identical to Solar-type Xe. The trapped Xe was subsequently subject to isotopic fractionation due to gravitational separation as planetesimals grew. Finally fissiogenic Xe from (244)Pu was added to form the present Xe isotope composition of the Earth's atmosphere. The amount of fissiogenic (136)Xe is estimated to be 2.6 percent of the total amount of (136)Xe in the atmosphere, which is about a half of that estimated by Pepin and Phinney (4.65 percent).

  18. Alisertib in Treating Young Patients With Recurrent or Refractory Solid Tumors or Leukemia

    ClinicalTrials.gov

    2016-07-20

    Hepatoblastoma; Previously Treated Childhood Rhabdomyosarcoma; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Childhood Kidney Neoplasm; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Neuroblastoma; Recurrent Osteosarcoma

  19. Stereotactic Radiosurgery in Treating Patients With Brain Tumors

    ClinicalTrials.gov

    2012-03-21

    Adult Central Nervous System Germ Cell Tumor; Adult Malignant Meningioma; Adult Medulloblastoma; Adult Noninfiltrating Astrocytoma; Adult Oligodendroglioma; Adult Craniopharyngioma; Adult Meningioma; Brain Metastases; Adult Ependymoma; Adult Pineal Parenchymal Tumor; Adult Brain Stem Glioma; Adult Infiltrating Astrocytoma; Mixed Gliomas; Stage IV Peripheral Primitive Neuroectodermal Tumor

  20. Ixabepilone in Treating Young Patients With Refractory Solid Tumors

    ClinicalTrials.gov

    2014-11-13

    Adult Rhabdomyosarcoma; Adult Synovial Sarcoma; Alveolar Childhood Rhabdomyosarcoma; Childhood Synovial Sarcoma; Embryonal Childhood Rhabdomyosarcoma; Previously Treated Childhood Rhabdomyosarcoma; Recurrent Adult Soft Tissue Sarcoma; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Neuroblastoma; Recurrent Osteosarcoma; Recurrent Wilms Tumor and Other Childhood Kidney Tumors

  1. Cixutumumab in Treating Patients With Relapsed or Refractory Solid Tumors

    ClinicalTrials.gov

    2015-03-18

    Adult Rhabdomyosarcoma; Adult Synovial Sarcoma; Childhood Hepatoblastoma; Childhood Synovial Sarcoma; Previously Treated Childhood Rhabdomyosarcoma; Recurrent Adrenocortical Carcinoma; Recurrent Adult Soft Tissue Sarcoma; Recurrent Childhood Liver Cancer; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Ewing Sarcoma/Peripheral Primitive; Neuroectodermal Tumor; Recurrent Neuroblastoma; Recurrent Osteosarcoma; Recurrent Retinoblastoma; Recurrent Wilms Tumor and Other Childhood Kidney Tumors

  2. Cixutumumab and Temsirolimus in Treating Younger Patients With Recurrent or Refractory Sarcoma

    ClinicalTrials.gov

    2016-05-26

    Childhood Alveolar Soft-part Sarcoma; Childhood Angiosarcoma; Childhood Epithelioid Sarcoma; Childhood Fibrosarcoma; Childhood Gliosarcoma; Childhood Leiomyosarcoma; Childhood Liposarcoma; Childhood Neurofibrosarcoma; Childhood Synovial Sarcoma; Previously Treated Childhood Rhabdomyosarcoma; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Osteosarcoma

  3. Nivolumab With or Without Ipilimumab in Treating Younger Patients With Recurrent or Refractory Solid Tumors or Sarcomas

    ClinicalTrials.gov

    2016-10-31

    Childhood Solid Neoplasm; Metastatic Melanoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Hodgkin Lymphoma; Recurrent Melanoma; Recurrent Neuroblastoma; Recurrent Non-Hodgkin Lymphoma; Recurrent Osteosarcoma; Recurrent Rhabdomyosarcoma; Refractory Hodgkin Lymphoma; Refractory Non-Hodgkin Lymphoma; Stage IIIA Skin Melanoma; Stage IIIB Skin Melanoma; Stage IIIC Skin Melanoma; Stage IV Skin Melanoma

  4. Design of Quasi-Terminator Orbits near Primitive Bodies

    NASA Technical Reports Server (NTRS)

    Lantoine, Gregory; Broschart, Stephen B.; Grebow, Daniel J.

    2013-01-01

    Quasi-terminator orbits are a class of quasi-periodic orbits around a primitive body that exist in the vicinity of the well-known terminator orbits. The inherent stability of quasi-terminator trajectories and their wide variety of viewing geometries make them a very compelling option for primitive body mapping missions. In this paper, we discuss orbit design methodologies for selection of an appropriate quasi-terminator orbit that would meet the needs of a specific mission. Convergence of these orbits in an eccentric, higher-fidelity model is also discussed with an example case at Bennu, the target of the upcoming NASA's OSIRIS-REx mission.

  5. Interstellar chemistry recorded in organic matter from primitive meteorites.

    PubMed

    Busemann, Henner; Young, Andrea F; Alexander, Conel M O'd; Hoppe, Peter; Mukhopadhyay, Sujoy; Nittler, Larry R

    2006-05-01

    Organic matter in extraterrestrial materials has isotopic anomalies in hydrogen and nitrogen that suggest an origin in the presolar molecular cloud or perhaps in the protoplanetary disk. Interplanetary dust particles are generally regarded as the most primitive solar system matter available, in part because until recently they exhibited the most extreme isotope anomalies. However, we show that hydrogen and nitrogen isotopic compositions in carbonaceous chondrite organic matter reach and even exceed those found in interplanetary dust particles. Hence, both meteorites (originating from the asteroid belt) and interplanetary dust particles (possibly from comets) preserve primitive organics that were a component of the original building blocks of the solar system. PMID:16675696

  6. Melanotic neuroectodermal tumor of infancy in an African-indigenous patient from the Amazon: a case report

    PubMed Central

    2013-01-01

    Melanotic neuroectodermal tumor of infancy (MNTI) is a rare condition that occurs normally in the anterior maxilla of infants aged <1 year. The use of clinical and imaging tools for MNTI is extremely important to prevent problems with function as well as the aesthetic features in a breastfeeding child. Brazil is a multiethnic country with a poor epidemiological policy and little data to track the incidence of certain diseases, including MNTI. It is important to study this pathology with ethnicity as a factor to improve the current epidemiological programs and establish better post-treatment management. This paper describes a case of a 2-month-old male of African-indigenous descent and Brazilian Amazon residency, who presented to our unit in 2009 with a history of an expanding mass involving the anterior maxilla. Clinical and computerized tomography scans were used to diagnose the mass as MNTI, which was removed by total excision. A biopsy later confirmed the MNTI diagnosis. PMID:24274360

  7. Could 433 Eros have a Primitive Achondritic Composition?

    NASA Technical Reports Server (NTRS)

    Burbine, T. H.; McCoy, T. J.; Nittler, L. R.; Bell, J. F., III

    2001-01-01

    One of the goals of the NEAR (Near Earth Asteroid Rendezvous) mission to 433 Eros is to determine if it has a meteoritic analog. We are currently investigating if primitive achondrites have bulk compositions and spectral properties similar to Eros. Additional information is contained in the original extended abstract.

  8. Addressing Nature Deficit Disorder through Primitive Camping Experiences

    ERIC Educational Resources Information Center

    Allen, Kevin; Varner, Keegan; Sallee, Jeff

    2011-01-01

    Today's youth suffer from Nature Deficit Disorder, a condition that has been connected to ADHD, shortage of creativity, and general lack of knowledge about the outdoors. A team of educators and specialists are addressing this issue with primitive camping. County educators were trained using experiential learning and train-the-trainer techniques.…

  9. Robust algorithms for anatomic plane primitive detection in MR

    NASA Astrophysics Data System (ADS)

    Dewan, Maneesh; Zhan, Yiqiang; Peng, Zhigang; Zhou, Xiang Sean

    2009-02-01

    One of primary challenges in the medical image data analysis is the ability to handle abnormal, irregular and/or partial cases. In this paper, we present two different robust algorithms towards the goal of automatic planar primitive detection in 3D volumes. The overall algorithm is a bottoms-up approach starting with the anatomic point primitives (or landmarks) detection. The robustness in computing the planar primitives is built in through both a novel consensus-based voting approach, and a random sampling-based weighted least squares regression method. Both these approaches remove inconsistent landmarks and outliers detected in the landmark detection step. Unlike earlier approaches focused towards a particular plane, the presented approach is generic and can be easily adapted to computing more complex primitives such as ROIs or surfaces. To demonstrate the robustness and accuracy of our approach, we present extensive results for automatic plane detection (Mig-Sagittal and Optical Triangle planes) in brain MR-images. In comparison to ground truth, our approach has marginal errors on about 90 patients. The algorithm also works really well under adverse conditions of arbitrary rotation and cropping of the 3D volume. In order to exhibit generalization of the approach, we also present preliminary results on intervertebrae-plane detection for 3D spine MR application.

  10. Ordered Sharing: A New Lock Primitive for Database Systems.

    ERIC Educational Resources Information Center

    Agrawal, Divyakant; El Abbadi, Amr

    1995-01-01

    Proposes a new lock primitive called ordered sharing that allows increased concurrency in database systems. Reliability and performance issues of the proposed protocol are addressed, a simulation study that demonstrates that ordered sharing results in improved performance in database systems is described; and use in several representative database…

  11. PARTI primitives for unstructured and block structured problems

    NASA Technical Reports Server (NTRS)

    Sussman, Alan; Saltz, Joel; Das, Raja; Gupta, S.; Mavriplis, Dimitri; Ponnusamy, Ravi; Crowley, Kay

    1992-01-01

    Described here is a set of primitives (PARTI) developed to efficiently execute unstructured and block structured problems on distributed memory parallel machines. We present experimental data from a 3-D unstructured Euler solver run on the Intel Touchstone Delta to demonstrate the usefulness of our methods.

  12. Flexible building primitives for 3D building modeling

    NASA Astrophysics Data System (ADS)

    Xiong, B.; Jancosek, M.; Oude Elberink, S.; Vosselman, G.

    2015-03-01

    3D building models, being the main part of a digital city scene, are essential to all applications related to human activities in urban environments. The development of range sensors and Multi-View Stereo (MVS) technology facilitates our ability to automatically reconstruct level of details 2 (LoD2) models of buildings. However, because of the high complexity of building structures, no fully automatic system is currently available for producing building models. In order to simplify the problem, a lot of research focuses only on particular buildings shapes, and relatively simple ones. In this paper, we analyze the property of topology graphs of object surfaces, and find that roof topology graphs have three basic elements: loose nodes, loose edges, and minimum cycles. These elements have interesting physical meanings: a loose node is a building with one roof face; a loose edge is a ridge line between two roof faces whose end points are not defined by a third roof face; and a minimum cycle represents a roof corner of a building. Building primitives, which introduce building shape knowledge, are defined according to these three basic elements. Then all buildings can be represented by combining such building primitives. The building parts are searched according to the predefined building primitives, reconstructed independently, and grouped into a complete building model in a CSG-style. The shape knowledge is inferred via the building primitives and used as constraints to improve the building models, in which all roof parameters are simultaneously adjusted. Experiments show the flexibility of building primitives in both lidar point cloud and stereo point cloud.

  13. Phosphorus, a key to life on the primitive earth

    NASA Technical Reports Server (NTRS)

    Griffith, E. J.; Ponnamperuma, C.; Gabel, N. W.

    1977-01-01

    The phosphorus of the primitive earth was present as phosphates. It is strongly probable that a portion of the phosphate was present as condensed phosphates. The primitive earth was highly deficient in the total available phosphorus until a sufficient quantity of phosphorus weathered from the igneous rocks in which it was entrapped. Approximately three billion years were required for the seas to become saturated. Until this time passed the seas acted as a giant sink for phosphorus, diluting it to the extent that all forms of life were deprived of the vital nutrient. When the seas became saturated, the rate of turnover of the phosphorus increased rapidly. As the seas pulsated, they left the excess precipitate phosphorus as sedimentary rock in locally rich deposits on which life could thrive.

  14. Morphological Study of Insoluble Organic Matter Residues from Primitive

    NASA Technical Reports Server (NTRS)

    Changela, H. G.; Stroud, R. M.; Peeters, Z.; Nittler, L. R.; Alexander, C. M. O'D.; DeGregorio, B. T.; Cody, G. D.

    2012-01-01

    Insoluble organic matter (IOM) constitutes a major proportion, 70-99%, of the total organic carbon found in primitive chondrites [1, 2]. One characteristic morphological component of IOM is nanoglobules [3, 4]. Some nanoglobules exhibit large N-15 and D enrichments relative to solar values, indicating that they likely originated in the ISM or the outskirts of the protoplanetary disk [3]. A recent study of samples from the Tagish Lake meteorite with varying levels of hydrothermal alteration suggest that nanoglobule abundance decreases with increasing hydrothermal alteration [5]. The aim of this study is to further document the morphologies of IOM from a range of primitive chondrites in order to determine any correlation of morphology with petrographic grade and chondrite class that could constrain the formation and/or alteration mechanisms.

  15. The Primitive Spectrum of a Basic Classical Lie Superalgebra

    NASA Astrophysics Data System (ADS)

    Coulembier, Kevin

    2016-05-01

    We prove Conjecture 5.7 in Coulembier and Musson (Math. J., arXiv:1409.2532, describing all inclusions between primitive ideals for the general linear superalgebra in terms of the {Ext1} -quiver of simple highest weight modules. For arbitrary basic classical Lie superalgebras, we formulate two types of Kazhdan-Lusztig quasi-orders on the dual of the Cartan subalgebra, where one corresponds to the above conjecture. Both orders can be seen as generalisations of the left Kazhdan-Lusztig order on Hecke algebras and are related to categorical braid group actions. We prove that the primitive spectrum is always described by one of the orders, obtaining for the first time a description of the inclusions. We also prove that the two orders are identical if category {{O}} admits `enough' abstract Kazhdan-Lusztig theories. In particular, they are identical for the general linear superalgebra, concluding the proof of the conjecture.

  16. Deuterium enrichment in the primitive ices of the protosolar nebula.

    PubMed

    Lutz, B L; Owen, T; De Bergh, C

    1990-01-01

    We have estimated the D/H ratio that may have been present in the primitive ices in the protosolar nebula. Using observations of the CH3D/CH4 ratio in the outer planets, we developed two simple but limiting models which constrain the amount of dilution that deuterated volatiles which were contributed to the planetary atmospheres by evaporated primordial ices may have undergone by mixing with the original hydrogen envelopes. The models suggest that the D/H ratio in these ices was probably somewhere between a few times 10(-4) and 10(-3). These planetary-atmosphere-derived results are compared with other solar system bodies thought to contain primitive material and with D/H ratios observed in interstellar polyatomic molecules.

  17. Locomotor primitives in newborn babies and their development.

    PubMed

    Dominici, Nadia; Ivanenko, Yuri P; Cappellini, Germana; d'Avella, Andrea; Mondì, Vito; Cicchese, Marika; Fabiano, Adele; Silei, Tiziana; Di Paolo, Ambrogio; Giannini, Carlo; Poppele, Richard E; Lacquaniti, Francesco

    2011-11-18

    How rudimentary movements evolve into sophisticated ones during development remains unclear. It is often assumed that the primitive patterns of neural control are suppressed during development, replaced by entirely new patterns. Here we identified the basic patterns of lumbosacral motoneuron activity from multimuscle recordings in stepping neonates, toddlers, preschoolers, and adults. Surprisingly, we found that the two basic patterns of stepping neonates are retained through development, augmented by two new patterns first revealed in toddlers. Markedly similar patterns were observed also in the rat, cat, macaque, and guineafowl, consistent with the hypothesis that, despite substantial phylogenetic distances and morphological differences, locomotion in several animal species is built starting from common primitives, perhaps related to a common ancestral neural network.

  18. Collaboration between primitive cell membranes and soluble catalysts

    PubMed Central

    Adamala, Katarzyna P.; Engelhart, Aaron E.; Szostak, Jack W.

    2016-01-01

    One widely held model of early life suggests primitive cells consisted of simple RNA-based catalysts within lipid compartments. One possible selective advantage conferred by an encapsulated catalyst is stabilization of the compartment, resulting from catalyst-promoted synthesis of key membrane components. Here we show model protocell vesicles containing an encapsulated enzyme that promotes the synthesis of simple fatty acid derivatives become stabilized to Mg2+, which is required for ribozyme activity and RNA synthesis. Thus, protocells capable of such catalytic transformations would have enjoyed a selective advantage over other protocells in high Mg2+ environments. The synthetic transformation requires both the catalyst and vesicles that solubilize the water-insoluble precursor lipid. We suggest that similar modified lipids could have played a key role in early life, and that primitive lipid membranes and encapsulated catalysts, such as ribozymes, may have acted in conjunction with each other, enabling otherwise-impossible chemical transformations within primordial cells. PMID:26996603

  19. Quantifying Mapping Orbit Performance in the Vicinity of Primitive Bodies

    NASA Technical Reports Server (NTRS)

    Pavlak, Thomas A.; Broschart, Stephen B.; Lantoine, Gregory

    2015-01-01

    Predicting and quantifying the capability of mapping orbits in the vicinity of primitive bodies is challenging given the complex orbit geometries that exist and the irregular shape of the bodies themselves. This paper employs various quantitative metrics to characterize the performance and relative effectiveness of various types of mapping orbits including terminator, quasi-terminator, hovering, pingpong, and conic-like trajectories. Metrics of interest include surface area coverage, lighting conditions, and the variety of viewing angles achieved. The metrics discussed in this investigation are intended to enable mission designers and project stakeholders to better characterize candidate mapping orbits during preliminary mission formulation activities.The goal of this investigation is to understand the trade space associated with carrying out remotesensing campaigns at small primitive bodies in the context of a robotic space mission. Specifically,this study seeks to understand the surface viewing geometries, ranges, etc. that are available fromseveral commonly proposed mapping orbits architectures.

  20. Collaboration between primitive cell membranes and soluble catalysts.

    PubMed

    Adamala, Katarzyna P; Engelhart, Aaron E; Szostak, Jack W

    2016-01-01

    One widely held model of early life suggests primitive cells consisted of simple RNA-based catalysts within lipid compartments. One possible selective advantage conferred by an encapsulated catalyst is stabilization of the compartment, resulting from catalyst-promoted synthesis of key membrane components. Here we show model protocell vesicles containing an encapsulated enzyme that promotes the synthesis of simple fatty acid derivatives become stabilized to Mg(2+), which is required for ribozyme activity and RNA synthesis. Thus, protocells capable of such catalytic transformations would have enjoyed a selective advantage over other protocells in high Mg(2+) environments. The synthetic transformation requires both the catalyst and vesicles that solubilize the water-insoluble precursor lipid. We suggest that similar modified lipids could have played a key role in early life, and that primitive lipid membranes and encapsulated catalysts, such as ribozymes, may have acted in conjunction with each other, enabling otherwise-impossible chemical transformations within primordial cells. PMID:26996603

  1. Phosphorus, a key to life on the primitive Earth.

    PubMed

    Griffith, E J; Ponnamperuma, C; Gabel, N W

    1977-08-01

    The phosphorus of the primitive Earth was present as phosphates. It is strongly probably that a portion of the phosphate was present as condensed phosphates. The primitive Earth was highly deficient in the total available phosphorus until a sufficient quantity of phosphorus weathered from the igneous rocks in which it was entrapped. Approximately three billion years were required for the seas to become saturated. Until this time passed the seas acted as a giant sink for phosphorus, diluting it to the extent that all forms of life were deprived of the vital nutrient. When the seas became saturated, the rate of turn over of the phosphorus increased rapidly. As the seas pulsated, they left the excess precipitate phosphorus as sedimentary rock in locally righ deposits on which life could thrive.

  2. Some results for the primitive equations with physical boundary conditions

    NASA Astrophysics Data System (ADS)

    Evans, Lawrence Christopher; Gastler, Robert

    2013-12-01

    In this paper, we consider the (simplified) 3-dimensional primitive equations with physical boundary conditions. We show that the equations with constant forcing have a bounded absorbing ball in the H 1-norm and that a solution to the unforced equations has its H 1-norm decay to 0. From this, we argue that there exists an invariant measure (on H 1) for the equations under random kick-forcing.

  3. Transitions between discrete and rhythmic primitives in a unimanual task

    PubMed Central

    Sternad, Dagmar; Marino, Hamal; Charles, Steven K.; Duarte, Marcos; Dipietro, Laura; Hogan, Neville

    2013-01-01

    Given the vast complexity of human actions and interactions with objects, we proposed that control of sensorimotor behavior may utilize dynamic primitives. However, greater computational simplicity may come at the cost of reduced versatility. Evidence for primitives may be garnered by revealing such limitations. This study tested subjects performing a sequence of progressively faster discrete movements in order to “stress” the system. We hypothesized that the increasing pace would elicit a transition to rhythmic movements, assumed to be computationally and neurally more efficient. Abrupt transitions between the two types of movements would support the hypothesis that rhythmic and discrete movements are distinct primitives. Ten subjects performed planar point-to-point arm movements paced by a metronome: starting at 2 s, the metronome intervals decreased by 36 ms per cycle to 200 ms, stayed at 200 ms for several cycles, then increased by similar increments. Instructions emphasized to insert explicit stops between each movement with a duration that equaled the movement time. The experiment was performed with eyes open and closed, and with short and long metronome sounds, the latter explicitly specifying the dwell duration. Results showed that subjects matched instructed movement times but did not preserve the dwell times. Rather, they progressively reduced dwell time to zero, transitioning to continuous rhythmic movements before movement times reached their minimum. The acceleration profiles showed an abrupt change between discrete and rhythmic profiles. The loss of dwell time occurred earlier with long auditory specification, when subjects also showed evidence of predictive control. While evidence for hysteresis was weak, taken together, the results clearly indicated a transition between discrete and rhythmic movements, supporting the proposal that representation is based on primitives rather than on veridical internal models. PMID:23888139

  4. The modelling of a primitive ‘sustainable’ conservative cell

    PubMed Central

    Bassingthwaighte, James B.

    2011-01-01

    The simple sustainable or ‘eternal’ cell model, assuming preservation of all proteins, is designed as a building block, a primitive element upon which one can build more complete functional cell models of various types, representing various species. In the modelling we emphasize the electrophysiological aspects, in part because these are a well-developed component of cell models and because membrane potentials and their fluctuations have been generally omitted from metabolically oriented cell models in the past. Fluctuations in membrane potential deserve heightened consideration because probably all cells have negative intracellular potentials and most cells demonstrate electrical activity with vesicular extrusion, receptor occupancy, as well as with stimulated excitation resulting in regenerative depolarization. The emphasis is on the balances of mass, charge, and of chemical species while accounting for substrate uptake, metabolism and metabolite loss from the cell. By starting with a primitive representation we emphasize the conservation ideas. As more advanced models are generated they must adhere to the same basic principles as are required for the most primitive incomplete model. PMID:21938260

  5. Pills for the Poor: John Wesley's Primitive Physick

    PubMed Central

    Rogal, Samuel J.

    1978-01-01

    While John Wesley's Primitive Physick (1747) cannot be termed a classic of British medical literature, it must certainly be identified as one of the most popular volumes published in England during the eighteenth century. Although the work came under attack from contemporary surgeons, physicians, and apothecaries, who maintained that its remedies were founded upon ignorance, Wesley probably knew as much as most members of the medical profession; in fact, on no less than twenty instances throughout the volume, he paraphrases or cites directly from prominent physicians and theorists—such figures as Sydenham, Boerhaave, Cheyne, Mead, and Huxham. However, despite its obvious emphasis upon practical remedies, the underlying focus of Primitive Physick is upon the soul of man. Wesley had consulted some sources, common sense, and his own experience, tempering those with the general principle of “doing good to all men,” particularly “those who desire to live according to the gospel....” Thus, the Methodist patriarch's own formula for life had as much to do with the spread of Primitive Physick throughout eighteenth-century Britain and America as did all of the remedies and suggestions imprinted upon its pages. PMID:354225

  6. Slow dynamics in a primitive tetrahedral network model.

    PubMed

    De Michele, Cristiano; Tartaglia, Piero; Sciortino, Francesco

    2006-11-28

    We report extensive Monte Carlo and event-driven molecular dynamics simulations of the fluid and liquid phase of a primitive model for silica recently introduced by Ford et al. [J. Chem. Phys. 121, 8415 (2004)]. We evaluate the isodiffusivity lines in the temperature-density plane to provide an indication of the shape of the glass transition line. Except for large densities, arrest is driven by the onset of the tetrahedral bonding pattern and the resulting dynamics is strong in Angell's classification scheme [J. Non-Cryst. Solids 131-133, 13 (1991)]. We compare structural and dynamic properties with corresponding results of two recently studied primitive models of network forming liquids-a primitive model for water and an angular-constraint-free model of four-coordinated particles-to pin down the role of the geometric constraints associated with bonding. Eventually we discuss the similarities between "glass" formation in network forming liquids and "gel" formation in colloidal dispersions of patchy particles. PMID:17144726

  7. A Cell ELISA for the quantification of MUC1 mucin (CD227) expressed by cancer cells of epithelial and neuroectodermal origin.

    PubMed

    Falahat, Rana; Wiranowska, Marzenna; Gallant, Nathan D; Toomey, Ryan; Hill, Robert; Alcantar, Norma

    2015-01-01

    Quantitative analysis of MUC1, a cell membrane associated mucin, expressed by intact cells of epithelial origin previously has been limited to flow cytometry, which requires using large quantities of cells and antibodies. Here, for the first time, we report the development of a novel Cellular-based Enzyme Linked Immunosorbent Assay (Cell ELISA) to quantify the expression of MUC1 by cell lines of epithelial and neuroectodermal origin using an antibody recognizing a specific tandem repeat found in the extracellular domain of MUC1. In contrast to flow cytometry, this method requires a much lower number of cells. We report here the results obtained from two variants of this Cell ELISA in live and fixed cells. We found that the Cell ELISA in live cells was not sensitive enough to detect a difference in MUC1 levels between the normal cells and tumor cells. However, we found that Cell ELISA in fixed cells followed by whole cell staining was a dependable method of MUC1 level detection in the normal and tumor cells showing significantly higher levels of MUC1 receptor in the tumor cells when compared to the normal controls. Therefore, we conclude that the Cell ELISA in fixed cells is an efficient method for quantifying the expression of MUC1 by epithelial and neuroectodermal cancer cell lines. PMID:26435344

  8. A Cell ELISA for the quantification of MUC1 mucin (CD227) expressed by cancer cells of epithelial and neuroectodermal origin.

    PubMed

    Falahat, Rana; Wiranowska, Marzenna; Gallant, Nathan D; Toomey, Ryan; Hill, Robert; Alcantar, Norma

    2015-01-01

    Quantitative analysis of MUC1, a cell membrane associated mucin, expressed by intact cells of epithelial origin previously has been limited to flow cytometry, which requires using large quantities of cells and antibodies. Here, for the first time, we report the development of a novel Cellular-based Enzyme Linked Immunosorbent Assay (Cell ELISA) to quantify the expression of MUC1 by cell lines of epithelial and neuroectodermal origin using an antibody recognizing a specific tandem repeat found in the extracellular domain of MUC1. In contrast to flow cytometry, this method requires a much lower number of cells. We report here the results obtained from two variants of this Cell ELISA in live and fixed cells. We found that the Cell ELISA in live cells was not sensitive enough to detect a difference in MUC1 levels between the normal cells and tumor cells. However, we found that Cell ELISA in fixed cells followed by whole cell staining was a dependable method of MUC1 level detection in the normal and tumor cells showing significantly higher levels of MUC1 receptor in the tumor cells when compared to the normal controls. Therefore, we conclude that the Cell ELISA in fixed cells is an efficient method for quantifying the expression of MUC1 by epithelial and neuroectodermal cancer cell lines.

  9. Angioplasty and stent placement - peripheral arteries - discharge

    MedlinePlus

    Percutaneous transluminal angioplasty - peripheral artery - discharge; PTA - peripheral artery - discharge; Angioplasty - peripheral artery - discharge; Balloon angioplasty - peripheral artery- discharge; PAD - PTA discharge; PVD - ...

  10. Peripheral Neuropathy: Symptoms and Signs

    MedlinePlus

    ... Research News Make a Difference Symptoms of Peripheral Neuropathy Print This Page Peripheral Neuropathy symptoms usually start ... slowly over many years. The symptoms of peripheral neuropathy often include: A sensation of wearing an invisible “ ...

  11. Mesoscale Eddy Parameterization in an Idealized Primitive Equations Model

    NASA Astrophysics Data System (ADS)

    Anstey, J.; Zanna, L.

    2014-12-01

    Large-scale ocean currents such as the Gulf Stream and Kuroshio Extension are strongly influenced by mesoscale eddies, which have spatial scales of order 10-100 km. The effects of these eddies are poorly represented in many state-of-the-art ocean general circulation models (GCMs) due to the inadequate spatial resolution of these models. In this study we examine the response of the large-scale ocean circulation to the rectified effects of eddy forcing - i.e., the role played by surface-intensified mesoscale eddies in sustaining and modulating an eastward jet that separates from an intense western boundary current (WBC). For this purpose a primitive equations ocean model (the MITgcm) in an idealized wind-forced double-gyre configuration is integrated at eddy-resolving resolution to reach a forced-dissipative equilibrium state that captures the essential dynamics of WBC-extension jets. The rectified eddy forcing is diagnosed as a stochastic function of the large-scale state, this being characterized by the manner in which potential vorticity (PV) contours become deformed. Specifically, a stochastic function based on the Laplacian of the material rate of change of PV is examined in order to compare the primitive equations results with those of a quasi-geostrophic model in which this function has shown some utility as a parameterization of eddy effects (Porta Mana and Zanna, 2014). The key question is whether an eddy parameterization based on quasi-geostrophic scaling is able to carry over to a system in which this scaling is not imposed (i.e. the primitive equations), in which unbalanced motions occur.

  12. Statistical study of aqueous alteration on primitive asteroids

    NASA Astrophysics Data System (ADS)

    Lantz, Cateline; Fornasier, S.; Barucci, M.

    2013-10-01

    The study of aqueous alteration is particularly important for unraveling the thermal and chemical conditions existing during the earliest times in Solar System history. The process consists in the low temperature (< 320 K) chemical alteration of materials by liquid water which acts as a solvent and produces hydrated materials. Hydrated minerals have been detected on main belt C, G, P, B and F-types asteroids as defined by Tholen taxonomy. Studying visible spectra of primitive bodies, one can detect signatures of phyllosilicates like the Fe2+-Fe3+ transition band centered around 0.7 microns. We have investigated 600 spectra of these primitive bodies available in the literature (Vilas observations 1982-1992, Sawyer PhD thesis 1991, Xu et al. 1995, Fornasier et al. 1999, Bus & Binzel 2002 and Lazzaro et al. 2004) and from our own observations, and we have characterized the 0.7 microns band when present. We have examined all the possible relationships between the aqueous alteration process and asteroid taxonomic classes, orbital elements, heliocentric distances, albedo and sizes of these objects. We find that the percentage of hydrated asteroids is 5% for the P, 8% for the F, 10% for the B, 51% for the C, and 100% for the G-type asteroids. The process seems to be mostly active on primitive asteroids located between 2.3 and 3.2 AU. The number of hydrated asteroids increases with the size and dominates for bodies larger than 100km. We also compare the properties of the 0.7 microns absorption band seen on asteroids with the one seen on CM carbonaceous chondrites spectra (from RELAB data): aqueous altered asteroids are the plausible parent bodies of CM2 meteorites, but we see a systematic difference in the band center position.

  13. Peripheral Artery Disease (PAD)

    MedlinePlus

    ... changes and medication . View an animation of atherosclerosis Atherosclerosis and PAD Atherosclerosis is a disease in which plaque builds up ... of an artery. PAD is usually caused by atherosclerosis in the peripheral arteries (or outer regions away ...

  14. Peripheral Vascular Disease

    MedlinePlus

    ... Information Center Back to previous page En español Aneurysms and Dissections Angina Arrhythmia Bundle Branch Block Cardiomyopathy ... blockage including peripheral artery disease or PAD Aortic aneurysms Buerger's Disease Raynaud's Phenomenon Disease of the veins ...

  15. Peripheral Arterial Disease

    MedlinePlus

    Peripheral arterial disease (PAD) happens when there is a narrowing of the blood vessels outside of your heart. The cause of ... smoking. Other risk factors include older age and diseases like diabetes, high blood cholesterol, high blood pressure, ...

  16. Occlusive Peripheral Arterial Disease

    MedlinePlus

    ... artery. Such people should seek medical care immediately. Did You Know... When people suddenly develop a painful, ... In This Article Animation 1 Peripheral Arterial Disease Did You Know 1 Did You Know... Figure 1 ...

  17. [Peripheral ulcerative keratitis].

    PubMed

    Stamate, Alina-cristina; Avram, Corina Ioana; Malciolu, R; Oprea, S; Zemba, M

    2014-01-01

    Ulcerative keratitis is frequently associated with collagen vascular diseases and presents a predilection for peripheral corneal localization, due to the distinct morphologic and immunologic features of the limbal conjunctiva, which provides access for the circulating immune complexes to the peripheral cornea via the capillary network. Deposition of immune complexes in the terminal ends of limbal vessels initiates an immune-mediated vasculitis process, with inflammatory cells and mediators involvement by alteration of the vascular permeability. Peripheral ulcerative keratitis generally correlates with exacerbations of the background autoimmune systemic disease. Associated sceritis, specially the necrotizing form, is usually observed in severe cases, which may evolve in corneal perforation and loss of vision. Although the first-line of treatment in acute phases is represented by systemic administration of corticosteroids, immunosuppressive and cytotoxic agents are necessary for the treatment of peripheral ulcerative keratitis associated with systemic diseases.

  18. CLOUD PEAK PRIMITIVE AREA AND ADJACENT AREAS, WYOMING.

    USGS Publications Warehouse

    Kiilsgaard, Thor H.; Patten, Lowell L.

    1984-01-01

    The results of a mineral survey of the Cloud Peak Primitive Area and adjacent areas in Wyoming indicated little promise for the occurrence of mineral resources. There are some prospect workings, particularly in the northern part of the area, but in none of them were there indications that ore had been mined. Samples from the workings, from nearby rocks and sediments from streams that drain the area did not yield any metal values of significance. The crystalline rocks that underlie the area do not contain oil and gas or coal, products that are extracted from the younger rocks that underlie basins on both sides of the study area.

  19. STUDY AREAS CONTIGUOUS TO THE UNCOMPAHGRE PRIMITIVE AREA, COLORADO.

    USGS Publications Warehouse

    Steven, Thomas A.; Bieniewski, Carl L.

    1984-01-01

    Important mineral deposits of several ages have been exploited at many places in the western San Juan Mountains, including the originally studied Uncompahgre Primitive Area, Colorado. Although the three contiguous areas - western, central, and eastern - considered here are largely outside the more productive mining areas, a mineral study indicated that there are areas of probable resource potential for base and precious metals near the margins of the areas. Results of this study indicate that there is little promise for the occurrence of fossil fuels and geothermal energy.

  20. Phase equilibria of size-asymmetric primitive model electrolytes.

    PubMed

    Yan, Q; de Pablo, J J

    2001-03-01

    The low-temperature phase coexistence of size-asymmetric primitive model electrolyte solutions has been investigated by means of Monte Carlo simulations. Binodal curves and critical parameters are reported as a function of size ratio lambda = sigma(+)/sigma(-) in the range 0.05 to 1. Both the critical temperature and the critical density are found to decrease as lambda decreases. These trends are in conflict with available theoretical predictions. For highly asymmetric systems, the depression of the critical parameters is accompanied by the formation of large chainlike and ringlike structures, thereby giving rise to considerable finite-size effects.

  1. Pathwise Solutions of the 2-D Stochastic Primitive Equations

    SciTech Connect

    Glatt-Holtz, Nathan Temam, Roger

    2011-06-15

    In this work we consider a stochastic version of the Primitive Equations (PEs) of the ocean and the atmosphere and establish the existence and uniqueness of pathwise, strong solutions. The analysis employs novel techniques in contrast to previous works (Ewald et al. in Anal. Appl. (Singap.) 5(2):183-198, 2007; Glatt-Holtz and Ziane in Discrete Contin. Dyn. Syst. Ser. B 10(4):801-822, 2008) in order to handle a general class of nonlinear noise structures and to allow for physically relevant boundary conditions. The proof relies on Cauchy estimates, stopping time arguments and anisotropic estimates.

  2. Circular-Orbit Maintenance Strategies for Primitive Body Orbiters

    NASA Technical Reports Server (NTRS)

    Wallace, Mark S.; Broschart, Stephen

    2013-01-01

    For missions to smaller primitive bodies, solar radiation pressure (SRP) is a significant perturbation to Keplerian dynamics. For most orbits, SRP drives large oscillations in orbit eccentricity, which leads to large perturbations from the irregular gravity field at periapsis. Ultimately, chaotic motion results that often escapes or impacts that body. This paper presents an orbit maintenance strategy to keep the orbit eccentricity small, thus avoiding the destabilizing secondary interaction with the gravity field. An estimate of the frequency and magnitude of the required maneuvers as a function of the orbit and body parameters is derived from the analytic perturbation equations.

  3. Amorphous Silicates in Primitive Meteoritic Materials: Acfer 094 and IDPs

    NASA Technical Reports Server (NTRS)

    Keller, L. P.; Nakamura-Messenger, K.; Messenger, S.; Walker, Robert M.

    2009-01-01

    The abundance of presolar grains is one measure of the primitive nature of meteoritic materials. Presolar silicates are abundant in meteorites whose matrices are dominated by amorphous silicates such as the unique carbonaceous chondrite Acfer 094. Presolar silicates are even more abundant in chondritic-porous interplanetary dust particles (CP-IDPs). Amorphous silicates in the form of GEMS (glass with embedded metal and sulfides) grains are a major component of CP IDPs. We are studying amorphous silicates in Acfer 094 matrix in order to determine whether they are related to the GEMS grains in CPIDPs

  4. Electrodiagnosis of peripheral neuropathy.

    PubMed

    Ross, Mark A

    2012-05-01

    Electrodiagnostic studies are an important component of the evaluation of patients with suspected peripheral nerve disorders. The pattern of findings and the features that are seen on the motor and sensory nerve conduction studies and needle electromyography can help to identify the type of neuropathy, define the underlying pathophysiology (axonal or demyelinating), and ultimately help to narrow the list of possible causes. This article reviews the electrodiagnostic approach to and interpretation of findings in patients with peripheral neuropathies.

  5. Permanent Peripheral Neuropathy

    PubMed Central

    Higgins, Elizabeth

    2014-01-01

    The health risks and side effects of fluoroquinolone use include the risk of tendon rupture and myasthenia gravis exacerbation, and on August 15, 2013, the Food and Drug Administration updated its warning to include the risk of permanent peripheral neuropathy. We present a case of fluoroquinolone-induced peripheral neuropathy in a patient treated for clinically diagnosed urinary tract infection with ciprofloxacin antibiotic. PMID:26425618

  6. Inorganic chemistry of O2 in a dense primitive atmosphere

    PubMed

    Rosenqvist, J; Chassefière, E

    1995-01-01

    A simple steady-state photochemical model is developed in order to determine typical molecular oxygen concentrations for a comprehensive range of primitive abiotic atmospheres. Carbon dioxide is assumed to be the dominant constituent in these atmospheres since CO2 photodissociation may potentially result in the enhancement of the O2 partial pressure. The respective effects of the H2O content, temperature, eddy diffusion coefficient and UV flux on the results are investigated. It is shown that for any pressure at the surface, the partial pressure of molecular oxygen does not exceed 10 mbar. The peculiar case of a runaway greenhouse which has possibly taken place on Venus is qualitatively envisaged. Although O2 is basically absent in the present Venus atmosphere, a transient presence in a primitive stage cannot be ruled out. Possible mechanisms for O2 removal in such an atmosphere are reviewed. At the present stage, we think that the detection of large O2 amounts would be at least a good clue for the presence of life on an extrasolar planet.

  7. A kind of auditory 'primitive intelligence' already present at birth.

    PubMed

    Carral, Vanessa; Huotilainen, Minna; Ruusuvirta, Timo; Fellman, Vineta; Näätänen, Risto; Escera, Carles

    2005-06-01

    'Primitive intelligence' in audition refers to the capacity of the auditory system to adaptatively model the acoustic regularity and react neurophysiologically to violations of such regularity, thus supporting the ability to predict future auditory events. In the present study, event-related brain potentials to pairs of tones were recorded in 11 human newborns to determine the infants' ability to extract an abstract acoustic rule, the direction of a frequency change. Most of the pairs (standard, P = 0.875) were of ascending frequency (i.e. the second tone higher than the first), while the remaining pairs (deviant, P = 0.125) were of descending frequency (the second tone being lower). Their frequencies varied among seven levels to prevent discrimination between standard and deviant pairs on the basis of absolute frequencies. We found that event-related brain potentials to deviant pairs differed in amplitude from those to standard pairs at 50-450 ms from the onset of the second tone of a pair, indicating the infants' ability to represent the abstract rule. This finding suggests the early ontogenetic origin of 'primitive intelligence' in audition that eventually may form a prerequisite for later language acquisition. PMID:15978029

  8. High water content in primitive continental flood basalts

    NASA Astrophysics Data System (ADS)

    Xia, Qun-Ke; Bi, Yao; Li, Pei; Tian, Wei; Wei, Xun; Chen, Han-Lin

    2016-05-01

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>105 km3) within short time span (<1–3 Ma) is in principle caused by an abnormally high temperature, extended decompression, a certain amount of mafic source rocks (e.g., pyroxenite), or an elevated H2O content in the mantle source. These four factors are not mutually exclusive. There are growing evidences for high temperature, decompression and mafic source rocks, albeit with hot debate. However, there is currently no convincing evidence of high water content in the source of CFB. We retrieved the initial H2O content of the primitive CFB in the early Permian Tarim large igneous province (NW China), using the H2O content of ten early-formed clinopyroxene (cpx) crystals that recorded the composition of the primitive Tarim basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB.

