bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of voice outcomes after radial forearm free flap reconstruction versus primary closure after laryngectomy
Authors: Alam Daniel S. , Vivek Prashant P. , Kmiecik Joann
Published: July 2008

OBJECTIVE

Laryngectomy with primary closure and tracheoesophageal prosthesis (TEP) voice rehabilitation has been the mainstay of the management of patients with advanced laryngeal malignancy. When adequate mucosal tissue is not available, pharyngeal reconstruction with free flaps can be utilized. The speech outcomes of these patients have been traditionally considered inferior based on the findings of a limited number of studies. We report the results of a review of our experience with radial forearm free flap (RFFF) reconstruction of extensive laryngopharyngectomy defects vs our institutional outcomes seen with primary closure.

STUDY DESIGN

Retrospective review.

SUBJECTS AND METHODS

All patients treated with laryngectomy procedures with either primary closure (28 patients) or RFFF (20 patients) reconstructions at the Cleveland Clinic from 2002 through 2007 were included. Blinded evaluation with statistical analysis of standard speech outcomes measures (maximal sustained phonation, fluent count) as well as qualitative variables are reported.

RESULTS

Based on our data collection, the two groups are statistically indistinguishable.

CONCLUSIONS

These findings support the utility and effectiveness of the RFFF in pharyngeal reconstruction in achieving good voice outcomes.
Transoral removal of submandibular hilar stone and sialodochoplasty
Authors: Roh Jong‐Lyel , Park Chan II
Published: July 2008

OBJECTIVE

To evaluate the efficacy of intraoral stone removal and sialodochoplasty in 59 patients with hilar submandibular stones.

STUDY DESIGN

Prospective, randomized, controlled study.

SUBJECTS AND METHODS

Fifty‐four patients underwent complete stone removal without significant complications, and five had unsuccessful removal of stones. The 54 patients with successful stone removal were randomized to additional sialodochoplasty (n = 28) or not (n = 26). Salivary scintigraphy was performed before and 6 months after surgery.

RESULTS

Salivary secretory function of the affected gland was less than that of a normal gland but returned to normal after stone removal. Symptom recurrence and recovery of salivary gland function were not affected by sialodochoplasty; rather, they were affected by successful removal of the stones.

CONCLUSION

Hilar submandibular stones can be transorally removed with high success rate, low‐level risk, and substantial recovery of gland function. Sialodochoplasty may have no effect in preventing symptom recurrence.
Making difficult ethical decisions in patient care during natural disasters and other mass casualty events
Authors: Holt G. Richard
Published: July 2008

OBJECTIVE

Recent experiences in the United States with unprecedented terrorist attacks (9/11) and a devastating natural disaster (Hurricane Katrina) have demonstrated that the medical care of mass casualties during such disasters poses ethical problems not normally experienced in civilian health care. It is important to 1) identify the unique ethical challenges facing physicians who feel an obligation to care for victims of such disasters and 2) develop a national consensus on ethical guidelines as a resource for ethical decision making in medical disaster relief.

STUDY DESIGN

A survey of pertinent literature was performed to assess experience and opinions on the condition of medical care in terrorist attacks and natural disasters, the ethical challenges of disaster medical care, and the professional responsibilities and responsiveness in disasters.

CONCLUSIONS

It is necessary to develop a national consensus on the ethical guidelines for physicians who care for patients, victims, and casualties of disasters, and to formulate a virtue‐based, yet practical, ethical approach to medical care under such extreme conditions. An educational curriculum for medical students, residents, and practicing physicians is required to best prepare all physicians who might be called upon, in the future, to triage patients, allocate resources, and make difficult decisions about treatment priorities and comfort care. It is not appropriate to address these questions at the time of the disaster, but rather in advance, as part of the ethics education of the medical profession. Important issues for resolution include inpatient and casualty triage and prioritization, medical liability, altered standards of care, justice and equity, informed consent and patient autonomy, expanding scope of practice in disaster medicine, and the moral and ethical responsibilities of physicians to care for disaster victims.
Predictors of quality of life after treatment for oral cavity and oropharyngeal carcinoma
Authors: Gurney Theresa A. , Eisele David W. , Orloff Lisa A. , Wang Steven J.
Published: July 2008

BACKGROUND

Treatment for head and neck cancer, including surgery, radiation, and chemotherapy, can impact quality of life.

DESIGN

Patients seen at an academic institution and treated for oral cavity and oropharyngeal carcinoma were asked to participate. The standardized University of Michigan Head and Neck Specific Quality of Life questionnaire was distributed.

RESULTS

Eighty‐seven patients completed the questionnaire. The majority had squamous cell carcinoma (94%), stage III or IV disease (53%), and a history of tobacco or alcohol dependence (59%), and were male (62%). Eighteen percent had free‐tissue transfer (fibula free flap in 8% and radial forearm free flap in 10%). Predictors of worse quality of life included advanced stage, gastrostomy‐tube dependence, complication, or recurrence.

