Miracle-dz/UniFAR-FTUs huggingface dataset:
Recommendation System Leveraging Heterogeneity of Trust in Social Networks

Recommendation systems are an integral part of many online services ranging from content streaming websites like Netflix to online shopping websites like Amazon. They improve the online experience by suggesting new products that match users’ interests and preferences. Collaborative filtering [4] methods are the most commonly used techniques in recommendation systems which rely on collection and analysis of users’ preferences and predicting what users will like based on their similarity to other users. Traditional collaborative filtering based recommendation systems can be categorized into three types: user based, item based and hybrid methods. Many algorithms have been used for measuring user and item similarity in recommendation systems like the k-nearest neighbor (k-NN) approach and the Pearson Correlation as first implemented in [5]. Neighborhood methods are good at detecting very localized relationships but poor at detecting a user’s overall user preference. In contrast, latent factor models are best at estimating the overall preferences of a user but poor at incorporating relationships between users. Due to this complementary nature of the two approaches, [3] integrates them to provide better recommendations. Trust is another aspect of recommendations in real life scenarios where we trust different friends for recommendations in different categories of products. For example, we may prefer movie recommendations from an entirely different set of friends as compared to electronics recommendations. We refer to this difference in trust for different categories of recommendations as heterogeneous trust. [7] attempts to improve on traditional methods by studying the relations between trust and product ratings in online consumer review sites. They propose an improvised matrix factorisation technique that can be used to improve rating predictions and estimate true strengths of trust relations at the same time. TrustWalker [8] proposes a random walk model which combines trust-based and item-based recommendations. This improves the performance of recommendations even for cold start users. Our goal in this project is to determine if we can leverage heterogeneous trust to improve recommendations. Our intuition is that what is true in real life should also hold true for online communities. More specifically, given a set of users, their ratings for products in several categories and a social network of users, we will predict ratings for products that have not been reviewed by a particular user. We will then evaluate whether modeling heterogeneous trust information improves the prediction accuracy. II. DATA
Approximation to Distribution of Product of Random Variables Using Orthogonal Polynomials for Lognormal Density

We derive a closed-form expression for the orthogonal polynomials associated with the general lognormal density. The result can be utilized to construct easily computable approximations for probability density function of a product of random variables, when the considered variates are either independent or correlated. As an example, we have calculated the approximative distribution for the product of Nakagami-m variables. Simulations indicate that accuracy of the proposed approximation is good with small cross-correlations under light fading condition.
Dock10, a Cdc42 and Rac1 GEF, induces loss of elongation, filopodia, and ruffles in cervical cancer epithelial HeLa cells

Dock10 is one of the three members of the Dock-D family of Dock proteins, a class of guanine nucleotide exchange factors (GEFs) for Rho GTPases. Its homologs Dock9 and Dock11 are Cdc42 GEFs. Dock10 is required for maintenance of rounded morphology and amoeboid-type movement. Full-length isoforms of Dock10 have been recently cloned. Here, we address GTPase specificity and GEF activity of Dock10. In order of decreasing intensity, Dock10 interacted with nucleotide-free Rac1, Cdc42, and Rac3, and more weakly with Rac2, RhoF, and RhoG. Inducible expression of Dock10 in HeLa epithelial cells promoted GEF activity on Cdc42 and Rac1, and a morphologic change in two-dimensional culture consisting in loss of cell elongation, increase of filopodia, and ruffles. Area in contact with the substrate of cells that spread with non-elongated morphology was larger in cells expressing Dock10. Inducible expression of constitutively active mutants of Cdc42 and Rac1 in HeLa cells also induced loss of elongation. However, Cdc42 induced filopodia and contraction, and Rac1 induced membrane ruffles and flattening. When co-expressed with Dock10, Cdc42 potentiated filopodia, and Rac1 potentiated ruffles. These results suggest that Dock10 functions as a dual GEF for Cdc42 and Rac1, affecting cell morphology, spreading and actin cytoskeleton protrusions of adherent HeLa cells.
Photolysis and the dimethylsulfide (DMS) summer paradox in the Sargasso Sea

