bluuebunny/crossref_metadata_2025 huggingface dataset:
Fine‐root morphological and growth traits in a Turkey‐oak stand in relation to seasonal changes in soil moisture in the Southern Apennines, Italy
Authors: Montagnoli Antonio , Terzaghi Mattia , Di Iorio Antonino , Scippa Gabriella Stefania , Chiatante Donato
Published: September 2012

We investigated the effects of seasonal changes in soil moisture on the morphological and growth traits of fine roots (<2 mm in diameter) in a mature Turkey‐oak stand (Quercus cerris L.) in the Southern Apennines of Italy. Root samples (diameter: <0.5, 0.5–1.0, 1.0–1.5, and 1.5–2.0 mm) were collected with the Auger method. Mean annual fine‐root mass and length on site was 443 g m−2 (oak fine roots 321 g m−2; other species 122 g m−2) and 3.18 km m−2 (oak fine roots 1.14 km m−2; other species 2.04 km m−2), respectively. Mean specific root length was 8.3 m g−1. All fine‐root traits displayed a complex pattern that was significantly related to season. In the four diameter classes, both fine‐root biomass and length peaked in summer when soil water content was the lowest and air temperature the highest of the season. Moreover, both fine‐root biomass and length were inversely related with soil moisture (p < 0.001). The finest roots (<0.5 mm in diameter) constituted an important fraction of total fine‐root length (79 %), but only 21 % of biomass. Only in this root class, consequent to change in mean diameter, specific root length peaked when soil water content was lowest showing an inverse relationship (p < 0.001). Furthermore, fine‐root production and turnover decreased with increasing root diameter. These results suggest that changes in root length per unit mass, and pulses in root growth to exploit transient periods of low soil water content may enable trees to increase nutrient and water uptake under seasonal drought conditions.
Development of microsatellite loci in the common reef starfish Linckia laevigata and Linckia multifora
Authors: Yasuda Nina , Taquet Coralie , Nagai Satoshi , Wörheide Gert , Nadaoka Kazuo
Published: September 2012

We isolated seven polymorphic microsatellite loci from the coral reef starfish Linckia laevigata—a common coral reef sea star distributed widely in the Indo‐Pacific. The number of alleles ranged from 4 to 13, with an average of 7.4. The ranges of observed and expected heterozygosities were 0.367/0.933 and 0.332/0.840 for L. laevigata and 0.182/0.818 and 0.329/0.697 for L. multifora, respectively. All of these markers can also be used in the sister species Linckia multifora. These microsatellite loci will be useful for population and conservation genetic studies in coral reef ecosystems.
Parallel transitive closure algorithm
Authors: Alves C. E. R. , Cáceres E. N. , de Castro A. A. , Song S. W. , Szwarcfiter J. L.
Published: September 2012

Using the BSP/CGM model, with
$$p$$
processors, where
$$p \ll n$$
, we present a parallel algorithm to compute the transitive closure of a digraph
$$D$$
with
$$n$$
vertices and
$$m$$
edges. Our algorithm uses
$$\log p + 1$$
communication rounds if the input is an acyclic directed graph labeled using a linear extension. For general digraphs, the algorithm requires
$$p$$
communication rounds in the worst case. In both cases,
$$O(M/p)$$
local computation is performed per round, where
$$M$$
is the amount of computation needed to compute a sequential transitive closure of a digraph. The presented algorithm can be implemented using any sequential algorithm that computes the transitive closure of a digraph
$$D$$
. We have implemented the algorithm using the Warshall transitive closure algorithm on two Beowulf clusters using MPI. The implementation results show its efficiency and scalability. It also compares favorably with other parallel implementations. The worst case (communication rounds) for a digraph was derived through an artificially elaborated example. However, in all our test cases, the algorithm never requires more than
$$\log p + 1$$
communication rounds and presents very promising implementation results. The algorithm also can be applied to any
$$n \times n$$
matrix that represents a binary relation.
RBM5 promotes exon 4 skipping of AID pre‐mRNA by competing with the binding of U2AF65 to the polypyrimidine tract
Authors: Jin Wenxing , Niu Zhaoyang , Xu Dan , Li Xialu
Published: September 2012

Alternative splicing is involved in functional regulation of the mutagenic enzyme activation‐induced cytidine deaminase (AID). However, the molecular basis for AID splicing regulation remains undefined. Using a mini‐gene‐based screen in HeLa cells, we found that overexpression of RNA binding motif protein 5 (RBM5, or LUCA‐15/H37) significantly promoted AID exon 4 skipping by suppressing the splicing of intron 3. The inhibitive effect of RBM5 on intron 3 splicing required a weak 3′‐splice site (ss). Indicative of the underlying mechanism, RBM5 interfered with the binding of U2AF65 to the polypyrimidine tract at the 3′‐ss in vitro. Our findings thus not only shed lights on the regulatory mechanism of AID exon 4 skipping, but also provide new insights into how RBM5 functions in splicing regulation.
Regulation of mean and noise of the in vivo kinetics of transcription under the control of the lac/ara‐1 promoter
Authors: Kandhavelu Meenakshisundaram , Lloyd-Price Jason , Gupta Abhishekh , Muthukrishnan Anantha-Barathi , Yli-Harja Olli , Ribeiro Andre S.
Published: September 2012

