bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative hail monitoring in an alpine area: 35‐year climatology and links with atmospheric variables
Authors: Eccel Emanuele , Cau Piero , Riemann‐Campe Kathrin , Biasioli Franco
Published: January 2011

Hail climatology is usually weakly known and unsatisfactorily standardised in measurement techniques. Trentino, in the Italian Alps, boasts a 271‐hailpad network operated since 1974, covering nearly the whole of the regional agricultural area. Many hail indices, concerning both extensive and energetic features of hailstorms, were investigated in a 35‐year period, seeking for climatic trends. The results show that, despite a slight, non‐significant trend of decrease in the number of events and in the hit surfaces, most energetic indices, which are directly correlated to the damage to crops, have increased in the period, some at considerable rates. Particularly, indices referring to extreme values show the clearest trends. The correlation with atmospheric variables from ECMWF's reanalysis (ERA‐40) was considered. Data were processed at six gridpoints, to calculate three instability‐related indices. Other ten variables were considered, either integrated over the atmospheric column or at separate atmospheric levels. Correlations between seasonally averaged single atmospheric predictors and hail indices show a varied record of cases, where only some pairs of atmospheric predictors and hail indices give positive results. Statistical links were also sought using a multivariate method involving principal component regression (PCR) and partial least square regression (PSLR) techniques. Despite the more general approach allowed by these methods, only some hail indices respond to the attempt of setting up satisfactory statistical models. The principal‐component predictors are built with many atmospheric variables, warning against a simplified use of correlations of some hail indices with few atmospheric predictors. Particularly, it is shown that the number of events is not a useful index for assessing general climatic features of hailstorms, and that the use of one instability index alone—like convective available potential energy (CAPE)—does not allow a thorough description of the links between atmospheric precursors of hail and its real occurrence. Copyright © 2010 Royal Meteorological Society
Spatiotemporal structures of the intraseasonal oscillations of precipitation over northern Eurasia during summer
Authors: Fukutomi Yoshiki , Masuda Kooiti , Yasunari Tetsuzo
Published: January 2011

This study identifies intraseasonal oscillations in summer precipitation over northern Eurasia using multi‐channel singular spectrum analysis (MSSA) and a gridded daily precipitation data set for northern Eurasia. The analysis period is June–August of 1979–2002. Empirical orthogonal function analysis was first performed on 8‐day low‐pass‐filtered precipitation anomalies at 2.5° grid resolution for northern Eurasia; MSSA was then carried out on the ten leading principal components (PCs). Three quasi‐periodic oscillations with timescales of 45, 15, and 9 days were identified. The spatiotemporal structures of precipitation oscillations were defined by composite analysis based on the reconstructed time series of the spatiotemporal PCs obtained from the MSSA. The composite life cycle of each mode was classified into eight phase categories. The 45‐day oscillation is characterised by a slow eastward progression of a broad east/west contrastive pattern which is associated with a replacement of elongated dry and wet zones across northern Eurasia. The 15‐day oscillation shows a regular eastward phase propagation of precipitation anomalies with a tripole structure across the domain. The eastward displacement of dry and wet zones occurs in association with this oscillation. Spatiotemporal behaviours of the precipitation anomalies associated with the 9‐day oscillation are similar to those of the 15‐day oscillation, but the spatial scale of this oscillation is somewhat smaller. To explore the connections between the oscillations of precipitation and large‐scale atmospheric circulation patterns, a similar composite method was applied to 300‐hPa geopotential height anomalies over the Northern Hemisphere. The circulation patterns responsible for the 45‐day oscillation are characterised by a wave train extending across the northeastern Atlantic/northern Eurasian sector. The wave train, with zonal wavenumbers of 3–4, indicates slow eastward moving and quasi‐stationary features. The circulation patterns linked to the 15‐day oscillation exhibit an eastward propagating wave train extending from northeastern Europe into the North Pacific/North American sector. In spatial scale, this wave train has zonal wavenumbers of 5–6. The wave trains associated with the 9‐ and 15‐day oscillations have similar behaviour patterns over northern Eurasian. However, the 9‐day wave train has a comparatively smaller spatial scale with zonal wavenumbers of 6–7. Therefore, the intraseasonal oscillations of precipitation are connected to the well‐organised wave trains that extend from the Euro‐Atlantic region to northern Eurasia, suggesting that the oscillation on each intraseasonal time scale must be produced by propagation of the corresponding wave train. Copyright © 2011 Royal Meteorological Society
Evaluation of long‐term changes of solar radiation in India
Authors: Soni V. K. , Pandithurai G. , Pai D. S.
Published: January 2011

Temporal and spatial variability in annually averaged global irradiance, diffuse irradiance, and bright sunshine duration over twelve stations of solar radiation network of India Meteorological Department (IMD) were evaluated for the period 1971–2005. Annually averaged all‐sky global irradiance decreased between 0.1% (0.3 Wm−2) and 3.6% (9.0 Wm−2) per decade at the stations. The decrease in sunshine duration was concomitant with the decrease in global solar irradiance. The long‐term trends in diffuse irradiance differed markedly between the twelve stations. Significant increasing trend in diffuse irradiance were found at the four stations under all‐sky conditions, while seven stations showed increasing trend under clear sky conditions. The two most probable causes of long‐term trends in radiation are changes in aerosol loading and cloud cover. Trend analyses of Angstrom's turbidity coefficient measured at three stations of IMD during the last three decades indicate that total column aerosol has increased significantly. Trend analysis of bright sunshine duration suggests long‐term decrease at all the stations. Reduction in bright sunshine hours varied from 0.0 to 0.5 h per decade. There is a strong northwest‐northeast gradient in sunshine duration which contributes to the spatial trends in global and diffuse solar irradiance. This paper examines the trends of global irradiance, diffuse irradiance and sunshine duration over India in all‐sky conditions as well as cloud‐free skies so the effect of cloud cover can be examined. Copyright © 2011 Royal Meteorological Society
Efficacy of mitomycin C in endonasal endoscopic dacryocystorhinostomy
Authors: Tirakunwichcha Suppapong , Aeumjaturapat Songklot , Sinprajakphon Siripong
Published: January 2011

