Environmental knowledge and behavioural outcomes of tourism students in Australia: towards testing a range of mediation and moderated mediation effects

Our study examines the environmental knowledge (EK) and behavioural outcomes of students studying ecotourism in Sydney, Australia. Three competing models were tested to examine the relationships between EK, participation intention (PI) in ecotourism programs, landscape likeability (LL) and social interactions (SI); and the study also tested the moderated mediation influence of gender differences and relationship length on mediators. Partial least squares-based structural equation modelling (PLS-SEM) was used to analyse the data collected from 173 residential tourism students. Key findings suggest whilst LL and PI are significant outcomes of EK, LL has a stronger mediating effect on PI compared to SI; and all mediation effects are further moderated by gender differences. However, only Model 3 confirms the moderating effect of the length of relationship. Noting the key role that EK plays in influencing their PI and LL, our study also suggests ways of developing the tourism students’ EK, through various experiential and pedagogical interventions.     

Glial cells: The other cells of the nervous system

Carl Ludwig Schleich (1859–1922) was an anaesthetist and a surgeon who for the first time emphasized the role of neuroglia in brain function. In an era that was dominated by the idea that neurons alone were functional units of the nervous system and that glial cells were a mere glue holding neurons in place, Schleich insisted that glia had a prominent functional role to play. He suggested that interactions between neurons and glia were so strong that it is necessary to consider brain as a neuron-glia system whose performance is dependent on both the cell types. Today Carl Ludwig Schleich is considered the forgotten ancestor to a new breed of neurobiologists, the gliologists, who specialize in working on these neglected cells of the nervous system. Though outnumbering the neurons and occupying almost half the volume of the brain, glial cells have been given little importance in textbooks of neurobiology and are very often cursorily mentioned in discussions related to brain function. Glial cells deserve a better deal, for over the years a lot of evidence has accumulated to prove that they perform a wide spectrum of functions. This is the first of a series of articles that aims to update students on what is known about glia today. It provides an overview of the various types of glia and their origins. The following articles will deal with each of the glial sub-types and their functions.     

Effect of prior domain knowledge and headings on processing of informative text

College students with either high or low prior domain knowledge (PK) read a text chapter presented in short pages on a computer monitor. Half of the participants read with headings present and half with headings absent. The computer recorded time spent reading and rereading each short page. Learning was assessed through a structured recall task. In general, headings seem to improve recall of high importance information, and headings were more effective for high PK learners. Analysis of time data showed that participants with headings spent more time per word reading the pages with headings than participants that did not have headings. Prior knowledge had no effect on attention to either high importance information or important supporting detail. Low prior knowledge readers decreased the amount of time spent reading each word as they progressed through the passage and neither the presence nor absence of headings influenced this effect.     

Phytochemical composition,biological potential and enzyme inhibition activity of <Emphasis Type="Italic">Scandix pecten-veneris</Emphasis> L.

Objective

Scandix pecten-veneris L. is a less studied wild edible herb and is considered an extinct plant species in many parts of the world. This study was designed to evaluate its phytochemical composition and biological potential of S. pecten-veneris L.

Methods

Phytochemicals including alkaloids, flavonoids, polyphenols, and tannins were determined in extracts of S. pecten-veneris. Antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), while reducing power was tested by ferric reducing/antioxidant power (FRAP) assay. Antimicrobial activity against seven bacterial and four fungal strains was evaluated using agar well diffusion assay. Enzymes inhibition study was performed for urease, phosphodiesterase-I, and catalase-II.

Results

S. pecten-veneris showed moderate antiradical activity and reducing potential of hydroxyl radicals to about 20% of the initial value. The antioxidant activity of various extracts of S. pecten-veneris showed a linear correlation with total phenolic contents in the order of water>n-butanol>chloroform>ethyl acetate>methanol extracts. S. pecten-veneris leaves showed the highest inhibitory activity against Staphylococcus aureus while the highest antifungal activity was observed against Candida albicans. The plant extract was most potent against urease enzymes but showed moderate activity against phosphodiestrase-I and carbonic anhydrase-II.

Conclusions

Our data demonstrate that in addition to its culinary uses, S. pecten-veneris has good medicinal potential and hence could be used for treating some specific health ailments.

     

Delinquency and reputational orientations of adolescent at‐risk and not‐at‐risk males and females

This research investigated differences in delinquent activities and the reputational orientations of at‐risk and not‐at‐risk male and female adolescents. Initially, we sought to establish that adolescent males and females differed in these respects. This was found to be the case: males (n = 722) scored significantly higher than females (n = 738) on seven self‐reported delinquency variables and on eight reputation enhancement variables pertaining to social deviance, non‐conforming reputation, and power/evaluation private identity. When a sample of 31 at‐risk females was subsequently pair‐wise age matched with 31 not‐at‐risk females, at‐risk females scored significantly higher on all delinquency variables other than school misdemeanors. These at‐risk females also scored significantly higher on four reputation enhancement variables relating to social deviance and non‐conformity. Given that at‐risk females did not differ from their not‐at‐risk counterparts in level of involvement in school misdemeanors, we sought to determine whether this was also the case for at‐risk and not‐at‐risk males. An age‐matched sample of 91 pairs revealed that at‐risk males reported significantly higher involvement than not‐at‐risk males in all aspects of delinquency, including school misdemeanors. They also sought a more non‐conforming reputation. To explore the relationships between delinquency and reputation enhancement, a canonical correlation analysis was performed. All findings are discussed in the light of reputation enhancement theory.     

