bluuebunny/crossref_metadata_2025 huggingface dataset:
Interactive effects of plant growth–promoting rhizobacteria and organic fertilization on P nutrition of Zea mays L. and Brassica napus L.
Authors: Krey Thomas , Caus Maria , Baum Christel , Ruppel Silke , Eichler‐Löbermann Bettina
Published: March 2011

The organic matter supply can promote the dispersal and activity of applied plant growth–promoting rhizobacteria (PGPR), but the complementary effect of organic fertilization and PGPR application on the turnover of P is scarcely known. The effects of the application of two PGPR strains (Pseudomonas fluorescens strain DR54 and Enterobacter radicincitans sp. nov. strain DSM 16656) alone and in combination with organic fertilization (cattle manure and biowaste compost) on growth and P uptake of maize (Zea mays L.) and oilseed rape (Brassica napus L.) were investigated under semi–field conditions. Furthermore, P pools and phosphatase activities in soil and the arbuscular mycorrhizal colonization of maize were examined. The organic‐fertilizer amendments increased the growth and P uptake of both plant species and the soil P pools. The application of the E. radicincitans strain increased P uptake of oilseed rape when no organic fertilizer was added. Furthermore, the application of both bacterial strains increased the activities of phosphatases under both plant species. Here, the effect of the PGPR application even exceeded the effect of organic fertilization. The magnitude of this effect varied between the different fertilizing treatments and between the two bacterial strains. Phosphatase activities were increased to the greatest extent after application of P. fluorescens in the unfertilized soil. Under rape increases of 52% for acid phosphatase activities (ACP), 103% for alkaline phosphatase activities (ALP), and 133% for phosphodiesterase (PDE) were observed therewith. In the unfertilized soil, the application of P. fluorescens also resulted in a strong increase of the arbuscular mycorrhizal colonization of maize. We conclude that application of PGPR can promote the P mobilization and supply of crops in P‐deficient soils, however, in combination with organic fertilization these effects might be masked by a general improved P supply of the crops. Interactive effects of applied bacterial strains and organic fertilization depend on the sort of organic fertilizer and crop species used.
Silicon nutrition of rice is affected by soil pH, weathering and silicon fertilisation
Authors: Tavakkoli Ehsan , Lyons Graham , English Peter , Guppy Chris N.
Published: March 2011

Silicon (Si) is a beneficial element for tropical grasses such as rice (Oryza sativa) and responses to applications of Si are common on highly weathered soils. However, the importance of pH (and hence Si speciation), weathering and fertilisation on Si uptake is still poorly understood. The responses of rice to Si fertilisation were studied in two variably weathered basalt soils (Red Ferrosol, Grey Vertosol) adjusted at different pH values (5.5–9.5) with three levels of acidulated wollastonite. Soil Si was extracted using deionised water (H2O), 0.01 M CaCl2, or 0.5 M NH4OAc. Significant increases in Si uptake and rice biomass were observed in the Red Ferrosol following fertilisation (p < 0.01). Greater biomass production was observed at lower pH, due to decreased Si sorption and higher solution Si concentrations. Silicon uptake by rice was greater at low pH, despite similar extractable Si concentrations; suggesting a relationship between Si speciation and uptake. In contrast, Si uptake and rice shoot dry matter in the less weathered Grey Vertosol were unaffected by Si fertilisation (p > 0.05) except at the highest rate and lowest pH (5.5). Solution Si concentrations were controlled by precipitation/polymerisation reactions in equilibrium with specific soil pH values rather than adsorption processes. Silicon speciation effects (monosilicic acid vs. silicate ions) were unable to be measured due to an induced phosphorus deficiency in both soils at pH values > 8.5. In conclusion, weathered soils are more responsive to Si fertilisation and Si uptake is increased at low pH.
Seawater‐irrigation effects on growth, ion concentration, and photosynthesis of transgenic poplar overexpressing the Na+/H+ antiporter AtNHX1
Authors: Jiang Chaoqiang , Zheng Qingsong , Liu Zhaopu , Liu Ling , Zhao Gengmao , Long Xiaohua , Li Hongyan
Published: March 2011

Tonoplast Na+/H+ antiporters increase the salt resistance of various plant species, but very little is known about the role of these antiporters in the salt resistance of trees. Understanding the physiological responses of plants to salinity stress is of paramount importance in examining the salt resistance of transgenic plants. In this study, the wild‐type poplar (WT; Populus × euramericana var. Neva) and its transgenic varieties (TR) that overexpress the AtNHX1 gene were exposed to various seawater concentrations (0%, 10%, 20%, and 30%) for 30 d to determine the effects of seawater on seedling growth, ion content, and photosynthetic productivity. Results show that TR plants grew much better than WT under saline conditions. Differences between WT and TR in most parameters were significant after 30 d exposure to 20% and 30% seawater concentrations. The dry weight of TR was higher than that of WT for each seawater treatment. Transgenic variety was able to maintain higher photosynthetic ability than WT upon exposure to salinity and maintained higher K+ concentrations and K+ : Na+ ratio but had less Cl– compared with WT. This suggests that AtNHX1 has a critical role in the regulation of K+ homeostasis, which in turn affects plant K+ nutrition and salt resistance.
Soil‐structure development including seasonal dynamics in a long‐term fertilization experiment
Authors: Schlüter Steffen , Weller Ulrich , Vogel Hans‐Jörg
Published: March 2011

