bluuebunny/crossref_metadata_2025 huggingface dataset:
A theory for the streamwise turbulent fluctuations in high Reynolds number pipe flow
Authors: Hultmark Marcus
Published: July 2012

A new theory for the streamwise turbulent fluctuations in fully developed pipe flow is proposed. The theory extends the similarities between the mean flow and the streamwise turbulence fluctuations, as observed in experimental high Reynolds number data, to also include the theoretical derivation. Connecting the derivation of the fluctuations to that of the mean velocity at finite Reynolds number as introduced by Wosnik, Castillo & George (J. Fluid Mech., vol. 421, 2000, pp. 115–145) can explain the logarithmic behaviour as well as the coefficient of the logarithm. The slope of the logarithm, for the fluctuations, depends on the increase of the fluctuations with Reynolds number, which is shown to agree very well with the experimental data. A mesolayer, similar to that introduced by Wosnik et al., exists for the fluctuations for $300\gt {y}^{+ } \gt 800$, which coincides with the mesolayer for the mean velocities. In the mesolayer, the flow is still affected by viscosity, which shows up as a decrease in the fluctuations.
The Value of Research to Business
Authors: Gras N. S. B.
Published: July 2012

When this subject was presented to me it appeared quite clearly as a challenge. When I first became interested in the history of business, it was as a study somewhat divorced from the ordinary routine of affairs. I was a student of economic history who had become convinced that the fundamental approach to this subject was along the line of private enterprise. Now I am asked to point out what value there may be in business history to the business man. At the very beginning of this discussion I ought to make a distinction between two types of business history; one, the history of individual business firms; the other, business history in general.
The John B. Alley, A Pioneer Locomotive
Authors: Larson Henrietta M.
Published: July 2012

A sheaf of old letters on deposit in the Baker Library of Harvard University gives a glimpse of an early type of locomotive which in a real sense epitomizes the pioneer stage of both American locomotive engineering and American business.
Some Remarks On Private Banking: Study of Jay Cooke given to Members
Authors: Hower Ralph M.
Published: July 2012

In sending copies of Dr. Henrietta M. Larson's Jay Cooke—Private Banker to its members, the Business Historical Society has taken a definite step forward. For the first time in its eleven years' existence, the Society has, with this presentation, been instrumental in distributing a significant historical volume prepared by a trained business historian and dealing with the business career of an important business man.
John Askin: Early Detroit Merchant
Authors: Rau Louise
Published: July 2012

Detroit is the oldest center of civilization in the vast area of the Great Lakes and the Mississippi Valley. Mission and trading posts there were at Chequamegon, Green Bay, Michilimackinac, Chicago, and possibly elsewhere, but all save Detroit were destroyed either temporarily or permanently. The missions at Chequamegon and Chicago were abandoned soon after their establishment, and except for the presence of a few independent traders, the modern settlement of these places dates from the nineteenth century. Michilimackinac, settled earlier than Detroit, still remains a center of civilization; but there have been several removals of the settlement as originally founded, and the present one on the Island dates only from 1780, while the place has steadily dwindled in relative importance from the commercial center of a wide region to a mere summer resort.
An Old-Time Novel About Business
Authors: Gras N. S. B.
Published: July 2012

In 1855 the German journalist, novelist, and historian, Gustav Freytag, gave to the world his popular novel Soll und Haben (Debit and Credit). The scene of the story is Eastern Germany, where Germans, Poles, and Jews lived in conflict about the year 1848.
Some Remarks on the Business of a New York Ship Chandler in the 1810's
Authors: Redlich Fritz
Published: July 2012

The Baker Library of Harvard University received during the past year an unidentified New York ship chandler's daybooks covering roughly the years 1811-15. These books depict some aspects of the work of a small concern in this line of trade, a trade which was typical of the numerous ports in the old and new worlds in the eighteenth and early nineteenth centuries.
The Business Activities of Eric Bollmann: Part II: The International Promoter
Authors: Redlich Fritz
Published: July 2012

Returning to Philadelphia after an unsuccessful trip to Louisiana in 1807 and 1808, Bollmann entered business again. When a character like Bollmann goes into business, he quite naturally turns promoter, and this Bollmann did in 1808. Foreign trade at the time being seriously interfered with by the struggle between England and France under Napoleon, Bollmann began with the promotion of domestic manufacture.
William Jones and His Unsuccessful Steamboat Venture of 1819
Authors: Redlich Fritz
Published: July 2012

In connection with some research in the field of banking history the author recently came across the William Jones Papers, acquired a few years ago by the Historical Society of Pennsylvania. These records, which are of unusual interest in many respects, are the basis of the present essay.

