bluuebunny/crossref_metadata_2025 huggingface dataset:
School of Medicine CBIL librarian: an educational informationist model
Authors: Seago Brenda L.
Published: March 2004

The Computer‐Based Instruction Lab (CBIL) librarian works with instructional faculty in the School of Medicine (SOM) to identify and integrate computer‐based instruction into the curricula and to coordinate the informatics curriculum throughout the years of the medical student educational program. Because the CBIL librarian teaches informatics and grades papers, is resident within the building where instruction of medical students occurs, and because her salary is paid by the SOM, she is considered a part of the SOM instructional team and serves as a model of an educational informationist.
Nursing librarian: an educator of future nurses
Authors: Sherwill‐Navarro Pamela
Published: March 2004

The importance of “information literacy” in the education of nursing students continues to increase. In response, partnerships between nursing faculty and librarians are developing. The shortage of nurses and the rapid changes in information technology have created opportunities for librarians to educate nursing faculty and students about locating information, evaluating resources, and managing information. The type of instruction and support needed varies, depending on the level of the nursing student. Become a partner with the nursing faculty by attending meetings, having an office in the college of nursing, participating in social networking, and exploring ways in which a librarian can provide assistance. These partnerships provide benefits to nursing programs, nursing faculty and librarians.
Health professional education, evidence‐based health care, and health sciences librarians
Authors: McKibbon K. Ann , Bayley Liz
Published: March 2004

Evidence‐based medicine (EBM) evolved from an innovative method of teaching residents to use published literature for patient care. The missing piece to this critical appraisal approach was the skills needed to find the “best evidence” to use. Acknowledgment of this need provided many opportunities for librarians to become partners in the care process, including changes in provision of collections and services, modifications in searching skills (comprehensive vs clinical), and planning and educating undergraduates and graduates across the health disciplines. Librarians have increased their skills, made changes in practice, and become more important in educating and providing resources for practicing clinicians.
The librarian as tutor/facilitator in a problem‐based learning (PBL) curriculum
Authors: Eldredge Jonathan D.
Published: March 2004

This article describes the experiences of a librarian in a tutor/facilitator role immersed within a mainstream problem‐based learning (PBL) curriculum at the University of New Mexico School of Medicine. The role of tutor might be a suitable non‐traditional role for librarians. Tutoring turns out to be an entirely different role from traditional teaching. This tutor role requires practicing reciprocity, patience and commitment. This role has provided a profound understanding of the curriculum as it relates to library and informatics services, earned respect from non‐librarians, and prompted one to re‐think the integrated model of library instruction. Librarians willing to meet the challenges of tutoring can succeed in this non‐traditional role with the many associated benefits.
Area Health Education Center (AHEC) outreach librarian
Authors: McDuffee Diana
Published: March 2004

Area Health Education Center (AHEC) librarians are first, and foremost, outreach librarians. Improving health care and the distribution of health‐care professionals in rural and under‐served areas is the origin of the AHEC program. AHEC librarians play an important role in clinical education and patient care. Their role has characteristics of both academic medical center and hospital librarians. Their primary clientele are clinicians and administrators who have patient care, professional development, or educational needs for information access. In addition, they provide curricular support to the clinical education of undergraduate and graduate health sciences faculty and students. AHEC librarians provide reference service, interlibrary loan, collection management, and perform many administrative tasks for the AHEC. Three areas of librarian expertise are particularly important. clinical reference, educational support, and outreach services.
Bioterrorism alert: reference and literature support for the CDC Director’s Emergency Operations Center (DEOC) and investigative field teams
Authors: Swain Robert , Oliver Kathleen B. , Rankin Jocelyn A. , Bonander Jason , Loonsk John W.
Published: March 2004

The Centers for Disease Control and Prevention (CDC) is developing and supporting various strategies for emergency bioterrorism preparedness and response. To assist response teams, an informationist participated in preparedness teamwork and developed an electronic reference library with books, journal articles, and CDC documents. This laptop reference library was structured to be completely autonomous but also updatable. The library was tested during an FEMA emergency response exercise that included the informationist librarian. The majority of response team members agreed that both the reference library and librarian were valuable during an emergency response. The exercise emphasized the response team’s need for information and a librarian to find the right information at the right time.
STM publishing meets NIH digital archive: librarian service on the PubMed Central National Advisory Committee
Authors: Homan J. Michael , Watson Linda A.
Published: March 2004

The PubMed Central (PMC) National Advisory Committee was established by the National Institutes of Health in 1999 to guide the development of a new, open‐access digital repository of biomedical research reports. Headquartered at the National Library of Medicine’s National Center for Biotechnology Information, PMC has achieved significant technical accomplishments, including a recommended publisher document type definition for digital archiving, but little interest in the use of the new digital archive has been shown by the medical publishing community. This article chronicles the evolution of the initial concept from digital publisher to digital archive and includes issues related to technology and the culture of scientific communication.
Which instruments should surveyors use to monitor moisture condition?
Authors: Burkinshaw Ralph F.
Published: March 2004

