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Carrot is an important source of sugars. The objective of this study was to investigate the effects of water supply (precipitation + irrigation) on the concentration and ratio of fructose, glucose, and sucrose in carrot. Irrigation did not decrease the dry matter content and the summed concentration of the three measured sugars. Glucose accumulation was not influenced either by irrigation or by year. Low amount of precipitation during the early growing period was detrimental for fructose accumulation. Irrigation enhanced sucrose concentration, presumably by ensuring better photosynthetic activity. However, dry and hot weather during the irrigation cut-off period in 2011 also resulted in increased sucrose accumulation, presumably as a stress effect. It was found that irrigation did not influence the ratio of the three investigated saccharides at all, and even the growing year had just a slight effect on that.

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Caffeine content of 377 food samples obtained from the Hungarian market was measured by a validated HPLC technique. The highest caffeine levels were observed in different instant coffees (3954±2355 mg/100 g) and ground coffee beans (1634±389 mg/100 g). Significant amount of caffeine could be detected in energy drinks (119 mg in 100 ml at the highest end). The caffeine content of different coffee drinks varied between 40 and 203 mg/100 ml. Significant amount of caffeine could be measured in special instant coffees called 2in1 and 3in1 (120 mg per serving at the highest end), cacao powders (125 mg in 100 g), in chocolates (on average, 16.1 mg and 52.5 mg in 100 g milk and dark chocolate, respectively), breakfast cereals (between 5.7 and 15.8 mg per 100 g), and ice creams (1.7–24.8 mg in 100 g).

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The aim of the present study is to extend the applicability of MRI measurements similar to those used in human diagnostics to the examination of water barriers in living plants, thus broadening their use in natural sciences. The cucumber, Cucumis sativus, and Phillyrea angustifolia, or false olive, were chosen as test plants. The MRI measurements were carried out on three samples of each plant in the same position vis-a-vis the MRI apparatus using a Siemens Avanto MRI scanner. Two different relaxation times were employed, T1, capable of histological mapping, and T2, used for the examination of water content. In the course of the analysis, it was found that certain histological formations and branching cause modifications to the intensity detected with relaxation time T2. Furthermore, these positions can also be found in T1 measurements. A monotonic correlation (cucumber: ρ = 0.829; false olive: ρ = –0.84) was observed between the T1 and T2 measurements. In the course of the statistical analysis of the signal intensities of the xylems it was concluded that they cannot be regarded as independent in a statistical sense; these changes rather depend on the anatomic structure of the plant, as the intensity profile is modified by nodes, leaves and branches. This serves as a demonstration of the applicability of MRI to the measurement of well know plant physiological processes. The special parametrization required for this equipment, which is usually used in human diagnostics, is also documented in the present study.

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Aim: To analyse and compare the ACE (angiotensin-converting enzyme), ACTN3 (actinin-3) and AMPD1 (adenosine monophosphate deaminase 1) genetic variants, oxygen uptake (VO2max), heart rate (HR), blood pressure (BP) and body mass index (BMI) of elite high altitude mountaineers and average athletes. Methods: Elite Bulgarian alpinists (n = 5) and control group of athletes (n = 72) were recruited. VO2max was measured using a treadmill graded protocol. HR, BP and BMI were recorded. Genotyping was done by polymerase chain reaction (PCR) amplification followed by agarose gel electrophoresis. Chi 2-test and Fisher’s exact test were used for statistical analysis. Results: Alpinists showed significantly higher frequencies of 60% ACE I allele (p = 0.002), 50% ACTN3 X allele (p = 0.032) and 30% AMPD1 T allele (p = 0.003) compared to controls — 39%, 36%, 13%, respectively. ACE ID genotype prevalence and null DD genotype were observed in mountaineers. Higher absolute VO2max, but no differences in VO2max ml kg−1 min−1, HR, oxygen pulse, blood pressure and BMI were found. Conclusions: The ID genotype and higher frequencies of ACE I allele could contribute to successful high altitude ascents in mountaineers. The genetic make-up of the two mountaineers who made the summit of Mt Everest was distinctive, revealing ACE ID genotype, mutant ACTN3 XX and AMPD1 TT genotypes.

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While the effects of instantaneous, single-bout exposure to hypoxia have been well researched, little is known about the autonomic response during, or as an adaptation to, repeated intermittent hypoxic exposure (IHE) in a sedentary population. Resting heart rate variability (HRV) and exercise capacity was assessed in 16 participants (8 receiving IHE, [Hyp] and 8 receiving a placebo treatment [C]) before and after a 4-week IHE intervention. Heart rate variability was also measured during an IHE session in the last week of the intervention. Post-intervention, the root mean squared successive difference (rMSSD) increased substantially in Hyp (71.6 ± 52.5%, mean change ± 90% confidence limits) compared to C suggesting an increase in vagal outflow. However, aside from a likely decrease in submaximal exercise heart rate in the Hyp group (–5.0 ± 6.4%) there was little evidence of improved exercise capacity. During the week 4 IHE measurement, HRV decreased during the hypoxic exposure (reduced R-R interval: –7.5 ± 3.2%; and rMSSD: –24.7 ± 17.3%) suggesting a decrease in the relative contribution of vagal activity. In summary, while 4 weeks of IHE is unlikely to improve maximal exercise capacity, it may be a useful means of increasing HRV in people unable to exercise.

