bluuebunny/crossref_metadata_2025 huggingface dataset:
Colloid mobilization in an undisturbed sediment core under semiarid recharge rates
Authors: Liu Ziru , Flury Markus , Harsh James B. , Mathison Jon B. , Vogs Carolina
Published: June 2013

The semiarid US Department of Energy Hanford site has a deep vadose zone with low recharge rates. Contaminants originating from nuclear waste processing are expected to move slowly through the vadose zone. The movement of certain contaminants can be facilitated by colloids. We hypothesized that the low recharge rates and low water contents in semiarid regions, however, tend to inhibit movement of colloidal particles, thereby reducing the risk for colloid‐facilitated contaminant transport. The goal of this study was to investigate whether in situ natural colloids can be mobilized and transported in undisturbed, deep vadose zone sediments at the Hanford site under typical, semiarid recharge rates. We sampled an undisturbed sediment core (i.d. 50 cm, 59.5 cm height) from a depth of 17 m below ground at the Hanford 200 Area. The core was set up as a laboratory lysimeter and exposed to an infiltration rate of 18 mm/yr by applying simulated pore water onto the surface. Particle concentrations were quantified in the column outflow, and selected samples were examined microscopically and for elemental composition (transmission electron microscopy and energy dispersive X‐ray). Measured water contents and potentials were used to calibrate a numerical model (HYDRUS‐1D), which was then applied to simulate colloid mobilization from the sediment core. During 5.3 years of monitoring, natural colloids like silicates, aluminosilicates, and Fe‐oxides were observed in the core outflow, indicating the continuous mobilization of in situ colloids. The total amount of particles mobilized during 5.3 years corresponded to 1.1% of the total dispersible colloids inside the core. Comparison of the amounts of colloids released with weathering rates suggests that mineral weathering can be a major source of the mobilized colloids. The fitted colloid release rate coefficient was 6 to 7 orders of magnitude smaller than coefficients reported from previous studies, where disturbed Hanford sediments and higher flow rates were used. Our findings demonstrate that even under low recharge rates and water contents typical for semiarid, deep vadose zone sediments, particles can continuously be mobilized, although the total mass of particles is low.
The S parameter for a light composite Higgs: a dispersion relation approach
Authors: Orgogozo Axel , Rychkov Slava
Published: June 2013

Abstract

We derive a dispersion relation for the S parameter in the SO(5)/SO(4) Minimal Composite Higgs model. This generalizes the Peskin-Takeuchi formula to the case when a light Higgs boson is present in the spectrum. Our result combines an IR effect due to the reduction in the Higgs boson couplings with a UV contribution from the strong sector. It also includes a finite matching term, achieving a very good relative accuracy O(m

h

/m

ρ
). We apply our formula in several toy examples, modeling the UV spectral density via Vector Meson Dominance.
Whole-body cryostimulation as an effective method of reducing low-grade inflammation in obese men
Authors: Ziemann Ewa , Olek Robert A. , Grzywacz Tomasz , Antosiewicz Jędrzej , Kujach Sylwester , Łuszczyk Marcin , Smaruj Mirosław , Śledziewska Ewelina , Laskowski Radosław
Published: June 2013

This study was aimed to evaluate anti-inflammatory effect of the whole body cryostimulation in obese men. Fourteen subjects (BMI >30 kg m−2), divided into two subgroups according to cardiorespiratory fitness: higher (HCF) or lower (LCF), have been exposed to 10 sessions in a cryogenic chamber (−110 °C). Blood samples were collected before, 30 min and 24 h after the first, fifth and last cryostimulation. Coldness exposures affected blood cytokine profile; however, the response depended on subjects’ fitness capacity. Concentrations of pro-inflammatory cytokines in the LCF decreased by 19, 6.8, and 7.4 % in IL-6, resistin, and visfatin, respectively. TNFα in the LCF dropped 4.3-fold compared to baseline, while in the HCF, changes were smaller, yet significant. Anti-inflammatory cytokine IL-10 increased in both groups. No changes in adiponectin and leptin were observed in either group. Obtained results suggest that whole body cryostimulation can be a supplementary method for obese in reducing systemic inflammation.
Mortality Increase in Late-Middle and Early-Old Age: Heterogeneity in Death Processes as a New Explanation
Authors: Li Ting , Yang Yang Claire , Anderson James J.
Published: June 2013

Deviations from the Gompertz law of exponential mortality increases in late-middle and early-old age are commonly neglected in overall mortality analyses. In this study, we examined mortality increase patterns between ages 40 and 85 in 16 low-mortality countries and demonstrated sex differences in these patterns, which also changed across period and cohort. These results suggest that the interaction between aging and death is more complicated than what is usually assumed from the Gompertz law and also challenge existing biodemographic hypotheses about the origin and mechanisms of sex differences in mortality. We propose a two-mortality model that explains these patterns as the change in the composition of intrinsic and extrinsic death rates with age. We show that the age pattern of overall mortality and the population heterogeneity therein are possibly generated by multiple dynamics specified by a two-mortality model instead of a uniform process throughout most adult ages.
Over‐expression of human cytomegalovirus miR‐US25‐2‐3p downregulates eIF4A1 and inhibits HCMV replication
Authors: Qi Manlong , Qi Ying , Ma Yanping , He Rong , Ji Yaohua , Sun Zhengrong , Ruan Qiang
Published: June 2013

