A global, spatially-explicit assessment of irrigated croplands influenced by urban wastewater flows

When urban areas expand without concomitant increases in wastewater treatment capacity, vast quantities of wastewater are released to surface waters with little or no treatment. Downstream of many urban areas are large areas of irrigated croplands reliant on these same surface water sources. Case studies document the widespread use of untreated wastewater in irrigated agriculture, but due to the practical and political challenges of conducting a true census of this practice, its global extent is not well known except where reuse has been planned. This study used GIS-based modeling methods to develop the first spatially explicit estimate of the global extent of irrigated croplands influenced by urban wastewater flows, including indirect wastewater use. These croplands were further classified by their likelihood of using poor quality water based on the spatial proximity of croplands to urban areas, urban wastewater return flow ratios, and proportion of wastewater treated. This study found that 65 percent (35.9 Mha) of downstream irrigated croplands were located in catchments with high levels of dependence on urban wastewater flows. These same catchments were home to 1.37 billion urban residents. Of these croplands, 29.3 Mha were located in countries with low levels of wastewater treatment and home to 885 million urban residents. These figures provide insight into the key role that water reuse plays in meeting the water and food needs of people around the world, and the need to invest in wastewater treatment to protect public health

Agents of Forest Disturbance in the Argentine Dry Chaco

Forest degradation in the tropics is a widespread, yet poorly understood phenomenon. This is particularly true for tropical and subtropical dry forests, where a variety of disturbances, both natural and anthropogenic, affect forest canopies. Addressing forest degradation thus requires a spatially-explicit understanding of the causes of disturbances. Here, we apply an approach for attributing agents of forest disturbance across large areas of tropical dry forests, based on the Landsat image time series. Focusing on the 489,000 km2 Argentine Dry Chaco, we derived metrics on the spectral characteristics and shape of disturbance patches. We then used these metrics in a random forests classification framework to estimate the area of logging, fire, partial clearing, riparian changes and drought. Our results highlight that partial clearing was the most widespread type of forest disturbance from 1990–to 2017, extending over 5520 km2 (±407 km2), followed by fire (4562 ± 388 km2) and logging (3891 ± 341 km2). Our analyses also reveal marked trends over time, with partial clearing generally becoming more prevalent, whereas fires declined. Comparing the spatial patterns of different disturbance types against accessibility indicators showed that fire and logging prevalence was higher closer to fields, while smallholder homesteads were associated with less burning. Roads were, surprisingly, not associated with clear trends in disturbance prevalence. To our knowledge, this is the first attribution of disturbance agents in tropical dry forests based on satellite-based indicators. While our study reveals remaining uncertainties in this attribution process, our framework has considerable potential for monitoring tropical dry forest disturbances at scale. Tropical dry forests in South America, Africa and Southeast Asia are some of the fastest disappearing ecosystems on the planet, and more robust monitoring of forest degradation in these regions is urgently needed.Peer Reviewe

Implementation of sustainable farming practices by cocoa farmers in Ecuador and Uganda: the influence of value chain factors

A key strategy of chocolate manufacturers is the promotion of sustainable farming practices amongst their supplying cocoa producers. A growing body of micro-economic literature has analysed factors influencing the adoption of such practices, yet broadly disregarded value chain factors. Information on how factors within single value chains increase the adoption of sustainable farming practices can help direct chocolate companies’ investments and increase return of investments in sustainability. The objective of this study was to understand: (a) how important value chain factors are, relative to farmer and farm factors, for cocoa farmers’ implementation of sustainable farming practices and (b) through which mechanisms value chain factors influence sustainable farming practices implementation. By integrating the practice adoption with sustainable supply chain management literature, we contribute to closing an important research gap. We collected data from 394 cocoa farmers in Ecuador and Uganda and analysed the determinants of implementation sustainable farming practices, testing quantitatively whether value chain factors with variation within single value chains are significantly associated with practice implementation. These factors included information factors (farmers’ access to training; advisory service through the value chain) and structural factors (value chain organisation and persistence; farmers’ dependency on this value chain). We selected 11 sustainable farming practices or indicators across three sustainability dimensions, i.e., environmental, social, and economic. We found that value chain factors are comparable to farmer and farm factors in explaining the implementation of sustainable farming practices across dimensions. Both capacity building and stable relationships were significantly related with the implementation of certain sustainable farming practices. Yet these results were weaker than expected, indicating that their potential was not fully exploited within our case study value chains. Through their value chain sustainability initiatives, chocolate companies should disseminate knowledge, address inhibitors to sustainable farming practices implementation beyond knowledge, and align sustainability goals with all value chain actors

The restructuring of South American soy and beef production and trade under changing environmental regulations

