bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of indoxacarb and five other insecticides on Phytoseiulus persimilis (Acari: Phytoseiidae), Amblyseius fallacis (Acari: Phytoseiidae) and nymphs of Orius insidiosus (Hemiptera: Anthocoridae)
Authors: Bostanian Noubar J , Akalach Mohammed
Published: February 2006

A laboratory study assessed the contact toxicity of indoxacarb, abamectin, endosulfan, insecticidal soap, S‐kinoprene and dimethoate to Amblyseius fallacis (Garman), Phytoseiulus persimilis Athias‐Henriot and nymphs of Orius insidiosus (Say). Amblyseius fallacis is a predacious phytoseiid mite and an integral part of integrated pest management (IPM) programmes in North American apple orchards. The other two beneficials are widely used in greenhouses to manage various arthropod pests infesting vegetable and ornamental crops. Indoxacarb is a slow‐acting insecticide, so toxicity data were recorded 7 days post‐treatment when the data had stabilised. It showed no toxicity to O. insidiosus nymphs or to A. fallacis or P. persimilis adults. The LC50 values for O. insidiosus nymphs and P. persimilis could not be estimated with their associated confidence limits, because the g values were greater than 0.5 and under such circumstances the lethal concentration would lie outside the limits. The LC50 for A. fallacis was 7.6× the label rate. The fecundity of P. persimilis was reduced by 26.7%. The eclosion of treated eggs from both species of beneficial mites was not affected adversely. Among the other pest control products, S‐kinoprene and endosulfan affected adversely at least one species of the predators, whereas dimethoate, abamectin and insecticidal soap were very toxic to all three beneficials. Indoxacarb should be evaluated as a pest control product in IPM programmes. Copyright © 2006 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.
Dissociation between M1‐facilitation of acetylcholine release and crosstalk with A2A‐ and M2‐receptors on rat motoneurons
Authors: Oliveira Laura , Correia‐de‐Sá Paulo
Published: February 2006

Acetylcholine (ACh) facilitates its own release acting at muscarinic M1receptors on rat motoneurons. While the M1positive feedback mechanism is operative there is a concomitant suppression of the ability of muscarinic M2‐inhibitory and adenosine A2A‐facilitatory receptors to control [3H]ACh release. We aimed at investigating whether M1‐occlusion of M2and A2Areceptors function could result from interplay at second messengers level. Drugs blocking the IP3pathway, like LiCl and 2‐aminoethoxydiphenylborane (2‐APB), but not the selective PKC inhibitor, chelerythrine, attenuated M1facilitation by McN‐A‐343. PKC activation with phorbol 12‐myristate 13‐acetate mimicked the ability of McN‐A‐343 to suppress M2‐inhibition and A2A‐facilitation of [3H]ACh release caused by oxotremorine and CGS 21680C, respectively. Co‐application of chelerythrine together with McN‐A‐343 restored oxotremorine‐inhibition and CGS 21680C‐facilitation, but this was not observed when the M1agonist was applied together with LiCl and 2‐APB. McN‐A‐343 also masked facilitation of [3H]ACh release caused by stimulators of the cyclic AMP pathway, forskolin and rolipram. Data suggest that M1‐facilitation of ACh release results mainly from activation of the IP3pathway. This mechanism can be dissociated from the way M1receptor operates suppression of neuromodulation through M2‐inhibitory and A2A‐facilitatory receptors, which might involve secondary PKC activation.
Cardiogenic shock after primary percutaneous coronary intervention: Effects of levosimendan compared with dobutamine on haemodynamics
Authors: García‐González Martín J. , Domínguez‐Rodríguez Alberto , Ferrer‐Hita Julio J. , Abreu‐González Pedro , Muñoz Miguel Bethencourt
Published: February 2006

Background:

Levosimendan is a new calcium sensitizer with positive inotropic properties. Cardiac power output (CPO) has been shown to be instrumental in the diagnosis of cardiogenic shock (CS) and is an important determinant of outcomes.

Aims:

To evaluate the haemodynamic effects of levosimendan compared to dobutamine in acute myocardial infarction (AMI) patients revascularised by primary percutaneous coronary intervention (PCI), who developed CS.

Methods and results:

Twenty two consecutive AMI patients revascularised by PCI, who developed CS, were randomly assigned to levosimendan (24μg kg−1 bolus plus 24‐h continuous infusion 0,1μg kg−1 min−1) or dobutamine (initial dose 5μg kg−1 min−1, with a maximum dose adjustment in order to reach the desired haemodynamic effect). Evaluations were performed from baseline to 30h. The primary end‐point was an increase ≥30% in CPO, after 24h of therapy. The baseline clinical and haemodynamic characteristics were similar in both groups. Levosimendan had a consistently better effect on CPO than dobutamine, while the decrease in PCWP was similar.