William Jones (1760-1831), as is generally known, was a Philadelphia shipping merchant and, during the War of 1812, both Madison's Secretary of the Navy and Secretary of the Treasury pro tem. In 1816 he became, for political reasons, the first president of the second Bank of the United States, but he resigned as early as January, 1819, after an inefficient and unsuccessful administration.
Hidden Treasure in Old-time Taxes
Authors: Crandall Ruth
Published: July 2012

The value of old tax data, as Professor Burbank has stated, lies in the wealth of detail in the tax lists, and more especially in the valuation lists. For each tax-payer these latter lists frequently give the amount and value of real estate, annual crops, live stock, stock in trade, shipping, mills of various sorts, warehouses, and occasionally even the silver plate owned by the family. Many of these headings, too, are in detailed form. For instance, real estate is divided into plow land, pasturage, orcharding, meadows, and wood land.
The Essex Institute of Salem
Authors: Corning Howard
Published: July 2012

As a depository of source material relating to a wide variety of subjects, the Essex Institute holds a unique position. For many years it has been natural to turn to Salem for material on ocean shipping. In decades past, Salem wharves were lined with vessels which Salem merchants had built and manned, and which brought rich products from every civilized and barbaric land. There were Eastern ports where the names of New York, Philadelphia and Baltimore were scarcely known, but where Salem was supposed to be the great emporium of the West. Letters addressed “Salem, U. S. A.” reached their destinations without delay. In 1825, there were one hundred ninety-eight vessels flying Salem signals, and Salem ships were the first to display the American flag in many foreign ports, as well as to open trade with St. Petersburg, Zanzibar, Sumatra, Calcutta, Bombay, Batavia, Arabia, Madagascar and Australia.
Beginnings of the Machine Age in New England: Documents Relating to the Introduction of the Power Loom
Authors: Lincoln Jonathan T.
Published: July 2012

Any attempt to describe the beginnings of the Machine Age in the United States leads the investigator back to the early records of the New England textile mills, for machine building in this country — using the term machinery in its modern meaning — had its origin in the workshops of the first cotton factories. Among the heroes of the period of beginnings are David Wilkinson, — the Pawtucket blacksmith, who, in 1790, assisted Samuel Slater to build the first Arkwright machinery to be successfully operated in the United States, and who, twenty years later, set up one of the earliest independent machine shops in New England, — and Francis Cabot Lowell, who, in 1814, introduced power weaving at the factory in Waltham, thus setting in motion the chain of events that led to the establishment of the great machine shops at Lowell.
The Railway & Locomotive Historical Society, Inc.
Authors: Fisher Charles E.
Published: July 2012

For at least twenty years prior to the formation of this Society, there were men in this country interested in the collection of records pertaining to the history of the railroads. Many of them the writer knew by personal acquaintance or through the medium of correspondence. With the Great War came the high price of scrap paper, and the railroads seized this opportunity of disposing of many of their old records in such fashion. Realizing that the individual could do but little toward the preservation of these records, two close friends, living in or near Boston, together with the writer, formed this Society.
A Kentucky Merchant's Problems in the Early Nineteenth Century
Authors: Tooker Elva
Published: July 2012

The eastern merchant who dealt with the West in the early nineteenth century was faced with many problems. But the western merchant was still worse off. Both sets of difficulties, particularly those of the latter, are illustrated in the correspondence between Christian Shultz and his various partners, of Maysville, Kentucky, and the metal-selling firm of Nathan Trotter & Co., of Philadelphia. These letters are found in the Trotter collection in the Baker Library.
The First American Business Man
Authors: Gras N. S. B.
Published: July 2012

Perhaps no two persons would agree who has the best claim to the honor of having been the first American (English colonial) business man. So far as the records go, a strong claim can be made for Thomas Studley, of Virginia.
The House of Baring and American Trade
Authors: Hidy R. W.
Published: July 2012

In these days of world-wide economic distress and intense nationalism the leading efforts in revival and recovery have been directed towards the rejuvenation of domestic economy. The United States stands today as one of the best examples of this tendency. Only a relatively few voices crying in the wilderness plead for balanced recovery through commensurate attention to foreign trade.
The Bancroft Collection
Authors: Cole Arthur H.
Published: July 2012

The Baker Library is particularly happy to announce the gift by Mrs. Hugh Bancroft of Boston, of an exceptionally rich and complete collection on the South Sea Bubble. The collection contains books and pamphlets, with many manuscripts, broadsides, Acts of Parliament, and other fugitive items relating to this strange episode. Except, perhaps, for the material scattered on the shelves of the British Museum, no collection rivals this which was assembled by the late Hugh Bancroft, in its fullness for a history of the South Sea speculation.
The Oldest American Business Firm
Authors: Gras N. S. B.
Published: July 2012

The Oldest business concern in America is not a railroad nor yet a canal or turnpike. It is not a bank nor an insurance company. It is not a tavern, at least not so far as I know. It is not even a publishing firm, although such firms have seen long life.
An Early Anglo-American Financial Transaction
Authors: Mayer Josephine , East Robert A.
Published: July 2012

The institutions and techniques for aiding the flow of capital and credit have had a long history. But it is a history which is not well known, especially in its earlier stages. In America the business of dealing in credit was at first chiefly in the hands of merchants, and, immediately after independence was established, chartered commercial banks took up the work. Some of the larger banks served as financial wholesalers, mobilizing credit and loaning it to small banks which were essentially retailers.
The Pioneer in American Life Insurance Marketing
Authors: Stalson J. Owen
Published: July 2012

Colonial America gave little thought to life insurance selling. The colonists secured protection against marine risks from private underwriters, first in London, eventually at home. It has been asserted that Philadelphia had no fire insurance until 1752; Boston none before 1795. The first corporations formed in this country for insuring lives were those of the Presbyterian Ministers Fund (1759) and a similar company organized for the benefit of Episcopal ministers (1769). Neither of these corporations offered insurance to the general public. In the last decade of the eighteenth century many insurance companies were formed in the United States. At least five were chartered to underwrite life risks, but only one, The Insurance Company of North America, appears to have accepted any. There is no basis for saying that any of these early companies tried to sell life insurance.
Reminiscences in Retailing
Authors: Appel Joseph H.
Published: July 2012

An address delivered by Mr. Joseph H. Appel at the Annual Meeting of the Business Historical Society.