This paper discusses the concept of “monitoring” moisture content (MC) as a surveying aid in connection with appraisal of buildings and when assessing the drying out of buildings, for example, after flooding damage. It also presents the findings of testing of various instruments to record the drying out of brick, timber and cement screed specimens. Conclusions are drawn on the most appropriate methods for the surveyor to use when monitoring the MC of construction materials.
Learning building pathology using computers – evaluation of a prototype application
Authors: Shelbourn Mark , Hoxley Mike , Aouad Ghassan
Published: March 2004

Building surveying employers are requiring graduates with a high level of cognitive and experiential skills to enable them to survey buildings directly after graduation with little or no supervision.This has led to a change in thinking for educators as providing this type of graduate requires learning and training material that is time‐consuming and costly to provide, as it requires learners to be actively involved in real surveying tasks. This paper presents the results of a prototype application developed to enable inexperienced surveyors to learn building pathology without leaving their desktops.
Towards improved construction waste minimisation: a need for improved supply chain integration?
Authors: Dainty Andrew R.J. , Brooke Richard J.
Published: March 2004

In recent years, economic, political and social pressures to adopt sustainable work practices have led to a renewed emphasis on developing effective waste minimisation measures for major construction projects. This research explored the efficacy of measures used for minimising waste in high profile UK‐based projects. The case studies revealed a diverse range of waste strategies, the broader applicability of which was then explored via a questionnaire survey of waste minimisation specialists. The most effective measures were deemed to be those that fostered “waste minimisation partnerships” throughout the supply chain. Questions remain, however, as to whether the industry is culturally prepared for the collaborative relationships necessary to engender radical improvements in waste minimisation performance.
GeoScience Information Society: 2003 National Meeting
Authors: Love April M.
Published: March 2004

Outlines the topics covered at the 2003 National Meeting of the GeoScience Information Society (GSIS) in Seattle, November 2003, which also included the announcement of the launch of GeoScience World, an aggregator resource for research and communications in geological and earth sciences on the Internet.
EDUCAUSE 2003: A Conference Summary
Authors: Riggs Colby
Published: March 2004

Provides an overview of the “Balancing Opportunities, Expectations, and Resources” conference, held in Anaheim, California in November 2003. The conference was organised by EDUCAUSE, a nonprofit association whose mission is to advance higher education by promoting the intelligent use of information technology. Outlines the seven track presentations of the conference.
IT@AGRILIBNET 2003: Report of the Second Phase
Authors: Murthy T.A.V. , Chandrakar Rajesh , Singh Kushwah Shivpal
Published: March 2004

Reports on the second phase of "ICAR‐INFLIBNET Training Programme for Agriculture Librarians on Networking and E‐Resources Management", a series of nine training programmes organized in two phases and hosted by the Indian Inter‐University Information & Network Centre. The programme, of two weeks duration, was supported by the World Bank through the National Agriculture Technology Project in New Delhi, India. The programme was specially designed for agricultural library professionals of Indian State Agriculture University, Agriculture Colleges and R&D institutes. The second phase was conducted during November 2003.
American Geophysical Union: Fall 2003 Conference
Authors: Love April M.
Published: March 2004

Reports on the Annual Fall Meeting of the American Geophysical Union held in December 2003 in San Francisco. Outlines some of the topics covered, including an update on Total Mapping Ozone Spectrometer technology which investigates destruction of the ozone layer and a poster session on alternative careers for geoscientists.
American Library Association Mid‐Winter Conference, San Diego, California
Authors: Gelfand Julia , Riggs Colby
Published: March 2004

Gives an overview of the American Library Association (ALA) Annual Mid‐Winter Conference, held in San Diego in January 2004.
Introduction to Streaming Video for Novices
Authors: Lee Scott , Burrell Carolyn
Published: March 2004

Explores the concept of using streaming video technology for distance library instruction. Outlines the planning and production of streaming video services for college libraries in the Antelope Valley area of northern Los Angeles County and gives technical requirements for streaming video production.
Talking Tech: Communicating and Collaborating more Effectively with Your IT Support Staff
Authors: Rose Taylor Laura , Taylor Michael
Published: March 2004

Provides some ideas and strategies to help users and technical support staff work together to create environments where communication and collaboration are more effective – and enjoyable.
From Sumeria to Sunny Hill: are we still cooking the books?
Authors: Chapman Anne
Published: March 2004

The accuracy, completeness and authenticity of a record assure its reliability as an acceptable informational and evidential document. An evaluative, historical survey of the possibility and desirability of achieving reliability in records with special application to the pupil records at Bruton School for Girls, Sunny Hill, Bruton, Somerset, UK indicates that such reliability has not been achieved since records began with the Sumerians, although every generation of record‐keepers has invented methods to aim to ensure it. Because definitions of accuracy or what makes a true record have not been universally accepted, although reliability is desirable for most record keepers, deliberate and accidental error occurs. Aiming for eradication of error by installing efficient records management systems will ensure a better approximation to the truth of a record.
From production line to drama school: higher education for the future of tourism
Authors: Morgan Michael
Published: March 2004

