Organic Agriculture and the Environmental Stability of Food Supply

CONCLUSIONS Organic production systems can make important contributions to food supply stability and farmer livelihoods by establishing soil fertility, providing diversity and, therefore, resilience to food production systems in light of the many uncertainties of climate change. In particular, they contribute positively to food stability in terms of fertile and well structured soils, improved water retention, protection of biodiversity with beneficial side-effects on phytomedical stability and nutrients, and water use efficiency. Agricultural production methods specifically adapted to microclimates, production of diverse products, and cropping methods emphasizing soil carbon retention are most likely to withstand climatic challenges and contribute to food stability, particularly in those countries most vulnerable to increased climate change. Organic agriculture is emphatic about making use of farmer and farmer-community knowledge, particularly about farm organization, crop design, manipulation of natural and seminatural habitats on the farm, use or even selection of locally appropriate seeds and breeds, on-farm preparation of natural plant strengtheners and traditional drugs and curing techniques for livestock, innovative and low budget technology, etc. It is unique in modern agriculture that a food production system is so strongly based on adaptive management. So far, no practical options other than organic agriculture have been proposed to address climate instability. Currently, it is an option which is based and more scientific evidence and field implementation than inexistent or untested technologies such as genetically improved crops that can withstand drought/flood and that can maintain a high resilience in order to cope with unpredictable impacts of climate change. This paper recognizes the deficits of organic agriculture that are mainly related to lower productivity and yield losses. However, the deficits should not be exaggerated. The massively lower yields, those in the range of more than 20 to 30 percent compared to conventional agriculture, occur only in cash-crop-focused production systems and under most favourable climate and soil conditions. Such deficits highlight needs in the current international and national research activities. European countries, leaders in organic agriculture research, spend approximately €60 million per year on specific problems of organic food and farming (Lange, et al., 2006), supplemented with roughly € 4 million per annum by the European Commission. This represents less than 1 percent of total food and agriculture research. In order to improve the performance of organic production, more research is needed on: - soil fertility management and crop growth and health; - habitat management with improved manipulation and exploitation of diversity at all levels; - crop breeding programmes focusing on the adaptability of plants to low input situations in soils, in weed competition, and in pest and disease tolerance; - improved techniques and compounds for plant protection from natural sources; - organic livestock production breeding concepts and programmes for adaptability to management and environmental stress situations; and - reduced tillage organic systems; Organic agriculture represents a positive example of how farmers can help mitigate climate change and adapt to its predictable and unpredictable impacts. It could be used as an indicator for allocating national or international development resources to climate change adaptation (e.g. Adaptation Fund) or to measure progress in implementing climate-related multilateral environment agreements (such as already done in 2010 targets of the Convention on Biological Diversity)

Examining the Behavior of Surface Tethered Enzymes.

Surface-immobilized enzymes are important for a wide range of technological applications, including industrial catalysis, drug delivery, medical diagnosis and biosensors. However, our understanding of how enzymes and proteins interact with abiological surfaces on the molecular level remains extremely limited. We have compared the structure, activity and thermal stability of beta-galactosidase variants attached to a chemically well-defined self assembled monolayer (SAM) surface. Maleimide-terminated ethylene glycol linkers were used to attach beta-galactosidase through a unique cysteinyl residue. These maleimide-terminated linkers were mixed with ethylene glycol linkers terminated with different chemical moieties to engineer surfaces with varying hydrophobicity and electrostatic charge. In collaboration with the Chen Lab, we used SFG and ATR-FTIR to experimentally measure the orientation of the surface tethered enzyme. In collaboration with the Brooks Lab, we conducted coarse grain model simulations to examine the atomic level interactions between the protein and the surface. Through coarse grain modelling, it was shown that the increased range of motion allowed to an enzyme tethered to a flexible loop region increased the number of protein surface interactions relative to the interactions experienced by an enzyme attached to the helix. For mildly hydrophibic surfaces, such as a full maleimide-terminated SAM, these increased interactions are destabilizing. This was confirmed experimentally by the reduction in thermal stability for beta-galactosidase attached by the loop region. Using SFG, it was shown that the distribution of orientations of an enzyme attached to a loop is greater than to an enzyme tethered to a helix. By varying the electrostatic properties of the terminal groups used in the SAMs, it was shown that beta-galactosidase immobilized onto SAMs containing a mixture of positively and negatively terminated residues retained a higher level of specific activity than surfaces terminated with either uncharged hydrophilic or hydrophobic surfaces. Thermal stability was highest on uncharged hydrophilic surfaces. Overall, we were able to develop a molecular level model for the behavior of surface attached enzymes, and a potential approach for predicting approaches for engineering tethered enzyme systems.PHDChemical BiologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/111541/1/tadlo_1.pd

Addressing the needs of traumatic brain injury with clinical proteomics.