It has been reported that human cytomegalovirus (HCMV) miR‐US25‐2 reduces DNA viral replication including HCMV. However, the mechanism remains unknown. In our study, eukaryotic translation initiation factor 4A1 (eIF4A1) was identified to be a direct target of miR‐US25‐2‐3p. Small interfering RNA (siRNA) and miR‐US25‐2‐3p mediated eIF4A1 knockdown experiments revealed that high level of miR‐US25‐2‐3p in MRC‐5 cells decreased HCMV and host genomic DNA synthesis, and inhibited cap‐dependent translation and host cell proliferation. However, eIF4A1 up‐regulation induced by miR‐US25‐2‐3p inhibitor increased HCMV copy number. Therefore, the over‐expression of miR‐US25‐2‐3p and consequent lower expression of eIF4A1 may contribute to the inhibition of HCMV replication.
Alternative splicing variants of proinsulin mRNA and the effects of excess proinsulin on cardiac morphogenesis
Authors: Martínez-Campos Enrique , Hernández-SanMiguel Esther , López-Sánchez Carmen , De Pablo Flora , Hernández-Sánchez Catalina
Published: June 2013

Alternative forms of proinsulin mRNA with differential translational capacities and unknown significance are expressed in several developing tissues and in the adult pancreas. In the chick embryo developing heart, we observed low expression of the translationally active transcript of embryonic proinsulin (Pro1B), and predominant expression of the intron 1‐unspliced variant, translationally inactive. In the embryonic mouse heart, intron 1‐unspliced isoform appeared after E12.5. This tight regulation is required for normal development, since overexpression of Pro1B resulted in abnormal cardiac morphogenesis in 40% of chick embryos, and was accompanied by changes in gene expression of Amhc1and Vmhc1.
Body enhancement through female genital cosmetic surgery creates ethical and rights dilemmas
Authors: Cain Joanna M. , Iglesia Cheryl B. , Dickens Bernard , Montgomery Owen
Published: June 2013

Female genital cosmetic surgery is surgery performed on a woman within a normal range of variation of human anatomy. The issues are heightened by a lack of long‐term and substantive evidence‐based literature, conflict of interest from personal financial gain through performing these procedures, and confusion around macroethical and microethical domains. It is a source of conflict and controversy globally because the benefit and harm of offering these procedures raise concerns about harmful cultural views, education, and social vulnerability of women with regard to both ethics and human rights. The rights issues of who is defining normal female anatomy and function, as well as the economic vulnerability of women globally, bequeath the profession a greater responsibility to ensure that there is adequate health and general education—not just among patients but broadly in society—that there is neither limitation nor interference in the decision being made, and that there are no psychological disorders that could be influencing such choices.
Luxury and locality in a late medieval book of hours from south-west England
Authors: Luxford Julian
Published: June 2013

This paper describes and analyses a previously unrecorded Sarum book of hours of considerable artistic and textual interest. Seven of its pages have bar-frame borders illuminated in a distinctive and remarkable style. Four of these pages also have initials with figure-subjects, some of which are contextually unusual or unique. There is also an initial with a coat of arms displaying a black engrailed cross on a gold field (the arms of Mohun of Dunster in west Somerset). While the manuscript cannot be linked to a member of the Mohun family, the occurrence of a Somerset toponym in an obit dated 1429 in the calendar and the early addition to the litany of St Urith of Chittlehampton show that it was owned by someone who lived in Somerset or Devon in the early fifteenth century. Indeed, the book may also have been made in this region. Several features of its border illumination are paralleled in the Sherborne Missal (London, British Library, Additionalms74236), produced in north Dorset or Somerset in the decadec1398–c1408. The parallels suggest a relationship (not necessarily direct) between the two manuscripts. Certainly, the book of hours discussed here is closer in style to the missal than it is to manuscripts made in or around London in the same period.
SHAPING THE SAUDI STATE: HUMAN AGENCY'S SHIFTING ROLE IN RENTIER-STATE FORMATION
Authors: Hertog Steffen
Published: June 2013

The article offers a revisionist account of how the modern Saudi state emerged in the 1950s
and 1960s. Differing with structuralist “rentier-state” accounts, I contend that individual agency
has been very important in shaping the Saudi bureaucracy as oil money gave unique, although
temporary, autonomy to princely elites to organize the state around their personal interests.
Emerging institutions functioned as power tokens, leading to a fragmented administrative setup in
which ministries serve as “fiefdoms” and bureaucratic capacities vary strongly from one institution
to another. Through state growth and the “locking in” of distributional commitments, the autonomy
of princely elites to redesign the state has strongly declined over time, meaning that many early
institutional decisions have permanently impacted the shape and capacities of today's Saudi state.
Vis-agrave;-vis rentier theory, I demonstrate that regime autonomy is not constant over time and that the
quality of institutions is historically contingent and not determined by oil, which merely enlarges
the menu of institutional choices available to rentier-state elites.
Bede's Agenda in Book IV of the ‘Ecclesiastical History of the English People’: A Tricky Matter of Advising the King
Authors: HIGHAM N. J.
Published: June 2013