The kinetics of transcription initiation in Escherichia coli depend on the duration of two rate‐limiting steps, the closed and the open complex formation. In a lac promoter variant, P
lac/ara‐1
, the kinetics of these steps is controlled by IPTG and arabinose. From in vivo single‐RNA measurements, we find that induction affects the mean and normalized variance of the intervals between consecutive RNA productions. Transcript production is sub‐Poissonian in all conditions tested. The kinetics of each step is independently controlled by a different inducer. We conclude that the regulatory mechanism of P
lac/ara‐1
allows the stochasticity of gene expression to be environment‐dependent.
On the origin of the secondary vortex street
Authors: Kumar Bhaskar , Mittal Sanjay
Published: September 2012

The origin of the secondary vortex street, observed in the far wake in the flow past a circular cylinder, is investigated. The Reynolds number, based on the diameter of the cylinder, is 150. The von Kármán vortex street, which originates in the near wake, decays exponentially downstream of the cylinder. Beyond the region of decay, a broad band of frequencies are selectively amplified, leading to the formation of a secondary vortex street consisting of packets of large-scale vortex structures. The streamwise location of the onset of the instability, frequency of the generation of packets and their convection speed are estimated via direct numerical simulation (DNS). Global linear stability analysis of the time-averaged flow reveals the presence of unstable convective modes that travel at almost the same speed and have a structure similar to the packet-like disturbances as observed in the DNS. Sensitivity analysis of the global convective modes to structural perturbations is carried out to locate the region of the wake that is most significant in generating the modes responsible for the appearance of the secondary vortex street. This information is utilized to control the flow. By placing a ‘slip’ splitter plate along the wake centre line, in the overlap region of the direct and the adjoint modes, the oscillations in the far wake are significantly reduced, though the oscillations related to the primary vortex shedding in the near wake are not. It is also found that suppression of the primary vortex shedding leads to annihilation of the secondary vortex street as well. Linear stability analysis of the steady-state flow does not yield any modes that can explain the appearance of the secondary vortex street. The steady and time-averaged wake profiles, for the $\mathit{Re}= 150$ flow, are compared to bring out the differences in the two. The effect of free-stream oscillations on the evolution of the secondary vortex street is investigated. By reducing the amplitude of inlet excitation, a gradual transition from ordered shedding in the far wake to the appearance of a broad-band spectrum of frequencies, as in the unforced wake, is observed. All the computations have been carried out using a stabilized finite element method.
Shelter from the Global Economic Crisis: New Zealand and Overseas-Born Employees' Concerns and Migration Intentions
Authors: Parsons Jill , Tabor Aidan S. , Fischer Ronald
Published: September 2012

This study aimed to explore the personal effect of the global crisis on both New Zealanders and migrants, as well as their intentions and reasons to stay or migrate to another country. Using a mixed method design, we investigated the major concerns of workers in the Wellington region during 2009 and 2010. The main concerns were: salary, workload, job security, disposable income, work budget and job opportunity. New Zealand-born participants were as likely as migrants to express interest in leaving due to the state of the economy. However, overseas-born participants were more likely than New Zealand-born participants to say they would leave if they lost their job.
The Decisions and Ideal Points of British Law Lords
Authors: Hanretty Chris
Published: September 2012

Policy-sensitive models of judicial behaviour, whether attitudinal or strategic, have largely passed Britain by. This article argues that this neglect has been benign, because explanations of judicial decisions in terms of the positions of individual judges fare poorly in the British case. To support this argument, the non-unanimous opinions of British Law Lords between 1969 and 2009 are analysed. A hierarchical item-response model of individual judges’ votes is estimated in order to identify judges’ locations along a one-dimensional policy space. Such a model is found to be no better than a null model that predicts that every judge will vote with the majority with the same probability. Locations generated by the model do not represent judges’ political attitudes, only their propensity to dissent. Consequently, judges’ individual votes should not be used to describe them in political terms.
The Diffusion of Policy Diffusion Research in Political Science
Authors: Graham Erin R. , Shipan Charles R. , Volden Craig
Published: September 2012

Over the past fifty years, top political science journals have published hundreds of articles about policy diffusion. This article reports on network analyses of how the ideas and approaches in these articles have spread both within and across the subfields of American politics, comparative politics and international relations. Then, based on a survey of the literature, the who, what, when, where, how and why of policy diffusion are addressed in order to identify and assess some of the main contributions and omissions in current scholarship. It is argued that studies of diffusion would benefit from paying more attention to developments in other subfields and from taking a more systematic approach to tackling the questions of when and how policy diffusion takes place.
Mating ofHelicoverpa armigera(Lepidoptera: Noctuidae) moths and their host plant origins as larvae within Australian cotton farming systems
Authors: Baker G.H. , Tann C.R.
Published: September 2012

