Achilles detachment in rat and stable gastric pentadecapeptide BPC 157: Promoted tendon-to-bone healing and opposed corticosteroid aggravation.

PubMed

Krivic, Andrija; Anic, Tomislav; Seiwerth, Sven; Huljev, Dubravko; Sikiric, Predrag

2006-05-01

Stable gastric pentadecapeptide BPC 157 (BPC 157, as an antiulcer agent in clinical trials for inflammatory bowel disease; PLD-116, PL 14736, Pliva, no toxicity reported) alone (without carrier) ameliorates healing of tendon and bone, respectively, as well as other tissues. Thereby, we focus on Achilles tendon-to-bone healing: tendon to bone could not be healed spontaneously, but it was recovered by this peptide. After the rat's Achilles tendon was sharply transected from calcaneal bone, agents [BPC 157 (10 microg, 10 ng, 10 pg), 6alpha-methylprednisolone (1 mg), 0.9% NaCl (5 mL)] were given alone or in combination [/kg body weight (b.w.) intraperitoneally, once time daily, first 30-min after surgery, last 24 h before analysis]. Tested at days 1, 4, 7, 10, 14, and 21 after Achilles detachment, BPC 157 improves healing functionally [Achilles functional index (AFI) values substantially increased], biomechanically (load to failure, stiffness, and Young elasticity modulus significantly increased), macro/microscopically, immunohistochemistry (better organization of collagen fibers, and advanced vascular appearance, more collagen type I). 6alpha-Methylprednisolone consistently aggravates the healing, while BPC 157 substantially reduces 6alpha-methylprednisolone healing aggravation. Thus, direct tendon-to-bone healing using stabile nontoxic peptide BPC 157 without a carrier might successfully exchange the present reconstructive surgical methods. Copyright 2006 Orthopaedic Research Society.

Therapy for unhealed gastrocutaneous fistulas in rats as a model for analogous healing of persistent skin wounds and persistent gastric ulcers: stable gastric pentadecapeptide BPC 157, atropine, ranitidine, and omeprazole.

PubMed

Skorjanec, Sandra; Dolovski, Zdravko; Kocman, Ivan; Brcic, Luka; Blagaic Boban, Alenka; Batelja, Lovorka; Coric, Marjana; Sever, Marko; Klicek, Robert; Berkopic, Lidija; Radic, Bozo; Drmic, Domagoj; Kolenc, Danijela; Ilic, Spomenko; Cesarec, Vedran; Tonkic, Ante; Zoricic, Ivan; Mise, Stjepan; Staresinic, Mario; Ivica, Mihovil; Lovric Bencic, Martina; Anic, Tomislav; Seiwerth, Sven; Sikiric, Predrag

2009-01-01

This study focused on unhealed gastrocutaneous fistulas to resolve whether standard drugs that promote healing of gastric ulcers may simultaneously have the same effect on cutaneous wounds, and corticosteroid aggravation, and to demonstrate why peptides such as BPC 157 exhibit a greater healing effect. Therefore, with the fistulas therapy, we challenge the wound/growth factors theory of the analogous nonhealing of wounds and persistent gastric ulcers. The healing rate of gastrocutaneous fistula in rat (2-mm-diameter stomach defect, 3-mm-diameter skin defect) validates macro/microscopically and biomechanically a direct skin wound/stomach ulcer relation, and identifies a potential therapy consisting of: (i) stable gastric pentadecapeptide BPC 157 [in drinking water (10 microg/kg) (12 ml/rat/day) or intraperitoneally (10 microg/kg, 10 ng/kg, 10 pg/kg)], (ii) atropine (10 mg/kg), ranitidine (50 mg/kg), and omeprazole (50 mg/kg), (iii) 6-alpha-methylprednisolone (1 mg/kg) [intraperitoneally, once daily, first application at 30 min following surgery; last 24 h before sacrifice (at postoperative days 1, 2, 3, 7, 14, and 21)]. Greater anti-ulcer potential and efficiency in wound healing compared with standard agents favor BPC 157, efficient in inflammatory bowel disease (PL-14736, Pliva), given in drinking water or intraperitoneally. Even after 6-alpha-methylprednisolone aggravation, BPC 157 promptly improves both skin and stomach mucosa healing, and closure of fistulas, with no leakage after up to 20 ml water intragastrically. Standard anti-ulcer agents, after a delay, improve firstly skin healing and then stomach mucosal healing, but not fistula leaking and bursting strength (except for atropine). We conclude that BPC 157 may resolve analogous nonhealing of wounds and persistent gastric ulcers better than standard agents.

Professor Eugen Cerkovnikov (1904-1985): the founder of the Chemical and Biochemical Institute of the Rijeka University School of Medicine.

PubMed

Milin, Cedomila

2008-01-01

Professor Eugen Cerkovnikov, PhD (Kamenska, Russia, 1904- Rijeka, Croatia 1985) graduated in chemical technology from the Faculty of Engineering in Zagreb in 1929. His first job was at the School of Medicine in Paris in 1930, and then he moved to Zagreb to the Department of Organic Chemistry of the Faculty of Engineering run by our Nobel Prize winner Vladimir Prelog (1935-1938). There he took his PhD degree with a dissertation on piperidine gamma derivatives. From 1938 to 1947 he was a research associate at an institute established by the pharmaceutical company Kastel (later Pliva). This is when he became a lecturer at the Faculty of Pharmacy in Zagreb and the first director of the Institute of Organic Chemistry, established in 1946/47. In 1948 he became reader, and in 1956 (full) professor. In 1957 he moved to the newly established School of Medicine in Rijeka, and set up the Institute of Chemistry and Biochemistry. He ran the Institute until retirement in 1975. He was the second dean of the Rijeka University School of Medicine and a pioneer of quantum chemistry and medical cybernetics in undergraduate and (post)graduate courses. His scientific work consists of over 200 papers published at home and abroad, 60 professional papers, 20 book reviews, three works of translation, and 27 volumes of lecture notes. In 1958, professor Cerkovnikov established the Croatian Chemical Society and the Rijeka and Istria branches of the nation's Association of Chemists and Chemical Engineers, chairing them until 1974. In addition, he was one of the founding fathers, and the first chair of the Health Culture Studies Association in Rijeka (that preceded today's Croatian Scientific Society for the History of Health Culture), established in 1965.

Major results of the MAARBLE project

NASA Astrophysics Data System (ADS)

Daglis, Ioannis A.; Bourdarie, Sebastien; Horne, Richard B.; Khotyaintsev, Yuri; Mann, Ian R.; Santolik, Ondrej; Turner, Drew L.; Balasis, Georgios

2016-04-01

The goal of the MAARBLE (Monitoring, Analyzing and Assessing Radiation Belt Loss and Energization) project was to shed light on the ways the dynamic evolution of the Van Allen belts is influenced by low-frequency electromagnetic waves. MAARBLE was implemented by a consortium of seven institutions (five European, one Canadian and one US) with support from the European Community's Seventh Framework Programme. The MAARBLE project employed multi-spacecraft monitoring of the geospace environment, complemented by ground-based monitoring, in order to analyze and assess the physical mechanisms leading to radiation belt particle energisation and loss. Particular attention was paid to the role of ULF/VLF waves. Within MAARBLE we created a database containing properties of ULF and VLF waves, based on measurements from the Cluster, THEMIS and CHAMP missions and from the CARISMA and IMAGE ground magnetometer networks. The database is now available to the scientific community through the Cluster Science Archive as auxiliary content. Based on the wave database, a statistical model of the wave activity dependent on the level of geomagnetic activity, solar wind forcing, and magnetospheric region has been developed. Multi-spacecraft particle measurements have been incorporated into data assimilation tools, leading to a more accurate estimate of the state of the radiation belts. The synergy of wave and particle observations is in the core of MAARBLE research studies of radiation belt dynamics. Results and conclusions from these studies will be presented in this paper. The MAARBLE (Monitoring, Analyzing and Assessing Radiation Belt Energization and Loss) collaborative research project has received funding from the European Unions Seventh Framework Programme (FP7-SPACE 2011-1) under grant agreement no. 284520. The complete MAARBLE Team: Ioannis A. Daglis, Sebastien Bourdarie, Richard B. Horne, Yuri Khotyaintsev, Ian R. Mann, Ondrej Santolik, Drew L. Turner, Georgios Balasis, Anastasios Anastasiadis, Vassilis Angelopoulos, David Barona, Eleni Chatzichristou, Stavros Dimitrakoudis, Marina Georgiou, Omiros Giannakis, Sarah Glauert, Benjamin Grison, Zuzana Hrbackova, Andy Kale, Christos Katsavrias, Tobias Kersten, Ivana Kolmasova, Didier Lazaro, Eva Macusova, Vincent Maget, Meghan Mella, Nigel Meredith, Fiori-Anastasia Metallinou, David Milling, Louis Ozeke, Constantinos Papadimitriou, George Ropokis, Ingmar Sandberg, Maria Usanova, Iannis Dandouras, David Sibeck, Eftyhia Zesta.

