bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanisms Controlling the Temperature‐Dependent Binding of Proteins to Poly(N‐isopropylacrylamide) Microgels
Authors: Grabstain Violet , Bianco‐Peled Havazelet 
Published: December 2003

AbstractPoly(N‐isopropylacrylamide) (PNIPA) microgels may offer several advantages over PNIPA‐modified surfaces when used as sorbents in temperature‐sensitive chromatography. Yet, a full exploitation of these advantages requires a better understanding of the mechanisms controlling the separation process. As a model system, we have studied the binding of three proteins (bovine serum albumin (BSA), ovalbumin, and lysozyme) to PNIPA microgels. Binding experiments were conducted both below (25 °C) and above (37 °C) the volume phase transition temperature of the gel, Tc. The analysis of the binding isotherms has shown that although an average gel particle contained a larger amount of protein below the phase transition temperature, the concentration of the protein within the particle was higher above this temperature. These findings were attributed to changes in the binding loci due to temperature swings around Tc: whereas a sorption mechanism is dominant below this temperature, surface‐adsorption was more important above it. A comparison between the three studied proteins has shown that below Tc the binding increases with a decrease in the molecular weight. On the other hand, no significant difference in the bound protein amounts was observed above the phase transition temperature. Our results imply that, despite the increase in the gelapos;s hydrophobicity above the phase transition temperature, the resolution in bioseparations based on PNIPA gels is not necessarily better above Tc.
Detection of Benzene, Toluene, Ethyl Benzene, and Xylenes (BTEX) Using Toluene Dioxygenase‐Peroxidase Coupling Reactions
Authors: Xu Zhaohui , Mulchandani Ashok , Chen Wilfred 
Published: December 2003

AbstractWe have developed a simple, whole‐cell bioassay for the detection of bioavailable benzene, toluene, ethyl benzene, and xylenes (BTEX) and similar compounds. A genetically engineered E. coli strain expressing toluene dioxygenase (TDO) and toluene dihydrodiol dehydrogenase (TodD) was constructed, enabling the conversion of BTEX into their respective catechols, which were quickly converted into colored products by a horseradish peroxidase (HRP)‐coupled reaction. The intensity of the color formation was correlated to concentrations of the BTEX compounds. Under the optimized conditions, a detection limit (defined as three times the standard deviation of the response obtained from the blank) of 10, 10, 20, and 50 μM was observed for benzene, toluene, ethyl benzene, and xylene, respectively. The bioassay was selective toward BTEX‐related compounds with no interference observed with commonly used pesticides, herbicides, and organic solvent. The bioassay was very stable with little change in response over a 10‐week period. The excellent stability suggests that the reported bioassay may be suitable for field monitoring of BTEX to identify and track contaminated water and follow the bioremediation progress.
Macro‐Level and Genetic‐Level Responses of Bacillus subtilis to Shear Stress
Authors: Sahoo Susmita , Verma Rajesh K. , Suresh A. K. , Rao K. Krishnamurthy , Bellare Jayesh , Suraishkumar G. K. 
Published: December 2003

