University of Maine

About: University of Maine is a education organization based out in Orono, Maine, United States. It is known for research contribution in the topics: Population & Ice sheet. The organization has 8637 authors who have published 16932 publications receiving 590124 citations. The organization is also known as: University of Maine at Orono.

The BIEN R package: A tool to access the Botanical Information and Ecology Network (BIEN) database

Abstract: There is an urgent need for large-scale botanical data to improve our understanding of community assembly, coexistence, biogeography, evolution, and many other fundamental biological processes. Understanding these processes is critical for predicting and handling human-biodiversity interactions and global change dynamics such as food and energy security, ecosystem services, climate change, and species invasions. The Botanical Information and Ecology Network (BIEN) database comprises an unprecedented wealth of cleaned and standardised botanical data, containing roughly 81 million occurrence records from c. 375,000 species, c. 915,000 trait observations across 28 traits from c. 93,000 species, and co-occurrence records from 110,000 ecological plots globally, as well as 100,000 range maps and 100 replicated phylogenies (each containing 81,274 species) for New World species. Here, we describe an r package that provides easy access to these data. The bien r package allows users to access the multiple types of data in the BIEN database. Functions in this package query the BIEN database by turning user inputs into optimised PostgreSQL functions. Function names follow a convention designed to make it easy to understand what each function does. We have also developed a protocol for providing customised citations and herbarium acknowledgements for data downloaded through the bien r package. The development of the BIEN database represents a significant achievement in biological data integration, cleaning and standardization. Likewise, the bien r package represents an important tool for open science that makes the BIEN database freely and easily accessible to everyone.

Chronic renal failure among farm families in cascade irrigation systems in Sri Lanka associated with elevated dietary cadmium levels in rice and freshwater fish ( Tilapia )

Abstract: Chronic renal failure (CRF), in the main agricultural region under reservoir based cascade irrigation in Sri Lanka has reached crisis proportion Over 5,000 patients in the region are under treatment for CRF The objective of this study is to establish the etiology of the CRF Concentrations of nine heavy metals were determined in sediments, soils of reservoir peripheries, water and Nelumbo nucifera (lotus) grown in five major reservoirs that supply irrigation water All five reservoirs carried higher levels of dissolved cadmium (Cd), iron (Fe) and lead (Pb) Dissolved Cd in reservoir water ranged from 003 to 006 mg/l Sediment Cd concentration was 178–245 mg/kg No arsenic (As) was detected Cd content in lotus rhizomes was 25382 mg/kg The Provisional Tolerable Weekly Intake (PTWI) of Cd based on extreme exposure of rice is 8702–15927 μg/kg body weight (BW) for different age groups, 5–50 years The PTWI of Cd due to extreme exposure of fish is 6773–12469 μg/kg BW The PTWI on a rice staple with fish is 15475–28396 μg/kg BW The mean urinary cadmium (UCd) concentration in CRF patients of age group 40–60 years was 758 μg Cd/g creatinine and in asymptomatic persons UCd was 1162 μg Cd/g creatinine, indicating a chronic exposure to Cd The possible source of Cd in reservoir sediments and water is Cd-contaminated agrochemicals The CRF prevalent in north central Sri Lanka is a result of chronic dietary intake of Cd, supported by high natural levels of fluoride in drinking water, coupled with neglecting of routine de-silting of reservoirs for the past 20 years

Temperature sensitivity of soil enzyme kinetics under N-fertilization in two temperate forests

Abstract: Soil microbes produce extracellular enzymes that degrade carbon (C)-containing polymers in soil organic matter. Because extracellular enzyme activities may be sensitive to both increased nitrogen (N) and temperature change, we measured the effect of long-term N addition and short-term temperature variation on enzyme kinetics in soils from hardwood forests at Bear Brook, Maine, and Fernow Forest, West Virginia. We determined the Vmax and Km parameters for five hydrolytic enzymes: a-glucosidase, b-glucosidase, b-xylosidase, cellobiohydrolase, and N-acetyl-glucosaminidase. Temperature sensitivities of Vmax and Km were assessed within soil samples subjected to a range of temperatures. We hypothesized that (1) N additions would cause microbial C limitation, leading to higher enzyme Vmax values and lower Km values; and (2) both Vmax and Km would increase at higher temperatures. Finally, we tested whether or not temperature sensitivity of enzyme kinetics is mediated by N addition. Nitrogen addition significantly or marginally significantly increased Vmax values for all enzymes, particularly at Fernow. Nitrogen fertilization led to significantly lower Km values for all enzymes at Bear Brook, but variable Km responses at Fernow Forest. Both Vmax and Km were temperature sensitive, with Q10 values ranging from 1.64–2.27 for enzyme Vmax and 1.04–1.93 for enzyme Km. No enzyme showed a significant interaction between N and temperature sensitivity for Vmax, and only b-xylosidase showed a significant interaction between N and temperature sensitivity for Km. Our study is the first to experimentally demonstrate a positive relationship between Km and temperature for soil enzymes. Higher temperature sensitivities for Vmax relative to Km imply that substrate degradation will increase with temperature. In addition, the Vmax and Km responses to N indicate greater substrate degradation under N addition. Our results suggest that increasing temperatures and N availability in forests of the northeastern US will lead to increased hydrolytic enzyme activity, despite the positive temperature sensitivity of Km.