bluuebunny/crossref_metadata_2025 huggingface dataset:
The Attic Orgeones
Authors: Ferguson William Scott
Published: August 2011

Who are these coming to the sacrifice?

To what green altar, O mysterious priest,

Lead'st thou that heifer lowing at the skies,

And all her silken flanks with garlands drest?

An inscription from the Areopagus recently published by Meritt in Hesperia (XI, 1942, 282 ff.) has thrown new light on the structure of the type of association of which the members were called orgeones. The occasion thus presents itself to bring together what we now know about this obscure Athenian institution.
“Probationers for Eternity.” Notes on Religion in the United States in the Year 1800
Authors: Oliver Peter
Published: August 2011

By 1800 the Puritan experiment in theocracy was over. It had been a great adventure in Utopianism, like none other in the centuries since Christ, noble in the magnitude of its vision of a Christian State, extraordinary in the accidental circumstance of its situation, the fertile unspoiled wilderness of a new world in which to work, and for a time successful in awakening in men's souls a hunger and a thirst for righteousness.
The Throne of the Emperor Henry in Dante's Paradise and the Mediaeval Conception of Christian Kingship
Authors: Silverstein Theodore
Published: August 2011

Nowhere has Dante offered more ample evidence of his faith in the Roman imperium and admiration of the Emperor Henry VII than in a brief passage of six lines in the thirtieth canto of the Paradiso. There, beyond the limits of the corporeal spheres in the heaven which is pure light, surrounded by the saintly splendors of the City of God, Beatrice directs the poet's gaze to a vacant seat among the thrones of the blessed:

E'n quel gran seggio a che tu li occhi tieni

Per la corona che già v' è su posta,

Prima che tu a queste nozze ceni

Sederà l' alma (che fia giù agosta)

De l' alto Arrigo, ch' a drizzare Italia

Verrà in prima che ella sia disposta.

(vv. 133–138)

And the power of these lines is consolidated by contrast with the bitter condemnation of Pope Clement V, which directly follows them.
The Coverdale Translation of Psalm LXXXIV
Authors: Smothers Edgar R.
Published: August 2011

The Coverdale Bible of 1535 in itself, in its sources, in its enduring vitality, is one of the remarkable monuments of the Protestant Reformation in England. Any historical study of it must set one at the heart of that astonishing release of human energies that put an end to an older epoch of Christendom and, along with other influences, set us on the road to our modern complexity of forces whose issue we do not descry. The new vernacular Bibles of the sixteenth century, embedded in the new doctrine of the private reader's emancipation from authority, were manifestly one of the chief engines of the popular appeal of Protestantism, which was to be in the event so sweepingly successful throughout northern Europe.
Boethius' Fourth Tractate, the So-Called De Fide Catholica
Authors: Bark William
Published: August 2011

The exact status of the fourth tractate included among the Opuscula Sacra of Boethius is still uncertain, though the other theological works are now almost universally accepted as genuine. Boethian scholars of the late nineteenth and early twentieth centuries were generally inclined to reject Tractate IV. Viktor Schurr, in the outstanding recent work devoted to the theological treatises, takes the same view, basing his judgment upon the lack of a title indicating authorship and upon the notation ‘actenus Boetius’ found between Tr. III and IV in Codex Augiensis XVIII (saec. IX). Schurr, like some of his predecessors, was strongly influenced in this conclusion by the doctoral dissertation of E. K. Rand. In that study Professor Rand attacked the authenticity of the unsigned treatise with vigor but also with prudence, tempering, in certain instances, the views of earlier proponents of his own position. Though he concluded that Tr. IV was not genuine, he made no secret of the uncertainties of the case.
The Mithraic Symbolism of Mercury Carrying the Infant Bacchus
Authors: Bober Phyllis Pray
Published: August 2011

An interesting sidelight on our knowledge of the mystery cult of Mithras in antiquity is provided by a group of provincial Roman sculptures which represent Mercury carrying the infant Bacchus. The popularity of the representation, attested by at least thirteen votive reliefs and three statues, and the concentration of these monuments in the region which is today Alsace-Lorraine are facts which need explanation. The subject is not unknown in other provinces of the Roman Empire, but it appears in isolated examples of sculpture and minor arts unlike the unified group from Germania Superior and adjacent territory, which in geographical distribution and in iconography is unique.
Philo on Immortality
Authors: Goodenough Erwin R.
Published: August 2011

The writings of mystics always seem nonsense to the non-mystical, and apparently nothing will ever explain the one to the other. The chief difficulty is, perhaps, the freedom with which the mystic contradicts himself, and this he does largely for three reasons. First, the mystic despairs of language as an expression of his ideas, and often treats words and figures of speech loosely just because they mean little to him themselves, since he apprehends most completely in silence. Yet sometimes, in the second place, the inconsistency is studied, and the mystic is trying to suggest an a-verbal idea, doing so by a process which may be compared to the “resultant” of stresses in physics: for by two pulls at an angle to each other one may move an object between them in a direction different from either pull. Or, the same figure, one may make a wind blow a sail-boat in a path directly against itself by going off on a sufficient number of mutually correcting tacks. In the same way the mystic often feels that one of the best devices he can use to express himself is to build up verbal inconsistencies. So he declares that he goes to glory through humiliation, loses himself in order to find himself, dies in order to live, and in these statements creates an impression different from the literal meaning of any single word he uses. In art he similarly makes a monogram of cross and crown.
Luke and the Samaritans
Authors: Enslin Morton S.
Published: August 2011