Objectives/Hypothesis:

To evaluate the efficacy of intraoperative mitomycin C (MMC) in endonasal endoscopic dacryocystorhinostomy.

Study Design:

Randomized controlled trial.

Methods:

Fifty patients with primary acquired nasolacrimal duct obstruction were enrolled and randomly allocated into the treatment and control group. The patients underwent standard endonasal endoscopic dacryocystorhinostomy with mucosal flaps and mitomycin C or placebo on each group. The ostium size was measured at 3 months, 6 months, and 12 months to evaluate the effect of mitomycin C and placebo, and the patency of the lacrimal drainage system was assessed.

Results:

There was no statistical significance in the success rate between the MMC group and the control group at 1‐year follow‐up (84.6% vs.79.2%, respectively, P = .59). At the 6‐month and 12‐month visits, the mean ostium size in the MMC group was 10.8 mm2 (SD = 3.17) and 3.0 mm2 (SD = 1.78), respectively, which were prominently larger than the control group at 7.1 mm2 (SD = 2.62; P < .001, 95% CI, 0.84–5.45) and 1.6 mm2 (SD = 1.18; P = .004, 95% CI, 0.49–2.38).

Conclusions:

There was no statistically significant difference in the success rates of both groups, but MMC seems to have a conspicuous effect on the healing process at the ostium. Laryngoscope, 2011
Central pontine myelinolysis as a cause of bilateral vocal fold immobility due to hyponatremia
Authors: Górriz Gil Carmen , Tuñón Gómez Mercedes , Escamilla Carlos , Romero Pizarro Yolanda , Goizueta Gabriela , García‐López Fernando , García‐Berrocal Jose Ramón
Published: January 2011

We report a patient admitted with severe dyspnea due to bilateral vocal fold immobility (BVFI), associated with hyponatremia and pneumonia that required emergency tracheotomy. Cerebral magnetic resonance imaging showed a pons lesion compatible with central pontine myelinolysis. Hyponatremia is thought to be caused by hypovolemia. The hyponatremia, and not its correction, is speculated to be the cause of central pontine myelinolysis in this patient. To our knowledge, this is the first case reported of a bilateral vocal fold immobility caused by central pontine myelinolysis induced by hyponatremia. Laryngoscope, 2010.
Immediate postoperative extubation in patients undergoing free tissue transfer
Authors: Allak Amir , Nguyen Tam N. , Shonka David C. , Reibel James F. , Levine Paul A. , Jameson Mark J.
Published: January 2011

Objectives/Hypothesis:

Extubation (cessation of ventilatory support) is often delayed in free flap patients to protect the microvascular anastomosis, presumably by reducing emergence‐related agitation. We sought to determine if immediate extubation in the operating room (OR) would improve the postoperative course compared to delayed extubation in the intensive care unit (ICU).

Study Design:

Retrospective chart review.

Methods:

Medical records of all patients undergoing free tissue transfer for head and neck reconstruction between January 2009 and July 2010 were reviewed (n = 52). Patients extubated immediately postoperatively in the OR (immediate group, n = 26) were compared to patients extubated in the ICU (delayed group, n = 26).

Results:

Tobacco use, alcohol use, pulmonary history, case length, and free flap type were not significantly different between the two groups. Although the average ICU stay for the immediate group was significantly shorter than the delayed group (2.0 days vs. 3.4 days; P = .008), the reduction in overall hospital stay for the immediate group did not achieve statistical significance (8.2 days vs. 9.5 days; P = .21). Use of treatment for agitation (27% vs. 65%) and physical restraints (8% vs. 69%) were significantly lower in the immediate versus delayed group (P = .01 and P < .001, respectively). Although flap‐related, surgical, and medical complication rates were not significantly different between the two groups, the delayed extubation group had a significantly higher incidence of pneumonia (15% vs. 0%; P = .05).

Conclusions:

Immediate postoperative extubation in the OR following head and neck microvascular free tissue transfer reduces ICU stay, anxiolytic use, restraint use, and incidence of pneumonia without an increase in flap‐ or wound‐related complications. Laryngoscope, 2011
Transmastoid resurfacing of superior semicircular canal dehiscence
Authors: Amoodi Hosam A. , Makki Fawaz M. , McNeil Michael , Bance Manohar
Published: January 2011

Objectives/Hypothesis:

To describe a new and fast surgical technique in treating superior semicircular canal dehiscence syndrome by resurfacing the canal defect via the transmastoid approach without retraction of the whole temporal lobe and to demonstrate the clinical and audiologic results of the superior canal dehiscence repair. Superior semicircular canal dehiscence syndrome is a well‐described pathology. Surgical procedures through the middle fossa approach to resurface the superior canal and transmastoid plugging are considered the main surgical therapeutic options for patients with debilitating symptoms. Both have drawbacks; plugging is invasive to the inner ear, and resurfacing requires a middle fossa approach.

