An attitude-behavioral model to understand people's behavior towards tourism during COVID-19 pandemic

The impact of pandemics on the tourism industry should be explored from the perspective of those who will travel, go to the tourist places on vacation, and avail services from tourism and hospitality-related organizations. This study has aimed to identify the reasons for the changed human psychology towards tourism during the COVID-19 Pandemic to develop an attitude-behavioral model. This investigation thus conducted an extensive empirical study among tourists to capture their social, emotional, and financial beliefs. The research then examined the measurement model through confirmatory factor analysis (CFA) before investigating the cause-effect relationship through the structural model. Analysis revealed that the negative effect of attitude on behavioral intention toward this new equilibrium is controlled by the emotional aspect of attitude. Furthermore this paper made several contributions to the literature on human psychology, crisis management, human behavior, marketing, and tourism.

Characterisation of carapace composition in developing and adult ostracods (Skogsbergia lerneri) and its potential for biomaterials

The protective carapace of Skogsbergia lerneri, a marine ostracod, is scratch-resistant and transparent. The compositional and structural organisation of the carapace that underlies these properties is unknown. In this study, we aimed to quantify and determine the distribution of chemical elements and chitin within the carapace of adult ostracods, as well as at different stages of ostracod development, to gain insight into its composition. Elemental analyses included X-ray absorption near-edge structure, X-ray fluorescence and X-ray diffraction. Nonlinear microscopy and spectral imaging were performed to determine chitin distribution within the carapace. High levels of calcium (20.3%) and substantial levels of magnesium (1.89%) were identified throughout development. Amorphous calcium carbonate (ACC) was detected in carapaces of all developmental stages, with the polymorph, aragonite, identified in A-1 and adult carapaces. Novel chitin-derived second harmonic generation signals (430/5 nm) were detected. Quantification of relative chitin content within the developing and adult carapaces identified negligible differences in chitin content between developmental stages and adult carapaces, except for the lower chitin contribution in A-2 (66.8 ± 7.6%) compared to A-5 (85.5 ± 10%) (p = 0.03). Skogsbergia lerneri carapace calcium carbonate composition was distinct to other myodocopid ostracods. These calcium polymorphs and ACC are described in other biological transparent materials, and with the consistent chitin distribution throughout S. lerneri development, may imply a biological adaptation to preserve carapace physical properties. Realisation of S. lerneri carapace synthesis and structural organisation will enable exploitation to manufacture biomaterials and biomimetics with huge potential in industrial and military applications.

Tourism sustainability during COVID-19: developing value chain resilience

The aim of this study is to evaluate the perceptions of prospective tourists through parameters by which the tourism and hospitality service sector can withstand the widespread implications to the sector as a result of the current pandemic. In turn this will lead to weighing up the means for recovery. The identified parameters are then classified, categorized and linked up with supply chain drivers to obtain a holistic picture that can feed into strategic planning from which the tourism and hospitality service sector could utilize to establish a resilient supply chain. This data can provide deep insight for both theorists and practitioners to utilize. It was found that reforming six supply chain drivers, whilst at the same time developing core competencies, is the central essence of a resilient supply chain within the tourism and hospitality business sector (who are at present working hard to counterbalance the many threats and consequent risks posed due to the pandemic).

The ultrastructural development and 3D reconstruction of the transparent carapace of the ostracod Skogsbergia lerneri

The Skogsbergia lerneri is a marine ostracod which possesses a carapace that is both protective and transparent. Since development of this carapace and how it is maintained in the adult is not known, the aim of this investigation was to carry out an in-depth ultrastructural study of the ostracod carapace at different developmental stages. Standard transmission electron microscopy and novel serial block face scanning electron microscopy (SBF-SEM) were undertaken to discern carapace ultrastructure in both two and three dimensions. Analysis revealed a carapace consisting of the same basic layer structure as other myodocopid ostracods, namely an epicuticle, exocuticle, endocuticle and membranous layer, but with a thinner adult carapace of mean thickness of 19.2 ± 1.78 µm, n = 5. The carapace layers, except for instar 1 ostracods, had similar relative proportions throughout development. The endocuticle and membranous layer thickened through advancing developmental stages due to an increase in calcified crystalline polyhedrons and a greater number of chitinous lamellae in the membranous layer. Crystalline polyhedron dimensions were significantly smaller near the boundary with the membranous layer. The borders between the carapace layers were indistinct; SBF-SEM revealed an abundance of epicuticle projections into the exocuticle and apparent gradual merging at the boundary of the exocuticle and the endocuticle. Here, we discuss how the S. lerneri carapace layer structure has evolved to serve a specific mechanical function, allowing surface protection and rigidity. In addition, we suggest that the lack of pigment and graduated layer boundaries contribute to the transparency of the carapace.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s00227-021-04006-7.

Hierarchical structures of cactus spines that aid in the directional movement of dew droplets

Three species of cactus whose spines act as dew harvesters were chosen for this study: Copiapoa cinerea var. haseltoniana, Mammillaria columbiana subsp. yucatanensis and Parodia mammulosa and compared with Ferocactus wislizenii whose spines do not perform as dew harvesters. Time-lapse snapshots of C. cinerea showed movement of dew droplets from spine tips to their base, even against gravity. Spines emanating from one of the areoles of C. cinerea were submerged in water laced with fluorescent nanoparticles and this particular areole with its spines and a small area of stem was removed and imaged. These images clearly showed that fluorescent water had moved into the stem of the plant. Lines of vascular bundles radiating inwards from the surface areoles (from where the spines emanate) to the core of the stem were detected using magnetic resonance imaging, with the exception of F. wislizenii that does not harvest dew on its spines. Spine microstructures were examined using SEM images and surface roughness measurements (Ra and Rz) taken of the spines of C. cinerea It was found that a roughness gradient created by tapered microgrooves existed that could potentially direct surface water from a spine tip to its base.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'.