There are comparatively few matters of any real importance in the confused story of the Christian beginnings concerning which responsible critics would care to say, “It is established beyond peradventure of a doubt.” Wilhelm Wrede, though dead, yet speaketh. And there is the wholesome apprehension that such a rash utterance may prove a boomerang: some disciple of the dead master who so hated those smug confidences is sure to step forward, indued with a double portion of his spirit, to challenge, if not to deflate, the incautious scholar.
The Date of the Adonia at Athens
Authors: Walton Francis Redding
Published: August 2011

Three dates have been suggested for the celebration of the festival of Adonis at Athens, all of which have found adherents in recent years. Deubner, relying solely on the apparent evidence of vase-paintings, as interpreted by Hauser, placed the Adonia at the beginning of autumn. The only argument in favor of so late a date, that bunches of fresh grapes appeared in representations of the κῆποι 'Aδώνιδος' was disposed of by Nock, who pointed out that grapes were also kept until the feast of Choes, Anthesterion 12.
Long-term clinical results of radiofrequency tissue volume reduction for inferior turbinate hypertrophy
Authors: Cukurova I , Demirhan E , Cetinkaya E A , Yigitbasi O G
Published: August 2011

Objective:

To investigate the long-term clinical results of radiofrequency tissue volume reduction for symptomatic inferior turbinate hypertrophy.

Study design:

Patients who were unresponsive to medical treatment (n = 197) received turbinate reduction using radiofrequency energy. Subjective symptoms were assessed using a 10 cm visual analogue scale, and all patients underwent acoustic rhinometry before the procedure and six, 24, 48 and 60 months afterwards.

Results:

Of the 197 treated patients, 148 completed the protocol. No significant peri-operative complications were observed. Thirty-two patients required follow-up treatment. Significant improvements were seen in nasal obstruction and discharge scores and in acoustic rhinometry values, at six, 24, 48 and 60 months post-operatively, compared with pre-operative values (p < 0.001 and p < 0.05, respectively).

Conclusion:

Radiofrequency tissue volume reduction is an effective procedure for inferior turbinate hypertrophy. The clinical benefit of this procedure persisted 60 months after the procedure.
Iatrogenic injury of the chorda tympani: a systematic review
Authors: McManus L J , Stringer M D , Dawes P J D
Published: August 2011

Objective:

To review the currently available literature on iatrogenic injury of the adult chorda tympani.

Design:

Systematic literature review.

Method

Five electronic databases and one search engine were used to access available English language literature on the chorda tympani, focusing on iatrogenic injury.

Results:

The chorda tympani is most often injured during middle-ear surgery, after which at least 15–22 per cent of patients experience symptoms, mostly changes in taste and dryness of the mouth. Numerous factors influence whether injury to the chorda tympani causes symptoms, including the extent of injury, type of surgery, age of the patient, anatomical variables and subjective adaptation. Although most patients experience gradual symptomatic recovery, complaints can be persistent and troublesome.

Conclusion:

Care should be taken to preserve the chorda tympani during middle-ear surgery, and to warn patients pre-operatively about this potential complication. This is particularly important if surgery is bilateral.
Endoscopic devascularisation of sphenopalatine bundle in intractable posterior epistaxis: technique, efficacy and safety
Authors: Eladl H M , Elmorsy S M , Khafagy Y W
Published: August 2011

Objective:

To evaluate endoscopic cauterisation of the sphenopalatine neurovascular bundle, as treatment for intractable posterior epistaxis, with regard to efficacy, safety and post-operative sequelae.

Patients and methods:

A prospective study reviewed 42 patients with severe posterior epistaxis who were treated with endoscopic cauterisation of the sphenopalatine neurovascular bundle, over a 17-month period.

Results:

Hypertension and hepatic disease were present as predisposing factors in 66.7 and 35.7 per cent of patients, respectively. Branching of the sphenopalatine artery at its foramen was present in more than 85 per cent of patients. The success rate was 100 per cent, with no recurrent epistaxis in the follow-up period. Severe nasal dryness was present in only four patients (9.5 per cent); hypoaesthesia was found in the nasal mucosa of eight patients, without any patient complaints.

Conclusion:

Endoscopic sphenopalatine neurovascular bundle cauterisation is an effective treatment for refractory posterior epistaxis. In this study, neurovascular bundle cauterisation did not cause any neurological deficits or major complications.
Clinical study of mucosa-associated lymphoid tissue lymphomas of the head and neck
Authors: Hosokawa S , Okamura J , Takizawa Y , Takahashi G , Hosokawa K , Mineta H
Published: August 2011

Background:

Limited information is available on mucosa-associated lymphoid tissue lymphomas arising in the head and neck.

