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1Latest Papers from Table of Contents or Articles in PressXiaolu Yin; Stephen E. Russek; Gary Zabow; Fan Sun; Jeotikanta Mohapatra; Kathryn E. Keenan; Michael A. Boss; Hao Zeng; J. Ping Liu; Alexandrea Viert; Sy-Hwang Liou; John Moreland
Nature Publishing Group (NPG)
Published 2018Staff ViewPublication Date: 2018-09-01Publisher: Nature Publishing Group (NPG)Electronic ISSN: 2045-2322Topics: Natural Sciences in GeneralPublished by: -
2Latest Papers from Table of Contents or Articles in PressW. J. Borucki ; E. Agol ; F. Fressin ; L. Kaltenegger ; J. Rowe ; H. Isaacson ; D. Fischer ; N. Batalha ; J. J. Lissauer ; G. W. Marcy ; D. Fabrycky ; J. M. Desert ; S. T. Bryson ; T. Barclay ; F. Bastien ; A. Boss ; E. Brugamyer ; L. A. Buchhave ; C. Burke ; D. A. Caldwell ; J. Carter ; D. Charbonneau ; J. R. Crepp ; J. Christensen-Dalsgaard ; J. L. Christiansen ; D. Ciardi ; W. D. Cochran ; E. DeVore ; L. Doyle ; A. K. Dupree ; M. Endl ; M. E. Everett ; E. B. Ford ; J. Fortney ; T. N. Gautier, 3rd ; J. C. Geary ; A. Gould ; M. Haas ; C. Henze ; A. W. Howard ; S. B. Howell ; D. Huber ; J. M. Jenkins ; H. Kjeldsen ; R. Kolbl ; J. Kolodziejczak ; D. W. Latham ; B. L. Lee ; E. Lopez ; F. Mullally ; J. A. Orosz ; A. Prsa ; E. V. Quintana ; R. Sanchis-Ojeda ; D. Sasselov ; S. Seader ; A. Shporer ; J. H. Steffen ; M. Still ; P. Tenenbaum ; S. E. Thompson ; G. Torres ; J. D. Twicken ; W. F. Welsh ; J. N. Winn
American Association for the Advancement of Science (AAAS)
Published 2013Staff ViewPublication Date: 2013-04-20Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsKeywords: Exobiology ; Extraterrestrial Environment ; Models, Theoretical ; *Planets ; Stars, Celestial ; *WaterPublished by: -
3Latest Papers from Table of Contents or Articles in PressL. R. Doyle ; J. A. Carter ; D. C. Fabrycky ; R. W. Slawson ; S. B. Howell ; J. N. Winn ; J. A. Orosz ; A. Prsa ; W. F. Welsh ; S. N. Quinn ; D. Latham ; G. Torres ; L. A. Buchhave ; G. W. Marcy ; J. J. Fortney ; A. Shporer ; E. B. Ford ; J. J. Lissauer ; D. Ragozzine ; M. Rucker ; N. Batalha ; J. M. Jenkins ; W. J. Borucki ; D. Koch ; C. K. Middour ; J. R. Hall ; S. McCauliff ; M. N. Fanelli ; E. V. Quintana ; M. J. Holman ; D. A. Caldwell ; M. Still ; R. P. Stefanik ; W. R. Brown ; G. A. Esquerdo ; S. Tang ; G. Furesz ; J. C. Geary ; P. Berlind ; M. L. Calkins ; D. R. Short ; J. H. Steffen ; D. Sasselov ; E. W. Dunham ; W. D. Cochran ; A. Boss ; M. R. Haas ; D. Buzasi ; D. Fischer
American Association for the Advancement of Science (AAAS)
Published 2011Staff ViewPublication Date: 2011-09-17Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsPublished by: -
4Latest Papers from Table of Contents or Articles in PressSah, B.-R., Ghafoor, S., Burger, I. A., ter Voert, E. E. G. W., Sekine, T., Delso, G., Huellner, M., Dedes, K. J., Boss, A., Veit-Haibach, P.
