bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wnt activity guides facial branchiomotor neuron migration, and involves the PCP pathway and JNK and ROCK kinases
Authors: Vivancos ValȲrie , Chen Ping , Spassky Nathalie , Qian Dong , Dabdoub Alain , Kelley Matthew , Studer Michȳle , Guthrie Sarah 
Published: February 2009

Abstract
Background
Wnt proteins play roles in many biological processes, including axon guidance and cell migration. In the mammalian hindbrain, facial branchiomotor (FBM) neurons undergo a striking rostral to caudal migration, yet little is known of the underlying molecular mechanisms. In this study, we investigated a possible role of Wnts and the planar cell polarity (PCP) pathway in this process.

Results
Here we demonstrate a novel role for Wnt proteins in guiding FBM neurons during their rostral to caudal migration in the hindbrain. We found that Wnt5a is expressed in a caudalhigh to rostrallow gradient in the hindbrain. Wnt-coated beads chemoattracted FBM neurons to ectopic positions in an explant migration assay. The rostrocaudal FBM migration was moderately perturbed in Wnt5a mutant embryos and severely disrupted in Frizzled3 mutant mouse embryos, and was aberrant following inhibition of Wnt function by secreted Frizzled-related proteins. We also show the involvement of the Wnt/PCP pathway in mammalian FBM neuron migration. Thus, mutations in two PCP genes, Vangl2 and Scribble, caused severe defects in FBM migration. Inhibition of JNK and ROCK kinases strongly and specifically reduced the FBM migration, as well as blocked the chemoattractant effects of ectopic Wnt proteins.

Conclusion
These results provide in vivo evidence that Wnts chemoattract mammalian FBM neurons and that Wnt5a is a candidate to mediate this process. Molecules of the PCP pathway and the JNK and ROCK kinases also play a role in the FBM migration and are likely mediators of Wnt signalling.
The New Dutch Timetable: The OR Revolution
Authors: Kroon Leo , Huisman Dennis , Abbink Erwin , Fioole Pieter-Jan , Fischetti Matteo , Maróti Gábor , Schrijver Alexander , Steenbeek Adri , Ybema Roelof 
Published: February 2009

In December 2006, Netherlands Railways introduced a completely new timetable. Its objective was to facilitate the growth of passenger and freight transport on a highly utilized railway network and improve the robustness of the timetable, thus resulting in fewer operational train delays. Modifications to the existing timetable, which was constructed in 1970, were not an option; additional growth would require significant investments in the rail infrastructure. Constructing a railway timetable from scratch for about 5,500 daily trains was a complex problem. To support this process, we generated several timetables using sophisticated operations research techniques. Furthermore, because rolling-stock and crew costs are principal components of the costs of a passenger railway operator, we used innovative operations research tools to devise efficient schedules for these two resources. The new resource schedules and the increased number of passengers resulted in an additional annual profit of €40 million ($60 million); the additional revenues generated approximately €10 million of this profit. We expect this profit to increase to €70 million ($105 million) annually in the coming years. However, the benefits of the new timetable for the Dutch society as a whole are much greater: more trains are transporting more passengers on the same railway infrastructure, and these trains are arriving and departing on schedule more than they ever have in the past. In addition, the rail transport system will be able to handle future transportation demand growth and thus allow cities to remain accessible to more people. Therefore, we expect that many will switch from car transport to rail transport, thus reducing the emission of greenhouse gases.
Reducing Flight Delays Through Better Traffic Management
Authors: Sud Ved P. , Tanino Midori , Wetherly James , Brennan Michael , Lehky Miro , Howard Ken , Oiesen Rick 
Published: February 2009

