Association of spatial proximity to fixed-site syringe services programs with HCV serostatus and injection equipment sharing practices among people who inject drugs in rural New England, United States

BACKGROUND

Hepatitis C virus (HCV) disproportionately affects rural communities, where health services are geographically dispersed. It remains unknown whether proximity to a syringe services program (SSP) is associated with HCV infection among rural people who inject drugs (PWID).

METHODS

Data are from a cross-sectional sample of adults who reported injecting drugs in the past 30 days recruited from rural counties in New Hampshire, Vermont, and Massachusetts (2018-2019). We calculated the road network distance between each participant's address and the nearest fixed-site SSP, categorized as ≤ 1 mile, 1-3 miles, 3-10 miles, and > 10 miles. Staff performed HCV antibody tests and a survey assessed past 30-day injection equipment sharing practices: borrowing used syringes, borrowing other used injection equipment, and backloading. Mixed effects modified Poisson regression estimated prevalence ratios (aPR) and 95% confidence intervals (95% CI). Analyses were also stratified by means of transportation.

RESULTS

Among 330 PWID, 25% lived ≤ 1 mile of the nearest SSP, 17% lived 1-3 miles of an SSP, 12% lived 3-10 miles of an SSP, and 46% lived > 10 miles from an SSP. In multivariable models, compared to PWID who lived within 1 mile of an SSP, those who lived 3 to 10 miles away had a higher prevalence of HCV seropositivity (aPR: 1.25, 95% CI 1.06-1.46), borrowing other used injection equipment (aPR: 1.23, 95% CI 1.04-1.46), and backloading (aPR: 1.48, 95% CI 1.17-1.88). Similar results were observed for PWID living > 10 miles from an SSP: aPR [HCV]: 1.19, 95% CI 1.01-1.40; aPR [borrowing other used equipment]:1.45, 95% CI 1.29-1.63; and aPR [backloading]: 1.59, 95% CI 1.13-2.24. Associations between living 1 to 3 miles of an SSP and each outcome did not reach statistical significance. When stratified by means of transportation, associations between distance to SSP and each outcome (except borrowing other used injection equipment) were only observed among PWID who traveled by other means (versus traveled by automobile).

CONCLUSIONS

Among PWID in rural New England, living farther from a fixed-site SSP was associated with a higher prevalence of HCV seropositivity, borrowing other used injection equipment, and backloading, reinforcing the need to increase SSP accessibility in rural areas. Means of transportation may modify this relationship.

Comparison of through-space homonuclear correlations between quadrupolar nuclei in solids

Various two-dimensional (2D) homonuclear correlation experiments have been proposed to observe proximities between identical half-integer spin quadrupolar nuclei in solids. These experiments select either the single- or double-quantum coherences during the indirect evolution period, t₁. We compare here the efficiency and the robustness of the 2D double-quantum to single-quantum (DQ-SQ) and SQ-SQ homonuclear correlations for two half-integer spin quadrupolar isotopes subject to small chemical shift anisotropy (CSA): ¹¹B with a nuclear spin I = 3/2 and ²⁷Al with I = 5/2. Such a comparison is performed using experiments on two model samples: Li₂B₄O₇ for ¹¹B and AlPO₄-14 for ²⁷Al. For both isotopes, the DQ-SQ homonuclear correlations are recommended since they allow probing the proximities between nuclei with close or identical frequencies. In the case of small or moderate isotropic chemical shift differences (e.g. ¹¹B) the [SR2₂¹] or [BR2₂¹] bracketed DQ-SQ recoupling schemes are recommended; whereas it is the BR2₂¹ un-bracketed one otherwise (e.g. ²⁷Al).

Assessing the spatial variability of raising public risk awareness for the intervention performance of COVID-19 voluntary screening: A spatial simulation approach

