Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 53491 - 53520 of 294392

Full-Text Articles in Physical Sciences and Mathematics

Do Pharmaceuticals In The Environment Pose A Risk To Wildlife?, Thomas G. Bean, Elizabeth A. Chadwick, Marta Herrero‐Villar, Rafael Mateo, Vinny Naidoo, Barnett A. Rattner Nov 2022

Do Pharmaceuticals In The Environment Pose A Risk To Wildlife?, Thomas G. Bean, Elizabeth A. Chadwick, Marta Herrero‐Villar, Rafael Mateo, Vinny Naidoo, Barnett A. Rattner

United States Geological Survey: Staff Publications

The vast majority of knowledge related to the question “To what extent do pharmaceuticals in the environment pose a risk to wildlife?” stems from the Asian vulture crisis (>99% decline of some species of Old World vultures on the Indian subcontinent related to the veterinary use of the nonsteroidal anti‐inflammatory drug [NSAID] diclofenac). The hazard of diclofenac and other NSAIDs (carprofen, flunixin, ketoprofen, nimesulide, phenylbutazone) to vultures and other avian species has since been demonstrated; indeed, only meloxicam and tolfenamic acid have been found to be vulture‐safe. Since diclofenac was approved for veterinary use in Spain and Italy in …


Minimizers Of Nonlocal Polyconvex Energies In Nonlocal Hyperelasticity, José C. Bellido, Javier Cueto, Carlos Mora-Corral Nov 2022

Minimizers Of Nonlocal Polyconvex Energies In Nonlocal Hyperelasticity, José C. Bellido, Javier Cueto, Carlos Mora-Corral

Department of Mathematics: Faculty Publications

We develop a theory of existence of minimizers of energy functionals in vectorial problems based on a nonlocal gradient under Dirichlet boundary conditions. The model shares many features with the peridynamics model and is also applicable to nonlocal solid mechanics, especially nonlinear elasticity. This nonlocal gradient was introduced in an earlier work, inspired by Riesz’ fractional gradient, but suitable for bounded domains. The main assumption on the integrand of the energy is polyconvexity. Thus, we adapt the corresponding results of the classical case to this nonlocal context, notably, Piola’s identity, the integration by parts of the determinant and the weak …


Music Genre Classification By Convolutional Neural Networks, Usame Suud Nov 2022

Music Genre Classification By Convolutional Neural Networks, Usame Suud

Mathematics & Statistics ETDs

In today’s world, deep learning models are widely used in a variety of fields. Audio

applications include speech recognition, audio classification, and music information

retrieval. In this paper, we will focus on the classification of music genres using an

artificial neural network. The development of audio machine learning techniques has

created an independence from traditional, more time-consuming signal processing

techniques. Starting with raw audio data, we will gain an understanding of what

audio is and its digital representation. Then, the focus will be on obtaining frequency

information from audio signals through the use of spectrograms. Transforming the

spectrograms into the …


Open-Source Clinical Machine Learning Models: Critical Appraisal Of Feasibility, Advantages, And Challenges, Keerthi B. Harish, W. Nicholson Price Ii, Yindalon Aphinyanaphongs Nov 2022

Open-Source Clinical Machine Learning Models: Critical Appraisal Of Feasibility, Advantages, And Challenges, Keerthi B. Harish, W. Nicholson Price Ii, Yindalon Aphinyanaphongs

Articles

Machine learning applications promise to augment clinical capabilities and at least 64 models have already been approved by the US Food and Drug Administration. These tools are developed, shared, and used in an environment in which regulations and market forces remain immature. An important consideration when evaluating this environment is the introduction of open-source solutions in which innovations are freely shared; such solutions have long been a facet of digital culture. We discuss the feasibility and implications of open-source machine learning in a health care infrastructure built upon proprietary information. The decreased cost of development as compared to drugs and …


Spectroscopic Study Of The Br−+Ch3i→I−+Ch3br Sn2 Reaction, Hayden T. Robinson, Timothy R. Corkish, Christian T. Haakansson, Peter D. Watson, Allan J. Mckinley, Duncan A. Wild Nov 2022

