On the Origin of Ultraviolet Emission and the Accretion Model of Low-luminosity AGNs

Low-luminosity active galactic nuclei (LLAGNs) are generally believed to be powered by an inner radiatively inefficient, advection-dominated accretion flow (ADAF), an outer truncated thin disk, and a jet. Maoz (2007) recently challenged this picture based on the observation that the strength of ultraviolet emission relative to the X-ray and radio bands does not depart from empirical trends defined by more luminous sources. He advocates that AGNs across all luminosities have essentially the same accretion and radiative processes, which in luminous sources are described by a standard optically thick, geometrically thin disk. We calculate ADAF models and demonstrate that they can successfully fit the observed spectral energy distributions of the LLAGNs in Maoz's sample. Our model naturally accommodates the radio and X-ray emission, and the ultraviolet flux is well explained by a combination of the first-order Compton scattering in the ADAF, synchrotron emission in the jet, and black body emission in the truncated thin disk. It is premature to dismiss the ADAF model for LLAGNs. The UV data can be fit equally well using a standard thin disk, but an additional corona and jet would be required to account for the X-ray and radio emission. We argue that there are strong theoretical reasons to prefer the ADAF model over the thin disk scenario. We discuss testable predictions that can potentially discriminate between the two accretion models.Comment: 20 pages, 3 figures; ApJ in pres

Ranking Volatility in Building Energy Consumption Using Ensemble Learning and Information Entropy

Given the rise in building energy consumption and demand worldwide, energy inefficiency detection has become extremely important. A significant portion of the energy used in commercial buildings is wasted as a result of poor maintenance, degradation or improperly controlled equipment. Most facilities employ sensors to track energy consumption across multiple buildings. Smart fault detection and diagnostic systems use various anomaly detection techniques to discover point anomalies in consumption. While these systems work reasonably well in detecting equipment anomalies over short-term intervals, further exploration is needed in finding methods that consider long-term consumption to detect anomalous buildings. This paper presents a novel approach for a multi-building campus to rank and visualize the long-term volatility of building consumption. This allows for the optimal allocation of limited time and resources for the detection and resolution of energy waste. The proposed method first classifies daily consumption into 5 classes using an ensemble learner and then calculates the information entropy on the resulting classification set to determine volatility. The ensemble learner receives input from a K-Nearest Neighbor classifier, a Random Forest classifier and an Artificial Neural Network. In general, buildings are expected to keep the same energy profile over time, all else being equal. Buildings that frequently change energy profiles are ranked and flagged by the system for review, which would call for the next step to reduce waste and costs and to increase the sustainability of buildings. Data on energy consumption for 132 buildings is obtained from energy management at the Georgia Institute of Technology. Experimental results show the effectiveness of the proposed approach

Exploring customers’ zone of tolerance for B2B professional service quality

Purpose: This paper aims to extend the current research on zone of tolerance (ZOT) and its antecedents, to the context of business-to-business (B2B) professional services from both client and service firms’ perspectives, with a modified ZOT framework including five client and service firms attributes as antecedents of desired (DSL) and adequate (ASL) service levels. Prior research on zone of tolerance (ZOT) and its antecedents mostly focuses on business-to-consumer services and customers’ perspective. The authors address these gaps with a modified ZOT framework with five attributes of client and service firms as antecedents of customer expectations, namely, desired service level (DSL) and adequate service level (ASL), for business-to-business (B2B) professional services. Design/methodology/approach: A combination of qualitative (focus groups) and quantitative (online survey) research methods with managers of professional audit firms and their clients, using a reduced AUDITQUAL instrument with 39 items and seven dimensions.Findings: Professional firm size and fee premium have a positive effect on DSL; service tenure positively influences both DSL and ASL; client firm size has a negative effect on DSL; both client and service firm sizes positively moderate each other’s influence on the DSL; and DSL positively influences ASL. Research limitations/implications: The authors study a single B2B professional service (audit) in a single city (Hong Kong) from a single perspective (customers) that may limit the generalizability of the findings. Future research should validate the findings for other B2B professional services in diverse locations and also include service providers’ expectations and perceptions. Practical implications: Managers in professional service firms should understand the factors influencing different levels of expectations for their customers and develop suitable strategies (e.g. customer education and employee training) to manage these expectations more effectively. Originality/value: The authors extend current research on customer expectations and ZOT by identifying five unique attributes of professional service and client firms and testing their roles as antecedents of adequate and DSLs using AUDITQUAL instrument