BackgroundNeurotrauma or injuries to the central nervous system (CNS) are a serious public health problem worldwide. Approximately 75% of all traumatic brain injuries (TBIs) are concussions or other mild TBI (mTBI) forms. Evaluation of concussion injury today is limited to an assessment of behavioral symptoms, often with delay and subject to motivation. Hence, there is an urgent need for an accurate chemical measure in biofluids to serve as a diagnostic tool for invisible brain wounds, to monitor severe patient trajectories, and to predict survival chances. Although a number of neurotrauma marker candidates have been reported, the broad spectrum of TBI limits the significance of small cohort studies. Specificity and sensitivity issues compound the development of a conclusive diagnostic assay, especially for concussion patients. Thus, the neurotrauma field currently has no diagnostic biofluid test in clinical use.ContentWe discuss the challenges of discovering new and validating identified neurotrauma marker candidates using proteomics-based strategies, including targeting, selection strategies and the application of mass spectrometry (MS) technologies and their potential impact to the neurotrauma field.SummaryMany studies use TBI marker candidates based on literature reports, yet progress in genomics and proteomics have started to provide neurotrauma protein profiles. Choosing meaningful marker candidates from such 'long lists' is still pending, as only few can be taken through the process of preclinical verification and large scale translational validation. Quantitative mass spectrometry targeting specific molecules rather than random sampling of the whole proteome, e.g., multiple reaction monitoring (MRM), offers an efficient and effective means to multiplex the measurement of several candidates in patient samples, thereby omitting the need for antibodies prior to clinical assay design. Sample preparation challenges specific to TBI are addressed. A tailored selection strategy combined with a multiplex screening approach is helping to arrive at diagnostically suitable candidates for clinical assay development. A surrogate marker test will be instrumental for critical decisions of TBI patient care and protection of concussion victims from repeated exposures that could result in lasting neurological deficits

An integrated native mass spectrometry and top-down proteomics method that connects sequence to structure and function of macromolecular complexes.

Mass spectrometry (MS) has become a crucial technique for the analysis of protein complexes. Native MS has traditionally examined protein subunit arrangements, while proteomics MS has focused on sequence identification. These two techniques are usually performed separately without taking advantage of the synergies between them. Here we describe the development of an integrated native MS and top-down proteomics method using Fourier-transform ion cyclotron resonance (FTICR) to analyse macromolecular protein complexes in a single experiment. We address previous concerns of employing FTICR MS to measure large macromolecular complexes by demonstrating the detection of complexes up to 1.8 MDa, and we demonstrate the efficacy of this technique for direct acquirement of sequence to higher-order structural information with several large complexes. We then summarize the unique functionalities of different activation/dissociation techniques. The platform expands the ability of MS to integrate proteomics and structural biology to provide insights into protein structure, function and regulation

Those who support the presence of Confederate symbols in public spaces in the South tend to have less knowledge of Civil War history, negating a commonly used defense that the emblems represent ‘heritage not hate’

The shooting of African-American church goers by white supremacist Dylann Roof reignited a fierce discussion in the American South about the role of Confederate symbols in public spaces. Much of this falls under the ‘hate vs. heritage’ debate; that confederate emblems represent heritage as opposed to racial animosity. Research by Logan Strother, Spencer Piston, and Thomas Ogorzalek finds that those who support the public presence of Confederate emblems tend to have less knowledge of Civil War history, demonstrating that racial prejudice does explain much of the observed support for the Confederate flag, while Southern heritage appears to explain relatively little

