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Sample records for original four-lumen double-balloon

  1. Double-balloon tamponade in the management of postpartum hemorrhage: a case series

    PubMed Central

    Kavak, Salih Burçin; Kavak, Ebru Çelik; Demirel, Ismail; Ilhan, Raşit

    2014-01-01

    To show the efficacy of double-balloon cervical ripening catheter in the management of postpartum hemorrhage originating from the lower segment of the uterus or the upper parts of the vagina. Methods Patients with intractable bleeding from the lower segment of the uterus and the upper parts of the vagina after Cesarean or vaginal deliveries were treated by double-balloon cervical ripening catheter. Results Double-balloon catheter was used in seven patients, and it was properly placed in all of them. No other intervention was needed to control bleeding. Two patients were delivered vaginally, and five patients were delivered by Cesarean section. Length of hospitalization was longer in the vaginal delivery patients (average hospitalization was 12 days in the vaginal delivery patients and 5 days in the Cesarean section patients). The need for blood and blood products transfusion (average of blood and blood products transfusion was 30 U in the vaginal delivery patients and 6 U in the Cesarean patients) was also higher in the vaginal delivery patients. Conclusion Although double-balloon cervical ripening catheter is designed for the induction of labor, it can successfully control intractable bleedings from the lower segment of the uterus and the upper parts of the vagina. This procedure can save patients from undergoing more morbid procedures. PMID:25120367

  2. Diagnosis of the jejunoileal lymphoma by double-balloon endoscopy

    PubMed Central

    Ibuka, Takashi; Araki, Hiroshi; Sugiyama, Tomohiko; Nakanishi, Takayuki; Onogi, Fumito; Shimizu, Masahito; Hara, Takeshi; Takami, Tsuyoshi; Tsurumi, Hisashi; Moriwaki, Hisataka

    2013-01-01

    AIM: To investigate the feasibility of double-balloon endoscopy (DBE) to detect jejunoileal lymphoma, compared with fluorodeoxyglucose positron emission tomography (FDG-PET). METHODS: Between March 2004 and January 2011, we histologically confirmed involvement of malignant lymphoma of the jejunoileum in 31 patients by DBE and biopsy. In 20 patients of them, we performed with FDG-PET. We retrospectively reviewed the records of these 20 patients. Their median age was 64 years (range 50-81). In the 20 patients, the pathological diagnosis of underlying non-Hodgkin’s lymphoma (NHL) comprised follicular lymphoma (FL, n = 12), diffuse large B cell lymphoma (DLBCL, n = 4), mantle cell lymphoma (MCL, n = 2), enteropathy associated T cell lymphoma (ETL, n = 1) and anaplastic large cell lymphoma (ALCL, n = 1). RESULTS: Ten cases showed accumulation by FDG-PET (50%). FDG-PET was positive in 3 of 12 FL cases (25%) while in 7 of 8 non-FL cases (88%, P < 0.05). Intestinal FL showed a significantly lower rate of positive FDG-PET, in comparison with other types of lymphoma. Cases with endoscopically elevated lesions (n = 10) showed positive FDG-PET in 2 (20%), but those with other type NHL did in 8 of 10 (80%, P < 0.05). When the cases having elevated type was compared with those not having elevated type lesion, the number of cases that showed accumulation of FDG was significantly smaller in the former than in the latter. CONCLUSION: In a significant proportion, small intestinal involvement cannot be pointed out by FDG-PET. Especially, FL is difficult to evaluate by FDG-PET but essentially requires DBE. PMID:23515341

  3. Urgent double balloon endoscopy provides higher yields than non-urgent double balloon endoscopy in overt obscure gastrointestinal bleeding

    PubMed Central

    Aniwan, Satimai; Viriyautsahakul, Vichai; Rerknimitr, Rungsun; Angsuwatcharakon, Phonthep; Kongkam, Pradermchai; Treeprasertsuk, Sombat; Kullavanijaya, Pinit

    2014-01-01

    Background and study aims: In overt obscure gastrointestinal bleeding (OV), double balloon endoscopy (DBE) is recommended as one of the most important investigations as it can provide both diagnosis and treatment. However, there is no set standard on the timing of DBE in OV. The aim of this study was to compare the diagnostic and therapeutic yields between urgent and non-urgent DBE in patients with OV. Patients and methods: Between January 2006 and February 2013, 120 patients with OV who underwent DBE were retrospectively reviewed. An urgent DBE was defined as DBE performed within 72 h from the last visible gastrointestinal bleeding (n = 74) whereas a non-urgent DBE was defined as DBE performed after 72 h (n = 46). Diagnostic yields, therapeutic impact and clinical outcomes were evaluated. Results: Diagnostic yield in urgent DBE was significantly higher than that in non-urgent DBE (70 % versus 30 %; P < 0.05). Urgent DBE offered significantly more therapies including endoscopic, angiographic embolization, and surgery than non-urgent DBE (54 % versus 15 %; P < 0.001). Endoscopic therapy was performed in 43 % of urgent-DBE patients whereas only 13 % of patients in the other group received endoscopic therapy (P < 0.01). In patients with identified bleeding sources, the rebleeding rate was lower in patients who underwent urgent DBE than in those who underwent non-urgent DBE (10 % versus 29 %, NS). Conclusions: Regarding diagnostic and therapeutic impacts in OV, our retrospective study showed that urgent DBE is better than non-urgent DBE. The recurrent bleeding rate in patients undergoing urgent DBE tended to be lower. PMID:26135267

  4. Double-balloon enteroscopy in small bowel diseases

    PubMed Central

    Chen, Wen-Guo; Shan, Guo-Dong; Zhang, Hong; Yang, Ming; L, Lin; Yue, Min; Chen, Guang-Wu; Gu, Qing; Zhu, Hua-Tuo; Xu, Guo-Qiang; Chen, Li-Hua

    2016-01-01

    Abstract The aim of the study was to evaluate the diagnostic and therapeutic value of double-balloon entoroscopy (DBE) in small bowel diseases (SBDs) in China. A retrospective review of 674 consecutive patients who underwent DBE between January 2007 and November 2015 was conducted. Patients were divided into 3 groups by age, young group (<45 years), middle-aged group (45–65 years), and elderly group (>65 years). Data were collected with regard to demographics, clinical, endoscopic findings, complications, diagnostic yield, and management. A total of 729 DBE procedures were performed successfully in our series. More than 20 types of SBDs were found with the detection rate of 70.9%(517/729). The majority of patients were Crohn's disease (33.4%,225/674), followed by tumor (18.8%,127/674) and angioectasia (7.9%, 53/674). Endoscopic treatment was performed in 60 patients in which hemostasis (17,28.3%) and polypectomy (15,25%) were the predominant form of intervention used. Adverse events occurred in 6 patients (0.96%,6/729) including perforation, hemorrhage, aspiration pneumonia. No acute pancreatitis or other major complications occurred. Adenocarcinoma, GIST, and lymphoma were the most common tumor detected, the majority of tumors located in the jejunum (56.7%), The detection rate of angioectasia was also higher in the jejunum (54.7%),77.8% of Crohn's disease was located in the ileum. The positive rate of DBE in small bowel tumor and Crohn's disease were significantly higher than that of angioectasia (P<0.05). In young cohort, Crohn's disease (48.1%) was the most commonly diseases followed by tumor (10.4%) and nonspecific enteritis (7.1%). Yet in the elderly group, the majority of patients were tumor (27.6%); angioectasia (21.3%) was also detected frequently. The positive rate of capsule endoscopy was 75.44 %(202/268) which was a little high than DBE (67.9%, 182/268) (P > 0.05). The obscure gastrointestinal bleeding (OGIB) was the most common indication, and

  5. Single-balloon versus double-balloon bipedicular kyphoplasty for osteoporotic vertebral compression fractures.

    PubMed

    Wang, Heng; Sun, Zhenzhong; Wang, Zhiwen; Jiang, Weimin

    2015-04-01

    Twenty-eight patients with osteoporotic vertebral compression fractures (OVCF) were treated with single-balloon bipedicular kyphoplasty (Group A), and 40 patients were treated with double-balloon bipedicular kyphoplasty (Group B). Visual Analogue Scale (VAS) score, vertebral height, and kyphotic angle (KA) were evaluated pre-operatively, post-operatively (3 days after surgery) and at final follow-up. Operative time, X-ray exposure frequency and costs were recorded. The mean operative time and X-ray exposure frequency in Group A were greater than in Group B (p<0.05). Significant improvement of the VAS score was noted in each group, and remained unchanged at final follow-up. Mean increases of anterior and middle height of the fractured vertebral body were 5.14mm and 4.14mm in Group A, respectively, and 6.22mm and 5.06mm in Group B, respectively, and the differences between the groups were statistically significant (p<0.05). Mean reduction of KA was 6.9° in Group A and 8.8° in Group B, which was statistically significant (p<0.05). No statistically significant difference was observed in terms of cement leakage between groups. The mean cost of Group A (US$4202) was significantly less than that of Group B (US$6220) (p<0.001). Single-balloon bipedicular kyphoplasty is a safe and cost-effective surgical method for the treatment of OVCF. It can achieve pain relief comparable with double-balloon bipedicular kyphoplasty. However, double-balloon bipedicular kyphoplasty is more efficacious in terms of the restoration of vertebral height and reduction of KA, and the operative time and X-ray exposure frequency are lower.

  6. ERCP using double-balloon enteroscopy in patients with Roux-en-Y anatomy.

    PubMed

    Kuga, Rogério; Furuya, Carlos Kiyoshi; Hondo, Fábio Yuji; Ide, Edson; Ishioka, Shinichi; Sakai, Paulo

    2008-01-01

    Double-balloon enteroscopy (DBE) is a useful method for endoscopic retrograde cholangiopancreatography (ERCP) in patients with Roux-en-Y anatomy. Depending on the distorted anatomy, endoscopic therapies with conventional scopes were very difficult or impossible before the advent of DBE and patients had to be submitted to a percutaneous or surgical approach. The case of 6 patients with different types of Roux-en-Y-altered anatomy in which DBE-ERCP was performed with 83.3% successful rate (5/6) is reported confirming recent data in the literature on the feasibility of this method. PMID:19188724

  7. Double balloon endoscopy in two hundred fifty cases for the diagnosis and treatment of small intestinal disorders.

    PubMed

    Kita, H; Yamamoto, H; Yano, T; Miyata, T; Iwamoto, M; Sunada, K; Arashiro, M; Hayashi, Y; Ido, K; Sugano, K

    2007-04-01

    Double balloon endoscopy is based on a new insertion mode in which two balloons at the distal ends of both an endoscope and an overtube are operated in combination. We have performed 419 enteroscopic examinations in 250 patients using the Fujinon double balloon endoscopy system between September 2000 and October 2005. Total enteroscopy was successfully achieved by the combination of both oral and anal approaches in 55 out of 71 cases in whom total enteroscopy was intended. Of 250 patients, ulcerative and/or erosive lesions were found in 49 cases and tumors/polyps were found in 49 cases. We also found 26 cases of vascular lesion, including angiodysplasia. Endoscopic treatments, including hemostasis using either clipping devices or electro coagulation, polypectomy, endoscopic mucosal resection, balloon dilation, and stent placement was successfully carried out. Double balloon enteroscopy is both feasible and useful technique for the diagnosis as well as treatment of small intestinal disorders. PMID:17450446

  8. Double balloon endoscopy in two hundred fifty cases for the diagnosis and treatment of small intestinal disorders.

    PubMed

    Kita, H; Yamamoto, H; Yano, T; Miyata, T; Iwamoto, M; Sunada, K; Arashiro, M; Hayashi, Y; Ido, K; Sugano, K

    2007-04-01

    Double balloon endoscopy is based on a new insertion mode in which two balloons at the distal ends of both an endoscope and an overtube are operated in combination. We have performed 419 enteroscopic examinations in 250 patients using the Fujinon double balloon endoscopy system between September 2000 and October 2005. Total enteroscopy was successfully achieved by the combination of both oral and anal approaches in 55 out of 71 cases in whom total enteroscopy was intended. Of 250 patients, ulcerative and/or erosive lesions were found in 49 cases and tumors/polyps were found in 49 cases. We also found 26 cases of vascular lesion, including angiodysplasia. Endoscopic treatments, including hemostasis using either clipping devices or electro coagulation, polypectomy, endoscopic mucosal resection, balloon dilation, and stent placement was successfully carried out. Double balloon enteroscopy is both feasible and useful technique for the diagnosis as well as treatment of small intestinal disorders.

  9. Double-Balloon-Assisted n-Butyl-2-Cyanoacrylate Embolization of Intrahepatic Arterioportal Shunt Prior to Chemoembolization of Hepatocellular Carcinoma.

    PubMed

    Takao, Hidemasa; Shibata, Eisuke; Ohtomo, Kuni

    2016-10-01

    A case of multiple hepatocellular carcinomas with a severe intrahepatic arterioportal shunt that was successfully embolized with n-butyl-2-cyanoacrylate with coaxial double-balloon occlusion prior to transcatheter arterial chemoembolization is presented. A proximal balloon positioned at the proper hepatic artery was used for flow control, and a coaxial microballoon, positioned in the closest of three arterial feeding branches to the arterioportal shunt, was used to control the delivery of n-butyl-2-cyanoacrylate. This coaxial double-balloon technique can prevent proximal embolization and distal migration of n-butyl-2-cyanoacrylate and enable precise control of the distribution of n-butyl-2-cyanoacrylate. It could also be applicable to n-butyl-2-cyanoacrylate embolization for other than intrahepatic arterioportal shunt.

  10. Primary intestinal lymphangiectasia diagnosed by capsule endoscopy and double balloon enteroscopy

    PubMed Central

    Oh, Tak Geun; Chung, Joo Won; Kim, Hee Man; Han, Seok-Joo; Lee, Jin Sung; Park, Jung Yeob; Song, Si Young

    2011-01-01

    Primary intestinal lymphangiectasia (PIL) is a rare disorder characterized by dilated intestinal lymphatics and the development of protein-losing enteropathy. Patients with PIL develop hypoalbuminemia, hypocalcemia, lymphopenia and hypogammaglobulinemia, and present with bilateral lower limb edema, fatigue, abdominal pain and diarrhea. Endoscopy reveals diffusely elongated, circumferential and polypoid mucosae covered with whitish enlarged villi, all of which indicate intestinal lymphangiectasia. Diagnosis is confirmed by characteristic tissue pathology, which includes dilated intestinal lymphatics with diffusely swollen mucosa and enlarged villi. The prevalence of PIL has increased since the introduction of capsule endoscopy. The etiology and prevalence of PIL remain unknown. Some studies have reported that several genes and regulatory molecules for lymphangiogenesis are related to PIL. We report the case of a patient with PIL involving the entire small bowel that was confirmed by capsule endoscopy and double-balloon enteroscopy-guided tissue pathology who carried a deletion on chromosome 4q25. The relationship between this deletion on chromosome 4 and PIL remains to be investigated. PMID:22110841

  11. Metallic stent insertion with double-balloon endoscopy for malignant afferent loop obstruction

    PubMed Central

    Fujii, Masakuni; Ishiyama, Shuhei; Saito, Hiroaki; Ito, Mamoru; Fujiwara, Akiko; Niguma, Takefumi; Yoshioka, Masao; Shiode, Junji

    2015-01-01

    Progress in double-balloon endoscopy (DBE) has allowed for the diagnosis and treatment of disease in the postoperative bowel. For example, a short DBE, which has a 2.8 mm working channel and 152 cm working length, is useful for endoscopic retrograde cholangiopancreatography in bowel disease patients. However, afferent loop and Roux-limb obstruction, though rare, is caused by postoperative recurrence of biliary tract cancer with intractable complications. Most of the clinical findings involving these complications are relatively nonspecific and include abdominal pain, nausea, vomiting, fever, and obstructive jaundice. Treatments by surgery, percutaneous transhepatic biliary drainage, percutaneous enteral stent insertion, and endoscopic therapy have been reported. The general conditions of patients with these complications are poor due to cancer progression; therefore, a less invasive treatment is better. We report on the usefulness of metallic stent insertion using an overtube for afferent loop and Roux-limb obstruction caused by postoperative recurrence of biliary tract cancer under short DBE in two patients with complexly reconstructed intestines. PMID:26078835

  12. Comparison of Capsule Endoscopy Findings to Subsequent Double Balloon Enteroscopy: A Dual Center Experience

    PubMed Central

    Kalra, Amandeep S.; Walker, Andrew J.; Benson, Mark E.; Soni, Anurag; Guda, Nalini M.; Misha, Mehak; Gopal, Deepak V.

    2015-01-01

    Background. There has been a growing use of both capsule endoscopy (CE) and double balloon enteroscopy (DBE) to diagnose and treat patients with obscure gastrointestinal blood loss and suspected small bowel pathology. Aim. To compare and correlate sequential CE and DBE findings in a large series of patients at two tertiary level hospitals in Wisconsin. Methods. An IRB approved retrospective study of patients who underwent sequential CE and DBE, at two separate tertiary care academic centers from May 2007 to December 2011, was performed. Results. 116 patients were included in the study. The mean age ± SD was 66.6 ± 13.2 years. There were 56% males and 43.9% females. Measure of agreement between prior capsule and DBE findings was performed using kappa statistics, which gave kappa value of 0.396 with P < 0.001. Also contingency coefficient was calculated and was found to be 0.732 (P < 0.001). Conclusions. Our study showed good overall agreement between DBE and CE. Findings of angioectasia had maximum agreement of 69%. PMID:26420979

  13. Effect of the manipulation of the duodenal papilla during double balloon enteroscopy

    PubMed Central

    Latorre, Rafael; López-Albors, Octavio; Soria, Federico; Candanosa, Eugenia; Pérez-Cuadrado, Enrique

    2016-01-01

    AIM: To determine the hypothesis that inflating the balloons in the duodenal papilla determines changes in the biochemical markers of pancreatitis. METHODS: Four groups of pigs were used: Group papilla (GP), the overtube’s balloon was inflated in the area of the papilla; GP + double balloon enteroscopy (GP + DBE), the overtube’s balloon was kept inflated in the area of the papilla for 20 min before a DBE; Group DBE (GDBE), DBE was carried out after insuring the balloon’s inflation far from the pancreatic papilla; and Group control (GC). Serum concentrations of amylase, lipase and C-reactive protein (CRP) were evaluated. Pancreases were processed for histopathology examination. RESULTS: Main changes occurred 24 h after the procedure compared with baseline levels. Amylase levels increased significantly in GP (59.2% higher) and were moderately higher in groups GP + DBE and GDBE (22.7% and 20%, respectively). Lipase increased in GP and GP + DBE, whereas it hardly changed in GDBE and in GC. CRP increased significantly in GP, GP + DBE and GDBE, while no changes were reported for GC. No statistically significant difference between groups GP and GP + DBE was found for the histopathological findings, except for vacuolization and necrosis of the pancreatic parenchyma that was higher in GP than in GP + DBE. CONCLUSION: The manipulation of the duodenal papilla by the inflated overtube’s balloon during DBE causes pancreatic structural damage and increased biochemical markers associated with pancreatitis. PMID:27158201

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

    PubMed

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

    2011-01-01

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

  15. Laparoscopic resection of a huge retroperitoneal cystic lymphangioma after successful reduction of tumor size with a double balloon catheter

    PubMed Central

    Ishibashi, Yusuke; Tsujimoto, Hironori; Kouzu, Keita; Horiguchi, Hiroyuki; Nomura, Shinsuke; Ito, Nozomi; Kanematsu, Kyohei; Yamazaki, Kenji; Hiraki, Shuichi; Aosasa, Suefumi; Noro, Takuji; Yamamoto, Junji; Hase, Kazuo

    2015-01-01

    Introduction Retroperitoneal cystic lymphangiomas are rare. We report a case of retroperitoneal huge cystic lymphangioma that was successfully aspirated the cyst’s contents with double balloon catheter and excised laparoscopically. Presentation of case A 34-year-old man was admitted to our hospital with low-grade fever and abdominal pain that had lasted for 1 week. Abdominal computed tomography and magnetic resonance imaging showed a fluid-filled multilocular mass measuring 13.5 cm in diameter around the tail of the pancreas, which was diagnosed as a retroperitoneal cystic lymphangioma. We successfully excised the tumor by laparoscopic distal pancreatosplenectomy. We punctured and aspirated the tumor with a double-balloon catheter to decrease the tumor’s size without spilling the tumor content. Cytology showed no malignant cells, and histopathological examination confirmed cystic lymphangioma. No recurrence was noted on radiographic imaging 10 months postoperatively. Discussion and conclusion Laparoscopic treatment for retroperitoneal huge cystic lymphangioma is feasible, and the double balloon catheter is useful for reducing the tumor volume. PMID:25898335

  16. Percutaneous Mitral Valve Dilatation: Single Balloon versus Double Balloon - A Finite Element Study

    SciTech Connect

    Schievano, Silvia; Kunzelman, Karyn; Nicosia, Mark; Cochran, R. P.; Einstein, Daniel R.; Khambadkone, Sachin; Bonheoffer, Philipp

    2009-01-01

    Background: Percutaneous mitral valve (MV) dilatation is performed with either a single balloon (SB) or double balloon (DB) technique. The aim of this study was to compare the two balloon system results using the finite element (FE) method. Methods and Results: An established FE model of the MV was modified by fusing the MV leaflet edges at commissure level to simulate a stenotic valve (orifice area=180mm2). A FE model of a 30mm SB (low-pressure, elastomeric balloon) and an 18mm DB system (high-pressure, non-elastic balloon) was created. Both SB and DB simulations resulted in splitting of the commissures and subsequent stenosis dilatation (final MV area=610mm2 and 560mm2 respectively). Stresses induced by the two balloon systems varied across the valve. At the end of inflation, SB showed higher stresses in the central part of the leaflets and at the commissures compared to DB simulation, which demonstrated a more uniform stress distribution. The higher stresses in the SB analysis were due to the mismatch of the round balloon shape with the oval mitral orifice. The commissural split was not easily accomplished with the SB due to its high compliance. The high pressure applied to the DB guaranteed the commissural split even when high forces were required to break the commissure welds. Conclusions: The FE model demonstrated that MV dilatation can be accomplished by both SB and DB techniques. However, the DB method resulted in higher probability of splitting of the fused commissures and less damage caused to the MV leaflets by overstretching.

  17. Evaluation of radiation exposure dose at double-balloon endoscopy for the patients with small bowel disease

    PubMed Central

    Nagura, Asuka; Nakamura, Masanao; Watanabe, Osamu; Yamamura, Takeshi; Funasaka, Kohei; Ohno, Eizaburo; Miyahara, Ryoji; Kawashima, Hiroki; Koyama, Shuji; Hinami, Tomoki; Goto, Hidemi; Hirooka, Yoshiki

    2016-01-01

    ABSTRACT Double-balloon endoscopy (DBE) is useful for the diagnosis and treatment of small bowel diseases. Although fluoroscopy is used to confirm the position of endoscope at DBE, the endoscopist does not have the knowledge with regard to the radiation exposure dose. In this study, we evaluated the absorbed dose during DBE in patients with suspected or established small bowel diseases. This was a retrospective study in which the estimated fluoroscopic radiation absorbed doses loaded on the small bowel and skin were determined according to the data of the referential X-ray experiment with a human body phantom. The subjects were 415 DBEs preformed in total. The mean small bowel absorbed doses on antegrade and retrograde DBEs were 42.2 and 53.8 mGy, respectively, showing that the organ dose applied in retrograde DBE was significantly higher (P<0.0001). The mean skin absorbed doses of them were 79.2 and 101.0 mGy, respectively, showing that the dose was also significantly higher on retrograde DBE (P<0.0001). Of 27 cases who were applied endoscopic balloon dilation, the mean fluoroscopy time was 16.0 minutes, and mean small bowel and skin absorbed doses were 121.9 and 228.9 mGy, respectively. In conclusion, endoscopist should be careful for reducing the organ exposure dose at DBE, particularly for the lower abdominal region. Abbreviations: Double-balloon enteroscopy (DBE), endoscopic balloon dilation (EBD), endoscopic mucosal resection (EMR), double-balloon endoscopic retrograde cholangiopancreatography (DBERCP), percutaneous coronary intervention (PCI) PMID:27578908

  18. A meta-analysis on efficacy and safety: single-balloon vs. double-balloon enteroscopy

    PubMed Central

    Wadhwa, Vaibhav; Sethi, Saurabh; Tewani, Sumeet; Garg, Sushil Kumar; Pleskow, Douglas K.; Chuttani, Ram; Berzin, Tyler M.; Sethi, Nidhi; Sawhney, Mandeep S.

    2015-01-01

    Background and aim: Double-balloon enteroscopy (DBE) and single-balloon enteroscopy (SBE) are new techniques capable of providing deep enteroscopy. Results of individual studies comparing these techniques have not been able to identify a superior strategy. Our aim was to systematically pool all available studies to compare the efficacy and safety of DBE with SBE for evaluation of the small bowel. Methods: Databases were searched, including PubMed, Embase, and the Cochrane Central Register of Controlled Trials. The main outcome measures were complete small-bowel visualization, diagnostic yield, therapeutic yield, and complication rate. Statistical analysis was performed using Review Manager (RevMan version 5.2). Meta-analysis was performed using fixed-effect or random-effect methods, depending on the absence or presence of significant heterogeneity. We used the χ2 and I2 test to assess heterogeneity between trials. Results were expressed as risk ratios (RR) or mean differences with 95% confidence intervals (CI). Results: Four prospective, randomized, controlled trials with a total of 375 patients were identified. DBE was superior to SBE for visualization of the entire small bowel [pooled RR = 0.37 (95% CI: 0.19–0.73; P = 0.004)]. DBE and SBE were similar in ability to provide diagnosis [pooled RR = 0.95 (95% CI: 0.77–1.17; P = 0.62)]. There was no significant difference between DBE and SBE in therapeutic yield [pooled RR = 0.78 (95% CI: 0.59–1.04; P = 0.09)] and complication rate [pooled RR = 1.08 (95% CI: 0.28–4.22); P = 0.91]. Conclusions: DBE was superior to SBE with regard to complete small bowel visualization. DBE was similar to SBE with regard to diagnostic yield, ability to provide treatment and complication rate, but these results should be interpreted with caution as they is based on very few studies and the overall quality of the evidence was rated as low to moderate, due to the small sample size. PMID:25698560

  19. A Case of Blind Loop Syndrome Caused by Infection with Giardia duodenalis Diagnosed with Double Balloon Enteroscopy.

    PubMed

    Nakagawa, Tomoo; Katsuno, Tatsuro; Mandai, Yasushi; Saito, Masaya; Yoshihama, Sayuri; Saito, Keiko; Minemura, Shoko; Maruoka, Daisuke; Matsumura, Tomoaki; Arai, Makoto; Yokosuka, Osamu

    2014-09-01

    A 75-year-old man who had undergone partial gastrectomy was referred to our hospital due to worsening leg edema, loose stools and malnutrition. Double balloon enteroscopy followed by insertion of an indwelling ileus tube was performed to investigate the microbial flora and for washing inside the blind loop. Trophozoites of Giardia were detected in the sampled fluid from the blind loop and DNA analysis disclosed an assemblage of genotype A-II of Giardia duodenalis. Treatment with oral metronidazole was effective. This case emphasizes the importance of a correct diagnosis when treating patients with blind loop syndrome in the digestive tract.

  20. A Case of Blind Loop Syndrome Caused by Infection with Giardia duodenalis Diagnosed with Double Balloon Enteroscopy

    PubMed Central

    Nakagawa, Tomoo; Katsuno, Tatsuro; Mandai, Yasushi; Saito, Masaya; Yoshihama, Sayuri; Saito, Keiko; Minemura, Shoko; Maruoka, Daisuke; Matsumura, Tomoaki; Arai, Makoto; Yokosuka, Osamu

    2014-01-01

    A 75-year-old man who had undergone partial gastrectomy was referred to our hospital due to worsening leg edema, loose stools and malnutrition. Double balloon enteroscopy followed by insertion of an indwelling ileus tube was performed to investigate the microbial flora and for washing inside the blind loop. Trophozoites of Giardia were detected in the sampled fluid from the blind loop and DNA analysis disclosed an assemblage of genotype A-II of Giardia duodenalis. Treatment with oral metronidazole was effective. This case emphasizes the importance of a correct diagnosis when treating patients with blind loop syndrome in the digestive tract. PMID:25408630

  1. Complimentary Imaging Modalities for Investigating Obscure Gastrointestinal Bleeding: Capsule Endoscopy, Double-Balloon Enteroscopy, and Computed Tomographic Enterography.

    PubMed

    Chu, Ye; Wu, Sheng; Qian, Yuting; Wang, Qi; Li, Juanjuan; Tang, Yanping; Bai, Tingting; Wang, Lifu

    2016-01-01

    Objectives. The complimentary value of computed tomographic enterography (CTE) and double-balloon enteroscopy (DBE) combined with capsule endoscopy (CE) was evaluated in the diagnosis of obscure gastrointestinal bleeding (OGIB). Methods. Patients who received CE examinations at Ruijin Hospital between July 2007 and July 2014 with the indication of OGIB were identified, and those who also underwent DBE and/or CTE were included. Their clinical information was retrieved, and results from each test were compared with findings from the other two examinations. Results. The overall diagnostic yield of CE was comparable with DBE (73.9% versus 60.9%) but was significantly higher than the yield of CTE (87% versus 25%, p < 0.001). The diagnostic yield of angiodysplasia at CE was significantly higher than CTE (73% versus 8%, p < 0.001) and DBE (39.1% versus 17.4%, p = 0.013), while no significant difference was found between the three approaches for small bowel tumors. DBE and CTE identified small bowel diseases undetected or undetermined by CE. Conversely, CE improved diagnosis in the cases with negative CTE and DBE, and findings at initial CE directed further diagnosis made by DBE. Conclusions. Combination of the three diagnostic platforms provides complementary value in the diagnosis of OGIB. PMID:26858753

  2. A case of a ruptured submucosal aneurysm of the small intestine identified using double-balloon enteroscopy.

    PubMed

    Chiba, Hirofumi; Endo, Katsuya; Fujishima, Fumiyoshi; Ohtsuka, Hideo; Naitoh, Takeshi; Kuroha, Masatake; Kimura, Tomoya; Shiga, Hisashi; Kakuta, Yoichi; Kinouchi, Yoshitaka; Unno, Michiaki; Shimosegawa, Tooru

    2016-04-01

    A 47-year-old woman was admitted to our hospital urgently with sudden-onset hematochezia. She was temporarily in a state of hemorrhagic shock. As we strongly suspected bleeding from the small intestine, peroral double-balloon enteroscopy was performed, and indicated a 2.0-cm diameter hemispheric elevated lesion in the jejunum. Moreover, a blood clot was observed at the top of the protrusion. The site was marked by injecting India ink, without taking a biopsy specimen, to avoid further hemorrhaging. Subsequently, laparoscopic partial small bowel resection was performed. On histopathological examination, the lesion was found to be a sac-like submucosal arterial aneurysm, with a diameter of 3.5 mm, comprising several small abnormal arteries. The final diagnosis was a ruptured submucosal aneurysm of the small intestine. Ruptured submucosal aneurysms are very rarely observed in the small intestine. Only a few reports have described their endoscopic findings. Our experience indicates that small bowel enteroscopy may be useful for managing ruptured submucosal aneurysms of the small intestine.

  3. Extranodal NK/T cell lymphoma, nasal type, of the small intestine diagnosed by double-balloon endoscopy.

    PubMed

    Wakabayashi, Shihoko; Arai, Ayako; Oshikawa, Gaku; Araki, Akihiro; Watanabe, Mamoru; Uchida, Naoyuki; Taniguchi, Shuichi; Miura, Osamu

    2009-12-01

    Extranodal NK/T-cell lymphoma (ENKL), nasal type, is rare and the small intestine is quite extraordinary as a primary lesion site. We report a 47-year-old man with ENKL of the small intestine. He was referred to our hospital because of bloody stool and the diagnosis was made by double-balloon endoscopy (DBE) of the small intestine without surgical procedure. His clinical stage was IVB and he was categorized in group 4 by prognostic index of ENKL. He went into complete remission (CR) after intensive chemotherapy (DeVIC) and subsequently underwent allogeneic bone marrow transplantation (BMT). Although he remained in CR for about 8 months after BMT, he died of disease recurrence 14 months after the diagnosis was made. ENKL of the small intestine follows a highly aggressive course. We describe the usefulness of DBE for diagnosis and management for ENKL of the small intestine. Additional cases, however, should be accumulated to establish optimal treatment strategy. PMID:19936878

  4. Success of Minimally Invasive Transumbilical Single-Incision Laparoscopic Surgery (T-SILS) Plus Double-Balloon Endoscopy (DBE) for Pediatric Intestinal Angiodysplasia: A Case Report.

    PubMed

    Mori, Koichiro; Koike, Yuhki; Inoue, Mikihiro; Ohtake, Kohei; Tanaka, Koji; Uchida, Keichi; Mohri, Yasuhiko; Kusunoki, Masato

    2015-05-01

    We describe here a child with angiodysplasia of the small intestine, diagnosed by double-balloon endoscopy (DBE), who was treated with transumbilical single-incision laparoscopic surgery (T-SILS). A 9-year-old boy presented to another hospital with intermittent fresh melena of a duration of 5 months and 4 days. Anoscopy and gastric mucosal membrane scintigraphy were unsuccessful diagnostically, and he was referred to our hospital for further examination and treatment. Under general anesthesia, we performed DBE by an anal route, with the ileum assessed for a distance of about 150 cm from the ileocecal valve. Although no bleeding lesion was found in the colon, a flat elevated venous lake approximately 20 mm in size was observed 20 cm from the ileocecal valve, suggesting angiodysplasia of the small intestine. A tattoo was made under DBE, and wedge resection by T-SILS was performed 1 month later under general anesthesia. The excised specimen appeared as a flat, elevated venous lake approximately 20 mm in size. Histopathologic analysis revealed several dilated and distorted veins within the submucosa of the small intestine. The patient was diagnosed with angiodysplasia of the small intestine. His postoperative course was uneventful, and he remained free of recurrent gastrointestinal bleeding 18 months after the operation. This is the first case report showing the diagnosis, localization, and tattooing of an obscure gastrointestinal bleeding lesion of the small intestine by preoperative DBE and removal of the lesion by subsequent T-SILS in children. PMID:26011216

  5. Double-balloon enteroscopy for ERCP in patients with Billroth II anatomy: results of a large series of papillary large-balloon dilation for biliary stone removal

    PubMed Central

    Cheng, Chi-Liang; Liu, Nai-Jen; Tang, Jui-Hsiang; Yu, Ming-Chin; Tsui, Yi-Ning; Hsu, Fang-Yu; Lee, Ching-Song; Lin, Cheng-Hui

    2015-01-01

    Background and study aims: Data on double-balloon enteroscopy (DBE)-assisted endoscopic retrograde cholangiopancreatogrphy (ERCP) in patients with Billroth II gastrectomy and the use of endoscopic papillary large-balloon dilation (EPLBD) for the removal of common bile duct stones in Billroth II anatomy are limited. The aims of the study were to evaluate the success of DBE-assisted ERCP in patients with Billroth II gastrectomy and examine the efficacy of EPLBD ( ≥ 10 mm) for the removal of common bile duct stones. Patients and methods: A total of 77 patients with Billroth II gastrectomy in whom standard ERCP had failed underwent DBE-assisted ERCP. DBE success was defined as visualizing the papilla and ERCP success as completing the intended intervention. The clinical results of EPLBD for the removal of common bile duct stones were analyzed. Results: DBE was successful in 73 of 77 patients (95 %), and ERCP success was achieved in 67 of these 73 (92 %). Therefore, the rate of successful DBE-assisted ERCP was 87 % (67 of a total of 77 patients). The reasons for ERCP failure (n = 10) included tumor obstruction (n = 2), adhesion obstruction (n = 2), failed cannulation (n = 3), failed stone removal (n = 2), and bowel perforation (n = 1). Overall DBE-assisted ERCP complications occurred in 5 of 77 patients (6.5 %). A total of 48 patients (34 male, mean age 75.5 years) with common bile duct stones underwent EPLBD. Complete stone removal in the first session was accomplished in 36 patients (75 %); mechanical lithotripsy was required in 1 patient. EPLBD-related mild perforation occurred in 2 patients (4 %). No acute pancreatitis occurred. Conclusions: DBE permits therapeutic ERCP in patients who have a difficult Billroth II gastrectomy with a high success rate and acceptable complication rates. EPLBD is effective and safe for the removal of common bile duct stones in patients with Billroth II anatomy. PMID:26171434

  6. Origins.

    ERIC Educational Resources Information Center

    Online-Offline, 1999

    1999-01-01

    Provides an annotated list of resources dealing with the theme of origins of life, the universe, and traditions. Includes Web sites, videos, books, audio materials, and magazines with appropriate grade levels and/or subject disciplines indicated; professional resources; and learning activities. (LRW)

  7. Origins.

    PubMed

    Weinberg, S

    1985-10-01

    The farthest of the galaxies that can be seen through the large ground-based telescopes of modern astronomy, such as those on La Palma in the Canary Islands, are so far away that they appear as they did close to the time of the origin of the universe, perhaps some 10 billion years ago. Much has been learned, and much has still to be learned, about the young universe from optical and radio telescopes, but these instruments cannot be used to look directly at the universe in its first few hundred thousand years. Instead, they are used to search the relatively recent past for relics of much earlier times. Together with experiments planned for the next generation of elementary particle accelerators, astronomical observations should continue to extend what is known about the universe backward in time to the Big Bang and may eventually help to reveal the origins of the physical laws that govern the universe.

  8. Original Misunderstanding

    ERIC Educational Resources Information Center

    Holtzman, Alexander

    2009-01-01

    Humorist Josh Billings quipped, "About the most originality that any writer can hope to achieve honestly is to steal with good judgment." Billings was harsh in his view of originality, but his critique reveals a tension faced by students every time they write a history paper. Research is the essence of any history paper. Especially in high school,…

  9. Eukaryotic origins.

    PubMed

    Lake, James A

    2015-09-26

    The origin of the eukaryotes is a fundamental scientific question that for over 30 years has generated a spirited debate between the competing Archaea (or three domains) tree and the eocyte tree. As eukaryotes ourselves, humans have a personal interest in our origins. Eukaryotes contain their defining organelle, the nucleus, after which they are named. They have a complex evolutionary history, over time acquiring multiple organelles, including mitochondria, chloroplasts, smooth and rough endoplasmic reticula, and other organelles all of which may hint at their origins. It is the evolutionary history of the nucleus and their other organelles that have intrigued molecular evolutionists, myself included, for the past 30 years and which continues to hold our interest as increasingly compelling evidence favours the eocyte tree. As with any orthodoxy, it takes time to embrace new concepts and techniques.

  10. Eukaryotic origins

    PubMed Central

    Lake, James A.

    2015-01-01

    The origin of the eukaryotes is a fundamental scientific question that for over 30 years has generated a spirited debate between the competing Archaea (or three domains) tree and the eocyte tree. As eukaryotes ourselves, humans have a personal interest in our origins. Eukaryotes contain their defining organelle, the nucleus, after which they are named. They have a complex evolutionary history, over time acquiring multiple organelles, including mitochondria, chloroplasts, smooth and rough endoplasmic reticula, and other organelles all of which may hint at their origins. It is the evolutionary history of the nucleus and their other organelles that have intrigued molecular evolutionists, myself included, for the past 30 years and which continues to hold our interest as increasingly compelling evidence favours the eocyte tree. As with any orthodoxy, it takes time to embrace new concepts and techniques. PMID:26323753

  11. Original Version

    Cancer.gov

    The EPEC-O (Education in Palliative and End-of-Life Care for Oncology) Self-Study Original Version is a free comprehensive multimedia curricula for health professionals caring for persons with cancer and their families. The curricula is available as an online Self-Study Section and as a CD-ROM you can order.

  12. The Origin(s) of Whales

    NASA Astrophysics Data System (ADS)

    Uhen, Mark D.

    2010-05-01

    Whales are first found in the fossil record approximately 52.5 million years ago (Mya) during the early Eocene in Indo-Pakistan. Our knowledge of early and middle Eocene whales has increased dramatically during the past three decades to the point where hypotheses of whale origins can be supported with a great deal of evidence from paleontology, anatomy, stratigraphy, and molecular biology. Fossils also provide preserved evidence of behavior and habitats, allowing the reconstruction of the modes of life of these semiaquatic animals during their transition from land to sea. Modern whales originated from ancient whales at or near the Eocene/Oligocene boundary, approximately 33.7 Mya. During the Oligocene, ancient whales coexisted with early baleen whales and early toothed whales. By the end of the Miocene, most modern families had originated, and most archaic forms had gone extinct. Whale diversity peaked in the late middle Miocene and fell thereafter toward the Recent, yielding our depauperate modern whale fauna.

  13. Multiple origins of life

    NASA Technical Reports Server (NTRS)

    Raup, D. M.; Valentine, J. W.

    1983-01-01

    There is some indication that life may have originated readily under primitive earth conditions. If there were multiple origins of life, the result could have been a polyphyletic biota today. Using simple stochastic models for diversification and extinction, we conclude: (1) the probability of survival of life is low unless there are multiple origins, and (2) given survival of life and given as many as 10 independent origins of life, the odds are that all but one would have gone extinct, yielding the monophyletic biota we have now. The fact of the survival of our particular form of life does not imply that it was unique or superior.

  14. DNA replication origins.

    PubMed

    Leonard, Alan C; Méchali, Marcel

    2013-10-01

    The onset of genomic DNA synthesis requires precise interactions of specialized initiator proteins with DNA at sites where the replication machinery can be loaded. These sites, defined as replication origins, are found at a few unique locations in all of the prokaryotic chromosomes examined so far. However, replication origins are dispersed among tens of thousands of loci in metazoan chromosomes, thereby raising questions regarding the role of specific nucleotide sequences and chromatin environment in origin selection and the mechanisms used by initiators to recognize replication origins. Close examination of bacterial and archaeal replication origins reveals an array of DNA sequence motifs that position individual initiator protein molecules and promote initiator oligomerization on origin DNA. Conversely, the need for specific recognition sequences in eukaryotic replication origins is relaxed. In fact, the primary rule for origin selection appears to be flexibility, a feature that is modulated either by structural elements or by epigenetic mechanisms at least partly linked to the organization of the genome for gene expression.

  15. Religion: Origins and Evolution.

    ERIC Educational Resources Information Center

    Meyer, John K.

    2004-01-01

    We present the purpose of study of the origins and development of affect-relevant and religion-relevant hypotheses, and conjectured prediction of proto-religious sequences in pre-human anthropoids and primitive human cultures. We anticipate more comprehensive study of modern cultural outcomes of these origins and developments.

  16. Chemical Origins of Life

    ERIC Educational Resources Information Center

    Fox, J. Lawrence

    1972-01-01

    Reviews ideas and evidence bearing on the origin of life. Shows that evidence to support modifications of Oparin's theories of the origin of biological constituents from inorganic materials is accumulating, and that the necessary components are readily obtained from the simple gases found in the universe. (AL)

  17. The Moon's Origin.

    ERIC Educational Resources Information Center

    Cadogan, Peter

    1983-01-01

    Presents findings and conclusions about the origin of the moon, favoring the capture hypothesis of lunar origin. Advantage of the hypothesis is that it allows the moon to have been formed elsewhere, specifically in a hotter part of the solar nebula, accounting for chemical differences between earth and moon. (JN)

  18. Originalism in the Classroom

    ERIC Educational Resources Information Center

    Forte, David F.

    2011-01-01

    In this article, the author provides a detailed legal history of originalism and investigates whether, and to what extent, originalism is a part of law school teaching on the Constitution. He shares the results of an examination of the leading constitutional law textbooks used in the top fifty law schools and a selection of responses gathered from…

  19. The Growth of Originalism

    ERIC Educational Resources Information Center

    Bork, Robert H.

    2011-01-01

    The latest episode in the long-running struggle for control of the Constitution, and the political power that goes with it, is playing out in the federal courts in California. The contending philosophies are originalism, which holds that the Constitution should be read as it was originally understood by the framers and ratifiers, and the congeries…

  20. [Hypotension from endocrine origin].

    PubMed

    Vantyghem, Marie-Christine; Douillard, Claire; Balavoine, Anne-Sophie

    2012-11-01

    Hypotension is defined by a low blood pressure either permanently or only in upright posture (orthostatic hypotension). In contrast to hypertension, there is no threshold defining hypotension. The occurrence of symptoms for systolic and diastolic measurements respectively below 90 and 60 mm Hg establishes the diagnosis. Every acute hypotensive event should suggest shock, adrenal failure or an iatrogenic cause. Chronic hypotension from endocrine origin may be linked to adrenal failure from adrenal or central origin, isolated hypoaldosteronism, pseudohypoaldosteronism, pheochromocytoma, neuro-endocrine tumors (carcinoïd syndrome) or diabetic dysautonomia. Hypotension related to hypoaldosteronism associates low blood sodium and above all high blood potassium levels. They are generally classified according to their primary (hyperreninism) or secondary (hyporeninism) adrenal origin. Isolated primary hypoaldosteronisms are rare in adults (intensive care unit, selective injury of the glomerulosa area) and in children (aldosterone synthase deficiency). Isolated secondary hypoaldosteronism is related to mellitus diabetes complicated with dysautonomia, kidney failure, age, iatrogenic factors, and HIV infections. In both cases, they can be associated to glucocorticoid insufficiency from primary adrenal origin (adrenal failure of various origins with hyperreninism, among which congenital 21 hydroxylase deficiency with salt loss) or from central origin (hypopituitarism with hypo-reninism). Pseudohypoaldosteronisms are linked to congenital (type 1 pseudohypoaldosteronism) or acquired states of resistance to aldosterone. Acquired salt losses from enteric (total colectomy with ileostomy) or renal (interstitial nephropathy, Bartter and Gitelman syndromes…) origin might be responsible for hypotension and are associated with hyperreninism-hyperaldosteronism. Hypotension is a rare manifestation of pheochromocytomas, especially during surgical removal when the patient has not been

  1. Controversy on chloroplast origins.

    PubMed

    Lockhart, P J; Penny, D; Hendy, M D; Howe, C J; Beanland, T J; Larkum, A W

    1992-04-20

    Controversy exists over the origins of photosynthetic organelles in that contradictory trees arise from different sequence, biochemical and ultrastructural data sets. We propose a testable hypothesis which explains this inconsistency as a result of the differing GC contents of sequences. We report that current methods of tree reconstruction tend to group sequences with similar GC contents irrespective of whether the similar GC content is due to common ancestry or is independently acquired. Nuclear encoded sequences (high GC) give different trees from chloroplast encoded sequences (low GC). We find that current data is consistent with the hypothesis of multiple origins for photosynthetic organelles and single origins for each type of light harvesting complex. PMID:1568469

  2. Thick Photoresist Original Master:

    NASA Astrophysics Data System (ADS)

    Mizuno, Hirotaka; Sugihara, Okihiro; Kaino, Toshikuni; Ohe, Yuka; Okamoto, Naomichi; Hoshino, Masahito

    A simple and low-cost fabrication method of polymeric optical waveguides with large core sizes for plastic optical fibers is presented. The waveguides are fabricated by hot embossing with a rectangular ridge ultraviolet (UV)-cured epoxy resin stamper. The stamper is fabricated by replication of a rectangular groove mold that is made from silicone rubber replicated from a rectangular ridge original master made from thick photoresist (SU-8). A rectangular ridge shape of the original photoresist master of 1 mm size was realized by using a flattening process, which involves hot embossing before the exposure process and using a UV-cut filter during the exposure process.

  3. Tektites and their origin

    NASA Technical Reports Server (NTRS)

    Okeefe, J. A.

    1976-01-01

    Questions concerning the tektite distribution are examined, taking into account the Australasian strewn field, the Ivory Coast strewn field, the Moldavite strewn field, the North American strewn field, the Libyan desert glass, the Aouelloul crater glass, and amerikanites. Attention is given to the shapes of tektites, the internal structure of tektites, the physical properties of tektite glass, the chemical composition of tektites, isotopes, fission tracks, cosmic ray tracks, and arguments in favor and against the terrestrial origin of tektites. It is concluded that tektites cannot be terrestrial in origin. They are probably volcanic ejects, of geologically recent epochs, from one or a number of lunar volcanoes.

  4. The Origin of Life

    ERIC Educational Resources Information Center

    Hodson, D.

    1975-01-01

    Presents an outline of lectures given on this topic to British secondary students. Man's various ideas about the origin of life are included in three categories: those that consider life to have been created by a Divine Being; those that consider life to have developed from non-living matter; and those that consider life to be eternal. (MLH)

  5. The Origins of Mass

    ScienceCinema

    Lincoln, Don

    2016-07-12

    The Higgs boson was discovered in July of 2012 and is generally understood to be the origin of mass. While those statements are true, they are incomplete. It turns out that the Higgs boson is responsible for only about 2% of the mass of ordinary matter. In this dramatic new video, Dr. Don Lincoln of Fermilab tells us the rest of the story.

  6. Conscientiousness: Origins in Childhood?

    ERIC Educational Resources Information Center

    Eisenberg, Nancy; Duckworth, Angela L.; Spinrad, Tracy L.; Valiente, Carlos

    2014-01-01

    In this review, we evaluate developmental and personality research with the aim of determining whether the personality trait of conscientiousness can be identified in children and adolescents. After concluding that conscientiousness does emerge in childhood, we discuss the developmental origins of conscientiousness with a specific focus on…

  7. Originality and Creativity.

    ERIC Educational Resources Information Center

    Tan, Shaun

    This paper discusses the creative process of one author, a professional author/illustrator of picture books. The paper muses about the meaning of creativity and originality and states inspiration has to do with careful research and looking for a challenge. Creativity is about testing one proposition against another and seeing how things combine…

  8. The origin of life

    NASA Astrophysics Data System (ADS)

    McClendon, John H.

