bluuebunny/crossref_metadata_2025 huggingface dataset:
Generalized analysis of spatial variation in yield monitor data
Authors: CLIFFORD D. , McBRATNEY A. B. , TAYLOR J. , WHELAN B. M.
Published: March 2006

Australian lupin and cotton yield monitor data were analysed using spatial models from the Matérn class of spatial covariance functions. Despite difficulties with the spatial disposition of the data, the analysis supports the statistical model in which the variation is a linear combination of white noise and the de Wijs process. The de Wijs process, also called the logarithmic covariance function, is a generalized covariance function that is conformally invariant and suggests that there is variation at all spatial scales. The present work also indicates that anisotropy and convolution are properties of yield monitor data and that it is hard to distinguish the two. The degree and causes of anisotropy require further investigation. Fitting this model is relatively easy for small, precision-agriculture datasets and open source software is available to this end. Comparing the de Wijs model with more general models in the Matérn class is computationally intensive for precision-agriculture datasets.
The cattle TB crisis – a radical rethink
Authors: HANCOX M.
Published: March 2006

Cattle tuberculosis in Great Britain is out of control, rising at some 18% a year, but there is great confusion as to why cattle control measures are not working (Hancox 2004a). Culling over 10000 badgers so far in the Krebs Randomised Badger Culling Trial has had no effect, despite repeated calls for mass culls by farmers and vets (Hancox 2004b). Badgers are blamed for this crisis because it is claimed cattle-to-cattle transmission is unimportant, and badgers with TB are found after repeat breakdowns in herds supposedly free of TB after negative tests.
Study on the n-alkane patterns of five dominant forage species of the typical steppe grassland in Inner Mongolia of China
Authors: LIN L. , LIU G. , ZHANG Y.
Published: March 2006

The alkane patterns of the dominant forage species of the typical steppe grassland in Inner Mongolia were clarified, and the effects of species, sampling time and site on the concentrations of alkanes were evaluated. The results showed that alkanes with odd-numbered carbon chains in the range C25 (n-pentacosane)–C35 (n-pentatriacontane) were predominant in cuticular wax in five dominant grasses of the typical steppe. The C31 (n-hentriacontane) alkanes were always present in the highest concentration in the grass species, especially in the Stipa daicalensis and Stipa grandis. Samples of Artemisia frigida contained not only high concentrations of odd-chain alkanes, but also the even-chain ones compared with other species. The effects of species and sampling time on alkane concentrations were significant, accounting for 0·912 and 0·067 of the total variance, respectively. The site effects on odd-chain alkanes were less than on even-chain. The results of principal component analysis indicated that the patterns of alkane concentrations in the five dominant species could be clearly distinguished during the whole growing season. Therefore, it should be possible to achieve accurate and precise estimations of intake and diet composition of grazing animals of the typical steppe grassland in Inner Mongolia using the alkane technique.
Phenological, agronomic and forage quality diversity among germplasm accessions of the tropical legume shrub Cratylia argentea
Authors: ANDERSSON M. S. , PETERS M. , SCHULTZE-KRAFT R. , FRANCO L. H. , LASCANO C. E.
Published: March 2006

Cratylia argentea (Desv.) O. Kuntze is a drought-tolerant tropical shrub legume that can help to ensure continuity of forage supply in smallholder systems either through direct grazing or as a cut-and-carry plant for fresh foliage or silage. A collection of 38 accessions was characterized agronomically and nutritionally. High diversity was detected between accessions. Time to flowering ranged from 217–329 days after transplanting seedlings to the field and from 129–202 days after cutting. Flowering is probably induced by reduction of day length. Seed production was high but variable. Dry matter production ranged from 190–382 g/plant in the rainy and from 124–262 g/plant in the dry season, content of in vitro digestible dry matter from 589–690 g/kg, crude protein content from 184–237 g/kg and fibre content from 403–528 g/kg (neutral detergent fibre, NDF), 240–335 g/kg (acid detergent fibre, ADF), and 9–13 g/kg (acid detergent fibre-bound nitrogen, N-ADF). Accessions CIAT 18674 and CIAT 22406 were identified as promising for further study. They were superior to the commercial cultivar in terms of dry matter (DM) production, particularly in the dry season. Further research is required to determine the prevailing reproduction strategy of C. argentea and to quantify outcrossing-rates. Multilocational trials with a selected set of accessions should be conducted under different environmental conditions.
STATUS OF WOMEN IN TWO BENGALS: EVIDENCE FROM LARGE SCALE SURVEYS
Authors: CHATTOPADHYAY APARAJITA , GOSWAMI BAISHALI
Published: March 2006

Greater female autonomy is mirrored through better performance in the major demographic and social indicators. This study attempts to capture the effect of religion on the status of women considering ‘Greater Bengal’. There is much evidence suggesting that when cultural factors are constant, religion does not have a significant effect on any demographic issue. In this paper, the validity of this proposition is examined using two datasets, namely NFHS II (98–99) and BDHS 2000. It is clear from the analyses that not only region but also religion has a distinct effect on the status of women. In West Bengal, the religious gap for all the indicators considered is pretty high, whereas in Bangladesh the gap is not that wide. A state-level population policy is needed in West Bengal to act as a social leveller.
Magnetohydrodynamic wave mixing in shear flows: Hamiltonian equations and wave action
Authors: WEBB G. M. , KAGHASHVILI E. Kh. , ZANK G. P.
Published: March 2006