In response to the extensive loss of forests caused by soy and cattle expansion in South America, several countries have increased their legal restrictions on deforestation, and stepped up their enforcement. In addition, in the Brazilian Amazon, new private agreements were initiated in 2006 and 2009 to limit the purchase of soy and cattle linked with deforestation. One concern is that such policies, because they are spatially heterogeneous or focus on a subset of relevant actors, might generate negative spillovers in the form of leakage of agricultural activities and deforestation to less-regulated areas, and/or a redistribution of non-compliant product sales to non-participants. In this study, we use panel data on soy and beef production and trade in agricultural frontiers of South America to examine how changes in deforestation regulations in South America have altered soy and cattle expansion and exports in this region, and to understand how these changes, if they have occurred, influence the overall effectiveness of deforestation regulations. We find no evidence of a change in soy or pasture area expansion patterns due to changes in regulations, except within the Amazon biome where pasture expansion slowed in response to more stringent regulations and coincided with pasture intensification. We do find, however, a decrease in beef imports from biomes with more stringent deforestation regulations. While this decrease may indicate the existence of leakage to countries outside the study area, it is likely offset by pasture intensification, continued opportunities for deforestation, and increasing domestic consumption from these biomes. These results point to the potential role of substitution effects between local and international consumer markets, and between different actors, in diminishing the overall effectiveness of deforestation regulations

The emergence of land change science for global environmental change and sustainability

Land change science has emerged as a fundamental component of global environmental change and sustainability research. This interdisciplinary field seeks to understand the dynamics of land cover and land use as a coupled human-environment system to address theory, concepts, models, and applications relevant to environmental and societal problems, including the intersection of the two. The major components and advances in land change are addressed: observation and monitoring; understanding the coupled system-causes, impacts, and consequences; modeling; and synthesis issues. The six articles of the special feature are introduced and situated within these components of study. Land Change and Its Science H uman-driven changes in the terrestrial surface of the earth hold wide-ranging significance for the structure and function of ecosystems to the earth system, with equally far-reaching consequences for human well-being (1). The antiquity of the unintended impacts of these changes is well documented for locales and regions (2, 3), and those linked to megafauna losses obtained a global reach by 10,000 B.P. (4-6). Deforestation and irrigation were the largest sources of human-released greenhouse gasses to the atmosphere until the advent of industrial era fossil-fuel burning, and as much as 35% of the human-induced CO 2 equivalents in the atmosphere today can be traced to the totality of landuse/cover changes Today, as much as 50% of the earth's ice-free land surface has been transformed (9, 10), and virtually all land has been affected in some way by such processes as coadapted landscapes, climate change, and tropospheric pollution ʈ In the face of these global dimensions, local to regional land changes remain important. For example, the largescale replacement of natural land cover by urban and agricultural land uses in southern Florida has reduced precipitation there (19), consistent with land changeregional climate impacts found elsewhere (20). Even more dramatically, massive irrigated agricultural projects triggered the collapse of the Aral Sea and its fishing industry, with feedbacks that include wind-dispersed deposition of surface salts from the dry sea bed on adjacent agricultural lands and even on the glacial sources of rivers feeding the sea (21). Changes in land and ecosystems and their implications for global environmental change and sustainability are a major research challenge for the humanenvironmental sciences The daunting objectives of LCS The Dimensions of LCS: Advances, Implications, and Challenges Observation, Monitoring, and Land Characterization. The number of and improvements in air-and space-borne sensors over the past two decades have fundamentally altered the capacity to observe Author contributions: B.L.T., E.F.L., and A.R. wrote the paper. The authors declare no conflict of interest. † To whom correspondence should be addressed. E-mail: [email protected]. ¶ ''Land transformation'' refers to radical changes in land use and cover, usually over the long term, such as forest to row crop cultivation, or wetlands to urban settlement. The various estimates of these changes differ owing to the use of different metrics and measures and the uncertainties involved. Regardless, transformations are sizable as proportion of the ice-free land surface. If lands altered by human activity-lands retaining their base land cover but configured differently than in the ''wildland'' state-are included, a much larger estimate would result. Examples include degraded arid lands, pasture and grasslands invaded by or planted to exotic flora, and coadapted forests and grassland. Coadapted land covers are shaped and maintained by prolonged and repeated human activity, such as burning, that enlarges land use or land production: for example, annual burning that expands savanna grasses relative to woody species and enlarges food stocks for livestock and native grazers. ʈ As with estimates of land transformations and alterations, there is little doubt that human activity usurps a large proportion of terrestrial net primary productivity, but the uncertainty in the estimates remains large (16)

Determinants of the geographic distribution of Puumala virus and Lyme borreliosis infections in Belgium