Transgenic (Bt) cotton dominates Australian cotton production systems. It is grown to control feeding damage by lepidopteran pests such asHelicoverpa armigera. The possibility that these moths might become resistant to Bt remains a threat. Consequently, refuge crops (with no Bt) must be grown with Bt cotton to produce large numbers of Bt-susceptible moths to reduce the risk of resistance developing. A key assumption of the refuge strategy, that moths from different host plant origins mate at random, remains untested. During the period of the study reported here, refuge crops included pigeon pea, conventional cotton (C3 plants), sorghum or maize (C4 plants). To identify the relative contributions made by these (and perhaps other) C3 and C4 plants to populations ofH. armigerain cotton landscapes, we measured stable carbon isotopes (δ13C) within individual moths captured in the field. Overall, 53% of the moths were of C4 origin. In addition, we demonstrated, by comparing the stable isotope signatures of mating pairs of moths, that mating is indeed random amongst moths of different plant origins (i.e. C3 and C4). Stable nitrogen isotope signatures (δ15N) were recorded to further discriminate amongst host plant origins (e.g. legumes from non-legumes), but such measurements proved generally unsuitable. Since 2010, maize and sorghum are no longer used as dedicated refuges in Australia. However, these plants remain very common crops in cotton production regions, so their roles as ‘unstructured’ refuges seem likely to be significant.
Effect of water availability and genetic diversity on flowering phenology, synchrony and reproductive investment in summer squash
Authors: CAMPBELL L. G. , LUO J. , MERCER K. L.
Published: September 2012

Current agricultural practices rely on crops with developmental phenologies adapted to local climate, photoperiods and soils; however, global climate change will alter some abiotic factors (e.g. temperature and precipitation). Previously adapted varieties may be poorly prepared for these changing conditions, if such conditions induce mismatched phenologies. Crops that depend on cross-pollination and synchronous flowering may be most susceptible, e.g. monoecious plants have separate male and female flowers, and changes in flowering synchrony may alter yield. Using genetically diverse (open-pollinated (OP)) and genetically homogeneous (hybrid) varieties of a monoecious crop, courgette, also known as zuchinni (Cucurbita pepo), phenological responses to experimentally manipulated moisture conditions were explored in an agricultural context. Under drier and wetter conditions, the hybrid courgette plants shifted towards a male-biased floral sex ratio due to the reduced production of female flowers. However, flowering synchrony and fruit production were unaffected by moisture treatment in both varieties. The hybrid and OP varieties differed in many traits related to floral sex ratios, phenology, synchrony and fruit production. Further, the OP variety displayed more phenotypic variation than the hybrid in many traits. Being in a population context rather than relying on self-pollination increased the availability of potential mates for a given female flower in both the hybrid and, particularly, the OP variety. Thus, the increased genetic diversity found in OP v. hybrid varieties may buffer the possible environmental effects on flowering synchrony within a cropping context. Finally, the likelihood of female flowers setting fruit increased with the number of male flowers within a population, and the rate of increase was higher in the hybrid variety. In summary, climate change is predicted to reduce investment in female function in some monoecious crops and genetically diverse varieties may play an important role in maintaining reproductive synchrony in altered environments.
High shear treatment of concentrates and drying conditions influence the solubility of milk protein concentrate powders
Authors: Augustin Mary Ann , Sanguansri Peerasak , Williams Roderick , Andrews Helen
Published: September 2012

The solubility of milk protein concentrate (MPC) powders was influenced by the method used for preparing the concentrate, drying conditions, and the type of dryer used. Increasing total solids of the ultrafiltered concentrates (23% total solids, TS) by diafiltration to 25% TS or evaporation to 31% TS decreased the solubility of MPC powders (80–83% protein, w/w dry basis), with ultrafiltration followed by evaporation to higher total solids having the greater detrimental effect on solubility. High shear treatment (homogenisation at 350/100 bar, microfluidisation at 800 bar or ultrasonication at 24 kHz, 600 watts) of ultrafiltered and diafiltered milk protein concentrates prior to spray drying increased the nitrogen solubility of MPC powders (82% protein, w/w dry basis). Of the treatments applied, microfluidisation was the most effective for increasing nitrogen solubility of MPC powders after manufacture and during storage. Manufacture of MPC powders (91% protein, w/w dry basis) prepared on two different pilot-scale dryers (single stage or two stage) from milk protein concentrates (20% TS) resulted in powders with different nitrogen solubility and an altered response to the effects of microfluidisation. Microfluidisation (400, 800 and 1200 bar) of the concentrate prior to drying resulted in increased long term solubility of MPC powders that were prepared on a single stage dryer but not those produced on a two stage spray dryer. This work demonstrates that microfluidisation can be used as a physical intervention for improving MPC powder solubility. Interactions between the method of preparation and treatment of concentrate prior to drying, the drying conditions and dryer type all influence MPC solubility characteristics.
New and little-known marine and freshwater species of the silica-scaled genera Thaumatomastix and Reckertia (Cercozoa: Thaumatomonadida)
Authors: Nicholls Kenneth H.
Published: September 2012