Spectroscopic Study Of The Br−+Ch3i→I−+Ch3br Sn2 Reaction, Hayden T. Robinson, Timothy R. Corkish, Christian T. Haakansson, Peter D. Watson, Allan J. Mckinley, Duncan A. Wild

Research outputs 2022 to 2026

Mass spectrometry and anion photoelectron spectroscopy have been used to study the gas-phase SN2 reaction involving Br- and CH3I. The anion photoelectron spectra associated with the reaction intermediates of this SN2 reaction are presented. High-level CCSD(T) calculations have been utilised to investigate the reaction intermediates that may form as a result of the SN2 reaction along various different reaction pathways, including back-side attack and front-side attack. In addition, simulated vertical detachment energies of each reaction intermediate have been calculated to rationalise the photoelectron spectra.


Adoption Of Brachiaria Grasses In Mexico And Central America: A Successful Story, F. Holmann, Pedro Argel, C. E. Lascano Nov 2022

Adoption Of Brachiaria Grasses In Mexico And Central America: A Successful Story, F. Holmann, Pedro Argel, C. E. Lascano

IGC Proceedings (1977-2023)

In Latin America and the Caribbean (LAC) there has been a major effort to develop new pastures technologies, to increase livestock productivity for the extensive systems prevailing in the tropical lowlands. This multi-national and inter-institutional effort was initiated through the International Network for the Evaluation of Tropical Pastures (RIEPT, by its name in Spanish), which operated from 1976 to 1996 under CIAT leadership. This network became a platform for institutions to train technicians, share forage material from existing gene banks, study the behaviour of new germplasm under different environments, and established the exchange of scientific information to extrapolate research results …


Improved Livelihoods From Grasslands; The Case Of Napier Grass In Smallholder Dairy Farms In Kenya, David Miano Mwangi, D. Romney, S. Staal, I. Baltenweck, S. Mwendia Nov 2022

Improved Livelihoods From Grasslands; The Case Of Napier Grass In Smallholder Dairy Farms In Kenya, David Miano Mwangi, D. Romney, S. Staal, I. Baltenweck, S. Mwendia

IGC Proceedings (1977-2023)

In Kenya, smallholder farmers produce about 80% of the marketed milk. The farming systems vary from mixed farms with up to 10 ha of land and < 10 dairy cows (Gitau et al., 1994; Anon., 1985), to intensive smallholder dairy producers in the high human population central Kenya region with 0.9 to 2 ha of land and 3-4 dairy cows (Staal et al., 2001a). Milk production depends heavily on the cultivation of forages, with Pennisetum purpureum (Napier grass) by far the most important. An estimated 350,000 of the 600,000 smallholder farms in Kenya grow and utilize P. purpureum on their farms.

There are …


One Iteration For The Second Boundary Condition For The Nonlinear One Dimensional Monge-Ampere Equation, Gerard Awanou Nov 2022

One Iteration For The Second Boundary Condition For The Nonlinear One Dimensional Monge-Ampere Equation, Gerard Awanou

Mathematics Colloquium Series

The design of lenses and mirrors, in free form i.e. with no a priori symmetry assumption, has a long list of applications including materials processing, energy concentrators, medicine, antennas, computing lithography, laser weapons, optical data storage, imaging etc. The design process can be reduced to solving a generalized Monge-Ampere equation where the unknown is a function with a convexity property and subject to a constraint that a generalized gradient maps a given domain onto a prescribed one. The latter type of constraint is known as second boundary condition. The model one dimensional Monge-Ampere equation is nonlinear in the first order …


Role Of Information And Information Providers In Technology Transfer, D. Undersander Nov 2022

Role Of Information And Information Providers In Technology Transfer, D. Undersander

IGC Proceedings (1977-2023)