Soil structure affects all soil functions especially those related to physical and biological processes. On the other hand, soil structure itself is directly affected by these agents. Hence, soil structure—from single pores to the pedon scale—is expected to reflect the capacity of soil to deliver ecosystem functions. We analyzed soil structure including its seasonal dynamics for two plots within the long‐term fertilization experiment in Bad Lauchstädt (Germany). The different plots received very different amounts of mineral and organic fertilizers over a period of 106 y. The quantification of structural properties includes pore‐size distribution and pore connectivity obtained by X‐ray microtomography. We present a methodological approach for image analysis that allows to combine samples of different size and resolution to cover pores within one order of magnitude in diameter. The results for the different plots obtained in spring and summer are compared. We found that the enormous difference in energy input only affects the structure of the topsoil (Ap horizon) towards a higher porosity and pore‐network connectivity and in terms of an increased resilience after tillage. However, the structural properties of the subsoil below the plowed horizon (Ah horizon) are not affected. We hypothesize that the structure of the subsoil reflects soil formation over much longer time scales, it allows for an increased turnover of soil organic matter, and it is rather stable at the time scale of the fertilization experiment.
In‐season calcium‐spray formulations improve calcium balance and fruit quality traits of peach
Authors: Val Jesus , Fernández Victoria
Published: March 2011

Experiments to evaluate the effect of in‐season calcium (Ca) sprays on late‐season peach (Prunus persica L. Batsch cv. Calrico) were carried out for a 2‐year period. Calcium formulations (0.5% and 1.0% in 2008 and only 0.5% tested in 2009) supplied either as CaCl2 or Ca propionate in combination with two or three adjuvants (0.05% of the nonionic surfactants Tween 20 and Break Thru, and 0.5% carboxymethylcellulose, CMC) were sprayed four to five times over the growing season. Peach mesocarp and endocarp Ca concentrations were determined on a 15‐day basis from the beginning of May until the end of June. Further tissue analyses were performed at harvest. A decreasing trend in fruit Ca concentrations over the growing season was always observed regardless of the Ca treatments. Both in 2008 and 2009, significant tissue Ca increments associated with the application of Ca‐containing sprays in combination with adjuvants were only observed in June, which may be coincident with the period of pit hardening. In 2008, both at harvest and after cold storage, the total soluble‐solids concentration (° Brix) of fruits supplied with Ca propionate (0.5% and 1.0% Ca) was always lower as compared to the rest of treatments. The application of multiple Ca‐containing sprays increased firmness at harvest and after cold storage, especially when CaCl2 was the active ingredient used. Supplying the adjuvants Tween 20 and CMC increased fruit acidity both at harvest and after cold storage. Evaluation of the development of physiological disorders after cold storage (2 weeks at 0°C) indicated a lower susceptibility of Ca‐treated fruits to internal browning. Fruits treated with multiple CaCl2‐, CMC‐, and Break Thru®‐containing sprays during the growing season were significantly less prone to the development of chilling injuries as compared to untreated peaches.
Relative effects of ammonia and nitrite on the germination and early growth of aerobic rice
Authors: Haden Van R. , Xiang Jing , Peng Shaobing , Bouman Bas A. M. , Visperas Romeo , Ketterings Quirine M. , Hobbs Peter , Duxbury John M.
Published: March 2011

Recent studies have documented adverse affects of urea on the establishment and growth of aerobic rice when applied at seeding. The following experiments were conducted to examine the relative importance of ammonia and nitrite (NO$ _2^- $) toxicities as mechanisms contributing to poor germination and early growth of aerobic rice. Soil was collected from an experiment in the Philippines where aerobic rice was grown continuously for 7 years. Subsamples of the soil were: (1) pretreated with sulfuric acid (0.5 M H2SO4 added at 75 mL kg–1), (2) oven‐heated at 120°C for 12 h, or (3) left untreated. In a greenhouse study N was applied to the untreated, acidified, and oven‐heated soils as either urea or ammonium sulfate (0.0 or 0.3 g N kg–1). Plant height, root length, total biomass, and number of seminal roots were evaluated after 10 d. Microdiffusion incubations were used to assess the effects of soil pretreatment, N source, and N rate (0, 0.5, 1.0, 1.5 g N kg–1) on ammonia (NH3) volatilization and germination. Nitrite incubations were conducted to establish a critical level for NO$ _2^- $ toxicity and measure the extractable NO$ _2^- $ and germination trends as affected by soil pretreatment, N source, and N rate. On untreated soil, urea reduced early growth and germination while ammonium sulfate caused no adverse effects. Progressively higher rates of urea increased NH3 volatilization and inhibited germination, while oven‐heating and acidification minimized the adverse effects. All treatment combinations (soil pretreatment, N source, N rate) had extractable NO$ _2^- $ levels below the critical level of 0.2 g N kg–1, suggesting that ammonia and not NO$ _2^- $ toxicity was the principal cause of inhibition. Since the risk of NH3 toxicity is highest just following urea hydrolysis, strategies to optimize the timing and placement of urea should be considered.
Methodological aspects of determining soil particle‐size distribution using the laser diffraction method
Authors: Ryżak Magdalena , Bieganowski Andrzej
Published: March 2011