    1999-07-01

    Microfossil finds have been firmly established at about 3.5 Ga (giga annee=10 9 years), but no rocks older than about 4.0 Ga have been demonstrated, leaving the history of the first 0.6 Ga missing. This gap has been filled by models of the solar system. The origin of the ocean, atmosphere, and much crustal material apparently lies in a heavy rain of comets, subsequent to the catastrophic Moon-forming event. The earliest microfossils are those of the Apex chert in Australia, about 3.5 Ga old. `Prebiotic' simulations of possible biochemistry have made some progress in recent years, but many obstacles remain, and there is no agreement as to the course of development. The `ribose nucleic acid (RNA) World', aboriginal `clay genes', and catalysis on iron-sulfide precipitates are not ruled out. The search for the `last common ancestor' has reached a point between the Bacteria and the Archaea. It is possible that this organism may have been a thermophile, similar to many modern hot spring organisms. But it is likely to have been an autotroph, and a late development after the true origin of life. Even more speculative are suggestions about the origins of metabolic sequences, in particular the origin of the genetic code. Since all modern organisms share this code (and many other things), there had to be a long history of development during the blank period of Earth history.

  9. The Origins of Mass

    SciTech Connect

    Lincoln, Don

    2014-07-30

    The Higgs boson was discovered in July of 2012 and is generally understood to be the origin of mass. While those statements are true, they are incomplete. It turns out that the Higgs boson is responsible for only about 2% of the mass of ordinary matter. In this dramatic new video, Dr. Don Lincoln of Fermilab tells us the rest of the story.

  10. Origins of Coordinate Searching.

    ERIC Educational Resources Information Center

    Kilgour, Frederick G.

    1997-01-01

    Reviews the origins of post-coordinate searching and emphasizes that the focal point should be on the searcher, not on the item being indexed. Highlights include the history of the term information retrieval; edge notched punch cards; the "peek-a-boo" system; the Uniterm system; and using computers to search for information. (LRW)

  11. The Origin of Gravitation

    NASA Astrophysics Data System (ADS)

    Zheng, Sheng Ming

    2012-10-01

    In the natural world, people have discovered four kinds of forces: electromagnetic force, gravitation, weak force, and strong force. Although the gravitation has been discovered more than three hundred years, its mechanism of origin is unclear until today. While investigating the origin of gravitation, I do some experiments discover the moving photons produce gravitation. This discovery shows the origin of gravitation. Meanwhile I do some experiments discover the light interference fringes are produced by the gravitation: my discovery demonstrate light is a particle, but is not a wave-particle duality. Furthermore, applications of this discovery to other moving particles show a similar effect. In a word: the micro particle moving produce gravitation and electromagnetic force. Then I do quantity experiment get a general formula: Reveal the essence of gravitational mass and the essence of electric charge; reveal the origin of gravitation and the essence of matter wave. Along this way, I unify the gravitation and electromagnetic force. Namely I find a natural law that from atomic world to star world play in moving track. See website: https://www.lap-publishing.com/catalog/details/store/gb/book/978-3-8473-2658-8/mechanism-of-interaction-in-moving-matter

  12. Bioenergetics and Life's Origins

    PubMed Central

    Deamer, David; Weber, Arthur L.

    2010-01-01

    Bioenergetics is central to our understanding of living systems, yet has attracted relatively little attention in origins of life research. This article focuses on energy resources available to drive primitive metabolism and the synthesis of polymers that could be incorporated into molecular systems having properties associated with the living state. The compartmented systems are referred to as protocells, each different from all the rest and representing a kind of natural experiment. The origin of life was marked when a rare few protocells happened to have the ability to capture energy from the environment to initiate catalyzed heterotrophic growth directed by heritable genetic information in the polymers. This article examines potential sources of energy available to protocells, and mechanisms by which the energy could be used to drive polymer synthesis. PMID:20182625

  13. Origin of Life

    NASA Astrophysics Data System (ADS)

    Lal, Ashwini Kumar

    2008-10-01

    The evolution of life has been a big enigma despite rapid advancements in the field of astrobiology, microbiology and genetics in recent years. The answer to this puzzle is as mindboggling as the riddle relating to evolution of the universe itself. Despite the fact that panspermia has gained considerable support as a viable explanation for origin of life on the earth and elsewhere in the universe, the issue, however, remains far from a tangible solution. This paper examines the various prevailing hypotheses regarding origin of life-like abiogenesis, RNA world, iron-sulphur world and panspermia, and concludes that delivery of life-bearing organic molecules by the comets in the early epoch of the earth alone possibly was not responsible for kick-starting the process of evolution of life on our planet.

  14. Endosymbionts and mitochondrial origins

    NASA Technical Reports Server (NTRS)

    Woese, C. R.

    1977-01-01

    The possibility is put forth that the mitochondrion did not originate from an endosymbiosis 1-2 billion years ago involving an aerobic bacterium. Rather, it arose by endosymbiosis in a much earlier anaerobic period and was initially a photosynthetic organelle analogous to the modern chloroplast. This suggestion arises from a reconsideration of the nature of endosymbiosis. It explains the remarkable diversity in mitochondrial information storage and processing systems.

  15. Origins of magnetospheric plasma

    SciTech Connect

    Moore, T.E. )

    1991-01-01

    A review is given of recent (1987-1990) progress in understanding of the origins of plasmas in the earth's magnetosphere. In counterpoint to the early supposition that geomagnetic phenomena are produced by energetic plasmas of solar origin, 1987 saw the publication of a provocative argument that accelerated ionospheric plasma could supply all magnetospheric auroral and ring current particles. Significant new developments of existing data sets, as well as the establishment of entirely new data sets, have improved the ability to identify plasma source regions and to track plasma through the magnetospheric system of boundary layers and reservoirs. These developments suggest that the boundary between ionospheric and solar plasmas, once taken to lie at the plasmapause, actually lies much nearer to the magnetopause. Defining this boundary as the surface where solar wind and ionosphere contribute equally to the plasma, it is referred to herein as the 'geopause'. It is now well established that the infusion of ionospheric O(+) plays a major role in the storm-time distention of the magnetotail and inflation of the inner magnetosphere. After more than two decades of observation and debate, the question remains whether magnetosheric are protons of solar or terrestrial origin. 161 refs.

  16. Origin of tektites

    NASA Technical Reports Server (NTRS)

    O'Keefe, John A.

    1994-01-01

    The origin of tektites has been obscure because of the following dilemma. The application of physical principles to the data available on tektites points strongly to origin from one or more lunar volcanoes; but few glasses of tektite composition have hitherto been reported from the lunar samples. Instead, the lunar silicic glasses consist chiefly of a material very rich in K2O and poor in MgO. The ratio of K2O/MgO is higher in these glasses than in any tektites reported. The solution of the dilemma seems to come from the study of some recently discovered terrestrial deposits of tektite glass with high values of K2O/MgO at the Cretaceous Tertiary boundary. These glasses are found to be very vulnerable to crystallization into sandine or to alteration to smectite. These end products are known and are more abundant than any terrestrial deposits of tektite glass. It seems possible that, in fact, the moon produces tektite glass, mostly of the high K2O-low MgO type; but on Earth these deposits are destroyed. The much less abundant deposits with lower K and higher Mg are observed because they survive. Other objections to the lunar origin hypothesis appear to be answerable.

  17. Origin of earth's moon

    NASA Technical Reports Server (NTRS)

    Wood, J. A.

    1977-01-01

    The major geochemical properties of the moon are briefly considered along with the significant facts of the moon's geologic history, and then the three current hypotheses regarding the moon's origin, namely, fission, capture, and binary accretion, are reviewed. The individual merits and improbabilities associated with each mechanism are taken into consideration. Special attention is given to the binary accretion model as the most promising one. In the variants of this model, of crucial importance is the nature of the more general hypothesis assumed for planetary formation from the solar nebula. The two main models differ considerably in the amount of chemical fractionation they allow to accompany planetary formation.

  18. Origin of Tektites.

    PubMed

    O'keefe, J A; Shute, B E

    1963-03-29

    A comet of the size recently postulated by H. C. Urey would leave a large crater. It is shown, from aerodynamic theory, from observations of distribution around terrestrial impact craters, and from experimental nuclear explosions, that the observed distribution of tektites cannot be the result of impact on the earth, whether cometary or meteoritic. It is further shown, from aerodynamic theory, from observation of a meteor shower, and from study of the breakup of artificial satellites, that the distribution of tektites can be accounted for as a result of fusion stripping of a satellite, as originally suggested by Suess. PMID:17757065

  19. The Origin of Echocardiography

    PubMed Central

    Singh, Siddharth; Goyal, Abha

    2007-01-01

    The original description of M-mode echocardiography in 1953, by Inge Edler (1911–2001) and his physicist friend Hellmuth Hertz, marked the beginning of a new diagnostic noninvasive technique. Edler used this technique primarily for the preoperative study of mitral stenosis and diagnosis of mitral regurgitation. His work was carried forward by cardiologists all over the world, who developed Doppler, 2-dimensional, contrast, and transesophageal echocardiography. These are now standard in cardiologic examinations. Edler also influenced neurologists and obstetricians at Lund University (Sweden) to use ultrasound in their fields. For his landmark discovery, Edler is recognized as the “Father of Echocardiography.” PMID:18172524

  20. Origin of Tektites.

    PubMed

    O'keefe, J A; Shute, B E

    1963-03-29

    A comet of the size recently postulated by H. C. Urey would leave a large crater. It is shown, from aerodynamic theory, from observations of distribution around terrestrial impact craters, and from experimental nuclear explosions, that the observed distribution of tektites cannot be the result of impact on the earth, whether cometary or meteoritic. It is further shown, from aerodynamic theory, from observation of a meteor shower, and from study of the breakup of artificial satellites, that the distribution of tektites can be accounted for as a result of fusion stripping of a satellite, as originally suggested by Suess.

  1. The Origins of Options

    PubMed Central

    Smaldino, Paul E.; Richerson, Peter J.

    2012-01-01

    Most research on decision making has focused on how human or animal decision makers choose between two or more options, posed in advance by the researchers. The mechanisms by which options are generated for most decisions, however, are not well understood. Models of sequential search have examined the trade-off between continued exploration and choosing one’s current best option, but still cannot explain the processes by which new options are generated. We argue that understanding the origins of options is a crucial but untapped area for decision making research. We explore a number of factors which influence the generation of options, which fall broadly into two categories: psycho-biological and socio-cultural. The former category includes factors such as perceptual biases and associative memory networks. The latter category relies on the incredible human capacity for culture and social learning, which doubtless shape not only our choices but the options available for choice. Our intention is to start a discussion that brings us closer toward understanding the origins of options. PMID:22514515

  2. Photocopy of photograph (original located at Mare Island Archives). Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of photograph (original located at Mare Island Archives). Original photographer unknown. Building 253; 1920. - Mare Island Naval Shipyard, Supply Building, Walnut Avenue, southeast corner of Walnut Avenue & Fifth Street, Vallejo, Solano County, CA

  3. Photocopy of photograph (original located at Mare Island Archives). Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of photograph (original located at Mare Island Archives). Original photographer unknown. Dry dock 2 with six destroyers; 1922 - Mare Island Naval Shipyard, Drydock No. 2, California Avenue, east side near Ninth Street, Vallejo, Solano County, CA

  4. 14. Photocopy of original drawing by Cass Gilbert, 1918 (original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Photocopy of original drawing by Cass Gilbert, 1918 (original in possession of NYC Economic Development Corp.) SECTIONS AND DETAILS-PIERS 2, 3, AND 4 - Brooklyn Army Supply Base, Pier 2, Brooklyn, Kings County, NY

  5. 13. Photocopy of original drawing by Cass Gilbert, 1918 (original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. Photocopy of original drawing by Cass Gilbert, 1918 (original in possession of NYC Economic Development Corp.) ARMY SUPPLY BASE-PLAN OF CONSTRUCTION PLANT - Brooklyn Army Supply Base, Pier 2, Brooklyn, Kings County, NY

  6. 18. Photocopy of original drawing by Cass Gilbert, 1918 (original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. Photocopy of original drawing by Cass Gilbert, 1918 (original in possession of NYC Economic Development Corp.) PLANS AND SECTIONS, MECHANICAL EQUIPMENT-PIERS 2, 3, AND 4 - Brooklyn Army Supply Base, Pier 2, Brooklyn, Kings County, NY

  7. Photocopy of photograph (original located at Mare Island Archives). Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of photograph (original located at Mare Island Archives). Original photographer unknown. Dry dock 1 with sailing ship, 1899. - Mare Island Naval Shipyard, Drydock No. 1, California Avenue, east side near Ninth Street, Vallejo, Solano County, CA

  8. Photocopy of photograph (original located at Mare Island Archives). Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of photograph (original located at Mare Island Archives). Original photographer unknown. View of sawmill after earthquake of 1898. - Mare Island Naval Shipyard, East of Nave Drive, Vallejo, Solano County, CA

  9. 2. Photocopy of original photograph (Original in collection of Historical ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Photocopy of original photograph (Original in collection of Historical Society of Montana) MAIN AND SIDE ELEVATIONS, SHOWING AWNINGS LOWERED OVER PORCH - W. C. Child Ranch, State Highway 279, Helena, Lewis and Clark County, MT

  10. Photocopy of photograph (original located at Mare Island Archives). Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of photograph (original located at Mare Island Archives). Original photographer unknown. Coal sheds with coals; 1906. - Mare Island Naval Shipyard, Coal Sheds, Waterfront Avenue, northwest corner of Waterfront Avenue & Fourth Street, Vallejo, Solano County, CA

  11. Photograph of original drawing (original in possession of National Passenger ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photograph of original drawing (original in possession of National Passenger Railroad Corporation). Canopy Plans, Sections, and Details (n.d.) - North Philadelphia Station, 2900 North Broad Street, on northwest corner of Broad Street & Glenwood Avenue, Philadelphia, Philadelphia County, PA

  12. Photocopy of photograph (original located at Mare Island Archives). Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of photograph (original located at Mare Island Archives). Original photographer unknown. QUARTERS A IN THE SNOW; 1913. - Mare Island Naval Shipyard, Commandant's Quarters, Walnut Avenue, west side near Eighth Street, Vallejo, Solano County, CA

  13. Photocopy of photograph (original located at Mare Island Archives). Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of photograph (original located at Mare Island Archives). Original photographer unknown. View of waterfront during World War II; N.D. - Mare Island Naval Shipyard, East of Nave Drive, Vallejo, Solano County, CA

  14. Conscientiousness: origins in childhood?

    PubMed

    Eisenberg, Nancy; Duckworth, Angela L; Spinrad, Tracy L; Valiente, Carlos

    2014-05-01

    In this review, we evaluate developmental and personality research with the aim of determining whether the personality trait of conscientiousness can be identified in children and adolescents. After concluding that conscientiousness does emerge in childhood, we discuss the developmental origins of conscientiousness with a specific focus on self-regulation, academic motivation, and internalized compliance/internalization of standards. On the basis of the accumulated body of evidence, we conclude that self-regulation fosters conscientiousness later in life, both directly and via academic motivation and internalized compliance with norms. We argue that elements of conscientiousness are evident by early childhood; self-regulation skills are likely a core developmental component of conscientiousness; and despite the contribution of heredity to the aforementioned aspects of functioning, environmental factors likely contribute to conscientiousness.

  15. Mechanical origin of aftershocks.

    PubMed

    Lippiello, E; Giacco, F; Marzocchi, W; Godano, C; de Arcangelis, L

    2015-01-01

    Aftershocks are the most striking evidence of earthquake interactions and the physical mechanisms at the origin of their occurrence are still intensively debated. Novel insights stem from recent results on the influence of the faulting style on the aftershock organisation in magnitude and time. Our study shows that the size of the aftershock zone depends on the fault geometry. We find that positive correlations among parameters controlling aftershock occurrence in time, energy and space are a stable feature of seismicity independently of magnitude range and geographic areas. We explain the ensemble of experimental findings by means of a description of the Earth Crust as an heterogeneous elastic medium coupled with a Maxwell viscoelastic asthenosphere. Our results show that heterogeneous stress distribution in an elastic layer combined with a coupling to a viscous flow are sufficient ingredients to describe the physics of aftershock triggering. PMID:26497720

  16. The origins of informatics.

    PubMed Central

    Collen, M F

    1994-01-01

    This article summarizes the origins of informatics, which is based on the science, engineering, and technology of computer hardware, software, and communications. In just four decades, from the 1950s to the 1990s, computer technology has progressed from slow, first-generation vacuum tubes, through the invention of the transistor and its incorporation into microprocessor chips, and ultimately, to fast, fourth-generation very-large-scale-integrated silicon chips. Programming has undergone a parallel transformation, from cumbersome, first-generation, machine languages to efficient, fourth-generation application-oriented languages. Communication has evolved from simple copper wires to complex fiberoptic cables in computer-linked networks. The digital computer has profound implications for the development and practice of clinical medicine. PMID:7719803

  17. Mechanical origin of aftershocks.

    PubMed

    Lippiello, E; Giacco, F; Marzocchi, W; Godano, C; de Arcangelis, L

    2015-10-26

    Aftershocks are the most striking evidence of earthquake interactions and the physical mechanisms at the origin of their occurrence are still intensively debated. Novel insights stem from recent results on the influence of the faulting style on the aftershock organisation in magnitude and time. Our study shows that the size of the aftershock zone depends on the fault geometry. We find that positive correlations among parameters controlling aftershock occurrence in time, energy and space are a stable feature of seismicity independently of magnitude range and geographic areas. We explain the ensemble of experimental findings by means of a description of the Earth Crust as an heterogeneous elastic medium coupled with a Maxwell viscoelastic asthenosphere. Our results show that heterogeneous stress distribution in an elastic layer combined with a coupling to a viscous flow are sufficient ingredients to describe the physics of aftershock triggering.

  18. Origin of the Moon

    NASA Technical Reports Server (NTRS)

    Stevenson, David

    2006-01-01

    Many ideas have been proposed for the origin of the Moon, but only one has stood the test of time: During the formation of Earth, about 4.5 billion years ago, our planet was hit by a projectile the size of Mars, leading to a close-in disk of molten material in earth orbit. From this material, our Moon formed in about a thousand years. I will explain how the properties of the Moon can be explained by this model and why the alternative ideas are either incorrect or highly improbable. I will also talk about some new developments in this area that come from a consideration of chemistry and isotopic measurements. Finally. I will talk about what we don't know and why the Moon is still an interesting place for further exploration.

  19. Comments on lunar origin.

    NASA Technical Reports Server (NTRS)

    Opik, E. J.

    1972-01-01

    Consideration of the tidal evolution of the earth-moon system in the light of recent published studies of lunar origin. The subjects include the factors of orbital evolution, the auxiliary Model Zero, orbital evolution along the outgoing branch, capture models, capture probability, capture with break-up, the tidal evolution of circular and elliptical fragmented rings, and precession and collisions in a ring of fragments. A numerical integration of precessions is performed for the actual nonzero mass of the moon and for a lunar distance of about 22 earth radii. A simplified Model Zero is found to compare well with Goldreich's solution (1968). It is concluded that the moon must have become freely yielding to tidal deformation at distances less than about 8 earth radii. Arguments are given in favor of the capture theory as a basis for the genesis of the moon.

  20. Origins of hydration lubrication.

    PubMed

    Ma, Liran; Gaisinskaya-Kipnis, Anastasia; Kampf, Nir; Klein, Jacob

    2015-01-14

    Why is friction in healthy hips and knees so low? Hydration lubrication, according to which hydration shells surrounding charges act as lubricating elements in boundary layers (including those coating cartilage in joints), has been invoked to account for the extremely low sliding friction between surfaces in aqueous media, but not well understood. Here we report the direct determination of energy dissipation within such sheared hydration shells. By trapping hydrated ions in a 0.4-1 nm gap between atomically smooth charged surfaces as they slide past each other, we are able to separate the dissipation modes of the friction and, in particular, identify the viscous losses in the subnanometre hydration shells. Our results shed light on the origins of hydration lubrication, with potential implications both for aqueous boundary lubricants and for biolubrication.

  1. Origins of adaptive immunity.

    PubMed

    Liongue, Clifford; John, Liza B; Ward, Alister

    2011-01-01

    Adaptive immunity, involving distinctive antibody- and cell-mediated responses to specific antigens based on "memory" of previous exposure, is a hallmark of higher vertebrates. It has been argued that adaptive immunity arose rapidly, as articulated in the "big bang theory" surrounding its origins, which stresses the importance of coincident whole-genome duplications. Through a close examination of the key molecules and molecular processes underpinning adaptive immunity, this review suggests a less-extreme model, in which adaptive immunity emerged as part of longer evolutionary journey. Clearly, whole-genome duplications provided additional raw genetic materials that were vital to the emergence of adaptive immunity, but a variety of other genetic events were also required to generate some of the key molecules, whereas others were preexisting and simply co-opted into adaptive immunity.

  2. Mechanical origin of aftershocks

    PubMed Central

    Lippiello, E.; Giacco, F.; Marzocchi, W.; Godano, C.; de Arcangelis, L.

    2015-01-01

    Aftershocks are the most striking evidence of earthquake interactions and the physical mechanisms at the origin of their occurrence are still intensively debated. Novel insights stem from recent results on the influence of the faulting style on the aftershock organisation in magnitude and time. Our study shows that the size of the aftershock zone depends on the fault geometry. We find that positive correlations among parameters controlling aftershock occurrence in time, energy and space are a stable feature of seismicity independently of magnitude range and geographic areas. We explain the ensemble of experimental findings by means of a description of the Earth Crust as an heterogeneous elastic medium coupled with a Maxwell viscoelastic asthenosphere. Our results show that heterogeneous stress distribution in an elastic layer combined with a coupling to a viscous flow are sufficient ingredients to describe the physics of aftershock triggering. PMID:26497720

  3. Conscientiousness: Origins in Childhood?

    PubMed Central

    Eisenberg, Nancy; Duckworth, Angela L.; Spinrad, Tracy L.; Valiente, Carlos

    2012-01-01

    In this review, we evaluate developmental and personality research with the aim of determining if the personality trait of conscientiousness can be identified in children and adolescents. After concluding that conscientiousness does emerge in childhood, we discuss the developmental origins of conscientiousness with a specific focus on self-regulation, academic motivation, and internalized compliance/internalization of standards. Based on the accumulated body of evidence, we conclude that self-regulation fosters conscientiousness later in life, both directly and via academic motivation and internalized compliance with norms. We argue that elements of conscientiousness are evident by early childhood, self-regulation skills are likely a core developmental component of conscientiousness, and despite the contribution of heredity to the aforementioned aspects of functioning, environmental factors likely contribute to conscientiousness. PMID:23244405

  4. Origins of adaptive immunity.

    PubMed

    Liongue, Clifford; John, Liza B; Ward, Alister

    2011-01-01

    Adaptive immunity, involving distinctive antibody- and cell-mediated responses to specific antigens based on "memory" of previous exposure, is a hallmark of higher vertebrates. It has been argued that adaptive immunity arose rapidly, as articulated in the "big bang theory" surrounding its origins, which stresses the importance of coincident whole-genome duplications. Through a close examination of the key molecules and molecular processes underpinning adaptive immunity, this review suggests a less-extreme model, in which adaptive immunity emerged as part of longer evolutionary journey. Clearly, whole-genome duplications provided additional raw genetic materials that were vital to the emergence of adaptive immunity, but a variety of other genetic events were also required to generate some of the key molecules, whereas others were preexisting and simply co-opted into adaptive immunity. PMID:21395512

  5. Origins of Stellar Halos

    NASA Astrophysics Data System (ADS)

    Johnston, Kathryn V.

    2016-08-01

    This contribution reviews ideas about the origins of stellar halos. It includes discussion of the theoretical understanding of and observational evidence for stellar populations formed ``in situ'' (meaning formed in orbits close to their current ones), ``kicked-out'' (meaning formed in the inner galaxy in orbits unlike their current ones) and ``accreted'' (meaning formed in a dark matter halo other than the one they currently occupy). At this point there is general agreement that a significant fraction of any stellar halo population is likely ``accreted''. There is modest evidence for the presence of a ``kicked-out'' population around both the Milky Way and M31. Our theoretical understanding of and the observational evidence for an ``in situ'' population are less clear.

  6. Origin of Sex Revisited

    NASA Astrophysics Data System (ADS)

    Santos, Mauro; Zintzaras, Elias; Szathmáry, Eörs

    2003-10-01

    Why did sex ever arise in the first place? Why it does not disappear in view of the greater efficiency of asexuals? These are clearly two different questions, and we suggest here that the solution for the origin of sex does not necessarily come from theoretical considerations based on currently existing genetic systems. Thus, while we agree with a number of authors in that the emergence of sex (understood as the exchange of genetic material between genomes) is deeply rooted in the origin of life and happened during the very early stages in the transition from individual genes (`replicators') to bacteria-like cells (`reproducers'), we challenge the idea that recombinational repair was the major selective force for the emergence of sex. Taking the stochastic corrector model as a starting point, we provide arguments that question the putative costs of redundancy in primitive protocells. In addition, if genes that cause intragenomic conflict (i.e., parasites) are taken into account, it is certainly wrong to suggest that cellular fusion would be beneficial at the population level (although this strong claim needs some qualifications). However, when a continuous input of deleterious mutations that impair the fitness of the protocell as a whole is considered in the model (in the realistic range in which stable mutant distributions of quasi-species within compartments are established), there are circumstances when sex could be beneficial as a side effect of the dynamic equilibrium between cellular fusion-mutation-selection. The scenario we have explored numerically is fully consistent with the idea that the universal ancestor was not a discrete entity but an ensemble of proto-organisms that exchanged much genetic information.

  7. Actinides and Life's Origins.

    PubMed

    Adam, Zachary

    2007-12-01

    There are growing indications that life began in a radioactive beach environment. A geologic framework for the origin or support of life in a Hadean heavy mineral placer beach has been developed, based on the unique chemical properties of the lower-electronic actinides, which act as nuclear fissile and fertile fuels, radiolytic energy sources, oligomer catalysts, and coordinating ions (along with mineralogically associated lanthanides) for prototypical prebiotic homonuclear and dinuclear metalloenzymes. A four-factor nuclear reactor model was constructed to estimate how much uranium would have been required to initiate a sustainable fission reaction within a placer beach sand 4.3 billion years ago. It was calculated that about 1-8 weight percent of the sand would have to have been uraninite, depending on the weight percent, uranium enrichment, and quantity of neutron poisons present within the remaining placer minerals. Radiolysis experiments were conducted with various solvents with the use of uraniumand thorium-rich minerals (metatorbernite and monazite, respectively) as proxies for radioactive beach sand in contact with different carbon, hydrogen, oxygen, and nitrogen reactants. Radiation bombardment ranged in duration of exposure from 3 weeks to 6 months. Low levels of acetonitrile (estimated to be on the order of parts per billion in concentration) were conclusively identified in 2 setups and tentatively indicated in a 3(rd) by gas chromatography/mass spectrometry. These low levels have been interpreted within the context of a Hadean placer beach prebiotic framework to demonstrate the promise of investigating natural nuclear reactors as power production sites that might have assisted the origins of life on young rocky planets with a sufficiently differentiated crust/mantle structure. Future investigations are recommended to better quantify the complex relationships between energy release, radioactive grain size, fissionability, reactant phase, phosphorus

  8. Actinides and Life's Origins.

    PubMed

    Adam, Zachary

    2007-12-01

    There are growing indications that life began in a radioactive beach environment. A geologic framework for the origin or support of life in a Hadean heavy mineral placer beach has been developed, based on the unique chemical properties of the lower-electronic actinides, which act as nuclear fissile and fertile fuels, radiolytic energy sources, oligomer catalysts, and coordinating ions (along with mineralogically associated lanthanides) for prototypical prebiotic homonuclear and dinuclear metalloenzymes. A four-factor nuclear reactor model was constructed to estimate how much uranium would have been required to initiate a sustainable fission reaction within a placer beach sand 4.3 billion years ago. It was calculated that about 1-8 weight percent of the sand would have to have been uraninite, depending on the weight percent, uranium enrichment, and quantity of neutron poisons present within the remaining placer minerals. Radiolysis experiments were conducted with various solvents with the use of uraniumand thorium-rich minerals (metatorbernite and monazite, respectively) as proxies for radioactive beach sand in contact with different carbon, hydrogen, oxygen, and nitrogen reactants. Radiation bombardment ranged in duration of exposure from 3 weeks to 6 months. Low levels of acetonitrile (estimated to be on the order of parts per billion in concentration) were conclusively identified in 2 setups and tentatively indicated in a 3(rd) by gas chromatography/mass spectrometry. These low levels have been interpreted within the context of a Hadean placer beach prebiotic framework to demonstrate the promise of investigating natural nuclear reactors as power production sites that might have assisted the origins of life on young rocky planets with a sufficiently differentiated crust/mantle structure. Future investigations are recommended to better quantify the complex relationships between energy release, radioactive grain size, fissionability, reactant phase, phosphorus

  9. The Origin of Alcohol Proof

    ERIC Educational Resources Information Center

    Jensen, William B.

    2004-01-01

    The origin of the "proof" system for measuring the ethanol content of alcoholic beverages is presented. The proof system was originally established for purposes of taxing liquors according to their alcohol content and is different in different countries.

  10. The Origin of Stratospheric Air

    NASA Astrophysics Data System (ADS)

    Schoeberl, M. R.; Dessler, A. E.; Wang, T.

    2012-12-01

    The domain-filling, forward trajectory calculation model developed by Schoeberl and Dessler [2011] is used to investigate the origin of air that enters the stratosphere, and the origin of the driest and wettest air parcels. We compare results from NASA's MERRA, NCEP's CFSR, and ECMWF's ERAi reanalyses in a non-convection simulation. The stratospheric air parcel origin is related to but distinct from the location of final dehydration zones. Final dehydration zones control stratospheric water vapor, but stratospheric air origin tells about the origin of non-water soluble constituents such as HCN or CO. The models broadly agree that stratospheric air parcel origins follow the ITCZ in winter with maxima over the tropical west Pacific and South America. The origins are more broadly dispersed in summer. Somewhat surprisingly, the seasonal cycle for the origins is small with most of the air parcels entering the stratosphere from 360K originate in non-DJF months. The origin of the wettest and driest parcels shows that the driest parcels (1-3 ppmv) originate in the tropical West Pacific while the wettest (6-10 ppmv) parcels originate in the East Pacific/ Central America.

  11. Origins of GEMS Grains

    NASA Technical Reports Server (NTRS)

    Messenger, S.; Walker, R. M.

    2012-01-01

    Interplanetary dust particles (IDPs) collected in the Earth s stratosphere contain high abundances of submicrometer amorphous silicates known as GEMS grains. From their birth as condensates in the outflows of oxygen-rich evolved stars, processing in interstellar space, and incorporation into disks around new stars, amorphous silicates predominate in most astrophysical environments. Amorphous silicates were a major building block of our Solar System and are prominent in infrared spectra of comets. Anhydrous interplanetary dust particles (IDPs) thought to derive from comets contain abundant amorphous silicates known as GEMS (glass with embedded metal and sulfides) grains. GEMS grains have been proposed to be isotopically and chemically homogenized interstellar amorphous silicate dust. We evaluated this hypothesis through coordinated chemical and isotopic analyses of GEMS grains in a suite of IDPs to constrain their origins. GEMS grains show order of magnitude variations in Mg, Fe, Ca, and S abundances. GEMS grains do not match the average element abundances inferred for ISM dust containing on average, too little Mg, Fe, and Ca, and too much S. GEMS grains have complementary compositions to the crystalline components in IDPs suggesting that they formed from the same reservoir. We did not observe any unequivocal microstructural or chemical evidence that GEMS grains experienced prolonged exposure to radiation. We identified four GEMS grains having O isotopic compositions that point to origins in red giant branch or asymptotic giant branch stars and supernovae. Based on their O isotopic compositions, we estimate that 1-6% of GEMS grains are surviving circumstellar grains. The remaining 94-99% of GEMS grains have O isotopic compositions that are indistinguishable from terrestrial materials and carbonaceous chondrites. These isotopically solar GEMS grains either formed in the Solar System or were completely homogenized in the interstellar medium (ISM). However, the

  12. Origins of mass

    NASA Astrophysics Data System (ADS)

    Wilczek, Frank

    2012-10-01

    Newtonian mechanics posited mass as a primary quality of matter, incapable of further elucidation. We now see Newtonian mass as an emergent property. That mass-concept is tremendously useful in the approximate description of baryon-dominated matter at low energy — that is, the standard "matter" of everyday life, and of most of science and engineering — but it originates in a highly contingent and non-trivial way from more basic concepts. Most of the mass of standard matter, by far, arises dynamically, from back-reaction of the color gluon fields of quantum chromodynamics (QCD). Additional quantitatively small, though physically crucial, contributions come from the intrinsic masses of elementary quanta (electrons and quarks). The equations for massless particles support extra symmetries — specifically scale, chiral, and gauge symmetries. The consistency of the standard model relies on a high degree of underlying gauge and chiral symmetry, so the observed non-zero masses of many elementary particles (W and Z bosons, quarks, and leptons) requires spontaneous symmetry breaking. Superconductivity is a prototype for spontaneous symmetry breaking and for mass-generation, since photons acquire mass inside superconductors. A conceptually similar but more intricate form of all-pervasive (i.e. cosmic) superconductivity, in the context of the electroweak standard model, gives us a successful, economical account of W and Z boson masses. It also allows a phenomenologically successful, though profligate, accommodation of quark and lepton masses. The new cosmic superconductivity, when implemented in a straightforward, minimal way, suggests the existence of a remarkable new particle, the so-called Higgs particle. The mass of the Higgs particle itself is not explained in the theory, but appears as a free parameter. Earlier results suggested, and recent observations at the Large Hadron Collider (LHC) may indicate, the actual existence of the Higgs particle, with mass m H

  13. Origins of mass

    NASA Astrophysics Data System (ADS)

    Wilczek, Frank

    2012-10-01

    Newtonian mechanics posited mass as a primary quality of matter, incapable of further elucidation. We now see Newtonian mass as an emergent property. That mass-concept is tremendously useful in the approximate description of baryon-dominated matter at low energy — that is, the standard "matter" of everyday life, and of most of science and engineering — but it originates in a highly contingent and non-trivial way from more basic concepts. Most of the mass of standard matter, by far, arises dynamically, from back-reaction of the color gluon fields of quantum chromodynamics (QCD). Additional quantitatively small, though physically crucial, contributions come from the intrinsic masses of elementary quanta (electrons and quarks). The equations for massless particles support extra symmetries — specifically scale, chiral, and gauge symmetries. The consistency of the standard model relies on a high degree of underlying gauge and chiral symmetry, so the observed non-zero masses of many elementary particles ( W and Z bosons, quarks, and leptons) requires spontaneous symmetry breaking. Superconductivity is a prototype for spontaneous symmetry breaking and for mass-generation, since photons acquire mass inside superconductors. A conceptually similar but more intricate form of all-pervasive ( i.e. cosmic) superconductivity, in the context of the electroweak standard model, gives us a successful, economical account of W and Z boson masses. It also allows a phenomenologically successful, though profligate, accommodation of quark and lepton masses. The new cosmic superconductivity, when implemented in a straightforward, minimal way, suggests the existence of a remarkable new particle, the so-called Higgs particle. The mass of the Higgs particle itself is not explained in the theory, but appears as a free parameter. Earlier results suggested, and recent observations at the Large Hadron Collider (LHC) may indicate, the actual existence of the Higgs particle, with mass m H

  14. Eusociality: origin and consequences.

    PubMed

    Wilson, Edward O; Hölldobler, Bert

    2005-09-20

    In this new assessment of the empirical evidence, an alternative to the standard model is proposed: group selection is the strong binding force in eusocial evolution; individual selection, the strong dissolutive force; and kin selection (narrowly defined), either a weak binding or weak dissolutive force, according to circumstance. Close kinship may be more a consequence of eusociality than a factor promoting its origin. A point of no return to the solitary state exists, as a rule when workers become anatomically differentiated. Eusociality has been rare in evolution, evidently due to the scarcity of environmental pressures adequate to tip the balance among countervailing forces in favor of group selection. Eusociality in ants and termites in the irreversible stage is the key to their ecological dominance and has (at least in ants) shaped some features of internal phylogeny. Their colonies are consistently superior to solitary and preeusocial competitors, due to the altruistic behavior among nestmates and their ability to organize coordinated action by pheromonal communication. PMID:16157878

  15. Origin of Neutron Stars

    NASA Astrophysics Data System (ADS)

    Brecher, K.

    1999-12-01

    The origin of the concept of neutron stars can be traced to two brief, incredibly insightful publications. Work on the earlier paper by Lev Landau (Phys. Z. Sowjetunion, 1, 285, 1932) actually predated the discovery of neutrons. Nonetheless, Landau arrived at the notion of a collapsed star with the density of a nucleus (really a "nucleus star") and demonstrated (at about the same time as, and independent of, Chandrasekhar) that there is an upper mass limit for dense stellar objects of about 1.5 solar masses. Perhaps even more remarkable is the abstract of a talk presented at the December 1933 meeting of the American Physical Society published by Walter Baade and Fritz Zwicky in 1934 (Phys. Rev. 45, 138). It followed the discovery of the neutron by just over a year. Their report, which was about the same length as the present abstract: (1) invented the concept and word supernova; (2) suggested that cosmic rays are produced by supernovae; and (3) in the authors own words, proposed "with all reserve ... the view that supernovae represent the transitions from ordinary stars to neutron stars (italics), which in their final stages consist of extremely closely packed neutrons." The abstract by Baade and Zwicky probably contains the highest density of new, important (and correct) ideas in high energy astrophysics ever published in a single paper. In this talk, we will discuss some of the facts and myths surrounding these two publications.

  16. Origins of metabolic profiling.

    PubMed

    Robinson, Arthur B; Robinson, Noah E

    2011-01-01

    Quantitative metabolic profiling originated as a 10-year project carried out between 1968 and 1978 in California. It was hypothesized and then demonstrated that quantitative analysis of a large number of metabolites - selected by analytical convenience and evaluated by computerized pattern recognition - could serve as a useful method for the quantitative measurement of human health. Using chromatographic and mass spectrometric methods to measure between 50 and 200 metabolites in more than 15,000 human specimens, statistically significant and diagnostically useful profiles for several human diseases and for other systematic variables including age, diet, fasting, sex, and other variables were demonstrated. It was also shown that genetically distinct metabolic profiles for each individual are present in both newborn infants and adults. In the course of this work, the many practical and conceptual problems involved in sampling, analysis, evaluation of results, and medical use of quantitative metabolic profiling were considered and, for the most part, solved. This article is an account of that research project. PMID:21207281

  17. Origins of magnetospheric physics

    SciTech Connect

    Van Allen, J.A.

    1983-01-01

    The history of the scientific investigation of the earth magnetosphere during the period 1946-1960 is reviewed, with a focus on satellite missions leading to the discovery of the inner and outer radiation belts. Chapters are devoted to ground-based studies of the earth magnetic field through the 1930s, the first U.S. rocket flights carrying scientific instruments, the rockoon flights from the polar regions (1952-1957), U.S. planning for scientific use of artificial satellites (1956), the launch of Sputnik I (1957), the discovery of the inner belt by Explorers I and III (1958), the Argus high-altitude atomic-explosion tests (1958), the confirmation of the inner belt and discovery of the outer belt by Explorer IV and Pioneers I-V, related studies by Sputniks II and III and Luniks I-III, and the observational and theoretical advances of 1959-1961. Photographs, drawings, diagrams, graphs, and copies of original notes and research proposals are provided. 227 references.

  18. Gould Belt Origin

    NASA Astrophysics Data System (ADS)

    Rivera, Leticia; Loinard, Laurent; Dzib, Sergio

    2013-07-01

    Using archive VLA data and recent observations on the Karl G. Jansky Very Large Array it is worked on a semi-automatic python/CASA code to select, reduce and plot several young stars belonging to the Ophiuchus core. This code mean to help to select observations made along the 30 years of the VLA done in the selected area with the wide configurations A and B, and in the X and C band, to determine their position and compare it with the most recent ones. In this way it is possible to determinate their proper motion with very high precision. It is presented the phases of the process and our first results worked on three well know stars: S1, DoAr 21 and VLA1623. This is the tip of a bigger work that includes Taurus molecular cloud and other important recent star formation regions belonging to the Gould Belt. Our goal is to support the most suitable among several theories about Gould Belt origin or provide a new one taking in count the dynamics of those regions.

  19. Fever of unknown origin.

    PubMed

    Shah, Nayan; Johnson, Karlon; Ghaly, Sabry

    2003-11-01

    This is a case study of a 26-year-old Hispanic male who presented with an initial complaint of fevers, chills and generalized weakness for three weeks. Patient reported a classical history of diurnal fever with temperature spikes as high as 105.8F after returning from a trip to Guatemala. His symptoms had waxed and waned for 3 weeks. This case study will focus on the initial presentation, value of complete history and physical exam, use of laboratory data and use of specialized diagnostic procedures in the outpatient setting. This case proves to be highly relevant to primary care in the context of treating patients with fevers of unknown etiology. Primary care physicians should be alert for unusual diseases in patients who are returning from foreign travel. Malaria is a potentially fatal disease that can be acquired by travelers to certain areas of the world, primarily developing nations. Transmitted through the bite of the Anopheles mosquito, malaria usually presents with fever and a vague systemic illness. The disease is diagnosed by demonstration of Plasmodium organisms on a specially prepared blood film. This case study speaks to the importance of prompt work up and treatment of fever of unknown origin that presents in an unusual clinical picture or that is not readily explainable.

  20. Moon (Form-Origin)

    NASA Astrophysics Data System (ADS)

    Tsiapas, Elias

    2016-04-01

    When the Earth was formed, it was in a state of burning heat. As time went by, temperature on the planet's surface was falling due to radiation and heat transfer, and various components (crusts) began taking solid form at the Earth's poles. The formation of crusts took place at the Earth's poles, because the stirring of burning and fluid masses on the surface of the Earth was significantly slighter there than it was on the equator. Due to centrifugal force and Coriolis Effect, these solid masses headed towards the equator; those originating from the North Pole followed a south-western course, while those originating from the South Pole followed a north-western course and there they rotated from west to east at a lower speed than the underlying burning and liquid earth, because of their lower initial linear velocity, their solid state and inertia. Because inertia is proportional to mass, the initially larger solid body swept all new solid ones, incorporating them to its western side. The density of the new solid masses was higher, because the components on the surface would freeze and solidify first, before the underlying thicker components. As a result, the western side of the initial islet of solid rocks submerged, while the east side elevated. . As a result of the above, this initial islet began to spin in reverse, and after taking on the shape of a sphere, it formed the "heart" of the Moon. The Moon-sphere, rolling on the equator, would sink the solid rocks that continued to descend from the Earth's poles. The sinking rocks partially melted because of higher temperatures in the greater depths that the Moon descended to, while part of the rocks' mass bonded with the Moon and also served as a heat-insulating material, preventing the descended side of the sphere from melting. Combined with the Earth's liquid mass that covered its emerging eastern surface, new sphere-shaped shells were created, with increased density and very powerful structural cohesion. During the

  1. Moon (Form-Origin)

    NASA Astrophysics Data System (ADS)

    Tsiapas, Elias

    2014-05-01

    When the Earth was formed, it was in a state of burning heat. As time went by, temperature on the planet's surface was falling due to radiation and heat transfer, and various components (crusts) began taking solid form at the Earth's poles. The formation of crusts took place at the Earth's poles, because the stirring of burning and fluid masses on the surface of the Earth was significantly slighter there than it was on the equator. Due to centrifugal force and Coriolis Effect, these solid masses headed towards the equator; those originating from the North Pole followed a south-western course, while those originating from the South Pole followed a north-western course and there they rotated from west to east at a lower speed than the underlying burning and liquid earth, because of their lower initial linear velocity, their solid state and inertia. Because inertia is proportional to mass, the initially larger solid body swept all new solid ones, incorporating them to its western side. The density of the new solid masses was higher, because the components on the surface would freeze and solidify first, before the underlying thicker components. As a result, the western side of the initial islet of solid rocks submerged, while the east side elevated. . As a result of the above, this initial islet began to spin in reverse, and after taking on the shape of a sphere, it formed the "heart" of the Moon. The Moon-sphere, rolling on the equator, would sink the solid rocks that continued to descend from the Earth's poles. The sinking rocks partially melted because of higher temperatures in the greater depths that the Moon descended to, while part of the rocks' mass bonded with the Moon and also served as a heat-insulating material, preventing the descended side of the sphere from melting. Combined with the Earth's liquid mass that covered its emerging eastern surface, new sphere-shaped shells were created, with increased density and very powerful structural cohesion. During the

  2. Moon (Form-Origin)

    NASA Astrophysics Data System (ADS)

    Tsiapas, Elias

    2013-04-01

    When the Earth was formed, it was in a state of burning heat. As time went by, temperature on the planet's surface was falling due to radiation and heat transfer, and various components (crusts) began taking solid form at the Earth's poles. The formation of crusts took place at the Earth's poles, because the stirring of burning and fluid masses on the surface of the Earth was significantly slighter there than it was on the equator. Due to centrifugal force and Coriolis Effect, these solid masses headed towards the equator; those originating from the North Pole followed a south-western course, while those originating from the South Pole followed a north-western course and there they rotated from west to east at a lower speed than the underlying burning and liquid earth, because of their lower initial linear velocity, their solid state and inertia. Because inertia is proportional to mass, the initially larger solid body swept all new solid ones, incorporating them to its western side. The density of the new solid masses was higher, because the components on the surface would freeze and solidify first, before the underlying thicker components. As a result, the western side of the initial islet of solid rocks submerged, while the east side elevated. As a result of the above, this initial islet began to spin in reverse, and after taking on the shape of a sphere, it formed the "heart" of the Moon. The Moon-sphere, rolling on the equator, would sink the solid rocks that continued to descend from the Earth's poles. The sinking rocks partially melted because of higher temperatures in the greater depths that the Moon descended to, while part of the rocks' mass bonded with the Moon and also served as a heat-insulating material, preventing the descended side of the sphere from melting. Combined with the Earth's liquid mass that covered its emerging eastern surface, new sphere-shaped shells were created, with increased density and very powerful structural cohesion. During the

  3. Moon (Form-Origin)

    NASA Astrophysics Data System (ADS)

    Tsiapas, Elias

    2015-04-01

    When the Earth was formed, it was in a state of burning heat. As time went by, temperature on the planet's surface was falling due to radiation and heat transfer, and various components (crusts) began taking solid form at the Earth's poles. The formation of crusts took place at the Earth's poles, because the stirring of burning and fluid masses on the surface of the Earth was significantly slighter there than it was on the equator. Due to centrifugal force and Coriolis Effect, these solid masses headed towards the equator; those originating from the North Pole followed a south-western course, while those originating from the South Pole followed a north-western course and there they rotated from west to east at a lower speed than the underlying burning and liquid earth, because of their lower initial linear velocity, their solid state and inertia. Because inertia is proportional to mass, the initially larger solid body swept all new solid ones, incorporating them to its western side. The density of the new solid masses was higher, because the components on the surface would freeze and solidify first, before the underlying thicker components. As a result, the western side of the initial islet of solid rocks submerged, while the east side elevated. . As a result of the above, this initial islet began to spin in reverse, and after taking on the shape of a sphere, it formed the "heart" of the Moon. The Moon-sphere, rolling on the equator, would sink the solid rocks that continued to descend from the Earth's poles. The sinking rocks partially melted because of higher temperatures in the greater depths that the Moon descended to, while part of the rocks' mass bonded with the Moon and also served as a heat-insulating material, preventing the descended side of the sphere from melting. Combined with the Earth's liquid mass that covered its emerging eastern surface, new sphere-shaped shells were created, with increased density and very powerful structural cohesion. During the

  4. The Cosmic Origins Spectrograph

    NASA Technical Reports Server (NTRS)

    Green, James C.; Froning, Cynthia S.; Osterman, Steve; Ebbets, Dennis; Heap, Sara H.; Leitherer, Claus; Linsky, Jeffrey L.; Savage, Blair D.; Sembach, Kenneth; Shull, J. Michael; Siegmund, Oswald H. W.; Snow, Theodore P.; Spencer, John; Stern, S. Alan; Stocke, John; Welsh, Barry; Beland, Stephane; Burgh, Eric B.; Danforth, Charles; France, Kevin; Keeney, Brian; McPhate, Jason; Penton, Steven V; Andrews, John; Morse, Jon

    2010-01-01

    The Cosmic Origins Spectrograph (COS) is a moderate-resolution spectrograph with unprecedented sensitivity that was installed into the Hubble Space Telescope (HST) in May 2009, during HST Servicing Mission 4 (STS-125). We present the design philosophy and summarize the key characteristics of the instrument that will be of interest to potential observers. For faint targets, with flux F(sub lambda) approximates 1.0 X 10(exp -14) ergs/s/cm2/Angstrom, COS can achieve comparable signal to noise (when compared to STIS echelle modes) in 1-2% of the observing time. This has led to a significant increase in the total data volume and data quality available to the community. For example, in the first 20 months of science operation (September 2009 - June 2011) the cumulative redshift pathlength of extragalactic sight lines sampled by COS is 9 times that sampled at moderate resolution in 19 previous years of Hubble observations. COS programs have observed 214 distinct lines of sight suitable for study of the intergalactic medium as of June 2011. COS has measured, for the first time with high reliability, broad Lya absorbers and Ne VIII in the intergalactic medium, and observed the HeII reionization epoch along multiple sightlines. COS has detected the first CO emission and absorption in the UV spectra of low-mass circumstellar disks at the epoch of giant planet formation, and detected multiple ionization states of metals in extra-solar planetary atmospheres. In the coming years, COS will continue its census of intergalactic gas, probe galactic and cosmic structure, and explore physics in our solar system and Galaxy.