Gastric pentadecapeptide BPC 157 accelerates healing of transected rat Achilles tendon and in vitro stimulates tendocytes growth.

PubMed

Staresinic, M; Sebecic, B; Patrlj, L; Jadrijevic, S; Suknaic, S; Perovic, D; Aralica, G; Zarkovic, N; Borovic, S; Srdjak, M; Hajdarevic, K; Kopljar, M; Batelja, L; Boban-Blagaic, A; Turcic, I; Anic, T; Seiwerth, S; Sikiric, P

2003-11-01

In studies intended to improve healing of transected Achilles tendon, effective was a stable gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, M.W. 1419). Currently in clinical trials for inflammatory bowel disease (PLD-116, PL 14736, Pliva), it ameliorates internal and external wound healing. In rats, the right Achilles tendon transected (5 mm proximal to its calcaneal insertion) presents with a large tendon defect between cut ends. Agents (/kg b.w., i.p., once time daily) (BPC 157 (dissolved in saline, with no carrier addition) (10 microg, 10 ng or 10 pg) or saline (5.0 ml)), were firstly applied at 30 min after surgery, the last application at 24 h before autopsy. Achilles functional index (AFI) was assessed once time daily. Biomechanical, microscopical and macroscopical assessment was on day 1, 4, 7, 10 and 14. Controls generally have severely compromised healing. In comparison, pentadecapeptide BPC 157 fully improves recovery: (i) biomechanically, increased load of failure, load of failure per area and Young's modulus of elasticity; (ii) functionally, significantly higher AFI-values; (iii) microscopically, more mononuclears and less granulocytes, superior formation of fibroblasts, reticulin and collagen; (iv) macroscopically, smaller size and depth of tendon defect, and subsequently the reestablishment of full tendon integrity. Likewise, unlike TGF-beta, pentadecapeptide BPC 157, presenting with no effect on the growth of cultured cell of its own, consistently opposed 4-hydroxynonenal (HNE), a negative modulator of the growth. HNE-effect is opposed in both combinations: BPC 157+HNE (HNE growth inhibiting effect reversed into growth stimulation of cultured tendocytes) and HNE+BPC 157(abolished inhibiting activity of the aldehyde), both in the presence of serum and serum deprived conditions. In conclusion, these findings, particularly, Achilles tendon transection fully recovered in rats, peptide stability suitable delivery, usefully favor gastric pentadecapeptide BPC 157 in future Achilles tendon therapy.

Gastric pentadecapeptide BPC 157 effective against serotonin syndrome in rats.

PubMed

Boban Blagaic, Alenka; Blagaic, Vladimir; Mirt, Mirela; Jelovac, Nikola; Dodig, Goran; Rucman, Rudolf; Petek, Marijan; Turkovic, Branko; Anic, Tomislav; Dubovecak, Miroslav; Staresinic, Mario; Seiwerth, Sven; Sikiric, Predrag

2005-04-11

Serotonin syndrome commonly follows irreversible monoamine oxidase (MAO)-inhibition and subsequent serotonin (5-HT) substrate (in rats with fore paw treading, hind limbs abduction, wet dog shake, hypothermia followed by hyperthermia). A stable gastric pentadecapeptide BPC 157 with very safe profile (inflammatory bowel disease clinical phase II, PL-10, PLD-116, PL-14736, Pliva) reduced the duration of immobility to a greater extent than imipramine, and, given peripherally, has region specific influence on brain 5-HT synthesis (alpha-[14C]methyl-L-tryptophan autoradiographic measurements) in rats, different from any other serotonergic drug. Thereby, we investigate this peptide (10 microg, 10 ng, 10 pg/kg i.p.) in (i) full serotonin syndrome in rat combining pargyline (irreversible MAO-inhibition; 75 mg/kg i.p.) and subsequent L-tryptophan (5-HT precursor; 100 mg/kg i.p.; BPC 157 as a co-treatment), or (ii, iii) using pargyline or L-tryptophan given separately, as a serotonin-substrate with (ii) pargyline (BPC 157 as a 15-min posttreatment) or as a potential serotonin syndrome inductor with (iii) L-tryptophan (BPC 157 as a 15 min-pretreatment). In all experiments, gastric pentadecapeptide BPC 157 contrasts with serotonin-syndrome either (i) presentation (i.e., particularly counteracted) or (ii) initiation (i.e., neither a serotonin substrate (counteraction of pargyline), nor an inductor for serotonin syndrome (no influence on L-tryptophan challenge)). Indicatively, severe serotonin syndrome in pargyline + L-tryptophan rats is considerably inhibited even by lower pentadecapeptide BPC 157 doses regimens (particularly disturbances such as hyperthermia and wet dog shake thought to be related to stimulation of 5-HT2A receptors), while the highest pentadecapeptide dose counteracts mild disturbances present in pargyline rats (mild hypothermia, feeble hind limbs abduction). Thereby, in severe serotonin syndrome, gastric pentadecapeptide BPC 157 (alone, no behavioral or temperature effect) has a beneficial activity, which is likely, particular, and mostly related to a rather specific counteraction of 5-HT2A receptors phenomena.

President of Czech Republic visits ESO's Paranal Observatory

NASA Astrophysics Data System (ADS)

2011-04-01

On 6 April 2011, the ESO Paranal Observatory was honoured with a visit from the President of the Czech Republic, Václav Klaus, and his wife Livia Klausová, who also took the opportunity to admire Cerro Armazones, the future site of the planned E-ELT. The distinguished visitor was shown the technical installations at the observatory, and was present when the dome of one of the four 8.2-metre Unit Telescopes of ESO's Very Large Telescope opened for a night's observing at Cerro Paranal, the world's most advanced visible-light observatory. "I'm delighted to welcome President Klaus to the Paranal Observatory and to show him first-hand the world-leading astronomical facility that ESO has designed, has built, and operates for European astronomy," said ESO's Director General, Tim de Zeeuw. President Klaus replied, "I am very impressed by the remarkable technology that ESO has built here in the heart of the desert. Czech astronomers are already making good use of these facilities and we look forward to having Czech industry and its scientific community contribute to the future E-ELT." From the VLT platform, the President had the opportunity to admire Cerro Armazones as well as other spectacular views of Chile's Atacama Desert surrounding Paranal. Adjacent to Cerro Paranal, Armazones has been chosen as the site for the future E-ELT (see eso1018). ESO is seeking approval from its governing bodies by the end of 2011 for the go-ahead for the 1-billion euro E-ELT. Construction is expected to begin in 2012 and the start of operations is planned for early in the next decade. President Klaus was accompanied by the Minister of Foreign Affairs of the Czech Republic, Karel Schwarzenberg, the Czech Ambassador in Chile, Zdenek Kubánek, dignitaries of the government, and a Czech industrial delegation. The group was hosted at Paranal by the ESO Director General, Tim de Zeeuw, the ESO Representative in Chile, Massimo Tarenghi, the Director of Operations, Andreas Kaufer, and Jan Palous, Czech representative at the ESO Council. After the opening of the telescopes, President Klaus had the opportunity to enjoy the spectacular sunset over the Pacific Ocean from the VLT platform. Then he visited the VLT control room, which operates the four Unit Telescopes and the VLT Interferometer (VLTI). Here, the President took part in the start of observations from the console of one of the VLT Unit telescopes. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Comet Hyakutake to Approach the Earth in Late March 1996

NASA Astrophysics Data System (ADS)