Method:

A retrospective analysis was conducted of 20 patients who were histologically diagnosed with mucosa-associated lymphoid tissue lymphoma and treated at our institution between January 1990 and December 2009.

Results:

Treatment consisted of surgical resection alone in two patients (10 per cent), surgical resection with consecutive radiotherapy in one (5 per cent), and radiotherapy alone in eight (40 per cent). Three patients (15 per cent) were treated with systemic chemotherapy, and three (15 per cent) received chemoradiotherapy. Three patients (15 per cent) were informed of the diagnosis but not treated for their condition.

Conclusion:

All of the 20 patients were still alive after a mean follow-up period of 50.8 months. Local treatment for mucosa-associated lymphoid tissue lymphoma of the head and neck should be the first choice in early-stage disease. However, prolonged follow up is important to determine these patients' long-term response to treatment.
Voice function following Han's uvulopalatopharyngoplasty
Authors: Han D , Xu W , Hu R , Zhang L
Published: August 2011

Objective:

To investigate voice function following Han's uvulopalatopharyngoplasty.

Patients and methods:

Acoustic and articulatory function was examined by acoustic analysis and by formant frequency and bandwidth analysis, before and after Han's uvulopalatopharyngoplasty, in 56 patients with obstructive sleep apnoea hypopnoea syndrome.

Results:

These patients' normalised noise energy was higher than normal, and improved post-operatively. Their pre-operative F1, F2, and F3 formant frequencies and B1 and B2 formant bandwidths were significantly lower than those of normal controls; however, one month after surgery their F1 and F2 frequencies were markedly higher.

Conclusion:

The acoustic and articulatory characteristics of obstructive sleep apnoea hypopnoea syndrome patients differed from those of normal subjects. After Han's uvulopalatopharyngoplasty, obstructive factors in the oropharynx were relieved, allowing oropharyngeal cavity expansion and a gradual increase in formant frequency to within the normal range. Patients' vocal quality improved and their resonator and articulator functions were protected and enhanced.
The molecular systematics of blowflies and screwworm flies (Diptera: Calliphoridae) using28S rRNA, COX1andEF-1α: insights into the evolution of dipteran parasitism
Authors: McDONAGH LAURA M. , STEVENS JAMIE R.
Published: August 2011

The Calliphoridae include some of the most economically significant myiasis-causing flies in the world – blowflies and screwworm flies – with many being notorious for their parasitism of livestock. However, despite more than 50 years of research, key taxonomic relationships within the family remain unresolved. This study utilizes nucleotide sequence data from the protein-coding genesCOX1(mitochondrial) andEF1α(nuclear), and the28S rRNA(nuclear) gene, from 57 blowfly taxa to improve resolution of key evolutionary relationships within the family Calliphoridae. Bayesian phylogenetic inference was carried out for each single-gene data set, demonstrating significant topological difference between the three gene trees. Nevertheless, all gene trees supported a Calliphorinae-Luciliinae subfamily sister-lineage, with respect to Chrysomyinae. In addition, this study also elucidates the taxonomic and evolutionary status of several less well-studied groups, including the genusBengalia(either within Calliphoridae or as a separate sister-family), genusOnesia(as a sister-genera to, or sub-genera within,Calliphora), genusDyscritomyiaandLucilia bufonivora, a specialised parasite of frogs and toads. The occurrence of cross-species hybridisation within Calliphoridae is also further explored, focusing on the two economically significant speciesLucilia cuprinaandLucilia sericata. In summary, this study represents the most comprehensive molecular phylogenetic analysis of family Calliphoridae undertaken to date.
Alcohol-use disorder severity predicts first-incidence of depressive disorders
Authors: Boschloo L. , van den Brink W. , Penninx B. W. J. H. , Wall M. M. , Hasin D. S.
Published: August 2011

Background

Previous studies suggest that alcohol-use disorder severity, defined by the number of criteria met, provides a more informative phenotype than dichotomized DSM-IV diagnostic measures of alcohol use disorders. Therefore, this study examined whether alcohol-use disorder severity predicted first-incident depressive disorders, an association that has never been found for the presence or absence of an alcohol use disorder in the general population.

Method

In a national sample of persons who had never experienced a major depressive disorder (MDD), dysthymia, manic or hypomanic episode (n=27 571), we examined whether a version of DSM-5 alcohol-use disorder severity (a count of three abuse and all seven dependence criteria) linearly predicted first-incident depressive disorders (MDD or dysthymia) after 3-year follow-up. Wald tests were used to assess whether more complicated models defined the relationship more accurately.

Results

First-incidence of depressive disorders varied across alcohol-use disorder severity and was 4.20% in persons meeting no alcohol-use disorder criteria versus 44.47% in persons meeting all 10 criteria. Alcohol-use disorder severity significantly predicted first-incidence of depressive disorders in a linear fashion (odds ratio 1.14, 95% CI 1.06–1.22), even after adjustment for sociodemographics, smoking status and predisposing factors for depressive disorders, such as general vulnerability factors, psychiatric co-morbidity and subthreshold depressive disorders. This linear model explained the relationship just as well as more complicated models.