  5. THE COSMIC ORIGINS SPECTROGRAPH

    SciTech Connect

    Green, James C.; Michael Shull, J.; Snow, Theodore P.; Stocke, John; Froning, Cynthia S.; Osterman, Steve; Beland, Stephane; Burgh, Eric B.; Danforth, Charles; France, Kevin; Ebbets, Dennis; Heap, Sara H.; Leitherer, Claus; Sembach, Kenneth; Linsky, Jeffrey L.; Savage, Blair D.; Siegmund, Oswald H. W.; Spencer, John; Alan Stern, S.; Welsh, Barry; and others

    2012-01-01

    The Cosmic Origins Spectrograph (COS) is a moderate-resolution spectrograph with unprecedented sensitivity that was installed into the Hubble Space Telescope (HST) in 2009 May, during HST Servicing Mission 4 (STS-125). We present the design philosophy and summarize the key characteristics of the instrument that will be of interest to potential observers. For faint targets, with flux F{sub {lambda}} Almost-Equal-To 1.0 Multiplication-Sign 10{sup -14} erg cm{sup -2} s{sup -1} A{sup -1}, COS can achieve comparable signal to noise (when compared to Space Telescope Imaging Spectrograph echelle modes) in 1%-2% of the observing time. This has led to a significant increase in the total data volume and data quality available to the community. For example, in the first 20 months of science operation (2009 September-2011 June) the cumulative redshift pathlength of extragalactic sight lines sampled by COS is nine times than sampled at moderate resolution in 19 previous years of Hubble observations. COS programs have observed 214 distinct lines of sight suitable for study of the intergalactic medium as of 2011 June. COS has measured, for the first time with high reliability, broad Ly{alpha} absorbers and Ne VIII in the intergalactic medium, and observed the He II reionization epoch along multiple sightlines. COS has detected the first CO emission and absorption in the UV spectra of low-mass circumstellar disks at the epoch of giant planet formation, and detected multiple ionization states of metals in extra-solar planetary atmospheres. In the coming years, COS will continue its census of intergalactic gas, probe galactic and cosmic structure, and explore physics in our solar system and Galaxy.

  6. "Origin," "creation," and "origin of life" some conceptual considerations.

    PubMed

    Charpa, Ulrich

    2012-01-01

    This paper opens by drawing attention to the fact that there is some conceptual confusion with regard to "origin" and "creation." This has its historical roots in the beginnings of modern science and undoubtedly affects our positioning towards the evolutionism/creationism-debate. This article argues that there are relevant ontological, epistemological, thematic, methodological, and logical differences between "origin" and "creation." As a result, the analysis suggests keeping the usage of both concepts strictly quite separate. Creation is not simply another word for origin nor does it stand for an (from a rigid scientific point of view) awkward example of an origin. Irrespective of the apparent similarities as explanatory factors, origin and creation belong to fundamentally different types of concepts. Consequently, "origin of life" and those scientific projects connected to it present themselves as something distinct that neither competes nor meshes with thinking about creation.

  7. "Origin," "creation," and "origin of life" some conceptual considerations.

    PubMed

    Charpa, Ulrich

    2012-01-01

    This paper opens by drawing attention to the fact that there is some conceptual confusion with regard to "origin" and "creation." This has its historical roots in the beginnings of modern science and undoubtedly affects our positioning towards the evolutionism/creationism-debate. This article argues that there are relevant ontological, epistemological, thematic, methodological, and logical differences between "origin" and "creation." As a result, the analysis suggests keeping the usage of both concepts strictly quite separate. Creation is not simply another word for origin nor does it stand for an (from a rigid scientific point of view) awkward example of an origin. Irrespective of the apparent similarities as explanatory factors, origin and creation belong to fundamentally different types of concepts. Consequently, "origin of life" and those scientific projects connected to it present themselves as something distinct that neither competes nor meshes with thinking about creation. PMID:23316571

  8. Generating original ideas: The neural underpinning of originality.

    PubMed

    Mayseless, Naama; Eran, Ayelet; Shamay-Tsoory, Simone G

    2015-08-01

    One of the key aspects of creativity is the ability to produce original ideas. Originality is defined in terms of the novelty and rarity of an idea and is measured by the infrequency of the idea compared to other ideas. In the current study we focused on divergent thinking (DT) - the ability to produce many alternate ideas - and assessed the neural pathways associated with originality. Considering that generation of original ideas involves both the ability to generate new associations and the ability to overcome automatic common responses, we hypothesized that originality would be associated with activations in regions related to associative thinking, including areas of the default mode network (DMN) such as medial prefrontal areas, as well as with areas involved in cognitive control and inhibition. Thirty participants were scanned while performing a DT task that required the generation of original uses for common objects. The results indicate that the ability to produce original ideas is mediated by activity in several regions that are part of the DMN including the medial prefrontal cortex (mPFC) and the posterior cingulate cortex (PCC). Furthermore, individuals who are more original exhibited enhanced activation in the ventral anterior cingulate cortex (vACC), which was also positively coupled with activity in the left occipital-temporal area. These results are in line with the dual model of creativity, according to which original ideas are a product of the interaction between a system that generates ideas and a control system that evaluates these ideas. PMID:26003860

  9. Dendrite development: a surprising origin.

    PubMed

    Ehlers, Michael D

    2005-08-15

    Neurons extend elaborate dendrites studded with spines. Unexpectedly, this cellular sculpting is regulated by the origin recognition complex -- the core machinery for initiating DNA replication. PMID:16103221

  10. 29. Photocopy of original construction drawing, dated February 1932 (original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. Photocopy of original construction drawing, dated February 1932 (original print in possession of Veterans Administration, Oakland Branch, Pittsburgh, Pennsylvania). DRAWING 1-1 -- INFIRMARY, BUILDING NO. 1 -- ADDITION TO INFIRMARY -- BASEMENT PLAN. - VA Medical Center, Aspinwall Division, Infirmary Building, 5103 Delafield Avenue (O'Hara Township), Aspinwall, Allegheny County, PA

  11. 19. Photocopy of original construction drawing, dated April 1924 (original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. Photocopy of original construction drawing, dated April 1924 (original print in possession of Veterans Administration, Oakland Branch, Pittsburgh, Pennsylvania). DRAWING 1-1 -- INFIRMARY, BUILDING NO. 1 -- CENTER PORTION -- BASEMENT PLAN. - VA Medical Center, Aspinwall Division, Infirmary Building, 5103 Delafield Avenue (O'Hara Township), Aspinwall, Allegheny County, PA

  12. 114. Photocopy of original construction drawing, 14 August 1935. (Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    114. Photocopy of original construction drawing, 14 August 1935. (Original print in the possession of U.S. Army Corps of Engineers, Portland District, Portland, OR.) (M-5-8, Sheet No. 14) SPILLWAY DAM FISHWAY ENTRANCE BAY DIFFUSION CHAMBER BEAN DETAILS. - Bonneville Project, Bonneville Dam, Columbia River, Bonneville, Multnomah County, OR

  13. Photocopy of original drawings (original located at the National Archives, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original drawings (original located at the National Archives, San Bruno, California, Navy # 104-A-14). Dept. of yards and docks, "Chapel amplifier support," October 1945. - Mare Island Naval Shipyard, St. Peter's Chapel, Walnut Street & Cedar Parkway, Vallejo, Solano County, CA

  14. 12. Photocopy of original construction drawing, dated November 1932 (original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Photocopy of original construction drawing, dated November 1932 (original print in possession of Veterans Administration, Oakland Branch, Pittsburgh, Pennsylvania). DRAWING 32-2 -- ADMINISTRATION BUILDING, BUILDING NO. 32 -- BASEMENT PLAN AND CUPOLA DETAIL. - VA Medical Center, Aspinwall Division, Administration Building, 5103 Delafield Avenue, Aspinwall, Allegheny County, PA

  15. Photocopy of original drawings (original located at the National Archives, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original drawings (original located at the National Archives, San Bruno, California, Navy # 104-A-22), showing current floor plan. Department of the Navy, Bureau of Yards and Docks, "Record drawing, N.D. - Mare Island Naval Shipyard, St. Peter's Chapel, Walnut Street & Cedar Parkway, Vallejo, Solano County, CA

  16. Photocopy of original drawings (original located at the National Archives, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original drawings (original located at the National Archives, San Bruno, California, Navy # 104-A-25) William Jeffries Associates, A.I.A., "Repair to stained glass window, building 104, elevation & details," September 1952. - Mare Island Naval Shipyard, St. Peter's Chapel, Walnut Street & Cedar Parkway, Vallejo, Solano County, CA

  17. Photocopy of original drawings (original located at the National Archives, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original drawings (original located at the National Archives, San Bruno, California, Navy # 104-A-5). Depts. Yards & docks, U.S. Navy Mare Island, Cal., "full sized detail of fretwork panels in back of organ recess, St. Peter's Chapel, Mare Island, Cal., December 1904. - Mare Island Naval Shipyard, St. Peter's Chapel, Walnut Street & Cedar Parkway, Vallejo, Solano County, CA

  18. Photocopy of original drawings (original located at the National Archives, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original drawings (original located at the National Archives, San Bruno, California, Navy # 104-A-13). (Signed) Ralph Whitman, public works officer, "Yard chapel organ addition mill details, exterior window," September 1929. - Mare Island Naval Shipyard, St. Peter's Chapel, Walnut Street & Cedar Parkway, Vallejo, Solano County, CA

  19. Photocopy of original drawings (original located at the National Archives, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original drawings (original located at the National Archives, San Bruno, California, Navy # 104-A-9). (Signed) Ralph Whitman, public works officer, "Yard chapel addition to house organ, etc., plans, elevations, details," September 1929. - Mare Island Naval Shipyard, St. Peter's Chapel, Walnut Street & Cedar Parkway, Vallejo, Solano County, CA

  20. Photocopy of original drawings (original located at the National Archives, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original drawings (original located at the National Archives, San Bruno, California, Navy # 104-A-4, showing organ recess. Dept. yards & docks, U.S. Navy, Mare Island, Cal., "Plan & Sections, proposed addition, St. Peter's Chapel, December 1904 - Mare Island Naval Shipyard, St. Peter's Chapel, Walnut Street & Cedar Parkway, Vallejo, Solano County, CA

  1. 56. Photograph of Original Plan (original plans in the possession ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    56. Photograph of Original Plan (original plans in the possession of the Los Angeles Union Passenger Terminal Corporation) BAGGAGE AND EXPRESS UNIT, MAIN FLOOR AND BOILER ROOM PLANS, SECTIONS IV-V - Los Angeles Union Passenger Terminal, Tracks & Shed, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  2. Photocopy of original drawings (original located at the National Archives, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original drawings (original located at the National Archives, San Bruno, California, Navy # A-21). Dept. of the Navy District Public Works Office, "additions, floor plan, elevations & details; architectural, mechanical & electrical," May 1963. - Mare Island Naval Shipyard, St. Peter's Chapel, Walnut Street & Cedar Parkway, Vallejo, Solano County, CA

  3. 55. Photograph of Original Plan (original plans in the possession ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    55. Photograph of Original Plan (original plans in the possession of the Los Angeles Union Passenger Terminal Corporation) BAGGAGE AND EXPRESS UNITY, STREET LEVEL FLOOR PLAN, SECTION III - Los Angeles Union Passenger Terminal, Tracks & Shed, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  4. Photocopy of photograph (original located at Mare Island Archives). Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of photograph (original located at Mare Island Archives). Original photographer unknown. Dry dock 2 with three submarines and one sailing ship; 1914. - Mare Island Naval Shipyard, Drydock No. 2, California Avenue, east side near Ninth Street, Vallejo, Solano County, CA

  5. 16. Photocopy of original USRS photograph (from original print in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Photocopy of original USRS photograph (from original print in the Umatilla Project History 1918, on file at National Archives, Rocky Mountain Region, Denver, Colorado) Photographer unknown, ca. 1918. Office of U.S. Reclamation Service - Hermiston, Umatilla Project, Oregon - Former Umatilla Project Headquarters Buildings, Office, Hermiston, Umatilla County, OR

  6. 127. Photocopy of original construction drawing, 20 March 1935. (Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    127. Photocopy of original construction drawing, 20 March 1935. (Original print in the possession of U.S. Army Corps of Engineers, Portland District, Portland, OR.) (M-4-30, Sheet No. 18) SPILLWAY DAM ELEVATIONS OF GANTRY FRAME DESIGN DETAILS. - Bonneville Project, Bonneville Dam, Columbia River, Bonneville, Multnomah County, OR

  7. 8. Photocopy of original USRS glass plate slide (from original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Photocopy of original USRS glass plate slide (from original slide on file at National Archives, Rocky Mountain Region, Denver, Colorado) Photographer unknown, ca. 1908 The diversion weir of the Okanogan National Irrigation Project - Salmon Creek Diversion Dam, Salmon Creek, Okanogan, Okanogan County, WA

  8. Photograph of original drawing (original in possession of National Passenger ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photograph of original drawing (original in possession of National Passenger Railroad Corporation). STATION BUILDING: Foundation Plan / Alterations and Additions (dated: 7/17/14) - North Philadelphia Station, 2900 North Broad Street, on northwest corner of Broad Street & Glenwood Avenue, Philadelphia, Philadelphia County, PA

  9. Photograph of original drawing (original in possession of National Passenger ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photograph of original drawing (original in possession of National Passenger Railroad Corporation). Plans, Elevations, and Details of Stair Canopies (n.d.) - North Philadelphia Station, 2900 North Broad Street, on northwest corner of Broad Street & Glenwood Avenue, Philadelphia, Philadelphia County, PA

  10. 21. Photocopy of Original Drawing (original in Michigan Department of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. Photocopy of Original Drawing (original in Michigan Department of Transportation, 425 West Ottawa, Lansing, MI 48909), Bridge X2 of 11-2-21, Sheet 9, July 23, 1935. EAST ELEVATION, LOOKING WEST - State Route M-139 Bridge, Spanning Ox Creek, Fair Plain, Berrien County, MI

  11. 12. Photocopy of original construction drawing, undated. (Original print in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Photocopy of original construction drawing, undated. (Original print in the possession of U.S. Army Corps of Engineers, Portland District, Portland, OR.) PROPOSED EXTENSION TO ADMINISTRATION BUILDING. - Bonneville Project, Administration Building, South side of main entrance, Bonneville Project, Bonneville, Multnomah County, OR

  12. 119. Photocopy of original construction drawing, 29 May 1935 (Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    119. Photocopy of original construction drawing, 29 May 1935 (Original print in the possession of U.S. Army Corps of Engineers, Portland District, Portland, OR.) (M-5-12, Sheet No. 11) SPILLWAY DAN SECTION THRU DAM FIRST STEP CONSTRUCTION. - Bonneville Project, Bonneville Dam, Columbia River, Bonneville, Multnomah County, OR

  13. 11. Photocopy of original construction drawing, dated 1934. (Original print ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Photocopy of original construction drawing, dated 1934. (Original print in the possession of U.S. Army Corps of Engineers, Portland District, Portland, OR.) ADMINISTRATION BUILDING MAIN FLOOR PLAN. - Bonneville Project, Administration Building, South side of main entrance, Bonneville Project, Bonneville, Multnomah County, OR

  14. 122. Photocopy of original construction drawing, 29 May 1935. (Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    122. Photocopy of original construction drawing, 29 May 1935. (Original print in the possession of U.S. Army Corps of Engineers, Portland District, Portland, OR.) (M-5-12, Sheet No. 2) SPILLWAY DAM PLAN OF DAM FROM PIER 13 TO ABUTMENT 2 SHOWN AT ELEV. -5. - Bonneville Project, Bonneville Dam, Columbia River, Bonneville, Multnomah County, OR

  15. Editing Paperback Reprints and Originals.

    ERIC Educational Resources Information Center

    Feiwel, Janet

    1982-01-01

    Outlines the functions of an editor of paperback reprint and original children's books at Avon Books, describes the strategies that go into the selection of books for paperback reprinting or original publication, and reviews the approaches to marketing paperback children's books, such as cover art, which distinguish them from hardcovers. (JL)

  16. The Origins of Soviet Sociolinguistics.

    ERIC Educational Resources Information Center

    Brandist, Craig

    2003-01-01

    Discusses the origins of Soviet sociolinguistics and suggests that the historical significance of the reception and reinterpretation of these ideas is considerable, leading to a reconsideration of the origins of sociolinguistics and the relationship between Marxism and the language sciences in the early years of the Soviet Union. (Author/VWL)

  17. The Origin of Malignant Malaria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plasmodium falciparum is the causative agent of malignant malaria, which is among the most severe human infectious diseases. Despite its overwhelming significance to human health, the parasite’s origins remain unclear. The favored origin hypothesis holds that P. falciparum and its closest known rel...

  18. 17. Photocopy of original USRS photograph (from original print in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Photocopy of original USRS photograph (from original print in the Umatilla Project History 1920, on file at National Archives, Rocky Mountain Region, Denver, Colorado) Photographer unknown, ca. 1920. Project office and employees - reading from left to right: Una H. Keck, Geo. C. Patterson, H.M. Schilling, Maurice D. Scroggs, Carl M. Voyen, Chas. Taylor, C.D. Porter - Former Umatilla Project Headquarters Buildings, Office, Hermiston, Umatilla County, OR

  19. Malignant chondroblastoma of extraskeletal origin

    PubMed Central

    Duttaluri, Ramu; Sultanpurkar, Guru Prasad; Raorane, Harshvardhan; Vikram, Harsha

    2016-01-01

    Chondroblastoma is a rare benign neoplasm of cartilaginous origin. It typically arises in the epiphysis of a long bone. They occur mostly in the second decade of life and is more common in males. Extraskeletal origin of chondroblastoma is a rarity and virulent behavior by its local aggressive nature or metastasis is reported in very few cases. We hereby, present a case of chondroblastoma in the left popliteal fossa first of its kind in a 62-year-old female, primary tumor extraskeletal in origin which turned locally aggressive and eventually metastasized to lungs. The patient is now on palliative therapy. PMID:27127749

  20. Malignant chondroblastoma of extraskeletal origin.

    PubMed

    Duttaluri, Ramu; Sultanpurkar, Guru Prasad; Raorane, Harshvardhan; Vikram, Harsha

    2016-01-01

    Chondroblastoma is a rare benign neoplasm of cartilaginous origin. It typically arises in the epiphysis of a long bone. They occur mostly in the second decade of life and is more common in males. Extraskeletal origin of chondroblastoma is a rarity and virulent behavior by its local aggressive nature or metastasis is reported in very few cases. We hereby, present a case of chondroblastoma in the left popliteal fossa first of its kind in a 62-year-old female, primary tumor extraskeletal in origin which turned locally aggressive and eventually metastasized to lungs. The patient is now on palliative therapy.

  1. Malignant chondroblastoma of extraskeletal origin.

    PubMed

    Duttaluri, Ramu; Sultanpurkar, Guru Prasad; Raorane, Harshvardhan; Vikram, Harsha

    2016-01-01

    Chondroblastoma is a rare benign neoplasm of cartilaginous origin. It typically arises in the epiphysis of a long bone. They occur mostly in the second decade of life and is more common in males. Extraskeletal origin of chondroblastoma is a rarity and virulent behavior by its local aggressive nature or metastasis is reported in very few cases. We hereby, present a case of chondroblastoma in the left popliteal fossa first of its kind in a 62-year-old female, primary tumor extraskeletal in origin which turned locally aggressive and eventually metastasized to lungs. The patient is now on palliative therapy. PMID:27127749

  2. The origins of originality: the neural bases of creative thinking and originality.

    PubMed

    Shamay-Tsoory, S G; Adler, N; Aharon-Peretz, J; Perry, D; Mayseless, N

    2011-01-01

    Although creativity has been related to prefrontal activity, recent neurological case studies postulate that patients who have left frontal and temporal degeneration involving deterioration of language abilities may actually develop de novo artistic abilities. In this study, we propose a neural and cognitive model according to which a balance between the two hemispheres affects a major aspect of creative cognition, namely, originality. In order to examine the neural basis of originality, that is, the ability to produce statistically infrequent ideas, patients with localized lesions in the medial prefrontal cortex (mPFC), inferior frontal gyrus (IFG), and posterior parietal and temporal cortex (PC), were assessed by two tasks involving divergent thinking and originality. Results indicate that lesions in the mPFC involved the most profound impairment in originality. Furthermore, precise anatomical mapping of lesions indicated that while the extent of lesion in the right mPFC was associated with impaired originality, lesions in the left PC were associated with somewhat elevated levels of originality. A positive correlation between creativity scores and left PC lesions indicated that the larger the lesion is in this area the greater the originality. On the other hand, a negative correlation was observed between originality scores and lesions in the right mPFC. It is concluded that the right mPFC is part of a right fronto-parietal network which is responsible for producing original ideas. It is possible that more linear cognitive processing such as language, mediated by left hemisphere structures interferes with creative cognition. Therefore, lesions in the left hemisphere may be associated with elevated levels of originality. PMID:21126528

  3. Word Origins: Building Communication Connections.

    ERIC Educational Resources Information Center

    Rubenstein, Rheta N.

    2000-01-01

    Proposes examining word origins as a teaching strategy for helping middle school students speak the language of mathematics as well as promote students' general vocabulary development. Includes roots, meanings, related words, and notes for middle school mathematics vocabulary. (KHR)

  4. Origin of the Uranian satellites

    NASA Technical Reports Server (NTRS)

    Pollack, James B.; Lunine, Jonathan I.; Tittemore, William C.

    1991-01-01

    The current understanding of the origin of the Uranian satellites is assessed by reviewing relevant data on the Uranian satellites, including those obtained by Voyager, and comparing these properties with those of the satellites of the other outer planets. The nature of the early solar system, including the origin of the giant planets, is discussed as a preface to alternative hypotheses for the origin of the nebular disk within which the Uranian satellites formed. The chemical and physical properties of this disk are discussed, as well as the accretion of the satellites from disk solid matter. Predictions of alternative scenarios for the satellites' origin with the relevant observational constraint are compared. The orbital evolution of the larger satellites of Uranus is discussed to gain an understanding of their present orbital properties and possibly important past tidal heating episodes.

  5. Input calibration for negative originals

    NASA Astrophysics Data System (ADS)

    Tuijn, Chris

    1995-04-01

    One of the major challenges in the prepress environment consists of controlling the electronic color reproduction process such that a perfect match of any original can be realized. Whether this goal can be reached depends on many factors such as the dynamic range of the input device (scanner, camera), the color gamut of the output device (dye sublimation printer, ink-jet printer, offset), the color management software etc. The characterization of the color behavior of the peripheral devices is therefore very important. Photographs and positive transparents reflect the original scene pretty well; for negative originals, however, there is no obvious link to either the original scene or a particular print of the negative under consideration. In this paper, we establish a method to scan negatives and to convert the scanned data to a calibrated RGB space, which is known colorimetrically. This method is based on the reconstruction of the original exposure conditions (i.e., original scene) which generated the negative. Since the characteristics of negative film are quite diverse, a special calibration is required for each combination of scanner and film type.

  6. The origins of research into the origins of life.

    PubMed

    Fry, Iris

    2006-03-01

    Most scientists at the end of the 19th and the beginning of the 20th century chose to ignore the question of the origin of life on Earth, regarding it as too mysterious and complex to handle. Yet, in the early 1950s an experimental field devoted to the study of the problem made its first steps. The pioneering theories of several scientists in the first decades of the 20th century played a major role in this transformation, notably those of the Russian biochemist Alexander I. Oparin and the British geneticist and biochemist J.B.S. Haldane. The ideas of the lesser-known American psycho-physiologist Leonard Troland also made a significant contribution to subsequent developments in origin-of-life research. Therefore, it is well worth taking a look at the professional, philosophical and ideological commitments that shaped the approaches of the three scientists to origin-of-life research. PMID:16469383

  7. Endosymbiotic theories for eukaryote origin.

    PubMed

    Martin, William F; Garg, Sriram; Zimorski, Verena

    2015-09-26

    For over 100 years, endosymbiotic theories have figured in thoughts about the differences between prokaryotic and eukaryotic cells. More than 20 different versions of endosymbiotic theory have been presented in the literature to explain the origin of eukaryotes and their mitochondria. Very few of those models account for eukaryotic anaerobes. The role of energy and the energetic constraints that prokaryotic cell organization placed on evolutionary innovation in cell history has recently come to bear on endosymbiotic theory. Only cells that possessed mitochondria had the bioenergetic means to attain eukaryotic cell complexity, which is why there are no true intermediates in the prokaryote-to-eukaryote transition. Current versions of endosymbiotic theory have it that the host was an archaeon (an archaebacterium), not a eukaryote. Hence the evolutionary history and biology of archaea increasingly comes to bear on eukaryotic origins, more than ever before. Here, we have compiled a survey of endosymbiotic theories for the origin of eukaryotes and mitochondria, and for the origin of the eukaryotic nucleus, summarizing the essentials of each and contrasting some of their predictions to the observations. A new aspect of endosymbiosis in eukaryote evolution comes into focus from these considerations: the host for the origin of plastids was a facultative anaerobe.

  8. Endosymbiotic theories for eukaryote origin

    PubMed Central

    Martin, William F.; Garg, Sriram; Zimorski, Verena

    2015-01-01

    For over 100 years, endosymbiotic theories have figured in thoughts about the differences between prokaryotic and eukaryotic cells. More than 20 different versions of endosymbiotic theory have been presented in the literature to explain the origin of eukaryotes and their mitochondria. Very few of those models account for eukaryotic anaerobes. The role of energy and the energetic constraints that prokaryotic cell organization placed on evolutionary innovation in cell history has recently come to bear on endosymbiotic theory. Only cells that possessed mitochondria had the bioenergetic means to attain eukaryotic cell complexity, which is why there are no true intermediates in the prokaryote-to-eukaryote transition. Current versions of endosymbiotic theory have it that the host was an archaeon (an archaebacterium), not a eukaryote. Hence the evolutionary history and biology of archaea increasingly comes to bear on eukaryotic origins, more than ever before. Here, we have compiled a survey of endosymbiotic theories for the origin of eukaryotes and mitochondria, and for the origin of the eukaryotic nucleus, summarizing the essentials of each and contrasting some of their predictions to the observations. A new aspect of endosymbiosis in eukaryote evolution comes into focus from these considerations: the host for the origin of plastids was a facultative anaerobe. PMID:26323761

  9. The origin of the moon.

    PubMed

    Boss, A P

    1986-01-24

    The origin of the moon is considered within the theory of formation of the terrestrial planets by accumulation of planetesimals. The theory predicts the occurrence of giant impacts, suggesting that the moon formed after a roughly Mars-sized body impacted on the protoearth. The impact blasted portions of the protoearth and the impacting body into geocentric orbit, forming a prelunar disk from which the moon later accreted. Although other mechanisms for formation of the moon appear to be dynamically impossible or implausible, fundamental questions must be answered before a giant impact origin can be considered both possible and probable.

  10. 7 CFR 201.14 - Origin.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... hybrid seed corn) shall be labeled to show: (1) The origin, if known; or (2) if the origin is not known... as originating in such portion of a State. (c) Reasonable precautions to insure that the origin of... precautions have been taken to insure the origin to be that which is represented....

  11. Origin of the 'Extra Entropy'

    NASA Technical Reports Server (NTRS)

    Mushotzky, R.

    2008-01-01

    I will discuss how one can determine the origin of the 'extra entropy' in groups and clusters and the feedback needed in models of galaxy formation. I will stress the use of x-ray spectroscopy and imaging and the critical value that Con-X has in this regard.

  12. The origin of the Earth.

    PubMed

    Taylor, S R

    1997-01-01

    It is not possible to consider the formation of the Earth in isolation without reference to the formation of the rest of the solar system. A brief account is given of the current scientific consensus on that topic, explaining the origin of an inner solar system rocky planet depleted in most of the gaseous and icy components of the original solar nebula. Volatile element depletion occurred at a very early stage in the nebula, and was probably responsible for the formation of Jupiter before that of the inner planets. The Earth formed subsequently from accumulation of a hierarchy of planetesimals. Evidence of these remains in the ancient cratered surfaces and the obliquities (tilts) of most planets. Earth melting occurred during this process, as well as from the giant Moon-forming impact. The strange density and chemistry of the Moon are consistent with an origin from the mantle of the impactor. Core-mantle separation on the Earth was coeval with accretion. Some speculations are given on the origin of the hydrosphere.

  13. The Chemistry of Life's Origin.

    ERIC Educational Resources Information Center

    Ferris, James P.

    1984-01-01

    From an understanding of how the solar system was formed, scientists have determined the conditions under which life probably originated on earth and, by experiment, have demonstrated a number of possible theories. These conditions, experiments, theories, and related topics are discussed. (JN)

  14. Originism - Ethics and Extraterrestrial Life

    NASA Astrophysics Data System (ADS)

    Cockell, C. S.

    How should we treat extraterrestrial life, if we ever find it, and does a different origin of life imply a different ethical status? The most likely source of an ethical difference, or `originism,' is the inability to find a coherent definition of `life,' required to assess moral relevance in the first place. Although from a normative point of view biochemical architecture, in itself, does not provide a reason for a difference, there are numerous positions that might encourage us to treat an independent origin of life differently to life that is related to life on Earth. For example, from an instrumental point of view it would provide an opportunity to study another biological data point; it will be a new source of information about the evolution of life, and thus it might be afforded special status. We might consider extraterrestrial life to be special as prudence against the possibility of its mistreatment through an erroneous moral assessment of its worth. Whether extraterrestrial life exists of an independent origin or not, this analysis ultimately can provide a useful device for considering how we should treat entities on Earth whose status as `living' organisms is disputed, specifically viruses.

  15. The Moon and Its Origin

    ERIC Educational Resources Information Center

    Urey, Harold C.

    1973-01-01

    Describes the origin of the Moon on the basis of the Apollo expeditions as an accumulated gas sphere at its very beginning and, later, a satellite captured by the Earth. Indicates that the model would be substantially believable if further observations should be proved to exist as estimated. (CC)

  16. The origins of cellular life.

    PubMed

    Koonin, Eugene V

    2014-07-01

    All life on earth can be naturally classified into cellular life forms and virus-like selfish elements, the latter being fully dependent on the former for their reproduction. Cells are reproducers that not only replicate their genome but also reproduce the cellular organization that depends on semipermeable, energy-transforming membranes and cannot be recovered from the genome alone, under the famous dictum of Rudolf Virchow, Omnis cellula e cellula. In contrast, simple selfish elements are replicators that can complete their life cycles within the host cell starting from genomic RNA or DNA alone. The origin of the cellular organization is the central and perhaps the hardest problem of evolutionary biology. I argue that the origin of cells can be understood only in conjunction with the origin and evolution of selfish genetic elements. A scenario of precellular evolution is presented that involves cohesion of the genomes of the emerging cellular life forms from primordial pools of small genetic elements that eventually segregated into hosts and parasites. I further present a model of the coevolution of primordial membranes and membrane proteins, discuss protocellular and non-cellular models of early evolution, and examine the habitats on the primordial earth that could have been conducive to precellular evolution and the origin of cells.

  17. Increasing Originality in Written Expression.

    ERIC Educational Resources Information Center

    Belasco, Jack Thomas

    This study partially replicated Moss's "A Study of the Effect of Selected Methods of Instruction Designed to Increase Originality in Written Expression," except for the fact that this investigator taught a 5th grade and an 11th grade class for most of a school year. Some of the conclusions of the study were: no particular teaching technique was…

  18. Climate Drives Polar Bear Origins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In their provocative analysis of northern bears (“Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage,” Reports, 20 April, p. 344), F. Hailer et al. use independent nuclear loci to show that polar bears originated during the middle Pleistocene, rather than during t...

  19. The origin of the constellations

    NASA Astrophysics Data System (ADS)

    Roy, Archie E.

    The problem of the origin of the stellar constellations familiar to western astronomers from ancient times is discussed in an attempt to answer the classical detective story questions: Who? When? Why? and Where? The available astronomical, literary and archaeological evidence is examined to suggest a possible solution.

  20. The Origin of Roman Numerals

    ERIC Educational Resources Information Center

    Dapre, P. A.

    1977-01-01

    A theory on the origin of Roman numerals proposes that the principal numbers can be stylized in terms of a square. It is speculated that the abacus or its equivalents, such as the counter or chequer-board, was used to count before the alphabet became common. (SW)

  1. Origin of Water on Mars

    NASA Technical Reports Server (NTRS)

    Lunine, J. I.; Morbidelli, A.; Chambers, J. E.

    2002-01-01

    Dynamical simulations suggest that the Earth's water budget was delivered primarily from the asteroid belt, in the form of large planetary embryos. The same simulations present a very different picture for Mars its water came from a mixture of cometary and small asteroidal bodies. Additional information is contained in the original extended abstract.

  2. Prostatic adenoma of ductal origin.

    PubMed

    Min, K W; Gyorkey, F

    1980-07-01

    A case of prostatic adenoma believed to originate from the prostatic duct is described. There were morphologic similarities to basal cell adenomas of salivary glands, and it was concluded that the tumor is a benign counterpart of "salivary gland" carcinomas, rarely observed in the prostate.

  3. Historical development of origins research.

    PubMed

    Lazcano, Antonio

    2010-11-01

    Following the publication of the Origin of Species in 1859, many naturalists adopted the idea that living organisms were the historical outcome of gradual transformation of lifeless matter. These views soon merged with the developments of biochemistry and cell biology and led to proposals in which the origin of protoplasm was equated with the origin of life. The heterotrophic origin of life proposed by Oparin and Haldane in the 1920s was part of this tradition, which Oparin enriched by transforming the discussion of the emergence of the first cells into a workable multidisciplinary research program. On the other hand, the scientific trend toward understanding biological phenomena at the molecular level led authors like Troland, Muller, and others to propose that single molecules or viruses represented primordial living systems. The contrast between these opposing views on the origin of life represents not only contrasting views of the nature of life itself, but also major ideological discussions that reached a surprising intensity in the years following Stanley Miller's seminal result which showed the ease with which organic compounds of biochemical significance could be synthesized under putative primitive conditions. In fact, during the years following the Miller experiment, attempts to understand the origin of life were strongly influenced by research on DNA replication and protein biosynthesis, and, in socio-political terms, by the atmosphere created by Cold War tensions. The catalytic versatility of RNA molecules clearly merits a critical reappraisal of Muller's viewpoint. However, the discovery of ribozymes does not imply that autocatalytic nucleic acid molecules ready to be used as primordial genes were floating in the primitive oceans, or that the RNA world emerged completely assembled from simple precursors present in the prebiotic soup. The evidence supporting the presence of a wide range of organic molecules on the primitive Earth, including membrane

  4. Historical Development of Origins Research

    PubMed Central

    Lazcano, Antonio

    2010-01-01

    Following the publication of the Origin of Species in 1859, many naturalists adopted the idea that living organisms were the historical outcome of gradual transformation of lifeless matter. These views soon merged with the developments of biochemistry and cell biology and led to proposals in which the origin of protoplasm was equated with the origin of life. The heterotrophic origin of life proposed by Oparin and Haldane in the 1920s was part of this tradition, which Oparin enriched by transforming the discussion of the emergence of the first cells into a workable multidisciplinary research program. On the other hand, the scientific trend toward understanding biological phenomena at the molecular level led authors like Troland, Muller, and others to propose that single molecules or viruses represented primordial living systems. The contrast between these opposing views on the origin of life represents not only contrasting views of the nature of life itself, but also major ideological discussions that reached a surprising intensity in the years following Stanley Miller’s seminal result which showed the ease with which organic compounds of biochemical significance could be synthesized under putative primitive conditions. In fact, during the years following the Miller experiment, attempts to understand the origin of life were strongly influenced by research on DNA replication and protein biosynthesis, and, in socio-political terms, by the atmosphere created by Cold War tensions. The catalytic versatility of RNA molecules clearly merits a critical reappraisal of Muller’s viewpoint. However, the discovery of ribozymes does not imply that autocatalytic nucleic acid molecules ready to be used as primordial genes were floating in the primitive oceans, or that the RNA world emerged completely assembled from simple precursors present in the prebiotic soup. The evidence supporting the presence of a wide range of organic molecules on the primitive Earth, including membrane

  5. Historical development of origins research.

    PubMed

    Lazcano, Antonio

    2010-11-01

    Following the publication of the Origin of Species in 1859, many naturalists adopted the idea that living organisms were the historical outcome of gradual transformation of lifeless matter. These views soon merged with the developments of biochemistry and cell biology and led to proposals in which the origin of protoplasm was equated with the origin of life. The heterotrophic origin of life proposed by Oparin and Haldane in the 1920s was part of this tradition, which Oparin enriched by transforming the discussion of the emergence of the first cells into a workable multidisciplinary research program. On the other hand, the scientific trend toward understanding biological phenomena at the molecular level led authors like Troland, Muller, and others to propose that single molecules or viruses represented primordial living systems. The contrast between these opposing views on the origin of life represents not only contrasting views of the nature of life itself, but also major ideological discussions that reached a surprising intensity in the years following Stanley Miller's seminal result which showed the ease with which organic compounds of biochemical significance could be synthesized under putative primitive conditions. In fact, during the years following the Miller experiment, attempts to understand the origin of life were strongly influenced by research on DNA replication and protein biosynthesis, and, in socio-political terms, by the atmosphere created by Cold War tensions. The catalytic versatility of RNA molecules clearly merits a critical reappraisal of Muller's viewpoint. However, the discovery of ribozymes does not imply that autocatalytic nucleic acid molecules ready to be used as primordial genes were floating in the primitive oceans, or that the RNA world emerged completely assembled from simple precursors present in the prebiotic soup. The evidence supporting the presence of a wide range of organic molecules on the primitive Earth, including membrane

  6. The Enigma of Angiosperm Origins

    NASA Astrophysics Data System (ADS)

    Hughes, Norman Francis

    1994-09-01

    The origins of angiosperms are still debated, despite many years of work by scientists from differing disciplines. The progress made toward resolving the problem is reviewed in this book. The author suggests that the only fruitful method of study is the total integrated use of the fossil record, particularly dispersed palynomorphs. This includes the use of electron microscopy and refined data handling to record the occurrence of microscopic fossils, rather than the extensive use of morphology and cladistics. The methods advocated in this book could result in a rethinking of the current classification of living plants, and it is hoped that the ideas presented will initiate discussion between both professionals and students of paleontology and plant science on the wider possibilities that may clarify the enigmatic origins of the dominant flowering plant groups.

  7. The Enigma of Angiosperm Origins

    NASA Astrophysics Data System (ADS)

    Hughes, Norman Francis

    2005-07-01

    The origins of angiosperms are still debated, despite many years of work by scientists from differing disciplines. The progress made toward resolving the problem is reviewed in this book. The author suggests that the only fruitful method of study is the total integrated use of the fossil record, particularly dispersed palynomorphs. This includes the use of electron microscopy and refined data handling to record the occurrence of microscopic fossils, rather than the extensive use of morphology and cladistics. The methods advocated in this book could result in a rethinking of the current classification of living plants, and it is hoped that the ideas presented will initiate discussion between both professionals and students of paleontology and plant science on the wider possibilities that may clarify the enigmatic origins of the dominant flowering plant groups.

  8. The origin of risk aversion.

    PubMed

    Zhang, Ruixun; Brennan, Thomas J; Lo, Andrew W

    2014-12-16

    Risk aversion is one of the most basic assumptions of economic behavior, but few studies have addressed the question of where risk preferences come from and why they differ from one individual to the next. Here, we propose an evolutionary explanation for the origin of risk aversion. In the context of a simple binary-choice model, we show that risk aversion emerges by natural selection if reproductive risk is systematic (i.e., correlated across individuals in a given generation). In contrast, risk neutrality emerges if reproductive risk is idiosyncratic (i.e., uncorrelated across each given generation). More generally, our framework implies that the degree of risk aversion is determined by the stochastic nature of reproductive rates, and we show that different statistical properties lead to different utility functions. The simplicity and generality of our model suggest that these implications are primitive and cut across species, physiology, and genetic origins. PMID:25453072

  9. The diapsid origin of turtles.

    PubMed

    Schoch, Rainer R; Sues, Hans-Dieter

    2016-06-01

    The origin of turtles has been a persistent unresolved problem involving unsettled questions in embryology, morphology, and paleontology. New fossil taxa from the early Late Triassic of China (Odontochelys) and the Late Middle Triassic of Germany (Pappochelys) now add to the understanding of (i) the evolutionary origin of the turtle shell, (ii) the ancestral structural pattern of the turtle skull, and (iii) the phylogenetic position of Testudines. As has long been postulated on the basis of molecular data, turtles evolved from diapsid reptiles and are more closely related to extant diapsids than to parareptiles, which had been suggested as stem group by some paleontologists. The turtle cranium with its secondarily closed temporal region represents a derived rather than a primitive condition and the plastron partially evolved through the fusion of gastralia.

  10. The origin of the moon.

    NASA Technical Reports Server (NTRS)

    Anderson, D. L.

    1972-01-01

    Recent studies of the dynamics and thermodynamics of the early solar nebula have provided a basis for a theory of the origin of the moon which is consistent with presently developed views of the origin of the solar system. The hypothesis of inhomogeneous planetary accretion is extended. It is suggested that the anomalous properties of the moon, such as its enrichment in Ca, Al, Ti, and other refractories and its depletion in iron and volatiles can be explained if the bulk of the moon represents a high temperature condensate. It is proposed that the moon is composed chiefly of compounds that condense before iron and that the volatile content of the moon was brought in as a thin veneer after the solar nebula dissipated.

  11. The origins of human ageing.

    PubMed Central

    Kirkwood, T B

    1997-01-01

    The origins of human ageing are to be found in the origins and evolution of senescence as a general feature in the life histories of higher animals. Ageing is an intriguing problem in evolutionary biology because a trait that limits the duration of life, including the fertile period, has a negative impact on Darwinian fitness. Current theory suggests that senescence occurs because the force of natural selection declines with age and because longevity is only acquired at some metabolic cost. In effect, organisms may trade late survival for enhanced reproductive investments in earlier life. The comparative study of ageing supports the general evolutionary theory and reveals that human senescence, while broadly similar to senescence in other mammalian species, has distinct features, such as menopause, that may derive from the interplay of biological and social evolution. PMID:9460059

  12. The Origin of the Elements

    ScienceCinema

    Murphy, Edward

    2016-07-12

    The world around us is made of atoms. Did you ever wonder where these atoms came from? How was the gold in our jewelry, the carbon in our bodies, and the iron in our cars made? In this lecture, we will trace the origin of a gold atom from the Big Bang to the present day, and beyond. You will learn how the elements were forged in the nuclear furnaces inside stars, and how, when they die, these massive stars spread the elements into space. You will learn about the origin of the building blocks of matter in the Big Bang, and we will speculate on the future of the atoms around us today.

  13. Determination of plutonium metal origins

    SciTech Connect

    Moody, K.J.

    1995-02-01

    Forensic signatures are present in any Pu sample that can determine the sample`s origin: isotopic ratio of Pu, progeny species that grow into the sample, and contaminant species left over from incomplete purification of the Pu in fuel reprocessing. In the context of intelligence information, this can result in attribution of responsibility for the product of clandestine proliferant operations or material smuggled from existing stockpiles. A list of signature elements and what can be determined from them have been developed. Work needs to be done in converting concentrations of signature species into a quantitative forensic analysis, particularly in regard to reactor performance, but this should require only a small effort. A radiochemical analysis scheme has been developed for measuring these nuclides; more work is needed, particularly for determining fission product concentrations. A sample of Pu metal has been analyzed and several parameters determined that are strong indicators of its point of origin.

  14. Origin of lunar light plains

    NASA Technical Reports Server (NTRS)

    Chao, E. C. T.; Hodges, C. A.; Boyce, J. M.; Soderblom, L. A.

    1975-01-01

    In order to determine the origin of Cayley-type lunar light plains, their physical properties, distribution, and relative ages are examined from Apollo orbital and Lunar Orbiter photographs. The distribution and apparent age of the plains deposits and data on highly feldspathic breccias indicate that these superficial materials are neither locally derived nor part of the Imbrium ejecta. The existence of a planar facies of continuous ejecta at Orientale and in the ejecta blankets of small craters is demonstrated. The data and interpretation presented support the hypothesis that the surface and near-surface materials of some light plains, including those at the Apollo 16 site, are at least partly composed of ejecta from the Orientale basin and that the materials of many rugged areas, such as the Descartes highlands, are overlain by similar material. The possibility that some Cayley-type plains may have a different origin is not excluded.

  15. The origin of lunar mascons

    NASA Astrophysics Data System (ADS)

    Czechowski, Leszek

    2012-07-01

    Mascons are the specific formations on the Moon that possess prominent topographic lows and positive gravitational anomalies (up to approx. 300 mgal). They are found on large lunar craters (impact basins) filled with basaltic magmas like the maria: Imbrium, Serenitatis, Crisium and Orientale. The mascons are evident examples of the lack of isostasy. There are several hypotheses of the mascons origin. Unfortunately all of them have some disadvantages. In the present research we consider the time of formation, thermal state of lunar mantle, and the role of decompressing. We have found that decompressing of the partially molten lunar mantle resulting from the impact could lead to filling the basin of the high density basaltic magma. The level of filling could be super-isostatic, so it could explain the origin of regions of high gravity field.

  16. The origin of risk aversion

    PubMed Central

    Zhang, Ruixun; Brennan, Thomas J.; Lo, Andrew W.

    2014-01-01

    Risk aversion is one of the most basic assumptions of economic behavior, but few studies have addressed the question of where risk preferences come from and why they differ from one individual to the next. Here, we propose an evolutionary explanation for the origin of risk aversion. In the context of a simple binary-choice model, we show that risk aversion emerges by natural selection if reproductive risk is systematic (i.e., correlated across individuals in a given generation). In contrast, risk neutrality emerges if reproductive risk is idiosyncratic (i.e., uncorrelated across each given generation). More generally, our framework implies that the degree of risk aversion is determined by the stochastic nature of reproductive rates, and we show that different statistical properties lead to different utility functions. The simplicity and generality of our model suggest that these implications are primitive and cut across species, physiology, and genetic origins. PMID:25453072

  17. The Origin of the Elements

    SciTech Connect

    Murphy, Edward

    2012-11-20

    The world around us is made of atoms. Did you ever wonder where these atoms came from? How was the gold in our jewelry, the carbon in our bodies, and the iron in our cars made? In this lecture, we will trace the origin of a gold atom from the Big Bang to the present day, and beyond. You will learn how the elements were forged in the nuclear furnaces inside stars, and how, when they die, these massive stars spread the elements into space. You will learn about the origin of the building blocks of matter in the Big Bang, and we will speculate on the future of the atoms around us today.

  18. Cosmic Ray Origins: An Introduction

    NASA Astrophysics Data System (ADS)

    Blandford, Roger; Simeon, Paul; Yuan, Yajie

    2014-11-01

    Physicists have pondered the origin of cosmic rays for over a hundred years. However the last few years have seen an upsurge in the observation, progress in the theory and a genuine increase in the importance attached to the topic due to its intimate connection to the indirect detection of evidence for dark matter. The intent of this talk is to set the stage for the meeting by reviewing some of the basic features of the entire cosmic ray spectrum from GeV to ZeV energy and some of the models that have been developed. The connection will also be made to recent developments in understanding general astrophysical particle acceleration in pulsar wind nebulae, relativistic jets and gamma ray bursts. The prospects for future discoveries, which may elucidate the origin of cosmic rays, are bright.

  19. Origin of neurotoxins from defensins.

    PubMed

    Zhu, Li-Mei; Gao, Bin; Zhu, Shun-Yi

    2015-06-25

    There are at least three conserved protein folds shared by ion channel-targeted neurotoxins and antimicrobial defensins, including cysteine-stabilized α-helix and β-sheet fold (CSαβ), inhibitor cystine knot fold (ICK) and β-defensin fold (BDF). Based on a combined data of sequences, structures and functions, it has been proposed that these neurotoxins could originate from related ancient antimicrobial defensins by neofunctionalization. This provides an ideal system to study how a novel function emerged from a conserved structural scaffold during evolution. The elucidation of functional novelty of proteins not only has great significance in evolutionary biology but also will be helpful in guiding rational molecular design. This review describes recent progresses in origin of neurotoxins, focusing on the three conserved protein scaffolds.

  20. Microbial origin of desert varnish.

    PubMed

    Dorn, R I; Oberlander, T M

    1981-09-11

    Scanning electron microscopy and energy dispersive x-ray analyses of desert varnish reveal that microorganisms concentrate ambient manganese that becomes greatly enhanced in brown to black varnish. Specific characteristics of desert varnish and of varnish bacteria support a microbial origin for manganese-rich films. Varnish microbes can be cultured and produce laboratory manganese films. Accordingly, natural desert varnish and also manganese-rich rock varnishes in nondesert environments appear to be a product of microbial activity. PMID:17744757

  1. Microbial origin of desert varnish.

    PubMed

    Dorn, R I; Oberlander, T M

    1981-09-11

    Scanning electron microscopy and energy dispersive x-ray analyses of desert varnish reveal that microorganisms concentrate ambient manganese that becomes greatly enhanced in brown to black varnish. Specific characteristics of desert varnish and of varnish bacteria support a microbial origin for manganese-rich films. Varnish microbes can be cultured and produce laboratory manganese films. Accordingly, natural desert varnish and also manganese-rich rock varnishes in nondesert environments appear to be a product of microbial activity.