It was two o'clock of a morning in late October, 1899. As night editor I had just put to press Colonel McClure's Philadelphia Times and was examining a first copy. My eye caught John Wanamaker's advertisement—with a banner head across the top—in color. A thought flashed in my mind—why not make it read: “Wanamaker's Daily News”? Make up the page like a newspaper—a newspaper of the store? Why not? Isn't a store a little world? Why not tell its news? I slept on the thought. Next day I wrote a letter—closing with “kindly reply at your earliest convenience.” The reply was prompt. “Come and see me,” signed John Wanamaker. Two days later I said goodbye to the Times and became an advertising writer in a great store.
Dickens' Brother and Western Railroad Publicity
Authors: Overton Richard C.
Published: July 2012

Among the manuscript collections deposited in the Baker Library are the Land Department records of the Burlington and Missouri River Railroad, now part of the Chicago, Burlington & Quincy Railroad.
Gail Borden as a Businessman
Authors: Frantz Joe B.
Published: July 2012

In the streaked shade of a scrub mesquite a vaquero pours boiling water into a can holding two spoonfuls of concentrated coffee, adds cream from a tin, spoons in sugar to suit, and miles away from the nearest house enjoys a cup of coffee. Chances are good that the coffee came in a jar marked “Borden's” and that the cream, condensed but fresh and pure though hours away from a refrigerator or a cool well, came in a can bearing a similar label; for radiating from its New York hub The Borden Company has pushed into American homes and American life until its products are known wherever food products are bought, sold, and used.
Short-term effects of biogas residue application on yield performance and N balance parameters of maize in different cropping systems
Authors: HERRMANN A. , SIELING K. , WIENFORTH B. , TAUBE F. , KAGE H.
Published: July 2012

The expansion of biogas production in Germany poses a challenge in terms of the production of substrates for co-fermentation and the efficient use of biogas residues as fertilizers. At present there is limited information on the fertilizer value of biogas residues from energy-cropping systems. A 2-year field experiment was conducted at two sites in northern Germany to quantify the yield, nitrogen (N) concentration and the N balance of maize (Zea maysL.) grown in different crop rotations: (i) maize monoculture (R1), (ii) maize – whole-crop wheat followed by Italian ryegrass as catch crop (R2) and (iii) maize – grain wheat followed by mustard as catch crop (R3). Crops were fertilized with different levels of biogas residues, cattle slurry, pig slurry, or mineral N fertilizer, which allowed quantification of the apparent N recovery (ANR) of the fertilizer types tested. The results revealed that crop rotation in interaction with N amount had a pronounced effect on the yield of maize. Maximum yield of 19·1 t dry matter (DM)/ha, corresponding to biogas production of 6685 m3NCH4/ha, was achieved in maize monoculture on a sandy loam site. Maize grown in R3 showed the lowest N response but had the highest yield under low N supply, whereas R2 generally had the lowest yield and N content. Differences in yield performance were reflected in the N balances, differing by 50 kg N/ha between R1 and R2, whereas R3 produced the lowest yield at low N supply. The carry-over effects from the preceding catch crops in R2 and R3, however, reduce the meaningfulness of the simple N balance. Nitrogen fertilizer type showed no interaction with crop rotation. Biogas residue application resulted in similar maize yielding performance to pig slurry and cattle slurry. However, relative N fertilizer value (RNFV) was 30% higher for biogas residue at optimal N supply, i.e. the minimum N input to achieve maximum DM yield.
Neuroendocrine carcinoma of the ethmoid sinuses treated with radiotherapy alone
Authors: Flavahan P W , Keir J , Srinivasan V
Published: July 2012

Objective:

We present the first report of a case of neuroendocrine carcinoma of the paranasal sinuses treated successfully with radiotherapy alone.

Method:

A case report and literature review are presented.

Results:

Fewer than 50 cases of paranasal sinus neuroendocrine carcinoma have been reported. We present an 82-year-old man referred with recurrent epistaxis. He was investigated by biopsy, computed tomography and magnetic resonance imaging, and was found to have a rare neuroendocrine carcinoma. He declined any surgery or chemotherapy but consented to radiotherapy. Thirty months later, he remained clinically free from cancer.