The Society of Nuclear Medicine (SNM)
Published 2018Staff ViewPublication Date: 2018-12-04Publisher: The Society of Nuclear Medicine (SNM)Print ISSN: 0022-3123Topics: MedicinePublished by: -
5Articles: DFG German National LicensesMuscarinic cholinergic receptors in the human melanoma cell line SK-Mel 28: modulation of chemotaxisStaff View
ISSN: 1365-2230Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: MedicineNotes: Primary and metastatic human melanomas express muscarinic receptors. In embryonic tissues, expression of muscarinic receptors is correlated with morphogenesis. The hypothesis has been put forward that muscarinic receptors are involved in morphogenetic movements in the embryo, and in cellular movements in melanoma cells during invasive growth. The purpose of the present study was to characterize the muscarinic receptors in the human melanoma cell line SK-Mel 28 and to test in a Boyden chamber assay whether the chemotactic activity towards fibronectin can be influenced by muscarinic stimulation. In Western blots with the monoclonal antibody M35, muscarinic receptors were localized in a strong band at 66 kDa, and in a weak band at 63 kDa. Western blot with M3 subtype specific antibodies reproduced the line at 66 kDa. RT-PCR revealed mRNA for subtypes M3 and M5. These findings suggest that SK-Mel 28 cells express a large number of subtype M3 and a small number of subtype M5 receptors. Microscopic observation of calcium mobilization after muscarinic stimulation indicated that all cells carried functional muscarinic receptors. A standardized chemotaxis assay was established in modified Boyden chambers using fibronectin as chemotactic agent. After addition of carbachol to the upper compartment, an increase of fibronectin induced chemotaxis of ∼30% was observed, an effect abrogated by atropine. These results demonstrate that muscarinic cholinergic treatment has a modulatory effect on fibronectin-induced chemotaxis in SK-Mel 28 melanoma cells, indicating that the muscarinic system is involved in regulation of cell movement.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesStaff View
ISSN: 1600-0536Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: MedicineType of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesStaff View
ISSN: 1572-9478Source: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract Finite difference codes for the solution of the fully three dimensional equations of hydrodynamics, self-gravitation, and radiative transfer have been developed for use on relatively modest computers. Originally developed to study the collapse and fragmentation of protostellar clouds, this family of codes has been used to study a variety of astrophysical problems, with a particular emphasis on cosmogonical issues.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesStaff View
ISSN: 1432-069XSource: Springer Online Journal Archives 1860-2000Topics: MedicineType of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesStaff View
ISSN: 1433-044XKeywords: Key words Humeral head fracture ; endoprosthesis ; primary implantation ; Schlüsselwörter Humeruskopffraktur ; Endoprothese ; PrimärimplantationSource: Springer Online Journal Archives 1860-2000Topics: MedicineDescription / Table of Contents: Zusammenfassung Trotz den Fortschritten in der konservativen und operativen Behandlung von Humeruskopffrakturen kommt es häufig nicht zu einem befriedigenden Ausheilungsergebnis, insbesondere im Falle von schweren Humeruskopftrümmerfrakturen beim älteren Patienten. In diesen Fällen wurde in den letzten Jahren vermehrt die primäre Versorgung mit einer Humeruskopfprothese vorgeschlagen. Das Ziel dieser prospektiven Studie war es, das funktionelle Resultat nach primär mit einer Kopfprothese versorgten Humeruskopftrümmerfraktur beim älteren Patienten zu bestimmen. Von 1993–1995 wurden 27 Patienten (23 Frauen, 4 Männer; Durchschnittsalter 76 (48–91) Jahre mit 27 Humeruskopffrakturen primär mit einer Neer-II-Modularhumeruskopfprothese versorgt. Postoperativ mußte eine Schulter in Narkose mobilisiert werden. Nach 16 (3–29) Monaten konnten 21/27 Patienten (21/27 Schultern) klinisch nachuntersucht werden; 4 Patienten (4 Schultern) waren in der Zwischenzeit verstorben, 2 wollten nicht zur Untersuchung anreisen, waren aber sehr zufrieden. Der Constant-Score betrug auf der operierten Seite 48 (25–76) Punkte und auf der Gegenseite 77 (5–96) Punkte; die intraindividuelle Differenz zwischen operierter und unverletzter Schulter betrug 30 (18–69) Punkte. Diese Differenz beruhte hauptsächlich auf Schmerzen und einer Kraftverminderung. Subjektiv war die überwiegende Mehrheit der Patienten mit dem Resultat zufrieden und würde erneut diese Behandlung akzeptieren. In Anbetracht der Schwere dieser Verletzungen mit von vornherein ungünstiger Prognose sind die Resultate dieser Studie doch positiv zu werten, insbesondere was die erreichte Schulterfunktion bezüglich Anforderungen