bluuebunny/crossref_metadata_2025_split huggingface dataset:
A hot‐deck multiple imputation procedure for gaps in longitudinal data on recurrent events
Authors: Little Roderick J. , Yosef Matheos , Cain Kevin C. , Nan Bin , Harlow Siobán D. 
Published: June 2007

AbstractWe consider the analysis of longitudinal data sets that include times of recurrent events, where interest lies in variables that are functions of the number of events and the time intervals between events for each individual, and where some cases have gaps when the information was not recorded. Discarding cases with gaps results in a loss of the recorded information in those cases. Other strategies such as simply splicing together the intervals before and after the gap potentially lead to bias. A relatively simple imputation approach is developed that bases the number and times of events within the gap on matches to completely recorded
histories. Multiple imputation is used to propagate imputation uncertainty. The procedure is developed here for menstrual calendar data, where the recurrent events are menstrual bleeds recorded longitudinally over time. The recording is somewhat onerous, leading to gaps in the calendar data. The procedure is applied to two important data sets for assessing the menopausal transition, the Melbourne Women's Midlife Health Project and the TREMIN data. A simulation study is presented to assess the statistical properties of the proposed procedure. Some possible extensions of the approach are also considered. Copyright © 2007 John Wiley & Sons, Ltd.
A binless correlation measure reduces the variability of memory reactivation estimates
Authors: Kruskal Peter B. , Stanis Jessica J. , McNaughton Bruce L. , Thomas Peter J. 
Published: June 2007

AbstractThe standard procedure for measuring correlations between pairs of spike trains is to count the numbers of spikes occurring within a specified set of time intervals partitioning the continuous time line into discrete bins of width w (seconds). One then computes the Pearson correlation between pairs of the bin occupancy vectors. This method introduces a form of quantization noise, similar to that in analog‐to‐digital signal processing devices, due to the arbitrary positioning of bin boundaries relative to pairs of spikes. Small changes in bin width and small uniform shifts in bin boundaries typically produce large variations in the apparent correlation. An alternative method of determining a correlation between pairs of spike trains was recently introduced. Rather than discretize the data in time, the original spike trains are convolved with a Gaussian kernel with parameter σ chosen to give an effective width matching the bin width $ \omega= \sqrt{12} \sigma $. Calculating the Pearson correlation of the resulting smooth functions gives an estimate of the correlation between the spike trains matching that given by the bin‐based procedure, without introducing the significant variability of the bin‐based estimate. Measures of memory reactivation based on the partial correlations between ensembles of pairwise spike train correlations are biased downwards by the quantization noise present in the pairwise correlation estimates. Using a binless method to measure pairwise correlation, we find that the partial correlation (or explained variance) of rat hippocampal maze activity and post‐maze sleep, taking into account pre‐maze sleep correlations, increases significantly over estimates made with the standard bin‐based procedure. Copyright © 2007 John Wiley & Sons, Ltd.
Global tests in the additive hazards regression model
Authors: Gandy Axel , Therneau Terry M. , Aalen Odd O. 
Published: June 2007

AbstractIn this article, we discuss testing for the effect of several covariates in the additive hazards regression model. Bhattacharyya and Klein (Statist. Med. 2005;24(14):2235–2240) note that anad hocweight function suggested by Aalen (Statist. Med. 1989;8:907–925) is inconsistent when used as a global test for comparing groups since the test statistic depends on which group is used as the baseline group. We will suggest a simple alternative test that does not exhibit this problem. This test is a natural extension of the logrank test. We shall also discuss an alternative covariance estimator. The tests are applied to a data set and a simulation study is performed. Copyright © 2007 John Wiley & Sons, Ltd.
Restoration of mangrove plantations and colonisation by native species in Leizhou bay, South China
Authors: Ren Hai , Jian Shuguang , Lu Hongfang , Zhang Qianmei , Shen Weijun , Han Weidong , Yin Zuoyun , Guo Qinfeng 
Published: June 2007