AbstractResponses of bacterial (Bacillus subtilis) cells under different shear levels, from both the macro and genetic viewpoints, have been presented. The responses were studied using a novel, couette flow bioreactor (CFB), in which the entire cultivation can be performed under defined shear conditions. Oxygen supply, the normal limiting factor for entire cultivations under defined shear conditions, has been achieved by passing air through a poly(tetrafluoroethylene) (PTFE) membrane fixed on the inner cylinder of the CFB. More importantly, analyses of the oxygen transfer capabilities as well as the shear rates show that in this CFB, the effects of defined shear can be studied without interference from the effects of oxygen supply. Further, the shake flask can be used as a proper control for studying the shear effects, mainly because the shear rate in the shake flask under normal shaker operating conditions of 190 rpm has been estimated to be a negligible 0.028 s‐1 compared to a value of 445 s‐1 at the lowest rpm employed in the CFB. At the macro level the cell size decreased by almost 50% at 1482 s‐1 compared to that at 0.028 s‐1, the growth rate increased by 245%, and the maximum cell concentration increased by 190% when the shear rate was increased from 0.028 to 1482 s‐1. The specific intracellular catalase level increased by 335% and protease by 87% at 1482 s‐1 as compared to the control cultures at a shear rate 0.028 s‐1. In addition, the specific intracellular reactive oxygen species level (siROS) at the highest shear rate was 9.3‐fold compared to the control conditions. At the genetic level we have established the involvement of the transcription factor, σB, in the bacterial responses to shear stress, which was unknown in the literature thus far; the σB expression correlated inversely with the siROS. Further, through experiments with ROS quenchers, we showed that ROS regulated σB expression under shear.
Diapycnal mixing in the Banda Sea: Results of the first microstructure measurements in the Indonesian Throughflow
Authors: Alford Matthew H. , Gregg Michael C. , Ilyas Muhammed 
Published: December 2003

Models involving basin‐averaged T/S properties [Ffield and Gordon, 1992; Hautala et al., 1996] and barotropic/baroclinic tidal energy conversion [Sjöberg and Stigebrandt, 1992] suggest that the Indonesian archipelago is a site of active mixing. This paper describes the first microstructure measurements made in the region. Aboard the R/V Baruna Jaya IV, we repeated 18 km legs centered on (6.5°S, 128°E), in the central Banda Sea, for two weeks during Oct/Nov 1998.With the Modular Microstructure Profiler, we gathered 519 profiles of potential temperature, salinity, potential density, pressure and kinetic energy dissipation rate. The cruise‐mean diapycnal diffusivity from 20–300 m is
, similar to “open ocean” [Garrett and Munk, 1975] values (Kρ = 5.1 × 10−6 m²s−1), and an order of magnitude below basin‐ and time‐averaged values obtained from the Ffield and Gordon [1992] and Hautala et al. [1996] models (Kρ ≥ 1 × 10−4 m²s−1). Sea‐surface temperature displays some evidence of a fortnightly modulation, interpreted by Ffield and Gordon [1996] as evidence for tidal mixing, but is uncorrelated with the dissipation rate just below the mixed layer.
Oceanic primary productivity and dissolved oxygen levels at the Cretaceous/Tertiary Boundary: Their decrease, subsequent warming, and recovery
Authors: Kaiho Kunio , Kajiwara Yoshimichi , Tazaki Kazue , Ueshima Masato , Takeda Nobuyori , Kawahata Hodaka , Arinobu Tetsuya , Ishiwatari Ryoshi , Hirai Akio , Lamolda Marcos A. 
Published: December 2003

Thirty‐six different geochemical and foraminiferal analyses were conducted on samples collected at closely spaced intervals across the Cretaceous/Tertiary (K/T) boundary exposed at Caravaca, Spain. A rapid reduction in the gradient between δ13C values in fine fraction carbonate and benthic foraminiferal calcite and a decrease in the abundance of phosphorus (a proxy for organic carbon) and calcium were recorded in sediments 0–0.5 cm above the K/T boundary. These trends imply that an abrupt mass mortality occurred among pelagic organisms, leading to a significant reduction in the flux of organic carbon to the seafloor. In addition, variations in sulfur isotope ratios, the hydrocarbon‐generating potential of kerogen (measured as the hydrogen index), and foraminiferal indices of dissolved oxygen level all imply that a rapid decrease in dissolved oxygen was coincident with the δ13C event. Evidence of the low oxygen event has also been recognized in Japan and New Zealand, suggesting that intermediate water oxygen minima were widely developed during earliest Danian time. A threefold increase in the kaolinite/illite ratio and a 1.2‰ decrease in δ18O (carbonate fine fraction) were recorded in the basal 0.1–2 cm of Danian age sediments. These trends suggest that atmospheric warming and an increase in surface water temperature occurred 0–3 kyr after the δ13C event. Recovery in the difference between δ13C values in the carbonate fine fraction and in benthic foraminiferal calcite as well as increases in phosphorus and calcium contents occur at the base of planktonic foraminiferal Zone Pla, implying that an increase in primary productivity commenced some 13 kyr after the K/T boundary.Tables A1‐A3 are available on diskette or via Anonymous FTP from kosmos.agu.org directory APENO (Username = anonymous, Password = guest). Diskette may be ordered from American Geophysical Union, 2000 Florida Avenue, N.W., Washington, DC 20009 or by phone at 800‐966‐2481; $15.00. Payment must accompany order.
Natural resources and ‘gradual’ reform in Uzbekistan and Turkmenistan
Authors: Auty Richard 
Published: December 2003