Bede's preoccupations in the later years of his life have recently come under close scrutiny. This article will set out the argument to this point, then explore how the Ecclesiastical history conforms to more general perceptions of Bede's purposes. It will conclude that this work was designed to address just one part of his wider reform agenda, as that pertained to the Northumbrian king of the day, Ceolwulf. To this end, Bede painted a picture of the current situation within the Church which is far more optimistic than that on offer in the Letter to Ecgberht just a few years later. It must be concluded that his specific purposes as regards any particular work, and the audience at which that work was aimed, exercised a considerable influence over his strategy, which varies enormously from one part of his output to another.
Work-related factors as predictors in the retirement decision-making process of older workers in the Netherlands
Authors: VAN SOLINGE HANNA , HENKENS KÈNE
Published: June 2013

This article examines work-related factors and their impact on the retirement decision-making process. We particularly focus on organisational human resources policies and normative climate regarding retirement. Organisations create opportunities and conditions for career extension via their personnel instruments. The normative climate may encourage or discourage retirement. We use a ten-year follow-up study among 1,458 older employees in the Netherlands aged 50–59 at baseline. Results reveal that older workers are sensitive to social approval earned from their co-workers and supervisor. A social climate that supports working up to higher ages is an important requisite for reducing the attractiveness of the early retirement option. Retirement intentions, formed in the years prior to retirement, are shaped by workplace norms and supervisors' attitudes. Results indicate that in order to delay retirement, policy initiatives cannot be reduced to altering financial restrictions surrounding retirement but need to address the forces at the organisational level that channel workers out of employment.
Alternate housing models for older people with disabilities: their clientele, structures and resources in relation to the quality of and satisfaction with care delivery
Authors: DUBUC NICOLE , DUBOIS MARIE-FRANCE , DEMERS LOUIS , TOURIGNY ANDRÉ , TOUSIGNANT MICHEL , DESROSIERS JOHANNE , CORBIN CINTHIA , TROTTIER LISE , RAÎCHE MICHEL
Published: June 2013

This paper reports on the study of a subsidy programme that was established in Quebec for alternate housing models (AHMs), which allows private and community organisations to offer housing services within the framework of a partnership with public health-care services. The research objectives were: (a) to compare how facility characteristics and services provided by AHMs and nursing homes (NHs) differ; (b) to examine the personal characteristics of residents living in AHMs; and (c) to compare residents with similar characteristics within AHMs and NHs in terms of unmet needs, quality of care, satisfaction with care and services, and psycho-social adaptation to the residence. A cross-sectional study was undertaken with individually matched groups to assess whether AHMs meet the needs of elders in a way similar to NHs. Overall, residents in both groups had moderate to severe levels of disability and about 60 per cent had mild to severe cognitive problems. While their general features were heterogeneous, the AHMs were more comfortable and homelike than the NHs. The quality of and satisfaction with care was appropriate in both settings, although AHMs performed better. Only one-quarter of residents in both settings, however, evidenced a good level of psycho-social adaptation to their residence. This partnership approach is a good strategy to provide a useful range of housing types in communities that can respond to the needs of elders with moderate to severe disabilities.
Subclinical infection and asymptomatic carriage of gastrointestinal zoonoses: occupational exposure, environmental pathways, and the anonymous spread of disease
Authors: QUILLIAM R. S. , CROSS P. , WILLIAMS A. PRYSOR , EDWARDS-JONES G. , SALMON R. L. , RIGBY D. , CHALMERS R. M. , THOMAS D. Rh. , JONES D. L.
Published: June 2013

Asymptomatic carriage of gastrointestinal zoonoses is more common in people whose profession involves them working directly with domesticated animals. Subclinical infections (defined as an infection in which symptoms are either asymptomatic or sufficiently mild to escape diagnosis) are important within a community as unknowing (asymptomatic) carriers of pathogens do not change their behaviour to prevent the spread of disease; therefore the public health significance of asymptomatic human excretion of zoonoses should not be underestimated. However, optimal strategies for managing diseases where asymptomatic carriage instigates further infection remain unresolved, and the impact on disease management is unclear. In this review we consider the environmental pathways associated with prolonged antigenic exposure and critically assess the significance of asymptomatic carriage in disease outbreaks Although screening high-risk groups for occupationally acquired diseases would be logistically problematical, there may be an economic case for identifying and treating asymptomatic carriage if the costs of screening and treatment are less than the costs of identifying and treating those individuals infected by asymptomatic hosts.
Can an archaeologist be a public intellectual?
Authors: Tarlow Sarah , Stutz Liv Nilsson
Published: June 2013

In the contributions that follow seven archaeologists, of different backgrounds and working in different ways and places, attempt to answer the question ‘Can an archaeologist be a public intellectual?’ This discussion follows a special forum, sponsored by this journal, held at the European Archaeologists’ Association annual conference in Helsinki in 2012. The participants in that forum were Åsa Larsson, Layla Renshaw, Ghattas Sajey, Audrey Horning and Thomas Meier, who was unfortunately unable to offer his contribution for publication. The published discussion is supplemented by contributions from Cornelius Holtorf, Fredrik Svanberg, Nathan Schlanger and Jaime Almansa Sánchez. We hope that this special section captures some of the spirit of lively debate that characterized the forum.
Participate or perish. Why archaeology must gain confidence
Authors: Larsson Åsa M.
Published: June 2013