1996-03-01

Astronomers Prepare for a Rare Event In the early morning of January 31, 1996, Japanese amateur astronomer Yuji Hyakutake made his second comet discovery within five weeks. He found the new comet near the border between the southern constellations of Hydra (The Water-Snake) and Libra (The Scales), amazingly just three degrees from the position where he detected another comet on December 26, 1995. After two weeks of hectic activity among amateur and professional astronomers all over the world, much interesting information has now been gathered about the new comet which has been designated C/1996 B2 (Hyakutake) . In particular, it has been found to move in a near-parabolic orbit that will bring it unusually close to the Earth next month. It is then expected to become bright enough to be seen with the unaided eye and to remain so during several weeks thereafter. Preparations are now made to observe the celestial visitor with a large number of telescopes, on the ground and in space. This event offers a rare opportunity to study the immediate surroundings of a cometary nucleus in detail and the specialists intend to make the most of it. Discovery and orbit Yuji Hyakutake, of profession photoengraver and a well-known amateur astronomer, announced his new discovery without delay, and within 24 hours, it had been sighted by several other observers in Japan and Australia. Experienced comet-watchers described its appearance as `diffuse with central condensation and of magnitude 11-12', i.e. a little more than 100 times fainter than what can be seen with the unaided eye. This brightness is not unusual for a comet discovered by an amateur, although it would probably have been missed, had it been just a little fainter. In the present case, the decisive factors for Hyakutake's success were undoubtedly his very powerful equipment (25 x 150 binoculars) and the advantageous combination of the comet's southern position in the sky and his location in Kagoshima, the southernmost prefecture of Japan. Within three days only, nearly 120 positional measurements of the comet were obtained, mostly by amateur observers in Australia, PR China, the Czech Republic, France, Japan, Spain and the U.S.A. This allowed Brian Marsden of the Central Bureau for Astronomical Telegrams of the International Astronomical Union (Cambridge, Mass., U.S.A.) to compute a preliminary orbit. It showed that the comet moves along a parabola - or at least an extremely elongated ellipse - and that it must therefore have come from far away and may never have been near the Sun before. At the time of discovery, the comet was about 280 million km from the Earth and outside the orbit of Mars. Moreover, the motion of the comet is such that it will continue to approach the Earth with a speed of about 58 km/sec during the next weeks and will pass within 15 million kilometres of our planet in late March. This corresponds to one tenth of the distance between the Earth and the Sun (0.1 AU) and, in cosmical terms, the passage is therefore a very close one. Information about some earlier comet encounters may be found in the Appendix at the end of this Press Release. Continued observations have confirmed this and have also allowed to fix the moment of closest passage as Monday, March 25, at about 7h UT. At that time, the comet will be moving northwards through the northern constellation of Draco (The Dragon) at the exceptional rate of 0.77 deg/hour. The event will be best observable from the northern hemisphere. Two days later, the comet passes within a few degrees of the northern celestial pole. The perihelion (the orbital point closest to the Sun) is reached on May 1, 1996, at a distance of 35 million kilometres from the Sun, far inside the orbit of the innermost planet, Mercury. From then on, the comet will rapidly move south, crossing the celestial equator in mid-May and reaching 70 degrees south in late July. Recent observations Comet Hyakutake obviously comes from far away, maybe even from the very distant `Oort Cloud' of comets that surrounds the solar system. In this sense it is different from the periodical comets which move in closed orbits around the Sun with revolution periods between a few years and some decades. Its `dirty snowball' nucleus of ices and dust has therefore not been heated by the Sun for a very long time, perhaps never, if this is its first visit to the inner regions of the solar system. Hence it is particularly difficult to predict its future performance. Nevertheless, the available observations seem to indicate that it is a quite `active' comet and that it may therefore become comparatively bright when it approaches the Earth and later at perihelion. But how bright ? Imaging as well as spectroscopic observations have been performed in order to better characterize Comet Hyakutake. On CCD-frames obtained of the comet in early February with telescopes at the ESO La Silla Observatory and elsewhere, an elongation is clearly visible (cf. ESO Press Photo 11/96 ) in the anti-sunward direction of the coma (the cloud of gas and dust that surrounds the cometary nucleus). A real tail has not yet developed, but this is expected to happen soon. The size of the coma was measured as at least 7 arcmin, corresponding to a projected diameter of nearly 500,000 kilometres. It is also of interest that until recently the coma otherwise appeared absolutely symmetrical - there was no indication of `jets', i.e. no large vents on the surface of the nucleus had yet become active. However, on images obtained with the ESO 3.6-metre telescope in the morning of February 13, a `jet'-like feature is seen which emerges south-east of the nucleus (i.e. from the sunlit side) and curls counter-clockwise towards the opposite side (the `tail'-direction). This is probably the first evidence of localized dust production on the surface of the nucleus. CCD observations were made on February 9 at the Lowell Observatory (Flagstaff, U.S.A.) through special optical filters which isolate the light from different components of the coma, e.g. the light emitted by the OH-, C2- and CN-molecules in gaseous form and also the reflected sunlight from the dust grains. They show that the gas production rates are almost as high as those measured at famous Comet Halley when it was at about the same distance from the Sun during its approach in late 1985. The dust production of Comet Hyakutake also seems to be quite impressive. The first spectra of the new comet were obtained at La Silla with the Boller and Chivens spectrograph at the ESO 1.52-metre telescope on February 8; they show comparatively strong emission of CN, C2 and C3 molecules, cf. ESO Press Photo 12/96. This is not unusual for a comet at the corresponding heliocentric distance. In conclusion, the recent observations show Comet Hyakutake to be an `active' comet. The evaporation of the ices on the surface of its nucleus, due to the heating of the Sun, is well underway and much dust is being ejected during this process. It is quite likely that this comet will put on a fine display, starting in mid-March and lasting until soon after the perihelion passage in early May. Nevertheless, there have been some cases [1] in recent times when the activity level of new comets did not develop as expected, so some caution is necessary. The encounter on March 25 By a straightforward extrapolation of the current brightness, it would appear that Comet Hyakutake will reach magnitude 1 on March 25, 1996, at the time of the closest approach to the Earth. This is almost as bright as the brightest stars in the sky. However, it is important to consider that this is the `integrated' brightness of the entire comet head which may fill an area of several degrees in diameter in the sky. Thus the comet will appear as a moderately bright, very diffuse object that is best visible in binoculars. There will be a central point of enhanced brightness, corresponding to the innermost part of the coma around the nucleus. The motion is sufficiently fast to be easily perceptible on the stellar background. We do not know the size of the nucleus yet, but assuming - optimistically, from the measured gas and dust production - that the diameter is 10 kilometres, i.e. about as large as that of Comet Halley, then the magnitude of the nucleus alone should be about 11 at the time of the closest encounter. It may therefore be well visible in even small telescopes, as a bright point near the centre of the diffuse coma. However, it will most probably not be possible to obtain resolved images of the nucleus with ground-based telescopes; even if the size turns out to be this large, the nucleus will only subtend an angle of about 0.15 arcsec and thus appear point-like. The comet's extremely rapid motion across the sky at the encounter will constitute a major technical-observational problem for most telescopes. Moreover, it cannot be excluded that the coma is so dense that the nucleus will be completely hidden from view. The only telescope which could possibly image the nucleus as an extended object is the Hubble Space Telescope, for which observations are now being planned. Still, there is no doubt that the upcoming event offers very bright prospects for the investigation of the near-nucleus environment of a comet. Another technique which will most likely be attempted is that of radar soundings; the return time for a signal will only be 100 seconds. In the past, only a handful of comets have been investigated in this way and none in great detail. However, in view of the recent, great technological advances in this field, it should in principle be possible to `image' the nucleus of Comet Hyakutake with some of the largest radio telescopes. Predictions for the appearance of the tail(s) at the encounter are still very uncertain, since their development has not yet started. In the best case, the dust tail may become quite impressive and reach a length of many degrees, and the expected ion tail could also be quite long. The perihel passage The brightness at perihel on May 1 will probably exceed that at the Earth encounter and Comet Hyakutake could then become a very spectacular object. How bright it will actually be is much dependent on the amount of dust released from the nucleus as it approaches the Sun. Unfortunately, the viewing conditions will not be very good and the full moon on May 3 will also adversely influence the sight. Appendix: Comet encounters with the Earth There is no doubt that the close encounter with C/1996 B2 (Hyakutake) is a relatively rare event. According to Brian Marsden (Central Bureau for Astronomical Telegrams of the International Astronomical Union, Cambridge, Mass., U.S.A.): The approach of C/1996 B2 to the Earth on March 25 (0.10 AU) [2] is the closest for any comet since 1983 (when there were two comets coming to 0.06 AU and 0.03 AU within a month of each other), and it is the fifth closest approach of any comet during the past century. What is unique about this comet is that no other comet is known then to have gone on to pass anything like as close to the Sun as this one does (0.23 AU on May 1). One of the 1983 comets had about twice this comet's perihelion distance, but the approach to the Earth was well after perihelion. There was possibly a comet with a perihelion distance comparable to this one that came closer to the Earth after perihelion in the year 400, but that is very uncertain. The time interval between passage near the Earth and subsequent passage near the Sun is longer for C/1996 B2 (37 days) than for any closer Earth approach since that of the famous Lexell comet in 1770 (43 days), that comet holding the record confirmed approach to the Earth (0.015 AU or 2.2 million kilometres). C/1996 B2 is intrinsically the brightest Earth-approacher since the early eighteenth century, and the 55 days between discovery and Earth approach is a record for a pre-perihelic Earth approach. More information about other close encounters and collisions of comets with the Earth may be found in an article by Zdenek Sekanina and Don Yeomans (Jet Propulsion Laboratory, CALTECH, Pasadena, U.S.A.) which appeared in 1984 in the American journal The Astronomical Journal , Volume 89, page 154. Notes: [1] Prominent examples are Comet Kohoutek in 1973 and Comet Austin in 1990. [2] 1 Astronomical Unit (AU) = 149.6 million kilometres (the mean distance between the Earth and the Sun). Note also that ESO has set up a special Home Page for the Comet Hyakutake event ( http://www.eso.org/educnpubrelns/comet-hyakutake.html) where new information from ESO will be brought.

