213 research outputs found
Must Organic certification fundamentally change for an Organic World?
Organic guarantee systems have evolved drastically in the past, accompanying changes in the uptake of Organic agriculture. From an originally fully stakeholder-driven and participatory process in the '70s and '80s, organic certification has become increasingly formalized and government-controlled. organic certification is a must-have for organic market access in more and more countries in the world, but is often not seen by producers to add much value beyond that. It claims to bring transparency and trust to the consumers, but it also delegates the judgment of agricultural practices to more or less anonymous entities. Certification is not designed to prevent fraud but it is expected to control and detect it. Organic certification and regulations are supposed to be tools to develop organic markets but at the same time create barriers to organic trade. Requirements for organic certification are continuously increasing and becoming more complex, yet organic certification is not seen as more reliable than it was a decade ago. Finally, standard setters are torn between the society's expectation that organic certification cover a wider range of sustainability topics, and the fear that more onerous requirements will inhibit conversion to Organic. All these paradoxes are becoming increasingly apparent as the organic movement reflects on how to scale up Organic Agriculture from a niche to the mainstream way of farming
Recommended from our members
Engineering Design Matrix for Carbon Fiber Monocoque Chassis Selection
The Formula Society of Automotive Engineers (FSAE) has provided a platform
for teams like Oregon State’s own Global Formula Racing Team (GFR) to produce a
formula style race car and compete with other schools across the world. The GFR team
has used the same carbon fiber monocoque chassis since the 2010 competition season and
will be designing a new chassis for the 2015 season. In order to select a new chassis there
must be ample research and consideration put into the process. A selection matrix will
provide the GFR team with a quantifiable source of information in order to help with this
design and selection process. The engineering matrix will provide valuable information
for present and future chassis design teams
A Case Study in Analytic Protocol Analysis in ACL2
When verifying computer systems we sometimes want to study their asymptotic
behaviors, i.e., how they behave in the long run. In such cases, we need real
analysis, the area of mathematics that deals with limits and the foundations of
calculus. In a prior work, we used real analysis in ACL2s to study the
asymptotic behavior of the RTO computation, commonly used in congestion control
algorithms across the Internet. One key component in our RTO computation
analysis was proving in ACL2s that for all alpha in [0, 1), the limit as n
approaches infinity of alpha raised to n is zero. Whereas the most obvious
proof strategy involves the logarithm, whose codomain includes irrationals, by
default ACL2 only supports rationals, which forced us to take a non-standard
approach. In this paper, we explore different approaches to proving the above
result in ACL2(r) and ACL2s, from the perspective of a relatively new user to
each. We also contextualize the theorem by showing how it allowed us to prove
important asymptotic properties of the RTO computation. Finally, we discuss
tradeoffs between the various proof strategies and directions for future
research.Comment: In Proceedings ACL2-2023, arXiv:2311.0837
The Impact of Adolescent Chronic Pain on Functioning: Disentangling the Complex Role of Anxiety
A number of adolescents with chronic pain have clinically significant disability across physical, social, and academic activities, and pain severity only explains a portion of the variance in functioning. Thus, it is important to identify therapeutic options to improve adolescents’ functioning. In contrast to studies with adults with chronic pain, research in pediatric pain has not consistently found anxiety to be a good predictor of pain-related disability. The present study evaluated pain, anxiety, and functioning in 222 adolescents with chronic pain. Results indicated that pain was consistently and linearly related to disability across measures of physical and social functioning, school attendance, and physician visits. The relation between anxiety and functioning was complex; increased anxiety was related to poorer physical and social functioning and was related to fewer physician visits, although it was not associated with school attendance. Additional analyses revealed that anxiety serves to moderate the relation between pain and functioning. Specifically, at high anxiety, pain was not related to functioning, but at low anxiety pain consistently predicted disability. In other words, highly anxious adolescents were functioning poorly regardless of the level of pain. The moderating role of anxiety highlights a number of research and clinical possibilities to explore with adolescents with chronic pain-related disability. Data suggest that high anxiety is associated with poor functioning irrespective of pain intensity. At low anxiety, higher pain predicted greater disability. Anxiety is important to assess when investigating potential reasons for pain-related disability
Parameterized Model-Checking for Timed-Systems with Conjunctive Guards (Extended Version)
In this work we extend the Emerson and Kahlon's cutoff theorems for process
skeletons with conjunctive guards to Parameterized Networks of Timed Automata,
i.e. systems obtained by an \emph{apriori} unknown number of Timed Automata
instantiated from a finite set of Timed Automata templates.
