bluuebunny/crossref_metadata_2025 huggingface dataset:
The Advanced Dvorak Technique: Continued Development of an Objective Scheme to Estimate Tropical Cyclone Intensity Using Geostationary Infrared Satellite Imagery
Authors: Olander Timothy L. , Velden Christopher S.
Published: April 2007

Tropical cyclones are becoming an increasing menace to society as populations grow in coastal regions. Forecasting the intensity of these often-temperamental weather systems can be a real challenge, especially if the true intensity at the forecast time is not well known. To address this issue, techniques to accurately estimate tropical cyclone intensity from satellites are a natural goal because in situ observations over the vast oceanic basins are scarce. The most widely utilized satellite-based method to estimate tropical cyclone intensity is the Dvorak technique, a partially subjective scheme that has been employed operationally at tropical forecast centers around the world for over 30 yr. With the recent advent of improved satellite sensors, the rapid advances in computing capacity, and accumulated experience with the behavioral characteristics of the Dvorak technique, the development of a fully automated, computer-based objective scheme to derive tropical cyclone intensity has become possible.

In this paper the advanced Dvorak technique is introduced, which, as its name implies, is a derivative of the original Dvorak technique. The advanced Dvorak technique builds on the basic conceptual model and empirically derived rules of the original Dvorak technique, but advances the science and applicability in an automated environment that does not require human intervention. The algorithm is the culmination of a body of research that includes the objective Dvorak technique (ODT) and advanced objective Dvorak technique (AODT) developed at the University of Wisconsin—Madison’s Cooperative Institute for Meteorological Satellite Studies. The ODT could only be applied to storms that possessed a minimum intensity of hurricane/typhoon strength. In addition, the ODT still required a storm center location to be manually selected by an analyst prior to algorithm execution. These issues were the primary motivations for the continued advancement of the algorithm (AODT). While these two objective schemes had as their primary goal to simply achieve the basic functionality and performance of the Dvorak technique in a computer-driven environment, the advanced Dvorak technique exceeds the boundaries of the original Dvorak technique through modifications based on rigorous statistical and empirical analysis. It is shown that the accuracy of the advanced Dvorak technique is statistically competitive with the original Dvorak technique, and can provide objective tropical cyclone intensity guidance for systems in all global basins.
Mesoscale Aspects of the Rapid Intensification of a Tornadic Convective Line across Central Florida: 22–23 February 1998
Authors: Wasula Alicia C. , Bosart Lance F. , Schneider Russell , Weiss Steven J. , Johns Robert H. , Manikin Geoffrey S. , Welsh Patrick
Published: April 2007

The 22–23 February 1998 central Florida tornado outbreak was one of the deadliest and costliest in Florida’s history; a number of long-track tornadoes moved across the Florida peninsula after 0000 UTC 23 February 1998. In the 12–24 h prior to 0000 UTC 23 February, a vigorous upper-level synoptic system was tracking across the southeast United States, and a north–south-oriented convective band located ahead of the cold front was moving eastward across the Gulf of Mexico. Strong vertical wind shear was present in the lowest 1 km, due to a ∼25 m s−1 low-level jet at 925 hPa and south-southeasterly surface flow over the Florida peninsula. Further, CAPE values across the central Florida peninsula exceeded 2500 J kg−1. Upon making landfall on the Florida peninsula, the convective band rapidly intensified and developed into a line of tornadic supercells. This paper examines the relationship between a diabatically induced front across the central Florida peninsula and the rapid development of tornadic supercells in the convective band after 0000 UTC 23 February. Results suggest that persistent strong frontogenesis helped to maintain the front and enhanced ascent in the warm, moist unstable air to the south of the east–west-oriented front on the Florida peninsula, thus allowing the updrafts to rapidly intensify as they made landfall. Further, surface observations from three key locations along the surface front suggest that a mesolow moved eastward along the front just prior to the time when supercells developed. It is hypothesized that the eastward-moving mesolow may have caused the winds in the warm air to the south of the surface front to back to southeasterly and create a favorable low-level wind profile in which supercells could rapidly develop.
An Alert Classification System for Monitoring and Assessing the ENSO Cycle
Authors: Kousky V. E. , Higgins R. W.
Published: April 2007

An alert classification system for the ENSO cycle is introduced. The system includes watches, advisories, and a five-class intensity scale for warm and cold phases of the ENSO cycle. A watch is issued when conditions are favorable for the formation of an El Niño or La Niña within the next 6 months. An advisory is issued when El Niño or La Niña conditions are present, based on NOAA’s operational definitions. The intensity scale, referred to as the ENSO Intensity Scale (EIS), is used for operational and retrospective assessments of the intensity of warm (El Niño) and cold (La Niña) episodes, without being prescriptive concerning ENSO-related anomalies or impacts. The Climate Prediction Center’s (CPC’s) monthly Climate Diagnostics Bulletin and ENSO Diagnostic Discussions will serve as the primary vehicles for disseminating real-time information concerning the ENSO alert status to the scientific community and public at large. An objective method that relates the EIS to anomalies is used to assess the effects of warm and cold episodes. The method is illustrated using precipitation in the global Tropics and subtropics and in the conterminous United States. The methodology is quite general and can be used to relate the ENSO cycle to other quantities.
Radar Signatures of Tropical Cyclone Tornadoes in Central North Carolina
Authors: Schneider Douglas , Sharp Scott
Published: April 2007