Magnetohydrodynamic wave interactions in a linear shear flow are investigated using the Lagrangian fluid displacement ξ and entropy perturbation Δ S, in which a spatial Fourier solution is obtained in the frame of the background shear flow (Kelvin's method). The equations reduce to three coupled oscillator equations, with time-dependent coefficients and with source terms proportional to the entropy perturbation. In the absence of entropy perturbations, the system admits a wave action conservation integral consisting of positive and negative energy waves. Variational and Hamiltonian forms of the equations are obtained. Examples of wave amplification phenomena and sharp resonant-type wave interactions are obtained. Implications for the interaction of magnetohydrodynamic waves in the shear flow between fast, polar coronal-hole solar wind and slow, streamer belt solar wind are discussed.
The prevalence of body dysmorphic disorder: a population-based survey
Authors: RIEF WINFRIED , BUHLMANN ULRIKE , WILHELM SABINE , BORKENHAGEN ADA , BRÄHLER ELMAR
Published: March 2006

Background. Body dysmorphic disorder (BDD) is a highly distressing and impairing disorder characterized by a preoccupation with imagined or slight physical defects in appearance. Well designed studies on its prevalence and on base rates for diagnostic criteria are rare. Therefore this study aimed to reveal prevalence rates of BDD in the general population and to examine clinical features associated with BDD.

Method. Of 4152 selected participants 2552, aged 14–99 years, participated in this German nationwide survey. Participants were carefully selected to ensure that the sample was representative; they were visited by a study assistant who provided instructions and help if needed. Participation rate was 62·3%. DSM-IV criteria for BDD, as well as subthreshold features (e.g. individuals who consider some part(s) of their body as ugly or disfigured, but do not fulfill all BDD criteria) were examined. We also assessed suicidal ideation associated with the belief of having an ugly body part, as well as the desire for cosmetic surgery. Furthermore, somatization symptoms were assessed.

Results. The prevalence of current BDD was 1·7% (CI 1·2–2·1%). Individuals with BDD reported higher rates of suicidal ideation (19% v. 3%) and suicide attempts due to appearance concerns (7% v. 1%) than individuals who did not meet criteria for BDD. Somatization scores were also increased in individuals with BDD, relative to those without. BDD was associated with lower financial income, lower rates of living with a partner, and higher rates of unemployment.

Conclusions. Our study shows that self-reported BDD is relatively common and associated with significant morbidity.
The impact of generalized anxiety disorder and stressful life events on risk for major depressive episodes
Authors: HETTEMA JOHN M. , KUHN JONATHAN W. , PRESCOTT CAROL A. , KENDLER KENNETH S.
Published: March 2006

Background. Both generalized anxiety disorder (GAD) and stressful life events (SLEs) are established risk factors for major depressive disorder, but no studies exist that examine the interrelationship of their impact on depressive onsets. In this study, we sought to analyze the joint effects of prior history of GAD and recent SLEs on risk for major depressive episodes, comparing these in men and women.

Method. In a population-based sample of 8068 adult twins, Cox proportional hazard models were used to predict onsets of major depression from reported prior GAD and last-year SLEs rated on long-term contextual threat.

Results. For all levels of threat, prior GAD increases risk for depression, with a monotonic relationship between threat level and risk. While females without prior GAD consistently show higher depressive risk than males, this is no longer the case in subjects with prior GAD who have experienced SLEs. Rather, males appear to be more vulnerable to the depressogenic effects of both prior GAD and SLEs.

Conclusion. The effects of prior GAD and SLEs jointly increase the risk of depression in both sexes, but disproportionately so in males.
DNA enables nanoscale control of the structure of matter
Authors: Seeman Nadrian C.
Published: March 2006

1. Introduction 363

2. Motif and sequence design 364

3. Structural and topological constructions 366

4. Nanomechanical devices 367

5. Conclusions, applications and challenges 370

6. Acknowledgments 371

7. References 371

Structural DNA nanotechnology consists of constructing objects, lattices and devices from branched DNA molecules. Branched DNA molecules open the way for the construction of a variety of N-connected motifs. These motifs can be joined by cohesive interactions to produce larger constructs in a bottom-up approach to nanoconstruction. The first objects produced by this approach were stick polyhedra and topological targets, such as knots and Borromean rings. These were followed by periodic arrays with programmable patterns. It is possible to exploit DNA structural transitions and sequence-specific binding to produce a variety of DNA nanomechanical devices, which include a bipedal walker and a machine that emulates the translational capabilities of the ribosome. Much of the promise of this methodology involves the use of DNA to scaffold other materials, such as biological macromolecules, nanoelectronic components, and polymers. These systems are designed to lead to improvements in crystallography, computation and the production of diverse and exotic materials.
Recognizing DNA
Authors: Lavery Richard
Published: March 2006

