The diversity and biogeography of bacterial communities in lake sediments across different climate zones.

Bacteria are diverse and play important roles in biogeochemical cycling of aquatic ecosystems, but the global distribution patterns of bacterial communities in lake sediments across different climate zones are still obscure. Here we integrated the high-throughput sequencing data of 750 sediment samples from published literature to investigate the distribution of bacterial communities in different climate zones and the potential driving mechanisms. The obtained results indicated that the diversity and richness of bacterial community were notably higher in temperate and cold zones than those in other climate zones. In addition, the bacterial community composition varied significantly in different climate zones, which further led to changes in bacterial functional groups. Specifically, the relative abundance of nitrogen cycling functional groups in polar zones was notably higher compared to other climate zones. Regression analysis revealed that climate (mean annual precipitation, MAP; and mean annual temperature, MAT), vegetation, and geography together determined the diversity pattern of sediment bacterial community on a global scale. The results of partial least squares path modeling further demonstrated that climate was the most significant factor affecting the composition and diversity of bacterial communities, and MAP was the most important climate factor affecting the composition of bacteria community (R2 = 0.443, P < 0.001). It is worth noting that a strong positive correlation was observed between the abundance of the dominant bacterial group uncultured_f_Anaerolineaceae and the normalized difference vegetation index (NDVI; P < 0.001), suggesting that vegetation could affect bacterial community diversity by influencing dominant bacterial taxa. This study enhances our understanding of the global diversity patterns and biogeography of sediment bacteria.

Threats to reptiles at global and regional scales.

Reptiles are an important, yet often understudied, taxon in nature conservation. They play a significant role in ecosystems1 and can serve as indicators of environmental health, often responding more rapidly to human pressures than other vertebrate groups.2 At least 21% of reptiles are currently assessed as threatened with extinction by the IUCN.3 However, due to the lack of comprehensive global assessments until recently, they have been omitted from spatial studies addressing conservation or spatial prioritization (e.g., Rosauer et al.,4,5,6,7,8 Fritz and Rahbek,4,5,6,7,8 Farooq et al.,4,5,6,7,8 Meyer et al., 4,5,6,7,8 and Farooq et al.4,5,6,7,8). One important knowledge gap in conservation is the lack of spatially explicit information on the main threats to biodiversity,9 which significantly hampers our ability to respond effectively to the current biodiversity crisis.10,11 In this study, we calculate the probability of a reptile species in a specific location being affected by one of seven biodiversity threats-agriculture, climate change, hunting, invasive species, logging, pollution, and urbanization. We conducted the analysis at a global scale, using a 50 km × 50 km grid, and evaluated the impact of these threats by studying their relationship with the risk of extinction. We find that climate change, logging, pollution, and invasive species are most linked to extinction risk. However, we also show that there is considerable geographical variation in these results. Our study highlights the importance of going beyond measuring the intensity of threats to measuring the impact of these separately for various biogeographical regions of the world, with different historical contingencies, as opposed to a single global analysis treating all regions the same.

Meeting the global protein supply requirements of a growing and ageing population.

Human dietary patterns are a major cause of environmental transformation, with agriculture occupying ~ 50% of global land space, while food production itself is responsible for ~ 30% of all greenhouse gas emissions and 70% of freshwater use. Furthermore, the global population is also growing, such that by 2050, it is estimated to exceed ~ 9 billion. While most of this expansion in population is expected to occur in developing countries, in high-income countries there are also predicted changes in demographics, with major increases in the number of older people. There is a growing consensus that older people have a greater requirement for protein. With a larger and older population, global needs for protein are set to increase. This paper summarises the conclusions from a Rank Prize funded colloquium evaluating novel strategies to meet this increasing global protein need.

Ecological dynamics and impacts of viruses in Chinese and global estuaries.