  2. Swine origin influenza (swine flu).

    PubMed

    Sebastian, Meghna R; Lodha, Rakesh; Kabra, S K

    2009-08-01

    Swine origin influenza was first recognized in the border area of Mexico and United States in April 2009 and during a short span of two months became the first pandemic. The currently circulating strain of swine origin influenza virus of the H1N1 strain has undergone triple reassortment and contains genes from the avian, swine and human viruses. It is transmitted by droplets or fomites. Incubation period is 2 to 7 days. Common clinical symptoms are indistinguishable by any viral respiratory illness, and include fever, cough, sore throat and myalgia. A feature seen more frequently with swine origin influenza is GI upset. Less than 10% of patients require hospitalization. Patients at risk of developing severe disease are - younger than five years, elderly, pregnant women, with chronic systemic illnesses, adolescents on aspirin. Of the severe manifestations of swine origin influenza, pneumonia and respiratory failure are the most common. Unusual symptoms reported are conjunctivitis, parotitis, hemophagocytic syndrome. Infants may present with fever and lethargy with no respiratory symptoms. Diagnosis is based on RT PCR, Viral culture or increasing neutralizing antibodies. Principle of treatment consist of isolation, universal precautions, good infection control practices, supportive care and use of antiviral drugs. Antiviral drugs effective against H1N1 virus include: oseltamivir and zamanavir. With good supportive care case fatality is less than 1%. Preventive measures include: social distancing, practicing respiratory etiquette, hand hygiene and use of chemoprohylaxis with antiviral drugs. Vaccine against H1N1 is not available at present, but will be available in near future.

  3. Changing ideas about eukaryotic origins.

    PubMed

    Williams, Tom A; Embley, T Martin

    2015-09-26

    The origin of eukaryotic cells is one of the most fascinating challenges in biology, and has inspired decades of controversy and debate. Recent work has led to major upheavals in our understanding of eukaryotic origins and has catalysed new debates about the roles of endosymbiosis and gene flow across the tree of life. Improved methods of phylogenetic analysis support scenarios in which the host cell for the mitochondrial endosymbiont was a member of the Archaea, and new technologies for sampling the genomes of environmental prokaryotes have allowed investigators to home in on closer relatives of founding symbiotic partners. The inference and interpretation of phylogenetic trees from genomic data remains at the centre of many of these debates, and there is increasing recognition that trees built using inadequate methods can prove misleading, whether describing the relationship of eukaryotes to other cells or the root of the universal tree. New statistical approaches show promise for addressing these questions but they come with their own computational challenges. The papers in this theme issue discuss recent progress on the origin of eukaryotic cells and genomes, highlight some of the ongoing debates, and suggest possible routes to future progress.

  4. The origins of medical physics.

    PubMed

    Duck, Francis A

    2014-06-01

    The historical origins of medical physics are traced from the first use of weighing as a means of monitoring health by Sanctorius in the early seventeenth century to the emergence of radiology, phototherapy and electrotherapy at the end of the nineteenth century. The origins of biomechanics, due to Borelli, and of medical electricity following Musschenbroek's report of the Leyden Jar, are included. Medical physics emerged as a separate academic discipline in France at the time of the Revolution, with Jean Hallé as its first professor. Physiological physics flowered in Germany during the mid-nineteenth century, led by the work of Adolf Fick. The introduction of the term medical physics into English by Neil Arnott failed to accelerate its acceptance in Britain or the USA. Contributions from Newton, Euler, Bernoulli, Nollet, Matteucci, Pelletan, Gavarret, d'Arsonval, Finsen, Röntgen and others are noted. There are many origins of medical physics, stemming from the many intersections between physics and medicine. Overall, the early nineteenth-century definition of medical physics still holds today: 'Physics applied to the knowledge of the human body, to its preservation and to the cure of its illnesses'.

  5. Changing ideas about eukaryotic origins

    PubMed Central

    Williams, Tom A.; Embley, T. Martin

    2015-01-01

    The origin of eukaryotic cells is one of the most fascinating challenges in biology, and has inspired decades of controversy and debate. Recent work has led to major upheavals in our understanding of eukaryotic origins and has catalysed new debates about the roles of endosymbiosis and gene flow across the tree of life. Improved methods of phylogenetic analysis support scenarios in which the host cell for the mitochondrial endosymbiont was a member of the Archaea, and new technologies for sampling the genomes of environmental prokaryotes have allowed investigators to home in on closer relatives of founding symbiotic partners. The inference and interpretation of phylogenetic trees from genomic data remains at the centre of many of these debates, and there is increasing recognition that trees built using inadequate methods can prove misleading, whether describing the relationship of eukaryotes to other cells or the root of the universal tree. New statistical approaches show promise for addressing these questions but they come with their own computational challenges. The papers in this theme issue discuss recent progress on the origin of eukaryotic cells and genomes, highlight some of the ongoing debates, and suggest possible routes to future progress. PMID:26323752

  6. Fetal origins of adult disease.

    PubMed

    Calkins, Kara; Devaskar, Sherin U

    2011-07-01

    Dr. David Barker first popularized the concept of fetal origins of adult disease (FOAD). Since its inception, FOAD has received considerable attention. The FOAD hypothesis holds that events during early development have a profound impact on one's risk for development of future adult disease. Low birth weight, a surrogate marker of poor fetal growth and nutrition, is linked to coronary artery disease, hypertension, obesity, and insulin resistance. Clues originally arose from large 20th century, European birth registries. Today, large, diverse human cohorts and various animal models have extensively replicated these original observations. This review focuses on the pathogenesis related to FOAD and examines Dr. David Barker's landmark studies, along with additional human and animal model data. Implications of the FOAD extend beyond the low birth weight population and include babies exposed to stress, both nutritional and nonnutritional, during different critical periods of development, which ultimately result in a disease state. By understanding FOAD, health care professionals and policy makers will make this issue a high health care priority and implement preventive measures and treatment for those at higher risk for chronic diseases.

  7. 31 CFR 538.312 - Sudanese origin.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Sudanese origin. 538.312 Section 538... § 538.312 Sudanese origin. The term goods or services of Sudanese origin includes: (a) Goods produced... Sudanese origin are not imported into the United States when such services are provided in the...

  8. 31 CFR 538.312 - Sudanese origin.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Sudanese origin. 538.312 Section 538... § 538.312 Sudanese origin. The term goods or services of Sudanese origin includes: (a) Goods produced... Sudanese origin are not imported into the United States when such services are provided in the...

  9. 7 CFR 201.14 - Origin.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Origin. 201.14 Section 201.14 Agriculture Regulations... Labeling Agricultural Seeds § 201.14 Origin. (a) Alfalfa, red clover, white clover, and field corn (except hybrid seed corn) shall be labeled to show: (1) The origin, if known; or (2) if the origin is not...

  10. 31 CFR 538.312 - Sudanese origin.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Sudanese origin. 538.312 Section 538... § 538.312 Sudanese origin. The term goods or services of Sudanese origin includes: (a) Goods produced... Sudanese origin are not imported into the United States when such services are provided in the...

  11. 7 CFR 201.14 - Origin.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Origin. 201.14 Section 201.14 Agriculture Regulations... Labeling Agricultural Seeds § 201.14 Origin. (a) Alfalfa, red clover, white clover, and field corn (except hybrid seed corn) shall be labeled to show: (1) The origin, if known; or (2) if the origin is not...

  12. Musical emotions: Functions, origins, evolution

    NASA Astrophysics Data System (ADS)

    Perlovsky, Leonid

    2010-03-01

    Theories of music origins and the role of musical emotions in the mind are reviewed. Most existing theories contradict each other, and cannot explain mechanisms or roles of musical emotions in workings of the mind, nor evolutionary reasons for music origins. Music seems to be an enigma. Nevertheless, a synthesis of cognitive science and mathematical models of the mind has been proposed describing a fundamental role of music in the functioning and evolution of the mind, consciousness, and cultures. The review considers ancient theories of music as well as contemporary theories advanced by leading authors in this field. It addresses one hypothesis that promises to unify the field and proposes a theory of musical origin based on a fundamental role of music in cognition and evolution of consciousness and culture. We consider a split in the vocalizations of proto-humans into two types: one less emotional and more concretely-semantic, evolving into language, and the other preserving emotional connections along with semantic ambiguity, evolving into music. The proposed hypothesis departs from other theories in considering specific mechanisms of the mind-brain, which required the evolution of music parallel with the evolution of cultures and languages. Arguments are reviewed that the evolution of language toward becoming the semantically powerful tool of today required emancipation from emotional encumbrances. The opposite, no less powerful mechanisms required a compensatory evolution of music toward more differentiated and refined emotionality. The need for refined music in the process of cultural evolution is grounded in fundamental mechanisms of the mind. This is why today's human mind and cultures cannot exist without today's music. The reviewed hypothesis gives a basis for future analysis of why different evolutionary paths of languages were paralleled by different evolutionary paths of music. Approaches toward experimental verification of this hypothesis in

  13. On the Origin of Monsoon

    NASA Technical Reports Server (NTRS)

    Chao, Winston C.; Chen, Baode; Einaudi, Franco (Technical Monitor)

    2000-01-01

    It is a long-held fundamental belief that the basic cause of a monsoon is land-sea thermal contrast on the continental scale. Through general circulation model experiments we demonstrate that this belief should be changed. The Asian and Australian summer monsoon circulations are largely intact in an experiment in which Asia, maritime continent, and Australia are replaced by ocean. It is also shown that the change resulting from such replacement is in general due more to the removal of topography than to the removal of land-sea contrast. Therefore, land-sea contrast plays only a minor modifying role in Asian and Australian summer monsoons. This also happens to the Central American summer monsoon. However, the same thing cannot be said of the African and South American summer monsoons. In Asian and Australian winter monsoons land-sea contrast also plays only a minor role. Our interpretation for the origin of monsoon is that the summer monsoon is the result of ITCZ's (intertropical convergence zones) peak being substantially (more than 10 degrees) away from the equator. The origin of the ITCZ has been previously interpreted by Chao. The circulation around thus located ITCZ, previously interpreted by Chao and Chen through the modified Gill solution and briefly described in this paper, explains the monsoon circulation. The longitudinal location of the ITCZs is determined by the distribution of surface conditions. ITCZ's favor locations of higher SST as in western Pacific and Indian Ocean, or tropical landmass, due to land-sea contrast, as in tropical Africa and South America. Thus, the role of landmass in the origin of monsoon can be replaced by ocean of sufficiently high SST. Furthermore, the ITCZ circulation extends into the tropics in the other hemisphere to give rise to the winter monsoon circulation there. Also through the equivalence of land-sea contrast and higher SST, it is argued that the basic monsoon onset mechanism proposed by Chao is valid for all monsoons.

  14. New perspectives on anthropoid origins

    PubMed Central

    Williams, Blythe A.; Kay, Richard F.; Kirk, E. Christopher

    2010-01-01

    Adaptive shifts associated with human origins are brought to light as we examine the human fossil record and study our own genome and that of our closest ape relatives. However, the more ancient roots of many human characteristics are revealed through the study of a broader array of living anthropoids and the increasingly dense fossil record of the earliest anthropoid radiations. Genomic data and fossils of early primates in Asia and Africa clarify relationships among the major clades of primates. Progress in comparative anatomy, genomics, and molecular biology point to key changes in sensory ecology and brain organization that ultimately set the stage for the emergence of the human lineage. PMID:20212104

  15. The origin of membrane bioenergetics.

    PubMed

    Lane, Nick; Martin, William F

    2012-12-21

    Harnessing energy as ion gradients across membranes is as universal as the genetic code. We leverage new insights into anaerobe metabolism to propose geochemical origins that account for the ubiquity of chemiosmotic coupling, and Na(+)/H(+) transporters in particular. Natural proton gradients acting across thin FeS walls within alkaline hydrothermal vents could drive carbon assimilation, leading to the emergence of protocells within vent pores. Protocell membranes that were initially leaky would eventually become less permeable, forcing cells dependent on natural H(+) gradients to pump Na(+) ions. Our hypothesis accounts for the Na(+)/H(+) promiscuity of bioenergetic proteins, as well as the deep divergence between bacteria and archaea. PMID:23260134

  16. Planetary Origin Evolution and Structure

    NASA Technical Reports Server (NTRS)

    Stevenson, David J.

    2005-01-01

    This wide-ranging grant supported theoretical modeling on many aspects of the formation, evolution and structure of planets and satellites. Many topics were studied during this grant period, including the evolution of icy bodies; the origin of magnetic fields in Ganymede; the thermal histories of terrestrial planets; the nature of flow inside giant planets (especially the coupling to the magnetic field) and the dynamics of silicate/iron mixing during giant impacts and terrestrial planet core formation. Many of these activities are ongoing and have not reached completion. This is the nature of this kind of research.

  17. On the origin of leprosy.

    PubMed

    Monot, Marc; Honoré, Nadine; Garnier, Thierry; Araoz, Romulo; Coppée, Jean-Yves; Lacroix, Céline; Sow, Samba; Spencer, John S; Truman, Richard W; Williams, Diana L; Gelber, Robert; Virmond, Marcos; Flageul, Béatrice; Cho, Sang-Nae; Ji, Baohong; Paniz-Mondolfi, Alberto; Convit, Jacinto; Young, Saroj; Fine, Paul E; Rasolofo, Voahangy; Brennan, Patrick J; Cole, Stewart T

    2005-05-13

    Leprosy, a chronic human disease with potentially debilitating neurological consequences, results from infection with Mycobacterium leprae. This unculturable pathogen has undergone extensive reductive evolution, with half of its genome now occupied by pseudogenes. Using comparative genomics, we demonstrated that all extant cases of leprosy are attributable to a single clone whose dissemination worldwide can be retraced from analysis of very rare single-nucleotide polymorphisms. The disease seems to have originated in Eastern Africa or the Near East and spread with successive human migrations. Europeans or North Africans introduced leprosy into West Africa and the Americas within the past 500 years.

  18. Electronic Computer Originated Mail Service

    NASA Astrophysics Data System (ADS)

    Seto, Takao

    Electronic mail originated by computer is exactly a new communication media which is a product of combining traditional mailing with electrical communication. Experimental service of this type of mailing started in June 10, 1985 at Ministry of Posts and Telecommunications. Its location in various communication media, its comparison with facsimile type electronic mailing, and status quo of electronic mailing in foreign countries are described. Then, this mailing is briefed centering around the system organization and the services. Additional services to be executed in near future are also mentioned.

  19. Origins of the "Western" Constellations

    NASA Astrophysics Data System (ADS)

    Frank, Roslyn M.

    The development of the 48 Greek constellations is analyzed as a complex mixture of cognitive layers deriving from different cultural traditions and dating back to different epochs. The analysis begins with a discussion of the zodiacal constellations, goes on to discuss the stellar lore in Homer and Hesiod, and then examines several theories concerning the origins of the southern non-zodiacal constellations. It concludes with a commentary concerning the age and possible cultural significance of stars of the Great Bear constellation in light of ethnohistorical documentation, folklore, and beliefs related to European bear ceremonialism.

  20. Origins of hydrogenosomes and mitochondria.

    PubMed

    Rotte, C; Henze, K; Müller, M; Martin, W

    2000-10-01

    Complete genome sequences for many oxygen-respiring mitochondria, as well as for some bacteria, leave no doubt that mitochondria are descendants of alpha-proteobacteria, a finding for which the endosymbiont hypothesis can easily account. Yet a wealth of data indicate that mitochondria and hydrogenosomes - the ATP-producing organelles of many anaerobic protists - share a common ancestry, a finding that traditional formulations of the endosymbiont hypothesis less readily accommodates. Available evidence suggests that a more in-depth understanding of the origins of eukaryotes and their organelles will hinge upon data from the genomes of protists that synthesize ATP without the need for oxygen.

  1. Origin and History of Magnolias

    NASA Astrophysics Data System (ADS)

    Hebda, R. J.; Irving, E.

    2004-12-01

    The classic disjunct distribution of living magnolias between southeast Asia and the Americas has been a puzzle for more than a century and a half. We propose a scheme for the origin and history of magnolias to explain this distribution by integrating paleogeographic, paleoclimatic, paleobotanical, and phytogeographic data. Our scheme is based on paleomagnetically determined latitudes. We assume that the moist warm temperate climate favoured by most extant magnolias has always been their preference. Molecular analyses (largely chloroplast DNA) reveal that several North American species are distinct and basal forms suggesting that magnolias likely originated in North America, a conclusion supported by the fossil record. We identify four evolutionary stages: (1) Ancestral magnolias originate in the Late Cretaceous of North America in high mid-latitudes (45° -60° N) at low altitudes under greenhouse climates. (2) During the exceptionally warm climate (super-greenhouse) of the Eocene, magnolias spread eastwards via the Iceland-Faroes isthmuses, to Europe and then across west and central Asia possibly to east Asia, still at low altitudes and high mid-latitudes. (3) With global cooling from the mid-Cenozoic, magnolias shift their core range to lower mid-latitudes (30° -45° N), become extinct in Europe and southern Siberia, breaking the once continuous distribution into two. (4) In the late Cenozoic, as ice-house conditions develop, magnolias diversify rapidly and expand southward into moist warm temperate uplands in newly uplifted mountain ranges of South and Central America, southeast Asia and the High Archipelago between southeast Asia and Australia. The late Cenozoic evolution of magnolias is characterized by the impoverishment of northerly species and diversification of southerly species. Thus, the centre of origin is not the center of diversity today. Disjunction at the generic level likely occurred as part of the mid-Tertiary southward displacement of the

  2. Origin of Homochirality in Biosystems

    PubMed Central

    Toxvaerd, Søren

    2009-01-01

    Experimental data for a series of central and simple molecules in biosystems show that some amino acids and a simple sugar molecule have a chiral discrimination in favor of homochirality. Models for segregation of racemic mixtures of chiral amphiphiles and lipophiles in aqueous solutions show that the amphiphiles with an active isomerization kinetics can perform a spontaneous break of symmetry during the segregation and self-assembly to homochiral matter. Based on this observation it is argued that biomolecules with a sufficiently strong chiral discrimination could be the origin of homochirality in biological systems. PMID:19399249

  3. [Origination and evolution of plastids].

    PubMed

    Mukhina, V S

    2014-01-01

    Plastids are photosynthetic DNA-containing organelles of plants and algae. In the review, the history of their origination and evolution within different taxa is considered. All of the plastids appear to be descendants of cyanobacteria that colonized eukaryotic cells. The first plastids arose through symbiosis of cyanobacteria with algal ancestors from Archaeplastida kingdom. Later, there occurred repeated secondary symbioses of other eukariotes with photosynthetic protists: in this way plastids emerged in organisms of other taxa. Co-evolution of cyanobacteria and ancestral algae led to extensive transformation of both: reduction of endosymbiont, mass transfer of cyanobacteria genes into karyogenome, formation of complex system of proteins transportation to plastids and their functioning regulation.

  4. Activation of a dormant replication origin is essential for Haloferax mediterranei lacking the primary origins

    PubMed Central

    Yang, Haibo; Wu, Zhenfang; Liu, Jingfang; Liu, Xiaoqing; Wang, Lei; Cai, Shuangfeng; Xiang, Hua

    2015-01-01

    The use of multiple origins for chromosome replication has been demonstrated in archaea. Similar to the dormant origins in eukaryotes, some potential origins in archaea appear to be inactive during genome replication. We have comprehensively explored the origin utilization in Haloferax mediterranei. Here we report three active chromosomal origins by genome-wide replication profiling, and demonstrate that when these three origins are deleted, a dormant origin becomes activated. Notably, this dormant origin cannot be further deleted when the other origins are already absent and vice versa. Interestingly, a potential origin that appears to stay dormant in its native host H. volcanii lacking the main active origins becomes activated and competent for replication of the entire chromosome when integrated into the chromosome of origin-deleted H. mediterranei. These results indicate that origin-dependent replication is strictly required for H. mediterranei and that dormant replication origins in archaea can be activated if needed. PMID:26374389

  5. The origins of modern divorce.

    PubMed

    Coontz, Stephanie

    2007-03-01

    High rates of marital dissolution and easy access to divorce are not unprecedented, historically or cross-culturally. But contemporary divorce in North America and Western Europe has different origins and features than divorce in previous cultures. The origins of modern divorce patterns date back more than 200 years, to the invention of the historically unprecedented idea that marriage should be based on love and mutual affection. Ironically, then, the fragility of modern marriage stems from the same values that have elevated the marital relationship above all other personal and familial commitments: the concentration of emotion, passion, personal identity, and self-validation in the couple relationship and the attenuation of emotional attachments and obligations beyond the conjugal unit. The immediate causes of divorce may range from factors as diverse as the personal psychological characteristics of one or both spouses to the stresses of economic hardship and community disintegration. But in a larger perspective, the role of divorce in modern societies and its relatively high occurrence both flow from the same complex of factors that have made good marriages so much more central to people's happiness than through most of the past, and deterioration of a marital relationship so much more traumatic.

  6. Origin of marine planktonic cyanobacteria.

    PubMed

    Sánchez-Baracaldo, Patricia

    2015-12-01

    Marine planktonic cyanobacteria contributed to the widespread oxygenation of the oceans towards the end of the Pre-Cambrian and their evolutionary origin represents a key transition in the geochemical evolution of the Earth surface. Little is known, however, about the evolutionary events that led to the appearance of marine planktonic cyanobacteria. I present here phylogenomic (135 proteins and two ribosomal RNAs), Bayesian relaxed molecular clock (18 proteins, SSU and LSU) and Bayesian stochastic character mapping analyses from 131 cyanobacteria genomes with the aim to unravel key evolutionary steps involved in the origin of marine planktonic cyanobacteria. While filamentous cell types evolved early on at around 2,600-2,300 Mya and likely dominated microbial mats in benthic environments for most of the Proterozoic (2,500-542 Mya), marine planktonic cyanobacteria evolved towards the end of the Proterozoic and early Phanerozoic. Crown groups of modern terrestrial and/or benthic coastal cyanobacteria appeared during the late Paleoproterozoic to early Mesoproterozoic. Decrease in cell diameter and loss of filamentous forms contributed to the evolution of unicellular planktonic lineages during the middle of the Mesoproterozoic (1,600-1,000 Mya) in freshwater environments. This study shows that marine planktonic cyanobacteria evolved from benthic marine and some diverged from freshwater ancestors during the Neoproterozoic (1,000-542 Mya).

  7. Ancient Voyaging and Polynesian Origins

    PubMed Central

    Soares, Pedro; Rito, Teresa; Trejaut, Jean; Mormina, Maru; Hill, Catherine; Tinkler-Hundal, Emma; Braid, Michelle; Clarke, Douglas J.; Loo, Jun-Hun; Thomson, Noel; Denham, Tim; Donohue, Mark; Macaulay, Vincent; Lin, Marie; Oppenheimer, Stephen; Richards, Martin B.

    2011-01-01

    The “Polynesian motif” defines a lineage of human mtDNA that is restricted to Austronesian-speaking populations and is almost fixed in Polynesians. It is widely thought to support a rapid dispersal of maternal lineages from Taiwan ∼4000 years ago (4 ka), but the chronological resolution of existing control-region data is poor, and an East Indonesian origin has also been proposed. By analyzing 157 complete mtDNA genomes, we show that the motif itself most likely originated >6 ka in the vicinity of the Bismarck Archipelago, and its immediate ancestor is >8 ka old and virtually restricted to Near Oceania. This indicates that Polynesian maternal lineages from Island Southeast Asia gained a foothold in Near Oceania much earlier than dispersal from either Taiwan or Indonesia 3–4 ka would predict. However, we find evidence in minor lineages for more recent two-way maternal gene flow between Island Southeast Asia and Near Oceania, likely reflecting movements along a “voyaging corridor” between them, as previously proposed on archaeological grounds. Small-scale mid-Holocene movements from Island Southeast Asia likely transmitted Austronesian languages to the long-established Southeast Asian colonies in the Bismarcks carrying the Polynesian motif, perhaps also providing the impetus for the expansion into Polynesia. PMID:21295281

  8. On the origin of life.

    PubMed

    Szostak, Jack W

    2016-01-01

    The origin of life is a very rich field, filled with possibilities and ripe for discovery. RNA replication requires chemical energy and vesicle division is easy to do with mechanical energy. These requirements point to a surface lake, perhaps at some time following the period of concentrated cyanide chemistry that gave rise to nucleotides, amino acids and (maybe) fatty acids. A second requirement follows specifically from the nature of the RNA replication cycle, which requires generally cool to moderate temperatures for the copying chemistry, punctuated by brief periods of high temperature for strand separation. Remarkably, lakes in a geothermal active area provide just such a fluctuating temperature environment, because lakes similar to Yellowstone can be generally cool (even ice covered in winter), but they contain numerous hydrothermal vents that emit streams of hot water. Protocells in such an environment would occasionally be swept into these hot water streams, where the transient high temperature exposure would cause RNA strand separation. However, the protocells would be quickly mixed with surrounding cold water, and would therefore cool quickly, before their delicate RNA molecules could be destroyed by heat. Because of the combination of favorable chemical and physical environments, this could be the most likely scenario for the early Earth environment that nurtured the origin of life.

  9. On the origin of life.

    PubMed

    Szostak, Jack W

    2016-01-01

    The origin of life is a very rich field, filled with possibilities and ripe for discovery. RNA replication requires chemical energy and vesicle division is easy to do with mechanical energy. These requirements point to a surface lake, perhaps at some time following the period of concentrated cyanide chemistry that gave rise to nucleotides, amino acids and (maybe) fatty acids. A second requirement follows specifically from the nature of the RNA replication cycle, which requires generally cool to moderate temperatures for the copying chemistry, punctuated by brief periods of high temperature for strand separation. Remarkably, lakes in a geothermal active area provide just such a fluctuating temperature environment, because lakes similar to Yellowstone can be generally cool (even ice covered in winter), but they contain numerous hydrothermal vents that emit streams of hot water. Protocells in such an environment would occasionally be swept into these hot water streams, where the transient high temperature exposure would cause RNA strand separation. However, the protocells would be quickly mixed with surrounding cold water, and would therefore cool quickly, before their delicate RNA molecules could be destroyed by heat. Because of the combination of favorable chemical and physical environments, this could be the most likely scenario for the early Earth environment that nurtured the origin of life. PMID:27576276

  10. The Origin of Cosmic Rays

    ScienceCinema

    Blasi, Pasquale [INAF/Arcetri-Italy and Fermilab, Italy

    2016-07-12

    Cosmic Rays reach the Earth from space with energies of up to more than 1020 eV, carrying information on the most powerful particle accelerators that Nature has been able to assemble. Understanding where and how cosmic rays originate has required almost one century of investigations, and, although the last word is not written yet, recent observations and theory seem now to fit together to provide us with a global picture of the origin of cosmic rays of unprecedented clarity. Here we will describe what we learned from recent observations of astrophysical sources (such as supernova remnants and active galaxies) and we will illustrate what these observations tell us about the physics of particle acceleration and transport. We will also discuss the “end” of the Galactic cosmic ray spectrum, which bridges out attention towards the so called ultra high energy cosmic rays (UHECRs). At ~1020 eV the gyration scale of cosmic rays in cosmic magnetic fields becomes large enough to allow us to point back to their sources, thereby allowing us to perform “cosmic ray astronomy”, as confirmed by the recent results obtained with the Pierre Auger Observatory. We will discuss the implications of these observations for the understanding of UHECRs, as well as some questions which will likely remain unanswered and will be the target of the next generation of cosmic ray experiments.

  11. The origin of the Moon

    NASA Technical Reports Server (NTRS)

    Wasson, J. T.; Warren, P. H.

    1984-01-01

    Bulk density alone shows that the Moon is depleted in metallic FeNi relative to the Earth or to chondritic meteorites. This depletion implies that the Moon formed not from chondrites but from differentiated material. Origin of the Moon by fission from the Earth offers a simple explanation for its depletion in FeNi, but this mechanism seems unlikely because of associated dynamical difficulties. Lunar volatile element depletions were invoked in support of fission, but volatile contents of eucritic meteorites are similarly low and the eucrites did not form by Earth fission. A more plausible origin of the Moon is accretion from the circumterrestrial swarm. The low FeNi content of the Moon is understood if the mean size of interplanetary silicate particles was much smaller than that for metal particles, since this would have led to preferential capture of silicates into Earth orbit, but the question arises whether the mean particle size of the metallic particles was great enough to prevent their capture into the swarm.

  12. Origin of marine planktonic cyanobacteria

    PubMed Central

    Sánchez-Baracaldo, Patricia

    2015-01-01

    Marine planktonic cyanobacteria contributed to the widespread oxygenation of the oceans towards the end of the Pre-Cambrian and their evolutionary origin represents a key transition in the geochemical evolution of the Earth surface. Little is known, however, about the evolutionary events that led to the appearance of marine planktonic cyanobacteria. I present here phylogenomic (135 proteins and two ribosomal RNAs), Bayesian relaxed molecular clock (18 proteins, SSU and LSU) and Bayesian stochastic character mapping analyses from 131 cyanobacteria genomes with the aim to unravel key evolutionary steps involved in the origin of marine planktonic cyanobacteria. While filamentous cell types evolved early on at around 2,600–2,300 Mya and likely dominated microbial mats in benthic environments for most of the Proterozoic (2,500–542 Mya), marine planktonic cyanobacteria evolved towards the end of the Proterozoic and early Phanerozoic. Crown groups of modern terrestrial and/or benthic coastal cyanobacteria appeared during the late Paleoproterozoic to early Mesoproterozoic. Decrease in cell diameter and loss of filamentous forms contributed to the evolution of unicellular planktonic lineages during the middle of the Mesoproterozoic (1,600–1,000 Mya) in freshwater environments. This study shows that marine planktonic cyanobacteria evolved from benthic marine and some diverged from freshwater ancestors during the Neoproterozoic (1,000–542 Mya). PMID:26621203

  13. Origins of narcissism in children.

    PubMed

    Brummelman, Eddie; Thomaes, Sander; Nelemans, Stefanie A; Orobio de Castro, Bram; Overbeek, Geertjan; Bushman, Brad J

    2015-03-24

    Narcissism levels have been increasing among Western youth, and contribute to societal problems such as aggression and violence. The origins of narcissism, however, are not well understood. Here, we report, to our knowledge, the first prospective longitudinal evidence on the origins of narcissism in children. We compared two perspectives: social learning theory (positing that narcissism is cultivated by parental overvaluation) and psychoanalytic theory (positing that narcissism is cultivated by lack of parental warmth). We timed the study in late childhood (ages 7-12), when individual differences in narcissism first emerge. In four 6-mo waves, 565 children and their parents reported child narcissism, child self-esteem, parental overvaluation, and parental warmth. Four-wave cross-lagged panel models were conducted. Results support social learning theory and contradict psychoanalytic theory: Narcissism was predicted by parental overvaluation, not by lack of parental warmth. Thus, children seem to acquire narcissism, in part, by internalizing parents' inflated views of them (e.g., "I am superior to others" and "I am entitled to privileges"). Attesting to the specificity of this finding, self-esteem was predicted by parental warmth, not by parental overvaluation. These findings uncover early socialization experiences that cultivate narcissism, and may inform interventions to curtail narcissistic development at an early age.

  14. Origins of narcissism in children

    PubMed Central

    Brummelman, Eddie; Thomaes, Sander; Nelemans, Stefanie A.; Orobio de Castro, Bram; Overbeek, Geertjan; Bushman, Brad J.

    2015-01-01

    Narcissism levels have been increasing among Western youth, and contribute to societal problems such as aggression and violence. The origins of narcissism, however, are not well understood. Here, we report, to our knowledge, the first prospective longitudinal evidence on the origins of narcissism in children. We compared two perspectives: social learning theory (positing that narcissism is cultivated by parental overvaluation) and psychoanalytic theory (positing that narcissism is cultivated by lack of parental warmth). We timed the study in late childhood (ages 7–12), when individual differences in narcissism first emerge. In four 6-mo waves, 565 children and their parents reported child narcissism, child self-esteem, parental overvaluation, and parental warmth. Four-wave cross-lagged panel models were conducted. Results support social learning theory and contradict psychoanalytic theory: Narcissism was predicted by parental overvaluation, not by lack of parental warmth. Thus, children seem to acquire narcissism, in part, by internalizing parents’ inflated views of them (e.g., “I am superior to others” and “I am entitled to privileges”). Attesting to the specificity of this finding, self-esteem was predicted by parental warmth, not by parental overvaluation. These findings uncover early socialization experiences that cultivate narcissism, and may inform interventions to curtail narcissistic development at an early age. PMID:25775577

  15. Origin of marine planktonic cyanobacteria.

    PubMed

    Sánchez-Baracaldo, Patricia

    2015-01-01

    Marine planktonic cyanobacteria contributed to the widespread oxygenation of the oceans towards the end of the Pre-Cambrian and their evolutionary origin represents a key transition in the geochemical evolution of the Earth surface. Little is known, however, about the evolutionary events that led to the appearance of marine planktonic cyanobacteria. I present here phylogenomic (135 proteins and two ribosomal RNAs), Bayesian relaxed molecular clock (18 proteins, SSU and LSU) and Bayesian stochastic character mapping analyses from 131 cyanobacteria genomes with the aim to unravel key evolutionary steps involved in the origin of marine planktonic cyanobacteria. While filamentous cell types evolved early on at around 2,600-2,300 Mya and likely dominated microbial mats in benthic environments for most of the Proterozoic (2,500-542 Mya), marine planktonic cyanobacteria evolved towards the end of the Proterozoic and early Phanerozoic. Crown groups of modern terrestrial and/or benthic coastal cyanobacteria appeared during the late Paleoproterozoic to early Mesoproterozoic. Decrease in cell diameter and loss of filamentous forms contributed to the evolution of unicellular planktonic lineages during the middle of the Mesoproterozoic (1,600-1,000 Mya) in freshwater environments. This study shows that marine planktonic cyanobacteria evolved from benthic marine and some diverged from freshwater ancestors during the Neoproterozoic (1,000-542 Mya). PMID:26621203

  16. The origins of modern divorce.

    PubMed

    Coontz, Stephanie

    2007-03-01

    High rates of marital dissolution and easy access to divorce are not unprecedented, historically or cross-culturally. But contemporary divorce in North America and Western Europe has different origins and features than divorce in previous cultures. The origins of modern divorce patterns date back more than 200 years, to the invention of the historically unprecedented idea that marriage should be based on love and mutual affection. Ironically, then, the fragility of modern marriage stems from the same values that have elevated the marital relationship above all other personal and familial commitments: the concentration of emotion, passion, personal identity, and self-validation in the couple relationship and the attenuation of emotional attachments and obligations beyond the conjugal unit. The immediate causes of divorce may range from factors as diverse as the personal psychological characteristics of one or both spouses to the stresses of economic hardship and community disintegration. But in a larger perspective, the role of divorce in modern societies and its relatively high occurrence both flow from the same complex of factors that have made good marriages so much more central to people's happiness than through most of the past, and deterioration of a marital relationship so much more traumatic. PMID:17375725

  17. On the Origin of Heterotrophy.

    PubMed

    Schönheit, Peter; Buckel, Wolfgang; Martin, William F

    2016-01-01

    The theory of autotrophic origins of life posits that the first cells on Earth satisfied their carbon needs from CO2. At hydrothermal vents, spontaneous synthesis of methane via serpentinization links an energy metabolic reaction with a geochemical homologue. If the first cells were autotrophs, how did the first heterotrophs arise, and what was their substrate? We propose that cell mass roughly similar to the composition of Escherichia coli was the substrate for the first chemoorganoheterotrophs. Amino acid fermentations, pathways typical of anaerobic clostridia and common among anaerobic archaea, in addition to clostridial type purine fermentations, might have been the first forms of heterotrophic carbon and energy metabolism. Ribose was probably the first abundant sugar, and the archaeal type III RubisCO pathway of nucleoside monophosphate conversion to 3-phosphoglycerate might be a relic of ancient heterotrophy. Participation of chemiosmotic coupling and flavin-based electron bifurcation--a soluble energy coupling process--in clostridial amino acid and purine fermentations is consistent with an autotrophic origin of both metabolism and heterotrophy, as is the involvement of S(0) as an electron acceptor in the facilitated fermentations of anaerobic heterotrophic archaea. PMID:26578093

  18. Origins of narcissism in children.

    PubMed

    Brummelman, Eddie; Thomaes, Sander; Nelemans, Stefanie A; Orobio de Castro, Bram; Overbeek, Geertjan; Bushman, Brad J

    2015-03-24

    Narcissism levels have been increasing among Western youth, and contribute to societal problems such as aggression and violence. The origins of narcissism, however, are not well understood. Here, we report, to our knowledge, the first prospective longitudinal evidence on the origins of narcissism in children. We compared two perspectives: social learning theory (positing that narcissism is cultivated by parental overvaluation) and psychoanalytic theory (positing that narcissism is cultivated by lack of parental warmth). We timed the study in late childhood (ages 7-12), when individual differences in narcissism first emerge. In four 6-mo waves, 565 children and their parents reported child narcissism, child self-esteem, parental overvaluation, and parental warmth. Four-wave cross-lagged panel models were conducted. Results support social learning theory and contradict psychoanalytic theory: Narcissism was predicted by parental overvaluation, not by lack of parental warmth. Thus, children seem to acquire narcissism, in part, by internalizing parents' inflated views of them (e.g., "I am superior to others" and "I am entitled to privileges"). Attesting to the specificity of this finding, self-esteem was predicted by parental warmth, not by parental overvaluation. These findings uncover early socialization experiences that cultivate narcissism, and may inform interventions to curtail narcissistic development at an early age. PMID:25775577

  19. Entropic origin of allometry relations

    NASA Astrophysics Data System (ADS)

    West, Bruce J.; West, Damien

    2015-03-01

    The theoretical allometry relation (AR) between the size of a network Y and a property of the network X is of the form X = aYb and has been known for nearly two centuries. The allometry coefficient a and allometry exponent b have been fit by various data sets over that time. The ubiquity of ARs in biology, sociology, ecology and indeed in virtually all the other science disciplines entreats science to find the origin of ARs. Data analysis indicates that the empirical AR is obtained with the replacements X → and Y → and the brackets denote an average over an ensemble of realizations of the network. It has been shown that the empirical AR cannot usually be derived from the theoretical one by simple averaging due to the fractal statistics of the fluctuations. Consequently we hypothesize that a possible origin of AR is the Principle of Minimum Entropy Generation (PMEG). We establish in support of this hypothesis that if the fluctuations in the allometry variables have fractal statistics then the PMEG entails the AR between a complex host network and a subnetwork strongly coupled to it.

  20. The origin of light hydrocarbons

    SciTech Connect

    Mango, F.D.

    2000-04-01

    The light hydrocarbons (LHs) are probably intermediates in the catalytic decomposition of oil to gas. Two lines of evidence support this possibility. First, the reaction was duplicated experimentally under moderate conditions. Second, natural LHs exhibit the characteristics of catalytic products, in particular a proportionality between isomers: (xy{sub i})/(x{sub i}y) = {alpha} (where x and x{sub i} are isomers; y and y{sub i} are isomers that are structurally similar to x and x{sub i}; and {alpha} is a constant). All oils exhibit this relationship with coefficients of correlation reaching 0.99. Isomer ratios change systematically with concentrations, some approaching thermodynamic equilibrium, others not. The correlations reported are the strongest yet disclosed for the LHs. Isomers are related in triads (e.g., n-hexane {leftrightarrow} 2-methylpentane {leftrightarrow} 3-methylpentane), consistent with cyclopropane precursors. The LHs obtained experimentally are indistinguishable from natural LHs in (xy{sub i})/(x{sub i}y). These relationships are not explained by physical fractionations, equilibrium control, or noncatalytic modes of origin. A catalytic origin, on the other hand, has precedence, economy and experimental support.

  1. Geochemical Origin of Biological Molecules

    NASA Astrophysics Data System (ADS)

    Bassez, Marie-Paule

    2013-04-01

    A model for the geochemical origin of biological molecules is presented. Rocks such as peridotites and basalts, which contain ferromagnesian minerals, evolve in the presence of water. Their hydrolysis is an exothermic reaction which generates heat and a release of H2 and of minerals with modified structures. The hydrogen reacts with the CO2 embedded inside the rock or with the CO2 of the environment to form CO in an hydrothermal process. With the N2 of the environment, and with an activation source arising from cosmic radiation, ferromagnesian rocks might evolve towards the abiotic formation of biological molecules, such as peptide like macromolecules which produce amino acids after acid hydrolysis. The reactions concerned are described. The production of hydrothermal CO is discussed in geological sites containing ferromagnesian silicate minerals and the low intensity of the Earth's magnetic field during Paleoarchaean Era is also discussed. It is concluded that excitation sources arising from cosmic radiation were much more abundant during Paleoarchaean Era and that macromolecular structures of biological relevance might consequently form during Archaean Eon, as a product of the chemical evolution of the rocks and of their mineral contents. This synthesis of abiotically formed biological molecules is consecutively discussed for meteorites and other planets such as Mars. This model for the geochemical origin of biological molecules has first been proposed in 2008 in the context of reactions involving catalysers such as kaolinite [Bassez 2008a] and then presented in conferences and articles [Bassez 2008b, 2009, 2012; Bassez et al. 2009a to 2012b]. BASSEZ M.P. 2008a Synthèse prébiotique dans les conditions hydrothermales, CNRIUT'08, Lyon 29-30/05/2008, Conf. and open access article:http://liris.cnrs.fr/~cnriut08/actes/ 29 mai 11h-12h40. BASSEZ M.P. 2008b Prebiotic synthesis under hydrothermal conditions, ISSOL'08, P2-6, Firenze-Italy, 24-29/08/2008. Poster at the

  2. Origins and Evolution of Life

    NASA Astrophysics Data System (ADS)

    Gargaud, Muriel; López-García, Purificación; Martin, Hervé

    2011-01-01

    Part I. What Is Life?: 1. Problems raised by a definition of life M. Morange; 2. Some remarks about uses of cosmological anthropic 'principles' D. Lambert; 3. Minimal cell: the biologist point of view C. Brochier-Armanet; 4. Minimal cell: the computer scientist point of view H. Bersini; 5. Origins of life: computing and simulation approaches B. Billoud; Part II. Astronomical and Geophysical Context of the Emergence of Life: 6. Organic molecules in interstellar medium C. Ceccarelli and C. Cernicharo; 7. Cosmochemical evolution and the origin of life: insights from meteorites S. Pizzarello; 8. Astronomical constraints on the emergence of life M. Gounelle and T. Montmerle; 9. Formation of habitable planets J. Chambers; 10. The concept of galactic habitable zone N. Prantzos; 11. The young Sun and its influence on planetary atmospheres M. Güdel and J. Kasting; 12. Climates of the Earth G. Ramstein; Part III. Role of Water in the Emergence of Life: 13. Liquid water: a necessary condition to all forms of life K. Bartik, G. Bruylants, E. Locci and J. Reisse; 14. The role of water in the formation and evolution of planets T. Encrenaz; 15. Water on Mars J. P. Bibring; Part IV. From Non-Living Systems to Life: 16. Energetic constraints on prebiotic pathways: application to the emergence of translation R. Pascal and L. Boiteau; 17. Comparative genomics and early cell evolution A. Lazcano; 18. Origin and evolution of metabolisms J. Peretó; Part V. Mechanisms for Life Evolution: 19. Molecular phylogeny: inferring the patterns of evolution E. Douzery; 20. Horizontal gene transfer: mechanisms and evolutionary consequences D. Moreira; 21. The role of symbiosis in eukaryotic evolution A. Latorre, A. Durbán, A. Moya and J. Peretó; Part VI. Life in Extreme Conditions: 22. Life in extreme conditions: Deinococcus radiodurans, an organism able to survive prolonged desiccation and high doses of ionising radiation S. Sommer and M. Toueille; 23. Molecular effects of UV and ionizing

  3. The origin of electrochemical nomenclature.

    PubMed

    Giddens, W R

    2001-09-01

    This article is about the origin and development of certain words that are important in the vocabulary of all physicians and scientists. The words that make up the electrochemical nomenclature were created in 1833 by Michael Faraday and several of his friends. Terms such as electrolyte, ion, and electrode were invented in a fashion that ignored theory but fitted the experimental facts of the laboratory. This nomenclature, derived from Greek, was so accurate and functional that is has been completely incorporated into modern chemistry, a fact that seems remarkable since the structure of the atom was completely unknown at the time. To fully develop the etymology of these words, the life of Faraday is summarized and the deliberations of the men involved are reviewed. PMID:11686262

  4. The Solar System Origin Revisited

    NASA Astrophysics Data System (ADS)

    Johnson, Fred M.

    2016-10-01

    A novel theory will be presented based in part on astronomical observations, plasma physics experiments, principles of physics and forensic techniques. The new theory correctly predicts planetary distances with a 1% precision. It accounts for energy production mechanism inside all of the planets including our Earth. A log-log mass-luminosity plot of G2 class stars and solar system planets results in a straight line plot, whose slope implies that a fission rather than a proton-proton fusion energy production is operating. Furthermore, it is a confirmation that all our planets had originated from within our Sun. Other still-born planets continue to appear on the Sun's surface, they are mislabeled as sunspots.

  5. Origins of life systems chemistry

    NASA Astrophysics Data System (ADS)

    Sutherland, J.

    2015-10-01

    By reconciling previously conflicting views about the origin of life - in which one or other cellular subsystem emerges first, and then 'invents' the others - a new modus operandi for its study is suggested. Guided by this, a cyanosulfidic protometabolism is uncovered which uses UV light and the stoichiometric reducing power of hydrogen sulfide to convert hydrogen cyanide, and a couple of other prebiotic feedstock molecules which can be derived therefrom, into nucleic acid, peptide and lipid building blocks. Copper plays several key roles in this chemistry, thus, for example, copper(I) catalysed cross coupling and copper(II) driven oxidative crosscoupling reactions generate key feedstock molecules. Geochemical scenarios consistent with this protometabolism are outlined. Finally, the transition of a system from the inanimate to the animate state is considered in the context of there being intermediate stages of partial 'aliveness'.

  6. Multiple origins of asteroid pairs

    NASA Astrophysics Data System (ADS)

    Jacobson, Seth A.

    2016-01-01

    Rotationally fissioned asteroids produce unbound asteroid pairs that have very similar heliocentric orbits. Backward integration of their current heliocentric orbits provides an age of closest proximity that can be used to date the rotational fission event. Most asteroid pairs follow a predicted theoretical relationship between the primary spin period and the mass ratio of the two pair members that is a direct consequence of the YORP-induced rotational fission hypothesis. If the progenitor asteroid has strength, asteroid pairs may have higher mass ratios or faster rotating primaries. However, the process of secondary fission leaves the originally predicted trend unaltered. We also describe the characteristics of pair members produced by four alternative routes from a rotational fission event to an asteroid pair. Unlike direct formation from the event itself, the age of closest proximity of these pairs cannot generally be used to date the rotational fission event since considerable time may have passed.

  7. The origin of cellular life

    NASA Technical Reports Server (NTRS)

    Ingber, D. E.

    2000-01-01

    This essay presents a scenario of the origin of life that is based on analysis of biological architecture and mechanical design at the microstructural level. My thesis is that the same architectural and energetic constraints that shape cells today also guided the evolution of the first cells and that the molecular scaffolds that support solid-phase biochemistry in modern cells represent living microfossils of past life forms. This concept emerged from the discovery that cells mechanically stabilize themselves using tensegrity architecture and that these same building rules guide hierarchical self-assembly at all size scales (Sci. Amer 278:48-57;1998). When combined with other fundamental design principles (e.g., energy minimization, topological constraints, structural hierarchies, autocatalytic sets, solid-state biochemistry), tensegrity provides a physical basis to explain how atomic and molecular elements progressively self-assembled to create hierarchical structures with increasingly complex functions, including living cells that can self-reproduce.

  8. Alcoholism's evolutionary and cultural origins.

    PubMed

    Abel, Ernest L

    2010-12-01

    Alcoholism's heritability has been convincingly documented but the question of why a disorder that is so damaging to the individual and to society should continue to persist is still baffling. A widely held assumption is that whatever genotype is involved, its components must originally have conferred survival value else it would never have evolved. The corollary to that assumption is that when conditions favoring that genotype changed, the former advantages became detrimental. However, the genotype has persisted because it does not affect sexual function, if at all, until after peak productive years. An appreciation of the evolutionary biology and the historical-cultural context associated with alcohol consumption may lead not only to a better understanding of this disorder but to treatment alternatives based on that understanding.

  9. The evolutionary origins of friendship.

    PubMed

    Seyfarth, Robert M; Cheney, Dorothy L

    2012-01-01

    Convergent evidence from many species reveals the evolutionary origins of human friendship. In horses, elephants, hyenas, dolphins, monkeys, and chimpanzees, some individuals form friendships that last for years. Bonds occur among females, among males, or between males and females. Genetic relatedness affects friendships. In species where males disperse, friendships are more likely among females. If females disperse, friendships are more likely among males. Not all friendships, however, depend on kinship; many are formed between unrelated individuals. Friendships often involve cooperative interactions that are separated in time. They depend, at least in part, on the memory and emotions associated with past interactions. Applying the term "friendship" to animals is not anthropomorphic: Many studies have shown that the animals themselves recognize others' relationships. Friendships are adaptive. Male allies have superior competitive ability and improved reproductive success; females with the strongest, most enduring friendships experience less stress, higher infant survival, and live longer. PMID:21740224

  10. The origin of electrochemical nomenclature.

    PubMed

    Giddens, W R

    2001-09-01

    This article is about the origin and development of certain words that are important in the vocabulary of all physicians and scientists. The words that make up the electrochemical nomenclature were created in 1833 by Michael Faraday and several of his friends. Terms such as electrolyte, ion, and electrode were invented in a fashion that ignored theory but fitted the experimental facts of the laboratory. This nomenclature, derived from Greek, was so accurate and functional that is has been completely incorporated into modern chemistry, a fact that seems remarkable since the structure of the atom was completely unknown at the time. To fully develop the etymology of these words, the life of Faraday is summarized and the deliberations of the men involved are reviewed.