Dew harvesting efficiency of four species of cacti

Four species of cacti were chosen for this study: Copiapoa cinerea var. haseltoniana, Ferocactus wislizenii, Mammillaria columbiana subsp. yucatanensis and Parodia mammulosa. It has been reported that dew condenses on the spines of C. cinerea and that it does not on the spines of F. wislizenii, and our preliminary observations of M. columbiana and P. mammulosa revealed a potential for collecting dew water. This study found all four cacti to harvest dew on their stems and spines (albeit rarely on the spines of F. wislizenii). Dew harvesting experiments were carried out in the UK, recording an increase in cacti mass on dewy nights. By applying a ranking relative to a polymethyl methacrylate (Plexiglas) reference plate located nearby, it was found that C. cinerea collected the most airborne moisture followed by M. columbiana, P. mammulosa and F. wislizenii respectively, with mean efficiency ratio with respect to the Plexiglas reference of 3.48 ± 0.5, 2.44 ± 0.06, 1.81 ± 0.14 and 1.27 ± 0.49 on observed dewy nights. A maximum yield of normalized performance of 0.72 ± 0.006 l/m(-2) on one dewy night was recorded for C. cinerea. Removing the spines from M. columbiana was found to significantly decrease its dew harvesting efficiency. The spines of three of the species were found to be hydrophilic in nature, while F. wislizenii was hydrophobic; the stems of all four species were hydrophilic. The results of this study could be translated into designing a biomimetic water collecting device that utilizes cactus spines and their microstructures.

Nature's moisture harvesters: a comparative review

Nature has adapted different methods for surviving dry, arid, xeric conditions. It is the focus of this comparative review to pull together the relevant information gleaned from the literature that could be utilized to design moisture harvesting devices informed by biomimetics. Most water harvesting devices in current use are not informed by nature and those that do are usually based on a biomimetic principle that has been based on one species only. This review draws on the published literature to establish a list of species (animals (vertebrates/invertebrates) and plants) whose habitat is in mainly dry or arid regions and that are known to harvest airborne moisture. Key findings have been outlined and review comments and discussion set out. Following this, surface feature convergences have been identified, namely hexagonal microstructures, groove-like and cone-like geometries. This has been coupled with direction of water flow that is driven by surface energy. As far as the authors are aware, this convergent evolution has not been brought together in this manner before. In the future this information could be translated into an engineered device for collecting water from airborne sources.

Significance of Qt Dispersion to Improve the Diagnostic Accuracy of Exercise Stress Tests for Myocardial Ischaemia

Background: This study consisted of 60 randomly selected patients (49 men and 11women) who had undergone both symptom-limited treadmill exercise tests andcoronary angiography, within one month, for clinical indications. This was a prospectivestudy done during the period of December 1998 to July 1999 in NICVD, DhakaBangladesh. The ECG is generally considered to provide a summation of the electricalactivity of the heart and to be insensitive to local electrophysiological events. Recentstudies suggest that important local electrophysiological differences can be detectedfrom a standard 12 -lead ECG, allowing new insights into the electrical behavior ofpatient’s hearts. The QT dispersion recorded as the difference between maximumand minimum QT intervals on a 12-lead ECG, is sensitive to myocardial ischaemiaand may improve the accuracy of exercise testing.Methods and Results: Exercise ECGs were analyzed in 60 patients who had undergoneexercise ECG and coronary angiography for clinical indications:1) The true-positive (TP) group consisted of 22 patients with mean ±SD age of 52 ± 9years. These patients had a positive treadmill test result with ³1 mm horizontal STsegmentdepression and an abnormal coronary angiogram, defined as ³ 50% diameterstenosis of a major epicardial coronary artery. Two patients were female in this group.2) The true negative (TN) group consisted of 20 patients who had a negative exercisetest and non significant CAD based on coronary angiography. The mean ± SD age ofthe group was 44 ± 8 years. Five patients were female in this group.3) Eight patients with positive treadmill test result with abnormal exercise ECGs andnon significant coronary artery disease (False positive [FP] group). This group had amean age of 43± 10 years. Three patients were female in this group.4) The false negative (FN) group consisted of 10 patients with mean ±SD age of 48± 7years. These patients had negative exercise ECG and an abnormal coronary angiogram.This group had one female patient.The exercise QTD Was 41±14ms in TN, 78±22ms in TP (P<0.001 versus TP) and47±16ms in FP (P=NS versus TN and P< 0.001 versus TP) groups. The exercise QTDwas 84±17ms in FN (P=NS versus TP) group.A stress QTD of >60ms had a sensitivity of 88% and specificity of 93% for the diagnosisof significant CAD compared with 68% (P<0.05) and 71% (P<0.01) respectively, for³ 1mm ST-segment depression during stress. When QTD of >60ms was added to STsegmentdepression as a condition for positive test, the specificity increased to 100%.Conclusion: Exercise QTD is an easily measurable ECG variable that significantlyincreases the accuracy of exercise testing.Key Words: QT dispersion . coronary disease . electrocardiography . exercise.