Miracle-dz/UniFAR-FTUs huggingface dataset:
Surge Pricing and Its Spatial Supply Response

We consider the pricing problem faced by a revenue-maximizing platform matching price-sensitive customers to flexible supply units within a geographic area. This can be interpreted as the problem faced in the short term by a ride-hailing platform. We propose a two-dimensional framework in which a platform selects prices for different locations and drivers respond by choosing where to relocate, in equilibrium, based on prices, travel costs, and driver congestion levels. The platform’s problem is an infinite-dimensional optimization problem with equilibrium constraints. We elucidate structural properties of supply equilibria and the corresponding utilities that emerge and establish a form of spatial decomposition, which allows us to localize the analysis to regions of movement. In turn, uncovering an appropriate knapsack structure to the platform’s problem, we establish a crisp local characterization of the optimal prices and the corresponding supply response. In the optimal solution, the platform applies different treatments to different locations. In some locations, prices are set so that supply and demand are perfectly matched; overcongestion is induced in other locations, and some less profitable locations are indirectly priced out. To obtain insights on the global structure of an optimal solution, we derive in quasi-closed form the optimal solution for a family of models characterized by a demand shock. The optimal solution, although better balancing supply and demand around the shock, quite interestingly also ends up inducing movement away from it. This paper was accepted by David Simchi-Levi, optimization.
The use of the theory of planned behavior to explore beliefs about sugar restriction.

OBJECTIVES To identify beliefs underlying attitudes, subjective norms and perceived behavioral control regarding sugar restriction using the theory of planned behavior, TPB. METHODS A survey of 981 students was conducted in Dar es Salaam, Tanzania. RESULTS The TPB predicted behavioral intention, with R2 = 0.25. Analysis of variance showed consistent differences between intenders (strong intentions) and nonintenders (weak intentions) with regard to beliefs of immediate sensory concerns and psychological control factors. CONCLUSIONS Support was provided for the TPB constructs to predict intended sugar restriction. Beliefs distinguishing intenders from nonintenders represent targets for interventions aimed at maintaining a low-level sugar intake among students in Tanzania.
Technology-based business incubators

PurposeTechnology-based incubators depend on high-level knowledge to constantly meet the demands of the market. Incubators offer a variety of specialized services to help startups increase the chances of crossing the valley of death. These services include infrastructure, access to a professional network of mentors and an intensive support of a consultant team to help with managerial and legal challenges. Therefore, it is critical to incubators to develop both highly skilled teams of consultants and social environment that facilitates communication. The purpose of this paper is to understand how innovation-oriented social networks created within technology-based incubators are shaped.Design/methodology/approachData were collected in five incubators participating connected to federal universities from the state of Minas Gerais. The network attributes collected in the survey were placed in a matrix form. The mapping and measurement of the relationships between individuals were developed using the Ucinet software. Ucinet enables the analysis of attributes (attitudes, behaviors and characteristics) characterized as relational (contacts, ties and relationships). The software also includes the Netdraw network visualization tool, which enables the creation of matrices and graphical network maps. The measurements of centrality, closeness and intermediation were analyzed to assess the intra-organizational social network.FindingsThe results indicate that although the flow of communication does not follow the formal hierarchy, the interaction between team members to spontaneously exchange ideas, information and experiences is rare. The workers are so concerned about their timely tasks, that they have few opportunities to exchange information and knowledge. The coordination is carried out by university professors, who also perform other tasks (e.g. teaching, research and administration activities) besides those related to the incubators. The results also suggest that in the technology-based incubators studied, besides dealing in an innovative environment, the distribution of tasks and responsibilities are still rigid and traditional.Originality/valueBy analyzing the degree of the relationship between team members, the proximity and the level of intermediation of co-workers, it is possible to see how the incubators workers interact, thereby identifying the flow of information. This study offers implications for theory and practice. To the theory, this study adds to the discussion of intra-organizational social network of technology-based companies in the Brazilian context. To practitioners, this research sheds light on the importance of the social network built within the organization to promote effective communication and knowledge sharing.
Demonstration of the Burkitt's lymphoma Epstein-Barr virus phenotype in dividing latently infected memory cells in vivo

Epstein-Barr virus (EBV) is a herpesvirus that establishes a lifelong, persistent infection. It was first discovered in the tumor Burkitt's lymphoma (BL). Despite intensive study, the role of EBV in BL remains enigmatic. One striking feature of the tumor is the unique pattern of viral latent protein expression, which is restricted to EBV-encoded nuclear antigen (EBNA) 1. EBNA1 is required to maintain the viral genome but is not recognized by cytotoxic T cells. Consequently, it was proposed that this expression pattern was used by latently infected B cells in vivo. This would be the site of long-term, persistent infection by the virus and, by implication, the progenitor of BL. We now know that EBV persists in memory B cells in the peripheral blood and that BL is a tumor of memory cells. However, a normal B cell expressing EBNA1 alone has been elusive. Here we show that most infected cells in the blood express no detectable latent mRNA or proteins. The exception is that when infected cells divide they express EBNA1 only. This is the first detection of the BL viral phenotype in a normal, infected B cell in vivo. It suggests that BL may be a tumor of a latently infected memory B cell that is stuck proliferating because it is a tumor and, therefore, constitutively expressing only EBNA1.
The approximate capacity for the 3-receiver writing on random dirty paper channel