As air traffic in the United States has grown over the last several years, traffic demand has begun to outstrip capacity. As of 2005, the Federal Aviation Administration (FAA) had no effective approach for strategically managing a weather event that has been very disruptive to the national aviation system—large-scale thunderstorms that block the major flight routes in the northeastern United States. The operations research team that supports the FAA's efforts to provide innovations in air traffic management, led by researchers at Metron Aviation, Inc. and the Volpe Transportation Center, recognized the consequence of this operational deficiency and set out to resolve it. In this paper, we show how this team (1) developed and applied system-simulation models to quantify the extent of the traffic flow management problem and convey its magnitude to the FAA and to the aviation industry; (2) designed the Airspace Flow Program (AFP), a new approach to managing air traffic that could correct the problem within the limitations of a short development cycle and a change-resistant culture; (3) designed and developed an interactive simulation system that could be and was used to refine and perfect this concept prior to deployment by developing policies on the use of a decision support system; (4) engaged FAA and airline traffic management experts in a series of interactive exercises using the simulation system to develop the final software design, operational procedures, and decision rules for deployment and use; and (5) provided a clear and convincing postdeployment benefits assessment for the new traffic management approach. The deployment of this new capability was an enormous success that both the FAA and the airline community heralded widely. The postdeployment impact assessment showed benefits to the aircraft operators and the flying public of almost $190 million in 2006 and 2007, the first two years of use, compared to less than $5 million in design and development costs. Broader usage of AFPs and new applications for them show a projected 10-year benefit of approximately $2.8 billion.
Priority Assignment Under Imperfect Information on Customer Type Identities
Authors: Argon Nilay Tanık , Ziya Serhan 
Published: February 2009

In many service systems, customers are not served in the order they arrive, but according to a priority scheme that ranks them with respect to their relative “importance.” However, it may not be an easy task to determine the importance level of customers, especially when decisions need to be made under limited information. A typical example is from health care: When triage nurses classify patients into different priority groups, they must promptly determine each patient's criticality levels with only partial information on their conditions. We consider such a service system where customers are from one of two possible types. The service time and waiting cost for a customer depends on the customer's type. Customers' type identities are not directly available to the service provider; however, each customer provides a signal, which is an imperfect indicator of the customer's identity. The service provider uses these signals to determine priority levels for the customers with the objective of minimizing the long-run average waiting cost. In most of the paper, each customer's signal equals the probability that the customer belongs to the type that should have a higher priority and customers incur waiting costs that are linear in time. We first show that increasing the number of priority classes decreases costs, and the policy that gives the highest priority to the customer with the highest signal outperforms any finite class priority policy. We then focus on two-class priority policies and investigate how the optimal policy changes with the system load. We also investigate the properties of “good” signals and find that signals that are larger in convex ordering are more preferable. In a simulation study, we find that when the waiting cost functions are nondecreasing, quadratic, and convex, the policy that assigns the highest priority to the customer with the highest signal performs poorly while the two-class priority policy and an extension of the generalized cμ rule perform well.
Emotion control in collaborative learning situations: Do students regulate emotions evoked by social challenges/
Authors: Järvenoja Hanna , Järvelä Sanna 
Published: February 2009

Background During recent decades, self‐regulated learning (SRL) has become a major research field. SRL successfully integrates the cognitive and motivational components of learning. Self‐regulation is usually seen as an individual process, with the social aspects of regulation conceptualized as one aspect of the context. However, recent research has begun to investigate whether self‐regulation processes are complemented by socially shared regulation processes.Aims The presented study investigated what kind of socio‐emotional challenges students experience during collaborative learning and whether the students regulate the emotions evoked during these situations. The interplay of the emotion regulation processes between the individual and the group was also studied.Sample The sample for this study was 63 teacher education students who studied in groups of three to five during three collaborative learning tasks.Method Students' interpretations of experienced social challenges and their attempts to regulate emotions evoked by these challenges were collected following each task using the Adaptive Instrument for the Regulation of Emotions.Results The results indicated that students experienced a variety of social challenges. Students also reported the use of shared regulation in addition to self‐regulation. Finally, the results suggested that intrinsic group dynamics are derived from both individual and social elements of collaborative situations.Conclusion The findings of the study support the assumption that students can regulate emotions collaboratively as well as individually. The study contributes to our understanding of the social aspects of emotional regulation in collaborative learning contexts.
Optimizing Hardware Options for Maximum Flexibility and Improved Success in Wireline Formation Testing, Sampling and Downhole Fluid Analysis Operations
Authors: Weinheber Peter , Gisof Adriaan , Jackson Richard R , De Santo Ilaria 
Published: February 2009