AbstractTo examine the natural colonisation of native mangrove species into remediated exotic mangrove stands in Leizhou Bay, South China, we compared soil physical–chemical properties, community structure and recruitments of barren mangrove areas, native mangrove species plantations, and exotic mangrove species—Sonneratia apetala Buch.Ham—between plantations and natural forest. We found that severely degraded mangrove stands could not regenerate naturally without human intervention due to severely altered local environments, whereas some native species had been recruited into the 4–10 year S. apetala plantations. In the first 10 years, the exotic species S. apetala grew better than native species such as Rhizophora stylosa Griff and Kandelia candel (Linn.) Druce. The mangrove plantation gradually affected soil physical and chemical properties during its recovery. The exotic S. apetala was more competitive than native species and its plantation was able to restore soil organic matter in about 14 years. Thus, S. apetala can be considered as a pioneer species to improve degraded habitats to facilitate recolonisation by native mangrove species. However, removal to control proliferation may be needed at late stages to facilitate growth of native species. To ensure sustainability of mangroves in South China, the existing mangrove wetlands must be managed as an ecosystem, with long‐term scientific monitoring program in place.
Positive Affect Predicts Improved Lip Movement in Facial Movement Disorder
Authors: Merkel Kathryn E. , Schmidt Karen L. , Levenstein Rachel M. , VanSwearingen Jessie M. , Bentley Barbara C. 
Published: June 2007

OBJECTIVESPositive affect in individuals with a facial movement disorder may promote lip corner movement (zygomaticus major) during smiling. We investigated whether a positive affect marker (orbicularis oculi activity) observed in an initial clinic visit of individuals with facial movement disorder (N = 28) predicted increased lip corner movement at a subsequent visit.STUDY DESIGN AND SETTINGIn this clinical outcomes study, lip corner movement was assessed with the use of automated facial analysis. Asymmetry of movement was compared in individuals who smiled with or without the positive affect marker at an initial clinic visit.RESULTSThe positive affect marker at the initial visit was associated with a reduction in the asymmetry of the lip corner movement at the second visit.CONCLUSIONPositive affect predicts improved facial movement outcomes in patients with facial movement disorders.SIGNIFICANCEPositive emotion in facial movement patients may be an important factor in recovery of facial movement during therapy.
Retrospective Analysis of Outcomes after Stapedotomy with Implantation of a Self‐Crimping Nitinol Stapes Prosthesis
Authors: Sorom Abraham J. , Driscoll Colin L.W. , Beatty Charles W. , Lundy Larry 
Published: June 2007

OBJECTIVETo review hearing results after implantation of a self‐crimping stapes prosthesis.STUDY DESIGN AND SETTINGAnalysis of hearing results in patients implanted with a self‐crimping stapes prosthesis at two academic hospitals from 2000 to 2004.RESULTSSeventy‐nine ears were divided into short‐term and intermediate follow‐up groups. The mean postoperative air‐bone gap (ABG), preoperative minus postoperative ABG, and preoperative minus postoperative bone conduction values were 5.7, 21.4, and 4.1 dB, respectively, for the short‐term group, and 6.3, 22.3, and 4.7dB, respectively, for the intermediate group. The ABG was <10 dB in 88 percent of the short‐term group and in 79 percent of the intermediate group.CONCLUSIONSThe self‐crimping Nitinol stapes prosthesis provides excellent short‐term and intermediate postoperative hearing results, and may overcome the limitations of stapes prostheses requiring manual crimping.SIGNIFICANCEThis paper provides evidence for the use of a self‐crimping Nitinol stapes prosthesis, which may simplify hearing restoration surgery for stapes fixation.
Malignant Head and Neck Paragangliomas in SDHB Mutation Carriers
Authors: Boedeker Carsten Christof , Neumann Hartmut P. H. , Maier Wolfgang , Bausch Birke , Schipper Jörg , Ridder Gerd Jürgen 
Published: June 2007

OBJECTIVEThree of four paraganglioma syndromes (PGLs) have been characterized on a molecular genetic basis. PGL 1 is associated with mutations of the succinate dehydrogenase subunit D (SDHD) gene, PGL 3 is caused by SDHC gene mutations, and PGL 4 is caused by SDHB gene mutations. The objective of this study was to investigate whether PGLs are associated with malignant head and neck paragangliomas (HNPs).STUDY DESIGN AND SETTINGThrough November 2005, we screened 195 HNP patients for mutations of the genes SDHB, SDHC, and SDHD.RESULTSWe detected 5 SDHC, 13 SDHB, and 45 SDHD gene mutations. In seven SDHB mutation carriers, there were distant metastases. No signs of metastases were found in SDHC and SDHD patients. One patient with a sporadic HNP presented with locally metastatic disease.CONCLUSIONSSDHB mutations are associated with a high rate of malignant HNPs.SIGNIFICANCEIn SDHB patients, a three‐body region imaging and scintigraphy or DOPA‐PET must be performed to exclude metastases.
Intratympanic Steroids for Treatment of Sudden Hearing Loss after Failure of Intravenous Therapy
Authors: Plaza Guillermo , Herráiz Carlos 
Published: June 2007