The rapid spread of a (re)emerging pandemic (e.g., COVID-19) is usually attributed to the invisible transmission caused by asymptomatic cases. Health authorities rely on large-scale voluntary screening to identify and isolate invisible spreaders as well as symptomatic people as early as possible to control disease spread. Raising public awareness is beneficial for improving the effectiveness of epidemic prevention because it could increase the usage and demand for testing kits. However, the effectiveness of testing could be influenced by the spatial demand for medical resources in different periods. Spatial demand could also be triggered by public awareness in areas with two geographical factors, including spatial proximity to resources and attractiveness of human mobility. Therefore, it is necessary to explore the spatial variations in raising public awareness on the effectiveness of COVID-19 screening. We implemented spatial simulation models to integrate various levels of public awareness and pandemic dynamics in time and space. Moreover, we also assessed the effects of the spatial proximity of testing kits and the ease of human mobility on COVID-19 testing at various levels of public awareness. Our results indicated that high public awareness promotes high willingness to be tested. This causes the demand to not be fully satisfied at the peak times during a pandemic, yet the shortage of tests does not significantly increase pandemic severity. We also found that when public awareness is low, concentrating on unattractive areas (such as residential or urban fringe areas) could promote a higher benefit of testing. On the other hand, when awareness is high, the factor of distances to testing stations is more important for promoting the benefit of testing; allocating additional testing resources in areas distant from stations could have a higher benefit of testing. This study aims to provide insights for health authorities into the allocation of testing resources against disease outbreaks with respect to various levels of public awareness.

Spatial proximity and access to buprenorphine or methadone treatment for opioid use disorder in a sample of people misusing opioids in Southern California

BACKGROUND

In response to the opioid crisis, over the last 10 years substantial strides have been made to increase the availability of evidence-based treatments for opioid use disorder, in particular buprenorphine maintenance, in the United States. Despite these worthwhile efforts, uptake rates of evidence-based treatment remain relatively low. As part of a broader study of opioid misuse, we examined proximity to evidence-based treatment as a potential barrier to treatment access.

METHODS

In 2017-2018, we surveyed 218 individuals misusing prescription opioids or using street opioids in three Southern Californian counties. The study calculated driving distance from place of residence to the closest treatment provider offering buprenorphine or methadone treatment for opioid use disorders.

RESULTS

Median distance to providers was 3.8 km (2.4 miles). Seventy one (33%) participants had received some form of treatment in the last 3 months; however, only 26 (40%) of these had received buprenorphine or methadone maintenance treatment. Participants receiving treatment at the time of their interview were traveling an average 16.8 km (10.4 miles) to reach treatment, indicating that as a group this population was both willing and able to seek and engage with treatment.

CONCLUSIONS

In the suburban and exurban communities in which our study was based, our findings suggest that simple physical proximity to providers of evidence-based treatment for opioid use disorder is no longer a critical barrier. Other barriers to uptake of buprenorphine or methadone maintenance treatment clearly remain and need to be addressed.

DISCLAIMER

Findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.

Spatial financial contagion during the COVID-19 outbreak: Local correlation approach

The purpose of this paper is to examine the effect of spatial proximity on financial contagion during the COVID-19 outbreak. We use the daily stock index series of Asian, American, and European countries from January 1, 2014 to January 30, 2021. Two groups of countries are considered: the first includes China and geographically close countries, namely Taiwan, Hong Kong, Singapore, India, Australia, Indonesia, Malaysia, South Korea, Singapore, Vietnam and Russia. The second group includes countries that are geographically distant from China: the United States, Brazil, Mexico, Argentina, Italy, France and Germany. Using local correlation measurement and polynomial regressions, we show that the spatial contagion effect exists between China and geographically distant countries. However, this effect is absent for geographically close countries (Taiwan, Vietnam and Hong Kong).

These findings have strong implications for investors and present guidance for regulators and policymakers in understanding the true impact of the COVID-19 on financial markets.

Change in outbreak epicentre and its impact on the importation risks of COVID-19 progression: A modelling study

BACKGROUND

The outbreak of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) that was first detected in the city of Wuhan, China has now spread to every inhabitable continent, but now the attention has shifted from China to other epicentres. This study explored early assessment of the influence of spatial proximities and travel patterns from Italy on the further spread of SARS-CoV-2 worldwide.

METHODS

Using data on the number of confirmed cases of COVID-19 and air travel data between countries, we applied a stochastic meta-population model to estimate the global spread of COVID-19. Pearson's correlation, semi-variogram, and Moran's Index were used to examine the association and spatial autocorrelation between the number of COVID-19 cases and travel influx (and arrival time) from the source country.

