Guest Type Research Articles

Interactions of Mycotoxin Alternariol with Cyclodextrins and Its Removal from Aqueous Solution by Beta-Cyclodextrin Bead Polymer

Alternariol is an Alternaria mycotoxin that appears in fruits, tomatoes, oilseeds, and corresponding products. Chronic exposure to it can induce carcinogenic and xenoestrogenic effects. Cyclodextrins (CDs) are ring-shaped molecules built up by glucose units, which form host–guest type complexes with some mycotoxins. Furthermore, insoluble CD polymers seem suitable for the extraction/removal of mycotoxins from aqueous solutions. In this study, the interactions of alternariol with β- and γ-CDs were tested by employing fluorescence spectroscopic and modeling studies. Moreover, the removal of alternariol from aqueous solutions by insoluble β-CD bead polymer (BBP) was examined. Our major observations/conclusions are the following: (1) CDs strongly increased the fluorescence of alternariol, the strongest enhancement was induced by the native γ-CD at pH 7.4. (2) Alternariol formed the most stable complexes with the native γ-CD (logK = 3.2) and the quaternary ammonium derivatives (logK = 3.4–3.6) at acidic/physiological pH and at pH 10.0, respectively. (3) BBP effectively removed alternariol from aqueous solution. (4) The alternariol-binding ability of β-CD polymers was significantly higher than was expected based on their β-CD content. (5) CD technology seems a promising tool to improve the fluorescence detection of alternariol and/or to develop new mycotoxin binders to decrease alternariol exposure.

Cyclodextrins Can Entrap Zearalenone-14-Glucoside: Interaction of the Masked Mycotoxin with Cyclodextrins and Cyclodextrin Bead Polymer.

Zearalenone (ZEN) is a Fusarium-derived xenoestrogenic mycotoxin. In plants, zearalenone-14-O-β-d-glucoside (Z14G) is the major conjugated metabolite of ZEN, and is a masked mycotoxin. Masked mycotoxins are plant-modified derivatives, which are not routinely screened in food and feed samples. Cyclodextrins (CDs) are cyclic oligosaccharides built up from D-glucopyranose units. CDs can form stable host–guest type complexes with lipophilic molecules (e.g., with some mycotoxins). In this study, the interaction of Z14G with native and chemically modified β- and γ-CDs was examined employing fluorescence spectroscopy and molecular modeling. Furthermore, the removal of Z14G from aqueous solution by insoluble β-CD bead polymer (BBP) was also tested. Our results demonstrate that Z14G forms the most stable complexes with γ-CDs under acidic and neutral conditions (K ≈ 103 L/mol). Among the CDs tested, randomly methylated γ-CD induced the highest increase in the fluorescence of Z14G (7.1-fold) and formed the most stable complexes with the mycotoxin (K = 2 × 103 L/mol). Furthermore, BBP considerably reduced the Z14G content of aqueous solution. Based on these observations, CD technology seems a promising tool to improve the fluorescence analytical detection of Z14G and to discover new mycotoxin binders which can also remove masked mycotoxins (e.g., Z14G).

Dementia Cafés as a Community Resource for Persons With Early-Stage Cognitive Disorders: A Nationwide Survey in Japan

ObjectivesDementia cafés are expected to serve as a new community resource based on the national dementia strategy in Japan. The objective of the present study was to examine effective ways to manage dementia cafés through an overview of dementia cafés in Japan and an analysis of the factors related to their effectiveness on attendees. DesignCross-sectional analysis. Setting and participantsRepresentatives of 1477 dementia cafés in Japan. MeasuresQuestionnaires regarding the dementia cafés' characteristics, management members, staff, their guests and effectiveness on people with dementia, their families, and community members were sent to the cafés, with instructions to have them completed by the café representatives. Logistic regression analysis was performed with the effect on each guest attribute as a dependent variable, and factors related to the effectiveness of dementia cafés were analyzed. ResultsQuestionnaires were sent to a total of 2728 dementia cafés in Japan, and responses were received from 1477 (54.1%). The most common meeting frequency and meeting hours were once a month (64.8%) and 2 hours (53.8%), respectively. Analysis of the effectiveness of dementia cafés on 3 groups of guests indicated the following preferences for café program: people with dementia preferred frequent meetings and activities, families of people with dementia preferred having a place for private consultation and advice and peer meetings, and community members preferred frequent meetings and both mini-lectures and private consultation and advice. Logistic regression analysis further revealed that all types of guests preferred the presence of the same types of guests. Conclusions/ImplicationsThis study revealed the multicomponent nature of dementia cafés. The results suggest that a good balance of programs and guests would enhance the cafés' effectiveness among the multiple stakeholders in regard to dementia, especially in the early stage of the disease.