  9. Unexpected primitive rodents in the Quaternary of Argentina

    NASA Astrophysics Data System (ADS)

    Vucetich, María G.; Vieytes, Emma C.; Verzi, Diego H.; Noriega, Jorge I.; Tonni, Eduardo P.

    2005-10-01

    This article describes the first fossils recorded in the Hernandarias Formation (Pleistocene) in Entre Ríos province (eastern Argentina). They are represented by three teeth assigned to the caviomorph rodents (Rodentia, Mammalia) Aenigmys diamantensis gen. et sp. nov. and Eumysops. To establish the phylogenetic affinities of the two most enigmatic teeth, their enamel microstructure was studied. Aenigmys diamantensis is considered the most primitive taxon of a clade formed by Dinomyidae-Neoepiblemidae-Heptaxodontidae. Evidence of the close relationships among these families also is presented herein. The new fossils reinforce previous hypotheses about the survival of primitive Brazilian taxa after their extinction in the Pampas and Patagonia of southern South America. They also show that the diversity of caviomorph rodents during the Quaternary was greater than supposed and that an important Quaternary extinction, not previously detected, affected several lineages. With the available evidence, it is not possible to determine if these rodents indicate a warm pulse or a particular biogeographic situation in Entre Ríos.

  10. Chemical effects of large impacts on the Earth's primitive atmosphere.

    PubMed

    Fegley, B; Prinn, R G; Hartman, H; Watkins, G H

    1986-01-23

    Intense bombardment of the moon and terrestrial planets approximately 3.9-4.0 x 10(9) years ago could have caused the chemical reprocessing of the Earth's primitive atmosphere. In particular, the shock heating and rapid quenching caused by the impact of large bodies into the atmosphere could produce molecules such as HCN and H2CO4 which are important precursors for the abiotic synthesis of complex organic molecules. Here we model the production of HCN and H2CO by thermochemical equilibrium and chemical kinetic calculations of the composition of shocked air parcels for a wide range of temperatures, pressures and initial compositions. For atmospheres with C/O > or = 1, our results suggest that bolide impacts cause HCN volume mixing ratios of approximately 10(-3) to 10(-5) in the impact region and global average ratios of 10(-5) to 10(-12). The corresponding H2CO mixing ratios in the impact region are 10(-7) to 10(-9); no-global mixing can occur, however, as H2CO is rapidly destroyed or rained out of the atmosphere within days to hours. Rainout to the oceans of 3-15% of the HCN produced can provide approximately (3-14) x 10(11) mol HCN per year. This is somewhat larger than other predicted sources of HCN and H2CO on the primitive Earth.

  11. High water content in primitive continental flood basalts.

    PubMed

    Xia, Qun-Ke; Bi, Yao; Li, Pei; Tian, Wei; Wei, Xun; Chen, Han-Lin

    2016-01-01

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>10(5) km(3)) within short time span (<1-3 Ma) is in principle caused by an abnormally high temperature, extended decompression, a certain amount of mafic source rocks (e.g., pyroxenite), or an elevated H2O content in the mantle source. These four factors are not mutually exclusive. There are growing evidences for high temperature, decompression and mafic source rocks, albeit with hot debate. However, there is currently no convincing evidence of high water content in the source of CFB. We retrieved the initial H2O content of the primitive CFB in the early Permian Tarim large igneous province (NW China), using the H2O content of ten early-formed clinopyroxene (cpx) crystals that recorded the composition of the primitive Tarim basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB. PMID:27143196

  12. Agile Science Operations: A New Approach for Primitive Exploration Bodies

    NASA Technical Reports Server (NTRS)

    Chien, Steve A.; Thompson, David R.; Castillo-Rogez, Julie C.; Doyle, Richard; Estlin, Tara; Mclaren, David

    2012-01-01

    Primitive body exploration missions such as potential Comet Surface Sample Return or Trojan Tour and Rendezvous would challenge traditional operations practices. Earth-based observations would provide only basic understanding before arrival and many science goals would be defined during the initial rendezvous. It could be necessary to revise trajectories and observation plans to quickly characterize the target for safe, effective observations. Detection of outgassing activity and monitoring of comet surface activity are even more time constrained, with events occurring faster than round-trip light time. "Agile science operations" address these challenges with contingency plans that recognize the intrinsic uncertainty in the operating environment and science objectives. Planning for multiple alternatives can significantly improve the time required to repair and validate spacecraft command sequences. When appropriate, time-critical decisions can be automated and shifted to the spacecraft for immediate access to instrument data. Mirrored planning systems on both sides of the light-time gap permit transfer of authority back and forth as needed. We survey relevant science objectives, identifying time bottlenecks and the techniques that could be used to speed missions' reaction to new science data. Finally, we discuss the results of a trade study simulating agile observations during flyby and comet rendezvous scenarios. These experiments quantify instrument coverage of key surface features as a function of planning turnaround time. Careful application of agile operations techniques can play a significant role in realizing the Decadal Survey plan for primitive body exploration

  13. High water content in primitive continental flood basalts.

    PubMed

    Xia, Qun-Ke; Bi, Yao; Li, Pei; Tian, Wei; Wei, Xun; Chen, Han-Lin

    2016-05-04

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>10(5) km(3)) within short time span (<1-3 Ma) is in principle caused by an abnormally high temperature, extended decompression, a certain amount of mafic source rocks (e.g., pyroxenite), or an elevated H2O content in the mantle source. These four factors are not mutually exclusive. There are growing evidences for high temperature, decompression and mafic source rocks, albeit with hot debate. However, there is currently no convincing evidence of high water content in the source of CFB. We retrieved the initial H2O content of the primitive CFB in the early Permian Tarim large igneous province (NW China), using the H2O content of ten early-formed clinopyroxene (cpx) crystals that recorded the composition of the primitive Tarim basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB.

  14. Superposition, Transition Probabilities and Primitive Observables in Infinite Quantum Systems

    NASA Astrophysics Data System (ADS)

    Buchholz, Detlev; Størmer, Erling

    2015-10-01

    The concepts of superposition and of transition probability, familiar from pure states in quantum physics, are extended to locally normal states on funnels of type I∞ factors. Such funnels are used in the description of infinite systems, appearing for example in quantum field theory or in quantum statistical mechanics; their respective constituents are interpreted as algebras of observables localized in an increasing family of nested spacetime regions. Given a generic reference state (expectation functional) on a funnel, e.g. a ground state or a thermal equilibrium state, it is shown that irrespective of the global type of this state all of its excitations, generated by the adjoint action of elements of the funnel, can coherently be superimposed in a meaningful manner. Moreover, these states are the extreme points of their convex hull and as such are analogues of pure states. As further support of this analogy, transition probabilities are defined, complete families of orthogonal states are exhibited and a one-to-one correspondence between the states and families of minimal projections on a Hilbert space is established. The physical interpretation of these quantities relies on a concept of primitive observables. It extends the familiar framework of observable algebras and avoids some counter intuitive features of that setting. Primitive observables admit a consistent statistical interpretation of corresponding measurements and their impact on states is described by a variant of the von Neumann-Lüders projection postulate.

  15. Primitive wing feather arrangement in Archaeopteryx lithographica and Anchiornis huxleyi.

    PubMed

    Longrich, Nicholas R; Vinther, Jakob; Meng, Qingjin; Li, Quangguo; Russell, Anthony P

    2012-12-01

    In modern birds (Neornithes), the wing is composed of a layer of long, asymmetrical flight feathers overlain by short covert feathers. It has generally been assumed that wing feathers in the Jurassic bird Archaeopteryx and Cretaceous feathered dinosaurs had the same arrangement. Here, we redescribe the wings of the archaic bird Archaeopteryx lithographica and the dinosaur Anchiornis huxleyi and show that their wings differ from those of Neornithes in being composed of multiple layers of feathers. In Archaeopteryx, primaries are overlapped by long dorsal and ventral coverts. Anchiornis has a similar configuration but is more primitive in having short, slender, symmetrical remiges. Archaeopteryx and Anchiornis therefore appear to represent early experiments in the evolution of the wing. This primitive configuration has important functional implications: although the slender feather shafts of Archaeopteryx and Anchiornis make individual feathers weak, layering of the wing feathers may have produced a strong airfoil. Furthermore, the layered arrangement may have prevented the feathers from forming a slotted tip or separating to reduce drag on the upstroke. The wings of early birds therefore may have lacked the range of functions seen in Neornithes, limiting their flight ability.

  16. Primitive soft-bodied cephalopods from the Cambrian.

    PubMed

    Smith, Martin R; Caron, Jean-Bernard

    2010-05-27

    The exquisite preservation of soft-bodied animals in Burgess Shale-type deposits provides important clues into the early evolution of body plans that emerged during the Cambrian explosion. Until now, such deposits have remained silent regarding the early evolution of extant molluscan lineages-in particular the cephalopods. Nautiloids, traditionally considered basal within the cephalopods, are generally depicted as evolving from a creeping Cambrian ancestor whose dorsal shell afforded protection and buoyancy. Although nautiloid-like shells occur from the Late Cambrian onwards, the fossil record provides little constraint on this model, or indeed on the early evolution of cephalopods. Here, we reinterpret the problematic Middle Cambrian animal Nectocaris pteryx as a primitive (that is, stem-group), non-mineralized cephalopod, based on new material from the Burgess Shale. Together with Nectocaris, the problematic Lower Cambrian taxa Petalilium and (probably) Vetustovermis form a distinctive clade, Nectocarididae, characterized by an open axial cavity with paired gills, wide lateral fins, a single pair of long, prehensile tentacles, a pair of non-faceted eyes on short stalks, and a large, flexible anterior funnel. This clade extends the cephalopods' fossil record by over 30 million years, and indicates that primitive cephalopods lacked a mineralized shell, were hyperbenthic, and were presumably carnivorous. The presence of a funnel suggests that jet propulsion evolved in cephalopods before the acquisition of a shell. The explosive diversification of mineralized cephalopods in the Ordovician may have an understated Cambrian 'fuse'.

  17. High water content in primitive continental flood basalts

    PubMed Central

    Xia, Qun-Ke; Bi, Yao; Li, Pei; Tian, Wei; Wei, Xun; Chen, Han-Lin

    2016-01-01

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>105 km3) within short time span (<1–3 Ma) is in principle caused by an abnormally high temperature, extended decompression, a certain amount of mafic source rocks (e.g., pyroxenite), or an elevated H2O content in the mantle source. These four factors are not mutually exclusive. There are growing evidences for high temperature, decompression and mafic source rocks, albeit with hot debate. However, there is currently no convincing evidence of high water content in the source of CFB. We retrieved the initial H2O content of the primitive CFB in the early Permian Tarim large igneous province (NW China), using the H2O content of ten early-formed clinopyroxene (cpx) crystals that recorded the composition of the primitive Tarim basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB. PMID:27143196

  18. Inorganic chemistry of O2 in a dense primitive atmosphere

    PubMed

    Rosenqvist, J; Chassefière, E

    1995-01-01

    A simple steady-state photochemical model is developed in order to determine typical molecular oxygen concentrations for a comprehensive range of primitive abiotic atmospheres. Carbon dioxide is assumed to be the dominant constituent in these atmospheres since CO2 photodissociation may potentially result in the enhancement of the O2 partial pressure. The respective effects of the H2O content, temperature, eddy diffusion coefficient and UV flux on the results are investigated. It is shown that for any pressure at the surface, the partial pressure of molecular oxygen does not exceed 10 mbar. The peculiar case of a runaway greenhouse which has possibly taken place on Venus is qualitatively envisaged. Although O2 is basically absent in the present Venus atmosphere, a transient presence in a primitive stage cannot be ruled out. Possible mechanisms for O2 removal in such an atmosphere are reviewed. At the present stage, we think that the detection of large O2 amounts would be at least a good clue for the presence of life on an extrasolar planet. PMID:11538435

  19. Erythropoietin critically regulates the terminal maturation of murine and human primitive erythroblasts

    PubMed Central

    Malik, Jeffrey; Kim, Ah Ram; Tyre, Kaitlin A.; Cherukuri, Anjuli R.; Palis, James

    2013-01-01

    Primitive erythroid cells, the first red blood cells produced in the mammalian embryo, are necessary for embryonic survival. Erythropoietin and its receptor EpoR, are absolutely required for survival of late-stage definitive erythroid progenitors in the fetal liver and adult bone marrow. Epo- and Epor-null mice die at E13.5 with a lack of definitive erythrocytes. However, the persistence of circulating primitive erythroblasts raises questions about the role of erythropoietin/EpoR in primitive erythropoiesis. Using Epor-null mice and a novel primitive erythroid 2-step culture we found that erythropoietin is not necessary for specification of primitive erythroid progenitors. However, Epor-null embryos develop a progressive, profound anemia by E12.5 as primitive erythroblasts mature as a synchronous cohort. This anemia results from reduced primitive erythroblast proliferation associated with increased p27 expression, from advanced cellular maturation, and from markedly elevated rates of apoptosis associated with an imbalance in pro- and anti-apoptotic gene expression. Both mouse and human primitive erythroblasts cultured without erythropoietin also undergo accelerated maturation and apoptosis at later stages of maturation. We conclude that erythropoietin plays an evolutionarily conserved role in promoting the proliferation, survival, and appropriate timing of terminal maturation of primitive erythroid precursors. PMID:23894012

  20. Peripheral nerve stimulation: definition.

    PubMed

    Abejón, David; Pérez-Cajaraville, Juan

    2011-01-01

    Recently, there has been a tremendous evolution in the field of neurostimulation, both from the technological point of view and from development of the new and different indications. In some areas, such as peripheral nerve stimulation, there has been a boom in recent years due to the variations in the surgical technique and the improved results documented by in multiple published papers. All this makes imperative the need to classify and define the different types of stimulation that are used today. The confusion arises when attempting to describe peripheral nerve stimulation and subcutaneous stimulation. Peripheral nerve stimulation, in its pure definition, involves implanting a lead on a nerve, with the aim to produce paresthesia along the entire trajectory of the stimulated nerve.

  1. Vismodegib and Gamma-Secretase/Notch Signalling Pathway Inhibitor RO4929097 in Treating Patients With Advanced or Metastatic Sarcoma

    ClinicalTrials.gov

    2016-06-09

    Adult Alveolar Soft Part Sarcoma; Adult Angiosarcoma; Adult Desmoplastic Small Round Cell Tumor; Adult Epithelioid Hemangioendothelioma; Adult Epithelioid Sarcoma; Adult Extraskeletal Myxoid Chondrosarcoma; Adult Extraskeletal Osteosarcoma; Adult Fibrosarcoma; Adult Leiomyosarcoma; Adult Liposarcoma; Adult Malignant Mesenchymoma; Adult Malignant Peripheral Nerve Sheath Tumor; Adult Rhabdomyosarcoma; Adult Synovial Sarcoma; Adult Unclassified Pleomorphic Sarcoma; Chondrosarcoma; Clear Cell Sarcoma of the Kidney; Conjunctival Kaposi Sarcoma; Dermatofibrosarcoma Protuberans; Gastrointestinal Stromal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Osteosarcoma; Ovarian Sarcoma; Recurrent Adult Soft Tissue Sarcoma; Recurrent Adult Unclassified Pleomorphic Sarcoma of Bone; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Kaposi Sarcoma; Recurrent Osteosarcoma; Recurrent Uterine Corpus Sarcoma; Small Intestine Leiomyosarcoma; Stage III Adult Soft Tissue Sarcoma; Stage III Uterine Sarcoma; Stage IV Adult Soft Tissue Sarcoma; Stage IV Uterine Sarcoma; Unclassified Pleomorphic Sarcoma of Bone

  2. Inherited Peripheral Neuropathies

    PubMed Central

    Saporta, Mario A.; Shy, Michael E.

    2013-01-01

    SYNOPSIS Charcot Marie Tooth disease (CMT) is a heterogeneous group of inherited peripheral neuropathies in which the neuropathy is the sole or primary component of the disorder, as opposed to diseases in which the neuropathy is part of a more generalized neurological or multisystem syndrome. Due to the great genetic heterogeneity of this condition, it can be challenging for the general neurologist to diagnose patients with specific types of CMT. Here, we review the biology of the inherited peripheral neuropathies, delineate major phenotypic features of the CMT subtypes and suggest strategies for focusing genetic testing. PMID:23642725

  3. Primitive chain network simulations for entangled DNA solutions

    NASA Astrophysics Data System (ADS)

    Masubuchi, Yuichi; Furuichi, Kenji; Horio, Kazushi; Uneyama, Takashi; Watanabe, Hiroshi; Ianniruberto, Giovanni; Greco, Francesco; Marrucci, Giuseppe

    2009-09-01

    Molecular theories for polymer rheology are based on conformational dynamics of the polymeric chain. Hence, measurements directly related to molecular conformations appear more appealing than indirect ones obtained from rheology. In this study, primitive chain network simulations are compared to experimental data of entangled DNA solutions [Teixeira et al., Macromolecules 40, 2461 (2007)]. In addition to rheological comparisons of both linear and nonlinear viscoelasticities, a molecular extension measure obtained by Teixeira et al. through fluorescent microscopy is compared to simulations, in terms of both averages and distributions. The influence of flow on conformational distributions has never been simulated for the case of entangled polymers, and how DNA molecular individualism extends to the entangled regime is not known. The linear viscoelastic response and the viscosity growth curve in the nonlinear regime are found in good agreement with data for various DNA concentrations. Conversely, the molecular extension measure shows significant departures, even under equilibrium conditions. The reason for such discrepancies remains unknown.

  4. A simple physical mechanism enables homeostasis in primitive cells

    NASA Astrophysics Data System (ADS)

    Engelhart, Aaron E.; Adamala, Katarzyna P.; Szostak, Jack W.

    2016-05-01

    The emergence of homeostatic mechanisms that enable maintenance of an intracellular steady state during growth was critical to the advent of cellular life. Here, we show that concentration-dependent reversible binding of short oligonucleotides, of both specific and random sequence, can modulate ribozyme activity. In both cases, catalysis is inhibited at high concentrations, and dilution activates the ribozyme via inhibitor dissociation, thus maintaining near-constant ribozyme specific activity throughout protocell growth. To mimic the result of RNA synthesis within non-growing protocells, we co-encapsulated high concentrations of ribozyme and oligonucleotides within fatty acid vesicles, and ribozyme activity was inhibited. Following vesicle growth, the resulting internal dilution produced ribozyme activation. This simple physical system enables a primitive homeostatic behaviour: the maintenance of constant ribozyme activity per unit volume during protocell volume changes. We suggest that such systems, wherein short oligonucleotides reversibly inhibit functional RNAs, could have preceded sophisticated modern RNA regulatory mechanisms, such as those involving miRNAs.

  5. A primitive cyanobacterium as pioneer microorganism for terraforming Mars.

    PubMed

    Friedmann, E I; Ocampo-Friedmann, R

    1995-03-01

    The primitive characteristics of the cyanobacterium Chroococcidiopsis suggest that it represents a very ancient type of the group. Its morphology is simple but shows a wide range of variability, and it resembles certain Proterozoic microfossils. Chroococcidiopsis is probably the most desiccation-resistant cyanobacterium, the sole photosynthetic organism in extreme arid habitats. It is also present in a wide range of other extreme environments, from Antarctic rocks to thermal springs and hypersaline habitats, but it is unable to compete with more specialized organisms. Genetic evidence suggests that all forms belong to a single species. Its remarkable tolerance of environmental extremes makes Chroococcidiopsis a prime candidate for use as a pioneer photosynthetic microorganism for terraforming of Mars. The hypolithic microbial growth form (which lives under stones of a desert pavement) could be used as a model for development of technologies for large-scale Martian farming.

  6. Pankinetoplast DNA structure in a primitive bodonid flagellate, Cryptobia helicis.

    PubMed Central

    Lukescaron, J; Jirkû, M; Avliyakulov, N; Benada, O

    1998-01-01

    The mitochondrial DNA (mtDNA) of a primitive kinetoplastid flagellate Cryptobia helicis is composed of 4.2 kb minicircles and 43 kb maxicircles. 85% and 6% of the minicircles are in the form of supercoiled (SC) and relaxed (OC) monomers, respectively. The remaining minicircles (9%) constitute catenated oligomers composed of both the SC and OC molecules. Minicircles contain bent helix and sequences homologous to the minicircle conserved sequence blocks. Maxicircles encode typical mitochondrial genes and are not catenated. The mtDNA, which we describe with the term 'pankinetoplast DNA', is spread throughout the mitochondrial lumen, where it is associated with multiple electron-lucent loci. There are approximately 8400 minicircles per pankinetoplast-mitochondrion, with the pan-kDNA representing approximately 36% of the total cellular DNA. Based on the similarity of the C.helicis minicircles to plasmids, we present a theory on the formation of the kDNA network. PMID:9451008

  7. Primitive forms of meiosis: the possible evolution of meiosis.

    PubMed

    Solari, Alberto J

    2002-04-01

    Meiosis is a basic process of most eukaryotes, as it forms with conjugation the basis of sexual reproduction. As sex seems to be present in the vast majority of eukaryotes, the origin of meiosis is presently unknown. Protists having optional or alternative sexual and asexual cycles seem to be the best targets for research on the evolution of meiosis. While the budding yeast Saccharomyces cerevisiae shows an elaborate and well-known meiotic process, the fission yeast Schizosaccharomyces pombe, has a much simpler meiosis, which may show some of the most primitive features of meiotic mechanisms. The present availability of whole genome sequences of many bacteria and some protists is revealing that eukaryotic sexual reproduction has recruited some prokaryotic processes for its own development. Some of these processes are analyzed and the basic role of chromosome linearity and telomere constitution in the development of meiosis is underlined.

  8. A new kind of primitive chondrite, Allan Hills 85085

    NASA Technical Reports Server (NTRS)

    Scott, Edward R. D.

    1988-01-01

    Allan Hills (ALH) 85085, a chemically and mineralogically unique chondrite whose components have suffered little metamorphism or alteration, is discussed. It is found that ALH 85085 has 4 wt pct chondrules (mean diameter 16 microns), 36 wt pct Fe, Ni, 56 wt pct lithic and mineral silicate fragments, and 2 wt pct trolite. It is suggested that, with the exception of matrix lumps, the components of ALH 85085 formed and accreted in the solar nebula. It is shown that ALH 85085 does not belong to any of the nine chondrite groups and is very different from Kakangari. Similarities between ALH 85085 and Bencubbin and Weatherford suggest that the latter two primitive meteorites may be chondrites with high metal abundances and very large, partly fragmented chondrules.

  9. Ly(alpha) Photolysis in the Primitive Solar Nebula

    NASA Astrophysics Data System (ADS)

    Gladstone, G. Randall

    1998-01-01

    This is the final report for the third year of work on this project. Our proposal was to quantitatively investigate the importance of photochemistry in the solar nebula. In the generally accepted theory for the chemical evolution of the primitive solar nebula, Prinn and Fegley argued that photochemistry is unimportant, and that thermochemistry controls the relative abundances of molecular species throughout the planet-forming region. They provided useful estimates of the chemical energy available to the solar nebula from a variety of sources, and established that even the small photolysis rate due to starlight is more important than the photolysis rate from direct sunlight (although small, the UV flux from starlight could have processed a non-negligible fraction of the solar nebula. The reason for this is that the opacity of the disk was so large that direct sunlight could only penetrate to 0.1 AU or so, despite the expectation that the protosun, if comparable to a T-Tauri star, would be emitting up to 104 more H I Ly(alpha) photons than the current sun. We developed a Monte Carlo resonance fine radiative transfer code, capable of accurately calculating the radiation field of H I Ly(alpha), He I 584 A, and He II 304 A emissions throughout the nebula and the nearby interstellar medium in which it is embedded. We applied the code to two appropriate models of the primitive solar nebula. Our model provided the photolysis rates of various species over the entire surface layer of the nebula, and from this we evaluated the importance of UV photochemistry due to backscattered solar UV resonance line emissions on different parts of the nebula. The results discussed below were presented.

  10. Ly(alpha) Photolysis in the Primitive Solar Nebula

    NASA Technical Reports Server (NTRS)

    Gladstone, G. Randall

    1998-01-01

    This is the final report for the third year of work on this project. Our proposal was to quantitatively investigate the importance of photochemistry in the solar nebula. In the generally accepted theory for the chemical evolution of the primitive solar nebula, Prinn and Fegley argued that photochemistry is unimportant, and that thermochemistry controls the relative abundances of molecular species throughout the planet-forming region. They provided useful estimates of the chemical energy available to the solar nebula from a variety of sources, and established that even the small photolysis rate due to starlight is more important than the photolysis rate from direct sunlight (although small, the UV flux from starlight could have processed a non-negligible fraction of the solar nebula. The reason for this is that the opacity of the disk was so large that direct sunlight could only penetrate to 0.1 AU or so, despite the expectation that the protosun, if comparable to a T-Tauri star, would be emitting up to 10(exp 4) more H I Ly(alpha) photons than the current sun. We developed a Monte Carlo resonance fine radiative transfer code, capable of accurately calculating the radiation field of H I Ly(alpha), He I 584 A, and He II 304 A emissions throughout the nebula and the nearby interstellar medium in which it is embedded. We applied the code to two appropriate models of the primitive solar nebula. Our model provided the photolysis rates of various species over the entire surface layer of the nebula, and from this we evaluated the importance of UV photochemistry due to backscattered solar UV resonance line emissions on different parts of the nebula. The results discussed below were presented.

  11. Formation of Primitive Bodies in the Protoplanetary Nebula

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey N.

    2003-01-01

    We have developed a simple model of global transport of solids in the protoplanetary nebula, including radial drift of large particles and diffusion of small ones. The model has been applied to the formation and redistribution of the Ca-A1 rich refractory mineral inclusions (CAIs) found in primitive chondrites. These objects form at much higher temperatures, and appear to be 1-3 million years older than, the dominant (chondrule) components found in the same parent bodies. A widespread concern has been the retention of CAIs for this long against gas-drag-induced radial drift into the sun. We show that outward radial diffusion in a weakly turbulent nebula can overwhelm inward drift, and prevent significant numbers of CAI-size particles from being lost into the sun for tines on the order of several Myr. An element of this model is rapid inward radial drift of boulder-sized primitive (carbon-rich) silicate material, more like Halley-dust than CI chondrites in the early days of the nebula. Thls process can enrich the abundance of silicate and carbon material in the inner nebula, and may provide possible explanations for both chemical and isotopic properties of CAIs. The predicted enhancement of CO relative to water might be of relevance to recent IR astronomical observations of CO in the inner disks of several actively accreting T Tauri stars. This process has applications to the transport and redistribution of volatiles in general. Depending on the rubble particle size distribution, rapid radial drift of boulder-sized solids can bring more material inwards across a condensation front, to evaporate, than can subsequently be removed by nebula advection or diffusion, until a strong local enhancement is produced which allows diffusive loss to balance the drifting source. Application of this process to enhancement of the abundance of water near the "ice line" will be discussed. Supported by the Origins of Solar Systems program.

  12. Primitive layered gabbros from fast-spreading lower oceanic crust

    NASA Astrophysics Data System (ADS)

    Gillis, Kathryn M.; Snow, Jonathan E.; Klaus, Adam; Abe, Natsue; Adrião, Álden B.; Akizawa, Norikatsu; Ceuleneer, Georges; Cheadle, Michael J.; Faak, Kathrin; Falloon, Trevor J.; Friedman, Sarah A.; Godard, Marguerite; Guerin, Gilles; Harigane, Yumiko; Horst, Andrew J.; Hoshide, Takashi; Ildefonse, Benoit; Jean, Marlon M.; John, Barbara E.; Koepke, Juergen; Machi, Sumiaki; Maeda, Jinichiro; Marks, Naomi E.; McCaig, Andrew M.; Meyer, Romain; Morris, Antony; Nozaka, Toshio; Python, Marie; Saha, Abhishek; Wintsch, Robert P.

    2014-01-01

    Three-quarters of the oceanic crust formed at fast-spreading ridges is composed of plutonic rocks whose mineral assemblages, textures and compositions record the history of melt transport and crystallization between the mantle and the sea floor. Despite the importance of these rocks, sampling them in situ is extremely challenging owing to the overlying dykes and lavas. This means that models for understanding the formation of the lower crust are based largely on geophysical studies and ancient analogues (ophiolites) that did not form at typical mid-ocean ridges. Here we describe cored intervals of primitive, modally layered gabbroic rocks from the lower plutonic crust formed at a fast-spreading ridge, sampled by the Integrated Ocean Drilling Program at the Hess Deep rift. Centimetre-scale, modally layered rocks, some of which have a strong layering-parallel foliation, confirm a long-held belief that such rocks are a key constituent of the lower oceanic crust formed at fast-spreading ridges. Geochemical analysis of these primitive lower plutonic rocks--in combination with previous geochemical data for shallow-level plutonic rocks, sheeted dykes and lavas--provides the most completely constrained estimate of the bulk composition of fast-spreading oceanic crust so far. Simple crystallization models using this bulk crustal composition as the parental melt accurately predict the bulk composition of both the lavas and the plutonic rocks. However, the recovered plutonic rocks show early crystallization of orthopyroxene, which is not predicted by current models of melt extraction from the mantle and mid-ocean-ridge basalt differentiation. The simplest explanation of this observation is that compositionally diverse melts are extracted from the mantle and partly crystallize before mixing to produce the more homogeneous magmas that erupt.

  13. Primitive layered gabbros from fast-spreading lower oceanic crust.

    PubMed

    Gillis, Kathryn M; Snow, Jonathan E; Klaus, Adam; Abe, Natsue; Adrião, Alden B; Akizawa, Norikatsu; Ceuleneer, Georges; Cheadle, Michael J; Faak, Kathrin; Falloon, Trevor J; Friedman, Sarah A; Godard, Marguerite; Guerin, Gilles; Harigane, Yumiko; Horst, Andrew J; Hoshide, Takashi; Ildefonse, Benoit; Jean, Marlon M; John, Barbara E; Koepke, Juergen; Machi, Sumiaki; Maeda, Jinichiro; Marks, Naomi E; McCaig, Andrew M; Meyer, Romain; Morris, Antony; Nozaka, Toshio; Python, Marie; Saha, Abhishek; Wintsch, Robert P

    2014-01-01

    Three-quarters of the oceanic crust formed at fast-spreading ridges is composed of plutonic rocks whose mineral assemblages, textures and compositions record the history of melt transport and crystallization between the mantle and the sea floor. Despite the importance of these rocks, sampling them in situ is extremely challenging owing to the overlying dykes and lavas. This means that models for understanding the formation of the lower crust are based largely on geophysical studies and ancient analogues (ophiolites) that did not form at typical mid-ocean ridges. Here we describe cored intervals of primitive, modally layered gabbroic rocks from the lower plutonic crust formed at a fast-spreading ridge, sampled by the Integrated Ocean Drilling Program at the Hess Deep rift. Centimetre-scale, modally layered rocks, some of which have a strong layering-parallel foliation, confirm a long-held belief that such rocks are a key constituent of the lower oceanic crust formed at fast-spreading ridges. Geochemical analysis of these primitive lower plutonic rocks--in combination with previous geochemical data for shallow-level plutonic rocks, sheeted dykes and lavas--provides the most completely constrained estimate of the bulk composition of fast-spreading oceanic crust so far. Simple crystallization models using this bulk crustal composition as the parental melt accurately predict the bulk composition of both the lavas and the plutonic rocks. However, the recovered plutonic rocks show early crystallization of orthopyroxene, which is not predicted by current models of melt extraction from the mantle and mid-ocean-ridge basalt differentiation. The simplest explanation of this observation is that compositionally diverse melts are extracted from the mantle and partly crystallize before mixing to produce the more homogeneous magmas that erupt.

  14. Efficient infection of primitive hematopoietic stem cells by modified adenovirus.

    PubMed

    Yotnda, P; Onishi, H; Heslop, H E; Shayakhmetov, D; Lieber, A; Brenner, M; Davis, A

    2001-06-01

    Almost all studies of adenoviral vector-mediated gene transfer have made use of the adenovirus type 5 (Ad5). Unfortunately, Ad5 has been ineffective at infecting hematopoietic progenitor cells (HPC). Chimeric Ad5/F35 vectors that have been engineered to substitute the shorter-shafted fiber protein from Ad35 can efficiently infect committed hematopoietic cells and we now show highly effective gene transfer to primitive progenitor subsets. An Ad5GFP and Ad5/F35GFP vector was added to CD34(+) and CD34(-)lineage(-) (lin(-)) HPC. Only 5-20% of CD34(+) and CD34(-)lin(-) cells expressed GFP after Ad5 exposure. In contrast, with the Ad5/F35 vector, 30-70% of the CD34(+), 50-70% of the CD34(-)lin(-) and up to 60% of the CD38(-) HPC expressed GFP and there was little evident cellular toxicity. Because of these improved results, we also analyzed the ability of Ad5/F35 virus to infect the hoechst negative 'side population' (SP) of marrow cells, which appear to be among the very earliest multipotent HPC. Between 51% and 80% of marrow SP cells expressed GFP. The infected populations retained their ability to form colonies in two short-term culture systems, with no loss of viability. We also studied the transfer and expression of immunomodulatory genes, CD40L (cell surface expression) and interleukin-2 (secreted). Both were expressed at immunomodulatory levels for >5 days. The ability of Ad5/F35 to deliver transgenes to primitive HPC with high efficiency and low toxicity in the absence of growth factors provides an improved means of studying the consequences of transient gene expression in these cells.

  15. Amylose primitive médiastinale d'aspect pseudotumoral

    PubMed Central

    Mahfoudhi, Madiha; Mamlouk, Habiba; Turki, Sami; Kheder, Adel

    2015-01-01

    L'amylose primitive médiastinale isolée est rare et de diagnostic difficile. Nous rapportons l'observation d'un patient âgé de 41 ans ayant présenté une dyspnée et des crachats hémoptoïques. A l'examen physique il n'avait pas d'hypotension orthostatique. Les aires ganglionnaires périphériques étaient libres. La tomodensitométrie thoracique a objectivé un magma d'adénopathies médiastinales réalisant une masse de 45 mm x 60 mm. L'examen anatomopathologique d'une biopsie ganglionnaire guidée par médiastinoscopie a conclut a une amylose médiastinale de type AL. Il n'avait pas d'autres localisations amyloïdes. Un myélome multiple a été éliminé. Le diagnostic d'amylose primitive médiastinale de type AL a été retenu. Le traitement s'est basé sur des cures de Melphalan-prednisone. La chirurgie était évitée vu le risque hémorragique élevé. L’évolution était marquée par l'amélioration de la dyspnée, la disparition de l'hémoptysie et la diminution de la taille de la masse ganglionnaire devenant 25 mm x 20 mm. PMID:26308913

  16. Treatment of peripheral neuropathies.

    PubMed Central

    Hallett, M; Tandon, D; Berardelli, A

    1985-01-01

    There are three general approaches to treatment of peripheral neuropathy. First, an attempt should be made to reverse the pathophysiological process if its nature can be elucidated. Second, nerve metabolism can be stimulated and regeneration encouraged. Third, even if the neuropathy itself cannot be improved, symptomatic therapy can be employed. This review outlines the options available for each approach. PMID:3003254

  17. Comparing Wild 2 Fine-Grained Material to Matrix of Primitive Meteorites

    NASA Astrophysics Data System (ADS)

    Stodolna, J.; Jacob, D.; Leroux, H.

    2011-03-01

    We report a TEM examination of the fine-grained material from track 80. It compares well with main characteristics of the matrix of primitive chondrites. This fine-grained Wild 2 material could constitute the very primitive part expected of the comet.

  18. Péritonite primitive: entité réelle mais de diagnostic difficile

    PubMed Central

    Yamou, Rajae; Najih, Mohammed; Absi, Mohamed; Ouanani, Mohamed; Echerrab, Mahjoub; EL Alami, Hassan; Amraoui, Mohamed; Errougani, Abdelkader; Chkoff, Mohamed Rachid

    2012-01-01

    Les péritonites primitives sont rares chez des patients sans facteurs de risques. Elles simulent les péritonites secondaires. C'est pourquoi leur diagnostic ne peut être que peropératoire. Nous rapportons deux cas de péritonites primitives dans le but de discuter leurs aspects diagnostique et thérapeutiques. PMID:23077704

  19. Formation of a Polarised Primitive Endoderm Layer in Embryoid Bodies Requires Fgfr/Erk Signalling

    PubMed Central

    Doughton, Gail; Wei, Jun; Tapon, Nicolas; Welham, Melanie J.; Chalmers, Andrew D.

    2014-01-01

    The primitive endoderm arises from the inner cell mass during mammalian pre-implantation development. It faces the blastocoel cavity and later gives rise to the extraembryonic parietal and visceral endoderm. Here, we investigate a key step in primitive endoderm development, the acquisition of apico-basolateral polarity and epithelial characteristics by the non-epithelial inner cell mass cells. Embryoid bodies, formed from mouse embryonic stem cells, were used as a model to study this transition. The outer cells of these embryoid bodies were found to gradually acquire the hallmarks of polarised epithelial cells and express markers of primitive endoderm cell fate. Fgf receptor/Erk signalling is known to be required for specification of the primitive endoderm, but its role in polarisation of this tissue is less well understood. To investigate the function of this pathway in the primitive endoderm, embryoid bodies were cultured in the presence of a small molecule inhibitor of Mek. This inhibitor caused a loss of expression of markers of primitive endoderm cell fate and maintenance of the pluripotency marker Nanog. In addition, a mislocalisation of apico-basolateral markers and disruption of the epithelial barrier, which normally blocks free diffusion across the epithelial cell layer, occurred. Two inhibitors of the Fgf receptor elicited similar phenotypes, suggesting that Fgf receptor signalling promotes Erk-mediated polarisation. This data shows that primitive endoderm cells of the outer layer of embryoid bodies gradually polarise, and formation of a polarised primitive endoderm layer requires the Fgf receptor/Erk signalling pathway. PMID:24752320

  20. Angioplasty and stent placement -- peripheral arteries

    MedlinePlus

    Percutaneous transluminal angioplasty - peripheral artery; PTA - peripheral artery; Angioplasty - peripheral arteries; Iliac artery -angioplasty; Femoral artery - angioplasty; Popliteal artery - angioplasty; Tibial artery - angioplasty; ...

  1. Discovery of survival factor for primitive chronic myeloid leukemia cells using induced pluripotent stem cells

    PubMed Central

    Suknuntha, Kran; Ishii, Yuki; Tao, Lihong; Hu, Kejin; McIntosh, Brian E.; Yang, David; Swanson, Scott; Stewart, Ron; Wang, Jean Y.J.; Thomson, James; Slukvin, Igor

    2016-01-01

    A definitive cure for chronic myeloid leukemia (CML) requires identifying novel therapeutic targets to eradicate leukemia stem cells (LSCs). However, the rarity of LSCs within the primitive hematopoietic cell compartment remains a major limiting factor for their study in humans. Here we show that primitive hematopoietic cells with typical LSC features, including adhesion defect, increased long-term survival and proliferation, and innate resistance to tyrosine kinase inhibitor (TKI) imatinib, can be generated de novo from reprogrammed primary CML cells. Using CML iPSC-derived primitive leukemia cells, we discovered olfactomedin 4 (OLFM4) as a novel factor that contributes to survival and growth of somatic lin−CD34+ cells from bone marrow of patients with CML in chronic phase, but not primitive hematopoietic cells from normal bone marrow. Overall, this study shows the feasibility and advantages of using reprogramming technology to develop strategies for targeting primitive leukemia cells. PMID:26561938

  2. Discovery of survival factor for primitive chronic myeloid leukemia cells using induced pluripotent stem cells.

    PubMed

    Suknuntha, Kran; Ishii, Yuki; Tao, Lihong; Hu, Kejin; McIntosh, Brian E; Yang, David; Swanson, Scott; Stewart, Ron; Wang, Jean Y J; Thomson, James; Slukvin, Igor

    2015-11-01

    A definitive cure for chronic myeloid leukemia (CML) requires identifying novel therapeutic targets to eradicate leukemia stem cells (LSCs). However, the rarity of LSCs within the primitive hematopoietic cell compartment remains a major limiting factor for their study in humans. Here we show that primitive hematopoietic cells with typical LSC features, including adhesion defect, increased long-term survival and proliferation, and innate resistance to tyrosine kinase inhibitor (TKI) imatinib, can be generated de novo from reprogrammed primary CML cells. Using CML iPSC-derived primitive leukemia cells, we discovered olfactomedin 4 (OLFM4) as a novel factor that contributes to survival and growth of somatic lin(-)CD34(+) cells from bone marrow of patients with CML in chronic phase, but not primitive hematopoietic cells from normal bone marrow. Overall, this study shows the feasibility and advantages of using reprogramming technology to develop strategies for targeting primitive leukemia cells. PMID:26561938

  3. NEOWISE: The distribution of the large primitive asteroids

    NASA Astrophysics Data System (ADS)

    Grav, T.; Mainzer, A.; Bauer, J.; Masiero, J.; Nugent, C.; Stevenson, R.; Sonnett, S.

    2014-07-01

    The Wide-field Infrared Survey Explorer (WISE) is a NASA Medium-class Explorer mission that surveyed the entire sky in four infrared wavelengths at 3.4, 4.6, 12, and 22 microns (denoted W1, W2, W3, and W4, respectively) [1,2]. The solar-system specific portion of the WISE project, known as NEOWISE, collected more than 2 million observations of more than 158,000 asteroids, including near-Earth objects, main-belt asteroids, comets, Hildas, Jovian Trojans, Centaurs, and scattered-disk objects [3]. The methods used for data extraction and thermal modeling have been extensively detailed in [3--6]. The resulting physical properties have been reported in a series of papers [3--13]. In [6] and [9], it was shown that the visible albedo in the V band and the near-infrared albedo in the W1 and W2 bands can be used to taxonomically classify a significant number of the largest members of the Hilda and Jovian Trojan populations (see Figure 1). This allows for the study of the distribution of primitive asteroids in the region between the main asteroid and the giant planets, down to sizes where the populations are completely sampled. Figure 2 shows that for the Hilda population, where the sample is observationally complete to about 40 km, the C/P types dominated over the D types at the larger sizes. However, for the smaller sizes, the D types become significantly more numerous. For the Jovian Trojan population, for which the sample is observationally complete to about 50 km, the D types are slightly more numerous at the largest sizes. As smaller sizes are included, the D types become more dominant, with more than 80 % of the objects larger than 50 km having this taxonomic type. We have now extended the study to include thermal fits and taxonomic classification of the outer main belt, Cybeles, irregular satellites of Jupiter and Saturn, and the Centaur population [13], and will present the results of this work. The distribution of primitive asteroids in the different populations

  4. Tensile strengths and porosities of solar system primitive bodies

    NASA Astrophysics Data System (ADS)

    Trigo-Rodriguez, J. M.; Llorca, J.; Blum, J.