Six new marine species of the silica-scaled heterotrophic genus Thaumatomastix are formally described: two were found in Canadian Atlantic Ocean coastal waters (T. asymmetrica sp. nov. and T. sablensis sp. nov.) and four from Canadian Pacific Ocean coastal waters (T. inornata sp. nov., T. multipora sp. nov., T. gwaii sp. nov. and T. curvata sp. nov.). These discoveries more than double the number of known marine species of this genus from four to ten. The scale structures of all differ significantly from those of previously known species and therefore warrant erection as new species. Amended descriptions of two previously little-known freshwater species (T. triangulata and T. nigeriensis) are provided based on specimens found in freshwater ponds and lakes in Ontario, Lanada, and provide evidence refuting the recent published proposals to transfer T. triangulata back to the photo-autotrophic genus Chrysosphaerella and to transfer T. nigeriensis to the related thaumatomonad genus Reckertia. Until now, all known species of Reckertia (including several taxa previously classified in Thaumatomastix) were marine. This paper describes the first known freshwater species of Reckertia (R. hindoni sp. nov.) found in two separate Ontario ponds. The similarities and differences among many of the marine and freshwater species of Thaumatomastix suggest a common ancestor but significant evolutionary divergence over time and space.
The relationship between happiness and intelligent quotient: the contribution of socio-economic and clinical factors
Authors: Ali A. , Ambler G. , Strydom A. , Rai D. , Cooper C. , McManus S. , Weich S. , Meltzer H. , Dein S. , Hassiotis A.
Published: September 2012

Background

Happiness and higher intelligent quotient (IQ) are independently related to positive health outcomes. However, there are inconsistent reports about the relationship between IQ and happiness. The aim was to examine the association between IQ and happiness and whether it is mediated by social and clinical factors.

Method

The authors analysed data from the 2007 Adult Psychiatric Morbidity Survey in England. The participants were adults aged 16 years or over, living in private households in 2007. Data from 6870 participants were included in the study. Happiness was measured using a validated question on a three-point scale. Verbal IQ was estimated using the National Adult Reading Test and both categorical and continuous IQ was analysed.

Results

Happiness is significantly associated with IQ. Those in the lowest IQ range (70–99) reported the lowest levels of happiness compared with the highest IQ group (120–129). Mediation analysis using the continuous IQ variable found dependency in activities of daily living, income, health and neurotic symptoms were strong mediators of the relationship, as they reduced the association between happiness and IQ by 50%.

Conclusions

Those with lower IQ are less happy than those with higher IQ. Interventions that target modifiable variables such as income (e.g. through enhancing education and employment opportunities) and neurotic symptoms (e.g. through better detection of mental health problems) may improve levels of happiness in the lower IQ groups.
DECONSTRUCTING THE SYMBOLIC CITY: JEROME AS GUIDE TO LATE ANTIQUE ROME
Authors: Grig Lucy
Published: September 2012

This article considers the writings of Saint Jerome as a source for writing a cultural history of the city of Rome in late antiquity. Jerome is of course, in many respects, an unreliable witness but his lively and often conflicted accounts of the city do none the less provide significant insights into the city during an age of transition. He provides a few snippets for the scholar of topography, but these do not constitute the main attraction. Jerome's city of Rome appears above all as a textual palimpsest: variously painted in Vergilian colours as Troy and frequently compared with the biblical cities of Babylon, Bethlehem and Jerusalem. In the final analysis, it is argued, Jerome's Rome is surprisingly unstable, indeed a ‘soft city’.
THIRTEENTH-CENTURY SEIGNIORIAL INSTITUTIONS AND OFFICIALS oF THE GUIDI COUNTS
Authors: Casini Tommaso
Published: September 2012

This paper illustrates some aspects of rural lordship in thirteenth-century north and central Italy, namely the territorial framework for the exercise of seigniorial powers and the seigniorial officials who administered the lords' dominions. How were seigniorial territories organized from an institutional point of view? How did the lords manage the adjustments and changes occurring in their lordships due to inheritance, purchases and sales of seigniorial rights? How was that framework connected to the institutional organization of rural communities? Who were the men who administered those lordships and how long did the connection between the families of those officials and the lords last? These are the questions I have tried to answer through the study of deeds (recorded in charters and notarial registers) regarding the Guidi counts, a family belonging to the upper aristocracy of north-central Italy. This study focuses on institutional matters, but in the section devoted to the relations between lords and seigniorial officials a prosopographical approach is adopted. The dynamics investigated in this study were fundamental in the historical evolution of the north-central Italian countryside, and their analysis provides useful material for further comparison with analogous phenomena in other parts of Europe.
PAINTINGS FOR DOMINICAN NUNS: A NEW LOOK AT THE IMAGES OF SAINTS, SCENES FROM THE NEW TESTAMENT AND APOCRYPHA, AND EPISODES FROM THE LIFE OF SAINT CATHERINE OF SIENA IN THE MEDIEVAL APSE OF SAN SISTO VECCHIO IN ROME
Authors: Barclay Lloyd Joan
Published: September 2012