This paper presents the influence of selected methodological aspects on the results of particle‐size distribution (PSD) as measured by the laser diffraction method (LDM). The investigations were carried out using the Mastersizer 2000 with Hydro MU attachment (Malvern Ltd., UK). It was found that for the investigated soils: (1) optimal speed of pump and stirrer was 2500 rpm, (2) optimal measurement time was ≈ 1 min, (3) there are two, practically equivalent methods for soil‐sample dispersion: chemical (with the use of a solution of sodium hexametaphosphate) or physical (by means of ultrasound application for 4 min at a maximum power of 35W), (4) one must not use the chemical and physical dispersing methods simultaneously, because this can lead to aggregation (not dispersion) of soil particles, (5) the Fraunhofer theory (physical models) can be used to convert scattered‐light data to PSD. In the case of the Mie theory, the best results were obtained for a refractive index (RI) in the range of 1.5–1.6 and an absorption index (AI) of 1.0. It was also found that most of the discussed parameters depend on design of the measuring device and on the type and volume of the investigated suspensions. It is necessary, therefore, to explain how the data was obtained every time and to specify the details in the methodological part of the paper.
Epidermal growth factor receptor overexpression in malignant pleural mesothelioma: Prognostic correlations
Authors: Rena Ottavio , Boldorini Luciano R , Gaudino Erica , Casadio Caterina
Published: March 2011

Background

To evaluate epidermal growth factor receptor (EGFR) phenotypic expression and related gene status in malignant pleural mesothelioma (MPM) and to correlate the results with patients' prognosis.

Method

Eighty‐three cases of MPM specimens were submitted to immunohistochemical (IHC) staining to evaluate the expression of EGFR protein; positive cases were submitted to fluorescence in situ hybridization (FISH) to investigate the gene status. Results were correlated with clinico‐pathological characteristics and long‐term survival.

Results

Thirty‐eight cases (46%) demonstrated a positive IHC reaction [30/57 (52%) epithelial and 8/20 (40%) biphasic whereas sarcomatous MPM were negative]. No association was recorded between EGFR IHC positive staining and age, gender, or asbestos exposure. Three out of 38 (8%) cases submitted to FISH were positive revealing gene amplification or polysomy. Mean follow‐up was 15.4 months (range 2–44). Epithelial subtype only was confirmed to affect prognosis (2‐years survival rate 40 vs. 18% for non‐epithelial subtype, P = 0.042). When epithelial MPM patients were considered, IHC EGFR positive staining was demonstrated to be a negative prognostic factor (2‐years survival rate 26 vs. 60% for IHC EGFR negative staining; P = 0.026).

Conclusions

EGFR overexpression is identified by IHC in 52% of epithelial MPM and is demonstrated to be a factor negatively affecting prognosis. Phenotypic overexpression seems not to be related to gene status alteration. J. Surg. Oncol. 2011; 104:701–705. © 2011 Wiley Periodicals, Inc.
REDUCING SHALLOW LANDSLIDE OCCURRENCE IN PASTORAL HILL COUNTRY USING WIDE‐SPACED TREES
Authors: Douglas G. B. , Mcivor I. R. , Manderson A. K. , Koolaard J. P. , Todd M. , Braaksma S. , Gray R. A. J.
Published: March 2011

Shallow landslides occur globally on soil‐mantled hilly and mountainous terrain. In New Zealand, they are a nation‐wide problem, particularly on pastoral hill country grazed by livestock. On these landscapes, trees are planted at low densities, often <70 stems per hectare (sph), to reduce landslide occurrence, but there has been limited quantification of their effectiveness in this role. This study determined the reduction in landslide occurrence at 65 sites planted with spaced trees (53 × Populus, 6 × Salix, 6 × Eucalyptus) following rainstorm events. Sites had a mean slope angle of 27 degrees and soils were predominantly silt or sand‐loams. Tree density across all sites was 32–65 sph, height was 8–43 m, canopy radius was 1–10 m and trunk diameter was 18–99 cm. Trees reduced landslide occurrence by 95 per cent compared to paired pasture control sites (0·4 per cent vs. 7·9 per cent scar area, respectively), and scars occurred on fewer sites with trees than pasture (10 vs. 45). For the 10 tree sites with scars, their area was <3·5 per cent, except at one site where it was 11·3 per cent. There were no significant differences between species in their effectiveness in reducing landslide occurrence. Analyses were partially successful in discriminating between sites with and without shallow landslides and identified some attributes with potentially useful discriminatory power. Aspect, mean slope angle and tree density did not feature significantly in the analyses because they were homogeneous across site groups. The study verified the large benefit from wide‐spaced tree planting on sites susceptible to shallow landslides. Copyright © 2011 John Wiley & Sons, Ltd.
RANGELAND DEGRADATION ON THE QINGHAI‐TIBET PLATEAU: IMPLICATIONS FOR REHABILITATION
Authors: Li X.‐L. , Gao J. , Brierley G. , Qiao Y.‐M. , Zhang J. , Yang Y.‐W.
Published: March 2011

