bluuebunny/crossref_metadata_2025 huggingface dataset:
A high-elevation Holocene pollen record from Iztaccihuatl volcano, central Mexico
Authors: Lozano-Garcial Socorro , Vizquez-Selem Lorenzo
Published: April 2005

Pollen data from 3860 m in the Agua El Marrano valley on the northwest side of Iztaccihuatl volcano (southeastern part of the Basin of Mexico, 19N), combined with data on the glacial chronology and tephrochronology, document Holocene climatic and vegetation changes near the present timberline. Glacial advances occurred between 12 000 and-10 500 cal. yr BP (Milpulco-l) and between 8300 and 7300 cal. yr BP (Milpulco-2). A 450-cm core was drilled in sediments accumulated in a Milpulco-I moraine depression. The sequence covers the last 11 000 cal. yr BP, according to three 14C dates and the presence of a distinctive pumice deposit dated elsewhere at 5700 cal. yr BP. The pollen record of Agua El Marrano shows barren conditions after glacier retreat, followed by a gradual colonization by elements of the alpine grasslands around 10900 cal. yr BP This plant community remained until c. 7200 cal. yr BP. Between c. 7200 cal. yr BP and 6500 cal. yr BP coniferous forest grew close to or at the site, but alpine grasslands were re-established between 6500 cal. yr BP and c. 5000 cal. yr BP, apparently in connection with mid-Holocene dry conditions recorded in central Mexico. The upper timberline attained its modern altitude (- 4000 m) in the last 3000 years. During this period no significant changes are observed in the pollen spectra. Comparison with other palaeoecological records from central Mexico suggests that the timberline fluctuated in response to both temperature and precipitation changes during the Holocene.
Palaeoecology of a palsa and a filled thermokarst pond in a permafrost peatland, subarctic Québec, Canada
Authors: Arlen-Pouliot Yann , Bhiry Najat
Published: April 2005

Radiocarbon dating and macrofossil data from a palsa and a filled thermokarst pond within a subarctic permafrost peatland were used to reconstruct their evolution and to distinguish between allogenic and autogenic processes that had been involved in their development. Peat began to accumulate in the peatland basin shortly after 6000 cal. BR The initial stage was a shallow bay or a salty marsh, followed by a wet marsh triggered by a relatively rapid drop in sea level related to a rapid isostatic uplift of land. By 5640 cal. BP, the site had transformed into a rich fen. A high rate of peat accumulation led to the establishment of a short-lived intermediate fen by 4610 cal. BP and to a poor fen from 4200 cal. BP until 1760 cal. BP. Low water-tables associated with decreased precipitation occurred between 5170 and 4610 cal. BP, and 3100 and 1760 cal. BP Between 1760 and the Little Ice Age, there was ombrotrophication of the site largely as a result of a thick peat accumulation. During this period, autogenic processes had controlled the general hydrosere, while allogenic processes, mainly precipitation, had influenced species composition. Permafrost established during the Little Ice Age leading to palsa formation and it has been melting in response to recent climate warming and precipitation increases. Macrofossil results from the filled thermokarst pond show that plant succession used the followed hydrosere: Calliergon giganteum and Sphagnum riparium when the pond's depth was at a maximum, S. riparium and C. giganteum when the pond was partly filled in, and S. lindbergii and S. riparium since the pond has been completely filled in.
Stick-nest rat middens and a late-Holocene record of White Range, central Australia
Authors: Webeck K. , Pearson S.
Published: April 2005

Stick-nest rat middens are preserved piles of macrofossils that record changes in plants and animals during the late Holocene at White Range. The builders, Lesser Stick-nest Rats (Leporillus apicalis), after at least 2500 years in the area, became extinct during the Modem radiocarbon period. The rats' collection of plant and animal material provides an ecological survey of the site during this period. The species composition of the vegetation has apparently responded to increased Aboriginal populations, fire incidence or rainfall in the last 2500 years. A dramatic increase in tree and shrub material between 2510 +40 BP and 835 +62 BP at the expense of herbs is possibly related to increasing moisture availability. The middens record a collapse of trees and shrubs by 606+136 BP then a strong recovery. Grasses have generally decreased in importance throughout the record. Bones of the Central Rock Rat (Zyzomys pedunculatus), which is currently restricted to the western MacDonnell Ranges, were found in middens dated at 433 +60 BP. Information about long-term changes in Australia's arid areas is accessible using the middens of stick-nest rats and provides a useful long-term perspective for environmental management.
Salinity changes in the central Baltic Sea (NW Europe) over the last 10 000 years: a comment on Emeis, Struk, Blanz, Kohly, Voβ
Authors: Wastegård Stefan , Andrén Thomas
Published: April 2005

We question the effort to date the lower part of a core from the Baltic Sea with a combination of tephra layers and stratigraphical markers. No geochemical data is presented for the two tephra layers, believed to be the Saksunarvatn Ash and Vedde Ash. Furthermore, the age used for one of the stratigraphical markers is erroneous. We present two alternative age models, of which the second gives a plausible sediment accumulation rate but excludes the identification of the Vedde Ash.
Molecular Analysis of Familial Endometrial Carcinoma: A Manifestation of Hereditary Nonpolyposis Colorectal Cancer or a Separate Syndrome?
Authors: Ollikainen Miina , Abdel-Rahman Wael M. , Moisio Anu-Liisa , Lindroos Annette , Kariola Reetta , Järvelä Irma , Pöyhönen Minna , Butzow Ralf , Peltomäki Päivi
Published: April 2005

Purpose

Familial clustering of endometrial carcinoma (EC) may occur as part of hereditary nonpolyposis colorectal cancer (HNPCC), a multiorgan cancer syndrome with mismatch repair (MMR) deficiency. Clustering of EC alone, termed as familial site-specific EC, may constitute a separate entity. Because its genetic basis is unknown, our purpose was to characterize such families molecularly.