While other fields of the humanities have often brought forth intellectuals taking part in public discourse, influencing politics and society, archaeologists have been wary of sticking their necks out after the Second World War. However, the tradition of leaving it to others to connect prehistoric narratives to current politics or new scientific results is damaging both to the public understanding of our past and to our own discipline. In this article I argue that preconceptions of human past are guiding much decision making both locally and globally, and that it is therefore our responsibility to take an active part and to problematize this. Failing to do so only means that other people will cherry-pick our research for their own ends. More specifically, it will also lead to a drying up of funding in these difficult economic times, as archaeology takes a back seat to anthropology and sociology. I draw on personal experience to offer suggestions on how one could go about becoming part of the public debate and, in the long run, perhaps carve out a position as a public intellectual.
Can archaeologists intervene in public debate on urgent questions of a social, cultural or political nature? A reflection on the Israeli–Palestinian Archaeology Working Group (IPAWG)
Authors: Sayej Ghattas Jeries
Published: June 2013

The archaeologist's role in public life is not limited to only understanding, reflecting and informing on the past, but also should reveal who we are at present and help society in manoeuvring into the future. We are a major part of the public intellectuals who should intervene in public debate, not only in the media but also as a part of the decision-making process. We can contribute to making a difference in many aspects of human life, intellectually, socially, culturally and politically. This paper will aim to shed light on my involvement in the Israeli–Palestinian Archaeology Working Group (IPAWG). I will focus on how a small group of archaeologists has contributed positively to one of the most complicated political conflicts in modern history. I will also address an example from Al-Jib to indicate the role of archaeologists as scientists, citizens and public figures.
How to go public as an intellectual
Authors: Svanberg Fredrik
Published: June 2013

Becoming a public intellectual, a voice read in major newspapers, asked for comments on television and in cultural debates, in an age where the range of platforms for expression are diversifying in a new digital landscape, has less to do with who you are – there are any number of potential public intellectuals – than with the mastery of public forms of expression. Going public as an intellectual is about the ability to build such a position, and there are typical paths to do so. It's a process. Cultural experts such as archaeological researchers have excellent starting points for engaging publicly and should do so in order to contribute with their specific cultural knowledge. Why don't you?
The global ring? Boxing, mobility, and transnational networks in the anglophone world, 1890–1914
Authors: Taylor Matthew
Published: June 2013

This article examines professional boxing as a compelling and dynamic example of globalization from below between 1890 and 1914. It explores the sport's fluctuating legal and organizational status and maps the movement of professional boxers – and the networks that facilitated this movement – across the anglophone world. Boxing was particularly suited to cross-national mobility because it developed alongside, and built upon, the global circuits of the late nineteenth-century entertainment industry. Yet the main sites of the anglophone boxing world were not connected in any structured or standardized fashion. Channels of communication and routes of traffic were continually shifting, with no one city, region or nation emerging as a consistent hub of activity. This article explores boxing's fluid, multiple and loosely structured ‘networks’, and shows how the sport remained largely resistant to international regulation and standardization in this period.
Making football global? FIFA, Europe, and the non-European football world, 1912–74
Authors: Dietschy Paul
Published: June 2013

The Fédération Internationale de Football Association (FIFA) played a major role in the transformation of association football into a global game. Between 1912 and 1974, before the era of rapid economic sports globalization, FIFA officials attempted to extend the boundaries of the football empire by creating the World Cup and trying to convert new parts of the world to the people's game. It was not an easy task since they met with resistance, obstruction, and contestation. They had to revise their Eurocentric way of thinking and be willing to negotiate. Far from being a mere imperialist process, the path to world football consisted of a series of exacting exchanges and mutual misunderstandings, especially with the South American associations. It is not clear that FIFA officials always understood the demands of the developing football world but they were often able to negotiate and adapt their discourses towards non-European national associations and continental confederations. By doing so, they helped to create, if not an equal football world, at least an international world space.
Prevalence and Behavioral Styles of Fear of Flying
Authors: van Almen Kimee L. M. , van Gerwen Lucas J.
Published: June 2013

According to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV), fear of flying is a specific situational phobia, but it has a heterogeneous character because it can be influenced by many other fears. Attention toward (monitoring) or away from (blunting) threatening information is influenced by people’s control of voluntary attention. In our online questionnaire study, 9,166 subjects (age 17–70 years) were selected for participation. The Flight Anxiety Modality (FAM) questionnaire and Miller Behavioral Style Scale (MBSS) were used to measure fear of flying and behavioral style. Also, demographic information was collected. Women reported a higher FAM sum score than men, as predicted. Participants who scored higher on the MBSS were found to have also scored higher on the FAM. Participants who had never flown before scored higher on the FAM than participants who had flown before. In this sample, monitoring can be associated with an increase in fear of flying. Future research should focus on gaining a more multicultural picture of fear of flying.
Predictive Validity of a Selection Procedure for Air Traffic Controller Trainees
Authors: Pecena Yvonne , Keye Doris , Conzelmann Kristin , Grasshoff Dietrich , Maschke Peter , Heintz Alexander , Eißfeldt Hinnerk
Published: June 2013

