15 research outputs found
CATMoS: Collaborative Acute Toxicity Modeling Suite.
BACKGROUND: Humans are exposed to tens of thousands of chemical substances that need to be assessed for their potential toxicity. Acute systemic toxicity testing serves as the basis for regulatory hazard classification, labeling, and risk management. However, it is cost- and time-prohibitive to evaluate all new and existing chemicals using traditional rodent acute toxicity tests. In silico models built using existing data facilitate rapid acute toxicity predictions without using animals. OBJECTIVES: The U.S. Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) Acute Toxicity Workgroup organized an international collaboration to develop in silico models for predicting acute oral toxicity based on five different end points: Lethal Dose 50 (LD50 value, U.S. Environmental Protection Agency hazard (four) categories, Globally Harmonized System for Classification and Labeling hazard (five) categories, very toxic chemicals [LD50 (LD50≤50mg/kg)], and nontoxic chemicals (LD50>2,000mg/kg). METHODS: An acute oral toxicity data inventory for 11,992 chemicals was compiled, split into training and evaluation sets, and made available to 35 participating international research groups that submitted a total of 139 predictive models. Predictions that fell within the applicability domains of the submitted models were evaluated using external validation sets. These were then combined into consensus models to leverage strengths of individual approaches. RESULTS: The resulting consensus predictions, which leverage the collective strengths of each individual model, form the Collaborative Acute Toxicity Modeling Suite (CATMoS). CATMoS demonstrated high performance in terms of accuracy and robustness when compared with in vivo results. DISCUSSION: CATMoS is being evaluated by regulatory agencies for its utility and applicability as a potential replacement for in vivo rat acute oral toxicity studies. CATMoS predictions for more than 800,000 chemicals have been made available via the National Toxicology Program's Integrated Chemical Environment tools and data sets (ice.ntp.niehs.nih.gov). The models are also implemented in a free, standalone, open-source tool, OPERA, which allows predictions of new and untested chemicals to be made. https://doi.org/10.1289/EHP8495
Recommended from our members
Western Land Managers will Need all Available Tools for Adapting to Climate Change, Including Grazing: A Critique of Beschta et al.
In a previous article, Beschta et al. (Environ
Manag 51(2):474–491, 2013) argue that grazing by large
ungulates (both native and domestic) should be eliminated
or greatly reduced on western public lands to reduce
potential climate change impacts. The authors did not
present a balanced synthesis of the scientific literature, and
their publication is more of an opinion article. Their conclusions
do not reflect the complexities associated with
herbivore grazing. Because grazing is a complex ecological process, synthesis of the scientific literature can be a
challenge. Legacy effects of uncontrolled grazing during
the homestead era further complicate analysis of current
grazing impacts. Interactions of climate change and grazing
will depend on the specific situation. For example,
increasing atmospheric CO₂ and temperatures may increase
accumulation of fine fuels (primarily grasses) and thus
increase wildfire risk. Prescribed grazing by livestock is
one of the few management tools available for reducing
fine fuel accumulation. While there are certainly points on
the landscape where herbivore impacts can be identified, there are also vast grazed areas where impacts are minimal.
Broad scale reduction of domestic and wild herbivores to
help native plant communities cope with climate change
will be unnecessary because over the past 20–50 years land
managers have actively sought to bring populations of
native and domestic herbivores in balance with the potential
of vegetation and soils. To cope with a changing climate,
land managers will need access to all available
vegetation management tools, including grazing.Keywords: Grazing, Riparian areas, Public lands, Climate chang
Parâmetros reprodutivos e produtivos em vacas leiteiras de manejo free stall
Resumo Avaliou-se parâmetros reprodutivos e produtivos em vacas da raça Holandês-PB no pós-parto imediato, manejadas em free stall . Utilizou-se 51 vacas entre primíparas e pluríparas. Os valores obtidos foram: escore de condição corporal ao parto 3,47±0,4; intervalos do parto à primeira ovulação 5,89±3,4 semanas; ao primeiro serviço 112,5±57,0 dias; a taxa de gestação ao primeiro serviço foi 43,6% e no período experimental 76,4%, não sendo observada diferença para ordens de parto (P>0,05). A produção de leite acumulada à concepção, produção diária leite até a concepção e produção de leite ajustado para 305 foi respectivamente, 3.335,6±1.488,4; 25,8±5,4 e 7.424,0±1.877,8 litros. Conclui-se que no manejo de Free stall , a detecção de estro, foi o principal fator limitante para alcançar melhor eficiência reprodutiva
Photo Monitoring for Ranchers Field Guide
This condensed version of PNW 671, Photo Monitoring for Ranchers Technical Guide, contains pointers and suggestions for photo monitoring. Side 2 serves as a photo board template
Photo Monitoring for Ranchers Technical Guide
Get started with photo monitoring of rangelands with this 8-step guide covering equipment, photo timing, site selection and identification, photography and photo boards, field notes, and photo storage
\u3ci\u3eGaman:\u3c/i\u3e “Enduring the Seemingly Unbearable with Dignity”
When considering the process of becoming American, Professor Sumer Seiki has a personal story that reveals the perseverance of four Japanese-American paternal generations that have endured a harrowing journey to become American. Through collaborative methods, participant-observation, ethnographic interviewing, and academic research, this poster provides insight into the lives of Japanese-Americans from the 1880’s to present day. It specifically highlights the hardships that Professor Seiki’s family faced when they were forced into an internment camp in Arizona during WWII. This poster examines and explains how the experiences of Professor Seiki’s great-grandfather, grandfather, and father have shaped her identity and how she understands her American citizenship. It additionally exposes the idea of how family and the determination to improve the quality of life for one’s family persists over all else