Fragments of frescoes were found in the late nineteenth century on the medieval apse wall, hidden behind the fifteenth-century chancel, of the Dominican nunnery church of San Sisto Vecchio, Rome. They were painted in two phases, one in the late thirteenth or early fourteenth century, the other approximately a century later. When they were restored in 1990–2, two new scenes came to light. This paper reconsiders the murals of both phases, including the images uncovered during the restoration campaigns. Historical evidence shines new light on the medieval patrons of the nunnery, who were relatives of individual nuns, and reveals the social context in which buildings and paintings were provided for the convent. It is argued that the frescoes were designed for the Dominican nuns, whose religious ideals are reflected in their iconography. Up until now studies of these murals have not paid much attention to their socio-historical importance, nor the Dominican significance of the images, even in two scenes from the life of Saint Catherine of Siena. Accordingly, this study contributes to the discussion of the frescoes by placing them in a ‘Dominican’ framework, attempting to show what they may have meant to the medieval nuns in the convent.
A HUNDRED YEARS OF ROMAN HISTORY: HISTORIOGRAPHY AND INTELLECTUAL CULTURE
Authors: Smith Christopher J.
Published: September 2012

In 2010, the Society for the Promotion of Roman Studies achieved its centenary. In 2012, the British School at Rome, which was closely linked to the origins of the Roman Society, celebrates the centenary of its Royal Charter. This marked the formal establishment of the distinctively broad and interdisciplinary remit of the School by the inclusion of humanities, art and architecture in a single institution. The combination of these two anniversaries has given rise to this attempt to think through some of the paths that Roman studies have taken, and to understand them within the context of broader developments in particularly British and Italian historiography. The Roman Society and the British School at Rome have many points of connection, both in terms of individuals and in terms of research interest. Recent work on the development of a British historical tradition has shown that it remains important to ground the reading of historical scholarship within the intellectual trajectory of its practitioners. This is, therefore, an argument about how the research represented in theJournal of Roman Studies, and conducted at the British School at Rome, and ultimately more widely, should be seen in a historiographical context.
Report of the Council for the Year 1931
Authors: Taylor M. V.
Published: September 2012

The Council has the honour to present to the members of the Society for the Promotion of Roman Studies, their Report for the year 1931.

1. It will be seen from the Income and Expenditure account for 1931 that subscriptions at £559 were slightly in excess of those received in 1930 and that there were no life composition fees, so that the amount received from members was smaller.

The income from the investments is slightly smaller, due chiefly to increased taxation which it is hoped to recover. On the expenditure side, publications cost £920, of which £250 was specially provided the previous year to cover vol. XX, part 2. Administration expenses remained almost the same. Library expenses at £279 w e r e slightly higher, due to additional cost of stationery and postage and reduced sales of lantern slides. Donations to excavation funds, etc., were £92 compared with £80 in 1930 and there wer no subscriptions to be written off. The result of the year's working was that the expenditure exceeded the income by .£240 as compared with £201 the previous year. It is obvious that in order to carry on the admirable work done by the Society new subscribers are urgently needed. It is hoped that members will make every effort to help the Society by bringing its merits before their friends.
Eduard Fraenkel: Bibliography
Authors: Horsfall Nicholas
Published: September 2012

Eduard Fraenkel would not allow a bibliography of his writings to be compiled during his lifetime: his opus was not yet complete. Now a bibliography may serve as a tribute to a very great scholar and teacher, and will, I hope, be of some practical value. This bibliography was put together in 1971; JRS has now most kindly obviated further delays in publication. I am grateful to Professors H. Haffter, G. N. Knauer, A. D. Momigliano, F. Munari, C. F. Russo, and O. Skutsch, to Signora N. De Luca, the late Dr. S. Weinstock, the staff of the Ashmolean Museum Library and above all to Mr. Colin Macleod for their co-operation.
Memantine as adjunctive treatment to risperidone in children with autistic disorder: a randomized, double-blind, placebo-controlled trial
Authors: Ghaleiha Ali , Asadabadi Mahtab , Mohammadi Mohammad-Reza , Shahei Maryam , Tabrizi Mina , Hajiaghaee Reza , Hassanzadeh Elmira , Akhondzadeh Shahin
Published: September 2012

Autism is a neurodevelopmental disorder that causes significant impairment in socialization and communication. It is also associated with ritualistic and stereotypical behaviour. Recent studies propose both hyper-and hypoglutamatergic ideologies for autism. The objective of this study was to assess the effects of memantine plus risperidone in the treatment of children with autism. Children with autism were randomly allocated to risperidone plus memantine or placebo plus risperidone for a 10-wk, double-blind, placebo-controlled study. The dose of risperidone was titrated up to 3 mg/d and memantine was titrated to 20 mg/d. Children were assessed at baseline and after 2, 4, 6, 8 and 10 wk of starting medication protocol. The primary outcome measure was the irritability subscale of Aberrant Behavior Checklist–Community (ABC-C). Difference between the two treatment arms was significant as the group that received memantine had greater reduction in ABC-C subscale scores for irritability, stereotypic behaviour and hyperactivity. Eight side-effects were observed over the trial, out of the 25 side-effects that the checklist included. The difference between the two groups in the frequency of side-effects was not significant. The present study suggests that memantine may be a potential adjunctive treatment strategy for autism and it was generally well tolerated. This trial is registered with the Iranian Clinical Trials Registry (IRCT1138901151556N10; www.irct.ir)
Autonomous agents coordination: Action languages meet CLP() and Linda
Authors: DOVIER AGOSTINO , FORMISANO ANDREA , PONTELLI ENRICO
Published: September 2012