Conclusion:

The primary objective of our study was achieved better by the end of the 24h infusion of levosimendan than by dobutamine.
Laminin α1 chain mediated reduction of laminin α2 chain deficient muscular dystrophy involves integrin α7β1 and dystroglycan
Authors: Gawlik Kinga I. , Mayer Ulrike , Blomberg Kristina , Sonnenberg Arnoud , Ekblom Peter , Durbeej Madeleine
Published: February 2006

Transgenically introduced laminin (LN) α1 chain prevents muscular dystrophy in LNα2 chain deficient mice. We now report increased integrin α7Bβ1D synthesis in dystrophic LNα2 chain deficient muscle. Yet, immunofluorescence demonstrated a reduced expression of integrin α7B subunit at the sarcolemma. Transgenic expression of LNα1 chain reconstituted integrin α7B at the sarcolemma. Expression of α‐ and β‐dystroglycan is enhanced in LNα2 chain deficient muscle and normalized by transgenic expression of LNα1 chain. We suggest that LNα1 chain in part ameliorates the development of LNα2 chain deficient muscular dystrophy by retaining the binding sites for integrin α7Bβ1D and α‐dystroglycan, respectively.
Effects of MdmX on Mdm2‐mediated downregulation of pRB
Authors: Uchida Chiharu , Miwa Seiichi , Isobe Tomoyasu , Kitagawa Kyoko , Hattori Takayuki , Oda Toshiaki , Yasuda Hideyo , Kitagawa Masatoshi
Published: February 2006

Mdm2, a RING‐finger type ubiquitin ligase, is overexpressed in a variety of human cancers. It promotes ubiquitination of the tumor suppressor p53 and can function as an oncogene by largely downregulating p53. Recently, we reported that Mdm2 degrades retinoblastoma tumor suppressor protein (pRB) via the ubiquitin–proteasome system. In the present study, we assessed the effects of MdmX, a structural homolog of Mdm2, on the Mdm2‐mediated ubiquitination of pRB. MdmX is known to negatively regulate p53 function by enhancing the Mdm2‐mediated ubiquitination and degradation of p53. Interestingly, MdmX inhibited the Mdm2‐mediated pRB ubiquitination. Furthermore, an MdmX siRNA decreased the endogenous pRB level, while MdmX overexpression stimulated pRB functions in cultured cells. Therefore, MdmX may have different roles in the regulation of Mdm2 activity for ubiquitination of pRB and p53.
Transoral Approach to the Superomedial Parapharyngeal Space
Authors: Ducic Yadranko , Oxford Lance , Pontius Allison T.
Published: February 2006

OBJECTIVES

To present our early experience with the transoral approach to the superomedial parapharyngeal space (PPS) and describe our technique for removal of these neoplasms.

STUDY DESIGN

Consecutive case series by one author (Y.D.). METHODS: Eight patients with various neoplasms of the superomedial PPS were retrospectively reviewed for type of neoplasm, size, success with the transoral approach, need for conversion to another approach, length of hospitalization, and complications.

RESULTS

The transoral approach described herein safely allowed for en bloc resection of benign neoplasms with intraoperative control and exposure of the internal carotid artery. The most common pathology encountered was that of schwannoma. All patients were started on liquid diet on postoperative day 1. Average length of stay was 3.2 days (range, 2 to 5). Mean tumor size was 3.3 cm (range, 1.5 to 7 cm). No significant complications were felt to be related to the approach itself and visualization was felt to be excellent in each case without the need for conversion to a more extensive approach.

CONCLUSIONS

The transoral approach safely provides access to superomedial PPS lesions with decreased morbidity compared with traditional approaches. This technique is indicated for neoplasms with benign appearance on preoperative imaging or fine needle aspiration. This approach alone may not provide adequate access for resection of malignant lesions especially those with extension intracranially or to more inferior or laterally placed lesions of the parapharyngeal space.

EBM rating: C‐4

© 2006 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved.
Botulinum Toxin Injection and Airflow Stability in Spasmodic Dysphonia
Authors: Cantarella Giovanna , Berlusconi Alessandra , Maraschi Barbara , Ghio Alain , Barbieri Sergio
Published: February 2006

OBJECTIVE

The aim of this study was to analyze the effects of botulinum toxin (BT) injection on airflow stability, by measuring mean phonatory oral airflow and its coefficient of variation (CV), in subjects with adductor spasmodic dysphonia (SD).

STUDY DESIGN AND SETTING

Twenty‐four subjects with SD (aged 31‐78 years) and 23 controls (aged 29‐63 years) were evaluated for mean airflow and its CV during sustained phonation. Fifteen of the subjects with SD were also evaluated within 3 weeks after BT injection.

RESULTS

BT increased airflow in subjects (P = 0.0130) but neither the preinjection nor postinjection values differed significantly from those of controls. Conversely, airflow CV was invariably higher in subjects than in controls (P < 0.0001). In 13 subjects in whom phonation perceptually improved, including 3 in whom airflow did not increase, airflow CV decreased significantly after BT treatment (P = 0.0232).

CONCLUSIONS

Subjects with SD have highly unstable phonatory airflow; its CV is a valid measure for assessing the outcome of a BT injection. A reduced airflow CV probably does not depend solely on increased airflow due to thyroarytenoid muscle paresis, and may indicate a change in laryngeal motoneuronal activity.

EBM rating: B‐3b

© 2006 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved.
p53 and Skin Carcinomas With Skull Base Invasion: A Case‐Control Study
Authors: Cernea Claudio R. , Ferraz Alberto R. , de Castro Inês V. , Sotto Miriam N. , Logullo Ângela F. , Bacchi Carlos E. , Potenza André S.
Published: February 2006

BACKGROUND

Some skin carcinomas may be very aggressive. Increased expression of the protein p53 has been associated with tumor aggressiveness. In this study, p53 expression was evaluated in basal cell carcinomas (BCC) and squamous cell carcinomas (SCC) with skull base invasion, and was compared to tumors with good outcome.