CONCLUSION

Stage, gastrostomy‐tube dependence, complication, recurrence, and treatment modality influence quality of life. A better understanding of the impact of oral cavity and oropharyngeal cancer treatment on quality of life will enable us to better advise our patients.
Crystal precipitation and dissolution in a thin strip
Authors: VAN NOORDEN T. L.
Published: July 2008

We present a two-dimensional micro-scale model for crystal dissolution and precipitation in a porous medium. The local geometry of the pore is represented as a thin strip and the model allows for changes in the pore volume. A formal limiting argument, for the limit of the width of the strip going to zero, leads to a system of one-dimensional effective upscaled equations. We show that the effective equations allow for travelling-wave solutions and prove the existence and uniqueness of these. Numerical solutions of the effective equations are compared with numerical solutions of the original equations on the thin strip and with analytical results. We also show that a model from the literature that does not allow changes in the pore volume can be obtained from the present model as a formal limit.
Prevalence of metabolic syndrome and associated risk factors in Brazilian schoolchildren
Authors: Seki Mario , Matsuo Tiemi , Faria Carrilho Alexandre Jose
Published: July 2008

Objective

To determine the prevalence of metabolic syndrome (MetS) in schoolchildren from 6 to 16 years old, while considering their socio-economic status and other potential risk factors.

Design

A cross-sectional study was conducted between April and November of 2005 in a semi-rural city with a total population of 13 000 inhabitants.

Setting

The study was conducted in Maracai city, located in the Brazilian state of Sao Paulo.

Subjects

Schoolchildren (n 2170) of both genders, corresponding to approximately 82 % of all Maracai schoolchildren, were evaluated for components of MetS, as defined by the National Cholesterol Education Program; reference values for children and adolescents were adjusted for age and sex.

Results

Overall, MetS prevalence was 3·6 % (95 % CI 2·9, 4·5) and did not differ statistically between genders, skin colour, between children and adolescents. However, when we analysed groups of subjects by weight, MetS prevalence progressively increased from 0·3 % (95 % CI 0·1, 0·8) in normal-weight subjects to 10·7 % (95 % CI 7·4, 14·8) and 34·5 % (95 % CI 25·9, 43·9) in overweight and obese subjects, respectively (both P < 0·001 compared to normal-weight controls). When socio-economic classes were considered, 4·7 % high-income students (95 % CI 3·5, 6·2) had MetS, which was significantly greater than low-income students (2·7 %; 95 % CI 1·9, 3·9; P = 0·023).

Conclusions

MetS prevalence was high in overweight and obese schoolchildren and these risk factors were present during childhood and adolescence. Changes in lifestyle and alimentary safety should be encouraged to avoid future cardiovascular morbidity and type 2 diabetes mellitus.
A short-term intervention for the treatment of severe malnutrition in a post-conflict country: results of a survey in Guinea Bissau
Authors: Colombatti Raffaella , Coin Alessandra , Bestagini Piero , Vieira Cesaltina Silva , Schiavon Laura , Ambrosini Venceslao , Bertinato Luigi , Zancan Lucia , Riccardi Fabio
Published: July 2008

Objectives

To determine (i) the extent of malnutrition and the risk factors for severe malnutrition in Guinea Bissau, a post-conflict country experiencing long-term consequences of civil war; and (ii) the feasibility and effectiveness of a short-term intervention characterized by outpatient treatment with locally produced food for the treatment of severe malnutrition during the rainy season.

Design and setting

Social, clinical, nutritional information were collected for children reaching the paediatric outpatient clinic of the Hospital ‘Comunità di Sant’Egidio’ in Bissau, Guinea Bissau, from 1 July to 12 August 2003. Severely malnourished children (weight-for-age <−3sd) in poor health status were admitted for daily nutritional and pharmacological treatment until complete recovery. Social and health indicators were analysed to define risk factors of severe malnutrition.

Results

In total, 2642 children were visited (age range: 1 month–17 years). Fever, cough and dermatological problems were the main reasons for access. Social data outlined poor housing conditions: 86·4 % used water from unprotected wells, 97·3 % did not have a bathroom at home, 78·2 % lived in a mud house. Weight-for-age was <−2sdin 23·0 % of the children and <−3sdin 10·3 %; thirty-seven children (1·4 %) were severely malnourished and admitted for day care. All recovered with a weight gain of 4·45 g/kg per d, none died or relapsed after 1 year. Severely malnourished children were mainly infants, part of large families and had illiterate mothers.

Conclusion

Short-term interventions performed in post-conflict countries during seasons of high burden of disease and malnutrition are feasible and successful at low cost; day-care treatment of severe malnutrition with locally produced food is an option that can be tested in other settings.
Non-Alcoholic Fatty Liver Disease in Overweight Children and its Relationship with Retinol Serum Levels
Authors: Suano de Souza  , Silverio Amancio  , Saccardo Sarni  , Sacchi Pitta  , Fernandes  , Affonso Fonseca  , Hix  , Ramalho
Published: July 2008