    Recent measurements of asteroid bulk densities suggest that rubble-pile asteroids with typical porosities of 30 to 50% may be common (Britt et al., 2006). However, the presence of such objects doesn't mean necessarily that the initial porosity had been preserved (Kerridge, 1993). In fact, the fluffy aggregates produced in laboratory experiments that we expect to be representative of the oldest protoplanetary disk materials, exhibit even higher porosities (Blum et al., 2006). Recent results confirm that primitive meteorites (like e.g. CM carbonaceous chondrites) are compacted samples of the nebula matter exhibiting different density and porosity that their precursors materials (Trigo-Rodríguez et al., 2006). Consequently, aqueous alteration, brecciation, and impact-induced metamorphism make very unlikely to find pristine bodies between the asteroidal population. However, there is clear evidence for the existence of high-porosity bodies between the C-type asteroids like e.g. Mathilde (Housen et al., 1999) or the Tagish Lake parent body (Brown et al., 2002). Although extensive post-accretionary processing of meteorite parent bodies can produce high degrees of porosity, only the most pristine ones seem to preserve more than 50% of porosity. Consequently, we should look for these low strength bodies among the C-type asteroids, or very especially in some unprocessed comets that continue being representative of the precursor materials. Recent suggestion that CI1 chondrites are originated from comets should be studied in this context (Gounelle et al., 2006). Particularly, we think that studies of the porosity and strength of primitive meteorites would provide valuable clues on the origin and nature of their parent bodies. REFERENCES Blum J., R. Schräpler, B.J.R. Davidson and J.M. Trigo-Rodríguez (2006) Astroph. J., submitted. Britt D.T., G.J. Consolmagno, and W.J. Merline (2006) Lunar Planet. Sci. Conf. Abstract #2214. Brown, P. G., D. O. Revelle, E. Tagliaferri, and A

  5. Ultrasound of Peripheral Nerves

    PubMed Central

    Suk, Jung Im; Walker, Francis O.; Cartwright, Michael S.

    2013-01-01

    Over the last decade, neuromuscular ultrasound has emerged as a useful tool for the diagnosis of peripheral nerve disorders. This article reviews sonographic findings of normal nerves including key quantitative ultrasound measurements that are helpful in the evaluation of focal and possibly generalized peripheral neuropathies. It also discusses several recent papers outlining the evidence base for the use of this technology, as well as new findings in compressive, traumatic, and generalized neuropathies. Ultrasound is well suited for use in electrodiagnostic laboratories where physicians, experienced in both the clinical evaluation of patients and the application of hands-on technology, can integrate findings from the patient’s history, physical examination, electrophysiological studies, and imaging for diagnosis and management. PMID:23314937

  6. [Peripheral precocious puberty].

    PubMed

    Krysiak, Robert; Marek, Bogdan; Okopień, Bogusław

    2009-01-01

    The term precocious puberty is defined as the appearance of secondary sex characteristics before the age of 8 in girls and 9 in boys. There are two major forms of premature sexual maturation: gonadotrophin-dependent (central, or 'true' precocious puberty) and gonadotrophin- independent precocious puberty. The latter, also called peripheral precocious puberty, is characterized by increased production of sex steroids, causing the typical physical changes of puberty, in the absence of reactivation of the hypothalamic-pituitary axis. It may result from several different disorders including testotoxicosis, McCune-Albright syndrome, congenital adrenal hyperplasia, adrenal and gonadal tumours. The accumulation of knowledge regarding the pathogenesis of symptoms and the development of safe, effective treatment modalities have led to earlier intervention in patients with peripheral precocious puberty to prevent the decline in their psychosocial wellbeing, adult height and quality of life. We review the ethiopathogenesis, clinical picture, diagnosis and treatment of various disorders causing peripheral precocious puberty and provide the reader with current recommendations concerning approach to the patient with this health problem.

  7. Peripheral nerve hyperexcitability syndromes.

    PubMed

    Küçükali, Cem Ismail; Kürtüncü, Murat; Akçay, Halil İbrahim; Tüzün, Erdem; Öge, Ali Emre

    2015-01-01

    Peripheral nerve hyperexcitability (PNH) syndromes can be subclassified as primary and secondary. The main primary PNH syndromes are neuromyotonia, cramp-fasciculation syndrome (CFS), and Morvan's syndrome, which cause widespread symptoms and signs without the association of an evident peripheral nerve disease. Their major symptoms are muscle twitching and stiffness, which differ only in severity between neuromyotonia and CFS. Cramps, pseudomyotonia, hyperhidrosis, and some other autonomic abnormalities, as well as mild positive sensory phenomena, can be seen in several patients. Symptoms reflecting the involvement of the central nervous system occur in Morvan's syndrome. Secondary PNH syndromes are generally seen in patients with focal or diffuse diseases affecting the peripheral nervous system. The PNH-related symptoms and signs are generally found incidentally during clinical or electrodiagnostic examinations. The electrophysiological findings that are very useful in the diagnosis of PNH are myokymic and neuromyotonic discharges in needle electromyography along with some additional indicators of increased nerve fiber excitability. Based on clinicopathological and etiological associations, PNH syndromes can also be classified as immune mediated, genetic, and those caused by other miscellaneous factors. There has been an increasing awareness on the role of voltage-gated potassium channel complex autoimmunity in primary PNH pathogenesis. Then again, a long list of toxic compounds and genetic factors has also been implicated in development of PNH. The management of primary PNH syndromes comprises symptomatic treatment with anticonvulsant drugs, immune modulation if necessary, and treatment of possible associated dysimmune and/or malignant conditions. PMID:25719304

  8. Synthesis of oligoguanylates on oligocytidylate templates. [on primitive earth

    NASA Technical Reports Server (NTRS)

    Fakhrai, H.; Van Roode, J. H. G.; Orgel, L. E.

    1981-01-01

    The influence of template length in the self-condensation of guanosine 5'-phosphorimidazole in the presence of oligocytidylate templates is investigated. Reactions were carried out with cyclic cytidine 2',3'-phosphate, oligo- or polyC, and radioactively labeled guanosine 5'-phosphorimidazolide in the presence of Zn(+2) or Pb(+2) catalyst; product yields were determined by paper chromatography, thin-layer chromatography, and high-performance liquid chromatography. In the absence of a catalytic metal or in the presence of Pb(+2), a significant template effect is observed starting with the cytidine dimer and increasing in yield up to the hexamer template. Oligomers longer than the template are observed, and are predominantly 2'-5' linked in the presence of Pb(+2) and of mixed linkages in the uncatalyzed reaction. With the zinc ion as the catalyst, the template effect is first observed with the pentamer and is maximal with the heptamer. Products are predominantly 3'-5', and only a small proportion of them are longer than the template. The importance of the demonstrated formation of molecules with up to 10 guanosine units from oligocytidines as short as the dimer on the primitive earth is noted.

  9. Common leukocyte antigen staining of a primitive sarcoma.

    PubMed

    McDonnell, J M; Beschorner, W E; Kuhajda, F P; deMent, S H

    1987-04-15

    A 4-year-old boy presented with symptoms of tracheal obstruction and was found to have a polypoid tracheal mass, which was studied by biopsy. Light microscopy showed a tumor composed of small cells with round to oval dark nuclei, clumped chromatin, one to two nucleoli, and small, variable amounts of indistinct pink cytoplasm. In other areas the tumor had a loose, spindle appearance, with some cells showing more elongated nuclei, and fibrillar pink cytoplasm consistent with strap cells. Cross striations were not found. Electron microscopy showed desmosomes and 7 to 10 nm cytoplasmic filaments forming dense bodies. The findings are most consistent with a primitive sarcoma, probably rhabdomyosarcoma. Immunoperoxidase with three monoclonal antibodies for common leukocyte antigen showed diffuse membraneous staining with fresh-frozen tissue. All other lymphocyte and monocyte marker studies were negative. We believe that this case of anticommon leukocyte antigen staining, a rhabdomyosarcoma, represents the first report of a false positive reaction with monoclonal antibody to common leukocyte antigen.

  10. Nonrelatives inherit colony resources in a primitive termite.

    PubMed

    Johns, Philip M; Howard, Kenneth J; Breisch, Nancy L; Rivera, Anahi; Thorne, Barbara L

    2009-10-13

    The evolution of eusociality, especially how selection would favor sterility or subfertility of most individuals within a highly social colony, is an unresolved paradox. Eusociality evolved independently in diverse taxa, including insects (all ants and termites; some bees, wasps, thrips, and beetles), snapping shrimp, and naked mole rats. Termites have received comparatively less focus than the haplodiploid Hymenoptera (ants, bees, and wasps); however, they are the only diploid group with highly complex colonies and an extraordinary diversity of castes. In this study we staged encounters between unrelated colonies of primitive dampwood termites, Zootermopsis nevadensis, mimicking natural meetings that occur under bark. During encounters, kings and/or queens were killed and surviving members merged into one colony. After encounters, members of both unrelated colonies cooperated as a single social unit. We determined the colony of origin of replacement reproductives that emerged after death of kings and/or queens. Here, we document that replacement reproductives developed from workers in either or both original colonies, inherited the merged resources of the colony, and sometimes interbred. Because this species shares many characteristics with ancestral termites, these findings demonstrate how ecological factors could have promoted the evolution of eusociality by accelerating and enhancing direct fitness opportunities of helper offspring, rendering relatedness favoring kin selection less critical. PMID:19805058

  11. Polycomb enables primitive endoderm lineage priming in embryonic stem cells

    PubMed Central

    Illingworth, Robert S; Hölzenspies, Jurriaan J; Roske, Fabian V; Bickmore, Wendy A; Brickman, Joshua M

    2016-01-01

    Mouse embryonic stem cells (ESCs), like the blastocyst from which they are derived, contain precursors of the epiblast (Epi) and primitive endoderm (PrEn) lineages. While transient in vivo, these precursor populations readily interconvert in vitro. We show that altered transcription is the driver of these coordinated changes, known as lineage priming, in a process that exploits novel polycomb activities. We find that intragenic levels of the polycomb mark H3K27me3 anti-correlate with changes in transcription, irrespective of the gene’s developmental trajectory or identity as a polycomb target. In contrast, promoter proximal H3K27me3 is markedly higher for PrEn priming genes. Consequently, depletion of this modification stimulates the degree to which ESCs are primed towards PrEn when challenged to differentiate, but has little effect on gene expression in self-renewing ESC culture. These observations link polycomb with dynamic changes in transcription and stalled lineage commitment, allowing cells to explore alternative choices prior to a definitive decision. DOI: http://dx.doi.org/10.7554/eLife.14926.001 PMID:27723457

  12. Early aqueous activity on primitive meteorite parent bodies.

    PubMed

    Endress, M; Zinner, E; Bischoff, A

    1996-02-22

    The interstellar material from which the solar system formed has been modified by many processes: evaporation and condensation in the solar nebula, accretion into protoplanetary bodies and post-accretion processes within these bodies. Meteorites provide a record of these events and their chronology. Carbonaceous CI chondrites are among the most primitive, undifferentiated meteorites, but nevertheless show evidence of post-accretion alteration; they contain carbonates that are believed to have formed by reactions between anhydrous CI precursor materials and circulating fluids in the meteorite parent body (or bodies), yet little is known about the nature of these reactions or the timescale on which they occurred. Here we report measurements of excess 53Cr--formed by the decay of short-lived 53Mn--in five carbonate fragments from the CI chondrites Orgueil and Ivuna. Our results show that aqueous alteration on small protoplanetary bodies must have begun less than 20 Myr after the time of formation of the oldest known solar-nebula condensates (Allende refractory inclusions). This upper limit is much shorter than that of 50 Myr inferred from previous studies, and clearly establishes aqueous alteration as one of the earliest processes in the chemical evolution of the solar system.

  13. Structure of entangled polymer network from primitive chain network simulations

    NASA Astrophysics Data System (ADS)

    Masubuchi, Yuichi; Uneyama, Takashi; Watanabe, Hiroshi; Ianniruberto, Giovanni; Greco, Francesco; Marrucci, Giuseppe

    2010-04-01

    The primitive chain network (PCN) model successfully employed to simulate the rheology of entangled polymers is here tested versus less coarse-grained (lattice or atomistic) models for what concerns the structure of the network at equilibrium (i.e., in the absence of flow). By network structure, we mean the distributions of some relevant quantities such as subchain length in space or in monomer number. Indeed, lattice and atomistic simulations are obviously more accurate, but are also more difficult to use in nonequilibrium flow situations, especially for long entangled polymers. Conversely, the coarse-grained PCN model that deals more easily with rheology lacks, strictly speaking, a rigorous foundation. It is therefore important to verify whether or not the equilibrium structure of the network predicted by the PCN model is consistent with the results recently obtained by using lattice and atomistic simulations. In this work, we focus on single chain properties of the entangled network. Considering the significant differences in modeling the polymer molecules, the results here obtained appear encouraging, thus providing a more solid foundation to Brownian simulations based on the PCN model. Comparison with the existing theories also proves favorable.

  14. Dynamical movement primitives: learning attractor models for motor behaviors.

    PubMed

    Ijspeert, Auke Jan; Nakanishi, Jun; Hoffmann, Heiko; Pastor, Peter; Schaal, Stefan

    2013-02-01

    Nonlinear dynamical systems have been used in many disciplines to model complex behaviors, including biological motor control, robotics, perception, economics, traffic prediction, and neuroscience. While often the unexpected emergent behavior of nonlinear systems is the focus of investigations, it is of equal importance to create goal-directed behavior (e.g., stable locomotion from a system of coupled oscillators under perceptual guidance). Modeling goal-directed behavior with nonlinear systems is, however, rather difficult due to the parameter sensitivity of these systems, their complex phase transitions in response to subtle parameter changes, and the difficulty of analyzing and predicting their long-term behavior; intuition and time-consuming parameter tuning play a major role. This letter presents and reviews dynamical movement primitives, a line of research for modeling attractor behaviors of autonomous nonlinear dynamical systems with the help of statistical learning techniques. The essence of our approach is to start with a simple dynamical system, such as a set of linear differential equations, and transform those into a weakly nonlinear system with prescribed attractor dynamics by means of a learnable autonomous forcing term. Both point attractors and limit cycle attractors of almost arbitrary complexity can be generated. We explain the design principle of our approach and evaluate its properties in several example applications in motor control and robotics.

  15. Primitive reflex evaluation in the clinical assessment of extrapyramidal syndromes.

    PubMed

    Borroni, B; Broli, M; Costanzi, C; Gipponi, S; Gilberti, N; Agosti, C; Padovani, A

    2006-09-01

    The aim of the present study was to evaluate the role of primitive reflexes (PRs) as additional alert sign in routine clinical practice in patients with extrapyramidal syndrome. We considered glabellar, snout, palmomental and grasp reflexes in patients with mild stage of Lewy body dementia (LBD), corticobasal degeneration, progressive supranuclear palsy or Parkinson disease (PD). We also enrolled mild Alzheimer disease (AD) patients, and healthy subjects, as controls. LBD patients showed the highest prevalence of PRs compared with the other groups. The odds ratio of the risk of LBD in PRs > or = 2 was 27.9 (95% CI 2.9-269.0) compared with control group, 14.6 (95% CI 2.7-79.6) compared with mild AD, and 19.7 (95% CI 3.7-104.3) compared with PD. These data suggest that the occurrence of combination of PRs might be an useful additional warning sign of possible diffuse Lewy body pathology more than other causes of extrapyramidal syndrome.

  16. A simple physical mechanism enables homeostasis in primitive cells.

    PubMed

    Engelhart, Aaron E; Adamala, Katarzyna P; Szostak, Jack W

    2016-05-01

    The emergence of homeostatic mechanisms that enable maintenance of an intracellular steady state during growth was critical to the advent of cellular life. Here, we show that concentration-dependent reversible binding of short oligonucleotides, of both specific and random sequence, can modulate ribozyme activity. In both cases, catalysis is inhibited at high concentrations, and dilution activates the ribozyme via inhibitor dissociation, thus maintaining near-constant ribozyme specific activity throughout protocell growth. To mimic the result of RNA synthesis within non-growing protocells, we co-encapsulated high concentrations of ribozyme and oligonucleotides within fatty acid vesicles, and ribozyme activity was inhibited. Following vesicle growth, the resulting internal dilution produced ribozyme activation. This simple physical system enables a primitive homeostatic behaviour: the maintenance of constant ribozyme activity per unit volume during protocell volume changes. We suggest that such systems, wherein short oligonucleotides reversibly inhibit functional RNAs, could have preceded sophisticated modern RNA regulatory mechanisms, such as those involving miRNAs. PMID:27102678

  17. Three boys and their stories: atypical eating and primitive relations.

    PubMed

    Escosteguy Carneiro, Maria Inês Neuenschwander

    2008-12-01

    Eating disorders of whatever category, especially the most severe ones such as anorexia or bulimia, are often considered typical of the female sex. While this is correct concerning these two disorders, I suggest that there are other eating disorders that are more frequent among boys, especially the ones concerning atypical relations to food, notwithstanding the evidence that the already very well-known syndromes of bulimia and anorexia are also gaining ground among males. However, similar, unspecified eating disorders do not seem to occur so often among girls. Clinical data from my private practice should be taken for granted considering these matters, since I do not yet have statistical data to back up my thesis. In examples from three clinical cases involving boys and one female vignette, I shall attempt to establish a relation between eating disorders and primitive relations with men and women. This relation goes well beyond the oft-cited 'contemporary' causes of eating disorders. In addition, I shall situate these differences among symptoms of both sexes and relate them to impasses in different stages of emotional development, as well as to the extent to which girls' identification with their mother's sex can influence their acquisition of eating disorders.

  18. Solar Electric Propulsion for Primitive Body Science Missions

    NASA Technical Reports Server (NTRS)

    Witzberger, Kevin E.

    2006-01-01

    This paper describes work that assesses the performance of solar electric propulsion (SEP) for three different primitive body science missions: 1) Comet Rendezvous 2) Comet Surface Sample Return (CSSR), and 3) a Trojan asteroid/Centaur object Reconnaissance Flyby. Each of these missions launches from Earth between 2010 and 2016. Beginning-of-life (BOL) solar array power (referenced at 1 A.U.) varies from 10 to 18 kW. Launch vehicle selections range from a Delta II to a Delta IV medium-class. The primary figure of merit (FOM) is net delivered mass (NDM). This analysis considers the effects of imposing various mission constraints on the Comet Rendezvous and CSSR missions. Specifically, the Comet Rendezvous mission analysis examines an arrival date constraint with a launch year variation, whereas the CSSR mission analysis investigates an Earth entry velocity constraint commensurate with past and current missions. Additionally, the CSSR mission analysis establishes NASA's New Frontiers (NF) Design Reference Mission (DRM) in order to evaluate current and future SEP technologies. The results show that transfer times range from 5 to 9 years (depending on the mission). More importantly, the spacecraft's primary propulsion system performs an average 5-degree plane change on the return leg of the CSSR mission to meet the previously mentioned Earth entry velocity constraint. Consequently, these analyses show that SEP technologies that have higher thrust-to-power ratios can: 1) reduce flight time, and 2) change planes more efficiently.

  19. A primitive therizinosauroid dinosaur from the Early Cretaceous of Utah.

    PubMed

    Kirkland, James I; Zanno, Lindsay E; Sampson, Scott D; Clark, James M; DeBlieux, Donald D

    2005-05-01

    Therizinosauroids are an enigmatic group of dinosaurs known mostly from the Cretaceous period of Asia, whose derived members are characterized by elongate necks, laterally expanded pelves, small, leaf-shaped teeth, edentulous rostra and mandibular symphyses that probably bore keratinized beaks. Although more than a dozen therizinosauroid taxa are known, their relationships within Dinosauria have remained controversial because of fragmentary remains and an unusual suite of characters. The recently discovered 'feathered' therizinosauroid Beipiaosaurus from the Early Cretaceous of China helped to clarify the theropod affinities of the group. However, Beipiaosaurus is also poorly represented. Here we describe a new, primitive therizinosauroid from an extensive paucispecific bonebed at the base of the Cedar Mountain Formation (Early Cretaceous) of east-central Utah. This new taxon represents the most complete and most basal therizinosauroid yet discovered. Phylogenetic analysis of coelurosaurian theropods incorporating this taxon places it at the base of the clade Therizinosauroiden, indicating that this species documents the earliest known stage in the poorly understood transition from carnivory to herbivory within Therizinosauroidea. The taxon provides the first documentation, to our knowledge, of therizinosauroids in North America during the Early Cretaceous.

  20. A primitive therizinosauroid dinosaur from the Early Cretaceous of Utah

    USGS Publications Warehouse

    Kirkland, J.I.; Zanno, L.E.; Sampson, S.D.; Clark, J.M.; DeBlieux, D.D.

    2005-01-01

    Therizinosauroids are an enigmatic group of dinosaurs known mostly from the Cretaceous period of Asia, whose derived members are characterized by elongate necks, laterally expanded pelves, small, leaf-shaped teeth, edentulous rostra and mandibular symphyses that probably bore keratinized beaks. Although more than a dozen therizinosauroid taxa are known, their relationships within Dinosauria have remained controversial because of fragmentary remains and an unusual suite of characters. The recently discovered 'feathered' therizinosauroid Beipiaosaurus from the Early Cretaceous of China helped to clarify the theropod affinities of the group. However, Beipiaosaurus is also poorly represented. Here we describe a new, primitive therizinosauroid from an extensive paucispecific bonebed at the base of the Cedar Mountain Formation (Early Cretaceous) of east-central Utah. This new taxon represents the most complete and most basal therizinosauroid yet discovered. Phylogenetic analysis of coelurosaurian theropods incorporating this taxon places it at the base of the clade Therizinosauroiden, indicating that this species documents the earliest known stage in the poorly understood transition from carnivory to herbivory within Therizinosauroidea. The taxon provides the first documentation, to our knowledge, of therizinosauroids in North America during the Early Cretaceous.

  1. Primitive immune systems: are your ways my ways?

    PubMed

    Rinkevich, Baruch

    2004-04-01

    Although vertebrate immune systems have been commonly conceived as exquisitely developed to combat pervasiveness by pathogens, they are not infallible. The enigmatic expression of histocompatibility in vertebrates, the manifestation of natural chimerism, autoimmunity, malignancy, and other puzzling outcomes hint that immunity did not arise in evolution to fight infections and that this capacity is a late evolutionary appendage, owing its appearance to the redeployment of a system developed for other reasons. Allorecognition in the colonial tunicate Botryllus schlosseri serves here as a platform for a contending paradigm, advocating that immunity has developed as a surveillance machinery against and for purging of nascent selfish cells (stemmed from a kin organism or from transformed cells within the organism of origin). Defense against pathogens (always representing xenogeneic aliens) appeared later, revealing the multiplicity of newly developed phenomena. Allorecognition events characteristic of the Botryllus primitive immune system, such as fusion versus rejection, the morphological resorption with its expressed hierarchy, and the somatic/germ-cell parasitic outcomes, provide clues to the evolutionary basis of allorecognition. Recent work on Botryllus immunity that highlights the cost of littering individuality by somatic variants/allogeneic cells is discussed.

  2. Interstellar grains in primitive meteorites - Diamond, silicon carbide, and graphite

    NASA Technical Reports Server (NTRS)

    Anders, Edward; Zinner, Ernst

    1993-01-01

    Primitive meteorites contain a few parts per million (ppm) of pristine interstellar grains that provide information on nuclear and chemical processes in stars. Their interstellar origin is proven by highly anomalous isotopic ratios, varying more than 1000-fold for elements such as C and N. Most grains isolated thus far are stable only under highly reducing conditions (C/O greater than 1), and apparently are 'stardust' formed in stellar atmospheres. Microdiamonds, of median size about 10 A, are most abundant (about 400-1800 ppm) but least understood. They contain anomalous noble gases including Xe-HL, which shows the signature of the r- and p-processes. Silicon carbide, of grain size 0.2-10 microns and abundance about 6 ppm, shows the signature of the s-process and apparently comes mainly from red giant carbon (AGB) stars of 1-3 solar masses. Some grains appear to be not less than 10 exp 9 a older than the solar system. Graphite spherules of grain size 0.8-7 microns and abundance less than 2 ppm contain highly anomalous C and noble gases, as well as large amounts of fossil Mg-26 from the decay of extinct Al-26. They seem to come from at least three sources, probably AGB stars, novae, and Wolf-Rayet stars.

  3. Rapid world modeling: Fitting range data to geometric primitives

    SciTech Connect

    Feddema, J.; Little, C.

    1996-12-31

    For the past seven years, Sandia National Laboratories has been active in the development of robotic systems to help remediate DOE`s waste sites and decommissioned facilities. Some of these facilities have high levels of radioactivity which prevent manual clean-up. Tele-operated and autonomous robotic systems have been envisioned as the only suitable means of removing the radioactive elements. World modeling is defined as the process of creating a numerical geometric model of a real world environment or workspace. This model is often used in robotics to plan robot motions which perform a task while avoiding obstacles. In many applications where the world model does not exist ahead of time, structured lighting, laser range finders, and even acoustical sensors have been used to create three dimensional maps of the environment. These maps consist of thousands of range points which are difficult to handle and interpret. This paper presents a least squares technique for fitting range data to planar and quadric surfaces, including cylinders and ellipsoids. Once fit to these primitive surfaces, the amount of data associated with a surface is greatly reduced up to three orders of magnitude, thus allowing for more rapid handling and analysis of world data.

  4. Peruvoside, a Cardiac Glycoside, Induces Primitive Myeloid Leukemia Cell Death.

    PubMed

    Feng, Qian; Leong, Wa Seng; Liu, Liang; Chan, Wai-In

    2016-01-01

    Despite the available chemotherapy and treatment, leukemia remains a difficult disease to cure due to frequent relapses after treatment. Among the heterogeneous leukemic cells, a rare population referred as the leukemic stem cell (LSC), is thought to be responsible for relapses and drug resistance. Cardiac glycosides (CGs) have been used in treating heart failure despite its toxicity. Recently, increasing evidence has demonstrated its new usage as a potential anti-cancer drug. Ouabain, one of the CGs, specifically targeted CD34⁺CD38(-) leukemic stem-like cells, but not the more mature CD34⁺CD38⁺ leukemic cells, making this type of compounds a potential treatment for leukemia. In search of other potential anti-leukemia CGs, we found that Peruvoside, a less studied CG, is more effective than Ouabain and Digitoxin at inducing cell death in primitive myeloid leukemia cells without obvious cytotoxicity on normal blood cells. Similar to Ouabain and Digitoxin, Peruvoside also caused cell cycle arrest at G₂/M stage. It up-regulates CDKN1A expression and activated the cleavage of Caspase 3, 8 and PARP, resulting in apoptosis. Thus, Peruvoside showed potent anti-leukemia effect, which may serve as a new anti-leukemia agent in the future. PMID:27110755

  5. A simple physical mechanism enables homeostasis in primitive cells

    PubMed Central

    Engelhart, Aaron E.; Adamala, Katarzyna; Szostak, Jack W.

    2016-01-01

    The emergence of homeostatic mechanisms that enabled maintenance of an intracellular steady-state during growth was critical to the advent of cellular life. Here, we show that concentration-dependent reversible binding of short oligonucleotides, of both specific and random sequence, can modulate ribozyme activity. In both cases, catalysis is inhibited at high concentrations, and dilution activates the ribozyme via inhibitor dissociation, thus maintaining near-constant ribozyme specific activity throughout protocell growth. To mimic the result of RNA synthesis within non-growing protocells, we co-encapsulated high concentrations of ribozyme and oligonucleotides within fatty acid vesicles; ribozyme activity was inhibited. Following vesicle growth, the resulting internal dilution produced ribozyme activation. This simple physical system enables a primitive homeostatic behavior: the maintenance of constant ribozyme activity per unit volume during protocell volume changes. We suggest such systems, wherein short oligonucleotides reversibly inhibit functional RNAs, could have preceded sophisticated modern RNA regulatory mechanisms, such as those involving miRNAs. PMID:27102678

  6. An artificial primitive mimic of the Gramicidin-A channel.

    PubMed

    Barboiu, Mihail; Le Duc, Yann; Gilles, Arnaud; Cazade, Pierre-André; Michau, Mathieu; Marie Legrand, Yves; van der Lee, Arie; Coasne, Benoît; Parvizi, Paria; Post, Joshua; Fyles, Thomas

    2014-06-26

    Gramicidin A (gA) is the simplest known natural channel, and important progress in improving conduction activity has previously been obtained with modified natural gAs. However, simple artificial systems mimicking the gA functions are unknown. Here we show that gA can be mimicked using a simple synthetic triazole or 'T-channel' forming compound (TCT), having similar constitutional functions as the natural gAs. As in gA channels, the carbonyl moieties of the TCT, which point toward the T-channel core and surround the transport direction, are solvated by water. The net-dipolar alignment of water molecules along the chiral pore surfaces influences the conduction of protons/ions, envisioned to diffuse along dipolar hydrophilic pathways. Theoretical simulations and experimental assays reveal that the conduction through the T-channel, similar to that in gA, presents proton/water conduction, cation/anion selectivity and large open channel-conductance states. T-channels--associating supramolecular chirality with dipolar water alignment--represent an artificial primitive mimic of gA.

  7. Sr-Pb isotopic studies of primitive and near-primitive basaltic magmas, Garibaldi volcanic belt, northern Cascadia subduction system

    NASA Astrophysics Data System (ADS)

    Green, N. L.; Sinha, A. K.

    2003-12-01

    The northern Cascadia subduction system is intimately associated with aseismic subduction of extremely young and presumably `hot' oceanic lithosphere beneath northwestern Washington and southwestern British Columbia. Sr and Pb isotopic analyses are presented for primitive and near-primitive (>6.0 wt. % MgO) basalts from a southeast-northwest transect along the Garibaldi volcanic belt (GVB), which overlies subducted oceanic lithosphere that decreases in age from ca. 22 m.y. below Glacier Peak at its southern end to about 13 m.y. beneath the northernmost eruptive centers in the Mosaic (Meager Mountain) and Salal Glacier-Bridge River areas. The basaltic rocks have initial 87Sr/86Sr ratios of 0.70317-0.70426, with minimum observed values in individual lava suites decreasing northward. Values of Pb isotopic ratios for GVB basaltic suites range from 18.22 to 18.97 for 206Pb/204Pb, from 15.51 to 15.59 for 207Pb/204Pb, and from 37.73 to 38.49 for 208Pb/204Pb. Sr isotopic compositions, unsupported by lava Rb contents, show positive correlations with Cs/Rb, La/Nb, Ba/La, Ba/Nb, Ba/Ta, B/La, B/Zr, Sr/Nd, and primitive mantle normalized Sr/P; and negative correlations with high field strength elements (HFSE: Nb, and Ta), FeO and other transition metals (Co and Zn), Ce/Pb,Cr/Ni, Sm/Yb, Ta/Yb, Hf/Yb, K/Ba, K/Sr, and La/Yb. Moderate to strong correlations between 87Sr/86Sr and ratios involving fluid-mobile and less-fluid-mobile elements are compatible with decreased slab input northward along the volcanic front as the subducted plate becomes hotter. The Pb isotopic compositions exhibit only limited variations when examined against position along the volcanic arc, but show uniform to extremely weak positive correlations of 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb with 87Sr/86Sr, Ba/La, Sr/Nd, Ba/Nb, Zr/Nb, Mg-Number and SiO2; and similarly weak negative correlation of Ce/Pb with 206Pb/204Pb and 207Pb/204Pb. The isotopic data suggest that GVB basaltic magmas have experienced with

  8. Biophysical characterization of hematopoietic cells from normal and leukemic sources with distinct primitiveness

    NASA Astrophysics Data System (ADS)

    Tan, Youhua; Fung, Tsz-Kan; Wan, Haixia; Wang, Kaiqun; Leung, Anskar Y. H.; Sun, Dong

    2011-08-01

    This letter reported the biophysical characterization of immunophenotypically distinct hematopoietic cells from normal and leukemic sources, through manipulation with optical tweezers at single cell level. The results show that the percentage of cells that are stretchable and their deformability are significantly higher in the more primitive cell populations. This study provides the evidence that normal and leukemic hematopoietic cell populations with distinct primitiveness exhibit differential biophysical properties. These findings raise a hypothesis that the high deformability may be related to the unique functions and activities of primitive hematopoietic cells.

  9. Peripherally induced oromandibular dystonia

    PubMed Central

    Sankhla, C.; Lai, E.; Jankovic, J.

    1998-01-01

    OBJECTIVES—Oromandibular dystonia (OMD) is a focal dystonia manifested by involuntary muscle contractions producing repetitive, patterned mouth, jaw, and tongue movements. Dystonia is usually idiopathic (primary), but in some cases it follows peripheral injury. Peripherally induced cervical and limb dystonia is well recognised, and the aim of this study was to characterise peripherally induced OMD.
METHODS—The following inclusion criteria were used for peripherally induced OMD: (1) the onset of the dystonia was within a few days or months (up to 1 year) after the injury; (2) the trauma was well documented by the patient's history or a review of their medical and dental records; and (3) the onset of dystonia was anatomically related to the site of injury (facial and oral).
RESULTS—Twenty seven patients were identified in the database with OMD, temporally and anatomically related to prior injury or surgery. No additional precipitant other than trauma could be detected. None of the patients had any litigation pending. The mean age at onset was 50.11 (SD 14.15) (range 23-74) years and there was a 2:1 female preponderance. Mean latency between the initial trauma and the onset of OMD was 65 days (range 1 day-1 year). Ten (37%) patients had some evidence of predisposing factors such as family history of movement disorders, prior exposure to neuroleptic drugs, and associated dystonia affecting other regions or essential tremor. When compared with 21 patients with primary OMD, there was no difference for age at onset, female preponderance, and phenomenology. The frequency of dystonic writer's cramp, spasmodic dysphonia, bruxism, essential tremor, and family history of movement disorder, however, was lower in the post-traumatic group (p<0.05). In both groups the response to botulinum toxin treatment was superior to medical therapy (p<0.005). Surgical intervention for temporomandibular disorders was more frequent in the post-traumatic group and was associated with

  10. Melting the hydrous, subarc mantle: the origin of primitive andesites

    NASA Astrophysics Data System (ADS)

    Mitchell, Alexandra L.; Grove, Timothy L.

    2015-08-01

    This experimental study is the first comprehensive investigation of the melting behavior of an olivine + orthopyroxene ± spinel—bearing fertile mantle (FM) composition as a function of variable pressure and water content. The fertile composition was enriched with a metasomatic slab component of ≤0.5 % alkalis and investigated from 1135 to 1470 °C at 1.0-2.0 GPa. A depleted lherzolite with 0.4 % alkali addition was also studied from 1225 to 1240 °C at 1.2 GPa. Melts of both compositions were water-undersaturated: fertile lherzolite melts contained 0-6.4 wt% H2O, and depleted lherzolite melts contained ~2.5 wt% H2O. H2O contents of experimental glasses are measured using electron microprobe, secondary ion mass spectrometry, and synchrotron-source reflection Fourier transform infrared spectroscopy, a novel technique for analyzing H2O in petrologic experiments. Using this new dataset in conjunction with results from previous hydrous experimental studies, a thermobarometer and a hygrometer-thermometer are presented to determine the conditions under which primitive lavas were last in equilibration with the mantle. These predictive models are functions of H2O content and pressure, respectively. A predictive melting model is also presented that calculates melt compositions in equilibrium with an olivine + orthopyroxene ± spinel residual assemblage (harzburgite). This model quantitatively predicts the following influences of H2O on mantle lherzolite melting: (1) As melting pressure increases, melt compositions become more olivine-normative, (2) as melting extent increases, melt compositions become depleted in the normative plagioclase component, and (3) as melt H2O content increases, melts become more quartz-normative. Natural high-Mg# [molar Mg/(Mg + Fe2+)], high-MgO basaltic andesite and andesite lavas—or primitive andesites (PAs)—contain high SiO2 contents at mantle-equilibrated Mg#s. Their compositional characteristics cannot be readily explained by melting

  11. Morphological and quantitative studies in the otic region of the neural tube in chick embryos suggest a neuroectodermal origin for the otic placode

    PubMed Central

    MAYORDOMO, RAQUEL; RODRÍGUEZ-GALLARDO, LUCÍA; ALVAREZ, IGNACIO S.

    1998-01-01

    Careful histological observation of the development of the anlage of the inner ear in chicken embryos led us to question the traditional view of otic placode (OP) formation. First, morphological studies in the cephalic region carried out on stages preceding the appearance of the placodal epithelium revealed that the medial placodal cells are continuous temporally and spatially with cells belonging to the neural fold (NF). Second, both the formation of the basal lamina between the dorsal region of the neural tube (NT) and ectoderm and the pattern of formation of the neural crest present distinctive characteristics between otic levels and regions located anteriorly and posteriorly. Third, numerical comparisons of parameters for the NT and the OP between different levels of the rhombencephalon allowed us to assign a differential behaviour in the growth pattern of the otic region. These results indicated that the medial part of the OP is not derived from already independent ectoderm that increases in thickness under the influence of the NT (as previously accepted) but that it develops directly from the NFs. Although we do not exclude other possibilities, we propose that at least a proportion of the OP cells originate directly from cells committed to be neural crest. After this incorporation, basal laminal formation would delimit the NT from the OP without transition of the otic cells to ectoderm. This hypothesis would imply that part of the otic cells originate directly from neuroepithelial cells having a neuroectodermal (rather than the previously established ectodermal) origin. PMID:9758135

  12. The role of H1 linker histone subtypes in preserving the fidelity of elaboration of mesendodermal and neuroectodermal lineages during embryonic development.

    PubMed

    Nguyen, Giang D; Gokhan, Solen; Molero, Aldrin E; Yang, Seung-Min; Kim, Byung-Ju; Skoultchi, Arthur I; Mehler, Mark F

    2014-01-01

    H1 linker histone proteins are essential for the structural and functional integrity of chromatin and for the fidelity of additional epigenetic modifications. Deletion of H1c, H1d and H1e in mice leads to embryonic lethality by mid-gestation with a broad spectrum of developmental alterations. To elucidate the cellular and molecular mechanisms underlying H1 linker histone developmental functions, we analyzed embryonic stem cells (ESCs) depleted of H1c, H1d and H1e subtypes (H1-KO ESCs) by utilizing established ESC differentiation paradigms. Our study revealed that although H1-KO ESCs continued to express core pluripotency genes and the embryonic stem cell markers, alkaline phosphatase and SSEA1, they exhibited enhanced cell death during embryoid body formation and during specification of mesendoderm and neuroectoderm. In addition, we demonstrated deregulation in the developmental programs of cardiomyocyte, hepatic and pancreatic lineage elaboration. Moreover, ectopic neurogenesis and cardiomyogenesis occurred during endoderm-derived pancreatic but not hepatic differentiation. Furthermore, neural differentiation paradigms revealed selective impairments in the specification and maturation of glutamatergic and dopaminergic neurons with accelerated maturation of glial lineages. These impairments were associated with deregulation in the expression profiles of pro-neural genes in dorsal and ventral forebrain-derived neural stem cell species. Taken together, these experimental observations suggest that H1 linker histone proteins are critical for the specification, maturation and fidelity of organ-specific cellular lineages derived from the three cardinal germ layers.

  13. Transient expression of an intermediate filament-associated protein (IFAPa-400) during in vivo and in vitro differentiation of chick embryonic cells derived from neuroectoderm.

    PubMed

    Chabot, P; Vincent, M

    1990-07-01

    The expression of an intermediate filament (IF) associated protein (IFAPa-400) and IF proteins was investigated during chick neurogenesis. Using immunoblots and indirect immunofluorescence we have found that IFAPa-400 was strongly expressed during the early events of nervous tissue ontogenesis and disappeared thereafter. IFAPa-400 was elevated in the brain and retina until ED 10 and until hatching in the cerebellum. This protein was shown to be transiently expressed in the Müller glia of the developing retina. In the brain, IFAPa-400 decreased as development proceeded in a way similar to vimentin but the latter remained elevated in the retina and the cerebellum radial glia (Müller and Bergmann cells). In all tissues examined, GFAP was detected long after the disappearance of IFAPa-400. In dorsal root ganglion cell cultures, IFAPa-400 and vimentin were absent from mature neurons but were coexpressed into supportive cells. In trunk neural crest cell cultures, IFAPa-400 and vimentin were present in all cells after one day but IFAPa-400 became undetectable after a few days of culture in differentiated melanocytes and catecholaminergic neurons. The transient expression of this giant cytoskeletal protein in non-differentiated cells deriving from the neuroectoderm could reflect a structural change which precedes overt cytodifferentiation.