Obituary: E. Dorrit Hoffleit, 1907-2007

NASA Astrophysics Data System (ADS)

Trimble, Virginia

2007-12-01

For Ellen Dorrit Hoffleit, who died on 9 April 2007 in New Haven, Connecticut, shortly after her 100th birthday, World War II, in which she did at least her fair share of the work, was "the war," but she also lived through World War I ("the Great War" until she was well into her 30s), Korea, Vietnam, the first Gulf War, and (we hope) most of Iraq. Hoffleit's early years were difficult, and she described her own life as having led "From Early Sadness to Happy Old Age" (Comments on Astrophysics, 18, p. 107, 1996), with a late autobiography entitled Misfortunes as Blessing in Disguise(American Association of Variable Star Astronomers, 2002). The name Dorrit came from Dickens, but her parents, who called her Dorchen in childhood, were German immigrants, and some of her classmates refused to play with her "because she's German!" Home oscillated between a failing farm in Florence, Alabama, where she was born on 12 March 1907 and rented space in the railroad town of New Castle, Pennsylvania, where her father was a bookkeeper for the Pennsylvania Railroad. Older brother, Herbert (1905-1981) was, perhaps inevitably, the favored child, a precocious student (Harvard PhD at 22) and devoted to that most respectable subject, Latin language and literature, of which he was a professor at UCLA from 1927 (when it was the Southern Branch of the University of California) until his retirement. He took the teaching part of his career more seriously than the research part (though he was not the most memorable of the three Latin professors I had there), but, at a time when Dorrit's publications outnumbered Herbert's by something like fifty to one, she remarked, a little sadly, that the only thing about her that her mother, who lived until 1974, really approved of was her long hair. Dorrit soon started catching up! She was the only member of the Radcliffe class of 1928 who had taken a graduate course in mathematics. She turned down a better paying job as a statistician to start work the next year as a research assistant (later research associate) at Harvard College Observatory, then directed by Harlow Shapley, about whom her opinion was much warmer than that expressed by Cecilia Payne Gaposchkin. Dorrit's immediate supervisor at Harvard was Henrietta Swope, daughter of the President of General Electric, and eventually best known for work at Mount Wilson Observatory with Walter Baade on variable stars in the Magellanic Clouds, published in papers that continued to appear long after Baade's death. Hoffleit's first ten papers were also on variable stars and appeared in Harvard Observatory publications. But the MA she completed in 1932 was on the light curves of meteors and was published in the Proceedings of the United States National Academy of Sciences. By this time, Dorrit had established a work pattern that was to persist right up to retirement - at least 40 hours per week on whatever the current boss thought she should be doing, and another 20 or so on other astronomical research that interested her. Hffleit had supposed that an MA would be her highest degree, but Shapley urged her to go on for a PhD, with, it would seem, a bit of urging on both sides from Bart Bok, who informed her that "if God recommends that you do something, it is your duty to do it." The thesis (PhD 1938) was on yet a third topic, spectroscopic parallaxes. This means determining the luminosities of stars, hence their distances, from line width and ratio diagnostics in their spectra. The pioneer was Antonia Maury, whose insights were not appreciated by Shapley's predecessor, E. C. Pickering. Another valuable Hoffleit mentor was Ernst Öpik, on a three-month visit to Harvard in 1934, from whom Dorrit learned stellar statistics and half a dozen other things. The thesis also provided her "break out" paper into the Astrophysical Journal (on CN as a giant/dwarf discriminator). Hoffleit began to branch out into astrometry, comets, and other parts of astronomy and, starting in 1941, began writing about eighty short news notes per year for Volumes 1-15 of the newly for med Sky & Telescope. And then there was a war. Women were not, of course, drafted nor required to find state-side war work to avoid deployment overseas, but Dorrit, still mindful of her German heritage, volunteered. After about six months working under Zdenek Kopal on preparation of firing tables for Navy cannons, she returned briefly to Harvard, having been employed (and paid) at roughly the high-school student level by the Navy. But soon it was on to the Ballistic Research Laboratory of the Army's Aberdeen Proving Ground and another computing job, this time for trajectories of anti-aircraft missiles. The other job opportunity was to measure missile tracks on photographic plates, which she would have preferred, but this would have placed her in the department headed by Edwin P. Hubble. No love was lost between Harvard's Shapley and Mount Wilson's Hubble, partly due to scientific differences, but also partly due to their very different views on what scientists should do in war time, so perhaps is was just as well she ended up in the computing section. There was another stage of fuss and bother to be got through before Dorrit received an appropriate, "professional" (meaning with PhD) rank and the commensurate salary. To the Colonel who complained that women were forever leaving their jobs to get married, she mentioned only her age, and not her early resolve never to marry or to have children, because of a deep worry that they might inherit the mental instability that had led to her maternal grandmother's institutionalization and early death. By the end of the war, her position, salary, and responsibilities a good match to her skills and credentials, Dorrit willingly put in another three years with the Army, working on reduction of records of "DOppler Velocity and Position" data for the captured V-2s being flown from White Sands Missile Range. But it was not the astronomy she loved, and late 1948 saw her back at Harvard (though with a consultant's appointment at Aberdeen for another ten years), salary cut back by a factor two, but with tenure as an astronomer, a bigger office, and an enormous pile of plates from the Blömfontein station to be measured for spectroscopic parallaxes. She undertook that and a wide range of other projects, with full support from above as long as Shapley was director. It must mean something that the next director, Donald H. Menzel, who eventually precipitated Hoffleit's departure from Harvard, had also been born in a Florence (Colorado, rather than Alabama), but what really mattered was that he wanted to move Harvard in the direction of his own field of astrophysics and saw no good reason to maintain extensive plate files or people who extracted data from them. Dorrit went job hunting, and, when the dust had finally settled, she was ensconced in two positions that she would occupy officially for the next twenty years (and unofficially long beyond that). It was in those two contexts that most of us came to know her. Hoffleit became, half-and-half, both director of the Maria Mitchell Observatory from 1957 to 1978 and a research astronomer at Yale (1956 to official 1975 retirement) under its long-term director Dirk Brouwer, where her primary task was to be preparation of astrometric catalogs. The Observatory directorship first. Maria Mitchell (MMO) was (and is) a small, private observatory on Nantucket Island (Massachusetts) founded as a memorial to the first woman astronomer in the USA by her family and friends. The primary instrument was a 7.5" refractor used (1912-1995) primarily for photographic monitoring of variable stars. Hoffleit proposed to work on some hundreds of her Harvard discoveries, employing for the first time during each summer a small group of undergraduate women to acquire additional plates, measure them, determine periods, and so forth, the results eventually to be published, often in the Journal of the American Association of Variable Star Observers, where MMO papers still turn up, though perhaps not so many as in Dorrit's day. She would also continue education and public outreach activities in the local community that her predecessor, Margaret Harwood, had established. Summer research experience for undergraduate opportunities have become common, but they were rare in 1957, especially for women students, and the ones who came to MMO (more than one hundred over her term) were undoubtedly very strongly motivated. They left even more so, with the striking result that about 25 of the Hoffleit students became professional astronomers. A few of the earliest are now retired; many remain in stellar astronomy, but others have spread across the Solar System and the galaxies. According to a list compiled by Dorrit, with minor additions, these are, in chronological order: Margo Friedel Aller, Andrea Knudsen Dupree, Barbara Welther, Gretchen Luft Hagen Harris, Nancy Houk, Martha Safford Hanner, Diane Reeve Moorhead, Nancy Remage Evans, Catherine Doremus Garmany, Jane Turner, Jean Warren Goad, Karen Alper Castle, Marcia Keyes Rieke, Judy Karpen, Karen Kwitter, Esther Hu, Bonnie Buratti, Harriet Dinerstein, Melissa McGrath, Constance Phillips Walker, John Briggs, Deborah Crocker, Edward Morgan, and Karen Meech. The program went co-ed shortly before Dorrit handed it over to Emilia Belaserne). A special paragraph must go to Janet Akyüz Mattei. She came to MMO in the summer of 1969 upon the recommendation of Paris Pismis, an Armenian-Turkish-Mexican astronomer who had known Janet in Turkey and was a very old friend of Dorrit's (and of mine). Janet's own obituary sadly appeared in these pages (BAAS, 36, pp. 1681-82, 2004), the last 30 of her only 61 years having been spent as the director of AAVSO. Among the many important things Janet did in that directorial capacity was to persuade Dorrit Hoffleit to write up the story of her life for publication by AAVSO in 2002, from which much of this material has been taken. And then there was Yale. "Dorrit Hoffleit?" "You know. The Yale Bright Star Catalogue." Indeed the Yale Bright Star Catalogue: the Third (1964) edition on her own; the Fourth (1982) with Carlos Jaschek; the 1983 Supplement; and the Fifth (1987) Edition with W. H. Warren. The value of these would be hard to overestimate. They were cited one hundred or more times per year from 1985 to 1999 (compared, to about twenty citations per year to Annie J. Cannon's HD catalogues and about 600 per year to the multiplet tables of Charlotte E. Moore during the same period). But there were also her contributions to a number of other Yale catalogues of positions and proper motions, and, especially, the 4th edition of the General Catalogue of Trigonometric Parallaxes with W. F. van Altena and J. T. Lee, plus a large number of papers based on subsets of the stars in these catalogues and compilations. Dirk Brouwer, who had chaired the search committee that selected Hoffleit as director of Maria Mitchell, was also department head and observatory director at Yale when she arrived there. Late in 2006, when Dorrit had become even more forthcoming than in her autobiography, she admitted in an extended phone conversation that he had been a very traditional director, not just primarily committed to positional astronomer (one of her own loves) but also of the opinion that the staff should work primarily on his projects. Yet the unexpected death of Brouwer in January 1966 could have been a disaster. The newly appointed acting director, Rupert Wildt (of H-minus opacity fame) made clear that the future of the department would lie with astrophysics, and he did some firm "deaccessioning" of non-tenured staff in celestial mechanics and astrometry. But when Pierre Demarque took up the chairmanship, making clear that it would not be for the rest of his life, he was very glad to have Hoffleit's programs continue and, in fact, gave her a good deal more freedom to choose then than had Brouwer. Dorrit used part of that freedom to begin writing about the history of astronomy, first book reviews and obituaries, but soon also articles on the history of variable star astronomy, a long 1993 article on women who had worked in the field (and she included supernovae!), and, most notably, the 1992 volume Astronomy at Yale 1701-1968. Eventually her historical interests were bound to overlap her own lifetime, and her last publication was the written version of a talk she gave at the April 2000 meeting of the American Physical Society on the pioneering women of stellar classification - Fleming, Maury, and Cannon (Physics in Perspective, 4, pp. 367-495, 2002). Among the honors bestowed upon Hoffleit, primarily rather late in her life, were two DSc's (Smith College 1984, Central Connecticut State University 1998), the George van Biesbroeck Prize (American Astronomical Society and University of Arizona, 1988) for extraordinary service to the astronomical community both as a mentor and as a cataloguer, and an asteroid (3416) in 1987. With no children or grandchildren of her own, Dorrit established close relationships with her brother's two children, many of the Maria Mitchell "girls," and the children of her younger Yale colleague Robert Zinn. In a slightly more ideal world, this piece would have been written either by Janet Mattei of AAVSO or by Martha (Liller) Hazen, whose friendship with Dorrit went right back to the plate stacks of Harvard. Both predeceased her. Dorrit once said of Annie J. Cannon that she (AJC) was the happiest person that she (EDH) had ever known. I am not quite sure we can say that, in turn, about Dorrit Hoffleit, but she certainly was in the running. And part of what it made it so wonderful to encounter her was not just that you were glad to see her, but that she was glad to see you.