During the tropical cyclone season of 2004, there were four tropical cyclones that spawned tornadoes in central North Carolina: Frances, Gaston, Ivan, and Jeanne. This study examines the environmental characteristics and radar signatures from these events. The tornado warning decision-making process is a difficult one during any severe weather event, but it is even more difficult in a tropical cyclone environment because of the subtlety of features and rapid tornadogenesis that can occur. Previous studies that have examined the characteristics of a tropical cyclone environment found that high low-level moisture content, high shear, and a midlevel intrusion of dry air are favorable for tornadoes. The tropical cyclones that are examined in the current study all exhibited these characteristics. Radar signatures associated with these tornadoes were more subtle and weaker when compared with nontropical cyclone tornadoes, but were still discernable. This study analyzed the radar signatures from tornadic and nontornadic storms in a tropical cyclone environment with the purpose of determining the best indicators of tornadogenesis. Three precursors were found to give good lead time for tornado touchdowns: 1) a near gate-to-gate mesocyclone rotational velocity of 20 kt (10.3 m s−1) or greater, 2) a hook or appendage signature in the reflectivity data, and 3) the presence of a velocity enhancement signature of 30 kt (15.4 m s−1) or greater between 7000 ft (2.1 km) and 14 000 ft (4.2 km) AGL. Using these signatures together in the tornado warning decision-making process can increase lead time and accuracy in the tropical cyclone environment.
Summer Rainfall Forecast Spread in an Ensemble Initialized with Different Soil Moisture Analyses
Authors: Aligo Eric A. , Gallus William A. , Segal Moti
Published: April 2007

The performance of an ensemble forecasting system initialized using varied soil moisture alone has been evaluated for rainfall forecasts of six warm season convective cases. Ten different soil moisture analyses were used as initial conditions in the ensemble, which used the Weather Research and Forecasting (WRF) Advanced Research WRF (ARW) model at 4-km horizontal grid spacing with explicit rainfall. Soil moisture analyses from the suite of National Weather Service operational models—the Rapid Update Cycle, the North American Model (formerly known as the Eta Model), and the Global Forecasting System—were used to design the 10-member ensemble. For added insight, two other runs with extremely low and high soil moistures were included in this study. Although the sensitivity of simulated 24-h rainfall to soil moisture was occasionally substantial in both weakly forced and strongly forced cases, a U-shaped rank histogram indicated insufficient spread in the 10-member ensemble. This result suggests that ensemble forecast systems using soil moisture perturbations alone might not add enough variability to rainfall forecasts. Perturbations to both atmospheric initial conditions and land surface initial conditions as well as perturbations to other aspects of model physics may increase forecast spread. Correspondence ratio values for the 0.01- and 0.5-in. rainfall thresholds imply some spread in the soil moisture ensemble, but mainly in the weakly forced cases. Relative operating characteristic curves for the 10-member ensemble and for various rainfall thresholds indicate modest skill for all thresholds with the most skill associated with the lowest rainfall threshold, a result typical of warm season events.
The Impact of 9/11 on Organizational Development Among State and Local Law Enforcement Agencies
Authors: Marks Daniel E. , Sun Ivan Y.
Published: April 2007

This study examines the impact of the 9/11 terrorist attacks on organizational development of American state and local law enforcement agencies. Content analyses of police discourse in two practitioner magazines spanning from 1999 to 2004 are used to determine specific organizational changes that have been triggered by 9/11. Findings from our analyses indicate that changes have occurred and continue to develop mainly in organizational structures and processes. Changes in internal structures, such as the creation of a counterterrorism unit, tend to occur only in larger metropolitan and state police agencies. Changes in organizational processes or operations tend to be far more universal and typically involve an increased collaboration among police departments, specifically greater openness toward information sharing. Implications for future research are discussed.
Eating Difference
Authors: Germann Molz Jennie
Published: April 2007

This article examines the intersecting mobilities that are involved in culinary tourism. The term culinary tourism refers to practices of exploratory eating, especially in which unfamiliar foods are seen as an encounter with Otherness. Through an analysis of the travel narratives recounted by travelers in their Web sites and interviews, the article speculates on the material relations among food, travelers' bodies, and consumption of “the global.” In “eating the Other” while on the move, these travelers are consuming not only the differences between their own White, Western culture and other cultures but also the differences among various Others. Culinary tourism is not necessarily about knowing or experiencing another culture but about performing a sense of adventure, adaptability, and openness to any other culture. Food and eating are mobilized as material symbols of the global in travelers' performances of cosmopolitanism through which travelers simultaneously transgress and reinforce their own culture's norms.
Influence of grinding on graphite crystallinity from experimental and natural data: implications for graphite thermometry and sample preparation
Authors: Crespo E. , Luque F. J. , Barrenechea J. F. , Rodas M.
Published: April 2007

This paper examines the effects of shear stress on the structural parameters that define the ‘crystallinity’ of graphite. The results show that highly crystalline graphite samples ground for up to 120 min do not undergo detectable changes in the three-dimensional arrangement of carbon layers but crystallite sizes (Lc and La) decrease consistently with increasing grinding time. Grinding also involves particle-size diminution that results in lower temperatures for the beginning of combustion and exothermic maxima in the differential thermal analysis curves. These changes in the structural and thermal characteristics of graphite upon grinding must be taken into account when such data are used for geothermometric estimations.