Materials and Methods

Twenty-three families with site-specific EC were identified among 519 consecutive patients diagnosed with EC during 1986 to 1997. Tumor tissues were examined for MMR protein expression by immunohistochemical (IHC) analysis, and MMR genes pinpointed by IHC changes were screened for germline mutations by exon-by-exon sequencing, multiplex ligation-dependent probe amplification, and direct tests for mutations common in the population.

Results

Among 33 ECs from 23 families, MLH1 protein was lost in seven tumors (21%), MSH2 together with MSH6 was lost in four tumors (12%), and MSH6 alone was lost in five tumors (15%). A truncating germline mutation in MSH6 (3261insC) was identified in one family and a likely pathogenic missense mutation in MSH2 (D603N) was identified in another family. Among the original 519 patients, nine (all with colon cancer in the family) were diagnosed with HNPCC at the outset—six with MLH1 and three with MSH2 mutations.

Conclusion

Our study gives a minimum overall frequency of 2.1% (11 of 519) for germline MMR defects ascertained through EC in the index patients. The fact that only two of 23 families with site-specific EC (8.7%) had germline mutations in MMR genes suggests another as yet unknown etiology in most families with site-specific EC.
Flavonoid galangin prevents smooth muscle fatigue of pig urinary bladder
Authors: Dambros Miriam , de Jongh Rik , van Koeveringe Gommert A , Bast Aalt , Heijnen C G M , van Kerrebroeck Philip E V
Published: April 2005

There is increasing evidence that the generation of free radicals plays a role in the development of bladder dysfunction. Flavonoids are a group of polyphenolic compounds with broad pharmacological activity. In the present study, the protective effects of the flavonoid galangin on the progressive decrease of bladder smooth muscle contractile responses during repetitive field stimulation (RFS; a model for muscular fatigue) were demonstrated. Pig detrusor strips were mounted for tension recording in organ baths and were subjected to RFS for 90 min at 32 Hz for 15 s every 5 min. The strips were then washed four times with fresh buffer and allowed a period of recovery for 90 min. The 90 min of RFS caused a progressive decrease in maximal contractile response to electrical field stimulation and to muscarinic agonist-induced contractions (34% and 46% decrease, respectively). Galangin (10−7m) prevented the decrease in contractile smooth muscle response of strips to electrical field stimulation during RFS compared with untreated tissues. The antioxidant activity of galangin was assessed by measuring its ability to inhibit the lipid peroxidation induced by iron and ascorbate in rat liver microsomes (IC50 1.7 + 0.12 times 10−6m). If the data are confirmed in-vivo, exogenously administered galangin may be a new approach in the prevention and/or treatment of bladder dysfunction.
Kinetic characterization of glycosidase activity from disaccharide conjugate to monosaccharide conjugate in Caco-2 cells
Authors: Mizuma Takashi , Fuseda Norihiko , Hayashi Masahiro
Published: April 2005

Glycosidase activity influences the intestinal absorption of glycosides. Our previous study in rats suggested that disaccharide conjugates might be prototypes for pre-prodrugs aiming at the Na+/ glucose co-transporter-mediated transport of prodrugs (drug glucoside) as a novel absorption pathway. One of the crucial factors is the formation of a glucoside drug from the disaccharide conjugate. Since there is a large species difference in metabolism, it is necessary to examine the cells and/or enzymes derived from human tissue to confirm this concept. In this paper, we kinetically characterized the glycosidase activity of disaccharide conjugates in Caco-2 cells. Disaccharide conjugates of p-nitrophenol (p-NP) (p-NP β-cellobioside, p-NP β-lactoside and p-NP β-maltoside) were hydrolysed to p-NP β-glucoside. β-glucosidase or β-galactosidase (lactase/phloridzin hydrolase, LPH) and α-glucosidase (sucrase-isomaltase) had different pH-dependent activities for disaccharide conjugates. At neutral pH, LPH has low affinity and low capacity, and sucrase-isomaltase has high affinity and high capacity, whereas at acid pH, LPH has high affinity and low capacity, and sucrase-isomaltase has low affinity and high capacity. The hydrolysis clearance calculated with Vmax/Km indicated that sucrase-isomaltase activity is much higher than LPH activity at either neutral or acid pH in Caco-2 cells. Since the hydrolysis rate of the disaccharide conjugate was highly dependent on the pH value and type of glycoside linkage, the appropriate selection of a glycoside form after consideration of these differences is the key to designing a sugar-conjugate prodrug.
Stabilization of somatropin by heparin
Authors: Zamiri Camellia , Groves Michael J
Published: April 2005

