Showing papers by "Florida Atlantic University published in 2016"

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

Abstract: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure flux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation, it is imperative to target by gene knockout or RNA interference more than one autophagy-related protein. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways implying that not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular assays, we hope to encourage technical innovation in the field.

A survey of transfer learning

Abstract: Machine learning and data mining techniques have been used in numerous real-world applications. An assumption of traditional machine learning methodologies is the training data and testing data are taken from the same domain, such that the input feature space and data distribution characteristics are the same. However, in some real-world machine learning scenarios, this assumption does not hold. There are cases where training data is expensive or difficult to collect. Therefore, there is a need to create high-performance learners trained with more easily obtained data from different domains. This methodology is referred to as transfer learning. This survey paper formally defines transfer learning, presents information on current solutions, and reviews applications applied to transfer learning. Lastly, there is information listed on software downloads for various transfer learning solutions and a discussion of possible future research work. The transfer learning solutions surveyed are independent of data size and can be applied to big data environments.

Astrophysical implications of the binary black hole merger gw150914

Abstract: The discovery of the gravitational-wave source GW150914 with the Advanced LIGO detectors provides the first observational evidence for the existence of binary black-hole systems that inspiral and merge within the age of the Universe. Such black-hole mergers have been predicted in two main types of formation models, involving isolated binaries in galactic fields or dynamical interactions in young and old dense stellar environments. The measured masses robustly demonstrate that relatively "heavy" black holes (≳25M⊙) can form in nature. This discovery implies relatively weak massive-star winds and thus the formation of GW150914 in an environment with metallicity lower than ∼1/2 of the solar value. The rate of binary black-hole mergers inferred from the observation of GW150914 is consistent with the higher end of rate predictions (≳1Gpc−3yr−1) from both types of formation models. The low measured redshift (z∼0.1) of GW150914 and the low inferred metallicity of the stellar progenitor imply either binary black-hole formation in a low-mass galaxy in the local Universe and a prompt merger, or formation at high redshift with a time delay between formation and merger of several Gyr. This discovery motivates further studies of binary-black-hole formation astrophysics. It also has implications for future detections and studies by Advanced LIGO and Advanced Virgo, and gravitational-wave detectors in space.

GW150914: The Advanced LIGO Detectors in the Era of First Discoveries

Abstract: Following a major upgrade, the two advanced detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) held their first observation run between September 2015 and January 2016. With a strain sensitivity of $10^{-23}/\sqrt{\mathrm{Hz}}$ at 100 Hz, the product of observable volume and measurement time exceeded that of all previous runs within the first 16 days of coincident observation. On September 14th, 2015 the Advanced LIGO detectors observed a transient gravitational-wave signal determined to be the coalescence of two black holes [Phys. Rev. Lett. 116, 061102 (2016)], launching the era of gravitational-wave astronomy. The event, GW150914, was observed with a combined signal-to-noise ratio of 24 in coincidence by the two detectors. Here we present the main features of the detectors that enabled this observation. At full sensitivity, the Advanced LIGO detectors are designed to deliver another factor of three improvement in the signal-to-noise ratio for binary black hole systems similar in masses to GW150914.

Understanding Satisfied and Dissatisfied Hotel Customers: Text Mining of Online Hotel Reviews

Abstract: This article aims to examine the underpinnings of satisfied and unsatisfied hotel customers. A text-mining approach was followed and online reviews by satisfied and dissatisfied customers were compared. Online reviews of 2,510 hotel guests were collected from TripAdvisor.com for Sarasota, Florida. The research findings revealed some common categories that are used in both positive and negative reviews, including place of business (e.g., hotel, restaurant, and club), room, furnishing, members, and sports. Study results further indicate that satisfied customers who are willing to recommend a hotel to others refer to intangible aspects of their hotel stay, such as staff members, more often than unsatisfied customers. On the other hand, dissatisfied customers mention more frequently the tangible aspects of the hotel stay, such as furnishing and finances. The study offers clear theoretical and managerial implications pertaining to understanding of satisfied and dissatisfied customers through the use of text mi...