OBJECTIVEWe sought to describe our experience with intratympanic steroid treatment of sudden sensorineural hearing loss after failure of intravenous steroid treatment.STUDY DESIGN AND SETTINGWe conducted a nonrandomized prospective clinical trial. Fifty patients presenting with sudden onset idiopathic hearing loss were treated intravenously over five days. After this period, patients with treatment failure (18 cases) were offered intratympanic steroid treatment. Nine patients refused, whereas the other nine patients received three weekly injections of methylprednisolone. Recovery of hearing was reported as improvement of more than 15 dB in pure tone average.RESULTSIntratympanic steroid treatment improved hearing loss in five patients (55%). This is significant compared with those patients who refused intratympanic treatment, who showed no further improvement (P < 0.05). No serious adverse effects were observed.CONCLUSIONIntratympanic steroids significantly improve the recovery outcome of sudden hearing loss that had not recovered after intravenous steroid treatment.SIGNIFICANCEIntratympanic steroids are an effective and safe therapy in sudden sensorineural hearing loss cases that are refractory to standard treatment.
Sinonasal Surfactant Protein A1, A2, and D Gene Expression in Cystic Fibrosis: A Preliminary Report
Authors: Woodworth Bradford A. , Wood Rachel , Baatz John E. , Schlosser Rodney J. 
Published: June 2007

OBJECTIVETo measure alterations in SPA1, A2, and D gene expression in various forms of inflammatory chronic rhinosinusitis (CRS).STUDY DESIGN AND SETTINGSinus mucosal biopsies were performed in patients with allergic fungal rhinosinusitis (AFS), CRS with nasal polyposis, cystic fibrosis (CF), and controls. SP mRNA was measured with quantitative polymerase chain reaction.RESULTS: Patients with CF (n = 4) showed significantly increased SPA1 (82‐fold), SPA2 (100‐fold), and SPD (47‐fold) mRNA (P < 0.05) when compared with controls (n = 5). Patients with CRS with nasal polyposis (n = 5) also demonstrated elevated SPA1 (27‐fold), SPA2 (13‐fold), and SPD (13‐fold). Patients with AFS (n = 7) had increased SPA1 (5‐fold), SPA2 (9‐fold), and SPD (17‐fold), but were not statistically significant.CONCLUSIONSPA1, A2, and D are upregulated in various forms of CRS, but are significantly elevated in cystic fibrosis CRS.SIGNIFICANCEUnderstanding the role of SPs in CRS will help develop novel treatment approaches for sinonasal pathoses.
Long‐Term Efficacy of Intra‐Oral Surgery for Sialorrhea
Authors: Martin Timothy J. , Conley Stephen F. 
Published: June 2007

OBJECTIVESTo investigate the efficacy and quality of life impact of intra‐oral surgery for sialorrhea and to provide long‐term outcome measures.METHODSA retrospective review and telephone survey of patients seen in a multi‐disciplinary saliva control clinic who underwent surgery between 1999 and 2003.RESULTSSixteen of 31 patients underwent 4‐duct ligation, 12 patients underwent submandibular gland duct ligation, and three patients underwent a 3‐duct ligation procedure. The mean presurgical drooling score (maximum 10) was 9.5, 8.8, and 9, respectively. Recurrence was seen in 68% of patients at a mean of four months. Additional surgery was required in five patients. Phone survey was accomplished in 10 patients. Two of 10 caregivers reported sustained improvement of sialorrhea at two and three years.CONCLUSIONSIntra‐oral surgery provides minimal longterm control of sialorrhea. Additional medical and surgical therapy was needed in a significant portion of patients in this long‐term review.
Additional Palatal Implants for Refractory Snoring
Authors: Catalano Peter , Goh Yao Hong , Romanow John 
Published: June 2007

OBJECTIVETo evaluate safety and efficacy of additional palatal implants for snoring treatment.STUDY DESIGN AND SETTINGA prospective case series at two clinical sites in an office setting. Patients who did not have an acceptable reduction in snoring intensity after an initial 3 implant procedure received additional implants. Bed partners rated snoring intensity on a 10 cm visual analog scale (VAS) at baseline and 90 days postprocedure.RESULTSSnoring intensity VAS decreased significantly from 6.4 ± 2.3 to 4.6 ± 2.9 (P < 0.01) for patients who received an additional fourth implant, and to 4.1 ± 2.8 after the 5th implant (P<0.01). Epworth sleepiness scale scores also decreased significantly for patients who received additional fourth or fifth implants. There were no adverse events.CONCLUSIONSAdditional palatal implants for snoring treatment were safe and effective in this case series.SIGNIFICANCEAdditional implants may offer relief for snorers not responding to the initial 3 implant procedure.
Past and Present Instrument Use in Pediatric Adenotonsillectomy
Authors: Walner David L. , Parker Noah P. , Miller Robert P. 
Published: June 2007