RESULTS

We found significant negative association between disease arrival time and number of cases imported from Italy (r = -0.43, p = 0.004) and significant positive association between the number of COVID-19 cases and daily travel influx from Italy (r = 0.39, p = 0.011). Using bivariate Moran's Index analysis, we found evidence of spatial interaction between COVID-19 cases and travel influx (Moran's I = 0.340). Asia-Pacific region is at higher/extreme risk of disease importation from the Chinese epicentre, whereas the rest of Europe, South-America and Africa are more at risk from the Italian epicentre.

CONCLUSION

We showed that as the epicentre changes, the dynamics of SARS-CoV-2 spread change to reflect spatial proximities.

Change in outbreak epicentre and its impact on the importation risks of COVID-19 progression: A modelling study

Background

The outbreak of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) that was first detected in the city of Wuhan, China has now spread to every inhabitable continent, but now the attention has shifted from China to other epicentres. This study explored early assessment of the influence of spatial proximities and travel patterns from Italy on the further spread of SARS-CoV-2 worldwide.

Methods

Using data on the number of confirmed cases of COVID-19 and air travel data between countries, we applied a stochastic meta-population model to estimate the global spread of COVID-19. Pearson's correlation, semi-variogram, and Moran's Index were used to examine the association and spatial autocorrelation between the number of COVID-19 cases and travel influx (and arrival time) from the source country.

Results

We found significant negative association between disease arrival time and number of cases imported from Italy (r = −0.43, p = 0.004) and significant positive association between the number of COVID-19 cases and daily travel influx from Italy (r = 0.39, p = 0.011). Using bivariate Moran's Index analysis, we found evidence of spatial interaction between COVID-19 cases and travel influx (Moran's I = 0.340). Asia-Pacific region is at higher/extreme risk of disease importation from the Chinese epicentre, whereas the rest of Europe, South-America and Africa are more at risk from the Italian epicentre.

Conclusion

We showed that as the epicentre changes, the dynamics of SARS-CoV-2 spread change to reflect spatial proximities.

Dear enemy effect in the Mexican volcano mouse Neotomodon alstoni: Implications of sex in the agonistic behaviour among neighbours

Two opposite phenomena have been found in territorial animals, the "dear enemy'' and the "nasty neighbour'', which refer to individuals that show less aggression toward neighbours than toward strangers and vice versa. However, the need to maintain territory should differ for males and females because sexual reproduction is the result of the different adaptive strategies of the sexes. In this study, we explore territorial behaviour in the context of dear-enemy and nasty neighbour effects in the Mexican volcano mouse (Neotomodon alstoni). Patterns of spatial relationships between individuals and the degrees of agonistic behaviour among neighbours were analysed for a period of one year. Results exhibit a greater spatial proximity between male pairs during the non-reproductive period than during the reproductive period, and greater spatial proximity between pairs of females during the reproductive period than during the non-reproductive period. The analysis of agonistic behaviour showed that there is less tolerance for distant neighbours than for nearest neighbours. However, there is a greater frequency of aggression between male pairs than between females, while females appear to exhibit non-aggressive avoidance among individuals. The results support the theory that Mexican volcano mouse exhibits the "dear enemy phenomenon".

Geographic Proximity to Parents, Intergenerational Support Exchange, and Migration Within Germany

Previous research on internal migration has emphasised the importance of local ties to family members outside the household, and to parents in particular. Family members who live close to an individual’s place of residence represent a form of local social capital that could make migrating costlier, and therefore less likely. This idea has been empirically supported. Yet, how family ties bind remains largely unexplained. We assume that intergenerational support is a manifestation of local social capital, and that spatial proximity is needed for support to be exchanged. Thus, we used mediation analysis that includes explicit measures of support exchanges between parents and their adult–children born in 1971–1973, 1981–1983, and 1991–1993 to explain the binding effect of living close to parents. Logistic regression models of migrating a distance of more than 40 km were conducted using eight waves of the German pairfam data. Living close to one’s parents was indeed found to be negatively associated with the likelihood of migration, and part of this association could be explained through intergenerational support: the more the instrumental support an adult child exchanged with her/his parent, the less likely she/he was to migrate. Receiving emotional support from the parents was associated with an increase in migration propensity. Neither giving emotional help nor receiving help with childcare functioned as mediators. It thus appears that adult children are particularly likely to value the proximity of their parents when they are exchanging instrumental support, but that the emotional bond between adult children and their parents can often be maintained over longer distances.