Tourism degree courses aim to meet the needs of students, employers and government funding bodies, but there is no agreement on how best to do this. Should courses aim to enable graduates to operate within the industry today, or to shape its future development? To what extent should these managerial goals be combined with those of a traditional liberal education? Is the business management focus of most tourism courses the best preparation for the future development of tourism? The relationship between education and industry is charted through past changes to the current debate on future directions. In the future, tourism will be part of the “experience economy” with a new theatrical metaphor replacing the current “military” strategy model. To succeed in this economy, graduates need to draw on qualities of self‐awareness, imagination and creativity. Higher education in tourism may need to rediscover these liberal humanistic values in order to fulfil its managerial objectives of creating successful business managers.
A comparison study of Chinese domestic tourism: China vs the USA
Authors: Wang Suosheng , Qu Hailin
Published: March 2004

After achieving great success in developing international travel business, China’s tourism authorities, the local and international travel agencies and lodging companies are now diverting their attention to the untapped and big potential market of China’s domestic tourism business. By using a comparison approach, this study examines the current features of China’s domestic tourism. Various aspects of China’s domestic tourism are analyzed and discussed in a way of comparison with the USA. The aspects are: sources of information used by tourists, tourists’ transport and lodging patterns, tourists’ traveling activities and spending patterns, and governments’ role in domestic tourism. Discussions and conclusions are made based on a series of comparisons. Implications for both China’s government and travel agencies and international companies interested in China’s domestic travel business are provided.
Foreign languages and the health of UK tourism
Authors: Russell Hilary , Leslie David
Published: March 2004

Deplores the decline of domestic trips, in the short‐term, in the UK, owing to various prohibitive events taking place such as petrol strike action, foot and mouth and even the 9/11 atrocity. The vulnerability of tourism in the face of such events, to a particular destination, means the tourism sector must be competitive as there are many more places to go. Posits the UK’s backward position with regard to language skills among both tourism enterprises and organizations. Concludes UK tourism as a whole will continue to be under attack unless simple things such as foreign language skills are properly addressed.
Managing equity: structure, policy and justice influences
Authors: French Erica , Maconachie Glenda
Published: March 2004

This paper outlines the methods and outcomes of a study into equity management strategies in Australian private sector organisations reporting to the Equal Opportunity for Women in the Workplace Agency (EOWA). Reports from 1,976 organisations indicate 11 key factors characterising equity management in Australia. The study highlights differences within previously identified social structural policies, temperamental and opportunity policies and identifies a further policy type, categorised as “support policies”. Differences have also been identified in relation to distribution structures, suggesting that gender is not the sole consideration in determining equity management strategies. The justice principle of distribution also figures strongly in equity management implementation.
Leveraging organizational learning for knowledge and performance
Authors: Cavaleri Steven A.
Published: March 2004

This article examines the alignment and fit between knowledge management and organizational learning to determine the potential feasibility of integrating the two approaches. The philosophical roots of both disciplines are traced to common ground in a philosophy known as “pragmatism”. Early generation forms of knowledge management are critiqued and a new more pragmatic version is proposed – one that is compatible with organizational learning. A new form of alignment between organizational learning and knowledge management is proposed.
Modeling how their business really works prepares managers for sudden change
Authors: Bürgi Peter , Victor Bart , Lentz Jody
Published: March 2004

“Chemcor”, a mid‐sized specialty chemicals firm must balance the disciplining effects of planning against the need for innovative and adaptive action. The top corporate strategy officer at Chemcor resolved to help three company divisions work towards finding a way. To complement the planned strategy development process, separate workshops were held for the strategists and senior managers at each of the organization’s three divisions. Built around a radical new technique for analyzing an organization’s identity, landscape and deepest interests in the face of a variety of potential situations, these workshops were intended to help managers learn to continuously assess their organization’s strategic situation in real time. Called “Real Time Strategy”, the workshops encourage a thorough conversation about issues of identity and strategy using a technique called LEGO Serious Play®. The representation of their strategic situation made from Lego construction materials that the Chemcor managers built in the real time strategy workshop enabled them to have a profitable conversation about how their business model would work in variety of different potential situations. In sum, the workshop encouraged senior managers to cultivate their ability to adapt rather than to only implement the plan.
Selective laser sintering and cladding of single‐component metal powders
Authors: Tolochko Nikolay K. , Mozzharov Sergei E. , Yadroitsev Igor A. , Laoui Tahar , Froyen Ludo , Titov Victor I. , Ignatiev Michail B.
Published: March 2004

A comparison of selective laser sintering (SLS) and selective laser cladding (SLC) methods is presented. Loose single‐component, Ni‐alloy powder was used in this study. The powder feeding system formed the flow of powder particles directed into the zone of laser spot. The particles were deposited directly onto a substrate or onto the top of a pedestal. The powders were treated with a CW‐ Nd:YAG laser (λ=1.06 μm). The beam was motionless relative to the powder bed. As a result, the samples of sintered or remelted powders were built up as the vertical rods. The geometrical characteristics, structure and mechanical properties of samples were investigated.
Three‐dimensional plotting as a visualisation aid for architectural use
Authors: de Beer Deon J. , Barnard Ludrick J. , Booysen Gerrie J.
Published: March 2004

