bluuebunny/crossref_metadata_2025 huggingface dataset:
Extra‐departmental anatomic pathology expert consultation inTaiwan: A research grant supported 4‐year experience
Authors: Hsu Chih‐Yi , Su Ih‐Jen , Lin Ming‐Chieh , Kuo Tseng‐tong , Jung Shih‐Ming , Ho Donald Ming‐Tak
Published: January 2010

Background

This report analyzed a research project supported nationwide expert consultation of anatomic pathology in Taiwan.

Methods

The data were collected from the requisitions and consultation reports of 2,686 cases in this project from 2003 to 2006. The number of cases, tissue origin, additional special stains, turnaround time (TAT), concordance, discordance, referring pathologists, and consultants were analyzed.

Results

Skin, hematopoietic system, and bone and soft tissue were the most common (48.3%) specimens sent for consultation. The tentative diagnosis and consultation diagnosis were discordant in 1,074 (64.3%) cases. Major discrepancy was seen in 205 (12.3%) cases, of which 66.8% were changed from malignant to benign, 21.0% were changed from benign to malignant, whereas 12.2% were changed from one category of malignancy to another. Additional special stains were performed on 38.7% of cases and hematology specimen was the most frequent. The mean TAT was 3.4 days. Pathologists working in institutes having fewer pathologists sent more cases for consultation. The opinion of the estimated annual consultation rate from the pathologists in Taiwan was 0.7%.

Conclusions

This program was beneficial simply by helping the referring pathologists in the workup and diagnosis. This result made the entire program a reasonable quality improvement program. J. Surg. Oncol. 2010; 101:430–435. © 2010 Wiley‐Liss, Inc.
Paley‐Wiener estimates for the Heisenberg group
Authors: Führ Hartmut
Published: January 2010

The Paley‐Wiener space PW (G) on a stratified Lie group G is defined via the spectral decomposition of the associated sub‐Laplacian. In this paper, we show that functions in PW (ℍ), where ℍ denotes the Heisenberg group, extend to an entire function on the complexification ℍℂ, satisfying a growth estimate of exponential order two. We also show that a converse, characterizing elements of PW (ℍ) only in terms of pointwise growth behaviour of the entire extension, is not available (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interpolation properties of Besov spaces defined on metric spaces
Authors: Gogatishvili Amiran , Koskela Pekka , Shanmugalingam Nageswari
Published: January 2010

Let X = (X, d, μ)be a doubling metric measure space. For 0 < α < 1, 1 ≤p, q < ∞, we define semi‐norms
equation image
When q = ∞ the usual change from integral to supremum is made in the definition. The Besov space Bp, qα (X) is the set of those functions f in Llocp(X) for which the semi‐norm ‖f ‖ is finite. We will show that if a doubling metric measure space (X, d, μ) supports a (1, p)‐Poincaré inequality, then the Besov space Bp, qα (X) coincides with the real interpolation space (Lp (X), KS1, p(X))α, q, where KS1, p(X) is the Sobolev space defined by Korevaar and Schoen [15]. This results in (sharp) imbedding theorems. We further show that our definition of a Besov space is equivalent with the definition given by Bourdon and Pajot [3], and establish a trace theorem (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Variant sandwich pairs
Authors: Schechter Martin
Published: January 2010

Since the development of the calculus of variations there has been interest in finding critical points of functionals. This was intensified by the fact that for many equations arising in practice, the solutions are critical points. In searching for such points, there is a distinct advantage if the functional G is semibounded. In this case one can find a Palais‐Smale (PS) sequence
G (uk) → c, G ′(uk) → 0
or even a Cerami sequence
G (uk) → c, (1 + ‖uk ‖)G ′(uk) → 0.
These sequences produce critical points if they have convergent subsequences. However, there is no clear method of finding critical points of functionals which are not semibounded. Linking subsets do provide such a method. They can produce a PS sequence provided they separate the functional. In previous papers we have shown that there are pairs of subsets that can produce Cerami‐like sequences even though they do not separate the functional. We call such sets sandwich pairs. All that is required is that the functional be bounded from above on one ofthe sets and bounded from below on the other, with no relationship needed between the bounds. This provides a distinct advantage in applications. The present paper discusses the situation in which one cannot find linking subsets which separate the functional or sandwich pairs for which the functional is bounded below on one set and bounded above on the other. We develop a method which can deal with such situations. We apply the method to problems in partial differential equations (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Estimates for the uniform norm of complex polynomials in the unit disk
Authors: Fournier Richard , Letac Gérard , Ruscheweyh Stephan
Published: January 2010

Let ‖ · ‖ denote the uniform norm in the unit disk of the complex plane ℂ. The main result in this note is as follows: For any complex polynomial P of degree at most n and any α ∈ ℂ the inequality
‖P ‖ ⩽ (n + 1)(‖z P (z) + α ‖ ‐ |α |)
holds. For any α ≠ 0 the factor n + 1 is best possible, and we determine the cases of equality (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Searching for good mood: Examining relationships between search task and mood
Authors: Lopatovska Irene
Published: January 2010