STUDY DESIGN AND SETTING

Expression of p53 was immunohistochemically analyzed and it was reported as present or absent in 24 BCC and 11 SCC with skull base invasion. Control group (good outcome) included 23 BCC and 10 SCC.

RESULTS

Expression of p53 was noted in 70.83% of BCC with skull base invasion, compared to 43.48% in the control group (P = 0.058). Regarding SCC, p53 positivity was noted in only 9.09% of SCC with skull base invasion, compared to 40.00% in the control group (P = 0.149).

CONCLUSIONS

In this study, p53 expression was more common among BCC with skull base invasion, compared to controls with good outcome, and the difference was considered marginally significant. This proportion was reversed in SCC, but the difference was not statistically significant.

EBM rating: B‐3b

© 2006 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved.
Surgical Consideration to Optic Nerve Protrusion According to Sinus Computed Tomography
Authors: Chen Ying‐Lin , Lee Li‐Ang , Lim Kun‐Eng
Published: February 2006

OBJECTIVES

This study aimed to investigate the prevalence of optic nerve protrusion (ONP) and its clinical indicators by using sinus computed tomography (CT) scan.

STUDY DESIGN

Sinus CT scans of 260 consecutive patients with chronic inflammatory sinus disease were reviewed.

RESULTS

The prevalence of ONP in our study population was 28%. Nineteen percent of the optic nerves protruded into the sphenoid sinuses including indentation of the sinus wall (12%) and coursing through the sphenoid sinus (8%). In the presence of contralateral ONP and/or ipsilateral anterior clinoid process pneumatization, the chance of ONP occurrence was significantly higher (both P < 0.01). They were reliable indicators of ONP (R 2 = 0.47, P < 0.01).

CONCLUSIONS

ONP is a common anatomic variation observed in patients with chronic inflammatory sinus disease. To reduce optic nerve damage in surgeries, the presence of ONP according to sinus CT scans and the intraoperative findings should be carefully evaluated.

EBM rating: C‐4

© 2006 American Academy of Otolaryngology‐Head and Neck Surgery Foundation, Inc. All rights reserved.
Effect of Nasal Valve Area on Inspirator Nasal Sound Spectra
Authors: Seren Erdal
Published: February 2006

OBJECTIVE

We have researched the effects of nasal valve area on the inspiratory nasal sound spectra in this study.

STUDY DESIGN AND SETTING

We have spectral analyzed and recorded the inspiratory nasal sound in 22 healthy people with and without the Cottle maneuver.

RESULTS

We have found an increase in sound intensity at high frequency in the sound analyses of the subjects without the Cottle maneuver; whereas, a decrease in sound intensity at high frequency was found in subjects with the Cottle maneuver.

CONCLUSIONS

The nasal valve area plays an important role in the transformation of the nasal airflow from a laminar pattern to a more turbulent one. This condition affects nasal sound spectra and produces a marked shift upward in frequencies in the spectra. This method may be a new way of evaluating the nasal valve area.

EBM rating: C‐4

© 2006 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved.
Patient Expectations and Recovery Following Endoscopic Sinus Surgery
Authors: Mehta Umang , Huber Todd C. , Sindwani Raj
Published: February 2006

OBJECTIVES

Studies examining the early postoperative period after endoscopic sinus surgery (ESS) are lacking. The objectives were to determine patient expectations of recovery following ESS and compare these expectations to actual outcomes.

STUDY DESIGN

A prospective study. An 11‐item survey regarding recovery from anesthesia and sinonasal outcomes was administered after ESS over postoperative days (POD) #1, #7, and #14. Preoperative surveys established baseline levels and explored patient expectations of POD #1 outcomes.

RESULTS

Forty‐six patients participated. Individual expectations generally did not correlate with POD #1 outcomes. Sinonasal symptoms, narcotic usage, and activity level (P < 0.05) demonstrated significant improvement over the postoperative period. Within one week, 75% of patients returned to work. By POD #14, nasal obstruction, discharge, fatigue, and overall health (P < 0.05) had improved over preoperative levels. Patients undergoing concomitant septoplasty had a more difficult postoperative course.

CONCLUSION

Patient expectations of ESS vary widely, although this surgery is generally well tolerated with a brief recovery period.

EBM rating: C‐4

© 2006 American Academy of Otolaryngology‐Head and Neck Surgery Foundation, Inc. All rights reserved.
Mitomycin‐c Application in Airway Stenosis Surgery: Analysis of Safety and Costs
Authors: Ubell Matthew L. , Ettema Sandra L. , Toohill Robert J. , Simpson C. Blake , Merati Albert L.
Published: February 2006

OBJECTIVE

This study describes a large series of patients receiving topical mitomycin‐c (MMC) during airway surgery, including complications, and carries out a cost analysis for its use in laryngotracheal stenosis.

STUDY DESIGN AND SETTING

Retrospective review, tertiary center. Airway patients receiving MMC are reviewed for demographics, stenosis characteristics, and MMC usage. A basic cost analysis is carried out.

RESULTS

Fifty patients underwent 93 MMC applications (mean = 50.8 years, 25 male, 25 female). In 89 of 93 applications (96%), the concentration of MMC was 0.4 mg/ml. One major complication occurred (1.1%). The expense for MMC is $455; the mean cost for airway surgery is $7,840. It is estimated that if 1 of 17 MMC treated patients requires one less operation, the cost ratio is favorable.