BACKGROUND: Vector-borne and zoonotic diseases generally display clear spatial patterns due to different space-dependent factors. Land cover and land use influence disease transmission by controlling both the spatial distribution of vectors or hosts, and the probability of contact with susceptible human populations. The objective of this study was to combine environmental and socio-economic factors to explain the spatial distribution of two emerging human diseases in Belgium, Puumala virus (PUUV) and Lyme borreliosis. Municipalities were taken as units of analysis. RESULTS: Negative binomial regressions including a correction for spatial endogeneity show that the spatial distribution of PUUV and Lyme borreliosis infections are associated with a combination of factors linked to the vector and host populations, to human behaviours, and to landscape attributes. Both diseases are associated with the presence of forests, which are the preferred habitat for vector or host populations. The PUUV infection risk is higher in remote forest areas, where the level of urbanisation is low, and among low-income populations. The Lyme borreliosis transmission risk is higher in mixed landscapes with forests and spatially dispersed houses, mostly in wealthy peri-urban areas. The spatial dependence resulting from a combination of endogenous and exogenous processes could be accounted for in the model on PUUV but not for Lyme borreliosis. CONCLUSION: A large part of the spatial variation in disease risk can be explained by environmental and socio-economic factors. The two diseases not only are most prevalent in different regions but also affect different groups of people. Combining these two criteria may increase the efficiency of information campaigns through appropriate targeting

Multi-level analyses of spatial and temporal determinants for dengue infection

BACKGROUND: Dengue is a mosquito-borne viral infection that is now endemic in most tropical countries. In Thailand, dengue fever/dengue hemorrhagic fever is a leading cause of hospitalization and death among children. A longitudinal study among 1750 people in two rural and one urban sites in northern Thailand from 2001 to 2003 studied spatial and temporal determinants for recent dengue infection at three levels (time, individual and household). METHODS: Determinants for dengue infection were measured by questionnaire, land-cover maps and GIS. IgM antibodies against dengue were detected by ELISA. Three-level multi-level analysis was used to study the risk determinants of recent dengue infection. RESULTS: Rates of recent dengue infection varied substantially in time from 4 to 30%, peaking in 2002. Determinants for recent dengue infection differed per site. Spatial clustering was observed, demonstrating variation in local infection patterns. Most of the variation in recent dengue infection was explained at the time-period level. Location of a person and the environment around the house (including irrigated fields and orchards) were important determinants for recent dengue infection. CONCLUSION: We showed the focal nature of asymptomatic dengue infections. The great variation of determinants for recent dengue infection in space and time should be taken into account when designing local dengue control programs

A case report and genetic characterization of a massive acinic cell carcinoma of the parotid with delayed distant metastases.

We describe the presentation, management, and clinical outcome of a massive acinic cell carcinoma of the parotid gland. The primary tumor and blood underwent exome sequencing which revealed deletions in CDKN2A as well as PPP1R13B, which induces p53. A damaging nonsynonymous mutation was noted in EP300, a histone acetylase which plays a role in cellular proliferation. This study provides the first insights into the genetic underpinnings of this cancer. Future large-scale efforts will be necessary to define the mutational landscape of salivary gland malignancies to identify therapeutic targets and biomarkers of treatment failure

Rodent control to fight plague : field assessment of methods based on rat density reduction

Research funding: Directorate General for International Relations and Strategy. Grant Number: 2018‐SB‐024‐18SSEOC049‐PMG7‐SSA5‐IPMMADAGASCAR ACKNOWLEDGMENTS: We are especially grateful to the health authorities and the population in Miantso and Ankazobe for allowing us to do this work and being so helpful. We thank the staff of the Plague Unit, Institut Pasteur de Madagascar, for helping with the field and laboratory work, especially Alain Berthin Rakotoarisoa and Andrianiaina Parfait Rakotonindrainy. This work was supported by a Directorate General for International Relations and Strategy grant (2018‐SB‐024‐18SSEOC049‐PMG7‐SSA5‐IPMMADAGASCAR) covering the project “Développement de contre‐mesures médicales à la peste à Madagascar” with scientific support of IRBA (French Armed Forces Biomedical Research Institute), within the framework of French MoD's involvement in G7 Global partnership. The French Agency for International Technical Expertise (AFETI) ensures the proper financial execution of the project and contributes to the implementation of cooperation actions under the control of the Directorate General for International Relations and Strategy. This research was also funded in part by the Wellcome Trust [095171/Z/10/Z] and the Institut Pasteur de Madagascar. For the purpose of Open Access, the authors have applied a CC BY public copyright license to any Author Accepted Manuscript version arising from this submission. K.S. was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) under the EastBio DTP (grant number BB/M010996/1).Peer reviewedPublisher PD