  14. Wall boundary model for primitive chain network simulations

    NASA Astrophysics Data System (ADS)

    Okuda, Satoru; Inoue, Yasuhiro; Masubuchi, Yuichi; Uneyama, Takasi; Hojo, Masaki

    2009-06-01

    In condensed polymeric liquids confined in slit channels, the movement of chains is constrained by two factors: entanglement among the chains and the excluded volume between the chains and the wall. In this study, we propose a wall boundary (WB) model for the primitive chain network (PCN) model, which describes the dynamics of polymer chains in bulk based on coarse graining upon the characteristic molecular weight of the entanglement. The proposed WB model is based on the assumptions that (i) polymers are not stuck but simply reflected randomly by the wall, and (ii) subchains below the entanglement length scale behave like those in bulk even near the wall. Using the WB model, we simulate the dynamics of entangled polymer chains confined in slit channels. The results show that as the slit narrows, the chains are compressed in the direction normal to the wall, while they are expanded in the parallel direction. In addition, the relaxation time of the end-to-end vector increases, and the diffusivity of the center of mass decreases. The compression in the normal direction is a natural effect of confinement, while the expansion is introduced by a hooking process near the wall. The trends revealed that the relaxation time and diffusivity depend on the increase in friction due to an increased number of entanglements near the wall, which is also associated with the hooking process in the PCN model. These results are expected within the assumptions of the PCN model. Thus, the proposed WB model can successfully reproduce the effects of wall confinement on chains.

  15. The colors of cometary nuclei and other primitive bodies

    NASA Astrophysics Data System (ADS)

    Toth, I.; Lamy, P. L.

    2005-12-01

    Primitive minor objects like Kuiper-belt objects (KBOs), Centaurs, cometary nuclei and low-albedo asteroids contain a considerable amount of information regarding the formation of early solar system planetesimals and some of the primordial processes. Broadband colors by themselves offer limited insight into surface composition but correlations either between different color indices or with other (e.g., orbital) parameters can shed some light on the questions of the composition and the evolution of the minor objects. Furthermore, a systematic comparison of the color indices of various populations may provide clues on their relationships, and concur along with dynamical studies, to establish a scenario of their formation and evolution in the solar system. We present new color results on cometary nuclei obtained with the Hubble Space Telescope (HST) whose superior resolution enables us to accurately isolate the nucleus signals from the surrounding comae. By combining with scrutinized available data obtained with ground-based telescopes, we accumulated a sample of 39 cometary nuclei, 34 ecliptic comets (ECs) and 5 nearly-isotropic comets (NICs) using the nomenclature of Levison (1996). We analyze color distributions and color-color correlations as well as correlations with other physical parameters. We present our own compilation of colors of 282 objects in the outer solar system, separately considering the different dynamical populations, classical KBOs in low and high-inclination orbits, resonant KBOs (practically Plutinos), scattered-disk objects (SDOs) and Centaurs. We perform a systematic analysis of color distributions of all plausible parent-child combinations and conclude by synthesizing the implications of the colors for the origin of ecliptic comets. We acknowledge the support of the French "Programme National de Planétologie", jointly funded by CNRS and CNES, and of the bilateral French--Hungarian cooperation program. I. Toth further acknowledges the

  16. An extremely primitive star in the Galactic halo.

    PubMed

    Caffau, Elisabetta; Bonifacio, Piercarlo; François, Patrick; Sbordone, Luca; Monaco, Lorenzo; Spite, Monique; Spite, François; Ludwig, Hans-G; Cayrel, Roger; Zaggia, Simone; Hammer, François; Randich, Sofia; Molaro, Paolo; Hill, Vanessa

    2011-09-01

    The early Universe had a chemical composition consisting of hydrogen, helium and traces of lithium; almost all other elements were subsequently created in stars and supernovae. The mass fraction of elements more massive than helium, Z, is known as 'metallicity'. A number of very metal-poor stars has been found, some of which have a low iron abundance but are rich in carbon, nitrogen and oxygen. For theoretical reasons and because of an observed absence of stars with Z < 1.5 × 10(-5), it has been suggested that low-mass stars cannot form from the primitive interstellar medium until it has been enriched above a critical value of Z, estimated to lie in the range 1.5 × 10(-8) to 1.5 × 10(-6) (ref. 8), although competing theories claiming the contrary do exist. (We use 'low-mass' here to mean a stellar mass of less than 0.8 solar masses, the stars that survive to the present day.) Here we report the chemical composition of a star in the Galactic halo with a very low Z (≤ 6.9 × 10(-7), which is 4.5 × 10(-5) times that of the Sun) and a chemical pattern typical of classical extremely metal-poor stars--that is, without enrichment of carbon, nitrogen and oxygen. This shows that low-mass stars can be formed at very low metallicity, that is, below the critical value of Z. Lithium is not detected, suggesting a low-metallicity extension of the previously observed trend in lithium depletion. Such lithium depletion implies that the stellar material must have experienced temperatures above two million kelvin in its history, given that this is necessary to destroy lithium. PMID:21886158

  17. Deep Interior: Probing the Structure of Primitive Bodies

    NASA Astrophysics Data System (ADS)

    Asphaug, Erik; Scheeres, Daniel; Safaeinili, Ali

    Deep Interior is a mature Discovery-class mission concept focused on probing the geophysical behavior of primitive bodies, from the mechanics of their exterior materials to the structures of their interiors. Its theme is to discover how small bodies work - to learn the natural origin and evolution of asteroids, comets and other primitive bodies through radar reflection tomography and through detailed observations of the local and global effects of cratering. Learning the structure and mechanical response of asteroids and comets is also a precursor to resource utilization and hazardous asteroid mitigation. Overall the mission is aligned with NASA strategic sub-goal 3C, to advance scientific knowledge of the origin and history of the solar system ... and the hazards and resources present as humans explore space. Deep Interior deploys no complex landers or sub-spacecraft; the scientific instruments are a radar and a camera. A blast cratering experiments triggered by grenades leads to a low cost seismological investigation which complements the radar investigation. A desired addition is an imaging spectrometer. The science instruments are high heritage, as are the navigation techniques for orbiting and station-keeping. The mission conducts the following investigations at one or more asteroids: Radar Reflection Tomography (RRT). The first science phase is to operate a penetrating radar during each several-month rendezvous, deployed in reflection mode in the manner of ongoing radar investigations underway by Mars Express, Mars Reconnaissance Orbiter, and Kaguya. The RRT technique (Safaeinili et al., MAPS 2002) is analogous to performing a "CAT scan" from orbit: closely sampled radar echoes are processed to yield volumetric maps of mechanical and compositional boundaries, and to measure interior dielectric properties. Deep Interior utilizes a polar orbit (or station keeping) while the asteroid spins underneath; the result is to "peel the apple" with thousands of unique

  18. Peripheral venous contrast echocardiography.

    PubMed

    Seward, J B; Tajik, A J; Hagler, D J; Ritter, D G

    1977-02-01

    Contrast echocardiography is the technique of injecting various echo-producing agents into the bloodstream and, with standard echocardiographic techniques, observing the blood flow patterns as revealed by the resulting cloud of echoes. These techniques have only recently been utilized to evaluate various cardiac defects. Two physical properties of these agents characterize their usefulness: (1) clouds of echoes can be observed downstream as well as at the injection site, and (2) the echo-producing quality of these agents is completely lost with a single transit through either the pulmonary or the systemic capillary bed. Thus, detection of resultant echoes in both the venous and the arterial blood pool is indicative of abnormal shunting. In 60 patients with a spectrum of cardiac defects and a wide range in age of presentation, studies were made of (1) the feasibility of performing contrast echocardiography with superficial peripheral venous injections, and (2) the clinical usefulness of this relatively noninvasive technique in detecting and localizing intracardiac right ot left shunting. Most superficial peripheral veins could be utilized, and the resultant contrast echograms were reproducible and similar in quality to those obtained more central (caval) injections. Right to left shunts could be localized in the atrial, ventricular or intrapulmonary level. Characteristic flow patterns were also recognized for tricuspid atresia and common ventricle.

  19. Coordinated Analyses of Hydrated Interplanetary Dust Particles: Samples of Primitive Solar System Bodies

    NASA Astrophysics Data System (ADS)

    Keller, L. P.; Snead, C. J.; McKeegan, K. D.

    2016-08-01

    The unusual oxygen isotopic compositions and high C contents suggest that hydrated IDPs are derived from primitive sources not yet represented in meteorite collections such as outer main belt P- and D-type asteroids or possibly comets.

  20. Une angiocholite secondaire à un thrombus tumoral d'une tumeur neuroendocrine primitive du foie

    PubMed Central

    Baba, Hicham; Allaoui, Mohamed; Elfahssi, Mohammed; Bounaim, Ahmed; Ali, Abdelmounaim Ait; Oukabli, Mohamed; Sair, Khalid; Zentar, Aziz

    2015-01-01

    Nous rapportons le cas exceptionnel d'une patiente de 54 ans prise en charge pour une angiocholite due à un thrombus tumoral, d'une tumeur neuroendocrine primitive (TNE Ive) du foie, dans la voie biliaire principale. PMID:26966504

  1. Peripheral nerve response to injury.

    PubMed

    Steed, Martin B

    2011-03-01

    Oral and maxillofacial surgeons caring for patients who have sustained a nerve injury to a branch of the peripheral trigeminal nerve must possess a basic understanding of the response of the peripheral nerves to trauma. The series of events that subsequently take place are largely dependent on the injury type and severity. Regeneration of the peripheral nerve is possible in many instances and future manipulation of the regenerative microenvironment will lead to advances in the management of these difficult injuries.

  2. Peripheral vision displays: The future

    NASA Technical Reports Server (NTRS)

    Assenhein, H. M.

    1984-01-01

    Several areas of research relating to peripheral vision displays used by aircraft pilots are outlined: fiber optics, display color, and holography. Various capacities and specifications of gas and solid state lasers are enumerated. These lasers are potential sources of green light for the peripheral vision displays. The relative radiance required for rod and cone vision at different wavelengths is presented graphically. Calculated and measured retinal sensitivities (foveal and peripheral) are given for wavelength produced by various lasers.

  3. A primitive caprine from the Upper Vallesian of La Roma 2 (Alfambra, Teruel, Aragon, Spain)

    NASA Astrophysics Data System (ADS)

    Alcalá, Luis; Morales, Jorge

    1997-06-01

    We describe a new caprine form from the Upper Vallesian of La Roma 2 (Teruel Basin, Aragon). Aragoral mudejar Gen.n., sp.n. is close to the primitive forms of the Hippotraginae-Caprinae group. It differs from Norbertia hellenica by its more primitive dentition, the greater separation between the bases of the horn cores, the decreased thickness of the frontal bone and the relatively smaller size of the horn cores.

  4. Primitive fitting based on the efficient multiBaySAC algorithm.

    PubMed

    Kang, Zhizhong; Li, Zhen

    2015-01-01

    Although RANSAC is proven to be robust, the original RANSAC algorithm selects hypothesis sets at random, generating numerous iterations and high computational costs because many hypothesis sets are contaminated with outliers. This paper presents a conditional sampling method, multiBaySAC (Bayes SAmple Consensus), that fuses the BaySAC algorithm with candidate model parameters statistical testing for unorganized 3D point clouds to fit multiple primitives. This paper first presents a statistical testing algorithm for a candidate model parameter histogram to detect potential primitives. As the detected initial primitives were optimized using a parallel strategy rather than a sequential one, every data point in the multiBaySAC algorithm was assigned to multiple prior inlier probabilities for initial multiple primitives. Each prior inlier probability determined the probability that a point belongs to the corresponding primitive. We then implemented in parallel a conditional sampling method: BaySAC. With each iteration of the hypothesis testing process, hypothesis sets with the highest inlier probabilities were selected and verified for the existence of multiple primitives, revealing the fitting for multiple primitives. Moreover, the updated version of the initial probability was implemented based on a memorable form of Bayes' Theorem, which describes the relationship between prior and posterior probabilities of a data point by determining whether the hypothesis set to which a data point belongs is correct. The proposed approach was tested using real and synthetic point clouds. The results show that the proposed multiBaySAC algorithm can achieve a high computational efficiency (averaging 34% higher than the efficiency of the sequential RANSAC method) and fitting accuracy (exhibiting good performance in the intersection of two primitives), whereas the sequential RANSAC framework clearly suffers from over- and under-segmentation problems. Future work will aim at further

  5. Primitive Fitting Based on the Efficient multiBaySAC Algorithm

    PubMed Central

    Kang, Zhizhong; Li, Zhen

    2015-01-01

    Although RANSAC is proven to be robust, the original RANSAC algorithm selects hypothesis sets at random, generating numerous iterations and high computational costs because many hypothesis sets are contaminated with outliers. This paper presents a conditional sampling method, multiBaySAC (Bayes SAmple Consensus), that fuses the BaySAC algorithm with candidate model parameters statistical testing for unorganized 3D point clouds to fit multiple primitives. This paper first presents a statistical testing algorithm for a candidate model parameter histogram to detect potential primitives. As the detected initial primitives were optimized using a parallel strategy rather than a sequential one, every data point in the multiBaySAC algorithm was assigned to multiple prior inlier probabilities for initial multiple primitives. Each prior inlier probability determined the probability that a point belongs to the corresponding primitive. We then implemented in parallel a conditional sampling method: BaySAC. With each iteration of the hypothesis testing process, hypothesis sets with the highest inlier probabilities were selected and verified for the existence of multiple primitives, revealing the fitting for multiple primitives. Moreover, the updated version of the initial probability was implemented based on a memorable form of Bayes’ Theorem, which describes the relationship between prior and posterior probabilities of a data point by determining whether the hypothesis set to which a data point belongs is correct. The proposed approach was tested using real and synthetic point clouds. The results show that the proposed multiBaySAC algorithm can achieve a high computational efficiency (averaging 34% higher than the efficiency of the sequential RANSAC method) and fitting accuracy (exhibiting good performance in the intersection of two primitives), whereas the sequential RANSAC framework clearly suffers from over- and under-segmentation problems. Future work will aim at further

  6. Spatiotemporal mechanical variation reveals critical role for rho kinase during primitive streak morphogenesis.

    PubMed

    Henkels, Julia; Oh, Jaeho; Xu, Wenwei; Owen, Drew; Sulchek, Todd; Zamir, Evan

    2013-02-01

    Large-scale morphogenetic movements during early embryo development are driven by complex changes in biochemical and biophysical factors. Current models for amniote primitive streak morphogenesis and gastrulation take into account numerous genetic pathways but largely ignore the role of mechanical forces. Here, we used atomic force microscopy (AFM) to obtain for the first time precise biomechanical properties of the early avian embryo. Our data reveal that the primitive streak is significantly stiffer than neighboring regions of the epiblast, and that it is stiffer than the pre-primitive streak epiblast. To test our hypothesis that these changes in mechanical properties are due to a localized increase of actomyosin contractility, we inhibited actomyosin contractility via the Rho kinase (ROCK) pathway using the small-molecule inhibitor Y-27632. Our results using several different assays show the following: (1) primitive streak formation was blocked; (2) the time-dependent increase in primitive streak stiffness was abolished; and (3) convergence of epiblast cells to the midline was inhibited. Taken together, our data suggest that actomyosin contractility is necessary for primitive streak morphogenesis, and specifically, ROCK plays a critical role. To better understand the underlying mechanisms of this fundamental process, future models should account for the findings presented in this study.

  7. Inherited peripheral neuropathy.

    PubMed

    Keller, M P; Chance, P F

    1999-01-01

    Hereditary disorders of the peripheral nerves constitute a group of frequently encountered neurological diseases. Charcot-Marie-Tooth neuropathy type 1 (CMT1) is genetically heterogeneous and characterized by demyelination with moderately to severely reduced nerve conduction velocities, absent muscle stretch reflexes and onion bulb formation. Genetic loci for CMT1 map to chromosome 17 (CMT1A), chromosome 1 (CMT1B), and another unknown autosome (CMT1C). CMT1A is most often associated with a tandem 1.5-megabase (Mb) duplication in chromosome 17p11.2-12, or in rare patients may result from a point mutation in the peripheral myelin protein-22 (PMP22) gene. CMT1 B result from point mutations in the myelin protein zero (Po or MPZ) gene. The molecular defect in CMT1 C is unknown. Mutations in the early growth response 2 gene (EGR2) are also associated with demyelinating neuropathy. Other rare forms of demyelinating peripheral neuropathies map to chromosome 8q, 10q, and 11q. X-linked Charcot-Marie-Tooth neuropathy (CMTX), which has clinical features similar to CMT1, is associated with mutations in the connexin32 gene. Charcot-Marie-Tooth neuropathy type 2 (CMT2) is characterized by normal or mildly reduced nerve conduction velocity with decreased amplitude and axonal loss without hypertrophic features. One form of CMT2 maps to chromosome 1 p36 (CMT2A), another to chromosome 3p (CMT2B) and another to 7p (CMT2D). Dejerine-Sottas disease (DSD), also called hereditary motor and sensory neuropathy type III (HMSNIII), is a severe, infantile-onset demyelinating polyneuropathy that may be associated with point mutations in either the PMP22 gene or the Po gene and shares considerable clinical and pathological features with CMT1. Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant disorder that results in a recurrent, episodic demyelinating neuropathy. HNPP is associated with a 1.5-Mb deletion in chromosome 17p11.2-12 and results from reduced

  8. The single dynamin family protein in the primitive protozoan Giardia lamblia is essential for stage conversion and endocytic transport.

    PubMed

    Gaechter, Verena; Schraner, Elisabeth; Wild, Peter; Hehl, Adrian B

    2008-01-01

    Dynamins are universally conserved large guanosine triphosphatases, which function as mechanoenzymes in membrane scission. The primitive protozoan Giardia lamblia has a single dynamin-related protein (GlDRP) with an unusual domain structure. Giardia lacks a Golgi apparatus but generates transient Golgi-like delay compartments dubbed encystation-specific vesicles (ESVs), which serve to accumulate and mature cyst wall proteins during differentiation to infectious cyst forms. Here, we analyze the function of GlDRP during growth and encystation and demonstrate that it relocalizes from peripheral endosomal-lysosomal compartments to nascent ESVs. We show that GlDRP is necessary for secretion of the cyst wall material and ESV homeostasis. Expression of a dominant-negative GlDRP variant does not interfere with ESV formation but blocks cyst formation completely prior to regulated exocytosis. GlDRP colocalizes with clathrin at the cell periphery and is necessary for endocytosis of surface proteins to endosomal-lysosomal organelles in trophozoites. Electron microscopy and live cell imaging reveal gross morphological changes as well as functional impairment of the endocytic system in cells expressing the dominant-negative GlDRP. Thus, giardial DRP plays a key role in two distinct trafficking pathways and in organelle homeostasis, both essential functions for the proliferation of the parasite in the gut and its transmission to a new host. PMID:17892527

  9. Peripheral ameloblastoma: case report.

    PubMed

    Clauser, L; Denes, S; Consorti, G

    2011-09-01

    Ameloblastoma is a benign tumour of the odontogenic tissues which may be aggressive in the involved area with a high rate of recurrence if not adequately removed, and represents 1% of all tumours of the mouth, generally appearing in the bones of the jaw. Although it is fairly rare, tumours with such histopathology have been described in the soft tissue and are named peripheral or extraosseus ameloblastoma. Potential cells of origin are ondontogenic residue of the dental lamina, pluripotent cells in the basal layer of the epithelial mucosa, and pluripotent cells of the minor salivary glands. Seven cases of extraosseus ameloblastoma in the extragengival area, unrelated to dental germs, have been described, six of which in the buccal mucosa and one in the mouth floor. We report a case of extraossous, extragengival ameloblastoma which originated in the subzygomatic area.

  10. Programable Interface Handles Many Peripherals

    NASA Technical Reports Server (NTRS)

    Jasinski, M.

    1982-01-01

    Microprocessor-based interface simplifies interconnection of peripheral device with common memory of network of minicomputers. Interface consists of microprocessor, bidirectional port that connects to common memory, bidirectional port that connects to user-selected peripheral, and asynchronous serial communications port. Programable interface is based around 6800 microprocessor. It is assembled from 90 integrated circuits.

  11. Intrathecal application of neuroectodermally converted stem cells into a mouse model of ALS: limited intraparenchymal migration and survival narrows therapeutic effects.

    PubMed

    Habisch, H-J; Janowski, M; Binder, D; Kuzma-Kozakiewicz, M; Widmann, A; Habich, A; Schwalenstöcker, B; Hermann, A; Brenner, R; Lukomska, B; Domanska-Janik, K; Ludolph, A C; Storch, A

    2007-01-01

    Stem and progenitor cells provide a promising therapeutic strategy for amyotrophic lateral sclerosis (ALS). To comparatively evaluate the therapeutic potentials of human bone marrow-derived mesodermal stromal cells (hMSCs) and umbilical cord blood cells (hUBCs) in ALS, we transplanted hMSCs and hUBCs and their neuroectodermal derivatives (hMSC-NSCs and hUBC-NSCs) into the ALS mouse model over-expressing the G93A mutant of the human SOD1 gene. We used a standardized protocol similar to clinical studies by performing a power calculation to estimate sample size prior to transplantation, matching the treatment groups for gender and hSOD-G93A gene content, and applying a novel method for directly injecting 100,000 cells into the CSF (the cisterna magna). Ten days after transplantation we found many cells within the subarachnoidal space ranging from frontal basal cisterns back to the cisterna magna, but only a few cells around the spinal cord. hMSCs and hMSC-NSCs were also located within the Purkinje cell layer. Intrathecal cell application did not affect survival times of mice compared to controls. Consistently, time of disease onset and first pareses, death weight, and motor neuron count in lumbar spinal cord did not vary between treatment groups. Interestingly, transplantation of hMSCs led to an increase of pre-symptomatic motor performance compared to controls in female animals. The negative outcome of the present study is most likely due to insufficient cell numbers within the affected brain regions (mainly the spinal cord). Further experiments defining the optimal cell dose, time point and route of application and particularly strategies to improve the homing of transplanted cells towards the CNS region of interest are warranted to define the therapeutic potential of mesodermal stem cells for the treatment of ALS.

  12. Peripheral Mechanisms of Itch.

    PubMed

    Azimi, Ehsan; Xia, Jimmy; Lerner, Ethan A

    2016-01-01

    A multitude of exogenous environmental stimuli and endogenous molecular and cellular components interface directly or indirectly with the free nerve endings of sensory nerves in the skin. Environmental stimuli include substances derived from the microbiome and materials, such as allergens, that otherwise come in contact with the skin. Endogenous stimuli include components of or mediators derived from the epidermal barrier, keratinocytes, mast cells, and additional resident and skin-homing immune cells. The sensation of itch is ultimately provoked by mediators that interact with and activate pruriceptors on the sensory nerve fibers. These peripheral fibers convey signals from the skin to the dorsal root and trigeminal ganglia and on to the spinal cord and brain where central processing of the itch sensation occurs. A discussion of the nature and sources of itch stimuli and receptors in the periphery form the basis of this chapter. The development of drugs that target these processes is in the process of revolutionizing therapeutic approaches to itch. PMID:27578066

  13. Epigenetics and Peripheral Artery Disease.

    PubMed

    Golledge, Jonathan; Biros, Erik; Bingley, John; Iyer, Vikram; Krishna, Smriti M

    2016-04-01

    The term epigenetics is usually used to describe inheritable changes in gene function which do not involve changes in the DNA sequence. These typically include non-coding RNAs, DNA methylation and histone modifications. Smoking and older age are recognised risk factors for peripheral artery diseases, such as occlusive lower limb artery disease and abdominal aortic aneurysm, and have been implicated in promoting epigenetic changes. This brief review describes studies that have associated epigenetic factors with peripheral artery diseases and investigations which have examined the effect of epigenetic modifications on the outcome of peripheral artery diseases in mouse models. Investigations have largely focused on microRNAs and have identified a number of circulating microRNAs associated with human peripheral artery diseases. Upregulating or antagonising a number of microRNAs has also been reported to limit aortic aneurysm development and hind limb ischemia in mouse models. The importance of DNA methylation and histone modifications in peripheral artery disease has been relatively little studied. Whether circulating microRNAs can be used to assist identification of patients with peripheral artery diseases and be modified in order to improve the outcome of peripheral artery disease will require further investigation.

  14. Identifying and modeling motion primitives for the hydromedusae Sarsia tubulosa and Aequorea victoria.

    PubMed

    Sledge, Isaac; Krieg, Michael; Lipinski, Doug; Mohseni, Kamran

    2015-12-01

    The movements of organisms can be thought of as aggregations of motion primitives: motion segments containing one or more significant actions. Here, we present a means to identify and characterize motion primitives from recorded movement data. We address these problems by assuming that the motion sequences can be characterized as a series of dynamical-system-based pattern generators. By adopting a nonparametric, Bayesian formalism for learning and simplifying these pattern generators, we arrive at a purely data-driven model to automatically identify breakpoints in the movement sequences. We apply this model to swimming sequences from two hydromedusa. The first hydromedusa is the prolate Sarsia tubulosa, for which we obtain five motion primitives that correspond to bell cavity pressurization, jet formation, jetting, cavity fluid refill, and coasting. The second hydromedusa is the oblate Aequorea victoria, for which we obtain five motion primitives that correspond to bell compression, vortex separation, cavity fluid refill, vortex formation, and coasting. Our experimental results indicate that the breakpoints between primitives are correlated with transitions in the bell geometry, vortex formation and shedding, and changes in derived dynamical quantities. These dynamics quantities include terms like pressure, power, drag, and thrust. Such findings suggest that dynamics information is inherently present in the observed motions. PMID:26495992

  15. The Primitive Endoderm Segregates from the Epiblast in β1 Integrin-Deficient Early Mouse Embryos

    PubMed Central

    Moore, Robert; Tao, Wensi; Smith, Elizabeth R.

    2014-01-01

    We analyzed the mechanism of developmental failure in implanted β1 integrin-null blastocysts and found that primitive endoderm cells are present but segregate away from, instead of forming an epithelial layer covering, the inner cell mass. This cell segregation phenotype was also reproduced in β1 integrin-null embryoid bodies, in which primitive endoderm cells segregated and appeared as miniature aggregates detached from the core spheroids, and a primitive endoderm layer failed to form on the surface. Restricted β1 integrin gene deletion in embryos using Ttr-Cre or Sox2-Cre indicated that the loss of integrin function in the cells of the inner core rather than the outer layer is responsible for the failure to form a primitive endoderm layer. We conclude that β1 integrin is essential for the attachment of the primitive endoderm layer to the epiblast during the formation of a basement membrane, a process concurrent with the transition from cadherin- to integrin-mediated cell adhesion. PMID:24277939

  16. Balanced motor primitive can explain generalization of motor learning effects between unimanual and bimanual movements

    PubMed Central

    Takiyama, Ken; Sakai, Yutaka

    2016-01-01

    Motor learning in unimanual and bimanual planar reaching movements has been intensively investigated. Although distinct theoretical frameworks have been proposed for each of these reaching movements, the relationship between these movements remains unclear. In particular, the generalization of motor learning effects (transfer of learning effects) between unimanual and bimanual movements has yet to be successfully explained. Here, by extending a motor primitive framework, we analytically proved that the motor primitive framework can reproduce the generalization of learning effects between unimanual and bimanual movements if the mean activity of each primitive for unimanual movements is balanced to the mean for bimanual movements. In this balanced condition, the activity of each primitive is consistent with previously reported neuronal activity. The unimanual-bimanual balance leads to the testable prediction that generalization between unimanual and bimanual movements is more widespread to different reaching directions than generalization within respective movements. Furthermore, the balanced motor primitive can reproduce another previously reported phenomenon: the learning of different force fields for unimanual and bimanual movements. PMID:27025168

  17. Intrapartum Synthetic Oxytocin Reduce the Expression of Primitive Reflexes Associated with Breastfeeding

    PubMed Central

    Olza Fernández, Ibone; Malalana Martínez, Ana M.; González Armengod, Carmen; Costarelli, Valeria; Millán Santos, Isabel; Fernández-Cañadas Morillo, Aurora; Pérez Riveiro, Pilar; López Sánchez, Francisco; García Murillo, Lourdes

    2015-01-01

    Abstract Aim: Several synthetic peptide manipulations during the time surrounding birth can alter the specific neurohormonal status in the newborn brain. This study is aimed at assessing whether intrapartum oxytocin administration has any effect on primitive neonatal reflexes and determining whether such an effect is dose-dependent. Materials and Methods: A cohort prospective study was conducted at a tertiary hospital. Mother–infant dyads who received intrapartum oxytocin (n=53) were compared with mother–infant dyads who did not receive intrapartum oxytocin (n=45). Primitive neonatal reflexes (endogenous, antigravity, motor, and rhythmic reflexes) were quantified by analyzing videotaped breastfeeding sessions in a biological nurturing position. Two observers blind to the group assignment and the oxytocin dose analyzed the videotapes and assesed the newborn's state of consciousness according to the Brazelton scale. Results: The release of all rhythmic reflexes (p=0.01), the antigravity reflex (p=0.04), and total primitive neonatal reflexes (p=0.02) in the group exposed to oxytocin was lower than in the group not exposed to oxytocin. No correlations were observed between the dose of oxytocin administered and the percentage of primitive neonatal reflexes released (r=0.03; p=0.82). Conclusions: Intrapartum oxytocin administration might inhibit the expression of several primitive neonatal reflexes associated with breastfeeding. This correlation does not seem to be dose-dependent. PMID:25785487

  18. Boolean operations with implicit and parametric representation of primitives using R-functions.

    PubMed

    Fougerolle, Yohan D; Gribok, Andrei; Foufou, Sebti; Truchetet, Frédéric; Abidi, Mongi A

    2005-01-01

    We present a new and efficient algorithm to accurately polygonize an implicit surface generated by multiple Boolean operations with globally deformed primitives. Our algorithm is special in the sense that it can be applied to objects with both an implicit and a parametric representation, such as superquadrics, supershapes, and Dupin cyclides. The input is a Constructive Solid Geometry tree (CSG tree) that contains the Boolean operations, the parameters of the primitives, and the global deformations. At each node of the CSG tree, the implicit formulations of the subtrees are used to quickly determine the parts to be transmitted to the parent node, while the primitives' parametric definition are used to refine an intermediary mesh around the intersection curves. The output is both an implicit equation and a mesh representing its solution. For the resulting object, an implicit equation with guaranteed differential properties is obtained by simple combinations of the primitives' implicit equations using R-functions. Depending on the chosen R-function, this equation is continuous and can be differentiable everywhere. The primitives' parametric representations are used to directly polygonize the resulting surface by generating vertices that belong exactly to the zero-set of the resulting implicit equation. The proposed approach has many potential applications, ranging from mechanical engineering to shape recognition and data compression. Examples of complex objects are presented and commented on to show the potential of our approach for shape modeling.

  19. Distinct Wnt-driven primitive streak-like populations reflect in vivo lineage precursors

    PubMed Central

    Tsakiridis, Anestis; Huang, Yali; Blin, Guillaume; Skylaki, Stavroula; Wymeersch, Filip; Osorno, Rodrigo; Economou, Costas; Karagianni, Eleni; Zhao, Suling; Lowell, Sally; Wilson, Valerie

    2014-01-01

    During gastrulation, epiblast cells are pluripotent and their fate is thought to be constrained principally by their position. Cell fate is progressively restricted by localised signalling cues from areas including the primitive streak. However, it is unknown whether this restriction accompanies, at the individual cell level, a reduction in potency. Investigation of these early transition events in vitro is possible via the use of epiblast stem cells (EpiSCs), self-renewing pluripotent cell lines equivalent to the postimplantation epiblast. Strikingly, mouse EpiSCs express gastrulation stage regional markers in self-renewing conditions. Here, we examined the differentiation potential of cells expressing such lineage markers. We show that undifferentiated EpiSC cultures contain a major subfraction of cells with reversible early primitive streak characteristics, which is mutually exclusive to a neural-like fraction. Using in vitro differentiation assays and embryo grafting we demonstrate that primitive streak-like EpiSCs are biased towards mesoderm and endoderm fates while retaining pluripotency. The acquisition of primitive streak characteristics by self-renewing EpiSCs is mediated by endogenous Wnt signalling. Elevation of Wnt activity promotes restriction towards primitive streak-associated lineages with mesendodermal and neuromesodermal characteristics. Collectively, our data suggest that EpiSC pluripotency encompasses a range of reversible lineage-biased states reflecting the birth of pioneer lineage precursors from a pool of uncommitted EpiSCs similar to the earliest cell fate restriction events taking place in the gastrula stage epiblast. PMID:24595287

  20. Identifying and modeling motion primitives for the hydromedusae Sarsia tubulosa and Aequorea victoria.

    PubMed

    Sledge, Isaac; Krieg, Michael; Lipinski, Doug; Mohseni, Kamran

    2015-10-23

    The movements of organisms can be thought of as aggregations of motion primitives: motion segments containing one or more significant actions. Here, we present a means to identify and characterize motion primitives from recorded movement data. We address these problems by assuming that the motion sequences can be characterized as a series of dynamical-system-based pattern generators. By adopting a nonparametric, Bayesian formalism for learning and simplifying these pattern generators, we arrive at a purely data-driven model to automatically identify breakpoints in the movement sequences. We apply this model to swimming sequences from two hydromedusa. The first hydromedusa is the prolate Sarsia tubulosa, for which we obtain five motion primitives that correspond to bell cavity pressurization, jet formation, jetting, cavity fluid refill, and coasting. The second hydromedusa is the oblate Aequorea victoria, for which we obtain five motion primitives that correspond to bell compression, vortex separation, cavity fluid refill, vortex formation, and coasting. Our experimental results indicate that the breakpoints between primitives are correlated with transitions in the bell geometry, vortex formation and shedding, and changes in derived dynamical quantities. These dynamics quantities include terms like pressure, power, drag, and thrust. Such findings suggest that dynamics information is inherently present in the observed motions.

  1. Learned graphical models for probabilistic planning provide a new class of movement primitives.

    PubMed

    Rückert, Elmar A; Neumann, Gerhard; Toussaint, Marc; Maass, Wolfgang

    2012-01-01

    BIOLOGICAL MOVEMENT GENERATION COMBINES THREE INTERESTING ASPECTS: its modular organization in movement primitives (MPs), its characteristics of stochastic optimality under perturbations, and its efficiency in terms of learning. A common approach to motor skill learning is to endow the primitives with dynamical systems. Here, the parameters of the primitive indirectly define the shape of a reference trajectory. We propose an alternative MP representation based on probabilistic inference in learned graphical models with new and interesting properties that complies with salient features of biological movement control. Instead of endowing the primitives with dynamical systems, we propose to endow MPs with an intrinsic probabilistic planning system, integrating the power of stochastic optimal control (SOC) methods within a MP. The parameterization of the primitive is a graphical model that represents the dynamics and intrinsic cost function such that inference in this graphical model yields the control policy. We parameterize the intrinsic cost function using task-relevant features, such as the importance of passing through certain via-points. The system dynamics as well as intrinsic cost function parameters are learned in a reinforcement learning (RL) setting. We evaluate our approach on a complex 4-link balancing task. Our experiments show that our movement representation facilitates learning significantly and leads to better generalization to new task settings without re-learning.

  2. Malignant Peripheral Nerve Sheath Tumor.

    PubMed

    James, Aaron W; Shurell, Elizabeth; Singh, Arun; Dry, Sarah M; Eilber, Fritz C

    2016-10-01

    Malignant peripheral nerve sheath tumor (MPNST) is the sixth most common type of soft tissue sarcoma. Most MPNSTs arise in association with a peripheral nerve or preexisting neurofibroma. Neurofibromatosis type is the most important risk factor for MPNST. Tumor size and fludeoxyglucose F 18 avidity are among the most helpful parameters to distinguish MPNST from a benign peripheral nerve sheath tumor. The histopathologic diagnosis is predominantly a diagnosis of light microscopy. Immunohistochemical stains are most helpful to distinguish high-grade MPNST from its histologic mimics. Current surgical management of high-grade MPNST is similar to that of other high-grade soft tissue sarcomas. PMID:27591499

  3. Endocranial preservation of a Carboniferous actinopterygian from Lancashire, UK, and the interrelationships of primitive actinopterygians

    PubMed Central

    Coates, M. I.

    1999-01-01

    The gross brain structure of an Upper Carboniferous (ca. 310 Myr ago) ray-finned fish (Actinopterygii) is described from exceptionally well-preserved fossil material from the Burnley region of Lancashire, UK. Previously identified as 'Rhadinichthys' planti, the species is reassigned to the genus Mesopoma. Morphological characters derived from these data are combined with reviews of cranial skeletal anatomy, enamel composition, oculomoter muscle insertion and paired fin morphology to test and reanalyse hypotheses of primitive actinopterygian interrelationships. Results indicate that ancestral chondrostean (sturgeon and paddlefish) and neopterygian (teleost, amiid and gar) lineages diverged earlier than current theories suggest. Palaeonisciformes, a taxonomic group widely used to include most Palaeozoic actinopterygians, include a significant number of primitive neopterygians, several of which may form a distinct monophyletic clade. Within this revised phylogenetic context, changes in gross brain morphology from primitive conditions, as revealed by fossil data, highlight likely specializations in extant non-teleostean actinopterygians.

  4. Primitive potentials and bounded solutions of the KdV equation

    NASA Astrophysics Data System (ADS)

    Dyachenko, S.; Zakharov, D.; Zakharov, V.

    2016-10-01

    We construct a broad class of bounded potentials of the one-dimensional Schrödinger operator that have the same spectral structure as periodic finite-gap potentials, but that are neither periodic nor quasi-periodic. Such potentials, which we call primitive, are non-uniquely parametrized by a pair of positive Hölder continuous functions defined on the allowed bands. Primitive potentials are constructed as solutions of a system of singular integral equations, which can be efficiently solved numerically. Simulations show that these potentials can have a disordered structure. Primitive potentials generate a broad class of bounded non-vanishing solutions of the KdV hierarchy, and we interpret them as an example of integrable turbulence in the framework of the KdV equation.

  5. Global Strong Well-Posedness of the Three Dimensional Primitive Equations in {L^p}-Spaces

    NASA Astrophysics Data System (ADS)

    Hieber, Matthias; Kashiwabara, Takahito

    2016-09-01

    In this article, an {L^p}-approach to the primitive equations is developed. In particular, it is shown that the three dimensional primitive equations admit a unique, global strong solution for all initial data {a in [X_p,D(A_p)]_{1/p}} provided {p in [6/5,infty)}. To this end, the hydrostatic Stokes operator {A_p} defined on {X_p}, the subspace of {L^p} associated with the hydrostatic Helmholtz projection, is introduced and investigated. Choosing {p} large, one obtains global well-posedness of the primitive equations for strong solutions for initial data {a} having less differentiability properties than {H^1}, hereby generalizing in particular a result by Cao and Titi (Ann Math 166:245-267, 2007) to the case of non-smooth initial data.

  6. The enigmatic primitive streak: prevailing notions and challenges concerning the body axis of mammals

    PubMed Central

    Downs, Karen M.

    2010-01-01

    The primitive streak establishes the antero-posterior body axis in all amniote species. It is thought to be the conduit through which mesoderm and endoderm progenitors ingress and migrate to their ultimate destinations. Despite its importance, the streak remains poorly defined and one of the most enigmatic structures of the animal kingdom. In particular, the posterior end of the primitive streak has not been satisfactorily identified in any species. Unexpectedly, and contrary to prevailing notions, recent evidence suggests that the murine posterior primitive streak extends beyond the embryo proper. In its extraembryonic site, the streak creates a node-like cell reservoir from which the allantois, a universal caudal appendage of all amniotes and the future umbilical cord of placental mammals, emerges. This new insight into the fetal/umbilical relationship may explain the etiology of a large number of umbilical-associated birth defects, many of which are correlated with abnormalities of the embryonic midline. PMID:19609969

  7. Method for concurrent execution of primitive operations by dynamically assigning operations based upon computational marked graph and availability of data

    NASA Technical Reports Server (NTRS)

    Stoughton, John W. (Inventor); Mielke, Roland V. (Inventor)

    1990-01-01

    Computationally complex primitive operations of an algorithm are executed concurrently in a plurality of functional units under the control of an assignment manager. The algorithm is preferably defined as a computationally marked graph contianing data status edges (paths) corresponding to each of the data flow edges. The assignment manager assigns primitive operations to the functional units and monitors completion of the primitive operations to determine data availability using the computational marked graph of the algorithm. All data accessing of the primitive operations is performed by the functional units independently of the assignment manager.

  8. About Peripheral Artery Disease (PAD)

    MedlinePlus

    ... changes and medication . View an animation of atherosclerosis Atherosclerosis and PAD Atherosclerosis is a disease in which plaque builds up ... of an artery. PAD is usually caused by atherosclerosis in the peripheral arteries (or outer regions away ...

  9. Peripheral Neuropathy and Agent Orange

    MedlinePlus

    ... registry health exam . Research on peripheral neuropathy and herbicides The Health and Medicine Division (HMD) (formally known ... acute or subacute onset may be associated with herbicide exposure. Based on this evidence, VA presumed an ...

  10. Peripheral artery bypass - leg - discharge

    MedlinePlus

    ... P. Peripheral arterial diseases. In: Mann DL, Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's ... noncoronary obstructive vascular disease. In: Mann DL, Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's ...

  11. Efficient conservative ADER schemes based on WENO reconstruction and space-time predictor in primitive variables

    NASA Astrophysics Data System (ADS)

    Zanotti, Olindo; Dumbser, Michael

    2016-01-01

    We present a new version of conservative ADER-WENO finite volume schemes, in which both the high order spatial reconstruction as well as the time evolution of the reconstruction polynomials in the local space-time predictor stage are performed in primitive variables, rather than in conserved ones. To obtain a conservative method, the underlying finite volume scheme is still written in terms of the cell averages of the conserved quantities. Therefore, our new approach performs the spatial WENO reconstruction twice: the first WENO reconstruction is carried out on the known cell averages of the conservative variables. The WENO polynomials are then used at the cell centers to compute point values of the conserved variables, which are subsequently converted into point values of the primitive variables. This is the only place where the conversion from conservative to primitive variables is needed in the new scheme. Then, a second WENO reconstruction is performed on the point values of the primitive variables to obtain piecewise high order reconstruction polynomials of the primitive variables. The reconstruction polynomials are subsequently evolved in time with a novel space-time finite element predictor that is directly applied to the governing PDE written in primitive form. The resulting space-time polynomials of the primitive variables can then be directly used as input for the numerical fluxes at the cell boundaries in the underlying conservative finite volume scheme. Hence, the number of necessary conversions from the conserved to the primitive variables is reduced to just one single conversion at each cell center. We have verified the validity of the new approach over a wide range of hyperbolic systems, including the classical Euler equations of gas dynamics, the special relativistic hydrodynamics (RHD) and ideal magnetohydrodynamics (RMHD) equations, as well as the Baer-Nunziato model for compressible two-phase flows. In all cases we have noticed that the new ADER

  12. Beta operations: efficient implementation of a primitive parallel operation. Technical report

    SciTech Connect

    Cohn, E.R.; Haddad, R.W.