Estuaries are important ecosystems providing irreplaceable services for humankind and, in turn, are extensively influenced by human activities and climate changes. Microbial processes, which are largely controlled by viruses, are always responsible for the ecological function and environmental problems in estuaries. However, we know little about the ecology and importance of viruses in estuarine systems. Here, we investigated viral ecological dynamics in estuarine systems on local (four largest estuaries in China in different seasons) and global scales. Viral production varied by almost 20-fold in Chinese estuaries with significant seasonality, being responsible for the removal of 1.41%-21.45% of the bacterioplankton standing stock each day, and contributed directly to the organic carbon pool by releasing an average of 3.57 µg of cellular carbon per liter per day. By compiling data from 21 estuaries across the world, we found for the first time that viral population size peaked at mid-latitude and viral production increased towards the equator in estuarine ecosystems. The results indicated the higher viral impact on microbial mortality and dissolved organic matter cycling in tropical estuaries. Our field investigation and global synthesized analysis provide compelling evidence of spatiotemporal variations in estuarine viral dynamics. The global view of viral impacts on estuarine microbial mortality offers important insight for incorporating viruses into ecological models and understanding the environmental implications of the tropicalization of temperate aquatic ecosystems under a scenario of climate warming.

Net plant interactions are highly variable and weakly dependent on climate at the global scale.

Although plant-plant interactions (i.e. competition and facilitation) have long been recognised as key drivers of plant community composition and dynamics, their global patterns and relationships with climate have remained unclear. Here, we assembled a global database of 10,502 pairs of empirical data from the literature to address the patterns of and climatic effects on the net outcome of plant interactions in natural communities. We found that plant interactions varied among plant performance indicators, interaction types and biomes, yet competition occurred more frequently than facilitation in plant communities worldwide. Unexpectedly, plant interactions showed weak latitudinal pattern and were weakly related to climate. Our study provides a global comprehensive overview of plant interactions, highlighting competition as a fundamental mechanism structuring plant communities worldwide. We suggest that further investigations should focus more on local factors (e.g. microclimate, soil and disturbance) than on macroclimate to identify key environmental determinants of interactions in plant communities.

Dispersers and environment drive global variation in fruit colour syndromes.

The colours of fleshy fruits play a critical role in plant dispersal by advertising ripe fruits to consumers. Fruit colours have long been classified into syndromes attributed to selection by animal dispersers, despite weak evidence for this hypothesis. Here, we test the relative importance of biotic (bird and mammal frugivory) and abiotic (wet season temperatures, growing season length and UV-B radiation) factors in determining fruit colour syndrome in 3163 species of fleshy-fruited plants. We find that both dispersers and environment are important, and they interact. In warm areas, contrastive, bird-associated fruit colours increase with relative bird frugivore prevalence, whereas in cold places these colours dominate even where mammalian dispersers are prevalent. We present near-global maps of predicted fruit colour syndrome based on our species-level model and our newly developed characterisations of relative importance of bird and mammal frugivores.

Global patterns of comprehensive cardiovascular risk factor control in patients with type 2 diabetes mellitus: Insights from the DISCOVER study.

AIM: To investigate global patterns of cardiovascular risk factor control in patients with type 2 diabetes mellitus (T2D). METHODS: DISCOVER is an international, observational cohort study of patients with T2D beginning second-line glucose-lowering therapy. Risk factor management was examined among eligible patients (ie, those with the risk factor) at study baseline. Inter-country variability was estimated using median odds ratios (MORs). RESULTS: Among 14 343 patients with T2D from 34 countries, the mean age was 57.4 ± 12.0 years and the median (interquartile range) duration of T2D was 4.2 (2.0-8.0) years; 11.8% had documented atherosclerotic cardiovascular disease (ASCVD). Among eligible patients, blood pressure was controlled in 67.5% (9284/13756), statins were prescribed in 43.7% (5775/13208), angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers were prescribed in 55.6% (5292/9512), aspirin was prescribed in 53.3% of those with established ASCVD (876/1645), and 84.4% (12 102/14343) were non-smoking. Only 21.5% of patients (3088/14343) had optimal risk factor management (defined as control of all eligible measures), with wide inter-country variability (10%-44%), even after adjusting for patient and site differences (MOR 1.47, 95% confidence interval 1.24-1.66). CONCLUSION: Globally, comprehensive control of ASCVD risk factors is not being achieved in most patients, with wide variability among countries unaccounted for by patient and site differences. Better country-specific strategies are needed to implement comprehensive cardiovascular risk factor control consistently in patients with T2D to improve long-term outcomes.

