Diverse and Complex Challenges to Migrant and Refugee Mental Health: Reflections of the M8 Alliance Expert Group on Migrant Health.

Forced migration is likely to continue to grow in the coming years due to climate change, disease outbreaks, conflict, and other factors. There are a huge number of challenges to maintaining good health, and specifically good mental health, among migrants at all stages of migration. It is vital to fully understand these diverse challenges so that we can work towards overcoming them. In 2017, as a response to the growing health challenges faced by migrants and refugees, the M8 Alliance created an expert group focussing on migrant and refugee health. The group meets annually at the Sapienza University of Rome, Italy, and this article is based on the discussions that took place at the third annual meeting (6-7 June 2019) and a special session on "Protecting the Mental Health of Refugees and Migrants," which took place on 27 October at the World Health Summit 2019 in Berlin. Our discussions are also supported by supplementary literature to present the diverse and complex challenges to the mental health of migrants and refugees. We conclude with some lessons learned and hope for the future.

Geneva Health Forum: The Forum of Innovative Practices in Global Health.

In the past years, Global Health has interfaced with important challenges related to several dynamic changes. Technological progress, the digital revolution and the emergence of new actors in the field of health, increase the possibility of finding solutions to these unprecedented challenges. Starting from these assumptions, the idea of providing an adequate platform for good management of the health system has flowed into the creation of a meeting place that would allow a wide exchange of information, ideas sharing and proposals for new collaborations: the Geneva Health Forum (GHF). The GHF is a global health conference that aims to promote critical reflections and constructive debates on contemporary global health issues, thus influencing and informing policy formulation with experience from the field. The profile and impact of the Geneva Health Forum has grown year on year, establishing itself as a unique forum, ranging from more traditional sessions to innovative events.

Critical reflections, challenges and solutions for migrant and refugee health: 2nd M8 Alliance Expert Meeting.

Throughout recent years, we have witnessed an increase in human migration as a result of conflict, political instability and changes in the climate. Despite the growing number of migrants and refugees, provisions to address their health needs remain inadequate and often unmet. Whilst a variety of instruments exist to assert and emphasise the importance for migrant and refugee health, the lack of shared priorities between partners and stakeholders results in poor access to healthcare and essential medicines. In response to the growing health challenges faced by migrants and refugees, members of the M8 Alliance launched an annual Expert Meeting on Migrants' and Refugees' Health. This report is shaped by discussions from the second M8 Alliance Expert Meeting (Sapienza University of Rome, Italy, 15-16 June 2018) and is supported by supplementing literature to develop a framework addressing critical reflections, challenges and solutions of and for migrant and refugee health. This report aims to inform decision-making fostering a humanitarian, ethics and rights-based approach. Through a series of country-specific case studies and discussions, this report captures the most prominent themes and recommendations such as mental health, tuberculosis (TB) and best practices for increased access.

Zooming into plant-flower visitor networks: an individual trait-based approach.

Understanding how ecological communities are structured is a major goal in ecology. Ecological networks representing interaction patterns among species have become a powerful tool to capture the mechanisms underlying plant-animal assemblages. However, these networks largely do not account for inter-individual variability and thus may be limiting our development of a clear mechanistic understanding of community structure. In this study, we develop a new individual-trait based approach to examine the importance of individual plant and pollinator functional size traits (pollinator thorax width and plant nectar holder depth) in mutualistic networks. We performed hierarchical cluster analyses to group interacting individuals into classes, according to their similarity in functional size. We then compared the structure of bee-flower networks where nodes represented either species identity or trait sets. The individual trait-based network was almost twice as nested as its species-based equivalent and it had a more symmetric linkage pattern resulting from of a high degree of size-matching. In conclusion, we show that by constructing individual trait-based networks we can reveal important patterns otherwise difficult to observe in species-based networks and thus improve our understanding of community structure. We therefore recommend using both trait-based and species-based approaches together to develop a clearer understanding of the properties of ecological networks.

Winning the arms race: host-parasite shared evolutionary history reduces infection risks in fish final hosts.

Parasite manipulation of intermediate hosts evolves to increase parasite trophic transmission to final hosts, yet counter selection should act on the final host to reduce infection risk and costs. However, determining who wins this arms race and to what extent is challenging. Here, for the first time, comparative functional response analysis quantified final host consumption patterns with respect to intermediate host parasite status. Experiments used two evolutionarily experienced fish hosts and two naive hosts, and their amphipod intermediate hosts of the acanthocephalan parasite Pomphorhynchus tereticollis The two experienced fish consumed significantly fewer infected than non-infected prey, with lower attack rates and higher handling times towards the former. Conversely, the two naive fish consumed similar numbers of infected and non-infected prey at most densities, with similar attack rates and handling times towards both. Thus, evolutionarily experienced final hosts can reduce their infection risks and costs via reduced intermediate host consumption, with this not apparent in naive hosts.

Interactions of warming and exposure affect susceptibility to parasite infection in a temperate fish species.

Predicting how elevated temperatures from climate change alter host-parasite interactions requires understandings of how warming affects host susceptibility and parasite virulence. Here, the effect of elevated water temperature and parasite exposure level was tested on parasite prevalence, abundance and burden, and on fish growth, using Pomphorhynchus laevis and its fish host Squalius cephalus. At 60 days post-exposure, prevalence was higher at the elevated temperature (22 °C) than ambient temperature (18 °C), with infections achieved at considerably lower levels of exposure. Whilst parasite number was significantly higher in infected fish at 22 °C, both mean parasite weight and parasite burden was significantly higher at 18 °C. There were, however, no significant relationships between fish growth rate and temperature, parasite exposure, and the infection parameters. Thus, whilst elevated temperature significantly influenced parasite infection rates, it also impacted parasite development rates, suggesting warming could have complex implications for parasite dynamics and host resistance.

Patterns of trophic niche divergence between invasive and native fishes in wild communities are predictable from mesocosm studies.

Ecological theory attempts to predict how impacts for native species arise from biological invasions. A fundamental question centres on the feeding interactions of invasive and native species: whether invasion will result in increased interspecific competition, which would result in negative consequences for the competing species, or trophic niche divergence, which would facilitate the invader's integration into the community and their coexistence with native species. Here, the feeding interactions of a highly invasive fish, topmouth gudgeon Pseudorasbora parva, with three native and functionally similar fishes were studied to determine whether patterns of either niche overlap or divergence detected in mesocosm experiments were apparent between the species at larger spatial scales. Using stable isotope analysis, their feeding relationships were assessed initially in the mesocosms (1000 L) and then in small ponds (<400 m(2) ) and large ponds (>600 m(2) ). In the mesocosms, a consistent pattern of trophic niche divergence was evident between the sympatric fishes, with niches shifting further apart in isotopic space than suggested in allopatry, revealing that sharing of food resources was limited. Sympatric P. parva also had a smaller niche than their allopatric populations. In eight small ponds where P. parva had coexisted for several years with at least one of the fish species used in the mesocosms, strong patterns of niche differentiation were also apparent, with P. parva always at a lower trophic position than the other fishes, as also occurred in the mesocosms. Where these fishes were sympatric within more complex fish communities in the large ponds, similar patterns were also apparent, with strong evidence of trophic niche differentiation. Aspects of the ecological impacts of P. parva invasion for native communities in larger ponds were consistent with those in the mesocosm experiments. Their invasion resulted in divergence in trophic niches, partly due to their reduced niche widths when in sympatry with other species, facilitating their coexistence in invaded ecosystems. Our study highlights the utility of controlled mesocosm studies for predicting the trophic relationships that can develop from introductions of non-native species into more complex ecosystems and at larger spatial scales.