    1986-08-01

    The ever-decreasing cost of computer processors has created a great interest in multi-processor computers. However, along with the increased power that this parallelism brings comes increased complexity in programming. One approach to lessening this complexity is to provide the programmer with general-purpose parallel primitives that shield him from the structure of the underlying machine. In The Connection Machine, Hillis suggests the beta operation as a parallel primitive for his hypercube-based machine. This paper explores efficient ways to perform this operation on several different well known architectures, including the hypercube. It presents some lower bounds associated with the problem.

  13. Ectomesenchymoma with embryonal rhabdomyosarcoma and ganglioneuroma, arising in association with benign triton tumor of the tongue.

    PubMed

    VandenHeuvel, Katherine A; Carpentieri, David F; Chen, Jie; Fung, Kar-Ming; Parham, David M

    2014-01-01

    Soft-tissue tumors known as "triton" tumors are rare lesions containing neural tissue and skeletal muscle at varying levels of maturity and malignant potential. Benign triton tumors, also called "neuromuscular choristomas" or "neuromuscular hamartomas," consist of neural tissue containing mature skeletal muscle in intimate relationship with peripheral nerve. These tumors are rare in the head and neck in children. Ectomesenchymomas are similar tumors consisting of a malignant mesenchymal component, usually embryonal rhabdomyosarcoma, and a neuroectodermal component represented by mature ganglion cells or primitive neuroblastic/neuroectodermal foci (primitive ectomesenchymoma). Benign triton tumors have been regarded as benign, whereas ectomesenchymomas have been operationally considered to be variants of rhabdomyosarcoma. We present here a unique case that combines features of these 2 entities in a recurrent lesion on the tongue of a 35-month-old girl. This lesion raises questions about the "benign" nature of benign triton tumor and its possible relationship to ectomesenchymoma.

  14. Oxaliplatin and Irinotecan in Treating Young Patients With Refractory Solid Tumors or Lymphomas

    ClinicalTrials.gov

    2013-06-04

    Childhood Burkitt Lymphoma; Childhood Central Nervous System Germ Cell Tumor; Childhood Diffuse Large Cell Lymphoma; Childhood Grade III Lymphomatoid Granulomatosis; Childhood Immunoblastic Large Cell Lymphoma; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Grade III Lymphomatoid Granulomatosis; Recurrent Childhood Large Cell Lymphoma; Recurrent Childhood Liver Cancer; Recurrent Childhood Lymphoblastic Lymphoma; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Medulloblastoma; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Small Noncleaved Cell Lymphoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway Glioma; Recurrent Colon Cancer; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Melanoma; Recurrent Nasopharyngeal Cancer; Recurrent Neuroblastoma; Recurrent Osteosarcoma; Recurrent Wilms Tumor and Other Childhood Kidney Tumors; Recurrent/Refractory Childhood Hodgkin Lymphoma; Unspecified Childhood Solid Tumor, Protocol Specific

  15. Peripheral facial nerve palsy after therapeutic endoscopy.

    PubMed

    Kim, Eun Jeong; Lee, Jun; Lee, Ji Woon; Lee, Jun Hyung; Park, Chol Jin; Kim, Young Dae; Lee, Hyun Jin

    2015-03-01

    Peripheral facial nerve palsy (FNP) is a mononeuropathy that affects the peripheral part of the facial nerve. Primary causes of peripheral FNP remain largely unknown, but detectable causes include systemic infections (viral and others), trauma, ischemia, tumor, and extrinsic compression. Peripheral FNP in relation to extrinsic compression has rarely been described in case reports. Here, we report a case of a 71-year-old man who was diagnosed with peripheral FNP following endoscopic submucosal dissection. This case is the first report of the development of peripheral FNP in a patient undergoing therapeutic endoscopy. We emphasize the fact that physicians should be attentive to the development of peripheral FNP following therapeutic endoscopy.

  16. Primitive Liquid Water of the Solar System in an Aqueous Altered Carbonaceous Chondrite

    NASA Technical Reports Server (NTRS)

    Tsuchiyama, A.; Miyake, A.; Kitayama, A.; Matsuno, J.; Takeuchi, A.; Uesugi, K.; Suzuki, Y.; Nakano, T.; Zolensky, M. E.

    2016-01-01

    Non-destructive 3D observations of the aqueous altered CM chondrite Sutter's Mill using scanning imaging x-ray microscopy (SIXM) showed that some of calcite and enstatite grains contain two-phase inclusion, which is most probably composed of liquid water and bubbles. This water should be primitive water responsible for aqueous alteration in an asteroid in the early solar system.

  17. Experimentally Testing the Hypothesis of a Limited Amino Acid Repertoire in Primitive Proteins

    NASA Astrophysics Data System (ADS)

    Akanuma, S.; Nakajima, Y.; Yokobori, S.; Yamagishi, A.

    2013-11-01

    It has been argued that a fewer amino acids were used in primitive proteins and later the repertoire increased up to 20. To test this hypothesis experimentally, we restricted the amino acid usage of a reconstructed, ancestral protein to reduced sets.

  18. Spatio-temporal articulatory movement primitives during speech production: Extraction, interpretation, and validation

    PubMed Central

    Ramanarayanan, Vikram; Goldstein, Louis; Narayanan, Shrikanth S.

    2013-01-01

    This paper presents a computational approach to derive interpretable movement primitives from speech articulation data. It puts forth a convolutive Nonnegative Matrix Factorization algorithm with sparseness constraints (cNMFsc) to decompose a given data matrix into a set of spatiotemporal basis sequences and an activation matrix. The algorithm optimizes a cost function that trades off the mismatch between the proposed model and the input data against the number of primitives that are active at any given instant. The method is applied to both measured articulatory data obtained through electromagnetic articulography as well as synthetic data generated using an articulatory synthesizer. The paper then describes how to evaluate the algorithm performance quantitatively and further performs a qualitative assessment of the algorithm's ability to recover compositional structure from data. This is done using pseudo ground-truth primitives generated by the articulatory synthesizer based on an Articulatory Phonology frame-work [Browman and Goldstein (1995). “Dynamics and articulatory phonology,” in Mind as motion: Explorations in the dynamics of cognition, edited by R. F. Port and T.van Gelder (MIT Press, Cambridge, MA), pp. 175–194]. The results suggest that the proposed algorithm extracts movement primitives from human speech production data that are linguistically interpretable. Such a framework might aid the understanding of longstanding issues in speech production such as motor control and coarticulation. PMID:23927134

  19. Automatic modelling of building façade objects via primitive shapes

    NASA Astrophysics Data System (ADS)

    Hetti Arachchige, N.; Perera, S.

    2014-08-01

    This paper presents a new approach to recognize individual façade objects and to reconstruct such objects in 3D using MLS point clouds. Core of the approach is a primitive shape based algorithm, which introduces building primitives, to identify the façade objects separately from other irrelevant objects and then to model the correct topology. The primitive shape is identified against defined different primitive shapes by using the Douglas-Peucker algorithm. The advantage of this process is that it offers an ability not only to model correct geometric shapes but also to remove occlusion effects from the final model. To evaluate the validity of the proposed approach, experiments have been conducted using two types of street scene point clouds captured by Optech Lynx Mobile Mapper System and Z+F laser scanner. Results of the experiments show that the completeness, correctness, and quality of the reconstructed building façade objects are well over 90 %, proving the proposed method is a promising solution for modelling 3D façade objects with different geometric shapes.

  20. Naturalistic arm movements during obstacle avoidance in 3D and the identification of movement primitives.

    PubMed

    Grimme, Britta; Lipinski, John; Schöner, Gregor

    2012-10-01

    By studying human movement in the laboratory, a number of regularities and invariants such as planarity and the principle of isochrony have been discovered. The theoretical idea has gained traction that movement may be generated from a limited set of movement primitives that would encode these invariants. In this study, we ask if invariants and movement primitives capture naturalistic human movement. Participants moved objects to target locations while avoiding obstacles using unconstrained arm movements in three dimensions. Two experiments manipulated the spatial layout of targets, obstacles, and the locations in the transport movement where an obstacle was encountered. We found that all movement trajectories were planar, with the inclination of the movement plane reflecting the obstacle constraint. The timing of the movement was consistent with both global isochrony (same movement time for variable path lengths) and local isochrony (same movement time for two components of the obstacle avoidance movement). The identified movement primitives of transport (movement from start to target position) and lift (movement perpendicular to transport within the movement plane) varied independently with obstacle conditions. Their scaling accounted for the observed double peak structure of movement speed. Overall, the observed naturalistic movement was astoundingly regular. Its decomposition into primitives suggests simple mechanisms for movement generation.

  1. Search for primitive Methanopyrus based on genetic distance between Val- and Ile-tRNA synthetases.

    PubMed

    Yu, Zhiliang; Takai, Ken; Slesarev, Alexei; Xue, Hong; Wong, J Tze-Fei

    2009-10-01

    Since evidence indicates that the Last Universal Common Ancestor (LUCA) was phylogenetically closest to Methanopyrus kandleri among living organisms with elucidated genomes, this study has been directed to a search for the most primitive Methanopyrus lineage. For this purpose, the divergence of valyl-tRNA synthetase (ValRS) and isoleucyl-tRNA synthetase (IleRS) was employed as a measure of primitivity. Comparison of Methanopyrus kandleri and the Methanopyrus isolates GC34 and GC37 from the Pacific Ocean and KOL6, TAG1, TAG11, and SNP6 from the Atlantic Ocean established that the Pacific lineages are more primitive than the Atlantic lineages. Both the groups, however, are younger than environmental genomes from the Kairei Field of Central Indian Ridge in the Indian Ocean. These results showed that different Methanopyrus isolates differ significantly with respect to ValRS-IleRS divergence. On this basis, genomes giving rise to the ValRS and IleRS gene fragments from the Central Indian Ridge represent the most primitive Methanopyrus, phylogenetically the oldest living lineage closest to LUCA. PMID:19841848

  2. Using Spatial-Temporal Primitives to Improve Geographic Skills for Preservice Teachers

    ERIC Educational Resources Information Center

    Kaufman, Martin M.

    2004-01-01

    An exercise to help improve the geographic skills of preservice teachers was developed and tested during a six year period on over 500 students. The exercise required these students to map two arrangements of roads and facilities within a small neighborhood. A set of special-temporal primitives (place, size, shape, distance, direction,…

  3. XUV complex refractive indices of aerosols in the atmospheres of Titan and the primitive Earth

    NASA Astrophysics Data System (ADS)

    Gavilan, Lisseth; Neumann, Maciej; Bulkin, Pavel; Popescu, Horia; Steffan, Martin; Esser, Norbert; Carrasco, Nathalie

    2016-10-01

    The complex refractive indices of tholins, simulating aerosols in the atmosphere of Titan and the primitive earth, have been measured over a wide spectral range, including the soft X-ray, vacuum-ultraviolet (VUV), and UV-Visible. The soft X-ray and VUV spectral ranges are in particular relevant to radiative transfer models of solar irradiation of primitive atmospheres (Lammer et al. 2008) and may elucidate the (anti-)greenhouse potential of photochemical aerosols.Thin films were grown using the PAMPRE capacitively coupled plasma setup (Szopa et al. 2006; Carrasco et al. 2009). Gas mixtures consisting of CH4/N2 with 5:95 ratios were used to simulate Titan's atmospheric composition. For the primitive Earth, gas mixtures of N2/CO2/H2 and N2/CO2/CH4 were used as described in Fleury et al. (2014).State-of-the-art laboratory techniques were used to determine the refractive indices of such tholin films. These include VUV ellipsometry (performed in collaboration with the Metrology Light Source in Berlin) and synchrotron X-ray spectroscopy (performed at the SEXTANTS beamline of the SOLEIL synchrotron). While VUV spectroscopy reveals new electronic transitions due to plasmon resonances in tholins, X-ray spectra reveal the C and O absorption edges of these solids. The refractive indices are compared to results from Khare et al. (1984). Implications on the optical properties of these aerosol analogs on the radiative modeling of primitive atmospheres will be discussed.

  4. Cytopatholologic features of gliosarcoma with areas of primitive neuroepithelial differentiation of the brain in squash smears.

    PubMed

    Hayashi, Toshitetsu; Kushida, Yoshio; Kadota, Kyuichi; Katsuki, Naomi; Bando, Kenji; Miyai, Yumi; Funamoto, Yasunobu; Haba, Reiji

    2009-12-01

    Gliosarcoma with areas of primitive neuroepithelial differentiation (GSPNED) is an extremely rare neoplasm. A case is presented here in which squash smears of a left temporal lobe tumor in a 76-year-old male demonstrated two distinct and easily recognizable cellular populations, i.e., densely hyperchromatic cells of a primitive nature in a fibrillary background and pleomorphic spindle-shaped cells. Occasional pseudo-rosette formations and nuclear cannibalism suggestive of neuroendocrine differentiation were also found. A cytologic diagnosis of a malignant tumor was suggested, and histochemical and immunohistochemical studies were conducted on formalin-fixed, paraffin-embedded material. Reticulin stain highlighted increased intercellular collagen and reticulin deposition within the spindled regions, whereas nodules with primitive cells were reticulin-poor. There was a diffuse and strong reactivity to neuron specific enolase, synaptophysin and CD56 immunostains. A stain for glial fibrillary acidic protein and S-100 protein demonstrated a subset of tumor cells including elongated cytoplasmic processes. The spindled component was positive for vimentin and smooth muscle actin, whereas the primitive-appearing tumor cells were negative. The diagnosis of GSPNED was confirmed based on cytopathologic, histopathological and immunohistochemical results. The cytomorphologic features of this distinctive tumor are illustrated, and the adjunctival value of squash smears for frozen-section diagnosis is also discussed. This is the first presentation of a cytopathologic analysis that provides an important clue to an accurate diagnosis of GSPNED.

  5. Primitive Reflexes and Attention-Deficit/Hyperactivity Disorder: Developmental Origins of Classroom Dysfunction

    ERIC Educational Resources Information Center

    Taylor, Myra; Houghton, Stephen; Chapman, Elaine

    2004-01-01

    The present research studied the symptomatologic overlap of AD/HD behaviours and retention of four primitive reflexes (Moro, Tonic Labyrinthine Reflex [TLR], Asymmetrical Tonic Neck Reflex [ATNR], Symmetrical Tonic Neck Reflex [STNR]) in 109 boys aged 7-10 years. Of these, 54 were diagnosed with AD/HD, 34 manifested sub-syndromal coordination,…

  6. Osmium Isotopic Compositions of Chondrites and Earth's Primitive Upper Mantle: Constraints on the Late Veneer

    NASA Technical Reports Server (NTRS)

    Walker, R. J.; Horan, M. F.; Morgan, J. W.; Meisel, T.

    2001-01-01

    The 187 Os/188 Os of carbonaceous chondrites averages approximately 2% lower than for enstatite and ordinary chondrites. The primitive upper mantle ratio for the Earth best matches that of ordinary and enstatite chondrites. Additional information is contained in the original extended abstract.

  7. Existence and Regularity of Invariant Measures for the Three Dimensional Stochastic Primitive Equations

    SciTech Connect

    Glatt-Holtz, Nathan; Kukavica, Igor Ziane, Mohammed; Vicol, Vlad

    2014-05-15

    We establish the continuity of the Markovian semigroup associated with strong solutions of the stochastic 3D Primitive Equations, and prove the existence of an invariant measure. The proof is based on new moment bounds for strong solutions. The invariant measure is supported on strong solutions and is furthermore shown to have higher regularity properties.

  8. Erythropoietin production in neuroepithelial and neural crest cells during primitive erythropoiesis.

    PubMed

    Suzuki, Norio; Hirano, Ikuo; Pan, Xiaoqing; Minegishi, Naoko; Yamamoto, Masayuki

    2013-01-01

    Erythropoietin (Epo) supports both primitive erythropoiesis in the yolk sac and definitive erythropoiesis in the fetal liver and bone marrow. Although definitive erythropoiesis requires kidney- and liver-secreted Epo, it is unclear which cells produce Epo for primitive erythropoiesis. Here we find neural Epo-producing (NEP) cells in mid-gestational stage embryos using mouse lines that express green fluorescent protein (GFP) under the Epo gene regulation. In these mice, GFP is expressed exclusively in a subpopulation of neural and neural crest cells at embryonic day 9.0 when Epo-deficient embryos exhibit abnormalities in primitive erythropoiesis. The GFP-positive NEP cells express Epo mRNA and the ex vivo culture of embryonic day 8.5 neural tubes results in the secretion of Epo, which is able to induce the proliferation and differentiation of yolk sac-derived erythroid cells. These results thus suggest that NEP cells secrete Epo and might support the development of primitive erythropoiesis. PMID:24309470

  9. Adaptive optics for peripheral vision

    NASA Astrophysics Data System (ADS)

    Rosén, R.; Lundström, L.; Unsbo, P.

    2012-07-01

    Understanding peripheral optical errors and their impact on vision is important for various applications, e.g. research on myopia development and optical correction of patients with central visual field loss. In this study, we investigated whether correction of higher order aberrations with adaptive optics (AO) improve resolution beyond what is achieved with best peripheral refractive correction. A laboratory AO system was constructed for correcting peripheral aberrations. The peripheral low contrast grating resolution acuity in the 20° nasal visual field of the right eye was evaluated for 12 subjects using three types of correction: refractive correction of sphere and cylinder, static closed loop AO correction and continuous closed loop AO correction. Running AO in continuous closed loop improved acuity compared to refractive correction for most subjects (maximum benefit 0.15 logMAR). The visual improvement from aberration correction was highly correlated with the subject's initial amount of higher order aberrations (p = 0.001, R 2 = 0.72). There was, however, no acuity improvement from static AO correction. In conclusion, correction of peripheral higher order aberrations can improve low contrast resolution, provided refractive errors are corrected and the system runs in continuous closed loop.

  10. Primitive Basalts Record Small-Scale Mantle Heterogeneities in the Lassen Region of the Southern Cascades

    NASA Astrophysics Data System (ADS)

    Wenner, J. M.; Teasdale, R.; Lenz, Q. A.

    2014-12-01

    The Poison Lake chain (PLC), located the Lassen region of the Southern Cascades, encompasses six geochemical, lithological and geographically distinct groups of primitive basalts, defined as MgO >6%, Ni >100 ppm, and Cr >200 ppm. In total, 22 cinder cones and flows of the PLC erupted in a small area (<30 km2) over a very short time frame (100 ka +/- 10 ka). The diversity of primitive compositions in the small spatial and temporal scales provide an ideal area in which to explore variations in mantle compositions that produce primitive basalts in the Lassen Segment of the Cascade Arc. We present major, trace, and isotope data and spinel-olivine compositions that reveal the diversity of mantle domains present in this small area. Chromium compositions of spinel in primitive basalts of the PLC indicate the presence of three distinct mantle sources: (1) depleted with Cr# = 0.44-0.52; (2) enriched with Cr# = 0.2-0.3 and (3) an intermediate composition, with Cr# = 0.4. Major and trace element compositions of PLC primitive basalts confirm the relative differences in depletion and reveal distinctions in the depth of melt generation. REE patterns and trace element ratios indicate variability in the presence of garnet in the source and define the source regions with varying depth. These mantle domains are geographically distributed with depleted compositions (high Cr# spinel, lower incompatible elements) in the northwest part of the PLC, grading to more enriched compositions (low Cr# spinel and higher incompatible elements) in the southeast. Previous workers recognize variations in the Cascadian sub-arc mantle at large scales across and along the arc, and at the scale of individual volcanic centers. However, the small area (30km2) and short timescale (within 10 ka) represented by the primitive basalts of the PLC allow us to hold time and space relatively constant while examining geochemical variations. Using primitive mantle proxy basalts from the PLC, we suggest that mantle

  11. Learned parametrized dynamic movement primitives with shared synergies for controlling robotic and musculoskeletal systems

    PubMed Central

    Rückert, Elmar; d'Avella, Andrea

    2013-01-01

    A salient feature of human motor skill learning is the ability to exploit similarities across related tasks. In biological motor control, it has been hypothesized that muscle synergies, coherent activations of groups of muscles, allow for exploiting shared knowledge. Recent studies have shown that a rich set of complex motor skills can be generated by a combination of a small number of muscle synergies. In robotics, dynamic movement primitives are commonly used for motor skill learning. This machine learning approach implements a stable attractor system that facilitates learning and it can be used in high-dimensional continuous spaces. However, it does not allow for reusing shared knowledge, i.e., for each task an individual set of parameters has to be learned. We propose a novel movement primitive representation that employs parametrized basis functions, which combines the benefits of muscle synergies and dynamic movement primitives. For each task a superposition of synergies modulates a stable attractor system. This approach leads to a compact representation of multiple motor skills and at the same time enables efficient learning in high-dimensional continuous systems. The movement representation supports discrete and rhythmic movements and in particular includes the dynamic movement primitive approach as a special case. We demonstrate the feasibility of the movement representation in three multi-task learning simulated scenarios. First, the characteristics of the proposed representation are illustrated in a point-mass task. Second, in complex humanoid walking experiments, multiple walking patterns with different step heights are learned robustly and efficiently. Finally, in a multi-directional reaching task simulated with a musculoskeletal model of the human arm, we show how the proposed movement primitives can be used to learn appropriate muscle excitation patterns and to generalize effectively to new reaching skills. PMID:24146647

  12. New hybrid voxelized/analytical primitive in Monte Carlo simulations for medical applications

    NASA Astrophysics Data System (ADS)

    Bert, Julien; Lemaréchal, Yannick; Visvikis, Dimitris

    2016-05-01

    Monte Carlo simulations (MCS) applied in particle physics play a key role in medical imaging and particle therapy. In such simulations, particles are transported through voxelized phantoms derived from predominantly patient CT images. However, such voxelized object representation limits the incorporation of fine elements, such as artificial implants from CAD modeling or anatomical and functional details extracted from other imaging modalities. In this work we propose a new hYbrid Voxelized/ANalytical primitive (YVAN) that combines both voxelized and analytical object descriptions within the same MCS, without the need to simultaneously run two parallel simulations, which is the current gold standard methodology. Given that YVAN is simply a new primitive object, it does not require any modifications on the underlying MC navigation code. The new proposed primitive was assessed through a first simple MCS. Results from the YVAN primitive were compared against an MCS using a pure analytical geometry and the layer mass geometry concept. A perfect agreement was found between these simulations, leading to the conclusion that the new hybrid primitive is able to accurately and efficiently handle phantoms defined by a mixture of voxelized and analytical objects. In addition, two application-based evaluation studies in coronary angiography and intra-operative radiotherapy showed that the use of YVAN was 6.5% and 12.2% faster than the layered mass geometry method, respectively, without any associated loss of accuracy. However, the simplification advantages and differences in computational time improvements obtained with YVAN depend on the relative proportion of the analytical and voxelized structures used in the simulation as well as the size and number of triangles used in the description of the analytical object meshes.

  13. New hybrid voxelized/analytical primitive in Monte Carlo simulations for medical applications.

    PubMed

    Bert, Julien; Lemaréchal, Yannick; Visvikis, Dimitris

    2016-05-01

    Monte Carlo simulations (MCS) applied in particle physics play a key role in medical imaging and particle therapy. In such simulations, particles are transported through voxelized phantoms derived from predominantly patient CT images. However, such voxelized object representation limits the incorporation of fine elements, such as artificial implants from CAD modeling or anatomical and functional details extracted from other imaging modalities. In this work we propose a new hYbrid Voxelized/ANalytical primitive (YVAN) that combines both voxelized and analytical object descriptions within the same MCS, without the need to simultaneously run two parallel simulations, which is the current gold standard methodology. Given that YVAN is simply a new primitive object, it does not require any modifications on the underlying MC navigation code. The new proposed primitive was assessed through a first simple MCS. Results from the YVAN primitive were compared against an MCS using a pure analytical geometry and the layer mass geometry concept. A perfect agreement was found between these simulations, leading to the conclusion that the new hybrid primitive is able to accurately and efficiently handle phantoms defined by a mixture of voxelized and analytical objects. In addition, two application-based evaluation studies in coronary angiography and intra-operative radiotherapy showed that the use of YVAN was 6.5% and 12.2% faster than the layered mass geometry method, respectively, without any associated loss of accuracy. However, the simplification advantages and differences in computational time improvements obtained with YVAN depend on the relative proportion of the analytical and voxelized structures used in the simulation as well as the size and number of triangles used in the description of the analytical object meshes. PMID:27032813

  14. New hybrid voxelized/analytical primitive in Monte Carlo simulations for medical applications.

    PubMed

    Bert, Julien; Lemaréchal, Yannick; Visvikis, Dimitris

    2016-05-01

    Monte Carlo simulations (MCS) applied in particle physics play a key role in medical imaging and particle therapy. In such simulations, particles are transported through voxelized phantoms derived from predominantly patient CT images. However, such voxelized object representation limits the incorporation of fine elements, such as artificial implants from CAD modeling or anatomical and functional details extracted from other imaging modalities. In this work we propose a new hYbrid Voxelized/ANalytical primitive (YVAN) that combines both voxelized and analytical object descriptions within the same MCS, without the need to simultaneously run two parallel simulations, which is the current gold standard methodology. Given that YVAN is simply a new primitive object, it does not require any modifications on the underlying MC navigation code. The new proposed primitive was assessed through a first simple MCS. Results from the YVAN primitive were compared against an MCS using a pure analytical geometry and the layer mass geometry concept. A perfect agreement was found between these simulations, leading to the conclusion that the new hybrid primitive is able to accurately and efficiently handle phantoms defined by a mixture of voxelized and analytical objects. In addition, two application-based evaluation studies in coronary angiography and intra-operative radiotherapy showed that the use of YVAN was 6.5% and 12.2% faster than the layered mass geometry method, respectively, without any associated loss of accuracy. However, the simplification advantages and differences in computational time improvements obtained with YVAN depend on the relative proportion of the analytical and voxelized structures used in the simulation as well as the size and number of triangles used in the description of the analytical object meshes.

  15. Ultrasonographic Evaluation of Peripheral Nerves.

    PubMed

    Ali, Zarina S; Pisapia, Jared M; Ma, Tracy S; Zager, Eric L; Heuer, Gregory G; Khoury, Viviane

    2016-01-01

    There are a variety of imaging modalities for evaluation of peripheral nerves. Of these, ultrasonography (US) is often underused. There are several advantages of this imaging modality, including its cost-effectiveness, time-efficient assessment of long segments of peripheral nerves, ability to perform dynamic maneuvers, lack of contraindications, portability, and noninvasiveness. It can provide diagnostic information that cannot be obtained by electrophysiologic or, in some cases, magnetic resonance imaging studies. Ideally, the neurosurgeon can use US as a diagnostic adjunct in the preoperative assessment of a patient with traumatic, neoplastic, infective, or compressive nerve injury. Perhaps its most unique use is in intraoperative surgical planning. In this article, a brief description of normal US nerve anatomy is presented followed by a description of the US appearance of peripheral nerve disease caused by trauma, tumor, infection, and entrapment.

  16. Pleiotrophin and peripheral nerve injury.

    PubMed

    Jin, Li; Jianghai, Chen; Juan, Liu; Hao, Kang

    2009-10-01

    The proto-oncogene pleiotrophin, discovered in 1989, was considered as a multifunctional growth factor, which played an important role in tumor occurrence, development, and central nervous system. The latest research showed that pleiotrophin signal pathway probably participated in neural repair after peripheral nerve injury, especially in the following critical points, such as the protection of spinal cord neuron, the promotion of the speed of neuron axon regeneration, the guidance of neuron axon regeneration, skeleton muscle reinnervation, and so on. It potentially plays a key role in the guidance of neural axon regeneration in peripheral nervous system and muscle reinnervation. With the deepening of related researches, pleiotrophin gene would become a controllable target for improving the repairing effect of peripheral nerve injury and reconstruction of the neuromuscular junction.

  17. Peripheral nerve conduits: technology update

    PubMed Central

    Arslantunali, D; Dursun, T; Yucel, D; Hasirci, N; Hasirci, V

    2014-01-01

    Peripheral nerve injury is a worldwide clinical problem which could lead to loss of neuronal communication along sensory and motor nerves between the central nervous system (CNS) and the peripheral organs and impairs the quality of life of a patient. The primary requirement for the treatment of complete lesions is a tension-free, end-to-end repair. When end-to-end repair is not possible, peripheral nerve grafts or nerve conduits are used. The limited availability of autografts, and drawbacks of the allografts and xenografts like immunological reactions, forced the researchers to investigate and develop alternative approaches, mainly nerve conduits. In this review, recent information on the various types of conduit materials (made of biological and synthetic polymers) and designs (tubular, fibrous, and matrix type) are being presented. PMID:25489251

  18. TCRαβ+/CD19+ Depleted Haploidentical HSCT + Zoledronate

    ClinicalTrials.gov

    2016-08-22

    Acute Myeloid Leukemia; Acute Lymphoblastic Leukemia; Hodgkin Lymphoma; Non-Hodgkin Lymphoma; Myelodysplastic Syndrome; Myeloproliferative Syndrome; Rhabdomyosarcoma; Ewing Sarcoma; Primitive Neuroectodermal Tumor; Osteosarcoma; Neuroblastoma

  19. p28 in Treating Younger Patients With Recurrent or Progressive Central Nervous System Tumors

    ClinicalTrials.gov

    2016-10-21

    Teratoid Tumor, Atypical; Choroid Plexus Neoplasms; Anaplastic Astrocytoma; Anaplastic Oligodendroglioma; Brainstem Tumors; Giant Cell Glioblastoma; Glioblastoma; Gliosarcoma; Medulloblastoma; Neuroectodermal Tumor, Primitive

  20. Peripheral neuropathy caused by methaqualone.

    PubMed

    Marks, P; Sloggem, J

    1976-01-01

    Three patients are described who each received methaqualone and developed signs and symptoms of peripheral neuropathy. The subsequent improvement after cessation of methaqualone was highly suggestive or a direct toxic action of the drug or one of its metabolites. In one patient methaqualone was recommended with reappearance of signs and symptoms of peripheral neuropathy. Again cessation of the drug caused disappearance of these signs. There was no evidence whatsoever of any electrolyte or metabolic disturbance or any other pathology which might have given rise to this symptom complex. In addition, no other drugs were prescribed besides methaqualone.

  1. Morphological spectrum of peripheral nerve sheath tumors: An insight into World Health Organization 2013 classification

    PubMed Central

    Chikkannaiah, Panduranga; Boovalli, Mythri M.; Nathiyal, Velusamy; Venkataramappa, Srinivasamurthy

    2016-01-01

    Introduction: Peripheral nerve sheath tumors (PNSTs) are neuroectodermal in origin. Now these tumors are classified under World Health Organization (WHO) classification of tumors of soft tissue and bone 2013. Objective: To study the morphological spectrum of PNST and to study the secondary degenerative changes associated with it. Materials and Methods: This study was conducted from January 2010 to June 2015. The gross details of tumor and patient's demographic profiles were reviewed. The hematoxylin and eosin stained slides were reassessed and the lesions were categorized and classified as per the WHO 2013 classification. The tumors were also assessed for secondary degenerative changes. Results: Our study comprised 143 cases of PNST. Age of the patients ranged from 5 to 75 years. 21–30 years is the most common age of occurrence with head and neck being the most common site. The PNSTs observed in the present study were neurofibroma (NF) (61.5%), schwannoma (36%), malignant PNST (2%), and granular cell tumor (0.5%). Nearly 10% of NF fulfilled the criteria for neurofibromatosis 1 (NF1). Rare tumors such as plexiform schwannoma and granular cell tumor were also observed. Malignant tumors were larger in dimension than benign. Myxoid, cystic, and hyaline changes were commonly associated with benign tumors while necrosis, hemorrhage, and mitotic activity were seen with malignant tumors. Conclusion: This series highlights the pathological variants of PNST along with their morphological changes and NF1 association. It is essential to be familiar with all these variants of PNST for accurate diagnosis as they have varied biological behavior. PMID:27365950

  2. How to Pick Computer Peripherals.

    ERIC Educational Resources Information Center

    Fisher, Glenn

    1983-01-01

    A guide to computer peripherals--additional hardware that can expand the educational uses of computers--is given. Tips are furnished on selection and possible use of computer printers; modulator/demodulators (modems); graphics tablets; plotters, speech synthesizers, and robots. (PP)

  3. [Peripheral Nerve Injuries in Sports].

    PubMed

    Tettenborn, B; Mehnert, S; Reuter, I

    2016-09-01

    Peripheral nerve injuries due to sports are relatively rare but the exact incidence is not known due to a lack of epidemiological studies. Particular sports activities tend to cause certain peripheral nerve injuries including direct acute compression or stretching, repetitive compression and stretching over time, or another mechanism such as ischemia or laceration. These nerve lesions may be severe and delay or preclude the athlete's return to sports, especially in cases with delayed diagnosis. Repetitive and vigorous use or overuse makes the athlete vulnerable to disorders of the peripheral nerves, and sports equipment may cause compression of the nerves. Depending on etiology, the treatment is primarily conservative and includes physiotherapy, modification of movements and sports equipment, shoe inserts, splinting, antiphlogistic drugs, sometimes local administration of glucocorticoids or, lately, the use of extracorporeal shock waves. Most often, cessation of the offending physical activity is necessary. Surgery is only indicated in the rare cases of direct traumatic nerve injury or when symptoms are refractory to conservative therapy. Prognosis mainly depends on the etiology and the available options of modifying measures.This article is based on the publications "Reuter I, Mehnert S. Engpasssyndrome peripherer Nerven bei Sportlern". Akt Neurol 2012;39:292-308 and Sportverl Sportschad 2013;27:130-146. PMID:27607069

  4. Sports and peripheral nerve injury.

    PubMed

    Hirasawa, Y; Sakakida, K

    1983-01-01

    Peripheral nerve injury is one of the serious complications of athletic injuries; however, they have rarely been reported. According to the report by Takazawa et al., there were only 28 cases of peripheral nerve injury among 9,550 cases of sports injuries which had been treated in the previous 5 years at the clinic of the Japanese Athletic Association. The authors have encountered 1,167 cases of peripheral nerve injury during the past 18 years. Sixty-six of these cases were related to sports (5.7%). The nerves most frequently involved were: brachial plexus, radial nerve, ulnar, peroneal, and axillary nerves (in their order of frequency). The most common causes of such injuries were mountain climbing, gymnastics, and baseball. More often, peripheral nerve injury seemed to be caused by continuous compression and repeated trauma to the involved nerve. Usually it appeared as an entrapment neuropathy and the symptoms could be improved by conservative treatment. Some of the cases were complicated by fractures and surgical exploration became necessary. Results of treatment produced excellent to good improvement in 87.9% of the cases. With regard to compartment syndrome, the authors stress the importance of early and precise diagnosis and a fasciotomy.

  5. Origin of lead from green glass of Apollo 15426: a search for primitive lunar lead.

    USGS Publications Warehouse

    Tatsumoto, M.; Premo, W.R.; Unruh, D.M.

    1987-01-01

    A major obstacle in lunar U-Pb chronology is the elusiveness of the primary Pb isotopic composition and U/Pb ratio and therefore the Pb evolution for the early history of the moon. In an attempt to seek the primitive lunar Pb isotopoc composition, green glass from lunar clod 15426,49 was studied for U-Th-Pb systematics because it is extremely Mg-rich and known to be the most primitive among sampled lunar volcanic rocks. Because of the low Pb concentration and high U/Pb ratio observed for the interior, the initial Pb was poorly defined. Nevertheless, the data indicate that lunar Pb evolved in an environment with 238U/204Pb = 19-55, which is considerably lower than those for mare basalts (around 300) but higher than values for the Earth (6-8).-from Authors

  6. Stochastic modelling of primitive equation and quasi-geostrophic subgrid turbulence

    NASA Astrophysics Data System (ADS)

    Frederiksen, Jorgen; Kitsios, Vassili; Dix, Martin; Osbrough, Stacey

    2016-04-01

    A general method for stochastic and deterministic modelling of subgrid scale turbulence is presented and applied to primitive equation and quasi-geostrophic models of atmospheric and oceanic flows. Dynamical and thermodynamical subgrid-scale parameterisations of eddy drain, net dissipation and stochastic backscatter are calculated for a multi-level primitive equation atmospheric general circulation model. The parameterisations have only moderate variability with height and a cusp behaviour with peaks near the largest retained wavenumber. They are compared with corresponding results for quasi-geostrophic models of the atmosphere and ocean for which the parameterisations are shown to satisfy scaling laws. Large-eddy simulations (LES) with the subgrid terms very closely reproduce the results of higher resolution direct numerical simulations. The method is shown to produce parameterisations and LES with similar skill for three-dimensional turbulence in boundary layer channel flow.

  7. Comets and the formation of biochemical compounds on the primitive Earth--a review.

    PubMed

    Oró, J; Mills, T; Lazcano, A

    1992-01-01

    Thirty years ago it was suggested that comets impacting on the primitive Earth may have represented a significant source of terrestrial volatiles, including some important precursors for prebiotic synthesis (Oró, 1961, Nature 190: 389). This possibility is strongly supported not only by models of the collisional history of the early Earth, but also by astronomical evidence that suggests that frequent collisions of comet-like bodies from the circumstellar disk around the star beta Pictoris are taking place. Although a significant fraction of the complex organic compounds that appear to be present in cometary nuclei were probably destroyed during impact, it is argued that cometary collisions with the primitive Earth represented an important source of both free-energy and volatiles, and may have created transient, gaseous environments in which prebiotic synthesis may have taken place.

  8. Organic cofactors participated more frequently than transition metals in redox reactions of primitive proteins.

    PubMed

    Ji, Hong-Fang; Chen, Lei; Zhang, Hong-Yu

    2008-08-01

    Protein redox reactions are one of the most basic and important biochemical actions. As amino acids are weak redox mediators, most protein redox functions are undertaken by protein cofactors, which include organic ligands and transition metal ions. Since both kinds of redox cofactors were available in the pre-protein RNA world, it is challenging to explore which one was more involved in redox processes of primitive proteins? In this paper, using an examination of the redox cofactor usage of putative ancient proteins, we infer that organic ligands participated more frequently than transition metals in redox reactions of primitive proteins, at least as protein cofactors. This is further supported by the relative abundance of amino acids in the primordial world. Supplementary material for this article can be found on the BioEssays website.

  9. Extra-embryonic Wnt3 regulates the establishment of the primitive streak in mice

    PubMed Central

    Yoon, Yeonsoo; Huang, Tingting; Tortelote, Giovane G.; Wakamiya, Maki; Hadjantonakis, Anna-Katerina; Behringer, Richard R.; Rivera-Pérez, Jaime A.

    2015-01-01

    The establishment of the head to tail axis at early stages of development is a fundamental aspect of vertebrate embryogenesis. In mice, experimental embryology, genetics and expression studies have suggested that the visceral endoderm, an extra-embryonic tissue, plays an important role in anteroposterior axial development. Here we show that absence of Wnt3 in the posterior visceral endoderm leads to delayed formation of the primitive streak and that interplay between anterior and posterior visceral endoderm restricts the position of the primitive streak. Embryos lacking Wnt3 in the visceral endoderm, however, appear normal by E9.5. Our results suggest a model for axial development in which multiple signals are required for anteroposterior axial development in mammals. PMID:25907228

  10. Analysis of Oceanic Internal Tides With PEZ-HAT, a Data-Assimilating Primitive Equations Model

    NASA Astrophysics Data System (ADS)

    Zaron, E. D.

    2006-12-01

    A software system for the generalized inversion of a primitive equations model has been developed and is currently being used to analyze the internal tides along the Hawaiian Ridge. The development of this system was facilitated by "The Inverse Ocean Model," a modular system that implements Weak-constraint, Four-Dimensional Variational (W4DVAR) assimilation for any dynamical model and observing array, both of which may be nonlinear but functionally smooth. The primitive equations, tangent-linear, and adjoint systems are solved in the frequency domain for this tidal application, and I will give an overview of their implementations, including the model forcing error convolutions. As an illustrative application, I will show results of assimilating HF-radar data into a regional model of the Kauai Channel, a site of intense conversion of barotropic to baroclinic tidal energy.

  11. Nucleic acid-like structures. II - Polynucleotide analogues as possible primitive precursors of nucleic acids

    NASA Technical Reports Server (NTRS)

    Schwartz, Alan W.; Visscher, J.; Bakker, C. G.; Niessen, J.

    1987-01-01

    Activated derivatives of purine-containing deoxynucleoside- diphosphates spontaneously oligomerize to produce pyrophosphate- linked oligodeoxynucleotide analogs. These analogs are of potential interest as models of primitive, polynucleotide precursors. The efficiency of oligomerization (ImpdGpIm and ImpdApIm much greater than ImpdIpIm) appears to reflect a combination of stacking forces and the specific geometric orientations of the stacked units. Under favorable conditions, chain lengths greater than 20 have been obtained for oligomers containing pdGp in the absence of a template. In the presence of a complementary template, the activated derivatives of pdGp and pdAp oligomerize much more extensively. An acyclo-analog of G has also been shown to undergo template-directed oligomerization on poly(C). These observations suggest the possibility that primitive information transfer might have evolved in much simpler systems and that this function was taken over by polynucleotides at a later stage in evolution.

  12. Primitive and contaminated basalts from the Southern Rocky Mountains, U.S.A

    USGS Publications Warehouse

    Doe, B.R.; Lipman, P.W.; Hedge, C.E.; Kurasawa, H.