Objectives: To evaluate the frequency of non-alcoholic fatty liver disease, the retinol serum levels, lipid profile, and insulin resistance in overweight/obese children. To relate these biochemical variables with the risk of this disease in the population studied. Methods: The study was cross-sectional and prospective, with 46 overweight/obese school children (28 female, 18 male; mean age 8.6 years). The control group consisted of 45 children, paired by age and gender. Hepatic steatosis, evaluated by ultrasound, was classified as normal, mild, moderate, or severe. Also evaluated were serum retinol levels; thiobarbituric acid reactive substances; lipid profile; and fasting glucose and serum insulin levels, used for the calculation of the Homeostasis Model Assessment. Results: Hepatic ultrasound alterations were found in 56.5% and 48,9% of the overweight/obese and control group children, respectively. Presence of obesity was associated with high levels of triglycerides (OR = 4.6; P = 0.002). In the studied children, the risk of steatosis was related to a trend to a higher percentage of retinol inadequacy (OR = 2.8; p = 0.051); there was no association with thiobarbituric acid reactive substances, lipid profile, or insulin resistance. Conclusions: The high frequency of non-alcoholic fatty liver disease in both groups, evaluated by hepatic ultrasound, in low-socioeconomic level children, independent of nutritional condition and without significant association with insulin resistance, emphasizes that especially in developing countries, other risk factors such as micronutrient deficiencies (e.g. vitamin A) are involved.
Molecular Mechanism of Apoptosis Induction by Resveratrol, a Natural Cancer Chemopreventive Agent
Authors: Fan  , Jiang  , Zhang  , Bai
Published: July 2008

In efforts to identify naturally occurring compounds that act as protective agents, resveratrol, a phytoalexin existing in wine, has attracted much interest because of its diverse pharmacological characteristics. Considering that apoptosis induction is the most potent defense approach for cancer treatment, we have tried to summarize our present understanding of apoptosis induction by resveratrol based on the two major apoptosis pathways.
Low Plasma Pyridoxal 5’-phosphate Concentration and MTHFR 677C→T Genotypes are Associated with Increased Risk of Hypertension
Authors: Lin  , Cheng  , Wei  , Huang
Published: July 2008

Few studies have linked homocysteine, B vitamins and/or genetic defects to the risk of hypertension. The purpose of this study was to investigate homocysteine, B-vitamins, and genetic mutation in relation to the risk of hypertension. Subjects were assigned to the hypertension (HTN) group (n = 50) or non-hypertension (non-HTN) group (n = 123). All subjects’ blood pressure (systolic blood pressure, SBP; diastolic blood pressure, DBP), biochemical values, plasma homocysteine, pyridoxal 5’-phosphate (PLP), serum folate, vitamin B12 concentrations, and methylenetetrafolate reductase (MTHFR) 677C→T gene polymorphism were measured. Results showed that subjects with T-allele were positively associated with DBP (β = 4.22, p = 0.04) but the significance became weaker (p = 0.06) after homocysteine and B vitamins were additionally adjusted. A significant association of plasma PLP with SBP remained (β = –0.06, p = 0.01) even after homocysteine and T-allele genotypes were additionally adjusted (β = –0.07, p = 0.02). The combined presence of low PLP (< 30 nmol/L) and carried T-allele enhanced the risk of hypertension and the risk magnitude was substantially greater (OR, 16.44, p < 0.001). Taken together, the results show that low plasma PLP levels and MTHFR 677C→T genotypes might be significant risk factors for hypertension.
Früherkennung und Frühbehandlung der Schizophrenie: Chance oder Dilemma?
Authors: Resch Franz
Published: July 2008

Zusammenfassung: Die Früherkennung und Frühbehandlung von Psychosen aus dem schizophrenen Formenkreis bei Kinder- und Jugendlichen gilt als wichtiges therapeutisches Ziel, da ein Zusammenhang zwischen verzögertem Behandlungsbeginn und ungünstigem Gesamtverlauf immer wieder postuliert wurde. Die Dauer der unbehandelten Psychose (DUP) ist bei Jugendlichen gegenüber Erwachsenen signifikant verlängert, was sowohl mit einem schleichenden Beginn der Symptomatik als auch mit möglicher Bagatellisierung durch Familien und Helfersysteme in Verbindung gebracht wird. Kritisch wird die Idee der Primärprävention beleuchtet, da die Vorfeldsymptomatik des Prodroms auf Grund ihrer Unspezifität eine schizophreniespezifische Intervention nicht möglich macht. Überlegungen zum Vulnerabilitätsmodell der Pathogenese und zukünftige Frühdiagnosestrategien einer mehrdimensionalen biopsychosozialen Risikoabschätzung werden vorgestellt.
Three‐dimensional VP and VP/VS structure of the upper crust in the Erzincan basin (eastern Turkey)
Authors: Kaypak Bülent
Published: July 2008

Using aftershocks of the 13 March 1992 Erzincan earthquake (Ms = 6.8) three dimensional VP and VP/VS velocity structure of the Erzincan basin and its surroundings were modeled by local earthquake tomography. Travel times of body waves, belonging to 1025 selected high‐quality events recorded by 58 temporary stations, were inverted iteratively and simultaneously by using the SIMUL2000 algorithm. Synthetic and resolution tests were performed to analyze the sensitivity of tomographic results and model parameterization. The resulting 3‐D VP and VP/VS tomographic images show velocity anomalies related to geologic and tectonic structures beneath the Erzincan basin. While low VP anomalies down to 2–3 km depths are associated to thick Neogene sediments deposited in the Erzincan basin, high VP anomalies indicate bed rocks and intrusive magmatic rocks beneath the mountain ranges. VP/VS anomalies are an important indicator of local tectonic structures, and the physical, mechanical, and compositional variations in the rocks. The low VP/VS anomalies (≤1.7) observed at shallow depths (0–4 km) track the main fault systems and thus the weakness zones in the basin. The high VP/VS anomalies (≥1.9) located between 4 and 6 km depth in the southeast of the Erzincan basin may correspond to fluid saturation, high pore pressure, and carbonate content in the rock matrix. The high VP/VS ratios play an important role for increasing seismicity in this area because of the fluid saturation and the high pore pressure. Finally, on the basis of the 3‐D tomographic images, basement of the Erzincan basin deepens down to about 10 km depth and possesses an irregular and asymmetric shape. The thick and unconsolidated sedimentary layer increases seismic risk to Erzincan and other cities located on the basin as it magnifies ground motion caused by large earthquakes.
Interaction of the 2‐day wave with solar tides
Authors: Salby Murry L. , Callaghan Patrick F.
Published: July 2008