Obituary: Brian Marsden (1937-2010)

NASA Astrophysics Data System (ADS)

Williams, Gareth; Marsden, Cynthia

2011-12-01

Brian Geoffrey Marsden was born on 1937 August 5 in Cambridge, England. His father, Thomas, was the senior mathematics teacher at a local high school. It was his mother, Eileen (nee West), however, who introduced him to the study of astronomy, when he returned home on the Thursday during his first week in primary school in 1942 and found her sitting in the back yard watching an eclipse of the sun. Using now frowned-upon candle-smoked glass, they sat watching the changing bite out of the sun. What most impressed the budding astronomer, however, was not that the eclipse could be seen, but the fact that it had been predicted in advance, and it was the idea that one could make successful predictions of events in the sky that eventually led him to his career. When, at the age of 11, he entered the Perse School in Cambridge he was developing primitive methods for calculating the positions of the planets. He soon realized that earlier astronomers had come up with more accurate procedures for doing this over the centuries, and during the next couple of years this led to his introduction to the library of the Cambridge University Observatories and his study of how eclipses, for example, could be precisely computed. Together with a couple of other students he formed a school Astronomical Society, of which he served as the secretary. At the age of 16 he joined and began regularly attending the monthly London meetings of the British Astronomical Association. He quickly became involved with the Association's Computing Section, which was known specifically for making astronomical predictions other than those that were routinely being prepared by professional astronomers for publication in almanacs around the world. Under the watchful eyes of the director and assistant director of the Computing Section, this led him to prepare and publish predictions of the occasions when one of Jupiter's moons could be seen to pass directly in front of another. He also calculated the gravitational effects of the planets on the dates and sky positions of the returns of some periodic comets. He carried out these computations using seven-place logarithms. After all, this was long before pocket calculators had been invented, and the construction of large electronic computers was still then very much in its infancy. He always maintained that making such computations by primitive means significantly increased one's understanding of the science involved. During his last year of high school he also became a junior member of the Royal Astronomical Society. He was an undergraduate at New College, University of Oxford. In his first year there he persuaded the British Astronomical Association to lend him a mechanical calculating machine, allowing him thereby to increase his computational productivity. By the time he received his undergraduate degree, in mathematics, he had already developed somewhat of an international reputation for the computation of orbits of comets, including new discoveries. He spent part of his first two undergraduate summer vacations working at the British Nautical Almanac Office. He also responded to an inquiry from Dorothy L. Sayers involving the ancient Roman poet Lucan. Incensed by what she perceived as grossly unfair criticism of Lucan by A. E. Housman and Robert Graves, she elicited his assistance during the last year of her life to support her view that Lucan's understanding of astronomy and geography was reasonably valid. Dr. Sayers' extensive correspondence in the course of this study is included in the last volume of her collected letters. After Oxford, he took up an invitation to cross the pond and work at the Yale University Observatory. He had originally planned to spend just a year there carrying out research on orbital mechanics, but on his arrival in 1959 he was also enrolled as a Yale graduate student. With the ready availability of the university's IBM 650 computer in the observatory building, he had soon programmed it to compute the orbits of comets. Recalling his earlier interest in Jupiter's moons, he completed the requirements for his Ph.D. degree with a thesis on "The Motions of the Galilean Satellites of Jupiter". At the invitation of director Fred Whipple, he joined the staff of the Smithsonian Astrophysical Observatory in Cambridge (MA) in 1965. Dr. Whipple was probably best known for devising the "dirty snowball" model for the nucleus of a comet a decade and a half earlier. At that time there was only rather limited evidence that the motion of a comet was affected by forces over and above those of gravitation (limited because of the need to compute the orbit by hand), and the Whipple model had it that those forces were due to the comet's reaction to vaporization of the cometary snow or ice by solar radiation. Dr. Marsden therefore developed a way to incorporate such forces directly into the equations that governed the motion of a comet. Application of a computer program that included these nongravitational effects to several comets soon gave results that were nicely compatible with Dr. Whipple's original idea. Continued refinement of the nongravitational terms, much of it done in collaboration with Zdenek Sekanina, a Czech astronomer and friend of Dr. Marsden whom he and Dr. Whipple succeeded in bringing to the U.S. as a refugee following the Soviet invasion of Prague in 1968, resulted in a wealth of improved computations of cometary orbits by the time Dr. Sekanina moved to California in 1980. It is noteworthy that the procedure devised and developed by Dr. Marsden is still widely used to compute the nongravitational effects of comets, with relatively little further modification by other astronomers. The involvement of the Smithsonian Astrophysical Observatory with comets had been given a boost, shortly before Dr. Marsden's arrival there, by the transfer there from Copenhagen of the office of the Central Bureau for Astronomical Telegrams, a quaintly named organization that was established by the International Astronomical Union soon after its founding in 1920. The CBAT is responsible for disseminating information worldwide about the discoveries of comets, novae, supernovae and other objects of generally transient astronomical interest. It is the CBAT that actually names the comets (generally for their discoverers), and it has also been a repository for the observations of comets to which orbit computations need to be fitted. Dr. Marsden succeeded Dr. Owen Gingerich as the CBAT director in 1968. He was joined by Daniel Green as a student assistant a decade later, and Dr. Green took over as CBAT director in 2000. Until the early 1980s the Bureau really did receive and disseminate the discovery information by telegram (with dissemination also by postcard Circular), although e-mail announcements then understandably began to take over. The last time the CBAT received a telegram was when Thomas Bopp sent word of his discovery of a comet in 1995. Since word of this same discovery had already been received from Alan Hale a few hours earlier by e-mail, the object was very nearly just named Comet Hale, rather than the famous Comet Hale-Bopp that beautifully graced the world's skies for several weeks two years later. The comet prediction of which he was most proud was of the return of comet Swift-Tuttle, which is the comet associated with the Perseid meteors each August. It had been discovered in 1862, and the conventional wisdom was that it would return around 1981. He followed that line for much of a paper he published on the subject in 1973. He had a strong suspicion, however, that the 1862 comet was identical with one seen in 1737, and this assumption allowed him to predict that Swift-Tuttle would not return until late-1992. This prediction proved to be correct, and this comet has the longest orbital period of all the comets whose returns have been successfully predicted. Although