des Alltags anbelangt. Zur primären Versorgung komplexer Humeruskopffrakturen beim älteren Patienten scheint die Humeruskopfprothese damit eine geeignete Alternative zu andern Verfahren zu sein.Notes: Summary The purpose of this prospective study was to determine the early subjective and functional result and outcome after primary implantation of humeral endoprosthesis in severely comminuted humeral head fractures in elderly patients. From 1993 to 1995, 27 humeral head fractures (27 patients) were treated by primary implantation of a Neer II modular shoulder prosthesis. Of these, 23 patients were women, 4 patients were men. The average age of patients was 76 (48–91) years. Postoperatively, one shoulder had to be mobilized under general anesthesia. Of the 27 patients 21 could be clinically examined after 16 (3–29) months postoperatively; 4 patients had died in the meantime, 2 did not come to the control examination because of a great distance and because they were happy. The average Constant Score was 48 (25–76) points; the difference to the other shoulder was 30 (18–69) points. Of the 21 patients 19 were satisfied by the result and 20 would reaccept the same procedure. These preliminary results suggest that primary shoulder prosthesis in humeral head fractures in the elderly patient is a valuable alternative option.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesStaff View
ISSN: 1433-044XKeywords: Schlüsselwörter Schulter ; Arthroskopie ; Instabilität ; Key words Shoulder ; Instability ; ArthroscopySource: Springer Online Journal Archives 1860-2000Topics: MedicineDescription / Table of Contents: Abstract The purpose of this prospective study was to determine concomittant lesions of glenohumeral dislocation and their correlation with the outcome, to determine the influence of various stabilizing operation techniques on the outcome. 106 shoulders [104 patients, 81 men, 23 women, mean age 36 (16–83) years] operated because of shoulder instability after at minimum one shoulder luxation between 1988 to 1995 were evaluated 3 years (0.8–8 years) postoperatively using Constant score. Preoperative arthroscopy was performed to document intraarticular lesions. There were 7 reluxations (5 because of a new accident), mostly after Putti-Platt procedures. The average modified Constant Score was 66 (10–85) points (maximum 85). 29 patients (27%) had less than 60 points, mostly because of pain and restriction of function, and were evaluated as poor. Lesions of rotator cuff, long biceps tendon and subscapularis tendon had a bad prognosis. The severity of arthroscopically found lesions correlated with the outcome. Operations with shortening of subscapularis tendon or using a bone graft gave bad results. Anatomic reconstruction of the labrum-ligament complex in combination with a plasty of the extended capsule gave best results. Preoperative arthroscopy can determine the extent of different lesions after shoulder luxation which influence the outcome and is useful to select the optimal operation technique.Notes: Zusammenfassung Die Ziele dieser prospektiven Studie waren, die primären Begleitverletzungen nach Schulterluxation mit dem Ausheilungsergebnis zu korrelieren sowie den Einfluß der verschiedenen Operationstechniken auf das Ergebnis zu bestimmen. 106 Schultern [104 Patienten; 81 Männer, 23 Frauen; mittleres Alter 36 (16–83) Jahre] wurden wegen Schulterinstabilität nach mindestens einer Luxation zwischen 1988–1995 operiert und durchschnittlich 3 (0,8–8) Jahre danach mittels Fragebogen nach Constant-Score nachkontrolliert. Eine praeoperative Arthroskopie diente zur Bestandesaufnahme von intraartikulären Veränderungen. Die Operationstechnik wurde aufgrund der Verletzungen gewählt. 7 Reluxationen (6%) wurden beobachtet. In 5 der Fälle handelte es sich um ein erneutes adaequates Trauma. In 4 Fällen erfolgte die primäre Rekonstruktion mit einer Subscapularisraffung nach Putti-Platt. Von den maximal 85 erreichbaren Punkten des modifizierten Constant-Scores wurden durchschnittlich 66 (10–85) erreicht; 29 Patienten (27%) erreichten weniger als 60 Punkte, meist wegen Schmerzen und Funktionseinbuße und wurden als unbefriedigende Resultate gewertet. Verletzungen der Rotatorenmanschette, der langen Bicepssehne und der Subskapularissehne verschlechterten die Prognose. Operationen mit Raffung der Subskapularissehne und mit Verwendung von Knochenspänen zeigten schlechtere Resultate. Anatomische Rekonstruktion des Labrum-Ligament-Komplexes kombiniert mit ventraler Kapselplastik bei elongierter Kapsel ergaben die besten Resultate. Die präoperative Arthroskopie kann das Ausmaß verschiedener intraartikulärer Verletzungen nach Schulterluxation bestimmen, welche den Outcome beeinflussen, und ist geeignet für die Auswahl des optimalen Operationsverfahrens.Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesStaff View