We analyzed mood changes before, during and after online information search and examined effects of search tasks' type on the mood. Searchers' mood was measured using the Positive Affect and Negative Affect Scale (PANAS). Search tasks were characterized by the topic, sequence in a search process, difficulty level, and searcher's interest in a task. Our analysis indicates that participants' mood remained stable during the course of the search and was not affected by the search task topic, sequence in a search process, difficulty level and searchers' interest level. Our findings suggest that searching is a complex experience and factors outside of the search task domain may contribute to searcher's mood.
The development of students' information literacy and IT skills via inquiry PBL and collaborative teaching
Authors: Chu Samuel Kai Wah , Chow Ken , Tse Shek‐kam
Published: January 2010

Recent research has shown that inquiry‐based learning and project‐based learning (PBL) are better than the traditional didactic approach in promoting various learning outcomes. There is also a large literature on how collaboration among different teachers can enhance student learning. In Hong Kong, inquiry‐based learning has been integrated into the General Studies curriculum. This study investigated the effects of an intervention that used a collaborative teaching approach and inquiry project‐based learning on the development of primary students' information literacy and information technology skills. Students in a Hong Kong primary school completed two inquiry‐based group projects as part of their General Studies curriculum. A collaborative teaching approach involving three teachers with different specialties (Language [Chinese], IT, and General Studies) and a school librarian was taken in guiding students through the two projects. Results indicated the positive impact of collaborative teaching and inquiry PBL on the development of students' information literacy and IT skills.
Results of a factorial survey investigating the health information seeking behaviors of older adults
Authors: Stansbury Mary , Ludwick Ruth
Published: January 2010

This paper presents the results of research of an experimental research method, the factorial survey, investigating the health information seeking preferences of older adults (60 years and older). Volunteer subjects from rural, urban, and suburban areas in Ohio participated in this study; 450 subjects responded to health information seeking vignettes (the key feature of factorial surveys) and provided demographic data. Using regression analysis and ANOVA, findings from this study address preferences for the format of materials, information on particular health topics, and, preferences for receiving assistance from information providers such as librarians, nurses, pharmacists, and, doctors.
“A lot of people didn't have a chance to support us because we never told them” Stigma management, information poverty and HIV/AIDS information/help networks
Authors: Veinot Tiffany
Published: January 2010

Because of fears of stigmatization, people with HIV/AIDS (PHAs) may avoid health care and refuse illness‐related information and support. However, HIV/AIDS‐related information, especially that which is provided by other people, has also been shown to a vital resource for PHAs and their loved ones. This research examines the role of stigmatization in PHAs' and their friends/family members' efforts to establish personal networks for HIV/AIDS‐related information and help ("information/help networks"). To investigate this question, I draw upon Goffman's (1963) stigma management theory and Chatman's (1996) theory of information poverty. Semi‐structured, in‐depth interviews were conducted with 114 PHAs, their friends/family members, health care and service providers in three rural regions of Canada. Results revealed that the majority of PHAs and friends/family members had relatively small networks for HIV/AIDS information/help. For many participants, the challenges of living with HIV/AIDS led to changes in their personal networks, and stigmatization playing a significant part in such changes. Participants developed information/help networks in a manner consistent with stigma management theory in their decisions to disclose selectively to others, to avoid the topic in conversation, to obtain information/help at a distance or to acquire information/help without disclosing their HIV status. However, in contrast to Chatman's theory, participants did not wholly avoid information from interpersonal sources nor believe that no one was available to help them. These findings suggest that information behaviour theory may need to evolve in order to account for the complexity of self‐protective behaviour.
Towards a cross‐disciplinary notion of data level in data curation
Authors: Renear Allen H. , Dolan Molly , Trainor Kevin , Cragin Melissa H.
Published: January 2010

Originally focused on scientific data, the data curation community is now taking up the curation problems of humanities data as well. Sharing concepts and terminology across these domains should be valuable for both the practice of data curation, and the education of data curation professionals. To convene a discussion of the possibilities we outline an exercise mapping NASA's well‐known four “data levels” to practices and concepts in traditional textual criticism.
Web analytics in library practice: Exploration of issues
Authors: Paul Anindita , Erdelez Sanda
Published: January 2010

This study examines the use of web analytics in libraries to understand how this tool can be used to interpret users' behavior on the library's website. Evaluating library and information services is important for library management decision‐making regarding the quality of library services. Because such decisions‐making is time consuming and requires investment of many resources, libraries are constantly looking for efficient approaches that would provide insights into planning and changes to the library services. The study data consist of reports collected by Google analytics on the University of Missouri's (MU) library website and interactive group interviews with the library's usability committee. The poster presents the preliminary findings and discusses the issues of implementing web analytics in a library setting. The study findings would benefit libraries in understanding how web analytics can be used as an evaluation tool for libraries, especially as an addition to the traditional evaluation tools.
Evidence of a new and evolving discipline: Neuroethics literature, 2002–2007
Authors: Comerford Kevin , Rasmussen Edie , Illes Judy
Published: January 2010