In this paper, the approximate capacity of the 3-receiver “writing on random dirty paper” (WRDP) channel is derived. In the M-receiver WRDP channel, the channel output is obtained as the sum of the channel input, white Gaussian noise and a channel state sequence randomly selected among a set of M independent Gaussian sequences. The transmitter has non-causal knowledge of the set of possible state sequences but does not know which one is selected to produce the channel output. In the following, we derive upper and lower bounds to the capacity of the 3-receiver WRDP channel which are to within a distance of at most 3 bits-per-channel-use (bpcu) for all channel parameters. In the achievability proof, the channel input is composed of the superposition of three codewords: the receiver opportunistically decodes a different set of codewords, depending on the variance of the channel state appearing in the channel output. Time-sharing among multiple transmission phases is employed to guarantee that transmitted message can be decoded regardless of the state realization. In the converse proof, we derive a novel outer bound which matches the pre-log coefficient arising in the achievability proof due to time-sharing. Although developed for the case of three possible state realizations, our results can be extended the general WRDP.
Effective Destination Promotion in Rural Communities: Management and Marketing Approaches

The highly competitive and growing tourism industry necessitates both effective destination management and marketing approaches (Ozdemir & Faruk Simsek, 2014) to reach consumers and draw visitors. This is a competitive and complex issue (Wang, 2011) and often requires a collective effort by interdependent agencies in rural communities, which, can be challenging for a myriad of reasons. In this study, the management and marketing approaches of interdependent agencies entering a formal marketing alliance (Wang & Ziang, 2007) and subsequent use of intentional and collective destination branding (Qu, Kim, & Im, 2011) are analyzed while considering tourists’ consumption values (e.g., utilitarianism and hedonism [Babin, Darden, & Griffin, 1994]) and their travel and visit intentions (Park & Yoon, 2009) as approaches to effective destination marketing of a rural community.
Effect of vine nitrogen status, grapevine variety and rootstock on the levels of berry S-glutathionylated and S-cysteinylated precursors of 3-sulfanylhexan-1-ol

Aim: To determine the effect of vine nitrogen status in interaction with grapevine variety and rootstock on vine development and on the synthesis of 3-sulfanylhexan-1-ol precursors (Glut-3SH and Cys-3SH) in grape berries produced in controlled conditions.Methods and results: Potted Sauvignon blanc (SB) and Cabernet-Sauvignon (CS) vines, grafted on two different rootstocks (110R and RGM), were irrigated with two nutritive solutions varying only by their nitrogen content (N(-) and N(+)). Vine nitrogen status of N(-) treatment was significantly different from that of N(+) treatment. Secondary leaf area was higher in N(+) treatment and ripening was delayed because of increased vigor. High N status increased Glut-3SH content in berries, while it did not impact Cys-3SH level. Moreover, the concentrations of 3SH precursors were higher in SB berries compared to CS and their synthesis was enhanced in berries produced by vines grafted onto RGM under N(+) treatment.Conclusion: Glut-3SH content was mainly determined by plant N status. Grapevine variety and rootstock/N treatment interaction also had a significant, although more limited, impact. Cys-3SH level was dependent on berry developmental stage and grapevine variety, but not on vine N status.Significance and impact of the study: A better understanding of the effect of terroir components on the biosynthesis of the precursors of volatile thiols is gained.
Evaluation scale to assess the accuracy of cuff-less blood pressure measuring devices