International variation in breast cancer incidence and mortality in young women.

PURPOSE: Breast cancer in young women (< 40 years) is rare and carries a poor prognosis relative to breast cancer in older women. Most studies examining global breast cancer patterns do not describe the trends in young women specifically. METHODS: Data from GLOBOCAN 2018 were used to compare breast cancer incidence and mortality rates among younger (ages 0-39) vs. older (ages 40+) women across 185 countries. The coefficient of variation (the ratio of the standard deviation to the mean) was used to quantify relative variability. RESULTS: The risk of developing breast cancer to age 39 ranged from 0.13% in Guinea to 0.95% in South Korea (coefficient of variation: 46%), and the risk of death from breast cancer to age 39 ranged from 0.02% in China to 0.72% in Cameroon (coefficient of variation: 81%). In contrast, the risk of developing breast cancer to age 74 ranged from 1.5% in Mozambique to 12.2% in Belgium (coefficient of variation: 50%), and the risk of death from breast cancer to age 74 ranged from 0.65% in South Korea to 3.0% in Somalia (coefficient of variation: 36%). CONCLUSIONS: Among young women, breast cancer mortality rates varied more worldwide than breast cancer incidence. In contrast, among older women/women of all ages, breast cancer incidence varied more than breast cancer mortality. Further research is required to examine the impact of stage at diagnosis, clinicopathologic features, and treatments received, on variations in the survival and mortality of breast cancer in young women around the world.

Recurrent pattern of picophytoplankton dynamics in estuaries around the world: The case of Río de la Plata.

The picoplankton is an important component of aquatic food webs and plays a significant biogeochemical and ecological role in the environment. Little is known about this fraction of the plankton in temperate estuaries and especially in South America. In this article, we study the absolute and relative importance of the picoplankton along an annual cycle, and their relationship with physical and chemical variables in the Río de la Plata estuary. We also review the existing research in estuaries around the world concerning this community and present our results in a global context. The seasonal variation in the abundance of the different groups analyzed was very noticeable. Phycocyanin-rich picocyanobacteria (Pcy) were the main component (in abundance and in biovolume) of the picophytoplankton (PPP) almost during the whole year, with a maximum abundance of 7.3 × 105 cell mL-1 in summer, three orders of magnitude higher compared to autumn-winter. Picoeukaryotes, larger phytoplankton and heterotrophic bacteria showed the same seasonal trend, although with a lower range of variation than that of the Pcy. Considering all the phototrophic planktonic fractions, in terms of biomass, the PPP reached a maximum of 43% of the total biomass in spring. The dynamics of PPP found in this area are consistent with the observed in other temperate estuaries, where temperature is the main variable that influences its development, and with a high seasonal variation. Additionally, the absolute and relative importance of Pcy showed a consistently increasing trend towards lower latitude estuaries. The review also showed us that there is scarce information related to the picoplankton fraction in the Southern Hemisphere, its sanitary implications due to their potential of toxicity or their ecological role in coastal zones. The results presented here show the importance of this fraction, not only in Río de la Plata, but in many estuaries of the world, with a clear increase of relative abundance as we approach the equator.

Comparing key drivers of cyanobacteria biomass in temperate and tropical systems.

