The cross-cultural impact of mobile payment technology:Fingerprint scanning vs. QR-code scanning

Mobile payment is becoming increasingly popular among consumers, with convenient and more or less risky means of identification and authentication. This study aims to investigate the attitudinal and behavioural preferences for two mobile payment application technologies, namely fingerprint scanning and QR-code scanning. Specifically, a comparison is made of consumers from cultures with different levels of uncertainty avoidance. For this purpose, Asian and European consumers from China (N = 70) and the Netherlands (N = 110) participated in an online survey. The findings revealed that both cultural groups regularly used mobile payment technology, whereby they clearly preferred the fingerprint scan technology over QR-code scan technology. Some culture-related differences were found. The Chinese group had higher trust in fingerprint scan technology compared to the Dutch group. In addition to this, the Chinese had higher hedonic and utilitarian attitudes towards QR-scan technology compared to the Dutch

Breakpoint mapping of 13 large parkin deletions/duplications reveals an exon 4 deletion and an exon 7 duplication as founder mutations

Early-onset Parkinson’s disease (EOPD) has been associated with recessive mutations in parkin (PARK2). About half of the mutations found in parkin are genomic rearrangements, i.e., large deletions or duplications. Although many different rearrangements have been found in parkin before, the exact breakpoints involving these rearrangements are rarely mapped. In the present study, the exact breakpoints of 13 different parkin deletions/duplications, detected in 13 patients out of a total screened sample of 116 EOPD patients using Multiple Ligation Probe Amplification (MLPA) analysis, were mapped using real time quantitative polymerase chain reaction (PCR), long-range PCR and sequence analysis. Deletion/duplication-specific PCR tests were developed as a rapid and low cost tool to confirm MLPA results and to test family members or patients with similar parkin deletions/duplications. Besides several different deletions, an exon 3 deletion, an exon 4 deletion and an exon 7 duplication were found in multiple families. Haplotype analysis in four families showed that a common haplotype of 1.2 Mb could be distinguished for the exon 7 duplication and a common haplotype of 6.3 Mb for the deletion of exon 4. These findings suggest common founder effects for distinct large rearrangements in parkin

A COMPARISON BETWEEN THE EFFECTS OF SMS 201–995, BROMOCRIPTINE AND A COMBINATION OF BOTH DRUGS ON HORMONE RELEASE BY THE CULTURED PITUITARY TUMOUR CELLS OF ACROMEGALIC PATIENTS

The in‐vivo reaction of the plasma GH concentration to the administration of the somatostatin analogue SMS 201‐995, bromocriptine and their combination were compared with the in‐vitro effects of both compounds and their combination on GH release and the GH tumour cell content of 9 acromegalic patients. Exposure of cultured GH‐secreting pituitary tumour cells for 4–96 h to SMS 201‐995 showed a variable, but in all instances during longer incubations statistically significant inhibition of GH release, which paralleled the sensitivity of GH secretion to the drug in vivo. This inhibitory effect on GH release was in two of the eight tumours accompanied by a decrease in the GH tumour cell content after 24‐72 h of culture. These changes either reflect an inhibition of GH synthesis and/or an increase in intracellular breakdown (crinophagy) of GH and might be the basis for the tumour shrinkage which has been observed in about half of the acromegalic patients during long‐term SMS 201‐995 therapy. The inhibitory effects of bromocriptine on GH secretion were antagonized by haloperidol, while the inhibitory effect of SMS 201‐995 was not affected by the dopamine receptor antagonist. This suggests that the effects of SMS 201‐995 and bromocriptine are mediated via separate mechanisms involving different receptors. Additive but no potentiating inhibitory effects of both drugs on GH release were observed in a group of six patients in vivo and in three of six tumours in vitro.</p

GLYCOPROTEIN HORMONE ALPHA‐SUBUNIT AND PROLACTIN RELEASE BY CULTURED PITUITARY ADENOMA CELLS FROM ACROMEGALIC PATIENTS:CORRELATION WITH GH RELEASE

In‐vitro data of pituitary adenoma cells from 28 acromegalic patients were evaluated. In addition to GH, PRL was produced by 16 adenomas (57%) and alpha‐subunit by 15 adenomas (54%) while there was a significantly higher incidence of tumours producing PRL and alpha‐subunit simultaneously. From 26 pituitary adenomas enough cells were obtained in order to perform secretion studies. Percentage basal hormone release (medium: (medium + intra‐cellular hormone)) ± 100% of GH and alpha‐subunit by 11 adenomas showed a close correlation while such a correlation for GH and PRL was present only in a subgroup of 10 of 13 adenomas. The responses of GH and alpha‐subunit release to 10nM SMS201–995, 10nM bromocriptine, 100nM TRH and 10nM GHRH were closely related in that a response or an absent response of GH release to the four secretagogues was virtually always attended with a response or an absent response respectively of alpha‐subunit release. Such a relationship was less evident with respect to the effects of SMS201–995, bromocriptine, TRH and GHRH on GH and PRL release. We conclude that basal and secretagogue‐induced alpha‐subunit release by cultured pituitary adenoma cells from acromegalic patients closely follows the pattern of GH release while such a relationship for GH and PRL is present only in a subgroup of the adenomas secreting GH and PRL simultaneously.</p