  11. The origins of symbolic racism.

    PubMed

    Sears, David O; Henry, P J

    2003-08-01

    The theory of symbolic racism places its origins in a blend of anti-Black affect and conservative values, particularly individualism. We clarify that hypothesis, test it directly, and report several findings consistent with it. Study 1 shows that racial prejudice and general political conservatism fall into 2 separate factors, with symbolic racism loading about equally on both. Study 2 found that the anti-Black affect and individualism significantly explain symbolic racism. The best-fitting model both fuses those 2 elements into a single construct (Black individualism) and includes them separately. The effects of Black individualism on racial policy preferences are mostly mediated by symbolic racism. Study 3 shows that Black individualism is distinctively racial, with effects distinctly different from either an analogous gender individualism or race-neutral individualism.

  12. Bacterial Influences on Animal Origins

    PubMed Central

    Alegado, Rosanna A.; King, Nicole

    2014-01-01

    Animals evolved in seas teeming with bacteria, yet the influences of bacteria on animal origins are poorly understood. Comparisons among modern animals and their closest living relatives, the choanoflagellates, suggest that the first animals used flagellated collar cells to capture bacterial prey. The cell biology of prey capture, such as cell adhesion between predator and prey, involves mechanisms that may have been co-opted to mediate intercellular interactions during the evolution of animal multicellularity. Moreover, a history of bacterivory may have influenced the evolution of animal genomes by driving the evolution of genetic pathways for immunity and facilitating lateral gene transfer. Understanding the interactions between bacteria and the progenitors of animals may help to explain the myriad ways in which bacteria shape the biology of modern animals, including ourselves. PMID:25280764

  13. Stratigraphic Systems: Origin and Application

    NASA Astrophysics Data System (ADS)

    Galloway, William E.

    In Stratigraphic Systems: Origin and Application, Glenn S.Visher attempts to synthesize and organize the knowledge and integrated interpretation system developed over 35 years in sedimentary analysis. The book sets forth an extremely aggressive agenda: to bring together a knowledge base that includes basin tectonics, stratigraphy, sedimentology paleogeomorphology seismic interpretation, and petroleum geoscience.The book contains more than 700 figures. An enclosed CD-ROM provides many additional figures, 24 color plates, and an expert system program—DE-EXPERT—developed by Visher and colleagues. Visher's approach is inclusive and emphasizes regional synthesis of multiple data sets. The analysis of stratigraphic systems is condensed into a suite of 15 siliciclastic and 6 biochemical depositional themes that reflect deposition over extended time, geographic area, and depositional settings. The themes are built around geomorphic patterns and basin tectonic contexts. In the end, however, the book is disappointing.

  14. The Origins of Counting Algorithms

    PubMed Central

    Cantlon, Jessica F.; Piantadosi, Steven T.; Ferrigno, Stephen; Hughes, Kelly D.; Barnard, Allison M.

    2015-01-01

    Humans’ ability to ‘count’ by verbally labeling discrete quantities is unique in animal cognition. The evolutionary origins of counting algorithms are not understood. We report that non-human primates exhibit a cognitive ability that is algorithmically and logically similar to human counting. Monkeys were given the task of choosing between two food caches. Monkeys saw one cache baited with some number of food items, one item at a time. Then, a second cache was baited with food items, one at a time. At the point when the second set approximately outnumbered the first set, monkeys spontaneously moved to choose the second set even before it was completely baited. Using a novel Bayesian analysis, we show that monkeys used an approximate counting algorithm to increment and compare quantities in sequence. This algorithm is structurally similar to formal counting in humans and thus may have been an important evolutionary precursor to human counting. PMID:25953949

  15. Huge waves of meteorite origin

    NASA Astrophysics Data System (ADS)

    Pelinovsky, Efim; Kozelkov, Andrey; Kurkin, Andrey

    2016-04-01

    Asteroid and meteorite risk is now actively investigated in various aspects. If the meteorite falls in the ocean it can generate huge waves with heights exceeded 10 m. For whole history about 10-20 events related with entry of meteorite in water are known. The last event occurred on February 15, 2013 when the meteorite exploded in sky of Chelyabinsk (Russia) and its big piece entered in the Chebarkul Lake. Very often, huge waves of meteorite origin are computed using the conception of equivalent (parametrical) source, whose parameters are determined through meteorite characteristics. Recently, direct methods based on numerical simulations of the Reynolds-averaged Navier-Stokes equations (RANS) have been applied to study wave processes generated by the entry of meteorite. These approaches and their applications to the historic events are discussed in paper.

  16. Impact origin of the Moon

    SciTech Connect

    Slattery, W.L.

    1998-12-31

    A few years after the Apollo flights to the Moon, it became clear that all of the existing theories on the origin of the Moon would not satisfy the growing body of constraints which appeared with the data gathered by the Apollo flights. About the same time, researchers began to realize that the inner (terrestrial) planets were not born quietly -- all had evidences of impacts on their surfaces. This fact reinforced the idea that the planets had formed by the accumulation of planetesimals. Since the Earth`s moon is unique among the terrestrial planets, a few researchers realized that perhaps the Moon originated in a singular event; an event that was quite probable, but not so probable that one would expect all the terrestrial planets to have a large moon. And thus was born the idea that a giant impact formed the Moon. Impacts would be common in the early solar system; perhaps a really large impact of two almost fully formed planets of disparate sizes would lead to material orbiting the proto-earth, a proto-moon. This idea remained to be tested. Using a relatively new, but robust, method of doing the hydrodynamics of the collision (Smoothed-Particle Hydrodynamics), the author and his colleagues (W. Benz, Univ. of Arizona, and A.G.W. Cameron, Harvard College Obs.) did a large number of collision simulations on a supercomputer. The author found two major scenarios which would result in the formation of the Moon. The first was direct formation; a moon-sized object is boosted into orbit by gravitational torques. The second is when the orbiting material forms a disk, which, with subsequent evolution can form the Moon. In either case the physical and chemical properties of the newly formed Moon would very neatly satisfy the physical and chemical constraints of the current Moon. Also, in both scenarios the surface of the Earth would be quite hot after the collision. This aspect remains to be explored.

  17. The interplanetary superhighway and the Origins Program

    NASA Technical Reports Server (NTRS)

    Lo, M. W.

    2002-01-01

    The origin of the universe and of life itself have been central to human inquiries since the dawn of consciousness. To develop and use the technologies to answer these timeless and profound questions is the mission of NASA's Origins Program.

  18. The Origin of the Chemical Elements, 1

    ERIC Educational Resources Information Center

    Selbin, Joel

    1973-01-01

    The problem of the origin is inextricably interwoven with such matters as the origin of the universe, the structure and evolution of galaxies, stars and other astronomical objects, and with nuclear physics. (Author/DF)

  19. 5 CFR 2500.3 - Original classification.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 2500.3 Administrative Personnel OFFICE OF ADMINISTRATION, EXECUTIVE OFFICE OF THE PRESIDENT INFORMATION SECURITY REGULATION § 2500.3 Original classification. No one in the Office of Administration has been granted authority for original classification of information....

  20. Ischemic etiopathogenesis as the possible origin of post-double baloon enteroscopy pancreatitis. A porcine model study.

    PubMed

    Soria, Federico; Pérez-Cuadrado, Enrique; López-Albors, Octavio; Morcillo, Esther; Sarriá, Ricardo; Candanosa, Eugenia; Esteban, Pilar; Carballo, Luis Fernando; Navarro, Marc; Nacher, Víctor; Sánchez, Francisco Miguel; Latorre, Rafael

    2015-01-01

    The aim is to evaluate the pancreatic vascular-ischemic effects related to double balloon enteroscopy in the porcine model as a possible etiopathogenesis of post-enteroscopic pancreatitis. For this reason we carry out two independent experiments in a porcine animal model. In the first arm protocol (group I), 10 animals underwent 90 minutes of oral enteroscopy with 7 days follow-up.The levels of amylase, lipase and C-reactive protein were measured at T0 basal-T1 -90 min, T2-24, T3-7 days. Also we perform upper gastrointestinal endoscopy in a control group. At 7 days, the animals of experimental protocol-I had their pancreases removed for a pathological and immunohistochemical study to evaluate vascular epithelial growth factor (VEGF) expression.The second experimental protocol in this study aims to evaluate possible changes in vascular topography due to the double balloon enteroscopy (DBE). Group-II (10 animals) underwent oral enteroscopy and selective angiography of the cranial mesenteric artery and celiac trunk. None of the group I or control group animals presented pancreatitis, although the biochemical results for group-I showed increases in the levels of amylase, lipase and C reactive protein at 24 hours. The microscopic study for group-I showed pancreatic necrotic foci and positive VEGF expression, though these changes were not expressed in the control group.These foci were found in 50% of the group I animals and in relation to the total of the parenchyma were quantified at 6% of the pancreas. The results for group-II showed that the enteroscopy caused mobilization of the mesenteric vascular axis, with signs of both intestinal and pancreatic hypoperfusion. The conclusions of this study are that, after enteroscopy in the porcine model, pancreatic necrotic foci are produced, in addition to ischemic phenomena causing VEGF expression. This could be related to episodes of visceral hypoperfusion caused by vascular alterations on a topographic level. This can be

  1. 5 CFR 2500.3 - Original classification.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Original classification. 2500.3 Section... SECURITY REGULATION § 2500.3 Original classification. No one in the Office of Administration has been granted authority for original classification of information....

  2. 5 CFR 2500.3 - Original classification.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Original classification. 2500.3 Section... SECURITY REGULATION § 2500.3 Original classification. No one in the Office of Administration has been granted authority for original classification of information....

  3. 5 CFR 2500.3 - Original classification.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Original classification. 2500.3 Section... SECURITY REGULATION § 2500.3 Original classification. No one in the Office of Administration has been granted authority for original classification of information....

  4. Darwin's Book: On the Origin of Species

    NASA Astrophysics Data System (ADS)

    Hodge, Jonathan

    2013-09-01

    This essay is an interpretation of Charles Darwin's Origin of Species. It focuses on the contents of the Origin as Darwin intended them to be understood and the background to the work, thus revealing the originality (or otherwise) of the work.

  5. The Origins of Competency-Based Training

    ERIC Educational Resources Information Center

    Hodge, Steven

    2007-01-01

    This article attempts to trace the origins of competency-based training (CBT), the theory of vocational education that underpins the National Training Framework in Australia. A distinction is made between societal and theoretical origins. This paper argues that CBT has its societal origins in the United States of America during the 1950s, 60s and…

  6. 7 CFR 201.14 - Origin.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.14 Origin. (a) Alfalfa, red clover, white clover, and field corn (except hybrid seed corn) shall be labeled to show: (1) The origin, if known; or (2) if the origin is not...

  7. 7 CFR 201.14 - Origin.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.14 Origin. (a) Alfalfa, red clover, white clover, and field corn (except hybrid seed corn) shall be labeled to show: (1) The origin, if known; or (2) if the origin is not...

  8. 5 CFR 2500.3 - Original classification.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Original classification. 2500.3 Section... SECURITY REGULATION § 2500.3 Original classification. No one in the Office of Administration has been granted authority for original classification of information....

  9. 32 CFR 2001.21 - Original classification.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Original classification. 2001.21 Section 2001.21... Markings § 2001.21 Original classification. (a) Primary markings. At the time of original classification, the following shall be indicated in a manner that is immediately apparent: (1)...

  10. Ambient neutrons of natural origin

    NASA Astrophysics Data System (ADS)

    Gusev, Anatoly; Martin, Inacio; Shkevov, Rumen; Alves, Mauro

    2016-07-01

    The laboratory of environmental radiation of ITA (São José dos Campos, 23°11'11″S, 45°52'43″W, 650 MAMSL) performs simultaneous monitoring of a natural radiation background and meteorological parameters. Neutron flux in the energy range of 0.02 eV - 10 MeV is registered with two sets of proportional ^{3}He tubes placed into cylindrical paraffin thermalizers: an {bf outdoor detector }of 250 cm² area and {bf indoor detector }of 70 cm² area located on the second floor of a concrete building. The counter efficiency for thermal neutrons is 80%. The characteristics of the observed flux variation are quite different from those inherent to the neutrons of the cosmic ray origin. {bf Four types of the outdoor flux variations }are observed: 1) {bf seasonal }with a maxima in wet seasons; 2) {bf diurnal }with maximum at about 6 h local time and an amplitude up to several dozens; 3) {bf abrupt transient} ( 1 min) increases with magnitudes up to two orders higher than the mean daily flux; 4) short (several days) {bf quasi-periodic enhancements }with amplitudes up to several times higher than the mean daily flux. A large variation of the outdoor flux and its phase synchronism with that of the radon decay products means with a high probability their common origin. An apparent source of the neutrons observed is nuclear reactions of decay α-particles with the ground matter. In this case the dynamics of the outdoor flux variations of the first two types is controlled by those of the meteorological parameters in the locality. The third type events correlate with lightning strokes in the vicinity (<200 m) of the detector. The more rare fourth type correlate neither with geomagnetic disturbances nor with meteorological phenomena and are probably a result of natural radon release from the Earth's crust triggered by minor seismological activity. The indoor flux is quite stable with a possible weak maximum at16 h not exceeding 0.1.

  11. On the origin of Laurentia

    SciTech Connect

    Dalziel, I.W.D. . Inst. for Geophysics)

    1992-01-01

    Laurentia, the Precambrian core of the North American continent, is surrounded by late Precambrian rift systems and therefore constitutes a suspect terrane''. A geometric and geological fit can be achieved between the Atlantic margin of Laurentia and the Pacific margin of the Gondwana craton. The enigmatic Arequipa massif along the southern Peruvian coast, that yields ca. 2.0 Ga radiometric ages, is juxtaposed with the Makkovik-Ketilidian province of the same age range in Labrador and southern Greenland. The Greenville belt continues beneath the ensialic Andes of the present day to join up with the 1.3--1.0 Ga San Ignacio and Sonsas-Aguapei orogens of the Transamazonian craton. Together with the recent identification of possible continuations of the Greenville orogen in East Antarctica and of the Taconic Appalachians in southern South America, the fit supports suggestions that Laurentia originated between East Antarctica-Australia and embryonic South America prior to the opening of the Pacific Ocean basin and amalgamation of the Gondwana Cordilleran and Appalachian margins, this implies that there may have been two supercontinents during the Neoproterozoic, before and after opening of the Pacific Ocean. As Laurentia and Gondwana appear to have collided on at least two occasions during the Paleozoic, this scenario therefore calls to question the existence of so-called supercontinental cycles. The Arica bight of the present day may reflect a primary reentrant in the South American continental margin that controlled subduction processes along the Andean margin and eventually led to uplift of the Altiplano.

  12. On the Origin of Interoception.

    PubMed

    Ceunen, Erik; Vlaeyen, Johan W S; Van Diest, Ilse

    2016-01-01

    Over the course of a century, the meaning of interoception has changed from the restrictive to the inclusive. In its inclusive sense, it bears relevance to every individual via its link to emotion, decision making, time-perception, health, pain, and various other areas of life. While the label for the perception of the body state changes over time, the need for an overarching concept remains. Many aspects can make any particular interoceptive sensation unique and distinct from any other interoceptive sensation. This can range from the sense of agency, to the physical cause of a sensation, the ontogenetic origin, the efferent innervation, and afferent pathways of the tissue involved amongst others. In its overarching meaning, interoception primarily is a product of the central nervous system, a construct based on an integration of various sources, not per se including afferent information. This paper proposes a definition of interoception as based on subjective experience, and pleas for the use of specific vocabulary in addressing the many aspects that contribute to it. PMID:27242642

  13. Human origins: Out of Africa

    PubMed Central

    Tattersall, Ian

    2009-01-01

    Our species, Homo sapiens, is highly autapomorphic (uniquely derived) among hominids in the structure of its skull and postcranial skeleton. It is also sharply distinguished from other organisms by its unique symbolic mode of cognition. The fossil and archaeological records combine to show fairly clearly that our physical and cognitive attributes both first appeared in Africa, but at different times. Essentially modern bony conformation was established in that continent by the 200–150 Ka range (a dating in good agreement with dates for the origin of H. sapiens derived from modern molecular diversity). The event concerned was apparently short-term because it is essentially unanticipated in the fossil record. In contrast, the first convincing stirrings of symbolic behavior are not currently detectable until (possibly well) after 100 Ka. The radical reorganization of gene expression that underwrote the distinctive physical appearance of H. sapiens was probably also responsible for the neural substrate that permits symbolic cognition. This exaptively acquired potential lay unexploited until it was “discovered” via a cultural stimulus, plausibly the invention of language. Modern humans appear to have definitively exited Africa to populate the rest of the globe only after both their physical and cognitive peculiarities had been acquired within that continent. PMID:19805256

  14. On the Origin of Sequence.

    PubMed

    Gulik, Peter T S van der

    2015-01-01

    Three aspects which make planet Earth special, and which must be taken in consideration with respect to the emergence of peptides, are the mineralogical composition, the Moon which is in the same size class, and the triple environment consisting of ocean, atmosphere, and continent. GlyGly is a remarkable peptide because it stimulates peptide bond formation in the Salt-Induced Peptide Formation reaction. The role glycine and aspartic acid play in the active site of RNA polymerase is remarkable too. GlyGly might have been the original product of coded peptide synthesis because of its importance in stimulating the production of oligopeptides with a high aspartic acid content, which protected small RNA molecules by binding Mg2+ ions. The feedback loop, which is closed by having RNA molecules producing GlyGly, is proposed as the essential element fundamental to life. Having this system running, longer sequences could evolve, gradually solving the problem of error catastrophe. The basic structure of the standard genetic code (8 fourfold degenerate codon boxes and 8 split codon boxes) is an example of the way information concerning the emergence of life is frozen in the biological constitution of organisms: the structure of the code contains historical information. PMID:26580656

  15. Endosymbiotic theory for organelle origins.

    PubMed

    Zimorski, Verena; Ku, Chuan; Martin, William F; Gould, Sven B

    2014-12-01

    Endosymbiotic theory goes back over 100 years. It explains the similarity of chloroplasts and mitochondria to free-living prokaryotes by suggesting that the organelles arose from prokaryotes through (endo)symbiosis. Gene trees provide important evidence in favour of symbiotic theory at a coarse-grained level, but the finer we get into the details of branches in trees containing dozens or hundreds of taxa, the more equivocal evidence for endosymbiotic events sometimes becomes. It seems that either the interpretation of some endosymbiotic events are wrong, or something is wrong with the interpretations of some gene trees having many leaves. There is a need for evidence that is independent of gene trees and that can help outline the course of symbiosis in eukaryote evolution. Protein import is the strongest evidence we have for the single origin of chloroplasts and mitochondria. It is probably also the strongest evidence we have to sort out the number and nature of secondary endosymbiotic events that have occurred in evolution involving the red plastid lineage. If we relax our interpretation of individual gene trees, endosymbiotic theory can tell us a lot.

  16. On the Origin of Sequence.

    PubMed

    Gulik, Peter T S van der

    2015-01-01

    Three aspects which make planet Earth special, and which must be taken in consideration with respect to the emergence of peptides, are the mineralogical composition, the Moon which is in the same size class, and the triple environment consisting of ocean, atmosphere, and continent. GlyGly is a remarkable peptide because it stimulates peptide bond formation in the Salt-Induced Peptide Formation reaction. The role glycine and aspartic acid play in the active site of RNA polymerase is remarkable too. GlyGly might have been the original product of coded peptide synthesis because of its importance in stimulating the production of oligopeptides with a high aspartic acid content, which protected small RNA molecules by binding Mg2+ ions. The feedback loop, which is closed by having RNA molecules producing GlyGly, is proposed as the essential element fundamental to life. Having this system running, longer sequences could evolve, gradually solving the problem of error catastrophe. The basic structure of the standard genetic code (8 fourfold degenerate codon boxes and 8 split codon boxes) is an example of the way information concerning the emergence of life is frozen in the biological constitution of organisms: the structure of the code contains historical information.

  17. The origin of intermediary metabolism

    PubMed Central

    Morowitz, Harold J.; Kostelnik, Jennifer D.; Yang, Jeremy; Cody, George D.

    2000-01-01

    The core of intermediary metabolism in autotrophs is the citric acid cycle. In a certain group of chemoautotrophs, the reductive citric acid cycle is an engine of synthesis, taking in CO2 and synthesizing the molecules of the cycle. We have examined the chemistry of a model system of C, H, and O that starts with carbon dioxide and reductants and uses redox couples as the energy source. To inquire into the reaction networks that might emerge, we start with the largest available database of organic molecules, Beilstein on-line, and prune by a set of physical and chemical constraints applicable to the model system. From the 3.5 million entries in Beilstein we emerge with 153 molecules that contain all 11 members of the reductive citric acid cycle. A small number of selection rules generates a very constrained subset, suggesting that this is the type of reaction model that will prove useful in the study of biogenesis. The model indicates that the metabolism shown in the universal chart of pathways may be central to the origin of life, is emergent from organic chemistry, and may be unique. PMID:10859347

  18. The origin of intermediary metabolism

    NASA Technical Reports Server (NTRS)

    Morowitz, H. J.; Kostelnik, J. D.; Yang, J.; Cody, G. D.

    2000-01-01

    The core of intermediary metabolism in autotrophs is the citric acid cycle. In a certain group of chemoautotrophs, the reductive citric acid cycle is an engine of synthesis, taking in CO(2) and synthesizing the molecules of the cycle. We have examined the chemistry of a model system of C, H, and O that starts with carbon dioxide and reductants and uses redox couples as the energy source. To inquire into the reaction networks that might emerge, we start with the largest available database of organic molecules, Beilstein on-line, and prune by a set of physical and chemical constraints applicable to the model system. From the 3.5 million entries in Beilstein we emerge with 153 molecules that contain all 11 members of the reductive citric acid cycle. A small number of selection rules generates a very constrained subset, suggesting that this is the type of reaction model that will prove useful in the study of biogenesis. The model indicates that the metabolism shown in the universal chart of pathways may be central to the origin of life, is emergent from organic chemistry, and may be unique.

  19. Phylogenetic Origins of Brain Organisers

    PubMed Central

    Robertshaw, Ellen; Kiecker, Clemens

    2012-01-01

    The regionalisation of the nervous system begins early in embryogenesis, concomitant with the establishment of the anteroposterior (AP) and dorsoventral (DV) body axes. The molecular mechanisms that drive axis induction appear to be conserved throughout the animal kingdom and may be phylogenetically older than the emergence of bilateral symmetry. As a result of this process, groups of patterning genes that are equally well conserved are expressed at specific AP and DV coordinates of the embryo. In the emerging nervous system of vertebrate embryos, this initial pattern is refined by local signalling centres, secondary organisers, that regulate patterning, proliferation, and axonal pathfinding in adjacent neuroepithelium. The main secondary organisers for the AP neuraxis are the midbrain-hindbrain boundary, zona limitans intrathalamica, and anterior neural ridge and for the DV neuraxis the notochord, floor plate, and roof plate. A search for homologous secondary organisers in nonvertebrate lineages has led to controversy over their phylogenetic origins. Based on a recent study in hemichordates, it has been suggested that the AP secondary organisers evolved at the base of the deuterostome superphylum, earlier than previously thought. According to this view, the lack of signalling centres in some deuterostome lineages is likely to reflect a secondary loss due to adaptive processes. We propose that the relative evolutionary flexibility of secondary organisers has contributed to a broader morphological complexity of nervous systems in different clades. PMID:24278699

  20. The origins of cellular life.

    PubMed

    Schrum, Jason P; Zhu, Ting F; Szostak, Jack W

    2010-09-01

    Understanding the origin of cellular life on Earth requires the discovery of plausible pathways for the transition from complex prebiotic chemistry to simple biology, defined as the emergence of chemical assemblies capable of Darwinian evolution. We have proposed that a simple primitive cell, or protocell, would consist of two key components: a protocell membrane that defines a spatially localized compartment, and an informational polymer that allows for the replication and inheritance of functional information. Recent studies of vesicles composed of fatty-acid membranes have shed considerable light on pathways for protocell growth and division, as well as means by which protocells could take up nutrients from their environment. Additional work with genetic polymers has provided insight into the potential for chemical genome replication and compatibility with membrane encapsulation. The integration of a dynamic fatty-acid compartment with robust, generalized genetic polymer replication would yield a laboratory model of a protocell with the potential for classical Darwinian biological evolution, and may help to evaluate potential pathways for the emergence of life on the early Earth. Here we discuss efforts to devise such an integrated protocell model.

  1. Endosymbiotic theory for organelle origins.

    PubMed

    Zimorski, Verena; Ku, Chuan; Martin, William F; Gould, Sven B

    2014-12-01

    Endosymbiotic theory goes back over 100 years. It explains the similarity of chloroplasts and mitochondria to free-living prokaryotes by suggesting that the organelles arose from prokaryotes through (endo)symbiosis. Gene trees provide important evidence in favour of symbiotic theory at a coarse-grained level, but the finer we get into the details of branches in trees containing dozens or hundreds of taxa, the more equivocal evidence for endosymbiotic events sometimes becomes. It seems that either the interpretation of some endosymbiotic events are wrong, or something is wrong with the interpretations of some gene trees having many leaves. There is a need for evidence that is independent of gene trees and that can help outline the course of symbiosis in eukaryote evolution. Protein import is the strongest evidence we have for the single origin of chloroplasts and mitochondria. It is probably also the strongest evidence we have to sort out the number and nature of secondary endosymbiotic events that have occurred in evolution involving the red plastid lineage. If we relax our interpretation of individual gene trees, endosymbiotic theory can tell us a lot. PMID:25306530

  2. Nanogranular origin of concrete creep.

    PubMed

    Vandamme, Matthieu; Ulm, Franz-Josef

    2009-06-30

    Concrete, the solid that forms at room temperature from mixing Portland cement with water, sand, and aggregates, suffers from time-dependent deformation under load. This creep occurs at a rate that deteriorates the durability and truncates the lifespan of concrete structures. However, despite decades of research, the origin of concrete creep remains unknown. Here, we measure the in situ creep behavior of calcium-silicate-hydrates (C-S-H), the nano-meter sized particles that form the fundamental building block of Portland cement concrete. We show that C-S-H exhibits a logarithmic creep that depends only on the packing of 3 structurally distinct but compositionally similar C-S-H forms: low density, high density, ultra-high density. We demonstrate that the creep rate ( approximately 1/t) is likely due to the rearrangement of nanoscale particles around limit packing densities following the free-volume dynamics theory of granular physics. These findings could lead to a new basis for nanoengineering concrete materials and structures with minimal creep rates monitored by packing density distributions of nanoscale particles, and predicted by nanoscale creep measurements in some minute time, which are as exact as macroscopic creep tests carried out over years.

  3. Nanogranular origin of concrete creep

    PubMed Central

    Vandamme, Matthieu; Ulm, Franz-Josef

    2009-01-01

    Concrete, the solid that forms at room temperature from mixing Portland cement with water, sand, and aggregates, suffers from time-dependent deformation under load. This creep occurs at a rate that deteriorates the durability and truncates the lifespan of concrete structures. However, despite decades of research, the origin of concrete creep remains unknown. Here, we measure the in situ creep behavior of calcium–silicate–hydrates (C–S–H), the nano-meter sized particles that form the fundamental building block of Portland cement concrete. We show that C–S–H exhibits a logarithmic creep that depends only on the packing of 3 structurally distinct but compositionally similar C–S–H forms: low density, high density, ultra-high density. We demonstrate that the creep rate (≈1/t) is likely due to the rearrangement of nanoscale particles around limit packing densities following the free-volume dynamics theory of granular physics. These findings could lead to a new basis for nanoengineering concrete materials and structures with minimal creep rates monitored by packing density distributions of nanoscale particles, and predicted by nanoscale creep measurements in some minute time, which are as exact as macroscopic creep tests carried out over years. PMID:19541652

  4. On the Origin of Interoception

    PubMed Central

    Ceunen, Erik; Vlaeyen, Johan W. S.; Van Diest, Ilse

    2016-01-01

    Over the course of a century, the meaning of interoception has changed from the restrictive to the inclusive. In its inclusive sense, it bears relevance to every individual via its link to emotion, decision making, time-perception, health, pain, and various other areas of life. While the label for the perception of the body state changes over time, the need for an overarching concept remains. Many aspects can make any particular interoceptive sensation unique and distinct from any other interoceptive sensation. This can range from the sense of agency, to the physical cause of a sensation, the ontogenetic origin, the efferent innervation, and afferent pathways of the tissue involved amongst others. In its overarching meaning, interoception primarily is a product of the central nervous system, a construct based on an integration of various sources, not per se including afferent information. This paper proposes a definition of interoception as based on subjective experience, and pleas for the use of specific vocabulary in addressing the many aspects that contribute to it. PMID:27242642

  5. Origin and properties of GEMS

    SciTech Connect

    Dai, Z R; Bradley, J P

    2006-04-11

    GEMS are to the outer solar system what chondrules are to the inner solar system. Ten years after it was first proposed that GEMS are the long-sought interstellar amorphous silicates, ion microprobe measurements have confirmed that some of them are indeed interstellar amorphous silicates. The new challenges are to obtain even higher precision isotope measurements from these submicrometer-sized objects and to clarify how and where they originally formed. Individual GEMS exhibit a strikingly narrow (0.1-0.5 {micro}m diameter) size distribution and they are systematically depleted from solar abundances in S/Si, Mg/Si, Ca/Si and Fe/Si, implying that they formed by a common mechanism. Mineralogical and petrographic evidence suggest that irradiation processing may be that mechanism. Recent nanometer-scale compositional mapping using new-generation transmission electron microscopes reveals that truly pristine GEMS may be relatively rare and new metrics need to be developed to distinguish the primordial properties of GEMS from more recent secondary alteration effects.

  6. The origins of counting algorithms.

    PubMed

    Cantlon, Jessica F; Piantadosi, Steven T; Ferrigno, Stephen; Hughes, Kelly D; Barnard, Allison M

    2015-06-01

    Humans' ability to count by verbally labeling discrete quantities is unique in animal cognition. The evolutionary origins of counting algorithms are not understood. We report that nonhuman primates exhibit a cognitive ability that is algorithmically and logically similar to human counting. Monkeys were given the task of choosing between two food caches. First, they saw one cache baited with some number of food items, one item at a time. Then, a second cache was baited with food items, one at a time. At the point when the second set was approximately equal to the first set, the monkeys spontaneously moved to choose the second set even before that cache was completely baited. Using a novel Bayesian analysis, we show that the monkeys used an approximate counting algorithm for comparing quantities in sequence that is incremental, iterative, and condition controlled. This proto-counting algorithm is structurally similar to formal counting in humans and thus may have been an important evolutionary precursor to human counting. PMID:25953949

  7. Geographic origin of Nepali doctors.

    PubMed

    Thapa, B K

    2004-01-01

    Though the history of in-country training of doctors in Nepal is not long, Nepal had started training doctors in abroad long ago. This is probably the first paper of its kind to correlate the developmental and ecological region to the country of training of Nepali doctors. This retrospective analysis reveals that nearly 38% doctors are trained in India, 22% each from former USSR and Nepal, 10% from Bangladesh, and 2.5% from Pakistan. Other countries contribute very few in the list. Nearly 2/3rd of the doctors represent the central developmental region and most of them are from Kathmandu valley. Ecologically mountain and hills are in great minority compared to Kathmandu valley and Terai. Interestingly training in former USSR shows a bit wider base regarding the origin in terms of developmental region. And Nepal has a clear broad base both in terms of developmental and ecological regions. As most of the doctors among Nepal trained ones are from IOM, the role of IOM way of selecting medical students need a deeper look into it.

  8. Origin of giant Martian polygons

    NASA Technical Reports Server (NTRS)

    Mcgill, George E.; Hills, L. S.

    1992-01-01

    Extensive areas of the Martian northern plains in Utopia and Acidalia planitiae are characterized by 'polygonal terrane'. Polygonal terrane consists of material cut by complex troughs defining a pattern resembling mudcracks, columnar joints, or frost-wedge polygons on earth. However, the Martian polygons are orders of magnitude larger than these potential earth analogues, leading to severe mechanical difficulties for genetic models based on simple analogy arguments. Plate-bending and finite element models indicate that shrinkage of desiccating sediment or cooling volcanics accompanied by differential compaction over buried topography can account for the stresses responsible for polygon troughs as well as the large size of the polygons. Although trough widths and depths relate primarily to shrinkage, the large scale of the polygonl pattern relates to the spacing between topographic elevations on the surface buried beneath polygonal terrane material. Geological relationships favor a sedimentary origin for polygonal terrane material, but our model is not dependent on the specific genesis. Our analysis also suggests that the polygons must have formed at a geologically rapid rate.

  9. On the Origin of Sequence

    PubMed Central

    van der Gulik, Peter T. S.

    2015-01-01

    Three aspects which make planet Earth special, and which must be taken in consideration with respect to the emergence of peptides, are the mineralogical composition, the Moon which is in the same size class, and the triple environment consisting of ocean, atmosphere, and continent. GlyGly is a remarkable peptide because it stimulates peptide bond formation in the Salt-Induced Peptide Formation reaction. The role glycine and aspartic acid play in the active site of RNA polymerase is remarkable too. GlyGly might have been the original product of coded peptide synthesis because of its importance in stimulating the production of oligopeptides with a high aspartic acid content, which protected small RNA molecules by binding Mg2+ ions. The feedback loop, which is closed by having RNA molecules producing GlyGly, is proposed as the essential element fundamental to life. Having this system running, longer sequences could evolve, gradually solving the problem of error catastrophe. The basic structure of the standard genetic code (8 fourfold degenerate codon boxes and 8 split codon boxes) is an example of the way information concerning the emergence of life is frozen in the biological constitution of organisms: the structure of the code contains historical information. PMID:26580656

  10. A Link between ORC-Origin Binding Mechanisms and Origin Activation Time Revealed in Budding Yeast

    PubMed Central

    Hoggard, Timothy; Shor, Erika; Müller, Carolin A.; Nieduszynski, Conrad A.; Fox, Catherine A.

    2013-01-01

    Eukaryotic DNA replication origins are selected in G1-phase when the origin recognition complex (ORC) binds chromosomal positions and triggers molecular events culminating in the initiation of DNA replication (a.k.a. origin firing) during S-phase. Each chromosome uses multiple origins for its duplication, and each origin fires at a characteristic time during S-phase, creating a cell-type specific genome replication pattern relevant to differentiation and genome stability. It is unclear whether ORC-origin interactions are relevant to origin activation time. We applied a novel genome-wide strategy to classify origins in the model eukaryote Saccharomyces cerevisiae based on the types of molecular interactions used for ORC-origin binding. Specifically, origins were classified as DNA-dependent when the strength of ORC-origin binding in vivo could be explained by the affinity of ORC for origin DNA in vitro, and, conversely, as ‘chromatin-dependent’ when the ORC-DNA interaction in vitro was insufficient to explain the strength of ORC-origin binding in vivo. These two origin classes differed in terms of nucleosome architecture and dependence on origin-flanking sequences in plasmid replication assays, consistent with local features of chromatin promoting ORC binding at ‘chromatin-dependent’ origins. Finally, the ‘chromatin-dependent’ class was enriched for origins that fire early in S-phase, while the DNA-dependent class was enriched for later firing origins. Conversely, the latest firing origins showed a positive association with the ORC-origin DNA paradigm for normal levels of ORC binding, whereas the earliest firing origins did not. These data reveal a novel association between ORC-origin binding mechanisms and the regulation of origin activation time. PMID:24068963

  11. Cosmic Origin and Theology of the Revelation

    NASA Astrophysics Data System (ADS)

    Guijarro, José Francisco

    2007-04-01

    All along cultural history man has asked himself about the origin of man, the origin of life ante the origin of the cosmos. Regarding the question about the origin of the cosmos, any theological research must settle before any other goal the question of its language: what we understand as scientific, mythical or theological language. The biblical texts on Creation are analyzed in their historical, cultural and theological context. It is concluded that the fundamental religious meanings of the biblical texts are not in opposition to scientific interpretation of cosmic origin.

  12. Fever of unknown origin: a clinical approach.

    PubMed

    Cunha, Burke A; Lortholary, Olivier; Cunha, Cheston B

    2015-10-01

    Fevers of unknown origin remain one of the most difficult diagnostic challenges in medicine. Because fever of unknown origin may be caused by over 200 malignant/neoplastic, infectious, rheumatic/inflammatory, and miscellaneous disorders, clinicians often order non-clue-based imaging and specific testing early in the fever of unknown origin work-up, which may be inefficient/misleading. Unlike most other fever-of-unknown-origin reviews, this article presents a clinical approach. Characteristic history and physical examination findings together with key nonspecific test abnormalities are the basis for a focused clue-directed fever of unknown origin work-up.

  13. [The origin of informed consent].

    PubMed

    Mallardi, V

    2005-10-01

    The principle of informed consent, aimed at the lawfulness of health assistance, tends to reflect the concept of autonomy and of decisional autodetermination of the person requiring and requesting medical and/or surgical interventions. This legal formula, over the last few years, has gained not only considerable space but also importance in the doctrinal elaboration and approaches, as well as juridical interpretations, thereby influencing the everyday activities of the medical profession. Informed consent is still the object of continuous explorations, not only asfar as concerns the already confirmed theoretical profile but, instead, the ambiguous practical and consequential aspect. Analysing how the concept and role of consensus was born and developed with the more adequate and reasonable excursions to make it valid and obtain it, it is impossible not to take into consideration, on the one hand, the very ancient philosophical origins and, on the other, the fact that it was conditioned by religion with the moral aspects and the accelerated deontological evolution with pathways parallel to the needs and the progress offered by new forms of treatment and novel biotechnological applications. The principle of consent is a relatively new condition. In fact, already in the times of not only the Egyptian civilisation, but also the Greek and Roman, documents have been found which show how the doctor's intervention had, in some way, first to be approved by the patient. Plato (law IV) had already foreseen the problems, the procedures and the modes of information which are, in synthesis, at the root of the principles of the present formula of informed consent and correlated the practice of the information and consensus with the quality and social position of the patient. The only guarantee that the patient might have, derived from a fundamental principle of medicine of all times: "in disease, focus on two aims, to improve and not to cause damage". A figure can be recognised

  14. [The origin of informed consent].

    PubMed

    Mallardi, V

    2005-10-01

    The principle of informed consent, aimed at the lawfulness of health assistance, tends to reflect the concept of autonomy and of decisional autodetermination of the person requiring and requesting medical and/or surgical interventions. This legal formula, over the last few years, has gained not only considerable space but also importance in the doctrinal elaboration and approaches, as well as juridical interpretations, thereby influencing the everyday activities of the medical profession. Informed consent is still the object of continuous explorations, not only asfar as concerns the already confirmed theoretical profile but, instead, the ambiguous practical and consequential aspect. Analysing how the concept and role of consensus was born and developed with the more adequate and reasonable excursions to make it valid and obtain it, it is impossible not to take into consideration, on the one hand, the very ancient philosophical origins and, on the other, the fact that it was conditioned by religion with the moral aspects and the accelerated deontological evolution with pathways parallel to the needs and the progress offered by new forms of treatment and novel biotechnological applications. The principle of consent is a relatively new condition. In fact, already in the times of not only the Egyptian civilisation, but also the Greek and Roman, documents have been found which show how the doctor's intervention had, in some way, first to be approved by the patient. Plato (law IV) had already foreseen the problems, the procedures and the modes of information which are, in synthesis, at the root of the principles of the present formula of informed consent and correlated the practice of the information and consensus with the quality and social position of the patient. The only guarantee that the patient might have, derived from a fundamental principle of medicine of all times: "in disease, focus on two aims, to improve and not to cause damage". A figure can be recognised

  15. The origin of malignant malaria.

    PubMed

    Rich, Stephen M; Leendertz, Fabian H; Xu, Guang; LeBreton, Matthew; Djoko, Cyrille F; Aminake, Makoah N; Takang, Eric E; Diffo, Joseph L D; Pike, Brian L; Rosenthal, Benjamin M; Formenty, Pierre; Boesch, Christophe; Ayala, Francisco J; Wolfe, Nathan D

    2009-09-01

    Plasmodium falciparum, the causative agent of malignant malaria, is among the most severe human infectious diseases. The closest known relative of P. falciparum is a chimpanzee parasite, Plasmodium reichenowi, of which one single isolate was previously known. The co-speciation hypothesis suggests that both parasites evolved separately from a common ancestor over the last 5-7 million years, in parallel with the divergence of their hosts, the hominin and chimpanzee lineages. Genetic analysis of eight new isolates of P. reichenowi, from wild and wild-born captive chimpanzees in Cameroon and Côte d'Ivoire, shows that P. reichenowi is a geographically widespread and genetically diverse chimpanzee parasite. The genetic lineage comprising the totality of global P. falciparum is fully included within the much broader genetic diversity of P. reichenowi. This finding is inconsistent with the co-speciation hypothesis. Phylogenetic analysis indicates that all extant P. falciparum populations originated from P. reichenowi, likely by a single host transfer, which may have occurred as early as 2-3 million years ago, or as recently as 10,000 years ago. The evolutionary history of this relationship may be explained by two critical genetic mutations. First, inactivation of the CMAH gene in the human lineage rendered human ancestors unable to generate the sialic acid Neu5Gc from its precursor Neu5Ac, and likely made humans resistant to P. reichenowi. More recently, mutations in the dominant invasion receptor EBA 175 in the P. falciparum lineage provided the parasite with preference for the overabundant Neu5Ac precursor, accounting for its extreme human pathogenicity.

  16. The origin of ambling horses.

    PubMed

    Wutke, Saskia; Andersson, Leif; Benecke, Norbert; Sandoval-Castellanos, Edson; Gonzalez, Javier; Hallsson, Jón Hallsteinn; Lõugas, Lembi; Magnell, Ola; Morales-Muniz, Arturo; Orlando, Ludovic; Pálsdóttir, Albína Hulda; Reissmann, Monika; Muñoz-Rodríguez, Mariana B; Ruttkay, Matej; Trinks, Alexandra; Hofreiter, Michael; Ludwig, Arne

    2016-08-01

    Horseback riding is the most fundamental use of domestic horses and has had a huge influence on the development of human societies for millennia. Over time, riding techniques and the style of riding improved. Therefore, horses with the ability to perform comfortable gaits (e.g. ambling or pacing), so-called 'gaited' horses, have been highly valued by humans, especially for long distance travel. Recently, the causative mutation for gaitedness in horses has been linked to a substitution causing a premature stop codon in the DMRT3 gene (DMRT3_Ser301STOP) [1]. In mice, Dmrt3 is expressed in spinal cord interneurons and plays an important role in the development of limb movement coordination [1]. Genotyping the position in 4396 modern horses from 141 breeds revealed that nowadays the mutated allele is distributed worldwide with an especially high frequency in gaited horses and breeds used for harness racing [2]. Here, we examine historic horse remains for the DMRT3 SNP, tracking the origin of gaitedness to Medieval England between 850 and 900 AD. The presence of the corresponding allele in Icelandic horses (9(th)-11(th) century) strongly suggests that ambling horses were brought from the British Isles to Iceland by Norse people. Considering the high frequency of the ambling allele in early Icelandic horses, we believe that Norse settlers selected for this comfortable mode of horse riding soon after arrival. The absence of the allele in samples from continental Europe (including Scandinavia) at this time implies that ambling horses may have spread from Iceland and maybe also the British Isles across the continent at a later date. PMID:27505236

  17. The origin of ambling horses.

    PubMed

    Wutke, Saskia; Andersson, Leif; Benecke, Norbert; Sandoval-Castellanos, Edson; Gonzalez, Javier; Hallsson, Jón Hallsteinn; Lõugas, Lembi; Magnell, Ola; Morales-Muniz, Arturo; Orlando, Ludovic; Pálsdóttir, Albína Hulda; Reissmann, Monika; Muñoz-Rodríguez, Mariana B; Ruttkay, Matej; Trinks, Alexandra; Hofreiter, Michael; Ludwig, Arne

    2016-08-01

    Horseback riding is the most fundamental use of domestic horses and has had a huge influence on the development of human societies for millennia. Over time, riding techniques and the style of riding improved. Therefore, horses with the ability to perform comfortable gaits (e.g. ambling or pacing), so-called 'gaited' horses, have been highly valued by humans, especially for long distance travel. Recently, the causative mutation for gaitedness in horses has been linked to a substitution causing a premature stop codon in the DMRT3 gene (DMRT3_Ser301STOP) [1]. In mice, Dmrt3 is expressed in spinal cord interneurons and plays an important role in the development of limb movement coordination [1]. Genotyping the position in 4396 modern horses from 141 breeds revealed that nowadays the mutated allele is distributed worldwide with an especially high frequency in gaited horses and breeds used for harness racing [2]. Here, we examine historic horse remains for the DMRT3 SNP, tracking the origin of gaitedness to Medieval England between 850 and 900 AD. The presence of the corresponding allele in Icelandic horses (9(th)-11(th) century) strongly suggests that ambling horses were brought from the British Isles to Iceland by Norse people. Considering the high frequency of the ambling allele in early Icelandic horses, we believe that Norse settlers selected for this comfortable mode of horse riding soon after arrival. The absence of the allele in samples from continental Europe (including Scandinavia) at this time implies that ambling horses may have spread from Iceland and maybe also the British Isles across the continent at a later date.

  18. Fascia Origin of Adipose Cells.

    PubMed

    Su, Xueying; Lyu, Ying; Wang, Weiyi; Zhang, Yanfei; Li, Danhua; Wei, Suning; Du, Congkuo; Geng, Bin; Sztalryd, Carole; Xu, Guoheng

    2016-05-01

    Adipocytes might arise from vascular stromal cells, pericytes and endothelia within adipose tissue or from bone marrow cells resident in nonadipose tissue. Here, we identified adipose precursor cells resident in fascia, an uninterrupted sheet of connective tissue that extends throughout the body. The cells and fragments of superficial fascia from the rat hindlimb were highly capable of spontaneous and induced adipogenic differentiation but not myogenic and osteogenic differentiation. Fascial preadipocytes expressed multiple markers of adipogenic progenitors, similar to subcutaneous adipose-derived stromal cells (ASCs) but discriminative from visceral ASCs. Such preadipocytes resided in fascial vasculature and were physiologically active in vivo. In growing rats, adipocytes dynamically arose from the adventitia to form a thin adipose layer in the fascia. Later, some adipocytes appeared to overlay on top of other adipocytes, an early sign for the formation of three-dimensional adipose tissue in fascia. The primitive adipose lobules extended invariably along blood vessels toward the distal fascia areas. At the lobule front, nascent capillaries wrapped and passed ahead of mature adipocytes to form the distal neovasculature niche, which might replenish the pool of preadipocytes and supply nutrients and hormones necessary for continuous adipogenesis. Our findings suggest a novel model for the origin of adipocytes from the fascia, which explains both neogenesis and expansion of adipose tissue. Fascial preadipocytes generate adipose cells to form primitive adipose lobules in superficial fascia, a subcutaneous nonadipose tissue. With continuous adipogenesis, these primitive adipose lobules newly formed in superficial fascia may be the rudiment of subcutaneous adipose tissue. Stem Cells 2016;34:1407-1419.

  19. Paleoflood hydrology: Origin, progress, prospects

    NASA Astrophysics Data System (ADS)

    Baker, Victor R.

    2008-10-01

    From an origin in diverse studies of flood geomorphology and Quaternary geology, paleoflood hydrology emerged as a geophysical and an applied hydrological science during the 1970s and 1980s. Since acquiring its formal name in 1982, the most productive approach in paleoflood hydrology has become energy-based inverse hydraulic modeling of discrete paleoflood events, recorded in appropriate settings as slackwater deposits and other paleostage indicators (SWD-PSI), or as various threshold indicators of non-exceedence. Technological advances, particularly in hydraulic modeling and geochronology, were instrumental in moving the discipline to its present status. The most recent advances include (1) new techniques for the accurate geochronology of flood sediments, notably TAMS radiocarbon analyses and OSL dating, and (2) the phenomenal increase in computer power that allows complex hydraulic calculations to become feasible for routine studies. From its initial demonstration in the southwestern United States, SWD-PSI paleoflood hydrology proved its widespread applicability to various landscape environments. Particularly important studies have been accomplished in Australia, China, India, Israel, South Africa, Spain, and Thailand. Paleoflood hydrology has also generated its share of controversy, in part because of the differing viewpoints and attitudes of the two scientific traditions from which it emerged: Quaternary geology/geomorphology versus applied hydrologic/hydraulic engineering. Nevertheless, the future growth of the discipline is assured, given the rapid pace of discoveries that it engenders. Indeed, so many international studies exist that it is appropriate to pursue global syntheses to address interesting and timely questions of extreme flood phenomena in relation to global climatic change.

  20. Philopatry: A return to origins

    USGS Publications Warehouse

    Pearce, John M.