ObjectiveThe call for early detection of hypertension and cardiac events creates a heavy demand for devices that can be used for blood pressure (BP) monitoring at home and in ambulatory settings. An emerging type of BP monitors without an occluding cuff has drawn great attentions for this application because it is comfortable and capable of providing continuous readings. For the development the cuff-less devices, it is crucial for the clinicians and engineers to joint efforts in establishing an evaluation standard. MethodsThis study attempts to contribute to its initiation in two ways. First, a new distribution model for measurement differences between the test device and the reference was proposed. We verified the model using evaluation results from 40 devices, of which 80% of the American Association for the Advancement of Medical Instrumentation and British Hypertension Society reporting results were in agreement, as compared with 50%, if the original normal model was used. We further tested a cuff-less device on 85 patients for 999 datasets and found that the differences between the proposed distribution and that of the device were nonsignificant for systolic BP measurements (Kolmogorov–Smirnov = 0.036, P = 0.15). Second, some evaluation scales were studied for their capability to assess the accuracy of cuff-less devices. For mean absolute difference, a map was developed to relate it with the criteria of American Association for the Advancement of Medical Instrumentation, British Hypertension Society, and European Society of Hypertension protocols, on the basis of the proposed distribution model; for mean absolute percentage difference, it is prominent in evaluating devices that have measurement errors often increasing with BP, which is an issue has not been fully explored in existing standards. ConclusionThis study focused on the statistical aspect of establishing standard to assess the accuracy of cuff-less BP measuring devices. The results of our study on the validation reports of various cuff-based devices and an experimental study on a cuff-less device showed that the t4 distribution is better than the normal distribution in portraying the underlying error distribution of both kinds of devices. Moreover, based on both the theoretical and experimental studies, mean absolute difference or mean absolute percentage difference is recommended as continuous scale to assess the accuracy of cuff-less devices for their own distinctive advantages.
GPGPU Computing for Microscopic Simulations of Crowd Dynamics

We compare GPGPU implementations of two popular models of crowd dynamics. Specifically, we consider a continuous social force model, based on differential equations (molecular dynamics) and a discrete social distances model based on non-homogeneous cellular automata. For comparative purposes both models have been implemented in two versions: on the one hand using GPGPU technology, on the other hand using CPU only. We compare some significant characteristics of each model, for example: performance, memory consumption and issues of visualization. We also propose and test some possibilities for tuning the proposed algorithms for efficient GPU computations.
Structural Determinants Underlying the Temperature-sensitive Nature of a Gα Mutant in Asymmetric Cell Division of Caenorhabditis elegans*

Heterotrimeric G-proteins are integral to a conserved regulatory module that influences metazoan asymmetric cell division (ACD). In the Caenorhabditis elegans zygote, GOA-1 (Gαo) and GPA-16 (Gαi) are involved in generating forces that pull on astral microtubules and position the spindle asymmetrically. GPA-16 function has been analyzed in vivo owing notably to a temperature-sensitive allele gpa-16(it143), which, at the restrictive temperature, results in spindle orientation defects in early embryos. Here we identify the structural basis of gpa-16(it143), which encodes a point mutation (G202D) in the switch II region of GPA-16. Using Gαi1(G202D) as a model in biochemical analyses, we demonstrate that high temperature induces instability of the mutant Gα. At the permissive temperature, the mutant Gα was stable upon GTP binding, but switch II rearrangement was compromised, as were activation state-selective interactions with regulators involved in ACD, including GoLoco motifs, RGS proteins, and RIC-8. We solved the crystal structure of the mutant Gα bound to GDP, which indicates a unique switch II conformation as well as steric constraints that suggest activated GPA-16(it143) is destabilized relative to wild type. Spindle severing in gpa-16(it143) embryos revealed that pulling forces are symmetric and markedly diminished at the restrictive temperature. Interestingly, pulling forces are asymmetric and generally similar in magnitude to wild type at the permissive temperature despite defects in the structure of GPA-16(it143). These normal pulling forces in gpa-16(it143) embryos at the permissive temperature were attributable to GOA-1 function, underscoring a complex interplay of Gα subunit function in ACD.
Estimating physical activity in youth using a wrist accelerometer.

PURPOSE The purpose of this study was to develop and validate methods for analyzing wrist accelerometer data in youth. METHODS A total of 181 youth (mean ± SD; age, 12.0 ± 1.5 yr) completed 30 min of supine rest and 8 min each of 2 to 7 structured activities, selected from a list of 25. Receiver operating characteristic (ROC) curves and regression analyses were used to develop prediction equations for energy expenditure (child-METs; measured activity V˙O2 divided by measured resting V˙O2) and cut points for computing time spent in sedentary behaviors (SB), light (LPA), moderate (MPA), and vigorous (VPA) physical activity. Both vertical axis (VA) and vector magnitude (VM) counts per 5 s were used for this purpose. The validation study included 42 youth (age, 12.6 ± 0.8 yr) who completed approximately 2 h of unstructured PA. During all measurements, activity data were collected using an ActiGraph GT3X or GT3X+, positioned on the dominant wrist. Oxygen consumption was measured using a Cosmed K4b. Repeated-measures ANOVA were used to compare measured versus predicted child-METs (regression only) and time spent in SB, LPA, MPA, and VPA. RESULTS All ROC cut points were similar for area under the curve (≥0.825), sensitivity (≥0.756), and specificity (≥0.634), and they significantly underestimated LPA and overestimated VPA (P < 0.05). The VA and VM regression models were within ±0.21 child-METs of mean measured child-METs and ±2.5 min of measured time spent in SB, LPA, MPA, and VPA, respectively (P > 0.05). CONCLUSIONS Compared to measured values, the VA and VM regression models developed on wrist accelerometer data had insignificant mean bias for child-METs and time spent in SB, LPA, MPA, and VPA; however, they had large individual errors.
Prenatal diagnosis of de novo (7;19)(q11.2;q13.3) translocation associated with a thick corpus callosum and Wilms tumor of the kidneys