Abstract
Wireline formation testers (WFT) are used for pressure measurements, fluid sampling, downhole fluid analysis and interval pressure transient testing. In three of these four applications how well we design and implement the flowrate requirements will determine if we will achieve the program objectives. In designing and executing even simple WFT jobs the inter-dependence of flow rate with drawdown, sand failure, phase change and contamination clean-up all must be considered. Until recently there has been relatively little "degrees of freedom" with respect to optimizing flow rate. There was typically one pump with one or two displacement units and one or two probe sizes to choose from. Now, however, when designing a typical WFT tool string one is faced with the choice of at least five different probe types, four different displacement units, and four different hydraulic pumps. Additionally, modern WFT strings now allow the use of two pumps simultaneously giving even more flow rate options.
In this paper we discuss the interplay between the four different hydraulic pumps and the four different displacement units and how to optimize tool string design to achieve the desired flow rate and drawdown characteristics. We show field examples from a near saturated low perm reservoir in Angola and from the Niger Delta during the acquisition of a sample using focused probe technology that requires careful balancing of two pumps operating simultaneously.
One of the implications of the pump design in the WFT is the ability of the pump to segregate two phase fluid as it passes through the pump. We show how to maximize the utility of this characteristic and provide field examples where the ability to segregate allows for large reductions in sampling times in the case of two phase fluids.
Finally, with all the work on the optimization of the hardware for maximum flow rate flexibility we introduce a newly developed software algorithm that provides a real time flowrate measurement.
Accelerated Postnatal Growth Increases Lipogenic Gene Expression and Adipocyte Size in Low–Birth Weight Mice
Authors: Isganaitis Elvira , Jimenez-Chillaron Jose , Woo Melissa , Chow Alice , DeCoste Jennifer , Vokes Martha , Liu Manway , Kasif Simon , Zavacki Ann-Marie , Leshan Rebecca L. , Myers Martin G. , Patti Mary-Elizabeth 
Published: February 2009

OBJECTIVE
To characterize the hormonal milieu and adipose gene expression in response to catch-up growth (CUG), a growth pattern associated with obesity and diabetes risk, in a mouse model of low birth weight (LBW).

RESEARCH DESIGN AND METHODS
ICR mice were food restricted by 50% from gestational days 12.5–18.5, reducing offspring birth weight by 25%. During the suckling period, dams were either fed ad libitum, permitting CUG in offspring, or food restricted, preventing CUG. Offspring were killed at age 3 weeks, and gonadal fat was removed for RNA extraction, array analysis, RT-PCR, and evaluation of cell size and number. Serum insulin, thyroxine (T4), corticosterone, and adipokines were measured.

RESULTS
At age 3 weeks, LBW mice with CUG (designated U-C) had body weight comparable with controls (designated C-C); weight was reduced by 49% in LBW mice without CUG (designated U-U). Adiposity was altered by postnatal nutrition, with gonadal fat increased by 50% in U-C and decreased by 58% in U-U mice (P &lt; 0.05 vs. C-C mice). Adipose expression of the lipogenic genes Fasn, AccI, Lpin1, and Srebf1 was significantly increased in U-C compared with both C-C and U-U mice (P &lt; 0.05). Mitochondrial DNA copy number was reduced by &gt;50% in U-C versus U-U mice (P = 0.014). Although cell numbers did not differ, mean adipocyte diameter was increased in U-C and reduced in U-U mice (P &lt; 0.01).