the CBAT also traditionally made announcements of the discoveries of asteroids that came close to the earth, the official organization for attending to discoveries of asteroids (more than 99% of which are located in a belt between Mars and Jupiter) is the Minor Planet Center. Also operated by the International Astronomical Union, the MPC was located until 1978 at the Cincinnati Observatory. In that year the director, Dr. Paul Herget, was retiring, and it was necessary for the Center to find a new home. Accordingly, the IAU asked Dr. Marsden also to take over the direction of the MPC. Thanks to the transfer of associate director Conrad Bardwell with the MPC records from Cincinnati, this task was rendered easier. While the CBAT and the MPC still maintained their separate entities, there was a lot of common ground between them. Dr. Marsden was therefore able to introduce some efficiencies into their combined operation. On Mr. Bardwell's retirement at the end of 1989, Gareth Williams joined the MPC staff and later became associate director. The advances in electronic communication during the 1990s also permitted improvements in MPC operation. Perhaps the most important of these was the development, in 1996, of the Internet "Near-Earth Object Confirmation Page". This draws attention to candidate earth-approaching objects in need of follow-up observations as soon as they have been reported to the MPC, following the derivation by Dr. Marsden of a particularly ingenious method for estimating the uncertainty of the prediction by automatically computing a series of orbits that represent just the first and the last observations. In 1998 he developed a certain amount of notoriety by suggesting that an object called 1997 XF11 could collide with the earth. He did this as a last-ditch effort to encourage the acquisition of further observations, including searches for possible data from several years earlier. The recognition of some observations from 1990 made it quite clear that there could be no collision with 1997 XF11 during the foreseeable future. Without those 1990 observations, however, the object's orbit would have become very uncertain following a close to moderate approach to the earth in 2028; indeed, Dr. Marsden correctly demonstrated that there was the possibility of an earth impact in 2040 and in several neighboring years. He was thereby able eventually to persuade his principal critics routinely to perform similar uncertainty computations for all near-earth objects as they were announced. Again, as more data accrue, it is almost certain to happen that all possible impacts with moderately large objects (i.e., those at least several hundred feet across) during the next century, say, will disappear. While the production of such computations was directly due to his encouragement, it was always with some amusement that he saw cases where further data forced his former critics sheepishly to withdraw their earlier frightening statements about a potentially dangerous object. Dr. Marsden was particularly fascinated by the appearance of a group of comets that passed close to the sun. Known as members of the Kreutz group, after a German astronomer who studied them in the late nineteenth century, the discovery of three more of these sungrazing comets in the mid-twentieth century led him to undertake a detailed examination of how the individual comets may have evolved from each other. He published this examination in 1967, following it up with a further study in 1989 involving a more recent bright Kreutz comet, as well as several much fainter objects that had been detected from sun-observing coronagraphs out in space. Beginning in 1996, these were being found by the SOHO coronagraphs at rates ranging from a few dozen to more than one hundred per year. Unfortunately, the faintness of the comets and the poor accuracy with which they could be measured made it difficult to establish their orbits as satisfactorily as Dr. Marsden would have liked. More significantly, however, he was able to recognize that the SOHO data also contained another group of comets with similar orbits, these comets now known as members of the "Marsden group". Unlike the individual Kreutz comets, which have orbital periods of several centuries, it seems that the Marsden comets have orbital periods of only five or six years, leading him to try and recognize the same object at different passages near the sun and thereby predict future returns. Two other well-populated groups have also been detected in the SOHO data. Another series of astronomical discoveries that greatly interested him were what he always called the "transneptunian objects", although many of his colleagues have insisted on calling them "objects in the Kuiper Belt". When what those same colleagues considered to be the first of these was discovered in 1992, Dr. Marsden immediately remarked that this was untrue, because Pluto, discovered in 1930 and admittedly somewhat larger in size, had to be the first. More specifically, he was the first to suggest, correctly, that three further transneptunian objects discovered in 1993 were exactly like Pluto in the sense that they all orbit the sun twice while Neptune orbits it thrice. This particular recognition set him firmly on the quest to "demote" Pluto. Success required the discovery of transneptunian objects more comparable to Pluto in size, something that finally happened in 2005 with the discovery of the object that came to be known as Eris. At its triennial meeting in 2006 in Prague, the IAU voted to designate these objects, together with two further transneptunian objects now known as Makemake and Haumea, as well as the largest asteroid, Ceres, members of a new class of "dwarf planet". It was also at the IAU meeting in Prague that Dr. Marsden stepped down as MPC director, and he was quite entertained by the thought that both he and Pluto had been retired on the same day. While he remained working at the MPC (and also the CBAT) in an emeritus capacity, the directorship was passed to Dr. Timothy Spahr, whom he had brought to the MPC in 2000. Dr. Marsden served as an associate director of the Harvard-Smithsonian Center for Astrophysics (the combination of the Smithsonian Astrophysical Observatory and the Harvard College Observatory) for 15.75 years from the beginning of 1987 (the longest tenure for any of the Center's associate directors). He was chair of the Division of Dynamical Astronomy of the American Astronomical Society during 1976-1978 and president of the IAU commissions that oversaw the operation of the minor Planet Center (1976-1979) and the Central Bureau for Astronomical Telegrams (2000-2003). He continued to serve subsequently on the two solar-system nomenclature committees of the IAU, being the perennial secretary of the one that decides on names for asteroids. He also continued to publish a "Catalogue of Cometary Orbits," the first of these having appeared in 1972 and its successors roughly at intervals of two years. Among the various awards he received from the U.S., the U.K. and a handful of other European countries, the ones he particularly appreciated were the 1995 Dirk Brouwer Award (named for his mentor at Yale) of the AAS Division on Dynamical Astronomy and the 1989 Van Biesbroeck Award (named for an old friend and observer of comets and double stars), then presented by the University of Arizona, now by the AAS, for service to astronomy. Dr. Marsden married Nancy Lou Zissell, of Trumbull, Connecticut, on 1964 December 26, and fathered Cynthia (who is married to Gareth Williams, still MPC associate director), of Arlington, Massachusetts; and Jonathan, of San Mateo, California. There are three Californian grandchildren, Nikhilas, Nathaniel and Neena. A sister, Sylvia Custerson, continues to reside in Cambridge, England. From material written by Brian Marsden, edited by Gareth Williams, Cynthia Marsden, and HAD. First posted by the Minor Planet Center on 18 November 2010 as Minor Planet Electronic Circular 2010-W10.

