Longitudinal evidence of the impact of dog ownership and dog walking on mental health

BACKGROUND

Emerging evidence supports the physical health and social benefits of dog ownership. This study examined the longitudinal effect of dog ownership and dog walking on mental health.

METHODS

Data from a cohort of 1023 participants taking part in the RESIDential Environments project, in Perth, Western Australia were collected over a 2 year period (baseline and follow-up). Self-report survey items measured mental health (stress and depression), dog ownership status and weekly minutes of dog walking. Logistic regression models accounted for potential confounding factors including socio-demographic, self-rated health and baseline mental health.

RESULTS

Overall, no statistically significant effects were observed over time between dog ownership and stress (adjusted OR: 1.20; 95% CI: 0.79, 1.81) or depression (adjusted OR: 1.51; 95% CI: 0.72, 3.16). There was a small inverse but non-significant association between weekly minutes of dog walking and stress over time (adjusted OR: 0.85; 95% CI: 0.60, 1.22).

CONCLUSION

There was little evidence of prospective associations between dog ownership or dog walking and mental health. Further research is required to confirm longitudinal relationships between dog ownership and dog walking and mental health and investigate dog-related factors, such as a person's attachment to their dog.

Prevalence and pattern of energy drink intake among Australian adolescents

BACKGROUND

Energy drinks (ED) are popular among young people despite evidence of associated health risks. Research into the prevalence and pattern of ED intake among young people is sparse. The present study investigates the prevalence and pattern of ED intake among a large sample of adolescents, including how many consume them, how often, for what reasons and in what contexts.

METHODS

In 2018, all students in grades 7-12 attending 25 randomly selected Western Australian schools were invited to complete an online self-report survey about EDs.

RESULTS

Of the 3688 respondents, 51.2% reported consuming an ED. Of these 'ever consumers', 23.4% drank them monthly, 19.2% weekly and 2% every day. The average age of first intake was 10.7 years. One-fifth (19.7%) of 'ever consumers' reported consuming more than two EDs in 1 day. Reasons for ED use included taste, to boost energy levels, sport performance and studying.

CONCLUSIONS

The findings add to limited international evidence about adolescent ED use and provide valuable information to help ensure interventions to reduce intake address the underlying reasons and contexts of ED consumption.

Submicrosecond Spectroscopy of Lightning-Like Discharges: Exploring New Time Regimes

Submicrosecond (0.476 μs per frame with an exposure time of 160 ns) high-resolution (0.38 nm) time-resolved spectra of laboratory-produced lightning-like electrical discharges have been recorded for the first time within the visible spectral range (645-665 nm). The spectra were recorded with the GrAnada LIghtning Ultrafast Spectrograph (GALIUS), a high-speed imaging spectrograph recently developed for lightning research in the IAA-CSIC. Unprecedented spectral time dynamics are explored for meter long laboratory electrical discharges produced with a 2.0 MV Marx generator. The maximum electron density and gas temperature measured in a timescale of ≤0.50 μs (160 ns) were, respectively, ≃1018 cm-3 and ≃32,000 K. Overpressure in the lightning-like plasma channel, black-body dynamics, and self-absorption in spectral lines were investigated.

Time domain simulations of preliminary breakdown pulses in natural lightning

Lightning discharge is a complicated process with relevant physical scales spanning many orders of magnitude. In an effort to understand the electrodynamics of lightning and connect physical properties of the channel to observed behavior, we construct a simulation of charge and current flow on a narrow conducting channel embedded in three-dimensional space with the time domain electric field integral equation, the method of moments, and the thin-wire approximation. The method includes approximate treatment of resistance evolution due to lightning channel heating and the corona sheath of charge surrounding the lightning channel. Focusing our attention on preliminary breakdown in natural lightning by simulating stepwise channel extension with a simplified geometry, our simulation reproduces the broad features observed in data collected with the Huntsville Alabama Marx Meter Array. Some deviations in pulse shape details are evident, suggesting future work focusing on the detailed properties of the stepping mechanism.

KEY POINTS

Preliminary breakdown pulses can be reproduced by simulated channel extension Channel heating and corona sheath formation are crucial to proper pulse shape Extension processes and channel orientation significantly affect observations.

Understanding the relationship between dog ownership and children's physical activity and sedentary behaviour

BACKGROUND

Dog ownership is a catalyst for physical activity in adults. Given 50-70% of Australian households with children have a dog, dog-facilitated physical activity may be an effective way to increase physical activity and decrease child obesity.

OBJECTIVE

We hypothesized that children with a family dog walk more, are more physically active and are more likely to achieve recommended levels of weekly physical activity compared with children who do not have a dog.

METHOD

Cross-sectional data from the Western Australian TRravel, Environment, and Kids project (TREK) were analyzed for 1218 children aged 10-12 years. Individual and environment factors, child physical activity, walking, screen use, sedentary behaviour and dog ownership status was collected from child and parent questionnaires. Children's height and weight were measured.