It has become clear that there is no simple ‘code’ for protein–DNA recognition and that selecting an optimal binding sequence along the DNA double helix corresponds to more than simply forming a set of specific hydrogen bonds or steric interactions. However, it has been difficult to characterize the so-called indirect components of recognition. While DNA deformation certainly underlies indirect recognition, it is not easy to determine how local fine structure and deformability depend on base sequence or exactly what percentage of recognition should be attributed to such factors. Molecular modelling can help to develop these ideas into a quantitative model, provided the calculations can be carried out fast enough to enable a comprehensive survey of base-sequence effects. I present here some recent results from our group and their consequences for improving our understanding of protein–DNA binding, and their potential for predicting, and eventually modulating, protein–DNA binding.
Nucleic acid structure and intracellular immunity: some recent ideas from the world of RNAi
Authors: Fire Andrew
Published: March 2006

1. Viruses and other informational parasites are a ‘fact of life’ 304

2. Evolution drives diversity in viral strategies and host interactions 304

3. Cellular defense often involves recognizing nucleic acid structures that are indicative of unwanted information duplication 305

3.1 Double-stranded RNA (dsRNA) 305

3.2 Single-stranded DNA (ssDNA) 305

3.3 Unspliced mRNAs 306

3.4 Polycistronic mRNAs 306

3.5 Multi-copy DNAs 306

3.6 Other structures 306

4. dsRNA as a case study: building a multilevel response to foreign structure 306

5. Getting there is half the fun: disseminated immunity in RNAi 308

6. Viruses strike back … so why do we still get sick? 308

Cells face a constant struggle against unwanted instructions that arrive in the form of viruses and transposons. At the core of this battle are two issues: how can cellular machinery recognize certain informational molecules as ‘unwanted’ and how can the cell use this recognition to effectively silence malicious genetic activity. While defenses against some specific parasites may be triggered by individual nucleic acid or protein sequences, such sequence-specific mechanisms have the limitation of allowing the parasite to evade following relatively minor evolutionary change. A more general set of defense mechanisms is based on recognition of structural features that are intrinsic aspects of one or more parasitic lifestyle. Recognition of extended regions of double-stranded RNA (dsRNA) provides cells with one such defensive modality. Essentially absent during ‘normal’ gene expression, long stretches of dsRNA within a cell serve as a dramatic warning that a segment of information may be replicating as RNA. In addition to exemplifying many of the mechanistic issues in genome defense, the cellular response to dsRNA provides several examples of the logic by which organisms attempt to focus their limited immunity resources on the most immediate and dangerous targets.
On stabilization of bipedal robots during disturbed standing using the concept of Lyapunov exponents
Authors: Yang Caixia , Wu Qiong
Published: March 2006

Design of balancing control and the stability analysis of a biped during disturbed standing are investigated. A PD-based switching state feedback control is used to stabilize the biped at the upright position while satisfying the constraints between the feet and the ground. The concept of Lyapunov exponents is used for the stability analysis, and a stability region is determined. Furthermore, the stability region is compared and agrees well with the one from the previous work that predicts the feasible movement during which balance of human standing can be maintained. This agreement shows the potential of the concept of Lyapunov exponents to be used as a measure of balancing of human standing. The work contributes to bipedal balancing control, which is important in the development of bipedal robots.
Editors' Introduction: Forgetting Freud? For a New Historiography of Psychoanalysis
Authors: Marinelli Lydia , Mayer Andreas
Published: March 2006

How does the advancement of the sciences relate to the ways in which their founding figures are remembered? According to the stark picture painted by Alfred N. Whitehead in 1917, “the establishment of a reverential attitude towards any statement made by a classical author” had barred the progress of logic for several centuries: “Scholars became commentators on truths too fragile to bear translation. A science which hesitates to forget its founders is lost” (Whitehead 1917, 115). In the eyes of many critics (who often tend to equate science and logic in similar fashion), Sigmund Freud's psychoanalysis may well be an example of such a lost cause. From the founding book The Interpretation of Dreams ([1899] 1900) to his very last statements, Freud never ceased to affirm that psychoanalysis was a science: “What else can it be?” (Freud 1940, 282). Yet not only the fact that he has become one of the classic authors of the twentieth century, but also a number of very specific traits of psychoanalytic institutions (such as the numerous schisms resulting from personal fights between their members) have nourished the suspicion that Freud was less the founder of a science than of a sort of quasi-religious movement, a secular sect thriving on a personality cult.
Lost Objects: From the Laboratories of Hypnosis to the Psychoanalytic Setting
Authors: Mayer Andreas
Published: March 2006

Argument

The psychoanalytic setting counts today as one of the familiar therapeutic rituals of the Western world. Taking up some of the insights of the anthropology of science will allow us to account for both the social and the material arrangements from which Freud's invention emerged at the end of the nineteenth century out of the clinical laboratories and private consulting rooms of practitioners of hypnosis. The peculiar way of neglecting or forgetting the object world and the institution of the psychoanalyst as a “transference object” will be traced back to multiple reconfigurations in the history of hypnotism in France and in Germany. In this process, different practitioners tried to achieve a synthesis of clinical work and experimental psychology, with the aim of objectifying knowledge about human subjectivity. While Freud retained the claim of psychoanalysis performing an experimental situation, he set apart his own setting from the objectifying practices which were characteristic of this experimental psychology located in the clinic and the private consulting room.