Nonlinear integrations with a three‐dimensional model of the middle and upper atmosphere are used to study how the 2‐day wave interacts with solar tides. At small 2‐day wave amplitude, the modulation by tides is linear and, therefore, largely reversible. At large 2‐day wave amplitude, however, the modulation leads to a nonlinear interaction that is irreversible. Local reinforcement, chiefly by the diurnal tide, introduces local instability and wave breaking. This nonlinear behavior results in a cascade of variance to small scales, at the expense of large‐scale wave activity. By accelerating wave damping, this process yields slower amplification and the 2‐day wave being limited to amplitudes at which nonlinear interaction prevails. At altitudes of strong tidal amplitude, regular propagation is disrupted, replaced by broadband behavior associated with secondary scales that are generated nonlinearly through eddy mixing. The same process influences solar tides. However, because they are continually forced, tidal amplitudes are reduced only modestly, by 10–20%. This contrasts with the 2‐day wave, which, for sufficiently strong tides, is limited to small amplitude.
S wave velocity structure of the Arabian Shield upper mantle from Rayleigh wave tomography
Authors: Park Yongcheol , Nyblade Andrew A. , Rodgers Arthur J. , Al‐Amri Abdullah
Published: July 2008

The shear wave velocity structure of the shallow upper mantle beneath the Arabian Shield was modeled by inverting Rayleigh wave phase velocity measurements between 45 and 140 s together with previously published Rayleigh wave group velocity measurements between 10 and 45 s. For measuring phase velocities, we applied a modified array method to data from several regional networks that minimizes the distortion of raypaths caused by lateral heterogeneity. The new shear wave velocity model shows a broad low‐velocity region to depths of ∼150 km in the mantle across the Shield and a narrower low‐velocity region at depths ≥150 km localized along the Red Sea coast and Makkah‐Madinah‐Nafud (MMN) volcanic line. The velocity reduction in the upper mantle corresponds to a temperature anomaly of ∼250–330 K. These findings, in particular the region of continuous low velocities along the Red Sea and MMN volcanic line, do not support interpretations for the origin of the Cenozoic plateau uplift and volcanism on the Shield invoking two separate plumes. When combined with images of the 410 and 660 km discontinuities, body wave tomographic models, a S wave polarization analysis, and SKS splitting results for the Arabian Peninsula, the anomalous upper mantle structure in our new velocity model can be attributed to an upwelling of warm mantle rock originating in the lower mantle under Africa that crosses through the mantle transition zone beneath Ethiopia and moves to the north and northwest under the eastern margin of the Red Sea and the Arabian Shield. In this interpretation, the difference in mean elevation between the Arabian Platform and Shield can be attributed to isostatic uplift caused by heating of the lithospheric mantle under the Shield, with the significantly higher elevations along the Red Sea coast possibly resulting also from lithospheric thinning and dynamic uplift.
Observations of the 2004 and 2006 Indian Ocean tsunamis from a pressure gauge array in Indonesia
Authors: Drushka Kyla , Sprintall Janet , Gille Sarah T. , Pranowo Widodo S.
Published: July 2008

Five shallow pressure gauges located in straits in the southern Indonesian islands were used to evaluate tsunami signals triggered by the earthquakes off the northwest coast of Sumatra in December 2004 and the south coast of Java in July 2006. Tsunami waves reached the pressure gauges around 5 to 6 hours after the 2004 earthquake; the largest waves arrived 10 to 23 hours later, with amplitudes ranging from 9 to 25 cm. After the 2006 earthquake, tsunami arrivals were only evident at the Ashmore and Roti pressure gauges in Timor Passage. At these two gauges, the first waves arrived around 2.25 hours after the earthquake, and the largest waves arrived 2 to 3 hours later, with amplitudes of 6 and 18 cm. Spectral analysis shows an increase of energy in the 40‐ to 80‐min‐period band during the 2004 tsunami, and at periods of 10 to 20 min in 2006. A simple ray tracing model of both the 2004 and 2006 events, which approximates the tsunami as a shallow water wave, was used to evaluate the effect of topography on tsunami propagation in order to provide a physical explanation for the features observed in the pressure gauge data.
An overview of UAE2 flight operations: Observations of summertime atmospheric thermodynamic and aerosol profiles of the southern Arabian Gulf
Authors: Reid Jeffrey S. , Piketh Stuart J. , Walker Annette L. , Burger Roelof P. , Ross Kristy E. , Westphal Douglas L. , Bruintjes Roelof T. , Holben Brent N. , Hsu Christina , Jensen Tara L. , Kahn Ralph A. , Kuciauskas Arunas P. , Al Mandoos Abdulla , Al Mangoosh Abdulla , Miller Steven D. , Porter John N. , Reid Elizabeth A. , Tsay Si‐Chee
Published: July 2008