In this way we aim at giving a tool to universally verify software systems
where an unknown number of software components (i.e. processes) interact with
continuous time temporal constraints. It is often the case, indeed, that
distributed algorithms show an heterogeneous nature, combining dynamic aspects
with real-time aspects. In the paper we will also show how to model check a
protocol that uses special variables storing identifiers of the participating
processes (i.e. PIDs) in Timed Automata with conjunctive guards. This is
non-trivial, since solutions to the parameterized verification problem often
relies on the processes to be symmetric, i.e. indistinguishable. On the other
side, many popular distributed algorithms make use of PIDs and thus cannot
directly apply those solutions
Proving acceptability properties of relaxed nondeterministic approximate programs
Approximate program transformations such as skipping tasks [29, 30], loop perforation [21, 22, 35], reduction sampling [38], multiple selectable implementations [3, 4, 16, 38], dynamic knobs [16], synchronization elimination [20, 32], approximate function memoization [11],and approximate data types [34] produce programs that can execute at a variety of points in an underlying performance versus accuracy tradeoff space. These transformed programs have the ability to trade accuracy of their results for increased performance by dynamically and nondeterministically modifying variables that control their execution.
We call such transformed programs relaxed programs because they have been extended with additional nondeterminism to relax their semantics and enable greater flexibility in their execution.
We present language constructs for developing and specifying relaxed programs. We also present proof rules for reasoning about properties [28] which the program must satisfy to be acceptable. Our proof rules work with two kinds of acceptability properties: acceptability properties [28], which characterize desired relationships between the values of variables in the original and relaxed programs, and unary acceptability properties, which involve values only from a single (original or relaxed) program. The proof rules support a staged reasoning approach in which the majority of the reasoning effort works with the original program. Exploiting the common structure that the original and relaxed programs share, relational reasoning transfers reasoning effort from the original program to prove properties of the relaxed program.
We have formalized the dynamic semantics of our target programming language and the proof rules in Coq and verified that the proof rules are sound with respect to the dynamic semantics. Our Coq implementation enables developers to obtain fully machine-checked verifications of their relaxed programs.National Science Foundation (U.S.). (Grant number CCF-0811397)National Science Foundation (U.S.). (Grant number CCF-0905244)National Science Foundation (U.S.). (Grant number CCF-1036241)National Science Foundation (U.S.). (Grant number IIS-0835652)United States. Defense Advanced Research Projects Agency (Grant number FA8650-11-C-7192)United States. Defense Advanced Research Projects Agency (Grant number FA8750-12-2-0110)United States. Dept. of Energy. (Grant Number DE-SC0005288
Which are the Parameters to be Controlled in Red Cell Products (Whole Blood, Red Cell Concentrates, Washed Red Cells, Leucocyte Poor Red Cell Concentrates, Frozen Red Cells) in Order that They May be Offered to the Medical Profession as Standardised Products with Specified Properties?
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73259/1/j.1423-0410.1980.tb01863.x.pd
Blueberry Progress Reports
The 1981 edition of the Blueberry Progress Reports was prepared for the Maine Blueberry Commission and the University of Maine Blueberry Advisory Committee by researchers with the Maine Life Sciences and Agriculture Experiment Station and Maine Cooperative Extension Service at the University of Maine, Orono. Projects in this report include:
1. Weed Control in Lowbush Blueberry Fields
2. Pruning of Blueberries
3. 1982 Blueberry Fruit Fly Monitoring IPM Program
4. Physiology and Culture of the Lowbush Blueberry
5. Blueberry Diseases: Incidence and Control
6. Control, biology, and ecology of insects affecting lowbush blueberries
7. Blueberry Extension Progress Report
8. Plan of Work - 1982 - Blueberry Extensio
Blueberry Progress Reports
The 1980 edition of the Blueberry Progress Reports was prepared for the Maine Blueberry Commission and the University of Maine Blueberry Advisory Committee by researchers with the Maine Life Sciences and Agriculture Experiment Station and Maine Cooperative Extension Service at the University of Maine, Orono. Projects in this report include:
1. Weed Control in Lowbush Blueberry Fields
2. Pruning of Blueberries
3. Integrated Pest Management of Blueberries in Maine
4. Physiology and Culture of the Lowbush Blueberry
5. Blueberry Diseases: Incidence and Control
6. Insects Affecting the Blueberry
7. Effect of Plant-Water Stress on Lowbush Blueberry Growth, Yield and Quality
8. Blueberry Extension Progress Report
9. Plan of Work -1981- Blueberry Extensio
- …