Abstract Among low‐income transition reformers, natural resource rents are an important initial condition that helps explain choice of reform strategy. Resource‐rich Uzbekistan and Turkmenistan and resource‐poor China and Vietnam all claim to pursue gradual reform, but their strategies differ. In China and Vietnam, low resource rents have nurtured developmental political conditions and encouraged efficient resource use, which initially promoted agriculture as a dynamic market sector, capable of absorbing labour from the lagging state sector. In contrast, the scale and ease of natural resource rent extraction in the Central Asian countries has consolidated authoritarian governments that postpone reform. Despite high energy rents, Uzbekistan and Turkmenistan still extract agricultural rents in ways that repress farm incentives, perpetuate environmental degradation and liquidate irrigation assets. Uzbekistan uses its rents to subsidize a manufacturing sector, that is neither dynamic nor competitive. As its dynamic sector, Turkmenistan promotes natural gas exports that depend on volatile markets. Resource‐driven development models suggest that reform is required in both countries to avert a growth collapse. Turkmenistan's large energy rent‐stream may postpone a collapse for some years, but Uzbekistan's position is already precarious: it has run down its rural infrastructure and accumulated sizeable foreign debts and will require external assistance to recover from a growth collapse. Such assistance should be made conditional on accelerated economic and political reform.
Risk attitudes and mitigation among gold miners and others in the Suriname rainforest
Authors: Heemskerk Marieke 
Published: December 2003

Abstract This article analyses the question: do attitudes towards risk influence participation in small‐scale gold mining, a hazardous activity that generates uncertain income? This question is examined by measuring and comparing the risk attitudes of gold miners and non‐mining community members in the rainforest of Suriname, South America. The author presents a multivariate model to predict the duration of work in mining areas as a function of risk tolerance, age, education, and household demographics. The results suggest that a greater tolerance to risk increases the duration of a person's mining career. However, attitudes explain only a fraction of the variation in occupational choices. Qualitative data suggest that these choices are primarily shaped by local barriers to human capital development and by national economic volatility. Given their marginal position in society and the multitude of mining risk mitigation strategies, it is questionable whether gold mining exposes Suriname forest peoples to greater risks than other subsistence alternatives. The author argues that sensitivity to local historical and cultural conditions would improve the efficiency of policies aimed at developing a more sustainable mining industry. By zooming in on the daily lives of miners, anthropology can complement macro‐scale analyses and contribute to policy interventions in the small‐scale mining sector.
Universal access to water and sanitation: Why the private sector must participate
Authors: Lee Terence , Floris Vinio 
Published: December 2003

AbstractAgainst the background of the current state of provision of drinking water and sanitation in the world — with one billion lacking safe water, and 2.2 billion not having adequate sanitation — this article argues that private participation is necessary. The most important issues for the management of water utilities in the 21stcentury are identified as mobilizing investment for the highly capital intensive operation of water supply and sanitation infrastructure, and achieving efficiency in the delivery of services. The article highlights the issues that need to be raised if private investment is to be seriously considered as an alternative. Case studies, especially from Latin America (Argentina, Chile, Peru, Bolivia), illustrate different modes of private participation, and possible reasons for successes and failures are discussed.The article stresses that regardless of the modality of private sector involvement, on‐going government regulatory responsibility in the water sector is crucial. It suggests that regulatory policy must go beyond just setting tariffs, to develop standards for drinking water quality and waste treatment, as well as other standards. In conclusion, the article recognizes that numerous and increasingly difficult challenges face utilities in fulfilling their responsibility to deliver drinking water of adequate quality, in sufficient quantity, and at affordable prices, as well as safe and sustainable disposal of wastewaters for members of urban and rural communities.
Nigerian Supreme Court and ownership of offshore oil
Authors: Ebeku Kaniye S.A. 
Published: December 2003