Conclusion:

There is no consensus for the management of paranasal sinus neuroendocrine carcinoma. Most cases are treated with surgery with or without chemoradiotherapy. This case shows that radiotherapy alone may be a viable treatment option for some cases.
Solidarity and Reciprocity in the Social Investment State: What Can be Learned from the Case of Flemish School Allowances and Truancy?
Authors: CANTILLON BEA , VAN LANCKER WIM
Published: July 2012

In this article, we discuss some of the new tensions that are emerging between the different foundations of the welfare state. Several developments have led to the advent of the social investment state, in which people are being activated and empowered instead of passively protected. We argue that this social policy shift has been accompanied by a normative shift towards a more stringent interpretation of social protection in which individual responsibility andquid pro quohave become the primordial focus. Using the Belgian (Flemish) disciplinary policy on truancy and school allowances as a case in point, we demonstrate that this social policy paradigm may have detrimental consequences for society's weakest: they will not always be able to meet the newly emerged standard of reciprocity. This implies an erosion of the ideal of social protection and encourages new forms of social exclusion. As these changes in the social policy framework are not confined to the Belgian case alone, our analysis bears relevance for all European welfare states.
Re-spacing and re-placing gerontology: relationality and affect
Authors: ANDREWS GAVIN J. , EVANS JOSHUA , WILES JANINE L.
Published: July 2012

This paper describes how space and place have been understood in gerontology as phenomenon that are both physical and social in character, yet are relatively bounded and static. The argument is posed as to how, following recent developments in human geography, a relational approach might be adopted. Involving a twist in current thinking, this would instead understand space and place each as highly permeable, fluid and networked at multiple scales. Moreover, it is proposed that the concept of ‘affect’ might also be insightful, recognising space and place as being relationally configured and performed, possessing a somatically registered energy, intensity and momentum that precedes deep cognition. Three vignettes illustrate the relationalities and affects in the lives and circumstances of older people, and how focusing more explicitly on them would allow for a richer understanding of where and how they live their lives. The paper closes with some thoughts on future theoretical, methodological and disciplinary considerations.
Older adults' spirituality and life satisfaction: a longitudinal test of social support and sense of coherence as mediating mechanisms
Authors: COWLISHAW SEAN , NIELE SYLVIA , TESHUVA KAREN , BROWNING COLETTE , KENDIG HAL
Published: July 2012

Spirituality is proposed to be a component of successful ageing and has been shown to predict wellbeing in old age. There has been conceptual discussion of possible mechanisms that link spirituality with positive psychological functioning in older adults, but few empirical examinations of these linking mechanisms over time. The current study examined the role of Antonovsky's Sense of Coherence (SOC) and social support in mediating the effects of spirituality on life satisfaction in older participants over a four-year period. The study used a cross-lagged panel analysis to evaluate longitudinal mediation within a path analysis framework. Results showed that the meaningfulness dimension of SOC mediated the influence of spirituality on life satisfaction over time, suggesting that spirituality may influence older adults' experience and perception of life events, leading to a more positive appraisal of these events as meaningful. Social support was not found to mediate the pathway between spirituality and life satisfaction. This study may be the first to examine the link between spirituality, sense of coherence, social support and wellbeing, as measured by life satisfaction, using longitudinal data from a community sample of older adults. The study provides evidence for the positive role of spirituality in the lives of older people. This is an area that requires further examination in models of successful ageing.
Empathy, Simulation, and Narrative
Authors: Gallagher Shaun
Published: July 2012

Argument

A number of theorists have proposed simulation theories of empathy. A review of these theories shows that, despite the fact that one version of the simulation theory can avoid a number of problems associated with such approaches, there are further reasons to doubt whether simulation actually explains empathy. A high-level simulation account of empathy, distinguished from the simulation theory of mindreading, can avoid problems associated with low-level (neural) simulationist accounts; but it fails to adequately address two other problems: the diversity problem and the starting problem. It is argued that a narrative approach to empathy obviates all these problems and offers a more parsimonious account.
Empathy in Translation: Movement and Image in the Psychological Laboratory
Authors: Lanzoni Susan
Published: July 2012

Argument

The new English term “empathy” was translated from the GermanEinfühlungin the first decade of the twentieth century by the psychologists James Ward at the University of Cambridge and Edward B. Titchener at Cornell. At Titchener's American laboratory, “empathy” was not a matter of understanding other minds, but rather a projection of imagined bodily movements and accompanying feelings into an object, a meaning that drew from its rich nineteenth-century aesthetic heritage. This rendering of “empathy” borrowed kinaesthetic meanings from German sources, but extended beyond a contemplation of the beautiful to include a variety of experimental stimuli and everyday objects in the laboratory. According to Titchener's structural psychology, all higher thought could be reduced to more elemental aspects of mind, and experimental introspection showed empathy to be constituted of kinaesthetic images. The existence of kinaesthetic images, Titchener argued, formed an incisive critique of the view that thought could take place without images, held by one of Titchener's major psychological rivals, the school of thought-psychologists in Würzburg, Germany. The new term “empathy” in early American academic psychology therefore delineated a kinaesthetic imaginative projection that took place on the basis of ontological difference between minds and things.
Einfühlungand Abstraction in the Moving Image: Historical and Contemporary Reflections
Authors: Curtis Robin
Published: July 2012