    2007-01-01

    The potential danger of applying philopatry to non-natal and nonbreeding conditions is that it creates the expectation of certain outcomes, such as low dispersal rates, population genetic differentiation, and unique population segments, when such conditions may not exist. Given that most avian species do not molt, winter, or have migratory stopovers where they breed, I propose that the term “philopatry” and its genetic expectations be used only in relation to natal philopatry and not extended to (1) breeding- site fidelity of individuals whose natal areas are unknown and (2) nonbreeding areas where site- faithful behavior is observed. I believe this correctly distinguishes natal philopatry as a specific type of site fidelity with its own implications for population genetics and dynamics. Thus, philopatry should be viewed as synonymous and interchangeable with the terms “natal-site fidelity” and “natal philopatry,” and the term “breeding-site fidelity” should replace “breeding philopatry,” because it reflects the unknown natal origins of birds captured as adults. Although the broader condition of site fidelity may have implications for fitness, mate pairing, and population delineation—as examined in several studies (Robertson and Cooke 1999, Merom et al. 2000, Iverson et al. 2004, Mehl et al. 2004)—future investigations of site fidelity should be pursued without automatically invoking the term “philopatry” and assuming that the genetic and demographic connotations of natal philopatry also apply. In contrast to philopatry, the probability of fidelity (F) and dispersal (1 − F) are estimable parameters (Burnham 1993, Kendall and Nichols 2004), and the demographic and genetic consequences of site fidelity, regardless of where it occurs, can serve as hypotheses for testing with multiple data types (e.g., Arsenault et al. 2005). Such data mergers should enhance our understanding of the demographic, behavioral, and genetic implications

  1. The Doctorate as an Original Contribution to Knowledge: Considering Relationships between Originality, Creativity, and Innovation

    ERIC Educational Resources Information Center

    Baptista, Ana; Frick, Liezel; Holley, Karri; Remmik, Marvi; Tesch, Jakob; Âkerlind, Gerlese

    2015-01-01

    This article explores the meaning of originality in doctoral studies and its relationship with creativity and innovation. Doctoral theses are expected to provide an original contribution to knowledge in their field all over the world. However, originality is not well defined. Using the literature on concepts of originality as a foundation, this…

  2. The Origin of River Meanders

    NASA Astrophysics Data System (ADS)

    Sahagian, D. L.; Chatanantavet, P.; Bradley, C.; Friedgen-Veitch, D.; Diplas, P.

    2015-12-01

    Various propositions for the origin of meanders have been suggested in the past, involving local disturbances such as variable bank material, obstructions to flow, and sediment transport. Each of these approaches has required a very special and complex set of circumstances for the onset of meandering. However, meanders have also been observed in other systems such as the gulf stream , window glass , glacial meltwater, channels in submarine fans, the jet stream, water faucets, and many others. What has not been satisfactorily demonstrated is why some rivers (or parts of rivers) should tend to meander in the first place rather than ply a straight course to base level. We suggest that the fundamental cause of the river meander instability is simply a minimization of power (rate of work done), with an onset that occurs when inertial terms exceed body forces (e.g. gravity) acting on the flow, and thus create an adverse pressure gradient directed in the opposite direction of the flow. A simple way to visualize the cause of the instability is that the water "backs up" upon itself, running into a parcel of water downstream that is flowing more slowly than the water upstream. This causes the direction of maximum local water surface slope to be diverted to one side or the other of the regional slope. This can occur when a river encounters the ocean (or a lake, or a break in slope), and can occur in many other situations as well. We analyzed various meandering systems globally, and conducted laboratory experiments under controlled conditions to determine the conditions necessary for the onset of the meander instability. The results indicate that the meander instability does not depend on sediment or erodible banks. The critical threshold for the onset of the meander instability occurs when inertial forces exceed body forces acting on the fluid such that an adverse pressure gradient arises. Better understanding of the meander instability should thus elucidate some of the

  3. Magnetofossils: Characteristics, Origins and Distribution

    NASA Astrophysics Data System (ADS)

    Vali, H.

    2005-12-01

    The term magnetofossil was introduced by Joseph Kirschvink and co-workers in the mid-eighties to describe fossil remains of magnetosomes in marine sediments after the discovery of magnetotactic bacteria by Richard Blakemore in the mid-seventies. Magnetofossils were initially considered as stable carriers of natural remanent magnetization (NRM) in sedimentary rocks. In the protracted debate over the possible bacterial origin of magnetite in carbonate in Martian meteorite ALH84001, the term magnetofossil has also been used as evidence for biological activity (i.e., biosignature) in ancient terrestrial and extraterrestrial environments. Magnetic methods sensitive to the single domain (SD) size specificity have been developed to detect the magnetosomes, distinction between biogenic and non-biogenic magnetic phases based upon magnetic analysis is difficult. In addition, with the discovery of SD magnetite formed by thermophilic bacteria isolated from deep subsurface and biogenic magnetite produced through reduction of Fe(III) by a variety of dissimilatory Fe(III)-reducing bacteria (DIRB) in diverse environments and a wide range of temperatures, new criteria has to be established to enable the distinction between biogenic and non-biogenic magnetic phases. Laboratory experiments have shown that the size and shape of magnetic phases formed by these bacteria strongly depend upon the growth culture conditions. Slight variation in the chemical composition, temperature and/or redox condition of the growth medium resulted in deviation in crystal morphology of magnetite making the morphological distinction between biogenic (magnetofossils) and non-biogenic magnetic minerals difficult. Magnetic phases with unique shape, morphology and organization have been observed in a variety of bacteria cultures. The existence of these types of magnetofossils in the natural environment, however, has not been explored. Although alternative preparation and analytical techniques have been

  4. How dormant origins promote complete genome replication.

    PubMed

    Blow, J Julian; Ge, Xin Quan; Jackson, Dean A

    2011-08-01

    Many replication origins that are licensed by loading MCM2-7 complexes in G1 are not normally used. Activation of these dormant origins during S phase provides a first line of defence for the genome if replication is inhibited. When replication forks fail, dormant origins are activated within regions of the genome currently engaged in replication. At the same time, DNA damage-response kinases activated by the stalled forks preferentially suppress the assembly of new replication factories, thereby ensuring that chromosomal regions experiencing replicative stress complete synthesis before new regions of the genome are replicated. Mice expressing reduced levels of MCM2-7 have fewer dormant origins, are cancer-prone and are genetically unstable, demonstrating the importance of dormant origins for preserving genome integrity. We review the function of dormant origins, the molecular mechanism of their regulation and their physiological implications.

  5. A Principled Approach to the Origin Problem.

    PubMed

    Aono, Masashi; Kitadai, Norio; Oono, Yoshi

    2015-09-01

    The key issue of the origin of life is the origin of a complex system rather than the abiotic formation of various organic substances, small and large. To consider this "origin problem" it is advantageous to abstract some principles from biology and statistical physics to guide our approach. Referring to these principles, we aim to construct a chemical system called "protometabolism," which would be a precursor of metabolism.

  6. Modern human origins: progress and prospects.

    PubMed Central

    Stringer, Chris

    2002-01-01

    The question of the mode of origin of modern humans (Homo sapiens) has dominated palaeoanthropological debate over the last decade. This review discusses the main models proposed to explain modern human origins, and examines relevant fossil evidence from Eurasia, Africa and Australasia. Archaeological and genetic data are also discussed, as well as problems with the concept of 'modernity' itself. It is concluded that a recent African origin can be supported for H. sapiens, morphologically, behaviourally and genetically, but that more evidence will be needed, both from Africa and elsewhere, before an absolute African origin for our species and its behavioural characteristics can be established and explained. PMID:12028792

  7. Prostate cancer in men of African origin.

    PubMed

    McGinley, Kathleen F; Tay, Kae Jack; Moul, Judd W

    2016-02-01

    Men of African origin are disproportionately affected by prostate cancer: prostate cancer incidence is highest among men of African origin in the USA, prostate cancer mortality is highest among men of African origin in the Caribbean, and tumour stage and grade at diagnosis are highest among men in sub-Saharan Africa. Socioeconomic, educational, cultural, and genetic factors, as well as variations in care delivery and treatment selection, contribute to this cancer disparity. Emerging data on single-nucleotide-polymorphism patterns, epigenetic changes, and variations in fusion-gene products among men of African origin add to the understanding of genetic differences underlying this disease. On the diagnosis of prostate cancer, when all treatment options are available, men of African origin are more likely to choose radiation therapy or to receive no definitive treatment than white men. Among men of African origin undergoing surgery, increased rates of biochemical recurrence have been identified. Understanding differences in the cancer-survivorship experience and quality-of-life outcomes among men of African origin are critical to appropriately counsel patients and improve cultural sensitivity. Efforts to curtail prostate cancer screening will likely affect men of African origin disproportionately and widen the racial disparity of disease.

  8. The Gestural Theory of Language Origins

    ERIC Educational Resources Information Center

    Armstrong, David F.

    2008-01-01

    The idea that iconic visible gesture had something to do with the origin of language, particularly speech, is a frequent element in speculation about this phenomenon and appears early in its history. Socrates hypothesizes about the origins of Greek words in Plato's satirical dialogue, "Cratylus", and his speculation includes a possible role for…

  9. 22 CFR 9.4 - Original classification.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Original classification. 9.4 Section 9.4... classification. (a) Definition. Original classification is the initial determination that certain information... classification. (b) Classification levels. (1) Top Secret shall be applied to information the...

  10. 46 CFR 503.54 - Original classification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 9 2014-10-01 2014-10-01 false Original classification. 503.54 Section 503.54 Shipping... Program § 503.54 Original classification. (a) No Commission Member or employee has the authority to... require classification, or receives any foreign government information as defined in section 6.1(s)...

  11. 22 CFR 9.4 - Original classification.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Original classification. 9.4 Section 9.4... classification. (a) Definition. Original classification is the initial determination that certain information... classification. (b) Classification levels. (1) Top Secret shall be applied to information the...

  12. 22 CFR 9.4 - Original classification.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Original classification. 9.4 Section 9.4... classification. (a) Definition. Original classification is the initial determination that certain information... classification. (b) Classification levels. (1) Top Secret shall be applied to information the...

  13. 17 CFR 200.505 - Original classification.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 3 2014-04-01 2014-04-01 false Original classification. 200...; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security Information and Material § 200.505 Original classification. (a) No Commission Member or employee has...

  14. 46 CFR 503.54 - Original classification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 9 2013-10-01 2013-10-01 false Original classification. 503.54 Section 503.54 Shipping... Program § 503.54 Original classification. (a) No Commission Member or employee has the authority to... require classification, or receives any foreign government information as defined in section 6.1(s)...

  15. 17 CFR 200.505 - Original classification.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Original classification. 200...; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security Information and Material § 200.505 Original classification. (a) No Commission Member or employee has...

  16. 17 CFR 200.505 - Original classification.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 2 2012-04-01 2012-04-01 false Original classification. 200...; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security Information and Material § 200.505 Original classification. (a) No Commission Member or employee has...

  17. 46 CFR 503.54 - Original classification.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 9 2012-10-01 2012-10-01 false Original classification. 503.54 Section 503.54 Shipping... Program § 503.54 Original classification. (a) No Commission Member or employee has the authority to... require classification, or receives any foreign government information as defined in section 6.1(s)...

  18. 17 CFR 200.505 - Original classification.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 2 2013-04-01 2013-04-01 false Original classification. 200...; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security Information and Material § 200.505 Original classification. (a) No Commission Member or employee has...

  19. 21 CFR 814.104 - Original applications.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....104 Original applications. (b) * * * (4) * * * (ii) * * * The effectiveness of this device for this... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Original applications. 814.104 Section 814.104... applications. Link to an amendment published at 79 FR 1740, Jan. 10, 2014. (a) United States applicant...

  20. 7 CFR 201.58b - Origin.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Origin. 201.58b Section 201.58b Agriculture... REGULATIONS Examinations in the Administration of the Act § 201.58b Origin. The presence of incidental weed seeds, foreign matter, or any other existing circumstances shall be considered in determining the...

  1. 7 CFR 201.58b - Origin.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Origin. 201.58b Section 201.58b Agriculture... REGULATIONS Examinations in the Administration of the Act § 201.58b Origin. The presence of incidental weed seeds, foreign matter, or any other existing circumstances shall be considered in determining the...

  2. 7 CFR 201.58b - Origin.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Origin. 201.58b Section 201.58b Agriculture... REGULATIONS Examinations in the Administration of the Act § 201.58b Origin. The presence of incidental weed seeds, foreign matter, or any other existing circumstances shall be considered in determining the...

  3. 7 CFR 201.58b - Origin.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Origin. 201.58b Section 201.58b Agriculture... REGULATIONS Examinations in the Administration of the Act § 201.58b Origin. The presence of incidental weed seeds, foreign matter, or any other existing circumstances shall be considered in determining the...

  4. 7 CFR 201.58b - Origin.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Origin. 201.58b Section 201.58b Agriculture... REGULATIONS Examinations in the Administration of the Act § 201.58b Origin. The presence of incidental weed seeds, foreign matter, or any other existing circumstances shall be considered in determining the...

  5. Starkweather Originality Test for Young Children.

    ERIC Educational Resources Information Center

    Starkweather, Elizabeth K.

    The Starkweather Originality Test is designed to measure the creative potential of children ranging in age from 3 years, 6 months to 6 years, 6 months. Children younger than 3 years, 6 months can be given the Originality Test if their ability to communicate verbally is satisfactorily demonstrated during the pretest. The test is individually…

  6. 31 CFR 575.311 - Iraqi origin.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Iraqi origin. 575.311 Section 575.311 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN... Government of Iraq, or of a business entity located in Iraq. Services of Iraqi origin are not imported...

  7. 17 CFR 200.505 - Original classification.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Original classification. 200...; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security Information and Material § 200.505 Original classification. (a) No Commission Member or employee has...

  8. 46 CFR 503.54 - Original classification.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 9 2010-10-01 2010-10-01 false Original classification. 503.54 Section 503.54 Shipping... Program § 503.54 Original classification. (a) No Commission Member or employee has the authority to... require classification, or receives any foreign government information as defined in section 1.1(d)...

  9. Impacts and the origin of life

    NASA Technical Reports Server (NTRS)

    Kasting, J. F.

    1990-01-01

    As living creatures, all of us have some interest in the question of how life originated. To some, the question is more religious than scientific; nonetheless, a small but dedicated group of scientists spend their careers trying to answer it from a rational standpoint. Logically, the question can be broken down into the three standard divisions of any mystery: When did life originate? Where did it originate? And how did it originate? Of these three sub-questions the last is by far the most difficult and I will make no attempt to address it here. I will however take a personal look at the two easier parts of the problem. In particular, I will outline my current view of the physical environment of the early Earth, and I will try to show how observations of other solar system bodies, especially our own Moon, provide clues as to when and where life could have originated.

  10. The origin of turtles: a paleontological perspective.

    PubMed

    Joyce, Walter G

    2015-05-01

    The origin of turtles and their unusual body plan has fascinated scientists for the last two centuries. Over the course of the last decades, a broad sample of molecular analyses have favored a sister group relationship of turtles with archosaurs, but recent studies reveal that this signal may be the result of systematic biases affecting molecular approaches, in particular sampling, non-randomly distributed rate heterogeneity among taxa, and the use of concatenated data sets. Morphological studies, by contrast, disfavor archosaurian relationships for turtles, but the proposed alternative topologies are poorly supported as well. The recently revived paleontological hypothesis that the Middle Permian Eunotosaurus africanus is an intermediate stem turtle is now robustly supported by numerous characters that were previously thought to be unique to turtles and that are now shown to have originated over the course of tens of millions of years unrelated to the origin of the turtle shell. Although E. africanus does not solve the placement of turtles within Amniota, it successfully extends the stem lineage of turtles to the Permian and helps resolve some questions associated with the origin of turtles, in particular the non-composite origin of the shell, the slow origin of the shell, and the terrestrial setting for the origin of turtles.

  11. The RNA World and its origins

    NASA Technical Reports Server (NTRS)

    Schwartz, A. W.

    1995-01-01

    The theory of the "RNA World" states that the first molecular systems to display the properties of self-replication and evolution were RNA molecules. The origin of life not only depended crucially upon this event, but RNA molecules can even be viewed as the first "living" things. In recent years this theory has gained ascendancy over competing ideas and is now largely accepted by biologists as the most satisfactory explanation for the origin of life. The reasons for this development will be reviewed and the problem of the origin of the first RNA molecules will be discussed.

  12. Geochemistry and origin of regional dolomites

    SciTech Connect

    Hanson, G.N.; Meyers, W.J.

    1992-01-01

    This grant supports research on the origins and geochemical aspects of regional dolomites. Eight graduate students are involved in research on dolomite allowing a diverse range of studies. This report outlines their work in the field. (JL)

  13. Geochemistry and the origin of life

    NASA Technical Reports Server (NTRS)

    Kvenvolden, K. A.

    1974-01-01

    The origin of life on earth is examined from a viewpoint stressing the validity of the concept of chemical evolution. The different geological formations supporting the mechanisms of the theory are described; the stage of chemical evolution (preceding that of biological evolution) would have taken place from the time of the origin of the earth and meteorites, 4.6 billion years ago, to the early Precambrian period, about 3.2 billion years ago. Specific aspects of the problem discussed include amino acids from spark discharges and their comparison with the Murchison meteorite amino acids, the properties and theory of genesis of the carbonaceous complex within the cold Bokevelt meteorite, ammonion ion concentration in the primitive ocean, the oxygen isotope chemistry of ancient charts, the origin and rise of oxygen concentration in the earth's atmosphere, Precambrian microorganisms and evolutionary events prior to the origin of vascular plants, and biogenicity and significance of the oldest known stromatolites.

  14. 46 CFR 503.54 - Original classification.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... FEDERAL MARITIME COMMISSION GENERAL AND ADMINISTRATIVE PROVISIONS PUBLIC INFORMATION Information Security... subject matter, or to the Information Security Oversight Office, for review and a classification... originally classify information. (b) If a Commission Member or employee develops information that appears...

  15. 31 CFR 538.312 - Sudanese origin.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., manufactured, grown, extracted, or processed within Sudan; (b) Goods which have entered into Sudanese commerce... United States. (e) The term goods or services of Sudanese origin does not include goods or services...

  16. Retroperitoneal Bronchogenic Cyst Originating from Diaphragmatic Crura.

    PubMed

    Herek, Duygu; Erbiş, Halil; Kocyigit, Ali; Yagci, Ahmet Baki

    2015-12-01

    Bronchogenic cyst is a benign lesion which is commonly seen in the posterior mediastinum. Diaphragmatic origin in retroperitoneum is an unusual location for a bronchogenic cyst. Cross-sectional imaging modalities describe the origin and content of the cyst evidently. Magnetic resonance (MR) images of a 42-year-old male patient who attended ER with back pain revealed a huge retroperitoneal complicated bronchogenic cyst arising from the diaphragm and surrounding the abdominal aorta anteriorly. Bronchogenic cysts in the retroperitoneum rarely originate from the diaphragm and should be kept in mind in the differential diagnoses of abdominal cystic lesions. MR imaging (MRI) is superior to other imaging techniques such as computerized tomography (CT) in detecting the origin and content of these cystic lesions.

  17. Blue Origin Conducts Pad Escape Test

    NASA Video Gallery

    Blue Origin conducted a successful pad escape test Oct. 19 at the company's West Texas launch site, firing its pusher escape motor and launching a full-scale suborbital crew capsule from a simulate...

  18. Blue Origin Tests BE-3 Engine

    NASA Video Gallery

    Blue Origin successfully fires the thrust chamber assembly for its new 100,000 pound thrust BE-3 liquid oxygen, liquid hydrogen rocket engine. As part of the company's Reusable Booster System (RBS)...

  19. The Origin and Evolution of Viruses

    NASA Astrophysics Data System (ADS)

    Agol, Vadim I.

    The lecture covers three main topics: (i) Viruses: properties, place in the living world, and possible origin; (ii) Molecular basis of viral variability and evolution; and (iii) Evolution of viral pathogenicity and emerging viral infections.

  20. The Origin of Life in Comets

    NASA Astrophysics Data System (ADS)

    Napier, W. M.; Wickramasinghe, J. T.; Wickramasinghe, N. C.

    Mechanisms of interstellar panspermia have recently been identified whereby life, wherever it has originated, will disperse throughout the habitable zone of the Galaxy within a few billion years. This re-opens the question of where life originated. The interiors of comets, during their aqueous phase, seem to provide environments no less favourable for the origin of life than that of the early Earth. Their combined mass throughout the Galaxy overwhelms that of suitable terrestrial environments by about 20 powers of ten, while the lifetimes of friendly prebiotic environments within them exceeds that of localised terrestrial regions by another four or five powers of ten. We propose that the totality of comets around G-dwarf Sun-like stars offers an incomparably more probable setting for the origin of life than any that was available on the early Earth.

  1. "Origins of Tolerance": Reply to Crockett

    ERIC Educational Resources Information Center

    Williams, J. Allen, Jr.; And Others

    1976-01-01

    Refutes the criticisms made by Harry Crockett (Social Forces 55(2), 1976) and conclude that there is no evidence in his criticisms that the interpretations of the origins of tolerance previously expressed are wrong. (AM)

  2. Human embryos in the original position?

    PubMed

    DiSilvestro, Russell

    2005-06-01

    Two different discussions in John Rawls' A Theory of Justice lead naturally to a rather conservative position on the moral status of the human embryo. When discussing paternalism, he claims that the parties in the original position would seek to protect themselves in case they end up as incapacitated or undeveloped human beings when the veil of ignorance is lifted. Since human embryos are examples of such beings, the parties in the original position would seek to protect themselves from their embryonic stages onward. When discussing the basis of equality, Rawls claims that the parties in the original position would guarantee basic rights for all those with the capacity to take part in this original position. To guarantee the basic rights of infants and young children, he goes on to interpret this capacity as a "potentiality that is ordinarily realized in due course." Since human embryos have this potentiality, they too should have basic rights.

  3. The Solar System and Its Origin

    ERIC Educational Resources Information Center

    Dormand, J. R.

    1973-01-01

    Presents a brief explanation of the solar system, including planets, asteroids, satellites, comets, planetary orbits, as well as, old and recent cosmogonic theories. Indicates that man is nearer a solution to the origin of the planetary system than ever before.

  4. An Introduction to Comets and Their Origin.

    ERIC Educational Resources Information Center

    Chapman, Robert D.; Brandt, John C.

    1985-01-01

    Presents excerpts from "The Comet Book," a nontechnical primer on comets. Various topics discusses in these excerpts include such basic information about comets as their components, paths, and origins. (DH)

  5. 2009 Swine Flu Originated in Mexico

    MedlinePlus

    ... fullstory_159679.html 2009 Swine Flu Originated in Mexico Genetic analysis pinpoints source of the pandemic influenza ... in pigs in a small region of central Mexico, a new study reports. Researchers used genetic analysis ...

  6. Identification of New Human Origins of DNA Replication by an Origin-Trapping Assay▿ †

    PubMed Central

    Gerhardt, Jeannine; Jafar, Samira; Spindler, Mark-Peter; Ott, Elisabeth; Schepers, Aloys

    2006-01-01

    Metazoan genomes contain thousands of replication origins, but only a limited number have been characterized so far. We developed a two-step origin-trapping assay in which human chromatin fragments associated with origin recognition complex (ORC) in vivo were first enriched by chromatin immunoprecipitation. In a second step, these fragments were screened for transient replication competence in a plasmid-based assay utilizing the Epstein-Barr virus latent origin oriP. oriP contains two elements, an origin (dyad symmetry element [DS]) and the family of repeats, that when associated with the viral protein EBNA1 facilitate extrachromosomal stability. Insertion of the ORC-binding human DNA fragments in oriP plasmids in place of DS enabled us to screen functionally for their abilities to restore replication. Using the origin-trapping assay, we isolated and characterized five previously unknown human origins. The assay was validated with nascent strand abundance assays that confirm these origins as active initiation sites in their native chromosomal contexts. Furthermore, ORC and MCM2-7 components localized at these origins during G1 phase of the cell cycle but were not detected during mitosis. This finding extends the current understanding of origin-ORC dynamics by suggesting that replication origins must be reestablished during the early stages of each cell division cycle and that ORC itself participates in this process. PMID:16954389

  7. The chromatin environment shapes DNA replication origin organization and defines origin classes

    PubMed Central

    Cayrou, Christelle; Ballester, Benoit; Peiffer, Isabelle; Fenouil, Romain; Coulombe, Philippe; Andrau, Jean-Christophe; van Helden, Jacques; Méchali, Marcel

    2015-01-01

    To unveil the still-elusive nature of metazoan replication origins, we identified them genome-wide and at unprecedented high-resolution in mouse ES cells. This allowed initiation sites (IS) and initiation zones (IZ) to be differentiated. We then characterized their genetic signatures and organization and integrated these data with 43 chromatin marks and factors. Our results reveal that replication origins can be grouped into three main classes with distinct organization, chromatin environment, and sequence motifs. Class 1 contains relatively isolated, low-efficiency origins that are poor in epigenetic marks and are enriched in an asymmetric AC repeat at the initiation site. Late origins are mainly found in this class. Class 2 origins are particularly rich in enhancer elements. Class 3 origins are the most efficient and are associated with open chromatin and polycomb protein-enriched regions. The presence of Origin G-rich Repeated elements (OGRE) potentially forming G-quadruplexes (G4) was confirmed at most origins. These coincide with nucleosome-depleted regions located upstream of the initiation sites, which are associated with a labile nucleosome containing H3K64ac. These data demonstrate that specific chromatin landscapes and combinations of specific signatures regulate origin localization. They explain the frequently observed links between DNA replication and transcription. They also emphasize the plasticity of metazoan replication origins and suggest that in multicellular eukaryotes, the combination of distinct genetic features and chromatin configurations act in synergy to define and adapt the origin profile. PMID:26560631

  8. Genetic characterization of Indian-origin and Chinese-origin rhesus macaques (Macaca mulatta).

    PubMed

    Smith, David Glenn

    2005-06-01

    Genetic differences between Indian-origin and Chinese-origin rhesus macaques are as great as those between some primate species and can influence the results of experiments in which both are used as animal models for the study of the same human diseases. Unfortunately, many breeding facilities do not know with certainty the origin of the founders of their rhesus breeding colonies. Here I summarize the most definitive of the genetic traits among the microsatellite (STR) loci and mitochondrial DNA sequences that my laboratory previously reported to characterize Indian-origin and Chinese-origin rhesus macaques and then estimate the frequencies of these traits and their reliability as indicators of country of origin. The expression of diagnostic traits at two or more of four different unlinked loci provides a nearly 100% reliability in distinguishing rhesus macaques of Indian and Chinese origin.

  9. Origins, Evolution, and Fate of Brown Dwarfs

    NASA Technical Reports Server (NTRS)

    Martin, Eduardo

    2003-01-01

    Research related to the origins, evolution and fate of brown dwarfs is presented. The topics include: 1) Imaging surveys for brown dwarfs; 2) Companion detection techniques; 3) Measurements of fundamental properties of brown dwarfs; 4) Classification schemes for ultracool dwarfs; 5) Origins and evolution of brown dwarfs; 6) Ultracool atmospheres and interiors; 7) Time variable phenomena in brown dwarfs; 8) Comparisons between brown dwarfs and planets; 9) Substellar mass functions; and 10) Future facilities.

  10. Luna 24 origins - Some trace element constraints

    NASA Technical Reports Server (NTRS)

    Jovanovic, S.; Jensen, K. J.; Reed, G. W., Jr.

    1978-01-01

    Luna 24 basaltic material originated in the particular volume of the lunar crust that produced Apollo 11 and Luna 16 basaltic material; it has the same Clr/P2O5 (r = residual) signature. Ru-Os contents (Barsukov et al., 1977) and a number of radiogenic age measurements place Luna 24 basalt origins stratigraphically in a layer between those from which Apollo 15 and Apollo 11 and 17 basalts were derived.

  11. Fisheries. Population of origin of Atlantic cod.

    PubMed

    Nielsen, E E; Hansen, M M; Schmidt, C; Meldrup, D; Grønkjaer, P

    2001-09-20

    Most of the world's cod (Gadus morhua) fisheries are now tightly regulated or closed altogether. Being able to link individual fish to their population of origin would assist enormously in policing regulations and in identifying poachers. Here we show that microsatellite genetic markers can be used to assign individual cod from three different populations in the northeastern Atlantic Ocean to their population of origin. PMID:11565021

  12. A Review of Ideas Concerning Life Origin

    NASA Astrophysics Data System (ADS)

    Gindilis, L. M.

    2014-10-01

    Since the times of Antiquity the and for a long time the idea of self-origination of life was the dominant one. It reappeared again after microorganisms were discovered (XVII century). The possibility of abiogenesis at microbial level was discussed for more than a century. Pateur demonstrated that spontaneous origination of microorganisms in sterile broth was due to those same microorganisms transported by dust particles. Thus proving that every form of life originates from the parental life form. So the question arises: how did the first microorganisms appear on the Earth. There are three possible versions: 1) accidental origination of a viable form; 2) primal organisms were transported to the Earth from outer space; 3) they were formed on the Earth in the process of prebiotic chemical evolution. We discuss the problems of prebiotic evolution from simple monomers up to living cells. An important item of nowadays conceptions of life origination is the hypothesis of the ancient world of RNA as possible precursor of life on Earth. The discovery in carbonaceous chondrites of traces of bacterial life evidences the existence of life in the Solar System even before the formation of the Earth. The idea of life as brought to the Earth out of Cosmos originated under the impression of self-origination hypothesis downfall. It went through several stages (Helmholtz, W. Thompson, XIX century; Arrhenius, early XX century; Hoyle and Wickramasinghe, second half of XX century) and presently evokes constantly growing interest. The panspermia theory does not solve the problem of origination of life, only moves it onto other planets. According to V.A. Mazur, the probability of accidental formation of RNA molecule is negligible not only on the Earth, but in the whole Universe over all the time span of its existence. But it is practically equal to unit in the domain formed at the inflation stage of the evolution of the Universe. A.D.Panov considered panspermia in the Galaxy at the level

  13. GC skew and mitochondrial origins of replication.

    PubMed

    Sahyoun, Abdullah H; Bernt, Matthias; Stadler, Peter F; Tout, Kifah

    2014-07-01

    The comprehensive understanding of mitochondrial genome evolution requires a detailed mechanistic picture of mitogenomic replication. Despite many previous efforts it has remained a non-trivial problem to determine the origins of replication and trace their fate across rearrangements of the gene order even in the small genomes of animal mitochondria. We elaborate here on the observation that the GC skew is correlated with the distance from the replication origins. This effect has been explained as a consequence of the standard model of mitochondrial DNA replication, i.e. the strand displacement model. According to this model chemical damage accumulates proportional to the duration that DNA is exposed in single-stranded form during replication (Dssh) which depends on the relative position with respect to the replication origins. Based on this model we developed a computational method to infer the positions of both the heavy strand and the light strand origin from nucleotide skew data. In a comprehensive survey of deuterostome mitochondria we infer conserved replication origins for the vast majority of vertebrates and cephalochordates. Deviations from the consensus picture are presumably associated with genome rearrangements.

  14. The precise temporal calibration of dinosaur origins

    NASA Astrophysics Data System (ADS)

    Marsicano, Claudia A.; Irmis, Randall B.; Mancuso, Adriana C.; Mundil, Roland; Chemale, Farid

    2016-01-01

    Dinosaurs have been major components of ecosystems for over 200 million years. Although different macroevolutionary scenarios exist to explain the Triassic origin and subsequent rise to dominance of dinosaurs and their closest relatives (dinosauromorphs), all lack critical support from a precise biostratigraphically independent temporal framework. The absence of robust geochronologic age control for comparing alternative scenarios makes it impossible to determine if observed faunal differences vary across time, space, or a combination of both. To better constrain the origin of dinosaurs, we produced radioisotopic ages for the Argentinian Chañares Formation, which preserves a quintessential assemblage of dinosaurian precursors (early dinosauromorphs) just before the first dinosaurs. Our new high-precision chemical abrasion thermal ionization mass spectrometry (CA-TIMS) U-Pb zircon ages reveal that the assemblage is early Carnian (early Late Triassic), 5- to 10-Ma younger than previously thought. Combined with other geochronologic data from the same basin, we constrain the rate of dinosaur origins, demonstrating their relatively rapid origin in a less than 5-Ma interval, thus halving the temporal gap between assemblages containing only dinosaur precursors and those with early dinosaurs. After their origin, dinosaurs only gradually dominated mid- to high-latitude terrestrial ecosystems millions of years later, closer to the Triassic-Jurassic boundary.

  15. The precise temporal calibration of dinosaur origins.

    PubMed

    Marsicano, Claudia A; Irmis, Randall B; Mancuso, Adriana C; Mundil, Roland; Chemale, Farid

    2016-01-19

    Dinosaurs have been major components of ecosystems for over 200 million years. Although different macroevolutionary scenarios exist to explain the Triassic origin and subsequent rise to dominance of dinosaurs and their closest relatives (dinosauromorphs), all lack critical support from a precise biostratigraphically independent temporal framework. The absence of robust geochronologic age control for comparing alternative scenarios makes it impossible to determine if observed faunal differences vary across time, space, or a combination of both. To better constrain the origin of dinosaurs, we produced radioisotopic ages for the Argentinian Chañares Formation, which preserves a quintessential assemblage of dinosaurian precursors (early dinosauromorphs) just before the first dinosaurs. Our new high-precision chemical abrasion thermal ionization mass spectrometry (CA-TIMS) U-Pb zircon ages reveal that the assemblage is early Carnian (early Late Triassic), 5- to 10-Ma younger than previously thought. Combined with other geochronologic data from the same basin, we constrain the rate of dinosaur origins, demonstrating their relatively rapid origin in a less than 5-Ma interval, thus halving the temporal gap between assemblages containing only dinosaur precursors and those with early dinosaurs. After their origin, dinosaurs only gradually dominated mid- to high-latitude terrestrial ecosystems millions of years later, closer to the Triassic-Jurassic boundary.

  16. The origin of mesoderm in phoronids

    NASA Technical Reports Server (NTRS)

    Freeman, Gary; Martindale, Mark Q.

    2002-01-01

    Descriptive studies of phoronid development have concluded that the mesoderm of these animals originates from the endoderm during gastrulation. This interpretation has been tested by labeling one blastomere of 4- through 16-cell embryos and examining the position and germ layers occupied by the labeled clones of cells in the larva. No 2 injections gave rise to identical clones of cells, suggesting that the cleavage program does not generate cells of unique identity and that cell fates are established at later developmental time points. In many cases, a relatively large sector composed of ectodermal cells was labeled. When these labeled cells were adjacent to the mouth or anus of the larva, muscle and mesenchyme cells originated from the labeled clones. Under these circumstances, nerve cells also originated from these labeled sectors. These labeling studies also showed that endodermal cells can give rise to mesodermal and neural cells. These results suggest that nerve and muscle cells are induced to form at ectodermal-endodermal boundaries from both germ layers. These marking experiments also confirmed the observation that nerve cells originate both from the apical organ and the trunk region and show for the first time that the intestine originates by ingression of posterior ectoderm.

  17. The precise temporal calibration of dinosaur origins

    PubMed Central

    Marsicano, Claudia A.; Irmis, Randall B.; Mancuso, Adriana C.; Mundil, Roland; Chemale, Farid

    2016-01-01

    Dinosaurs have been major components of ecosystems for over 200 million years. Although different macroevolutionary scenarios exist to explain the Triassic origin and subsequent rise to dominance of dinosaurs and their closest relatives (dinosauromorphs), all lack critical support from a precise biostratigraphically independent temporal framework. The absence of robust geochronologic age control for comparing alternative scenarios makes it impossible to determine if observed faunal differences vary across time, space, or a combination of both. To better constrain the origin of dinosaurs, we produced radioisotopic ages for the Argentinian Chañares Formation, which preserves a quintessential assemblage of dinosaurian precursors (early dinosauromorphs) just before the first dinosaurs. Our new high-precision chemical abrasion thermal ionization mass spectrometry (CA-TIMS) U–Pb zircon ages reveal that the assemblage is early Carnian (early Late Triassic), 5- to 10-Ma younger than previously thought. Combined with other geochronologic data from the same basin, we constrain the rate of dinosaur origins, demonstrating their relatively rapid origin in a less than 5-Ma interval, thus halving the temporal gap between assemblages containing only dinosaur precursors and those with early dinosaurs. After their origin, dinosaurs only gradually dominated mid- to high-latitude terrestrial ecosystems millions of years later, closer to the Triassic–Jurassic boundary. PMID:26644579

  18. Two maternal origins of Chinese domestic goose.

    PubMed

    Li, H F; Zhu, W Q; Chen, K W; H, Y; Xu, W J; Song, W

    2011-12-01

    China is particularly rich in goose genetic resources. Systematic study of the genetic diversity and origin of Chinese domestic geese will provide an important scientific basis for the conservation and utilization of these resources and for human history. The 521-bp control region (D-loop) of mitochondrial DNA from 26 goose breeds and 6 Landaise geese were sequenced. The results showed that the average haplotype diversity and nucleotide diversity of Chinese domestic geese were 0.1384 and 0.00029, respectively. Shared haplotype analysis and systematic evolution analysis revealed that Chinese domestic geese had 2 maternal origins. The Yili goose breed originated from the Greylag goose (Anser anser), and the other 25 domestic goose breeds originated from the swan goose (Anser cygnoides). An interesting finding was that 1 Linxian white goose and 1 Wanxi white goose shared the same H4 haplotype with the Rhine goose and the Landaise goose, which originated from the Greylag goose (A. anser). Further research on this finding is planned.

  19. The precise temporal calibration of dinosaur origins.

    PubMed

    Marsicano, Claudia A; Irmis, Randall B; Mancuso, Adriana C; Mundil, Roland; Chemale, Farid

    2016-01-19

    Dinosaurs have been major components of ecosystems for over 200 million years. Although different macroevolutionary scenarios exist to explain the Triassic origin and subsequent rise to dominance of dinosaurs and their closest relatives (dinosauromorphs), all lack critical support from a precise biostratigraphically independent temporal framework. The absence of robust geochronologic age control for comparing alternative scenarios makes it impossible to determine if observed faunal differences vary across time, space, or a combination of both. To better constrain the origin of dinosaurs, we produced radioisotopic ages for the Argentinian Chañares Formation, which preserves a quintessential assemblage of dinosaurian precursors (early dinosauromorphs) just before the first dinosaurs. Our new high-precision chemical abrasion thermal ionization mass spectrometry (CA-TIMS) U-Pb zircon ages reveal that the assemblage is early Carnian (early Late Triassic), 5- to 10-Ma younger than previously thought. Combined with other geochronologic data from the same basin, we constrain the rate of dinosaur origins, demonstrating their relatively rapid origin in a less than 5-Ma interval, thus halving the temporal gap between assemblages containing only dinosaur precursors and those with early dinosaurs. After their origin, dinosaurs only gradually dominated mid- to high-latitude terrestrial ecosystems millions of years later, closer to the Triassic-Jurassic boundary. PMID:26644579

  20. An integrative approach to understanding bird origins.

    PubMed

    Xu, Xing; Zhou, Zhonghe; Dudley, Robert; Mackem, Susan; Chuong, Cheng-Ming; Erickson, Gregory M; Varricchio, David J

    2014-12-12

    Recent discoveries of spectacular dinosaur fossils overwhelmingly support the hypothesis that birds are descended from maniraptoran theropod dinosaurs, and furthermore, demonstrate that distinctive bird characteristics such as feathers, flight, endothermic physiology, unique strategies for reproduction and growth, and a novel pulmonary system originated among Mesozoic terrestrial dinosaurs. The transition from ground-living to flight-capable theropod dinosaurs now probably represents one of the best-documented major evolutionary transitions in life history. Recent studies in developmental biology and other disciplines provide additional insights into how bird characteristics originated and evolved. The iconic features of extant birds for the most part evolved in a gradual and stepwise fashion throughout archosaur evolution. However, new data also highlight occasional bursts of morphological novelty at certain stages particularly close to the origin of birds and an unavoidable complex, mosaic evolutionary distribution of major bird characteristics on the theropod tree. Research into bird origins provides a premier example of how paleontological and neontological data can interact to reveal the complexity of major innovations, to answer key evolutionary questions, and to lead to new research directions. A better understanding of bird origins requires multifaceted and integrative approaches, yet fossils necessarily provide the final test of any evolutionary model.

  1. What is the origin of pancreatic adenocarcinoma?

    PubMed Central

    Pour, Parviz M; Pandey, Krishan K; Batra, Surinder K

    2003-01-01

    The concept of pancreatic cancer origin is controversial. Acinar, ductal or islet cells have been hypothesized as the cell of origin. The pros and cons of each of these hypotheses are discussed. Based on the world literature and recent observations, pancreatic cells seem to have potential for phenotypical transdifferentiation, i.e ductal-islet, ductal-acinar, acinar-ductal, acinar-islet, islet-acinar and islet-ductal cells. Although the possibility is discussed that cancer may arise from either islet, ductal or acinar cells, the circumstances favoring the islet cells as the tumor cell origin include their greater transdifferentiation potency into both pancreatic and extrapancreatic cells, the presence of a variety of carcinogen-metabolizing enzymes, some of which are present exclusively in islet cells and the growth factor-rich environment of islets. PMID:12636873

  2. Symbiosis and the origin of eukaryotic motility

    NASA Technical Reports Server (NTRS)

    Margulis, L.; Hinkle, G.

    1991-01-01

    Ongoing work to test the hypothesis of the origin of eukaryotic cell organelles by microbial symbioses is discussed. Because of the widespread acceptance of the serial endosymbiotic theory (SET) of the origin of plastids and mitochondria, the idea of the symbiotic origin of the centrioles and axonemes for spirochete bacteria motility symbiosis was tested. Intracellular microtubular systems are purported to derive from symbiotic associations between ancestral eukaryotic cells and motile bacteria. Four lines of approach to this problem are being pursued: (1) cloning the gene of a tubulin-like protein discovered in Spirocheata bajacaliforniesis; (2) seeking axoneme proteins in spirochets by antibody cross-reaction; (3) attempting to cultivate larger, free-living spirochetes; and (4) studying in detail spirochetes (e.g., Cristispira) symbiotic with marine animals. Other aspects of the investigation are presented.

  3. The origin of the vertebrate skeleton

    NASA Astrophysics Data System (ADS)

    Pivar, Stuart

    2011-01-01

    The anatomy of the human and other vertebrates has been well described since the days of Leonardo da Vinci and Vesalius. The causative origin of the configuration of the bones and of their shapes and forms has been addressed over the ensuing centuries by such outstanding investigators as Goethe, Von Baer, Gegenbauer, Wilhelm His and D'Arcy Thompson, who sought to apply mechanical principles to morphogenesis. However, no coherent causative model of morphogenesis has ever been presented. This paper presents a causative model for the origin of the vertebrate skeleton, based on the premise that the body is a mosaic enlargement of self-organized patterns engrained in the membrane of the egg cell. Drawings illustrate the proposed hypothetical origin of membrane patterning and the changes in the hydrostatic equilibrium of the cytoplasm that cause topographical deformations resulting in the vertebrate body form.

  4. Book Review: The Origins of Comets

    NASA Technical Reports Server (NTRS)

    McKay, Christopher P.

    1992-01-01

    In The Origins of Comets, Bailey, Clube, and Napier propose that the answer to whether the ancient heavens were more interesting is a resounding "yes." The sky, in fact, has changed and is still changing. The authors trace the study of comets back to ancient Babylonian times with a focus on theories of the origins of these enigmatic visitors. The book is really of three distinct parts: the first six chapters provide an excellent and delightfully readable historical account of comet studies up to this century. The next few chapters give a rather detailed treatment of current models for comet origins. The last section treats the authors' own theories about the relationship between giant comets and extinctions on Earth.

  5. The origin of life from primordial planets

    NASA Astrophysics Data System (ADS)

    Gibson, Carl H.; Schild, Rudolph E.; Wickramasinghe, N. Chandra

    2011-04-01

    The origin of life and the origin of the Universe are among the most important problems of science and they might be inextricably linked. Hydro-gravitational-dynamics cosmology predicts hydrogen-helium gas planets in clumps as the dark matter of galaxies, with millions of planets per star. This unexpected prediction is supported by quasar microlensing of a galaxy and a flood of new data from space telescopes. Supernovae from stellar over-accretion of planets produce the chemicals (C, N, O, P, etc.) and abundant liquid-water domains required for first life and the means for wide scattering of life prototypes. Life originated following the plasma-to-gas transition between 2 and 20 Myr after the big bang, while planetary core oceans were between critical and freezing temperatures, and interchanges of material between planets constituted essentially a cosmological primordial soup. Images from optical, radio and infrared space telescopes suggest life on Earth was neither first nor inevitable.

  6. Origin of Spliceosomal Introns and Alternative Splicing

    PubMed Central

    Irimia, Manuel; Roy, Scott William

    2014-01-01

    In this work we review the current knowledge on the prehistory, origins, and evolution of spliceosomal introns. First, we briefly outline the major features of the different types of introns, with particular emphasis on the nonspliceosomal self-splicing group II introns, which are widely thought to be the ancestors of spliceosomal introns. Next, we discuss the main scenarios proposed for the origin and proliferation of spliceosomal introns, an event intimately linked to eukaryogenesis. We then summarize the evidence that suggests that the last eukaryotic common ancestor (LECA) had remarkably high intron densities and many associated characteristics resembling modern intron-rich genomes. From this intron-rich LECA, the different eukaryotic lineages have taken very distinct evolutionary paths leading to profoundly diverged modern genome structures. Finally, we discuss the origins of alternative splicing and the qualitative differences in alternative splicing forms and functions across lineages. PMID:24890509

  7. The Cosmic Origins Program Analysis Group (COPAG)

    NASA Astrophysics Data System (ADS)

    Sembach, Kenneth

    2014-01-01

    The Cosmic Origins Program Analysis Group (COPAG) is tasked by the NASA Advisory Council's Astrophysics Subcommittee to support community coordination and analysis of scientific and technological issues impacting NASA's Cosmic Origins Program. NASA's Cosmic Origins theme encompasses a diversity of astrophysical phenomena ranging from the formation of stars to the development and evolution of the largest assemblages of matter in the universe. The principal tasks of the COPAG in 2013-2014 will be to assess and provide input on technological needs for future space missions, and to form several new study analysis groups with the community on science related to Hubble, JWST, and WFIRST-AFTA. This talk will summarize the status of ongoing analyses and briefly describe these new initiatives, some of which will involve coordination with other Program Analysis Groups.

  8. The origin of modern terrestrial life

    PubMed Central

    Forterre, Patrick; Gribaldo, Simonetta

    2007-01-01

    The study of the origin of life covers many areas of expertise and requires the input of various scientific communities. In recent years, this research field has often been viewed as part of a broader agenda under the name of “exobiology” or “astrobiology.” In this review, we have somewhat narrowed this agenda, focusing on the origin of modern terrestrial life. The adjective “modern” here means that we did not speculate on different forms of life that could have possibly appeared on our planet, but instead focus on the existing forms (cells and viruses). We try to briefly present the state of the art about alternative hypotheses discussing not only the origin of life per se, but also how life evolved to produce the modern biosphere through a succession of steps that we would like to characterize as much as possible. PMID:19404443

  9. Origin of strong dispersion in Hubbard insulators

    DOE PAGES

    Wang, Y.; Wohlfeld, K.; Moritz, B.; Jia, C. J.; van Veenendaal, M.; Wu, K.; Chen, C. -C.; Devereaux, T. P.

    2015-08-10

    Using cluster perturbation theory, we explain the origin of the strongly dispersive feature found at high binding energy in the spectral function of the Hubbard model. By comparing the Hubbard and $t₋J₋3s$ model spectra, we show that this dispersion does not originate from either coupling to spin fluctuations ($∝ J$ ) or the free hopping ($∝ t$ ). Instead, it should be attributed to a long-range, correlated hopping $∝ t²/U$ which allows an effectively free motion of the hole within the same antiferromagnetic sublattice. This origin explains both the formation of the high-energy anomaly in the single-particle spectrum and themore » sensitivity of the high-binding-energy dispersion to the next-nearest-neighbor hopping $t'$ .« less

  10. Origin of strong dispersion in Hubbard insulators

    SciTech Connect

    Wang, Y.; Wohlfeld, K.; Moritz, B.; Jia, C. J.; van Veenendaal, M.; Wu, K.; Chen, C. -C.; Devereaux, T. P.

    2015-08-10

    Using cluster perturbation theory, we explain the origin of the strongly dispersive feature found at high binding energy in the spectral function of the Hubbard model. By comparing the Hubbard and $t₋J₋3s$ model spectra, we show that this dispersion does not originate from either coupling to spin fluctuations ($∝ J$ ) or the free hopping ($∝ t$ ). Instead, it should be attributed to a long-range, correlated hopping $∝ t²/U$ which allows an effectively free motion of the hole within the same antiferromagnetic sublattice. This origin explains both the formation of the high-energy anomaly in the single-particle spectrum and the sensitivity of the high-binding-energy dispersion to the next-nearest-neighbor hopping $t'$ .

  11. Origin, development, and evolution of butterfly eyespots.

    PubMed

    Monteiro, Antónia

    2015-01-01

    This article reviews the latest developments in our understanding of the origin, development, and evolution of nymphalid butterfly eyespots. Recent contributions to this field include insights into the evolutionary and developmental origin of eyespots and their ancestral deployment on the wing, the evolution of eyespot number and eyespot sexual dimorphism, and the identification of genes affecting eyespot development and black pigmentation. I also compare features of old and more recently proposed models of eyespot development and propose a schematic for the genetic regulatory architecture of eyespots. Using this schematic I propose two hypotheses for why we observe limits to morphological diversity across these serially homologous traits.

  12. The complex origin of Astyanax cavefish

    PubMed Central

    2012-01-01

    Background The loss of phenotypic characters is a common feature of evolution. Cave organisms provide excellent models for investigating the underlying patterns and processes governing the evolutionary loss of phenotypic traits. The blind Mexican cavefish, Astyanax mexicanus, represents a particularly strong model for both developmental and genetic analyses as these fish can be raised in the laboratory and hybridized with conspecific surface form counterparts to produce large F2 pedigrees. As studies have begun to illuminate the genetic bases for trait evolution in these cavefish, it has become increasingly important to understand these phenotypic changes within the context of cavefish origins. Understanding these origins is a challenge. For instance, widespread convergence on similar features renders morphological characters less informative. In addition, current and past gene flow between surface and cave forms have complicated the delineation of particular cave populations. Results Past population-level analyses have sought to: 1) estimate at what time in the geological past cave forms became isolated from surface-dwelling ancestors, 2) define the extent to which cave form populations originated from a common invasion (single origin hypothesis) or several invasions (multiple origin hypothesis), and 3) clarify the role of geological and climatic events in Astyanax cavefish evolution. In recent years, thanks to the combined use of morphological and genetic data, a much clearer picture has emerged regarding the origins of Astyanax cavefish. Conclusions The consensus view, based on several recent studies, is that cave forms originated from at least two distinct ancestral surface-dwelling stocks over the past several million years. In addition, each stock gave rise to multiple invasions of the subterranean biotope. The older stock is believed to have invaded the El Abra caves at least three times while the new stock separately invaded the northern Guatemala and

  13. RNA catalysis and the origins of life

    NASA Technical Reports Server (NTRS)

    Orgel, Leslie E.