In August through September 2004 the United Arab Emirates Unified Aerosol Experiment (UAE2) was conducted in the southern Arabian Gulf region. We present atmospheric thermodynamic and aerosol data collected on 18 flights by the South African Aerocommander aircraft. In the first few kilometers, we observed high concentrations of both regional dust (from 100 to 300 μg m−3 in background, to over 1.5 mg m−3 in events) and ubiquitous sulfate based pollution from the Gulf's prevalent petroleum industry (10–100 μg m−3). Smoke and pollution from Europe and possibly Africa were found at levels between 1.5 and 5 km. Inland, classic deep over desert boundary layer characteristics were found. Over the Arabian Gulf, dust and pollution were most often either trapped below or sequestered above a strong stable boundary. However, there were cases where a well‐distributed aerosol layer crossed the inversion uniformly. Data suggest that the observed vertical profiles can be explained by the rapid formation of stable marine boundary layers as air moves offshore. This can decouple aerosol layers from within the boundary layer to those aloft in regions of vertical wind shear. In the case of pollution, the ability of flaring plumes to penetrate the inversion may also in part determine layering. In coastal regions without vertical wind shear, uniform concentrations with height across the inversion are a result of internal boundary layer development. We conclude that the bulk of the observed variability in particle vertical distribution appear to be controlled by mesoscale and microscale processes, such as the sea/land breeze.
Physical and optical properties of mineral dust aerosol during the Dust and Biomass‐burning Experiment
Authors: Osborne S. R. , Johnson B. T. , Haywood J. M. , Baran A. J. , Harrison M. A. J. , McConnell C. L.
Published: July 2008

We present aircraft measurements of dust aerosol during the Dust and Biomass‐burning Experiment (DABEX), a project affiliated with the African Monsoon Multidisciplinary Analysis. DABEX took place between 13 January and 3 February 2006 in Sahelian west Africa, with the aircraft based at Niamey, Niger. The data set is augmented with Aerosol Robotic Network (AERONET) data. A mineral dust layer below 1–2 km (sourced from the north) and an overlying biomass burning (BB) layer (sourced from anthropogenic fires to the south) was observed on all days, although variability was observed in both layers. There is evidence of ozone loss within the dust, but with CO levels between 140 and 170 ppbv some history of combustion has occurred. Size distribution of the dust is compared with that of the BB aerosol and with dust measured near Senegal, during the Dust Outflow and Deposition to the Ocean (DODO‐1) experiment. For accurate representation of the optical properties, five log‐normals to the size distribution across sizes 0.05–5 μm are required, although two log‐normals are adequate. The single scattering albedo was almost purely scattering, with values of 0.99 ± 0.01. During the strongest dust events the dust contribution to the column optical depth was 75–80%, compared to a DABEX mean of 50%. The aircraft‐derived optical depth varied between 0.19 and 1.07, with the dust‐only contribution between 0.07 and 0.81. AERONET optical depth trends are in good agreement with aircraft during DABEX, albeit with a bias to higher aircraft values. Retrieved AERONET aerosol size distributions show variable agreement with the aircraft. Differences between Versions 1 and 2 of the AERONET algorithm are highlighted.
Radiative susceptibility of cloudy atmospheres to droplet number perturbations: 1. Theoretical analysis and examples from MODIS
Authors: Platnick Steven , Oreopoulos Lazaros
Published: July 2008

Theoretical and satellite‐based assessments of the sensitivity of broadband shortwave radiative fluxes in cloudy atmospheres to small perturbations in the cloud droplet number concentration (N) of liquid water clouds under constant water conditions are performed. Two approaches to study this sensitivity are adopted: absolute increases in N, for which the radiative response is referred to as “absolute cloud susceptibility,” and relative increases in N or “relative cloud susceptibility.” Estimating the former is more challenging as it requires an assumed value for either cloud liquid water content or geometrical thickness; both susceptibilities require an assumed relationship between the droplet volume and effective radius. Expanding upon previous susceptibility studies, present radiative calculations include the effect of ΔN perturbations on droplet asymmetry parameter and single‐scattering albedo, in addition to extinction. Absolute cloud susceptibility has a strong nonlinear dependence on the droplet effective radius as expected, while relative cloud susceptibility is primarily dependent on optical thickness. Molecular absorption and reflecting surfaces both reduce the relative contribution of the cloud to the top‐of‐atmosphere (TOA) flux and therefore also reduce the TOA albedo susceptibility. Transmittance susceptibilities are negative with absolute values similar to albedo susceptibility, while atmospheric absorptance susceptibilities are about an order of magnitude smaller than albedo susceptibilities and can be either positive or negative. Observation‐based susceptibility calculations are derived from MODIS pixel‐level retrievals of liquid water cloud optical thickness, effective radius, and cloud top temperature; two data granule examples are shown. Susceptibility quantifies the aerosol indirect effect sensitivity in a way that can be easily computed from model fields. As such, susceptibilities derived from MODIS observations provide a higher‐order test of model cloud properties used for indirect effect studies. MODIS‐derived global distributions of cloud susceptibility and radiative forcing calculations are presented in a companion paper.
Radiative susceptibility of cloudy atmospheres to droplet number perturbations: 2. Global analysis from MODIS
Authors: Oreopoulos Lazaros , Platnick Steven
Published: July 2008