Somatropin, human growth hormone (hGH), is an unstable protein, posing challenging problems for its formulation and long-term stability. Since hGH formed insoluble adducts with heparin our aim was to evaluate heparin as a stabilizing agent for the drug. These adducts were characterized by particle diameter, tertiary structure variations and release studies. Studies were also carried out to determine the stability of hGH in the presence and absence of heparin by an interfacial denaturation method and real-time stability studies by measuring hGH activity and particle diameter. Moreover, biological activity of hGH and hGH/UH (unfractionated heparin) adducts was identified by daily subcutaneous injections to hypophysectomized rats. There was a decrease in mean hydrodynamic particle diameter of hGH/UH adducts with increased pH (54.4 to 12.2 nm from pH 3 to pH 7) indicating that the adducts were either dissociating or dissolving at high pH. Furthermore, second-derivative spectroscopy indicated that complexation of hGH with heparin did not cause a major disruption in the tertiary structure of hGH but decreased the hydrophilic environment around the tyrosine residues. Release of hGH from hGH/UH adducts was pH and ionic strength dependent with the highest release at pH 8 (93%) and lowest release at pH 3 (0%) over the first hour. Interfacial denaturation methods indicated that vortex agitation over 120 s resulted in no change in the optical density of hGH/UH adducts compared with a substantial increase for hGH alone at pH 6.8. Real-time stability studies over 93 days demonstrated that hGH/UH adducts at both pH 3 and 7 with an excess of heparin produced the highest percent of active hGH remaining in the solution at 4°C and 37°C. The higher stability of hGH/UH adducts with excess heparin compared with the stoichiometric ratio was also confirmed by particle size measurements during storage. The biological activity of these adducts was comparable with hGH alone by weight-gain studies in hypophysectomized rats. The findings suggest the value of using hGH/heparin adducts to stabilize the protein.
S-adenosyl-l-methionine: transcellular transport and uptake by Caco-2 cells and hepatocytes
Authors: McMillan J M , Walle U K , Walle T
Published: April 2005

S-adenosyl-l-methionine (SAMe) is an endogenous molecule that is known to be protective against hepatotoxic injury. Although oral SAMe appears to be absorbed across the intestinal mucosa, its systemic bioavailability is low. The reason for this is unknown. Using the Caco-2 cell culture model for enterocyte absorption, we determined the mode by which SAMe is transported across this cell monolayer. We also determined the extent it is taken up by both Caco-2 cells and hepatocytes. In Caco-2 cells transport was observed in both apical to basolateral and basolateral to apical directions. The apparent permeability coefficients (Papp) appeared to be concentration independent and were similar in both directions (0.7 times 10−6 and 0.6 times 10−6 cms−1, respectively), i.e. identical to that of the paracellular transport marker mannitol (0.9 times 10−6 and 0.7 times 10−6 cms−1). This mode of transport was supported by a four-fold increase in the Papp for SAMe transport in Ca++-free buffer. Cellular uptake of SAMe was examined in both Caco-2 cells and cultured rat hepatocytes. Uptake by hepatocytes was not saturable in a concentration range of 0.001–100 μm. Accumulation by both cell types was very low, with a cell:medium ratio at equilibrium of only 0.2–0.5. This low cell accumulation supports the finding of paracellular transport as the only mode of cell membrane transport. Increased hepatocellular protection for SAMe may be accomplished by converting SAMe to a more lipid-soluble prodrug.
Preliminary design and wind tunnel tests of a micro air vehicle for surveillance and sensor-bearing applications
Authors: La Rosa G , Mirone G , Risitano A
Published: April 2005

This work presents the preliminary design of a micro air vehicle (MAV) and the wind tunnel tests of some wing configurations identified, in the design phase, as potentially suitable for the MAV realization. After some considerations about the airfoil adoption and its performance estimation, five possible plan shapes for the wing are defined and the three-dimensional model realization is described. These wings are experimentally tested in a wind tunnel as simple wings and as complete MAV dummies, equipped with vertical fins. The results from the tests allow the selection of the most promising configurations among those tested for the achievement of the desired MAV performance. A final evaluation on the better performing wing is carried out with regard to the placement of the components in its interior and to the calculation of its stability parameters.
An approach to the use of hydrogen for commercial aircraft engines
Authors: Corchero G , Montañés J L
Published: April 2005

This paper presents some results on the performance of hydrogen-based engines. In particular, the following aspects are addressed: Benefits associated with specific fuel and energy consumption, net thrust, turbine entry temperature, and hardware changes needed in the upgrading process from kerosene to hydrogen. Hydrogen is a high-energy clean-burning fuel whose main combustion product is water vapour plus traces of nitrogen oxides. This fact suggests that, provided that the technology is available, the use of hydrogen could offer some opportunities for the environmentally friendly development and sustained growth of commercial aviation. The study has been performed in the frame of the Liquid Hydrogen Fuelled Aircraft — System Analysis (CRYOPLANE) project. This is a Fifth Framework Programme, supported by the European Commission, whose objective was to assess the feasibility of using hydrogen as a clean energy source for air transportation systems.
Remote interpretation in medical encounters: a systematic review
Authors: Azarmina Pejman , Wallace Paul
Published: April 2005

We conducted a systematic review of remote interpretation. Any published or unpublished research article that had telephone or videoconferenced interpretation as an intervention was included in the review. Nine articles were identified: seven on telephone and two on videoconferenced interpretation. Only one study was a randomized controlled trial. Remote interpretation was associated with shorter intervals between consultations, but there were no consistent differences in relation to consultation length. Client and doctor satisfaction was as good with remote interpretation as with face-to-face interpretation, but interpreters preferred face-to-face interpretation. Although the costs associated with remote interpreting are higher, especially in the case of videoconferencing, these may be offset by efficiency gains. The review suggests that remote interpretation is an acceptable and accurate alternative to traditional methods, although the associated costs are higher.
Information on telemedicine
Authors: Brown Nancy A
Published: April 2005