Conclusions

Alcohol-use disorder severity was a significant linear predictor of first-incident depressive disorders after 3-year follow-up and may be useful in identifying a high-risk group for depressive disorders that could be targeted by prevention strategies.
Let us not put the probabilistic cart before the uncertainty bull
Authors: Politzer Guy , Bonnefon Jean-François
Published: August 2011

Although we endorse the primacy of uncertainty in reasoning, we argue that a probabilistic framework cannot model the fundamental skill of proof administration. Furthermore, we are skeptical about the assumption that standard probability calculus is the appropriate formalism to represent human uncertainty. There are other models up to this task, so let us not repeat the excesses of the past.
International migration and health inequalities in later life
Authors: LANARI DONATELLA , BUSSINI ODOARDO
Published: August 2011

The aim of this paper is to ascertain the existence of differences in self-perceived health and depression between immigrants and native-born populations aged 50 years and older living in Western and Northern European countries. We examine the effect of country of origin, length of time in the host country and citizenship on the health of adults, using data from the Survey on Health, Ageing and Retirement in Europe (SHARE). As the logistic regressions reveal, some immigrant groups are more likely to perceive worse self-rated health and to suffer from depression than native-born groups, even when demographic and socio-economic variables are taken into account. In particular, people born in Eastern Europe living in Germany, France and Sweden have the highest odds ratio of poor health with respect to natives. Nativity status, duration and citizenship clearly contribute towards explaining health differences which are shown to vary significantly across countries. Furthermore, the perception of poor health rises as the length of stay increases, although a non-linear pattern was found. Results indicate that greater efforts by policy makers are needed in order to improve the health of specific middle-aged and older groups of immigrants in Europe.
Symposium – Bloomsbury Round Table on communication, cognition and culture: The multiple faces of multilingualism
Authors: Peek Ron
Published: August 2011

Hosted by Birkbeck College, University of London, and co-organised by the International Association of Multilingualism, the AILA Research network ‘Multilingualism: Acquisition and Use’ and the Centre for Multilingual & Multicultural Research, Birkbeck; 24–25 June 2010.
Kinematic coupling complexity of heavy-payload forging manipulator
Authors: Chu Xiaobing , Gao Feng
Published: August 2011

There exist several kinds of definitions for complexity in different areas. In mechanical engineering area, some formulations capable of measuring the complexity of robotic architectures have been proposed at the conceptual-design stage. This paper presents the definition of Kinematic Coupling Complexity to measure the kinematic coupling degree of a manipulator based on the input/output velocity matrix. In order to distinguish the differences among many matrixes, three factors will be considered including the proportion of nonzero elements in matrix J, the difference of nonzero elements' numbers in every row among many matrixes, and the difference of nonzero elements' positions among many matrixes. To illustrate the methods introduced in this paper, four types of heavy-payload forging manipulators are analyzed and the type of forging manipulator with the smallest Kinematic Coupling Complexity is chosen as our prototype.
Pinned fluxons in a Josephson junction with a finite-length inhomogeneity
Authors: DERKS GIANNE , DOELMAN ARJEN , KNIGHT CHRISTOPHER J. K. , SUSANTO HADI
Published: August 2011

We consider a Josephson junction system installed with a finite length inhomogeneity, either of micro-resistor or micro-resonator type. The system can be modelled by a sine-Gordon equation with a piecewise-constant function to represent the varying Josephson tunneling critical current. The existence of pinned fluxons depends on the length of the inhomogeneity, the variation in the Josephson tunneling critical current and the applied bias current. We establish that a system may either not be able to sustain a pinned fluxon, or – for instance by varying the length of the inhomogeneity – may exhibit various different types of pinned fluxons. Our stability analysis shows that changes of stability can only occur at critical points of the length of the inhomogeneity as a function of the (Hamiltonian) energy density inside the inhomogeneity – a relation we determine explicitly. In combination with continuation arguments and Sturm–Liouville theory, we determine the stability of all constructed pinned fluxons. It follows that if a given system is able to sustain at least one pinned fluxon, a microresistor has exactly one pinned fluxon, i.e. the system selects one unique pinned stable pinned configuration, and a microresonator has at least one stable pinned configuration. Moreover, it is shown that both for micro-resistors and micro-resonators this stable pinned configuration may be non-monotonic – something which is not possible in the homogeneous case. Finally, it is shown that results in the literature on localised inhomogeneities can be recovered as limits of our results on micro-resonators.
Water infiltration and surface-soil structural properties as influenced by animal traffic in the Southern Piedmont USA
Authors: Franzluebbers Alan J. , Stuedemann John A. , Franklin Dorcas H.
Published: August 2011