    1986-01-01

    The role of RNA catalysis in the origins of life is considered in connection with the discovery of riboszymes, which are RNA molecules that catalyze sequence-specific hydrolysis and transesterification reactions of RNA substrates. Due to this discovery, theories positing protein-free replication as preceding the appearance of the genetic code are more plausible. The scope of RNA catalysis in biology and chemistry is discussed, and it is noted that the development of methods to select (or predict) RNA sequences with preassigned catalytic functions would be a major contribution to the study of life's origins.

  14. The origin and destiny of our universe

    NASA Astrophysics Data System (ADS)

    Kolb, Rocky

    2005-04-01

    The discoveries of Albert Einstein rank among humanity's greatest achievements. Although his theory of gravity is the framework for understanding the origin and destiny of our Universe, it does not really tell us how or why the universe began, or how or if it will end. Recent developments and discoveries have shed new light on these issues. I will describe how observations and theory can shed light on what powered the big bang and the mysterious dark energy that is pulling the Universe apart. Perhaps we are close to completing Einstein's legacy and unraveling the cosmic mysteries of our origin and destiny.

  15. Nebular chemistry and theories of lunar origin

    NASA Technical Reports Server (NTRS)

    Larimer, John W.

    1986-01-01

    The cosmic history of planetary matter is traced from nucleosynthesis through accretion in an attempt to understand the origin of the moon. It is noted that nebular processes must be considered in any theory of lunar origin and that planetary differentiation and volcanism determine the final character of lunar rocks. The moon's unique blend of nebular components suggests that the earth and moon accreted from the same mix of components as the proto-moon orbited the proto-earth, with the earth winning and the moon progressively losing, its solar complement of the components.

  16. Origins of the protein synthesis cycle

    NASA Technical Reports Server (NTRS)

    Fox, S. W.

    1981-01-01

    Largely derived from experiments in molecular evolution, a theory of protein synthesis cycles has been constructed. The sequence begins with ordered thermal proteins resulting from the self-sequencing of mixed amino acids. Ordered thermal proteins then aggregate to cell-like structures. When they contained proteinoids sufficiently rich in lysine, the structures were able to synthesize offspring peptides. Since lysine-rich proteinoid (LRP) also catalyzes the polymerization of nucleoside triphosphate to polynucleotides, the same microspheres containing LRP could have synthesized both original cellular proteins and cellular nucleic acids. The LRP within protocells would have provided proximity advantageous for the origin and evolution of the genetic code.

  17. Origin, development, and evolution of butterfly eyespots.

    PubMed

    Monteiro, Antónia

    2015-01-01

    This article reviews the latest developments in our understanding of the origin, development, and evolution of nymphalid butterfly eyespots. Recent contributions to this field include insights into the evolutionary and developmental origin of eyespots and their ancestral deployment on the wing, the evolution of eyespot number and eyespot sexual dimorphism, and the identification of genes affecting eyespot development and black pigmentation. I also compare features of old and more recently proposed models of eyespot development and propose a schematic for the genetic regulatory architecture of eyespots. Using this schematic I propose two hypotheses for why we observe limits to morphological diversity across these serially homologous traits. PMID:25341098

  18. Cosmic Origins Program Annual Technology Report

    NASA Technical Reports Server (NTRS)

    Pham, Bruce Thai; Neff, Susan Gale

    2016-01-01

    What is the Cosmic Origins (COR) Program? From ancient times, humans have looked up at the night sky and wondered: Are we alone? How did the universe come to be? How does the universe work? COR focuses on the second question. Scientists investigating this broad theme seek to understand the origin and evolution of the universe from the Big Bang to the present day, determining how the expanding universe grew into a grand cosmic web of dark matter enmeshed with galaxies and pristine gas, forming, merging, and evolving over time.

  19. On the origin of visual dyslexia.

    PubMed

    Dunlop, D B

    1981-08-01

    Analysis of the binocular co-ordination errors of a young dyslexic reveals a simple optical explantation for one of two types of letter confusion found in dyslexia. Although binocular control was grossly abnormal in reading, no ocular defect could be found in standard ophthalmic and orthoptic tests. Re-examination of the same patient six years later, again showed no ocular defect on normal testing but binocular movements in reading, while still abnormal, showed no trace of the striking original defect. This complete masking of the original condition with time must severely restrict the value of mass surveys of established dyslexics.

  20. 19 CFR 102.23 - Origin and Manufacturer Identification

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Origin and Manufacturer Identification 102.23...; DEPARTMENT OF THE TREASURY RULES OF ORIGIN Rules of Origin § 102.23 Origin and Manufacturer Identification (a... address of the entity performing the origin-conferring operations pursuant to § 102.21 or § 102.22 of...

  1. 19 CFR 102.23 - Origin and Manufacturer Identification

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Origin and Manufacturer Identification 102.23...; DEPARTMENT OF THE TREASURY RULES OF ORIGIN Rules of Origin § 102.23 Origin and Manufacturer Identification (a... address of the entity performing the origin-conferring operations pursuant to § 102.21 or § 102.22,...

  2. 19 CFR 102.23 - Origin and Manufacturer Identification

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Origin and Manufacturer Identification 102.23...; DEPARTMENT OF THE TREASURY RULES OF ORIGIN Rules of Origin § 102.23 Origin and Manufacturer Identification (a... address of the entity performing the origin-conferring operations pursuant to § 102.21 or § 102.22 of...

  3. 19 CFR 102.23 - Origin and Manufacturer Identification

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Origin and Manufacturer Identification 102.23...; DEPARTMENT OF THE TREASURY RULES OF ORIGIN Rules of Origin § 102.23 Origin and Manufacturer Identification (a... address of the entity performing the origin-conferring operations pursuant to § 102.21 or § 102.22 of...

  4. 19 CFR 102.23 - Origin and Manufacturer Identification

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Origin and Manufacturer Identification 102.23...; DEPARTMENT OF THE TREASURY RULES OF ORIGIN Rules of Origin § 102.23 Origin and Manufacturer Identification (a... address of the entity performing the origin-conferring operations pursuant to § 102.21 or § 102.22 of...

  5. 32 CFR 1907.23 - Response by originator(s) and/or any interested party.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... INTELLIGENCE AGENCY CHALLENGES TO CLASSIFICATION OF DOCUMENTS BY AUTHORIZED HOLDERS PURSUANT TO § 1.9 OF EXECUTIVE ORDER 12958 Action on Challenges § 1907.23 Response by originator(s) and/or any interested party... challenge; other interested parties may become involved through the request of the Executive Secretary...

  6. 21. Photographic contact print from a 8x10 original negative. (Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. Photographic contact print from a 8x10 original negative. (Original drawing located on abandoned NASA site, currently owned by the City of Downey, Downey, California). 1954 NORTH AMERICAN AVIATION BUILDING 41 CONSTRUCTION LAYOUT. - NASA Industrial Plant, Missile Research Laboratory, 12214 Lakewood Boulevard, Downey, Los Angeles County, CA

  7. 16. Photographic contact print from a 8x10 original negative. (Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Photographic contact print from a 8x10 original negative. (Original drawing located on abandoned NASA site, currently owned by the City of Downey, Downey, California). 1956 RECORD DRAWINGS. NORTH AMERICAN AVAIATION INC, INDUSTRIAL ENGINEERS. BLDGS 10, 25, & 42 ELEVATIONS & FLOOR PLANS. - NASA Industrial Plant, Maintenance Facility, 12214 Lakewood Boulevard, Downey, Los Angeles County, CA

  8. 8. Photographic contact print from a 8x10 original negative. (Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Photographic contact print from a 8x10 original negative. (Original drawing located on abandoned NASA site, currently owned by the City of Downey, Downey, California). 1956 RECORD DRAWINGS. NORTH AMERICAN AVAIATION INC, INDUSTRIAL ENGINEERS. 1956 BLDG 25 & BLDG 42 ELEVATIONS. - NASA Industrial Plant, Storage Facility, 12214 Lakewood Boulevard, Downey, Los Angeles County, CA

  9. 73. Photocopy of original drawing, author unknown, late 1990's (original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    73. Photocopy of original drawing, author unknown, late 1990's (original in possession of New York City Department of Transportation), bridge elevation - Macombs Dam Bridge, Spanning Harlem River Between 155th Street Viaduct, Jerome Avenue, & East 162nd Street, Bronx, Bronx County, NY

  10. 74. Photocopy of original drawing, author unknown, late 1890's (original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    74. Photocopy of original drawing, author unknown, late 1890's (original in possession of New York City Department of Transportation), plan & elevation - Pier III to Pier A - Bronx approach - Macombs Dam Bridge, Spanning Harlem River Between 155th Street Viaduct, Jerome Avenue, & East 162nd Street, Bronx, Bronx County, NY

  11. Exploring the Divergent Academic Outcomes of U.S.-Origin and Immigrant-Origin Black Undergraduates

    ERIC Educational Resources Information Center

    Tauriac, Jesse J.; Liem, Joan H.

    2012-01-01

    To explore the divergent academic experiences and outcomes of U.S.-origin and immigrant-origin Black Americans, we drew on Tinto's (1993) model of persistence to test a 3-wave longitudinal model of college persistence using path analysis. Our sample comprised 101 ethnically diverse Black students who were randomly selected from 9 public high…

  12. Precambrian biota: protistan origin of trace fossils?

    PubMed

    Pawlowski, Jan; Gooday, Andrew J

    2009-01-13

    Some Precambrian trace fossils have been presented as evidence for the early origin of bilaterians; the recent finding that large amoeboid protists leave macroscopic traces at the bottom of the deep ocean questions the metazoan nature of early trace fossils, stressing the importance of single-cell organisms in Precambrian biota.

  13. 19 CFR 10.770 - Originating goods.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Originating goods. 10.770 Section 10.770 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free Trade...

  14. 19 CFR 10.770 - Originating goods.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Originating goods. 10.770 Section 10.770 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free Trade...

  15. 19 CFR 10.770 - Originating goods.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Originating goods. 10.770 Section 10.770 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free Trade...

  16. 19 CFR 10.770 - Originating goods.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Originating goods. 10.770 Section 10.770 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free Trade...

  17. Human Behaviour and the Origin of Man

    ERIC Educational Resources Information Center

    Raleigh, M. J.; Washburn, S. L.

    1973-01-01

    The study of origin and evolution of man gives new perspective for understanding his behavior. Physical behaviors such as walking and throwing are results of biological evolution which has not kept pace with sociocultural evolution. Irrational decisions by man in social, cultural, and political fields are results of this brain activity. (PS)

  18. 19 CFR 10.594 - Originating goods.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Originating goods. 10.594 Section 10.594 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. Dominican Republic-Central...

  19. 19 CFR 10.594 - Originating goods.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Originating goods. 10.594 Section 10.594 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. Dominican Republic-Central...

  20. 19 CFR 10.594 - Originating goods.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Originating goods. 10.594 Section 10.594 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. Dominican Republic-Central...

  1. 19 CFR 10.594 - Originating goods.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Originating goods. 10.594 Section 10.594 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. Dominican Republic-Central...

  2. 19 CFR 10.594 - Originating goods.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Originating goods. 10.594 Section 10.594 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. Dominican Republic-Central...

  3. Origin and evolution of the Saturn system

    NASA Technical Reports Server (NTRS)

    Pollack, J. B.; Consolmagno, G.

    1983-01-01

    A review is provided of current concepts concerning the formation of the Saturn system and the subsequent history of the planet, its satellites, and rings. Emphasis is placed upon numerical models of Saturn's evolution and interior models of its satellites. Alternative theories are presented and assessed for the origins of the Saturn system, the rings of Saturn, and the atmosphere of Titan.

  4. Origins of food crops connect countries worldwide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research into the origins of food plants has led to the recognition that specific geographic regions around the world have been of particular importance to the development of agricultural crops. Yet the relative contributions of these different regions in the context of current food systems have not...

  5. On the Origins of Dynamical Awareness.

    ERIC Educational Resources Information Center

    Gilden, David L.

    1991-01-01

    An inquiry into the origins of dynamical awareness shows that impressions of dynamical quantities are not generally correlated with the values that these quantities take in equations of motion but are highly correlated with simple ratios of kinematic quantities or with specific kinematic features that do not specify underlying dynamics. (SLD)

  6. Origins and Outcomes of Judgments about Work

    ERIC Educational Resources Information Center

    Johnson, Monica Kirkpatrick; Mortimer, Jeylan T.

    2011-01-01

    We evaluate the importance of judgments about work for the attainment process in the "new economy." Findings show continuing links between social origins and work orientations at age 21/22, as well as significant effects of work orientations on occupational outcomes at age 31/32. Higher socio-economic status background, and stronger self-perceived…

  7. Origin Stories: Geography, Culture, and Belief

    ERIC Educational Resources Information Center

    Gandy, S. Kay; Matthew, Kathleen

    2010-01-01

    At a very young age children become curious about themselves and their place in the world around them. As children mature, questions of origin signal the desire for a broader explanation of the world, a desire for a deeper understanding of something bigger than themselves to explain events that happen around them. There is a great variety of…

  8. Prevolutionary dynamics and the origin of evolution.

    PubMed

    Nowak, Martin A; Ohtsuki, Hisashi

    2008-09-30

    Life is that which replicates and evolves. The origin of life is also the origin of evolution. A fundamental question is when do chemical kinetics become evolutionary dynamics? Here, we formulate a general mathematical theory for the origin of evolution. All known life on earth is based on biological polymers, which act as information carriers and catalysts. Therefore, any theory for the origin of life must address the emergence of such a system. We describe prelife as an alphabet of active monomers that form random polymers. Prelife is a generative system that can produce information. Prevolutionary dynamics have selection and mutation, but no replication. Life marches in with the ability of replication: Polymers act as templates for their own reproduction. Prelife is a scaffold that builds life. Yet, there is competition between life and prelife. There is a phase transition: If the effective replication rate exceeds a critical value, then life outcompetes prelife. Replication is not a prerequisite for selection, but instead, there can be selection for replication. Mutation leads to an error threshold between life and prelife.

  9. Vascular precursors: origin, regulation and function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this miniseries, we discuss the phenotype, origin, and specialized microenvironment (niche) of distinct populations of stem and progenitor cells that exhibit vascular potential. Their usefulness and effectiveness for clinical therapies are also described. We have learned a great deal about post...

  10. The origin of the eukaryotic cell

    NASA Technical Reports Server (NTRS)

    Hartman, H.

    1984-01-01

    The endosymbiotic hypothesis for the origin of the eukaryotic cell has been applied to the origin of the mitochondria and chloroplasts. However as has been pointed out by Mereschowsky in 1905, it should also be applied to the nucleus as well. If the nucleus, mitochondria and chloroplasts are endosymbionts, then it is likely that the organism that did the engulfing was not a DNA-based organism. In fact, it is useful to postulate that this organism was a primitive RNA-based organism. This hypothesis would explain the preponderance of RNA viruses found in eukaryotic cells. The centriole and basal body do not have a double membrane or DNA. Like all MTOCs (microtubule organising centres), they have a structural or morphic RNA implicated in their formation. This would argue for their origin in the early RNA-based organism rather than in an endosymbiotic event involving bacteria. Finally, the eukaryotic cell uses RNA in ways quite unlike bacteria, thus pointing to a greater emphasis of RNA in both control and structure in the cell. The origin of the eukaryotic cell may tell us why it rather than its prokaryotic relative evolved into the metazoans who are reading this paper.

  11. Language Origin from an Emergentist Perspective

    ERIC Educational Resources Information Center

    Ke, Jinyun; Holland, John H.

    2006-01-01

    In recent decades, there has been a surge of interest in the origin of language across a wide range of disciplines. Emergentism provides a new perspective to integrate investigations from different areas of study. This paper discusses how the study of language acquisition can contribute to the inquiry, in particular when computer modeling is…

  12. 5 CFR 1201.2 - Original jurisdiction.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Original jurisdiction. 1201.2 Section 1201.2 Administrative Personnel MERIT SYSTEMS PROTECTION BOARD ORGANIZATION AND PROCEDURES PRACTICES... deficiencies, for informal hearings; and (c) Actions taken against administrative law judges under 5...

  13. Collecting and Using Original Student Work.

    ERIC Educational Resources Information Center

    Farmer, Lesley S. J.

    2001-01-01

    Examines innovative ways for school libraries to collect organize, and make effective use of student work. Highlights include recognizing original work; student writing; student posters of favorite books or characters; databases for organizing information; videotaping of students' activities and presentations; electronic products; events;…

  14. On the origin of metabolic pathways

    NASA Technical Reports Server (NTRS)

    Lazcano, A.; Miller, S. L.; Bada, J. L. (Principal Investigator)

    1999-01-01

    The heterotrophic theory of the origin of life is the only proposal available with experimental support. This comes from the ease of prebiotic synthesis under strongly reducing conditions. The prebiotic synthesis of organic compounds by reduction of CO(2) to monomers used by the first organisms would also be considered an heterotrophic origin. Autotrophy means that the first organisms biosynthesized their cell constituents as well as assembling them. Prebiotic synthetic pathways are all different from the biosynthetic pathways of the last common ancestor (LCA). The steps leading to the origin of the metabolic pathways are closer to prebiotic chemistry than to those in the LCA. There may have been different biosynthetic routes between the prebiotic and the LCAs that played an early role in metabolism but have disappeared from extant organisms. The semienzymatic theory of the origin of metabolism proposed here is similar to the Horowitz hypothesis but includes the use of compounds leaking from preexisting pathways as well as prebiotic compounds from the environment.

  15. The Origin of the Term "Hypervalent"

    ERIC Educational Resources Information Center

    Jensen, William B.

    2006-01-01

    The debate related to origin of the term "hypervalent" that was first introduced by Jeremy Musher in 1969 to describe compounds and complex ions of the heavier main-block elements in which the use of traditional Lewis 2c-2e covalent bonds requires the additional assumption of "octer expansion" for the central atom is presented. The traditional…

  16. Acid Rain Students Do Original Research.

    ERIC Educational Resources Information Center

    Outdoor Communicator, 1984

    1984-01-01

    At Park Senior High School (Cottage Grove, Minnesota), 46 juniors and seniors planted 384 red pine seedlings in connection with their original research on acid rain, with advice from Dr. Harriet Stubbs, director of the Acid Precipitation Awareness Program (West Saint Paul), which has been developing acid rain teaching materials. (MH)

  17. 21 CFR 814.104 - Original applications.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Original applications. 814.104 Section 814.104... applications. (a) United States applicant or representative. The applicant or an authorized representative... or diagnose the disease or condition. The application also shall contain a discussion of the...

  18. 76 FR 45402 - Rules of Origin

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection 19 CFR Part 102 Rules of Origin CFR Correction In Title 19 of the Code of Federal Regulations, Parts 0 to 140, revised as of April 1, 2011, on page 578, in Sec....

  19. Conflict Resolution between Mexican Origin Adolescent Siblings

    ERIC Educational Resources Information Center

    Killoren, Sarah E.; Thayer, Shawna M.; Updegraff, Kimberly A.

    2008-01-01

    We investigated correlates of adolescents' sibling conflict resolution strategies in 246, two-parent Mexican origin families. Specifically, we examined links between siblings' conflict resolution strategies and sibling dyad characteristics, siblings' cultural orientations and values, and sibling relationship qualities. Data were gathered during…

  20. Cosmic Ray Origin, Acceleration and Propagation

    NASA Technical Reports Server (NTRS)

    Baring, Matthew G.

    2000-01-01

    This paper summarizes highlights of the OG3.1, 3.2 and 3.3 sessions of the 26th International Cosmic Ray Conference in Salt Lake City, which were devoted to issues of origin/composition, acceleration and propagation.

  1. Fibromatoses of multicentric origin: a case report.

    PubMed

    Suzuki, Y; Yamamoto, A; Ku, Y; Minami, R; Hanioka, K; Shimizu, M; Kuroda, Y

    2000-06-01

    We experienced a very rare case with fibromatoses of multicentric origin. One of the 2 intraabdominal fibromatoses showed a extremely rapid growing and another fibromatosis arising from the abdominal wall showed an invasive behavior. All lesions were diagnosed and resected simultaneously. This patient has been followed for 2 years postoperatively and no recurrent lesion has been detected so far.

  2. The Complex Origins of the Registrar

    ERIC Educational Resources Information Center

    Smith, Shawn C.

    2012-01-01

    The origins of the registrar's office are complex. According to common tradition, the registrar was, or evolved from, the office of the beadle (sometimes referred to as "bedel") in the medieval university. This tradition is incorrect; the story is more complex. The beadle sometimes performed functions similar to those performed by the modern-day…

  3. Photosynthesis and the origin of life.

    PubMed

    Hartman, H

    1998-10-01

    The origin and evolution of photosynthesis is considered to be the key to the origin of life. This eliminates the need for a soup as the synthesis of the bioorganics are to come from the fixation of carbon dioxide and nitrogen. No soup then no RNA world or Protein world. Cyanobacteria have been formed by the horizontal transfer of green sulfur bacterial photoreaction center genes by means of a plasmid into a purple photosynthetic bacterium. The fixation of carbon dioxide is considered to have evolved from a reductive dicarboxylic acid cycle (Chloroflexus) which was then followed by a reductive tricarboxylic acid cycle (Chlorobium) and finally by the reductive pentose phosphate cycle (Calvin cycle). The origin of life is considered to have occurred in a hot spring on the outgassing early earth. The first organisms were self-replicating iron-rich clays which fixed carbon dioxide into oxalic and other dicarboxylic acids. This system of replicating clays and their metabolic phenotype then evolved into the sulfide rich region of the hotspring acquiring the ability to fix nitrogen. Finally phosphate was incorporated into the evolving system which allowed the synthesis of nucleotides and phospholipids. If biosynthesis recapitulates biopoesis, then the synthesis of amino acids preceded the synthesis of the purine and pyrimidine bases. Furthermore the polymerization of the amino acid thioesters into polypeptides preceded the directed polymerization of amino acid esters by polynucleotides. Thus the origin and evolution of the genetic code is a late development and records the takeover of the clay by RNA.

  4. Origins of Life: A Current Controversy.

    ERIC Educational Resources Information Center

    Moore, John N.

    This paper advocates that a creation model, as well as an evolution model, should be presented to students when discussing the origins of life. The author argues that the traditional evidence supporting evolution is circumstantial in nature, whereas a major prediction from the creation model (that gaps exist between distinct kinds of living…

  5. Researching with Original Sources in Culture Studies.

    ERIC Educational Resources Information Center

    Carter, Douglas

    1997-01-01

    Describes the method employed for scholarship that involves the analysis of original unpublished scripts. A professional-development grant provided an opportunity to travel to a university archive to read primary research materials unavailable through conventional means, and to develop a detailed analysis of selected works by Ray Bradbury,…

  6. Particle dynamics in the original Schwarzschild metric

    NASA Astrophysics Data System (ADS)

    Fimin, N. N.; Chechetkin, V. M.

    2016-04-01

    The properties of the original Schwarzschild metric for a point gravitating mass are considered. The laws of motion in the corresponding space-time are established, and the transition from the Schwarzschildmetric to the metric of a "dusty universe" are studied. The dynamics of a system of particles in thr post-Newtonian approximation are analyzed.

  7. Chemical origins of life: Prebiotic RNA unstuck

    NASA Astrophysics Data System (ADS)

    Hernández, Armando R.; Piccirilli, Joseph A.

    2013-05-01

    Non-enzymatic copying of an RNA template is appealing as a transition from pre-life to an RNA world, but it has been difficult to demonstrate in the laboratory. Now, two separate studies focusing on RNA's backbone connectivity offer partial solutions to some of the problems raised with this hypothesis for the origin of life.

  8. Origins and evolution of spliceosomal introns.

    PubMed

    Rodríguez-Trelles, Francisco; Tarrío, Rosa; Ayala, Francisco J

    2006-01-01

    Research into the origins of introns is at a critical juncture in the resolution of theories on the evolution of early life (which came first, RNA or DNA?), the identity of LUCA (the last universal common ancestor, was it prokaryotic- or eukaryotic-like?), and the significance of noncoding nucleotide variation. One early notion was that introns would have evolved as a component of an efficient mechanism for the origin of genes. But alternative theories emerged as well. From the debate between the "introns-early" and "introns-late" theories came the proposal that introns arose before the origin of genetically encoded proteins and DNA, and the more recent "introns-first" theory, which postulates the presence of introns at that early evolutionary stage from a reconstruction of the "RNA world." Here we review seminal and recent ideas about intron origins. Recent discoveries about the patterns and causes of intron evolution make this one of the most hotly debated and exciting topics in molecular evolutionary biology today. PMID:17094737

  9. Origins of molecular biology in Japan.

    PubMed

    Obayashi, M

    1986-06-01

    The purpose of this paper is to discuss the origins of molecular biology in Japan. Japanese molecular biology does not have a long history since it started only after World War II. Especially, molecular genetics which uses "bacteriophage" had hardly been studied before the war and only a few scientists were interested in it immediately after the war. This is one of the origins of molecular biology in Japan. But there are other origins, one of which is the group formed by biologists, biochemists and physicists interested in nucleic acids. This group also started just after the war. Still another origin is the group of enzymologists. Enzymology was one of the main subjects of biochemistry from before the war. In Japan, biochemistry developed in conjunction with the medical and agricultural sciences from the pre-war era. These played an important role in introducing molecular biology from Europe and the United States after the war. A historical study of the development of molecular biology in Japan, comparing it with the history of molecular biology in Europe and the United States, should contribute to the elucidation of the features of the history of molecular biology in Japan.

  10. 7 CFR 201.5 - Origin.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Records for Agricultural and Vegetable Seeds § 201.5 Origin. (a) The complete record for any lot of seed of alfalfa, red clover, white clover, or field corn, except hybrid seed corn, shall include...

  11. 7 CFR 201.5 - Origin.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Records for Agricultural and Vegetable Seeds § 201.5 Origin. (a) The complete record for any lot of seed of alfalfa, red clover, white clover, or field corn, except hybrid seed corn, shall include...

  12. 7 CFR 201.5 - Origin.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Records for Agricultural and Vegetable Seeds § 201.5 Origin. (a) The complete record for any lot of seed of alfalfa, red clover, white clover, or field corn, except hybrid seed corn, shall include...

  13. 7 CFR 201.5 - Origin.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Records for Agricultural and Vegetable Seeds § 201.5 Origin. (a) The complete record for any lot of seed of alfalfa, red clover, white clover, or field corn, except hybrid seed corn, shall include...

  14. 7 CFR 201.5 - Origin.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Records for Agricultural and Vegetable Seeds § 201.5 Origin. (a) The complete record for any lot of seed of alfalfa, red clover, white clover, or field corn, except hybrid seed corn, shall include...

  15. Action Research: Its Origins and Early Application.

    ERIC Educational Resources Information Center

    Cook, Stuart W.

    This paper contains informal remarks on action research in social psychology from its post World War II origins to its current status. Kurt Lewin first described action research in the 1946 article, "Action Research and Minority Problems," as a three-step process of program planning, program execution, and follow-up evaluation. Ronald Lippitt and…

  16. Originalism and Subjectivism in the Bicentennial Year.

    ERIC Educational Resources Information Center

    Reid, John Phillip

    1987-01-01

    Surveys the debate over how the United States Constitution is to be regarded for purposes of judicial interpretation in federal court cases. Focuses on the views of U.S. Attorney General Edwin Meese, Ronald Dworkin, and Chief Justice William Rehnquist. Discusses the underlying values of original intent and its opposite, judicial activism.…

  17. The origin of granites and related rocks

    USGS Publications Warehouse

    Brown, Michael; Piccoli, Philip M.

    1995-01-01

    This Circular is a compilation of abstracts for posters and oral presentations given at the third Hutton symposium on the Origin of granites and related rocks. The symposium was co-sponsored by the Department of Geology, University of Maryland at College Park; the U.S. Geological Survey, Reston, Virginia; and the Department of Terrestrial Magnetism and Geophysical Laboratory, Carnegie Institution of Washington.

  18. Eukaryotic replication origins: Strength in flexibility

    PubMed Central

    Kumar, Charanya; Remus, Dirk

    2016-01-01

    ABSTRACT The eukaryotic replicative DNA helicase, Mcm2-7, is loaded in inactive form as a double hexameric complex around double-stranded DNA. To ensure that replication origins fire no more than once per S phase, activation of the Mcm2-7 helicase is temporally separated from Mcm2-7 loading in the cell cycle. This 2-step mechanism requires that inactive Mcm2-7 complexes be maintained for variable periods of time in a topologically bound state on chromatin, which may create a steric obstacle to other DNA transactions. We have recently found in the budding yeast, Saccharomyces cerevisiae, that Mcm2-7 double hexamers can respond to collisions with transcription complexes by sliding along the DNA template. Importantly, Mcm2-7 double hexamers remain functional after displacement along DNA and support replication initiation from sites distal to the origin. These results reveal a novel mechanism to specify eukaryotic replication origin sites and to maintain replication origin competence without the need for Mcm2-7 reloading. PMID:27416360

  19. Search for the Origin of Life

    ERIC Educational Resources Information Center

    Brown, R. D.

    1975-01-01

    Presents various ideas on the origin of life including very early ideas, Oparin's view, and an alternative view related to carbonaceous chondrites. Outlines one currently tenable hypothesis in the formation of the solar system and explains the method involved in detecting polyatomic molecules in dark nebulae. (GS)

  20. Social Origins of American Scientists and Scholars

    ERIC Educational Resources Information Center

    Hardy, Kenneth R.

    1974-01-01

    Reported is an investigation of the social origins of American scientists and scholars. Exhaustive data, gathered over a 40 year period, were reviewed and were gathered from sources reflecting geographical, baccalaureate, and social class variations. To a significant extent these variations were associated with the kind of a religious-ethnic group…

  1. 19 CFR 10.810 - Originating goods.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...; (2) The good is a new or different article of commerce, as defined in § 10.809(i) of this subpart, that has been grown, produced, or manufactured in the territory of one or both of the Parties, is...-originating materials used in the production of the good undergoes an applicable change in...

  2. 19 CFR 10.770 - Originating goods.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...; (2) The good is a new or different article of commerce, as defined in § 10.769(i) of this subpart, that has been grown, produced, or manufactured in the territory of one or both of the Parties, is...-originating materials used in the production of the good undergoes an applicable change in...

  3. Precambrian biota: protistan origin of trace fossils?

    PubMed

    Pawlowski, Jan; Gooday, Andrew J

    2009-01-13

    Some Precambrian trace fossils have been presented as evidence for the early origin of bilaterians; the recent finding that large amoeboid protists leave macroscopic traces at the bottom of the deep ocean questions the metazoan nature of early trace fossils, stressing the importance of single-cell organisms in Precambrian biota. PMID:19138588

  4. Photosynthesis: what color was its origin?

    PubMed

    Xiong, Jin

    2006-01-01

    Recent studies using geological and molecular phylogenetic evidence suggest several alternative evolutionary scenarios for the origin of photosynthesis. The earliest photosynthetic group is variously thought to be heliobacteria, proteobacteria or a precursor of cyanobacteria, organisms whose photosynthetic pigments make them different colors.

  5. Live @ The Exploratorium: Origins. Final Evaluation Report

    ERIC Educational Resources Information Center

    Spielvogel, Robert; Chang, Han-Hua

    2004-01-01

    In the summer of 2000, Education Development Center's Center for Children and Technology (CCT) was contracted to evaluate the LIVE @ THE EXPLORATORIUM: Origins project as part of the Exploratorium's three-year funding from the National Science Foundation. Evaluation planning and work began in August of 2000 and continued through December 2003.…

  6. 19 CFR 10.914 - Originating goods.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Originating goods. 10.914 Section 10.914 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Peru Trade Promotion...

  7. 19 CFR 10.914 - Originating goods.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Originating goods. 10.914 Section 10.914 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Peru Trade Promotion...

  8. 19 CFR 10.914 - Originating goods.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Originating goods. 10.914 Section 10.914 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Peru Trade Promotion...

  9. Embryonic origin of amphibian taste buds.

    PubMed

    Barlow, L A; Northcutt, R G

    1995-05-01

    Despite numerous descriptive studies, the embryonic origin of vertebrate taste buds has never been experimentally determined. A number of different alternatives have been suggested for taste bud origins, including epibranchial placodes, the neural crest, and the local epithelium of the oropharyngeal cavity. The role of a series of epibranchial placodes and the cephalic neural crest, which together give rise to the cranial nerves innervating taste buds, was examined with regard to the development of oropharyngeal taste buds in an ambystomatid salamander, the axolotl. When pigmented placodal ectoderm or neural folds were grafted isotopically and isochronically into nonpigmented host embryos, known derivatives of each tissue contained pigmented cells, but labeled taste buds were never encountered. Thus, neither epibranchial placodes nor neural crest contribute cells to taste buds during embryogenesis. The majority of the oropharyngeal cavity of ambystomatid salamanders is lined by an endodermal epithelium. In order to demonstrate conclusively that taste buds arise from this local epithelium, the presumptive cephalic endoderm of early axolotl gastrulae was microinjected with the lipophilic dye, DiI. In the oropharyngeal epithelium of all larvae examined, both taste buds and general epithelial cells were labeled with DiI, indicating their common endodermal origin. Our findings are novel in that this is the first experimental demonstration of the endodermal origin of a vertebrate sensory receptor cell class. PMID:7750643

  10. Concise Historical Origins of Selected Registrar's Terms.

    ERIC Educational Resources Information Center

    Hudson, Paul Stephen

    1989-01-01

    The history and etymology of terms commonly used by registrars in maintaining records are summarized, with focus on their Latin origins. Terms include record, copy, file, rolls, register, data, enrollment, total, census, notary, minutes, office, delegate, catalog, schedule, procedure, memorandum, authentic, seal, signature, diploma, certify, and…

  11. Historical reminiscence: origin of the Greenfield filter.

    PubMed

    Greenfield, Lazar J

    2010-12-01

    The Greenfield filter was the result of collaboration between a surgeon and a petroleum engineer. Originally it was a component of a catheter management approach to massive pulmonary embolism. Industry support allowed further technical improvements and long-term patient followup studies. PMID:21265342

  12. Origins of rainbow smelt in Lake Ontario

    USGS Publications Warehouse

    Bergstedt, Roger A.

    1983-01-01

    The first rainbow smelt (Osmerus mordax) to enter Lake Ontario were probably migrants from an anadromous strain introduced into New York's Finger Lakes. Since the upper Great Lakes were originally stocked with a landlocked strain from Green Lake, Maine, subsequent migration to Lake Ontario from Lake Erie makes Lake Ontario unique among the Great Lakes in probably having received introductions from two distinct populations.

  13. Original Sin and T. E. Hulme's Aesthetics

    ERIC Educational Resources Information Center

    Kishler, Thomas C.

    1976-01-01

    T. E. Hulme, a vigorous opponent of romanticism in art, poetry, and philosophy, insisted that the underlying flaw of the romantic view was its rejection of the dogma of Original Sin and the fall of man. His views are explored for the significant bearing they have on the development of aesthetic insight and indirectly on value and outlook.…

  14. 31 CFR 538.312 - Sudanese origin.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., employee, or contractor of the Government of Sudan or of a business entity located in Sudan. Services of... Government of Sudan; (2) Diplomatic and consular services performed by or on behalf of the Government of the United States. (e) The term goods or services of Sudanese origin does not include goods or services...

  15. Global Rotation of Non-Rotating Origin

    NASA Astrophysics Data System (ADS)

    Fukushima, T.

    2001-11-01

    At its 24th General Assembly held at Manchester last year, the IAU has adopted the Celestial Ephemeris Origin (CEO) as a new longitude origin of the celestial coordinate system (Capitaine et al. 2000, IAU 2001). The CEO is the application of Guinot's non-rotating origin (NRO) to the Earth's equator (Guinot 1979, Capitaine et al. 1986, Capitaine 1990). By using the current IAU precession/nutation theory, we integrated the global orbit of CEO. It is a slightly curved zigzag pattern of the amplitude of around 23o moving secularly along the ecliptic. Among its kinematical features, we note that CEO has a large secular component of rotation with respect to the inertial reference frame. The current speed of this global rotation is as large as around -4.15 ''/yr. The negative sign shows that CEO rotates clockwise with respect to the inertial frame when viewed from the north celestial pole. Unfortunately this is a general property of NROs. On the other hand, such secular rotation does not exist for some geometrically-defined longitude origins like K, H, and Σ already discussed in Kovalevsky and McCarthy (1998). We think that the existence of a global secular rotaion means that the CEO, and NROs in general, is not appropriate to be specified as the x-axis of celestial coordinate systems.

  16. Precipitation of Continental Origin over South America

    NASA Astrophysics Data System (ADS)

    Martinez-Agudelo, J. A.; Dominguez, F.

    2012-12-01

    The Amazon forest receives high amounts of moisture from the tropical Atlantic. A significant part of this moisture is returned back to the atmosphere by the forest, and further redistributed to the rest of the continent by the meridional flow imposed by the Andes. Thus, the land-atmosphere interaction between the Amazon forest and the large-scale flow affects not only the forest itself but also the downstream regions. We develop a method to quantify the precipitation of continental origin over South America, and identify the contribution that selected source regions make to continental precipitation. The average annual cycle of precipitation of continental origin for the five-year period 2000-2004 shows a band of high values aligned along the northwest-southeast direction, from southern Peru to northeastern Argentina. The lowest values of precipitation of continental origin occur upstream, over the northeastern coast of South America. Precipitation that originates as moisture from the Amazon forest shows maximum values over the western side of the Amazon, east of the Andes, especially over southern Peru. The Amazon forest also contributes to precipitation over La Plata River Basin (LPRB) and the Pacific coast of Colombia. During its dry season, up to 29.3% of the precipitation over LPRB originates as moisture from the Amazon forest. Throughout the year, the contributions to precipitation over LPRB by the Amazon forest and LPRB (recycled precipitation) are in the same range, but out of phase. The average contribution of the rest of the continent to precipitation over LPRB is smaller but of the same order as that of the Amazon and LPRB.

  17. Multiple origins for olivine at Copernicus crater

    NASA Astrophysics Data System (ADS)

    Dhingra, Deepak; Pieters, Carle M.; Head, James W.

    2015-06-01

    Multiple origins for olivine-bearing lithologies at Copernicus crater are recognized based on integrated analysis of data from Chandrayaan-1 Moon Mineralogy Mapper (M3), Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera (NAC) and Kaguya Terrain Camera (TC). We report the diverse morphological and spectral character of previously known olivine-bearing exposures as well as the new olivine occurrences identified in this study. Prominent albedo differences exist between olivine-bearing exposures in the central peaks and a northern wall unit (the latter being ∼40% darker). The low-albedo wall unit occurs as a linear mantling deposit and is interpreted to be of impact melt origin, in contrast with the largely unmodified nature of olivine-bearing peaks. Small and localized occurrences of olivine-bearing lithology have also been identified on the impact melt-rich floor, representing a third geologic setting (apart from crater wall and peaks). Recent remote sensing missions have identified olivine-bearing exposures around lunar basins (e.g. Yamamoto et al., 2010; Pieters et al., 2011; Kramer et al., 2013) and at other craters (e.g. Sun and Li, 2014), renewing strong interest in its origin and provenance. A direct mantle exposure has commonly been suggested in this regard. Our detailed observations of the morphological and spectral diversity in the olivine-bearing exposures at Copernicus have provided critical constraints on their origin and source regions, emphasizing multiple formation mechanisms. These findings directly impact the interpretation of olivine exposures elsewhere on the Moon. Olivine can occur in diverse environments including an impact melt origin, and therefore it is unlikely for all olivine exposures to be direct mantle occurrences as has generally been suggested.

  18. 19 CFR 181.75 - Issuance of origin determination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the origin verification, Customs shall provide the exporter or producer whose good is the subject of... calendar days after conclusion of the origin verification process, unless circumstances require...

  19. The Origin of Eucrites: An Experimental Perspective

    NASA Technical Reports Server (NTRS)

    Jones, J. H.; Mittlefehldt, David W.; Jurewicz, A. J. G.; Lauer, H. V., Jr.; Hanson, B. Z.; Paslick, C. R.; McKay, G. A.

    1996-01-01

    The origin of eucrites has been the subject of debate. At issue is whether high-Mg# eucrites such as Sioux County are primitive or evolved liquids. We believe that the problem of the origin of eucrites is essentially solved. Problems associated with the petrogenesis of other achondrite groups remain, but the eucrites, taken as a whole, seem to present a clear and understandable story that we will present using experiments, analyses, and calculations. The two traditional eucrite groupings, the partial melting trend a.k.a. Stannem trend) and the fractional crystallization trend (a.k.a. Nuevo Laredo trend) have both been reproduced experimentally. The partial melting trend culminates in Sioux County. Sioux County is also an acceptable starting point for the fractional crystallization trend. The implication of these experimental results is that it is extremely difficult to relate the eucrites to diogenites, a group of pyroxene cumulates that conceivably could have crystallized from eucrite parent magmas.

  20. The origin of the Everettian heresy

    NASA Astrophysics Data System (ADS)

    Osnaghi, Stefano; Freitas, Fábio; Freire, Olival

    In 1956, Hugh Everett, then a PhD student at Princeton, proposed his "relative state" formulation of quantum mechanics. John Wheeler, who was Everett's advisor, recognized the originality and importance of such a proposal, but he denied that its non-conventional approach to measurement questioned the orthodox view. Indeed, Wheeler made serious efforts to obtain the blessing of Niels Bohr for Everett's ideas. These efforts gave rise to a lively debate with the Copenhagen group, the existence and content of which have been only recently disclosed by the discovery of unpublished documents. The analysis of such documents opens a window on the conceptual background of Everett's proposal, and illuminates at the same time some crucial aspects of the Copenhagen view of the measurement problem. Also, it provides an original insight into the interplay between philosophical and social factors which underlay the postwar controversies on the interpretation of quantum mechanics.

  1. Charles Darwin and the origin of life.

    PubMed

    Peretó, Juli; Bada, Jeffrey L; Lazcano, Antonio

    2009-10-01

    When Charles Darwin published The Origin of Species 150 years ago he consciously avoided discussing the origin of life. However, analysis of some other texts written by Darwin, and of the correspondence he exchanged with friends and colleagues demonstrates that he took for granted the possibility of a natural emergence of the first life forms. As shown by notes from the pages he excised from his private notebooks, as early as 1837 Darwin was convinced that "the intimate relation of Life with laws of chemical combination, & the universality of latter render spontaneous generation not improbable". Like many of his contemporaries, Darwin rejected the idea that putrefaction of preexisting organic compounds could lead to the appearance of organisms. Although he favored the possibility that life could appear by natural processes from simple inorganic compounds, his reluctance to discuss the issue resulted from his recognition that at the time it was possible to undertake the experimental study of the emergence of life. PMID:19633921

  2. Fever of unknown origin in returning travellers.

    PubMed

    Korzeniewski, Krzysztof; Gaweł, Bartłomiej; Krankowska, Dagny; Wasilczuk, Katarzyna

    2015-01-01

    The aim of the article is to discuss issues associated with the occurrence of febrile illnesses in leisure and business travellers, with a particular emphasis on fevers of unknown origin (FUO). FUO, apart from diarrhoeas, respiratory tract infections and skin lesions, are one of the most common health problems in travellers to tropical and subtropical countries. FUO are manifestations of various diseases, typically of infectious or invasive aetiology. In one out of 3 cases, the cause of a fever in travellers returning from the hot climate zone is malaria, and therefore diagnostic tests should first aim at ruling out this specific disease entity. Other illnesses with persistent fever include dengue, enteric fever, viral hepatitis A, bacterial diarrhoeas and rickettsioses. Fever may also occur in travellers suffering from diseases of non-tropical origin, e.g. cosmopolitan respiratory tract or urinary tract infections, also, fever may coexist with other illnesses or injuries (skin rashes, bites, burns).

  3. Origin of flaw-tolerance in nacre

    PubMed Central

    Huang, Zaiwang; Li, Xiaodong

    2013-01-01

    Over the past decades, our understanding of nacre's toughening origin has long stayed at the level of crack deflection along the biopolymer interface between aragonite platelets. It has been widely thought that the ceramic aragonite platelets in nacre invariably remain shielded from the propagating crack. Here we report an unexpected experimental observation that the propagating crack, surprisingly, invades the aragonite platelet following a zigzag crack propagation trajectory. The toughening origin of previously-thought brittle aragonite platelet is ascribed to its unique nanoparticle-architecture, which tunes crack propagation inside the aragonite platelet in an intergranular manner. For comparison, we also investigated the crack behavior in geologic aragonite mineral (pure monocrystal) and found that the crack propagates in a cleavage fashion, in sharp contrast with the intergranular cracking in the aragonite platelet of nacre. These two fundamentally different cracking mechanisms uncover a new toughening strategy in nacre's hierarchical flaw-tolerance design. PMID:23603788

  4. Killing Me Softly: The Fetal Origins Hypothesis*

    PubMed Central

    Almond, Douglas

    2013-01-01

    In the epidemiological literature, the fetal origins hypothesis associated with David J. Barker posits that chronic, degenerative conditions of adult health, including heart disease and type 2 diabetes, may be triggered by circumstance decades earlier, in utero nutrition in particular. Economists have expanded on this hypothesis, investigating a broader range of fetal shocks and circumstances and have found a wealth of later-life impacts on outcomes including test scores, educational attainment, and income, along with health. In the process, they have provided some of the most credible observational evidence in support of the hypothesis. The magnitude of the impacts is generally large. Thus, the fetal origins hypothesis has not only survived contact with economics, but has flourished. PMID:25152565

  5. Identifying the seasonal origins of human campylobacteriosis.

    PubMed

    Strachan, N J C; Rotariu, O; Smith-Palmer, A; Cowden, J; Sheppard, S K; O'Brien, S J; Maiden, M C J; Macrae, M; Bessell, P R; Matthews, L; Reid, S W J; Innocent, G T; Ogden, I D; Forbes, K J

    2013-06-01

    Human campylobacteriosis exhibits a distinctive seasonality in temperate regions. This paper aims to identify the origins of this seasonality. Clinical isolates [typed by multi-locus sequence typing (MLST)] and epidemiological data were collected from Scotland. Young rural children were found to have an increased burden of disease in the late spring due to strains of non-chicken origin (e.g. ruminant and wild bird strains from environmental sources). In contrast the adult population had an extended summer peak associated with chicken strains. Travel abroad and UK mainland travel were associated with up to 17% and 18% of cases, respectively. International strains were associated with chicken, had a higher diversity than indigenous strains and a different spectrum of MLST types representative of these countries. Integrating empirical epidemiology and molecular subtyping can successfully elucidate the seasonal components of human campylobacteriosis. The findings will enable public health officials to focus strategies to reduce the disease burden.

  6. Carbonaceous chondrites and the origin of life

    NASA Technical Reports Server (NTRS)

    Hartman, Hyman; Sweeney, Michael A.; Kropp, Michael A.; Lewis, John S.

    1993-01-01

    Organic matter in carbonaceous chondrites can be separated into three fractions. The first component, the fraction that is insoluble in chloroform and methanol, has a part which is of interstellar origin. The other two fractions (chloroform-soluble hydrocarbons and methanol-soluble polar organics) are hypothesized to have been synthesized on a planetoid body. We propose that the polar organics, i.e., amino acids, were synthesized close to its surface by the radiolysis of hydrocarbons and ammonium carbonate in a liquid water environment. Some hydrocarbons may have been synthesized by a Fischer-Tropsch mechanism in the interior of the body. Ferrous ion acted as a protection against back reactions. The simultaneous synthesis of iron-rich clays with the polar organics may be indicative of events related to the origin of life on Earth.

  7. Tektites and their origin. [properties and distribution

    NASA Technical Reports Server (NTRS)

    Okeefe, J. A.

    1975-01-01

    A study was conducted of the literature pertaining to the origin and characteristics of tektites. Topics discussed include tektite distribution in geographical locations, shapes of tektites, internal structure of tektites, physical properties, mechanical properties, optical properties, chemical composition, and comparisons with compositions of impact materials. Various arguments are presented on the terrestrial origin of tektites. It was found that some lunar craters of considerable size must be the products of volcanism which occurred during the past few million years, and that the moon must have within it a reservoir of rock which is considerably more like the mantle of the earth than like the rocks from which the basalts of the lunar crust are derived.

  8. Open Questions on the Origin of Eukaryotes.

    PubMed

    López-García, Purificación; Moreira, David

    2015-11-01

    Despite recent progress, the origin of the eukaryotic cell remains enigmatic. It is now known that the last eukaryotic common ancestor was complex and that endosymbiosis played a crucial role in eukaryogenesis at least via the acquisition of the alphaproteobacterial ancestor of mitochondria. However, the nature of the mitochondrial host is controversial, although the recent discovery of an archaeal lineage phylogenetically close to eukaryotes reinforces models proposing archaea-derived hosts. We argue that, in addition to improved phylogenomic analyses with more comprehensive taxon sampling to pinpoint the closest prokaryotic relatives of eukaryotes, determining plausible mechanisms and selective forces at the origin of key eukaryotic features, such as the nucleus or the bacterial-like eukaryotic membrane system, is essential to constrain existing models.