Tectonic shear stress also induces reduction of the particle size and the Lc and La values of highly crystalline graphite. Thus, the temperature of formation of graphite according to structural as well as thermal data is underestimated by up to 100°C in samples that underwent the most intense shear stress. Therefore, application of graphite geothermometry to fluid-deposited veins where graphite is the only mineral found should take into consideration the effect of tectonic shearing, or the estimated temperatures must be considered as minimum temperatures of formation only.
A mechanism for the formation of the mineralized Mn deposits at Merehead Quarry, Cranmore, Somerset, England
Authors: Turner R.
Published: April 2007

Mississippi Valley type galena deposits emplaced into Carboniferous limestones throughout the Mendip Hills during the late Permian or Triassic period were locally exposed to the action of seawater during the Jurassic period following regional uplift and erosion of the intervening strata. Oxidation of galena initiated the deposition of manganate minerals from the seawater, and these adsorbed heavy metals from both the seawater and local environment. A subsequent hydrothermal event heated the lead-manganate deposits causing decomposition of the galena and creating the conditions which led to the formation of the suite of unusual secondary minerals – including a number of rare oxychlorides – now found at Merehead. Heating of the manganate phases converted them to Mn oxides and released the entrained heavy metals which were then incorporated into unusual mineral phases. The impervious Mn oxide coating which enclosed the cooling Pb-rich areas isolated them chemically, leading to closed-system behaviour. The high-T phases at Merehead are similar to those found in the Pb-bearing silicic skarns at Långban, whilst the suite of secondary minerals which evolved in the closed-system environments bears striking similarities to the ‘anomalous sequence’ of minerals found at the Mammoth-St. Antony Mine. The complexity of these formation processes probably explains the rarity of Mendip-type Pb-Mn deposits. The collective importance of the disconformity, the hydrothermal event, and subsequent sealing of the deposits are recognized for the first time, and the temperature of the hydrothermal event is shown to have been much greater than has heretofore been realized. Silurian volcanic strata underlying the Carboniferous limestones which have previously been assumed to be the source of heavy metals are shown to have been uninvolved in the process.
Fe(II)/Fe(III) ‘green rust’ developed within ochreous coal mine drainage sediment in South Wales, UK
Authors: Bearcock J. M. , Perkins W. T. , Dinelli E. , Wade S. C.
Published: April 2007

‘Green rusts’ are a group of reduced Fe hydroxides with a pyroaurite-like structure. In a new occurrence, green rust is present as a 45–60 mm thick band which lies just below the surface (∼4 mm) of an ochreous deposit at an abandoned coal mine site. The sample is characterized by the presence of μm-sized hexagonal crystals which have been identified from SEM imaging. Chemical analyses reveal an Fe(II):Fe(III) ratio which is close to the characteristic 2:1 ratio, and XRD analysis identifies the material by characteristic lattice spacings. The green rust layer also contains aragonite which is not present in the surrounding ochre. Green rusts are important as they have the potential to be used in water treatment.
The C-MYB locus is involved in chromosomal translocation and genomic duplications in human T-cell acute leukemia (T-ALL), the translocation defining a new T-ALL subtype in very young children
Authors: Clappier Emmanuelle , Cuccuini Wendy , Kalota Anna , Crinquette Antoine , Cayuela Jean-Michel , Dik Willem A. , Langerak Anton W. , Montpellier Bertrand , Nadel Bertrand , Walrafen Pierre , Delattre Olivier , Aurias Alain , Leblanc Thierry , Dombret Hervé , Gewirtz Alan M. , Baruchel André , Sigaux François , Soulier Jean
Published: April 2007

The C-Myb transcription factor is essential for hematopoiesis, including in the T-cell lineage. The C-Myb locus is a common site of retroviral insertional mutagenesis, however no recurrent genomic involvement has been reported in human malignancies. Here, we identified 2 types of genomic alterations involving the C-MYB locus at 6q23 in human T-cell acute leukemia (T-ALL). First, we found a reciprocal translocation, t(6;7)(q23;q34), that juxtaposed the TCRB and C-MYB loci (n = 6 cases). Second, a genome-wide copy-number analysis by array-based comparative genomic hybridization (array-CGH) identified short somatic duplications that include C-MYB (MYBdup, n = 13 cases of 84 T-ALL, 15%). Expression analysis, including allele-specific approaches, showed stronger C-MYB expression in the MYB-rearranged cases compared with other T-ALLs, and a dramatically skewed C-MYB allele expression in the TCRB-MYB cases, which suggests that a translocation-driven deregulated expression may overcome a cellular attempt to down-regulate C-MYB. Strikingly, profiling of the T-ALLs by clinical, genomic, and large-scale gene expression analyses shows that the TCRB-MYB translocation defines a new T-ALL subtype associated with a very young age for T-cell leukemia (median, 2.2 years) and with a proliferation/mitosis expression signature. By contrast, the MYBdup alteration was associated with the previously defined T-ALL subtypes.
Constructing second‐order accurate confidence intervals for communalities in factor analysis
Authors: Ichikawa Masanori , Konishi Sadanori
Published: April 2007

In an effort to find accurate alternatives to the usual confidence intervals based on normal approximations, this paper compares four methods of generating second‐order accurate confidence intervals for non‐standardized and standardized communalities in exploratory factor analysis under the normality assumption. The methods to generate the intervals employ, respectively, the Cornish–Fisher expansion and the approximate bootstrap confidence (ABC), and the bootstrap‐t and the bias‐corrected and accelerated bootstrap (BCa). The former two are analytical and the latter two are numerical. Explicit expressions of the asymptotic bias and skewness of the communality estimators, used in the analytical methods, are derived. A Monte Carlo experiment reveals that the performance of central intervals based on normal approximations is a consequence of imbalance of miscoverage on the left‐ and right‐hand sides. The second‐order accurate intervals do not require symmetry around the point estimates of the usual intervals and achieve better balance, even when the sample size is not large. The behaviours of the second‐order accurate intervals were similar to each other, particularly for large sample sizes, and no method performed consistently better than the others.
Kant, cognitive psychotherapy, and the hardening of the categories
Authors: Nevid Jeffrey S.
Published: April 2007