Study Design:

Retrospective review.

Methods:

Four patients presented with classic symptomatic semicircular canal dehiscence syndrome with radiographic confirmation of their dehiscence. The patients underwent the resurfacing procedure with a transmastoid approach.

Results:

All four patients reported resolution of their symptoms. Audiograms documented some improvement in three subjects.

Conclusions:

The transmastoid approach for resurfacing superior semicircular canal dehiscence is a safe and less‐invasive technique than the standard middle fossa approach, which has many potential complications and requires much longer hospitalization. In our study, the surgeries were completed within 90 minutes, and patients stayed in the hospital only overnight.
Treatment of postinfectious olfactory disorders with minocycline: A double‐blind, placebo‐controlled study
Authors: Reden Jens , Herting Birgit , Lill Katja , Kern Robert , Hummel Thomas
Published: January 2011

Objectives/Hypothesis:

Infection of the upper respiratory tract is one of the most common causes of olfactory loss. One of the possible underlying pathologic pathways is an increase of apoptosis of olfactory receptor neurons. Therefore, treatment with the antibiotic minocycline, which has been shown to act as an antiapoptotic agent, is thought to accelerate improvement of olfactory function. To investigate this idea, 55 patients with postinfectious olfactory dysfunction were tested for their olfactory ability.

Study Design:

Randomized, prospective, double‐blind, placebo‐controlled.

Methods:

Olfactory function was examined by means of a standardized psychophysical method (Sniffin' Sticks) before and 7 months after a 3‐week treatment with either minocycline (2 × 50 mg/d) or a placebo.

Results:

Statistical analyses did not reveal any influence of the treatment on the progress of olfactory function, possibly indicating that pathologic changes other than apoptosis contribute to postinfectious olfactory loss, either on a peripheral level (e.g., scarring/reorganization of the olfactory epithelium) or on a central nervous level.

Conclusions:

In conclusion, the present results indicate that minocycline in the given dosage has little or no effect on the recovery of human olfactory function following postinfectious olfactory loss. However, spontaneous recovery is found in approximately 20% of the patients over an observation period of 7 months. Laryngoscope, 2011
Olfactory impairment in older adults: Five‐year incidence and risk factors
Authors: Schubert Carla R. , Cruickshanks Karen J. , Klein Barbara E.K. , Klein Ronald , Nondahl David M.
Published: January 2011

Objectives/Hypothesis:

The objective of this study was to determine the five‐year incidence of olfactory impairment and associated risk factors in a general population of older adults.

Study Design:

Longitudinal population‐based study.

Methods:

Participants (n = 1,556) in the population‐based Epidemiology of Hearing Loss Study had olfaction measured at the 5‐ and 10‐year examinations (1998–2000 and 2003–2005, respectively). Olfactory ability was measured by the San Diego Odor Identification Test.

Results:

The five‐year incidence of olfactory impairment was 12.5%. Incidence rates increased with age for men and women. In a multivariate model, age (odds ratio [OR] = 1.79, 95% CI, 1.61–2.00; for every five‐year increase), a history of nasal polyps (OR = 2.33, 95% CI, 1.13–4.59), a history of deviated septum (OR = 2.05, 95% CI, 1.14–3.56), and a history of heavy alcohol use (OR = 1.84, 95% CI, 1.13–2.93) were associated with an increased risk of olfactory impairment, whereas use of lipid‐lowering agents (OR = 0.68, 95% CI, 0.46–0.99; yes vs. no), exercising at least once a week (OR = 0.69, 95% CI, 0.48–0.98), and oral steroid use (OR = 0.37, 95% CI, 0.11–0.94) were associated with a decreased risk.

Conclusions:

The five‐year incidence of olfactory impairment is high in this population of older adults. Modifiable risk factors associated with impairment suggest some impairment could be amenable to prevention or treatment. Laryngoscope, 2011
Injection of cultured autologous fibroblasts for human vocal fold scars
Authors: Chhetri Dinesh K. , Berke Gerald S.
Published: January 2011

Objectives:

This study evaluated the safety and effectiveness of injection of autologous fibroblasts into the lamina propria layer to treat vocal fold scarring.

Study Design:

A prospective, open‐label, single arm, pilot study at a single tertiary care center.

Methods:

Autologous fibroblasts were expanded in cell culture from punch biopsies of the buccal mucosa of five human subjects with vocal fold scarring. Three doses of 1–2 × 107 cells/mL were injected into the superficial lamina propria layer of each scarred vocal fold at four‐week intervals. The primary efficacy measure was an objective evaluation of the mucosal wave grade; secondary measures included acoustic analyses, a patient‐completed voice handicap index (VHI) survey, and voice quality questionnaire. Safety assessments included clinical laboratory blood tests, vital signs, and monitoring for adverse events. Patients were followed for 12 months following the first treatment.

Results:

Mucosal wave grade improved and the improvement was sustained through month 12. Sustained improvements through month 12 were also noted for the VHI and voice quality questionnaire. Multiple injections of autologous fibroblasts into the lamina propria were well tolerated. Temporary otalgia was noted following treatment in two subjects.