Tri-party deep network representation

Abstract: Information network mining often requires examination of linkage relationships between nodes for analysis. Recently, network representation has emerged to represent each node in a vector format, embedding network structure, so off-the-shelf machine learning methods can be directly applied for analysis. To date, existing methods only focus on one aspect of node information and cannot leverage node labels. In this paper, we propose TriDNR, a tri-party deep network representation model, using information from three parties: node structure, node content, and node labels (if available) to jointly learn optimal node representation. TriDNR is based on our new coupled deep natural language module, whose learning is enforced at three levels: (1) at the network structure level, TriDNR exploits inter-node relationship by maximizing the probability of observing surrounding nodes given a node in random walks; (2) at the node content level, TriDNR captures node-word correlation by maximizing the co-occurrence of word sequence given a node; and (3) at the node label level, TriDNR models label-word correspondence by maximizing the probability of word sequence given a class label. The tri-party information is jointly fed into the neural network model to mutually enhance each other to learn optimal representation, and results in up to 79% classification accuracy gain, compared to state-of-the-art methods.

Meta-analysis of genome-wide association studies of anxiety disorders.

Abstract: Anxiety disorders (ADs), namely generalized AD, panic disorder and phobias, are common, etiologically complex conditions with a partially genetic basis. Despite differing on diagnostic definitions based on clinical presentation, ADs likely represent various expressions of an underlying common diathesis of abnormal regulation of basic threat–response systems. We conducted genome-wide association analyses in nine samples of European ancestry from seven large, independent studies. To identify genetic variants contributing to genetic susceptibility shared across interview-generated DSM-based ADs, we applied two phenotypic approaches: (1) comparisons between categorical AD cases and supernormal controls, and (2) quantitative phenotypic factor scores (FS) derived from a multivariate analysis combining information across the clinical phenotypes. We used logistic and linear regression, respectively, to analyze the association between these phenotypes and genome-wide single nucleotide polymorphisms. Meta-analysis for each phenotype combined results across the nine samples for over 18 000 unrelated individuals. Each meta-analysis identified a different genome-wide significant region, with the following markers showing the strongest association: for case–control contrasts, rs1709393 located in an uncharacterized non-coding RNA locus on chromosomal band 3q12.3 (P=1.65 × 10−8); for FS, rs1067327 within CAMKMT encoding the calmodulin-lysine N-methyltransferase on chromosomal band 2p21 (P=2.86 × 10−9). Independent replication and further exploration of these findings are needed to more fully understand the role of these variants in risk and expression of ADs.

The development of explosions in axisymmetric ab initio core-collapse supernova simulations of 12–25 M⊙ stars

Abstract: We present four ab initio axisymmetric core-collapse supernova simulations initiated from 12, 15, 20, and 25 M⊙ zero-age main sequence progenitors. All of the simulations yield explosions and have been evolved for at least 1.2 s after core bounce and 1 s after material first becomes unbound. These simulations were computed with our Chimera code employing RbR spectral neutrino transport, special and general relativistic transport effects, and state-of-the-art neutrino interactions. Continuing the evolution beyond 1 s after core bounce allows the explosions to develop more fully and the processes involved in powering the explosions to become more clearly evident. We compute explosion energy estimates, including the negative gravitational binding energy of the stellar envelope outside the expanding shock, of 0.34, 0.88, 0.38, and 0.70 Bethe (B ≡ 1051 erg) and increasing at 0.03, 0.15, 0.19, and 0.52 BS–1, respectively, for the 12, 15, 20, and 25 M⊙ models at the endpoint of this report. We examine the growth of the explosion energy in our models through detailed analyses of the energy sources and flows. We discuss how the explosion energies may be subject to stochastic variations as exemplfied by the effect of the explosion geometry of the 20 M⊙ modelmore » in reducing its explosion energy. We compute the proto-neutron star masses and kick velocities. In conclusion, we compare our results for the explosion energies and ejected 56Ni masses against some observational standards despite the large error bars in both models and observations.« less

Towards a unified customer experience in online shopping environments

Abstract: Purpose – New developments in e-commerce and m-commerce technologies along with the wide adoption of mobile devices and social media have enabled companies to enhance customers’ shopping experiences and their interaction with brands anytime, anywhere. The purpose of this paper is to develop a theoretical model for a unified online customer experience by drawing from related literature on consumer behavior in the online contexts. Design/methodology/approach – By synthesizing extant consumer behavior and e-commerce literature, this paper seeks further understanding of online customer experience and offers strategies for e-commerce marketers and Web site designers. Findings – The findings of this paper indicate that easiness to locate the Web site/app, ease of use, perceived usefulness, hedonic and utilitarian features, perceived enjoyment, personalization, social interactions and multi-device compatibility are the antecedents of the unified online customer experience. Brand engagement, positive word of mout...