Contemporary models of psychotherapy owe a considerable intellectual debt to philosophy, even though the contributions of philosophers to contemporary practice in the field often go unrecognized. A case in point is Kant's epistemology, which is foundational to cognitive approaches to psychotherapy. Here, it is argued that the rigid use of certain judgments represented in Kant's conceptual scheme underlies patterns of distorted or dysfunctional thinking associated with emotional disorders. Kantian judgments of necessity, disjunction, particularity and universality have counterpoints in contemporary conceptions of cognitive distortions. Moreover, Kantian epistemology has important therapeutic implications with respect to helping people with emotional disorders recognize and challenge rigidly held judgments or categories of understanding. The Kantian perspective also leads us to consider the cognitive frameworks or thought structures that underlie dysfunctional thinking patterns.
Upper-Limb Botulinum Toxin A Injection and Occupational Therapy in Children With Hemiplegic Cerebral Palsy Identified From a Population Register: A Single-Blind, Randomized, Controlled Trial
Authors: Russo Remo N. , Crotty Maria , Miller Michelle D. , Murchland Sonya , Flett Peter , Haan Eric
Published: April 2007

OBJECTIVES. The purpose of this work was to assess the effect of botulinum toxin A and occupational therapy compared with occupational therapy alone on body structure, activities participation, and self-perception in a sample of children (aged 3–16 years) with hemiplegic cerebral palsy recruited from a statewide register.

PATIENTS AND METHODS. Participants of this single-blind, randomized, controlled trial identified from a population-based cerebral palsy register received either an individually prescribed and localized injection of botulinum toxin A with 4 sessions of occupational therapy over 4 weeks (intervention) or occupational therapy alone (control). Outcomes were assessed from 2 domains of the World Health Organization International Classification of Functioning, Disability, and Health: body structure (Modified Ashworth Scale and Tardieu Scale) and activities participation (Assessment of Motor and Process Skills, Goal Attainment Scale, Pediatric Evaluation of Disability Inventory, and Pediatric Quality of Life Inventory). Self-perception was also measured.

RESULTS. All of the participants (intervention: n = 21; control: n = 22) provided data at baseline and 3 and 6 months. Mean age was 8.6 years; 23 were boys and 20 were girls. At 3 months, children allocated to receive the intervention performed significantly better in terms of body structure and activities participation. They reported improvements in self-perception for the global self-worth domain. At 6 months, the differences between the intervention and control groups persisted for the measures of body structure but not for activities participation or self-perception.

CONCLUSION. Botulinum toxin A injection combined with a low-intensity occupational therapy program achieves significant improvements in body structure, activity participation, and self-perception.
Cardiac disease in pregnancy. Part 2: acquired heart disease
Authors: Gelson Emily , Johnson Mark , Gatzoulis Michael , Abselm Uebing
Published: April 2007

Key content

The incidence of both rheumatic and ischaemic heart disease is expected to increase in the UK because of changes in ethnicity and increasing maternal age.

Effective management of valvular heart lesions is based on the treatment of symptoms, with the option of balloon valvuloplasty and valve replacement.

Acute myocardial infarction poses a significant risk of maternal mortality and requires prompt treatment with heparin, beta‐blockers and nitrates.

Peripartum cardiomyopathy, although rare, is associated with significant maternal mortality and morbidity.

Learning objectives

To know about the causes of acquired heart disease in pregnancy.

To understand the general management principles for valvular heart lesions, ischaemic heart disease and cardiac arrhythmias when encountered during pregnancy.

Ethical issues

Warfarin is teratogenic if used in the first trimester. Is it ethical not to use it, knowing that it reduces the risk of valve thrombosis and maternal mortality?

Please cite this article as: Gelson E, Johnson M, Gatzoulis M, Uebing A. Cardiac disease in pregnancy. Part 2: acquired heart disease. The Obstetrician & Gynaecologist 2007;9:83–87.
Modern management of miscarriage
Authors: Sagili Haritha , Divers Mike
Published: April 2007

Key content

• Miscarriage has traditionally been treated by surgical evacuation, on the assumption that any retained tissue increases the risk of infection and haemorrhage.

• Over the last decade, effective non‐surgical alternatives have been advocated to minimise unnecessary surgical intervention while maintaining low rates of morbidity and mortality.

• Improved access to early pregnancy assessment units and greater awareness among women has led to increasing demand for more conservative management of miscarriage.

Learning objectives

• To learn about the use of appropriate miscarriage terminology.

• To learn about the advantages and disadvantages of expectant, medical and surgical management.

• To understand that women's choice is paramount in planning treatment.

Ethical issues

• Guidance on the sensitive disposal of fetal remains is essential.

Please cite this article as: Sagili H, Divers M. Modern management of miscarriage. The Obstetrician & Gynaecologist 2007;9:102–108.
Health technology assessment in obstetrics and gynaecology. Part 1: an overview of the process
Authors: Abedin Parveen , Daniels Jane , Khan Khalid S
Published: April 2007

Key content

A health technology is any method used to promote health; diagnose, prevent or treat disease; or improve long‐term rehabilitation and care.

Systematic reviews are summaries of the total evidence on a defined subject, using explicit techniques and critical appraisal of the relevant primary research to generate recommendations for practice and policy.