Abstract This article discusses the decision of the Supreme Court of Nigeria on the constitutional provision dealing with the sharing of revenues derived from natural resources located within the states of the Federation, the ‘derivation principle.’ Although the case relates to the interpretation of a constitutional provision, the arguments of the parties suggest that the real battle was — and still is — about the ownership and control of Nigeria's offshore oil. The article details the legal history and precedents as well as constitutional provisions relevant to the case. Disagreements arose over legal questions such as the seaward boundaries of littoral states (from which oil revenues are derived), and whether a distinction can be made between offshore and onshore oil revenues in applying a 13% constitutionally prescribed derivation principle. The article shows that, in its judgment, Nigeria's Supreme Court relied heavily on rules of international law, while failing to apply existing Nigerian laws and constitutional provision, and argues that the decision might have been different had the court investigated and invoked the legislative history of the provision in question, as required in Nigerian law. Furthermore, it is argued that the court was wrong to disregard the provision of the law which had abolished any distinction between onshore and offshore natural resources in the application of the derivation principle. The article concludes that the legal tug of war is set to continue for some years.
Tropical deciduous forests and the adivasi. Indigenous traditions as response to leaf fall in Bastar, India
Authors: Ramnath Madhu 
Published: December 2003

Abstract This article draws attention to the crucial link between the tropical deciduous forest ecosystem and the lifestyle of the adivasi (indigenous) people. Taking the case of Bastar District in Chhattisgarh, Central India, an analysis is made of the various commonly used wild plants, their deciduous habit, and the adivasi calendar that regulates the peoples’ use of these plants. By examining the specific seasonal patterns of leaf fall of plants and the dates set for the commencement of their use, the article shows that there is an implicit relation between adivasi festivals and the deciduous character of Bastar's forests.
Preventive home visits for community‐dwelling frail elderly people based on Minimum Data Set‐Home Care: Randomized controlled trial
Authors: Yamada Yukari , Ikegami Naoki 
Published: December 2003

Background:  Although preventive home visits for the elderly are mandatory in Japan, there has been little research into their effectiveness. The present study used the Minimum Data Set‐Home Care (MDS‐HC) as the basis for assessing community‐dwelling frail elderly persons.Methods:  The present study was a randomized controlled, community‐based investigation of 368 elderly people aged 65 years and older who were dependent in the instrumental activities of daily living, but independent in activities of daily living. The participants were randomly assigned to an intervention group (184) or a control group (184). For 18 months, the intervention group received scheduled home visits by public health nurses who had been instructed that the primary objective of these visits was human interaction. The MDS‐HC was used to assess the elderly person at each visit. The primary outcome was the EQ‐5D score of the EuroQol and secondary outcomes were five items constituting the EQ‐5D, self‐rated health, and health behaviors. The types of advice given and subject compliance were also analyzed.Results:  Intervention had no effect on the EQ‐5D score, and positive results were limited to some aspects of health behavior. Subgroup analyses showed that the home visits were effective for elderly people who perceived their own health as poor at baseline, and for participants who complied with advice.Conclusions:  The preventive home visits based on the MDS‐HC were effective in selected groups of frail elderly people. Further modification in the use of the MDS‐HC and more focused targeting are needed to make the visits more effective.
Student Hits in an Internet‐Supported Course: How Can Instructors Use Them and What Do They Mean?
Authors: Baugher Varanelli Weisbord Dan, Andrew, Ellen 
Published: December 2003