CONCLUSIONS

This large series contributes to literature that MMC is a safe adjunct to laryngotracheal surgery. The marginal cost for MMC application is favorable based on our basic cost analysis and existing efficacy data.

SIGNIFICANCE

Mitomycin‐c seems to be safe and cost‐effective in endoscopic airway surgery.
Long‐Term Changes in Behavior after Adenotonsillectomy for Obstructive Sleep Apnea Syndrome in Children
Authors: Mitchell Ron B. , Kelly James
Published: February 2006

OBJECTIVE

To study long‐term changes in behavior after adenotonsillectomy for obstructive sleep apnea syndrome (OSAS) in children.

DESIGN AND SETTING

Prospective study at the University of New Mexico Children's Hospital, Albuquerque, NM.

METHODS

Children with polysomnography‐proven OSAS underwent adenotonsillectomy. The Behavior Assessment System for Children (BASC) was completed before surgery, within 6 months and 9 to 18 months after surgery. Scores were compared using a paired t test. A P value <0.05 was considered significant.

RESULTS

The study population included 23 children. Preoperative mean BASC T scores were >50. Children showed significant improvement after adenotonsillectomy in aggression, atypicality, depression, hyperactivity, and somatization within 6 months and 9 to 18 months after surgery (P < 0.05). The differences within 6 months and 9 to 18 months after surgery were not statistically significant.

CONCLUSIONS

Caregivers report abnormalities in the behavior of children with OSAS. Behavioral abnormalities improve significantly after adenotonsillectomy and are maintained in the long‐term.
Effect of Recurrent Laryngeal Nerve Section on the Laryngeal Muscles of Adult Rabbits
Authors: Shinners Michael J. , Goding George S. , McLoon Linda K.
Published: February 2006

OBJECTIVE

To examine the effect of recurrent laryngeal nerve section on myonuclear addition and myofiber remodeling in adult rabbit laryngeal muscles.

STUDY DESIGN AND SETTING

Unilateral section of the recurrent laryngeal nerve was performed on adult rabbits. Rabbits were labeled with bromodeoxyuridine, euthanized, and the laryngeal muscles were examined for bromodeoxyuridine (brdU) and neonatal myosin heavy chain (MyHC) expression.

RESULTS

One week after nerve section, brdU‐positive myonuclei were significantly increased on the denervated and contralateral sides. Neonatal MyHC expression significantly increased. By 24 weeks, the upregulation of myonuclear addition returned to control levels.

CONCLUSION

Laryngeal muscle denervation results in significant upregulation of myonuclear addition. Denervation also resulted in a significant upregulation of neonatal MyHC expression.

SIGNIFICANCE

Laryngeal muscles can be successfully reinnervated after long periods of denervation. This significant and maintained increase in myonuclear addition may contribute to the ability of laryngeal muscles to survive for extended periods following interruption of the recurrent laryngeal nerve.
PREMARITAL FERTILITY IN NAMIBIA: TRENDS, FACTORS AND CONSEQUENCES
Authors: GARENNE MICHEL , ZWANG JULIEN
Published: February 2006

Premarital fertility, defined as fertility before first marriage, was found to be highly prevalent in Namibia. According to data from the 1992 and 2000 DHS surveys, the proportion of premarital births was 43% for all births, and 60% for the first birth. This seemed to be primarily due to a late mean age at first marriage (26·4 years) and low levels of contraception before first marriage. Data were analysed using a variety of demographic methods, including multiple decrement life table and multivariate logistic models. Major variations were found by ethno-linguistic groups: Herero and Nama/Damara had the highest levels of premarital fertility (above 60%); Ovambo and Lozi had intermediate levels of premarital fertility (around 40%); Kavongo and San appeared to have kept a more traditional behaviour of early marriage and low levels of premarital fertility (around 20%). The largest ethno-linguistic group, the Ovambo, were in a special situation, with fast increasing age at marriage and average level of premarital fertility. Whites and mixed races also differed, with Afrikaans-speaking groups having a behaviour closer to the average, whereas other Europeans had less premarital fertility despite an average age at marriage. Ethnic differences remained stable after controlling for various socioeconomic factors, such as urbanization, level of education, wealth, access to mass media, and religion. Results are discussed in light of the population dynamics and political history of Namibia in the 20th century.
Early relations between lexical and grammatical development in very immature Italian preterms
Authors: SANSAVINI ALESSANDRA , GUARINI ANNALISA , ALESSANDRONI ROSINA , FALDELLA GIACOMO , GIOVANELLI GIULIANA , SALVIOLI GIANPAOLO
Published: February 2006

This study aimed to investigate early lexical and grammatical development and their relations in a sample of very immature healthy preterms, in order to assess whether their linguistic development was typical, at risk or atypical. The effects of biological factors and parental level of education on preterms' linguistic development were also investigated. Seventy-three Italian preterms and 22 Italian fullterms (control sample) were assessed at 2;6 with an Italian test of repetition of sentences (TRF). Their mothers completed the Italian version of the MacArthur questionnaire (PVB). Our results showed that most of the preterm sample displayed a typical development, compared with the fullterms, with lexicon and grammar within the normal range and a normal relation between these competencies. However, preterms characterized by an extremely low birthweight (ELBW), a very low gestational age and male gender were at risk, with slight delays in the lexicon and grammar, but still retaining the normal relation between the two.
Facilitating the acquisition of UNDER by means of IN and ON – a training study in Polish
Authors: ROHLFING KATHARINA J.
Published: February 2006