The paper presents a knowledge representation formalism, in the form of a high-levelAction Description Language (ADL)for multi-agent systems, where autonomous agents reason and act in a shared environment. Agents are autonomously pursuing individual goals, but are capable of interacting through a shared knowledge repository. In their interactions through shared portions of the world, the agents deal with problems of synchronization and concurrency; the action language allows the description of strategies to ensure a consistent global execution of the agents’ autonomously derived plans. A distributed planning problem is formalized by providing the declarative specifications of the portion of the problem pertaining to a single agent. Each of these specifications is executable by a stand-alone CLP-based planner. The coordination among agents exploits a Linda infrastructure. The proposal is validated in a prototype implementation developed in SICStus Prolog.
The Genetic and Environmental Structure of the Covariation Among the Symptoms of Insomnia, Fatigue, and Depression in Adult Females
Authors: Hur Yoon-Mi , Burri Andrea , Spector Tim D.
Published: September 2012

Although the co-occurrence among symptoms of insomnia, fatigue, and depression has been frequently reported, the etiology of this co-occurrence remains poorly understood. A total of 3,758 adult female twins in the United Kingdom completed a mail-out survey including six questions concerning frequency and severity of symptoms of insomnia, fatigue, and depression. Correlations among the scores of the three symptoms ranged from 0.35 to 0.44. Among various multivariate models we tested, the common-pathway model explained the data best. In the best-fitting model, the common factor was explained approximately equally by genetic and unique environmental factors (49% and 51%, respectively). In addition to the common variance, there was a significant specific variance in each symptom, where unique environmental factors were much larger than genetic factors. These results imply that although there are shared genetic liabilities for the development of symptoms of depression, fatigue, and insomnia, it is environmental experiences that make etiological distinctions among three symptoms.
Cosmic rays: 1912–2012
Authors: Israel Martin H.
Published: September 2012

One hundred years ago, using balloon flights up to 5 kilometers altitude, Victor Hess demonstrated that the intensity of penetrating ionizing radiation increased with altitude, indicating that Earth is exposed to high‐energy radiation from space [Hess, 1912]. Since that observation, these “cosmic rays” have enabled discoveries basic to elementary particle physics and astrophysics. This discovery earned Hess the 1936 Nobel Prize in Physics, shared with Carl Anderson, who discovered the positron among the secondary cosmic rays near the ground [Anderson, 1933]. Then, the only known ionizing radiation with range in air more than about 30 centimeters was the g ray (electromagnetic radiation with energy above about 100 kiloelectron volts), so the radiation from space was assumed to be g rays and was called “cosmic rays.” That name has stuck, although the “cosmic rays” studied today are not actually rays but particles. Indeed, g rays do impinge on Earth, and g ray astronomy is a burgeoning area of astrophysics, but the term “cosmic rays” continues to apply to the charged particles that make up the bulk of the incident ionizing radiation.
Armstrong remembered at memorial
Authors: Showstack Randy
Published: September 2012

Neil Armstrong, who died on 25 August, was recognized during a 13 September memorial service as a courageous, humble, and reluctant hero who in 1969 became the first person to step onto the Moon. The service, held at the National Cathedral in Washington, D. C., included remembrances from astronauts and friends, an excerpt from President John Kennedy's 1962 “We choose to go to the Moon” speech, and a somber rendition of the jazz standard “Fly Me to the Moon.” NASA administrator Charles Bolden said that Armstrong, commander of NASA's Apollo 11 mission, “left a foundation for the future and paved the way for future American explorers to be first to step foot on Mars or another planet. Today, let us recommit ourselves to this grand challenge in honor of the man who first demonstrated it was possible to reach new worlds—and whose life demonstrated the quiet resolve and determination that makes every new, more difficult step into space possible.”
New AGU scientific integrity and professional ethics policy available for review
Authors: Gundersen Linda
Published: September 2012

The AGU Task Force on Scientific Ethics welcomes your review and comments on AGU's new Scientific Integrity and Professional Ethics Policy. The policy has at its heart a code of conduct adopted from the internationally accepted “Singapore Statement,” originally created by the Second World Conference on Research Integrity (http://www.singaporestatement.org/), held in 2010. The new policy also encompasses professional and publishing ethics, providing a single source of guidance to AGU members, officers, authors, and editors.
Water Resources Research supports water economics submissions
Authors: Griffin Ronald C.
Published: September 2012