    1969-01-01

    Basalts in the Southern Rocky Mountains province have been analyzed to determine if any of them are primitive. Alkali plagioclase xenocrysts armored with calcic plagioclase seem to be the best petrographic indicator of contamination. The next best indicator of contamination is quartz xenocrysts armored with clinopyroxene. On the rocks and the region studied, K2O apparently is the only major element with promise of separating primitive basalt from contaminated basalt inasmuch as it constitutes more than 1 % in all the obviously contaminated basalts. K2O: lead (> 4 ppm) and thorium (> 2 ppm) contents and Rb/Sr (> 0.035) are the most indicative of the trace elements studied. Using these criteria, three basalt samples are primitive (although one contains 1.7% K2O) and are similar in traceelement contents to Hawaiian and Eastern Honshu, Japan, primitive basalts. Contamination causes lead isotope ratios, 206Pb/204Pb and 208Pb/204Pb, to become less radiogenic, but it has little or no effect on 87Sr/86Sr. We interpret the effect on lead isotopes to be due to assimilation either of lower crustal granitic rocks, which contain 5-10 times as much lead as basalt and which have been low in U/Pb and Th/Pb since Precambrian times, or of upper crustal Precambrian or Paleozoic rocks, which have lost much of their radiogenic lead because of heating prior to assimilation. The lack of definite effects on strontium isotopes may be due to the lesser strontium contents of granitic crustal rocks relative to basaltic rocks coupled with lack of a large radiogenic enrichment in the crustal rocks. Lead isotope ratios were found to be less radiogenic in plagioclase separates from an obviously contaminated basalt than in the primitive basalts. The feldspar separate that is rich in sodic plagioclase xenocrysts was found to be similar to the whole-rock composition for 206Pb/204Pb and 208Pb/204Pb whereas a more dense fraction probably enriched in more calcic plagioclase phenocrysts is more similar

  13. Viscoelasticity and primitive path analysis of entangled polymer liquids: From F-actin to polyethylene

    NASA Astrophysics Data System (ADS)

    Uchida, Nariya; Grest, Gary S.; Everaers, Ralf

    2008-01-01

    We combine computer simulations and scaling arguments to develop a unified view of polymer entanglement based on the primitive path analysis of the microscopic topological state. Our results agree with experimentally measured plateau moduli for three different polymer classes over a wide range of reduced polymer densities: (i) semidilute theta solutions of synthetic polymers, (ii) the corresponding dense melts above the glass transition or crystallization temperature, and (iii) solutions of semiflexible (bio)polymers such as F-actin or suspensions of rodlike viruses. Together, these systems cover the entire range from loosely to tightly entangled polymers. In particular, we argue that the primitive path analysis renormalizes a loosely to a tightly entangled system and provide a new explanation of the successful Lin-Noolandi packing conjecture for polymer melts.

  14. The composition of the primitive atmosphere and the synthesis of organic compounds on the early Earth

    NASA Technical Reports Server (NTRS)

    Bada, J. L.; Miller, S. L.

    1985-01-01

    The generally accepted theory for the origin of life on the Earth requires that a large variety of organic compounds be present to form the first living organisms and to provide the energy sources for primitive life either directly or through various fermentation reactions. This can provide a strong constraint on discussions of the formation of the Earth and on the composition of the primitive atmosphere. In order for substantial amounts of organic compounds to have been present on the prebiological Earth, certain conditions must have existed. There is a large body of literature on the prebiotic synthesis of organic compounds in various postulated atmospheres. In this mixture of abiotically synthesized organic compounds, the amino acids are of special interest since they are utilized by modern organisms to synthesize structural materials and a large array of catalytic peptides.

  15. Pyomyosite tuberculeuse primitive chez une patiente immunocompétente: à propos d'un cas

    PubMed Central

    Daghfous, Alifa; Bouzaidi, Khaled; Marhoul, Lamia Rezgui

    2014-01-01

    L'atteinte du muscle strié au cours de la tuberculose chez un sujet immunodéprimé ou à partir de l'extension d'un foyer ostéo-articulaire de voisinage est rare mais bien connue. Toutefois, l'atteinte primitive est exceptionnelle ainsi que celle chez un sujet immunocompétent. L'imagerie par résonnance magnétique (IRM) est d'un grand apport pour le diagnostic avec une excellente sensibilité. Nous rapportons un cas de pyomyosite tuberculeuse primitive du mollet chez une patiente non immunodéprimé tout en précisant l'apport de l'IRM. PMID:25821543

  16. Gene therapy for peripheral nervous system diseases.

    PubMed

    Federici, Thais; Boulis, Nicholas

    2007-08-01

    Peripheral nerve diseases, also known as peripheral neuropathies, affect 15-20 million of Americans and diabetic neuropathy is the most common condition. Currently, the treatment of peripheral neuropathies is more focused on managing pain rather than providing permissive conditions for regeneration. Despite advances in microsurgical techniques, including nerve grafting and reanastomosis, axonal regeneration after peripheral nerve injury remains suboptimal. Also, no satisfactory treatments are available at this time for peripheral neurodegeneration occurring in motor neuron diseases (MND), including amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). Peripheral nerves have the inherent capacity of regeneration. Gene therapy strategies focused on neuroprotection may help optimizing axonal regrowth. A better understanding of the cellular and molecular events involved in axonal degeneration and regeneration have helped researchers to identify targets for intervention. This review summarizes the current state on the clinical experience as well as gene therapy strategies for peripheral neuropathies, including MND, peripheral nerve injury, neuropathic pain, and diabetic neuropathy.

  17. An empirically-derived taxonomy of interaction primitives for interactive cartography and geovisualization.

    PubMed

    Roth, Robert E

    2013-12-01

    Proposals to establish a 'science of interaction' have been forwarded from Information Visualization and Visual Analytics, as well as Cartography, Geovisualization, and GIScience. This paper reports on two studies to contribute to this call for an interaction science, with the goal of developing a functional taxonomy of interaction primitives for map-based visualization. A semi-structured interview study first was conducted with 21 expert interactive map users to understand the way in which map-based visualizations currently are employed. The interviews were transcribed and coded to identify statements representative of either the task the user wished to accomplish (i.e., objective primitives) or the interactive functionality included in the visualization to achieve this task (i.e., operator primitives). A card sorting study then was conducted with 15 expert interactive map designers to organize these example statements into logical structures based on their experience translating client requests into interaction designs. Example statements were supplemented with primitive definitions in the literature and were separated into two sorting exercises: objectives and operators. The objective sort suggested five objectives that increase in cognitive sophistication (identify, compare, rank, associate, & delineate), but exhibited a large amount of variation across participants due to consideration of broader user goals (procure, predict, & prescribe) and interaction operands (space-alone, attributes-in-space, & space-in-time; elementary & general). The operator sort suggested five enabling operators (import, export, save, edit, & annotate) and twelve work operators (reexpress, arrange, sequence, resymbolize, overlay, pan, zoom, reproject, search, filter, retrieve, & calculate). This taxonomy offers an empirically-derived and ecologically-valid structure to inform future research and design on interaction.

  18. Transvenous Embolization of Primitive Trigeminal Artery Variant-Cavernous Fistula with Guglielmi Detachable Coils

    PubMed Central

    Wu, Yi-Ming; Wong, Ho-Fai

    2008-01-01

    Summary Here, we present a 32-year-old male with proptosis and chemosis of the left eye following a close head injury. Digital subtraction angiography of the left internal carotid artery showed a left carotid-cavernous fistula (CCF) associated with a primitive trigeminal artery (PTA) variant. The patient was successfully treated with transvenous Guglielmi detachable coils embolization via the inferior petrosal sinus. The PTA variant was preserved without cerebellar or brainstem infarct. PMID:20557808

  19. Abundances of presolar silicon carbide grains in primitive meteorites determined by NanoSIMS

    NASA Astrophysics Data System (ADS)

    Davidson, Jemma; Busemann, Henner; Nittler, Larry R.; Alexander, Conel M. O.'D.; Orthous-Daunay, François-Régis; Franchi, Ian A.; Hoppe, Peter

    2014-08-01

    It has been suggested that the matrices of all chondrites are dominated by a common material with Ivuna-like (CI) abundances of volatiles, presolar grains and insoluble organic matter (IOM) (e.g., Alexander, 2005). However, matrix-normalized abundances of presolar silicon carbide (SiC) grains estimated from their noble gas components show significant variations in even the most primitive chondrites (Huss and Lewis, 1995; Huss et al., 2003), in contradiction to there being a common chondrite matrix material. Here we report presolar SiC abundances determined by NanoSIMS raster ion imaging of IOM extracted from primitive members of different meteorite groups. We show that presolar SiC abundance determinations are comparable between NanoSIMS instruments located at three different institutes, between residues prepared by different demineralization techniques, and between microtomed and non-microtomed samples. Our derived SiC abundances in CR chondrites are comparable to those found in the CI chondrites (∼30 ppm) and are much higher than previously determined by noble gas analyses. The revised higher CR SiC abundances are consistent with the CRs being amongst the most primitive chondrites in terms of the isotopic compositions and disordered nature of their organic matter. Similar abundances between CR1, CR2, and CR3 chondrites indicate aqueous alteration on the CR chondrite parent body has not progressively destroyed SiC grains in them. A low SiC abundance for the reduced CV3 RBT 04133 can be explained by parent body thermal metamorphism at an estimated temperature of ∼440 °C. Minor differences between primitive members of other meteorite classes, which did not experience such high temperatures, may be explained by prolonged oxidation at lower temperatures under which SiC grains formed outer layers of SiO2 that were not thermodynamically stable, leading to progressive degassing/destruction of SiC.

  20. Formation and Processing of Amorphous Silicates in Primitive Carbonaceous Chondrites and Cometary Dust

    NASA Technical Reports Server (NTRS)

    Keller, Lindsay P.; Messenger, S.

    2012-01-01

    Chondritic-porous interplanetary dust particles (CP IDPs) exhibit strongly heterogeneous and unequilibrated mineralogy at sub-micron scales, are enriched in carbon, nitrogen and volatile trace elements, and contain abundant presolar materials [1-4]. These observations suggest that CP IDPs have largely escaped the thermal processing and water-rock interactions that have severely modified or destroyed the original mineralogy of primitive meteorites. CP IDPs are believed to represent direct samples of the building blocks of the Solar System - a complex mixture of nebular and presolar materials largely unperturbed by secondary processing. The chemical and isotopic properties of CP IDPs and their atmospheric entry velocities are also consistent with cometary origins. GEMS (glass with embedded metal and sulfides) grains are a major silicate component of CP IDPs. GEMS grains are < 0.5 microns in diameter objects that consist of numerous 10 to 50 nm-sized Fe-Ni metal and Fe-Ni sulfide grains dispersed in a Mg-Si-Al-Fe amorphous silicate matrix [2, 5]. Based on their chemistry and isotopic compositions, most GEMS appear to be non-equilibrium condensates from the early solar nebula [2]. If GEMS grains are a common nebular product, then they should also be abundant in the matrices of the most physically primitive chondritic meteorites. Although amorphous silicates are common in the most primitive meteorites [6-9], their relationship to GEMS grains and the extent to which their compositions and microstructure have been affected by parent body processing (oxidation and aqueous alteration) is poorly constrained. Here we compare and contrast the chemical, microstructural and isotopic properties of amorphous silicates in primitive carbonaceous chondrites to GEMS grains in IDPs.

  1. Peripheral arterial disease: implications beyond the peripheral circulation.

    PubMed

    Paraskevas, Kosmas I; Mukherjee, Debabrata; Whayne, Thomas F

    2013-11-01

    Peripheral arterial disease (PAD) affects a considerable percentage of the population. The manifestations of this disease are not always clinically overt. As a result, PAD remains underdiagnosed and undertreated. PAD is not just a disease of the peripheral arteries, but also an indication of generalized vascular atherosclerosis. PAD patients also have a high prevalence of other arterial diseases, such as coronary/carotid artery disease and abdominal aortic aneurysms. PAD is also a predictor of increased risk of lung and other cancers. The most often used examination for the establishment of the diagnosis of PAD, the ankle-brachial pressure index (ABPI), is also a predictor of generalized atherosclerosis, future cardiovascular events and cardiovascular mortality. Several markers that have been linked with PAD (e.g. C-reactive protein, serum bilirubin levels) may also have predictive value for other conditions besides PAD (e.g. kidney dysfunction). The management of PAD should therefore not be restricted to the peripheral circulation but should include measurements to manage and decrease the systemic atherosclerotic burden of the patient. PMID:23221278

  2. [Peripheral neuropathy caused by acute arsenic poisoning].

    PubMed

    Ramírez-Campos, J; Ramos-Peek, J; Martínez-Barros, M; Zamora-Peralta, M; Martínez-Cerrato, J

    1998-01-01

    Although peripheral neuropathy is a fairly common finding in chronic arsenic poisoning, little is known about the acute effects of this metal on peripheral nerves. This report shows clinical and electrophysiological findings in a patient who developed peripheral neuropathy only three days after a high-dose ingestion of this metal due to a failed suicide attempt. We speculate that peripheral nerves and some cranial nerves can show not only clinical but also subclinical involvement that can only be detected by neurophysiological studies.

  3. Theory underlying the peripheral vision horizon device

    NASA Technical Reports Server (NTRS)

    Money, K. E.

    1984-01-01

    Peripheral Vision Horizon Device (PVHD) theory states that the likelihood of pilot disorientation in flight is reduced by providing an artificial horizon that provides orientation information to peripheral vision. In considering the validity of the theory, three areas are explored: the use of an artificial horizon device over some other flight instrument; the use of peripheral vision over foveal vision; and the evidence that peripheral vision is well suited to the processing of orientation information.

  4. Looking for the most ``primitive'' organism(s) on Earth today: the state of the art

    NASA Astrophysics Data System (ADS)

    Forterre, Patrick

    1995-02-01

    Molecular phylogenetic studies have revealed a tripartite division of the living world into two procaryotic groups, Bacteria and Archaea, and one eucaryotic group, Eucarya. Which group is the most "primitive"? Which groups are sister? The answer to these questions would help to delineate the characters of the last common ancestor to all living beings, as a first step to reconstruct the earliest periods of biological evolution on Earth. The current "Procaryotic dogma" claims that procaryotes are primitive. Since the ancestor of Archaea was most probably a hyperthermophile, and since bacteria too might have originated from hyperthermophiles, the procaryotic dogma has been recently connected to the hot origin of life hypothesis. However, the notion that present-day hyperthermophiles are primitive has been challenged by recent findings, in these unique microorganisms, of very elaborate adaptative devices for life at high temperature. Accordingly, I discuss here alternative hypotheses that challenge the procaryotic dogma, such as the idea of a universal ancestor with molecular features in between those of eucaryotes and procaryotes, or the origin of procaryotes via thermophilic adaptation. Clearly, major evolutionary questions about early cellular evolution on Earth remain to be settled before we can speculate with confidence about which kinds of life might have appeared on other planets.

  5. The logical primitives of thought: Empirical foundations for compositional cognitive models.

    PubMed

    Piantadosi, Steven T; Tenenbaum, Joshua B; Goodman, Noah D

    2016-07-01

    The notion of a compositional language of thought (LOT) has been central in computational accounts of cognition from earliest attempts (Boole, 1854; Fodor, 1975) to the present day (Feldman, 2000; Penn, Holyoak, & Povinelli, 2008; Fodor, 2008; Kemp, 2012; Goodman, Tenenbaum, & Gerstenberg, 2015). Recent modeling work shows how statistical inferences over compositionally structured hypothesis spaces might explain learning and development across a variety of domains. However, the primitive components of such representations are typically assumed a priori by modelers and theoreticians rather than determined empirically. We show how different sets of LOT primitives, embedded in a psychologically realistic approximate Bayesian inference framework, systematically predict distinct learning curves in rule-based concept learning experiments. We use this feature of LOT models to design a set of large-scale concept learning experiments that can determine the most likely primitives for psychological concepts involving Boolean connectives and quantification. Subjects' inferences are most consistent with a rich (nonminimal) set of Boolean operations, including first-order, but not second-order, quantification. Our results more generally show how specific LOT theories can be distinguished empirically. (PsycINFO Database Record

  6. Anatomy and relationships of Pachyrhachis problematicus, a primitive snake with hindlimbs

    PubMed Central

    Lee, M. S. Y.

    1998-01-01

    The anatomy of Pachyrhachis problematicus, an elongate, limb-reduced squamate from the Upper Cretaceous of Israel, is described and evaluated in detail. Previously considered a snake-like 'lizard' of uncertain affinities, it is here shown to be the most primitive snake, and the sister-group to all other snakes. Pachyrhachis exhibits numerous derived characters uniting it with modern snakes (scolecophidians and alethinophidians): e.g. mobile premaxilla-maxilla articulation, braincase enclosed by frontals and parietals, sagittal parietal crest, absence of tympanic recess, single postdentary bone, over 140 presacral vertebrae, and complete loss of shoulder girdle and forelimb. However, it is more primitive than all modern snakes in retaining some strikingly primitive (lizard-like) features: presence of a jugal, squamosal, normal sacral attachment, and well-developed hindlimb composed of femur, tibia, fibula, and tarsals. Pachyrhachis provides additional support for the hypothesis that snakes are most closely related to Cretaceous marine lizards (mosasauroids). Almost all of the derived characters proposed to unite snakes and mosasauroids are highly developed in Pachyrhachis: the mobile mandibular symphysis, intramandibular joint, long and recurved pterygoid teeth, quadrate suspended by the supratemporal, loosely united pelvic elements (ilium, ischium, and pubis), and separate astragalus and calcaneum.

  7. The logical primitives of thought: Empirical foundations for compositional cognitive models.

    PubMed

    Piantadosi, Steven T; Tenenbaum, Joshua B; Goodman, Noah D

    2016-07-01

    The notion of a compositional language of thought (LOT) has been central in computational accounts of cognition from earliest attempts (Boole, 1854; Fodor, 1975) to the present day (Feldman, 2000; Penn, Holyoak, & Povinelli, 2008; Fodor, 2008; Kemp, 2012; Goodman, Tenenbaum, & Gerstenberg, 2015). Recent modeling work shows how statistical inferences over compositionally structured hypothesis spaces might explain learning and development across a variety of domains. However, the primitive components of such representations are typically assumed a priori by modelers and theoreticians rather than determined empirically. We show how different sets of LOT primitives, embedded in a psychologically realistic approximate Bayesian inference framework, systematically predict distinct learning curves in rule-based concept learning experiments. We use this feature of LOT models to design a set of large-scale concept learning experiments that can determine the most likely primitives for psychological concepts involving Boolean connectives and quantification. Subjects' inferences are most consistent with a rich (nonminimal) set of Boolean operations, including first-order, but not second-order, quantification. Our results more generally show how specific LOT theories can be distinguished empirically. (PsycINFO Database Record PMID:27077241

  8. A primitive Late Pliocene cheetah, and evolution of the cheetah lineage.

    PubMed

    Christiansen, Per; Mazák, Ji H

    2009-01-13

    The cheetah lineage is a group of large, slender, and long-limbed cats with a distinctive skull and dental morphology, of which only the extant cheetah (Acinonyx jubatus) is present today. The lineage is characterized by having abbreviated, tall, and domed crania, and a trenchant dentition with a much reduced, posteriorly placed protocone on the upper carnassial. In this article, we report on a new discovery of a Late Pliocene specimen from China with an estimated age of approximately 2.2-2.5 million years, making it one of the oldest specimens known to date. A cladistic analysis confirmed that it is the most primitive cheetah known, and it shares a number of unambiguous derived cranial traits with the Acinonyx lineage, but has more primitive dentition than previously known cheetahs, demonstrating that the many unusual skull and dental characters hitherto considered characteristic of cheetahs evolved in a gradual fashion. Isolated teeth of primitive cheetahs may not be recognizable as such, but can be confused with, for instance, those of leopards or other similar-sized pantherine cats or pumas. The age and morphology of the new specimen supports an Old World origin of the cheetah lineage, not a New World one, as has been suggested. We name the new species Acinonyx kurteni in honor of the late Björn Kurtén.

  9. The origin of the mammalian form of GnRH in primitive fishes.

    PubMed

    Sherwood, N M; Lovejoy, D A

    1989-06-01

    The presence of neuroendocrine hormones in extant agnathan fishes suggests that a method of control involving these hormones was operating 500-600 million years ago in emerging vertebrates. Data on a limited number of species show that several members of the GnRH family of peptides may have arisen in non-teleost fishes. Lamprey (Petromyzon marinus) GnRH has a unique composition and has not been detected in other vertebrates. It is not yet clear whether the chicken II GnRH-like molecule arose in cartilaginous fishes, but a chromatographically and immunologically similar molecule is found in dogfish (Squalus acanthias) and ratfish (Hydrolagus colliei). Finally, a mammalian GnRH-like molecule is detected in three primitive bony fish: sturgeon (Acipenser transmontanus), reed fish (Calamoichthys calabaricus), and alligator gar (Lepidosteus spatula). Minor forms are also present, but are not yet characterized. Clearly, the basic structure of GnRH peptides was established in primitive fish. In contrast, at least three other identified forms of GnRH have been detected in teleosts or tetrapods: Salmon I, catfish I, and chicken I GnRH. Evidence for the presence of members of the GnRH family and the neurohypophysial hormone family in primitive fishes argues for the importance of neuroendocrine control throughout the history of vertebrates. PMID:24221758

  10. The origin of the mammalian form of GnRH in primitive fishes.

    PubMed

    Sherwood, N M; Lovejoy, D A

    1989-06-01

    The presence of neuroendocrine hormones in extant agnathan fishes suggests that a method of control involving these hormones was operating 500-600 million years ago in emerging vertebrates. Data on a limited number of species show that several members of the GnRH family of peptides may have arisen in non-teleost fishes. Lamprey (Petromyzon marinus) GnRH has a unique composition and has not been detected in other vertebrates. It is not yet clear whether the chicken II GnRH-like molecule arose in cartilaginous fishes, but a chromatographically and immunologically similar molecule is found in dogfish (Squalus acanthias) and ratfish (Hydrolagus colliei). Finally, a mammalian GnRH-like molecule is detected in three primitive bony fish: sturgeon (Acipenser transmontanus), reed fish (Calamoichthys calabaricus), and alligator gar (Lepidosteus spatula). Minor forms are also present, but are not yet characterized. Clearly, the basic structure of GnRH peptides was established in primitive fish. In contrast, at least three other identified forms of GnRH have been detected in teleosts or tetrapods: Salmon I, catfish I, and chicken I GnRH. Evidence for the presence of members of the GnRH family and the neurohypophysial hormone family in primitive fishes argues for the importance of neuroendocrine control throughout the history of vertebrates.

  11. Search for the Most `primitive' Membranes and Their Reinforcers: A Review of the Polyprenyl Phosphates Theory

    NASA Astrophysics Data System (ADS)

    Nakatani, Yoichi; Ribeiro, Nigel; Streiff, Stéphane; Gotoh, Mari; Pozzi, Gianluca; Désaubry, Laurent; Milon, Alain

    2014-09-01

    Terpenoids have an essential function in present-day cellular membranes, either as membrane reinforcers in Eucarya and Bacteria or as principal membrane constituents in Archaea. We have shown that some terpenoids, such as cholesterol and α, ω-dipolar carotenoids reinforce lipid membranes by measuring the water permeability of unilamellar vesicles. It was possible to arrange the known membrane terpenoids in a `phylogenetic' sequence, and a retrograde analysis led us to conceive that single-chain polyprenyl phosphates might have been `primitive' membrane constituents. By using an optical microscopy, we have observed that polyprenyl phosphates containing 15 to 30 C-atoms form giant vesicles in water in a wide pH range. The addition of 10 % molar of some polyprenols to polyprenyl phosphate vesicles have been shown to reduce the water permeability of membranes even more efficiently than the equimolecular addition of cholesterol. A `prebiotic' synthesis of C10 and C15 prenols from C5 monoprenols was achieved in the presence of a montmorillonite clay. Hypothetical pathway from C1 or C2 units to `primitive' membranes and that from `primitive' membranes to archaeal lipids are presented.

  12. Looking for the most "primitive" organism(s) on Earth today: the state of the art.

    PubMed

    Forterre, P

    1995-01-01

    Molecular phylogenetic studies have revealed a tripartite division of the living world into two procaryotic groups, Bacteria and Archaea, and one eucaryotic group, Eucarya. Which group is the most "primitive"? Which groups are sister? The answer to these questions would help to delineate the characters of the last common ancestor to all living beings, as a first step to reconstruct the earliest periods of biological evolution on Earth. The current "Procaryotic dogma" claims that procaryotes are primitive. Since the ancestor of Archaea was most probably a hyperthermophile, and since bacteria too might have originated from hyperthermophiles, the procaryotic dogma has been recently connected to the hot origin of life hypothesis. However, the notion that present-day hyperthermophiles are primitive has been challenged by recent findings, in these unique microorganisms, of very elaborate adaptative devices for life at high temperature. Accordingly, I discuss here alternative hypotheses that challenge the procaryotic dogma, such as the idea of a universal ancestor with molecular features in between those of eucaryotes and procaryotes, or the origin of procaryotes via thermophilic adaptation. Clearly, major evolutionary questions about early cellular evolution on Earth remain to be settled before we can speculate with confidence about which kinds of life might have appeared on other planets.

  13. A primitive Late Pliocene cheetah, and evolution of the cheetah lineage

    PubMed Central

    Christiansen, Per; Mazák, Ji H.

    2009-01-01

    The cheetah lineage is a group of large, slender, and long-limbed cats with a distinctive skull and dental morphology, of which only the extant cheetah (Acinonyx jubatus) is present today. The lineage is characterized by having abbreviated, tall, and domed crania, and a trenchant dentition with a much reduced, posteriorly placed protocone on the upper carnassial. In this article, we report on a new discovery of a Late Pliocene specimen from China with an estimated age of ≈2.2–2.5 million years, making it one of the oldest specimens known to date. A cladistic analysis confirmed that it is the most primitive cheetah known, and it shares a number of unambiguous derived cranial traits with the Acinonyx lineage, but has more primitive dentition than previously known cheetahs, demonstrating that the many unusual skull and dental characters hitherto considered characteristic of cheetahs evolved in a gradual fashion. Isolated teeth of primitive cheetahs may not be recognizable as such, but can be confused with, for instance, those of leopards or other similar-sized pantherine cats or pumas. The age and morphology of the new specimen supports an Old World origin of the cheetah lineage, not a New World one, as has been suggested. We name the new species Acinonyx kurteni in honor of the late Björn Kurtén. PMID:19114651

  14. Kinematic primitives for walking and trotting gaits of a quadruped robot with compliant legs

    PubMed Central

    Spröwitz, Alexander T.; Ajallooeian, Mostafa; Tuleu, Alexandre; Ijspeert, Auke Jan

    2014-01-01

    In this work we research the role of body dynamics in the complexity of kinematic patterns in a quadruped robot with compliant legs. Two gait patterns, lateral sequence walk and trot, along with leg length control patterns of different complexity were implemented in a modular, feed-forward locomotion controller. The controller was tested on a small, quadruped robot with compliant, segmented leg design, and led to self-stable and self-stabilizing robot locomotion. In-air stepping and on-ground locomotion leg kinematics were recorded, and the number and shapes of motion primitives accounting for 95% of the variance of kinematic leg data were extracted. This revealed that kinematic patterns resulting from feed-forward control had a lower complexity (in-air stepping, 2–3 primitives) than kinematic patterns from on-ground locomotion (νm4 primitives), although both experiments applied identical motor patterns. The complexity of on-ground kinematic patterns had increased, through ground contact and mechanical entrainment. The complexity of observed kinematic on-ground data matches those reported from level-ground locomotion data of legged animals. Results indicate that a very low complexity of modular, rhythmic, feed-forward motor control is sufficient for level-ground locomotion in combination with passive compliant legged hardware. PMID:24639645

  15. Kinematic primitives for walking and trotting gaits of a quadruped robot with compliant legs.

    PubMed

    Spröwitz, Alexander T; Ajallooeian, Mostafa; Tuleu, Alexandre; Ijspeert, Auke Jan

    2014-01-01

    In this work we research the role of body dynamics in the complexity of kinematic patterns in a quadruped robot with compliant legs. Two gait patterns, lateral sequence walk and trot, along with leg length control patterns of different complexity were implemented in a modular, feed-forward locomotion controller. The controller was tested on a small, quadruped robot with compliant, segmented leg design, and led to self-stable and self-stabilizing robot locomotion. In-air stepping and on-ground locomotion leg kinematics were recorded, and the number and shapes of motion primitives accounting for 95% of the variance of kinematic leg data were extracted. This revealed that kinematic patterns resulting from feed-forward control had a lower complexity (in-air stepping, 2-3 primitives) than kinematic patterns from on-ground locomotion (νm4 primitives), although both experiments applied identical motor patterns. The complexity of on-ground kinematic patterns had increased, through ground contact and mechanical entrainment. The complexity of observed kinematic on-ground data matches those reported from level-ground locomotion data of legged animals. Results indicate that a very low complexity of modular, rhythmic, feed-forward motor control is sufficient for level-ground locomotion in combination with passive compliant legged hardware.

  16. Coaching Peripheral Vision Training for Soccer Athletes

    ERIC Educational Resources Information Center

    Marques, Nelson Kautzner, Jr.

    2010-01-01

    Brazilian Soccer began developing its current emphasis on peripheral vision in the late 1950s, by initiative of coach of the Canto do Rio Football Club, in Niteroi, Rio de Janeiro, a pioneer in the development of peripheral vision training in soccer players. Peripheral vision training gained world relevance when a young talent from Canto do Rio,…

  17. PERIPHERAL BLOOD FILM - A REVIEW

    PubMed Central

    Adewoyin, AS; Nwogoh, B.

    2014-01-01

    The peripheral blood film (PBF) is a laboratory work-up that involves cytology of peripheral blood cells smeared on a slide. As basic as it is, PBF is invaluable in the characterization of various clinical diseases. This article highlights the basic science and art behind the PBF. It expounds its laboratory applications, clinical indications and interpretations in the light of various clinical diseases. Despite advances in haematology automation and application of molecular techniques, the PBF has remained a very important diagnostic test to the haematologist. A good quality smear, thorough examination and proper interpretation in line with patient's clinical state should be ensured by the haemato-pathologist. Clinicians should be abreast with its clinical utility and proper application of the reports in the management of patients. PMID:25960697

  18. Peripheral blood film - a review.

    PubMed

    Adewoyin, A S; Nwogoh, B

    2014-12-01

    The peripheral blood film (PBF) is a laboratory work-up that involves cytology of peripheral blood cells smeared on a slide. As basic as it is, PBF is invaluable in the characterization of various clinical diseases. This article highlights the basic science and art behind the PBF. It expounds its laboratory applications, clinical indications and interpretations in the light of various clinical diseases. Despite advances in haematology automation and application of molecular techniques, the PBF has remained a very important diagnostic test to the haematologist. A good quality smear, thorough examination and proper interpretation in line with patient's clinical state should be ensured by the haemato-pathologist. Clinicians should be abreast with its clinical utility and proper application of the reports in the management of patients. PMID:25960697

  19. Peripheral facial palsy in children.

    PubMed

    Yılmaz, Unsal; Cubukçu, Duygu; Yılmaz, Tuba Sevim; Akıncı, Gülçin; Ozcan, Muazzez; Güzel, Orkide

    2014-11-01

    The aim of this study is to evaluate the types and clinical characteristics of peripheral facial palsy in children. The hospital charts of children diagnosed with peripheral facial palsy were reviewed retrospectively. A total of 81 children (42 female and 39 male) with a mean age of 9.2 ± 4.3 years were included in the study. Causes of facial palsy were 65 (80.2%) idiopathic (Bell palsy) facial palsy, 9 (11.1%) otitis media/mastoiditis, and tumor, trauma, congenital facial palsy, chickenpox, Melkersson-Rosenthal syndrome, enlarged lymph nodes, and familial Mediterranean fever (each 1; 1.2%). Five (6.1%) patients had recurrent attacks. In patients with Bell palsy, female/male and right/left ratios were 36/29 and 35/30, respectively. Of them, 31 (47.7%) had a history of preceding infection. The overall rate of complete recovery was 98.4%. A wide variety of disorders can present with peripheral facial palsy in children. Therefore, careful investigation and differential diagnosis is essential.

  20. Insertion of 3-D-primitives in mesh-based representations: towards compact models preserving the details.

    PubMed

    Lafarge, Florent; Keriven, Renaud; Brédif, Mathieu

    2010-07-01

    We propose an original hybrid modeling process of urban scenes that represents 3-D models as a combination of mesh-based surfaces and geometric 3-D-primitives. Meshes describe details such as ornaments and statues, whereas 3-D-primitives code for regular shapes such as walls and columns. Starting from an 3-D-surface obtained by multiview stereo techniques, these primitives are inserted into the surface after being detected. This strategy allows the introduction of semantic knowledge, the simplification of the modeling, and even correction of errors generated by the acquisition process. We design a hierarchical approach exploring different scales of an observed scene. Each level consists first in segmenting the surface using a multilabel energy model optimized by -expansion and then in fitting 3-D-primitives such as planes, cylinders or tori on the obtained partition where relevant. Experiments on real meshes, depth maps and synthetic surfaces show good potential for the proposed approach.

  1. Peripheral doses from pediatric IMRT

    SciTech Connect

    Klein, Eric E.; Maserang, Beth; Wood, Roy; Mansur, David

    2006-07-15

    Peripheral dose (PD) data exist for conventional fields ({>=}10 cm) and intensity-modulated radiotherapy (IMRT) delivery to standard adult-sized phantoms. Pediatric peripheral dose reports are limited to conventional therapy and are model based. Our goal was to ascertain whether data acquired from full phantom studies and/or pediatric models, with IMRT treatment times, could predict Organ at Risk (OAR) dose for pediatric IMRT. As monitor units (MUs) are greater for IMRT, it is expected IMRT PD will be higher; potentially compounded by decreased patient size (absorption). Baseline slab phantom peripheral dose measurements were conducted for very small field sizes (from 2 to 10 cm). Data were collected at distances ranging from 5 to 72 cm away from the field edges. Collimation was either with the collimating jaws or the multileaf collimator (MLC) oriented either perpendicular or along the peripheral dose measurement plane. For the clinical tests, five patients with intracranial or base of skull lesions were chosen. IMRT and conventional three-dimensional (3D) plans for the same patient/target/dose (180 cGy), were optimized without limitation to the number of fields or wedge use. Six MV, 120-leaf MLC Varian axial beams were used. A phantom mimicking a 3-year-old was configured per Center for Disease Control data. Micro (0.125 cc) and cylindrical (0.6 cc) ionization chambers were appropriated for the thyroid, breast, ovaries, and testes. The PD was recorded by electrometers set to the 10{sup -10} scale. Each system set was uniquely calibrated. For the slab phantom studies, close peripheral points were found to have a higher dose for low energy and larger field size and when MLC was not deployed. For points more distant from the field edge, the PD was higher for high-energy beams. MLC orientation was found to be inconsequential for the small fields tested. The thyroid dose was lower for IMRT delivery than that predicted for conventional (ratio of IMRT/cnventional ranged

  2. Persisting primitive reflexes in medication-naïve girls with attention-deficit and hyperactivity disorder

    PubMed Central

    Konicarova, Jana; Bob, Petr; Raboch, Jiri

    2013-01-01

    Background and objectives Recent and historical findings suggest that later-developed functions during brain ontogenesis related to higher levels of cognitive and motor integration tend to replace the older, more primitive, ones, and the persistence of the older functions may be linked to specific neuropsychiatric disorders. Currently, there is growing evidence to suggest that persisting primitive reflexes may be related to developmental and neurodegenerative disorders. Preliminary data also suggest that persisting primitive reflexes may be specifically linked to attention-deficit and hyperactivity disorder (ADHD). Methods In the study reported here, we tested to what extent the persisting primitive asymmetric tonic neck reflex and symmetric tonic neck reflex are related to ADHD symptoms measured by Conners’ Parent Questionnaire in 35 medication-naïve girls of school age (8–11 years) with ADHD. The results were compared with those of a control group of 30 girls of the same age. Results This study showed that persisting primitive reflexes are closely linked to ADHD symptoms. Conclusion The data suggest that ADHD symptoms may be linked to more primitive neural mechanisms interfering with higher brain functions due to insufficiently developed cognitive and motor integration. PMID:24092983

  3. Detection of peripheral nerve pathology

    PubMed Central

    Seelig, Michael J.; Baker, Jonathan C.; Mackinnon, Susan E.; Pestronk, Alan

    2013-01-01

    Objective: To compare accuracy of ultrasound and MRI for detecting focal peripheral nerve pathology, excluding idiopathic carpal or cubital tunnel syndromes. Methods: We performed a retrospective review of patients referred for neuromuscular ultrasound to identify patients who had ultrasound and MRI of the same limb for suspected brachial plexopathy or mononeuropathies, excluding carpal/cubital tunnel syndromes. Ultrasound and MRI results were compared to diagnoses determined by surgical or, if not performed, clinical/electrodiagnostic evaluation. Results: We identified 53 patients who had both ultrasound and MRI of whom 46 (87%) had nerve pathology diagnosed by surgical (n = 39) or clinical/electrodiagnostic (n = 14) evaluation. Ultrasound detected the diagnosed nerve pathology (true positive) more often than MRI (43/46 vs 31/46, p < 0.001). Nerve pathology was correctly excluded (true negative) with equal frequency by MRI and ultrasound (both 6/7). In 25% (13/53), ultrasound was accurate (true positive or true negative) when MRI was not. These pathologies were typically (10/13) long (>2 cm) and only occasionally (2/13) outside the MRI field of view. MRI missed multifocal pathology identified with ultrasound in 6 of 7 patients, often (5/7) because pathology was outside the MRI field of view. Conclusions: Imaging frequently detects peripheral nerve pathology and contributes to the differential diagnosis in patients with mononeuropathies and brachial plexopathies. Ultrasound is more sensitive than MRI (93% vs 67%), has equivalent specificity (86%), and better identifies multifocal lesions than MRI. In sonographically accessible regions ultrasound is the preferred initial imaging modality for anatomic evaluation of suspected peripheral nervous system lesions. PMID:23553474

  4. Primitive magmas at five Cascade volcanic fields: Melts from hot, heterogeneous sub-arc mantle

    USGS Publications Warehouse

    Bacon, C.R.; Bruggman, P.E.; Christiansen, R.L.; Clynne, M.A.; Donnelly-Nolan, J. M.; Hildreth, W.

    1997-01-01

    Major and trace element concentrations, including REE by isotope dilution, and Sr, Nd, Pb, and O isotope ratios have been determined for 38 mafic lavas from the Mount Adams, Crater Lake, Mount Shasta, Medicine Lake, and Lassen volcanic fields, in the Cascade arc, northwestern part of the United States. Many of the samples have a high Mg# [100Mg/(Mg + FeT) > 60] and Ni content (>140 ppm) such that we consider them to be primitive. We recognize three end-member primitive magma groups in the Cascades, characterized mainly by their trace-element and alkali-metal abundances: (1) High-alumina olivine tholeiite (HAOT) has trace element abundances similar to N-MORB, except for slightly elevated LILE, and has Eu/Eu* > 1. (2) Arc basalt and basaltic andesite have notably higher LILE contents, generally have higher SiO2 contents, are more oxidized, and have higher Cr for a given Ni abundance than HAOT. These lavas show relative depletion in HFSE, have lower HREE and higher LREE than HAOT, and have smaller Eu/Eu* (0.94-1.06). (3) Alkali basalt from the Simcoe volcanic field east of Mount Adams represents the third end-member, which contributes an intraplate geochemical signature to magma compositions. Notable geochemical features among the volcanic fields are: (1) Mount Adams rocks are richest in Fe and most incompatible elements including HFSE; (2) the most incompatible-element depleted lavas occur at Medicine Lake; (3) all centers have relatively primitive lavas with high LILE/HFSE ratios but only the Mount Adams, Lassen, and Medicine Lake volcanic fields also have relatively primitive rocks with an intraplate geochemical signature; (4) there is a tendency for increasing 87Sr/86Sr, 207Pb/204Pb, and ??18O and decreasing 206Pb/204Pb and 143Nd/144Nd from north to south. The three end-member Cascade magma types reflect contributions from three mantle components: depleted sub-arc mantle modestly enriched in LILE during ancient subduction; a modern, hydrous subduction component

  5. Rehabilitation of peripheral nerve injuries.

    PubMed

    Robinson, Michael D; Shannon, Steven

    2002-02-01

    Traumatic injuries to peripheral nerves pose complex challenges to both military and civilian physicians. Treatment of nerve injuries must consider all aspects of the inherent disability. Pain control is of paramount importance. Little will be accomplished until pain is brought down to tolerable levels. Rehabilitation needs to be instituted as first-line treatment. Focus must be first placed on protection of the affected area from complications stemming from disuse and immobility and then on enhancement of strength, flexibility, sensory discrimination, and dexterity. Early intervention sets the stage for optimal physiologic and functional recovery. PMID:11878078

  6. Scleritis and Peripheral Ulcerative Keratitis

    PubMed Central

    Galor, Anat; Thorne, Jennifer E.

    2008-01-01

    Scleritis and peripheral ulcerative keratitis (PUK) can present as isolated conditions or as part of a systemic inflammatory or infectious disorder. Both are serious ocular conditions that can result in vision loss and therefore require early diagnosis and treatment. Nearly two-thirds of patients with non-infectious scleritis require systemic glucocorticoid therapy, and one fourth need a glucocorticoid-sparing agent, as well. Essentially all patients with non-infectious PUK require systemic glucocorticoids. Detailed clinical history, thorough physical examination, and thoughtful laboratory evaluations are all important in the exclusion of underlying disorders and extraocular involvement. PMID:18037120

  7. Peripheral nerve disease in pregnancy.

    PubMed

    Klein, Autumn

    2013-06-01

    Neuropathies during pregnancy and the postpartum period are common and are usually due to compression around pregnancy and childbirth. The most common peripheral neuropathies are Bell's palsy, carpal tunnel syndrome (CTS), and lower extremity neuropathies. Although most neuropathies are usually reversible, associated disabilities or morbidities can limit functioning and require therapy. Nerve conduction study tests and imaging should only be considered if symptoms are unusual or prolonged. Some neuropathies may be associated with preeclampsia or an inherent underlying neuropathy that increases the risk of nerve injury. All neuropathies in pregnancy should be followed as some may be persistent and require follow-up. PMID:23563878

  8. [Trigeminal neuralgia associated with primitive trigeminal artery: report of two cases].