RESULTS

Approximately 60% of children had a family dog. Dog ownership was associated with, on average, 29 more minutes of walking and 142 more minutes of physical activity per week (P ≤ 0.01). After adjustment, children with a dog were 49% more likely to achieve the recommended level of weekly physical activity (420 min) and 32% more likely to have walked in their neighbourhood in the last week, compared with non-dog owners (P ≤ 0.05). These relationships varied by gender. Dog ownership was not associated with screen use or weight status.

CONCLUSIONS

Dog ownership was associated with walking and physical activity, but not screen use or weight status. Within dog-owning families, the promotion of walking and active play with a dog may be a strategy to increase children's physical activity.

A secreted fluorescent reporter targeted to pituitary growth hormone cells in transgenic mice

In stable transfection experiments in the GH-producing GC cell line, a construct containing the entire signal peptide and the first 22 residues of human GH linked in frame with enhanced green fluorescent protein (eGFP), produced brightly fluorescent cells with a granular distribution of eGFP. This eGFP reporter was then inserted into a 40-kb cosmid transgene containing the locus control region for the hGH gene and used to generate transgenic mice. Anterior pituitaries from these GH-eGFP transgenic mice showed numerous clusters of strongly fluorescent cells, which were also immunopositive for GH, and which could be isolated and enriched by fluorescence-activated cell sorting. Confocal scanning microscopy of pituitary GH cells from GH-eGFP transgenic mice showed a markedly granular appearance of fluorescence. Immunogold electron microscopy and RIA confirmed that the eGFP product was packaged in the dense cored secretory vesicles of somatotrophs and was secreted in parallel with GH in response to stimulation by GRF. Using eGFP fluorescence, it was possible to identify clusters of GH cells in acute pituitary slices and to observe spontaneous transient rises in their intracellular Ca2+ concentrations after loading with Ca2+ sensitive dyes. This transgenic approach opens the way to direct visualization of spontaneous and secretagogue-induced secretory mechanisms in identified GH cells.

Annexin I is stored within gelatinase granules of human neutrophil and mobilized on the cell surface upon adhesion but not phagocytosis

Annexin I, a member of the calcium- and phospholipid-binding annexin superfamily of proteins, is largely present in human neutrophils. To determine its exact intracellular distribution a combination of flow cytometry, confocal microscopy and electron microscopy analyses were performed on resting human neutrophils as well as on cells which had been activated. In resting neutrophils, annexin I was found to be present in small amounts in the nucleus, in the cytoplasm and partially also associated with the plasma membrane. The cytoplasmic pool of annexin I was predominant, and the protein was co-localized with gelatinase (marker of gelatinase granules), but not with human serum albumin or CD35 (markers of secretory vesicles), or with lysosomes. Electron microscopy showed the presence of annexin I inside the gelatinase granules. Neutrophil adhesion to monolayers of endothelial cells, but not phagocytosis of particles of opsonized zymosan, provoked an intense mobilization of annexin I, with a marked externalization on the outer leaflet of the plasma membrane. Remaining intracellular annexin I was also found in proximity of the plasma membrane. These results provide a novel mechanism for annexin I secretion from human neutrophils, which is via a degranulation event involving gelatinase granules.

Dendritic secretion of peptides from hypothalamic magnocellular neurosecretory neurones: a local dynamic control system and its functions

The role of the dendrites of magnocellular neurones in the release of neurosecretory peptides and the synthesis of many proteins locally is reviewed. Oxytocin and vasopressin contained in dense-cored neurosecretory vesicles are released from magnocellular dendrites not only by excitatory transmitters such as glutamate acting through well-established receptors, but also by a rapid action of oestradiol acting by a mechanism which appears to involve NMDA receptors. Magnocellular dendrites also contain substantial amounts of the synthetic machinery which could synthesise proteins for local use. The presence in dendrites of polysomes and of mRNAs encoding microtubule-associated protein 2, calcium calmodulin kinase II, alpha-synapsin-associated protein, and components of the GABA(A) and NMDA receptors strongly suggests that these proteins can be translated in the dendrites, close to the sites at which they function. Mechanism(s) which control the translation of these dendritic mRNAs and the insertion into the dendritic membranes of proteins translated by dendritic ribosomes remain to be determined. However, an overall picture emerges of magnocellular dendrites as active secretory and synthetic components of the neurosecretory neurones.

[School psychology in conflict between the individual and the system]

Viewing literature about aspects, goals and methods of school psychology a conceptual framework for the work of a school psychological counselling center is described. A broad perspective is intended through two guiding principles: Polarities like individual and system, single case counselling and school organisation development are connected; the role bearers--counsellors and the addressees of this counselling--take part as active and competent fashioners of the guidance process within the system of relationships growing from this process.