Apparent quantum yields and rates of dimethylsulfide (DMS) photolysis were determined from Sargasso Sea seawater with the goal of assessing the extent to which photoreactions affect the unusually elevated upper ocean concentrations of DMS during the summer, the so‐called DMS summer paradox. Apparent quantum yields determined with monochromatic radiation decrease exponentially with increasing wavelength and indicate that DMS photolysis is driven by ultraviolet (UV) radiation. The relative spectral partitioning differs between samples collected from the surface mixed layer (15 m) and from the chlorophyll a maximum (80 m), presumably because of differences in chromophoric dissolved organic matter (CDOM) quality (e.g., apparent degree of bleaching). Quantum yields are also temperature dependent, and an approximate doubling of photolysis rates occurs for a 20°C increase in temperature. The significance of DMS photolysis to upper ocean sulfur budgets is explored using a multiyear (1992–1994) DMS time series, concurrent irradiance determinations and temperature profiles, and estimates of CDOM absorption. Depth‐integrated, mixed‐layer DMS photolysis rates peak in the summer (15–25 µmol m−2 d−1) and decline to ,1 µmol m−2 d−1 in the winter. These rates correspond to specific turnover rates of ~0.29 d−1 in the summer and > 0.02 d−1 in the winter. Seasonal changes in solar radiation, temperature, and DMS concentrations drive the 30‐fold differences in photolysis rates, overshadowing differences caused by photosensitizer (CDOM) quantity or quality (21–35%). These results demonstrate that although photolysis is not the primary driver of the summer paradox, it makes an important contribution to the time‐depth pattern of DMS concentrations observed in the Sargasso Sea.
Understanding and Application of Learning Theory in UK-based Equestrians

ABSTRACT Learning in equines occurs through a predictable chain of stimulus–response–consequence processing. Whether the behavior persists will depend on the nature and timing of the consequence, whether it punishes or reinforces the response behavior. Knowledge and application of learning theory in UK-based equestrians was assessed by an online survey which probed three aspects of knowledge and understanding. Fifty-eight UK individuals (91% female) took part in the study and had an average of 12.4 years’ equestrian experience. Almost one-third (31%) described themselves as professional equestrians. A questionnaire was used to assess participants’ ability to identify and describe terminology associated with learning theory; self-report on their own knowledge and training methodology; and to express how they would respond in different training situations. Human-focused educational strategies were tested to assess their effectiveness and suitability for increasing understanding of learning theory. Professional equestrians expressed higher levels of subjective knowledge than amateurs (t(27) = –2.752, p = 0.018), with a moderate positive correlation between subjective knowledge and observer-scored knowledge (r = 0.443, p < 0.001). Professionals scored higher than amateurs on all questions asked, however a deficit of knowledge was observed across the board; in particular, in defining positive punishment (professional 38.8%, amateur 12.5% successful) and negative reinforcement (professional 33%, amateur 12.5% successful). Application of both an educational video and a leaflet increased respondents’ ability to correctly define terminology (Video t(8) = –4.07, p = 0.004: Leaflet t(12) = –5.02, p < 0.001). Improving understanding and application of learning theory in amateurs and professionals alike has the potential to improve equine welfare and training outcomes for both leisure and performance horses through reducing wastage attributed to behavioral problems or poor training.
Analysing the integration of engineering in science lessons with the Engineering-Infused Lesson Rubric

ABSTRACT Science teachers are being called on to incorporate engineering practices into their classrooms. This study explores whether the Engineering-Infused Lesson Rubric, a new rubric designed to target best practices in engineering education, could be used to evaluate the extent to which engineering is infused into online science lessons. Eighty lessons were selected at random from three online repositories, and coded with the rubric. Overall results documented the strengths of existing lessons, as well as many components that teachers might strengthen. In addition, a subset of characteristics was found to distinguish lessons with the highest level of engineering infusion. Findings are discussed in relation to the potential of the rubric to help teachers use research evidence-informed practice generally, and in relation to the new content demands of the U.S. Next Generation Science Standards, in particular.
Facebook Use and Its Role in Shaping Access to Social Benefits among Older Adults

Adults who are 65 years or older have increasingly adopted social network sites (SNSs), Facebook in particular. Yet the ramifications of SNS use in this population remain understudied. Using a nationally representative sample of U.S. adults (N = 2,003), this study focuses on Facebook users (N = 1,138) and examines patterns of Facebook use by younger (aged 18–65 years) and older users (aged 65 or older), as well as the social benefits associated with older users’ Facebook use. Findings show that older users have different network structures, but the frequency of their visits and engagement in Social Media Relationship Maintenance Behaviors (SMRMB), a measure of perceived likelihood to engage with others via social media, do not significantly differ from those of younger users. Moreover, our results suggest that among older users (N = 98), the number of self-reported “actual” friends on Facebook and SMRMB positively predict perceived support, while SMRMB contributes to perceptions of access to useful information. Overall, the study highlights unique usage patterns and social benefits associated with Facebook use among older adults. As such, its findings provide insights for the future design of technological interventions to help older adults better access social benefits associated with SNS use.
Non-linear structure formation and ‘apparent’ acceleration: an investigation

We present an analytically tractable non-linear model of structure formation in a Universe with only dust. The model is a Lemaître–Tolman–Bondi solution (of general relativity) and structures are shells of different density. We show that the luminosity distance–redshift relation has significant corrections at low redshift when the density contrast becomes non-linear. A minimal effect is a correction in apparent magnitudes of order . We discuss different possibilities that could further enhance this effect and mimic dark energy.
O EMPREENDEDORISMO SOCIAL COMO POSSIBILIDADE DE CIDADANIA