    PubMed

    Tokimura, H; Atsuchi, M; Kawasaki, T; Sato, E; Todoroki, K; Asakura, T; Fukushima, T

    1990-02-01

    Two cases of trigeminal neuralgia associated with the primitive trigeminal artery are reported. From 1981, the authors have treated 131 trigeminal neuralgia patients with microvascular decompression. Among them, we encountered two rare cases of trigeminal neuralgia associated with the primitive trigeminal artery (PTA) and its variant (PTAV). Case 1 is a 74-year-old woman who was admitted to our hospital due to pain of maxilla and mandible. We diagnosed her pain as trigeminal neuralgia. Preoperative angiogram showed the primitive trigeminal artery arising from the cavernous portion of the right internal carotid artery (ICA). She underwent a microvascular decompression operation. We found that her right trigeminal nerve was compressed by the right superior cerebellar artery (SCA) and the right anterior inferior cerebellar artery (AICA). We transferred the offending arteries, and her pain disappeared. Case 2 is a 48-year-old man who was admitted to our hospital due to severe mandibular pain. We diagnosed his pain as trigeminal neuralgia, and he underwent a microvascular decompression operation. His left trigeminal nerve was found compressed by the left SCA and the AICA, and the AICA was arising from the direction of Meckel's cave. His severe pain disappeared completely after operation. Postoperative angiogram of his left ICA showed an aberrant artery arising from the cavernous portion of the ICA, to the region of the left AICA. This aberrant artery is a variant of PTA (PTAV). PTA and PTAV, the so called persistent congenital arteries, are said to accompany aneurysms and other vascular lesions, and affect hemodynamic stress.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2336149

  9. Phosphate Sorption and Desorption on Pyrite in Primitive Aqueous Scenarios: Relevance of acidic → Alkaline Transitions

    NASA Astrophysics Data System (ADS)

    de Souza-Barros, Fernando; Braz-Levigard, Raphael; Ching-San, Yonder; Monte, Marisa M. B.; Bonapace, José A. P.; Montezano, Viviane; Vieyra, Adalberto

    2007-02-01

    Phosphate (P i) sorption assays onto pyrite in media simulating primeval aquatic scenarios affected by hydrothermal emissions, reveal that acidic conditions favour P i sorption whereas mild alkaline media as well as those simulating sulfur oxidation to SO2- 4 revert this capture process. Several mechanisms relevant to P i availability in prebiotic eras are implicated in the modulation of these processes. Those favouring sorption are: (a) hydrophobic coating of molecules, such as acetate that could be formed in the vicinity of hydrothermal vents; (b) water and Mg2+ bridging in the interface mineral-aqueous media; (c) surface charge neutralization by monovalent cations (Na+ and K+). The increase of both the medium pH and the SO2- 4 trapping by the mineral interface would provoke the release of sorbed P i due to charge polarization. Moreover it is shown that P i self-modulates its sorption, a mechanism that depends on the abundance of SO2- 4 in the interface. The relevance of the proposed mechanisms of P i capture, release and trapping arises from the need of abundant presence of this molecule for primitive phosphorylations, since similarly to contemporary aqueous media inorganic phosphate concentrations in primitive seas should have been low. It is proposed that the presence of sulphide minerals with high affinity to P i could have trapped this molecule in an efficient manner, allowing its concentration in specific niches. In these niches, the conditions studied in the present work would have been relevant for its availability in soluble form, specially in primitive insulated systems with pH gradients across the wall.

  10. Phosphate sorption and desorption on pyrite in primitive aqueous scenarios: relevance of acidic --> alkaline transitions.

    PubMed

    de Souza-Barros, Fernando; Braz-Levigard, Raphael; Ching-San, Yonder; Monte, Marisa M B; Bonapace, José A P; Montezano, Viviane; Vieyra, Adalberto

    2007-02-01

    Phosphate (P(i)) sorption assays onto pyrite in media simulating primeval aquatic scenarios affected by hydrothermal emissions, reveal that acidic conditions favour P(i) sorption whereas mild alkaline media--as well as those simulating sulfur oxidation to SO(2-) (4)--revert this capture process. Several mechanisms relevant to P(i) availability in prebiotic eras are implicated in the modulation of these processes. Those favouring sorption are: (a) hydrophobic coating of molecules, such as acetate that could be formed in the vicinity of hydrothermal vents; (b) water and Mg(2+) bridging in the interface mineral-aqueous media; (c) surface charge neutralization by monovalent cations (Na+ and K+). The increase of both the medium pH and the SO(2-) (4) trapping by the mineral interface would provoke the release of sorbed P(i) due to charge polarization. Moreover it is shown that P(i) self-modulates its sorption, a mechanism that depends on the abundance of SO(2-) (4) in the interface. The relevance of the proposed mechanisms of P(i) capture, release and trapping arises from the need of abundant presence of this molecule for primitive phosphorylations, since--similarly to contemporary aqueous media--inorganic phosphate concentrations in primitive seas should have been low. It is proposed that the presence of sulphide minerals with high affinity to P(i) could have trapped this molecule in an efficient manner, allowing its concentration in specific niches. In these niches, the conditions studied in the present work would have been relevant for its availability in soluble form, specially in primitive insulated systems with pH gradients across the wall.

  11. A compact representation of drawing movements with sequences of parabolic primitives.

    PubMed

    Polyakov, Felix; Drori, Rotem; Ben-Shaul, Yoram; Abeles, Moshe; Flash, Tamar

    2009-07-01

    Some studies suggest that complex arm movements in humans and monkeys may optimize several objective functions, while others claim that arm movements satisfy geometric constraints and are composed of elementary components. However, the ability to unify different constraints has remained an open question. The criterion for a maximally smooth (minimizing jerk) motion is satisfied for parabolic trajectories having constant equi-affine speed, which thus comply with the geometric constraint known as the two-thirds power law. Here we empirically test the hypothesis that parabolic segments provide a compact representation of spontaneous drawing movements. Monkey scribblings performed during a period of practice were recorded. Practiced hand paths could be approximated well by relatively long parabolic segments. Following practice, the orientations and spatial locations of the fitted parabolic segments could be drawn from only 2-4 clusters, and there was less discrepancy between the fitted parabolic segments and the executed paths. This enabled us to show that well-practiced spontaneous scribbling movements can be represented as sequences ("words") of a small number of elementary parabolic primitives ("letters"). A movement primitive can be defined as a movement entity that cannot be intentionally stopped before its completion. We found that in a well-trained monkey a movement was usually decelerated after receiving a reward, but it stopped only after the completion of a sequence composed of several parabolic segments. Piece-wise parabolic segments can be generated by applying affine geometric transformations to a single parabolic template. Thus, complex movements might be constructed by applying sequences of suitable geometric transformations to a few templates. Our findings therefore suggest that the motor system aims at achieving more parsimonious internal representations through practice, that parabolas serve as geometric primitives and that non-Euclidean variables are

  12. The human lung during the embryonic period: vasculogenesis and primitive erythroblasts circulation

    PubMed Central

    Pereda, J; Sulz, L; San Martin, S; Godoy-Guzmán, C

    2013-01-01

    Vascularization and blood cell circulation are crucial steps during lung development. However, how blood vessels are generated and when lung circulation is initiated is still a matter of debate. A morpho-functional analysis of pulmonary vasculature was done using human lung samples between 31 and 56 days post-fertilization (pf). The immunolocalization and expression of CD31, CD34, FLT-1, KDR and the vascular growth factor (VEGF) were investigated. The results showed that at day 31 pf, a capillary plexus is already installed, and a few primitive erythroblasts were seen for the first time within the lumen of some blood vessels. Around day 45 pf, an increase in the amount of primitive erythroblasts was detected in the parenchyma surrounding the distal segment of the bronchial tree. The expression of FLT-1, KDR, CD31 and CD34 was observed in endothelial cells of the capillary plexus and the VEGF was detected in the endodermal epithelium. Our results support the hypothesis that the initial formation of the capillary plexus around the tip of the growing airway bud occurs by vasculogenesis, probably regulated by VEGF and KDR. We also showed a very early onset of blood circulation, starting from day 34 pf, concomitant with the generation of new lung buds. In addition, the increasing number of primitive erythroblasts from week 6 onward, associated with a change in the shape of the blood vessels, suggests a remodeling process and that the generation of new distal vessels at the tip of the lung bud occurs mainly by a process of angiogenesis. PMID:23520979

  13. The human lung during the embryonic period: vasculogenesis and primitive erythroblasts circulation.

    PubMed

    Pereda, J; Sulz, L; San Martin, S; Godoy-Guzmán, C

    2013-05-01

    Vascularization and blood cell circulation are crucial steps during lung development. However, how blood vessels are generated and when lung circulation is initiated is still a matter of debate. A morpho-functional analysis of pulmonary vasculature was done using human lung samples between 31 and 56 days post-fertilization (pf). The immunolocalization and expression of CD31, CD34, FLT-1, KDR and the vascular growth factor (VEGF) were investigated. The results showed that at day 31 pf, a capillary plexus is already installed, and a few primitive erythroblasts were seen for the first time within the lumen of some blood vessels. Around day 45 pf, an increase in the amount of primitive erythroblasts was detected in the parenchyma surrounding the distal segment of the bronchial tree. The expression of FLT-1, KDR, CD31 and CD34 was observed in endothelial cells of the capillary plexus and the VEGF was detected in the endodermal epithelium. Our results support the hypothesis that the initial formation of the capillary plexus around the tip of the growing airway bud occurs by vasculogenesis, probably regulated by VEGF and KDR. We also showed a very early onset of blood circulation, starting from day 34 pf, concomitant with the generation of new lung buds. In addition, the increasing number of primitive erythroblasts from week 6 onward, associated with a change in the shape of the blood vessels, suggests a remodeling process and that the generation of new distal vessels at the tip of the lung bud occurs mainly by a process of angiogenesis.

  14. De novo synthesis and functional study of primitive polypeptides in the prebiotic protein world

    NASA Astrophysics Data System (ADS)

    Fujishima, Kosuke; Wang, Kendrick; Ferreira, Raphael; Rothschild, Lynn

    DNA, RNA and proteins within a lipid-bound membrane are the core components of life, but the order of their appearance during the origin and evolution of life is still under debate. The widely accepted “RNA World” hypothesis states that RNA likely emerged prior to proteins and DNA since RNA can serve both replicative and catalytic roles. While biochemists have reproduced the synthesis, polymerization, and replication of nucleotides/RNA under controlled prebiotic conditions, such complex organic molecules were not present in significant amounts on the prebiotic Earth. In contrast, amino acids are naturally abundant in various prebiotic contexts such as carbonaceous chondrites and Urey-Miller type experiments, and many studies have demonstrated plausible prebiotic conditions that could condense/polymerize amino acids to give rise to short peptides. These findings support the basis of a “Protein World” hypothesis for life, however little has been done to study the functions of such primitive peptides. Here, we present a novel synthetic biology-based approach to the de novo synthesis of over billions of primitive peptides/proteins derived from a limited set of naturally abundant proteinogenic amino acids. Of these peptides, ones with divalent metal-binding capability are of particular interest and will be screened and identified. Certain divalent metals are likely present in prebiotic environments and both coordinate well with amino acids and catalyze reactions, which are difficult to achieve in organic chemistry. Furthermore, since D-chiral and non-proteinogenic amino acids are also abundant in the universe and may provide insight into the pathway by which life developed, the methods to analyze primitive peptides consisting of these amino acids will be discussed. By understanding this natural pathway, we will be able to better understand how life developed here on Earth and the probability of life arising elsewhere.

  15. Versatility of `hemorheologic fitness' according to exercise intensity: emphasis on the "healthy primitive lifestyle"

    NASA Astrophysics Data System (ADS)

    Brun, Jean-Frédéric; Varlet-Marie, Emmanuelle; Chevance, Guillaume; Pollatz, Marion; Fedou, Christine; de Mauverger, Eric Raynaud

    2014-05-01

    We recently proposed a unifying hypothesis to reconcile unexpected findings in exercise hemorheology and the classical concepts of "hemorheologic fitness" and the "triphasic effects of exercise", based on the "healthy primitive lifestyle" paradigm. This paradigm assumes that evolution has selected genetic polymorphisms leading to insulin resistance as an adaptative strategy to cope with continuous low intensity physical activity and a special alimentation moderately high in protein, rich in low glycemic index carbohydrates, and poor in saturated fat. According to this protocol the true physiological picture would be that of an individual whose exercise and nutritional habits are close from this lifestyle, both sedentary subjects and trained athletes representing situations on the edge of this model. Unfortunately samples of people truly adhering to this ancestral lifestyle are hard to obtain. In order to address this picture we tried to compare databases obtained with our preceding published studies. As a model of the "healthy primitive lifestyle" we selected patients trained at low intensity (LI) and given an advice of protein intake around 1.2 g/kg/day. Results show a continuum for plasma viscosity which seems to be lower in athletes than LI-trained and even more sedentaries. When sedentary subjects become obese the most obvious characteristic is an increase in red blood cell (RBC) aggregation correlated to the size of fat stores. It is clear that 3 months of LI are not a perfect model of "healthy primitive lifestyle", but these data suggest that the most important effect of LI regular exercise is to decrease plasma viscosity and that sedentarity increases RBC aggregation mostly when it results in increased fat storage.

  16. Early cosmic ray irradiation of chondrules and prolonged accretion of primitive meteorites

    NASA Astrophysics Data System (ADS)

    Beyersdorf-Kuis, Uta; Ott, Ulrich; Trieloff, Mario

    2015-08-01

    Chondrules, together with Ca-Al-rich inclusions (CAIs) and matrix, are the major constituents of primitive meteorites. It is clear that chondrules formed as molten objects and the conditions under which this happened seem well constrained. Partially overlapping in age, but mostly ∼2-3 million years younger than the CAIs, they appear to have formed over an extended period of time (e.g., Kita et al., 2013). We have analyzed chondrules in two highly primitive CR3 meteorites, QUE 99177 and MET 00426, and find that they contain highly variable amounts of noble gases produced by irradiation with cosmic rays. The lack of implanted solar wind and the composition of the cosmogenic component in QUE 99177 chondrules argue against irradiation in a parent body regolith, which leaves irradiation in the early solar system as the most likely explanation. The cosmogenic composition also points to irradiation primarily by galactic cosmic rays (GCR), not solar cosmic rays (SCR), i.e. not by an active early sun. To allow effective production of cosmogenic isotopes by GCR, but not SCR, this should have happened rather "late" in a largely, but not completely, dust-free environment. Our results support the suggestion that chondrules formed as free-floating objects in the solar nebula; also consistent with the noble gas data is pre-irradiation in small (∼dm-size) aggregates that broke up before or during accretion to the CR parent body. In both cases, chondrules spent an extended period of time before incorporation into the most primitive meteorite parent bodies, which puts constraints on accretion time scales.

  17. Amino acid codes in mitochondria as possible clues to primitive codes

    NASA Technical Reports Server (NTRS)

    Jukes, T. H.

    1981-01-01

    Differences between mitochondrial codes and the universal code indicate that an evolutionary simplification has taken place, rather than a return to a more primitive code. However, these differences make it evident that the universal code is not the only code possible, and therefore earlier codes may have differed markedly from the previous code. The present universal code is probably a 'frozen accident.' The change in CUN codons from leucine to threonine (Neurospora vs. yeast mitochondria) indicates that neutral or near-neutral changes occurred in the corresponding proteins when this code change took place, caused presumably by a mutation in a tRNA gene.

  18. A human supervisory approach to rapid world modeling through the use of geometric primitives

    SciTech Connect

    Luck, J.; Roberts, R.

    1997-08-11

    A three-dimensional world model is crucial for many robot-oriented tasks. The most efficient mapping configuration use geometric primitives to model environments, and are easy to store and process. In the past, modeling techniques have been either fully manual or autonomous. Manual methods are extremely time consuming but also highly accurate and flexible. On the other hand autonomous techniques are fast but inflexible and often inaccurate. The method presented in this paper combines the two thereby yielding a highly efficient, flexible, and accurate tool. Our methods enable a human supervisor to quickly construct a fully defined world model from unfiltered and unsegmented real-world range data.

  19. HCN - A plausible source of purines, pyrimidines and amino acids on the primitive earth

    NASA Technical Reports Server (NTRS)

    Ferris, J.-P.; Joshi, P. C.; Edelson, E. H.; Lawless, J. G.

    1978-01-01

    Dilute (0.1 M) solutions of HCN condense to oligomers at pH 9.2, and hydrolysis of these oligomers yields 4,5-dihydroxypyrimidine, orotic acid, 5-hydroxyuracil, adenine, 4-aminoimidazole-5-carboxamide, and amino acids. It is suggested that the three main classes of nitrogen-containing biomolecules - purines, pyrimidines, and amino acids may have originated from HCN on the primitive earth. It is also suggested that the presence of orotic acid and 4-aminoimidazole-5-carboxamide might indicate that contemporary biosynthetic pathways for nucleotides evolved from the compounds released on hydrolysis of HCN oligomers.

  20. A two-dimensional primitive equation model of frontogenesis forced by confluence and horizontal shear

    NASA Technical Reports Server (NTRS)

    Keyser, D.; Pecnick, M. J.

    1985-01-01

    A two-dimensional primitive equation model of frontogenesis is presented. The model treats confluence and horizontal shear in combination. The structure and evolution of model frontal zones forced by confluence are described for a control case featuring a zero alongfront thermal gradient and positive and negative thermal gradients, facing downstream. A comparison is made with Miller's (1948) equation for the zero gradient situation to illustrate the significance of horizontal and vertical motions for the structure of the upper level frontal zone. Finally, the effects of ageostrophic circulations on the evolutionary and structural differences of frontal formations are studied.

  1. Pb isotopes in anorthositic breccias 67075 and 62237 - A search for primitive lunar lead

    NASA Technical Reports Server (NTRS)

    Premo, W. R.; Tatsumoto, M.; Wang, J.-W.

    1989-01-01

    The lunar Pb isotopic evolution is explored based on an investigation of the U-Th-Pb systematics of the primitive Apollo 16 anorthositic breccias 76075 and 62237. The isotope data for acid-leached residues from 67075 lie within or on a triangle formed by plagioclase, opaques, and a pyroxen-olivine mixture, and the isotope data for 62237 lie within or on a triangle formed by plagioclase, olivine, and pyroxene. The results suggest that the moon had high first-stage values for the Pb evolution equations from the onset.

  2. Memory efficient solution of the primitive equations for numerical weather prediction on the CYBER 205

    NASA Technical Reports Server (NTRS)

    Tuccillo, J. J.

    1984-01-01

    Numerical Weather Prediction (NWP), for both operational and research purposes, requires only fast computational speed but also large memory. A technique for solving the Primitive Equations for atmospheric motion on the CYBER 205, as implemented in the Mesoscale Atmospheric Simulation System, which is fully vectorized and requires substantially less memory than other techniques such as the Leapfrog or Adams-Bashforth Schemes is discussed. The technique presented uses the Euler-Backard time marching scheme. Also discussed are several techniques for reducing computational time of the model by replacing slow intrinsic routines by faster algorithms which use only hardware vector instructions.

  3. Crystallization of the Focal Adhesion Kinase Targeting (FAT) Domain in a Primitive Orthorhombic Space Group

    SciTech Connect

    Magis,A.; Bailey, K.; Kurenova, E.; Hernandez Prada, J.; Cance, W.; Ostrov, D.

    2008-01-01

    X-ray diffraction data from the targeting (FAT) domain of focal adhesion kinase (FAK) were collected from a single crystal that diffracted to 1.99 Angstroms resolution and reduced to the primitive orthorhombic lattice. A single molecule was predicted to be present in the asymmetric unit based on the Matthews coefficient. The data were phased using molecular-replacement methods using an existing model of the FAK FAT domain. All structures of human focal adhesion kinase FAT domains solved to date have been solved in a C-centered orthorhombic space group.

  4. The primitive equations of the atmosphere in presence of vapour saturation

    NASA Astrophysics Data System (ADS)

    Coti Zelati, Michele; Huang, Aimin; Kukavica, Igor; Temam, Roger; Ziane, Mohammed

    2015-03-01

    A modification of the classical primitive equations of the atmosphere is considered in order to take into account important phase transition phenomena due to air saturation and condensation. We provide a mathematical formulation of the problem that appears to be new in this setting, by making use of differential inclusions and variational inequalities, and which allows to develop a rather complete theory for the solutions to what turns out to be a nonlinearly coupled system of non-smooth partial differential equations. Specifically we prove the global existence of quasi-strong and strong solutions, along with uniqueness results and maximum principles of physical interest.

  5. Petrographic Variations in Primitive Basalts as Indicators of Mantle Heterogeneities beneath the Poison Lake Chain, California

    NASA Astrophysics Data System (ADS)

    Wenner, J. M.; Teasdale, R.

    2011-12-01

    We present new petrographic data for primitive basalts in the Poison Lake chain east of Lassen Volcanic National Park in northern California. The primitive composition and location of Poison Lake chain cinder cones on the western margin of the Basin and Range suggest that extensional tectonics may facilitate efficient magma ascent with little contamination. The limited area (5 km east-west and 20 km north-south) and proximity to the Basin and Range make the Poison Lake chain an ideal location to study small-scale variations in the mantle beneath the southern Cascades. The volcanic field encompasses 39 units that comprise nine groups of chemically distinct primitive calc-alkaline basalts (defined by major element geochemistry). Trace-element and isotope data for four of the groups confirm distinct chemistries that show little evidence of direct genetic relationships or a common source for these basalts. We collected new microprobe data for two of the four extensively analyzed groups: the basalts of old railroad grade (~102 ka) and Bogard Buttes (~100 ka), which were chosen based on their spatial distribution and disparate chemical compositions. The small volume and distinct isotopic characteristics of individual groups suggest that they are the product of small mantle source domains. CaO compositions of olivine crystals further support that these basalts represent small independent magma batches. Olivine phenocrysts from Bogard Buttes are generally smaller, less abundant and lower in CaO than those of the old railroad grade. Microprobe data also indicate that olivine phenocryst cores are in equilibrium with their whole rock compositions but rims show evidence of differentiation. Previous geochemical work suggested that compositional variation within groups may be produced by one of the following processes: variable degrees of partial melting, minimal fractional crystallization, or mixing with mafic magmas of similar composition. Olivine compositions and petrographic

  6. Model-Free Primitive-Based Iterative Learning Control Approach to Trajectory Tracking of MIMO Systems With Experimental Validation.

    PubMed

    Radac, Mircea-Bogdan; Precup, Radu-Emil; Petriu, Emil M

    2015-11-01

    This paper proposes a novel model-free trajectory tracking of multiple-input multiple-output (MIMO) systems by the combination of iterative learning control (ILC) and primitives. The optimal trajectory tracking solution is obtained in terms of previously learned solutions to simple tasks called primitives. The library of primitives that are stored in memory consists of pairs of reference input/controlled output signals. The reference input primitives are optimized in a model-free ILC framework without using knowledge of the controlled process. The guaranteed convergence of the learning scheme is built upon a model-free virtual reference feedback tuning design of the feedback decoupling controller. Each new complex trajectory to be tracked is decomposed into the output primitives regarded as basis functions. The optimal reference input for the control system to track the desired trajectory is next recomposed from the reference input primitives. This is advantageous because the optimal reference input is computed straightforward without the need to learn from repeated executions of the tracking task. In addition, the optimization problem specific to trajectory tracking of square MIMO systems is decomposed in a set of optimization problems assigned to each separate single-input single-output control channel that ensures a convenient model-free decoupling. The new model-free primitive-based ILC approach is capable of planning, reasoning, and learning. A case study dealing with the model-free control tuning for a nonlinear aerodynamic system is included to validate the new approach. The experimental results are given.

  7. Assessment of Peripheral Lung Mechanics

    PubMed Central

    Bates, Jason H.T.; Suki, Béla

    2008-01-01

    The mechanical properties of the lung periphery are major determinants of overall lung function, and can change dramatically in disease. In this review we examine the various experimental techniques that have provided data pertaining to the mechanical properties of the lung periphery, together with the mathematical models that have been used to interpret these data. These models seek to make a clear distinction between the central and peripheral compartments of the lung by encapsulating functional differences between the conducing airways, the terminal airways and the parenchyma. Such a distinction becomes problematic in disease, however, because of the inevitable onset of regional variations in mechanical behavior throughout the lung. Accordingly, lung models are used both in the inverse sense as vehicles for extracting physiological insight from experimental data, and in the forward sense as virtual laboratories for the testing of specific hypothesis about mechanisms such as the effects of regional heterogeneities. Pathologies such as asthma, acute lung injury and emphysema can alter the mechanical properties of the lung periphery through the direct alteration of intrinsic tissue mechanics, the development of regional heterogeneities in mechanical function, and the complete derecruitment of airspaces due to airway closure and alveolar collapse. We are now beginning to decipher the relative contributions of these various factors to pathological alterations in peripheral lung mechanics, which may eventually lead to the development and assessment of novel therapies. PMID:18463006

  8. Noninvasive imaging of peripheral nerves.

    PubMed

    Rangavajla, Gautam; Mokarram, Nassir; Masoodzadehgan, Nazanin; Pai, S Balakrishna; Bellamkonda, Ravi V

    2014-01-01

    Recent developments in the field of peripheral nerve imaging extend the capabilities of imaging modalities to assist in the diagnosis and treatment of patients with peripheral nerve maladies. Methods such as magnetic resonance imaging (MRI) and its derivative diffusion tensor imaging (DTI), ultrasound (US) and positron emission tomography (PET) are capable of assessing nerve structure and function following injury and relating the state of the nerve to electrophysiological and histological analysis. Of the imaging methods surveyed here, each offered unique and interesting advantages related to the field. MRI offered the opportunity to visualize immune activity on the injured nerve throughout the course of the regeneration process, and DTI offered numerical characterization of the injury and the ability to develop statistical bases for diagnosing injury. US extends imaging to the treatment phase by enabling more precise analgesic applications following surgery, and PET represents a novel method of assessing nerve injury through analysis of relative metabolism rates in injured and healthy tissue. Exciting new possibilities to enhance and extend the abilities of imaging methods are also discussed, including innovative contrast agents, some of which enable multimodal imaging approaches and present opportunities for treatment application. PMID:25766202

  9. Diagnostic approach to peripheral neuropathy

    PubMed Central

    Misra, Usha Kant; Kalita, Jayantee; Nair, Pradeep P.

    2008-01-01

    Peripheral neuropathy refers to disorders of the peripheral nervous system. They have numerous causes and diverse presentations; hence, a systematic and logical approach is needed for cost-effective diagnosis, especially of treatable neuropathies. A detailed history of symptoms, family and occupational history should be obtained. General and systemic examinations provide valuable clues. Neurological examinations investigating sensory, motor and autonomic signs help to define the topography and nature of neuropathy. Large fiber neuropathy manifests with the loss of joint position and vibration sense and sensory ataxia, whereas small fiber neuropathy manifests with the impairment of pain, temperature and autonomic functions. Electrodiagnostic (EDx) tests include sensory, motor nerve conduction, F response, H reflex and needle electromyography (EMG). EDx helps in documenting the extent of sensory motor deficits, categorizing demyelinating (prolonged terminal latency, slowing of nerve conduction velocity, dispersion and conduction block) and axonal (marginal slowing of nerve conduction and small compound muscle or sensory action potential and dennervation on EMG). Uniform demyelinating features are suggestive of hereditary demyelination, whereas difference between nerves and segments of the same nerve favor acquired demyelination. Finally, neuropathy is classified into mononeuropathy commonly due to entrapment or trauma; mononeuropathy multiplex commonly due to leprosy and vasculitis; and polyneuropathy due to systemic, metabolic or toxic etiology. Laboratory investigations are carried out as indicated and specialized tests such as biochemical, immunological, genetic studies, cerebrospinal fluid (CSF) examination and nerve biopsy are carried out in selected patients. Approximately 20% patients with neuropathy remain undiagnosed but the prognosis is not bad in them. PMID:19893645

  10. Optoacoustic angiography of peripheral vasculature

    NASA Astrophysics Data System (ADS)

    Ermilov, Sergey; Su, Richard; Zamora, Mario; Hernandez, Travis; Nadvoretsky, Vyacheslav; Oraevsky, Alexander

    2012-02-01

    We developed a new optoacoustic microangiography system (OmAS) intended for in-vivo vascular imaging of a human finger. The system employs an arc-shaped acoustic array that is rotated 360 degrees around the finger providing optoacoustic data necessary for tomographic reconstruction of the three-dimensional images of a finger. A near-infrared Q-switched laser is used to generate optoacoustic signals with increased contrast of blood vessels. The laser is coupled through two randomized fiberoptic bundles oriented in orthogonal optoacoustic mode. To demonstrate OmAS capabilities, we present a time-series of optoacoustic images of a human finger taken after the hypothermia stress test. The images show a detailed vascular anatomy of a finger down to the capillary level. A series of quick 30s scans allowed us to visualize the thermoregulatory response within the studied finger as it was manifested via vasomotor activity during the hypothermia recovery. We propose that the developed system can be used for diagnostics of various medical conditions that are manifested in change of the peripheral (finger) blood flow. Examples of the medical conditions that could be diagnosed and staged using the OmAS include the peripheral arterial disease (PAD), thrombosis, frostbite, and traumas.

  11. Melphalan, Carboplatin, Mannitol, and Sodium Thiosulfate in Treating Patients With Recurrent or Progressive CNS Embryonal or Germ Cell Tumors

    ClinicalTrials.gov

    2016-04-28

    Adult Central Nervous System Germ Cell Tumor; Adult Ependymoblastoma; Adult Medulloblastoma; Adult Pineoblastoma; Adult Supratentorial Primitive Neuroectodermal Tumor; Childhood Atypical Teratoid/Rhabdoid Tumor; Childhood Central Nervous System Germ Cell Tumor; Childhood Ependymoblastoma; Medulloepithelioma; Ototoxicity; Recurrent Adult Brain Neoplasm; Recurrent Childhood Central Nervous System Embryonal Neoplasm; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Medulloblastoma; Recurrent Childhood Pineoblastoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor

  12. Peripheral visual performance enhancement by neurofeedback training.

    PubMed

    Nan, Wenya; Wan, Feng; Lou, Chin Ian; Vai, Mang I; Rosa, Agostinho

    2013-12-01

    Peripheral visual performance is an important ability for everyone, and a positive inter-individual correlation is found between the peripheral visual performance and the alpha amplitude during the performance test. This study investigated the effect of alpha neurofeedback training on the peripheral visual performance. A neurofeedback group of 13 subjects finished 20 sessions of alpha enhancement feedback within 20 days. The peripheral visual performance was assessed by a new dynamic peripheral visual test on the first and last training day. The results revealed that the neurofeedback group showed significant enhancement of the peripheral visual performance as well as the relative alpha amplitude during the peripheral visual test. It was not the case in the non-neurofeedback control group, which performed the tests within the same time frame as the neurofeedback group but without any training sessions. These findings suggest that alpha neurofeedback training was effective in improving peripheral visual performance. To the best of our knowledge, this is the first study to show evidence for performance improvement in peripheral vision via alpha neurofeedback training.

  13. Solitary peripheral osteomas of the jaws

    PubMed Central

    de França, Talita Ribeiro Tenório; Gueiros, Luiz Alcino Monteiro; de Castro, Jurema Freire Lisboa; Catunda, Ivson; Leão, Jair Carneiro

    2012-01-01

    Osteoma is a benign osteogenic tumor composed of cancellous or compact bone, classified as peripheral, central, or extraskeletal. Peripheral osteomas are uncommon. Excluding the maxillary sinuses, the maxilla is a rare site for osteomas. The purpose of this report was to describe clinicopathological and radiological features of two peripheral osteomas occurring in the jaws, one located in the mandible and another in the edentulous maxillary alveolar ridge. The tumors were asymptomatic and were fully excised without any complications or recurrence. The lesions were submitted to histopathological analysis and diagnosed as peripheral osteoma, compact type. PMID:22783479

  14. Synthetic biology of minimal living cells: primitive cell models and semi-synthetic cells

    PubMed Central

    2010-01-01

    This article summarizes a contribution presented at the ESF 2009 Synthetic Biology focused on the concept of the minimal requirement for life and on the issue of constructive (synthetic) approaches in biological research. The attempts to define minimal life within the framework of autopoietic theory are firstly described, and a short report on the development of autopoietic chemical systems based on fatty acid vesicles, which are relevant as primitive cell models is given. These studies can be used as a starting point for the construction of more complex systems, firstly being inspired by possible origins of life scenarioes (and therefore by considering primitive functions), then by considering an approach based on modern biomacromolecular-encoded functions. At this aim, semi-synthetic minimal cells are defined as those man-made vesicle-based systems that are composed of the minimal number of genes, proteins, biomolecules and which can be defined as living. Recent achievements on minimal sized semi-synthetic cells are then discussed, and the kind of information obtained is recognized as being distinctively derived by a constructive approach. Synthetic biology is therefore a fundamental tool for gaining basic knowledge about biosystems, and it should not be confined at all to the engineering side. PMID:21886680

  15. Physical effects underlying the transition from primitive to modern cell membranes.

    PubMed

    Budin, Itay; Szostak, Jack W

    2011-03-29

    To understand the emergence of Darwinian evolution, it is necessary to identify physical mechanisms that enabled primitive cells to compete with one another. Whereas all modern cell membranes are composed primarily of diacyl or dialkyl glycerol phospholipids, the first cell membranes are thought to have self-assembled from simple, single-chain lipids synthesized in the environment. We asked what selective advantage could have driven the transition from primitive to modern membranes, especially during early stages characterized by low levels of membrane phospholipid. Here we demonstrate that surprisingly low levels of phospholipids can drive protocell membrane growth during competition for single-chain lipids. Growth results from the decreasing fatty acid efflux from membranes with increasing phospholipid content. The ability to synthesize phospholipids from single-chain substrates would have therefore been highly advantageous for early cells competing for a limited supply of lipids. We show that the resulting increase in membrane phospholipid content would have led to a cascade of new selective pressures for the evolution of metabolic and transport machinery to overcome the reduced membrane permeability of diacyl lipid membranes. The evolution of phospholipid membranes could thus have been a deterministic outcome of intrinsic physical processes and a key driving force for early cellular evolution. PMID:21402937

  16. First complete mitochondrial genome of primitive crab Homologenus malayensis (Decapoda: Brachyura: Podotremata: Homolidae).

    PubMed

    Hui, Min; Liu, Yuan; Cui, Zhaoxia

    2016-01-01

    The taxonomy and phylogeny of brachyuran crabs, and particularly of the Podotremata, have been the subjects of controversy due to their morphological diversity and complexity. The first complete mitochondrial genome (mitogenome) sequence of primitive crab Homologenus malayensis has been determined. The mitogenome is 15,793 bp in length, with A + T content 71.7%. The gene content and order are consistent with those in typical brachyuran crabs. A putative control region of 883 bp is identified due to its position (between srRNA and tRNA(Ile)) and AT richness (75.5%). Notably, the control region in H. malayensis contains nine identical specific repeat units of 42 bp and 11 identical repeat units of 2 bp with a total length of 400 bp, which is different from other crabs. These results are expected to provide useful information on both genomics and the future phylogenetic study of primitive crabs.

  17. A single aromatic core mutation converts a designed "primitive" protein from halophile to mesophile folding.

    PubMed

    Longo, Liam M; Tenorio, Connie A; Kumru, Ozan S; Middaugh, C Russell; Blaber, Michael

    2015-01-01

    The halophile environment has a number of compelling aspects with regard to the origin of structured polypeptides (i.e., proteogenesis) and, instead of a curious niche that living systems adapted into, the halophile environment is emerging as a candidate "cradle" for proteogenesis. In this viewpoint, a subsequent halophile-to-mesophile transition was a key step in early evolution. Several lines of evidence indicate that aromatic amino acids were a late addition to the codon table and not part of the original "prebiotic" set comprising the earliest polypeptides. We test the hypothesis that the availability of aromatic amino acids could facilitate a halophile-to-mesophile transition by hydrophobic core-packing enhancement. The effects of aromatic amino acid substitutions were evaluated in the core of a "primitive" designed protein enriched for the 10 prebiotic amino acids (A,D,E,G,I,L,P,S,T,V)-having an exclusively prebiotic core and requiring halophilic conditions for folding. The results indicate that a single aromatic amino acid substitution is capable of eliminating the requirement of halophile conditions for folding of a "primitive" polypeptide. Thus, the availability of aromatic amino acids could have facilitated a critical halophile-to-mesophile protein folding adaptation-identifying a selective advantage for the incorporation of aromatic amino acids into the codon table.

  18. Signaling hunger through aggression—the regulation of foraging in a primitively eusocial wasp

    NASA Astrophysics Data System (ADS)

    Lamba, Shakti; Chandrasekhar, K.; Gadagkar, Raghavendra

    2008-07-01

    Primitively eusocial wasps are generally headed by behaviorally dominant queens who use their aggression to suppress worker reproduction. In contrast, queens in the primitively eusocial wasp Ropalidia marginata are strikingly docile and non-aggressive. However, workers exhibit dominance-subordinate interactions among themselves. These interactions do not appear to reflect reproductive competition because there is no correlation between the relative position of an individual in the dominance hierarchy of the colony and the likelihood that she will succeed a lost/removed queen. Based on the observation that foraging continues unaltered in the absence of the queen and the correlation between dominance behavior and foraging, we have previously suggested that dominance-subordinate interactions among workers in R. marginata have been co-opted to serve the function of decentralized, self-organized regulation of foraging. This idea has been supported by an earlier experimental study where it was found that a reduced demand for food led to a significant decrease in dominance behavior. In this study, we perform the converse experiment, demonstrate that dominance behavior increases under conditions of starvation, and thus provide further evidence in support of the hypothesis that intranidal workers signal hunger through aggression.

  19. A Dominant-Negative Isoform of IKAROS Expands Primitive Normal Human Hematopoietic Cells

    PubMed Central

    Beer, Philip A.; Knapp, David J.H.F.; Kannan, Nagarajan; Miller, Paul H.; Babovic, Sonja; Bulaeva, Elizabeth; Aghaeepour, Nima; Rabu, Gabrielle; Rostamirad, Shabnam; Shih, Kingsley; Wei, Lisa; Eaves, Connie J.

    2014-01-01

    Summary Disrupted IKAROS activity is a recurrent feature of some human leukemias, but effects on normal human hematopoietic cells are largely unknown. Here, we used lentivirally mediated expression of a dominant-negative isoform of IKAROS (IK6) to block normal IKAROS activity in primitive human cord blood cells and their progeny. This produced a marked (10-fold) increase in serially transplantable multipotent IK6+ cells as well as increased outputs of normally differentiating B cells and granulocytes in transplanted immunodeficient mice, without producing leukemia. Accompanying T/natural killer (NK) cell outputs were unaltered, and erythroid and platelet production was reduced. Mechanistically, IK6 specifically increased human granulopoietic progenitor sensitivity to two growth factors and activated CREB and its targets (c-FOS and Cyclin B1). In more primitive human cells, IK6 prematurely initiated a B cell transcriptional program without affecting the hematopoietic stem cell-associated gene expression profile. Some of these effects were species specific, thus identifying novel roles of IKAROS in regulating normal human hematopoietic cells. PMID:25418728

  20. A primitive placoderm sheds light on the origin of the jawed vertebrate face.

    PubMed

    Dupret, Vincent; Sanchez, Sophie; Goujet, Daniel; Tafforeau, Paul; Ahlberg, Per E

    2014-03-27

    Extant vertebrates form two clades, the jawless Cyclostomata (lampreys and hagfishes) and the jawed Gnathostomata (all other vertebrates), with contrasting facial architectures. These arise during development from just a few key differences in the growth patterns of the cranial primordia: notably, the nasal sacs and hypophysis originate from a single placode in cyclostomes but from separate placodes in gnathostomes, and infraoptic ectomesenchyme migrates forward either side of the single placode in cyclostomes but between the placodes in gnathostomes. Fossil stem gnathostomes preserve cranial anatomies rich in landmarks that provide proxies for developmental processes and allow the transition from jawless to jawed vertebrates to be broken down into evolutionary steps. Here we use propagation phase contrast synchrotron microtomography to image the cranial anatomy of the primitive placoderm (jawed stem gnathostome) Romundina, and show that it combines jawed vertebrate architecture with cranial and cerebral proportions resembling those of cyclostomes and the galeaspid (jawless stem gnathostome) Shuyu. This combination seems to be primitive for jawed vertebrates, and suggests a decoupling between ectomesenchymal growth trajectory, ectomesenchymal proliferation, and cerebral shape change during the origin of gnathostomes.

  1. N-isotope composition of the primitive mantle compared to diamonds

    NASA Astrophysics Data System (ADS)

    Jia, Yiefei; Kerrich, Robert

    2015-09-01

    The nitrogen isotopic composition of the Earth's primitive mantle is controversial. Chromium-isotopic ratios of various terrestrial minerals and rocks, and chondritic meteorites are consistent with the silicate Earth being a mixture of enstatite and carbonaceous chondrites. From their relative proportions and N-isotope compositions we estimate that the bulk primitive mantle δ15N is - 7 ± 3‰. The negative value, as also evidenced by mantle-derived oceanic basalts and diamonds, is an intrinsic long-term feature of Earth's mantle. Some enstatite chondrite-like δ15N values down to - 24‰ measured in very rare diamonds could be interpreted as a heterogeneous mantle. δ15N values in oceanic island basalts derived from the deep mantle have three components: deep mantle of ~- 9‰ consistent with estimate, recycled sediments of about 15‰, and atmospheric N incorporated from groundwater and/or subducted atmospheric N (Mohapatra and Murty, 2000a; Chem. Geol. 164, 305-320). Some enriched δ15N values in MORB and OIB result from degassing fractionation. Shift of the upper mantle from an initial - 7‰ to - 5‰ by the Neoarchean can be explained by a combination of sediment recycling through subduction and upper mantle magma degassing processes.