Conclusions:

This study demonstrates that injection of autologous fibroblasts into the scarred vocal fold lamina propria layer is safe. Sustained trends for improved outcome were supported by 12‐month data for mucosal wave grade, VHI, and voice quality questionnaire. Laryngoscope, 2011
Nasoseptal “Rescue” flap: A novel modification of the nasoseptal flap technique for pituitary surgery
Authors: Rivera‐Serrano Carlos M. , Snyderman Carl H. , Gardner Paul , Prevedello Daniel , Wheless Stephen , Kassam Amin B. , Carrau Ricardo L. , Germanwala Anand , Zanation Adam
Published: January 2011

Objectives:

The introduction of the pedicled nasoseptal flap (NSF) has decreased postoperative cerebrospinal fluid (CSF) leak rates from >20% to <5% during expanded endoscopic skull base surgery. The NSF must be raised at the beginning of the operation to protect the posterior pedicle during the expanded sphenoidotomy. However, in most pituitary tumor cases, an intraoperative CSF leak is not expected but at times encountered. In these cases, a “rescue” flap approach can be used, which consists of partially harvesting the most superior and posterior aspect of the flap to protect its pedicle and provide access to the sphenoid face during the approach. The rescue flap can be fully harvested at the end of the case if the resultant defect is larger than expected, or if an unexpected CSF leak develops. This technique minimized septum donor site morbidity for those patients without intraoperative CSF leaks.

Results:

The rescue flap technique allows for binaural and bimanual access to the sella without compromise of the pedicle during the extended sphenoidotomies and tumor removal. If an intraoperative CSF leak is encountered, the rescue flap is then converted into a normal nasoseptal flap for skull base reconstruction. If no leak is obtained, then the patient does not suffer additional donor site morbidity from the full flap harvest.

Conclusions:

This new technique allows for sellar tumor removal prior to the nasoseptal harvest, thereby eliminating donor site morbidity for those pituitary tumor patients who do not have an intraoperative CSF leak.
Concurrent neck dissection and transoral robotic surgery
Authors: Moore Eric J. , Olsen Kerry D. , Martin Eliot J.
Published: January 2011

Objectives:

1) Determine the incidence of pharyngocutaneous fistula associated with transoral robotic oropharyngectomy with concurrent neck dissection. 2) Discuss prevention and treatment of pharyngocutaneous fistulization as a consequence of transoral oropharyngeal surgery with concurrent neck dissection.

Methods:

Retrospective, single‐institution chart review of 148 consecutive patients who underwent transoral robotic surgery with synchronous neck dissection for oropharyngeal neoplasia April 2007 to February 2010.

Results:

Forty‐two of 148 (29%) patients were identified as having an orocervical communication intraoperatively. All were managed with some combination of primary closure, local tissue advancement, fibrin glue application, and cervical drain placement. Of these, six (4%) developed a subcutaneous pharyngeal fluid accumulation requiring postoperative management via controlled incision and drainage with daily packing placement. All the patients had aesthetic and functional results comparable to those patients who did not have/develop an orocervical communication. No patients experienced a delay from their operative treatment that prevented them from initiating recommended adjuvant therapy on schedule.

Conclusions:

Transoral robotic surgery is emerging as a primary treatment modality for oropharyngeal malignancies. Neck dissection is a required portion of operative therapy in many of these patients, and many surgeons delay neck dissection to prevent pharyngocutaneous fistula. Pharyngeal communication with the neck is a common occurrence during transoral surgery when it is combined concurrently with neck dissection, but persistent fistula formation is an uncommon, preventable, but potentially problematic, complication resulting from this operative technique. Prompt recognition and intervention are of paramount importance in preventing acute, long‐term functional impairment. Laryngoscope, 2011
Molecular dynamics simulations of BMP‐2 adsorption on a hydrophobic surface
Authors: Oliveira A. F. , Gemming S. , Seifert G.
Published: January 2011

In the present work, the adsorption of BMP‐2 on a hydrophobic surface model is investigated by means of molecular‐dynamics simulations within the NVT ensemble. The adsorption paths of the single monomer and the homodimer of BMP‐2 have been compared. The nature of the residues interacting directly with the hydrophobic monolayer at different adsorption stages is shown. Conformational changes driven by the adsorption process, as well as the influence of aqueous environment on the stabilization of the BMP‐2 secondary structure are also discussed.

Die Adsorption des knochenmorphogenetischen Proteins BMP‐2 auf einer hydrophoben Oberfläche wurde mit Hilfe klassischer molekulardynamischer Simulationen in einem NVT‐Ensemble untersucht. Die Adsorptionspfade des einzelnen BMP‐Monomers und der homodimeren Spezies werden verglichen. Für die verschiedenen Phasen des Adsorptionsvorgangs wird untersucht, mit welchen Seitenketten das Protein mit der hydrophoben Monolage auf der Oberfläche wechselwirkt. Konformationsänderungen, die sich durch den Adsorptionsvorgang ergeben, wie auch der Einfluss des umgebenden wässrigen Mediums auf die Stabilisierung der BMP‐2‐Sekundärstruktur werden vorgestellt und diskutiert.
Profound differences in the in‐vivo‐degradation and biocompatibility of two very similar rare‐earth containing Mg‐alloys in a rabbit model
Authors: Reifenrath J. , Krause A. , Bormann D. , von Rechenberg B. , Windhagen H. , Meyer‐Lindenberg A.
Published: January 2011