Global distributions of albedo susceptibility for areas covered by liquid clouds are presented for 4 months in 2005. The susceptibility estimates are based on expanded definitions presented in a companion paper and include relative cloud droplet number concentration (CDNC) changes, perturbations in cloud droplet asymmetry parameter and single‐scattering albedo, atmospheric/surface effects, and incorporation of the full solar spectrum. The cloud properties (optical thickness and effective radius) used as input in the susceptibility calculations come from MODIS Terra and Aqua Collection 5 gridded data. Geographical distributions of susceptibility corresponding to absolute (“absolute cloud susceptibility”) and relative (“relative cloud susceptibility”) CDNC changes are markedly different indicating that the detailed nature of the cloud microphysical perturbation is important for determining the radiative forcing associated with the first indirect aerosol effect. However, both types of susceptibility exhibit common characteristics such as significant reductions when perturbations in single‐scattering properties are omitted, significant increases when atmospheric absorption and surface albedo effects are ignored, and the tendency to decrease with latitude, to be higher over ocean than over land, and to be statistically similar between the morning and afternoon MODIS overpasses. The satellite‐based susceptibility analysis helps elucidate the role of present‐day cloud and land surface properties in indirect aerosol forcing responses. Our realistic yet moderate CDNC perturbations yield forcings on the order of 1–2 W m−2 for cloud optical property distributions and land surface spectral albedos observed by MODIS. Since susceptibilities can potentially be computed from model fields, these results have practical application in assessing the reasonableness of model‐generated estimates of the aerosol indirect radiative forcing.
An interactive Bayesian geostatistical inverse protocol for hydraulic tomography
Authors: Fienen Michael N. , Clemo Tom , Kitanidis Peter K.
Published: July 2008

Hydraulic tomography is a powerful technique for characterizing heterogeneous hydrogeologic parameters. An explicit trade‐off between characterization based on measurement misfit and subjective characterization using prior information is presented. We apply a Bayesian geostatistical inverse approach that is well suited to accommodate a flexible model with the level of complexity driven by the data and explicitly considering uncertainty. Prior information is incorporated through the selection of a parameter covariance model characterizing continuity and providing stability. Often, discontinuities in the parameter field, typically caused by geologic contacts between contrasting lithologic units, necessitate subdivision into zones across which there is no correlation among hydraulic parameters. We propose an interactive protocol in which zonation candidates are implied from the data and are evaluated using cross validation and expert knowledge. Uncertainty introduced by limited knowledge of dynamic regional conditions is mitigated by using drawdown rather than native head values. An adjoint state formulation of MODFLOW‐2000 is used to calculate sensitivities which are used both for the solution to the inverse problem and to guide protocol decisions. The protocol is tested using synthetic two‐dimensional steady state examples in which the wells are located at the edge of the region of interest.
Relationship between ENSO and northward propagating intraseasonal oscillation in the east Asian summer monsoon system
Authors: Yun Kyung‐Sook , Seo Kyong‐Hwan , Ha Kyung‐Ja
Published: July 2008

Observational studies are presented on the relationship between El Niño–Southern Oscillation (ENSO) and the northward propagating intraseasonal oscillation (NPISO) in the east Asian summer monsoon (EASM) system. The summer NPISO activity shows a significant correlation with the preceding winter extreme phase of ENSO cycles. A higher correlation appears during late summer, which is consistent with frequent heavy rainfall events at that time as revealed in some previous case studies. The westward expansion of broad anticyclonic circulation over the western North Pacific and the smaller cyclonic circulation around Korea and Japan are found to be associated with the NPISO activity. ENSO affects the late summer NPISO activity through an atmospheric bridge and wave propagation; the springtime Indian Ocean sea surface temperature warming induced by ENSO through the Walker circulation leads to the downward motion and suppressed convection over the Philippine Sea, and this generates the forced Rossby wave train, forming the above south‐to‐north low‐level circulation anomalies.
Transcription of nitrification genes by the methane-oxidizing bacterium, Methylococcus capsulatus strain Bath
Authors: Poret-Peterson Amisha T , Graham James E , Gulledge Jay , Klotz Martin G
Published: July 2008

Methylococcus capsulatus strain Bath, a methane-oxidizing bacterium, and ammonia-oxidizing bacteria (AOB) carry out the first step of nitrification, the oxidation of ammonia to nitrite, through the intermediate hydroxylamine. AOB use hydroxylamine oxidoreductase (HAO) to produce nitrite. M. capsulatus Bath was thought to oxidize hydroxylamine with cytochrome P460 (cytL), until the recent discovery of an hao gene in its genome. We used quantitative PCR analyses of cDNA from M. capsulatus Bath incubated with CH4 or CH4 plus 5 mm (NH4)2SO4 to determine whether cytL and hao transcript levels change in response to ammonia. While mRNA levels for cytL were not affected by ammonia, hao mRNA levels increased by 14.5- and 31-fold in duplicate samples when a promoter proximal region of the transcript was analyzed, and by sixfold when a region at the distal end of the transcript was analyzed. A conserved open reading frame, orf2, located 3′ of hao in all known AOB genomes and in M. capsulatus Bath, was cotranscribed with hao and showed increased mRNA levels in the presence of ammonia. These data led to designating this gene pair as haoAB, with the role of haoB still undefined. We also determined mRNA levels for additional genes that encode proteins involved in N-oxide detoxification: cytochrome c′-β (CytS) and nitric oxide (NO) reductase (NorCB). Whereas cytS mRNA levels increased in duplicate samples by 28.5- and 40-fold in response to ammonia, the cotranscribed norC-norB mRNA did not increase. Our results strongly suggest that M. capsulatus Bath possesses a functional, ammonia-responsive HAO involved in nitrification.
Differences in Age-Related Alterations in Muscle Contraction Properties in Rat Tongue and Hindlimb
Authors: Connor Nadine P. , Ota Fumikazu , Nagai Hiromi , Russell John A. , Leverson Glen
Published: July 2008