Forty Polish children aged between 1;8 and 2;3 were trained over two training sessions in the comprehension of the preposition POD [UNDER]. In the experiment, two variables were manipulated: a within subjects variable of SITUATION and a between subjects variable of LINGUISTIC INPUT. The effect of situation could be found in all trained groups, showing that children's understanding in familiar and transfer situations differed significantly from the performance of the control group in the post-test. The results further suggest that depending on the type of a situation, the linguistic task requires different word learning abilities from a child.
The Phonological Mean Length of Utterance: methodological challenges from a crosslinguistic perspective
Authors: SAARISTO-HELIN KATRI , SAVINAINEN-MAKKONEN TUULA , KUNNARI SARI
Published: February 2006

The present study assesses the phonological development of 17 children acquiring Finnish at the developmental point of 25 words (ages 1;2–2;0). The analysis is made using the PHONOLOGICAL MEAN LENGTH OF UTTERANCE (PMLU) method (Ingram & Ingram, 2001; Ingram, 2002), which focuses on the children's whole-word productions. Two separate analyses are carried out: the first analysis concentrates on consonants and follows the procedure devised by Ingram and Ingram (2001), and the second analysis also scores the correctness of vowels. The PMLU results of both analyses are found to be much higher than those reported for children acquiring English. The results show the apparent need for more language-specific research in order to develop the PMLU method suitable for various language environments.
Disease caused by non-tuberculous mycobacteria in a university hospital in Taiwan, 1997–2003
Authors: DING L. W. , LAI C. C. , LEE L. N. , HSUEH P. R.
Published: February 2006

From January 1997 to December 2003, all patients with non-tuberculous mycobacteria (NTM) isolation who were treated at a university hospital in Taiwan were evaluated. Among the 2650 NTM isolates, 1225 (46·2%) were from 412 patients with clinically significant diseases. The annual incidence (per 100000 patients) of disease caused by NTM was 8·96 in 1997, 21·53 in 2002, and 16·55 in 2003. The major types of infections caused by NTM included isolated pulmonary infection and pleurisy (59·5%), skin/soft-tissue infections and osteomyelitis (13·8%), and disseminated diseases (13·3%). The two most common groups of organisms involved were rapidly growing mycobacteria (RGM) (41·4%) and Mycobacteriumavium complex (MAC) (39%). The most common organism involved in isolated pulmonary infection and pleurisy was MAC (44·1%). RGM predominated in keratitis (94%), skin/soft-tissue infections and osteomyelitis (43·9%), and lymphadenitis (66·7%). This retrospective 7-year study demonstrated an increase in the incidence of NTM disease in a university hospital.
Coxiella burnetii and milk pasteurization: an early application of the precautionary principle?
Authors: CERF O. , CONDRON R.
Published: February 2006

Stringency of milk pasteurization has been established on requirements for Coxiella burnetii as being the most heat-resistant organisms of public heath significance. This paper discusses the estimation of the efficiency of pasteurization time/temperature combinations as required in regulations for food safety. Epidemiological studies have been interpreted as C. burnetii being a significant pathogen causing clinical disease through ingestion of milk. The paper examines the evidence and challenges the designation of C. burnetii as a foodborne pathogen. Consequently it questions the need for pasteurization parameters to be established on its heat resistance characteristics.
Point and areal validation of forecast precipitation fields
Authors: Yates Eddy , Anquetin Sandrine , Ducrocq Véronique , Creutin Jean‐Dominique , Ricard Didier , Chancibault Katia
Published: February 2006

Two high resolution quantitative precipitation forecasts with different levels of realism are evaluated. Classical scores (bias, correlation and scores based on contingency tables) confirm that the two forecasts do not have the same quality. A multi‐scale extension of these scores has then been made to produce a validation for hydrological purposes. Rainfall fields are integrated over surfaces of various scales. For better simulation, scores indicate an increase in the quality of the simulated precipitation for larger surfaces (typically more than 100 km2): the localisation errors are reduced by the aggregation. This helps to determine the usefulness of such forecasts for hydrological purposes. Copyright © 2006 Royal Meteorological Society.
Comparative analysis of estimators for wind direction standard deviation
Authors: Farrugia P. S. , Micallef A.
Published: February 2006

Wind direction is a circular variable. This makes the algorithms used to find its standard deviation different from that of the linear variables. In particular, the requirement for storing all the data points before the standard deviation can be computed limits the storage capacity and puts great strain on remote data acquisition systems. Various algorithms have therefore been developed to estimate the standard deviation in order to reduce the number of terms stored. The following work consists of a comparative analysis of such estimators together with the parameters used. It emerges that some of the assumptions adopted to produce the equations being analysed do not hold in practice, even though this does not affect significantly the performance of the estimators that depend on them. On the other hand, the parameter that has the best trend with the algorithm adopted is the magnitude of the vector to the centre of gravity of the system. However, such a result gives rise to some concerns since it does not account for the ‘vectorial’ nature of the angle being treated. Copyright © 2006 Royal Meteorological Society.
Crustal structure and implications for the tectonic evolution of the Archean Western Superior craton from forward and inverse gravity modeling
Authors: Nitescu B. , Cruden A. R. , Bailey R. C.
Published: February 2006