The current study applies bibliometric techniques to the study of the emerging field of Neuroethics, which saw its official formation only seven years ago, in 2002. The object of Neuroethics as a discipline is to understand the impact that neuroscience and neurotechnology have on both the medical professions and society in general. The first goal of the studyis to identify and characterize the core literature of Neuroethics as it exists today; this segment of the research has been completed. The second goal of the studyis to track the gradual infusion of Neuroethics ideas into the general literature of Medical Ethics and Bioethics; this phase of the reseach is in progress.
Viral video: Describing online multimedia information flows
Authors: Goodrum Abby , Devereaux Zachary , Smith Andrew
Published: January 2010

This paper examines why certain videos go viral while other languish and die. To answer this question metadata associated with YouTube videos was collected (over the course of three separate weeks in 2009) and analyzed. The results show that virality is intimately connected to how one defines popularity, as different components of the metadata highlight the importance of different sets of videos over time. For this reason different elements of the metadata are explored and examples are given from the dataset that indicate popularity.
User interface for FRBR user tasks in online catalogs
Authors: Zhang Yin , Salaba Athena
Published: January 2010

Functional Requirements for Bibliographic Records (FRBR) is a new conceptual model for representing the bibliographic universe with a strong user focus. Such a user focus offers opportunities for creating online catalogs that better support user information seeking. There have been a few online catalogs developed to explore effective implementations of FRBR. However, there has been a lack of user research of such prototype online catalogs. The major purpose of this study is to explore how well current FRBR‐based catalogs support user tasks as defined by FRBR and how users interact with and evaluate the user interfaces in the FRBR‐based catalogs. The FRBR‐based online catalogs selected in this study include OCLC WorldCat.org, FictionFinder, and Libraries Australias FRBR prototype demonstration system. These three catalogs were evaluated by 75 users from both public libraries (40 participants) and academic libraries (35 participants). The user tasks for this study were designed around the four general user task categories as defined by FRBR. Users system interactions and feedback were captured through a multi‐method approach, including screen captures, eye‐tracking, think‐aloud protocol, and survey interviews, as well as two focus groups of academic and public library users. Some preliminary findings show that there were noted differences in user success in completing various tasks in the FRBR‐based catalogs. In terms of user interactions with the interface features provided in the catalogs, users chose different options for various tasks. The eye‐tracking data and user input on interface features provided some helpful explanations to the user interactions and pointed to useful features and possible improvements of the individual catalog interfaces. The results of this study will help identify useful interface options for future FRBR implementation and contribute toward the development of more effective online catalogs that support various user tasks from users perspectives.
Integrating strong and weak discontinuities without integration subcells and example applications in an XFEM/GFEM framework
Authors: Natarajan Sundararajan , Mahapatra D. Roy , Bordas Stéphane P. A.
Published: January 2010

Partition of unity methods, such as the extended finite element method, allows discontinuities to be simulated independently of the mesh (Int. J. Numer. Meth. Engng. 1999; 45:601–620). This eliminates the need for the mesh to be aligned with the discontinuity or cumbersome re‐meshing, as the discontinuity evolves. However, to compute the stiffness matrix of the elements intersected by the discontinuity, a subdivision of the elements into quadrature subcells aligned with the discontinuity is commonly adopted. In this paper, we use a simple integration technique, proposed for polygonal domains (Int. J. Numer. Meth. Engng 2009; 80(1):103–134. DOI: 10.1002/nme.2589) to suppress the need for element subdivision. Numerical results presented for a few benchmark problems in the context of linear elastic fracture mechanics and a multi‐material problem show that the proposed method yields accurate results. Owing to its simplicity, the proposed integration technique can be easily integrated in any existing code. Copyright © 2010 John Wiley & Sons, Ltd.
Prevalence and predictors of anti‐infective use during pregnancy
Authors: Santos Fabiano , Oraichi Driss , Bérard Anick
Published: January 2010

Purposes

(1) Measure the prevalence and trends of anti‐infective drug use before, during, and after pregnancy; (2) to list the doses, classes, types, and indications for anti‐infective use during pregnancy; and (3) to identify predictors associated with anti‐infective drug use during pregnancy.

Methods

Retrospective cohort study within the Quebec Pregnancy Registry, which was created by the linkage of three administrative databases: RAMQ, Méd‐Echo, and ISQ. Women were eligible if they were (1) continuously insured by the RAMQ drug plan for at least 12 months before the first day of gestation, during pregnancy and 12 months after the end of the pregnancy and (2) if they gave birth to a live born between January 1998 and December 2003. Ninety‐seven thousand six hundred and eighty pregnant women met the eligibility criteria. Data were collected for systemic agents. Logistic regression models were used to quantify predictors of use.