  9. Origin of the Amphibian Chytrid Fungus

    PubMed Central

    du Preez, Louis H.; Hyatt, Alex D.; Muller, Reinhold; Speare, Rick

    2004-01-01

    The sudden appearance of chytridiomycosis, the cause of amphibian deaths and population declines in several continents, suggests that its etiologic agent, the amphibian chytrid Batrachochytrium dendrobatidis, was introduced into the affected regions. However, the origin of this virulent pathogen is unknown. A survey was conducted of 697 archived specimens of 3 species of Xenopus collected from 1879 to 1999 in southern Africa in which the histologic features of the interdigital webbing were analyzed. The earliest case of chytridiomycosis found was in a Xenopus laevis frog in 1938, and overall prevalence was 2.7%. The prevalence showed no significant differences between species, regions, season, or time period. Chytridiomycosis was a stable endemic infection in southern Africa for 23 years before any positive specimen was found outside Africa. We propose that Africa is the origin of the amphibian chytrid and that the international trade in X. laevis that began in the mid-1930s was the means of dissemination. PMID:15663845

  10. Identifying the seasonal origins of human campylobacteriosis

    PubMed Central

    STRACHAN, N. J. C.; ROTARIU, O.; SMITH-PALMER, A.; COWDEN, J.; SHEPPARD, S. K.; O’BRIEN, S. J.; MAIDEN, M. C. J.; MACRAE, M.; BESSELL, P. R.; MATTHEWS, L.; REID, S. W. J.; INNOCENT, G. T.; OGDEN, I. D.; FORBES, K. J.

    2014-01-01

    SUMMARY Human campylobacteriosis exhibits a distinctive seasonality in temperate regions. This paper aims to identify the origins of this seasonality. Clinical isolates [typed by multi-locus sequence typing (MLST)] and epidemiological data were collected from Scotland. Young rural children were found to have an increased burden of disease in the late spring due to strains of non-chicken origin (e.g. ruminant and wild bird strains from environmental sources). In contrast the adult population had an extended summer peak associated with chicken strains. Travel abroad and UK mainland travel were associated with up to 17% and 18% of cases, respectively. International strains were associated with chicken, had a higher diversity than indigenous strains and a different spectrum of MLST types representative of these countries. Integrating empirical epidemiology and molecular subtyping can successfully elucidate the seasonal components of human campylobacteriosis. The findings will enable public health officials to focus strategies to reduce the disease burden. PMID:22989449

  11. [Medical anthropology evidences on the Pishtaco origin].

    PubMed

    de Pribyl, Rosario

    2010-03-01

    This paper will contribute to the scientific development of a new approach on the pishtaco in Peru by means of medical anthropological analysis. The model emphasizes presentation and analysis of historical, pharmaceutical, and anthropological evidence supporting use of human tissues with specific medical goals in Peruvian and European regions. We can find the origin of this phenomenon around the sixteen and seventeen centuries in Europe: The pishtaco has no an Andean origin. The methodology and main conclusions of this paper could provide to the scientific community an alternative perspective to the conventional anthropological and ethnological research, as an example of a medical anthropological analysis of the pishtaco character. Professionals involved in intercultural health projects could have a new insight on this issue thanks to these results. They will obtain an adequate historical-cultural context for the interpretation and understanding of people and native communities' beliefs about health, body and medical systems.

  12. On the origins of psychoanalytic psychohistory.

    PubMed

    Pietikainen, Petteri; Ihanus, Juhani

    2003-05-01

    This article examines the origins and early development of psychoanalytically inspired psychohistory from the late 1950s to the early 1970s. It focuses on Erik H. Erikson, Bruce Mazlish, and Robert Jay Lifton and illustrates their contributions to psychoanalytic psychohistory. Erikson, Mazlish, and Lifton were core members of the Wellfleet group, a research project originally funded by the American Academy of Arts and Sciences in 1965 to conceptualize the foundation of psychohistory. The article gives an account of the early history of the Wellfleet group and argues for specific historical reasons to explain why psychoanalytic psychohistory emerged on the East Coast of the United States in the late 1950s and early 1960s. A critique of the Wellfleet group in unpublished correspondence of Erich Fromm and David Riesman is also discussed.

  13. Could Life Originate between Mica Sheets?

    NASA Astrophysics Data System (ADS)

    Hansma, Helen

    2014-11-01

    Muscovite mica has many advantages as a site for the origins of life. Some of these advantages are: A. Spaces between mica sheets serve as cell-like compartments. B. K+ ions bridge Muscovite mica sheets, providing a high K+ environment, as found in all living cells. C. Mica's hexagonal 0.5-nm clay crystal lattice is comparable to the length of the amino acids, sugars, and nucleotides that polymerize to form life's major biological macromolecules. D. Mechanical energy from mica sheets, moving in response to water flows and temperature changes, provide an endless energy source for forming chemical bonds, rearranging polymers, and blebbing off protocells in a primitive form of cell division. How might fluid dynamics in the planar nanometer- to micron-high spaces between mica sheets affect the processes involved in the origins of life?

  14. The origins of Ptolemy's astronomical tables.

    NASA Astrophysics Data System (ADS)

    Newton, R. R.

    Following the line set by his earlier book 'The crime of Claudius Ptolemy' the author discusses here the numerous astronomical tables in Ptolemy's work that have been calculated with the aid of trigonometric tables, as well as a few that are nonlinear but that do not involve trigonometry. The purpose in this study is to determine, if possible, whether Ptolemy calculated these tables or whether he copied them from now-lost original works. The conclusion isthat Ptolemy made few if any original contributions to astronomy, either observational or computational.Contents: 1. Introduction; thetable of chords. 2. The tables of the latitude and of gnomon shadows.3. Tables of the Sun. 4. Astronomical geography. 5. The tables of theMoon. 6. Eclipse tables. 7. Tables of the planets. 8. The empirical basis for Hipparchus's mean motions of the Moon. 9. Summary and conclusions.

  15. Origin and Variation of Tunicate Secondary Metabolites⊥

    PubMed Central

    Schmidt, Eric W.; Donia, Mohamed S.; McIntosh, John A.; Fricke, W. Florian; Ravel, Jacques

    2012-01-01

    Ascidians (tunicates) are rich sources of structurally elegant, pharmaceutically potent secondary metabolites and more recently, potential biofuels. It has been demonstrated that some of these compounds are made by symbiotic bacteria and not by the animals themselves, and for a few other compounds evidence exists supporting a symbiotic origin. In didemnid ascidians, compounds are highly variable even in apparently identical animals. Recently, we have explained this variation at the genomic and metagenomic levels and have applied the basic scientific findings to drug discovery and development. This review discusses what is currently known about the origin and variation of symbiotically derived metabolites in ascidians, focusing on Family Didemnidae, where most research has occurred. Applications of our basic studies are also described. PMID:22233390

  16. Cosmic Origins Program Annual Technology Report

    NASA Technical Reports Server (NTRS)

    Pham, Bruce Thai; Neff, Susan Gale

    2015-01-01

    What is the Cosmic Origins (COR) Program? From ancient times, humans have looked up at the night sky and wondered: Are we alone? How did the universe come to be? How does the universe work? COR focuses on the second question. Scientists investigating this broad theme seek to understand the origin and evolution of the universe from the Big Bang to the present day, determining how the expanding universe grew into a grand cosmic web of dark matter enmeshed with galaxies and pristine gas, forming, merging, and evolving over time. COR also seeks to understand how stars and planets form from clouds in these galaxies to create the heavy elements that are essential to life starting with the first generation of stars to seed the universe, and continuing through the birth and eventual death of all subsequent generations of stars. The COR Programs purview includes the majority of the field known as astronomy, from antiquity to the present.

  17. Premetazoan origin of the Hippo signaling pathway

    PubMed Central

    Sebé-Pedrós, Arnau; Zheng, Yonggang; Ruiz-Trillo, Iñaki; Pan, Duojia

    2012-01-01

    Summary Non-aggregative multicellularity requires strict control of cell number. The Hippo signaling pathway coordinates cell proliferation and apoptosis and is a central regulator of organ size in animals. Recent studies have shown the presence of key members of the Hippo pathway in non-bilaterian animals, but failed to identify this pathway outside Metazoa. Through comparative analyses of recently sequenced holozoan genomes, we show that Hippo pathway components, such as the kinases Hippo and Warts, the co-activator Yorkie and the transcription factor Scalloped, were already present in the unicellular ancestors of animals. Remarkably, functional analysis of Hippo components of the amoeboid holozoan Capsaspora owczarzaki, performed in Drosophila, demonstrate that the growth-regulatory activity of the Hippo pathway is conserved in this unicellular lineage. Our findings show that the Hippo pathway evolved well before the origin of Metazoa and highlight the importance of Hippo signaling as a key developmental mechanism pre-dating the origin of Metazoa. PMID:22832104

  18. Origin of the earth's ocean basins

    NASA Technical Reports Server (NTRS)

    Frex, H.

    1977-01-01

    The earth's original ocean basins were mare-type basins produced 4 billion years ago by the flux of asteroid-sized objects responsible for the lunar mare basins. Scaling upwards from the observed number of lunar basins for the greater capture cross-section and impact velocity of the Earth indicates that at least 50 percent of an original global crust would have been converted to basin topography. These basins were flooded by basaltic liquids in times short compared to the isostatic adjustment time for the basin. The modern crustal dichotomy (60 percent oceanic, 40 percent continental crust) was established early in the history of the earth, making possible the later onset of plate tectonic processes. These later processes have subsequently reworked, in several cycles, principally the oceanic parts of the earth's crust, changing the configuration of the continents in the process. Ocean basins (and oceans themselves) may be rare occurrences on planets in other star systems.

  19. Common origin of visible and dark universe

    SciTech Connect

    Gu Peihong; Sarkar, Utpal

    2010-02-01

    Dark matter, baryonic matter, and dark energy have different properties but contribute comparable energy density to the present Universe. We point out that they may have a common origin. As the dark energy has a scale far lower than all known scales in particle physics but very close to neutrino masses, while the excess matter over antimatter in the baryonic sector is probably related to the neutrino-mass generation, we unify the origin of the dark and visible universe in a variant of the seesaw model. In our model (i) the dark matter relic density is a dark matter asymmetry emerged simultaneously with the baryon asymmetry from leptogenesis; (ii) the dark energy is due to a pseudo-Nambu-Goldstone-Boson associated with the neutrino-mass generation.

  20. On the origins of psychoanalytic psychohistory.

    PubMed

    Pietikainen, Petteri; Ihanus, Juhani

    2003-05-01

    This article examines the origins and early development of psychoanalytically inspired psychohistory from the late 1950s to the early 1970s. It focuses on Erik H. Erikson, Bruce Mazlish, and Robert Jay Lifton and illustrates their contributions to psychoanalytic psychohistory. Erikson, Mazlish, and Lifton were core members of the Wellfleet group, a research project originally funded by the American Academy of Arts and Sciences in 1965 to conceptualize the foundation of psychohistory. The article gives an account of the early history of the Wellfleet group and argues for specific historical reasons to explain why psychoanalytic psychohistory emerged on the East Coast of the United States in the late 1950s and early 1960s. A critique of the Wellfleet group in unpublished correspondence of Erich Fromm and David Riesman is also discussed. PMID:12822567

  1. The origins of parasitism in the protists.

    PubMed

    Baker, J R

    1994-12-01

    The origins of parasitism among the protists are, like the group itself, polyphyletic. Probably the majority of present-day parasitic forms evolved from free-living ancestors which were ingested as part of the food of their hosts, though origins from ectoparasitic forms and via a phase of facultative parasitism are possibilities, particularly among the ciliated protozoa and (for ectoparasitism) the Kinetoplasta. Sporozoan parasites most probably developed via a stage which was ingested and became adapted to life in the host's gut. Further developments in parasitism involved deeper penetration into the host's tissues and the adoption of more than one host in the life cycle, thus avoiding entirely the potentially hazardous phase of existence outside the host.

  2. The path to life's origins. Remaining hurdles.

    PubMed

    Di Mauro, Ernesto; Saladino, Raffaele; Trifonov, Edward N

    2014-04-01

    Recent progress in abiotic syntheses, especially self-catalytic syntheses, as well as theoretical breakthroughs such as reconstruction of events of early molecular evolution and tracing repeat expansions in contemporary genomes, converge to a rather simple possible scenario of origin of life, notwithstanding the enormity of the problem. The scenario includes self-replicating RNA duplexes, supplemented by monomers and high-energy compounds that, as demonstrated or assumed, can all be synthesized abiotically. The self-replication would proceed with occasional mutational changes, propagated in later cycles. This audacious, as it may seem, walk toward the life origin already involves many laboratories, each exploring its own scenario. The one suggested in this outline seems to the authors well justified to engage in, while bypassing few steps to deal with later.

  3. The burrowing origin of modern snakes.

    PubMed

    Yi, Hongyu; Norell, Mark A

    2015-11-01

    Modern snakes probably originated as habitat specialists, but it controversial unclear whether they were ancestrally terrestrial burrowers or marine swimmers. We used x-ray virtual models of the inner ear to predict the habit of Dinilysia patagonica, a stem snake closely related to the origin of modern snakes. Previous work has shown that modern snakes perceive substrate vibrations via their inner ear. Our data show that D. patagonica and modern burrowing squamates share a unique spherical vestibule in the inner ear, as compared with swimmers and habitat generalists. We built predictive models for snake habit based on their vestibular shape, which estimated D. patagonica and the hypothetical ancestor of crown snakes as burrowers with high probabilities. This study provides an extensive comparative data set to test fossoriality quantitatively in stem snakes, and it shows that burrowing was predominant in the lineages leading to modern crown snakes.

  4. Origin of flaw-tolerance in nacre

    NASA Astrophysics Data System (ADS)

    Huang, Zaiwang; Li, Xiaodong

    2013-04-01

    Over the past decades, our understanding of nacre's toughening origin has long stayed at the level of crack deflection along the biopolymer interface between aragonite platelets. It has been widely thought that the ceramic aragonite platelets in nacre invariably remain shielded from the propagating crack. Here we report an unexpected experimental observation that the propagating crack, surprisingly, invades the aragonite platelet following a zigzag crack propagation trajectory. The toughening origin of previously-thought brittle aragonite platelet is ascribed to its unique nanoparticle-architecture, which tunes crack propagation inside the aragonite platelet in an intergranular manner. For comparison, we also investigated the crack behavior in geologic aragonite mineral (pure monocrystal) and found that the crack propagates in a cleavage fashion, in sharp contrast with the intergranular cracking in the aragonite platelet of nacre. These two fundamentally different cracking mechanisms uncover a new toughening strategy in nacre's hierarchical flaw-tolerance design.

  5. Nepalese origin of cholera epidemic in Haiti.

    PubMed

    Frerichs, R R; Keim, P S; Barrais, R; Piarroux, R

    2012-06-01

    Cholera appeared in Haiti in October 2010 for the first time in recorded history. The causative agent was quickly identified by the Haitian National Public Health Laboratory and the United States Centers for Disease Control and Prevention as Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor. Since then, >500 000 government-acknowledged cholera cases and >7000 deaths have occurred, the largest cholera epidemic in the world, with the real death toll probably much higher. Questions of origin have been widely debated with some attributing the onset of the epidemic to climatic factors and others to human transmission. None of the evidence on origin supports climatic factors. Instead, recent epidemiological and molecular-genetic evidence point to the United Nations peacekeeping troops from Nepal as the source of cholera to Haiti, following their troop rotation in early October 2010. Such findings have important policy implications for shaping future international relief efforts. PMID:22510219

  6. Cholangiocarcinomas can originate from hepatocytes in mice

    PubMed Central

    Fan, Biao; Malato, Yann; Calvisi, Diego F.; Naqvi, Syed; Razumilava, Nataliya; Ribback, Silvia; Gores, Gregory J.; Dombrowski, Frank; Evert, Matthias; Chen, Xin; Willenbring, Holger

    2012-01-01

    Intrahepatic cholangiocarcinomas (ICCs) are primary liver tumors with a poor prognosis. The development of effective therapies has been hampered by a limited understanding of the biology of ICCs. Although ICCs exhibit heterogeneity in location, histology, and marker expression, they are currently thought to derive invariably from the cells lining the bile ducts, biliary epithelial cells (BECs), or liver progenitor cells (LPCs). Despite lack of experimental evidence establishing BECs or LPCs as the origin of ICCs, other liver cell types have not been considered. Here we show that ICCs can originate from fully differentiated hepatocytes. Using a mouse model of hepatocyte fate tracing, we found that activated NOTCH and AKT signaling cooperate to convert normal hepatocytes into biliary cells that act as precursors of rapidly progressing, lethal ICCs. Our findings suggest a previously overlooked mechanism of human ICC formation that may be targetable for anti-ICC therapy. PMID:22797301

  7. The origin of OB runaway stars.

    PubMed

    Fujii, Michiko S; Portegies Zwart, Simon

    2011-12-01

    About 20% of all massive stars in the Milky Way have unusually high velocities, the origin of which has puzzled astronomers for half a century. We argue that these velocities originate from strong gravitational interactions between single stars and binaries in the centers of star clusters. The ejecting binary forms naturally during the collapse of a young (≤1 million years old) star cluster. This model replicates the key characteristics of OB runaways in our galaxy, and it explains the presence of runaway stars of ≥100 solar masses (M(⊙)) around young star clusters, such as R136 and Westerlund 2. The high proportion and the distributions in mass and velocity of runaways in the Milky Way are reproduced if the majority of massive stars are born in dense and relatively low-mass (5000 to 10,000 M(⊙)) clusters. PMID:22096104

  8. The burrowing origin of modern snakes

    PubMed Central

    Yi, Hongyu; Norell, Mark A.

    2015-01-01

    Modern snakes probably originated as habitat specialists, but it controversial unclear whether they were ancestrally terrestrial burrowers or marine swimmers. We used x-ray virtual models of the inner ear to predict the habit of Dinilysia patagonica, a stem snake closely related to the origin of modern snakes. Previous work has shown that modern snakes perceive substrate vibrations via their inner ear. Our data show that D. patagonica and modern burrowing squamates share a unique spherical vestibule in the inner ear, as compared with swimmers and habitat generalists. We built predictive models for snake habit based on their vestibular shape, which estimated D. patagonica and the hypothetical ancestor of crown snakes as burrowers with high probabilities. This study provides an extensive comparative data set to test fossoriality quantitatively in stem snakes, and it shows that burrowing was predominant in the lineages leading to modern crown snakes. PMID:26702436

  9. The Origin of Fluorescence from Graphene Oxide

    PubMed Central

    Shang, Jingzhi; Ma, Lin; Li, Jiewei; Ai, Wei; Yu, Ting; Gurzadyan, Gagik G.

    2012-01-01

    Time-resolved fluorescence measurements of graphene oxide in water show multiexponential decay kinetics ranging from 1 ps to 2 ns. Electron-hole recombination from the bottom of the conduction band and nearby localized states to wide-range valance band is suggested as origin of the fluorescence. Excitation wavelength dependence of the fluorescence was caused by relative intensity changes of few emission species. By introducing the molecular orbital concept, the dominant fluorescence was found to originate from the electronic transitions among/between the non-oxidized carbon regions and the boundary of oxidized carbon atom regions, where all three kinds of functionalized groups C-O, C = O and O = C-OH were participating. In the visible spectral range, the ultrafast fluorescence of graphene oxide was observed for the first time. PMID:23145316

  10. Open questions on the origin of eukaryotes

    PubMed Central

    López-García, Purificación; Moreira, David

    2015-01-01

    Despite recent progress, the origin of the eukaryotic cell remains enigmatic. It is now known that the last eukaryotic common ancestor was complex and that endosymbiosis played a crucial role in eukaryogenesis at least via the acquisition of the alphaproteobacterial ancestor of mitochondria. However, the nature of the mitochondrial host is controversial, although the recent discovery of an archaeal lineage phylogenetically close to eukaryotes reinforces models proposing archaea-derived hosts. We argue that, in addition to improved phylogenomic analyses with more comprehensive taxon sampling to pinpoint the closest prokaryotic relatives of eukaryotes, determining plausible mechanisms and selective forces at the origin of key eukaryotic features, such as the nucleus or the bacterial-like eukaryotic membrane system, is essential to constrain existing models. PMID:26455774

  11. Charles Darwin and the origin of life.

    PubMed

    Peretó, Juli; Bada, Jeffrey L; Lazcano, Antonio

    2009-10-01

    When Charles Darwin published The Origin of Species 150 years ago he consciously avoided discussing the origin of life. However, analysis of some other texts written by Darwin, and of the correspondence he exchanged with friends and colleagues demonstrates that he took for granted the possibility of a natural emergence of the first life forms. As shown by notes from the pages he excised from his private notebooks, as early as 1837 Darwin was convinced that "the intimate relation of Life with laws of chemical combination, & the universality of latter render spontaneous generation not improbable". Like many of his contemporaries, Darwin rejected the idea that putrefaction of preexisting organic compounds could lead to the appearance of organisms. Although he favored the possibility that life could appear by natural processes from simple inorganic compounds, his reluctance to discuss the issue resulted from his recognition that at the time it was possible to undertake the experimental study of the emergence of life.

  12. Dynamically plausible hypotheses of lunar origin

    NASA Technical Reports Server (NTRS)

    Kaula, W. M.; Harris, A. W.

    1973-01-01

    The implausibility of the capture hypothesis of lunar origin is pointed out. The reason for this implausibility is the extreme weakness of the only known energy sink for pure capture, tidal friction. A mechanism proposed by Alfven and Arrhenius (1972) is the locking of the moon in synchronization with a longitudinal variation in the earth's gravitational field. It is shown that collision with preexisting satellite matter is the most effective means of capturing a moon.

  13. Moon origin - The impact-trigger hypothesis

    NASA Technical Reports Server (NTRS)

    Hartmann, William K.

    1986-01-01

    Arguments in favor of the impact-trigger model of lunar origin are presented. Lunar properties favoring this hypothesis include: (1) lunar iron and volatile deficiency; (2) angular momentum of the earth-moon system; and (3) similar O isotopes, bulk iron contents, and densities of earth's mantle and the moon. It is shown that the intense early bombardment averaged during earth's formation was several billion times the present meteoritic mass flux, consistent with a giant impact.

  14. The binary fission origin of the moon

    NASA Technical Reports Server (NTRS)

    Binder, Alan B.

    1986-01-01

    The major arguments for and against the binary fission model of lunar origin are reviewed. Unresolved problems include: (1) how the protoearth acquired sufficient angular velocity to fission, and (2) how the earth-moon system lost its excess angular momentum after fission. Despite these uncertainties, the compositional similarities between the earth's mantle and the bulk moon suggest that the fission model is worth considering. The proposed sequence of events in the formation of the moon by binary fission is given.

  15. The origin of Sarcoptes scabiei in wombats.

    PubMed

    Morrison, David A; Ljunggren, Erland L; Mattsson, Jens G

    2003-12-01

    In 2002, Skerratt et al. phylogenetically analysed sequence data for several haplotypes of the parasitic mite Sarcoptes scabiei from wombat, human and dog hosts in Australia, to test scenarios concerning the origin and diversification of the scabies infections in wombats. Here we note that their substantive conclusions can be called into question by the choice of model used in their phylogenetic analysis, the lack of a root for their phylogenetic trees, and their interpretation of the evolutionary scenario. PMID:14530970

  16. The origin of the planetesimal theory.

    PubMed

    Brush, S G

    1977-04-01

    T. C. Chamberlin suggested in 1897, on the basis of geological and climatological arguments, that the planets were formed by accretion of cold solid partices. With F. R. Moulton he developed convincing arguments against the Laplace nebular hypothesis and published a comprehensive 'planetesimal theory' of the origin of the solar system in 1905. The Chamberlin-Moulton theory has current as well as historical interest.

  17. The origin of the temporalis muscle flap.

    PubMed

    Speculand, B

    1992-12-01

    This paper explores the origin of the temporalis muscle flap which has been attributed to Golovine, a Moscow ophthalmic surgeon, who described a forehead skin transposition flap. Small temporalis muscle transpositions were used in surgery for TMJ ankylosis, but the use of the majority of the muscle for reconstruction of facial defects was first described by Sir Harold Gillies during the 1914-18 war.

  18. Research into the origins of engineering thermodynamics

    SciTech Connect

    Bejan, A.

    1988-09-01

    This paper draws attention to a series of misconceptions and misstatements regarding the origin and meaning of some of the most basic concepts of engineering thermodynamics. The six examples exhibited in the paper relate to the concepts of reversibility, entropy, mechanical equivalent of the calorie, the first law of thermodynamics for open systems, enthalpy and the Diesel cycle. A complete list of the pioneering references concludes the paper.

  19. Life Origination Hydrate Hypothesis (LOH-Hypothesis)

    PubMed Central

    Ostrovskii, Victor; Kadyshevich, Elena

    2012-01-01

    The paper develops the Life Origination Hydrate Hypothesis (LOH-hypothesis), according to which living-matter simplest elements (LMSEs, which are N-bases, riboses, nucleosides, nucleotides), DNA- and RNA-like molecules, amino-acids, and proto-cells repeatedly originated on the basis of thermodynamically controlled, natural, and inevitable processes governed by universal physical and chemical laws from CH4, niters, and phosphates under the Earth's surface or seabed within the crystal cavities of the honeycomb methane-hydrate structure at low temperatures; the chemical processes passed slowly through all successive chemical steps in the direction that is determined by a gradual decrease in the Gibbs free energy of reacting systems. The hypothesis formulation method is based on the thermodynamic directedness of natural movement and consists ofan attempt to mentally backtrack on the progression of nature and thus reveal principal milestones alongits route. The changes in Gibbs free energy are estimated for different steps of the living-matter origination process; special attention is paid to the processes of proto-cell formation. Just the occurrence of the gas-hydrate periodic honeycomb matrix filled with LMSEs almost completely in its final state accounts for size limitation in the DNA functional groups and the nonrandom location of N-bases in the DNA chains. The slowness of the low-temperature chemical transformations and their “thermodynamic front” guide the gross process of living matter origination and its successive steps. It is shown that the hypothesis is thermodynamically justified and testable and that many observed natural phenomena count in its favor. PMID:25382120

  20. Origins: an outreach project towards children

    NASA Astrophysics Data System (ADS)

    Moutou, C.

    2010-12-01

    We have developed and realised an outreach project about Origins, from the universe formation to the present epoch, in the context of the International Year of Astronomy. The aimed public is primary school, from 8 years age. Various media have been used, from the creation of a theater play to a pedagogical exhibition. The project was shown as a whole ten times during 2009, and the pedagogical elements are still used for school events.

  1. Life Origination Hydrate Hypothesis (LOH-Hypothesis).

    PubMed

    Ostrovskii, Victor; Kadyshevich, Elena

    2012-01-01

    The paper develops the Life Origination Hydrate Hypothesis (LOH-hypothesis), according to which living-matter simplest elements (LMSEs, which are N-bases, riboses, nucleosides, nucleotides), DNA- and RNA-like molecules, amino-acids, and proto-cells repeatedly originated on the basis of thermodynamically controlled, natural, and inevitable processes governed by universal physical and chemical laws from CH4, niters, and phosphates under the Earth's surface or seabed within the crystal cavities of the honeycomb methane-hydrate structure at low temperatures; the chemical processes passed slowly through all successive chemical steps in the direction that is determined by a gradual decrease in the Gibbs free energy of reacting systems. The hypothesis formulation method is based on the thermodynamic directedness of natural movement and consists ofan attempt to mentally backtrack on the progression of nature and thus reveal principal milestones alongits route. The changes in Gibbs free energy are estimated for different steps of the living-matter origination process; special attention is paid to the processes of proto-cell formation. Just the occurrence of the gas-hydrate periodic honeycomb matrix filled with LMSEs almost completely in its final state accounts for size limitation in the DNA functional groups and the nonrandom location of N-bases in the DNA chains. The slowness of the low-temperature chemical transformations and their "thermodynamic front" guide the gross process of living matter origination and its successive steps. It is shown that the hypothesis is thermodynamically justified and testable and that many observed natural phenomena count in its favor. PMID:25382120

  2. The origin and evolution of model organisms

    NASA Technical Reports Server (NTRS)

    Hedges, S. Blair

    2002-01-01

    The phylogeny and timescale of life are becoming better understood as the analysis of genomic data from model organisms continues to grow. As a result, discoveries are being made about the early history of life and the origin and development of complex multicellular life. This emerging comparative framework and the emphasis on historical patterns is helping to bridge barriers among organism-based research communities.

  3. Infectious causes of fever of unknown origin.

    PubMed

    McGregor, Alastair C; Moore, David A

    2015-06-01

    The causes of fever of unknown origin (FUO) are changing because advances in clinical practice and diagnostics have facilitated the identification of some infections. A variety of bacterial infections can cause FUO, and these can be divided into those that are easy to identify using culture and those that require serological or molecular tests for identification. A number of viral, parasitic and fungal infections can also cause prolonged fever. This article summarises the clinical features and diagnostic strategy of these infections.

  4. The origin of Sarcoptes scabiei in wombats.

    PubMed

    Morrison, David A; Ljunggren, Erland L; Mattsson, Jens G

    2003-12-01

    In 2002, Skerratt et al. phylogenetically analysed sequence data for several haplotypes of the parasitic mite Sarcoptes scabiei from wombat, human and dog hosts in Australia, to test scenarios concerning the origin and diversification of the scabies infections in wombats. Here we note that their substantive conclusions can be called into question by the choice of model used in their phylogenetic analysis, the lack of a root for their phylogenetic trees, and their interpretation of the evolutionary scenario.

  5. A Strategy for Origins of Life Research.

    PubMed

    Scharf, Caleb; Virgo, Nathaniel; Cleaves, H James; Aono, Masashi; Aubert-Kato, Nathanael; Aydinoglu, Arsev; Barahona, Ana; Barge, Laura M; Benner, Steven A; Biehl, Martin; Brasser, Ramon; Butch, Christopher J; Chandru, Kuhan; Cronin, Leroy; Danielache, Sebastian; Fischer, Jakob; Hernlund, John; Hut, Piet; Ikegami, Takashi; Kimura, Jun; Kobayashi, Kensei; Mariscal, Carlos; McGlynn, Shawn; Menard, Brice; Packard, Norman; Pascal, Robert; Pereto, Juli; Rajamani, Sudha; Sinapayen, Lana; Smith, Eric; Switzer, Christopher; Takai, Ken; Tian, Feng; Ueno, Yuichiro; Voytek, Mary; Witkowski, Olaf; Yabuta, Hikaru

    2015-12-01

    Contents 1. Introduction 1.1. A workshop and this document 1.2. Framing origins of life science 1.2.1. What do we mean by the origins of life (OoL)? 1.2.2. Defining life 1.2.3. How should we characterize approaches to OoL science? 1.2.4. One path to life or many? 2. A Strategy for Origins of Life Research 2.1. Outcomes-key questions and investigations 2.1.1. Domain 1: Theory 2.1.2. Domain 2: Practice 2.1.3. Domain 3: Process 2.1.4. Domain 4: Future studies 2.2. EON Roadmap 2.3. Relationship to NASA Astrobiology Roadmap and Strategy documents and the European AstRoMap   Appendix I   Appendix II   Supplementary Materials  References.

  6. Planetary Systems and the Origins of Life

    NASA Astrophysics Data System (ADS)

    Pudritz, Ralph; Higgs, Paul; Stone, Jonathon

    2013-01-01

    Preface; Part I. Planetary Systems and the Origins of Life: 1. Observations of extrasolar planetary systems Shay Zucker; 2. The atmospheres of extrasolar planets L. Jeremy Richardson and Sara Seager; 3. Terrestrial planet formation Edward Thommes; 4. Protoplanetary disks, amino acids and the genetic code Paul Higgs and Ralph Pudritz; 5. Emergent phenomena in biology: the origin of cellular life David Deamer; Part II. Life on Earth: 6. Extremophiles: defining the envelope for the search for life in the Universe Lynn Rothschild; 7. Hyperthermophilic life on Earth - and on Mars? Karl Stetter; 8. Phylogenomics: how far back in the past can we go? Henner Brinkmann, Denis Baurain and Hervé Philippe; 9. Horizontal gene transfer, gene histories and the root of the tree of life Olga Zhaxybayeva and J. Peter Gogarten; 10. Evolutionary innovation versus ecological incumbency Adolf Seilacher; 11. Gradual origins for the Metazoans Alexandra Pontefract and Jonathan Stone; Part III. Life in the Solar System?: 12. The search for life on Mars Chris McKay; 13. Life in the dark dune spots of Mars: a testable hypothesis Eörs Szathmary, Tibor Ganti, Tamas Pocs, Andras Horvath, Akos Kereszturi, Szaniszlo Berzci and Andras Sik; 14. Titan: a new astrobiological vision from the Cassini-Huygens data François Raulin; 15. Europa, the Ocean Moon: tides, permeable ice, and life Richard Greenberg; Index.

  7. Titan's Plains: Global Distribution and Possible Origin

    NASA Astrophysics Data System (ADS)

    Lopes, R. M.; Le Gall, A.; Kirk, R. L.; Kargel, J. S.; Stofan, E. R.; Mitchell, K. L.; Lucas, A.; Janssen, M. A.; Wall, S. D.; Malaska, M. J.

    2012-12-01

    Titan's diverse and Earth-like geologic features have been mapped and interpreted based on their morphological characteristics (Lopes et al., 2010, Icarus 205; Aharonson et al., 2012, Titan: Surface, Atmosphere, Magnetosphere, Cambridge University Press). While the interpretation for the origin of some units, such as dunes and well-preserved impact craters, has been relatively straightforward, others have been more challenging. In particular, the undifferentiated plains first mapped by Lopes et al. (2010) remain mysterious. These vast expanses, mostly found at mid-latitudes are relatively featureless and appear to have low relief. Their gradational boundaries and paucity of features in SAR data make geologic interpretation particularly difficult using only this dataset. Plains may be sedimentary in origin, resulting from fluvial or lacustrine deposition or accumulation of photolysis products created in the upper atmosphere. Alternatively, the plains may be cryovolcanic, consisting of overlapping flows of low relief, obscured by accumulation of sediments. In this paper, we use SAR, radiometry, scatterometry, and SARTopo data to examine the characteristics of the plains and compare them with other geologic units. We also compare their global distribution with that of other units and examine the implications of a possible cryovolcanic origin.

  8. ORIGIN OF DUST AROUND V1309 SCO

    SciTech Connect

    Zhu, Chunhua; Lü, Guoliang; Wang, Zhaojun

    2013-11-01

    The origin of dust grains in the interstellar medium is still an unanswered problem. Nicholls et al. found the presence of a significant amount of dust around V1309 Sco, which may originate from the merger of a contact binary. We investigate the origin of dust around V1309 Sco and suggest that these dust grains are produced in the binary-merger ejecta. By means of the AGBDUST code, we estimate that ∼5.2 × 10{sup –4} M{sub ☉} dust grains are produced with a radii of ∼10{sup –5} cm. These dust grains are mainly composed of silicate and iron grains. Because the mass of the binary merger ejecta is very small, the contribution of dust produced by binary merger ejecta to the overall dust production in the interstellar medium is negligible. However, it is important to note that the discovery of a significant amount of dust around V1309 Sco offers a direct support for the idea that common-envelope ejecta provides an ideal environment for dust formation and growth. Therefore, we confirm that common envelope ejecta can be important source of cosmic dust.

  9. Ancient single origin for Malagasy primates.

    PubMed Central

    Yoder, A D; Cartmill, M; Ruvolo, M; Smith, K; Vilgalys, R

    1996-01-01

    We report new evidence that bears decisively on a long-standing controversy in primate systematics. DNA sequence data for the complete cytochrome b gene, combined with an expanded morphological data set, confirm the results of a previous study and again indicate that all extant Malagasy lemurs originated from a single common ancestor. These results, as well as those from other genetic studies, call for a revision of primate classifications in which the dwarf and mouse lemurs are placed within the Afro-Asian lorisiforms. The phylogenetic results, in agreement with paleocontinental data, indicate an African origin for the common ancestor of lemurs and lorises (the Strepsirrhini). The molecular data further suggest the surprising conclusion that lemurs began evolving independently by the early Eocene at the latest. This indicates that the Malagasy primate lineage is more ancient than generally thought and places the split between the two strepsirrhine lineages well before the appearance of known Eocene fossil primates. We conclude that primate origins were marked by rapid speciation and diversification sometime before the late Paleocene. Images Fig. 1 Fig. 2 PMID:8643538

  10. Asynchronous origins of ectomycorrhizal clades of Agaricales.

    PubMed

    Ryberg, Martin; Matheny, P Brandon

    2012-05-22

    The ectomycorrhizal (ECM) symbiosis is the most widespread biotrophic nutritional mode in mushroom-forming fungi. ECM fungi include, though are not limited to, about 5000 described species of Agaricales from numerous, independently evolved lineages. Two central hypotheses suggest different explanations for the origin of ECM fungal diversity: (i) dual origins, initially with the Pinaceae in the Jurassic and later with angiosperms during the Late Cretaceous, and (ii) a simultaneous and convergent radiation of ECM lineages in response to cooling climate during the Palaeogene and advancing temperate ECM plant communities. Neither of these hypotheses is supported here. While we demonstrate support for asynchronous origins of ECM Agaricales, the timing of such events appears to have occurred more recently than suggested by the first hypothesis, first during the Cretaceous and later during the Palaeogene. We are also unable to reject models of rate constancy, which suggests that the diversity of ECM Agaricales is not a consequence of convergent rapid radiations following evolutionary transitions from saprotrophic to ECM habits. ECM lineages of Agaricales differ not only in age, but also in rates of diversification and rate of substitution at nuclear ribosomal RNA loci. These results question the biological uniformity of the ECM guild.

  11. On the origin of Earth's Moon

    NASA Astrophysics Data System (ADS)

    Barr, Amy C.

    2016-09-01

    The Giant Impact is currently accepted as the leading theory for the formation of Earth's Moon. Successful scenarios for lunar origin should be able to explain the chemical composition of the Moon (volatile content and stable isotope ratios), the Moon's initial thermal state, and the system's bulk physical and dynamical properties. Hydrocode simulations of the impact have long been able to match the bulk properties, but recent, more detailed work on the evolution of the protolunar disk has yielded great insight into the origin of the Moon's chemistry and its early thermal history. Here I show that the community has constructed the elements of an end-to-end theory for lunar origin that matches the overwhelming majority of observational constraints. In spite of the great progress made in recent years, new samples of the Moon, clarification of processes in the impact-generated disk, and a broader exploration of impact parameter space could yield even more insights into this fundamental and uniquely challenging geophysical problem.

  12. On the Origin of Cancer Metastasis

    PubMed Central

    Seyfried, Thomas N.; Huysentruyt, Leanne C.

    2013-01-01

    Metastasis involves the spread of cancer cells from the primary tumor to surrounding tissues and to distant organs and is the primary cause of cancer morbidity and mortality. In order to complete the metastatic cascade, cancer cells must detach from the primary tumor, intravasate into the circulatory and lymphatic systems, evade immune attack, extravasate at distant capillary beds, and invade and proliferate in distant organs. Currently, several hypotheses have been advanced to explain the origin of cancer metastasis. These involve an epithelial mesenchymal transition, an accumulation of mutations in stem cells, a macrophage facilitation process, and a macrophage origin involving either transformation or fusion hybridization with neoplastic cells. Many of the properties of metastatic cancer cells are also seen in normal macrophages. A macrophage origin of metastasis can also explain the long-standing “seed and soil” hypothesis and the absence of metastasis in plant cancers. The view of metastasis as a macrophage metabolic disease can provide novel insight for therapeutic management. PMID:23237552

  13. Chirality and the origin of life

    NASA Astrophysics Data System (ADS)

    Bailey, Jeremy

    2000-06-01

    The homochirality of biological molecules (the use of only left handed amino acids and only right handed sugars) has long been known to be an important characteristic of life. Current ideas on the origin of life do not explain the origin of homochirality, yet the widely accepted 'RNA world' model cannot work without it. The recent discoveries of chiral asymmetry in the Murchison meteorite, and of strong circular polarization in star formation regions lead to a plausible model for an extraterrestrial origin of homochirality. UV light circularly polarized by scattering can introduce chiral asymmetry into interstellar molecules. These molecules can then be delivered to the surface of the Earth by comets and meteorites during the heavy bombardment phase in the first few hundred million years of the solar system. This model suggests that the probability of finding life on planets of other stars may depend on the polarization environment in the star formation region from which they came. Our solar system may well have been particularly favoured in having the right conditions for the emergence of life.

  14. A Strategy for Origins of Life Research.

    PubMed

    Scharf, Caleb; Virgo, Nathaniel; Cleaves, H James; Aono, Masashi; Aubert-Kato, Nathanael; Aydinoglu, Arsev; Barahona, Ana; Barge, Laura M; Benner, Steven A; Biehl, Martin; Brasser, Ramon; Butch, Christopher J; Chandru, Kuhan; Cronin, Leroy; Danielache, Sebastian; Fischer, Jakob; Hernlund, John; Hut, Piet; Ikegami, Takashi; Kimura, Jun; Kobayashi, Kensei; Mariscal, Carlos; McGlynn, Shawn; Menard, Brice; Packard, Norman; Pascal, Robert; Pereto, Juli; Rajamani, Sudha; Sinapayen, Lana; Smith, Eric; Switzer, Christopher; Takai, Ken; Tian, Feng; Ueno, Yuichiro; Voytek, Mary; Witkowski, Olaf; Yabuta, Hikaru

    2015-12-01

    Contents 1. Introduction 1.1. A workshop and this document 1.2. Framing origins of life science 1.2.1. What do we mean by the origins of life (OoL)? 1.2.2. Defining life 1.2.3. How should we characterize approaches to OoL science? 1.2.4. One path to life or many? 2. A Strategy for Origins of Life Research 2.1. Outcomes-key questions and investigations 2.1.1. Domain 1: Theory 2.1.2. Domain 2: Practice 2.1.3. Domain 3: Process 2.1.4. Domain 4: Future studies 2.2. EON Roadmap 2.3. Relationship to NASA Astrobiology Roadmap and Strategy documents and the European AstRoMap   Appendix I   Appendix II   Supplementary Materials  References. PMID:26684503

  15. Topological Origins of the Slow Solar Wind

    NASA Technical Reports Server (NTRS)

    Antiochos, Spiro

    2008-01-01

    Although the slow solar wind has been studied for decades with both in situ and remote sensing observations, its origin is still a matter of intense debate. In the standard quasi-steady model, the slow wind is postulated to originate near coronal hole boundaries that define topologically well-behaved separatrices between open and closed field regions. In the interchange model, on the other hand, the slow wind is postulated to originate on open flux that is dynamically diffusing throughout the seemingly closed-field corona. We argue in favor of the quasi-steady scenario and propose that the slow wind is due to two effects: First, the open-closed boundary is highly complex due to the complexity of the photospheric flux distribution. Second, this boundary is continuously driven by the transport of magnetic helicity from the closed field region into the open. The implications of this model for the structure and dynamics of the corona and slow wind are discussed, and observational tests of the mode

  16. [Heinrich Georg Bronn and Origin of Species].

    PubMed

    Junker, T

    1991-01-01

    Heinrich Georg Bronn, one of the leading nineteenth-century palaeontologists was also known as the translator of Charles Darwin's Origin of Species. He undertook his translation soon after the publication of Darwin's work and added a critical post-scriptum. Still in 1857 Bronn had written unambiguously in favour of the constancy of biological species. After the publication of the Origin of Species he thought that in spite of a number of objections which could be brought forward, the future belonged to Darwin's theory and supported with great commitment its spreading. It is puzzling that Bronn did so when he was almost 60 and committed to a religious outlook. The history of the reception of Darwin's doctrine shows that, as a rule, older scientists with such religious worldviews would not support Darwin. The analysis of Bronn's earlier writings and the correspondence between Darwin and Bronn will throw light on the reasons why he represented an exemption. Bronns opinion of Darwin's theory shows the wide gap between the older typologically-inclined natural history and Darwin's evolutionary theory. To conclude, Bronn's translation of the Origin of Species as well as his post-scriptum were of considerable importance for the reception of Darwin's ideas in the german-speaking world.

  17. The origins of colour vision in vertebrates.

    PubMed

    Collin, Shaun P; Trezise, Ann E O

    2004-07-01

    The capacity for colour vision is mediated by the comparison of the signal intensities from photoreceptors of two or more types that differ in spectral sensitivity. Morphological, physiological and molecular analyses of the retina in an agnathan (jawless) fish, the lamprey Geotria australis, may hold important clues to the origins of colour vision in vertebrates. Lampreys are extant representatives of an ancient group of vertebrates, the origins of which are thought to date back to at least the early Cambrian, approximately 540 million years ago. G. australis possesses five photoreceptor types, each with cone-like ultrastructural features and different spectral sensitivities. Recent molecular genetic studies have also revealed that five visual pigment (opsin) genes are expressed in the retina, each of which is orthologous to the major classes of vertebrate opsin genes. These findings reveal that multiple opsin genes originated very early in vertebrate evolution, prior to the separation of the jawed and jawless vertebrate lineages, thereby providing the genetic basis for colour vision in all vertebrates.

  18. A Strategy for Origins of Life Research

    PubMed Central

    Scharf, Caleb; Virgo, Nathaniel; Aono, Masashi; Aubert-Kato, Nathanael; Aydinoglu, Arsev; Barahona, Ana; Barge, Laura M.; Benner, Steven A.; Biehl, Martin; Brasser, Ramon; Butch, Christopher J.; Chandru, Kuhan; Cronin, Leroy; Danielache, Sebastian; Fischer, Jakob; Hernlund, John; Hut, Piet; Ikegami, Takashi; Kimura, Jun; Kobayashi, Kensei; Mariscal, Carlos; McGlynn, Shawn; Menard, Brice; Packard, Norman; Pascal, Robert; Pereto, Juli; Rajamani, Sudha; Sinapayen, Lana; Smith, Eric; Switzer, Christopher; Takai, Ken; Tian, Feng; Ueno, Yuichiro; Voytek, Mary; Witkowski, Olaf; Yabuta, Hikaru

    2015-01-01

    Contents 1. Introduction 1.1. A workshop and this document 1.2. Framing origins of life science 1.2.1. What do we mean by the origins of life (OoL)? 1.2.2. Defining life 1.2.3. How should we characterize approaches to OoL science? 1.2.4. One path to life or many? 2. A Strategy for Origins of Life Research 2.1. Outcomes—key questions and investigations 2.1.1. Domain 1: Theory 2.1.2. Domain 2: Practice 2.1.3. Domain 3: Process 2.1.4. Domain 4: Future studies 2.2. EON Roadmap 2.3. Relationship to NASA Astrobiology Roadmap and Strategy documents and the European AstRoMap  Appendix I  Appendix II  Supplementary Materials  References PMID:26684503

  19. West Florida shelf upwelling: Origins and pathways

    NASA Astrophysics Data System (ADS)

    Weisberg, Robert H.; Zheng, Lianyuan; Liu, Yonggang

    2016-08-01

    Often described as oligotrophic, the west Florida continental shelf supports abundant fisheries, experiences blooms of the harmful alga, Karenia brevis, and exhibits subsurface chlorophyll maxima evident in shipboard and glider surveys. Renewal of inorganic nutrients by the upwelling of deeper ocean water onto the shelf may account for this, but what are the origins and pathways by which such new water may broach the shelf break and advance toward the shoreline? We address these questions via numerical model simulations of pseudo-Lagrangian, isopycnic water parcel trajectories. Focus is on 2010, when the west Florida shelf was subjected to an anomalously protracted period of upwelling caused by Gulf of Mexico Loop Current interactions with the shelf slope. Origins and pathways are determined by integrating trajectories over successive 45 day intervals, beginning from different locations along the shelf break and at various locations and depths along the shelf slope. Waters upwelling across the shelf break are found to originate from relatively shallow depths along the shelf slope. Even for the anomalous 2010 year, much of this upwelling occurs from about 150 m and above, although waters may broach the shelf break from 300 m depth, particularly in the Florida Panhandle. Such interannual renewal of west Florida shelf waters appears to have profound effects on west Florida shelf ecology.

  20. An earlier origin for the Acheulian.

    PubMed

    Lepre, Christopher J; Roche, Hélène; Kent, Dennis V; Harmand, Sonia; Quinn, Rhonda L; Brugal, Jean-Philippe; Texier, Pierre-Jean; Lenoble, Arnaud; Feibel, Craig S

    2011-09-01

    The Acheulian is one of the first defined prehistoric techno-complexes and is characterized by shaped bifacial stone tools. It probably originated in Africa, spreading to Europe and Asia perhaps as early as ∼1 million years (Myr) ago. The origin of the Acheulian is thought to have closely coincided with major changes in human brain evolution, allowing for further technological developments. Nonetheless, the emergence of the Acheulian remains unclear because well-dated sites older than 1.4 Myr ago are scarce. Here we report on the lithic assemblage and geological context for the Kokiselei 4 archaeological site from the Nachukui formation (West Turkana, Kenya) that bears characteristic early Acheulian tools and pushes the first appearance datum for this stone-age technology back to 1.76 Myr ago. Moreover, co-occurrence of Oldowan and Acheulian artefacts at the Kokiselei site complex indicates that the two technologies are not mutually exclusive time-successive components of an evolving cultural lineage, and suggests that the Acheulian was either imported from another location yet to be identified or originated from Oldowan hominins at this vicinity. In either case, the Acheulian did not accompany the first human dispersal from Africa despite being available at the time. This may indicate that multiple groups of hominins distinguished by separate stone-tool-making behaviours and dispersal strategies coexisted in Africa at 1.76 Myr ago.