ABSTRACTThe world of education is changing as Web‐based technology and courseware are increasingly used for delivery of course material. In this environment, instructors may need new measures for determining student involvement, and ultimately student performance. This study examines whether hits to a Web site have any value for predicting student performance in a traditional course supported by Web activities. Total Hits at the end of the semester was used as one measure. Hit Consistency, determined by assigning a 0 when no hits occurred between class meetings and by assigning a 1 when one or more hits occurred between class meetings, was another. Hit Consistency was significantly correlated with course average (r= .37, p < .001) for 108 students in two course sections. Hit Consistency started to show a significant relationship with course average by the third week (or class). Total Hits was not found to significantly correlate with course average (r= .08, p > .05) at the end of the semester or during any week. These results suggest that students who consistently access a Web site will perform better than those who do not. When Hit Consistency and Total Hits were entered as independent variables into a stepwise regression with course average as the dependent variable, the model was enhanced by the addition of Total Hits after Hit Consistency was entered (R= .43, p < .001). Hierarchical regression analysis in which cumulative grade point average was entered as the first controlling variable suggested that online access may go beyond the predictive value of achievement alone for predicting course performance with Hit Consistency appearing to be the dominant causal variable.
Graduate Business Students Performance with Synchronous and Asynchronous Interaction e‐Learning Methods
Authors: Clouse Shawn F. , Evans Gerald E. 
Published: December 2003

ABSTRACTThe effects of synchronous and asynchronous lectures and interaction formats were examined with graduate business students in on‐campus and off‐campus MBA programs. The dependent variables were scores on exams questions and learning styles and cognitive styles were used as covariates. The results indicated significant differences for discussion and lecture format and for on‐campus and off‐campus students. The results were discussed relative to learning in electronic environments.
Evaluation of a Computer‐Supported Learning System
Authors: Janicki Thomas , Steinberg Geoffrey 
Published: December 2003

ABSTRACTEducational content on the Internet is rapidly increasing. Academics and businesses are placing more course material online to supplement classroom and business training situations. In addition, significant increases in undergraduate enrollments in information system courses, and the rapid pace of new knowledge in the field, have led researchers to call for new innovative approaches to learning. Prior researchers have reported that this new Web‐based training technology (which has its foundation in computer‐based training) has not integrated sound pedagogical practices into the authoring process when developing new tutorials. This paper summarizes an experiment to evaluate the effect on posttest scores of a Web‐based authoring tool that prompts the developer to build multiple presentation styles into the learning module. Early results indicate that the tool is more effective than traditional HTML‐authoring tools and that the number of exercises affects posttest scores in a positive manner. No effect on posttest scores was observed for the number of examples in the learning module.
Perceived Role of Multimedia Instructional Materials on Multicriteria Technology and Engineering Decisions*
Authors: Mbarika Victor W. , Sankar Chetan S. , Raju P. K. 
Published: December 2003

ABSTRACTStudies have shown that it is difficult for people to deal with multicriteria decision‐making situations. Information technology tools such as decision‐support systems and expert systems have been developed in order to help them in such situations. Another tool that has been identified as helping managers understand complex engineering decision‐making situations is multimedia instructional materials. This research investigates the perceptions of business versus engineering students on improvement of their higher‐level cognitive skills when they participated in a multimedia‐based case study that used an expert system to model a complex engineering and technical problem. Two groups of students, business and engineering, participated in an experiment, where they analyzed the case study and made their recommendations. Two questionnaires measured their perceptions on the improvements achieved on different constructs. A structural equations model was developed in order to test the research hypotheses with business students being the experimental group and the engineering students as a control group. The major findings are no significant relationship between student major and higher‐order cognitive skills improvement, business students perceived more higher‐order skills improvement compared to engineering students, both groups perceived an improvement in learning‐driven factor, and business students valued learning‐driven factors more compared to engineering students. These results show that multimedia instructional materials were perceived to be very useful in making multicriteria engineering and technical decisions.