A chamada sociedade “pós-moderna” está instituída em um contexto social de uma complexidade existencial extremamente complexa, em que as relações sociais são envolvidas por lógicas, interesses e raciocínios deslocados totalmente do bem comum, uma ação arbitrária e particularizada que desconsidera toda e qualquer panorâmica presente no seu entorno, mesmo que ela represente uma pandemia de miserabilidade mundial dos indivíduos. Através da pesquisa bibliográfica, do debate crítico-analítico e uma abordagem exploratório acerca das questões que permeiam a constituição do Empreendedorismo Social, como forma de oportunizar a ver e a voz dos “invisíveis” socialmente, este estudo procura questionar o modelo de sociedade que se tem em curso atualmente. A totalidade vigente não pode se manter, é insustentável a concentração de riqueza nesse “mundo moderno”, cabendo às camadas menos abastadas socialmente se unirem para superar essa problemática e a academia de mostrar-lhes o caminho a ser triado nesse ambiente infestado por “predadores vorazes” do capital.
The influence of search engines on preferential attachment

There is much current interest in the evolution of social networks, especially, the Web graph, through time. "Preferential attachment" and the "copying model" are well-known models which explain the observed degree distribution of the Web graph reasonably closely. We claim that the presence of highly popular search engines like Google substantially mediate the act of hyperlink creation by limiting the author's attention to a small set of "celebrity" URLs. Page authors (who are also Web surfers) frequently (with probability p) locate pages using a search engine. Then they link to popular pages among those they visit. We initiate an analysis of this more realistic process, and show that the celebrity nodes eventually accumulate a constant fraction of all links created whp, and that the degrees of the other nodes still follow a power-law distribution, but with a steeper power: Pr(degree = k) α k-(1+2/(1-p)) Whp. Our analysis adds evidence to the recent concern that search engines offer new Web pages a steep, self-sustaining barrier to entry to well-connected, entrenched Web communities.
Automatic and Controlled Semantic Retrieval: TMS Reveals Distinct Contributions of Posterior Middle Temporal Gyrus and Angular Gyrus

Semantic retrieval involves both (1) automatic spreading activation between highly related concepts and (2) executive control processes that tailor this activation to suit the current context or goals. Two structures in left temporoparietal cortex, angular gyrus (AG) and posterior middle temporal gyrus (pMTG), are thought to be crucial to semantic retrieval and are often recruited together during semantic tasks; however, they show strikingly different patterns of functional connectivity at rest (coupling with the “default mode network” and “frontoparietal control system,” respectively). Here, transcranial magnetic stimulation (TMS) was used to establish a causal yet dissociable role for these sites in semantic cognition in human volunteers. TMS to AG disrupted thematic judgments particularly when the link between probe and target was strong (e.g., a picture of an Alsatian with a bone), and impaired the identification of objects at a specific but not a superordinate level (for the verbal label “Alsatian” not “animal”). In contrast, TMS to pMTG disrupted thematic judgments for weak but not strong associations (e.g., a picture of an Alsatian with razor wire), and impaired identity matching for both superordinate and specific-level labels. Thus, stimulation to AG interfered with the automatic retrieval of specific concepts from the semantic store while stimulation of pMTG impaired semantic cognition when there was a requirement to flexibly shape conceptual activation in line with the task requirements. These results demonstrate that AG and pMTG make a dissociable contribution to automatic and controlled aspects of semantic retrieval. SIGNIFICANCE STATEMENT We demonstrate a novel functional dissociation between the angular gyrus (AG) and posterior middle temporal gyrus (pMTG) in conceptual processing. These sites are often coactivated during neuroimaging studies using semantic tasks, but their individual contributions are unclear. Using transcranial magnetic stimulation and tasks designed to assess different aspects of semantics (item identity and thematic matching), we tested two alternative theoretical accounts. Neither site showed the pattern expected for a “thematic hub” (i.e., a site storing associations between concepts) since stimulation disrupted both tasks. Instead, the data indicated that pMTG contributes to the controlled retrieval of conceptual knowledge, while AG is critical for the efficient automatic retrieval of specific semantic information.
An Experimental Comparison of Constraint-Based Algorithms for the Preemptive Job-Shop Scheduling Problem