Charting multidisciplinary research and action priorities towards the conservation and sustainable management of sea turtles in the Pacific ocean : a focus on Malaysia

Conservation, Turtle culture, Malaysia,

Učinci prenatalne i postnatalne izloženosti perfluorooktanskoj kiselini na ekspresiju glavnih gena povezanih s reprodukcijom u mišjem hipotalamusu i spolnim žlijezdama

Perfluorooctanoic acid (PFOA), a ubiquitous environmental pollutant reported to be an endocrine disruptor, is used in many industrial and consumer products. Although the adverse effects of PFOA on the reproductive health of animals and humans have been widely reported, most studies have focused on assessing the anatomical features and conventional histology of adult gonads. Therefore, the molecular mechanisms activated in the hypothalamus and gonads following PFOA exposure during the pre- and postnatal periods are not clear. This study used a mouse model to evaluate the effects of PFOA exposure on the alteration of molecular mechanisms in the hypothalamus and gonads during the prenatal and postpartum periods. Changes in gene and protein expression following PFOA exposure were evaluated by quantitative polymerase chain reaction and Western blotting, respectively. Kisspeptin 1 and gonadotropin-releasing hormone expression in the hypothalamus of female and male mouse pups was significantly decreased. Additionally, Cyp17a1 expression was upregulated in male offspring testes, while Cyp17a1 and Cyp19a1 expression was downregulated in female offspring ovaries. Changes at the molecular level due to PFOA exposure in the early stages of development did not show sex-related differences in the hypothalamus; however, such differences were confirmed in the gonads. These results could be used as basic data to study the molecular mechanisms underlying the reproductive dysfunction caused by PFOA exposure in the early stages of embryonic development.Perfluorooktanska kiselina (PFOA) sveprisutna je onečišćujuća tvar za okoliš, za koju je zabilježeno da uzrokuje i endokrinopatije, a upotrebljava se u mnogim industrijskim proizvodima. Bez obzira na poznate i zabilježene nuspojave PFOA-e na reproduktivno zdravlje životinja i ljudi, većina se istraživanja usredotočuje na procjenu anatomskih histoloških značajki u spolnim žlijezdama odraslih jedinki. Molekularni mehanizmi koji se aktiviraju u hipotalamusu i spolnim žlijezdama nakon izlaganja PFOA-i stoga nisu razjašnjeni. U ovom je istraživanju upotrijebljen mišji model za procjenu učinaka izlaganja PFOA-i na promjenu molekularnih mehanizama u hipotalamusu i spolnim žlijezdama za vrijeme prijeporođajnog i poslijeporođajnog razdoblja. Promjene u ekspresiji gena i proteina nakon izloženosti PFOA-i analizirane su kvantitativnom PCR metodom i metodom Western blotting. Ekspresija kispeptina 1 i hormona koji oslobađa gonadotropin u hipotalamusu ženske i muške mladunčadi bila je znakovito smanjena. Osim toga ekpresija Cyp17a1 bila je pojačana u testisima muških potomaka, dok je ekspresija Cyp17a1 i Cyp19a1 u jajnicima ženskih potomaka bila smanjena. Kod promjena na molekularnoj razini u hipotalamusu u ranim razvojnim stadijima nije bilo razlike među spolovima, dok je kod promjena u spolnim žlijezdama povrđena razlika među spolovima. Rezultati ovog istraživanja mogli bi biti korisni kao osnovni podaci u proučavanju molekularnih mehanizama podležeće reproduktivne disfunkcije uzrokovane izloženošću PFOA-i u ranim stadijima embrionalnog razvoja