The job of an air traffic controller (ATCO) is very specific and demanding. The assessment of potential suitable candidates requires a customized and efficient selection procedure. The German Aerospace Center DLR conducts a highly selective, multiple-stage selection procedure for ab initio ATCO applicants for the German Air Navigation Service Provider DFS. Successful applicants start their training with a training phase at the DFS Academy and then continue with a unit training phase in live traffic. ATCO validity studies are scarcely reported in the international scientific literature and have mainly been conducted in a military context with only small and male samples. This validation study encompasses the data from 430 DFS ATCO trainees, starting with candidate selection and extending to the completion of their training. Validity analyses involved the prediction of training success and several training performance criteria derived from initial training. The final training success rate of about 79% was highly satisfactory and higher than that of other countries. The findings demonstrated that all stages of the selection procedure showed predictive validity toward training performance. Among the best predictors were scores measuring attention and multitasking ability, and ratings on general motivation from the interview.
Cell cycle-arrested tumor cells exhibit increased sensitivity towards TRAIL-induced apoptosis
Authors: Ehrhardt H , Wachter F , Grunert M , Jeremias I
Published: June 2013

Resting tumor cells represent a huge challenge during anticancer therapy due to their increased treatment resistance. TNF-related apoptosis-inducing ligand (TRAIL) is a putative future anticancer drug, currently in phases I and II clinical studies. We recently showed that TRAIL is able to target leukemia stem cell surrogates. Here, we tested the ability of TRAIL to target cell cycle-arrested tumor cells. Cell cycle arrest was induced in tumor cell lines and xenografted tumor cells in G0, G1 or G2 using cytotoxic drugs, phase-specific inhibitors or RNA interference against cyclinB and E. Biochemical or molecular arrest at any point of the cell cycle increased TRAIL-induced apoptosis. Accordingly, when cell cycle arrest was disabled by addition of caffeine, the antitumor activity of TRAIL was reduced. Most important for clinical translation, tumor cells from three children with B precursor or T cell acute lymphoblastic leukemia showed increased TRAIL-induced apoptosis upon knockdown of either cyclinB or cyclinE, arresting the cell cycle in G2 or G1, respectively. Taken together and in contrast to most conventional cytotoxic drugs, TRAIL exerts enhanced antitumor activity against cell cycle-arrested tumor cells. Therefore, TRAIL might represent an interesting drug to treat static-tumor disease, for example, during minimal residual disease.
Cotargeting histone deacetylases and oncogenic BRAF synergistically kills human melanoma cells by necrosis independently of RIPK1 and RIPK3
Authors: Lai F , Guo S T , Jin L , Jiang C C , Wang C Y , Croft A , Chi M N , Tseng H-Y , Farrelly M , Atmadibrata B , Norman J , Liu T , Hersey P , Zhang X D
Published: June 2013

Past studies have shown that histone deacetylase (HDAC) and mutant BRAF (v-Raf murine sarcoma viral oncogene homolog B1) inhibitors synergistically kill melanoma cells with activating mutations in BRAF. However, the mechanism(s) involved remains less understood. Here, we report that combinations of HDAC and BRAF inhibitors kill BRAFV600E melanoma cells by induction of necrosis. Cotreatment with the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) or panobinostat (LBH589) and the BRAF inhibitor PLX4720 activated the caspase cascade, but caspases appeared dispensable for killing, in that inhibition of caspases did not invariably block induction of cell death. The majority of dying cells acquired propidium iodide positivity instantly when they became positive for Annexin V, suggesting induction of necrosis. This was supported by caspase-independent release of high-mobility group protein B1, and further consolidated by rupture of the plasma membrane and loss of nuclear and cytoplasmic contents, as manifested by transmission electron microscopic analysis. Of note, neither the necrosis inhibitor necrostatin-1 nor the small interference RNA (siRNA) knockdown of receptor-interacting protein kinase 3 (RIPK3) inhibited cell death, suggesting that RIPK1 and RIPK3 do not contribute to induction of necrosis by combinations of HDAC and BRAF inhibitors in BRAFV600E melanoma cells. Significantly, SAHA and the clinically available BRAF inhibitor vemurafenib cooperatively inhibited BRAFV600E melanoma xenograft growth in a mouse model even when caspase-3 was inhibited. Taken together, these results indicate that cotreatment with HDAC and BRAF inhibitors can bypass canonical cell death pathways to kill melanoma cells, which may be of therapeutic advantage in the treatment of melanoma.
Dynamic cyanobacterial response to hydration and dehydration in a desert biological soil crust
Authors: Rajeev Lara , da Rocha Ulisses Nunes , Klitgord Niels , Luning Eric G , Fortney Julian , Axen Seth D , Shih Patrick M , Bouskill Nicholas J , Bowen Benjamin P , Kerfeld Cheryl A , Garcia-Pichel Ferran , Brodie Eoin L , Northen Trent R , Mukhopadhyay Aindrila
Published: June 2013