With ever intensifying land use, land degradation is becoming an increasingly important issue around the world, especially in China. This paper evaluates the extent and underlying causes of rangeland degradation on the Qinghai‐Tibet Plateau in China through a comprehensive review of the literature. Diverse forms and differing intensities of rangeland degradation have been reported in several regions of the Plateau. Rangeland degradation is particularly severe in South Qinghai, North Tibet and the Qaidam Basin. Anthropogenic activities, especially changing land use practices, are identified as the primary force driving rangeland degradation. Dissimilar to climate change‐induced degradation, such anthropogenic degradation is a rather short‐term process altering the abiotic properties of the underlying soil. On the basis of these findings, we assessed the prospects of rehabilitating degraded rangeland to productive uses. Different measures are proposed to rehabilitate rangelands that have been degraded by different mechanisms. Reduction in grazing intensity is prescribed to rehabilitate reversibly degraded rangelands. Targeted human intervention in the forms of selective planting of grasses and artificial seeding, in conjunction with ecological and biological control of the plateau rodent population, is recommended to rehabilitate ‘irreversibly’ degraded rangelands. Our studies suggest it is very difficult or even impossible to rehabilitate new assemblage of species which appear as a result of climate change. Copyright © 2011 John Wiley & Sons, Ltd.
Complement Component 4D Immunostaining in Liver Allografts of Patients with De Novo Immune Hepatitis
Authors: Aguilera Isabel , Sousa José Manuel , Gavilan Francisco , Gomez Lourdes , Álvarez-Márquez Antonia , Núñez-Roldán Antonio
Published: March 2011

De novo immune hepatitis (DNIH) is a form of late graft dysfunction after liver transplantation. The fine mechanisms leading to the development of DNIH are not known, and whether this hepatitis is a form of rejection or a result of an auto/alloimmune injury has not been established. In our patients, DNIH was always preceded by the production of donor-specific antibodies against the glutathione S-transferase T1 (GSTT1) enzyme because of a genetic mismatch in which the donors carried the wild-type gene and the recipients displayed the null genotype. Complement component 4d (C4d) immunopositivity in 12 paraffin-embedded liver biopsy samples from 8 patients diagnosed with DNIH associated with anti-GSTT1 antibodies was retrospectively evaluated. Six patients with a diagnosis of chronic rejection (CR) and 7 patients with hepatitis C virus recurrence were included as control groups. Among the patients with DNIH, 7 showed C4d-positive immunostaining localized in the portal tracts, whereas in the tested biopsy samples of the 2 control groups, this staining pattern was absent. Four biopsy samples of the CR group showed C4d-positive sinusoidal staining. This study confirms the activation of the complement pathway in the presence of donor-specific antibodies, which was shown by the deposition of C4d elements in liver biopsy samples of patients with DNIH. The use of C4d as a marker of antibody-mediated rejection in liver allografts in the presence of antidonor antibodies is discussed, and it may contribute to improved differential diagnoses based on biopsy findings. Liver Transpl 17:779-788, 2011. © 2011 AASLD.
Immune Response to Extracellular Matrix Collagen in Chronic Hepatitis C–Induced Liver Fibrosis
Authors: Borg Brian B. , Seetharam Anil , Subramanian Vijay , Basha Haseeb Ilias , Lisker-Melman Mauricio , Korenblat Kevin , Anderson Christopher D. , Shenoy Surendra , Chapman William C. , Crippin Jeffrey S. , Mohanakumar Thalachallour
Published: March 2011

Hepatitis C virus (HCV) infection and its recurrence after orthotopic liver transplantation (OLT) are associated with the remodeling of extracellular matrix (ECM) components [particularly collagen (Col)], which leads to fibrosis. Our aim was to determine whether the development of antibodies (Abs) to self-antigen Col in HCV-infected patients correlates with the fibrosis stage and the peripheral cytokine response. Patients with chronic HCV infection, patients with HCV recurrence after OLT who had undergone a biopsy procedure, and healthy control subjects were enrolled. The HCV subjects (n = 70) were stratified as follows: (1) a non-OLT group without fibrosis (Scheuer stages 0-2), (2) a non-OLT group with fibrosis (Scheuer stages 3-4), (3) a post-OLT group without fibrosis (Scheuer stages 0-2), and (4) a post-OLT group with fibrosis (Scheuer stages 3-4). Serum samples were analyzed for Abs against Col1, Col2, Col4, Col5, and vimentin with enzyme-linked immunosorbent assays. Serum levels of cytokines were measured with multiplex bead immunoassays. The levels of Abs to Col1 were higher in the fibrosis groups versus the no-fibrosis groups and the controls for both non-OLT patients (P < 0.001) and post-OLT patients (P = 0.01). There were increased levels of Abs to Col2, Col4, Col5, and vimentin in the non-OLT fibrosis group (Col2, P = 0.0001; Col4, P = 0.122; Col5, P < 0.0001; vimentin, P = 0.36) and in the post-OLT fibrosis group (Col2, P = 0.006; Col4, P = 0.19; Col5, P < 0.0001; vimentin, P = 0.24) in comparison with the no-fibrosis groups. The non-OLT and post-OLT fibrosis groups demonstrated significantly higher T helper 2 (Th2) and T helper 17 (Th17) cytokine levels and lower T helper 1 cytokine levels in comparison with the no-fibrosis groups. Our results demonstrate that in HCV-infected patients, the levels of Abs to ECM Col1, Col2, and Col5 positively correlate with liver fibrosis, which is associated with a predominantly Th2 and Th17 cytokine profile. Liver Transpl 17:814-823, 2011. © 2011 AASLD.
Cobordism invariance of the family index
Authors: Carvalho Catarina C.
Published: March 2011