We present a case of prenatal diagnosis of a de novo (7;19)(q11.2;q13.3) translocation associated with ultrasound features, including enlarged cisterna magna, normal vermis, thick corpus callosum, micrognathia, small and low‐set ears and right hyperechogenic kidney. Karyotyping was performed at 24 weeks of gestation. Termination of pregnancy was accepted at the parents' request. Postmortem examination confirmed the prenatal findings, but revealed bilateral Wilms tumors of the kidneys. Parental karyotype was normal. Copyright © 2005 John Wiley & Sons, Ltd.
Digital Information Literacy: Explorations of History Tasks in Singapore Schools

Pedagogy of the 21st century is focusing on visible thinking of the students. Educators today are creating learning environments and processes where students' learning is self regulated, active, collaborative and self-directed. The visibility of students' cognition is important for effective mediation and facilitation by the teacher whose role is more of a coach. With the emergence of the internet, new possibilities for learning and teaching have evolved (Tan, 2004). The internet provides access to a plethora of information which is multi faceted and multimodal. Digital Information Literacy promotes 'self-regulated', self-directed' and 'exploratory' learning. It also focuses on information problem solving strategies, the research process and the related skills that make up these information-seeking processes. The Digital curricular Literacies project (DCL) focuses on the key initiatives of the Singapore Ministry of Education (MOE) on the use of ICTs (Information and Communication Technologies) in school learning. This paper is based on the data from one section of the larger study, which looked at some of the students' online usage skills when working on history and science tasks. Secondary 1 students from 6 Singapore local schools participated in this project. 13 pairs of students worked on the digital experiment. Each computer was equipped with the screen capturing software Snapzpro that produced a real time video of the students working on the task. Audio recorders were used to capture the discussion between the pairs of students as they worked to complete the task. This paper is a case study of 7 pairs of students working on history tasks. Kuhlthau's (1993), Pitts/Stripling's (1988) and Eisenberg/Berkowitz's (1996) models of information literacy are compared. The data of this case study was analyzed qualitatively using the framework of Eisenberg/Berkowitz's Big6 model. It was found that the students were making conscious choices on selection of websites. They spent most of their time thoughtfully searching and scanning for relevant information on the topic in a broad sense. In most cases they used phrases from the task. They did not spend time to evaluate the sources they had selected for authority, the credentials of the author and the accuracy of the information. The students' artifacts produced did show evidence of multi-modality with a combination of images and text and the resulting artifacts were good examples of exploratory, self-regulatory and collaborative learning.
Models for Recommender Systems in Web Usage Mining Based on User Ratings

 Abstract - In web applications, recommender systems apply statistical and knowledge discovery techniques to predict and make recommendations to the users. Automatic predictions on the interests of the users are made by the collection of ratings and other information from many other users. Collaborative filtering recommender systems make such predictions. Most of the recommendation techniques are based on navigation behaviors and ratings that might be implicit or explicit. Traditional collaborative filtering techniques are quite vulnerable to injection attacks as many provide noisy ratings that can be detrimental to the quality of predictions and also in sensitivity and sparsity problems. To alleviate these issues this paper presents two unique recommendation models namely RANK-RECO and TEST-RECO using ranking and testing measures respectively. These models evolve into algorithms that were experimented and results were provided. The approach to the recommender system is based on either individual's past behavior, which is personalized recommendation, or on the past behavior of similar users, which is social recommendation or on the items of interest, which is item recommendation. The combination of the three approaches can also be used for predictions. It is illustrated in Table 1. Amazon uses all the three approaches that are based on individual behavior, item and the behavior of other users for its recommendations. For the predictions, a few commercial sites focus on some specific methods for RS. For instance Pandora.com deeply analyses the items. It's a site for music and the technology adopted in the system recommends songs to the users based on the structural data. Basically the technology is based on a deep structural analysis of music files. The subtle musical patterns are detected and the groups are formed based on the patterns. So, the recommendations are made based on the structure of songs.
High‐Performance Monolayer WS2 Field‐Effect Transistors on High‐κ Dielectrics

The combination of high-quality Al2 O3 dielectric and thiol chemistry passivation can effectively reduce the density of interface traps and Coulomb impurities, leading to a significant improvement of the mobility and a transition of the charge transport from the insulating to the metallic regime. A record high mobility of 83 cm(2) V(-1) s(-1) (337 cm(2) V(-1) s(-1) ) is reached at room temperature (low temperature) for monolayer WS2 . A theoretical model for electron transport is also developed.