Functional design is closely linked to manufacturing and building. Designers' freedom to express themselves is often limited by the capabilities of craftsmen who have to give physical substance to the designer's ideas. This paper reviews the use of rapid prototyping (RP) to construct complex geometry. Three‐dimensional computer aided design data are transferred to a build volume on a 2D layer‐by‐layer basis. This manufacturing method results in the rapid production of a physical model that can be used to verify designs, check form, fit and functionality, as well as to create a depth perspective. The paper describes a fresh approach into an old industry, i.e. model making. Results proved that models built by conventional methods can be cost‐effectively substituted by RP methods without the surface limitations created by cardboard models.
Intermediates and the folding of proteins L and G
Authors: Brown Scott , Head‐Gordon Teresa
Published: March 2004

We use a minimalist protein model, in combination with a sequence design strategy, to determine differences in primary structure for proteins L and G, which are responsible for the two proteins folding through distinctly different folding mechanisms. We find that the folding of proteins L and G are consistent with a nucleation‐condensation mechanism, each of which is described as helix‐assisted β‐1 and β‐2 hairpin formation, respectively. We determine that the model for protein G exhibits an early intermediate that precedes the rate‐limiting barrier of folding, and which draws together misaligned secondary structure elements that are stabilized by hydrophobic core contacts involving the third β‐strand, and presages the later transition state in which the correct strand alignment of these same secondary structure elements is restored. Finally, the validity of the targeted intermediate ensemble for protein G was analyzed by fitting the kinetic data to a two‐step first‐order reversible reaction, proving that protein G folding involves an on‐pathway early intermediate, and should be populated and therefore observable by experiment.
Alignment of protein sequences by their profiles
Authors: Marti‐Renom Marc A. , Madhusudhan M.S. , Sali Andrej
Published: March 2004

The accuracy of an alignment between two protein sequences can be improved by including other detectably related sequences in the comparison. We optimize and benchmark such an approach that relies on aligning two multiple sequence alignments, each one including one of the two protein sequences. Thirteen different protocols for creating and comparing profiles corresponding to the multiple sequence alignments are implemented in the SALIGN command of MODELLER. A test set of 200 pairwise, structure‐based alignments with sequence identities below 40% is used to benchmark the 13 protocols as well as a number of previously described sequence alignment methods, including heuristic pairwise sequence alignment by BLAST, pairwise sequence alignment by global dynamic programming with an affine gap penalty function by the ALIGN command of MODELLER, sequence‐profile alignment by PSI‐BLAST, Hidden Markov Model methods implemented in SAM and LOBSTER, pairwise sequence alignment relying on predicted local structure by SEA, and multiple sequence alignment by CLUSTALW and COMPASS. The alignment accuracies of the best new protocols were significantly better than those of the other tested methods. For example, the fraction of the correctly aligned residues relative to the structure‐based alignment by the best protocol is 56%, which can be compared with the accuracies of 26%, 42%, 43%, 48%, 50%, 49%, 43%, and 43% for the other methods, respectively. The new method is currently applied to large‐scale comparative protein structure modeling of all known sequences.
Conformational mapping of the N‐terminal peptide of HIV‐1 gp41 in lipid detergent and aqueous environments using 13C‐enhanced Fourier transform infrared spectroscopy
Authors: Gordon Larry M. , Mobley Patrick W. , Lee William , Eskandari Sepehr , Kaznessis Yiannis N. , Sherman Mark A. , Waring Alan J.
Published: March 2004

The N‐terminal domain of HIV‐1 glycoprotein 41,000 (gp41) participates in viral fusion processes. Here, we use physical and computational methodologies to examine the secondary structure of a peptide based on the N terminus (FP; residues 1–23) in aqueous and detergent environments. 12C‐Fourier transform infrared (FTIR) spectroscopy indicated greater α‐helix for FP in lipid‐detergent sodium dodecyl sulfate (SDS) and aqueous phosphate‐buffered saline (PBS) than in only PBS. 12C‐FTIR spectra also showed disordered FP conformations in these two environments, along with substantial β‐structure for FP alone in PBS. In experiments that map conformations to specific residues, isotope‐enhanced FTIR spectroscopy was performed using FP peptides labeled with 13C‐carbonyl. 13C‐FTIR results on FP in SDS at low peptide loading indicated α‐helix (residues 5 to 16) and disordered conformations (residues 1–4). Because earlier 13C‐FTIR analysis of FP in lipid bilayers demonstrated α‐helix for residues 1–16 at low peptide loading, the FP structure in SDS micelles only approximates that found for FP with membranes. Molecular dynamics simulations of FP in an explicit SDS micelle indicate that the fraying of the first three to four residues may be due to the FP helix moving to one end of the micelle. In PBS alone, however, electron microscopy of FP showed large fibrils, while 13C‐FTIR spectra demonstrated antiparallel β‐sheet for FP (residues 1–12), analogous to that reported for amyloid peptides. Because FP and amyloid peptides each exhibit plaque formation, α‐helix to β‐sheet interconversion, and membrane fusion activity, amyloid and N‐terminal gp41 peptides may belong to the same superfamily of proteins.
Biological functions of the disulfides in bovine pancreatic deoxyribonuclease
Authors: Chen Wei‐Jung , Lee I‐Shuan , Chen Ching‐Ying , Liao Ta‐Hsiu
Published: March 2004