Although the practice of telemedicine is still not considered part of mainstream health care, there has been a steady growth in information about telemedicine since 1999. The increasing body of literature about telemedicine, the staying power of various telemedicine societies and Websites, and the growing number of well-attended conferences about telemedicine all attest that interest in and the practice of telemedicine worldwide are very much alive and well. Searching for information has also become easier with the advent of better and faster search engines, particularly Google. Nonetheless, many Websites are out of date and the semantic confusion between 'telemedicine' and other terms such as 'telehealth' means that considerable perseverance is required to sift the wheat from the chaff. There is a wide variety of both electronic and print resources that have proven to be reliable sources of information. These include: the Internet (Web), books and reports, journals and trade magazines, telemedicine societies and conferences. While telemedicine cannot yet be considered to be part of mainstream health care, it has become a more familiar part of health terminology worldwide.
Remote psychotherapy for terminally ill cancer patients
Authors: Cluver Jeffrey S , Schuyler Dean , Frueh B Christopher , Brescia Frank , Arana George W
Published: April 2005

We conducted a feasibility study of remote psychotherapy in 10 terminally ill cancer patients with diagnoses of adjustment disorder or major depression. Subjects received six sessions of individual cognitive therapy with the same therapist. Sessions alternated between face-to-face sessions and remote sessions delivered by analogue videophone. After each therapy session, a brief questionnaire was used to evaluate the subjects' level of satisfaction with the session, sense of connectedness to the therapist and overall progress being made in the therapy. Nine patients completed the study. Of 53 completed therapy sessions, 21 were by videophone and 32 were conducted face to face. Participants reported strong positive perceptions and acceptance after almost all therapy sessions, regardless of service delivery mode. The study suggests that there may be a role for the delivery of psychotherapy using low-bandwidth videophones.
Role of telehealth in seating clinics: a case study of learners' perspectives
Authors: Khoja Shariq , Casebeer Ann , Young Sybil
Published: April 2005

We conducted a qualitative case study of the introduction of telehealth in a seating clinic, which was an existing outreach service between two hospitals in Alberta, approximately 300 km apart. Interviews were conducted with the staff who were involved in planning and implementing the telehealth initiative. The study showed that, from the perspective of the staff (who were learners), implementation of telehealth in seating clinics differs from other less tactile telehealth applications in certain ways: (1) the importance of multidisciplinary teams in the procedures, (2) the importance of proper visualization and communication among the staff to convey the pressure changes and measurements to the technicians at the major centre to help them build or adjust the seating devices and (3) the reluctance of staff to trust others' judgements. Planning of service provision and telelearning for seating clinics requires the involvement of staff at all stages. Thus, the implementation of telehealth should be a stepwise process, allowing a highly interactive approach, without affecting the multidisciplinary nature of seating clinics.
RNA hydrolysis and inhibition of translation by a Co(III)–cyclen complex
Authors: DELEHANTY JAMES B. , STUART THOMAS C. , KNIGHT D. ANDREW , GOLDMAN ELLEN R. , THACH DZUNG C. , BONGARD JASON E. , CHANG EDDIE L.
Published: April 2005

Metal ion-chelator catalysts based on main-group, lanthanide, or transition metal complexes have been developed as nonenzymatic alternatives for the hydrolysis of the phosphodiester bonds in DNA and RNA. Cobalt (III), with its high-charge density, is known for its ability to hydrolyze phosphodiesters with rate constants as high as 2 × 10−4 s−1. We have developed a kinetically inert Co(III)-cyclen-based complex, Co(III)–cycmmb that is very potent in inhibiting the translation of RNA into protein. Contact time as short as 10 min is sufficient to achieve the complete inhibition of the translation of a concentrated luciferase RNA solution into the enzyme in a cell-free translation system. The inhibition appears to proceed through two pathways. The first pathway involves the kinetic or substitutional inertness of Co(III) for the RNA template at short contact times. This interaction is mediated through the kinetic inertness of Co(III) for the phosphate groups of the nucleotides, as well as coordination of Co(III) to the nitrogenous bases. The second pathway occurs at longer contact times and is mediated by the hydrolysis of the phosphodiester backbone. This report represents the first demonstrated use of a metal–chelate complex to achieve the inhibition of the translation of RNA into protein. This Co(III) system can be useful in its present nonsequence-specific form as a novel viral decontamination agent. When functionalized to recognize specific nucleic acid sequences, such a system could potentially be used in gene-silencing applications as an alternative to standard antisense or RNAi technologies.
A novel RNA pentaloop fold involved in targeting ADAR2
Authors: STEFL RICHARD , ALLAIN FRÉDÉRIC H.-T.
Published: April 2005

Adenosine deaminases that act on RNA (ADARs) catalyze the site-specific conversion of adenosine to inosine in primary mRNA transcripts, thereby affecting coding potential of mature mRNAs. Structural determinants that define the adenosine moieties for specific ADARs-mediated deaminations are currently unknown. We report the solution structure of the central region of the human R/G stem–loop pre-mRNA, a natural ADAR2 substrate encoding the subunit B of the glutamate receptor (R/G site). The structure reveals that the GCU(A/C)A pentaloop that is conserved in mammals and birds adopts a novel fold. The fold is stabilized by a complex interplay of hydrogen bonds and stacking interactions. We propose that this new pentaloop structure is an important determinant of the R/G site recognition by ADAR2.
Complete, gene-specific siRNA libraries: Production and expression in mammalian cells
Authors: SEYHAN ATTILA A. , VLASSOV ALEXANDER V. , ILVES HEINI , EGRY LEVENTE , KASPAR ROGER L. , KAZAKOV SERGEI A. , JOHNSTON BRIAN H.
Published: April 2005

