bluuebunny/crossref_metadata_2025_split huggingface dataset:
Medical students who decompress during the M-1 year outperform those who fail and repeat it: A study of M-1 students at the University of Illinois College of Medicine at Urbana-Champaign 1988–2000
Authors: Kies Susan M , Freund Gregory G 
Published: May 2005

Abstract

Background
All medical schools must counsel poor-performing students, address their problems and assist them in developing into competent physicians. The objective of this study was to determine whether students with academic deficiencies in their M-1 year graduate more often, spend less time to complete the curriculum, and need fewer attempts at passing USMLE Step 1 and Step 2 by entering the Decompressed Program prior to failure of the M-1 year than those students who fail the M-1 year and then repeat it.

Method
The authors reviewed the performance of M-1 students in the Decompressed Program and compared their outcomes to M-1 students who failed and fully repeated the M-1 year. To compare the groups upon admission, t-Tests comparing the Cognitive Index of students and MCAT scores from both groups were performed. Performance of the two groups after matriculation was also analyzed.

Results
Decompressed students were 2.1 times more likely to graduate. Decompressed students were 2.5 times more likely to pass USMLE Step 1 on the first attempt than the repeat students. In addition, 46% of those in the decompressed group completed the program in five years compared to 18% of the repeat group.

Conclusion
Medical students who decompress their M-1 year prior to M-1 year failure outperform those who fail their first year and then repeat it. These findings indicate the need for careful monitoring of M-1 student performance and early intervention and counseling of struggling students.
Nanotechnology for the biologist
Authors: McNeil Scott E 
Published: May 2005

AbstractNanotechnology refers to research and technology development at the atomic, molecular, and macromolecular scale, leading to the controlled manipulation and study of structures and devices with length scales in the 1- to 100-nanometers range. Objects at this scale, such as “nanoparticles,” take on novel properties and functions that differ markedly from those seen in the bulk scale. The small size, surface tailorability, improved solubility, and multifunctionality of nanoparticles open many new research avenues for biologists. The novel properties of nanomaterials offer the ability to interact with complex biological functions in new ways—operating at the very scale of biomolecules. This rapidly growing field allows cross-disciplinary researchers the opportunity to design and develop multifunctional nanoparticles that can target, diagnose, and treat diseases such as cancer. This article presents an overview of nanotechnology for the biologist and discusses “nanotech” strategies and constructs that have already demonstrated in vitro and in vivo efficacy.
Polarity of the ascidian egg cortex and relocalization of cER and mRNAs in the early embryo
Authors: Prodon François , Dru Philippe , Roegiers Fabrice , Sardet Christian 
Published: May 2005

The mature ascidian oocyte is a large cell containing cytoplasmic and cortical domains polarized along a primary animal-vegetal (a-v) axis. The oocyte cortex is characterized by a gradient distribution of a submembrane monolayer of cortical rough endoplasmic reticulum (cER) and associated maternal postplasmic/PEM mRNAs (cER-mRNA domain). Between fertilization and first cleavage, this cER-mRNA domain is first concentrated vegetally and then relocated towards the posterior pole via microfilament-driven cortical contractions and spermaster-microtubule-driven translocations. The cER-mRNA domain further concentrates in a macroscopic cortical structure called the centrosome attracting body (CAB), which mediates a series of asymmetric divisions starting at the eight-cell stage. This results in the segregation of determinant mRNAs and their products in posterior cells of the embryo precursors of the muscle and germ line.Using two species of ascidians (Ciona intestinalis and Phallusia mammillata), we have pursued and amplified the work initiated in Halocynthia roretzi. We have analysed the cortical reorganizations in whole cells and in cortical fragments isolated from oocytes and from synchronously developing zygotes and embryos. After fertilization, we observe that a cortical patch rich in microfilaments encircles the cER-mRNA domain, concentrated into a cortical cap at the vegetal/contraction pole (indicating the future dorsal pole). Isolated cortices also retain microtubule asters rich in cER (indicating the future posterior pole). Before mitosis, parts of the cER-mRNA domain are detected, together with short microtubules, in isolated posterior (but not anterior) cortices. At the eight-cell stage, the posteriorly located cER-mRNA domain undergoes a cell-cycle-dependant compaction into the CAB. The CAB with embedded centrosomal microtubules can be isolated with cortical fragments from eight-cell-stage embryos.These and previous observations indicate that cytoskeleton-driven repositioning and compaction of a polarized cortical domain made of rough ER is a conserved mechanism used for polarization and segregation of cortical maternal mRNAs in embryos of evolutionarily distant species of ascidians.
Channel Coordination in the Presence of a Dominant Retailer
Authors: Raju Jagmohan , Zhang Z. John 
Published: May 2005