‘Bias’ exaggerates or underestimates the true effect of an intervention or exposure. There are several possible types of bias such as selection, performance, measurement and attrition.

Learning objectives

To learn about the role of health technology assessments (HTAs) in the formulation of health policy and the adoption of new technologies.

To understand the methodology involved in conducting systematic reviews and economic evaluations in HTA.

To learn about the role of institutions (for example, NICE) in utilising HTA to formulate health policy.

Ethical issues

Systematic reviews are the highest level of evidence as they incorporate the results of multiple studies but can be biased if individual studies are not published.

Meta‐analysis should only be conducted when there is sufficient heterogeneity (decided by statistical tests) between the studies under consideration in a systematic review.

The investigators in a clinical trial should be transparent in any shortcomings of conduct or design that can question the conclusions.

Please cite this article as: Abedin P, Daniels JP, Khan KS. Health technology assessment in obstetrics and gynaecology. Part 1: an overview of the process. The Obstetrician & Gynaecologist 2007;9:109–115.
Obstetric haemorrhage at Queen Charlotte's and Chelsea Hospital
Authors: Paterson‐Brown Sara
Published: April 2007

Key content

Obstetric haemorrhage complicates 10% of pregnancies globally.

There is a 1% case mortality rate.

It is the leading cause of maternal death worldwide, accounting for over a quarter of all direct deaths.

In the United Kingdom, death from obstetric haemorrhage is 100 times less common than in developing countries, but this is rising. It is unclear whether more women are bleeding or whether standards of care are falling.

Learning objectives

To be aware of the risk factors for obstetric haemorrhage and why they are increasing.

To learn about how detailed systematic audit of cases of massive obstetric haemorrhage, together with staff feedback, can improve and maintain standards of care.

To learn how multidisciplinary training in the local workplace can help staff to manage this condition and promote teamwork.

Ethical issues

How anonymous, systematic audit of patient details can benefit future patients.

Please cite this article as: Paterson‐Brown S. Obstetric haemorrhage at Queen Charlotte's and Chelsea Hospital. The Obstetrician & Gynaecologist 2007;9:116–120.
Depth‐ and viewing‐angle‐enhanced 3‐D/2‐D switchable display system with high contrast ratio using multiple display devices and a lens array
Authors: Choi Heejin , Kim Yunhee , Kim Joohwan , Cho Seong‐Woo , Lee Byoungho
Published: April 2007

Abstract— An improved 3‐D/2‐D switchable display system with enhanced depth and viewing angle by adding two LCD panels to an integral imaging system has been realized. The proposed system uses the see‐through property of an LCD panel and displays multiple sets of elemental images on the LCD panels to integrate them on multiple locations simultaneously. As a result, the depth of the 3‐D image can be enhanced. For wide viewing angles, the time‐multiplexing method was adopted by displaying mask patterns on the front LCD panel. In addition, another technique to increase the contrast ratio of the proposed system has also been developed. Some experimental results will be provided.
Electronic Portfolios in a Teacher Education Program
Authors: Wray Susan
Published: April 2007

While much of the research literature focuses on the traditional paper and pencil format of teaching portfolios, the increased integration of electronic technology into teacher preparation curricula has propelled the use of electronic portfolios for a range of evaluative purposes. Electronic portfolios, or e-portfolios as they are commonly labeled, are similar in many respects to paper and pencil format portfolios in terms of content and alignment with a pre-designated purpose, and the artifacts included in the portfolio usually represent a variety of experiences over time. However, characteristics specific to e-portfolios are many and important to address when considering their effective implementation. This article discusses the benefits and challenges specific to implementing electronic portfolios within a teacher education program. Suggestions for navigating key aspects of planning, implementation, and assessment are also included.
A New View: Reflection and Student Teacher Growth through an E-Practicum Model
Authors: Holstrom Lisa , Ruiz Donna , Weller Gerry
Published: April 2007

This article explores innovations in assessment of student teaching practice employed in the University of Cincinnati, USA, online associate's degree in early childhood education, the Early Childhood Learning Community. The program's components are identified with a specific focus on assessment of teaching practicum. The use of a range of information technologies, including video, is discussed, and evaluated through the voices of participating students. Student feedback shows the importance of integrating video and conference calling into an effective e-practicum model that provides self, mentor, and faculty evaluation of student teaching practice in a distance education program.
Detection of ultrasonic cavitation based on low-frequency analysis of acoustic signal
Authors: Brabec Kamil , Mornstein Vojtĕch
Published: April 2007

The acoustic cavitation phenomenon constitutes a potential hazard in ultrasound diagnostics and therapy so that early and effective detection of cavitation is of great interest. However, cavitation might even bring a higher risk especially when an echocontrast agent based on microbubbles is used. The major goal of the present work was to develop a cavitation detection method based on increased level of cavitation noise in the range of low frequencies (about 1 Hz). This method was applied in vitro using a model of body fluid containing a model echocontrast agent, such as 5% solution of lyophilized egg albumin, which was sonicated by ultrasound disintegrator. Ultrasound signal evokes cavitation in microbubble suspension accompanied by a certain level of cavitation acoustic noise. The level of noise voltage increased in the frequency range of 0.1 to 2 Hz in the presence of cavitation. Hence, this method makes it possible to determine the value of cavitation threshold. In addition, we examined how the cavitation threshold is affected by temperature and viscosity. It was found that the cavitation threshold decreased with growing temperature while it increased with growing viscosity.
New data on the morphology of Comephoronema oschmarini (Nematoda, Cystidicolidae), a little-known gastrointestinal parasite of Lota lota (Teleostei) in Palaearctic Eurasia
Authors: Moravec František , Hanzelová Vladimíra , Gerdeaux Daniel
Published: April 2007