We characterized the biochemical functions of the small nonessential (C101–C104) and the large essential (C173–C209) disulfides in bovine pancreatic (bp) DNase using alanine mutants [brDNase(C101A)] and [brDNase(C173A) and brDNase(C209A)], respectively. We also characterized the effects of an additional third disulfide [brDNase(F192C/A217C)]. Without the Ca2+ protection, bpDNase and brDNase(C101A) were readily inactivated by trypsin, whereas brDNase(F192C/A217C) remained active. With Ca2+, all forms of DNase, except for brDNase(C101A), were protected against trypsin. All forms of DNase, after being dissolved in 6 M guanidine‐HCl, were fully reactivated by diluting into a Ca2+‐containing buffer. However, when diluted into a Ca2+‐free buffer, bpDNase and brDNase(C101A) remained inactive, but 60% of the bpDNase activity was restored with brDNase(F192C/A217C). When heated, bpDNase was inactivated at a transition temperature of 65°C, brDNase(C101A) at 60°C, and brDNase(F192C/A217C) at 73°C, indicating that the small disulfide, albeit not essential for activity, is important for the structural integrity, and that the introduction of a third disulfide can further stabilize the enzyme. When pellets of brDNase(C173A) and brDNase(C209A) in inclusion bodies were dissolved in 6 M guanidine‐HCl and then diluted into a Ca2+‐containing buffer, 10%–18% of the bpDNase activity was restored, suggesting that the “essential” disulfide is not absolutely crucial for enzymatic catalysis. Owing to the structure‐based sequence alignment revealing homology between the “nonessential” disulfide of bpDNase and the active‐site motif of thioredoxin, we measured 39% of the thioredoxin‐like activity for bpDNase based on the rate of insulin precipitation (ΔA650nm/min). Thus, the disulfides in bpDNase not only play the role of stabilizing the protein molecule but also may engage in biological functions such as the disulfide/dithiol exchange reaction.
Solution structure of a novel calcium binding protein, MTH1880, from Methanobacterium thermoautotrophicum
Authors: Lee Chang‐Hun , Jung Jin‐Won , Yee Adelinda , Arrowsmith Cheryl H. , Lee Weontae
Published: March 2004

MTH1880 is a hypothetical protein from Methanobacterium thermoautotrophicum, a target organism of structural genomics. The solution structure determined by NMR spectroscopy demonstrates a typical α + β‐fold found in many proteins with different functions. The molecular surface of the protein reveals a small, highly acidic pocket comprising loop B (Asp36, Asp37, Asp38), the end of β2 (Glu39), and loop D (Ser57, Ser58, Ser61), indicating that the protein would have a possible cation binding site. The NMR resonances of several amino acids within the acidic binding pocket in MTH1880, shifted upon addition of calcium ion. This calcium binding motif and overall topology of MTH1880 differ from those of other calcium binding proteins. MTH1880 did not show a calcium‐induced conformational change typical of calcium sensor proteins. Therefore, we propose that the MTH1880 protein contains a novel motif for calcium‐specific binding, and may function as a calcium buffering protein.
A new, structurally nonredundant, diverse data set of protein–protein interfaces and its implications
Authors: Keskin Ozlem , Tsai Chung‐Jung , Wolfson Haim , Nussinov Ruth
Published: March 2004

Here, we present a diverse, structurally nonredundant data set of two‐chain protein–protein interfaces derived from the PDB. Using a sequence order‐independent structural comparison algorithm and hierarchical clustering, 3799 interface clusters are obtained. These yield 103 clusters with at least five nonhomologous members. We divide the clusters into three types. In Type I clusters, the global structures of the chains from which the interfaces are derived are also similar. This cluster type is expected because, in general, related proteins associate in similar ways. In Type II, the interfaces are similar; however, remarkably, the overall structures and functions of the chains are different. The functional spectrum is broad, from enzymes/inhibitors to immunoglobulins and toxins. The fact that structurally different monomers associate in similar ways, suggests “good” binding architectures. This observation extends a paradigm in protein science: It has been well known that proteins with similar structures may have different functions. Here, we show that it extends to interfaces. In Type III clusters, only one side of the interface is similar across the cluster. This structurally nonredundant data set provides rich data for studies of protein–protein interactions and recognition, cellular networks and drug design. In particular, it may be useful in addressing the difficult question of what are the favorable ways for proteins to interact. (The data set is available at http://protein3d.ncifcrf.gov/∼keskino/ and http://home.ku.edu.tr/∼okeskin/INTERFACE/INTERFACES.html.)
Orientational potentials extracted from protein structures improve native fold recognition
Authors: Buchete Nicolae‐Viorel , Straub John E. , Thirumalai Devarajan
Published: March 2004