The retail trade today is increasingly dominated by large, centrally managed “power retailers.” In this paper, we develop a channel model in the presence of a dominant retailer to examine how a manufacturer can best coordinate such a channel. We show that such a channel can be coordinated to the benefit of the manufacturer through either quantity discounts or a menu of two-part tariffs. Both pricing mechanisms allow the manufacturer to charge different effective prices and extract different surpluses from the two different types of retailers, even though they both have the appearance of being “fair.” However, quantity discounts and two-part tariffs are not equally efficient from the manufacturer’s perspective as a channel coordination mechanism. Therefore, the manufacturer must judiciously select its channel coordination mechanism. Our analysis also sheds light on the role of “street money” in channel coordination. We show that such a practice can arise from a manufacturer’s effort to mete out minimum incentives to engage the dominant retailer in channel coordination. From this perspective, we derive testable implications with regard to the practice of street money.
Modeling high‐pressure wax formation in petroleum fluids
Authors: Sansot Jean‐Marc , Pauly Jérôme , Daridon Jean‐Luc , Coutinho Joao A. P. 
Published: May 2005

AbstractA procedure is presented for the simultaneous prediction of fluid–fluid and solid–fluid equilibrium of light gases/heavy hydrocarbons systems under pressure. The objective of this work is to simplify the predictive approach previously proposed by the authors, making it more useful and accessible to users at the petroleum industry. The main modification with respect to the complex LCVM (linear combination of Huron–Vial and Michelsen) mixing rule that was previously used for the attractive term “a” of the equation of state (EOS). To avoid the use of a group contribution method, which is difficult to bring into play with real fluids, the LCVM mixing rule is here replaced by the classical quadratic van der Walls one‐fluid mixing rule. The deviation that using this mixing rule introduces into the gamma–phi approach is cancelled by a new parameter ξ, introduced in the calculation of the solid‐phase activity coefficient. This procedure was tested for a large range of multicomponent systems where the parameter ξ was fitted to match the wax appearance temperature (WAT) at atmospheric pressure. From the ξ values obtained a correlation relating the parameter ξ to the carbon number in the heavy fraction was developed, allowing a prediction of wax formation in petroleum fluids. It is shown that this approach can successfully be applied to the prediction of wax formation at high pressure for live oils. © 2005 American Institute of Chemical Engineers AIChE J, 2005
A novel EOS that combines van der Waals and Dieterici potentials
Authors: Polishuk Ilya , Vera Juan H. 
Published: May 2005

AbstractA novel approach is proposed for solving the problem of the overestimation of the liquid–liquid equilibrium (LLE) range in mixtures typically associated with the use of equations of state (EOS) of the van der Waals type. This approach modifies the internal EOS structure by combining the van der Waals and the Dieterici forms. It advantageously uses the drawback of the Dieterici form, which strongly underestimates the LLE range. Thus, the new EOS is capable of generating an appropriate balance for the representation of vapor–liquid equilibria (VLE) and LLE critical data and therefore represents a major improvement in comparison with typical van der Waals–type EOSs. In addition, it gives accurate representation of the Joule–Thomson inversion curve and predicts critical data for nonpolar mixtures without any binary parameters. For polar systems, the novel EOS predicts critical data for complete homologous series of mixtures using a pair of binary parameters evaluated from a single system. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Direct determination of energy dissipation in stirred vessels with two‐point LDA
Authors: Ducci A. , Yianneskis M. 
Published: May 2005