Applying Grover's Algorithm to AES: Quantum Resource Estimates

Abstract: We present quantum circuits to implement an exhaustive key search for the Advanced Encryption Standard AES and analyze the quantum resources required to carry out such an attack. We consider the overall circuit size, the number of qubits, and the circuit depth as measures for the cost of the presented quantum algorithms. Throughout, we focus on Clifford$$+T$$ gates as the underlying fault-tolerant logical quantum gate set. In particular, for all three variants of AES key size 128, 192, and 256i¾źbit that are standardized in FIPS-PUB 197, we establish precise bounds for the number of qubits and the number of elementary logical quantum gates that are needed to implement Grover's quantum algorithm to extract the key from a small number of AES plaintext-ciphertext pairs.

Components of cultural tourists’ experiences in destinations

Abstract: Destinations provide a combination of products and services. Using these resources, tourists create their own experiences. Providing a pleasing tourist experience is crucial for destinations’ long-term success. Although travellers’ experiences have been subject to extensive research, various segments might perceive them differently based on their motivations. Despite the fact that cultural tourism is considered as an important segment for most urban destinations, factors affecting cultural travel experiences have not been clarified in the literature so far. Therefore, the primary purpose of this study is to determine the factors affecting cultural tourists’ overall travel experiences. In order to achieve this study's goals, we chose Istanbul as a research context. After interviewing 21 tourists and analysis of transcribed data, 64 items were merged under 5 dimensions emerging as the key constructs affecting cultural tourist experiences in a destination, namely social interaction, local authentic clues, se...

Theories of the (state-owned) firm

Abstract: State-owned enterprises (SOEs) contribute approximately 10% of the world’s GDP. SOEs at one time were predicted to disappear from the economic landscape of the world, but today SOEs are growing more prevalent in the world economy. The current theories of the firm that form the pillars of the management discipline largely ignore the theoretical differences that SOEs introduce into the conceptualization of the firm. Therefore, we extend four core theories of the firm by incorporating SOEs as a mainstream (not special or marginal) organizational form into these theories. We focus specifically on property rights theory, transaction cost theory, agency theory, and resource-based theory, culminating in a research agenda with 12 testable propositions.

Discovery of an enzyme and substrate selective inhibitor of ADAM10 using an exosite-binding glycosylated substrate.

Abstract: ADAM10 and ADAM17 have been shown to contribute to the acquired drug resistance of HER2-positive breast cancer in response to trastuzumab. The majority of ADAM10 and ADAM17 inhibitor development has been focused on the discovery of compounds that bind the active site zinc, however, in recent years, there has been a shift from active site to secondary substrate binding site (exosite) inhibitor discovery in order to identify non-zinc-binding molecules. In the present work a glycosylated, exosite-binding substrate of ADAM10 and ADAM17 was utilized to screen 370,276 compounds from the MLPCN collection. As a result of this uHTS effort, a selective, time-dependent, non-zinc-binding inhibitor of ADAM10 with Ki = 883 nM was discovered. This compound exhibited low cell toxicity and was able to selectively inhibit shedding of known ADAM10 substrates in several cell-based models. We hypothesize that differential glycosylation of these cognate substrates is the source of selectivity of our novel inhibitor. The data indicate that this novel inhibitor can be used as an in vitro and, potentially, in vivo, probe of ADAM10 activity. Additionally, results of the present and prior studies strongly suggest that glycosylated substrate are applicable as screening agents for discovery of selective ADAM probes and therapeutics.

The interface between organizational learning capability, entrepreneurial orientation, and SME growth

Abstract: This paper investigates the interface between organizational learning capability, entrepreneurial orientation (EO), and small business performance. It reports on the findings from 350 small and medium enterprises (SMEs) in North Cyprus operating in the services and retailing sectors. The findings indicate a positive relationship between EO and sales and market share growth, but not between EO and employment growth. There is also a positive relationship between organizational learning capability and EO. This paper contributes to the small business management literature by providing a holistic analysis of the interface between organizational learning capability, EO, and growth.

