3,055 research outputs found
Politically engaged artistic practice: Strategies and tactics
This paper explores political forms of artistic practice operating within Tate Exchange broadly and within the authors’ creative practice specifically. It identifies the tensions and obstacles inherent to socially engaged artistic practice and forms of expertise, and proposes a method of practice that is grounded in prefiguration and solidarity
Isoprene Emission and Carbon Dioxide Protect Aspen Leaves from Heat Stress
High temperature, especially above 35oC, is known to reduce leaf photosynthetic rate in many tree species. This study investigated the effect of high temperature on isoprene-emitting (aspen) and non- emitting (birch) trees under ambient and elevated CO2 under open field conditions. Aspen trees tolerate heat better than birch trees and elevated CO2 protects both species against moderate heat stress. The increased thermotolerance in aspen trees compared to the birch trees may result from the aspen's ability to produce isoprene. Elevated CO2 increased carboxylation capacity, photosynthetic electron transport capacity and triose phosphate use in both birch and aspen trees. High temperature decreased all of these parameters in birch regardless of CO2 treatment but only photosynthetic electron transport and triose phosphate use at ambient CO2 were reduced in aspen. As temperature rises, non-isoprene-emitting trees will be at a disadvantage and biological diversity and species richness might be lost in some ecosystems. Our results indicate that isoprene emitting tree species will have an advantage over non-isoprene emitting ones under high temperatures
An Integrated Cyber-Physical Risk Assessment Framework for Worst-Case Attacks in Industrial Control Systems
Industrial Control Systems (ICSs) are widely used in critical infrastructures
that face various cyberattacks causing physical damage. With the increasing
integration of the ICSs and information technology (IT), ensuring the security
of ICSs is of paramount importance. In an ICS, cyberattacks exploit
vulnerabilities to compromise sensors and controllers, aiming to cause physical
damage. Maliciously accessing different components poses varying risks,
highlighting the importance of identifying high-risk cyberattacks. This aids in
designing effective detection schemes and mitigation strategies. This paper
proposes an optimization-based cyber-risk assessment framework that integrates
cyber and physical systems of ICSs. The framework models cyberattacks with
varying expertise and knowledge by 1) maximizing physical impact in terms of
failure time of the physical system, 2) quickly accessing the sensors and
controllers in the cyber system while exploiting limited vulnerabilities, 3)
avoiding detection in the physical system, and 4) complying with the cyber and
physical restrictions. These objectives enable us to jointly model the
interactions between the cyber and physical systems and study the critical
cyberattacks that cause the highest impact on the physical system under certain
resource constraints. Our framework serves as a tool to understand the
vulnerabilities of an ICS with a holistic consideration of cyber and physical
systems and their interactions and assess the risk of existing detection
schemes by generating the worst-case attack strategies. We illustrate and
verify the effectiveness of our proposed method in a numerical and a case
study. The results show that a worst-case strategic attacker causes almost 19%
further acceleration in the failure time of the physical system while remaining
undetected compared to a random attacker
Maltose Biochemistry and Transport in Plant Leaves
Starch is a desirable plant product for both food and biofuel. Leaf starch is ideal for use in biofuels because it does not compete with grain starch, which is used for food. Starch is accumulated in plant leaves during the day and broken down at night. If we can manipulate leaf starch breakdown it may be possible to design a plant that provides both grain starch for food and leaf starch for biofuel. The pathway of leaf starch breakdown was not known when this work started. Preliminary evidence had shown that maltose was the primary product of leaf starch breakdown (Weise, Weber & Sharkey, 2004) and that it was metabolized by a disproportionating enzyme called amylomaltase but given the initials DPE2 (Lu & Sharkey, 2004). In this work we showed that only one form of maltose was metabolically active (Weise et al., 2005a) and that maltose was located in two different places when the amylomaltase was knocked out but only inside the chloroplast when the maltose transporter was knocked out (Lu et al., 2006a). This allowed us to estimate the energetics of maltose export and to show that maltose export is more efficient than glucose export (Weise et al., 2005b). We examined how daylength affected starch breakdown rate and found that starch breakdown rate could respond to changes in daylength within one day (Lu, Gehan & Sharkey, 2005). We also were able to show a second starch breakdown pathway by chloroplastic starch phosphorylase (Weise et al., 2006). Work to this point was summarized in a review (Lu & Sharkey, 2006). We were able to show that the amylomaltase in plants could substitute for the amylomaltase in bacteria (Lu et al., 2006b). In this paper we also showed the importance of a second enzyme called alpha-glucan phosphorylase in starch breakdown. Finally, we were able to determine the enzymatic mechanism of the amylomaltase (Steichen, Petty & Sharkey, 2008). These results have laid the groundwork for manipulating plants for improved biofuel production
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Italian-American ethnic identity and school achievement : an exploration of the persistence of conflict between the home and school cultures of Italian-American high school students.
Autonomy in Weapons Systems. The Military Application of Artificial Intelligence as a Litmus Test for Germany’s New Foreign and Security Policy
The future international security landscape will be critically impacted by the military use of artificial intelligence (AI) and robotics. With the advent of autonomous weapon systems (AWS) and a currently unfolding transformation of warfare, we have reached a turning point
and are facing a number of grave new legal, ethical and political concerns.
In light of this, the Task Force on Disruptive Technologies and 21st Century Warfare, deployed by the Heinrich Böll Foundation, argues that meaningful human control over weapon systems and the use of force must be retained. In their report, the task force authors offer recommendations to the German government and the German armed forces to that effect
Diet, nutrition, obesity and their role in arthritis
Obesity and poor nutrition, individually and together, have created costly musculoskeletal disease epidemic in the United States. Processed food, with abundant empty calories, has contributed greatly to our dietary woes. Much of the food consumed today is packed with calories but refined to the point that essential nutrients are lacking. Even worse, processed food may have ingredients added that are detrimental to good health. Abundant research has documented a close relationship between obesity, poor diet and orthopaedic problems. Dietary supplements have been proven to provide both disease prevention and therapeutic benefits. Unfortunately, many weight loss programs and methods are ineffective and possibly dangerous. Additionally, the FDA does not regulate the nutritional supplement industry and product quality is high variable. It is imperative that physicians treating patients with musculoskeletal complaints understand these disease producing relationships and have a network in place to refer patients to reputable weight loss entities and for high quality nutritional supplements
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