It is not easy to over-estimate the importance of the part played by hypnotism in the history of the origin of psychoanalysis. From a theoretical as well as from a therapeutic point of view, psycho-analysis has at its command a legacy which it has inherited from hypnotism.

Sigmund Freud, A Short Account of Psycho-Analysis ([1923] 1924, 192)
Remembering and Forgetting Freud in Early Twentieth-Century Dreams
Authors: Forrester John
Published: March 2006

Argument

The paper explores the use of Freud's methods of dream interpretation by four English writers of the early twentieth century: T. H. Pear, W. H. R. Rivers, Ernest Jones, and Alix Strachey. Each employed their own dreams in rather different ways: as part of an assessment of Freud's work as a psychological theory, as illustrative of the cogency of Freud's method and theories as part of the psychoanalytic process. Each adopted different approaches to the question of privacy and decorum. The paper argues that assessment of the impact of Freud's work must take account of the application of the method to the researcher's own dreams and the personal impact this process of analysis had upon them, and must also gauge how the dreamers' deployment of Freud's methods influenced their explicit relationship to him and his theories.

The dream, then, is the chief gate by which we can enter into the knowledge of the unconscious…. Thoughts and desires, which, if they attempted to dominate consciousness in waking life, would be promptly suppressed, arise, develop and expand to an astonishing extent in the dream.

This statement, of course, is entirely independent of the implications of any one “theory of dreams.” Its truth is evident to anyone who has honestly recorded or considered his own dreams for even a short period.

(Elliot Smith and Pear 1917, 61)
Screening Wish Theories: Dream Psychologies and Early Cinema
Authors: Marinelli Lydia
Published: March 2006

Argument

The analogy between dream and film represents a central thread in the psychoanalytic discussion of cinema. Using examples taken from films created between 1900 and 1906, this paper develops a typology of dream scenes in early film. The basis for the proposed typology is provided by the dream knowledge in circulation toward the end of the nineteenth century. This knowledge was fed by a great variety of sources, some of them in the proximity of scientific research and some of them far from it, including wish-fulfilling prognostic models and those based on the reservoir of memory or on bodily stimuli. By setting cinema in a context of contemporary dream psychologies, it is possible to trace the specific conditions under which the analogy between dream and cinema could become effective.
Remembering the Evolutionary Freud
Authors: Young Allan
Published: March 2006

Argument

Throughout his career as a writer, Sigmund Freud maintained an interest in the evolutionary origins of the human mind and its neurotic and psychotic disorders. In common with many writers then and now, he believed that the evolutionary past is conserved in the mind and the brain. Today the “evolutionary Freud” is nearly forgotten. Even among Freudians, he is regarded to be a red herring, relevant only to the extent that he diverts attention from the enduring achievements of the authentic Freud. There are three ways to explain these attitudes. First, the evolutionary Freud's key work is the “Overview of the Transference Neurosis” (1915). But it was published at an inopportune moment, forty years after the author's death, during the so-called “Freud wars.” Second, Freud eventually lost interest in the “Overview” and the prospect of a comprehensive evolutionary theory of psychopathology. The publication of The Ego and the Id (1923), introducing Freud's structural theory of the psyche, marked the point of no return. Finally, Freud's evolutionary theory is simply not credible. It is based on just-so stories and a thoroughly discredited evolutionary mechanism, Lamarckian use-inheritance. Explanations one and two are probably correct but also uninteresting. Explanation number three assumes that there is a fundamental difference between Freud's evolutionary narratives (not credible) and the evolutionary accounts of psychopathology that currently circulate in psychiatry and mainstream journals (credible). The assumption is mistaken but worth investigating.
Blauverfärbung der Finger
Authors: Geeser
Published: March 2006

Das Raynaud-Phänomen wird als abnorme Gefässkonstriktion im Bereich der Finger und Zehen auf Kälteexposition und Stress verstanden, welche sich klinisch in Form einer scharf demarkierten Blau- oder Weissverfärbung mit konsekutiver Hyperämie in der Erholungsphase manifestiert. Es wird eine primäre Form ohne Grunderkrankung von einer sekundären Form unterschieden, wobei letztere vor allem im Zusammenhang mit rheumatologischen Systemerkrankungen (z.B. Vaskulitiden, Sjögren-Syndrom, Poly- und Dermatomyositis), okkludierenden Gefässerkrankungen (z.B. Atherosklerose, M.Bürger), Medikamenten (z.B. Kokain, b-Blocker, Cisplatin), Hyperviskositätssyndromen (z.B. Kryoglobulinämie, Paraproteinämie) und häufiger Exposition gegenüber Vibrationen und übermässiger Kälte auftritt. Klinische Hinweise für eine sekundäre Form sind ein Symptombeginn nach dem 40. LJ, männliches Geschlecht, asymmetrischer Befall, ischämische Ulzerationen und Beteiligung von Körperregionen proximal der Finger und Zehen. Bei der vorgestellten Patientin erfolgten Weiterabklärungen bezüglich einer sekundären Form wegen des fortgeschrittenen Alters bei Erstmanifestation der Raynaud-Symptomatik. Diese blieben jedoch ergebnislos, sodass wir dennoch von einer primären Form ausgehen.
Time‐lapse monitoring of rock properties with coda wave interferometry
Authors: Grêt Alexandre , Snieder Roel , Scales John
Published: March 2006