Results

Prevalence of anti‐infective use during pregnancy was 24.5%. Penicillins use increased compared to other classes. The most frequently diagnosed infections were respiratory and urinary tract infections. Predictors associated with use at the beginning of gestation were having ≥2 different prescribers [OR = 3.83 (95% confidence interval 95%CI: 3.3–4.3)], diagnosis of urinary [OR = 1.50 (95%CI: 1.3–1.8)], and respiratory tract infection [OR = 1.40 (95%CI: 1.2–1.6)] in the year before pregnancy. Visits to an obstetrician/gynecologist were protective for use [OR = 0.81 (95%CI: 0.67–0.97)].

Conclusion

Anti‐infective use during pregnancy is prevalent. The oldest and safest agents are preferred. Copyright © 2010 John Wiley & Sons, Ltd.
Using a family systems approach to investigate cancer risk communication within melanoma families
Authors: Harris Julie N. , Hay Jennifer , Kuniyuki Alan , Asgari Maryam M. , Press Nancy , Bowen Deborah J.
Published: January 2010

Objective: The family provides an important communication nexus for information and support exchange about family cancer history, and adoption of family‐wide cancer risk reduction strategies. The goals of this study were to (1) use the family systems theory to identify characteristics of this sample of families at increased risk of developing melanoma and (2) to relate familial characteristics to the frequency and style of familial risk communication.

Methods: Participants were first‐degree relatives (n=313) of melanoma patients, recruited into a family web‐based intervention study. We used multivariable logistic regression models to analyze the association between family functioning and family communication.

Results: Most participants were female (60%), with an average age of 51 years. Fifty percent of participants reported that they spoke to their relatives about melanoma risk and people were more likely to speak to their female family members. Familial adaptation, cohesion, coping, and health beliefs were strongly associated with an open style of risk communication within families. None were associated with a blocked style of risk communication. Only cohesion and adaptation were associated with the amount of risk communication that occurred within families.

Conclusions: Overall, individuals who came from families that were more highly cohesive, adaptable, and shared strong beliefs about melanoma risk were more likely to communicate openly about melanoma. The fact that this association was not consistent across blocked communication and communication frequency highlights the multifaceted nature of this process. Future research should focus on the interplay between different facets of communication. Copyright © 2010 John Wiley & Sons, Ltd.
A population‐based study on the determinants of hospice utilization in the last year of life for Taiwanese cancer decedents, 2001–2006
Authors: Tang Siew Tzuh , Huang Ean‐Wen , Liu Tsang‐Wu , Wang Hung‐Ming , Chen Jen‐Shi
Published: January 2010

Background: No population‐based studies conducted outside Western countries have identified determinants of hospice utilization for all ages and cancer groups.

 Objective: To evaluate associations between hospice utilization in the last year of life and patient demographics, disease characteristics, physician specialty, hospital characteristics, and availability of healthcare resources at the hospital and regional levels in Taiwan.

 Methods: Retrospective cohort study using administrative data among 204, 850 Taiwanese cancer decedents, 2001–2006.

 Results: Rates of hospice utilization increased significantly (12.99–17.24%) over the study period. Hospice utilization was more likely for cancer patients who were female; over 65 years old; currently or formerly married; with ≤1 concurrent disease; diagnosed with breast cancer or cancer having a poorer prognosis; with distant metastasis, and longer illness duration (>2 months since diagnosis); receiving care in a teaching hospital or hospital with an inpatient‐hospice unit; and receiving care in a region with greater density of inpatient‐hospice beds. However, patients with hematological malignancies and esophageal cancer were less likely to use hospice care.

 Conclusions: Despite the 1.33 times increase in hospice utilization among cancer patients who died from 2001 to 2006, only one in six Taiwanese cancer decedents used hospice care in their last year of life. Our findings regarding determinants of hospice utilization should be used by healthcare professionals and policy makers to guide the development of policies and interventions that facilitate prognosis disclosure and EOL care discussions between physicians and patients, especially younger patients, to help the transition from curative to palliative care. Copyright © 2010 John Wiley & Sons, Ltd.
Mining protein dynamics from sets of crystal structures using “consensus structures”
Authors: van Westen Gerard J. P. , Wegner Jörg K. , Bender Andreas , IJzerman Adriaan P. , van Vlijmen Herman W. T.
Published: January 2010

In this work, we describe two novel approaches to utilize the dynamic structure information implicitly contained in large crystal structure data sets. The first approach visualizes both consistent as well as variable ligand‐induced changes in ligand‐bound compared with apo protein crystal structures. For this purpose, information was mined from B‐factors and ligand‐induced residue displacements in multiple crystal structures, minimizing experimental error and noise. With this approach, the mechanism of action of non‐nucleoside reverse transcriptase inhibitors (NNRTIs) as an inseparable combination of distortion of protein dynamics and conformational changes of HIV‐1 reverse transcriptase was corroborated (a combination of the previously proposed “molecular arthritis” and “distorted site” mechanisms). The second approach presented here uses “consensus structures” to map common binding features that are present in a set of structures of NNRTI‐bound HIV‐1 reverse transcriptase. Consensus structures are based on different levels of structural overlap of multiple crystal structures and are used to analyze protein–ligand interactions. The structures are shown to yield information about conserved hydrogen bonding interactions as well as binding‐pocket flexibility, shape, and volume. From the consensus structures, a common wild type NNRTI binding pocket emerges. Furthermore, we were able to identify a conserved backbone hydrogen bond acceptor at P236 and a novel hydrophobic subpocket, which are not yet utilized by current drugs. Our methods introduced here reinterpret the atom information and make use of the data variability by using multiple structures, complementing classical 3D structural information of single structures.
Mutations within a human IgG2 antibody form distinct and homogeneous disulfide isomers but do not affect Fc gamma receptor or C1q binding
Authors: Lightle Sandra , Aykent Serdar , Lacher Nathan , Mitaksov Vesselin , Wells Kristine , Zobel James , Oliphant Theodore
Published: January 2010