The distribution of mass anomalies within the crust of the Archean Western Superior Province has been investigated with forward and inverse gravity modeling routines. The gravity models indicate that in most of the Western Superior Province, significant mass anomalies occur only within the top 10 km of the crust, where they are generally related to dense metavolcanic rocks and low‐density granitoid plutons, and at the crust‐mantle boundary, where they are linked to undulations of this interface. An exception is the region encompassing the central Wabigoon Subprovince and the segments of the Quetico and Wawa belts south of it, where implied large intracrustal mass anomalies are associated with a segment of denser lower crust, and with overlying depressions of the interfaces between the main crustal layers. We interpret the predominant lateral mass homogeneity observed at deep crustal levels as evidence of mass redistribution processes associated with a major postaccretionary episode of thermal softening of the Western Superior crust. The incongruent presence of a denser lower crustal segment may reflect the subsequent modification of the lower crust through magmatic intra and underplating, possibly in relation with the Mesoproterozoic midcontinent rifting event.
Observations of the mid‐mantle discontinuity beneath Indonesia from S to P converted waveforms
Authors: Vanacore Elizabeth , Niu Fenglin , Kawakatsu Hitoshi
Published: February 2006

S to P conversions were employed to derive a coherent discontinuity structure beneath Indonesia. Analysis of data recorded by three regional arrays from nine deep earthquakes not only confirmed the results of previous studies on the existence of the mid‐mantle discontinuity beneath the Java arc but also revealed its presence north to Kalimantan Island. S to P waves converted at the discontinuity were observed on the stacked diagrams with a negative slowness relative to the P wave and a conversion depth ranging from ∼1080 km in the west to ∼930 km in the east.
Assessing the idealized predictability of precipitation and temperature in the NCEP Climate Forecast System
Authors: Luo Lifeng , Wood Eric F.
Published: February 2006

The 24‐year retrospective forecast data set from the NCEP Climate Forecast System (CFS) is analyzed to study its idealized predictability of precipitation and temperature under its current configuration. The analysis approach assumes the forecasting model and system to be predicted share exactly the same physics so that the idealized predictability is calculated and serves as the upper limit of the predictive skill in practical forecasts. The analysis shows that CFS is not capable of predicting itself over much of the mid‐latitudes land areas for precipitation and temperature anomalies having small temporal (monthly) and spatial (2.5° × 2.5° grid) scales at lead‐times longer than a month. Anomalies become more predictable with the increase in temporal and spatial scales and with the decrease in lead‐times, as illustrated with results from the central US region. The results imply that additional care should be taken when using climate model seasonal forecast products.
A study into the errors in vertical total electron content mapping using GPS data
Authors: Meggs R. W. , Mitchell C. N.
Published: February 2006

A simulation is used to compare two different methods of generating maps of vertical total electron content (TEC) in the ionosphere for 24 days in 2001. The first method is the established thin shell, in which the ionosphere is represented by a thin shell at a fixed altitude. The second method uses a new four‐dimensional inversion algorithm called Multi‐Instrument Data Analysis System (MIDAS). The differences between the vertical TEC in the simulated ionosphere and that determined by each method provide a measure of the error in the vertical TEC maps. It was found that in general, the MIDAS method produced a threefold improvement in the accuracy of the determination of daytime TEC compared with the thin shell. At nighttime, the errors were much smaller and were similar for both methods.
Chronic Hydrocephalus-Induced Changes in Cerebral Blood Flow: Mediation through Cardiac Effects
Authors: Dombrowski Stephen M , Schenk Soren , Leichliter Anna , Leibson Zack , Fukamachi Kiyotaka , Luciano Mark G
Published: February 2006

Decreased cerebral blood flow (CBF) in hydrocephalus is believed to be related to increased intracranial pressure (ICP), vascular compression as the result of enlarged ventricles, or impaired metabolic activity. Little attention has been given to the relationship between cardiac function and systemic blood flow in chronic hydrocephalus (CH). Using an experimental model of chronic obstructive hydrocephalus developed in our laboratory, we investigated the relationship between the duration and severity of hydrocephalus and cardiac output (CO), CBF, myocardial tissue perfusion (MTP), and peripheral blood flow (PBF). Blood flow measures were obtained using the microsphere injection method under controlled hemodynamic conditions in experimental CH ( n = 23) and surgical control ( n = 8) canines at baseline and at 2, 4, 8, 12, and 16 weeks. Cardiac output measures were made using the Swan–Ganz thermodilution method. Intracranial compliance (ICC) via cerebrospinal fluid (CSF) bolus removal and infusion, and oxygen delivery in CSF and prefrontal cortex (PFC) were also investigated. We observed an initial surgical effect relating to 30% CO reduction and ∼50%> decrease in CBF, MTP, and PBF in both groups 2 weeks postoperatively, which recovered in control animals but continued to decline further in CH animals at 16 weeks. Cerebral blood flow, which was positively correlated with CO ( P = 0.028), showed no significant relationship with either CSF volume or pressure. Decreased CBF correlated with oxygen deprivation in PFC ( P = 0.006). Cardiac output was inversely related with ventriculomegaly ( P = 0.019), but did not correlate with ICP. Decreased CO corresponded to increased ICC, as measured by CSF infusion ( P = 0.04). Our results suggest that CH may have more of an influence on CO and CBF in the chronic stage than in the early condition, which was dominated by surgical effect. The cause of this late deterioration of cardiac function in hydrocephalus is uncertain, but may reflect cardiac regulation secondary to physiologic response or brain injury. The relationship between cardiac function and CBF should be considered in the pathophysiology and clinical treatment of CH.
General explanation of geometric phase effects in reactive systems: Unwinding the nuclear wave function using simple topology
Authors: Althorpe Stuart C.
Published: February 2006