Argument

Despite the fact that “empathy” is often simply used as a translation ofEinfühlung, the two terms have distinct meanings and distinct disciplinary affiliations. This text considers the manner in which the moving image (whether within a film, video, or art installation) invites spatial forms of engagement akin to those described both by historical accounts ofEinfühlung, a form of engagement that pertains not only to the activities of humans represented within images, but also to the aesthetic qualities of images in a more abstract sense and to the forms to be found there.
Formal Dementia Care among First Nations in Southwestern Ontario
Authors: Finkelstein Sara A. , Forbes Dorothy A. , Richmond Chantelle A.M.
Published: July 2012

Cet article traite la façon dont les soins de la démence sont prévus pour les collectivités des Premiers Nations du sud-ouest de l’Ontario. Les données ont été saisies au moyen d’entretiens approfondis avec les prestataires de soins de santé et analysées en utilisant une méthodologie fondée sur une théorie constructiviste. Afin de comprendre les soins de la démence, deux cadres interdépendants ont été identifiés : un cadre de prestation des soins et un cadre de connaissances. Le cadre de prestation des soins a défini des objectifs de soins, des éléments de soins dispensés, les barrières de soins, et des stratégies et des solutions de prestation de soins pour surmonter les obstacles. Le cadre de connaissances a défini quatre groupes de parties prenantes : les personnes atteintes de la démence, les prestataires de soins informels, les prestataires de soins formels et la communauté des Premiers Nations. On a précisé les connaissances qu’il faut que chaque partie possède ou dont elle a besoin et les processus de partage – ou, à défaut de partage – des connaissances dans les soins de la démence. Plusieurs barrières, dont beaucoup sont créées par un manque de connaissances, ont eu un impact négatif sur les soins de la démence. Cependant, les professionels de soins de santé avaient des stratégies efficaces pour la prestation de soins qui ont été conçus pour surmonter les obstacles y compris le partage des connaissances.
Cardiac performance and quality of life in patients who have undergone the Fontan procedure with and without prior superior cavopulmonary connection
Authors: Atz Andrew M. , Travison Thomas G. , McCrindle Brian W. , Mahony Lynn , Glatz Andrew C. , Kaza Aditya K. , Breitbart Roger E. , Colan Steven D. , Kaltman Jonathan R. , Margossian Renee , Pasquali Sara K. , Wang Yanli , Gersony Welton M.
Published: July 2012

Background

A superior cavopulmonary connection is commonly performed before the Fontan procedure in patients with a functionally univentricular heart. Data are limited regarding associations between a prior superior cavopulmonary connection and functional and ventricular performance late after the Fontan procedure.

Methods

We compared characteristics of those with and without prior superior cavopulmonary connection among 546 subjects enrolled in the Pediatric Heart Network Fontan Cross-Sectional Study. We further compared different superior cavopulmonary connection techniques: bidirectional cavopulmonary anastomosis (n equals 229), bilateral bidirectional cavopulmonary anastomosis (n equals 39), and hemi-Fontan (n equals 114).

Results

A prior superior cavopulmonary connection was performed in 408 subjects (75%); the proportion differed by year of Fontan surgery and centre (p-value less than 0.0001 for each). The average age at Fontan was similar, 3.5 years in those with superior cavopulmonary connection versus 3.2 years in those without (p-value equals 0.4). The type of superior cavopulmonary connection varied by site (p-value less than 0.001) and was related to the type of Fontan procedure. Exercise performance, echocardiographic variables, and predominant rhythm did not differ by superior cavopulmonary connection status or among superior cavopulmonary connection types. Using a test of interaction, findings did not vary according to an underlying diagnosis of hypoplastic left heart syndrome.

Conclusions

After controlling for subject and era factors, most long-term outcomes in subjects with a prior superior cavopulmonary connection did not differ substantially from those without this procedure. The type of superior cavopulmonary connection varied significantly by centre, but late outcomes were similar.
A physiological role for the dopamine D5 receptor as a regulator of BDNF and Akt signalling in rodent prefrontal cortex
Authors: Perreault Melissa L. , Jones-Tabah Jace , O'Dowd Brian F. , George Susan R.
Published: July 2012

The dopamine D5 receptor (D5R) exhibits a wide distribution in prefrontal cortex (PFC) but its role in this region has not yet been elucidated. In the present study, we identified a novel physiological function for the D5R as a regulator of brain-derived neurotrophic factor (BDNF) and Akt signalling in PFC. Specifically, acute activation of the D5R by the dopamine agonist SKF 83959 enhanced BDNF expression and signalling through its receptor, tropomyosin receptor kinase B (TrkB), in rats and in mice gene-deleted for the D1 receptor but not the D5R. These changes were concomitant with increased expression of GAD67, a protein whose down-regulation has been implicated in the aetiology of schizophrenia. Furthermore, D5R activation increased phosphorylation of Akt at the Ser473 site, consequently decreasing the activity of its substrate GSK-3β. These findings could have wide-reaching implications given evidence showing activation of these pathways in PFC has therapeutic effects in neuropsychiatric disorders such as drug addiction, schizophrenia and depression.
Polarization of Class I methanol (CH3OH) masers
Authors: Sarma A. P.
Published: July 2012