Surface-soil structural condition in perennial pastures is expected to be modified by how forage is (a) harvested through haying or grazing and (b) stimulated through source of nutrients applied, as well as by compactive forces, e.g., grazing cattle or hay harvest machinery. Changes in surface-soil condition can affect hydrologic processes that have important implications for plant growth, greenhouse gas emissions and off-site water quality. We determined the effects of harvest management and nutrient source on the rate of ponded water infiltration and penetration resistance in a bermudagrass [Cynodon dactylon (L.) Pers.]/tall fescue (Lolium arundinaceum Schreb. S.J. Darbyshire) pasture on a Typic Kanhapludult in Georgia. During a period when soil was wet (61% water-filled pore space), the rate of water infiltration was 2.8 ± 1.5 times greater when forage was left unharvested as when hayed or grazed (mean ± standard deviation among nine nutrient source × harvest management comparisons). During a subsequent period, when soil was dry (28% water-filled pore space), the rate of water infiltration followed the same treatment pattern, but was not statistically different among harvest-management practices (1.5 ± 0.4 times greater between unharvested and other systems). Penetration resistance of the surface at 10 cm depth followed the order: unharvested (62 J) < hayed (100 J) < low grazing pressure (119 J) < high grazing pressure (137 J). Water infiltration during the wet period was negatively related (P ⩽ 0.01) to soil-water content (r = − 0.57), penetration resistance at 0–10 cm depth (r = − 0.50) and bulk density at 3–6 cm depth (r = − 0.53), but was positively related to surface residue C (r = 0.47) and soil organic C concentration at 12–20 cm depth (r = 0.42). These results suggest that complex soil physical (i.e., aggregation, penetration resistance and infiltration) and biological (i.e., plant growth, surface residues and soil organic matter) interactions occur in pastures. We conclude that well-managed grazing systems with excellent ground cover should have adequate hydrologic condition to promote pasture productivity and limit environmental contamination from runoff. Further work is needed to understand the linkages between field- and watershed-scale hydrology in perennial pastures and their implications on water quality.
The role of green roof technology in urban agriculture
Authors: Whittinghill Leigh J. , Rowe D. Bradley
Published: August 2011

Urban agriculture is a global and growing pursuit that can contribute to economic development, job creation, food security and community building. It can, however, be limited by competition for space with other forms of urban development, a lack of formalized land use rights and health hazards related to food contamination. The use of green roof technology in urban agriculture has the potential to alleviate some of these problems, without adversely affecting the benefits provided by urban agriculture. It would not only enable the use of land for development and agriculture, but may also facilitate the formation of formal space and water use agreements, and enable redistribution of ground-level resources among urban farmers. This could decrease the use of contaminated land and water at ground level and alleviate health concerns. Before green roof technology can be incorporated into urban agriculture on a larger scale, installation costs must be reduced, roof weight limitations should be assessed, and appropriate management practices should be developed which will ensure that the benefits of green roofs, such as energy savings and storm water management, are still provided to urban communities.
Frequent cultivation prior to planting to prevent weed competition results in an opportunity for the use of arbuscular mycorrhizal fungus inoculum
Authors: Douds David D. , Nagahashi Gerald , Shenk John E.
Published: August 2011

Inoculation with arbuscular mycorrhizal (AM) fungi is a potentially useful tool in agricultural systems with limited options regarding use of synthetic chemicals for fertility and pest control. We tested the response ofAllium porrumcv. Lancelot to inoculation with AM fungi in a field high in available P (169 μg g−1soil) that had been repeatedly cultivated to control weeds. Seedlings were inoculated during the greenhouse production period with a mixed species inoculum produced on-farm in a compost and vermiculite medium withPaspalum notatumFlugge as a nurse host. Inoculated and uninoculated seedlings were the same size at outplanting. Inoculated seedlings were over 2.5-fold greater in shoot weight and shoot P content than uninoculated seedlings at harvest. These results demonstrate the potential yield benefits from inoculation with AM fungi in situations where farm management practices may negatively impact on indigenous populations of AM fungi.
Cosmic magnetic fields in the Sun: Current Outstanding Problems (Invited Review)
Authors: Priest Eric
Published: August 2011

In the Sun there has been much progress towards answering fundamental problems with profound implications for the behaviour of cosmic magnetic fields in other stars. A review is given here of such problems, including identifying some of the outstanding questions that remain. In the solar interior, the main dynamo operates at the base of the convection zone, but its details have not been identified. In the solar surface, recent observations have revealed many new and surprising properties of magnetic fields, but understanding the key processes of flux emergence, fragmentation, merging and cancellation is rudimentary. Sunspots have until very recently been an enigma. In the atmosphere, there are many new ideas for coronal heating and solar wind acceleration, but the mechanisms have not yet been pinned down. Also, the detailed mechanisms for solar flares and coronal mass ejections remain controversial. In future, new generations of space and ground-based measurements and computational modelling should enable a definitive physical understanding of these puzzles.
Rapid changes of sunspot structure associated with solar eruptions
Authors: Wang Haimin , Liu Chang
Published: August 2011