In this in‐vivo study magnesium alloys with a rare earth composition metal (LAE442) on the one hand and cerium as single rare earth element (LACer442) on the other hand were compared. Extruded cylindrical identically machined implants of both alloys were implanted intramedullary in both tibiae of five New Zealand White rabbits each (group 1 – LAE442, group 2 – LACer442). Three months were planned as postoperative observation period with clinical and radiographical examinations. Postmortal, μ‐computed tomographical and histological analyses of the tibiae were done. Although the alloys were very similar, profound differences could be found in biocompatibility. The LAE442‐alloys were tolerated well. The μCT showed an even implant degradation as well as marginal new bone formation. Histologically, a good biocompatibility was seen. The rabbits with LACer442‐implants had to be euthanized ahead of schedule because of massive implant intolerance due to gas formation and fast implant degradation which could be confirmed and differentiated in the radiographic, μ‐computed tomographical and histological examinations. These results show that the single rare earth element cerium can not successfully substitute the rare earth composition metal in a magnesium alloy for biomedical use.

In dieser in‐vivo Studie wurde eine Magnesium‐Legierung mit einem Seltenen‐Erden‐Mischmetall (LAE442) mit einer Magnesium‐Legierung mit Cer als Einzelelement aus der Gruppe der Seltenen Erden (LACer442) verglichen. Identisch hergestellte stranggepresste, zylinderförmige Implantate beider Legierungen wurden beidseits intramedullär in Tibiae von je fünf New Zealand White Kaninchen implantiert (Gruppe 1 – LAE442, Gruppe 2 – LACer442). Der Untersuchungszeitraum sollte drei Monate betragen. Während des Untersuchungszeitraumes wurden die Tiere klinisch und radiologisch untersucht. Postmortal erfolgte eine μ‐computertomographische und histologische Beurteilung der Tibiae. Obwohl die Legierungen sehr ähnlich in ihrer Zusammensetzung waren, wurden fulminante Unterschiede in der Biokompatibilität gefunden. Die LAE442‐Legierung wurde sehr gut vertragen. Im μCT zeigte sich eine beginnende gleichmäßige Degradation der Implantate sowie geringgradige Knochenneubildung. Die Histologie zeigte eine gute Biokompatibilität. Die Kaninchen mit LACer442‐Implantaten mussten vorzeitig euthanasiert werden da sie klinisch hochgradige Implantatunverträglichkeiten bedingt durch Gasbildung und schnelle Implantatdegradation zeigten, welche in den radiologischen, μ‐computertomographischen und histologischen Untersuchungen bestätigt wurden. Die Ergebnisse zeigen, dass das Einzelelement Cerium für das Seltene‐Erden‐Mischmetall keinen adäquaten Ersatz bei der Verwendung von biodegradablen Magnesiumlegierungen darstellt.
Biomaterials for medical devices: Are current hemo‐ or biocompatibility tests adequate?
Authors: Vienken J.
Published: January 2011

Many factors can affect the characterisation of biomaterials during testing. Among them is the type of the testing solution, such as human, animal blood or saline solutions of even different composition. Further influencing factors are drugs that have been administered to the blood donor prior to testing. Experimental details affecting the quality of testing refer to the guidance of blood across the biomaterial leading to different shear stress on blood cells and specific blood donor conditions, such as the age, race and gender. Some of the misconceptions in testing are described here and serve to indicate that a systems approach, and not only individual test parameters, is best when reliably testing for the biocompatibility of biomaterials for further use in medical devices.

Viele Faktoren können die Charakterisierung von Biomaterialien in der Testphase beeinflussen. Darunter fällt z.B. die Art der Testlösung, wie Humanblut oder tierisches Blut, NaCl‐Lösungen verschiedener Tonizität, u. a. Weitere Einflussfaktoren sind Pharmaka, die der Blutspender vor der Blutspende zu sich genommen hat. Experimentelle Einflussgrößen sind auch die rheologischen Randbedingungen, mit denen die Testlösung über das Biomaterial geleitet wird, da damit unterschiedliche Scherraten auf Blutzellen ausgeübt werden. Für Blutspender findet man Unterschiede beim Testen je nach Alter, Rasse und Geschlecht des Spenders. In dieser kurzen Übersicht sollen einige grundsätzliche Fehler beim Testen von Biomaterialien angesprochen werden. Für das zuverlässige Testen von Polymeren und Biomaterialien ist ein Systemansatz notwendig, der nicht nur individuelle Testparameter in den Mittelpunkt stellt, sondern das gesamte Spektrum der klinischen Randbedingungen berücksichtigt.
Meteorological influences on the design of advanced aircraft approach procedures for reduced environmental impacts
Authors: Ren Liling , Reynolds Tom G. , Clarke John‐Paul B. , Hooper David A. , Parton Graham A. , Dore Anthony J.
Published: January 2011