OBJECTIVEExamine changing trends/instrument usage for pediatric adenotonsillectomy.STUDY DESIGN AND SETTINGSurvey of 300 members of the American Society of Pediatric Otolaryngology assessing instruments used in adenotonsillectomy currently and over the past 15 years.RESULTSA total of 120 surveys were returned. The most common total tonsillectomy instruments for obstruction/infection were: monopolar electrocautery (ME) (53.1%/54.5%) and coblation (CT) (16.0%/16.1%). The most common subtotal tonsillectomy instrument for obstruction/infection was microdebrider (51.4%/30.8%). Over the past 15 years, ME predominated, cold utilization declined, and CT rose. The most common adenoidectomy instruments were ME (25.0%/25.0%), curette with touch‐up ME (22.4%/22.4%), and microdebrider with touch‐up ME (19.0%/14.7%). Over the past 15 years, curette with touch‐up ME predominated early, curette utilization alone declined, and ME, microdebrider, and CT have risen.CONCLUSIONPediatric otolaryngologist technique/instrument use for adenotonsillectomy has changed over the past 15 years. This study may be limited by the low survey response rate.
Office‐Based Laryngeal Laser Surgery: A Review of 443 Cases Using Three Wavelengths
Authors: Koufman Jamie A. , Rees Catherine J. , Frazier William D. , Kilpatrick Lauren A. , Wright S. Carter , Halum Stacey L. , Postma Gregory N. 
Published: June 2007

BACKGROUNDUnsedated office‐based laser surgery (UOLS) of the larynx and trachea has significantly improved the treatment options for patients with laryngotracheal pathology including recurrent respiratory papillomas, granulomas, leukoplakia, and polypoid degeneration. UOLS delivered by flexible endoscopes has dramatically impacted office‐based surgery by reducing the time, costs, and morbidity of surgery.OBJECTIVESTo review our experience with 443 laryngotracheal cases treated by UOLS.METHODSThe laser logbooks at the Center for Voice and Swallowing Disorders were reviewed for UOLS, and the medical and laryngological histories were detailed, as were the treatment modalities, frequencies, and complications.RESULTSOf the 443 cases, 406 were performed with the pulsed‐dye laser, 10 with the carbon‐dioxide laser, and 27 with the thulium: yttrium‐aluminum‐garnet laser. There were no significant complications in this series. A review of indications and wavelength selection criteria is presented.CONCLUSIONUnsedated, office‐based, upper aerodigestive tract laser surgery appears to be a safe and effective treatment option for many patients with laryngotracheal pathology.
Outcome of Adenotonsillectomy for Obstructive Sleep Apnea in Obese and Normal‐Weight Children
Authors: Mitchell Ron B. , Kelly James 
Published: June 2007

OBJECTIVES1) To evaluate the relative severity of obstructive sleep apnea (OSA) in obese and normal‐weight children; 2) to compare changes in respiratory parameters after adenotonsillectomy in obese and normal‐weight children.STUDY DESIGN AND SETTINGProspective controlled trial that included children aged 3 to 18 years. All study participants underwent pre‐ and postoperative polysomnography.RESULTSThe study population included 33 obese children and 39 normal‐weight controls. Preoperatively, the median obstructive apnea‐hypopnea index (AHI) was 23.4 (range 3.7‐135.1) for obese and 17.1 (range 3.9‐36.5) for controls (P < 0.001). Postoperatively, the AHI was 3.1 (range 0‐33.1) for obese and 1.9 (range 0.1‐7.0) for controls (P < 0.01). Twenty‐five obese children (76%) and 11 controls (28%) had persistent OSA.CONCLUSION AND SIGNIFICANCEAHI scores are higher in obese than in normal‐weight children with OSA. Both groups show a dramatic improvement in AHI after adenotonsillectomy, but persistent OSA is more common in obese children.
Intestinal parasitism and Vibrio cholerae infection among diarrhoeal patients in Kolkata, India
Authors: SAHA D. R. , RAJENDRAN K. , RAMAMURTHY T. , NANDY R. K. , BHATTACHARYA S. K. 
Published: June 2007