The coda of seismic waves consists of that part of the signal after the directly arriving phases. In a finite medium, or in one that is strongly heterogeneous, the coda is dominated by waves which have repeatedly sampled the medium. Small changes in a medium which may have no detectable influence on the first arrivals are amplified by this repeated sampling and may thus be detectable in the coda. We refer to this use of multiple‐sampling coda waveforms as coda wave interferometry. We have exploited ultrasonic coda waves to monitor time‐varying rock properties in a laboratory environment. We have studied the dependence of velocity on uniaxial stress in Berea sandstone, the temperature dependence of velocity in granite and in aluminum, and the change in velocity due to an increase of water saturation in sandstone. There are many other possible applications of coda wave interferometry in geophysics, including dam and volcano monitoring, time‐lapse reservoir characterization, earthquake relocation, and stress monitoring in mining and rock physics.
A strong lateral shear velocity gradient and anisotropy heterogeneity in the lowermost mantle beneath the southern Pacific
Authors: Ford Sean R. , Garnero Edward J. , McNamara Allen K.
Published: March 2006

Velocity heterogeneity and seismic anisotropy in the D″ region beneath the southern Pacific Ocean is investigated using broadband shear waves from southwest Pacific and South American earthquakes recorded by permanent and temporary stations in Antarctica, Australia, South America, and on islands in the South Pacific. Shear velocity perturbations (δVS) are inferred from the differential travel times between hand‐picked horizontally polarized (SH) direct or diffracted S arrivals and vertically polarized (SV) SKS arrivals. Derived patterns in δVS roughly agree with global shear velocity models but reveal a stronger shear velocity lateral gradient north of approximately 52°S where δVS transitions from approximately +0.5 to −1.0% (relative to radially averaged reference models) over less than 600 km along the base of D″. Waveform analyses provide an even stronger constraint on the transitional region, where there is a change in waveform behavior occurring over length scales less than 300 km. Differential travel times between SKKS and SKS, calculated by cross‐correlating SKS with Hilbert transformed SKKS, support large δVS amplitudes and help to constrain the location of the transitional region. Anisotropy in D″ (kS) is inferred from handpicked differential travel times between the SV and SH components of direct or diffracted S and display a slight spatial trend where the SH component precedes the SV in the north and east of the study area but arrives after SV in the center and southwest of it. However, there is high kS variability in the center of the study region. There is no apparent correlation between δVS and kS. Abrupt changes in the character of velocity and anisotropy in this region of D″ may be related to chemical heterogeneity at the boundary of the Pacific Superswell, as well as small‐scale convection in the deep mantle.
Chemical size distributions of boundary layer aerosol over the Atlantic Ocean and at an Antarctic site
Authors: Virkkula Aki , Teinilä Kimmo , Hillamo Risto , Kerminen Veli‐Matti , Saarikoski Sanna , Aurela Minna , Koponen Ismo K. , Kulmala Markku
Published: March 2006

Chemical size distributions of aerosols were measured using a 12‐stage low‐pressure impactor over the Atlantic Ocean in November–December 1999 and at an Antarctic site, Aboa, in January 2000. In the polluted latitudes north of the equator, particles were neutral in all sizes but accumulation mode was acidic in the clean areas. Chloride depletion was analyzed in detail. In most areas, chloride depletion could be explained by replacement by sulfate, nitrate, and methane sulfonate. In Antarctica the chloride losses increased in all size ranges and the contribution of each anion to the chloride depletion varied with increasing air mass residence time over continental Antarctica. The modal structure of the size distributions of ionic compounds was analyzed. The modes derived from chemical mass size distributions were compared with modes obtained from number size distributions. The modes of non‐sea‐salt sulfate and MSA were very similar suggesting that these particles were internally mixed. The nitrate mass modes were closer to the sea salt surface modes than the sea salt mass modes, suggesting that nitrate was on the surface of sea salt particles.
Temperature variations at diffuse and focused flow hydrothermal vent sites along the northern East Pacific Rise
Authors: Scheirer Daniel S. , Shank Timothy M. , Fornari Daniel J.
Published: March 2006