Magnetic fields are known to play an important role in several stages of the star formation process. Class I methanol (CH3OH) masers offer the possibility of measuring the large-scale magnetic field in star forming regions at high angular resolution, due to connections between the large-scale magnetic field in the pre-shock regions to the observed magnetic field along the outflows in the post-shock regions where these masers are formed. The detection of the Zeeman effect in the 36 GHz and 44 GHz Class I methanol maser lines by Sarma and Momjian has opened an exciting new window into the study of the star formation process, but for the results to be interpreted correctly, the Zeeman splitting factor (z) for both these lines needs to be urgently measured by experiment. Ratios between the pre-shock and post-shock magnetic fields and densities lead to the conclusion that the value of z cannot be too different from 1 Hz mG−1, unless the predicted densities at which 36 GHz and 44 GHz methanol masers are excited are drastically incorrect. Similarities between the detected fields in 36 GHz and 44 GHz Class I masers, and 6.7 GHz Class II masers, support the claim that these masers may be tracing the large-scale magnetic field or that the magnetic field remains the same during different evolutionary stages of the star formation process, provided such similarities are not just due to the assumption of a uniform nominal value for z, or result simply from selection effects due to orientation and/or the shock process. Given the exciting possibilities, a larger statistical sample of measurements in both the 36 GHz and 44 GHz lines is certainly needed.
Polarization of the Recombination Line Maser in MWC349
Authors: Thum C. , Morris D. , Wiesemeyer H.
Published: July 2012

We present observations of the circular polarization of the recombination line maser in MWC 349. Six good quality Ha30α spectra were obtained during 2010 – 2011 which show that the Zeeman features are complex, time variable, and usually different for the blue- and red-shifted maser spikes. We propose that the magnetic field, located in the corona of the circumstellar disk, has toroidal and radial components. It is plausibly generated in a disk dynamo.
High resolution magnetic field measurements in high-mass star-forming regions using masers
Authors: Surcis Gabriele , Vlemmings Wouter H. T. , van Langevelde Huib J. , Kramer Busaba Hutawarakorn
Published: July 2012

The bright and narrow spectral line emission of masers is ideal for measuring the Zeeman-splitting as well as for determining the orientation of magnetic fields in 3-dimensions around massive protostars. Recently, polarization observations at milliarcsecond resolution of 6.7-GHz CH3OH masers have uniquely been able to resolve the morphology of magnetic fields close to massive protostars. The observations reveal that the magnetic fields are along outflows and/or on the surfaces of circumstellar tori. Here we present three different examples selected from a total number of 7 massive star-forming regions that were investigated at 6.7-GHz with the EVN in the last years.
The magnetic field of IRAS 16293-2422 as traced by shock-induced H2O masers
Authors: Alves Felipe O. , Vlemmings Wouter H. T. , Girart Josep M. , Torrelles José M.
Published: July 2012

H2O masers are important magnetic field tracers in very high density gas. We show one of the first magnetic field determinations at such high density in a low-mass protostar: IRAS 16293-2422. We used the Very Large Array (VLA) to carry out spectro-polarimetric observations of the 22 GHz Zeeman emission of H2O masers. A blend of at least three maser features can be inferred from our data. They are excited in zones of compressed gas produced by shocks between the outflows ejected by this source and the ambient gas. The post-shock particle density is in the range 1 - 3 × 109 cmt−3, and the line-of-sight component of the magnetic field is estimated as ~ 113 mG. The outflow dynamics is likely magnetically dominated.
Observational tests of SiO maser polarisation models
Authors: Richter L. L. , Kemball A. J. , Jonas J. L.
Published: July 2012

SiO masers are often observed in the near-circumstellar envelope of late-type evolved stars. The polarisation of the masers can be used as a probe of the magnetic field in this region, subject to maser polarisation radiative transfer model. Two main maser polarisation models have been developed for the weak Zeeman splitting case applicable to circumstellar SiO masers. Observational tests aimed at discriminating between these models were performed at maser component level, using VLBA observations of v=1 J=1-0, v=2 J=1-0 and v=1 J=2-1 SiO masers towards the high-luminosity source VY CMa.
Variability of Class II methanol masers in massive star forming regions
Authors: Goedhart Sharmila , Gaylard Mike , van der Walt Johan
Published: July 2012

Class II methanol masers are known to be tracers of an early phase of massive star formation. The 6.7- and 12.2-GHz methanol maser transitions can show a significant amount of variability, including periodic variations. Studying maser variability can lead to important insights into conditions in the maser environment but first the maser time-series need to be characterised. The results of long-term monitoring of 8 regularly-varying sources will be presented and methods of period-search discussed.
Binary systems: implications for outflows & periodicities relevant to masers
Authors: Singh Nishant K. , Deshpande Avinash A.
Published: July 2012

Bipolar molecular outflows have been observed and studied extensively in the past, but some recent observations of periodic variations in maser intensity pose new challenges. Even quasi-periodic maser flares have been observed and reported in the literature. Motivated by these data, we have tried to study situations in binary systems with specific attention to the two observed features, i.e., the bipolar flows and the variabilities in the maser intensity. We have studied the evolution of spherically symmetric wind from one of the bodies in the binary system, in the plane of the binary. Our approach includes the analytical study of rotating flows with numerical computation of streamlines of fluid particles using PLUTO code. We present the results of our findings assuming simple configurations, and discuss the implications.
Chasing the flare in Orion KL: Observations of the 22 GHz H2O Masers at HartRAO
Authors: Otto Sunelle , Gaylard Michael J.
Published: July 2012

