The effects of crossing ethnic boundaries on the autonomic nervous system in Muslim and Jewish young women in Israel

The short term adaptation of the autonomic nervous systems (ANS) by type of urban environment and ethnicity

BACKGROUND

Previous studies examined the effects of urban environments on the Autonomic Nervous System (ANS). These studies measured the effects of environments on Heart Rate Variability (HRV) averaging different time intervals to one value. Yet, the dynamics of change, reflecting the functions and their derivatives that describe the adaptation to the new environments remain unknown. In addition, ethnic differences in the ANS adaptation were not investigated.

METHOD

Forty-eight Arab and 24 Jewish women ages 20-35 years, all healthy, non-smokers were recruited by a snowball sample. Both groups were of a similar socioeconomic status and BMI distributions. Using a portable monitor, the HRV response was continuously analyzed for 35 min of sedentary sitting in each of the three environments: a park, a city center and a residential area. LF/HF polynomial function was adapted to describe the dynamic change in each environment for each ethnic group.

RESULTS

Green area exposure was associated with 90% immediate change while in built-up areas, the change in HRV is about 40% adaptive (changing gradually). The adaptive process of HRV may stabilize after 15 min in the city center yet not even after 35 min in the residential environment. The total change (immediate + adaptive) reached 24% in city centers and 10% in residential areas. Changes in HRV rates in the park and the city center environments were higher among Arab women as compared to Jewish women but similar between the two groups in the residential area. The distributions of LF/HF in each time cohort were normal, meaning that shifting the focus to analyze functions of change in HRV, opens the possibility to employ analytic methods that assume the normal distribution.

CONCLUSIONS

Changing the focus from average levels of HRV to functions of change and their derivatives brings new insight into the understanding of the ANS response to environmental challenges. ANS short term adaptation to different environments is gradual and spans differently both in magnitude of response and latencies between different environments. Importantly, in green areas, the response is immediate unlike the adaptation to urban environments that is significantly more gradual. The ethnic differences in ANS adaptation is also noteworthy. In addition, adaptation proceeesses are normaly distributed in each time cohort suggesting a possible novel ANS index.

Comparative genomic analysis revealed genetic divergence between Bifidobacterium catenulatum subspecies present in infant versus adult guts

BACKGROUND

The two subspecies of Bifidobacterium catenulatum, B. catenulatum subsp. kashiwanohense and B. catenulatum subsp. catenulatum, are usually from the infant and adult gut, respectively. However, the genomic analysis of their functional difference and genetic divergence has been rare. Here, 16 B. catenulatum strains, including 2 newly sequenced strains, were analysed through comparative genomics.

RESULTS

A phylogenetic tree based on 785 core genes indicated that the two subspecies of B. catenulatum were significantly separated. The comparison of genomic characteristics revealed that the two subspecies had significantly different genomic sizes (p < 0.05) but similar GC contents. The functional comparison revealed the most significant difference in genes of carbohydrate utilisation. Carbohydrate-active enzymes (CAZyme) present two clustering patterns in B. catenulatum. The B. catenulatum subsp. kashiwanohense specially including the glycoside hydrolases 95 (GH95) and carbohydrate-binding modules 51 (CBM51) families involved in the metabolism of human milk oligosaccharides (HMO) common in infants, also, the corresponding fucosylated HMO gene clusters were detected. Meanwhile, B. catenulatum subsp. catenulatum rich in GH3 may metabolise more plant-derived glycan in the adult intestine.

CONCLUSIONS

These findings provide genomic evidence of carbohydrate utilisation bias, which may be a key cause of the genetic divergence of two B. catenulatum subspecies.

Ethnic Differences in Environmental Restoration: Arab and Jewish Women in Israel

Throughout the last few decades, plenty of attention has been paid to restorative environments that positively affect human psychological health. These studies show that restorative environments affect human beings emotionally, physiologically, and cognitively. Some studies focus on the cognitive effects of exposure to restorative environments. A widely used index that measures the cognitive response is the Perceived Restoration Potential Scale (PRS). Most studies employing the PRS have examined differences in human cognitive response between types of urban environments mainly urban versus green ones. We use Hartig's questionnaire to expose differences between types of urban environments and ethnic groups. Variances between Arab and Jewish women were calculated in four environments: home; park; residential and central city environments. The effect of intervening variables such as exposure to thermal, noise, social and CO loads and social discomfort were tested. We find that dissimilar to urban typical built-up environments, green areas are highly restorative. Furthermore, differences in the restorativeness of different urban environments are low though significant. These differences depend on their function, aesthetic qualities, and amount of greenery. Ethno-national differences appear to affect the experience of restoration. While both ethnic related groups experienced a tremendous sense of restoration in parks, Jewish women enjoyed slightly higher levels of restoration mainly at home and in residential environments compared to Arab women who experienced higher sense of restorativness in central city environments. Jewish women experienced higher sense of being away and fascination. From the intervening variables, social discomfort explained 68 percent of the experience of restoration, noise explained 49 percent, thermal load explained 43 percent and ethnicity 14 percent of the variance in PRS.