SUMMARYIn this study, we have analysed the epidemiological significance of the concurrent infections caused by Vibrio cholerae and intestinal parasites among different age groups of hospitalized diarrhoeal patients in Kolkata. A total of 3556 stool samples collected during 1996–2004 were screened for vibrios and parasites. The seasonality of V. cholerae and parasitic infections were studied in detail. The detection rates for Ascaris lumbricoides and Giardia lamblia infection were more than for the hookworm, Trichuris trichiura and Entamoeba histolytica. V. cholerae O1 was identified as the predominant serogroup among diarrhoeal patients. The highest rates for V. cholerae infection were in the 2–5 years age group and combined infection of V. cholerae and parasites was recorded among children aged between 2 and 10 years.
Newly launched satellite to study ice clouds
Authors: Zielinski Sarah 
Published: June 2007

A new satellite to study clouds of water ice that form at the edge of the atmosphere successfully launched on 25 April.Over at least the next 2 years, NASA's Aeronomy of Ice in the Mesosphere (AIM) mission will investigate polar mesospheric clouds (PMCs, also known as noctilucent or ‘night shining’ clouds), which form about 80 kilometers above the Earth's surface in the mesosphere over the polar regions during the polar summer. The clouds are visible only at night when illuminated by sunlight from beyond the horizon. Since PMCs were discovered in 1885, they have increased in brightness and prevalence and have been forming at lower latitudes.
2006 Greenland Ice Sheet snowmelt from spaceborne microwave brightness temperatures
Authors: Tedesco Marco 
Published: June 2007

Brightness temperatures over the Greenland ice sheet, as measured by the Special Sensor Microwave Imager radiometer (SSM/I) aboard the U.S. Air Force Defense Meteorological Satellite (DMSP) Program's F13 satellite, have now been released (available at ftp://sidads.colorado.edu/pub/DATASETS/brightness‐temperatures/easegrid/ssmi/). These data support the quantification of the number of snow melting days in 2006 (Figure l a ) and the 2006 melting days anomaly (e.g., the difference between 2006 melting days and the average number of melting days between 1988 and 2005; Figure l b ). Updated results are fundamental to longterm trend analyses of snowmelt extent and duration.The 2006 melting index (e.g., the number of melting days × melt extent) follows the trend derived from the analysis of 1988–2005 data, and ranks seventh when using the 19.35‐gigahertz data (with 2005, 2002, 1998, 2004, 1999, and 2003 in this order having a greater melting index). The 2006 melting index ranks fifth when using the 37‐gigahertz data, which are more sensitive to surface processes (with 1998, 2002, 2005, and 2004 in this order having a greater melting index).
Advances in the study of volcanic ash
Authors: Taddeucci Jacopo , Scarlato Piergiorgio , Andronico Daniele , Cristaldi Antonio , Büttner Ralph , Zimanowski Bernd , Küppers Ullrich 
Published: June 2007

Every month, small‐scale explosive volcanic eruptions inject more than a million cubic meters of ash into Earth's atmosphere [Simkin and Siebert, 2000]. Of all the troubles caused by this relatively mild volcanic activity, ashfall is by far the longest‐reaching one, mantling the volcano slopes and surroundings with a slippery, heavy, unhealthy, and snow‐like but Sun‐resistant cover.Volcanic ash is composed of pyroclasts (fragments generated and emplaced by explosive eruptions) smaller than 2 millimeters, which are easily transported by wind and have a high surface‐to‐volume ratio. These same features, however, also allow safe collection of the ash away from the volcano. Such pyroclasts bear the signature of the fragmentation and dispersal processes they have experienced during eruption and transport. Thus, volcanic ash provides sample material well suited for studying quasi time correlated eruption dynamics [Taddeucci et al, 2002].
Downsized Weather Satellite Program on track, but uncertainty remains
Authors: Zielinski Sarah 
Published: June 2007

The National Polar‐orbiting Operational Environmental Satellite System (NPOESS) was downsized after a review that was required when the program far exceeded its budget and schedule. A year later, NPOESS—a major civilian and military weather satellite program—appears to be proceeding well with its new schedule and budget. However, whether the program will remain on track is uncertain.In July 2006, NPOESS was scaled back from six satellites in three orbits to four satellites in two orbits, and several climate and space weather sensors were cancelled (see Eos 87(25), 2006). Since then, NOAA and NASA held an internal review to determine which of the cancelled climate sensors were most important and to develop recommendations to ensure continuity of those data sets (the December 2006 internal white paper has now been posted at http://www.climatesciencewatch.org).