There is increasing interest in the development of aircraft operating procedures that reduce the environmental impacts of commercial aviation through minimization of fuel burn, emissions and noise impacts. Meteorological factors can have a major influence on the behaviour of aircraft in different phases of flight, thus they must be carefully considered in the development of any new procedures. In this paper the most important of these factors are considered (wind profiles and local pressure variations) within the context of development of advanced approach procedures at a major UK airport. Models of the wind characteristics were developed for the region around the airport using data collected from the Natural Environment Research Council Mesosphere‐Stratosphere‐Troposphere Radar at Aberystwyth and surface wind measurements made at the airport, while an analysis of local pressure effects was based on readings taken at the airport. These models were used in a Monte Carlo flight simulator to determine the suitability of different approach procedure designs in terms of flight and environmental performance. Flight tests of the final procedure design were conducted at the airport with a variety of commercial aircraft. These demonstrated the suitability of the procedures (and hence validated the modelling strategies used) and that significant environmental benefits in terms of reduced noise, fuel burn and emissions were achieved compared to existing procedures. Copyright © 2010 Royal Meteorological Society
The use of lidar‐detected smoke puff evolution for dispersion calculations
Authors: Choukulkar A. , Calhoun R. , Fernando H. J. S.
Published: January 2011

Dispersion modelling is a key component of modern emergency responses to catastrophic atmospheric releases. However, periodic algorithmic advances are needed to effectively use new datasets acquired with modern remote sensing instruments. This work demonstrates that coherent Doppler lidar can be used to provide valuable new inputs for dispersion models. While related research seeks to retrieve other required inputs for dispersion modelling systems, for example velocity vectors from radial velocities, this paper assembles and contextualizes analytical and algorithmic approaches for an improved understanding of dispersion characteristics in specific atmospheric scenarios using Doppler lidar data. Longitudinal (along‐wind), lateral (cross‐wind), and vertical dispersion parameters are calculated and used to estimate eddy diffusivities based on Gaussian curve fitting and first‐order closure. Empirical relations based on similarity theory are used to verify these estimates, and reasonable agreement is found between the two approaches. Several improvements are also suggested for the lidar scanning techniques to facilitate retrieval of dispersion parameters. Copyright © 2010 Royal Meteorological Society
Long‐term trends of zonally averaged aerosol optical thickness observed from operational satellite AVHRR instrument
Authors: Zhao X.‐P. Tom , Heidinger Andrew K. , Knapp Kenneth R.
Published: January 2011

Atmospheric aerosols are solid and liquid particles suspended in air. Aerosols have important consequences for global climate, ecosystem processes and human health due to their various sizes and chemical compositions. In this paper, nearly 23 years of aerosol optical thickness (AOT) data from operational satellite AVHRR observations over the global ocean have been used to study the latitudinal variations of the linear long‐term trends (LLT) of zonal mean AOT. For the LLT of zonally averaged AOT over the global ocean, their significance generally falls below the 95% confidence level. However, the LLT of zonal mean AOT for the individual oceans, such as the Atlantic Ocean (AO), Indian Ocean (IO), and West Pacific Ocean (WPO), can easily pass 95% confidence level in some latitude belts (e.g. 5–25°N for IO, 33–40°N for WPO, 30–50°N for AO) and may produce zonally averaged solar dimming/brightening accordingly in cloudless conditions. The results will help us to understand the latitudinal features of the decadal changes in aerosol loadings, as well as surface solar radiation, better. Published in 2011 by John Wiley & Sons, Ltd.
A global hail climatology using the UK Met Office convection diagnosis procedure (CDP) and model analyses
Authors: Hand Will H. , Cappelluti Gennaro
Published: January 2011

Five years of UK Met Office global model analyses from 1 January 2004 to 31 December 2008 have been used to generate a global hail climatology at 1° latitude by 1° longitude resolution. Hail has been diagnosed from model vertical profiles of temperature and humidity using a simple algorithm based on a paper by Fawbush and Miller (1953). Results have been compared with published observational climatologies on both a global and regional basis. The model diagnoses compare favourably with the observed data with both orographic and seasonal signals. However, there are differences, and possible reasons for these are discussed. These include limitations of the simple algorithm, the difficulty of observing hail in sparsely populated areas and the problem of population growth influencing the number of hail reports. Copyright © 2011 Royal Meteorological Society and Crown Copyright
Wind speed interpolation in the vicinity of the Panama Canal
Authors: Cheng Fang‐Yi , Georgakakos Konstantine P.
Published: January 2011

A simplified boundary layer (SBL) model formulation is tested against the mesoscale meteorological model MM5 with respect to the 2 km interpolation of hourly surface wind station data for stations in the close vicinity of the Panama Canal. The required short computation time for the real time interpolation of the wind during air pollution incidents involving crossing cargo ships makes the use of simplified wind models an alternative to the full implementation of mesoscale models. The SBL model does take into consideration the land cover of the ground surface, which exhibits substantial variability in the study region. The SBL model produces features of wind speed that are similar to those of the MM5 simulation along the better‐observed Canal centreline. The presence of orographic features makes the applicability of the simplified formulation reasonable only near the Canal where the terrain has small undulations. The simulated wind fields show that the dry season (January to April) is more spatially and temporally coherent than the wet season and that it also has higher wind speeds than the wet season. The evening hours have higher wind speeds than the morning hours in both seasons. The simulated wind exhibits higher average wind speeds and higher frequencies of exceeding 5 m s−1 within the Gatun Lake on the Caribbean side of the Isthmus and the entrance/exit of the Canal on the Caribbean and Pacific coasts. These results are useful for the development of effective disaster mitigation strategies for air pollution events in the region. Copyright © 2011 Royal Meteorological Society
Analysis of weather factors responsible for the traffic ‘Black Day’ in Helsinki, Finland, on 17 March 2005
Authors: Juga Ilkka , Hippi Marjo , Moisseev Dmitri , Saltikoff Elena
Published: January 2011