AbstractThe ensemble‐averaged kinetic energy viscous dissipation rate was determined with a multipoint LDA technique in a vessel stirred by a Rushton turbine. Nine out of the total of 12 mean squared velocity gradients constituting the dissipation rate were directly measured in the impeller stream, and the deviation of the flow from local isotropy was investigated. The dissipation rate normalized with N3D2, where N and D are the impeller rotational speed and the impeller diameter, respectively, was found to be approximately constant for Reynolds numbers of 20,000–40,000, whereas the fluctuating gradients were found to vary significantly, by up to three times the ensemble‐averaged values, with blade angular position. The ensemble‐averaged dissipation rate values were also assessed through a local turbulence kinetic energy balance. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Extended statistical associating fluid theory (SAFT) equations of state for dipolar fluids
Authors: Karakatsani Eirini K. , Spyriouni Theodora , Economou Ioannis G. 
Published: May 2005

AbstractPolar forces have a considerable effect on the thermodynamic and phase equilibrium properties of pure and mixture fluids. In this work, the statistical associating fluid theory (SAFT) and perturbed chain–SAFT (PC‐SAFT) are extended to explicitly account for dipole–dipole interactions. A recently proposed perturbation theory for pure dipolar fluids is incorporated in both models and further extended to mixtures. Polar SAFT (PSAFT) and PC‐polar SAFT (PC‐PSAFT) are applied to alcohols, ketones, water, and other dipolar fluids. Vapor pressure and saturated liquid densities are correlated over a wide temperature range from low temperature up to very near the critical point. Critical constants, second virial coefficients, and monomer fraction predictions are reported. Furthermore, the models are applied to correlate the vapor–liquid equilibria of binary mixtures. A temperature‐independent binary interaction parameter is regressed from experimental data. Finally, model predictions for representative polar ternary mixtures are presented. In all cases, very good agreement with experimental data is obtained. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Hydrogen generation in a reverse‐flow microreactor: 1. Model formulation and scaling
Authors: Kaisare Niket S. , Lee Jay H. , Fedorov Andrei G. 
Published: May 2005

AbstractA 1‐D model for methane partial oxidation in a tubular microreactor is considered. This work is motivated by a recent report by Kikas et al. that experimentally demonstrated the possibility of autothermal generation of hydrogen by partial oxidation of methane in a tubular microreactor. The reactor consists of four cylindrical channels, each 500 microns in diameter, containing Pt/13%–Rh catalyst. Autothermal generation of hydrogen was possible in both unidirectional (UD) and reverse‐flow (RF) operations of the reactor, with the RF operation providing better hydrogen yield and lower temperatures than those of the UD operation. Critical comparison of methane oxidation and reforming kinetics from the literature is performed. An analysis of the timescales of individual processes within the reactor is presented to gain fundamental insight into the reactor operation. Finally, the effect of radiation heat transfer is also considered, and it is found to play an important role for a shorter‐size reactor. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Hydrogen generation in a reverse‐flow microreactor: 2. Simulation and analysis
Authors: Kaisare Niket S. , Lee Jay H. , Fedorov Andrei G. 
Published: May 2005