Technology transfer is an essential component of economic change in society. Developers of new technology often fail to realize that there is a science to technology transfer. This lack of appreciation for the skills involved in information dissemination and in activities necessary to affect a change of action in an audience often severely limits the rate and amount of technology transfer that occurs. Significant differences exist between doing a news release or writing a publication and causing audience acceptance of a new technology. The old standards of expecting adoption of a new technology simply because it “will profit farmers” or …


The Contribution Of Participatory Research: On-Farm Research, P. F. Fennessy, N. J. Daniels, S. A. Chadwick, P. A. Speck Nov 2022

The Contribution Of Participatory Research: On-Farm Research, P. F. Fennessy, N. J. Daniels, S. A. Chadwick, P. A. Speck

IGC Proceedings (1977-2023)

Participatory research in agriculture may range from research and technology development (R&D), carried out on a research station with some involvement of farmers, through to genuine participatory research involving researchers and farmers working together. The latter involves the end-user in actually carrying out aspects of the research and/or in the development and evaluation of technology that is appropriate to commercial enterprises. Researchers often question the validity of the ‘findings of on-farm participatory research’ as they are more comfortable with the ‘controlled’ environment of the research station. However if research is to be applied appropriately on farms, it must go through …


Participatory Research For Smallholder Livestock Systems: Applying Common Sense To Complex Problems, P. M. Horne, Werner Stür Nov 2022

Participatory Research For Smallholder Livestock Systems: Applying Common Sense To Complex Problems, P. M. Horne, Werner Stür

IGC Proceedings (1977-2023)

Key Points:

1. Participatory approaches to research (PAR) bring researchers closer to farmers, the intended users of research outputs.

2. Active, functional participation of farmers in the evaluation and development of new technologies requires researchers to make an important commitment: respecting the knowledge, skills and opinions of farmers while maintaining confidence in their own scientific knowledge.

3. Farmer experimentation is not usually suitable to provide quantitative biophysical data (this can be achieved more effectively in researcher controlled experiments), but to provide qualitative information and improve understanding. This type of information can be collected systematically to enable rigorous analysis.

4. While …


Soil Biology And The Emergence Of Adventive Grassland Ecosystems, T. R. Seastedt Nov 2022

Soil Biology And The Emergence Of Adventive Grassland Ecosystems, T. R. Seastedt

IGC Proceedings (1977-2023)

The last few years have seen an explosion of information on the responses and feedbacks of soil biota to species and environmental changes. Soil biologists, plant ecologists, and biogeochemists have been searching for patterns, generality and predictability in these relationships. A few brave souls have had the courage to assemble comprehensive assessments of soil biology in our rapidly changing world. Several years ago, I reviewed Wardle’s (2002) book emphasising the links between above- and belowground components of ecosystems. That activity – as well as the present one – provided me with the opportunity to survey recent findings in soil biology. …


Computer-Based Forage Management Tools: Historical, Current, And Future Applications, David B. Hannaway, C. Daly, D. F. Chapman, B. B. Baker, A. S. Cooper Nov 2022

Computer-Based Forage Management Tools: Historical, Current, And Future Applications, David B. Hannaway, C. Daly, D. F. Chapman, B. B. Baker, A. S. Cooper

IGC Proceedings (1977-2023)

Forage management has been an important human activity since the beginning of civilization. By comparison, the personal computer has been available only in the immediate past. The software developed to deal with the complexity of climate, soil, plant, animal, and socioeconomic factors has seen huge changes in a few decades. Mainframe computers facilitated numerical calculations for exploring relationships among dozens of variables. Personal computers opened the door for more individual scientist creativity and routine communication. Web-based communication globalised the option for multidisciplinary teams to tackle problems. Forage-related computer applications abound, allowing farmers, ranchers, and others to more effectively manage the …


Paying For Our Keep: Grasslands Decision Support In More-Developed Countries, Andrew D. Moore Nov 2022

Paying For Our Keep: Grasslands Decision Support In More-Developed Countries, Andrew D. Moore

IGC Proceedings (1977-2023)

“Models in grassland science have come to stay, and so they must be made to pay for their keep. To do that, it will be necessary to improve their scientific sophistication and their management relevance...” (Seligman, 1993).