Biological soil crusts (BSCs) cover extensive portions of the earth’s deserts. In order to survive desiccation cycles and utilize short periods of activity during infrequent precipitation, crust microorganisms must rely on the unique capabilities of vegetative cells to enter a dormant state and be poised for rapid resuscitation upon wetting. To elucidate the key events involved in the exit from dormancy, we performed a wetting experiment of a BSC and followed the response of the dominant cyanobacterium, Microcoleus vaginatus, in situ using a whole-genome transcriptional time course that included two diel cycles. Immediate, but transient, induction of DNA repair and regulatory genes signaled the hydration event. Recovery of photosynthesis occurred within 1 h, accompanied by upregulation of anabolic pathways. Onset of desiccation was characterized by the induction of genes for oxidative and photo-oxidative stress responses, osmotic stress response and the synthesis of C and N storage polymers. Early expression of genes for the production of exopolysaccharides, additional storage molecules and genes for membrane unsaturation occurred before drying and hints at preparedness for desiccation. We also observed signatures of preparation for future precipitation, notably the expression of genes for anaplerotic reactions in drying crusts, and the stable maintenance of mRNA through dormancy. These data shed light on possible synchronization between this cyanobacterium and its environment, and provides key mechanistic insights into its metabolism in situ that may be used to predict its response to climate, and or, land-use driven perturbations.
Comparative genomics of pathogenic lineages of Vibrio nigripulchritudo identifies virulence-associated traits
Authors: Goudenège David , Labreuche Yannick , Krin Evelyne , Ansquer Dominique , Mangenot Sophie , Calteau Alexandra , Médigue Claudine , Mazel Didier , Polz Martin F , Le Roux Frédérique
Published: June 2013

Vibrio nigripulchritudo is an emerging pathogen of farmed shrimp in New Caledonia and other regions in the Indo-Pacific. The molecular determinants of V. nigripulchritudo pathogenicity are unknown; however, molecular epidemiological studies have suggested that pathogenicity is linked to particular lineages. Here, we performed high-throughput sequencing-based comparative genome analysis of 16 V. nigripulchritudo strains to explore the genomic diversity and evolutionary history of pathogen-containing lineages and to identify pathogen-specific genetic elements. Our phylogenetic analysis revealed three pathogen-containing V. nigripulchritudo clades, including two clades previously identified from New Caledonia and one novel clade comprising putatively pathogenic isolates from septicemic shrimp in Madagascar. The similar genetic distance between the three clades indicates that they have diverged from an ancestral population roughly at the same time and recombination analysis indicates that these genomes have, in the past, shared a common gene pool and exchanged genes. As each contemporary lineage is comprised of nearly identical strains, comparative genomics allowed differentiation of genetic elements specific to shrimp pathogenesis of varying severity. Notably, only a large plasmid present in all highly pathogenic (HP) strains encodes a toxin. Although less/non-pathogenic strains contain related plasmids, these are differentiated by a putative toxin locus. Expression of this gene by a non-pathogenic V. nigripulchritudo strain resulted in production of toxic culture supernatant, normally an exclusive feature of HP strains. Thus, this protein, here termed ‘nigritoxin’, is implicated to an extent that remains to be precisely determined in the toxicity of V. nigripulchritudo.
Tailorable stimulated Brillouin scattering in nanoscale silicon waveguides
Authors: Shin Heedeuk , Qiu Wenjun , Jarecki Robert , Cox Jonathan A. , Olsson Roy H. , Starbuck Andrew , Wang Zheng , Rakich Peter T.
Published: June 2013

Nanoscale modal confinement is known to radically enhance the effect of intrinsic Kerr and Raman nonlinearities within nanophotonic silicon waveguides. By contrast, stimulated Brillouin-scattering nonlinearities, which involve coherent coupling between guided photon and phonon modes, are stifled in conventional nanophotonics, preventing the realization of a host of Brillouin-based signal-processing technologies in silicon. Here we demonstrate stimulated Brillouin scattering in silicon waveguides, for the first time, through a new class of hybrid photonic–phononic waveguides. Tailorable travelling-wave forward-stimulated Brillouin scattering is realized—with over 1,000 times larger nonlinearity than reported in previous systems—yielding strong Brillouin coupling to phonons from 1 to 18 GHz. Experiments show that radiation pressures, produced by subwavelength modal confinement, yield enhancement of Brillouin nonlinearity beyond those of material nonlinearity alone. In addition, such enhanced and wideband coherent phonon emission paves the way towards the hybridization of silicon photonics, microelectromechanical systems and CMOS signal-processing technologies on chip.
Extraordinary levitation height in diamagnetically stabilised levitation system with superconductors
Authors: Küstler G.
Published: June 2013

The diamagnetically stabilised levitation of an NdFeB cube magnet over superconductors is reported. The achieved levitation height of 44 mm is about three times higher than in a comparable conventional superconducting levitation setup with flux pinning only. The extraordinary levitation height may offer new applications in the field of highly sensitive seismometers or force meters.
Dual‐wideband bandstop filter using transversal signal‐interaction concept
Authors: Xue S.J. , Zhu H.T. , Feng W.J. , Che W.Q.
Published: June 2013