There is growing evidence that cyanobacterial blooms are becoming more common in different parts of the world; within this context, predictive cyanobacteria models have an essential role in lake management. Several models have been successfully used in temperate systems to describe the main drivers of cyanobacterial blooms, but relatively less work has been conducted in the Tropics. We analyzed data from six Brazilian reservoirs and from five Canadian lakes using a combination of regression tree analyses and variation partitioning to evaluate the similarities and differences between regions. Our results, together with a synthesis of the literature from different latitudes, showed that trophic state (i.e. nutrients), climatic variables (e.g., temperature and/or precipitation) and hydrodynamic regimes (i.e. water residence time) are significant drivers of cyanobacteria biomass over several scales. Nutrients came out as the primary predictor in both regions, followed by climate, but when all systems were pooled together, water residence time came out as most important. The consistency in variables identified between regions suggests that these drivers are widely important and cyanobacteria responded quite similarly in different geographical settings and waterbody types (i.e. lakes or reservoirs). However, more work is needed to identify key thresholds across latitudinal gradients. Taken together, these results suggest that multi-region syntheses can help identify drivers that predict broad-scale patterns of cyanobacteria biomass.

Recent Global Patterns in Prostate Cancer Incidence and Mortality Rates.

CONTEXT: Previous studies have reported significant variation in prostate cancer rates and trends mainly due to differences in detection practices, availability of treatment, and underlying genetic susceptibility. OBJECTIVE: To assess recent worldwide prostate cancer incidence, mortality rates, and trends using up-to-date incidence and mortality data. EVIDENCE ACQUISITION: We present estimated age-standardized prostate cancer incidence and mortality rates by country and world regions for 2018 based on the GLOBOCAN database. We also examined rates and temporal trends for incidence (44 countries) and mortality (76 countries) based on data series from population-based registries. EVIDENCE SYNTHESIS: The highest estimated incidence rates were found in Australia/New Zealand, Northern America, Western and Northern Europe, and the Caribbean, and the lowest rates were found in South-Central Asia, Northern Africa, and South-Eastern and Eastern Asia. The highest estimated mortality rates were found in the Caribbean (Barbados, Trinidad and Tobago, and Cuba), sub-Saharan Africa (South Africa), parts of former Soviet Union (Lithuania, Estonia, and Latvia), whereas the lowest rates were found in Asia (Thailand and Turkmenistan). Prostate cancer incidence rates during the most recent 5 yr declined (five countries) or stabilized (35 countries), after increasing for many years; in contrast, rates continued to increase for four countries in Eastern Europe and Asia. During the most recent 5 data years, mortality rates among the 76 countries examined increased (three countries), remained stable (59 countries), or decreased (14 countries). CONCLUSIONS: As evident from available data, prostate cancer incidence and mortality rates have been on the decline or have stabilized recently in many countries, with decreases more pronounced in high-income countries. These trends may reflect a decline in prostate-specific antigen testing (incidence) and improvements in treatment (mortality). PATIENT SUMMARY: We examined recent trends in prostate cancer incidence and mortality rates in 44 and 76 countries, respectively, and found that rates in most countries stabilized or decreased.

Unsupervised Learning Reveals Geography of Global Ocean Dynamical Regions.

Dynamically similar regions of the global ocean are identified using a barotropic vorticity (BV) framework from a 20-year mean of the Estimating the Circulation and Climate of the Ocean state estimate at 1° resolution. An unsupervised machine learning algorithm, K-means, objectively clusters the standardized BV equation, identifying five unambiguous regimes. Cluster 1 covers 43 ± 3.3% of the ocean area. Surface and bottom stress torque are balanced by the bottom pressure torque and the nonlinear torque. Cluster 2 covers 24.8 ± 1.2%, where the beta effect balances the bottom pressure torque. Cluster 3 covers 14.6 ± 1.0%, characterized by a "Quasi-Sverdrupian" regime where the beta effect is balanced by the wind and bottom stress term. The small region of Cluster 4 has baroclinic dynamics covering 6.9 ± 2.9% of the ocean. Cluster 5 occurs primarily in the Southern Ocean. Residual "dominantly nonlinear" regions highlight where the BV approach is inadequate, found in areas of rough topography in the Southern Ocean and along western boundaries.

Global mismatches in aboveground and belowground biodiversity.