Human IgG2 antibodies may exist in at least three distinct structural isomers due to disulfide shuffling within the upper hinge region. Antibody interactions with Fc gamma receptors and the complement component C1q contribute to immune effector functions. These interactions could be impacted by the accessibility and structure of the hinge region. To examine the role structural isomers may have on effector functions, a series of cysteine to serine mutations were made on a human IgG2 backbone. We observed structural homogeneity with these mutants and mapped the locations of their disulfide bonds. Importantly, there was no observed difference in binding to any of the Fc gamma receptors or C1q between the mutants and the wild‐type IgG2. However, differences were seen in the apparent binding affinity of these antibodies that were dependent on the selection of the secondary detection antibody used.
Albedo, atmospheric solar absorption and heating rate measurements with stacked UAVs
Authors: Ramana M. V. , Ramanathan V. , Kim D. , Roberts G. C. , Corrigan C. E.
Published: January 2010

This paper reports unique measurements of albedo, atmospheric solar absorption, and heating rates in the visible (0.4 to 0.7 µm) and broadband (0.3 to 2.8 µm) spectral regions using vertically stacked multiple lightweight autonomous unmanned aerial vehicles (UAVs). The most significant finding of this study is that when absorbing aerosols and water vapour concentrations are measured accurately and accounted for in models, and when heating rates are measured directly with stacked aircraft, the simulated clear sky heating rates are consistent with the observed broadband heating rates within experimental errors (about 15%). We conclude that there is no need to invoke anomalous or excess absorption or unknown physics in clear skies.

Aerosol–radiation–cloud measurements were made over the tropical Indian Ocean within the lowest 3 km of the atmosphere during the Maldives Autonomous UAV Campaign (MAC). The UAVs and ground‐based remote sensing instruments determined most of the parameters required for calculating the albedo and vertical distribution of solar fluxes. The paper provides a refined analytical procedure to reduce errors and biases due to the offset errors arising from mounting of the radiometers on the aircraft and due to the aircraft attitude. Measured fluxes have been compared with those derived from a Monte‐Carlo radiative transfer algorithm which can incorporate both gaseous and aerosol components. Under cloud‐free conditions the calculated and measured incoming fluxes agree within 2–10 W m−2 (<1%) depending upon the altitudes. Similarly, the measured and calculated reflected fluxes agreed within 2–5 W m−2 (<5%).

The analysis focuses on a cloud‐free day when the air was polluted due to long‐range transport from India, and the mean aerosol optical depth (AOD) was 0.31 and mean single scattering albedo was 0.92. The UAV‐measured absorption AOD was 0.019 which agreed within 20% of the value of 0.024 reported by a ground‐based instrument. The observed and simulated solar absorption agreed within 5% above 1.0 km and aerosol absorption accounted for 30% to 50% of the absorption depending upon the altitude and solar zenith angle. Thus there was no need to invoke spurious or anomalous absorption, provided we accounted for aerosol black carbon. The diurnal mean absorption values for altitudes between 0.5 and 3.0 km above mean sea level were observed to be 41 ± 3 W m−2 (1.5 K/day) in the broadband region and 8 ± 2 W m−2 (0.3 K/day) in the visible region. The contribution of absorbing aerosols to the heating rate was an order of magnitude larger than the contribution of CO2 and one‐third that of the water vapour. In the lowest 3 km of the tropical atmosphere, aerosols accounted for more than 80% of the atmospheric absorption in the visible region. Copyright © 2007 Royal Meteorological Society
On the representation of initial uncertainties with multiple sets of singular vectors optimized for different criteria
Authors: Leutbecher Martin
Published: January 2010

Initial uncertainties can be represented effectively in ensemble prediction systems by sampling errors in a subspace spanned by the leading singular vectors of the forecast model's tangent‐linear propagator. The initial‐time metric in the singular‐vector computation is the inverse of the assumed analysis‐error covariance matrix A. The singular vectors evolve into the leading eigenvectors of the forecast‐error covariance estimate obtained by linearly propagating A to the singular‐vector optimization time. In this sense, singular vectors provide an optimal subspace for sampling initial uncertainties. However, the optimality is only guaranteed for the particular optimization criterion used in the singular‐vector computation. For instance, it could be suboptimal for forecast ranges that differ from the singular‐vector optimization time.