Key Provisions of the Patient Protection and Affordable Care Act (ACA): A Systematic Review and Presentation of Early Research Findings

Abstract: Objectives To conduct a systematic literature review of selected major provisions of the Affordable Care Act (ACA) pertaining to expanded health insurance coverage We present and synthesize research findings from the last 5 years regarding both the immediate and long-term effects of the ACA We conclude with a summary and offer a research agenda for future studies Study Design We identified relevant articles from peer-reviewed scholarly journals by performing a comprehensive search of major electronic databases We also identified reports in the “gray literature” disseminated by government agencies and other organizations Principal Findings Overall, research shows that the ACA has substantially decreased the number of uninsured individuals through the dependent coverage provision, Medicaid expansion, health insurance exchanges, availability of subsidies, and other policy changes Affordability of health insurance continues to be a concern for many people and disparities persist by geography, race/ethnicity, and income Early evidence also indicates improvements in access to and affordability of health care All of these changes are certain to ultimately impact state and federal budgets Conclusions The ACA will either directly or indirectly affect almost all Americans As new and comprehensive data become available, more rigorous evaluations will provide further insights as to whether the ACA has been successful in achieving its goals

Bleeding Risk with Long-Term Low-Dose Aspirin: A Systematic Review of Observational Studies.

Abstract: Background Low-dose aspirin has proven effectiveness in secondary and primary prevention of cardiovascular events, but is also associated with an increased risk of major bleeding events. For primary prevention, this absolute risk must be carefully weighed against the benefits of aspirin; such assessments are currently limited by a lack of data from general populations.

Changes in American Adults’ Reported Same-Sex Sexual Experiences and Attitudes, 1973–2014

Abstract: We examined change over time in the reported prevalence of men having sex with men and women having sex with women and acceptance of those behaviors in the nationally representative General Social Survey of U.S. adults (n’s = 28,161–33,728, ages 18–96 years), 1972–2014. The number of U.S. adults who had at least one same-sex partner since age 18 doubled between the early 1990s and early 2010s (from 3.6 to 8.7 % for women and from 4.5 to 8.2 % for men). Bisexual behavior (having sex with both male and female partners) increased from 3.1 to 7.7 %, accounting for much of the rise, with little consistent change in those having sex exclusively with same-sex partners. The increase in same-sex partners was larger for women than for men, consistent with erotic plasticity theory. Attitudes toward same-sex sexual behavior also became substantially more accepting, d = .75, between the early 1970s and early 2010s. By 2014, 49 % of American adults believed that same-sex sexual activity was “not wrong at all,” up from 11 % in 1973 and 13 % in 1990. Controlling for acceptance reduced, but did not eliminate, the increase in same-sex behavior over time. Mixed effects (hierarchical linear modeling) analyses separating age, time period, and cohort showed that the trends were primarily due to time period. Increases in same-sex sexual behavior were largest in the South and Midwest and among Whites, were mostly absent among Blacks, and were smaller among the religious. Overall, same-sex sexual behavior has become both more common (or at least more commonly reported) and more accepted.

Emerging Loop-Mediated Isothermal Amplification-Based Microchip and Microdevice Technologies for Nucleic Acid Detection

Abstract: Rapid, sensitive, and selective pathogen detection is of paramount importance in infectious disease diagnosis and treatment monitoring. Currently available diagnostic assays based on polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) are time-consuming, complex, and relatively expensive, thus limiting their utility in resource-limited settings. Loop-mediated isothermal amplification (LAMP) technique has been used extensively in the development of rapid and sensitive diagnostic assays for pathogen detection and nucleic acid analysis and hold great promise for revolutionizing point-of-care molecular diagnostics. Here, we review novel LAMP-based lab-on-a-chip (LOC) diagnostic assays developed for pathogen detection over the past several years. We review various LOC platforms based on their design strategies for pathogen detection and discuss LAMP-based platforms still in development and already in the commercial pipeline. This review is intended as a guide to the use of LAMP techni...