In this paper we summarize the studies of flare-related changes of photospheric magnetic fields. When vector magnetograms are available, we always find an increase of transverse field at the polarity inversion line (PIL). We also discuss 1 minute cadence line-of-sight MDI magnetogram observations, which usually show prominent changes of magnetic flux contained in the flaring δ spot region. The observed limb-ward flux increases while disk-ward flux decreases rapidly and irreversibly after flares. These observations provides evidences, either direct or indirect, for the theory and prediction of Hudson, Fisher & Welsch (2008) that the photospheric magnetic fields would respond to coronal field restructuring and turn to a more horizontal state near the PIL after eruptions. From the white-light observations, we find that at flaring PIL, the structure becomes darker after an eruption, while the peripheral penumbrae decay. Using high-resolution Hinode data, we find evidence that only dark fibrils in the “uncombed” penumbral structure disappear while the bright grains evolve to G-band bright points after flares.
Helicity of the solar magnetic field
Authors: Tiwari Sanjiv Kumar
Published: August 2011

Helicity measures complexity in the field. Magnetic helicity is given by a volume integral over the scalar product of magnetic field B and its vector potential A. A direct computation of magnetic helicity in the solar atmosphere is not possible due to unavailability of the observations at different heights and also due to non-uniqueness of A. The force-free parameter α has been used as a proxy of magnetic helicity for a long time. We have clarified the physical meaning of α and its relationship with the magnetic helicity. We have studied the effect of polarimetric noise on estimation of various magnetic parameters. Fine structures of sunspots in terms of vertical current (Jz) and α have been examined. We have introduced the concept of signed shear angle (SSA) for sunspots and established its importance for non force-free fields. We find that there is no net current in sunspots even in presence of a significant twist, showing consistency with their fibril-bundle nature. The finding of existence of a lower limit of SASSA for a given class of X-ray flare will be very useful for space weather forecasting. A good correlation is found between the sign of helicity in the sunspots and the chirality of the associated chromospheric and coronal features. We find that a large number of sunspots observed in the declining phase of solar cycle 23 do not follow the hemispheric helicity rule whereas most of the sunspots observed in the beginning of new solar cycle 24 do follow. This indicates a long term behaviour of the hemispheric helicity patterns in the Sun. The above sums up my PhD thesis.
On the manifestation in the Sun-as-a-star magnetic field measurements of the quiet and active regions
Authors: Demidov Mikhail
Published: August 2011

The best way to test the stellar magnetic field mapping codes is to apply them, with some changes, to the Sun, where high-precision disk-integrated and disk-resolved observations are available for a long time. Data sets of the full-disk magnetograms and the solar mean magnetic fields (SMMF) measurements are provided, for example, by the J.M.Wilcox Solar observatory (WSO) and by the Sayan Solar observatory (SSO). In the second case the measurements in the Stokes-meter mode simultaneously in many spectral lines are available. This study is devoted to analysis of the SSO quasi-simultaneous full-disk magnetograms and SMMF measurements. Changes of the SMMF signal with rotation of the surface large-scale magnetic fields are demonstrated. Besides, by deleting of selected pixels with active regions (AR) from the maps their contribution to the integrated SMMF signal is evaluated. It is shown that in some cases the role of AR can be rather significant.
Starspots, cycles, and magnetic fields
Authors: Saar Steven H.
Published: August 2011

I make a perhaps slightly foolhardy attempt to synthesize a semi-coherent scenario relating cycle characteristics, starspots, and the underlying magnetic fields with stellar properties such as mass and rotation. Key to this attempt is to first study single dwarfs; differential rotation plays a surprising role.
Starspot variability and evolution from modeling Kepler photometry of active late-type stars
Authors: Brown Alexander , Korhonen Heidi , Berdyugina Svetlana , Tofany Barton , Ayres Thomas R. , Kowalski Adam , Hawley Suzanne , Harper Graham , Piskunov Nikolai
Published: August 2011

The Kepler satellite provides a unique opportunity to study the detailed optical photometric variability of late-type stars with unprecedentedly long (several year) continuous monitoring and sensitivity to very small-scale variations. We are studying a sample of over two hundred cool (mid-A - late-K spectral type) stars using Kepler long-cadence (30 minute sampling) observations. These stars show a remarkable range of photometric variability, but in this paper we concentrate on rotational modulation due to starspots and flaring. Modulation at the 0.1% level is readily discernable. We highlight the rapid timescales of starspot evolution seen on solar-like stars with rotational periods between 2 and 7 days.
The negative magnetic pressure effect in stratified turbulence
Authors: Kemel K. , Brandenburg A. , Kleeorin N. , Rogachevskii I.
Published: August 2011

While the rising flux tube paradigm is an elegant theory, its basic assumptions, thin flux tubes at the bottom of the convection zone with field strengths two orders of magnitude above equipartition, remain numerically unverified at best. As such, in recent years the idea of a formation of sunspots near the top of the convection zone has generated some interest. The presence of turbulence can strongly enhance diffusive transport mechanisms, leading to an effective transport coefficient formalism in the mean-field formulation. The question is what happens to these coefficients when the turbulence becomes anisotropic due to a strong large-scale mean magnetic field. It has been noted in the past that this anisotropy can also lead to highly non-diffusive behavior. In the present work we investigate the formation of large-scale magnetic structures as a result of a negative contribution of turbulence to the large-scale effective magnetic pressure in the presence of stratification. In direct numerical simulations of forced turbulence in a stratified box, we verify the existence of this effect. This phenomenon can cause formation of large-scale magnetic structures even from initially uniform large-scale magnetic field.
Study of stellar activity through transit mapping of starspots
Authors: Valio Adriana
Published: August 2011