ISSN: 1433-7347Keywords: Keywords Meniscus ; Transplantation ; Allograft ; Arthroscopy ; Surgical techniqueSource: Springer Online Journal Archives 1860-2000Topics: MedicineSports ScienceNotes: Abstract The important functions of the meniscus have been well described. Lack of a meniscus may lead to instability and early osteoarthrosis of the knee. Meniscal transplantation is an option following complete or subtotal meniscectomy in symptomatic patients with correct alignment, and mild to moderate chondrosis with the goal of preventing further degenerative sequelae to the knee. Since the first meniscus allograft implantation was performed 1984, there have been reported several open and arthroscopic techniques. We present our technique of arthroscopically assisted transplantation of a cryopreserved meniscal allograft with special consideration given to the technical details of this procedure. This technique employs creation of a circumferential osseocancellous trough in combination with transosseous tibial tunnel fixation and arthroscopic suture passage to both secure and enhance healing of the meniscal allograft.Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesAnterior cruciate ligament reconstruction combined with valgus tibial osteotomy (combined procedure)Staff View
ISSN: 1433-7347Keywords: Anterior cruciate ligament ; High tibial osteotomySource: Springer Online Journal Archives 1860-2000Topics: MedicineSports ScienceDescription / Table of Contents: Zusammenfassung Im Sinne einer Qualitätskontrolle wurden die von 1980 bis 1992 an der orthopaedisch-traumatologischen Abteilung des Kantonsspitals Basel einzeitig operierten Patienten bei vorderer Kreuzbandinsuffizienz. medialem Knorpelschaden, medialer Meniskuslaesion und Varusmorphotyp nachuntersucht. Es handelt sich um einen Kombinationseingriff von vorderer intraartikulaerer Kreuzbandersatzplastik mit mittlerem Drittel des Ligamentum patellae-z.T. augmentiert mit einem LAD Band nach Kennedy in hot dog Technik-und Achsenkorrektur der proximalen Tibia. Die Patienten wurden gemäß Richtlinien des IKDC klinisch nachuntersucht und zusätzlich apparativ die Stabilität mittels KT-1000-Arthrometer untersucht und radiologisch Achsen und Arthrose nach Kannus bestimmt. Zusatzfragen wurden anhand eines Fragebogens beantwortet. 27 von 34 die Einschlußkriterien erfüllenden Patienten (79%) konnten in 3 Kategorien (2–5 Jahre postoperativ, 5–10 J. postop und über 10 J. postop) nachuntersucht werden. Die Gesamtqualifikation war gut bei 37%, peri- und frühpostoperative Komplikationen fehlten, die Dauer der Rehabilitation war nicht verlängert, 89% gingen dem praeoperativ ausgeübten Beruf nach, über die Hälfte der Patienten konnte die sportliche Aktivität gegenüber praeoperativ steigern und 1 Viertel sogar die Sportaktivität vor dem Unfall wiedererlangen und die subjektive (2/3 ohne Giving way) und objektive Stabilität (2/3 bis 3 mm Translationsdifferenz zur gesunden Seite) der operierten Kniegelenke war gut. Drei Viertel der Patienten würden sich den Eingriff wieder durchführen lassen. Die radiologischen Ergebnisse korrelieren nicht mit der Gesamtqualifikation. Die ermutigenden Nachkontrollergebnisse hinsichtlich vieler kontrollierter Kriterien sprechen für das einzeitige Verfahren beim jüngeren Patienten mit vorderer Instabilität, Varusmorphotyp und medialem Kompartimentsschaden inklusive medialer Meniskuslaesion anstelle der Durchführung nur eines Eingriffs oder beider mit Intervall.Notes: Abstract We assessed the patients who were operated on in a combined procedure from 1980 to 1992 with anterior cruciate ligament (ACL) insufficiency, cartilaginous lesions of the medial compartment, lesion of medial meniscus and varus malalignment. The combined operative procedure was autologous intra-articular ACL reconstruction with the middle third of the patellar ligament-partially augmented with Kennedy-ligament augmentation device (LAD) in hot dog technique-and high tibial osteotomy. The patients were examined according to the criteria of IKDC including testing of anterior stability with the KT-1000 arthrometer. Radiographically we checked axis and arthritis according to a modified score of Kannus. Twentyseven of 34 patients who fulfilled the inclusion criteria could be followed up in three categories (2–5 years postoperatively, 5–10 years postoperatively, over 10 years postoperatively). Total qualification was good in 37%; there were no perioperative complications. Rehabilitation was not prolonged. Eighty-nine percent practised their prcoperative job, over 50% had a higher level of sports activities than preoperatively, and more than 25% regained their pretraumatic sports capacity. Two-thirds had no giving way and less than 3 mm translation difference in comparison to the contralateral knee. Seventy-five percent of patients would accept the operation again. Radiological findings had no correlation to overall qualification. The encouraging results with respect to many of the criteria suggest using the combined procedure in a young patient with ACL insufficiency, varus malalignment and medial compartment damage including medial meniscus lesion.Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesStaff View