PREFACE: CEWQO Topical Issue CEWQO Topical Issue

NASA Astrophysics Data System (ADS)

Bozic, Mirjana; Man'ko, Margarita

2009-09-01

This topical issue of Physica Scripta collects selected peer-reviewed contributions based on invited and contributed talks and posters presented at the 15th Central European Workshop on Quantum Optics (CEWQO) which took place in Belgrade 29 May-3 June 2008 (http://cewqo08.phy.bg.ac.yu). On behalf of the whole community took place in Belgrade 29 May-3 June 2008 (http://cewqo08.phy.bg.ac.yu, cewqo08.phy.bg.ac.yu). On behalf of the whole community of the workshop, we thank the referees for their careful reading and useful suggestions which helped to improve all of the submitted papers. A brief description of CEWQO The Central European Workshop on Quantum Optics is a series of conferences started informally in Budapest in 1992. Sometimes small events transform into important conferences, as in the case of CEWQO. Professor Jozsef Janszky, from the Research Institute of Solid State Physics and Optics, is the founder of this series. Margarita Man'ko obtained the following information from Jozsef Janszky during her visit to Budapest, within the framework of cooperation between the Russian and Hungarian Academies of Sciences in 2005. He organized a small workshop on quantum optics in Budapest in 1992 with John Klauder as a main speaker. Then, bearing in mind that a year before Janszky himself was invited by Vladimir Buzek to give a seminar on the same topic in Bratislava, he decided to assign the name 'Central European Workshop on Quantum Optics', considering the seminar in Bratislava to be the first workshop and the one in Budapest the second. The third formal workshop took place in Bratislava in 1993 organized by Vladimir Buzek, then in 1994 (Budapest, by Jozsef Janszky), 1995 and 1996 (Budmerice, Slovakia, by Vladimir Buzek), 1997 (Prague, by Igor Jex), 1999 (Olomouc, Czech Republic, by Zdenek Hradil), 2000 (Balatonfüred, Hungary, by Jozsef Janszky ), 2001 (Prague, by Igor Jex), 2002 (Szeged, Hungary, by Mihaly Benedict), 2003 (Rostock,Germany, by Werner Vogel and Sascha Wallentowitz), 2004 (Trieste, Italy, by Naseem Rahman and Sascha Wallentowitz), 2005 (Bilkent, Ankara, by Alexander Shumovsky), 2006 (Vienna, by Helmut Rauch), 2007 (Palermo, Italy, by Antonino Messina) and 2008 (Belgrade, by Mirjana Bozic). The CEWQO series developed in two directions following the rapid development of quantum optics and the transitional development of the scientific collaboration of Central European researchers with researchers from old and new emerging Central European countries, and from all over the world. The topics discussed at CEWQO 08 were divided into ten groups that aimed to cover the broad scope of modern quantum optics: Fundamental aspects of quantum optics and quantum mechanics Single photons and photon pairs Cavity and circuit QED Atoms in intense fields Neutron, atom and molecular quantum optics Quantum gases and fluids Coherence, entanglement and decoherence Optical properties of condensed matter and nanostructures Open quantum systems and chaos Quantum information processing Central European Workshops on Quantum Optics realize and are consistent with a wider idea, and a social, economical, cultural and political program promoted since 1989 by the Central European Initiative (CEI), the main goal of which was to help transition countries in Central Europe to become closer to the EU. The resulting support of the CEI, first obtained thanks to the scientific reputation, organizing activities, and efforts of Helmut Rauch, has been very important for the organization of the CEWQO in recent years, particularly in 2008. The support of the Sixth and Seventh Framework Programs of the European Commission was also very important. A short review of papers in this topical issue A principal role in this topical issue is played by the photon. Vuletic et al describe the mapping of the photon-polarization state onto a single collective-spin excitation (magnon) shared between two atomic ensembles. A heralded quantum memory based on this mapping is demonstrated. Dodonov derives a formula which predicts a photon generation rate in a cavity due to strong variations of the complex dielectric function in a thin layer near an ideally conducting wall (simulation of the dynamic Casimir effect). Skenderovic reports how photons from two femptosecond laser pulses prepare a large molecule in a coherent superposition of vibrational states. The time evolution of this state is interrogated with a third (delayed) pulse which creates a fourth wave, the signal, giving information on the molecular dynamics. Dimitrova et al present lecture demonstrations of interference and quantum erasing with single photons. By considering electromagnetic energy flow lines as photon paths Davidovic et al explain the emergence of an interference pattern in the process of the accumulation of single photon events behind an interference grating. Atoms in a cavity, atom-atom interactions, interactions of atoms with photons and macroscopic bodies is the next important topic in this topical issue. Khanbekyan et al deal with the problem of the spontaneous emission of an excited atom in a high-Q cavity and investigate the regime when the emitted photon belongs to a wave packet simultaneously located inside and outside the cavity. Sambale et al study the resonant Casimir-Polder potential of an excited atom in front of meta-material half-space and show that for long distances it exhibits attenuated oscillations, while close to the surface the potential becomes attractive or repulsive. Buhmann et al study the nonequilibrium Casimir-Polder force on an atom prepared in an incoherent superposition of internal energy-eigenstates, which is placed in a magnetoelectric environment of nonuniform temperature. Lazarou et al discuss how two atoms, interacting with a single cavity, can be coherently evolved into an entangled state when they are controlled by a sequence of Gaussian pulses, named frequency chirps. Bougouffa et al report on field quantization between two parallel conducting plates (modifications of the decay rate between such plates) and the three-level Jaynes-Cummings dynamics in the single-mode regime. Tomas studies the interaction between two atoms, one excited and the other in its ground state near the interface between two media. It is shown that the nonretarded van der Waals force gets enhanced by almost three orders of magnitude at the surface mode resonance. Vuskovic et al write about the plasma treatment of a bulk Nb surface which is very efficient for producing high-Q factor microwave cavities. Nemeth et al review the theory and experiments of the coherently pumped micromaser. With varied atomic inversion in a coherently pumped micromaser, a sudden switch occurs between two distinctively different field states, with high and low photon numbers. Moi et al show that alkali-metal atoms adsorbed either in organic films or in porous glass are released into the vapor phase (desorbed) under illumination, the action of many photons. Several papers are devoted to matter-wave interference and quantum fluids. By analyzing unavoidable quantum losses as they appear in neutron phase-echo and spin rotation experiments, Rauch concludes that basic quantum irreversibility exists in neutron interferometry. Rauch also shows how entanglement effects in a single particle system demonstrate quantum contextuality, and then argues that a quantum system carries much more information than is usually extracted. The time evolution of the wave function of an atom hit by a photon in a three-grating interferometer is used by Arsenovic et al to interpret the intriguing results of the corresponding experiment by Chapman et al. Grujic et al demonstrate dark Raman resonance due to Ramsey interference in a spatially separated pump and probe laser beams co-propagating through a pure 87Rb vapor cell. Obtained EIT profiles are explained by solving Bloch's equations for an atom in a magnetic field moving through pump and probe laser regions. Gawlik et al present results of experiments on finite-temperature Bose-Einstein condensate of 87Rb atoms in a magnetic trap. In the Thomas-Fermi (TF) regime, the condensate dynamics has a hydrodynamic character. The dynamics of non-TF condensates reflect the interaction between BEC and non-condensed thermal atoms. Atoms in intense fields is the subject of several papers. Gainutdinov et al show that the contribution to the radiative shift of the side bands of the Mollow spectrum is very significant. Using Gell-Mann, Low S-matrix formalism, and QED, Glushkov et al present an approach to study multiphoton processes during the interaction of an atom with a realistic intense laser field. The paper by Khetselius is devoted to two related problems: the calculation of the atomic hyperfine structure of the Li-like ions and an estimation of the effectiveness of the three-step scheme of isotope separation for the case of Cs isotopes. Vvedenskii et al present the results concerning the excitation of a residual quasi-dc current in the plasma, which are based on the solution of the time-dependent Schrödinger equation for the hydrogen atom in a few-cycle laser pulse. Information processing is one of the important aspects of this issue and it is considered in several papers. M Man'ko et al presented a new notion of tomographic entropy and new entropic uncertainty relations applied to the problem of light propagation in optical fibers. Nonlinearity in the quantum-information processing is considered in the paper by Chirkin et al. D'Arrigo et al investigated