The nematode Comephoronema oschmarini Trofimenko, 1974 (Cystidicolidae) was found in the stomach of the burbot Lota lota (Linnaeus) of Lake Geneva, Savoy, France, collected on 23 March 2000 [prevalence 60% (3/5); intensity of infection 2–66 (mean 35)]. This material made it possible to study in detail the morphology of this so far little-known parasite, using both light and scanning electron microscopy (the latter not previously used for this species). The SEM examination showed taxonomically important morphological features, not previously reported, including the presence of distinct terminal pseudolabial projections (protuberances), four submedian labia, four bilobed submedian sublabia, and only four cephalic papillae. Deirids were found to be bifurcated. A description of the true arrangement of the two last pairs of minute caudal papillae and phasmids in the male is given. Species of Compehoronema Layman, 1933 are considered to be closely related to those of Ascarophis van Beneden, 1871. A key to valid species of Comephoronema is provided.
Acrolein and Methacrolein
Authors: Arntz Dietrich , Fischer Achim , Höpp Mathias , Jacobi Sylvia , Sauer Jörg , Ohara Takashi , Sato Takahisa , Shimizu Noboru , Schwind Helmut
Published: April 2007

The article contains sections titled:1.Introduction2.Properties2.1.Physical Properties2.2.Chemical Properties3.Production3.1.Acrolein by Propene Oxidation3.2.Methacrolein4.Quality and Analysis5.Handling, Storage, and Transportation6.Uses and Production Data7.Toxicology and Ecotoxicology7.1.Toxicology7.2.Ecotoxicology

Acrolein is the simplest unsaturated aldehyde. It is an important intermediate in the production processes of a variety of substances. The main use of isolated acrolein is in the production ofd,l‐methionin, but in far more production processes, acrolein is used without purification. Acrolein is an extremely reactive chemical and, in very low concentrations, acts as a very effective broad‐spectrum biocide. Methacrolein is produced commercially as an organic intermediate, which is used as building block for chain expansions or, in limited application, in the synthesis of flavors and fragrances.
Aluminum Compounds, Inorganic
Authors: Helmboldt Otto , Keith Hudson L. , Misra Chanakya , Wefers Karl , Heck Wolfgang , Stark Hans , Danner Max , Rösch Norbert
Published: April 2007

The article contains sections titled:

1.Aluminum Sulfate and Alums1.1.Aluminum Sulfate1.1.1.Properties1.1.2.Production1.1.3.Uses1.2.Alums1.2.1.Potassium Aluminum Sulfate1.2.2.Ammonium Aluminum Sulfate1.2.3.Sodium Aluminum Sulfate2.Aluminates2.1.Sodium Aluminate2.2.Barium Aluminates3.Aluminum Alkoxides4.Aluminum Chloride4.1.Anhydrous Aluminum Chloride4.1.1.Properties4.1.2.Production4.1.3.Quality Specifications and Analysis4.1.4.Handling, Storage, and Transportation4.1.5.Uses4.2.Aluminum Chloride Hexahydrate4.3.Basic Aluminum Chlorides5.Toxicology
Amino Acids
Authors: Drauz Karlheinz , Grayson Ian , Kleemann Axel , Krimmer Hans‐Peter , Leuchtenberger Wolfgang , Weckbecker Christoph
Published: April 2007

The article contains sections titled:1.Introduction and History2.Properties2.1.Physical Properties and Structure2.2.Chemical Properties2.3.Important Amino Acids2.3.1.Proteinogenic Amino Acids2.3.2.Other Important Amino Acids3.Industrial Production of Amino Acids3.1.General Methods3.2.Production of Specific Amino Acids3.2.1.l‐Alanine3.2.2.l‐Arginine3.2.3.l‐Aspartic Acid and Asparagine3.2.4.l‐Cystine andl‐Cysteine3.2.5.l‐Glutamic Acid3.2.6.l‐Glutamine3.2.7.l‐Histidine3.2.8.l‐Hydroxyproline3.2.9.l‐Isoleucine3.2.10.l‐Leucine3.2.11.l‐Lysine3.2.12.d,l‐Methionine andl‐Methionine3.2.13.l‐Phenylalanine3.2.14.l‐Proline3.2.15.l‐Serine3.2.16.l‐Threonine3.2.17.l‐Tryptophan3.2.18.l‐Tyrosine3.2.19.l‐Valine4.Biochemical and Physiological Significance5.Uses5.1.Human Nutrition5.1.1.Supplementation5.1.2.Flavorings, Taste Enhancers, and Sweeteners5.1.3.Other Uses in Foodstuff Technology5.2.Animal Nutrition5.3.Pharmaceuticals5.3.1.Nutritive Agents5.3.2.Therapeutic Agents5.4.Cosmetics5.5.Agrochemicals5.5.1.Herbicides5.5.2.Fungicides5.5.3.Insecticides5.5.4.Plant Growth Regulators5.6.Industrial Uses6.Chemical Analysis7.Economic Significance8.Toxicology
Crystal Growth
Authors: Brice John C. , Rudolph Peter
Published: April 2007