Heterogeneity of pituitary adenoma cell subpopulations from acromegalic patients obtained by Percoll density gradient centrifugation

Pituitary adenoma cells from 6 acromegalic patients were separated on continuous Percoll density gradients according to differences in their density. Two adenomas produced GH only in culture, the other 4 adenomas produced either GH and PRL (one adenoma) or GH and α-subunit (one adenoma) or GH, PRL and α-subunit (2 adenomas). The cell subpopulations obtained by this technique differed in the amount of hormone production per 105 cells: GH release decreased from the low density fractions to the higher density fractions in 5 of 6 adenomas. Intracellular GH levels completely followed this profile. In the mixed GH/α-subunit adenomas the α-subunit profile completely paralleled the GH profile, whereas in the mixed GH/PRL adenomas the PRL profile showed a pattern different from that of GH (and α-subunit). In neither of the adenomas did we find any differences between the subpopulations with respect to the responsiveness of GH, PRL or α-subunit release to GHRH, TRH and the somatostatin analogue SMS 201-995. Conclusions: 1. Within pituitary adenomas from acromegalic patients heterogeneity exists with respect to hormone production per cell. 2. The cell subpopulations obtained by density gradient centrifugation are not different in their responsiveness to SMS 201-995, GHRH or TRH. 3. Because GH and α-subunit release by the fractions from the mixed GH/α-subunit secreting adenomas were completely parallel, further evidence for co-release of GH and α-subunit by the same tumoural cells is provided.</p

Long-term culture of rat mammotrope and somatotrope subpopulations separated on continuous Percoll density gradients:Effects of dopamine, TRH, GHRH and somatostatin

Normal adult female rat mammotrope and somatotrope subpopulations were separated on continuous Percoll density gradients according to differences in their density. Viable cells were recovered in 16 fractions. The cells from each fraction were cultured during 7 days after which period 4-h incubations were performed. rPRL secretion per cell increased towards the higher density fractions. No major difference in TRH, dopamine and somatostatin responsiveness was observed between mammotropes that were recovered in the different gradient fractions. In addition, no differences in somatostatin responsiveness between the somatotrope cells in the different gradient fractions were observed. However, somatotropes that were recovered in the highest density region of the gradient appeared to be more responsive to GHRH than the lower density somatotropes. In the various gradient fractions there were no paradoxical effects of TRH and dopamine on rGH release and of GHRH on rPRL release. Conclusions: 1. In long-term cultures there is no evidence for functionally different subpopulations of mammotropes and somatotropes, separated according to differences in their density, with regard to dopamine and TRH responsiveness and with regard to somatostatin responsiveness, respectively. 2. There is no evidence for a (mammosomatotrope?) subpopulation of cells showing paradoxical responses of PRL or GH release to GHRH and dopamine or TRH, respectively.</p

A high resolution magnetic spectrograph for ion beam analysis

A magnetic spectrograph especially designed for interface and thin film analysis has been installed at the 6.5 MV tandem accelerator of the University of Utrecht. It is provided with a Wien filter, so that both the mass and the charge of the ions arriving in the focal plane is determined. In the focal plane a two-dimensional position-sensitive detector is used to obtain spectra with resolved energy along one axis, and resolved angles (perpendicular to the scattering plane) along the other axis, A special bellows construction allows the spectrograph to be rotated over an angular range of 120 degrees while maintaining the ultra-high vacuum conditions. The first results of RBS and ERD measurements are presented

Surface termination of CePt5/Pt(111): the key to chemical inertness

The surface termination of CePt5/Pt(111) is determined experimentally by LEED-IV. In accordance with recent theoretical predictions, a dense Pt terminated surface is being found. Whereas the CePt5 volume lattice comprises Pt kagome layers, additional Pt atoms occupy the associated hole positions at the surface. This finding provides a natural explanation for the remarkable inertness of the CePt5 intermetallic. Implications of the structural relaxations determined by LEED-IV analysis are discussed with regard to observations by scanning tunneling microscopy and electron spectroscopies