Here, two alternative approaches, accounting for several optimization criteria, are discussed. The first is a simple orthonormalization approach applied to multiple sets of singular vectors. Potentially, the orthonormalization can yield suboptimal perturbations. The second approach has been developed in response to the expected deficiency of the orthonormalization approach. It yields orthogonal subspaces for different optimization criteria without compromising optimality. For a given subspace L, spanned by a set of leading singular vectors optimized for the first criterion (or criteria), singular vectors are computed in the subspace orthogonal to L. The optimality properties of these subspace‐singular vectors are described and proved.

Subspaces obtained with the two approaches are compared in two examples. First, an idealized example based on singular vectors computed for two optimization times in the Eady model is considered. Then, both techniques are applied to initial perturbations targeted on tropical cyclones in the ECMWF Ensemble Prediction System. The methodologies allow a consistent representation of initial uncertainties during extratropical transitions. Copyright © 2007 Royal Meteorological Society
The optimal density of atmospheric sounder observations in the Met Office NWP system
Authors: Dando M. L. , Thorpe A. J. , Eyre J. R.
Published: January 2010

Large numbers of satellite observations are discarded from the numerical weather prediction (NWP) process because high‐density observations may have a negative impact on the analysis. In current assimilation schemes, the observation error covariance matrix R is usually represented as a diagonal matrix, which assumes there are no correlations in the observation errors and that each observation is an independent piece of information. This is not the case when there are strong error correlations and this can lead to a degraded analysis. The experiments conducted in this study were designed to identify the optimal density and to determine if there were circumstances when exceeding this density might be beneficial to forecast skill.

The global optimal separation distance of Advanced TIROS Operational Vertical Sounder (ATOVS) observations was identified by comparing global forecast errors produced using different densities of ATOVS. The global average of the absolute forecast error produced by each different density was found for a 3‐week period from December 2004 to January 2005. The results showed that, when using the Met Office NWP system with a horizontal model resolution of ∼60 km, the lowest global forecast errors were produced when using separation distances of 115–154 km. However, localized regions of the atmosphere containing large gradients such as frontal regions may benefit from thinning distances as small as 40 km and therefore the global optimal separation distance is not necessarily applicable in these circumstances. Copyright © 2007 Royal Meteorological Society
Dependence of ensemble spread on model uncertainties for extratropical cyclone simulations
Authors: Zhu Hongyan , Thorpe Alan J.
Published: January 2010

In order to examine the dependence of the ensemble forecast spread on model uncertainty, we use the model grid‐point spacing and the index of shallow‐convection top as surrogates for model uncertainty, to construct two groups of ensemble forecasts (‘experiments’). In each ensemble, we use several members that differ only in the size of their model uncertainties. An initial baroclinic‐jet basic state is constructed, with a balanced three‐dimensional perturbation, to trigger development of a baroclinic wave.

In terms of the minimum central surface pressure, the spread associated with each ensemble increases with increasing model uncertainty. Similar sensitivity is observed for the maximum ensemble spread and the domain‐averaged spread in terms of surface pressure. In both experiments, the domain‐averaged spread is linearly proportional to the size of the model uncertainty, and varies in time with a power‐law dependence.

The ensemble spread is mainly collocated with the primary cyclone during the cyclone development stage, when amplitude error dominates, and is elongated along the regions with strong gradients during the mature stage, when the phase error dominates.

Forecast errors also grow in association with the secondary cyclones that develop in the simulation. The maximum ensemble spread associated with secondary cyclones increases with increasing model uncertainty, as for the primary cyclones. It is found that model uncertainties have a larger effect at the surface on the spread associated with the upstream cyclone, compared to the downstream cyclone (at the same integration time), because of the different stages of development of the upstream and downstream cyclones. Copyright © 2007 Royal Meteorological Society
Assessing the benefit of flow constraints on the drifting invertebrate community of a regulated river
Authors: Patterson R. J. , Smokorowski K. E.
Published: January 2010

The downstream effects of hydroelectric dam operations on the abundance and diversity of the macroinvertebrate drift community of a regulated river were compared to that of an unregulated river, longitudinally and across three seasons. The regulated river operated under minimum flow and ramping rate (rate of change of flow) restrictions resulting in a ‘modified peaking’ regime, which means the facility could still peak, but at a slower rate and may not reach maximum turbine flows in the short time typically required to respond to market energy demand. The unregulated river had no dams or other water control structures. There was a trend of increasing abundance and diversity with distance from the dam on the regulated river, with no discernable trend along the unregulated river. While feeding guild proportions did not vary along the unregulated river, within the regulated river feeding guild proportions changed longitudinally as scrapers and collector gatherers increased, and filterers and predators decreased with distance downstream. The regulated river had similar or higher abundance across all seasons, with lower diversity in the spring. Seasonal average discharge was found to be lowest in summer on both rivers, with the regulated river benefiting from a minimum flow to help maintain higher abundance and diversity. Overall, our examination of the drifting invertebrate community on a regulated river support that operational constraints associated with modified peaking regimes helped mitigate the typical negative effects associated with river regulation. Copyright © 2010 Crown in the right of Canada and John Wiley & Sons, Ltd.
Effects of reservoir management on abundance, condition, parasitism and reproductive traits of downstream mussels
Authors: Galbraith H. S. , Vaughn C. C.
Published: January 2010