We give a K‐theory proof of the invariance under cobordism of the family index. We consider elliptic pseudodifferential families on a continuous fibre bundle with smooth fibres \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$M\hookrightarrow \mbox{$\cal M$}\rightarrow B$\end{document}, and define a notion of cobordant families using K1‐groups on fibrations with boundary. We show that the index of two such families is the same using properties of the push‐forward map in K‐theory to reduce it to families on \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$B\times \mathbb {R}^n$\end{document}.
Self‐adjoint extensions for singular linear Hamiltonian systems
Authors: Sun Huaqing , Shi Yuming
Published: March 2011

This paper is concerned with self‐adjoint extensions for singular linear Hamiltonian systems. The domain of the closure of the corresponding minimal Hamiltonian operator is described by the properties of its elements at the endpoints of the discussed interval, and two different decompositions of the domain of the corresponding maximal Hamiltonian operator are provided. Based on them, complete and direct characterizations of all the self‐adjoint extensions for a Hamiltonian system are obtained in terms of square integrable solutions. As a consequence, the characterizations of all the self‐adjoint extensions are given for systems in the two special cases: the limit point case and limit circle case. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Cognitive correlates of visual hallucinations in dementia associated with Parkinson's disease
Authors: Bronnick Kolbjorn , Emre Murat , Tekin Sibel , Haugen Siri B. , Aarsland Dag
Published: March 2011

Background:

There may be a relationship between cognitive impairment and visual hallucinations (VHs) in patients with Parkinson's disease (PD). The objective of this study was to compare the cognitive profile of hallucinating vs. nonhallucinating patients with Parkinson's disease dementia (PDD).

Methods:

The cognitive profile of 86 PDD patients with hallucinations was compared with that of a carefully matched PDD group without hallucinations, all drawn from the baseline assessments of the EXPRESS study with rivastigmine. Logistic regression analysis was employed to identify cognitive measures that have an independent relationship with presence of hallucinations.

Results:

Worse choice reaction time was the only independent predictor of hallucinations in the logistic regression. A further analysis of the reaction time tasks showed that response selection deficit as opposed to stimulus discrimination deficit was the main difference between the groups.

Discussion:

These results indicate that attentional control is an important cognitive correlate of VHs in patients with PDD. © 2011 Movement Disorder Society
Depression comorbidity in spinocerebellar ataxia
Authors: Schmitz‐Hübsch Tanja , Coudert Mathieu , Tezenas du Montcel Sophie , Giunti Paola , Labrum Robyn , Dürr Alexandra , Ribai Pascale , Charles Perrine , Linnemann Christoph , Schöls Ludger , Rakowicz Maryla , Rola Rafal , Zdzienicka Elszbieta , Fancellu Roberto , Mariotti Caterina , Baliko Lazlo , Melegh Bela , Filla Alessandro , Salvatore Elena , van de Warrenburg Bart P.C. , Szymanski Sandra , Infante Jon , Timmann Dagmar , Boesch Sylvia , Depondt Chantal , Kang Jun‐Suk , Schulz Jörg B. , Klopstock Thomas , Lossnitzer Nicole , Löwe Bernd , Frick Caroline , Rottländer Daniela , Schlaepfer Thomas E. , Klockgether Thomas
Published: March 2011

This is a description of the prevalence and profile of depressive symptoms in dominant spinocerebellar ataxia (SCA). Depressive symptoms were assessed in a convenience sample of 526 genetically confirmed and clinically affected patients (117 SCA1, 163 SCA2, 139 SCA3, and 107 SCA6) using the Patient Health Questionnaire (PHQ). In addition, depressive status according to the examiner and the use of antidepressants was recorded. Depression self‐assessment was compared with an interview‐based psychiatric assessment in a subset of 26 patients. Depression prevalence estimates were 17.1% according to the PHQ algorithm and 15.4% when assessed clinically. The sensitivity of clinical impression compared with PHQ classification was low (0.35), whereas diagnostic accuracy of PHQ compared with psychiatric interview in the subset was high. Antidepressants were used by 17.7% of patients and in >10% of patients without current clinically relevant depressive symptoms. Depression profile in SCA did not differ from a sample of patients with major depressive disorder except for the movement‐related item. Neither depression prevalence nor use of antidepressants differed between genetic subtypes, with only sleep disturbance more common in SCA3. In a multivariate analysis, ataxia severity and female sex independently predicted depressive status in SCA. The PHQ algorithmic classification is appropriate for use in SCA but should stimulate further psychiatric evaluation if depression is indicated. Despite a higher risk for depression with more severe disease, the relation of depressive symptoms to SCA neurodegeneration remains to be shown. © 2011 Movement Disorder Society
Study of Stratosphere‐troposphere exchange events of ozone in India and Greece using ozonesonde ascents
Authors: Ganguly Nandita D. , Tzanis Chris
Published: March 2011