a very specific semiclassical Hamiltonian model of a quantum memory channel. They evaluated the performance of the three-qubit code error correcting code by means of entanglement fidelity. The fundamental aspects of quantum optics are the subject of several papers, namely, Bell's inequalities are studied in the paper by Andreev, the star-product quantization scheme was discussed by O Man'ko, and probabilistic representation was investigated in the paper by Adam et al. In the paper by V Man'ko et al the diagonal representation of the density operator (usually called P-function of Glauber-Sudarshan) is related to the star-product quantization method and to the tomographic-probability representation of quantum states. Laskowski et al suggest an elegant geometrical criterion for the separability, which is based on the local correlation measurements readily available in the laboratory. Mizrahi describes a method to derive the Pauli-Schrödinger equation starting from a simple model of a qubit carried by a massive particle. By analyzing unavoidable quantum losses as they appear in neutron phase-echo and spin rotation experiments, Rauch concludes that basic quantum irreversibility exists in neutron interferometry. Rauch also shows how entanglement effects in a single particle system demonstrate quantum contextuality, and then argues that a quantum system carries much more information than is usually extracted. Kupczynski advocates various statistical tests which could be used to search for a fine structure in experimental data in order to answer the question: is quantum theory predictably complete? For an ion confined within a Paul trap, Mihalcea constructs an invariant operator based on the Lews and Riesenfeld approach and determines the spectrum of the quasienergy operator. Popov et al construct pair-coherent states of the Barut-Girardello kind for two noninteracting subsystems of pseudoharmonic oscillators and examine their statistical properties in different regions of parameters. The property of entanglement, considered to be the most intriguing property of composite quantum systems, has been an important research subject in recent years. It is considered to be a possible resource for quantum computation and communication. Therefore, a substantial number of papers in this topical issue is devoted to entanglement. Leon et al write that two-photon emission from two atoms initially excited in a common electromagnetic vacuum may generate atom-atom entanglement. Dömötör et al elucidate a connection between entanglement and coherent states. Earlier they proved that in the symmetric subspace of a system of N qubits a pure state is not globally entangled, if and only if, it is a coherent state. Here they extend this proof to a system of N 'quKits' (subsystems of arbitrary finite dimension K). Napoli et al compute exactly localizable entanglement as a function of temperature for the system of three interacting spins in a thermal state. Isar considers entanglement in open quantum dynamics by studying the system of two independent oscillators interacting with the general environment. He proposes some special parameters of the environment that manifest interesting properties (e.g., the environment is entangling initially separable states). Lindén et al study the decay of entanglement in rings of qubits that live in the Markov environment. They use the entanglement of formation as the measure whose time evolution announces (or not) the decay. Jivulescu et al consider the time evolution of a spin-1/2 particle nonuniformly coupled through the Heisenberg interaction to the environment composed of N spins. Considering arbitrary initial conditions the authors determine a numerically manipulative general solution from which information on full dynamics may be extracted. Ferraro et al investigate the entanglement evolution of two qubits interacting with a common environment through a Heisenberg XX mechanism and show that the phenomena of entanglement hidden death and entanglement hidden revival take place. Stochastic processes have been very important in quantum optics. Pascazio et al review and compare three algorithms for the generation of sequences of symmetric stable Levy random variables. They draw conclusions on the efficiency of the algorithms used and on some applications in quantum optics. Hul et al report on the possibilities of explaining the statistical properties of the spectra of irregular quantum systems by invoking the random matrix theory. The authors calculated the spectra, spectral correlation functions, and the distributions of avoided crossings, for two types of idealized model of one-dimensional quantum wires forming a quantum graph. Sirko et al present the experimental study of microwave networks displaying an irregular hexagonal structure. In a sense, these networks model quantum graphs with special properties. Kiss et al consider the recurrence of quantum walks on lattices by studying the properties of the generalized Polya number. The properties of this number are compared for classical and quantum cases. A number of interesting papers are devoted to the optical properties of condensed matter and nanostructures. Gorelik derives analytical expressions for photonic dispersion law in 3D photonic crystals filled by dielectrics or metal. Nemilentsau et al evaluate the photon density of states near a single-wall finite length carbon nanotube. The authors found definite singularities in the density of photon states that may be observable in light-matter interaction, thermal radiation distribution, and micromechanical phenomena related to Casimir forces. Perinova et al pay attention to the interesting relationship between microscopic and macroscopic approaches to the quantization of the electromagnetic field in the medium. They examine the problem of a source atom radiating into a dielectric. Radovanovic et al present an extended approach for estimating the tunneling times through all linear materials, including metamaterials having a negative refractive index. Vasic et al describe the optical design of 2D confined structures with metamaterial layers which is based on coordinate transformations. Using the Green's functions method, Ilic et al analyze the influence of boundaries of the molecular ultrathin film on exciton dispersion law. Jeknic-Dugic proposes the model of optically induced transitions in an electronic subsystem of a bio-molecule that is able to describe relatively slow conformational transitions of a bio-molecule. Stef et al present their goal to grow good quality YbF3-doped and PbF2-codoped CaF2 crystals with high divalent Ytterbium content for investigating the influence of Pb2+ ions on the valence conversion, on the dielectric and optical absorption spectra. Vasile et al present the fabrication and SEM and photoluminescence characterization of zinc gallate doped with Eu and Er ions. The results could be important for photonic applications of spinels. Vasiljevic et al present the process of production of microlenses by irradiation of a tot'hema eosin sensitized gelatin (TESG) layer with a laser beam (2nd Nd:YAG harmonic, 532 nm). Microlenses chemically processed after production with 10% alum solution had near diffraction limited performance. The production and application of microlenses are fast expanding because they are increasingly used in biomedical and general optics. Prizes for the poster presentations Authors under 35 years of age were invited to take part in the poster competition. Two first prizes EX-AEQUOAE were awarded to Zoran Grujic from the Institute of Physics, Belgrade, Serbia, for the poster 'Numerical simulation of Raman-Ramsey effects induced by thermal motion of rubidium atoms' and to Andrey Popov from Altai State Technical University, Bernaul, Russia, for the poster 'Beryllium atoms in intense fields'. The third prize was awarded to Alex Crosse from Imperial College, London, UK, for the poster 'Quantum electrodynamics in absorbing nonlinear media'. Members of the Jury were: Mirjana Bozic (Chairperson), Victor Dodonov, Margarita Man'ko, Helmut Rauch, Saverio Pascazio, Richard Tanas and Philip Walther. Sponsors of the awards were the Institute of Physics, Belgrade, European Physical Journal (EPJ) and John Wiley and Sons. CEWQO 2009 and 2010 The 16th Central European Workshop on Quantum Optics was held in Turku, Finland, 23-27 May 2009. CEWQO09 was chaired by Professor Kalle-Antti Suominen (http://www.congress.utu.fi/cewqo2009). The conference site is the new ICT building at chaired by Professor Kalle-Antti Suominen (http://www.congress.utu.fi/cewqo2009, www.congress.utu.fi/cewqo2009). The conference site was the new ICT building at the University of Turku campus area and the Viking Line ferry boat. Turku is the central city of historical Finland established on the mouth of the river Aura in the 13th century. It is the birthplace of Finnish academic life, since the Academy of Turku was established there in 1640. In 2011, Turku will be one of the cultural capitals of Europe. The city has a strong maritime tradition and is shielded from the Baltic sea by a large and beautiful archipelago. The 17th Central European Workshop on Quantum Optics will be held in 2010 in St Andrews, UK. It will be chaired by Professors Ulf Leonhardt and Natalia Korolkova from the School of Physics and Astronomy, University of St Andrews. St Andrews is home to the first university of Scotland, the third-oldest in the English-speaking world, and is the home of golf. It remains a charming, eccentric seaside town that is sufficiently secluded - the ideal place for a stimulating and thought-provoking conference.