Microclimate–forage growth linkages across two strongly contrasting precipitation years in a Mediterranean catchment

Given the complex topography of California rangelands, contrasting microclimates affect forage growth at catchment scales. However, documentation of microclimate–forage growth associations is limited, especially in Mediterranean regions experiencing pronounced climate change impacts. To better understand microclimate–forage growth linkages, we monitored forage productivity and root-zone soil temperature and moisture (0–15 and 15–30 cm) in 16 topographic positions in a 10-ha annual grassland catchment in California's Central Coast Range. Data were collected through two strongly contrasting growing seasons, a wet year (2016–17) with 287-mm precipitation and a dry year (2017–18) with 123-mm precipitation. Plant-available soil water storage (0–30 cm) was more than half full for most of the wet year; mean peak standing forage was 2790 kg ha−1 (range: 1597–4570 kg ha−1). The dry year had restricted plant-available water and mean peak standing forage was reduced to 970 kg ha−1 (range: 462–1496 kg ha−1). In the wet year, forage growth appeared energy limited (light and temperature): warmer sites produced more forage across a 3–4°C soil temperature gradient but late season growth was associated with moister sites spanning this energy gradient. In the dry year, the warmest topographic positions produced limited forage across a 10°C soil temperature gradient until late season rainfall in March. Linear models accounting for interactions between soil moisture and temperature explained about half of rapid, springtime forage growth variance. These findings reveal dynamic but clear microclimate–forage growth linkages in complex terrain, and thus, have implications for rangeland drought monitoring and dryland ecosystems modeling under climate change

Association of Serum γ-Tocopherol Levels with Mortality: The Multiethnic Cohort Study

Background/Objectives—γ-Tocopherol has unique properties that protect against nitrogen oxide-mediated cellular damage. To elucidate the potential role of γ-tocopherol in the aging process, we examined the associations of serum γ-tocopherol levels with all-cause and cause-specific mortality. Subjects/Methods—Among participants in the biorepository subcohort of the Multiethnic Cohort Study, pre-cancer diagnostic serum γ-tocopherol levels were measured in a subset of 3904 men and 4461 women. Of these, 22.7% of men and 13.5% of women died during a mean follow- up time of 9.6±2.6 years. Hazard ratios (HRs) and 95% confidence intervals (95%CIs) for mortality associated with γ-tocopherol were estimated by Cox proportional hazards regression. Results—Positive associations of serum γ-tocopherol with all-cause, cancer and cardiovascular disease mortality (CVD) (Ptrend\u3c0.05) were detected after adjusting for age, race-ethnicity and serum cholesterol levels. The respective HRs (95%CIs) for the highest versus the lowest sex- specific γ-tocopherol quartile were 1.43 (1.17–1.74), 1.79 (1.22–2.64), and 1.52 (1.10–2.11) for men and 1.58 (1.25–2.00), 1.59 (1.05–2.41), and 1.59 (1.07–2.37) for women. Associations remained significant for all-cause mortality among women after further adjusting for smoking variables and history of cancer, CVD, diabetes, and hypertension at cohort entry (highest vs. lowest γ-tocopherol quartile: HR=1.38; 95%CI=1.08–1.75; Ptrend= 0.005). Overall, associations with all-cause mortality were consistent across race/ethnicity and were significant in three of ten sex-specific racial/ethnic groups in the fully adjusted models with no interactions between ethnicity and γ-tocopherol. Conclusions—The positive association between γ-tocopherol and mortality suggests a potential physiological role for γ-tocopherol in response to pathological conditions

The neglected social dimensions to a vehicle-to-grid (V2G) transition: a critical and systematic review