We describe a simple topological approach which was used recently to explain geometric phase (GP) effects in the hydrogen-exchange reaction [Juanes-Marcos et al., Science 309, 1227 (2005)]. The approach is general and applies to any reactive system in which the nuclear wave function encircles a conical intersection (CI) and is confined to one adiabatic surface. The only numerical work required is to add and subtract nuclear wave functions computed with normal and GP boundary conditions. This is equivalent to unwinding the nuclear wave function onto a double cover space, which separates out two components whose relative sign is changed by the GP. By referring to earlier work on the Aharanov-Bohm effect, we show that these two components contain all the Feynman paths that follow, respectively, an even and an odd number of loops around the CI. These two classes of path are essentially decoupled in the Feynman sum, because they belong to different homotopy classes (meaning that they cannot be continuously deformed into one another). Care must be taken in classifying the two types of path when the system can enter the encirclement region from several different start points. This applies to bimolecular reactions with identical reagents and products, for which our approach allows a symmetry argument developed by Mead [J. Chem. Phys. 72, 3839 (1980)] to be generalized from nonencircling to encircling systems. The approach can be extended in order to unwind the wave function completely onto a higher cover space, thus separating contributions from individual winding numbers. The scattering boundary conditions are ultimately what allow the wave function to be unwound from the CI, and hence a bound state wave function cannot be unwound. The GP therefore has a much stronger effect on the latter than on the wave function of a reactive system.
Coherent random lasing in the deep blue from self-assembled organic nanofibers
Authors: Andreev A. , Quochi F. , Cordella F. , Mura A. , Bongiovanni G. , Sitter H. , Hlawacek G. , Teichert C. , Sariciftci N. S.
Published: February 2006

We report on the morphological and nonlinear optical properties of highly ordered para-sexiphenyl nanofibers grown by hot-wall epitaxy on muscovite mica. For suitable substrate temperatures and deposition times, needle-shaped aggregates are obtained. These nanoaggregates, which are formed by regrouping of small islands of the material, can support optical waveguiding and amplification of the deep-blue emission of para-sexiphenyl. We show evidence of low-threshold coherent random lasing in ensembles of nanofibers and study the dependence of lasing on the nanofibers’ film thickness. We also present spatially resolved lasing measurements on individual nanofiber segments. The achievement of isolated nanofibers with suitable morphology and low optical losses could open the route to unprecedented photonic and optoelectronic devices at the submicrometric scale.
Adsorption of oxygen molecules on individual single-wall carbon nanotubes
Authors: Tchernatinsky A. , Desai S. , Sumanasekera G. U. , Jayanthi C. S. , Wu S. Y. , Nagabhirava B. , Alphenaar B.
Published: February 2006

Our study of the adsorption of oxygen molecules on individual semiconductiong single-walled carbon nanotubes at ambient conditions reveals that the adsorption is physisorption, the resistance without O2 increases by approximately two orders of magnitude as compared to that with O2, and the sensitive response is due to the pinning of the Fermi level near the top of the valence band of the tube, resulting from impurity states of O2 appearing above the valence band.
Molecular theory of thermal conductivity of the Lennard-Jones fluid
Authors: Eskandari Nasrabad Afshin , Laghaei Rozita , Eu Byung Chan
Published: February 2006

In this paper the thermal conductivity of the Lennard-Jones fluid is calculated by applying the combination of the density-fluctuation theory, the modified free volume theory of diffusion, and the generic van der Waals equation of state. A Monte Carlo simulation method is used to compute the equilibrium pair-correlation function necessary for computing the mean free volume and the coefficient in the potential-energy and virial contributions to the thermal conductivity. The theoretical results are compared with our own molecular dynamics simulation results and with those reported in the literature. They agree in good accuracy over wide ranges of density and temperature examined in molecular dynamics simulations. Thus the combined theory represents a molecular theory of thermal conductivity of the Lennard-Jones fluid and by extension simple fluids, which enables us to compute the nonequilibrium quantity by means of the Monte Carlo simulations for the equilibrium pair-correlation function.
Electron scattering due to threading edge dislocations in n-type wurtzite GaN
Authors: You Jeong Ho , Lu Jun-Qiang , Johnson H. T.
Published: February 2006

The effect of electrically active VGa–ON threading edge dislocations on drift and Hall mobilities in n-type epitaxial wurtzite (WZ) GaN is investigated theoretically. The charge distribution along the dislocation core is first obtained by means of a density-functional theory atomistic calculation; the two N atoms near the missing Ga atom at the dislocation core are found to be electron acceptors. An accurate analytical expression for dislocation electrostatic strength is then derived for the case of up to −2q charge per structural unit of the threading dislocation core. This strength factor is determined by minimizing the total increase of free energy per site of the partially charged dislocation line. Two different models of scattering potentials for charged dislocation lines are then used to determine the dislocation effect on in-plane electron mobility, and closed-form solutions for the dislocation contribution to drift and Hall mobilities are derived for the more accurate potential. By estimating the effects of other scattering mechanisms, the total mobility is then compared with available experimental data. It is found that for free-carrier concentrations higher than 1016cm−3, reducing dislocation density below ndis=108cm−2 has little beneficial effect on total mobility for typical WZ GaN samples.
Nanoanalytical quantification of the nitrogen content in Ga(NAs)∕GaAs by using transmission electron microscopy in combination with refined structure factor calculation
Authors: Volz K. , Rubel O. , Torunski T. , Baranovskii S. D. , Stolz W.
Published: February 2006