Short interfering RNAs (siRNAs) are widely used to silence the expression of specific genes. Current practice for designing effective siRNAs is to use algorithms based on sequence-efficacy correlations; however, there are many highly effective sequences that these algorithms do not anticipate. To ensure that the best siRNAs are identified, all possible gene-specific siRNA sequences of appropriate lengths should be screened in cell culture. Synthesizing and testing all such sequences individually is costly. A potentially much easier alternative is to prepare a mixture of all these sequences (a gene-specific library), express them in cells, select cells having the desired phenotype, and identify the siRNA contained within the selected cells. Here we describe two new methods for preparing and expressing such libraries. The first uses cloned Dicer or RNase III to digest gene-specific RNA duplexes to siRNAs, which are then converted to the corresponding DNA sequences by attaching RNA primers and performing reverse transcription-PCR. The second method involves partial DNase I digestion of gene-specific DNA, purification of a 20–30-bp fraction, and amplification by attaching DNA adapters followed by PCR. DNA libraries specific for TNF-α, DsRed, and part of the hepatitis C virus genome, generated by methods, were inserted into siRNA expression vectors between convergent human U6 and H1 promoters. Randomly selected clones from each library together with vectors expressing the corresponding target genes were cotransfected into 293FT cells and assayed for target gene inhibition. About 10%–20% of siRNAs represented in these libraries show significant inhibition of their target genes. Most of these inhibitory sequences are not predicted by existing algorithms.
Embedding technology in community-based production systems through People's Technology Initiatives: Lessons from the Indian experience
Authors: Abrol Dinesh
Published: April 2005

The People's Technology Initiative (PTI) represents a radical departure from the conventional paradigm to science and technology (S&T) and rural development by providing an alternative to it. The PTI approach emerged out of the broader People's Science Movement in India, itself
a backlash against what was viewed as the weak governance of science and its failure to meet the needs of the poor and enhance their productive capacities. Elements of the PTI philosophy reflect these contextual origins with an approach that seeks to build technology systems around local knowledge,
resources, and economies, rather than vice versa, as is the case with conventional models of technology development. Networking as an aspect of building partnership has been a very important component in PTI - both in terms of individual initiatives and in promoting and supporting the PTI
approach. Notable also is the capacity development focus of PTI in terms of enhancing the skills and technologies of poor people and linking them to sources of S&T, thereby enhancing the capacity of the local technology system. The evolutionary characteristics of this capacity development
reflect the learning-based nature of the PTI approach. PTI presents a rather radical alternative to mainstream S&T and rural development initiatives. It also contains principles of partnership and learning that are of generic significance, capable of being applied to poverty reduction
programmes in different countries.
Globalization, technological competitiveness and the ‘catch-up’ challenge for developing countries: some lessons of experience
Authors: Zhouying Jin
Published: April 2005

The rapid pace of globalization has increased the desire of many developing countries to catch up on the developed ones as quickly as possible. The reality, however, is that the gap between the poor and the rich has widened over the years. This article takes up the case for building
technological competitiveness as the way forward for developing countries to face the ‘catch-up’ challenge. Technological competitiveness is conditional on three key factors - access to competitive technology, continuous innovation of soft technology and provision of a soft environment
or macro environment system (including a hard environment and a soft environment) that is favourable for innovation. The article attributes the gap between developed and developing countries mainly to differences in soft technology and soft environment.
Explaining economic growth in South Africa: a Kaldorian approach
Authors: Millin Mark , Nichola Tennassie
Published: April 2005

The share of the manufacturing sector of South Africa in GDP doubled in the two decades following World War II. The growth of this sector after 1975 however, has been modest. Nevertheless, with respect to employment and income generation, manufacturing is the leading sector in the South
African economy. This study examined the growth characteristics of South Africa using the Kaldorian approach, which purports that the manufacturing sector is the engine of economic growth. Various specifications of Kaldor's three growth laws were estimated. The empirical results support the
predictions of Kaldor's growth model and are comparable to similar studies done in the United Kingdom, Greece, Turkey and China.
Effects of Automation of Information-Processing Functions on Teamwork
Authors: Wright Melanie C. , Kaber David B.
Published: April 2005

We investigated the effects of automation as applied to different stages of information processing on team performance in a complex decision-making task. Forty teams of 2 individuals performed a simulated Theater Defense Task. Four automation conditions were simulated with computer assistance applied to realistic combinations of information acquisition, information analysis, and decision selection functions across two levels of task difficulty. Multiple measures of team effectiveness and team coordination were used. Results indicated different forms of automation have different effects on teamwork. Compared with a baseline condition, an increase in automation of information acquisition led to an increase in the ratio of information transferred to information requested; an increase in automation of information analysis resulted in higher team coordination ratings; and automation of decision selection led to better team effectiveness under low levels of task difficulty but at the cost of higher workload. The results support the use of early and intermediate forms of automation related to acquisition and analysis of information in the design of team tasks. Decision-making automation may provide benefits in more limited contexts. Applications of this research include the design and evaluation of automation in team environments.
Automation in Future Air Traffic Management: Effects of Decision Aid Reliability on Controller Performance and Mental Workload
Authors: Metzger Ulla , Parasuraman Raja
Published: April 2005