During the morning rush hours of 17 March 2005, a band of intense snowfall affected the Helsinki metropolitan area in southern Finland. The event caused severe pile‐ups on the highways, with almost 300 crashed cars, the deaths of three people and more than 60 people injured. The snowfall was soon followed by freezing drizzle. Some of the media later blamed this as being responsible for the unprecedented number and severity of the accidents that had occurred. However, the official inquiry came to the conclusion that the pile‐ups had been caused by the very poor visibility due to intense snowfall and excessive driving speeds combined with reduced road surface friction. In this study, these two viewpoints are investigated, by using high time‐resolution dual‐polarization radar observations to analyse the changes in intensity and form of the precipitation leading to the event. The radar data were particularly useful in supplementing weather observations. Copyright © 2011 Royal Meteorological Society
Call center arrival modeling: A Bayesian state‐space approach
Authors: Aktekin Tevfik , Soyer Refik
Published: January 2011

In this article, we introduce three discrete time Bayesian state‐space models with Poisson measurements, each aiming to address different issues in call center arrival modeling. We present the properties of the models and develop their Bayesian inference. In so doing, we provide sequential updating and smoothing for call arrival rates and discuss how the models can be used for intra‐day, inter‐day, and inter‐week forecasts. We illustrate the implementation of the models by using actual arrival data from a US commercial bank's call center and provide forecasting comparisons. © 2011 Wiley Periodicals, Inc. Naval Research Logistics 58: 28–42, 2011
Optimal control of a capacitated inventory system with multiple demand classes
Authors: Zhou Weihua , Lee Chung‐Yee , Wu David
Published: January 2011

This article studies the optimal control of a periodic‐review make‐to‐stock system with limited production capacity and multiple demand classes. In this system, a single product is produced to fulfill several classes of demands. The manager has to make the production and inventory allocation decisions. His objective is to minimize the expected total discounted cost. The production decision is made at the beginning of each period and determines the amount of products to be produced. The inventory allocation decision is made after receiving the random demands and determines the amount of demands to be satisfied. A modified base stock policy is shown to be optimal for production, and a multi‐level rationing policy is shown to be optimal for inventory allocation. Then a heuristic algorithm is proposed to approximate the optimal policy. The numerical studies show that the heuristic algorithm is very effective. © 2011 Wiley Periodicals, Inc. Naval Research Logistics 58: 43–58, 2011
Inventory control in divergent supply chains with time‐based dispatching and shipment consolidation
Authors: Marklund Johan
Published: January 2011

This article analyses a divergent supply chain consisting of a central warehouse and N nonidentical retailers. The focus is on joint evaluation of inventory replenishment and shipment consolidation effects. A time‐based dispatching and shipment consolidation policy is used at the warehouse in conjunction with real‐time point‐of‐sale data and centralized inventory information. This represents a common situation, for example, in various types of vendor managed inventory systems. The main contribution is the derivation of an exact recursive procedure for determining the expected inventory holding and backorder costs for the system, under the assumption of Poisson demand. Two heuristics for determining near optimal shipment intervals are also presented. The results are applicable both for single‐item and multiitem systems. © 2011 Wiley Periodicals, Inc. Naval Research Logistics 58: 59–71, 2011
Fetal micrognathia: objective assessment and associated anomalies on prenatal sonogram
Authors: Luedders Doerte W. , Bohlmann Michael K. , Germer Ute , Axt‐Fliedner Roland , Gembruch Ulrich , Weichert Jan
Published: January 2011

Objective

To determine the accuracy and characteristics of prenatally detected fetal micrognathia.

Methods

A retrospective analysis of all pregnancies with the suspicion of fetal micrognathia was performed. The affected fetuses were reassessed by estimation of the inferior facial angle (IFA) and the frontal nasomental angle on stored gray scale images to objectively establish the diagnosis.

Results

Of the 28.935 ultrasounds (USs) reviewed, 58 cases were eligible and 4 were excluded because of inconclusive data. The mean values for IFA and frontal nasomental angle were 44.8° and 123.3°, respectively. In 33 cases, the pregnancy was terminated. Four fetuses died sub partu or immediately after birth, five were stillborn. Invasive testing in 40/54 cases revealed aneuploidies in 35%. Associated anomalies comprised musculoskeletal disorders (43%) and non‐skeletal anomalies (15%). Less than one fifth (9/54) were alive beyond postnatal period. Four fetuses had an isolated micrognathia, one of which was found to have a cleft palate postnatally.

Conclusion

The diagnosis of micrognathia has a crucial impact on both prenatal and postnatal outcomes of affected individuals due to its association with additional abnormalities. A detailed sonographic survey using objective criteria for defining micrognathia is mandatory. Once the diagnosis is confirmed, an intensive interdisciplinary counseling of the parents is needed. Copyright © 2011 John Wiley & Sons, Ltd.
Evaluation of normal fetal atrio‐ventricular septum dimensions during pregnancy
Authors: Jadaon Jimmy E. , Haddad Sami , Mukary Maggi , Ben‐Shlomo Izhar , Ben‐Ami Moshe
Published: January 2011

Objectives

Ebstein anomaly and atrio‐ventricular septal defect involve a profound change in the appearance of the atrio‐ventricular septum (AVS). AVS is the area between the insertion of the mitral valve and the tricuspid valve leaflets to the ventricular septum. In normal fetuses, the tricuspid valve has an apical displacement relative to the mitral valve. We aimed to create a nomogram of its normal dimensions, beginning in the 11th gestational week.