AbstractThe second part in this series presents parametric simulation and sensitivity analysis of methane partial oxidation in a microreactor operated with periodic flow reversal. The reverse‐flow (RF) operation provides up to a 5% increase in the hydrogen yield compared to that of the unidirectional (UD) operation. The effect of varying the inlet CH4:O2 feed ratio, the inlet velocity, and the inlet gas temperature is studied. The optimal feed ratio is found to be CH4:O2 = 1.15:1 with the feed at ambient room temperature. The effects of varying the reactor length and heat losses to the ambient are also investigated. In both these cases, the performance of the UD operation degrades significantly, whereas the performance of the RF operation is more robust to the variations in reactor size and heat losses. The issue of choosing the optimal switching time is also addressed. Switching the input and output ports near the natural timescale of reaction heat release is shown to provide the optimum yield. Through these results, design and operation guidelines based on simple timescale analysis have emerged. © 2005 American Institute of Chemical Engineers AIChE J, 2005
New developments in the behavioral ecology and conservation of ruffed lemurs (Varecia)
Authors: Vasey Natalie 
Published: May 2005

AbstractThe papers in this issue were presented at a symposium during the 25th Annual Meeting of the American Society of Primatologists held in Oklahoma City, Oklahoma, in June 2002. This symposium brought together many of the scientists who have contributed to our knowledge of ruffed lemur ecology, behavior, and conservation in the past decade. One objective was to share and compare key findings about ruffed lemurs (Varecia) resulting from long‐term field studies at various sites in Madagascar. A second objective was to cross‐fertilize work being done in the wild with that being done in captivity, with the aim of advancing a common conservation mission for this critically endangered genus. Varecia is a prime candidate for synthetic assessments such as these because it has now been studied in both the northern and southern reaches of its geographic range, and has also been the focus of a captive‐to‐wild reinforcement project. The papers in this issue contribute to 1) the establishment of reference ranges for a suite of physiological parameters in healthy wild Varecia populations; 2) environmental enrichment aimed at preserving species‐typical behaviors in captivity; 3) an understanding of how forest structure, floristic composition, and fruiting phenology in areas with differing disturbance histories correlate with the natural occurrence and abundance of Varecia; 4) primary knowledge concerning dominance relations between the sexes and group leadership in wild Varecia; and 5) primary knowledge concerning how wild Varecia, with their unusual reproductive pattern and heavy reliance on fruit, modulate their activity budgets seasonally and in tandem with reproductive stages. Am. J. Primatol. 66:1–6, 2005. © 2005 Wiley‐Liss, Inc.
Activity budgets and activity rhythms in red ruffed lemurs (Varecia rubra) on the Masoala Peninsula, Madagascar: seasonality and reproductive energetics
Authors: Vasey Natalie 
Published: May 2005

AbstractThe activity budgets and daily activity rhythms of Varecia rubra were examined over an annual cycle according to season and reproductive stage. Given the relatively high reproductive costs and patchy food resources of this species, I predicted that V. rubra would 1) travel less and feed more during seasonal resource scarcity in an attempt to maintain energy balance, and 2) show sex differences in activity budgets due to differing reproductive investment. Contrary to the first prediction, V. rubra does not increase feeding time during seasonal food scarcity; rather, females feed for a consistent amount of time in every season, whereas males feed most during the resource‐rich, hot dry season. The results are consistent with other predictions: V. rubra travels less in the resource‐scarce cold rainy season, and there are some pronounced sex differences, with females feeding more and resting less than males in every season and in every reproductive stage except gestation. However, there are also some provocative similarities between the sexes when activity budgets are examined by reproductive stage. During gestation, female and male activity budgets do not differ and appear geared toward energy accumulation: both sexes feed and rest extensively and travel least during this stage. During lactation, activity budgets are geared toward high energy expenditure: both sexes travel most and in equal measure, and rest least, although it remains the case that females feed more and rest less than males. These similarities between female and male activity budgets appear related to cooperative infant care. The high energetic costs of reproduction in V. rubra females may require that they allot more time to feeding year round, and that their overall activity budget be more directly responsive to seasonal climate change, seasonal food distribution, and reproductive schedules. Am. J. Primatol. 66:23–44, 2005.
Effects of forest structure and composition on food availability for Varecia variegata at Ranomafana National Park, Madagascar
Authors: Balko Elizabeth A. , Brian Underwood H. 
Published: May 2005