In the decade following documented volcanic activity on the East Pacific Rise near 9°50′N, we monitored hydrothermal vent fluid temperature variations in conjunction with approximately yearly vent fluid sampling to better understand the processes and physical conditions that govern the evolution of seafloor hydrothermal systems. The temperature of both diffuse flow (low‐temperature) and focused flow (high‐temperature) vent fluids decreased significantly within several years of eruptions in 1991 and 1992. After mid‐1994, focused flow vents generally exhibited periods of relatively stable, slowly varying temperatures, with occasional high‐ and low‐temperature excursions lasting days to weeks. One such positive temperature excursion was associated with a crustal cracking event. Another with both positive and negative excursions demonstrated a subsurface connection between adjacent focused flow and diffuse flow vents. Diffuse flow vents exhibit much greater temperature variability than adjacent higher‐temperature vents. On timescales of a week or less, temperatures at a given position within a diffuse flow field often varied by 5°–10°C, synchronous with near‐bottom currents dominated by tidal and inertial forcing. On timescales of a week and longer, diffuse flow temperatures varied slowly and incoherently among different vent fields. At diffuse flow vent sites, the conceptual model of a thermal boundary layer immediately above the seafloor explains many of the temporal and spatial temperature variations observed within a single vent field. The thermal boundary layer is a lens of warm water injected from beneath the seafloor that is mixed and distended by lateral near‐bottom currents. The volume of the boundary layer is delineated by the position of mature communities of sessile (e.g., tubeworms) and relatively slow‐moving organisms (e.g., mussels). Vertical flow rates of hydrothermal fluids exiting the seafloor at diffuse vents are less than lateral flow rates of near‐bottom currents (5–10 cm/s). The presence of a subsurface, shallow reservoir of warm hydrothermal fluids can explain differing temperature behaviors of adjacent diffuse flow and focused flow vents at 9°50′N. Different average temperatures and daily temperature ranges are explained by variable amounts of mixing of hydrothermal fluids with ambient seawater through subsurface conduits that have varying lateral permeability.
Water mass characteristics in the deep layers of the western Ionian Basin observed during May 2003
Authors: Hainbucher D. , Rubino A. , Klein B.
Published: March 2006

CTD measurements carried out in the southern Adriatic Sea and in the western Ionian basin (Eurafrican Mediterranean Sea) during May 2003 by the German research vessel Poseidon (Poseidon cruise 298) and numerical simulations are used to elucidate aspects of the abyssal circulation of this oceanic region. The observations reveal that dense waters of Adriatic origin were strongly diluted along their way on the Italian continental slope, whilst their characteristics remained better preserved in a region located further east. Numerical simulations carried out by means of a nonlinear, reduced‐gravity plume model confirm the observations and contribute to explain their cause: The very steep topographic slope along the Italian shelf in the region of the Gulf of Taranto induces strong entrainment of intermediate waters in the bottom layers. Instead, the bottom waters of Adriatic origin which, along their path further east, encounter gentler topographic variations, are weakly diluted by turbulent mixing and, therefore, better preserve their original characteristics. The remarkable differences in the simulated turbulent mixing along these two different paths are accentuated by the presence of a noticeable zonal gradient of potential density existing in the near‐bottom layers of the northern Ionian basin.
Plasmaspheric depletion, refilling, and plasmapause dynamics: A coordinated ground‐based and IMAGE satellite study
Authors: Dent Z. C. , Mann I. R. , Goldstein J. , Menk F. W. , Ozeke L. G.
Published: March 2006

This paper presents a coordinated ground‐based magnetometer and IMAGE satellite study of plasma mass density and plasmapause location on L shells between 2.39 and 6.54 throughout an extended interval of moderate geomagnetic activity from 5 to 17 May 2001. Storm‐time plasmaspheric depletion is monitored using three different data sets, and our results show the importance of local time history effects on plasma depletion, including determining that shorter intervals of enhanced convection do not necessarily cause all meridian sectors to be depleted. Analysis of ground‐based magnetometer derived mass density implies that poststorm refilling is not a steady process through the dayside sector. Our results also suggest that refilling may be a two‐stage process, operating with a much increased rate on the third day of clear refilling. Comparisons between time‐dependent ground‐based magnetometer cross‐phase and IMAGE RPI determined plasma mass density profile evolution imply the presence of an enhanced heavy ion population in the inner plasmatrough during an active refilling interval. These results further demonstrate the potential of using ground‐based magnetometer data to study cold plasma dynamics.
Phase space density analysis of the outer radiation belt energetic electron dynamics
Authors: Iles Roger H. A. , Meredith Nigel P. , Fazakerley Andrew N. , Horne Richard B.
Published: March 2006