The work here represents the summary of observations made with the Hartebeesthoek Radio Astronomy Observatory (HartRAO) 26 m telescope of the water vapour (H2O) Masers in the Orion KL source region for a period of 8 months during the flare of 2011. The observation setup, calibration method together with the resulting maser time series are discussed.
Masers in GLIMPSE Extended Green Objects (EGOs)
Authors: Cyganowski Claudia J. , Brogan Crystal L. , Hunter Todd R. , Churchwell Ed , Koda Jin , Rosolowsky Erik , Towers Sarah , Whitney Barb , Zhang Qizhou
Published: July 2012

Large-scale Spitzer surveys of the Galactic plane have yielded a new diagnostic for massive young stellar objects (MYSOs) that are actively accreting and driving outflows: extended emission in the IRAC 4.5 μm band, believed to trace shocked molecular gas. Maser studies of these extended 4.5 μm sources (called EGOs, Extended Green Objects, for the common coding of 3-color IRAC images) have been and remain crucial for understanding the nature of EGOs. High detection rates in VLA CH3OH maser surveys provided the first proof that EGOs were indeed MYSOs driving outflows; our recent Nobeyama 45-m survey of northern EGOs shows that the majority are associated with H2O masers. Maser studies of EGOs also provide important constraints for the longstanding goal of a maser evolutionary sequence for MYSOs, particularly in combination with high resolution (sub)mm data. New SMA results show that Class I methanol masers can be excited by both young (hot core) and evolved (ultracompact HII region) sources within the same massive star-forming region.
44 GHz Methanol Maser Surveys
Authors: Kurtz S. E.
Published: July 2012

Class I 44 GHz methanol masers are not as well-known, as common, or as bright as their more famous Class II cousins at 6.7 and 12.2 GHz. Nevertheless, the 44 GHz masers are commonly found in high-mass star forming regions. At times they appear to trace dynamically important phenomena; at other times they show no obvious link to the star formation process. Here, we summarize the major observational efforts to date, including both dedicated surveys and collateral observations. The principal results are presented, some that were expected, and others that were unexpected.
Dynamical detection of a magnetocentrifugal wind driven by a 20 M⊙ YSO
Authors: Greenhill L. J. , Goddi C. , Chandler C. J. , Humphreys E. M. L. , Matthews L. D.
Published: July 2012

We have tracked the proper motions of ground-state λ7mm SiO maser emission excited by radio Source I in the Orion BN/KL region. Based on dynamical arguments, Source I is believed to be a hard 20 M⊙ binary. The SiO masers trace a linear bipolar outflow (NE-SW) 100 to 1000 AU from the binary. The median 3D velocity is 18 km s−1. An overlying distribution of 1.3 cm H2O masers betrays similar characteristics. The outflow is aligned with the rotation axis of an edge-on disk and wide angle flow known inside 100 AU. Gas dynamics and emission morphology traced by masers around Source I provide dynamical evidence of a magnetocentrifugal disk-wind around this massive YSO, notably a measured gradient in line-of-sight velocity perpendicular to the flow axis, in the same direction as the disk rotation and with comparable speed. The linearity of the flow, despite the high proper motion of Source I and the proximity of dense gas associated with the Orion Hot Core, is also more readily explained for a magnetized flow. The extended arcs of ground-state maser emission bracketing Source I are a striking feature, in particular since dust formation occurs at smaller radii. We propose that the arcs mark two C-type shocks at the transition radius to super-Alfvénic flow.
The W51 Main/South SFR complex seen through 6-GHz OH and methanol masers
Authors: Etoka Sandra , Gray Malcolm D. , Fuller Gary A.
Published: July 2012

W51 Main/South is one of the brightest and richest high-mass star-forming regions (SFR) in the complex W51. It is known to host many ultra-compact HII (UCHII) regions thought to be the site of massive young stellar objects. Maser emission from various species is also found in the region. We have performed MERLIN astrometric observations of excited-OH maser emission at 6.035 GHz and Class II methanol maser emission at 6.668 GHz towards W51 to investigate the relationship between the maser emission and the compact continuum sources in this SFR complex. Here we present the astrometric distributions of both 6.668-GHz methanol and 6.035-GHz excited-OH maser emission in the W51 Main/South region. The location of maser emission in the two lines is compared with that of previously published OH groundstate emission. The interesting coherent velocity and spatial structure observed in the methanol maser distribution as well as the relationship of the masers to infall or outflow in the region are discussed. It appears that the masers are excited by multiple objects potentially at different stages of evolution.
Infrared characteristics of sources associated with OH, H2O, SiO and CH3OH masers
Authors: Esimbek Jarken , Zhou Jian Jun. , Wu Gang. , Tang Xin Di.
Published: July 2012