Hamilton Receptor‐Mediated Self‐Assembly of Orthogonally Functionalized Au and TiO2 Nanoparticles

AbstractA new prototype of reversible self‐assembly between functionalized gold and titanium dioxide nanoparticles (NPs) utilizing hydrogen bonding interactions was developed and established. The gold nanoparticles were functionalized with a Hamilton‐receptor functionality bearing a thiol moiety as anchoring group. The titanium dioxide nanoparticles were modified with cyanurate derivatives which contained phosphonic acids as anchoring groups. The host–guest type interaction between two functionalized nanoparticles yielded a highly integrated nanoparticle system in chloroform. Moreover, by presenting a competing ligand in an exchange reaction, the product of self‐assembly can be segregated into the individual soluble components of functionalized nanoparticles. The self‐assembly and the exchange reaction were followed and monitored in detail by UV/Vis spectroscopy. The structure of the self‐assembly product was investigated using scanning electron microscopy (SEM) and small‐angle X‐ray scattering (SAXS).

Undoped and Eu3+ Doped Magnesium-Aluminium Layered Double Hydroxides: Peculiarities of Intercalation of Organic Anions and Investigation of Luminescence Properties.

The Mg3/Al and Mg3/Al0.99Eu0.01 layered double hydroxides (LDHs) were fabricated using a sol-gel chemistry approach and intercalated with different anions through ion exchange procedure. The influence of the origin of organic anion (oxalate, laurate, malonate, succinate, tartrate, benzoate, 1,3,5-benzentricarboxylate (BTC), 4-methylbenzoate (MB), 4-dimethylaminobenzoate (DMB) and 4-biphenylacetonate (BPhAc)) on the evolution of the chemical composition of the inorganic-organic LDHs system has been investigated. The obtained results indicated that the type and arrangement of organic guests between layers of the LDHs influence Eu3+ luminescence in the synthesized different hybrid inorganic–organic matrixes. For the characterization of synthesis products X-ray diffraction (XRD) analysis, infrared (FTIR) spectroscopy, fluorescence spectroscopy (FLS), and scanning electron microscopy (SEM), were used.

Exploring Environmental Awareness and Behavior among Guests at Hotels That Apply Water-Saving Measures

The aim of this study was to investigate guest profiles at a hotel that has created a best-practices water management model to determine how different types of guests contribute to saving water during their stay. To do this, we analyzed levels of environmental awareness and pro-environmental behavior among the guests. Information was gathered through 648 structured surveys with guests at Hotel Samba in the Spanish seaside resort of Lloret de Mar between September 2015 and August 2016. Cluster analysis revealed four profiles of guests with different sociodemographic characteristics and different levels of awareness and proactivity in relation to water conservation. We combined our findings to develop a framework that illustrates how the two dimensions of environmental awareness and pro-environmental behavior are related in this setting. This article provides new insights into how hotel guests’ environmental awareness and engagement can influence a hotel’s water-saving efforts. These insights should help hotel operators to devise new, guest-centered strategies for saving water.

The Relationship between the Existence of Butler and Service Quality received by VIP Guests

Good service quality in the hotel can be achieved if employees are able to anticipate and meet the guest’s needs. Therefore, it is necessary to have a section focusing on a certain type of guests, namely VIP and VVIP guests. in order to achieve good relations with guests. This section is called Butler which cover personal services so that the service quality is expected to increase. This study aims to study the guests opinion about the existence of Butler at Raffles Hotel, Jakarta and to find out the relationships between Butler and service quality. Research methods used is descriptive correlational where correlational coefficient and coefficient of determination are computed. Data was collected using questionnaire distributed to VIP/VVIP guests at Raffles Hotel Jakarta. Sample size was 53 and sampling technique was non probability purposive sampling. The result showed that on the whole the existence of butler was rated very good by VIP guests in Raffles Hotel Jakarta. Meanwhile, service quality received by guests was also very good. There was a strong positive relationship between Butler's existence and service quality in Raffles Hotel Jakarta.

Report on Network Sunday Morning Talk Show Content and Ratings, Comparing 1983, 1999, and 2015

We studied the content and Nielsen ratings for interviews on the three network Sunday morning talk shows—Meet the Press (henceforth MTP), Face the Nation (FTN), and This Week (TW). We compared three time periods—1983 (MTP, FTN), 1999 (all three shows), and 2015 (all three shows). In order to insure apples-to-apples comparisons, for over time comparisons, we either restricted our analyses to MTP and FTN or analyzed the data with and without TW. For “overall” snapshots we included all three shows (MTP, FTN, TW). Our goals were fourfold: (1) identify any discernable trends in the topics and types of guests featured on the Sunday talk shows, (2) identify any trends in audience ratings, (3) assess whether and to what extent trends in topics and guests correlate with audience ratings, and (4) assess whether, to what extent, and under what circumstances, the Sunday talk shows influence the subsequent news agenda.

Switchable Dielectric Constant in the Cyanometalate‐Based Hydrogen‐Bonded [(CH3)2NH2]2(H3O)[Co(CN)6] Framework

AbstractInvited for the cover of this issue is the group of Wen Zhang from Southeast University, Nanjing, China. The cover image shows host–guest type organic–inorganic frameworks that have switchable dielectric constants.

An investigation of the complexation of host N,N′-bis(9-phenyl-9-thioxanthenyl)ethylenediamine with dihaloalkane guests

Two wheel-and-axle host compounds were synthesized and assessed for their host ability. After growing crystals of N,N′-bis(9-phenyl-9-thioxanthenyl)ethylenediamine from various alkyl halide solvents, we discovered that this host is highly proficient for the enclathration of these guest types. However, the novel compound N,N′-bis(9-phenyl-9-xanthenyl)-1,6-hexamethylenediamine, bearing the more flexible axle, showed no inclusion ability whatsoever. Competition experiments where the title host compound was recrystallized from equimolar binary and ternary mixtures of CH2Cl2, CH2Br2 and CH2I2 showed this host to have a selectivity in the order CH2Br2 > CH2I2 > CH2Cl2 for these guests. Varying the molar ratios of guests in these mixtures beyond equimolar revealed that the host remained selective for the bromine derivative whenever it was present, even at low dibromomethane concentrations. Single crystal X-ray diffraction data and, more specifically, host–guest interactions in the crystal, were used to explain the selectivity order; lattice energies were also considered in this context. The relative thermal stabilities of the three complexes, obtained from thermal experiments, showed that the selectivity order and these thermal stabilities are unrelated.

Formation of Supramolecular Structures in the β-Cyclodextrin–β-Resorcylic Acid System

It was found with the help of spectrophotometry, IR spectroscopy, X-ray phase analysis, and thermogravimetry, that new supramolecular structures in the β-cyclodextrin–β-resorcylic acid system are generated as a result of a spontaneous exothermic process. It was proven that the inclusion complexes of the host–guest type with a 1:1 ratio between β-cyclodextrin and the molecular form of β-resorcylic acid (or its monovalent anion) are formed through van der Waals interactions of the aromatic ring of β-resorcylic acid with the inner hydrophobic cavity of β-cyclodextrin. It was shown that partial displacement of water molecules from the inner cavity of the cyclic oligosaccharide and complete immersion of β-resorcylic acid molecule inside it occur in this case; thermal stability of β-resorcylic acid increases.

Colloidal magnetic nanoparticles coated with self-dissolving mixed fatty acid bilayer: A novel host–guest material for controlled release applications

We have recently reported that magnetic nanoparticles coated with oleic acid bilayer can form highly stable colloidal suspension in water. The particles were shown to extract and accommodate dye molecules inside its bilayer structure form solution and from solid surface. Here in, we design a novel colloidal system that can accommodate the dye and then gradually release the same as a function of time without the application of external stimuli. The host–guest type of system is composed of iron oxide nanoparticle as core and a self-dissolving mixed fatty acid bilayer as shell. Rhodamine 6G (R6G) dye was used as probe to study the controlled release process. Increased fluidity was shown to gradually denature the bilayer resulting in slow and controlled release of R6G. Fluidity of the bilayer was tuned with the addition of controlled amounts of linoleic acid. Iron oxide nanoparticles were characterized with high resolution transmission electron microscope and X-ray diffraction. Bilayer formation was characterized with pyrene probe experiments, Fourier transform Infrared spectroscopy, thermogravimetry and dynamic light scattering. Release profiles of R6G were studied in PBS and SBF buffer using fluorescence spectroscopy.

Domestic hospitality, gender, and impression management among Danish women

ABSTRACTDomestic life and domestic work are often studied in a family setting that only includes members of the focal family unit. However, when opening the home for guests, family life becomes both a back and front stage arena, where guests are relaxed but hosts are not. Being a host includes not only domestic chores but also “doing” identity, relations, and friendship. In this article, we combine Goffman's work with thirteen qualitative interviews from Denmark to investigate domestic hospitality and hosts' perceptions hereof. Domestic hospitality involves not only “putting on a show” but also extensive preparation and complex assessments of appropriate levels of staging. Such staging depends on occasions, host-guest relations, and hosts' predispositions. We discuss how reflexive and well-educated women, who are aware of their “putting on a show,” nevertheless put on such “shows.” Even in Denmark, which is rather progressive in terms of gender equality compared to other European countries, gender still matters and affects women's self-conceptualizations in domestic hospitality. It is well known that people manage the impressions they seek to make and adapt to different types of guests, but the contribution of this article is to pinpoint the extent to which the participants are aware of these processes, and of the fact that they are sometimes almost ridiculous, but still cannot not care.

Modelling spa-goers' choices of therapeutic activities

Abstract Owing to the dearth of studies analysing choices of treatments in spa settings, this study drew on choice theory and Gesler's concept of therapeutic landscape to offer novel insights on spa-goers' choice of treatments. Evidence from 314 spa-goers in Ghana revealed that on average, spa-goers undertake three main treatments in varied combinations, with massage, beauty therapy and thermotherapy being the most patronised. Further, a multinomial logit and a zero truncated negative binomial regression showed that choice of type and number of treatments are both influenced by a multiplicity of factors including age, level of education, travel party size, spa experience, type of guest, length of stay and expected benefits. Given the increasing desire of governments and other policy makers in enhancing the health status of citizens, this information could serve as a valuable means for enticing participation in promotional health activities in spas. Much more, wellness service providers and destination marketing organisations can rely on these findings for segmenting patrons of wellness products and services.

Theoretical modeling of the thermodynamic properties and the phase diagram of binary gas hydrates of argon and hydrogen

Theoretical calculation of the thermodynamic properties and determining of equilibrium hydrate composition of binary argon + hydrogen hydrates has been performed with taking into account the concurrent cage occupation by different guest types. For this purpose the original previously developed approach has been used that allows to take into account multiple cage occupancy and the possibility of mixed clusters inside the cages as well as the influence of guest molecules on the host lattice. Separately, argon and hydrogen form cubic structure II (sII) hydrates. Therefore, in this work we considered only sII gas hydrates formation. It is shown that thermodynamic stability of binary argon + hydrogen hydrates strongly depends on the presence of argon in the gas phase as the heavier component. Thus, with increasing argon content in the system the hydrate stability field extends to low pressures with increase of argon fraction in the small cavities.

Diffusional behavior and guest conformational analysis of hexadecane-1,16-diol and hexadecane in urea crystal model via molecular dynamics simulation approach.

Diffusion at the atomic or molecular level is a source of many physical, chemical, and biological processes taking place in plentiful materials. This work is an endeavor toward investigating the diffusional behavior of two different type of guests, hexadecane-1,16-diol and hexadecane enclathration in urea tunnel architecture, whereby the correlation of the diffusion mechanism with the guest's structural and conformational properties is explored. To carry out this study, molecular dynamics simulation approach is adopted. It is found that hexadecane-1,16-diol exhibit slower diffusion with an average diffusion coefficient value [Formula: see text], where hexadecane diffuse more rapidly with an average diffusion coefficient value [Formula: see text]. It is also observed that the structural properties influence the guest's travel distance and torsion angle distribution of the trans and gauche conformational proportion. Furthermore, the observed high energy barrier accounted for hexadecane-1,16-diol and low energy barrier for hexadecane along urea tunnel systems was analyzed. The comparison of our obtained results are in close agreement with the available experimental measurements, i.e., gauche proportion properties between two different guest molecules correlate well with Raman spectroscopy investigation on α,ω-dihalogenoalkane/urea inclusion compounds. Our calculations also successfully endorse the structure-property relation between the two systems.

ChemInform Abstract: Host—Guest Binding Motifs Based on Hyperbranched Polymers

AbstractReview: 138 refs.

Which hotel guest segments reuse towels? Selling sustainable tourism services through target marketing

ABSTRACT This paper reviews and evaluates the wide range of supply and demand side measures employed and tested to reduce the environmental impacts of tourist accommodation. It focuses on the importance of understanding market segments and their pro-environmental behaviour by exploring the personal and travel characteristics significantly associated with pro-environment beneficial change, empirically investigating hotel guest characteristics associated with higher towel reuse. Towel use per day, per room, is modelled according to the number of adults in the room, the number of children, and the type and origins of guests. Observed actual towel use by 204 travel parties spending 480 nights in a four-star hotel in Slovenia reveals key personal and travel characteristics of hotel guests which are predictive of towel reuse: their country of origin, booking methods used, being a business traveller and not being a family. Results point to a-priori market segments which could be given booking preference in periods of high demand to reduce hotel environmental footprints. Results also point to promising leverage points for interventions designed to modify the behaviour of hotel guests on site. The approach and methodology used could be applied to marketing pro-environmental concepts more widely across other sustainable initiatives.

PENGARUH STRATEGI REPOSITIONING HOLIDAY INN BANDUNG TERHADAP KEPERCAYAAN TAMU MEMBER

Hospitality industry has three classifications of the National Chain Hotel, International Hotel Chain and hotels that are managed independently. International Hotel Chain is standing in Bandung one of them is the Holiday Inn. Holiday Inn Bandung is one of the four-star hotel which has the highest actual share best among customary international chain hotel in the city of Bandung. One of the guests that must be maintained is a guest member. The effort to maintain it is to make changes or repositioning. The purpose of this study was to obtain findings on repositioning strategies undertaken, the level of trust and influence of repositioning strategies undertaken Holiday Inn Bandung guest member of the trust. Repositioning strategy used theory is Muzellec & Lambkin, whereas the theory of confidence used was Doney & Canon. Objects in this study was the guest of a member who stays good corporate member guest and guest of individual members. Independent variable (X) is a repositioning strategy that consists of three dimensions of brand logos, building renovation and staff performance. Dependent variable (Y), namely trust. This type of study is a descriptive verifikatif, and the method used is survey with stratified random sampling technique, the obtained sample size of 100 respondents to the division of 56 respondents for this type of corporate members and 44 guests respondents for this type of individual member guest. Techniques of data analysis and hypothesis test used is multiple regression. The results showed that the repositioning strategy did have an influence on trust. Dimensional result greatest value of the brand logo of amounting to 5.742, then the second highest value obtained through the staff performance of 5.363, while the building renovation is considered guest members have no influence because the guest member has not felt comfortable and familiar with the appearance and location of new facilities.

Novel quinoxaline based chemosensors with selective dual mode of action: nucleophilic addition and host–guest type complex formation

New quinoxalinium salts1–5have been exploited as chemosensorsvianaked eye, UV-Vis absorption, fluorescence quenching and1H NMR experiments.