During the eclipse of a planet, spots and other features on the surface of the host star may be occulted. This will cause small variations in the light curve of the star. Detailed studies of these variations during planetary transits provide a wealth of information about the starspots properties such as size, position, temperature (i.e. intensity), and magnetic field. If observation of multiple transits is available, the spots lifetime can be estimated. Moreover it may also be possible to determine the stellar rotation and whether differential rotation is present. Here, the study is performed using a method that simulates the passage of a planet (dark disk) in front of a star with multiple spots of different sizes, intensities, and positions on its surface. The data variations in the light curve of the star are fit using this method, yielding the starspots properties. Results are presented for solar-like stars, such as the active star CoRoT-2a.
Long-term evolution of sunspot magnetic fields
Authors: Penn Matthew J. , Livingston William
Published: August 2011

Independent of the normal solar cycle, a decrease in the sunspot magnetic field strength has been observed using the Zeeman-split 1564.8nm Fe I spectral line at the NSO Kitt Peak McMath-Pierce telescope. Corresponding changes in sunspot brightness and the strength of molecular absorption lines were also seen. This trend was seen to continue in observations of the first sunspots of the new solar Cycle 24, and extrapolating a linear fit to this trend would lead to only half the number of spots in Cycle 24 compared to Cycle 23, and imply virtually no sunspots in Cycle 25.

We examined synoptic observations from the NSO Kitt Peak Vacuum Telescope and initially (with 4000 spots) found a change in sunspot brightness which roughly agreed with the infrared observations. A more detailed examination (with 13,000 spots) of both spot brightness and line-of-sight magnetic flux reveals that the relationship of the sunspot magnetic fields with spot brightness and size remain constant during the solar cycle. There are only small temporal variations in the spot brightness, size, and line-of-sight flux seen in this larger sample. Because of the apparent disagreement between the two data sets, we discuss how the infrared spectral line provides a uniquely direct measurement of the magnetic fields in sunspots.
Twist and writhe of δ-island active regions
Authors: López Fuentes M. C. , Mandrini C. H. , Démoulin P.
Published: August 2011

We study the magnetic helicity properties of a set of peculiar active regions (ARs) including δ-islands and other high-tilt bipolar configurations. These ARs are usually identified as the most active in terms of flare and CME production. Due to their observed structure, they have been associated with the emergence of magnetic flux tubes that develop a kink instability. Our main goal is to determine the chirality of the twist and writhe components of the AR magnetic helicity in order to set constrains on the possible mechanisms producing the flux tube deformations. We determine the magnetic twist comparing observations of the AR coronal structure with force-free models of the magnetic field. We infer the flux-tube writhe from the rotation of the main magnetic bipole during the observed evolution. From the relation between the obtained twist and writhe signs we conclude that the development of the kink instability cannot be the single mechanism producing deformed flux-tubes.
Magnetic field evolution of active regions and sunspots in connection with chromospheric and coronal activities
Authors: Shimizu Toshifumi
Published: August 2011

Ca II H imaging observations by the Hinode Solar Optical Telescope (SOT) have revealed that the chromosphere is extremely dynamic and that ejections and jets are well observed in moat region around sunspots. X-ray and EUV observations show frequent occurrence of microflaring activities around sunspots; small emerging flux or moving magnetic features approaching opposite pre-existing magnetic flux can be identified on the footpoints for half of microflares studied, while no encounters of opposite polarities are observed at footpoints for the others even with SOT high spatial magnetorams (Kano et al. 2010). Another observations tell the involvement of twisted magnetic fields in the microflares accompanied by no polarity encounters at the footpoints. Some type of sunspot light bridges shows recurrent occurrence of chromospheric ejections, and photospheric vector magnetic field data suggests that twsited magnetic flux tubes lying along light bridge play vital roles in producing such ejections (Shimizu et al. 2009). This presentation reviewed observational findings from these studies. We will need to understand the 3D configuration of magnetic fields for better understanding of activity triggers in the solar atmosphere.
The zoo of starspots
Authors: Strassmeier Klaus G.
Published: August 2011

Starspots are being observed with many different techniques but not always with coherent results. In particular not if model-dependent data analysis must be employed, e.g. through two-dimensional spot modelling of one-dimensional photometric light curves. I review the zoo of currently available physical spot parameters, i.e. their size, temperature and variability time scales, and also compare results from different techniques. Most of the current values come from Doppler imaging and multi-color photometry. I also list a few cases where starspot detections turned out to be very different to the solar analog.
Exploring the magnetic topologies of cool stars
Authors: Morin J. , Donati J.-F. , Petit P. , Albert L. , Auriére M. , Cabanac R. , Catala C. , Delfosse X. , Dintrans B. , Fares R. , Forveille T. , Gastine T. , Jardine M. , Konstantinova-Antova R. , Lanoux J. , Lignires F. , Morgenthaler A. , Paletou F. , Velez J.C. Ramirez , Solanki S.K. , Thado S. , Van Grootel V.
Published: August 2011

Magnetic fields of cool stars can be directly investigated through the study of the Zeeman effect on photospheric spectral lines using several approaches. With spectroscopic measurement in unpolarised light, the total magnetic flux averaged over the stellar disc can be derived but very little information on the field geometry is available. Spectropolarimetry provides a complementary information on the large-scale magnetic topology. With Zeeman-Doppler Imaging (ZDI), this information can be retrieved to produce a map of the vector magnetic field at the surface of the star, and in particular to assess the relative importance of the poloidal and toroidal components as well as the degree of axisymmetry of the field distribution.