Human activities are accelerating global biodiversity change and have resulted in severely threatened ecosystem services. A large proportion of terrestrial biodiversity is harbored by soil, but soil biodiversity has been omitted from many global biodiversity assessments and conservation actions, and understanding of global patterns of soil biodiversity remains limited. In particular, the extent to which hotspots and coldspots of aboveground and soil biodiversity overlap is not clear. We examined global patterns of these overlaps by mapping indices of aboveground (mammals, birds, amphibians, vascular plants) and soil (bacteria, fungi, macrofauna) biodiversity that we created using previously published data on species richness. Areas of mismatch between aboveground and soil biodiversity covered 27% of Earth's terrestrial surface. The temperate broadleaf and mixed forests biome had the highest proportion of grid cells with high aboveground biodiversity but low soil biodiversity, whereas the boreal and tundra biomes had intermediate soil biodiversity but low aboveground biodiversity. While more data on soil biodiversity are needed, both to cover geographic gaps and to include additional taxa, our results suggest that protecting aboveground biodiversity may not sufficiently reduce threats to soil biodiversity. Given the functional importance of soil biodiversity and the role of soils in human well-being, soil biodiversity should be considered further in policy agendas and conservation actions by adapting management practices to sustain soil biodiversity and considering soil biodiversity when designing protected areas.

Disparidades Mundiales entre la Biodiversidad Sobre y Bajo el Suelo Resumen Las actividades humanas están acelerando el cambio en la biodiversidad mundial y han tenido como resultado unos servicios ambientales severamente amenazados. Una gran proporción de la biodiversidad terrestre está albergada en el suelo, pero la biodiversidad de este ha sido omitida de varias evaluaciones mundiales de biodiversidad y de las acciones de conservación, además de que el entendimiento de los patrones mundiales de la biodiversidad del suelo permanece limitado; particularmente, la extensión del traslape entre los puntos fríos y calientes de biodiversidad sobre y bajo suelo no está clara. Examinamos los patrones mundiales de estos traslapes mapeando los índices de biodiversidad sobre el suelo (mamíferos, aves, anfibios y plantas vasculares) y bajo el suelo (bacterias, hongos y macrofauna) que creamos con datos previamente publicados de la riqueza de especies. Las áreas de disparidad entre la biodiversidad sobre y bajo el suelo cubrieron el 27% de la superficie terrestre del planeta. El bioma de los bosques templados de plantas frondosas y mixtas tuvo la proporción más alta de celdas de cuadrícula con una biodiversidad alta sobre el suelo, pero baja para en el subsuelo, mientras que los biomas boreales y de la tundra tuvieron una biodiversidad intermedia bajo el suelo, pero baja para el sobre suelo. Aunque se requieren más datos sobre la biodiversidad del suelo, tanto para cubrir los vacíos geográficos como para incluir a taxones adiciones, nuestros resultados sugieren que la protección a la biodiversidad sobre el suelo puede no reducir suficientemente las amenazas para la biodiversidad del suelo. Dada la importancia funcional de la biodiversidad del suelo y el papel de los suelos en el bienestar humano, se debería considerar a la biodiversidad del suelo mucho más en las agendas políticas y en las acciones de conservación, adaptando a las prácticas de manejo para que mantengan a la biodiversidad del suelo y la consideren cuando designen áreas protegidas.

Which Latitudinal Gradients for Genetic Diversity?

A recent global analysis of GenBank DNA sequences from amphibians and mammals indicated consistent poleward decrease of intraspecific genetic diversity in both classes. We highlight that this result was biased by not accounting for distance decay of similarity and reanalyse the datasets, revealing distinct latitudinal gradients in mammals and amphibians.

The epidemic spreading model and the direction of information flow in brain networks.

The interplay between structural connections and emerging information flow in the human brain remains an open research problem. A recent study observed global patterns of directional information flow in empirical data using the measure of transfer entropy. For higher frequency bands, the overall direction of information flow was from posterior to anterior regions whereas an anterior-to-posterior pattern was observed in lower frequency bands. In this study, we applied a simple Susceptible-Infected-Susceptible (SIS) epidemic spreading model on the human connectome with the aim to reveal the topological properties of the structural network that give rise to these global patterns. We found that direct structural connections induced higher transfer entropy between two brain regions and that transfer entropy decreased with increasing distance between nodes (in terms of hops in the structural network). Applying the SIS model, we were able to confirm the empirically observed opposite information flow patterns and posterior hubs in the structural network seem to play a dominant role in the network dynamics. For small time scales, when these hubs acted as strong receivers of information, the global pattern of information flow was in the posterior-to-anterior direction and in the opposite direction when they were strong senders. Our analysis suggests that these global patterns of directional information flow are the result of an unequal spatial distribution of the structural degree between posterior and anterior regions and their directions seem to be linked to different time scales of the spreading process.