ISSN: 1433-7347Keywords: Anterior cruciate ligament ; Ligament augmentation device ; High tibial osteotomySource: Springer Online Journal Archives 1860-2000Topics: MedicineSports ScienceNotes: Abstract In a follow-up study 27 patients were evaluated after anterior cruciate ligament (ACL-)reconstruction combined with high tibial osteotomy because of chronic rupture of the ACL, cartilaginous lesions of the medial compartment and varus malalignment. They were divided into two groups. In 14 patients (non-LAD group) ACL reconstruction was performed using the central third of the autologous patellar tendon modified according to Eriksson-Trillat. Thirteen patients (LAD group) underwent repair with the same technique, but a Kennedy ligament augmentation device (LAD) in ‘hot dog’ technique and fixed over the top was added. The postoperative treatment was the same in both groups. All patients were examined according to IKDC criteria. KT-1000 arthrometer testing at maximum manual traction was performed. Although the mean follow-up interval was more than double in the non-LAD group (non-LAD: 127 months vs LAD: 58 months), the subjective and clinical results, IKDC evaluation and KT-1000 arthrometer testing results were similar, showing no statistically significant difference. Further, no complications due to the use of LAD occurred. In this study no evident functional or clinical advantage from the augmentation performed could be shown.Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesStaff View
ISSN: 1432-5195Source: Springer Online Journal Archives 1860-2000Topics: MedicineDescription / Table of Contents: Résumé Nous rapportons l’évolution clinique de 20 patients avec 20 fractures humérales proximales multifragmentaires suivis consécutivement pendant 32.5 mois (17–44) après la mise en place d’une prothese humérale modulaire (Neer II). L’âge moyen était 77 ans (63–91). L’intervention a été réalisée en moyenne 3.5 jours (0–17) après l’accident. Le score de Constant était en moyenne 52 points (30–76) - l’épaule controlaterale 80 points (53–100) - avec une différence significative (P=0,0001) de 28 points (11–66). L’abduction active moyenne était de 90° (controlaterale 157°) et la flexion active de 99° (controlaterale 161°). 90% des patients ne présentaient pas de douleurs et seraient prêts à accepter, à nouveau, une telle opération.Notes: Abstract The purpose of this study was to determine the early subjective and functional results after primary endoprosthesis replacement for comminuted humeral head fractures in patients over 60 years old. Twenty comminuted humeral head fractures in 20 patients were treated primarily (within 3.5 days (range 0–17 days) with a Neer II modular shoulder prosthesis, and were then followed up for an average of 32.5 months (range 17–44 months). The average age of the patients was 77 years (range 63–91 years). The average post-operative Constant score was 52 points (range 30–76). This was significantly less than that of the contralateral side where the score was 80 points (range 53–100), P=0.0001. The average active abduction was 90° (contralateral 157°) and active flexion 99° (contralateral 161°). Eighteen of the 20 patients experienced relief of pain and would accept the same procedure again.Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 1573-2568Source: Springer Online Journal Archives 1860-2000Topics: MedicineNotes: Abstract The absorption of nonheme59ferric chloride from a test meal was measured, using a whole-body counter, in 34 alcoholics with liver disease of varying severity, 30 of whom had normal hemoglobin values and four of whom were anemic. The results were compared with those obtained in five patients with iron-deficient anemia and nine healthy control subjects. There were no significant differences in mean percentage iron absorption (±sem) in the nonanemic alcoholic patients with fatty liver (14.6±3.7), alcoholic hepatitis (18.6±5.7), or cirrhosis (21.1±3.5) when compared with control subjects (22.0±2.5). Significantly increased mean percentage iron absorptions were seen, however, in the patients with iron-deficient anemia (64.8±5.6;P〈0.0001) and the alcoholics with anemia (60.7±7.8;P〈0.0001). There was an inverse relationship between iron absorption and serum ferritin concentration in the nonanemic alcoholics (r=−0.37;P〈0.025) but no correlation between iron absorption and liver iron concentration. The addition of absolute alcohol (0.5 g/kg body weight) to the test meal resulted in an increase in mean percentage iron absorption in eight control subjects (21.6±1.6 to 29.0±6.1) and in ten nonanemic alcoholics (15.8±3.2 to 20.0±3.8), although these differences did not achieve significance. Similarly when intravenous alcohol was given to four control subjects at the time of the test meal, iron absorption increased in all four so that the mean percentage iron absorption increased, although not significantly, from 17.6±2.7 to 39.3±9.5. Iron absorption in alcoholics does not differ significantly from normal. While the increased liver iron concentrations seen in approximately one third of alcoholics cannot be attributed to an increase in iron absorption as a result of chronic alcohol ingestion, further studies are needed to elucidate the acute effects of alcohol on iron absorption.Type of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesStaff View