  2. The atmosphere of the primitive earth and the prebiotic synthesis of organic compounds

    NASA Technical Reports Server (NTRS)

    Miller, S. L.; Schlesinger, G.

    1983-01-01

    The prebiotic synthesis of organic compounds is investigated using a spark discharge on various simulated prebiotic atmospheres at 25 C. It is found that glycine is almost the only amino acid produced from the model atmospheres containing CO and CO2. These results show that the maximum yield is about the same for the three carbon sources (CO, CO2, and CH4) at high H2/carbon ratios, but that CH4 is superior at low H2/carbon ratios. CH4 is found to yield a much greater variety of amino acids than either CO or CO2. If it is assumed that amino acids more complex than glycine were required for the origin of life, then these findings indicate the need for CH4 in the primitive atmosphere. The yields of cyanide and formaldehyde are shown to parallel the amino acid results, with yields of HCN and H2CO as high as 13 percent based on carbon. Ammonia is also found to be produced from N2 in experiments with no added NH3 in yields as high as 4.9 percent. These results indicate that large amounts of NH3 would have been synthesized on the primitive earth by electric discharges.

  3. Vasotocin immunoreactivity in goldfish brains: characterizing primitive circuits associated with social regulation.

    PubMed

    Thompson, Richmond R; Walton, James C

    2009-01-01

    The neuroanatomical characteristics of vasotocin (VT) and vasopressin (VP) systems have been described in numerous species from diverse vertebrate groups, including teleost fish. However, there are very few teleost species in which VT's effects on social behavior have been established and the neural circuits associated with that regulation fully described. We have previously shown that VT inhibits social approach behaviors in goldfish via actions in the hindbrain. Here we further describe that primitive VT circuit, as well as others throughout the goldfish brain that might contribute to social regulation in this species. In particular, we highlight forebrain projections to the dorsal telencephalon that have not been described previously in any teleost, projections to limbic forebrain areas, most notably the medial division of the dorsal telencephalon and the ventral telencephalon, and midbrain projections to the optic tectum and torus semicircularis that have rarely been described. However, the most dense VT projection in goldfish is to the hindbrain, particularly to motor divisions of the vagal complex and to area postrema, which we argue might influence social approach behaviors through autonomic regulatory mechanisms. Because hindbrain VT projections are some of the most primitive in vertebrates, we suggest they might represent an ancestral mechanism through which VT influenced social behavior.

  4. Aqueous alteration on main belt primitive asteroids: Results from visible spectroscopy

    NASA Astrophysics Data System (ADS)

    Fornasier, S.; Lantz, C.; Barucci, M. A.; Lazzarin, M.

    2014-05-01

    This work focuses on the study of the aqueous alteration process which acted in the main belt and produced hydrated minerals on the altered asteroids. Hydrated minerals have been found mainly on Mars surface, on main belt primitive asteroids and possibly also on few TNOs. These materials have been produced by hydration of pristine anhydrous silicates during the aqueous alteration process, that, to be active, needed the presence of liquid water under low temperature conditions (below 320 K) to chemically alter the minerals. The aqueous alteration is particularly important for unraveling the processes occurring during the earliest times of the Solar System history, as it can give information both on the asteroids thermal evolution and on the localization of water sources in the asteroid belt. To investigate this process, we present reflected light spectral observations in the visible region (0.4-0.94 μm) of 80 asteroids belonging to the primitive classes C (prevalently), G, F, B and P, following the Tholen (Tholen, D.J. [1984]. Ph.D. Dissertation, University of Arizona, Tucson). classification scheme. We find that about 65% of the C-type and all the G-type asteroids investigated reveal features suggesting the presence of hydrous materials, mainly a band centered around 0.7 μm, while we do not find evidence of hydrated materials in the other low albedo asteroids (B, F, and P) investigated. We combine the present observations with the visible spectra of asteroids available in the literature for a total of 600 primitive main belt asteroids. We analyze all these spectra in a similar way to characterize the absorption band parameters (band center, depth and width) and spectral slope, and to look for possible correlations between the aqueous alteration process and the asteroids taxonomic classes, orbital elements, heliocentric distances, albedo and sizes. Our analysis shows that the aqueous alteration sequence starts from the P-type objects, practically unaltered, and

  5. First discovery of a primitive coelacanth fin fills a major gap in the evolution of lobed fins and limbs.

    PubMed

    Friedman, Matt; Coates, Michael I; Anderson, Philip

    2007-01-01

    The fossil record provides unique clues about the primitive pattern of lobed fins, the precursors of digit-bearing limbs. Such information is vital for understanding the evolutionary transition from fish fins to tetrapod limbs, and it guides the choice of model systems for investigating the developmental changes underpinning this event. However, the evolutionary preconditions for tetrapod limbs remain unclear. This uncertainty arises from an outstanding gap in our knowledge of early lobed fins: there are no fossil data that record primitive pectoral fin conditions in coelacanths, one of the three major groups of sarcopterygian (lobe-finned) fishes. A new fossil from the Middle-Late Devonian of Wyoming preserves the first and only example of a primitive coelacanth pectoral fin endoskeleton. The strongly asymmetrical skeleton of this fin corroborates the hypothesis that this is the primitive sarcopterygian pattern, and that this pattern persisted in the closest fish-like relatives of land vertebrates. The new material reveals the specializations of paired fins in the modern coelacanth, as well as in living lungfishes. Consequently, the context in which these might be used to investigate evolutionary and developmental relationships between vertebrate fins and limbs is changed. Our data suggest that primitive actinopterygians, rather than living sarcopterygian fishes and their derived appendages, are the most informative comparators for developmental studies seeking to understand the origin of tetrapod limbs.

  6. First discovery of a primitive coelacanth fin fills a major gap in the evolution of lobed fins and limbs.

    PubMed

    Friedman, Matt; Coates, Michael I; Anderson, Philip

    2007-01-01

    The fossil record provides unique clues about the primitive pattern of lobed fins, the precursors of digit-bearing limbs. Such information is vital for understanding the evolutionary transition from fish fins to tetrapod limbs, and it guides the choice of model systems for investigating the developmental changes underpinning this event. However, the evolutionary preconditions for tetrapod limbs remain unclear. This uncertainty arises from an outstanding gap in our knowledge of early lobed fins: there are no fossil data that record primitive pectoral fin conditions in coelacanths, one of the three major groups of sarcopterygian (lobe-finned) fishes. A new fossil from the Middle-Late Devonian of Wyoming preserves the first and only example of a primitive coelacanth pectoral fin endoskeleton. The strongly asymmetrical skeleton of this fin corroborates the hypothesis that this is the primitive sarcopterygian pattern, and that this pattern persisted in the closest fish-like relatives of land vertebrates. The new material reveals the specializations of paired fins in the modern coelacanth, as well as in living lungfishes. Consequently, the context in which these might be used to investigate evolutionary and developmental relationships between vertebrate fins and limbs is changed. Our data suggest that primitive actinopterygians, rather than living sarcopterygian fishes and their derived appendages, are the most informative comparators for developmental studies seeking to understand the origin of tetrapod limbs. PMID:17651357

  7. ZFAT plays critical roles in peripheral T cell homeostasis and its T cell receptor-mediated response

    SciTech Connect

    Doi, Keiko; Fujimoto, Takahiro; Okamura, Tadashi; Ogawa, Masahiro; Tanaka, Yoko; Mototani, Yasumasa; Goto, Motohito; Ota, Takeharu; Matsuzaki, Hiroshi; Kuroki, Masahide; Tsunoda, Toshiyuki; Sasazuki, Takehiko; Shirasawa, Senji

    2012-08-17

    Highlights: Black-Right-Pointing-Pointer We generated Cd4-Cre-mediated T cell-specific Zfat-deficient mice. Black-Right-Pointing-Pointer Zfat-deficiency leads to reduction in the number of the peripheral T cells. Black-Right-Pointing-Pointer Impaired T cell receptor-mediated response in Zfat-deficient peripheral T cells. Black-Right-Pointing-Pointer Decreased expression of IL-7R{alpha}, IL-2R{alpha} and IL-2 in Zfat-deficient peripheral T cells. Black-Right-Pointing-Pointer Zfat plays critical roles in peripheral T cell homeostasis. -- Abstract: ZFAT, originally identified as a candidate susceptibility gene for autoimmune thyroid disease, has been reported to be involved in apoptosis, development and primitive hematopoiesis. Zfat is highly expressed in T- and B-cells in the lymphoid tissues, however, its physiological function in the immune system remains totally unknown. Here, we generated the T cell-specific Zfat-deficient mice and demonstrated that Zfat-deficiency leads to a remarkable reduction in the number of the peripheral T cells. Intriguingly, a reduced expression of IL-7R{alpha} and the impaired responsiveness to IL-7 for the survival were observed in the Zfat-deficient T cells. Furthermore, a severe defect in proliferation and increased apoptosis in the Zfat-deficient T cells following T cell receptor (TCR) stimulation was observed with a reduced IL-2R{alpha} expression as well as a reduced IL-2 production. Thus, our findings reveal that Zfat is a critical regulator in peripheral T cell homeostasis and its TCR-mediated response.

  8. Homeostasis of peripheral immune effectors.

    PubMed

    Warrender, Christina; Forrest, Stephanie; Segel, Lee

    2004-11-01

    In this paper, we use both mathematical modeling and simulation to explore homeostasis of peripheral immune system effector cells, particularly alveolar macrophages. Our interest is in the distributed control mechanisms that allow such a population to maintain itself. We introduce a multi-purpose simulator designed to study individual cell responses to local molecular signals and their effects on population dynamics. We use the simulator to develop a model of growth factor regulation of macrophage proliferation and survival. We examine the effects of this form of regulation in the context of two competing hypotheses regarding the source of new alveolar macrophages. In one model, local cells divide to replenish the population; in the other, only cells migrating from circulation divide. We find that either scenario is plausible, although the influx-driven system is inherently more stable. The proliferation-driven system requires lower cell death and efflux rates than the influx-driven system.

  9. Technology for Peripheral Nerve Stimulation.

    PubMed

    Parker, John L; Cameron, Tracy

    2015-01-01

    Peripheral nerve stimulation (PNS) has been in use for over 50 years to treat patients suffering from chronic pain who have failed conservative treatments. Despite this long history, the devices being used have changed very little. In fact, current PNS technology was developed specifically for spinal cord stimulation. The use of technology developed for other applications in PNS has led to an unnecessary number of device complications and the limited adoption of this promising therapy. The following chapter provides an overview of PNS technology throughout the years, outlining both the benefits and limitations. We will briefly explore the electrophysiology of PNS stimulation, with an emphasis on technology and indication-specific devices. Finally, design and technical requirements of an ideal PNS device will be discussed.

  10. Treatment of Peripheral Precocious Puberty.

    PubMed

    Schoelwer, Melissa; Eugster, Erica A

    2016-01-01

    There are many etiologies of peripheral precocious puberty (PPP) with diverse manifestations resulting from exposure to androgens, estrogens, or both. The clinical presentation depends on the underlying process and may be acute or gradual. The primary goals of therapy are to halt pubertal development and restore sex steroids to prepubertal values. Attenuation of linear growth velocity and rate of skeletal maturation in order to maximize height potential are additional considerations for many patients. McCune-Albright syndrome (MAS) and familial male-limited precocious puberty (FMPP) represent rare causes of PPP that arise from activating mutations in GNAS1 and the LH receptor gene, respectively. Several different therapeutic approaches have been investigated for both conditions with variable success. Experience to date suggests that the ideal therapy for precocious puberty secondary to MAS in girls remains elusive. In contrast, while the number of treated patients remains small, several successful therapeutic options for FMPP are available. PMID:26680582

  11. Peripheral Developing Odontoma or Peripheral Ameloblastic Fibroodontoma: A Rare Challenging Case.

    PubMed

    Atarbashi Moghadam, Saede; Mokhtari, Sepideh

    2016-01-01

    Peripheral odontogenic lesions are considered to be rare within the classification of odontogenic tumors. They share the same microscopic characteristics of their central counterparts. Here, we report an ulcerated mass of the maxillary gingiva that on histopathological examination was diagnosed as peripheral developing odontoma or peripheral ameloblastic fibroodontoma. The diagnosis of this tumor is challenging and may lead to unnecessary treatment.

  12. Peripheral Developing Odontoma or Peripheral Ameloblastic Fibroodontoma: A Rare Challenging Case

    PubMed Central

    Atarbashi Moghadam, Saede

    2016-01-01

    Peripheral odontogenic lesions are considered to be rare within the classification of odontogenic tumors. They share the same microscopic characteristics of their central counterparts. Here, we report an ulcerated mass of the maxillary gingiva that on histopathological examination was diagnosed as peripheral developing odontoma or peripheral ameloblastic fibroodontoma. The diagnosis of this tumor is challenging and may lead to unnecessary treatment. PMID:26981293

  13. Fine structures of embryonic discs of in vivo post-hatching porcine blastocysts at the pre-primitive streak stage.

    PubMed

    Xia, P; Liu, Z; Qin, P

    2011-04-01

    To date, reports about the ultrastructure of porcine embryonic discs have not shown details of the primitive streak. The main objective of this study was to examine the ultrastructure of interior and exterior embryonic discs in porcine in vivo blastocysts with diameters of 1, 3 and 9 mm using scanning electron microscopy and transmission electron microscopy. For the first time, we revealed the ultrastructure of the unusual group of cells in the pre-primitive streak area of embryonic discs. The cells were 1-2 μm in diameter, had high electron density and contained abundant, free ribosomes and endoplasmic reticulum. These primitive streak cells could represent original embryonic stem cells or represent a stem cell niche. The results also showed three types of cells on the exterior surface of the embryonic discs. Moreover, our results provided morphological evidence of condensed nuclei in the smooth cells on the surface of the embryonic disc.

  14. Raman microspectroscopy for visualization of peripheral nerves

    NASA Astrophysics Data System (ADS)

    Minamikawa, Takeo; Harada, Yoshinori; Koizumi, Noriaki; Takamatsu, Tetsuro

    2013-02-01

    The peripheral nervous system plays an important role in motility, sensory, and autonomic functions of the human body. Preservation of peripheral nerves in surgery is essential for improving quality of life of patients. To preserve peripheral nerves, detection of ne peripheral nerves that cannot be identi ed by human eye or under white light imaging is necessary. In this study, we sought to provide a proof-of-principle demonstration of a label-free detection technique of peripheral nerve tissues against adjacent tissues that employs spontaneous Raman microspectroscopy. A line-illumination confocal Raman microscope was used for the experiment. A laser operating at the wavelength of 532 nm was used as an excitation laser light. We obtained Raman spectra of peripheral nerve, brous connective tissue, skeletal muscle, blood vessel, and adipose tissue of Wistar rats, and extracted speci c spectral features of peripheral nerves and adjacent tissues. By applying multivariate image analysis, peripheral nerves were clearly detected against adjacent tissues without any preprocessing neither xation nor staining. These results suggest the potential of the Raman spectroscopic observation for noninvasive and label-free nerve detection, and we expect this method could be a key technique for nerve-sparing surgery.

  15. Beauty and cuteness in peripheral vision.

    PubMed

    Kuraguchi, Kana; Ashida, Hiroshi

    2015-01-01

    Guo et al. (2011) showed that attractiveness was detectable in peripheral vision. Since there are different types of attractiveness (Rhodes, 2006), we investigated how beauty and cuteness are detected in peripheral vision with a brief presentation. Participants (n = 45) observed two Japanese female faces for 100 ms, then were asked to respond which face was more beautiful (or cuter). The results indicated that both beauty and cuteness were detectable in peripheral vision, but not in the same manner. Discrimination rates for judging beauty were invariant in peripheral and central vision, while discrimination rates for judging cuteness declined in peripheral vision as compared with central vision. This was not explained by lower resolution in peripheral vision. In addition, for male participants, it was more difficult to judge cuteness than beauty in peripheral vision, thus suggesting that gender differences can have a certain effect when judging cuteness. Therefore, central vision might be suitable for judging cuteness while judging beauty might not be affected by either central or peripheral vision. This might be related with the functional difference between beauty and cuteness.

  16. [Peripheral artery disease and acute coronary syndrome].

    PubMed

    Martínez-Quintana, Efrén; Rodríguez-González, Fayna

    2015-01-01

    Peripheral arterial disease is a common manifestation of systemic atherosclerosis that is associated with increased cardiovascular risk. When presented in the context of an acute coronary syndrome a differential diagnosis with aorta dissection should be made, because peripheral arterial disease may be asymptomatic despite the absence or asymmetry of femoral pulses.

  17. Beauty and cuteness in peripheral vision

    PubMed Central

    Kuraguchi, Kana; Ashida, Hiroshi

    2015-01-01

    Guo et al. (2011) showed that attractiveness was detectable in peripheral vision. Since there are different types of attractiveness (Rhodes, 2006), we investigated how beauty and cuteness are detected in peripheral vision with a brief presentation. Participants (n = 45) observed two Japanese female faces for 100 ms, then were asked to respond which face was more beautiful (or cuter). The results indicated that both beauty and cuteness were detectable in peripheral vision, but not in the same manner. Discrimination rates for judging beauty were invariant in peripheral and central vision, while discrimination rates for judging cuteness declined in peripheral vision as compared with central vision. This was not explained by lower resolution in peripheral vision. In addition, for male participants, it was more difficult to judge cuteness than beauty in peripheral vision, thus suggesting that gender differences can have a certain effect when judging cuteness. Therefore, central vision might be suitable for judging cuteness while judging beauty might not be affected by either central or peripheral vision. This might be related with the functional difference between beauty and cuteness. PMID:25999883

  18. Color vision in the peripheral retina.

    PubMed

    Johnson, M A

    1986-02-01

    Until recently, color vision in the peripheral field has been thought to be substantially less developed than color vision in the central field. Although the exact dimensions vary from study to study, most estimates of peripheral chromatic perception place the limit of trichromatic vision at no more than 30 degrees from fixation; the visual field is thought to be completely color blind at about 50 degrees of eccentricity. Within the last 10 years, an increased understanding of the changing spatial scale in the peripheral field has led researchers to reevaluate what is believed about peripheral function. We now know that virtually every measure of peripheral color perception can be improved by using a suitably large stimulus in the peripheral field. This paper examines current and past perspectives on peripheral color function, and describes two studies which demonstrate that peripheral and central chromatic processing are the same to the first order if the changes in spatial scale and photopic sensitivity with eccentricity are considered. PMID:3953765

  19. Peripheral Arterial Disease (P.A.D.)

    MedlinePlus

    ... turn Javascript on. Peripheral Artery Disease (P.A.D.) What is P.A.D.? Arteries Clogged With Plaque Peripheral arterial disease (P. ... button on your keyboard.) Why Is P.A.D. Dangerous? Click for more information Blocked blood flow ...

  20. Lymphokine-activated killer cells targeted by monoclonal antibodies to the disialogangliosides GD2 and GD3 specifically lyse human tumor cells of neuroectodermal origin.

    PubMed

    Honsik, C J; Jung, G; Reisfeld, R A

    1986-10-01

    Monoclonal antibodies 14.18 (IgG3) and 11C64 (IgG3) directed against disialogangliosides GD2 and GD3, respectively, when used in conjunction with human peripheral blood mononuclear cells (PBMCs) stimulated with human recombinant interleukin (rIL-2) lyse both human melanoma and neuroblastoma cells by antibody-dependent cellular cytotoxicity. Such monoclonal antibody-"armed" effector cells are specifically directed to targets expressing the given disialoganglioside without detectable cross-reactivity. In addition, antibody-dependent cellular cytotoxicity as well as the natural killing ability of human PBMCs is augmented by a brief coincubation with rIL-2. PBMCs augmented by rIL-2 and armed with monoclonal antibodies significantly suppressed tumor growth in the xenotransplant nude mouse model. Our results suggest that once a threshold level of activation of PBMCs is achieved, additional rIL-2 (over three orders of magnitude of concentration) does not significantly enhance cytolytic augmentation. Furthermore, anti-GD3 monoclonal antibody 11C64 together with rIL-2-stimulated PBMCs from melanoma patients with widely differing tumor burdens effectively lyse melanoma tumor targets in antibody-dependent cellular cytotoxicity. Our results also suggest that GD2 and GD3 represent distinct and relevant immunotherapeutic target structures on melanoma whereas GD2 does the same for neuroblastoma tumors. Our data suggest that targeting of activated human effector cells may provide a new and effective cancer immunotherapy protocol.

  1. Lymphokine-activated killer cells targeted by monoclonal antibodies to the disialogangliosides GD2 and GD3 specifically lyse human tumor cells of neuroectodermal origin.

    PubMed Central

    Honsik, C J; Jung, G; Reisfeld, R A

    1986-01-01

    Monoclonal antibodies 14.18 (IgG3) and 11C64 (IgG3) directed against disialogangliosides GD2 and GD3, respectively, when used in conjunction with human peripheral blood mononuclear cells (PBMCs) stimulated with human recombinant interleukin (rIL-2) lyse both human melanoma and neuroblastoma cells by antibody-dependent cellular cytotoxicity. Such monoclonal antibody-"armed" effector cells are specifically directed to targets expressing the given disialoganglioside without detectable cross-reactivity. In addition, antibody-dependent cellular cytotoxicity as well as the natural killing ability of human PBMCs is augmented by a brief coincubation with rIL-2. PBMCs augmented by rIL-2 and armed with monoclonal antibodies significantly suppressed tumor growth in the xenotransplant nude mouse model. Our results suggest that once a threshold level of activation of PBMCs is achieved, additional rIL-2 (over three orders of magnitude of concentration) does not significantly enhance cytolytic augmentation. Furthermore, anti-GD3 monoclonal antibody 11C64 together with rIL-2-stimulated PBMCs from melanoma patients with widely differing tumor burdens effectively lyse melanoma tumor targets in antibody-dependent cellular cytotoxicity. Our results also suggest that GD2 and GD3 represent distinct and relevant immunotherapeutic target structures on melanoma whereas GD2 does the same for neuroblastoma tumors. Our data suggest that targeting of activated human effector cells may provide a new and effective cancer immunotherapy protocol. PMID:3094017

  2. A musculoskeletal model of human locomotion driven by a low dimensional set of impulsive excitation primitives

    PubMed Central

    Sartori, Massimo; Gizzi, Leonardo; Lloyd, David G.; Farina, Dario

    2013-01-01

    Human locomotion has been described as being generated by an impulsive (burst-like) excitation of groups of musculotendon units, with timing dependent on the biomechanical goal of the task. Despite this view being supported by many experimental observations on specific locomotion tasks, it is still unknown if the same impulsive controller (i.e., a low-dimensional set of time-delayed excitastion primitives) can be used as input drive for large musculoskeletal models across different human locomotion tasks. For this purpose, we extracted, with non-negative matrix factorization, five non-negative factors from a large sample of muscle electromyograms in two healthy subjects during four motor tasks. These included walking, running, sidestepping, and crossover cutting maneuvers. The extracted non-negative factors were then averaged and parameterized to obtain task-generic Gaussian-shaped impulsive excitation curves or primitives. These were used to drive a subject-specific musculoskeletal model of the human lower extremity. Results showed that the same set of five impulsive excitation primitives could be used to predict the dynamics of 34 musculotendon units and the resulting hip, knee and ankle joint moments (i.e., NRMSE = 0.18 ± 0.08, and R2 = 0.73 ± 0.22 across all tasks and subjects) without substantial loss of accuracy with respect to using experimental electromyograms (i.e., NRMSE = 0.16 ± 0.07, and R2 = 0.78 ± 0.18 across all tasks and subjects). Results support the hypothesis that biomechanically different motor tasks might share similar neuromuscular control strategies. This might have implications in neurorehabilitation technologies such as human-machine interfaces for the torque-driven, proportional control of powered prostheses and orthoses. In this, device control commands (i.e., predicted joint torque) could be derived without direct experimental data but relying on simple parameterized Gaussian-shaped curves, thus decreasing the input drive complexity

  3. Disaggregation of primitive cumulates in the Skuggafjöll eruption, Iceland

    NASA Astrophysics Data System (ADS)

    Neave, D.; Maclennan, J.; Edmonds, M.; Thordarson, T.

    2013-12-01

    There are significant limitations in using genetic terms, such as phenocryst and xenocryst, when describing macrocrysts carried by magmas. Despite being largely out of equilibrium with their carrier melt, zoned macrocrysts bring with them a record of their past crystallisation. Furthermore, macrocrysts may have resided in crystal mushes or cumulates prior to being entrained into melts and carried to the surface during eruptions. These entrained macrocrysts can therefore provide insights into the development of plutonic rocks within magmatic plumbing systems paused at the moment of disaggregation. Diverse petrologic observations are therefore required to disentangle the volcanic and plutonic processes operating during the assembly of phyric magmas. Here we present the results of an integrated study performed on glassy pillow basalts from the subglacial Skuggafjöll eruption in the Eastern Volcanic Zone (EVZ) of Iceland. Olivine and plagioclase compositions are strongly bimodal with peaks at Fo86 and Fo80 and An88 and An75 respectively. Both QEMSCAN* and SEM imaging indicate that the most forsteritic and anorthitic compositions are found in the cores of large macrocrysts and are texturally associated with one another, forming a primitive macrocryst population. The lowest forsterite and anorthite contents are present in rims of large macrocrysts and in smaller macrocrysts, which are associated clinopyroxene, forming an evolved macrocryst population. Calculations using published mineral-melt equilibrium models indicate that the evolved population is in equilibrium with the groundmass glass composition. The relationship between the primitive population and the evolved, equilibrium population was investigated using combined whole rock geochemistry and point counting systematics for samples with 5-46 modal % macrocryst contents. Highly incompatible trace element concentrations (e.g. Ce, Zr) correlate negatively with the mass fraction of macrocrysts. Regression lines

  4. Interfacing intelligent software to robotic peripherals

    NASA Technical Reports Server (NTRS)

    Orlando, N. E.

    1986-01-01

    A paradigm for the specification of robotic behavior is proposed, based on a template of control and data elements replicated in a hierarchical lattice. Considerations from physiological psychology are proposed as control elements for the model. The resulting model allows freedom in implementational details within a symmetrical design, and should also provide a framework for evolving robotic behavior from relatively primitive to extremely complex. The model's implications for realizing learning capabilities in robotic systems are discussed, and its implementation and demonstration are described.

  5. Photostability of glycine and nitrogen basis in cometary grains : application to the transport of organic matter within the primitive Earth

    NASA Astrophysics Data System (ADS)

    Saiagh, K.; Belilla, J.; Fray, N.; Valorso, R.; Cottin, H.

    2015-10-01

    The study of photochemistry in the solar system is of prime importance to assess complex organic chemistry in any extraterrestrial environment. Among those environments, comets and grains ejected from their nuclei are of particular interest in the context of astrobiology as they could have brought organic matter on the primitive Earth, and hence contribute to the emergence of life. Furthermore, they can provide precious information on the physico-chemical parameters prevailing in the primitive solar nebula during its formation. In this context, we are studying the extent to which organic matter within grains may survive to solar radiation and the fraction of these organic molecules destroyed when it is subjected to sunlight.

  6. A Primitive Endogenous Lentivirus in a Colugo: Insights into the Early Evolution of Lentiviruses

    PubMed Central

    Han, Guan-Zhu; Worobey, Michael

    2015-01-01

    Lentiviruses infect a wide range of mammal species. Much remains unknown about their deep history and host distribution. Here, we report the discovery of an endogenous lentivirus within the genome of the Sunda flying lemur (Galeopterus variegatus) (which we designate “Galeopterus variegatus endogenous lentivirus” [GvaELV]). We estimate the GvaELV genome invasion to have occurred more than 14 Ma, supporting an ancient origin of the lentivirus clade and an ancient lentiviral infection in colugo. Phylogenetic analyses show that GvaELV is a sister group of all previously known lentiviruses. The GvaELV genome appears to possess some primitive genomic features of a lentivirus, encoding not only a trans-activator of transcription (tat) gene but also two additional putative accessory genes that share no discernible similarity with other lentiviral accessory genes. The discovery of GvaELV provides novel insights into the prehistory and host distribution of lentivirus. PMID:25349288

  7. [Diversity and viability of prokaryotes in primitive soils of the larsemann oasis (East Antarctica)].

    PubMed

    Kudinova, A G; Lysak, L V; Lapygina, E V; Soina, V S; Mergelov, N S

    2015-01-01

    The diversity and viability of prokaryotic communities in the primitive organomineral soils of East Antarctica have been studied; it has been shown that the total number of bacteria is smaller than and the viability of bacteria is similar to that in soils of the temperate zone. The prokaryotic communities are characterized by the occurrence of a major part of cells in filterable forms, which is higher than the analogous parameter for the temperate soils. The method of fluorescence in situ hybridization (FISH) revealed that the distribution of the main taxons is similar to that in the temperate soils: the portion of the domain Archaea is smaller than that of the domain Bacteria; the total content of Gram-negative bacteria (the phyla Proteobacteria, Acidobacteria, and Planctomycetes) is higher than that of Gram-positive bacteria (Actinobacteria). Within the phylum Proteobacteria, a significant variation of three proteobacterial classes has been noted along the profiles of the soils studied.

  8. Chromosome conservation among the advanced pecorans and determination of the primitive bovid karyotype.

    PubMed

    Gallagher, D S; Derr, J N; Womack, J E

    1994-01-01

    Extensive monobrachial QFH-band homologies were found among cattle (Bovidae), pronghorn (Antilocapridae), Masai giraffe (Giraffidae), and mule and whitetail deer (Cervidae). The deer species had identical karyotypes (2n = 70, NAA = 70). Interfamily comparisons demonstrated that cattle (2n = 60, NAA = 58) and pronghorn (2n = 58, NAA = 60) were karyotypically the most similar. The giraffe possessed a 2n = 30, NAA = 54, and differed from the other artiodactyls by having a preponderance of biarmed autosomes. The primarily acrocentric deer karyotypes showed several chromosome arm disruptions relative to the other species. Comparative cytogenetic data among the advanced pecorans strongly suggest that the 2n = 60, NAA = 58 karyotype found in several species of the tribe Bovini is probably near the primitive condition for the Bovidae. However, the ancestral conditions of the sex chromosomes within the Bovidae and among the advanced pecorans remain in question. PMID:8014460

  9. Molecular dynamics study of the primitive model of 1 3 electrolyte solutions

    NASA Astrophysics Data System (ADS)

    Suh, S.-H.; Mier-y-Teran, L.; White, H. S.; Davis, H. T.

    1990-04-01

    Molecular dynamics simulations at constant temperature have been carried out for the primitive model of 1-3 electrolyte solutions. Thermodynamics, pair distribution functions, and self-diffusion coefficients were computed to examine the electrostatic effects on the structural and dynamical properties. The simulation results were used to evaluate various theoretical equations, namely, the exponential form of Debye-Hückel theory, the mean spherical approximation, and the hypernetted chain approximation. As has been observed for symmetrical electrolytes, the latter turns out to be the best approximation. For asymmetrically charged 1-3 electrolytes, it was found that ionic aggregation significantly influenced the dynamical properties of electrolytes. Coherent motion between highly charged negative ions and positive ions surrounding them was deduced from the time dependence of the velocity autocorrelation functions, particularly at concentrations between 0.4 and 4 total ion molarity.

  10. Isotopic Fractionation in Primitive Material: Quantifying the Contribution of Interstellar Chemistry

    NASA Technical Reports Server (NTRS)

    Charnley, Steven

    2010-01-01

    Anomalously fractionated isotopic material is found in many primitive Solar System objects, such as meteorites and comets. It is thought, in some cases, to trace interstellar matter that was incorporated into the Solar Nebula without undergoing significant processing. We will present the results of models of the nitrogen, oxygen, and carbon fractionation chemistry in dense molecular clouds, particularly in cores where substantial freeze-out of molecules on to dust has occurred. The range of fractionation ratios expected in different interstellar molecules will be discussed and compared to the ratios measured in molecular clouds, comets and meteoritic material. These models make several predictions that can be tested in the near future by molecular line observations, particularly with ALMA.

  11. Low-temperature condensates in comets. [using primitive solar nebula model

    NASA Technical Reports Server (NTRS)

    Delsemme, A. H.; Rud, D.

    1977-01-01

    Recent observational data on the volatile fraction of comets are confronted with a model based on the fractional condensation, in the 80-100 K range, of a higher-temperature equilibrium obtained from a solar mixture, more or less depleted in oxygen and in hydrogen. It is possible to almost duplicate the observational data, only by assuming that the solar ratio of C/O is at least as large as 0.66 and that the hydrogen was drastically depleted by an unknown process in the primitive solar nebula. Although none of these two assumptions is at variance with present knowledge, the latter is sufficiently exotic to propose a simpler explanation, namely that comets could be made of interstellar grains relatively unprocessed by heat.

  12. Rates of fixation by lightning of carbon and nitrogen in possible primitive atmospheres

    NASA Technical Reports Server (NTRS)

    Chameides, W. L.; Walker, J. C. G.

    1981-01-01

    A thermochemical-hydrodynamic model of the production of trace species by electrical discharges has been used to estimate the rates of fixation of C and N by lightning in the primitive atmosphere. Calculations for various possible mixtures of CH4, CO2, CO, N2, H2, and H2O reveal that the prime species produced were probably HCN and NO and that the key parameter determining the rates of fixation was the ratio of C atoms to O atoms in the atmosphere. Atmospheres with C more abundant than O have large HCN fixation rates, in excess of 10 to the 17th molecules/J, but small NO yields. However, when O is more abundant than C, the NO fixation rate approaches 10 to the 17th molecules/J while the HCN yield is small. The implications for the evolution of life are discussed.

  13. Two computational primitives for algorithmic self-assembly: copying and counting.

    PubMed

    Barish, Robert D; Rothemund, Paul W K; Winfree, Erik

    2005-12-01

    Copying and counting are useful primitive operations for computation and construction. We have made DNA crystals that copy and crystals that count as they grow. For counting, 16 oligonucleotides assemble into four DNA Wang tiles that subsequently crystallize on a polymeric nucleating scaffold strand, arranging themselves in a binary counting pattern that could serve as a template for a molecular electronic demultiplexing circuit. Although the yield of counting crystals is low, and per-tile error rates in such crystals is roughly 10%, this work demonstrates the potential of algorithmic self-assembly to create complex nanoscale patterns of technological interest. A subset of the tiles for counting form information-bearing DNA tubes that copy bit strings from layer to layer along their length.

  14. Ion Irradiation Experiments on the Murchison CM2 Carbonaceous Chondrite: Simulating Space Weathering of Primitive Asteroids

    NASA Technical Reports Server (NTRS)

    Keller, L. P.; Christoffersen, R.; Dukes, C. A.; Baragiola, R. A.; Rahman, Z.

    2015-01-01

    Remote sensing observations show that space weathering processes affect all airless bodies in the Solar System to some degree. Sample analyses and lab experiments provide insights into the chemical, spectroscopic and mineralogic effects of space weathering and aid in the interpretation of remote- sensing data. For example, analyses of particles returned from the S-type asteroid Itokawa by the Hayabusa mission revealed that space-weathering on that body was dominated by interactions with the solar wind acting on LL ordinary chondrite-like materials [1, 2]. Understanding and predicting how the surface regoliths of primitive carbonaceous asteroids respond to space weathering processes is important for future sample return missions (Hayabusa 2 and OSIRIS-REx) that are targeting objects of this type. Here, we report the results of our preliminary ion irradiation experiments on a hydrated carbonaceous chondrite with emphasis on microstructural and infrared spectral changes.

  15. Association sarcoïdose et cirrhose biliaire primitive: à propos d'un nouveau cas

    PubMed Central

    Aqodad, Nourdin; Loukili, Bouchra; Gallouj, Salim; Harmouch, Taoufik; Amarti, Afaf; Mernissi, FZ; Ibrahimi, Adil

    2014-01-01

    La sarcoïdose est une maladie systémique d’étiologie inconnue. Elle est caractérisée par la présence de lésions granulomateuses, non caséeuses, au niveau des organes atteints. La cirrhose biliaire primitive (CBP) est une hépatopathie cholestatique auto-immune chronique, caractérisée par une destruction des canalicules biliaires et la présence d'anticorps antimitchondries type M2. L'association sarcoïdose et CBP est rare. Nous rapportons un nouveau cas de cette association avec revue de la littérature. PMID:25489373

  16. Origin of organic compounds on the primitive earth and in meteorites

    NASA Technical Reports Server (NTRS)

    Miller, S. L.; Urey, H. C.; Oro, J.

    1976-01-01

    The paper examines the role and relative contributions of different forms of energy to the synthesis of amino acids and other organic compounds on the primitive earth and in the solar nebula. Attention is directed mainly to the activation steps and formation of reactive intermediate compounds. Electric discharges appear to be not only the most efficient energy for amino acid synthesis but also yield a mixture of amino acids that is qualitatively and quantitatively the same as that found in the Murchison carbonaceous chondrite. Ultraviolet light is likely to have played a major role in prebiotic synthesis. The reaction of CO plus H2 plus NH3 on the surface of a Fischer-Tropsch catalyst produces reactive intermediates which lead to amino acids and other organic compounds in a much less efficient way than electric discharges.

  17. Detailed balance condition and effective free energy in the primitive chain network model

    NASA Astrophysics Data System (ADS)

    Uneyama, Takashi; Masubuchi, Yuichi

    2011-11-01

    We consider statistical mechanical properties of the primitive chain network (PCN) model for entangled polymers from its dynamic equations. We show that the dynamic equation for the segment number of the PCN model does not reduce to the standard Langevin equation which satisfies the detailed balance condition. We propose heuristic modifications for the PCN dynamic equation for the segment number, to make it reduce to the standard Langevin equation. We analyse some equilibrium statistical properties of the modified PCN model, by using the effective free energy obtained from the modified PCN dynamic equations. The PCN effective free energy can be interpreted as the sum of the ideal Gaussian chain free energy and the repulsive interaction energy between slip-links. By using the single chain approximation, we calculate several distribution functions of the PCN model. The obtained distribution functions are qualitatively different from ones for the simple slip-link model without any direct interactions between slip-links.

  18. Oxygen isotope variation in primitive achondrites: The influence of primordial, asteroidal and terrestrial processes

    NASA Astrophysics Data System (ADS)

    Greenwood, R. C.; Franchi, I. A.; Gibson, J. M.; Benedix, G. K.

    2012-10-01

    A detailed oxygen isotope study of the acapulcoites, lodranites, winonaites, brachinites and various related achondrites has been undertaken to investigate the nature of their precursor materials. High levels of terrestrial alteration displayed by many of these samples have been mitigated by leaching in ethanolamine thioglycollate (EATG) solution. Due to their high metal and sulphide content, acapulcoite, lodranite and winonaite samples show much greater isotopic shifts during weathering than brachinites. As observed in previous studies, Antarctic weathered finds are displaced to lighter oxygen isotope compositions and non-Antarctic finds to heavier values. Leached primitive achondrite residues continue to show high levels of oxygen isotope heterogeneity. This variation is reflected in the 2σ error on group mean Δ17O values, which decrease in the following order: acapulcoite-lodranite clan > brachinites > winonaites. On an oxygen three-isotope diagram, the acapulcoite--lodranite clan define a limited trend with a slope of 0.61 ± 0.08 and an intercept of -1.43 ± 0.27 (R2 = 0.78). A broad positive correlation between Δ17O and olivine fayalite contents displayed by both acapulcoite and lodranite samples may be the result of early aqueous alteration and subsequent dehydration. Winonaites experienced a greater degree of differentiation than the acapulcoite-lodranite clan and define a distinct mass fractionation line, with a slope of 0.53 ± 0.01 and an intercept of -0.53 ± 0.04 (R2 = 1). A number of samples currently classified as acapulcoites (NWA 725, NWA 1052 and Dho 1222) have oxygen isotope compositions indicating that they are winonaites. The relatively high level of oxygen isotope heterogeneity displayed by the brachinites supports their designation as primitive achondrites. A number of ungrouped olivine-rich achondrites (Divnoe, NWA 4042, NWA 4363, NWA 4518, NWA 5400, Zag (b)) as well as the unique plagioclase-rich achondrites GRA 06128 and GRA 06129 have

  19. Motor primitives and synergies in spinal cord and after injury– the current state of play

    PubMed Central

    Giszter, Simon F.; Hart, Corey B.

    2013-01-01

    Modular pattern generator elements, also known as burst synergies or motor primitives, have become a useful and important way of describing motor behavior, albeit controversial. It is suggested that these synergy elements may comprise part of the pattern shaping layers of a McCrea/Rybak two layer pattern generator, as well as being used in other ways in spinal cord. The data supporting modular synergies ranges across species including man and encompasses motor pattern analyses and neural recordings. Recently, synergy persistence and changes following clinical trauma have been presented. These new data underscore the importance of understanding the modular structure of motor behaviors and the underlying circuitry in order to best provide principled therapies and to understand phenomena reported in the clinic. We discuss the evidence and different viewpoints on modularity, the neural underpinnings identified thus far, and possible critical issues for the future of this area. PMID:23531009

  20. Melt production beneath Mt. Shasta from boron data in primitive melt inclusions.

    PubMed

    Rose, E F; Shimizu, N; Layne, G D; Grove, T L

    2001-07-13

    Most arc magmas are thought to be generated by partial melting of the mantle wedge induced by infiltration of slab-derived fluids. However, partial melting of subducting oceanic crust has also been proposed to contribute to the melt generation process, especially when young and hot lithosphere is being subducted. The isotopic composition of boron measured in situ in olivine-hosted primitive melt inclusions in a basaltic andesite from Mt. Shasta, California, is characterized by large negative values that are also highly variable (delta(11)B = -21.3 to -0.9 per mil). The boron concentrations, from 0.7 to 1.6 parts per million, are lower than in most other arc lavas. The relation between concentration and isotopic composition of boron observed here supports a hypothesis that materials left after dehydration of the subducting slab may have contributed to the generation of basaltic andesite lavas at Mt. Shasta.