The article contains sections titled:1.Introduction1.1.Historical Aspects1.2.Uses of Single Crystals1.3.Specification of Crystals1.4.Commercial Aspects1.5.Sources of Information2.Thermodynamic Aspects2.1.Free Energy and Driving Force of Crystallization2.2.Phase Relations for Major Components2.3.Phase Relations for Minor Components2.4.Interfacial Effects2.5.Shortcomings of the Thermodynamic Approach3.Growth Kinetics3.1.Atomic Structure of Growing Interfaces3.2.Rough Faces3.3.Perfect Singular Faces3.4.Imperfect Singular Faces4.Transport Effects4.1.Transport Processes4.2.Boundary Layers4.3.Mass Flow of Major Components4.4.Mass Flow of Minor Components4.5.Heat Flow4.6.Interface Stability5.Practical Considerations5.1.Raw Materials5.2.Temperature Control5.3.Containers and Atmospheres5.4.Selection and Optimization of Methods5.5.Characterization6.Melt Growth Techniques6.1.Crystal Pulling6.2.Bridgman Method6.3.Skull Melting Methods6.4.Zone Melting6.5.Verneuil Process7.Solution Growth Techniques7.1.General Aspects7.2.Low‐Temperature Methods7.3.High‐Temperature Methods7.4.Liquid‐Phase Epitaxy7.5.Electrolytic Methods7.6.Hydrothermal Growth8.Vapor Growth Techniques8.1.Sublimation and Evaporation Methods8.2.Molecular Beam Epitaxy8.3.Chemical Vapor Transport8.4.Vapor‐Liquid‐Solid Growth9.Solid‐Phase Growth Techniques9.1.Strain ‐ Anneal Method9.2.Methods Not Involving Applied Strain9.3.Solid‐Phase Epitaxy9.4.Gel Growth10.Trends

This article summarizes the theory and practice of the growth of single crystals. Today, the growth of crystals having dimensions of some hundred millimeters in diameter and weights over 200 kg under extreme pure conditions is well‐matured in industrial scale. The major user of the crystals is the electronics industry.

Growth of crystals demands theoretical knowledge of thermodynamics, kinetics, and transport processes. In practice, some general aspects have to be considered, including choice of raw materials, conditions, methods, and characterization. The industrial and laboratory techniques of crystal growth are discussed. Economical aspects dominate the developments in the future, that is, growing of larger crystals at higher quality to raise yields and device performance. Furthermore, the demand for tighter specifications and increasing range of materials and uses will require more sophisticated methods and an extensive use of automation.
Hydrogen Peroxide
Authors: Goor Gustaaf , Glenneberg Jürgen , Jacobi Sylvia
Published: April 2007

The article contains sections titled:

1.

Introduction and Historical Aspects

2.

Physical Properties

3.

Chemical Properties

4.

Production

4.1.

Anthraquinone Process (AO Process)

4.1.1.

Principles

4.1.2.

Process Description

4.1.2.1.

Hydrogenation

4.1.2.2.

Oxidation

4.1.2.3.

Extraction and Drying

4.1.2.4.

Working Solution Purification and Regeneration

4.1.2.5.

Purification of Crude Hydrogen Peroxide

4.1.2.6.

Concentration of Hydrogen Peroxide

4.2.

2‐Propanol Process (Shell Process)

4.3.

Electrochemical Processes

4.3.1.

Degussa ‐ Weissenstein Process

4.3.2.

Münchner Process

4.4.

Other Processes

4.4.1.

Production from Peroxy Compounds

4.4.2.

Production from Hydrogen and Oxygen

4.4.3.

Production from Carbon Monoxide, Oxygen, and Water

4.4.4.

Production by Autoxidation of Organic Compounds

4.4.5.

Production by Cathodic Reduction of Oxygen

5.

Storage and Transportation

6.

Safety

7.

Uses

8.

Toxicology, Occupational Health, and Ecotoxicology

9.

Environmental Effects

9.1

Atmospheric Fate

9.2

Aquatic Fate

9.3

Biodegradation

9.4

Environmental Releases

9.5

Environmental Effects

This review deals with chemical and physical properties of hydrogen peroxide and gives detailed descriptions about the various production processes. Today, almost all hydrogen peroxide is produced by organic autoxidation processes, primarily the anthraquinone process. Other aspects in this review are handling, safety and usage of hydrogen peroxide. Hydrogen peroxide occurs naturally. Because of its chemical reactivity, hydrogen peroxide also has toxic properties. The formation and degradation of atmospheric hydrogen peroxide is photochemically mediated. Degradation of aquatic hydrogen peroxide is catalyzed by biological material or by transition metals. Toxicity data are collected for various organisms.
Automotive Fuels
Authors: Dabelstein Werner , Reglitzky Arno , Schütze Andrea , Reders Klaus
Published: April 2007