Stratosphere‐troposphere Exchange (STE) is an important factor controlling the budget of ozone in the upper troposphere and lower stratosphere. Studies of STE events in India are so far restricted to co‐ordinated campaigns, and measurements over longer periods are relatively scarce. In the light of this observation, this paper aims to identify the Indian latitudes most likely to be affected by STE, the frequency of occurrence of shallow and deep STE events, the depth up to which the ozone from the stratosphere descends into the troposphere during STE events and the resultant trend of ozone in the troposphere under the possible influence of STE over the 24 years from 1982 to 2006. In addition, a case study of the STE of ozone, which occurred during a cut‐off low event at Athens, Greece, is presented in order to understand the parameters that may contribute to the evolution of these events. It is concluded that STE plays a minor role in the Indian tropospheric ozone budget. On the whole, the occurrence of STE events in India is found to increase with increase in latitude and occur more frequently during winter followed by summer. The occurrence of deep STE is higher at high latitudes while the occurrence of shallow STE is higher at low latitudes. Copyright © 2011 Royal Meteorological Society
Scale‐invariant rainstorm hazard modelling for slopeland warning
Authors: Diodato Nazzareno , Petrucci Olga , Bellocchi Gianni
Published: March 2011

Periods characterized by heavy rain and storms can trigger Multiple Damaging Hydrological Events (MDHE), in turn developing flooding, erosion, downpours and other phenomena affecting human habitats and ecosystems. However, approaches and applications to model MDHE and weather warning under specific environmental conditions are still poor. Based on the interpretation of the rainstorm—MDHE relationship, it was reconsidered and extended to a model‐based rainstorms hazard index (RHI) developed in a previous paper, where rainstorm‐pulsing force and resistance state are combined. In this way, landscape response was achieved by individual formative rainfall events, while the specific sequence of events that can affect landscape was only assessed in a qualitative way. A retrospective evaluation of rainstorm hazard modelling, control runs, are also given for different precipitation durations (from 1 to 240 h), to be compared with MDHE at two test‐sites of Southern Italy (Benevento, Campania region; Scilla, Calabria region). For these sites, the complete series of historical MDHE which occurred during a 10 year period (1997–2008) was gathered and used to validate the results of the rainfall model. The tool is relatively simple and potentially attractive to rapidly prediction of adverse consequences of rainstorms. Perspectives for real‐time applications in emergency planning are ultimately given for an agenda in future research. Copyright © 2011 Royal Meteorological Society
A compact low power ultra wideband impulse generator on 0.18 μM CMOS technology
Authors: Dong Ruibing , Pokharel Ramesh K. , Kanaya Haruichi , Yoshida Keiji
Published: March 2011

This article presents a compact ultra wideband (UWB) impulse generator (IG) with special shaping circuit that can operate intermittently.The pulse last for 4 ns and the measured −10 dB bandwidth is about 460 MHz. The UWB IG employs biphase shift keying (BPSK) scrambling and the power consumption is 7.3 mW at a repetition frequency of 125 Mbps. It was fabricated using Taiwan Semi‐conductor Manufacture Company (TSMC) 0.18 μm CMOS process. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1128–1131, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25890
Dual‐band bandpass filter using stepped‐impedance stub‐loaded hexagonal stepped impedance resonator (SIR)
Authors: Luo Xun , Ma Jian‐Guo , Li Erping
Published: March 2011

In this article, a series of compact dual‐band bandpass filters are proposed using the stepped‐impedance stub loaded hexagonal stepped‐impedance resonator. The resonator has three functions in the filter as follow: (1) dual‐resonances operation introduced by the first‐ and second‐resonance modes to dominate two passbands, (2) independent control of the operated frequencies of both passbands, (3) flexible configuration of the resonators implemented‐scheme for specific bandwidth requirement. Then, based on the proposed resonator, two dual‐band bandpass filters with wide‐ and narrow‐passbands are fabricated, respectively. Good agreement between the measured and simulated results demonstrates the design feasibility of the dual‐band bandpass filters. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1147–1150, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25894
Design of a compact wideband high‐gain microstrip grid array antenna
Authors: Wang Guosheng , Lin Shuiyang , Fang Weidong , Zhang Wuxiong
Published: March 2011

A compact wideband high‐gain microstrip grid array antenna is presented.The antenna is printed on a dielectric substrate, backed by a metal board, and directly fed from a 50 Ω coaxial cable. It adopts elliptical radiation elements to enhance its impedance, gain bandwidths, and sinusoid lines to reduce its size. Structural parameters of a proposed antenna with seven radiation elements were optimized by a parallel genetic algorithm on a cluster system. A prototype antenna was fabricated and tested. Results of simulation and measurement agree well and show the antenna exhibits encouraging properties, for example, a S11 < −10 dB bandwidth of 25.1% and a 3 dB gain‐drop bandwidth of 16.5%, both of which are much wider than that of conventional grid array antennas, as well as a maximum gain of approximately 13.8 dBi with an area‐reduction factor of 46%. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1144–1147, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25895
Experimental study of electromagnetic band gaps using plasmas or defaults in a metallic photonic crystal
Authors: Kumar Rajneesh
Published: March 2011

An attempt is made to control microwave propagation in a metallic photonic crystal (MPC) making defaults or plasma columns. Electromagnetic band gaps (EBGs) are studied with defaults or holes in different configurations of MPC. Further, a plasma column is formed in defaults to increase the controllability and tunability of MPC. Moreover, a plasma column is also formed between microwave transmitter and MPC. Findings of this study show that flat and forbidden bands can be controlled in such a way that the negative and positive refractions can be achieved at particular angles. Hence, it reveals importance of plasma to enhance the controllability of microwave propagation in photonic crystals. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1109–1113, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25896
Marching‐on‐in‐degree solution of volume integral equations for analysis of transient electromagnetic scattering by inhomogeneous dielectric bodies with conduction loss
Authors: Shi Yan , Jin Jian‐Ming
Published: March 2011