Purpose

Because of differences in muscle architecture and biomechanics, the purpose of this study was to determine whether muscle contractile properties of rat hindlimb and tongue were differentially affected by aging.

Method

Deep peroneal and hypoglossal nerves were stimulated in 6 young and 7 old Fischer 344-Brown Norway rats to allow recording of muscle contractile properties of tongue and extensor digitorum longus (EDL) muscle in the hindlimb. In the same animals, the following measurements were made: (a) twitch contraction time (CT; in milliseconds), (b) half decay time (HDT; in milliseconds), (c) maximum twitch force (in grams), (d) tetanic force, and (e) fatigue index determined from repetitive stimulation of the muscles.

Results

No significant differences were observed in young versus old groups in retrusive tongue forces, whereas a significant (
p
< .05) decrement in EDL tetanic forces was found in old rats. Slower CT in old rats was observed only in the tongue. Old and young groups were not significantly different in fatigue index or HDT for tongue or EDL.

Conclusions

Old animals generated equivalent maximum tongue forces with stimulation, but they were slower in achieving these forces than young animals. Limb and cranial muscles were not affected equally by aging. As such, information derived from limb muscle studies may not easily generalize to the cranial motor system.
Phonotactic Probability Effects in Children Who Stutter
Authors: Anderson Julie D. , Byrd Courtney T.
Published: July 2008

Purpose

The purpose of this study was to examine the influence of
phonotactic probability,
which is the frequency of different sound segments and segment sequences, on the overall fluency with which words are produced by preschool children who stutter (CWS) as well as to determine whether it has an effect on the type of stuttered disfluency produced.

Method

A 500+ word language sample was obtained from 19 CWS. Each stuttered word was randomly paired with a fluently produced word that closely matched it in grammatical class, word length, familiarity, word and neighborhood frequency, and neighborhood density. Phonotactic probability values were obtained for the stuttered and fluent words from an online database.

Results

Phonotactic probability did not have a significant influence on the overall susceptibility of words to stuttering, but it did impact the type of stuttered disfluency produced. In specific, single-syllable word repetitions were significantly lower in phonotactic probability than fluently produced words, part-word repetitions, and sound prolongations.

Conclusions

In general, the differential impact of phonotactic probability on the type of stuttering-like disfluency produced by young CWS provides some support for the notion that different disfluency types may originate in the disruption of different levels of processing.
The Effect of Frequency Altered Feedback on Stuttering Duration and Type
Authors: Stuart Andrew , Frazier Carmen L. , Kalinowski Joseph , Vos Paul W.
Published: July 2008

Purpose

The effect of frequency altered feedback (FAF) on stuttering type (i.e., prolongation, repetition, or silent block) and stuttering duration (i.e., average duration of stuttering event and total stuttering time) was examined.

Method

Retrospective analyses of previously collected data from 12 adult persons who stutter who participated in an
ABA
time-series design while reading orally was undertaken. It was hypothesized that stuttering duration would decrease and there would be a differential reduction in the type of stuttering during FAF, concurrent with previously confirmed reduction of stuttering episodes. A total of 2,971 stuttered syllables were analyzed.

Results

The total stuttering duration (s/min) was significantly reduced by approximately 50% irrespective of stuttering type (
p
= .0014). Although significant differences in the average duration(s) of the 3 stuttering types (
p
= .0064) existed, FAF significantly reduced each type of stuttering by approximately 20% (
p
= .0055). There was no differential effect on the reduction of proportion of stuttering type during FAF (
p
= .36).

Conclusions

FAF positively affects the speech of persons who stutter by reducing the proportion of stuttered events with a concomitant decrease in duration of residual stuttering and total stuttering time during oral reading.
An Evaluation of the Aurora System as a Flesh-Point Tracking Tool for Speech Production Research
Authors: Kröger Bernd J. , Pouplier Marianne , Tiede Mark K.
Published: July 2008

Purpose

Northern Digital Instruments (NDI; Waterloo, Ontario, Canada) manufactures a commercially available magnetometer device called Aurora that features real-time display of sensor position tracked in 3 dimensions. To test its potential for speech production research, data were collected to assess the measurement accuracy and reliability of the system.

Method

First, sensors affixed at a known distance on a rigid ruler were moved systematically through the measurement space. Second, sensors attached to the speech articulators of a human participant were tracked during various speech tasks.