We develop coarse‐grained, distance‐ and orientation‐dependent statistical potentials from the growing protein structural databases. For protein structural classes (α, β, and α/β), a substantial number of backbone–backbone and backbone–side‐chain contacts stabilize the native folds. By taking into account the importance of backbone interactions with a virtual backbone interaction center as the 21st anisotropic site, we construct a 21 × 21 interaction scheme. The new potentials are studied using spherical harmonics analysis (SHA) and a smooth, continuous version is constructed using spherical harmonic synthesis (SHS). Our approach has the following advantages: (1) The smooth, continuous form of the resulting potentials is more realistic and presents significant advantages for computational simulations, and (2) with SHS, the potential values can be computed efficiently for arbitrary coordinates, requiring only the knowledge of a few spherical harmonic coefficients. The performance of the new orientation‐dependent potentials was tested using a standard database of decoy structures. The results show that the ability of the new orientation‐dependent potentials to recognize native protein folds from a set of decoy structures is strongly enhanced by the inclusion of anisotropic backbone interaction centers. The anisotropic potentials can be used to develop realistic coarse‐grained simulations of proteins, with direct applications to protein design, folding, and aggregation.
Tyrosine phenol‐lyase and tryptophan indole‐lyase encapsulated in wet nanoporous silica gels: Selective stabilization of tertiary conformations
Authors: Pioselli Barbara , Bettati Stefano , Demidkina Tatyana V. , Zakomirdina Lyudmila N. , Phillips Robert S. , Mozzarelli Andrea
Published: March 2004

The pyridoxal 5′‐phosphate‐dependent enzymes tyrosine phenol‐lyase and tryptophan indole‐lyase were encapsulated in wet nanoporous silica gels, a powerful method to selectively stabilize tertiary and quaternary protein conformations and to develop bioreactors and biosensors. A comparison of the enzyme reactivity in silica gels and in solution was carried out by determining equilibrium and kinetic parameters, exploiting the distinct spectral properties of catalytic intermediates and reaction products. The encapsulated enzymes exhibit altered distributions of ketoenamine and enolimine tautomers, increased values of inhibitors dissociation constants, slow attaining of steady‐state in the presence of substrate and substrate analogs, modified steady‐state distribution of catalytic intermediates, and a sixfold–eightfold decrease of specific activities. This behavior can be rationalized by a reduced conformational flexibility for the encapsulated enzymes and a selective stabilization of either the open (inactive) or the closed (active) form of the enzymes. Despite very similar structures and catalytic mechanisms, the influence of encapsulation is more pronounced for tyrosine phenol‐lyase than tryptophan indole‐lyase. This finding indicates that subtle structural and dynamic differences can lead to distinct interactions of the protein with the gel matrix.
Trypsin specificity as elucidated by LIE calculations, X‐ray structures, and association constant measurements
Authors: Leiros Hanna‐Kirsti Schrøder , Brandsdal Bjørn Olav , Andersen Ole Andreas , Os Vibeke , Leiros Ingar , Helland Ronny , Otlewski Jacek , Willassen Nils Peder , Smalås Arne O.
Published: March 2004

The variation in inhibitor specificity for five different amine inhibitors bound to CST, BT, and the cold‐adapted AST has been studied by use of association constant measurements, structural analysis of high‐resolution crystal structures, and the LIE method. Experimental data show that AST binds the 1BZA and 2BEA inhibitors 0.8 and 0.5 kcal/mole more strongly than BT. However, structural interactions and orientations of the inhibitors within the S1 site have been found to be virtually identical in the three enzymes studied. For example, the four water molecules in the inhibitor‐free structures of AST and BT are channeled into similar positions in the S1 site, and the nitrogen atom(s) of the inhibitors are found in two cationic binding sites denoted Position1 and Position2. The hydrophobic binding contributions for all five inhibitors, estimated by the LIE calculations, are also in the same order (−2.1 ± 0.2 kcal/mole) for all three enzymes. Our hypothesis is therefore that the observed variation in inhibitor binding arises from different electrostatic interactions originating from residues outside the S1 site. This is well illustrated by AST, in which Asp 150 and Glu 221B, despite some distance from the S1 binding site, lower the electrostatic potential of the S1 site and thus enhance substrate binding. Because the trends in the experimentally determined binding energies were reproduced by the LIE calculations after adding the contribution from long‐range interactions, we find this method very suitable for rational studies of protein–substrate interactions.
Inhibitor binding in a class 2 dihydroorotate dehydrogenase causes variations in the membrane‐associated N‐terminal domain
Authors: Hansen Majbritt , Le Nours Jérôme , Johansson Eva , Antal Torben , Ullrich Alexandra , Löffler Monika , Larsen Sine
Published: March 2004