Planck star tunneling time: An astrophysically relevant observable from background-free quantum gravity

Abstract: A gravitationally collapsed object can bounce out from its horizon via a tunnelling process that violates the classical equations in a finite region. Since tunnelling is a nonperturbative phenomenon, it cannot be described in terms of quantum fluctuations around a classical solution, and a background-free formulation of quantum gravity is needed to analyze it. Here, we use loop quantum gravity to compute the amplitude for this process, in a first approximation. The amplitude determines the tunnelling time as a function of the mass. This is the key information to evaluate the relevance of this process for the interpretation of fast radio bursts or high-energy cosmic rays. The calculation offers a template and a concrete example of how a background-free quantum theory of gravity can be used to compute a realistic observable quantity.

Application of the Repetitions in Reserve-Based Rating of Perceived Exertion Scale for Resistance Training

Abstract: RATINGS OF PERCEIVED EXERTION ARE A VALID METHOD OF ESTIMATING THE INTENSITY OF A RESISTANCE TRAINING EXERCISE OR SESSION. SCORES ARE GIVEN AFTER COMPLETION OF AN EXERCISE OR TRAINING SESSION FOR THE PURPOSES OF ATHLETE MONITORING. HOWEVER, A NEWLY DEVELOPED SCALE BASED ON HOW MANY REPETITIONS ARE REMAINING AT THE COMPLETION OF A SET MAY BE A MORE PRECISE TOOL. THIS APPROACH ADJUSTS LOADS AUTOMATICALLY TO MATCH ATHLETE CAPABILITIES ON A SET-TO-SET BASIS AND MAY MORE ACCURATELY GAUGE INTENSITY AT NEAR-LIMIT LOADS. THIS ARTICLE OUTLINES HOW TO INCORPORATE THIS NOVEL SCALE INTO A TRAINING PLAN.

Is the Crowd Sensitive to Distance? — How Investment Decisions Differ by Investor Type

Abstract: This paper presents the first evidence of the influence of geographic distance among retail, accredited, and overseas investors and venture location in an equity crowdfunding context. By analyzing investment decisions, we show that geographic distance is negatively correlated with investment probability for all investor types. Our comparison of home country and overseas investors reveals that overseas investors are sensitive to distance, but considerably less so than home country investors. However, when comparing only home country investors (subdivided into retail and the more sophisticated accredited), we document that both investor types are similarly sensitive to the distance of possible ventures.

Workers Without Paid Sick Leave Less Likely To Take Time Off For Illness Or Injury Compared To Those With Paid Sick Leave

Abstract: Paid sick leave is an important employer-provided benefit that helps people obtain health care for themselves and their dependents. But paid sick leave is not universally available to US workers. Little is known about paid sick leave and its relationship to health behaviors. Contrary to public health goals to reduce the spread of illness, our findings indicate that in 2013 both full- and part-time working adults without paid sick leave were more likely than workers with that benefit to attend work when ill. Those without paid sick leave were 3.0 times more likely to forgo medical care for themselves and 1.6 times more likely to forgo medical care for their family compared to working adults with paid sick leave benefits. Moreover, the lowest-income group of workers without paid sick leave were at the highest risk of delaying and forgoing medical care for themselves and their family members. Policy makers should consider the potential public health implications of their decisions when contemplating guarante...

Homophily, Structure, and Content Augmented Network Representation Learning

Abstract: Advances in social networking and communication technologies have witnessed an increasing number of applications where data is not only characterized by rich content information, but also connected with complex relationships representing social roles and dependencies between individuals. To enable knowledge discovery from such networked data, network representation learning (NRL) aims to learn vector representations for network nodes, such that off-the-shelf machine learning algorithms can be directly applied. To date, existing NRL methods either primarily focus on network structure or simply combine node content and topology for learning. We argue that in information networks, information is mainly originated from three sources: (1) homophily, (2) topology structure, and (3) node content. Homophily states social phenomenon where individuals sharing similar attributes (content) tend to be directly connected through local relational ties, while topology structure emphasizes more on global connections. To ensure effective network representation learning, we propose to augment three information sources into one learning objective function, so that the interplay roles between three parties are enforced by requiring the learned network representations (1) being consistent with node content and topology structure, and also (2) following the social homophily constraints in the learned space. Experiments on multi-class node classification demonstrate that the representations learned by the proposed method consistently outperform state-of-the-art NRL methods, especially for very sparsely labeled networks.