Future air traffic management concepts envisage shared decision-making responsibilities between controllers and pilots, necessitating that controllers be supported by automated decision aids. Even as automation tools are being introduced, however, their impact on the air traffic controller is not well understood. The present experiments examined the effects of an aircraft-to-aircraft conflict decision aid on performance and mental workload of experienced, full-performance level controllers in a simulated Free Flight environment. Performance was examined with both reliable (Experiment 1) and inaccurate automation (Experiment 2). The aid improved controller performance and reduced mental workload when it functioned reliably. However, detection of a particular conflict was better under manual conditions than under automated conditions when the automation was imperfect. Potential or actual applications of the results include the design of automation and procedures for future air traffic control systems.
Interruption Management: The Use of Attention-Directing Tactile Cues
Authors: Hopp Pamela J. , Smith C. A. P. , Clegg Benjamin A. , Heggestad Eric D.
Published: April 2005

Previous research has suggested that providing informative cues about interrupting stimuli aids management of multiple tasks. However, auditory and visual cues can be ineffective in certain situations. The objective of the present study was to explore whether attention-directing tactile cues aid or interfere with performance. A two-group posttest-only randomized experiment was conducted. Sixty-one participants completed a 30-min performance session consisting of aircraft-monitoring and gauge-reading computer tasks. Tactile signals were administered to a treatment group to indicate the arrival and location of interrupting tasks. Control participants had to remember to visually check for the interrupting tasks. Participants in the treatment group responded to more interrupting tasks and responded faster than did control participants. Groups did not differ on error rates for the interrupting tasks, performance of the primary task, or subjective workload perceptions. In the context of the tasks used in the present research, tactile cues allowed participants to effectively direct attention where needed without disrupting ongoing information processing. Tactile cues should be explored in a variety of other visual, interruptladen environments. Potential applications exist for aviation, user-interface design, vigilance tasks, and team environments.
Interacting With Notebook Input Devices: An Analysis of Motor Performance and Users' Expertise
Authors: Sutter Christine , Ziefle Martina
Published: April 2005

In the present study the usability of two different types of notebook input devices was examined. The independent variables were input device (touchpad vs. minijoystick) and user expertise (expert vs. novice state). There were 30 participants, of whom 15 were touchpad experts and the other 15 were mini-joystick experts. The experimental tasks were a point-click task (Experiment 1) and a point-drag-drop task (Experiment 2). Dependent variables were the time and accuracy of cursor control. To assess carryover effects, we had the participants complete both experiments, using not only the input device for which they were experts but also the device for which they were novices. Results showed the touchpad performance to be clearly superior to mini-joystick performance. Overall, experts showed better performance than did novices. The significant interaction of input device and expertise showed that the use of an unknown device is difficult, but only for touchpad experts, who were remarkably slower and less accurate when using a mini-joystick. Actual and potential applications of this research include an evaluation of current notebook input devices. The outcomes allow ergonomic guidelines to be derived for optimized usage and design of the mini-joystick and touchpad devices.
Design and Evaluation of a Prototype Rear Obstacle Detection and Driver Warning System
Authors: Llaneras Robert E. , Green Charles A. , Kiefer Raymond J. , Chundrlik William J. , Altan Osman D. , Singer Jeremiah P.
Published: April 2005

This study, concerned with the development of driver interface criteria for a rear obstacle detection system, assessed the appropriateness of alternative warning timing algorithms and evaluated various interface approaches for presenting warning information to drivers. Interface testing used a minivan and a passenger sedan equipped with a prototype rear obstacle detection system. Two different warning timing algorithms and four different interface conditions were examined. The appropriateness of the warning timing algorithms was tested using an alerted backing procedure wherein drivers backed to known obstacles and braked in response to the warning. A surprise event scenario was also included in order to examine driver reaction to the warning under unexpected conditions. Alerted backing results suggest that although both timing algorithms led to few target strikes, one algorithm led to more acceptable ratings, fewer target strikes and close calls, and less urgent braking. None of the interface warning conditions reliably induced avoidance braking under the surprise event condition. Actual or potential applications of this work include the appropriate design of effective backing warning systems.
The Science of Public Messages for Suicide Prevention: A Workshop Summary
Authors: Chambers David A. , Pearson Jane L. , Lubell Keri , Brandon Susan , O'Brien Kevin , Zinn Janet
Published: April 2005

There is minimal guidance for efforts to create effective public messages that increase awareness that suicide is preventable. To address this need, several agencies in the U.S. Department of Health and Human Services and the Annenberg Foundation convened a workshop consisting of suicide prevention advocates and persons with expertise in public health evaluation, suicide contagion, decision‐making, and marketing. “Logic models” were used to define intended messages and audiences, assumed mechanisms of change, and outcomes. This summary describes some of the challenges and opportunities identified by workshop participants in evaluating public awareness campaigns in suicide prevention, technical assistance needs, and a proposed research agenda.
Historical Change of Suicide Seasonality in the Canton of Zurich, Switzerland
Authors: Ajdacic‐Gross Vladeta , Bopp Matthias , Eich Dominique , Gostynski Michal , Rössler Wulf , Gutzwiller Felix
Published: April 2005