ISSN: 1573-0794Source: Springer Online Journal Archives 1860-2000Topics: GeosciencesPhysicsType of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesStaff View
ISSN: 1572-9672Source: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Summary Using values of d, γmin, and γmax that Van Riper (1978) has found most promising for a hydrodynamic envelope ejection, we have shown that even a small amount of rotation in the initial core can stop its collapse before nuclear densities are reached. We expected χi 〉 0.02 to produce significant deviations from a spherically symmetric collapse, but have found that χi as much as ten times smaller than this will not allow the core to reach densities as high as in the spherical collapse. In no case, however, does the core flatten very much, nor does the value of β become very large. Low final β's preclude the formation of an axisymmetric torus. They also indicate that deformation of an iron core into a triaxial configuration or fragmentation of the core during its collapse is an extremely unlikely event. (Note: Classically, β must exceed 0.27 before a dynamic instability to non-axisymmetric perturbations is encountered.) The small degree of flattening of the core also suggests that the reduced moment of inertia I of the core will always be relatively small in magnitude and hence that the third time derivative of I, which is proportional to the energy emitted in gravity wave radiation, will not be very significant. Numerically calculated estimates of I- during some of these model evolutions supports this suspicion. If the γmin and used here are found to be realistic values after the detailed physics of the core collapse is well understood, it is clear that gravitational radiation from a core collapse will be difficult to measure. Finally, we should point out that it is the relatively large values of Ymin (near 4/3) combined with values of d near unity that (a) prevented the core from flattening significantly in these models and (b) prevented the core from reaching high β configurations. If “realistic” values of either one (or both) of these parameters are found to be much smaller in more complete models of the core collapse, then the core will have to become flatter (and denser) before pressure gradients will support it along the rotation axis. All of the conclusions drawn here would be modified accordingly under those circumstances. It should also be noted that in general relativistic models, the critical Γ for spherical collapse is somewhat larger than 4/3 (Van Riper, 1979). Therefore, we predict that when fully general relativistic core collapses are performed including rotation, a given choice of γmin and βi will produce a slightly flatter and slightly denser core than the corresponding model that has been presented here.Type of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesStaff View
ISSN: 1572-9672Source: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract Numerical calculations of the collapse of adiabatic clouds from uniform density and rotation initial conditions show that when restricted to axisymmetry, the clouds form either near-equilibrium spheroids or rings. Rings form in the collapse of low thermal energy clouds and have β = T/ ¦W¦≳ 0.43. When the axisymmetric constraint is removed and an initial m=2 density variation is introduced, clouds either collapse to form near-equilibrium ellipsoids or else fragment into binary systems through a bar phase. Ellipsoids form in the collapse of high thermal energy clouds and have 3 ≲ 0.27. The results are consistent with the critical values of β for instabilities in Maclaurin spheroids, and suggest that protostellar clouds may undergo a dynamic fragmentation in the nonisothermal collapse regime.Type of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesStarkweather, H. W. ; Hönigschmid, O. ; Goubeau, J. ; Hevesy, G. ; Lögstrup, Marie ; Biltz, M. ; Ziegert, H. ; Richards, Th. W. ; Françon, M. ; Sachtleben, R. ; Holch, H. ; Boss, A. E. ; Hopkins, B. S. ; Baxter, G. P. ; Butler, A. Q. ; Schilz, W. E. ; Noddack, W. ; Noddack, Ida
Springer
Published 1929Staff ViewISSN: 1618-2650Source: Springer Online Journal Archives 1860-2000Topics: Chemistry and PharmacologyType of Medium: Electronic ResourceURL: