136 research outputs found
A Strategic Household Purchase: Consumer House Buying Behavior
The aim of this study is to examine consumer house-buying behavior from the consumers’ perspective. In view of the existing literature exploring consumer decision making, the purpose of this research was threefold: (a) to propose a conceptual model of consumer decision making within the frame of consumer behavior; (b) to gain knowledge of factors impacting this process from the empirical standpoint with the focus on prefabricated house purchases; and (c) to offer implications for beneficial purchases of prefabricated houses. The results of our in-depth interviews with recent owners and potential buyers of a custom-made prefabricated house suggest that cognitive and rational factors do not offer sufficient explanation of consumer behavior in the case of a high-involvement product such as a house. In addition to the idiosyncratic characteristics of the customer, his/her personal situation and environmental factors, the role of feelings, experience, subconscious factors, needs and goals should to be taken into account to better understand this kind of decision making.consumer decision-making, strategic purchase, prefabricated house, qualitative research
Lysolipid containing liposomes for transendothelial drug delivery
BACKGROUND: Designing efficient 'vectors', to deliver therapeutics across endothelial barriers, in a controlled manner, remains one of the key goals of drug development. Recently, transcytosis of liposome encapsulated fluorescence marker calcein across a tight cell barrier was studied. The most efficient liposomes were found to be liposomes containing sufficient amount of alkyl phospholipid (APL) perifosine. APLs have similar structure as lysophosphatidyl choline (LPC), since APLs were synthesized as metabolically stable analogues of LPC, which increases endothelial permeability directly by inducing endothelial cell contraction, resulting in formation of gaps between endothelial cells. Since one of the unique properties of lysolipid, containing liposomal formulations is dynamic equilibrium of lysolipids, which are distributed among liposomes, micelles, and free form, such liposomes represent a reservoir of free lysolipids. On the other hand lysolipid containing liposomes also represent a reservoir of an encapsulated hydrophilic drug. PRESENTATION OF THE HYPOTHESIS: We hypothesize that free lysolipids, with highest concentration in vicinity of drug carrying liposomes, compromise endothelial integrity, primarily where concentrations of liposomes is the highest, in a similar manner as LPC, by formation of gaps between endothelial cells. Liposome encapsulated drug, which leaks from liposomes, due to liposome destabilization, caused by lysolipid depletion, can therefore be efficiently transported across the locally compromised endothelial barrier. TESTING THE HYPOTHESIS: This hypothesis could be verified: by measuring binding of perifosine and other lysolipids to albumin and to lysophospholipid receptor (LPL-R) group; formation of stress fibers and subsequent cell contraction; activation of RhoA, and endothelial barrier dysfunction; by a synthesis of other LPC analogues with high critical micellar concentration and measuring their effect on transendothelial permeability in presence and absence of albumin. IMPLICATIONS OF THE HYPOTHESIS: We propose that lysolipid containing liposomal formulations might be used as nonspecific transendothelial transport vector, since leakage of liposome encapsulated active drug occurs simultaneously with the release of the lysolipids. The concentration of the active drug is therefore expected to be the highest at the site of compromised endothelial barrier. By appropriate choice of the lysolipids an endothelial barrier would stay open only for a short time. Use of such liposomes would potentially maximize the delivery of the drug while limiting the passage of toxic substances and pathogens across the endothelial barrier. Combining lysolipid containing liposomes with superparamagnetic iron oxide nanoparticles or a targeting ligand might be required to efficiently localize drug delivery to a disease affected tissue and to avoid endothelial disruption over the entire body
Non-Deceptive Counterfeiting Purchase Behavior: Antecedents Of Attitudes And Purchase Intentions
This study offers insights into factors underlying consumers' intentions to purchase counterfeit products. Based on existing literature in the field, we posit that intention to buy is influenced by consumers' attitudes, moral intensity and perceived risk. In addition, we hypothesize that attitudes are determined by moral intensity and perceived risk. The hypotheses are tested with data gathered from a random sample of adult consumers using structural equations modeling. Implications of different patterns of results identified are also discussed
Interplay of the drivers and deterrents of leisure counterfeit purchase intentions
Drawing on complementary theoretical perspectives, in this study we empirically investigate the drivers and deterrents underlying the formation of attitudes to leisure counterfeits and purchase intentions, and examine rationalization as a moderator of the attitude-intention relationship. The research model is examined via mail survey data of adult consumers using structural equations modelling. The findings indicate that perceived benefits and moral intensity significantly influence attitudes, while the impact of performance risk is negligible. The attitude and moral intensity significantly predict the purchase intention. Our analyses confirm rationalization as a salient factor moderating the relationship between attitude and behavioral intention. Based on this pattern of results, we discuss study implications in three areas: the perception of positive consequences for oneself, the perception of consequences for others, and the use of previously rarely examined consumer justifications. The finding that performance risk is not significant in affecting consumer attitude calls into question various appeals featuring adverse effects of buying counterfeits for an individual.
First published online: 29 Dec 201
A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions
Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like oligomeric clusters of these yellow nanoparticles of narrow size distribution are synthesized under ambient conditions via two methods. The delay-time method controls the number of subunits in the oligoclusters by varying the time between the addition of HAuCl4 to alkaline solution and the subsequent addition of reducing agent, NaSCN. The yellow oligoclusters produced range in size from ~3 to ~25 nm. This size range can be further extended by an add-on method utilizing hydroxylated gold chloride (Na+[Au(OH4-x)Clx]-) to auto-catalytically increase the number of subunits in the as-synthesized oligocluster nanoparticles, providing a total range of 3 nm to 70 nm. The crude oligocluster preparations display narrow size distributions and do not require further fractionation for most purposes. The oligoclusters formed can be concentrated >300 fold without aggregation and the crude reaction mixtures remain stable for weeks without further processing. Because these oligomeric clusters can be concentrated before derivatization they allow expensive derivatizing agents to be used economically. In addition, we present two models by which predictions of particle size can be made with great accuracy
Ecology eclipses phylogeny as a major driver of nematode parasite community structure in a graminivorous primate
Understanding how ecology and phylogeny shape parasite communities can inform parasite control and wildlife conservation initiatives while contributing to the study of host species evolution.We tested the relative strengths of phylogeny and ecology in driving parasite community structure in a host whose ecology diverges significantly from that of its closest phylogenetic relatives.We characterized the gastrointestinal (GI) parasite community of wild geladas Theropithecus gelada, primates that are closely related to baboons but specialized to graminovory in the Ethiopian Highlands.Geladas exhibited very constrained GI parasite communities: only two genera (Oesophagostomum and Trichostrongylus) were identified across 305 samples. This is far below the diversity reported for baboons (Papio spp.) and at the low end of the range of domestic grazers (e.g. Bos taurus, Ovis aries) inhabiting the same region and ecological niche.Using deep amplicon sequencing, we identified 15 amplicon sequence variants (ASVs) within the two genera, seven of which matched to Oesophagostomum sp., seven to Trichostrongylus sp., and one to T. vitrinus.Population was an important predictor of ASV richness. Geladas in the most ecologically disturbed area of the national park exhibited approximately four times higher ASV richness than geladas at a less disturbed location within the park.In this system, ecology was a stronger predictor of parasite community structure than was phylogeny, with geladas sharing more elements of their parasite communities with other grazers in the same area than with closely related sister taxa.A free Plain Language Summary can be found within the Supporting Information of this article.A free Plain Language Summary can be found within the Supporting Information of this article.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162742/3/fec13603_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162742/2/fec13603.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162742/1/fec13603-sup-0001-Summary.pd
Ca 2+ switches the effect of PS-containing membranes on Factor Xa from activating to inhibiting: implications for initiation of blood coagulation