Decision support (DS) tools in grassland agriculture have also come to stay. This review will examine the ways and means by which DS tools are being made to pay for their keep, with a focus upon DS efforts from the last decade and on the lessons that arise for those who develop DS tools for grasslands. A survey of the present state of …


Ferrocenium Salt Aided Substitution Reactions And Synthesis Of Glycosylated Curcumin Derivatives, Deva Saroja Talasila Nov 2022

Ferrocenium Salt Aided Substitution Reactions And Synthesis Of Glycosylated Curcumin Derivatives, Deva Saroja Talasila

Dissertations

Organic synthesis has been significantly advanced with the employment of transition metal complexes. The discovery of transition metal catalysts provided the synthetic community with powerful tools for accelerating reactions and making them more selective and efficient. Many chemical reactions do not happen without a catalyst.

Iron-based catalysts have several advantages for the chemical industry because it is a non-toxic and ecologically friendly metal. Our group previously found that ferrocenium cations with a 3+ oxidation state of iron-catalyzed propargylic substitution reactions at low temperatures. The sandwich structure of ferrocenes allows substituents to be introduced on the cyclopentadienyl rings, which allows for …


A 14,100 Cal B. P. Rocky Mountain Locust Cache From Winnemucca Lake, Pershing County, Nevada, Evan J. Pellegrini, Eugene M. Hattori, Larry Benson, John Southon, Hojun Song, Derek A. Woller Nov 2022

A 14,100 Cal B. P. Rocky Mountain Locust Cache From Winnemucca Lake, Pershing County, Nevada, Evan J. Pellegrini, Eugene M. Hattori, Larry Benson, John Southon, Hojun Song, Derek A. Woller

United States Geological Survey: Staff Publications

The remains of approximately 1000 (MNI) Rocky Mountain locusts (Melanoplus spretus) from an archaeological cache pit in Crypt Cave, Winnemucca (dry) Lake, Nevada, date to between 14,305–14,067 calendar years before present (95.4 % confidence; 12,238 ± 18 14C yrs. B.P.). The age of this western Great Basin occupation along the shoreline of Lake Lahontan is consistent with occupation of several other Western North American terminal Pleistocene sites dating prior to 14,000 cal. B.P., including distinctive petroglyphs on the western shore of Winnemucca Lake dating as early as 14,800–13,200 cal. B.P.


Mgrre_Thinsections_Mgrre-04_19, Mgrre Nov 2022

Mgrre_Thinsections_Mgrre-04_19, Mgrre

Thin Sections

No abstract provided.


2022 November 3 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University Nov 2022

2022 November 3 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.


Mgrre_Thinsections_05_A_70, Mgrre Nov 2022

Mgrre_Thinsections_05_A_70, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-04_10, Mgrre Nov 2022

Mgrre_Thinsections_Mgrre-04_10, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-04_11, Mgrre Nov 2022

Mgrre_Thinsections_Mgrre-04_11, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-04_12, Mgrre Nov 2022

Mgrre_Thinsections_Mgrre-04_12, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-04_13, Mgrre Nov 2022

Mgrre_Thinsections_Mgrre-04_13, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-04_14, Mgrre Nov 2022

Mgrre_Thinsections_Mgrre-04_14, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-04_15, Mgrre Nov 2022

Mgrre_Thinsections_Mgrre-04_15, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-04_16, Mgrre Nov 2022

Mgrre_Thinsections_Mgrre-04_16, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-04_17, Mgrre Nov 2022

Mgrre_Thinsections_Mgrre-04_17, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-04_18, Mgrre Nov 2022

Mgrre_Thinsections_Mgrre-04_18, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-04_20, Mgrre Nov 2022

Mgrre_Thinsections_Mgrre-04_20, Mgrre

Thin Sections

No abstract provided.


Erm Corrective Action Response, Elsie King Nov 2022

Erm Corrective Action Response, Elsie King

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.