Characterization of lectins and their specificity in carcinomas—An appraisal

Lectins, a group of specific glycoproteins present in animal as well as plant cells, are used as differentiating markers to study cancers and metastatic cell lines. This property of lectins depends on the process of cellular glycosylation. Glycosylation of some of the extracellular membrane proteins and lipids maintains the cell/cell and cell/matrix interactions. Chemical alterations in glycosylation play an important role in the metastatic behavior of tumor cells. Carbohydrate residues of the membrane glycoproteins can be detected using lectins due to their binding specificity to carbohydrates. Lectins, therefore have gained an importance in the field of cancer research. Galectins, a specialized group of lectin like proteins that are Ca+ independent and galactoside binding, are also considered as differentiation markers in some specific cancers like the carcinomas of thyroid. Thus the use of lectins and galectins to identify specific carbohydrates present on cell surface help in invasion and metastasis processes.     

Blunted Myoglobin and Quadriceps Soreness After Electrical Stimulation During the Luteal Phase or Oral Contraception

Purpose: Acute muscle damage after exercise triggers subsequent regeneration, leading to hypertrophy and increased strength after repeated exercise. It has been debated whether acute exercise-induced muscle damage is altered under various premenopausal estrogen conditions. Acute contraction-induced muscle damage was compared during exogenous (oral contraceptive, OC), endogenous (luteal phase, HI), or low (menses, LO) estrogen in healthy young women aged 21 to 30 years old. Methods: Women (OC, n = 9; HI, n = 9; LO, n = 8; total N = 26) performed 1 neuromuscular electrical stimulation (NMES) bout. Soreness, measured via visual analog scale and the Likert Scale of Muscle Soreness for Lower Limb (LSMSLL), quadriceps strength, and plasma myoglobin (Mb), interleukin (IL)-6, IL-8, and granulocyte-colony stimulating factor were measured before and after NMES. Results: NMES performance was similar across groups. Meaningful within-group increases in Mb (effect size [ES] = 1.12) and IL-8 (ES = 0.38) occurred in LO; ES for HI and OC were trivial. ES of the between-group difference in change was moderate for Mb (LO vs. HI = 1.15) and IL-8 (LO vs. HI = 0.86; LO vs. OC = 0.73). 17-β estradiol correlated moderately and negatively with Mb relative change (r = –.52, p < .05). LO had ~5% greater strength loss than OC and HI. The mean change score for the LSMSLL 2 days post-NMES was clinically greater in LO than OC or HI. Conclusions: Acute NMES-induced indicators of muscle fiber damage and qualitative muscle soreness may be attenuated during the luteal phase or active OC pill consumption compared with the menstrual phase.     

Hypoglycemic, lipid lowering and antioxidant activities in root extract of Anthocephalus indicus in alloxan induced diabetic rats

The present study was carried out to evaluate the hypoglycemic, lipid lowering and antioxidant activities in root extract of Anthocephalus indicus (A indicus) in alloxan inducd diabetic rats. Oral administration of ethanol extract of root (500mg/ kg body weight) for 21 days resulted in significant decrease in the levels of blood glucose, triglycerides, total cholesterol, phospholipid and free fatty acids. Furthermore, the root extract (100–400μg) inhibited the generation of superoxide anions and hydroxyl radicals, in both enzymic and non-enzymic systems, in vitro. The result of the present study demonstrated hypoglycemic, lipid lowering and antioxidant activities in root extract of A indicus, which could help in prevention of diabetic dyslipidemia and related diseases.     

Prioritizing natural-selection signals from the deep-sequencing genomic data suggests multi-variant adaptation in Tibetan highlanders

Human genetic adaptation to high altitudes (>2500 m) has been extensively studied over the last few years, but few functional adaptive genetic variants have been identified, largely owing to the lack of deep-genome sequencing data available to previous studies. Here, we build a list of putative adaptive variants, including 63 missense, 7 loss-of-function, 1,298 evolutionarily conserved variants and 509 expression quantitative traits loci. Notably, the top signal of selection is located in TMEM247, a transmembrane protein-coding gene. The Tibetan version of TMEM247 harbors one high-frequency (76.3%) missense variant, rs116983452 (c.248C > T; p.Ala83Val), with the T allele derived from archaic ancestry and carried by >94% of Tibetans but absent or in low frequencies (<3%) in non-Tibetan populations. The rs116983452-T is strongly and positively correlated with altitude and significantly associated with reduced hemoglobin concentration (p = 5.78 × 10⁻⁵), red blood cell count (p = 5.72 × 10⁻⁷) and hematocrit (p = 2.57 × 10⁻⁶). In particular, TMEM247-rs116983452 shows greater effect size and better predicts the phenotypic outcome than any EPAS1 variants in association with adaptive traits in Tibetans. Modeling the interaction between TMEM247-rs116983452 and EPAS1 variants indicates weak but statistically significant epistatic effects. Our results support that multiple variants may jointly deliver the fitness of the Tibetans on the plateau, where a complex model is needed to elucidate the adaptive evolution mechanism.