Spatial and sociodemographic correlates of gambling participation and disorder among female Filipino migrant workers in Macao, People's Republic of China

BACKGROUND AND AIMS

Correlates and risk factors for gambling disorder among vulnerable or transient populations such as transnational migrant workers are unknown. The current study examined sociodemographic and spatial correlates of gambling disorder among female Filipino domestic workers in Macao (SAR), China.

DESIGN

Survey-based, respondent-driven sampling study administered from November 2016 to August 2017.

SETTING

Macao (SAR), which encompassed 38 casinos within its 30.4 km² area at the time of this study.

PARTICIPANTS

Representative sample of N = 1194 female Filipino domestic workers in Macao.

MEASUREMENTS

Symptoms of gambling disorder based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Correlates evaluated included sociodemographic information, proximity to venues, perceived social support, and symptoms of depression and anxiety.

FINDINGS

Prevalence of gambling disorder was 5.1%. Multivariable regression analyses indicated that likelihood of gambling participation (i.e., ever gambling) was associated with current indebtedness (RR = 1.56, 95%CI = 1.08-2.25, p = .017) and worse self-reported health (RR = 1.31, 95%CI = 1.04-1.65, p = .02). Increased symptoms of gambling disorder were independently associated with lower perceived social support (RR = 0.92, 95%CI = 0.87-0.98, p = .006), increased dependents relying upon monthly remittances (RR = 1.10, 95%CI = 1.06-1.16, p < .001), increased depression severity (RR = 1.16, 95%CI = 1.07-1.25, p < .001), decreased salary quintile (RR = 0.97, 95%CI = 0.94-1.00, p = .04), and proximity to the nearest Mocha Club gaming venues (RR = 1.04, 95%CI = 1.02-1.07, p = .005). The association between proximity to casinos and increased symptoms of gambling disorder was significant only for domestic workers living apart from employers (RR = 1.07, 95%CI = 1.00-1.14, p = .04).

CONCLUSIONS

Increased spatial proximity to gambling venues and greater financial and psychosocial burdens are associated with gambling disorder among domestic workers in Macao.

Boundary conditions for the influence of spatial proximity on context-specific attentional settings

Flexibility of cognitive control is illustrated by the context-specific proportion compatibility (CSPC) effect, the now well-documented pattern showing that compatibility effects are reduced in mostly incompatible relative to mostly compatible locations. The episodic-retrieval account attributes the CSPC effect to location-specific representations that include the attentional settings formed via experience within a given location (e.g., a "focused" attentional setting becomes bound to a location with frequent conflict, whereas a "relaxed" setting becomes bound to one with infrequent conflict). However, Diede and Bugg (Attention, Perception, & Psychophysics, 78, 1255-1266, 2016) demonstrated that the attentional setting associated with a given location can be based on experiences that accumulate across multiple "grouped" locations-namely, those that are proximal to each other, relative to other (distal) locations. This spatial grouping effect supported the relative-proximity hypothesis, which we further tested in the present study. Experiment 1 replicated the spatial grouping effect and showed that it could be disrupted by a horizontal line dividing the otherwise grouped locations. Experiments 2 through 4 suggested that grouping might be a form of "chunking"-that is, the spatial grouping effect did not occur when the proximal locations were few enough in number (two) to represent independently, but it did occur when there were six locations. When there were eight proximal locations (and ten locations overall), the CSPC effect disappeared entirely. These findings suggest important boundary conditions for the relative-proximity hypothesis and inform our understanding of how past experiences with conflict are organized in the form of episodic representations that enable on-the-fly adjustments in cognitive control.

Gut microbiome composition is associated with spatial structuring and social interactions in semi-feral Welsh Mountain ponies

BACKGROUND

Microbiome composition is linked to host functional traits including metabolism and immune function. Drivers of microbiome composition are increasingly well-characterised; however, evidence of group-level microbiome convergence is limited and may represent a multi-level trait (i.e. across individuals and groups), whereby heritable phenotypes are influenced by social interactions. Here, we investigate the influence of spatial structuring and social interactions on the gut microbiome composition of Welsh mountain ponies.

RESULTS

We show that semi-feral ponies exhibit variation in microbiome composition according to band (group) membership, in addition to considerable within-individual variation. Spatial structuring was also identified within bands, suggesting that despite communal living, social behaviours still influence microbiome composition. Indeed, we show that specific interactions (i.e. mother-offspring and stallion-mare) lead to more similar microbiomes, further supporting the notion that individuals influence the microbiome composition of one another and ultimately the group. Foals exhibited different microbiome composition to sub-adults and adults, most likely related to differences in diet.