Calcium (Ca2+) plays a pivotal role in cellular and organismal physiology. The Ca2+ ion has an intermediate protein-binding affinity, thus it can serve as an on/off switch in regulation of different biochemical processes. The serum level of ionized Ca2+ is regulated with normal ionized Ca2+ being in the range from 1.10 to 1.29 mM. Hypocalcaemia (free Ca2+ < 1.1mM) in critically ill patients is commonly accompanied by hemostatic abnormalities, ranging from isolated thrombocytopenia to complex defects such as disseminated intravascular coagulation, commonly thought to be due to insufficient functioning of anticoagulation pathways. A small amount of Factor Xa (fXa) produced by Factor VIIa and exposed tissue factor is key to initiating blood coagulation by producing enough thrombin to induce later stages of coagulation. FXa must bind to phosphatidylserine (PS)-containing membranes to produce thrombin at a physiologically significant rate. In this work, we show that overall fXa activity on PS-containing membranes is sharply regulated by a “Ca2+ switch” centered at 1.16 mM, below which fXa is active and above which fXa forms inactive dimers on PS-exposing membranes. Our data lead to a mathematical model that predicts the variation of fXa activity as a function of both calcium and membrane concentrations. Because the critical Ca2+ concentration is at the lower end of the normal plasma ionized Ca2+ concentration range, we propose a new regulatory mechanism by which local Ca2+ concentration switches fXa from an intrinsically active form to a form requiring its cofactor (fVa) to achieve significant activity
Membrane fluidity matters: Hyperthermia from the aspects of lipids and membranes
Hyperthermia is a promising treatment modality for cancer in combination both with radio- and chemotherapy. In spite of its great therapeutic potential, the underlying molecular mechanisms still remain to be clarified. Due to lipid imbalances and 'membrane defects' most of the tumour cells possess elevated membrane fluidity. However, further increasing membrane fluidity to sensitise to chemo-or radiotherapy could have some other effects. In fact, hyperfluidisation of cell membrane induced by membrane fluidiser initiates a stress response as the heat shock protein response, which may modulate positively or negatively apoptotic cell death. Overviewing some recent findings based on a technology allowing direct imaging of lipid rafts in live cells and lipidomics, novel aspects of the intimate relationship between the 'membrane stress' of tumour cells and the cellular heat shock response will be highlighted. Our findings lend support to both the importance of membrane remodelling and the release of lipid signals initiating stress protein response, which can operate in tandem to control the extent of the ultimate cellular thermosensitivity. Overall, we suggest that the fluidity variable of membranes should be used as an independent factor for predicting the efficacy of combinational cancer therapies
THE ROLE OF SUBJECTIVE KNOWLEDGE AND PERCEIVED CONSEQUENCES IN SHAPING ATTITUDE AND INTENTION TOWARD DIGITAL PIRACY
Digital piracy represents a significant threat, especially to music, film and software industry worldwide. In order to provide insights into consumer behavior related to digital piracy, this study aimed at developing and empirically testing the role of subjective knowledge and three types of expected consequences (i.e., perceived benefits, moral intensity, perceived risk) as antecedents of attitude toward digital piracy and intention to pirate digital content. In view of the existing literature, the purpose of this research was twofold: (a) to develop a conceptual model of consumer’s attitude and intention to pirate, and (b) to empirically test the role of subjective knowledge, perceived benefits, moral intensity and perceived risk as antecedents of consumers’ attitude toward pirating, as well as the role of subjective knowledge, perceived benefits, and attitude as antecedents of intention to pirate. The hypotheses were tested by collecting data via self-administered mail survey sent to an initial sample of 10,000 adult consumers in Slovenia, yielding a usable random sample of 843 consumers. The data were analyzed using structural equation modeling. The results of the study show that moral intensity and perceived risk do not play an important role in shaping one’s attitude toward piracy, while subjective knowledge and perceived benefits exhibit a statistically significant impact upon both, attitude toward digital piracy and intention to pirate. In addition, consistent with previous studies, attitude is a significant predictor of behavioral intention. Taking into consideration the specifics of the selected context, it is hoped that this study contributes to a better understanding of the demand side of digital piracy
- …
