59 research outputs found
Computational fluid dynamics modelling of pumonary airflow in varanid lizards
Understanding the biomechanical basis of undirectional pulmonary airflow, a condition where lung gases travel in the one direction through most of the airways and throughout the respiratory cycle, has long been of interest to scientists. Recent work has revealed a wide phylogenic distribution of this trait, beyond the confines of Aves, to include crocodilians, green goannas and monitor lizards. Advances in computational fluid dynamics, a technique where patterns of flow are simulated from prescribed boundary conditions by laws of fluid motions, provide a powerful tool to study airflow through these complex and fascinating structures. Australian monitor lizards (varanidae) are a promising group to investigate the significance of these lung traits because their adaptive radiation crosses many ecological [unreadable] with a similar body plan. Computed tomography scans of varanid species being made and segmented into a detailed computational meshes, representing the major and minor airways as has already been done for the savannah monitor, Varanus exanthematicus. Flow patterns are simulated through these airways in two ways on a high performance computing cluster using dynamic and static OpenFOAM solvers and visualized using ParaView
Relative value of ruminally degradable and undegradable protein on the utilization of low-quality prairie hay by steers
An experiment was performed to investigate
the impact of providing six levels of ruminally degradable protein (RDP; protein that is available to ruminal microbes) in combination with two levels of ruminally undegradable protein (RUP; protein that is not available to the ruminal microbes, but can be digested directly by cattle) on the intake and digestion of low-quality prairie hay. Twelve steers were provided unlimited access to low-quality prairie hay (5.3% crude protein and 71.7% neutral detergent fiber) throughout the trial. To simulate
dietary RUP, casein was infused abomasally
once daily at either 0 or 0.087% of body
weight. To simulate dietary RDP, casein was
infused ruminally once daily at 0, 0.029,
0.058, 0.087, 0.116, or 0.145% of body weight. As provision of RDP increased, forage
intake and fiber digestion increased. Supplementing with RUP alone increased forage
intake but not fiber digestion, although the
intake response was not as large as providing
the same amount of RDP. In conclusion, RUP
is less efficient than RDP in stimulating forage intake and digestion
Human Rights and the Pink Tide in Latin America : Which Rights Matter?
Latin America witnessed the election of ‘new Left’ governments in the early 21 st century that, in different ways, sought to open a debate about alternatives to paradigms of neoliberal development. What has this meant for the way that human rights are understood and for patterns of human rights compliance? Using qualitative and quantitative evidence, this article discusses how human rights are imagined and the compliance records of new Left governments through the lens of the three ‘generations’ of human rights — political and civil, social and economic, and cultural and environmental rights. The authors draw in particular on evidence from Andean countries and the Southern Cone. While basic civil and individual liberties are still far from guaranteed, especially in the Andean region, new Left countries show better overall performances in relation to socio-economic rights compared to the past and to other Latin American countries. All new Left governments also demonstrate an increasing interest in ‘third generation’ (cultural and environmental) rights, though this is especially marked in the Andean Left. The authors discuss the tensions around interpretations and categories of human rights, reflect on the stagnation of first generation rights and note the difficulties associated with translating second and third generation rights into policy
Horizons: nuclear astrophysics in the 2020s and beyond
Nuclear astrophysics is a field at the intersection of nuclear physics and astrophysics, which seeks to understand the nuclear engines of astronomical objects and the origin of the chemical elements. This white paper summarizes progress and status of the field, the new open questions that have emerged, and the tremendous scientific opportunities that have opened up with major advances in capabilities across an ever growing number of disciplines and subfields that need to be integrated. We take a holistic view of the field discussing the unique challenges and opportunities in nuclear astrophysics in regards to science, diversity, education, and the interdisciplinarity and breadth of the field. Clearly nuclear astrophysics is a dynamic field with a bright future that is entering a new era of discovery opportunities
AgBioData consortium recommendations for sustainable genomics and genetics databases for agriculture
The future of agricultural research depends on data. The sheer volume of agricultural biological data being produced today makes excellent data management essential. Governmental agencies, publishers and science funders require data management plans for publicly funded research. Furthermore, the value of data increases exponentially when they are properly stored, described, integrated and shared, so that they can be easily utilized in future analyses. AgBioData (https://www.agbiodata.org) is a consortium of people working at agricultural biological databases, data archives and knowledgbases who strive to identify common issues in database development, curation and management, with the goal of creating database products that are more Findable, Accessible, Interoperable and Reusable. We strive to promote authentic, detailed, accurate and explicit communication between all parties involved in scientific data. As a step toward this goal, we present the current state of biocuration, ontologies, metadata and persistence, database platforms, programmatic (machine) access to data, communication and sustainability with regard to data curation. Each section describes challenges and opportunities for these topics, along with recommendations and best practices
Determining the influence of different levels of urea supplementation when beef cows grazing winter pasture are supplemented at different frequencies during the prepartum period
One hundred sixty spring-calving
Hereford × Angus cows grazing low-quality,
tallgrass-prairie range during the
winter of 2000-2001 were supplemented
before calving either daily or three times
weekly. The supplement contained 40%
CP with 0, 15, 30, or 45% of the
supplemental degradable intake protein
from urea. Supplement was fed at 4
lbs/head daily to cows receiving
supplement daily. Cows receiving
supplement three times weekly were fed
the same amount of weekly supplement,
but split equally among their
supplementation events. After calving, all
cows received a supplement without urea
on a daily basis. In general, prepartum
supplements that contained more urea
prompted greater body weight loss;
however, the effect of increasing urea was
most noticeable when supplements were
fed only three times weekly. When
averaged across supplementation
frequencies, increasing the level of
supplemental urea tended (P=0.15) to
decrease pregnancy rate in beef cows that
had received urea supplementation before
calving
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