A dual‐wideband bandstop filter with high selectivity using transversal signal‐interaction concept is proposed. Five transmission poles in the passband between the two stopbands can be achieved due to the superposition of signals for the two transmission paths. A planar dual‐wideband bandstop filter prototype for WLAN bands with 10 dB fractional bandwidths of 76.2% and 26.9% has been designed and fabricated.
Discrete Green's function approach to disjoint domain simulations in 3D FDTD method
Authors: Stefański T.P.
Published: June 2013

A discrete Green's function (DGF) approach to couple 3D FDTD subdomains is developed. The total‐field/scattered‐field subdomains are simulated using the explicit FDTD method whilst interaction between them is computed as a convolution of the DGF with equivalent current sources measured over Huygens surfaces. In the developed method, the DGF waveforms are truncated using the Hann's window. The error varies in the range − 65 to − 40 dB depending on the DGF length and positions of the subdomains. However, if the DGF length is equal to the number of iterations in a simulation, this approach returns the same results as the direct FDTD method.
S‐RVoG model for forest parameters inversion over underlying topography
Authors: Lu Hongxi , Suo Zhiyong , Guo Rui , Bao Zheng
Published: June 2013

Since the terrain slope cannot be neglected for forest height inversion with polarimetric synthetic aperture radar interferometry (PolInSAR), a sloped random volume over ground (S‐RVoG) model is proposed to correct the terrain distortion for forest parameters estimation. A significant model complexity reduction is achieved by aligning the reference frame along the local terrain slope and changing the corresponding radar geometrical configuration. The proposed S‐RVoG model inversion promises to provide much more accurate estimation of forest parameters and is validated with L‐band PolInSAR data produced by PolSARpro software developed by the European Space Agency (ESA).
Current‐tunable chaotic jerk oscillator
Authors: Srisuchinwong B. , Nopchinda D.
Published: June 2013

A new chaotic jerk circuit has been realised using a current‐tunable technique. Based on traditional nonlinearity of a signum function, newly smooth transitions from a balanced double‐scroll chaotic jerk attractor to an unbalanced double‐scroll and eventually to either a left‐half or a right‐half single‐scroll chaotic jerk attractor are experimentally revealed using either a negative or a positive adjustable current source I0, respectively. Current‐tunable bifurcations are demonstrated. A plot of the largest Lyapunov exponent resembles a symmetrically balanced image centred at I0 = 0.
Low complexity twiddle factor multiplication with ROM partitioning in FFT processor
Authors: Kang Hyeong‐Ju , Yang Byung‐Do , Lee Jong‐Yeol
Published: June 2013

Proposed is a low‐complexity twiddle factor multiplication structure for fast Fourier transform (FFT). In an FFT implementation, the twiddle factor multiplication requires a large ROM to store the twiddle factors. In the proposed structure, the ROM is partitioned into two small ROMs, whose sum of areas is much smaller than that of the original ROM. The proposed structure requires an additional multiplier, but the multiplier is shown to be small in the experimental results. The results show that the proposed structure reduces the area of the twiddle factor multiplication by around 30% with a marginal degradation in SQNR performance.
Photonic crystal VCSELs with narrow spectral width and high bandwidth operating at low current density
Authors: Tan M. , Fryslie S.T.M. , Guenter J.K. , Tatum J.A. , Johnson R.H. , Choquette K.D.
Published: June 2013

A photonic crystal vertical‐cavity surface‐emitting laser with a spectral width of 0.16 nm and a 3dB small signal modulation bandwidth of 16.2 GHz is demonstrated. Separation of optical and current apertures enables a narrow spectral width and an extremely low operating current density of ∼ 1 kA/cm2 simultaneously. It can potentially be used as a high‐reliability laser source that enables error‐free transmission over long multimode fibre links at high data rate.
3D channel emulation in multi‐probe setup
Authors: Fan W. , Sun F. , Kyösti P. , Nielsen J. , Carreño X. , Knudsen M. , Pedersen G.
Published: June 2013

A technique to emulate 3D geometry‐based channel models in a multi‐probe over the air test setup is presented. The proposed technique provides a general emulation framework for any spherical incoming power spectrum. The emulation method results in two optimisation objectives, which are both convex. They give optimal emulation accuracy and allow relatively low computational complexity.
Reduced‐complexity tracking scheme based on adaptive weighting for location estimation
Authors: Wang Chin‐Liang , Chiou Yih‐Shyh , Tsai Fuan
Published: June 2013

This study presents an efficient location tracking algorithm to reduce the computational complexity of the conventional Kalman filtering algorithm. In the proposed location estimation and tracking approach, using the inherent message‐passing nature of factor graphs, the data information is passed efficiently between the variable nodes and the factor nodes by taking weights based on the message reliability, thus simplifying implementation of the Bayesian filtering approach for location tracking. Numerical simulations and experimental results show that the proposed location tracking scheme not only can achieve the location accuracy close to that of the Kalman filtering scheme, but also has lower computational complexity with decoupling approach.
Design of ultra‐wideband pulses based on spectrum shifted Gaussian waveforms
Authors: Bai Zhiquan , Liu Jenting , Chen Hsiao‐Hwa
Published: June 2013