CONCLUSIONS
CUG results in increased adipose tissue lipogenic gene expression and adipocyte diameter but not increased cellularity, suggesting that catch-up fat is primarily associated with lipogenesis rather than adipogenesis in this murine model.
Inhibition of Contraction-Stimulated AMP-Activated Protein Kinase Inhibits Contraction-Stimulated Increases in PAS-TBC1D1 and Glucose Transport Without Altering PAS-AS160 in Rat Skeletal Muscle
Authors: Funai Katsuhiko , Cartee Gregory D. 
Published: February 2009

OBJECTIVE
Phosphorylation of two members of the TBC1 domain family of proteins, Akt substrate of 160 kDa (AS160, also known as TBC1D4) and TBC1D1, has been implicated in the regulation of glucose transport in skeletal muscle. Insulin-stimulated phosphorylation (measured using the phospho-Akt substrate [PAS] antibody) of AS160 and TBC1D1 appears to occur in an Akt-dependent manner, but the kinases responsible for contraction-stimulated PAS-AS160 and PAS-TBC1D1 remain unclear. AMP-activated protein kinase (AMPK) and Akt, both activated by contraction, can each phosphorylate AS160 and TBC1D1 in cell-free assays.

RESEARCH DESIGN AND METHODS
To evaluate the roles of AMPK and Akt on insulin- or contraction-stimulated PAS-AS160, PAS-TBC1D1, and glucose transport, rat epitrochlearis was incubated with and without compound C (inhibitor of AMPK) or Wortmannin (inhibitor of phosphatidylinositol [PI] 3-kinase, which is upstream of Akt) before and during insulin stimulation or contraction.

RESULTS
Insulin-stimulated glucose transport and phosphorylation of both AS160 and TBC1D1 were completely inhibited by Wortmannin. Wortmannin eliminated contraction stimulation of phospho-Ser21/9glycogen synthase kinase 3α/β (pGSK3; Akt substrate) and PAS-AS160 but did not significantly alter pAMPK, phospho-Ser79acetyl CoA carboxylase (pACC; AMPK substrate), PAS-TBC1D1, or glucose transport in contraction-stimulated muscle. Compound C completely inhibited contraction-stimulated pACC and PAS-TBC1D1 and partially blocked glucose transport, but it did not significantly alter pAkt, pGSK3, or PAS-AS160.

CONCLUSIONS
These data suggest that 1) insulin stimulates glucose transport and phosphorylation of AS160 and TBC1D1 in a PI 3-kinase/Akt–dependent manner, 2) contraction stimulates PAS-AS160 (but not PAS-TBC1D1 or glucose transport) in a PI 3-kinase/Akt–dependent manner, and 3) contraction stimulates PAS-TBC1D1 and glucose transport (but not PAS-AS160) in an AMPK-dependent manner.
A three-phase nonequilibrium model for catalytic distillation
Authors: Kotora Marcel , Švandová Zuzana , Markoš Jozef 
Published: February 2009

AbstractNonequilibrium model for steady state simulation of catalytic distillation is presented. Mathematical model takes into account both mass and heat transfers across the gas liquid interface and through the liquid-solid (catalyst) interface. Equations describing the mentioned phenomena are based on the effective diffusivity approach. The resulting system of nonlinear algebraic equations was implemented in the FORTRAN programming language and solved by the BUNLSI (Ferraris & Tronconi, 1986) solver. The described model was verified using the experimental data obtained from a continuous distillation column equipped with catalytic packing. As an experimental model system, synthesis of propyl propionate from propan-1-ol and propionic acid was chosen. Comparison of experimental and simulation data is presented, and appropriateness of the developed model for other types of catalytic distillation processes is discussed.
Prediction Markets: The Practical and Normative Possibilities for the Social Production of Knowledge
Authors: Bragues George 
Published: February 2009

ABSTRACTThe quest to foretell the future is omnipresent in human affairs. A potential solution to this epistemological conundrum has emerged through mass collaboration. Motored by the Internet, prediction markets allow a multitude of individuals to assume a stake in a security whose value is tied to a future event. The resulting prices offer a continuously updated probability estimate of the event actually taking place. This paper gives a survey of prediction markets, their history, mechanics, uses, and theoretical foundation. We also review the literature surrounding their efficacy. Though there are shortcomings with prediction markets, as well as practical constraints, they hold out the prospect of improving the quality of organizational decisions and increasing the level of participation in the deliberative process. We also note that lessons can be drawn from these markets to guide the epistemological practices of disciplines and inquiries in which empirical methods are difficult to apply.
Toxicity Evaluation for Safe Use of Nanomaterials: Recent Achievements and Technical Challenges
Authors: Hussain Saber M. , Braydich‐Stolle Laura K. , Schrand Amanda M. , Murdock Richard C. , Yu Kyung O. , Mattie David M. , Schlager John J. , Terrones Mauricio 
Published: February 2009

