Toward a quantum-mechanical description of metal-assisted phosphoryl transfer in pyrophosphatase

The wealth of kinetic and structural information makes inorganic pyrophosphatases (PPases) a good model system to study the details of enzymatic phosphoryl transfer. The enzyme accelerates metal-complexed phosphoryl transfer 1010-fold: but how? Our structures of the yeast PPase product complex at 1.15 Å and fluoride-inhibited complex at 1.9 Å visualize the active site in three different states: substrate-bound, immediate product bound, and relaxed product bound. These span the steps around chemical catalysis and provide strong evidence that a water molecule (Onu) directly attacks PPi with a pKa vastly lowered by coordination to two metal ions and D117. They also suggest that a low-barrier hydrogen bond (LBHB) forms between D117 and Onu, in part because of steric crowding by W100 and N116. Direct visualization of the double bonds on the phosphates appears possible. The flexible side chains at the top of the active site absorb the motion involved in the reaction, which may help accelerate catalysis. Relaxation of the product allows a new nucleophile to be generated and creates symmetry in the elementary catalytic steps on the enzyme. We are thus moving closer to understanding phosphoryl transfer in PPases at the quantum mechanical level. Ultra-high resolution structures can thus tease out overlapping complexes and so are as relevant to discussion of enzyme mechanism as structures produced by time-resolved crystallography.

Plant biology in the future

In the beginning of modern plant biology, plant biologists followed a simple model for their science. This model included important branches of plant biology known then. Of course, plants had to be identified and classified first. Thus, there was much work on taxonomy, genetics, and physiology. Ecology and evolution were approached implicitly, rather than explicitly, through paleobotany, taxonomy, morphology, and historical geography. However, the burgeoning explosion of knowledge and great advances in molecular biology, e.g., to the extent that genes for specific traits can be added (or deleted) at will, have created a revolution in the study of plants. Genomics in agriculture has made it possible to address many important issues in crop production by the identification and manipulation of genes in crop plants. The current model of plant study differs from the previous one in that it places greater emphasis on developmental controls and on evolution by differential fitness. In a rapidly changing environment, the current model also explicitly considers the phenotypic variation among individuals on which selection operates. These are calls for the unity of science. In fact, the proponents of “Complexity Theory” think there are common algorithms describing all levels of organization, from atoms all the way to the structure of the universe, and that when these are discovered, the issue of scaling will be greatly simplified! Plant biology must seriously contribute to, among other things, meeting the nutritional needs of the human population. This challenge constitutes a key part of the backdrop against which future evolution will occur. Genetic engineering technologies are and will continue to be an important component of agriculture; however, we must consider the evolutionary implications of these new technologies. Meeting these demands requires drastic changes in the undergraduate curriculum. Students of biology should be trained in molecular, cellular, organismal, and ecosystem biology, including all living organisms.

The wagon wheel illusion in movies and reality.

Wheels turning in the movies or in other forms of stroboscopic presentation often appear to be rotating backward. Remarkably, a similar illusion is also seen in continuous light. The occurrence of this perception in the absence of intermittent illumination suggests that we normally see motion, as in movies, by processing a series of visual episodes.

bioNMF: a versatile tool for non-negative matrix factorization in biology

Medical imaging has become an absolutely essential diagnostic tool for clinical practices; at present, pathologies can be detected with an earliness never before known. Its use has not only been relegated to the field of radiology but also, increasingly, to computer-based imaging processes prior to surgery. Motion analysis, in particular, plays an important role in analyzing activities or behaviors of live objects in medicine. This short paper presents several low-cost hardware implementation approaches for the new generation of tablets and/or smartphones for estimating motion compensation and segmentation in medical images. These systems have been optimized for breast cancer diagnosis using magnetic resonance imaging technology with several advantages over traditional X-ray mammography, for example, obtaining patient information during a short period. This paper also addresses the challenge of offering a medical tool that runs on widespread portable devices, both on tablets and/or smartphones to aid in patient diagnostics.