Results

In the ruler task, results showed mean distance errors of less than 1 mm, with some sensitivity to location within the measurement field. In the speech tasks, Euclidean distance between jaw-mounted sensors showed comparable accuracy; however, a high incidence of missing samples was observed, positively correlated with sensor velocity.

Conclusions

The real-time positional feedback provided by the system makes it potentially useful in speech therapy applications. The overall missing data rate observed during speech tasks makes use of the system in its current form problematic for the quantitative measurement of speech articulator movements; however, NDI is actively working to improve the Aurora system for use in this context.
Language-Specific Effects of Task Demands on the Manifestation of Specific Language Impairment: A Comparison of English and Icelandic
Authors: Thordardottir Elin
Published: July 2008

Purpose

Previous research has indicated that the manifestation of specific language impairment (SLI) varies according to factors such as language, age, and task. This study examined the effect of task demands on language production in children with SLI cross-linguistically.

Method

Icelandic- and English-speaking school-age children with SLI and normal language (NL) peers (
n
= 42) were administered measures of verbal working memory. Spontaneous language samples were collected in contexts that vary in task demands: conversation, narration, and expository discourse. The effect of the context-related task demands on the accuracy of grammatical inflections was examined.

Results

Children with SLI in both language groups scored significantly lower than their NL peers in verbal working memory. Nonword repetition scores correlated with morphological accuracy. In both languages, mean length of utterance (MLU) varied systematically across sampling contexts. Context exerted a significant effect on the accuracy of grammatical inflection in English only. Error rates were higher overall in English than in Icelandic, but whether the difference was significant depended on the sampling context. Errors in Icelandic involved verb and noun phrase inflection to a similar extent.

Conclusions

The production of grammatical morphology appears to be more taxing for children with SLI who speak English than for those who speak Icelandic. Thus, whereas children with SLI in both language groups evidence deficits in language processing, cross-linguistic differences are seen in which linguistic structures are vulnerable when processing load is increased. Future research should carefully consider the effect of context on children’s language performance.
Cortical Mechanisms of Speech Perception in Noise
Authors: Wong Patrick C. M. , Uppunda Ajith K. , Parrish Todd B. , Dhar Sumitrajit
Published: July 2008

Purpose

The present study examines the brain basis of listening to spoken words in noise, which is a ubiquitous characteristic of communication, with the focus on the dorsal auditory pathway.

Method

English-speaking young adults identified single words in 3 listening conditions while their hemodynamic response was measured using fMRI: speech in quiet, speech in moderately loud noise (signal-to-noise ratio [SNR] 20 dB), and in loud noise (SNR −5 dB).

Results

Behaviorally, participants’ performance (both accuracy and reaction time) did not differ between the quiet and SNR 20 dB condition, whereas they were less accurate and responded slower in the SNR −5 dB condition compared with the other 2 conditions. In the superior temporal gyrus (STG), both left and right auditory cortex showed increased activation in the noise conditions relative to quiet, including the middle portion of STG (mSTG). Although the right posterior STG (pSTG) showed similar activation for the 2 noise conditions, the left pSTG showed increased activation in the SNR −5 dB condition relative to the SNR 20 dB condition.

Conclusion

We found cortical task-independent and noise-dependent effects concerning speech perception in noise involving bilateral mSTG and left pSTG. These results likely reflect demands in acoustic analysis, auditory–motor integration, and phonological memory, as well as auditory attention.
Silicon nanowires for rechargeable lithium-ion battery anodes
Authors: Peng Kuiqing , Jie Jiansheng , Zhang Wenjun , Lee Shuit-Tong
Published: July 2008

Large-area, wafer-scale silicon nanowire arrays prepared by metal-induced chemical etching are shown as promising scalable anode materials for rechargeable lithium battery. In addition to being low cost, large area, and easy to prepare, the electroless-etched silicon nanowires (SiNWs) have good conductivity and nanometer-scale rough surfaces; both features facilitate charge transport and insertion/extraction of Li ions. The electroless-etched SiNWs anode showed larger charge capacity and longer cycling stability than the conventional planar-polished Si wafer.
Carbon chains of type C2n+1N− (n=2–6): A theoretical study of potential interstellar anions
Authors: Botschwina Peter , Oswald Rainer
Published: July 2008

Linear anions of type C2n+1N− (n=2–6), which are expected to be good candidates for experimental investigation by microwave spectroscopy and radio astronomy, were studied by means of the coupled cluster variant CCSD(T). Making use of corrections taken over from HC3N∕C3N− and HC5N, accurate equilibrium structures (∼0.0005Å accuracy in bond lengths) have been established for all five anions. The electric dipole moments increase strongly with increasing chain length. For C13N−, a very large equilibrium dipole moment of 16.53D (with respect to center-of-mass coordinate system, negative end of dipole at terminal carbon site) is predicted. The lowest vertical detachment energies, leading to Σ2 states of the radicals for C3N− and C5N− and to Π2 states in the case of the larger anions, are calculated to lie in the range of 4.40–4.63eV. The ground-state rotational and quartic centrifugal distortion constants of C5N− are predicted to be 1389.4MHz and 33.8Hz, respectively. All anions studied appear to be fairly normal semirigid linear molecules. Throughout, good agreement with available matrix isolation IR spectroscopic data is obtained and many predictions of spectroscopic properties are made.