Circadian rhythms have significant effects on leaf-to-canopy scale gas exchange under field conditions

Background Molecular clocks drive oscillations in leaf photosynthesis, stomatal conductance, and other cell and leaf-level processes over ~24 h under controlled laboratory conditions. The influence of such circadian regulation over whole-canopy fluxes remains uncertain; diurnal CO2 and H2O vapor flux dynamics in the field are currently interpreted as resulting almost exclusively from direct physiological responses to variations in light, temperature and other environmental factors. We tested whether circadian regulation would affect plant and canopy gas exchange at the Montpellier European Ecotron. Canopy and leaf-level fluxes were constantly monitored under field-like environmental conditions, and under constant environmental conditions (no variation in temperature, radiation, or other environmental cues). Results We show direct experimental evidence at canopy scales of the circadian regulation of daytime gas exchange: 20–79 % of the daily variation range in CO2 and H2O fluxes occurred under circadian entrainment in canopies of an annual herb (bean) and of a perennial shrub (cotton). We also observed that considering circadian regulation improved performance by 8–17 % in commonly used stomatal conductance models. Conclusions Our results show that circadian controls affect diurnal CO2 and H2O flux patterns in entire canopies in field-like conditions, and its consideration significantly improves model performance. Circadian controls act as a ‘memory’ of the past conditions experienced by the plant, which synchronizes metabolism across entire plant canopies

Global, regional, and national age-sex-specific mortality for 282 causes of death in 195 countries and territories, 1980-2017: a systematic analysis for the Global Burden of Disease Study 2017.

BACKGROUND: Global development goals increasingly rely on country-specific estimates for benchmarking a nation's progress. To meet this need, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 estimated global, regional, national, and, for selected locations, subnational cause-specific mortality beginning in the year 1980. Here we report an update to that study, making use of newly available data and improved methods. GBD 2017 provides a comprehensive assessment of cause-specific mortality for 282 causes in 195 countries and territories from 1980 to 2017. METHODS: The causes of death database is composed of vital registration (VR), verbal autopsy (VA), registry, survey, police, and surveillance data. GBD 2017 added ten VA studies, 127 country-years of VR data, 502 cancer-registry country-years, and an additional surveillance country-year. Expansions of the GBD cause of death hierarchy resulted in 18 additional causes estimated for GBD 2017. Newly available data led to subnational estimates for five additional countries-Ethiopia, Iran, New Zealand, Norway, and Russia. Deaths assigned International Classification of Diseases (ICD) codes for non-specific, implausible, or intermediate causes of death were reassigned to underlying causes by redistribution algorithms that were incorporated into uncertainty estimation. We used statistical modelling tools developed for GBD, including the Cause of Death Ensemble model (CODEm), to generate cause fractions and cause-specific death rates for each location, year, age, and sex. Instead of using UN estimates as in previous versions, GBD 2017 independently estimated population size and fertility rate for all locations. Years of life lost (YLLs) were then calculated as the sum of each death multiplied by the standard life expectancy at each age. All rates reported here are age-standardised

Agricultural exposure and risk of soft tissue sarcomas and gastrointestinal stromal sarcoma in the AGRIculture and CANcer (AGRICAN) cohort

BACKGROUND: Sarcomas are a heterogeneous group of tumors whose incidence is nearly 5 per 100 000 inhabitants in Europe. Their causes are poorly understood, although occupational exposures (especially farming and pesticides) are suspected. METHODS: The AGRICAN cohort is a prospective study of 181,842 individuals enrolled in 2005-2007 who completed an enrolment questionnaire with data on lifelong agricultural exposure. Associations between agricultural exposure and sarcoma overall, GIST (gastro-intestinal stromal tumors) and myomatous and fibrous sarcoma together, were analyzed with a Cox model. RESULTS: Until 2015, 188 incident cases of sarcoma were identified. Increased risks were observed (1) among cattle farmers working < 10 years (HR(<10years) =2.45, 95%CI 1.36-4.43) and breeding ≥ 50 livestock (HR(≥50 animals) =3.84, 95%CI 1.60-9.22), especially if involved in animal care and building disinfection, (2) in greenhouse production (HR=1.82, 95%CI 1.01-3.30), and (3) in field-grown vegetable production (HR=1.49, 95%CI 0.96-2.32). Concerning histological subtypes, GIST were positively associated with pesticide use in vineyards (HR=2.24, 95%CI 0.95-5.30). For myomatous and fibrous sarcoma, the only increase was seen in field-grown vegetable production (HR=2.37, 95%CI 1.16-4.85). CONCLUSION: In AGRICAN, the risk of sarcomas was increased in several farming activities with differences according to histological subtype

Int J Epidemiol

Background: Pesticide exposures are suspected to be implicated in the excess of central nervous system (CNS) tumours observed in farmers, but evidence concerning individual pesticides remains limited. Carbamate insecticides, used on a wide range of crops, have shown evidence of carcinogenicity in some experimental studies. In the cohort AGRICAN (AGRIculture & CANcer), we assessed the associations between potential exposures to carbamate insecticides and the incidence of CNS tumours, overall and by histological subtype. Methods: AGRICAN enrolled 181 842 participants involved in agriculture. Incident CNS tumours were identified by linkage with cancer registries from enrolment (2005-07) until 2013. Carbamate exposure was assessed by combining information on lifetime periods of pesticide use on crop or livestock and the French crop-exposure matrix PESTIMAT, individually for each of the 19 carbamate insecticides registered in France since 1950. Associations were estimated using proportional hazards models with age as the underlying time scale, adjusting for gender, educational level and smoking. Results: During a 6.9-year average follow-up, 381 incident cases of CNS tumours occurred, including 164 gliomas and 134 meningiomas. Analyses showed increased risks of CNS tumours with overall exposure to carbamate insecticides and linear trends with duration of use of each carbamate. Considering tumour subtypes, hazard ratios for gliomas ranged from 1.18 for thiofanox to 4.60 for formetanate, and for meningiomas from 1.51 for carbaryl to 3.67 for thiofanox. Conclusions: Findings reinforce carcinogenicity evidence for already suspected active ingredients and draw attention to additional active ingredients, notably used on fruit trees, vineyards, potatoes and beets

Cancer Causes Control

PURPOSE: Epidemiological studies have found an increased risk of multiple myeloma (MM) in farmers. Few studies have investigated the detailed circumstances of occupational pesticide exposure which could explain these increased risks (pesticide use on crops, seeds or on animals, contact with treated crops) and the role of other exposures. In the Agriculture and Cancer cohort (AGRICAN), we assessed the associations between MM and crop- or animal-related activities, with specific attention to pesticide exposure via use on animals and crops or contact with treated crops and to disinfectant exposure. METHODS: Analyses concerned 155,192 participants, including 269 incident MM identified by cancer registries from enrolment (2005-2007) to 2013. Cox models using attained age as time scale were run to calculate hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: MM risk was increased in farmers (i) who started using pesticides on crops in the 1960s, especially among those applying pesticides on corn (>/= 20 years: HR 1.73, 95% CI 1.08, 2.78, p for trend /= 10 years: HR 2.77, 95% CI 1.22-6.27, p for trend = 0.01). We also observed significant elevated risks with disinfectant use in animal barns. CONCLUSIONS: Findings support the role of pesticide use on crops and animals in the occurrence of MM risk in farmers