Phosphorus accumulates faster than nitrogen globally in freshwater ecosystems under anthropogenic impacts.

Combined effects of cumulative nutrient inputs and biogeochemical processes that occur in freshwater under anthropogenic eutrophication could lead to myriad shifts in nitrogen (N):phosphorus (P) stoichiometry in global freshwater ecosystems, but this is not yet well-assessed. Here we evaluated the characteristics of N and P stoichiometries in bodies of freshwater and their herbaceous macrophytes across human-impact levels, regions and periods. Freshwater and its macrophytes had higher N and P concentrations and lower N : P ratios in heavily than lightly human-impacted environments, further evidenced by spatiotemporal comparisons across eutrophication gradients. N and P concentrations in freshwater ecosystems were positively correlated and N : P was negatively correlated with population density in China. These results indicate a faster accumulation of P than N in human-impacted freshwater ecosystems, which could have large effects on the trophic webs and biogeochemical cycles of estuaries and coastal areas by freshwater loadings, and reinforce the importance of rehabilitating these ecosystems.

Lung Cancer Statistics.

Lung cancer is the leading cause of cancer death among both men and women in the United States. It is also the leading cause of cancer death among men and the second leading cause of cancer death among women worldwide. Lung cancer rates and trends vary substantially by sex, age, race/ethnicity, socioeconomic status, and geography because of differences in historical smoking patterns. Lung cancer mortality rates in the United States are highest among males, blacks, people of lower socioeconomic status, and in the mid-South (e.g., Kentucky, Mississippi, Arkansas, and Tennessee). Globally, rates are highest in countries where smoking uptake began earliest, such as those in North America and Europe. Although rates are now decreasing in most of these countries (e.g., United States, United Kingdom, Australia), especially in men, they are increasing in countries where smoking uptake occurred later. Low- and middle-income countries now account for more than 50% of lung cancer deaths each year. This chapter reviews lung cancer incidence and mortality patterns in the United States and globally.

Characterizing differences in precipitation regimes of extreme wet and dry years: implications for climate change experiments.

Climate change is intensifying the hydrologic cycle and is expected to increase the frequency of extreme wet and dry years. Beyond precipitation amount, extreme wet and dry years may differ in other ways, such as the number of precipitation events, event size, and the time between events. We assessed 1614 long-term (100 year) precipitation records from around the world to identify key attributes of precipitation regimes, besides amount, that distinguish statistically extreme wet from extreme dry years. In general, in regions where mean annual precipitation (MAP) exceeded 1000 mm, precipitation amounts in extreme wet and dry years differed from average years by ~40% and 30%, respectively. The magnitude of these deviations increased to >60% for dry years and to >150% for wet years in arid regions (MAP<500 mm). Extreme wet years were primarily distinguished from average and extreme dry years by the presence of multiple extreme (large) daily precipitation events (events >99th percentile of all events); these occurred twice as often in extreme wet years compared to average years. In contrast, these large precipitation events were rare in extreme dry years. Less important for distinguishing extreme wet from dry years were mean event size and frequency, or the number of dry days between events. However, extreme dry years were distinguished from average years by an increase in the number of dry days between events. These precipitation regime attributes consistently differed between extreme wet and dry years across 12 major terrestrial ecoregions from around the world, from deserts to the tropics. Thus, we recommend that climate change experiments and model simulations incorporate these differences in key precipitation regime attributes, as well as amount into treatments. This will allow experiments to more realistically simulate extreme precipitation years and more accurately assess the ecological consequences.