Current research is yielding an increasingly heteregeneous picture of suicide seasonalities: They seem to depend on methods and, moreover, they seem to have smoothed in recent decades. This work examines the latter issue by comparing suicide seasonalities in the canton of Zurich, Switzerland, in the 16th–18th centuries, 1901–1920 and 1969–94. The results indicate shifts of peaks and lows on suicide seasonalities over the centuries, with a smoothing of seasonalities toward the 21th century. The recent period does not show any suicide seasonality at all. The canton of Zurich seems to be ahead of the general trend found in other regions of Switzerland.
In-situ-Messung von Strom- und Spannungsverläufen in Mikrowellentransistoren (In-situ Measurement of Current and Voltage Waveforms in Microwave-Transistors)
Authors: Arthaber Holger
Published: April 2005

Dieser Artikel stellt ein Messsystem vor, welches über indirekte Messung eine Echtzeitdarstellung von Strom und Spannung am aktiven Kanal eines nichtlinear betriebenen Mikrowellentransistors erlaubt. Zusätzlich ist es möglich, die Lastimpedanzen sowohl bei der Ausgangsfrequenz als auch bei den durch die Nichtlinearität entstehenden Oberwellen getrennt voneinander einzustellen. Um die Messung von Transistoren in hocheffizienten Betriebspunkten zu ermöglichen, ist eine nahezu perfekte Reflexion der Oberwellen erforderlich, welche mittels „aktiver Lasten“ erzielt wird. Die Funktion des Aufbaus wird mit Messungen an einem pHEMT-Mikrowellentransistor gezeigt.
Einzelelektronen-Schaltungen für Anwendungen in der Metrologie (Single-Electron Circuits for Metrological Applications)
Authors: Scherer Hansjörg
Published: April 2005

Die elektrische Abstoßung zwischen einzelnen Elektronen manifestiert sich in ultrakleinen metallischen Tunnelkontakt-Schaltungen als makroskopisch beobachtbarer Effekt, wenn deren Coulomb-Wechselwirkung auf der Energieskala dominiert. Die resultierenden Einzelladungseffekte erlauben eine gezielte Manipulation einzelner Ladungsquanten und damit einzigartige Anwendungen für die elektrische Metrologie. Zu den metrologisch interessanten Einzelelektronen-Bauelementen zählen Elektrometer, die den Nachweis kleinster elektrischer Ladungen in der Größenordnung von Bruchteilen der Elementarladung ermöglichen, und die so genannte Einzelelektronenpumpe, die den getakteten Transfer von Ladungsquanten durch eine Schaltung und damit prinzipiell die Realisierung eines Quantenstromnormals gestattet. Die Kombination beider Schaltungstypen ermöglicht schließlich die Implementierung eines neuartigen Kapazitätsstandards. Dieser Beitrag gibt einen Überblick über die genannten Themenfelder und geht auf den aktuellen Stand der metrologischen Anwendung an der PTB ein.
Monolithische Korrelationsempfänger für optische Abstandsmessung (Integrated Correlation Receivers for Runtime Based Optical Distance Measurement)
Authors: Oberhauser Klaus , Nemecek Alexander , Zimmermann Horst
Published: April 2005

Durch Laufzeitmessung von Licht können diffus reflektierende räumliche Objekte mit integrierten optischen Abstandssensoren sehr schnell vermessen werden. Mögliche Anwendungsgebiete sind z.B. Sicherheitsanwendungen im Automobil. Sehr kurze Laufzeiten (ns) sowie geringe optische Empfangsleistung (nW), resultierend aus der notwendigen Augensicherheit, stellen hohe Anforderungen an den Empfänger, denen die integrierten PIN-Photodioden durch hohen Wirkungsgrad (R=0.36A/W @ 660nm) bei hoher Detektorbandbreite (f
3dB=1.35GHz) genügen. Anhand zweier realisierter Sensorkonzepte werden unterschiedliche Funktionsweisen demonstriert: interne und externe Signalkorrelation des Photodetektors. Der Laboraufbau, bestehend aus modulierter Lichtquelle (Laser), Optik, Sensorchip, Ansteuerlogik und Messauswertung, ermöglicht durch Mittelung Messgenauigkeiten von 1% für Abstände bis zu 3.7m. Die optoelektronischen integrierten Schaltungen (OEICs) sind in einem modifizierten 0,6-μm-BiCMOS-Prozess hergestellt.
INTELIGÊNCIA ARTIFICIAL: SISTEMAS ESPECIALISTAS NO GERENCIAMENTO DA INFORMAÇÃO
Authors: Mendes Raquel Dias
Published: April 2005

O principal objetivo deste artigo é propor um modelo para sistemas de gerenciamento da informação baseado em técnicas de inteligência artificial. O modelo propõe uma arquitetura de sistema especialista para gerenciamento da informação, sugerindo a utilização de um analisador semântico embutido na interface do usuário final. A abordagem enfatiza a dificuldade em se obter informações com precisão e qualidade, para apoiar tomadores de decisões, e a necessidade de prover os usuários finais com mecanismos, poderosos, capazes de analisar, selecionar e direcionar-lhes informações, de acordo com as necessidades e urgências de cada um
BIBLIOTECONOMIA: PRODUÇÃO E ADMINISTRAÇÃO DA INTERPRETAÇÃO
Authors: Lucas Clarinda Rodrigues
Published: April 2005