The role of social vs. physical environmental nuisances in affecting stress among Jewish and Muslim women in Israel

We calculate the effects of selected social and physical environmental nuisances on the autonomic nervous system balance among Jewish and Muslim mothers. Seventy-two Jewish and Muslim young healthy mothers from an Arab and Jewish neighboring city were tested in seven urban environments. Three social mediators (social discomfort, participation in household's decision-making and freedom of movement) and three physical mediators (thermal load, carbon monoxide and noise) were considered. Mean differences between Jewish and Muslim heart rate variability (HRV) and the effects of the mediating variables were calculated by ANOVA and stepwise multiple regressions. The results suggest that HRV was predominantly affected by social discomfort. Jewish and Muslim mothers experienced similar levels of social discomfort albeit; their responses differed by type of environment. Jewish mothers experienced stronger social discomfort in outdoor environments while Muslim mothers felt stronger social discomfort at home. Crossing ethnic boundaries was associated with increase in stress in both groups. Social discomfort played a stronger role in predicting stress in inter-ethnic environments. In conclusion, the study shows that social discomfort is a predominant environmental factor in predicting stress and related risk to health as reflected in the ANS balance across ethnicities. In addition ethnic specific factors like women freedom of movement played a minor role in effecting stress. At the same time the physical environmental aspects played essential role in effecting stress.

The Relationship between City Size and Carbon Monoxide (CO) Concentration and Their Effect on Heart Rate Variability (HRV)

Generally, larger cities are characterized by traffic congestion, which is associated with higher concentrations of pollution, including Carbon Monoxide (CO) pollution. However, this convention requires empirical support on the basis of accurate and reliable measurements. In addition, the assessment of the effect of CO on the autonomic nervous system (ANS), as measured by heart rate variability (HRV), has yielded conflicting results. A majority of the (few) studies on the topic have shown that increases in CO concentration of up to about 10 parts per million (ppm) are associated with a decrease in stress and risk to health in subjects. Beyond the hypothesis postulating city size as a determinant of increased CO concentration, the hypothesis proposing a causal link between CO concentration and HRV balance also requires empirical support. This article compares CO concentrations in a large metropolis with those in a small town, analyzing the relationship between CO and the HRV responses of young women in terms of city size. Four different types of environments were compared, taking into account mediating variables. The study participants spent 35 min in selected environments (a city center, a residential environment, a park, and a home) wearing Polar devices to measure HRV, and portable devices to measure noise thermal load and CO. The average concentrations of CO in each environment were calculated, along with the time distribution of the CO concentration, and the regression slopes between the concentrations of CO and the ANS balance, as measured by the low frequency power/high frequency power ratio (LF/HF) expressed as an HRV index. The results show that, regardless of size, the cities measured were all characterized by low levels of CO, far below the maximal accepted threshold standards, and that urban residents were exposed to these concentrations for less than half of the daytime hours. Furthermore, in contrast to the common view, larger cities do not necessarily accumulate higher concentrations of CO compared to small cities, regardless of the level of transport congestion. This study confirms the findings of the majority of the other studies on the subject, which showed a decrease in stress (as measured by HRV) as a result of an increase in CO concentrations below 7 ppm. Finally, following the assessment of the differential contribution attributed to the different environmental factors, it appears that noise, thermal load, and congestion all contribute more to a higher level of HRV balance than CO. This finding highlights the importance of a multivariable approach to the study, and a remediation of the effect of environmental factors on stress in urban environments.

There's no place like home? The psychological, physiological, and cognitive effects of short visits to outdoor urban environments compared to staying in the indoor home environment, a field experiment on women from two ethnic groups

BACKGROUND

The home environment is regarded as a safe, comfortable environment, however, home can also be a stressful place. Compared to staying in the indoor home environment, the effects of short visits to outdoor urban environments on short-term psychological, physiological and cognitive responses were not studied previously.

AIM

To evaluate whether visits to different urban and ethnic environments, in comparison to staying in the home indoor environment, leads to short-term changes in psychological, physiological and cognitive responses and whether these responses are independent of ethnicity.

METHODS

The participants, 20-35 year-old healthy women (N = 72, 48 Arab and 24 Jewish), started the experiment at their home and visited six different outdoor urban environments in predominantly ethnic Arab or Jewish cities, in Israel. First they visited intra-ethnic city and afterward inter-ethnic city environments. In each city they first visited an urban park and afterward, in a random order, a residential neighborhood and the city center. In each environment (including home) the following measures were used to evaluate psychological, physiological and cognitive effects: mood (measured as positive and negative emotions, cheerfulness, relaxed, natural and discomfort feelings), autonomic nervous system balance (assessed using heart rate variability (HRV)) and working memory (measured by a backwards digit-span task). Several potential mediators were measured: carbon monoxide (CO), heat, noise, social aspects, and the self-perceived restoration scale.

RESULTS

Compared to staying in the indoor home environment, short visits to outdoor urban environments, specifically intra and inter-ethnic parks, were associated with beneficial psychological, physiological, and cognitive responses, and the strongest effects were found for the intra-ethnic park. The results for the other urban environments were different between Jewish and Arab women. The self-perceived restoration, social aspects and reduced CO, heat and noise exposures during the visits did not explain the observed changes between the outdoor environments and home.

CONCLUSIONS

Visits to urban parks compared to staying in the home environment had beneficial short-term changes in psychological, physiological, and cognitive responses, regardless of ethnicity. The changes could not be attributed to the investigated mediators. Women should be encouraged to go outdoors and specifically visit parks to improve their psychological and physiological health.