The large‐scale impoundment of rivers has led to global declines in freshwater mussel populations. It is important to understand the mechanisms underlying these declines to initiate an effective recovery strategy. We examined population traits of threeQuadrulaspecies (Quadrula pustulosa,Q. cylindricaandQ. quadrula) at three locations that were exposed to two different reservoir management regimes: releases that mimicked natural flow patterns and releases that were higher and colder in summer months than the natural system. We found lower mussel density, higher hermaphroditism and parasitism rates, and reduced body condition downstream of the dam with unnatural flow regimes. Sex ratios varied on a species and site basis. We found moreQuadrula cylindricafemales than males averaged across all three sampling sites whileQ. pustulosawas male biased across all sites and at site 1. We observed approximately equal sex ratios inQuadrula quadrula. Population disturbances downstream of the more naturally‐regulated dam were not as severe. Our data indicate that dam operation can have effects on a variety of mussel life history characteristics that may ultimately reduce population viability. Copyright © 2010 John Wiley & Sons, Ltd.
Relationship of thermoplastic starch crystallinity to plasticizer structure
Authors: Dai Hongguang , Chang Peter R. , Yu Jiugao , Geng Fengying , Ma Xiaofei
Published: January 2010

The crystallinity of hydroxyalkylformamides‐platicized thermoplastic starch (HAFTPS) was characterized by X‐ray diffraction (XRD). The HAFTPS crystallinity related to the structure of plasticizer hydroxyalkylformamides (HAF). If there was one H atom attaching to N atom of HAF, the corresponding HAFTPS only had VA crystallinity; if there was no H atom attaching to N atom of HAF, the corresponding HAFTPS had EH crystallinity due to the bulky plasticizer.
A study of practical‐moral knowledge in science teaching: Case studies in physical science classrooms
Authors: Salloum Sara , Abd‐El‐Khalick Fouad
Published: January 2010

This study further extends a conceptual framework that explores science teaching as a “practice” not reducible to the application of formal knowledge, but as informed by teachers' practical‐moral knowledge. A hermeneutic model was developed to examine practical‐moral knowledgeindirectlyby investigating teachers' commitments, interpretations, actions, and dialectic interactions between them. The study also aimed to analyze teachers' actions in terms of their interpretations and commitments as they realize “internal goods” of their practice. Ethnographic case studies of three science teachers were conducted through classroom observation, in‐depth interviews and dialogues, and artifact analysis. A commitment of preparing students for national exams was common to the three teachers but was manifested differently in classroom practices. This commitment originated from interpretations about the duty of “good” teachers notletting students and schools down. Other emergent commitments were commitments: to conceptual understandings, to “challenge” learners, and to social modeling. We present each with associated interpretations and actions. The concepts of practical wisdom (phronesis) and gap closing are used to characterize teachers' practical knowledge and its development respectively. Implications for teacher education are discussed. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 929–951, 2010
Gene–environment interactions, folate metabolism and the embryonic nervous system
Authors: Ross M. Elizabeth
Published: January 2010

Formation of brain and spinal cord requires the successful closure of neural ectoderm into an embryonic neural tube. Defects in this process result in anencephaly or spina bifida, which together constitute a leading cause of mortality and morbidity in children, affecting all ethnic and socioeconomic groups. The subject of intensive research for decades, neural tube defects (NTDs), are understood to arise from complex interactions of genes and environmental conditions, though systems‐level details are still elusive. Despite the variety of underlying causes, a single intervention, folic acid supplementation given in the first gestational month, can measurably reduce the occurrence of NTDs in a population. Evidence for and the scope of gene‐environment interactions in the genesis of NTDs is discussed. A systems‐based approach is now possible toward studies of genetic and environmental influences underlying NTDs that will enable the assessment of individual risk and personalized optimization of prevention. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Developmental Biology > Developmental Processes in Health and Disease
Halogenomercury Salts of Sterically Crowded Triazenides – Convenient Starting Materials for Redox‐Transmetallation Reactions
Authors: Hauber Sven‐Oliver , Woo Seo Jang , Niemeyer Mark
Published: January 2010