AbstractWe present a summary of a long‐term field study that examined the effects of forest disturbance on the availability of palatable fruit and its utilization by V. variegata. Forest structure and tree species composition were measured in three adjacent study areas, with different histories of disturbance, in Ranomafana National Park (RNP), Madagascar. V. variegata abundance was monitored by frequent encounters with resident groups and periodic censuses conducted along trails. Finally, the abundance of mature fruit in species used by V. variegata was scored monthly at representative trees at several locations. V. variegata abundance was most consistent in the least anthropogenically disturbed site, while no established lemur groups were observed in the heavily logged site for over a decade post‐harvest. Lemur abundance was variable in the selectively logged site. The presence of select food trees, particularly specimens with voluminous crowns capable of producing abundant fruit crops, appears to be key to the establishment and expansion of V. variegata groups. Our analysis of year‐long fruit utilization revealed a high degree of preference for several species of trees. Two species exhibited mature fruit in a low percentage of stems but were available for a protracted period of time, while two additional species showed high intraspecific fruiting synchrony and were available for a shorter period of time. These contrasting phenologies, rather than the individual tree species, may be most important to V. variegata due to their coincident timing of fruit maturation with key lemur life‐history events. Any disturbance–natural or anthropogenic–that disrupts the phenology cycles of food trees has the potential to impact lemur abundance and dispersion. Intense disturbances, such as heavy logging or severe cyclones, have long‐lasting impacts on fruit production, while selective logging or moderate cyclonic windthrow cause more transient impacts. V. variegata is adapted to deal with an intrinsically erratic food supply by virtue of its reproductive biology and social behavior. Am. J. Primatol. 66:45–70, 2005. © 2005 Wiley‐Liss, Inc.
Preliminary biomedical evaluation of wild ruffed lemurs (Varecia variegata and V. rubra)
Authors: Junge Randall E. , Louis Edward E. 
Published: May 2005

AbstractComplete medical examinations were performed on 11 wild ruffed lemurs (Varecia variegata and V. rubra) from three sites in Madagascar. Each animal received a complete physical examination, several physiological parameters were analyzed (complete blood count, serum biochemical profile, and fecal bacterial culture), and the animals were examined for endo‐, ecto‐, and hemoparasites. Additional tests were performed as samples were available, including fat‐soluble vitamin analysis, trace mineral analysis, toxoplasmosis serology, and viral serology. We found that the ruffed lemurs were in good health, harbored a low endoparasite load, and frequently had external parasites (e.g., ticks (Haemophysalis lemuris)). Statistically significant differences between captive and wild lemurs were found for the following serum biochemical and blood count parameters: alanine aminotransferase (ALT), total protein (TP), albumin, blood urea nitrogen, cholesterol, glucose, amylase, band neutrophil count, and eosinophil count. Low blood urea nitrogen (BUN) and serum cholesterol values in wild lemurs (compared to those of North American captive zoo ruffed lemurs) may suggest differences between diets in the wild and captivity. Am. J. Primatol. 66:85–94, 2005. © 2005 Wiley‐Liss, Inc.
Conceptual framework for tasks in information studies
Authors: Byström Katriina , Hansen Preben 
Published: May 2005

AbstractToday information‐intensive work tasks in professional settings involve highly dynamic information utilization in which information seeking and searching tasks are taking a more central role. This article considers the concept of task in the context of information studies in order to provide a definitional clarity for task‐based information seeking and retrieval studies. We identify (1) the central task levels as well as (2) the kinds of dimensions connected to the levels from the perspective of information studies. The analysis is aimed to serve as a conceptual starting point for empirical studies in the research area. The focus is on some central aspects of tasks that are recognized within information studies as well as related research areas (e.g., organizational studies). We define two levels of information‐related subtasks: information seeking tasks and information search tasks. Information retrieval tasks are explicitly considered as a specific type of information search task. We describe differences and connections between these task levels. Finally, the implications of the proposed conceptual framework for information studies are discussed.