We collect all published OH, H2O, SiO and CH3OH masers in the literature. The associated infrared sources of these four masers were identified with MSX PSC catalogues. We look for common infrared properties among the sources associated with four masers and make a statistical study. The MSX sources associated with stellar OH, stellar H2O and SiO masers concentrated in a small regions and the MSX sources associated with interstellar OH, interstellar H2O and CH3OH masers also concentrated in a small regions in an [A]-[D].vs.[A][-[E] diagram. These results give us new criterion to search for coexisting stellar maser samples for OH, H2O and SiO masers and interstellar maser samples for OH, H2O and CH3OH masers.
Massive star-formation toward G28.87+0.07
Authors: Li J. J. , Moscadelli L. , Cesaroni R. , Furuya R. S. , Xu Y. , Usuda T. , Menten K. M. , Pestalozzi M. , Eliav D. , Schisano E.
Published: July 2012

We investigated the high-mass star-forming region G28.87+0.07 by means of maser kinematics, including H2O, CH3OH, and OH, and radio to infrared, continuum observations. All observational evidence suggests that these masers are associated with the same young star of 20-30 M⊙, still in the main accretion phase and surrounded by a rich stellar cluster.
A Circumstellar Disk toward the High-mass Star-forming Region IRAS 23033+5951
Authors: Trinidad M. A. , Rodríguez T. , Migenes V.
Published: July 2012

We present water maser observations toward IRAS 23033+5951 carried out with the VLA-EVLA in the A configuration. In order to study the spatio-kinematical distribution of the water masers detected in the region, we made a simple geometrical and kinematical model based on the conical equation. We find that the water masers are tracing a rotating and contracting circumstellar disk of about 110 AU around a very young source of 18 M⊙, which has not enough ionizing photons to be detected at centimeter wavelengths.
Radio and IR interferometry of SiO maser stars
Authors: Wittkowski Markus , Boboltz David A. , Gray Malcolm D. , Humphreys Elizabeth M. L. , Karovicova Iva , Scholz Michael
Published: July 2012

Radio and infrared interferometry of SiO maser stars provide complementary information on the atmosphere and circumstellar environment at comparable spatial resolution. Here, we present the latest results on the atmospheric structure and the dust condensation region of AGB stars based on our recent infrared spectro-interferometric observations, which represent the environment of SiO masers. We discuss, as an example, new results from simultaneous VLTI and VLBA observations of the Mira variable AGB star R Cnc, including VLTI near- and mid-infrared interferometry, as well as VLBA observations of the SiO maser emission toward this source. We present preliminary results from a monitoring campaign of high-frequency SiO maser emission toward evolved stars obtained with the APEX telescope, which also serves as a precursor of ALMA images of the SiO emitting region. We speculate that large-scale long-period chaotic motion in the extended molecular atmosphere may be the physical reason for observed deviations from point symmetry of atmospheric molecular layers, and for the observed erratic variability of high-frequency SiO maser emission.
The first water fountain in a planetary nebula
Authors: Suárez Olga , Francisco Gómez José , Bendjoya Philippe , Miranda Luis. F. , Guerrero Martín. A. , Ramos-Larios Gerardo , Ricardo Rizzo J. , Uscanga Lucero
Published: July 2012

Water fountains are evolved stars showing water masers with velocity spanning more than ~100 km/s. They usually appear at the end of the Asymptotic Giant Branch (AGB) phase or at the beginning of the post-AGB phase, and their masers trace the first manifestation of axisymmetric collimated mass-loss. For the first time, masers with water fountain characteristics have been detected towards a PN (IRAS 15103–5754), which might require a revision of the current theories about jet formation and survival times. IRAS 15103-5754 was observed using the ATCA interferometer at 22 GHz (both continuum and water maser). The main results of these observations are summarized here. The evolutionary classification of this object is also discussed.
Polarization properties of R Cas SiO masers
Authors: Assaf K. A. , Diamond P. J. , Richards A. M. S. , Gray M. D.
Published: July 2012

Silicon monoxide maser emission has been detected in the circumstellar envelopes of many evolved stars. It is a good tracer of the wind dynamics within a few stellar radii of the central star. We investigated the polarization morphology in the circumstellar envelope of an AGB star, R Cas, by using the VLBA to map the linear and circular polarization of the v=1, J=1-0 SiO maser transition during 23 epochs over two stellar cycles. The average fractional circular polarization is a few percent. The average fractional linear polarization per epoch is 11–58%, but some isolated features exceed 100%, probably because the total intensity emission is smoother and more resolved-out. The maser electric polarization vector angle has a preferrential tendency to be either parallel or perpendicular to the radial direction to the star.
High Resolution Radio and IR Observations of AGB Stars
Authors: Cotton W. , Perrin G. , Millan-Gabet R. , Delaa O. , Mennesson B.
Published: July 2012

Asymptotic Giant Branch Stars (AGB) are evolved, mass losing red giants with tenuous molecular envelopes which have been the subject of much recent study using infrared and radio interferometers. In oxygen rich stars, radio SiO masers form in the outer regions of the molecular envelopes and are powerful diagnostics of the extent of these envelopes. Spectroscopically resolved infrared interferometry helps constrain the extent of various species in the molecular layer. We made VLBA 7 mm SiO maser, Keck Interferometer near IR and VLTI/MIDI mid IR high resolution observations of the stars U Ari, W Cnc, RX Tau, RT Aql, S Ser and V Mon. This paper presents evidence that the SiO is depleted from the gas phase and speculate that it is frozen onto Al2O3 grains and that radiation pressure on these grains help drive the outflow.