We present an analysis of the electron phase space density in the Earth's outer radiation belt during three magnetically disturbed periods to determine the likely roles of inward radial diffusion and local acceleration in the energization of electrons to relativistic energies. During the recovery phase of the 9 October 1990 storm and the period of prolonged substorms between 11 and 16 September 1990, the relativistic electron phase space density increases substantially and peaks in the phase space density occur in the region 4.0 < L* < 5.5 for values of the first adiabatic invariant, M ≥ 550 MeV/G, corresponding to energies, E > ∼0.8 MeV. The peaks in the phase space density are associated with prolonged substorm activity, enhanced chorus amplitudes, and predominantly low values of the ratio between the electron plasma frequency, fpe, and the electron gyrofrequency, fce (fpe/fce < ∼4). The data provide further evidence for a local wave acceleration process in addition to radial diffusion operating in the heart of the outer radiation belt. During the recovery phase of the 9 October 1990 storm the peaks are more pronounced at large M (550 MeV/G) and large Kaufmann K (0.11 RE) than large M (700 MeV/G) and small K (0.025 RE), which suggests that radial diffusion is more effective below about 0.7 MeV for 5.0 < L* < 5.5 during this period. At low M (M ≤ 250 MeV/G), corresponding to energies, E < ∼0.8 MeV, there is no evidence for a peak in phase space density and the data are more consistent with inward radial diffusion and losses to the atmosphere by pitch angle scattering. During the 26 August 1990 storm there is a net loss in the relativistic electron phase space density for 3.3 < L* < 6.0. At low M (M ≤ 250 MeV/G) the phase space density decreases by almost a constant factor and the gradient remains positive for all L*, but at high M (M ≥ 550 MeV/G) the decrease in phase space density is greater at larger L* and the gradient changes from positive to negative. The data show that it is possible to have inward radial diffusion at low energies and outward radial diffusion at higher energies, which would fill the outer radiation belt.
Coupling effects throughout the solar atmosphere: Emerging magnetic flux and structure formation
Authors: Ryutova M. , Shine R.
Published: March 2006

We report observations of the “birth,” formation, and evolution of compact coronal structures associated with strong localized motions generated by emerging magnetic flux in the photosphere. We use multiwavelength time series of data taken simultaneously with the Swedish Vacuum Solar Telescope (SVST) on La Palma, the TRACE satellite, and the MDI instrument on SOHO. We find that long before the magnetic pore is formed, the chromosphere and transition region show a high activity above the future site of pore formation: rising but not yet visible magnetic flux exerts a strong pressure on the overlying plasma generating highly collimated plasma flows seen in the Hα images. About the time when the magnetic pores are formed and the Hα surges bifurcate into the established arc‐like flows, a system of compact coronal loops is formed, showing direct connection between the motions associated with the evolving magnetic fields and the coronal structure formation. We propose a mechanism that may lead to the observed phenomena based on the generation of currents by strong disturbances propagating upward from a limited surface area.
Monte Carlo modeling of toroidal ion distributions and ion temperatures at high altitudes equatorward of the cusp: Effect of finite gyroradius
Authors: Barghouthi I. A. , Atout M. A.
Published: March 2006

We report that the effect of finite gyroradius is responsible for production of the H+ and O+ toroids at high altitudes equatorward of the cusp that are observed by TIDE and TIMAS ion instruments on board the polar spacecraft. The energization of charged particles, owing to interaction with electromagnetic turbulence, has an important influence on the plasma outflow in space. The effect of wave‐particle interactions (WPI) on H+ and O+ outflow at high altitudes equatorward of the cusp was investigated by using Monte Carlo method. The Monte Carlo model includes the effect of WPI, gravity, polarization electrostatic field, and the divergence of the geomagnetic field within the simulation tube (1.2–10 Earth radii, RE). As the ions drift upward along the geomagnetic field lines, they interact with the electromagnetic turbulence and consequently get heated in the direction perpendicular to the geomagnetic field. The mirror force converts some of the gained ion energy in the perpendicular direction into parallel kinetic energy. These effects combine to form an ion‐conic velocity distribution. However, as the ions are heated and move to higher altitudes, the ion gyroradius ρi may become comparable to the perpendicular wavelength of the electromagnetic turbulence λ⊥. As the ratio ρi/λ⊥ becomes >1, then the heating rate turns to be self‐limited and the ion velocity distribution displays toroidal features. A comparison has been made between the Monte Carlo calculations obtained in this study and observations of H+ and O+ ion velocity distributions and temperatures. The comparison showed a remarkably close agreement in the corresponding results for the ion velocity distribution and its temperature. As a result of the comparison, we were able to predict the characteristic value of the perpendicular wavelength of the electromagnetic turbulence λ⊥ at high altitudes equatorward of the cusp. To our knowledge, this represents the first successful comparison of observed toroids with a theoretical model.
Cloud liquid‐water profile retrieval algorithm and validation
Authors: Rosenkranz Philip W.
Published: March 2006

In the first stage of the Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit‐A/Humidity Sounder for Brazil (AIRS/AMSU/HSB) geophysical retrieval algorithm, cloud liquid‐water profiles are retrieved from the microwave measurements. These profiles are used in the forward radiative‐transfer calculation for microwave channels in subsequent retrieval steps. The retrieval of cloud liquid water is based on a model for moisture condensation in which the relative humidity for onset of clouds is a retrieved parameter, which makes the retrieval more robust with respect to errors in the retrieved temperature profile and horizontal inhomogeneities of the moisture field within an instrument footprint. Retrieved cloud liquid is compared with ground‐based radiometric measurements, and the vertical distribution is compared to relative humidity profiles from dedicated radiosondes launched underneath the Aqua satellite.
A comparison of aerosol optical properties obtained from in situ measurements and retrieved from Sun and sky radiance observations during the May 2003 ARM Aerosol Intensive Observation Period
Authors: Ricchiazzi Paul , Gautier Catherine , Ogren John A. , Schmid Beat
Published: March 2006