AGU's international interdisciplinary journal Water Resources Research (WRR) publishes original contributions in hydrology; the physical, chemical, and biological sciences; and the social and policy sciences, including economics, systems analysis, sociology, and law. With the rising relevance of water economics and related social sciences, the editors of WRR continue to encourage submissions on economics and policy. WRR was originally founded in the mid 1960s by Walter Langbein and economist Allen Kneese. Several former WRR editors have been economists—including David Brookshire, Ron Cummings, and Chuck Howe—and many landmark articles in water economics have been published in WRR.
Dryland climatology
Authors: D'Odorico Paolo
Published: September 2012

Almost anyone, if asked to define drylands, would mention the scarce and variable precipitation and the consequently sparse vegetation cover typical of these environments. Dryland climates play a crucial role in determining the hydrologic conditions of soils and streams, the composition and spatial organization of vegetation, the rate of biogeochemical cycles, and the dominant geomorphic processes. What, more specifically, are the physical and biotic mechanisms controlling the effect of climate on ecosystem dynamics and Earth surface processes in dryland regions? How does climate, in turn, respond to changes in land surface conditions? The answer to these questions requires not only a multiscale analysis of atmospheric processes (from microclimate to the global circulation) but also the study of hydrologic, ecologic, and geomorphic dynamics.
Desert dust deposition reduces snow cover in Colorado Mountains
Authors: Bhattacharya Atreyee
Published: September 2012

Dust deposition on the mountains of southwest Colorado may have reduced springtime snow cover by 1–2 months per year compared to low‐dust conditions, a new study finds. When dust is deposited on snow surface, it increases absorption of solar radiation, accelerating snowmelt. Increasing land disturbances, beginning since the early settlers arrived in the western United States during the mid‐1800s, have kicked large quantities of dust into the atmosphere; this dust gets deposited on the snow‐covered mountains of Colorado. Skiles et al. used 6 years of observations, between 2005 and 2010, to understand how soil dust loading has affected snow cover on the San Juan Mountains of southwest Colorado during the springtime snow‐melting season. The authors found that dust loading, which varied by an order of magnitude over the study period, was not necessarily related to the number of seasonal dust events. The increased dust load reduced snow cover by 25–51 days during spring, with the magnitude of impact being directly related to the amount of dust loading. The authors further suggest that the thinning of snow cover due to dust is greater than that expected from the projected 2°C–4°C increase in regional temperature.
Submesoscale dynamics: Bringing physics to life
Authors: Balcerak Ernie
Published: September 2012

Vertical motions play a key role in primary production in the upper ocean, as they transport nutrients that phytoplankton need to grow. Until recently, scientists believed that three main types of dynamics dominated vertical motions in the upper ocean: mesoscale geostrophic eddies at horizontal scales on the order of 10–100 kilometers, internal waves with horizontal scales on the order of 0.1–10 kilometers, and microscale turbulence on scales of 0.01 kilometers or less. Now, scientists are beginning to realize the importance a fourth type of dynamics: submesoscale dynamics near the ocean surface. Submesoscale dynamics have horizontal scales on the order of 1–10 kilometers, vertical scales on the order of 100 meters, and time scales on the order of 1 day. Submesoscale dynamics arise through advective interactions that involve mesoscale currents and are influenced by Earth's rotation and the ocean's density stratification.
Spherical-sapphire-based whispering gallery mode resonator thermometer
Authors: Yu Lili , Fernicola V.
Published: September 2012

A novel microwave whispering gallery mode (WGM) resonator based on a spherical sapphire crystal was developed at INRIM and its use as a thermometer was tested. The temperature dependence of the WGM frequencies was studied and the most promising resonance near to 13.6 GHz, with a loaded quality factor as large as 82 000, was carefully investigated. Its potential use in thermometry was evaluated through a study of its main metrological characteristics, such as the temperature sensitivity, the frequency stability, the repeatability, and the resolution at several temperatures over the temperature range −40 °C to 85 °C. Finally, the INRIM spherical sapphire thermometer was compared with the NIST SWGT, a dielectric thermometer based on a cylindrical sapphire resonator [V. B. Braginsky, V. S. Ilchenko, and Kh. S. Bagdassarov, Phys. Lett. A 120(3), 300 (1987)10.1016/0375-9601(87)90676-1].
On the method of photoluminescence spectral intensity ratio imaging of silicon bricks: Advances and limitations
Authors: Mitchell Bernhard , Weber Jürgen W. , Walter Daniel , Macdonald Daniel , Trupke Thorsten
Published: September 2012

Spectral photoluminescence imaging is able to provide quantitative bulk lifetime and doping images if applied on silicon bricks or thick silicon wafers. A comprehensive study of this new method addresses previously reported artefacts in low lifetime regions and provides a more complete understanding of the technique. Spectrally resolved photoluminescence measurements show that luminescence originating from sub band gap defects does not cause those artefacts. Rather, we find that optical light spreading within the silicon CCD is responsible for most of the distortion in image contrast and introduce a method to measure and remove this spreading via image deconvolution. Alternatively, image blur can be reduced systematically by using an InGaAs camera. Results of modelling this alternative camera type and experiments are shown and discussed in comparison. In addition to eliminating the blur effects, we find a superior accuracy for lifetimes above 100 μs with significantly shorter, but dark noise limited exposure times.
Heat transfer enhancement with actuation of magnetic nanoparticles suspended in a base fluid
Authors: Şeşen Muhsincan , Tekşen Yiğit , Şendur Kürşat , Pınar Mengüç M. , Öztürk Hande , Yağcı Acar H. F. , Koşar Ali
Published: September 2012