Este trabalho privilegia a leitura do bibliotecário para fins de indexação e, trazendo para a discussão as contribuições da Análise do Discurso, verifica o lugar deste profissional na divisão social do trabalho de leitura. Contrapondo textos que tratam da teoria de indexação (o modo de leitura do bibliotecário) às palavras-chave, os cabeçalhos de assunto que são o resultado desta leitura, dá visibilidade à subjetividade deste leitor. Conclui que a explicitação dos processos que informam a leitura do bibliotecário em sua prática de indexação, somado ao instrumental teórico-metodológico que a apóia, contribui para que esta leitura seja mais fecunda e desdobradora de representações dos textos existentes nas bases de dados das bibliotecas
A INTERNET E SEU IMPACTO NOS PROCESSOS DE RECUPERAÇÃO DA INFORMAÇÃO
Authors: Teixeira Cenidalva Miranda de Sousa , Schiel Ulrich
Published: April 2005

Mostramos como as tecnologias da informação, em particular a Internet, estão provocando uma globalização das atividades de recuperação de informação e pesquisa bibliográfica. Apresentamos as diversas formas de interação na Internet e os principais serviços existentes atualmente referentes à recuperação bibliográfica
INCUBADORA DO CONHECIMENTO
Authors: Barbosa Eduardo José Siqueira
Published: April 2005

A partir da experiência de cinco anos na criação e operação de um sistema de atendimento de demandas "tecnológicas", especialmente de micro e pequenas empresas (Disque-Tecnologia da USP), o autor reflete sobre as possibilidades da utilização da informação como matéria-prima para construção de conhecimento. Propõe uma filosofia a ser empregada na criação da incubadora de conhecimento, que considera, em primeiro lugar, atenção total à demanda para criar mecanismos de identificação dos interesses e necessidades imediatas dos hospedes. Ilustra, com alguns exemplos, que o conhecimento, construído a partir do cotidiano, é adquirido na exata medida das necessidades e capacidades de cada pessoa em um processo mais rápido e produtivo que o formal. A disponibilização, para consumo, de informação simples e básica é o ambiente favorável, que se deseja, para o crescimento do conjunto de conhecimentos dos hóspedes da Incubadora
Perspectivas profissionais e educacionais em biblioteconomia e ciência da informação
Authors: Barbosa Ricardo Rodrigues
Published: April 2005

O artigo analisa a área de biblioteconomia/ciência da informação em termos dos desafios e oportunidades atuais para os profissionais e para os programas de formação profissional. As desvantagens da denominação tradicional da profissão, usualmente associada à biblioteca e ao livro, são abordadas. Soluções adotadas por escolas, departamentos e entidades profissionais, especialmente na América do Norte e na Grã-Bretanha, são relatadas. Aponta oportunidades para profissionais de informação possuidores de habilidades diversificadas. Apresenta modelos que retratam a importação e exportação de conhecimento entre a biblioteconomia/ ciência da informação e outras áreas. Defende a necessidade de se promover a aplicação do conhecimento específico da área de biblioteconomia/ciência da informação em contextos e ambientes informacionais amplos.
Análise das citações das dissertações de mestrado e teses de doutorado em saúde pública (1990-1994): estudo exploratório
Authors: Noronha Daisy Pires
Published: April 2005

Parte de análise de dissertações de mestrado e teses de doutorado defendidas, de 1990 a 1994, nos cursos de pós-graduação em saúde pública da Escola Nacional de Saúde Pública da Fundação Oswaldo Cruz (ENSP/Fiocruz), Faculdade de Saúde Pública da Universidade de São Paulo (FSP/USP) e Instituto de Medicina Social da Universidade Estadual do Rio de Janeiro (IMS/UERJ), visando a detectar aspectos referentes às características dos documentos citados, como subsídios para estabelecimento de indicadores necessários à avaliação da produção científica brasileira no campo da saúde pública. O conjunto das citações amostradas (6 019) de 266 dissertações de mestrado e 84 teses de doutorado revelou que os artigos de periódicos contribuíram com maior número de citações (46,7%); o percentual de livros foi mais representativo para as teses de doutorado; a maior concentração dos documentos citados encontra-se no conjunto publicado de 6 a 10 anos da defesa da dissertação/tese; o idioma português predominou nas citações (49,3%) e o inglês para os artigos de periódicos; os alunos valeram-se mais de dissertações/teses de outras instituições do que das escolas que freqüentaram.
Mudança estrutural no fluxo do conhecimento: a comunicação eletrônica
Authors: Barreto Aldo de Albuquerque
Published: April 2005

A estrutura da relação entre o fluxo de informação e o público a quem o conhecimento é dirigido vem se modificando com o tempo, como uma função das diferentes técnicas que operam na transferência da informação, do gerador ao receptor. O fluxo em si, uma sucessão de eventos, de um processo de mediação, entre a geração da informação por uma fonte emissora, e a aceitação da informação pela entidade receptora, realiza uma das bases conceituais que se acredita ser o cerne da ciência da informação: a geração de conhecimento no indivíduo e no seu espaço de convivência. Assim, o propósito deste artigo é mostrar que o fluxo da informação que interliga gerador e receptor vem agregando competência na transmissão, em uma relação direta com as fases por que passou o desenvolvimento do processo de transferência da informação até chegar ao tempo da comunicação eletrônica que viabiliza com maior intensidade a relação de interação que nos interessa observar.