A time‐domain volume integral equation (TDVIE) solved by the marching‐on‐in‐degree (MOD) scheme is presented for the analysis of transient electromagentic scattering from a three‐dimensional inhomogeneous dielectric object of arbitrary shape with conduction loss.The volume of the object is discretized into curvilinear hexahedral elements, and conformal basis functions are utilized to expand the spatial variation of the electric flux density in the TDVIE. The transient variation of the electric flux density is expressed in term of weighted Laguerre polynomials so that the first, second, and third temporal derivatives of the electric flux density can be handled analytically. By applying the Galerkin spatial and temporal testing procedure, the TDVIE is converted into a recursive matrix equation in terms of the orders of the weighted Laguerre polynomials. Because of the elimination of the time variable in the MOD scheme, the proposed algorithm overcomes the late‐time instability problem that often occur in the conventional marching‐in‐on‐time (MOT) approach. Numerical results are presented to illustrate the good performance of the TDVIE algorithm. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1104–1109, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25897
A new differential stacked spiral inductor with improved self‐resonance frequency
Authors: Kim Joonchul , Nam Byungjae , Kim Hyeongdong
Published: March 2011

A new silicon‐based differential stacked spiral inductor (DSSI) was implemented using a standard 0.18‐μm complimentary metal‐oxide semiconductor technology. Based on the measured two‐port S‐parameter using a standard de‐embedding procedure, the self‐resonance frequency, fsr, and quality factor, Q, of the new DSSI were compared with a conventional DSSI. The fsr of the new DSSI was nearly twice as high as that of the conventional DSSI, and the Q value of the new DSSI was also enhanced. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1024–1026, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25900
Ultra‐wideband bandpass filter using multilayer microstrip‐slot‐microstrip coupled structure
Authors: Abbosh Amin , Bakar Aslina Abu
Published: March 2011

A bandpass filter that uses broadside‐coupled structures and covers the ultra‐wideband (UWB) frequency range (3.1–10.6 GHz) is presented.It utilizes a broadside‐coupled microstrip‐slot‐microstrip structure with embedded low‐pass filter to achieve the required UWB performance. The simulated and measured results of the proposed filter prove its UWB performance with about 0.4‐dB insertion loss, more than 17‐dB return loss, and less than 0.3‐ns peak‐to‐peak deviation in the group delay across the UWB passband. The filter has a wide high cutoff band that extends beyond 20 GHz. It has a compact size with overall dimensions of 1.5 × 2.5 cm2. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1053–1056, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25903
Reconfigurable digital receiver for 8PSK subcarrier multiplexed and 16QAM single carrier phase‐modulated radio over fiber links
Authors: Guerrero Gonzalez N. , Zibar D. , Yu X. , Tafur Monroy I.
Published: March 2011

A reconfigurable digital receiver based on the k‐means algorithm is proposed for phase‐modulated subcarrier multiplexed (SCM) and quadrature amplitude‐modulated single carrier, phase‐modulated radio‐over‐fiber links. We report successful demodulation after 40 km single mode fiber transmission with three 50 Mbaud 8PSK SCM signals and a 312.5 Mbaud 16QAM single carrier. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1015–1018, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25905
Acceleration method for propagation prediction
Authors: Yoon Young‐Keun
Published: March 2011

This letter focuses on an acceleration method using a child node construction to completely enhance the wave propagation prediction time in linking between parent and child nodes.The child node construction, corresponding and linking with an actual parent node, is called an interobject visibility set (IVS) and is a source‐independent (i.e., transmitter or image) structure. Also, child node construction is independent of database information and is used for linking dynamically to a higher‐order parent node. After linking, the entire ray path construction is completed from the receiver to transmitter, and the received signal level is estimated using backward ray tracing. Finally, we demonstrate that the computational time needed for ray tracing prediction less than in a general ray tracing prediction method, and the prediction results using the ray tracing model are in good agreement with measurements at the millimeter wave band in terms of accuracy. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:982–984, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25907
Design of a high tuning range and low phase noise transformer‐based LC voltage‐controlled oscillator
Authors: Huang Jhin‐Fang , Mao Che‐Chi
Published: March 2011

This article proposes a wide tuning voltage‐controlled oscillator (VCO) by employing a transformer‐based LC‐tank and is fabricated in a TSMC 0.18 μm CMOS process with 1.5 V supply voltage. We choose decoupling effect to decrease primary and secondary inductances and then decrease quality factors to obtain higher oscillation frequency and wide tuning range. Measurement results show that at the supply voltage of 1.5 V, the proposed VCO is tunable from 5.96 GHz to 7.3 GHz corresponding to a tuning range of 20.1%, the measured phase noise is −110.9 dBc/Hz at 1 MHz offset from the oscillation frequency of 5.97 GHz, the total power consumption is 9.51 mW with an output signal power of −4.74 dBm at the frequency of 6.2 GHz. The chip area including pads occupies only 0.69 × 0.696 mm2. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1165–1169, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25908
Small global positioning system patch antennas with self‐biased NiCo‐ferrite films
Authors: Yang Guo‐Min , Obi Ogheneyunume , Sun Nian X.
Published: March 2011