In this study, we have experimentally demonstrated that heat transfer can be substantially increased by actuating magnetic nanoparticles inside a nanofluid. In order to materialize this, we have utilized a miniature heat transfer enhancement system based on the actuation of magnetic nanoparticles dispersed in a base fluid (water). This compact system consists of a pool filled with a nanofluid containing ferromagnetic nanoparticles, a heater, and two magnetic stirrers. The ferromagnetic particles within the pool were actuated with the magnetic stirrers. Single-phase heat transfer characteristics of the system were investigated at various fixed heat fluxes and were compared to those of stationary nanofluid (without magnetic stirring). The heat transfer enhancement realized by the circulation of ferromagnetic nanoparticles dispersed in a nanofluid was studied using the experimental setup. The temperatures were recorded from the readings of thin thermocouples, which were integrated to the heater surface. The surface temperatures were monitored against the input heat flux and data were processed to compare the heat transfer results of the configuration with magnetic stirrers to the heat transfer of the configuration without the magnetic stirrers.
Affine-response model of molecular solvation of ions: Accurate predictions of asymmetric charging free energies
Authors: Bardhan Jaydeep P. , Jungwirth Pavel , Makowski Lee
Published: September 2012

Two mechanisms have been proposed to drive asymmetric solvent response to a solute charge: a static potential contribution similar to the liquid-vapor potential, and a steric contribution associated with a water molecule's structure and charge distribution. In this work, we use free-energy perturbation molecular-dynamics calculations in explicit water to show that these mechanisms act in complementary regimes; the large static potential (∼44 kJ/mol/e) dominates asymmetric response for deeply buried charges, and the steric contribution dominates for charges near the solute-solvent interface. Therefore, both mechanisms must be included in order to fully account for asymmetric solvation in general. Our calculations suggest that the steric contribution leads to a remarkable deviation from the popular “linear response” model in which the reaction potential changes linearly as a function of charge. In fact, the potential varies in a piecewise-linear fashion, i.e., with different proportionality constants depending on the sign of the charge. This discrepancy is significant even when the charge is completely buried, and holds for solutes larger than single atoms. Together, these mechanisms suggest that implicit-solvent models can be improved using a combination of affine response (an offset due to the static potential) and piecewise-linear response (due to the steric contribution).
Full extraction methods to retrieve effective refractive index and parameters of a bianisotropic metamaterial based on material dispersion models
Authors: Hsieh Feng-Ju , Wang Wei-Chih
Published: September 2012

This paper discusses two improved methods in retrieving effective refractive indices, impedances, and material properties, such as permittivity (ε) and permeability (μ), of metamaterials. The first method modified from Kong's retrieval method allows effective constitutive parameters over all frequencies including the anti-resonant band, where imaginary parts of ε or μ are negative, to be solved. The second method is based on genetic algorithms and optimization of properly defined goal functions to retrieve parameters of the Drude and Lorentz dispersion models. Equations of effective refractive index and impedance at any reference planes are derived. Split ring resonator-rod based metamaterials operating in terahertz frequencies are designed and investigated with proposed methods. Retrieved material properties and parameters are used to regenerate S-parameters and compared with simulation results generated by cst microwave studio software.
Possibility of a (bi)polaron high-temperature superconductivity in Poly A/ Poly T DNA duplexes
Authors: Lakhno Victor D. , Sultanov Vladislav B.
Published: September 2012

Dynamical equations for a polaron and bipolaron in a DNA duplex are obtained on the basis of Holstein-Hubbard Hamiltonian. It is shown that in a Poly A/Poly T duplex especially stable is a bipolaron state in which holes are localized on different chains of the duplex. With the use of the polaron and bipolaron free energy, the temperature of bipolaron decay is found to be Td ≈ 350 K which can serve as an approximate estimate of the superconducting transition temperature. The way of constructing superconducting nanowires on the basis of DNA is suggested.
Measurement setup for the simultaneous determination of diffusivity and Seebeck coefficient in a multi-anvil apparatus
Authors: Jacobsen M. K. , Liu W. , Li B.
Published: September 2012

In this paper, a high pressure setup is presented for performing simultaneous measurements of Seebeck coefficient and thermal diffusivity in multianvil apparatus for the purpose of enhancing the study of transport phenomena. Procedures for the derivation of Seebeck coefficient and thermal diffusivity/conductivity, as well as their associated sources of errors, are presented in detail, using results obtained on the filled skutterudite, Ce0.8Fe3CoSb12, up to 12 GPa at ambient temperature. Together with recent resistivity and sound velocity measurements in the same apparatus, these developments not only provide the necessary data for a self-consistent and complete characterization of the figure of merit of thermoelectric materials under pressure, but also serve as an important tool for furthering our knowledge of the dynamics and interplay between these transport phenomena.