Methods

Measurement of the length of the AVS was performed during ultrasonographic fetal echocardiography, in the four‐chamber view from 11 to 34 gestational weeks in otherwise normal pregnancies. In addition, standard fetal biometry was measured. Linear regression analysis was used to evaluate the correlation between variables.

Results

Two hundred and ninety‐two examinations of normal fetuses were included. A positive correlation was found between AVS length and gestational age (r2 = 0.96, P < 0.001), each week adding 0.165 mm (β = 0.165, P < 0.001). AVS length was also proportional to inter‐ventricular septum (IVS) length with increasing gestational age (r2 = 0.882, β = 0.94, P < 0.001). Positive linear correlation was obtained between AVS length and fetal biometry (P < 0.001).

Conclusion

We provide a nomogram for AVS length which can be used as a reference when either Ebstein anomaly or atrio‐ventricular septal defects are suspected. Copyright © 2011 John Wiley & Sons, Ltd.
PAPP‐A and free β‐hCG measured prior to 10 weeks is associated with preterm delivery and small‐for‐gestational‐age infants
Authors: Kirkegaard Ida , Henriksen Tine Brink , Tørring Niels , Uldbjerg Niels
Published: January 2011

Objective

To evaluate whether measuring pregnancy‐associated plasma protein A (PAPP‐A) and free β‐human chorionic gonadotrophin (β‐hCG) before 10 weeks of gestation affect the association between these biomarkers and adverse pregnancy outcomes.

Methods

Singleton pregnant women (9450) who attended the prenatal screening program, Aarhus University Hospital, Denmark, were included. Maternal serum levels of PAPP‐A and free β‐hCG were measured between week 8 and 13 weeks and 6 days. The risk of preterm delivery (<37 weeks) and small for gestational age (SGA) (<the fifth centile) was evaluated in relation to PAPP‐A and free β‐hCG < 0.4 multiples of the median, stratified according to early (<10 weeks) or late (≥10 weeks) biochemical testing.

Results

A stronger association between low PAPP‐A and SGA was found with early serum sampling compared to late, but the difference was not statistically significant [odds ratio (OR) 3.2 vs 1.8; P value = 0.11]. This difference did not apply to PAPP‐A and preterm delivery. For free β‐hCG, a stronger association with preterm delivery was found with early testing (OR 1.9 vs 1.1; P value = 0.31), whereas this difference was not found regarding SGA.

Conclusion

Biochemical testing before 10 weeks does not affect the association between low PAPP‐A and free β‐hCG and adverse pregnancy outcomes. Whether the association is actually stronger with early testing, requires further study. Copyright © 2011 John Wiley & Sons, Ltd.
Changes in the recipient fetal Tei index in the peri‐operative period after laser photocoagulation of placental anastomoses for twin–twin transfusion syndrome
Authors: Papanna Ramesha , Mann Lovepreet K. , Molina Saulo , Johnson Anthony , Moise Kenneth J.
Published: January 2011

Objective

To assess serial changes in the Tei index of the recipient fetus secondary to fetoscopic laser photocoagulation of placental anastomoses (FLP) for twin‐twin transfusion syndrome (TTTS) during the peri‐operative period.

Study design

A prospective study of cases that underwent FLP at the Texas Children's Fetal Center was performed. Mean and individual changes in the Tei index measurements were obtained during the pre‐operative, intra‐operative and the post‐operative (12‐h and 24‐h) periods after surgery and were compared using paired t‐test. A p‐value of < 0.05 was considered as significant.

Results

A total of 20 patients were included in the study. In both the right and the left side, the mean Tei indices appeared to be increased from baseline during the intra‐operative period, with a subsequent decrease to pre‐operative values within 24 h of laser surgery. These changes were also noted when individualized patient results were analyzed in a serial fashion.

Conclusion

FLP results in a transient increase in the intra‐operative myocardial performance index in the recipient fetus. These changes appear to resolve in the post‐operative period. Copyright © 2011 John Wiley & Sons, Ltd.
Prenatal diagnosis of non‐immune hydrops fetalis: what do we tell the parents?
Authors: Santo Susana , Mansour Sahar , Thilaganathan Basky , Homfray Tessa , Papageorghiou Aris , Calvert Sandra , Bhide Amar
Published: January 2011

Objective

The aim of this study is to outline the aetiology and outcome of a series of fetuses with non‐immune hydrops (NIH), detected prenatally. The findings are compared with a comprehensive review of recent reports.

Methods

This is a retrospective study reviewing all pregnancies complicated by NIH in the fetus and continued after 20 weeks of pregnancy over a period of 10 years. Outcome was obtained from postmortem reports, discharge summaries, communication with the clinicians or information from the parents. A literature search was also performed to identify all reports on NIH in the last 10 years.

Results

Seventy‐one fetuses affected by NIH were included in this study. The aetiology of the NIH was identified prenatally in 40 cases. The most common causes of NIH were thoracic disorders, infections and cardiovascular disorders. Forty‐four of the 71 (62%) fetuses were live‐born. There were 10 neonatal deaths. Of the remaining 34 babies, 17 infants survived without morbidity.

Conclusion

The survival rate of NIH is at least 48% in this study. Prenatal identification of the cause is possible in 56% of cases. The risk of neurodevelopmental delay in those that survive is 3 of 28 (11%). Copyright © 2011 John Wiley & Sons, Ltd.