Aerosol single scattering albedo and phase function were retrieved from Cimel Sun photometer observations of sky radiance during the May 2003 Atmospheric Radiation Measurement (ARM) Aerosol Intensive Observation Period. Single scattering albedo and backscattered fraction were compared to data obtained from the ARM program In situ Aerosol Profile (IAP) flights and a similar airborne experiment conducted by the University of Washington. The retrieved single scattering albedo was within about 0.05 of the in situ measurements for many of the considered cases, though much larger deviations were also seen. The retrieved aerosol properties were also used to compute the ratio of diffuse and direct irradiance at the surface, which was compared to the same ratio measured by a Multi Filter Rotating Shadowband Radiometer. The radiation model included correction factors to account for the effect of the instrument cosine response on both the direct and diffuse irradiance components. These comparisons showed very good agreement for most of the cases considered.
Atmospheric Radiation Measurements Aerosol Intensive Operating Period: Comparison of aerosol scattering during coordinated flights
Authors: Hallar A. G. , Strawa A. W. , Schmid B. , Andrews E. , Ogren J. , Sheridan P. , Ferrare R. , Covert D. , Elleman R. , Jonsson H. , Bokarius K. , Luu A.
Published: March 2006

In May 2003, a Twin Otter airplane, equipped with instruments for making in situ measurements of aerosol optical properties, was deployed during the Atmospheric Radiation Measurements (ARM) Program's Aerosol Intensive Operational Period in Oklahoma. Several of the Twin Otter flights were flown in formation with an instrumented light aircraft (Cessna 172XP) that makes routine in situ aerosol profile flights over the site. This paper presents comparisons of measured scattering coefficients at 467 nm, 530 nm, and 675 nm between identical commercial nephelometers aboard each aircraft. Overall, the agreement between the two nephelometers decreases with longer wavelength. During the majority of the flights, the Twin Otter flew with a diffuser inlet while the Cessna had a 1 μm impactor, allowing for an estimation of the fine mode fraction aloft. The fine mode fraction aloft was then compared to the results of a ground‐based nephelometer. Comparisons are also provided in which both nephelometers operated with identical 1 μm impactors. These scattering coefficient comparisons are favorable at the longer wavelengths (i.e., 530 nm and 675 nm), yet differed by approximately 30% at 467 nm. Mie scattering calculations were performed using size distribution measurements, made during the level flight legs. Results are also presented from Cadenza, a new continuous wave cavity ring‐down (CW‐CRD) instrument, which compared favorably (i.e., agreed within 2%) with data from other instruments aboard the Twin Otter. With this paper, we highlight the significant implications of coarse mode (larger than 1 μm) aerosol aloft with respect to aerosol optical properties.
Comparison of 7 years of satellite‐borne and ground‐based tropospheric NO2 measurements around Milan, Italy
Authors: Ordóñez C. , Richter A. , Steinbacher M. , Zellweger C. , Nüß H. , Burrows J. P. , Prévôt A. S. H.
Published: March 2006

Tropospheric NO2 vertical column densities (VCDs) over the Lombardy region were retrieved from measurements of the Global Ozone Monitoring Experiment (GOME) spectrometer for the period 1996–2002 using a differential optical absorption method. This data set was compared with in situ measurements of NO2 at around 100 ground stations in the Lombardy region, northern Italy. The tropospheric NO2 VCDs are reasonably well correlated with the near‐surface measurements under cloud‐free conditions. However, the slope of the tropospheric VCDs versus ground measurements is higher in autumn‐winter than in spring‐summer. This effect is clearly reduced when the peroxyacetyl nitrate and nitric acid (HNO3) interferences of conventional NOx analyzers are taken into account. For a more quantitative comparison, the NO2 ground measurements were scaled to tropospheric VCDs using a seasonal NO2 vertical profile over northern Italy calculated by the Model of Ozone and Related Tracers 2 (MOZART‐2). The tropospheric VCDs retrieved from satellite and those determined from ground measurements agree well, with a correlation coefficient R = 0.78 and a slope close to 1 for slightly polluted stations. GOME cannot reproduce the high NO2 amounts over the most polluted stations, mainly because of the large spatial variability in the distribution of pollution within the GOME footprint. The yearly and weekly cycles of the tropospheric NO2 VCDs are similar for both data sets, with significantly lower values in the summer months and on Sundays, respectively. Considering the pollution level and high aerosol concentrations of this region, the agreement is very good. Furthermore, uncertainties in the ground‐based measurements, including the extrapolation to NO2 VCDs, might be as important as those of the NO2 satellite retrieval itself.