Magneto‐dielectric substrates with thin ferrite films show great potential in realizing small antennas with improved omni‐directional performance than those realized on dielectric substrates.This article introduces self‐biased NiCo‐ferrite films as a practical means to tune a patch antenna by loading a commercially available dielectric substrate. Novel antenna designs with self‐biased ferrite films were investigated, and these magnetic antennas have improved the axial ratio from 1.45 to 1.0 dB with respect to the central frequency ranging from 1.575 to 1.561 GHz in the simulations. Experimental global positioning system patch antennas with/without ferrite films were fabricated and tested. The measured results demonstrate that antennas with ferrite films can miniaturize the geometrical dimension by shifting down the resonance. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1162–1165, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25909
A Ka‐band low‐noise amplifier using semicircle stacked‐GCPW transmission line
Authors: Chiu Hsien‐Chin , Chen Ting‐Huei , Fu Jeffrey S. , Nirmalathas T. A.
Published: March 2011

A high‐gain Ka‐band 0.18‐μm CMOS low‐noise amplifier with semicircle stacked grounded coplanar waveguide (SCS‐GCPW) structure transmission line is proposed. SCS‐GCPW transmission line is adopted to reduce the signal loss by shaping the electric fields under the signal line especially at microwave and millimeter wave applications. The SCS‐GCPW demonstrated a similar electric field distribution of coaxial cable and achieved a substrate dielectric attenuation constant of 0.075 Np/m. It is superior to 0.081 Np/m and 0.144 Np/m of traditional microstrip transmission line and CPW transmission line, respectively. By adopting the low loss SCS‐GCPW transmission line, the Ka‐band LNA demonstrated a 24.5 dB gain together with a noise figure (NF) of 7.5 dB at 33 GHz operation. The measured output power 1 dB compression point (P1 dB) was −2 dBm. The dc power consumption was 40 mW and chip size was 0.6 × 1 mm2 for this Ka‐band LNA. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1131–1134, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25910
Single‐layer microstrip reflectarray with double elliptical ring elements for bandwidth enhancement
Authors: Li Yuezhou , Biakowski Marek E. , Sayidmarie Khalil H. , Shuley Nicholas V.
Published: March 2011

The design of a microstrip reflectarray formed by 81 variable size double elliptical rings illuminated by a conical feed is presented.Because of double resonance, the double elliptical rings provide an increased phasing range of unit cells that exceeds the required minimum of 360°. Printed on a single substrate and supported by a layer of foam and a conducting ground, they also offer a slow phase slope as a function of their size, and thus provide an increased operational bandwidth and a good manufacturing error tolerance. The performance of the designed reflectarray is investigated via full‐wave electromagnetic simulations and measurements on the manufactured prototype. The presented results show a wideband performance of the designed reflectarray. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1083–1087, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25912
Optical OFDM signal generation by an optical phase modulator and its application in a 40‐GHZ ROF symmetric system with turbo coding
Authors: Chen Lin
Published: March 2011

We have experimentally demonstrated optical orthogonal frequency division multiplexing (OFDM) signal generation by an optical phase modulator and a 40 GHz radio‐over‐fiber symmetric system with turbo coding technique. The power penalty for the 2.5 Gb/s downlink data carried by 40‐GHz millimeter‐wave after transmission over 50‐km SMF‐28 is smaller than 0.5 dB. The OFDM signals without coding and with coding after transmission at a BER of 1 × 10−3 is −17.5 and −20 dBm, respectively. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1050–1053, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25913
Fabrication of microfiber loop resonator‐based comb filter
Authors: Lim K. S. , Harun S. W. , Jasim A. A. , Ahmad H.
Published: March 2011

Microfiber loop resonator (MLR) is fabricated by coiling of a microfiber, which was obtained by the fast stretching of a heated single mode fiber. The MLR is embedded in low refractive index material to keep the system robust. Two comb filters with a constant spacing of 0.16 nm and 0.71 nm are successfully achieved, which the extinction ratio can be adjusted by controlling the state of polarization of the input light. It was also found that the wavelength of each peak and the spacing remain unchanged regardless of the state of polarization of the input light. This MLR does not have major issues with input–output coupling and presents a completely integrated fiberized solution. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1119–1121, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25916
Strong and weak FEM formulations of higher order for quasi‐static analysis of shielded planar transmission lines
Authors: Mančić Žaklina J. , Petrovic Vladimir V.
Published: March 2011

We present strong and weak Finite Element Method formulations for 2D closed electrostatic problems. Special hierarchical higher (arbitrary) order basis functions are applied. Results for characteristic impedance of shielded planar transmission lines, obtained by the two formulations are compared with results from the literature, and their specific advantages briefly commented. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1114–1119, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25917
Half mode substrate integrated waveguide miniaturization using complementary split ring resonators
Authors: Qiang Li , Lu Hong‐Min , Zhao Wei , Qin Hong‐Bo , Liu Bing
Published: March 2011

A miniaturization technology of half mode substrate integrated waveguide (HMSIW) is realized by complementary split ring resonators (CSRRs) in this article. The HMSIW etched with CSRRs can be regarded as the one filled with a dielectric material with higher εr. With specific CSRR arrays introduced, the CSRR‐loaded structure can be 15% more compact than the original one. Moreover, the above CSRRs can be also used to enhance the rejection skirt of the bandpass filter in this article. Finally, a compact and sharp rejection ultra‐wideband bandpass filter with designed notched‐band is fabricated. Very good agreement is observed between measurement and simulation results. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1074–1077, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25918