The flavin enzyme dihydroorotate dehydrogenase (DHOD; EC 1.3.99.11) catalyzes the oxidation of dihydroorotate to orotate, the fourth step in the de novo pyrimidine biosynthesis of UMP. The enzyme is a promising target for drug design in different biological and clinical applications for cancer and arthritis. The first crystal structure of the class 2 dihydroorotate dehydrogenase from rat has been determined in complex with its two inhibitors brequinar and atovaquone. These inhibitors have shown promising results as anti‐proliferative, immunosuppressive, and antiparasitic agents. A unique feature of the class 2 DHODs is their N‐terminal extension, which folds into a separate domain comprising two α‐helices. This domain serves as the binding site for the two inhibitors and the respiratory quinones acting as the second substrate for the class 2 DHODs. The orientation of the first N‐terminal helix is very different in the two complexes of rat DHOD (DHODR). Binding of atovaquone causes a 12 Å movement of the first residue in the first α‐helix. Based on the information from the two structures of DHODR, a model for binding of the quinone and the residues important for the interactions could be defined. His 56 and Arg 136, which are fully conserved in all class 2 DHODs, seem to play a key role in the interaction with the electron acceptor. The differences between the membrane‐bound rat DHOD and membrane‐associated class 2 DHODs exemplified by the Escherichia coli DHOD has been investigated by GRID computations of the hydrophobic probes predicted to interact with the membrane.
Fast and faster: A designed variant of the B‐domain of protein A folds in 3 μsec
Authors: Arora Pooja , Oas Terrence G. , Myers Jeffrey K.
Published: March 2004

We have introduced the mutation glycine 29 to alanine, designed to increase the rate of protein folding, into the B‐domain of protein A (BdpA). From NMR lineshape analysis, we find the G29A mutation increases the folding rate constant by threefold; the folding time is 3 μsec. Although wild‐type BdpA folds extremely fast, simple‐point mutations can still speed up the folding; thus, the folding rate is not evolutionarily maximized. The short folding time of G29A BdpA (the shortest time yet reported) makes it an attractive candidate for an all‐atom molecular dynamics simulation that could potentially show a complete folding reaction starting from an extended chain. We also constructed a fluorescent variant of BdpA by mutating phenylalanine 13 to tryptophan, allowing fluorescence‐based time‐resolved temperature‐jump measurements. Temperature jumps and NMR complement each other, and give a very complete picture of the folding kinetics.
Observation of a hybrid random ping‐pong mechanism of catalysis for NodST: A mass spectrometry approach
Authors: Pi Na , Yu Yonghao , Mougous Joseph D. , Leary Julie A.
Published: March 2004

An efficient enzyme kinetics assay using electrospray ionization mass spectrometry (ESI‐MS) was initially applied to the catalytic mechanism investigation of a carbohydrate sulfotransferase, NodST. Herein, the recombinant NodST was overexpressed with a His6‐tag and purified via Ni‐NTA metal‐affinity chromatography. In this bisubstrate enzymatic system, an internal standard similar in structure and ionization efficiency to the product was chosen in the ESI‐MS assay, and a single point normalization factor was determined and used to quantify the product concentration. The catalytic mechanism of NodST was rapidly determined by fitting the MS kinetic data into a nonlinear regression analysis program. The initial rate kinetics analysis and product inhibition study described support a hybrid double‐displacement, two‐site ping‐pong mechanism of NodST with formation of a sulfated NodST intermediate. This covalent intermediate was further isolated and detected via trypsin digestion and Fourier transform ion cyclotron resonance mass spectrometry. To our knowledge, these are the first mechanistic data reported for the bacterial sulfotransferase, NodST, which demonstrated the power of mass spectrometry in elucidating the reaction pathway and catalytic mechanism of promising enzymatic systems.
Collective Representation Among High‐Tech Workers at Microsoft and Beyond: Lessons from WashTech/CWA
Authors: Van Jaarsveld Danielle D.
Published: March 2004

The obstacles that discourage organizing among high‐tech workers are well documented in the industrial relations literature. Discussion about factors that help workers overcome these obstacles, however, is sparse. This case study uses interviews and other evidence to analyze how high‐tech workers formed the Washington Alliance of Technology Workers (WashTech/CWA). I find that WashTech/CWA improved constituents’ working conditions through attempts to engage in collective bargaining, mutual benefit activities, and political action. WashTech/CWA is having greater success using mutual benefits, such as information and training services, and political action in part as a result of the obstacles workers encountered when trying to access collective bargaining.
English‐Language Skills and the Earnings of Self‐Employed Immigrants in the United States: A Note
Authors: Dávila Alberto , Mora Marie T.
Published: March 2004

Employing U.S. Census data, this study analyzes how English‐language fluency affected the earnings of self‐employed immigrant men in the 1980s. Our results suggest that English proficiency became a more important determinant of earnings for foreign‐born entrepreneurs in 1990 compared with 1980, even while controlling for factors affecting selection into self‐employment.
Why Do Employers Retrain At‐Risk Workers? The Role of Social Capital
Authors: Cappelli Peter
Published: March 2004