The development of high-performance spectropolarimeters associated with multi-lines techniques and ZDI allows us to explore magnetic topologies throughout the Hertzsprung-Russel diagram, on stars spanning a wide range of mass, age and rotation period. These observations bring novel constraints on magnetic field generation by dynamo effect in cool stars. In particular, the study of solar twins brings new insight on the impact of rotation on the solar dynamo, whereas the detection of strong and stable dipolar magnetic fields on fully convective stars questions the precise role of the tachocline in this process.
The Butterfly diagram leopard skin pattern
Authors: Ternullo Maurizio
Published: August 2011

A time-latitude diagram where spotgroups are given proportional relevance to their area is presented. The diagram reveals that the spotted area distribution is higly dishomogeneous, most of it being concentrated in few, small portions (“knots”) of the Butterfly Diagram; because of this structure, the BD may be properly described as a cluster of knots. The description, assuming that spots scatter around the “spot mean latitude” steadily drifting equatorward, is challenged. Indeed, spots cluster around at as many latitudes as knots; a knot may appear at either lower or higher latitudes than previous ones, in a seemingly random way; accordingly, the spot mean latitude abruptly drifts equatorward or even poleward at any knot activation, in spite of any smoothing procedure. Preliminary analyses suggest that the activity splits, in any hemisphere, into two or more distinct “activity waves”, drifting equatorward at a rate higher than the spot zone as a whole.
Turbulence and magnetic spots at the surface of hot massive stars
Authors: Cantiello Matteo , Braithwaite Jonathan , Brandenburg Axel , Del Sordo Fabio , Käpylä Petri , Langer Norbert
Published: August 2011

Hot luminous stars show a variety of phenomena in their photospheres and in their winds which still lack clear physical explanations at this time. Among these phenomena are non-thermal line broadening, line profile variability (LPVs), discrete absorption components (DACs), wind clumping and stochastically excited pulsations. Cantiello et al. (2009) argued that a convection zone close to the surface of hot, massive stars, could be responsible for some of these phenomena. This convective zone is caused by a peak in the opacity due to iron recombination and for this reason is referred to as the “iron convection zone” (FeCZ). 3D MHD simulations are used to explore the possible effects of such subsurface convection on the surface properties of hot, massive stars. We argue that turbulence and localized magnetic spots at the surface are the likely consequence of subsurface convection in early type stars.
What determines the penumbral size and Evershed flow speed?
Authors: Deng Na , Shimizu Toshifumi , Choudhary Debi Prasad , Wang Haimin
Published: August 2011

Using Hinode SP and G-band observations, we examined the relationship between magnetic field structure and penumbral length as well as Evershed flow speed. The latter two are positively correlated with magnetic inclination angle or horizontal field strength within 1.5 kilogauss, which is in agreement with recent magnetoconvective simulations of Evershed effect. This work thus provides direct observational evidence supporting the magnetoconvection nature of penumbral structure and Evershed flow in the presence of strong and inclined magnetic field.
Coronal heating and flaring in QSLs
Authors: Aulanier Guillaume
Published: August 2011

Quasi-Separatrix Layers (QSLs) are 3D geometrical objects that define narrow volumes across which magnetic field lines have strong, but finite, gradients of connectivity from one footpoint to another. QSLs extend the concept of separatrices, that are topological objects across which the connectivity is discontinuous. Based on analytical arguments, and on magnetic field extrapolations of the Sun's coronal force-free field above observed active regions, it has long since been conjectured that QSLs are favorable locations for current sheet (CS) formation, as well as for magnetic reconnection, and therefore are good predictors for the locations of magnetic energy release in flares and coronal heating. It is only up to recently that numerical MHD simulations and solar observations, as well as a laboratory experiment, have started to address the validity of these conjectures. When put all together, they suggest that QSL reconnection is involved in the displacement of EUV and SXR brightenings along chromospheric flare ribbons, that it is related with the heating of EUV coronal loops, and that the dissipation of QSL related CS may be the cause of coronal heating in initially homogeneous, braided and turbulent flux tubes, as well as in coronal arcades rooted in the slowly moving and numerous small-scale photospheric flux concentrations, both in active region faculae and in the quiet Sun. The apparent ubiquity of QSL-related CS in the Sun's corona, which will need to be quantified with new generation solar instruments, also suggests that QSLs play an important role in stellar's atmospheres, when their surface radial magnetic fields display complex patterns.