We have studied systematically the nitrogen content in Ga(NAs)∕GaAs quantum wells by (002) dark-field transmission electron microscopy (TEM). The nitrogen contents derived from this analysis, when assuming that all the atoms occupy their unperturbed positions in a virtual crystal, deviate significantly from the nitrogen contents we derive for the same samples by other methods; for example, high-resolution x-ray diffraction (XRD) and dynamical simulation of those XRD patterns. The nitrogen causes a significant local strain in the crystal and can accordingly displace the neighboring atoms dramatically. We show that, if the structure factor of the crystals is recalculated, taking these static displacements of the Ga atoms into account, the composition derived from the TEM analysis with that from XRD is in perfect agreement. It is hence necessary for tetragonally distorted crystals that have mixed sublattices containing atoms with different covalent radii to take these static displacements into account when quantification of the composition from dark-field or high-resolution TEM images is aimed for.
Studies on the La substitution site in Bi4−xLaxTi3O12 by polarization-dependent x-ray absorption spectroscopy
Authors: Lee D. W. , Seo J. W. , Cho S. , Park S. R. , Kim C. , Kim B. J. , Oh S.-J. , Kang B. S. , Noh T. W. , Park B. H.
Published: February 2006

We performed polarization-dependent x-ray absorption spectroscopy studies on epitaxially grown Bi4−xLaxTi3O12 thin films at the 3p→6s edges to find the La substitution site. Our results show a clear difference between the absorption spectra taken with parallel and perpendicular polarizations, which is consistent with the view that La replaces Bi in the layer rather than at the perovskite site. Calculated absorption spectra also support the interpretation. We therefore conclude that some, if not all, La atoms replace the Bi atoms in the layer.
Electronic structures in single pair of InAs∕GaAs coupled quantum dots with various interdot spacings
Authors: Yamauchi Shohgo , Komori Kazuhiro , Morohashi Isao , Goshima Keishiro , Sugaya Takeyoshi
Published: February 2006

The electronic structures in a single pair of InAs∕GaAs coupled quantum dots (CQDs) with various interdot spacings are investigated by performing photoluminescence (PL) and photoluminescence excitation (PLE) measurements. Luminescence from the bonding (X+) and antibonding (X−) states caused by electron-wave-function coupling was observed in the micro-PL spectra of the CQDs. We indicate the contribution of the hole excited states to the PL spectra in QDs based on the results for the spectral dependence on circularly polarized light and the structures of PLE spectra. PLE spectra reveal the electronic structures of the CQD system at higher energy states where both the common excited levels due to the level sharing between the electron excited states and the individual excited levels related to the hole excited states coexist. In addition, we mention that the energy-level mixing due to the strong-wave-function coupling between two QDs influences the decoherence of the carrier relaxation processes.
Spin filtering through ferrimagnetic NiFe2O4 tunnel barriers
Authors: Lüders U. , Bibes M. , Bouzehouane K. , Jacquet E. , Contour J.-P. , Fusil S. , Bobo J.-F. , Fontcuberta J. , Barthélémy A. , Fert A.
Published: February 2006

We report experiments of spin-filtering through ultrathin insulating layers of the high Curie temperature ferrimagnetic oxide NiFe2O4 (NFO). The spin-filtering efficiency of electrons tunneling from a gold electrode through NFO is analyzed with a counter-electrode of La2∕3Sr1∕3MnO3 (LSMO). We measure a tunnel magnetoresistance of 40%–50% when the configuration of the magnetizations of the NFO and LSMO goes from parallel to antiparallel. This value corresponds to a spin-filtering efficiency of up to 22% by the NFO barrier. We discuss the sign and temperature dependence of the spin-filter effect and argue that our results show the potential of spinel ferrites for spin-filtering and injection.
Low-frequency active surface plasmon optics on semiconductors
Authors: Gómez Rivas J. , Kuttge M. , Kurz H. , Haring Bolivar P. , Sánchez-Gil J. A.
Published: February 2006

A major challenge in the development of surface plasmon optics or plasmonics is the active control of the propagation of surface plasmon polaritons (SPPs). Here, we demonstrate the feasibility of low-frequency active plasmonics using semiconductors. We show experimentally that the Bragg scattering of terahertz SPPs on a semiconductor grating can be modified by thermal excitation of free carriers. The transmission of SPPs through the grating at certain frequencies can be switched completely by changing the temperature less than 100°C. This semiconductor switch provides a basis for the development of low-frequency surface-plasmon optical devices.
Photoluminescence modification by high-order photonic bandsin TiO2∕ZnS:Mn multilayer inverse opals
Authors: King Jeffrey S. , Graugnard Elton , Summers Christopher J.
Published: February 2006

The formation of multilayered inverse opal photonic crystals by atomic layer deposition has been investigated, and shown to provide a flexible and precise technique to control the properties of photonic crystals. Inverse opals were formed by infiltration of SiO2 opal templates with conformal layers of ZnS:Mn and TiO2, followed by etching. The optical properties were further tuned by backfilling the structures with TiO2. The high-order band structure and its influence on the photoluminescent properties were studied and modification of the Cl− and Mn2+ emission peaks at 460 and 585nm were demonstrated, respectively.