Purification and Characterization of a Lectin from Phaseolus vulgaris cv. (Anasazi Beans)

A lectin has been isolated from seeds of the Phaseolus vulgaris cv. “Anasazi beans” using a procedure that involved affinity chromatography on Affi-gel blue gel, fast protein liquid chromatography (FPLC)-ion exchange chromatography on Mono S, and FPLC-gel filtration on Superdex 200. The lectin was comprised of two 30-kDa subunits with substantial N-terminal sequence similarity to other Phaseolus lectins. The hemagglutinating activity of the lectin was stable within the pH range of 1–14 and the temperature range of 0–80°C. The lectin potently suppressed proliferation of MCF-7 (breast cancer) cells with an IC50 of 1.3 μM, and inhibited the activity of HIV-1 reverse transcriptase with an IC50 of 7.6 μM. The lectin evoked a mitogenic response from murine splenocytes as evidenced by an increase in [3H-methyl]-thymidine incorporation. The lectin had no antifungal activity. It did not stimulate nitric oxide production by murine peritoneal macrophages. Chemical modification results indicated that tryptophan was crucial for the hemagglutinating activity of the lectin

Role of ZrO2 and CeO2 support on the In2O3 catalyst activity for CO2 hydrogenation

Methanol synthesis from CO2 hydrogenation has drawn global attention as catalytic CO2 hydrogenation is an attractive choice to mitigate CO2 emissions and lessen dependency on fossil resources. In the present study, we have synthesized ZrO2 and CeO2-supported In2O3 catalysts for methanol synthesis from CO2 hydrogenation and the catalytic performances of Inx/ZrO2, and Inx/CeO2 (x = 1 % and 13 %) were compared. Specifically, the effect of the ZrO2 and CeO2 supports on In2O3 catalyst during CO2 hydrogenation was explored. This study reveals that ZrO2 support increased the catalytic activity while the CeO2 support decreased although both supports have almost the same indium loading and surface area. Various characterizations like XRD, DRIFT, CO2-TPD, H2-TPR and XPS analysis of catalysts provided insight into changes that arise after mixing the two oxides and during the reaction as well as after the reaction. The stabilities of In2O3, In13/ZrO2, and In13/CeO2 were tested for up to 50 h and we found In13/ZrO2 was stable during this time-on-stream, while In13/CeO2 lost activity after 2 h of reaction. XPS results of spent catalysts showed that In(OH)3 was observed significantly over the spent In13/CeO2. OH groups were also verified by DRIFT experiments, however at low levels due to low CO2 conversion at atmospheric pressure. XRD analysis confirmed the sintering of CeO2 support during the reaction. Thus, the hydrophilic nature of CeO2, redox properties of CeO2 and sintering of CeO2 support in the presence of water, were the main reasons for the early deactivation of In13/CeO2. A regeneration study was carried out to regenerate the catalyst and the results showed that partial regeneration of the In13/CeO2 catalyst is possible by Ar flushing. We, therefore, suggest that the build-up of OHgroups deactivate the In13/CeO2 catalyst and some of these OH groups could be removed during flushing with inert gas, causing a partial regeneration. However, the decreased surface area is not reversible, and this results in a continuous decrease in the activity of the catalyst after repeated experiments, even if the catalyst is flushed with Ar between the experiments

A Design Functionality Study of IDM Web-Stores

One of the advantages of conducting business over the Internet is the ability to collect information about customer preferences in order to serve them accordingly. Personalisation provides a means of doing this. In this paper, we have attempted to study the effect of personalisation on the success of IDM web-stores. The major contribution of our paper is the extension of the IDM Platform Functionality Model of Srinivasan et al [24] to include personalisation. The second contribution is the investigation of six personalisation features that specify and describe this functionality in its various forms. We have used both quantitative and qualitative research techniques such as click-stream analysis and emphatic design in a focus group. Our findings suggest that personalisation is a significant component of IDM web-store design