The article contains sections titled:1.History1.1.The Spark Ignition (Otto) Engine and Its Fuel1.2.The Diesel Engine and Its Fuel2.Engine Technology2.1.Otto Engines2.2.Diesel Engines3.Fuel Composition and Engine Efficiency3.1.Quality Aspects of Gasoline3.1.1.Octane Quality3.1.2.Volatility3.1.3.Fuel Composition to Reduce Toxicity and Exhaust Emissions3.1.4.Stability, Cleanliness, etc3.1.5.Performance Additives3.2.Quality Aspects of Diesel Fuels3.2.1.Ignition Quality3.2.2.Density3.2.3.Sulfur Content3.2.4.Cold Flow Properties3.2.5.Lubricity3.2.6.Viscosity3.2.7.Volatility3.2.8.Diesel Fuel Stability, Cleanliness, etc3.2.9.Diesel Fuel Effects on Exhaust Emissions3.2.10.Performance Additives4.Fuel Components4.1.Gasoline Components4.1.1.Straight‐Run Gasoline4.1.2.Thermally Cracked Gasoline4.1.3.Catalytically Cracked Gasoline4.1.4.Catalytic Reformate (Platformate)4.1.5.Isomerate4.1.6.Alkylate4.1.7.Polymer Gasoline4.1.8.Oxygenates4.2.Diesel Fuel Components4.2.1.Straight‐Run Middle Distillate4.2.2.Thermally Cracked Gas Oil4.2.3.Catalytically Cracked Gas Oil4.2.4.Hydrocracked Gas Oil4.2.5.Kerosene4.2.6.Synthetic Diesel Fuel5.Fuel Additives5.1.Gasoline Additives5.1.1.Corrosion Inhibitors5.1.2.Detergents5.1.3.Antioxidants5.1.4.Metal Deactivators5.1.5.Anti‐Icing Additives5.1.6.Additives for Combating Combustion Chamber Deposits5.1.7.Valve Seat Recession Protection Additives5.1.8.Antiknock Agents5.1.9.Dehazers and Antistatic Additives5.2.Additives for Diesel Fuel5.2.1.Ignition Improvers (Cetane Improvers)5.2.2.Detergent Additives5.2.3.Cold Flow Additives5.2.4.Lubricity Additives5.2.5.Antifoam Additives5.2.6.Additives for Increasing Storage Stability ‐ Antioxidants5.2.7.Dehazers5.2.8.Biocides5.2.9.Antistatic Additives5.2.10.Reodorants6.Fuel Standardization and Testing7.Storage and Transportation8.Alternative Fuels
Uranium, Uranium Alloys, and Uranium Compounds
Authors: Peehs Martin , Walter Thomas , Walter Sabine , Zemek Martin
Published: April 2007

The article contains sections titled:

1.Introduction2.History3.Physical Properties3.1.Radioactivity3.2.Modifications3.3.Mechanical Properties3.4.Thermal Properties3.5.Electrical and Electrochemical Properties3.6.Magnetic Properties4.Chemical Properties5.Occurrence, Requirement, and Production Figures5.1.Occurrence5.2.Resources, Requirement, and Production Figures6.Production6.1.Uses of Uranium and Uranium Compounds6.2.From Ore to End Product‐A Review of Processes6.2.1.From Crude Ore to Yellow Cake6.2.2.From Yellow Cake to UF66.2.3.From UF6to the Nuclear Fuel UO26.3.Detailed Description of the Processes6.3.1.Digestion and Leaching of Ores6.3.1.1.Acidic Ores6.3.1.2.Alkaline Ores6.3.1.3.Digestion of Phosphate Rock6.3.2.Treatment of the Liquor6.3.2.1.Uranium Recovery by Ion Exchange6.3.2.2.Uranium Recovery by Solvent Extraction6.3.2.3.Eluex Process6.3.3.Production of Uranium Ore Concentrate6.3.3.1.From Precipitation to Yellow Cake Production6.3.3.2.Processing of Phosphate Liquor and Precipitation of AUC6.3.4.Final Purification of Uranium Concentrate6.3.4.1.Dissolution of Yellow Cake6.3.4.2.Extractive Purification6.3.5.Production of UO3and UO2from Purified Uranyl Nitrate Solution6.3.5.1.Evaporation of Uranyl Nitrate Solution and Denitration by Thermal Decomposition6.3.5.2.Precipitation of Uranium by the ADU and AUC Processes6.3.5.3.Reduction of Precipitated Product to UO2Powder6.3.6.Production of UF46.3.6.1.Hydrofluorination of UO26.3.6.2.Hydration and Hydrofluorination of UO36.3.7.Production of UF6from UF46.3.7.1.Process Description6.3.7.2.Chemical Reactors6.3.7.3.Removal of Excess Fluorine from UF66.3.8.Complete Plant for Production of UF6from Uranyl Nitrate6.3.8.1.French Process in Pierrelatte6.3.8.2.Allied Chemical Process6.3.9.Enrichment of235U6.3.9.1.Diffusion Process6.3.9.2.Ultracentrifuges6.3.9.3.Nozzle Process6.3.9.4.Chemical Enrichment6.3.9.5.Laser Separation Process6.3.9.6.Plasma Processes6.3.10.Production of UO2Pellets from UF66.3.10.1.Conversion of UF6to UO26.3.10.2.Possible Future Developments in the Conversion of UF6to UO2Powder6.3.10.3.Pelletizing of UO2Powder6.3.11.Production of Uranium Metal6.3.11.1.Reduction of UF6to UF46.3.11.2.Reduction of UF4to Uranium Metal6.3.11.3.Production of Uranium Powder7.Uranium Alloys7.1.Classification7.2.Production of Important Alloys8.Uranium Compounds8.1.Halides8.1.1.Trivalent Halides8.1.2.Uranium Tetrahalides8.1.3.Uranium Pentafluoride8.1.4.Uranium Hexafluoride8.2.Carbides8.3.Nitrides8.4.Oxides8.4.1.Uranium Dioxide8.4.2.Uranium Trioxide8.4.3.Triuranium Octaoxide8.4.4.Peroxides8.5.Nitrates, Sulfates, and the Carbonato Complex8.5.1.Nitrates8.5.2.Sulfates8.5.3.Tricarbonatodioxouranate9.Safety9.1.Radiation Shielding9.2.Safety Against Uncontrolled Criticality9.3.Geometrically Safe Vessels9.4.Apparatus with Heterogeneous Neutron Absorbers9.5.Neutron Interactions in the UO2Fabrication Plant9.6.Transportation