In the recent years, constraint programming has been applied to a wide variety of academic and industrial non-preemptive scheduling problems, i.e., problems in which activities cannot be interrupted. In comparis on, preemptive scheduling problems have received almost no attention from both the Operations Research and the Artificial Intelligence community (see, for example, (Demeulemeester, 1992) as one of a few exceptions). Motivated by the needs of a specific application, we engaged in a study of the applicability of const raint programming techniques to preemptive scheduling problems. This paper presents the algorithms we developed and the results we obtained on the preemptive variant of the famous “job-shop scheduling problem. ” Eight heuristic search stra tegies, combined with two different constraint propagation techniques, are presented and compared using the preemptiv variant of job-shop scheduling instances from the literature. The best combination, which relies on “limited dis crepancy search” and on “edge-finding” techniques, is shown to provide excellent solutions to the preemptive job-shop scheduli ng problem. In particular, an optimal solution is derived for the preemptive variant of “FT10” in less than two minutes of CPU time. A mean relative distance to the optimal solution of 0.32% is achieved in five minutes, on a series of hard instances with 10 jobs and 10 machines (100 activities).
Risk factors of postoperative pulmonary complications following elective craniotomy for patients with tumors of the brainstem or adjacent to the brainstem

The aim of the present study was to analyze the risk factors of postoperative pulmonary complications (PPCs) of elective craniotomy for patients presenting with brainstem tumors or tumors adjacent to the brainstem. A total of 162 consecutive patients with a brainstem tumor or adjacent brainstem tumor undergoing elective craniotomy were included and monitored. Potential risk factors were identified by data collection and monitoring of the PPCs, as well as the performance of single factor analysis (using the χ2 test). In addition, the independent risk factors of PPCs were screened by logistic analysis. A total of 39 cases of PPC were included in the current study, with an incidence rate of 23.9%. The analysis indicated that smoking history, previous pulmonary diseases, an American Society of Anesthesiologists classification >II and partial tumor resection were risk factors of PPC following an elective craniotomy. Smoking history and partial tumor resection were identified to be independent risk factors of PPCs.
Life history, diversity and distribution: a study of Japanese pteridophytes

Many studies address the relationships between diversity or distribution and attributes of the physical environment. However, how these relationships are connected to variation in life history is poorly understood. This is particularly true in the case of pteridophytes. Japanese ferns and their allies comprise one of the best-known pteridophyte floras in the world. We analyzed ca 600 species of Japanese pteridophytes for which there is detailed information on distribution, reproduction, and chromosome number. Species richness was greatest in groups with a single reproductive mode (sexual, followed by apogamous), but distribution was greatest in species groups with multiple reproductive modes: sexual plus either sterile (irregular in meiosis) or apogamous. Geographical ranges varied greatly among species with small chromosome numbers but were uniformly small among species having high chromosome numbers. Seasonally green (mostly summer green) species had significantly larger distribution ranges than evergreen species. Endemic species had higher proportions of apogamy and sterility than non-endemic species. Seasonally green species had significantly larger distributional ranges, and a smaller proportion of species with apogamous reproduction, than evergreen species. There was no clear relationship between distribution and spore size, either among endemic species, non-endemic species, or all species combined. There was no relationship between spore size and chromosome number when all species were combined. However, positive relationships were detected within three of the nine largest genera, suggesting potential phylogenetic effects. We concluded that habitat availability, rather than dispersability, may be the limiting factor for the distribution of pteridophytes in Japan.
Quantum vs. Classical Read-Once Branching Programs

A simple, explicit boolean function on 2n input bits is presented that is computable by errorfree quantum read-once branching programs of size O(n^3), while each classical randomized read-once branching program and each quantum OBDD for this function with bounded two-sided error requires size 2^{omega(n)}.
The Spatial Variation and Routine Sampling of Spawning Gravels in Small Coastal Streams Stephen Rice Province of British

The size distribution of the sediments in the bed of a stream channel is a significant characteristic of fish habitat. Spawning gravels are sampled during habitat assessments and monitoring programs. Within a given stream, effective, representative sampling requires a clear understanding of the spatial variation of spawning gravel characteristics. This study documents and explains the spatial variation of spawning gravels in two streams on the Queen Charlotte Islands. In many respects these are representative of the small, coastal watersheds of British Columbia. An oversized McNeil sampler was used to collect representative subsurface samples at 29 spawning sites. Surface material was characterized at 35 sites using Wolman counts, and an expedient photographic technique provided limited surface information at 116 sites. Detailed sediment sampling, magnetic tracer stones, and scour chains were used to study the impact of log jams on grain size. Strong hillslope-channel interactions and an abundance of large organic debris preclude the development of simple grain-size trends. Two fisheries indices of gravel texture, the Fredle Index and percent finer than 3.36 mm (64.0 mm truncation), do not differ significantly between spawning sites. In contrast, surface median size and percent finer than 0.85 mm (64.0 mm truncation) differ significantly and stochastically between sites. A sampling strategy, which aims to establish the general fisheries value of the bed material in a given stream, is then proposed. Number of samples, site selection, sample size, and mode of collection are specified in view of practical field considerations. This is regarded as an improvement on existing sampling methodologies. An issue of pressing concern, and one which hinders the development of effective field sampling, is the poor understanding of the relationships among fish survival, gravel quality indices, and sample truncation limits.