CONCLUSIONS

We provide novel evidence that microbiome composition is structured at multiple levels within populations of social mammals and thus may form a unit on which selection can act. High levels of within-individual variation in microbiome composition, combined with the potential for social interactions to influence microbiome composition, suggest the direction of microbiome selection may be influenced by the individual members present in the group. Although the functional implications of this require further research, these results lend support to the idea that multi-level selection can act on microbiomes.

Spatial proximity as a determinant of context-specific attentional settings

People implicitly encode the history of conflict associated with particular contexts and use this information to modulate attention to distractors. This manifests as a reduction in the compatibility effect in mostly incompatible locations compared to mostly compatible locations, a difference termed the context-specific proportion compatibility (CSPC) effect. CSPC effects are explained by an episodic retrieval account positing that abstract attentional settings bind to contextual cues-allowing rapid, context-driven modulation of attention. The current study interrogated this binding process by testing the influence of relative spatial proximity on the association of attentional settings with particular locations. In Experiment 1, like typical CSPC paradigms, biased locations appeared near top (e.g., mostly compatible) and bottom (e.g., mostly incompatible) edges of the screen. A novel feature was the addition of two mostly compatible (above fixation) and two mostly incompatible (below fixation) locations placed within close proximity at the middle of the screen. A CSPC effect was found for outer but not middle mostly compatible and mostly incompatible locations, suggesting the attentional setting bound to the middle locations reflected the average history of conflict (i.e., 50 % compatible) for the group of middle locations. In Experiment 2, distance between middle locations was increased, allowing middle locations to group with outer locations. The CSPC effect was found for outer and middle mostly compatible and mostly incompatible locations. Results support the relative proximity hypothesis, positing that attentional settings bound to a particular location are influenced by experience within a location and relatively close neighboring locations.

Applying Quantitative Genetic Methods to Primate Social Behavior

Increasingly, behavioral ecologists have applied quantitative genetic methods to investigate the evolution of behaviors in wild animal populations. The promise of quantitative genetics in unmanaged populations opens the door for simultaneous analysis of inheritance, phenotypic plasticity, and patterns of selection on behavioral phenotypes all within the same study. In this article, we describe how quantitative genetic techniques provide studies of the evolution of behavior with information that is unique and valuable. We outline technical obstacles for applying quantitative genetic techniques that are of particular relevance to studies of behavior in primates, especially those living in noncaptive populations, e.g., the need for pedigree information, non-Gaussian phenotypes, and demonstrate how many of these barriers are now surmountable. We illustrate this by applying recent quantitative genetic methods to spatial proximity data, a simple and widely collected primate social behavior, from adult rhesus macaques on Cayo Santiago. Our analysis shows that proximity measures are consistent across repeated measurements on individuals (repeatable) and that kin have similar mean measurements (heritable). Quantitative genetics may hold lessons of considerable importance for studies of primate behavior, even those without a specific genetic focus.

The Influence of Kinship on Familiar Natal Migrant Rhesus Macaques (Macaca mulatta)

In most primate species, females remain in the natal group with kin while males disperse away from kin around the time of puberty. Philopatric females bias their social behavior toward familiar maternal and paternal kin in several species, but little is known about kin bias in the dispersing sex. Male dispersal is likely to be costly because males encounter an increased risk of predation and death, which might be reduced by dispersing together with kin and/or familiar males (individuals that were born and grew up in same natal group) or into a group containing kin and/or familiar males. Here we studied the influence of kinship on familiar natal migrant rhesus macaques (Macaca mulatta) on Cayo Santiago, Puerto Rico, by combining demographic, behavioral, and genetic data. Our data suggest that kinship influences spatial proximity between recent natal immigrants and males familiar to them. Immigrants were significantly nearer to more closely related familiar males than to more distantly related individuals. Within a familiar subgroup, natal migrants were significantly closer to maternal kin, followed by paternal kin, then non-kin, and finally to males related via both the maternal and paternal line. Spatial proximity between natal immigrants and familiar males did not decrease over time in the new group, suggesting that there is no decline in associations between these individuals within the first months of immigration. Overall, our results might indicate that kinship is important for the dispersing sex, at least during natal dispersal when kin are still available.