Vehicle-to-grid (V2G) refers to efforts to bi-directionally link the electric power system and the transportation system in ways that can improve the sustainability and security of both. A transition to V2G could enable vehicles to simultaneously improve the efficiency (and profitability) of electricity grids, reduce greenhouse gas emissions for transport, accommodate low-carbon sources of energy, and reap cost savings for owners, drivers, and other users. To understand the recent state of this field of research, here we conduct a systematic review of 197 peer-reviewed articles published on V2G from 2015 to early 2017. We find that the majority of V2G studies in that time period focus on technical aspects of V2G, notably renewable energy storage, batteries, or load balancing to minimize electricity costs, in some cases including environmental goals as constraints. A much lower proportion of studies focus on the importance of assessing environmental and climate attributes of a V2G transition, or on the role of consumer acceptance and knowledge of V2G systems. Further, there is need for exploratory work on natural resource use and externalities, discourses and narratives as well as social justice, gender, and urban resilience considerations. These research gaps need to be addressed if V2G is to achieve the societal transition its advocates seek

Temporal and Spatial Patterns of Ambient Endotoxin Concentrations in Fresno, California

BackgroundEndotoxins are found in indoor dust generated by human activity and pets, in soil, and adsorbed onto the surfaces of ambient combustion particles. Endotoxin concentrations have been associated with respiratory symptoms and the risk of atopy and asthma in children.ObjectiveWe characterized the temporal and spatial variability of ambient endotoxin in Fresno/Clovis, California, located in California's Central Valley, to identify correlates and potential predictors of ambient endotoxin concentrations in a cohort of children with asthma [Fresno Asthmatic Children's Environment Study (FACES)].MethodsBetween May 2001 and October 2004, daily ambient endotoxin and air pollutants were collected at the central ambient monitoring site of the California Air Resources Board in Fresno and, for shorter time periods, at 10 schools and indoors and outdoors at 84 residences in the community. Analyses were restricted to May-October, the dry months during which endotoxin concentrations are highest.ResultsDaily endotoxin concentration patterns were determined mainly by meteorologic factors, particularly the degree of air stagnation. Overall concentrations were lowest in areas distant from agricultural activities. Highest concentrations were found in areas immediately downwind from agricultural/pasture land. Among three other measured air pollutants [fine particulate matter, elemental carbon (a marker of traffic in Fresno), and coarse particulate matter (PMc)], PMc was the only pollutant correlated with endotoxin. Endotoxin, however, was the most spatially variable.ConclusionsOur data support the need to evaluate the spatial/temporal variability of endotoxin concentrations, rather than relying on a few measurements made at one location, in studies of exposure and and respiratory health effects, particularly in children with asthma and other chronic respiratory diseases

Virus effects on plant quality and vector behavior are species specific and do not depend on host physiological phenotype

There is growing evidence that plant viruses manipulate host plants to increase transmission-conducive behaviors by vectors. Reports of this phenomenon frequently include only highly susceptible, domesticated annual plants as hosts, which constrains our ability to determine whether virus effects are a component of an adaptive strategy on the part of the pathogen or simply by-products of pathology. Here, we tested the hypothesis that transmission-conducive effects of a virus (Turnip yellows virus [TuYV]) on host palatability and vector behavior (Myzus persicae) are linked with host plant tolerance and physiological phenotype. Our study system consisted of a cultivated crop, false flax (Camelina sativa) (Brassicales: Brassicaceae), a wild congener (C. microcarpa), and a viable F1 hybrid of these two species. We found that the most tolerant host (C. microcarpa) exhibited the most transmission-conducive changes in phenotype relative to mock-inoculated healthy plants: Aphids preferred to settle and feed on TuYV-infected C. microcarpa and did not experience fitness changes due to infection—both of which will increase viruliferous aphid numbers. In contrast, TuYV induced transmission-limiting phenotypes in the least tolerant host (C. sativa) and to a greater degree in the F1 hybrid, which exhibited intermediate tolerance to infection. Our results provide no evidence that virus effects track with infection tolerance or physiological phenotype. Instead, vector preferences and performance are driven by host-specific changes in carbohydrates under TuYV infection. These results provide evidence that induction of transmission-enhancing phenotypes by plant viruses is not simply a by-product of general pathology, as has been proposed as an explanation for putative instances of parasite manipulation by viruses and many other taxa