The Cities on the Hill: Urban Politics in National Institutions

The contemporary "Red-Blue" political alignment is characterized by a national divide between cities and rural areas. This urbanicity divide is stronger than it has ever been in our modern history, but it began with the development of an urban political order that changed the Democratic Party during the New Deal era. These cities, despite being the site of serious, multidimensional conflicts at home, have been remarkably cohesive in the way they represent themselves in national politics, forming "city delegations" whose members attend to more than their own district's concerns. These city delegations tend to cohesively represent a "city" interest that often coincides with what we think of as liberalism. Using evidence from Congress, where cities represented themselves within the nation, and a unique dataset measuring the urbanicity of House districts over time, this dissertation evaluates the strength of this urban political order and argues that city delegation cohesion, which is a basic strategic tool if cities are to address their urgent governance needs through action at higher levels of government, is fostered by local institutions developed to provide local political order. Importantly, these integrative institutions also helped foster the development of civil rights liberalism by linking constituencies composed largely of groups that were not natural allies on such issues. This development in turn contributed to the departure of the Southern Democratic bloc, and to our contemporary political environment. This combination--of diversity and liberalism, supported by institutions that make allies of constituencies that might easily be rivals--has significant implications for an America characterized by deep social difference and political fragmentation

A deep, multi-epoch Chandra HETG study of the ionized outflow from NGC 4051

Actively accreting supermassive black holes significantly impact the evolution of their host galaxies, truncating further star formation by expelling large fractions of gas with wide-angle outflows. The X-ray band is key to understanding how these black hole winds affect their environment, as the outflows have high temperatures ($\sim$10$^{5-8}$K). We have developed a Bayesian framework for characterizing Active Galactic Nuclei (AGN) outflows with an improved ability to explore parameter space and perform robust model selection. We applied this framework to a new 700 ks and an archival 315 ks Chandra High Energy Transmission Gratings observation of the Seyfert galaxy NGC 4051. We have detected six absorbers intrinsic to NGC 4051. These wind components span velocities from 400 km s$^{-1}$ to 30,000 km s$^{-1}$. We have determined that the most statistically significant wind component is purely collisionally ionized, which is the first detection of such an absorber. This wind has $T\approx10^7$ K and $v\approx880$ km s$^{-1}$ and remains remarkably stable between the two epochs. Other slow components also remain stable across time. Fast outflow components change their properties between 2008 and 2016, suggesting either physical changes or clouds moving in and out of the line of sight. For one of the fast components we obtain one of the tightest wind density measurements to date, log $n/$[cm$^{-3}$]=13.0$^{+0.01}_{-0.02}$, and determine that it is located at $\sim$240 gravitational radii. The estimated total outflow power surpasses 5% of the bolometric luminosity (albeit with large uncertainties) making it important in the context of galaxy-black hole interactions.Comment: 27 pages, 17 figures, 10 tables, accepted for publication in MNRA

Editorial

In recent years, we have observed spectacular advancements in the area of nano-circuits and systems at several levels, from the fabrication material and device levels to the system and application levels. New emerging materials provide us with a wealth of new devices such as (silicon) nanowires, graphene, and carbon nanotubes fabricated in various technologies. Applications of these devices are vast and include, but are not limited to, new computing and memory structures, super-capacitors, as well as nano-bio-sensors based on the molecular combination of molecular probes to electronic devices. This special issue of the Journal on Emerging and Selected Topics in Circuits and Systems (JETCAS) has the purpose to collect some selected contributions to the workshop as well as other works in this domain, all subject to peer review. In particular, this issue focuses on two specific topics: biomedical circuits and systems, and 3-D integrated circuits and systems. This choice is motivated by a synergy of the spontaneous contributions in these areas as well as by the importance of these fields. We will review these two areas at large before briefly summarizing the contributions

Photoionization Models for High-density Gas

Relativistically broadened and redshifted 6.4–6.9 keV iron K lines are observed from many accretion powered objects, including X-ray binaries and active galactic nuclei. The existence of gas close to the central engine implies large radiation intensities and correspondingly large gas densities if the gas is to remain partially ionized. Simple estimates indicate that high gas densities are needed to allow for the survival of iron against ionization. These are high enough that rates for many atomic processes are affected by mechanisms related to interactions with nearby ions and electrons. Radiation intensities are high enough that stimulated processes can be important. Most models currently in use for interpreting relativistic lines use atomic rate coefficients designed for use at low densities and neglect stimulated processes. In our work so far we have presented atomic structure calculations with the goal of providing physically appropriate models at densities consistent with line-emitting gas near compact objects. In this paper we apply these rates to photoionization calculations, and produce ionization balance curves and X-ray emissivities and opacities that are appropriate for high densities and high radiation intensities. The final step in our program will be presented in a subsequent paper in which model atmosphere calculations will incorporate these rates into synthetic spectra