AbstractRecent developments in the field of nanotechnology involving the synthesis of novel nanomaterials (NM) have attracted the attention of numerous scientists owing to the possibility of degradative perturbations in human health. This Review evaluates previous investigations related to NM toxicity studies using biological models and describes the limitations that often prevent toxicologists from identifying whether NM pose a real hazard to human health. One major limitation to assess toxicity is the characterization of the NM prior to and after exposure to living cells or animals. The most relevant physicochemical characteristics of NM are: size, surface chemistry, crystallinity, morphology, solubility, aggregation tendency, homogeneity of dispersions, and turbidity. All of these properties need to be assessed in order to determine their contribution to toxicity. Due to the lack of appropriate methods to determine the physicochemical nature of nanoparticles in biological systems, the exact nature of NM toxicity is not fully described or understood at this time. This Review emphasizes the need for state‐of‐the‐art physicochemical characterization, the determination of appropriate exposure protocols and reliable methods for assessing NM internalization and their kinetics in living organisms. Once these issues are addressed, optimal experimental conditions could be established in order to identify if NM pose a threat to human health. Multidisciplinary research between materials scientists and life scientists should overcome these limitations in identifying the true hazards of NM.
Neurotoxic effect of occupational exposure to mixed organic solvents in Korea: Posturographic study
Authors: Park Jae‐Beom , Lee Kyung‐Jong , Lee Keou‐Weon , Lim Kwang‐Jin 
Published: February 2009

AbstractBackgroundThis study used static posturography to investigate the neurotoxic effects on workers exposed to mixed organic solvents at low concentrations under the levels of the threshold limit values (TLV).MethodsForty‐one workers from four plants exposed to mixed solvents and 90 non‐exposed referents were examined. The lifetime cumulative biological exposure (CE) was estimated according to subject's occupational history and biological monitoring results. Static posturography and questionnaire were the basis of data collection.ResultsThe mean exposure index of mixed organic solvents of four plants was 0.47 (SD: 0.33, range: 0.08–1.39). The exposed group showed a larger sway area and length under the eye open condition than did the non‐exposed group. In a multiple linear regression, a significant positive association was demonstrated between postural sway area and CE.ConclusionsThis study results suggest that the exposure to organic solvents under TLV levels may cause disturbance in postural stability. Am. J. Ind. Med. 52:429–437, 2009. © 2009 Wiley‐Liss, Inc.
Primary hypogonadism, partial alopecia, and Mullerian hypoplasia: Report of a third family and review
Authors: Tatar Abdulgani , Ocak Zeynep , Tatar Arzu , Yesilyurt Ahmet , Borekci Bunyamin , Oztas Sitki 
Published: February 2009

AbstractTwo sisters presented with partial alopecia, primary hypergonadotropic hypogonadism and Mullerian hypoplasia associated with mild mental retardation, microcephaly, flat occiput, sparse eyebrows, absence of breast tissue, absent ovaries, mild‐moderate dorsal kyphosis, thin upper lip and unilateral sensorioneural deafness in one of them. They were the product of a Turkish consanguineous marriage. The clinical course for our patients is similar to two families reported by Al‐Awadi et al. [Al‐Awadi et al. (1985) Am J Med Genet 22:619–622] and Megarbane et al. [Megarbane et al. (2003) Am J Med Genet Part A 119A:214–217]. This report supports the literature by proposing an autosomal recessive syndrome which was firstly reported by Al‐Awadi et al. [Al‐Awadi et al. (1985) Am J Med Genet 22:619–622]. This condition may be due to a founder mutation. © 2009 Wiley‐Liss, Inc.