Why are some employers willing to retrain workers who are at risk of layoff for new jobs in their organization, whereas others “churn” their workforce through layoffs and outside hiring? The question seems central to understanding why some employers and some jobs are “good,” whereas others are not and, more generally, for understanding employment security. The arguments herein use national probability data to examine this question and find that the retraining option is associated with preserving the social capital among current employees. Employers who make greater use of work systems that rely on social capital are more likely to retrain their workers. Alternative explanations—that retraining is an employee benefit associated with employee‐friendly policies or is part of overall strategy to invest in training—receive no support. These results extend our understanding of the role that social capital can play in organizations. They also suggest that being a “good” employer may have a great deal to do with other choices about systems of work organization.
Employer Pension Contributions and 401(k) Plans: A Note
Authors: Wei Sun Teresa Ghilarducci , Nyce Steve
Published: March 2004

We investigate the pension choices of over 800 firms between 1988 and 1996. Using the data on pension plan finances from the Internal Revenue Service (IRS) Form 5500, required annually from firms sponsoring plans, and on firm finances from Compustat, we find support that a 10 percent increase in the use of 401(k) plans reduces pension costs per worker by 1.8 to 2.0 percent. Collective bargaining helps to mitigate the decline in employer costs.
Structure and rheology of semisolid o/w creams containing cetyl alcohol/non‐ionic surfactant mixed emulsifier and different polymers
Authors: Ribeiro H. M. , Morais J. A. , Eccleston G. M.
Published: March 2004

Synopsis

Oil‐in‐water (o/w) emulsions for cosmetic use, such as lotions and creams, are complex multiple‐phase systems, which may contain a number of interacting surfactants, fatty amphiphiles, polymers and other excipients. This study investigates the influence of two synthetic cationic polymers, Polyquaternium‐7 and Polyquaternium‐11, and the natural anionic polymer, gum of acacia, on the rheology and microstructure of creams prepared with a non‐ionic mixed emulsifier (cetyl stearyl alcohol‐12EO/cetyl alcohol) using rheology (continuous shear, and viscoelastic creep and oscillation), microscopy and differential scanning calorimetry (DSC). A control cream containing no polymer was also investigated. The semisolid control cream was structured by a swollen lamellar gel network phase formed from the interaction of cetyl alcohol and the POE surfactant, in excess of that required to stabilize oil droplets, with continuous phase water. Endothermic transitions between 25 and 100 °C were identified as components of this phase. Incorporation of cationic polymer into the formulation caused significant loss of structure to produce a mobile semisolid containing larger oil droplets. The microscopical and thermal data implied that the cationic polymer caused the swollen lamellar gel network phase to transform into non‐swollen crystals of cetyl alcohol. In contrast, incorporation of gum of acacia produced a thicker cream than the control, with smaller droplet sizes and little evidence of the gel network. Microscopical and thermal data implied that although there were also interactions between gum of acacia and both the surfactant and the swollen gel network phase, the semisolid properties were probably because of the ability of the gum of acacia to stabilize and thicken the emulsion in the absence of the swollen lamellar network.
Diffusion and distribution of element‐labelled surfactants in human hair
Authors: Wortmann F.‐J. , Gotsche M. , Schmidt‐Lewerkühne H.
Published: March 2004

Synopsis

To directly follow the diffusion process of cosmetically relevant agents into human hair, a specific methodological approach is presented and elucidated for selected surfactants. For this, practically relevant anionic and cationic surfactants were synthesized with a chlorine atom at the end of their alkyl chain. The property changes of the surfactants through the modification are corresponding to an extension of the alkyl chain by about two methylene groups, thus representing a moderate increase of hydrophobicity. After the application of a modified surfactant to hair, it can be localized and quantified through its chlorine atom in cross‐sections by scanning electron microscopy combined with micro X‐ray fluorescence analysis. The determination of the diffusion coefficient D is realized through the application of the Matano‐equation to element intensity profiles. Values for D vary within the chosen range of pH and temperature between 10−14 and 10−16 m2 s−1. The diffusion coefficients for the anionic surfactants increase with decreasing pH and increasing temperature, The temperature dependence follows in all cases the Arrhenius relationship with activation energies EA of 50–100 kJ mol−1, which decrease with pH. The pH‐related effects, with comparable values for D and EA, are opposite for the cationic surfactant. These observations are consistently interpreted on the basis of ionic and hydrophobic interactions in hair.
Contribution of encapsulation on the biodisponibility of retinol
Authors: Failloux N. , Baron M.‐H. , Abdul‐Malak N. , Perrier E.
Published: March 2004

Synopsis

To show the benefits of retinol encapsulation in cosmetic industry, we compared the diffusion of two different retinol preparations through skin:oil‐in‐water (o/w) emulsions of retinol, also called ‘free retinol’, and suspension of Cylasphere® including retinol, also called ‘encapsulated retinol’. Two methods were used: Franz cell elucidated retinol release and storage in a hairless mouse skin according to time for the two types of preparations. The dosage of retinol by high performance liquid chromatography (HPLC) showed that encapsulated retinol was maintained into the skin for a longer time than free retinol. Raman microspectrometry measurements established a spectral image of the skin and determined the localization of retinol. Maps were collected according to time. They detailed the shifts of free and encapsulated retinol in the epidermis of a human biopsy. Spheres were smaller than droplets and they moved two times faster at this level of the skin.