In this study, the authors propose a new pulse waveform design methodology for ultra‐wideband (UWB) applications, namely spectrum shifted Gaussian waveform (SSGW) approach. Specifically, UWB pulses can be generated by superposition of Gaussian sub‐carriers, which can be used to fit Federal Communication Commission (FCC) spectrum masks specified for UWB applications. In this way, it can match with the FCC masks much better than those generated using the traditional methods based on Gaussian or Hermite pulses and their higher order derivatives. The SSGW works with a low computational complexity and offers a unique agility in design of time‐domain pulse shapes to fit different power spectrum density masks. In principle, the SSGW approach can also be used for pulse waveform design in many other bandwidth efficient communication systems, not necessarily limited only to UWB systems.
Generalised grouped minimum mean‐squared error‐based multi‐stage interference cancellation scheme for orthogonal frequency division multiple access uplink systems with carrier frequency offsets
Authors: Fa Rui , Zhang Li
Published: June 2013

In uplink orthogonal frequency division multiple access (OFDMA) systems with carrier frequency offsets (CFOs), there always be a dilemma that high performance and low complexity cannot be obtained simultaneously. In this study, in order to achieve better trade‐off between performance and complexity, the authors propose a grouped minimum mean squared error (G‐MMSE)‐based multi‐stage interference cancellation (MIC) scheme. The first stage of the proposed scheme is a G‐MMSE detector, where the signal is detected group by group using banks of partial MMSE filters. The signal group can be either user based or subcarrier based. Multiple novel interference cancellation (IC) units are serially concatenated with the G‐MMSE detector. Reusing the filters in the G‐MMSE detector significantly reduces the computational complexity in the subsequent IC units as shown by the complexity analysis. The performance of the proposed G‐MMSE‐MIC schemes are evaluated by theoretical analysis and simulation. The results show that the proposed schemes outperform other existing schemes with considerably low complexity.
Practical analysis of codebook design and frequency offset estimation for virtual‐multiple‐input–multiple‐output systems
Authors: Jiang Jing , Thompson John S. , Sun Hongjian , Grant Peter M.
Published: June 2013

A virtual‐multiple‐input–multiple‐output (MIMO) wireless system using the receiver‐side cooperation with the compress‐and‐forward (CF) protocol, is an alternative to a point‐to‐point MIMO system, when a single receiver is not equipped with multiple antennas. It is evident that the practicality of CF cooperation will be greatly enhanced if an efficient source coding technique can be used at the relay. It is even more desirable that CF cooperation should not be unduly sensitive to carrier frequency offsets (CFOs). This study presents a practical study of these two issues. Firstly, codebook designs of the Voronoi vector quantisation (VQ) and the tree‐structure VQ (TSVQ) to enable CF cooperation at the relay are described. A comparison in terms of the codebook design and encoding complexity is analysed. It is shown that the TSVQ is much simpler to design and operate, and can achieve a favourable performance‐complexity tradeoff. Furthermore, this study demonstrates that CFO can lead to significant performance degradation for the virtual‐MIMO system. To overcome this, it is proposed to maintain clock synchronisation and jointly estimate the CFO between the relay and the destination. This approach is shown to provide a significant performance improvement.
Practical polar code construction over parallel channels
Authors: Chen Kai , Niu Kai , Lin Jia‐Ru
Published: June 2013

Channel polarisation results are extended to the case of communications over parallel channels, where the channel state information is known to both the encoder and decoder. Given a set of parallel binary‐input discrete memoryless channels (B‐DMCs), by performing the channel polarising transformation over independent copies of these component channels, we obtain a second set of synthesised binary‐input channels. Similar to the single‐channel case, we prove that as the size of the transformation goes infinity, some of the resulting channels tend to completely noised, and the others tend to noise‐free, where the fraction of the latter approaches the average symmetric capacity of the underlying component channels. For finite‐length polar coding over parallel channels, performance is found to be relied heavily on the specific channel‐mapping scheme. To avoid exhaustive searching, an empirically good scheme that is called equal‐capacity partition channel mapping is proposed and numerical results show that the proposed scheme significantly outperforms random mapping. Further, utilising the above results, a polar coding method for arbitrary code length is proposed, which has potential applications in practical systems.
Cooperative decode‐and‐forward relaying with orthogonal space–time block code over doubly correlated Nakagami‐m fading channels
Authors: Yang Kai , Yang Jie
Published: June 2013

In this study, the authors investigate the performance of cooperative decode‐and‐forward multiple‐input multiple‐output relaying system with orthogonal space–time block code transmissions over doubly correlated Nakagami‐m fading channels, where the source, relay and destination nodes are all equipped with multiple antennas. They also include correlated and independent Rayleigh fading channels as special cases. Only when the relay node could receive the signal from the source correctly, it will forward source information to the destination. For two types of receivers at the destination, maximal ratio combining and selection combining, the authors provide the compact closed‐form expressions for cumulative distribution function (CDF) and probability density function of the instantaneous end‐to‐end signal‐to‐noise ratio (SNR). Besides, the exact analytical expressions are also derived for the outage probability (OP) and symbol error rate (SER) relying on CDF. Furthermore, they present the asymptotic expressions for OP and SER in the high SNR regime, from which they gain an insight into the system performance and derive the achievable diversity order and array gain. The analytical expressions are validated by Monte‐Carlo simulations.