Diaryl‐substituted triazenides Ar(Ar′)N3HgX [Ar/Ar′ = Dmp/Mph, X = Cl (2a), Br (3a), I (4a); Ar/Ar′ = Dmp/Tph, X = Cl (2b), I (4b) with Mph = 2‐MesC6H4, Mes = 2,4,6‐Me3C6H2, Tph = 2′,4′,6′‐triisopropylbiphenyl‐2‐yl and Dmp = 2,6‐Mes2C6H3] were synthesized by salt‐metathesis reactions in ethyl ether from the readily available starting materials Ar(Ar′)N3Li and HgX2. These compounds may be used for redox‐transmetallation reactions with rare‐earth or alkaline earth metals. Thus, reaction of 4b or 2b with magnesium or ytterbium in tetrahydrofuran afforded the triazenides Dmp(Tph)N3MX(thf) (5b: M = Mg, X = I; 6b: M = Yb, X = Cl) in good yield. All new compounds were characterized by melting point, 1H and 13C NMR spectroscopy and for selected species by IR spectroscopy or mass spectrometry. In addition, the solid‐state structures of triazenides 2a, 2b, 3a, 4b, 5b and 6b were investigated by single‐crystal X‐ray diffraction.
Synthesis of Single‐Walled Carbon Nanotubes in a High Frequency Furnace
Authors: Müller Andreas , Jansen Martin
Published: January 2010

An alternative method for the synthesis of single‐walled carbon nanotubes (SWCNTs) is presented, which is based on the co‐evaporation of a pure graphite body and a metal catalyst (nickel). The graphite body is inductively heated in a high frequency furnace up to ~2400 °C. Characterization of the produced soot was performed using SEM, TEM and Raman spectroscopy techniques.
An algebraic characterisation of elementary net system (observable) state space
Authors: Pomello L. , Simone C.
Published: January 2010

The paper proposes a characterisation of the state space ofan Elementary Net (EN) system in terms of a relational algebraic structure, called Local State Transformation (LST) algebra. The latter allows one to take into consideration in an explicit way local state transformations performed by the occurrence of events. A class of injective morphisms between LST algebras allows one to compare system behaviours at different levels of abstraction and to introduce a notion of preorder in the class of EN systems. This leads in a natural way to a notion of equivalence which preserves the system degree of concurrency, and whose equivalence classes have a unique (up to isomorphism) canonical representative which is minimal with respect to net elements. Moreover, the class of morphisms allows the definition of a notion of state observability and of a notion of equivalence between Observable Elementary Net Systems. All these notions provide the system designer with a set of useful tools for an incremental design process, in which the (concurrent and nondeterministic) control of the considered system need not be fixed ‘a priori’.
Deciding bisimilarity is
P
-complete
Authors: Balcázar José , Gabarró Joaquim , Sántha Miklós
Published: January 2010

In finite labelled transition systems the problems of deciding strong bisimilarity, observation equivalence and observation congruence are
P
-complete under many—one
NC
-reducibility. As a consequence, algorithms for automated analysis of finite state systems based on bisimulation seem to be inherently sequential in the following sense: the design of an
NC
algorithm to solve any of these problems will require an algorithmic breakthrough, which is exceedingly hard to achieve.
Program morphisms
Authors: Burton C. T. P.
Published: January 2010

An algebraic view of recursive definitions is presented, extending an already familiar analogy with homomorphisms. A notion of simulation of one recursive definition by another is then defined. This leads to a particular approach to verification and transformation, which places emphasis on the arrows between programs, rather than the programs themselves. These arrows are the program morphisms of the title. Examples are given, together with certain extensions of the idea. Also indicated is a methodology which can lead to the discovery of program morphisms and new equivalent versions of a given program.
Machine checked proofs of the design of a fault-tolerant circuit
Authors: Bevier William R. , Young William D.
Published: January 2010

We describe a formally verified implementation of the “Oral Messages” algorithm of Pease, Shostak and Lamport
J. ACM
(1980)
27
, 228–234;
ACM TOPLAS
(1982)
4
, 382–401. An abstract implementation of the algorithm is proved to achieve interactive consistency in the presence of faults. This abstract characterisation is then mapped down to a hardware level implementation which inherits the fault-tolerant characteristics of the abstract version. All steps in the proof were checked with the Boyer-Moore theorem prover. A significant result of this work is the demonstration of a fault-tolerant device that is formally specified and the development of an implementation proved correct with respect to this specification. A significant simplifying assumption is that the redundant processors behave synchronously. We also describe a mechanically checked proof that the Oral Messages algorithm is “optimal” in the sense that no algorithm which achieves agreement via similar message passing can tolerate a larger proportion of faulty processors.
The systematic construction of a one-combinator basis for Lambda-Terms
Authors: Fokker Jeroen
Published: January 2010

A single closed λ-expression that generates all λ-expressions is constructed. The derivation is carried out with simplicity as driving force. The result is simpler than single-combinator bases known in the literature.
Re‐conceptualizing Risk in Genetic Counseling: Implications for Clinical Practice
Authors: Austin Jehannine C.
Published: January 2010

Risk communication is an important component of genetic counseling. However, many authors have noted that after genetic counseling, subjective risk frequently does not match the objective risk provided by the counselor. This inevitably leads to the conclusion that the risk communication process was not “effective”. There has been much discussion about how this problem can be better addressed, such that our clients recall numeric risks more accurately after genetic counseling. This article draws on the risk and probability literature from other fields (including psychology, economics, philosophy and climate change) to deconstruct the concepts of “risk” and risk perception to attempt to expand upon and develop thought and discussion about and investigation of the risk communication process in genetic counseling.