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Journal of Evolutionary Psychology
Authors:
Ryo Oda
,
Kai Hiraishi
,
Yasuyuki Fukukawa
, and
Akiko Matsumoto-Oda

Abstract

Possible effects of external and internal factors affecting prosociality in Japanese undergraduates were investigated. We employed social support as an external factor and helping norms, self-consciousness, other-consciousness, self-esteem, and religious attitude as internal factors. Prosociality toward friends/acquaintances was significantly positively correlated with social support from siblings, social support from friends/acquaintances, self-sacrifice norms, and private self-consciousness, whereas prosociality toward strangers was significantly positively correlated with social support from mothers, private self-consciousness, and self-esteem but negatively correlated with social support from siblings. The results support claims of an altruism niche that rest on the assumption that prosociality can be maintained only in an environment or a society in which altruistic acts are rewarded. Among the internal factors, private self-consciousness was the only factor found to correlate with both aspects of prosociality. Higher scores on private selfconsciousness were related to irrational altruism, making people less susceptible to the features of particular situations and, consequently, producing reputational benefits.

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We present a test involving a large number of data-analytical techniques to identify a rigorous numerical classification method optimising on statistically identified faithful species. The test follows a stepwise filtering process involving various numerical-classification tools. Five steps were involved in the testing: (1) evaluation of 322 classification tools using Optim-Class 1; (2) comparison of 20 best performing methods by standardising the various performances across a range of fidelity values using OptimClass 1 and OptimClass 2, to assess the effectiveness of the agglomerative clustering and one divisive technique; (3) calculation and comparison of Uniqueness values and ISAMIC (Indicator Species Analysis Minimising Intermediate Constancies) scores of the resulting classifications; (4) comparison of different classifications by analysing the similarities of the resulting synoptic tables using faithful species, assuming that clusters with similar faithful species represent corresponding vegetation types, and (5) final selection of the single best method based on an expert review of non-geometric internal evaluators, NMDS ordinations and mapped classification solutions. A complex data set, representing many forest vegetation types and consisting of 506 relevés of 20 m × 20 m sampled in the indigenous forests of Mpumalanga Province (South Africa), was tested. Analysis of Uniqueness provided insight into which methods produced classifications that did not share faithful species. The analysis of synoptic table similarity showed that the classification results were at most 88% similar, while in the most divergent case similarity of only 50% was achieved. OptimClass eliminated poorly performing numerical-classification combinations and highlighted the best performing methods. Yet it was unable to reveal the single best performing method unequivocally across the range of fidelity values used. In such cases, we suggest the solution can be sought in relying on involving external data through expert opinion. Ordinal Clustering and TWINSPAN produced the most outlying classification results. Flexible beta clustering (β= −0.25) in combination with Bray-Curtis coefficient, standardised by sample unit totals, produced the most informative result for our data set when using informal expert-defined ecological and biogeographical judgement criteria. We recommend that the performance of a set of methods be tested prior to selecting the final classification approach.

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Background and aims

Perceived stress has been regarded as a risk factor for problematic social networking site (SNS) use, yet little is known about the underlying processes whereby confounding variables may mediate or moderate this relationship. To answer this question, this study examined whether depression and anxiety mediated the relationship between perceived stress and problematic SNS use, and whether these mediating processes were moderated by psychological resilience and social support.

Methods

Participants were 641 Chinese college students who completed anonymous questionnaires measuring perceived stress, depression/anxiety, psychological resilience, social support, and problematic SNS use.

Results

The results showed that (a) depression/anxiety mediated the relationship between perceived stress and problematic SNS use; (b) the mediating effects of depression/anxiety on the association between perceived stress and problematic SNS use were moderated by psychological resilience. Specifically, the mediating effects of depression/anxiety were stronger for individuals with lower levels of psychological resilience, compared with those with higher levels of psychological resilience; and (c) the mediating effects of depression/anxiety were not moderated by social support, although social support was negatively related to depression/anxiety.

Discussion and conclusion

This study can contribute to a better understanding of how and when perceived stress increases the risk of problematic SNS use, and implies the importance of enhancing psychological resilience in preventing problematic SNS use.

Open access

Contemporary radical changes in the European geographical setting, combined with the consolidation of the globalised international market have resulted in a totally competitive international business environment. Nowadays, as in almost all countries, the Greek enterprises have to operate with a new perspective, based on strategic alliances. These business strategies should be implemented on at least a middle-term basis. This article explains the necessity for adopting these operative techniques in light of the limited presence of the Greek enterprises in the international market. Furthermore, it analyses a sufficient model of cooperative operation, which gives to the enterprises - mainly the small- and medium-sized enterprises (SMEs) - the ability of adapting to the international market.

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Abstract

In our study, using a combination of eye-tracking parameter analysis and the van Westendorp method, we investigate whether participants pay more attention to products that they perceive as more expensive or to those that they prefer in the ranking process. The experiment involved 50 participants, a questionnaire with ranking and pricing tasks, and an eye-tracking measurement. Three wine varieties (Irsai Olivér, Rosé and Merlot-Shiraz) and three different label alternatives were tested. When comparing the results of the ranking and the pricing tasks, the product that is considered more expensive is not always the one that is most appealing to the participants. If we compare the results from the analysis of the eye-tracking parameters and the pricing, we can say that in all cases the labels that received the most visual attention were those that were priced more expensively by the participants.

Open access