Save the Planet - Buy Organic: The Role of Consumers in the Sustainable Agricultural Movement

The severity of the environmental situation in agriculture is described. Progress made so far is then listed and critiqued. Misconceptions that sustainable agriculture cannot produce as much food as industrial agriculture, as well as the false impression that sustainably-produced foods must cost more are discussed. In conclusion, the only force strong enough to convince farmers to switch to sustainable practices is the consumer. Advertisements and educational campaigns will inform consumers about industrial agriculture. The shift in demand for sustainable goods will eventually cause prices to fall, allowing more consumers to purchase these formally expensive goods. This process will make a sustainable agricultural revolution possible and profitable.

Ijé: the journey

Chioma, a child growing up in the Nigerian countryside, warned her restless sister, Anya, about the trappings of the American Dream. In "Ijé: The Journey" movie, ten years later, Anya is accused of killing 3 men in a Hollywood Hills mansion - one of them her record-producer husband. Chioma travels from Nigeria to Los Angeles, and with the help of a young attorney, discovers that the dark secret her sister wants to keep hidden might be the only thing that can win her freedom.

Drivers of agricultural capital productivity in selected EU member states. Factor Markets Working Paper No. 30, September 2012

The aim of this Working Paper is to provide an empirical analysis of the marginal return on working capital and fixed capital in agriculture, based on data gathered by the Farm Accountancy Data Network from seven EU member states. Particular emphasis is placed on the detection of credit market imperfections. The key idea is to provide farm group-specific estimates of the shadow price of capital, and to use these to analyse the drivers of on-farm capital use in European agriculture. Based on Cobb Douglas estimates of farm-type specific production functions, we find that working capital is typically used in more than economically optimal quantities and often displays negative marginal returns across countries and farm types. This is less often the case with regard to fixed capital, but it is only in a small set of sectors where access to fixed capital appears severely constrained. These sectors include field crop and mixed farms in Denmark, dairy farms in East Germany, as well as mixed farms in Italy and the UK. The relationship between farm financial indicators and the estimated shadow prices of capital varies considerably across countries and sectors. Among the farms with a high shadow price for fixed capital in Denmark, high debt levels and little owned land tended to induce more intensive capital use, which may reflect the liberal Danish banking system. In East Germany, Italy and the UK, high debt levels made farmers more tightly capital constrained. Hence, in the latter group of countries, more traditional mechanisms of capital allocation based on debt capacity seemed to be at work. As a general conclusion, EU agriculture appears to be characterised by overcapitalisation rather than by credit constraints.

The Role of Pluriactivity in Farm Exit and Labour Supply Decisions. Factor Markets Working Document No. 67, August 2013

EDITED VERSION TO BE PUBLISHED SOON Pluriactivity has been a topic of research in agriculture for the best part of a century. It is a term which has both broad and narrow definitions and hence is subject to multiple interpretations. This paper considers two forms of pluriactivity: within the farm gate pluriactivity, also commonly referred to as farm diversification, and beyond the farm-gate pluriactivity, also known as multiple job holding. Previous studies of pluriactivity have shown that it can inhibit the natural process of structural change in the farm sector, by allowing small and unprofitable farms to survive with the support of income from outside the sector. In this paper, two empirical models of pluriactivity are estimated using farm level data for Ireland. The first examines the impact of on-farm diversification on off-farm labour supply, while the second investigates the relationship between off-farm labour supply and farm exit which is specified in the context of retirement and non-succession. The result of the first model suggests that farms that engage in within the farm gate pluriactivity are less likely to engage in beyond the farm gate pluriactivity, in other words more diversified farmers are less likely to work off farm. The second model confirms previous findings in the literature that part-time farmers have a reduced probability of having a farm successor. While the model results are specific to the Irish case, they do provide some value insights into the impacts of pluriactivity on structural change in farming.

Quantifying Non-Tariff Measures for TTIP. Paper No. 12 in the CEPS-CTR project ‘TTIP in the Balance’ and CEPS Special Report No. 116/July 2015

This paper provides an overview of methods employed to quantify non-tariff measures (NTMs) and then analyses their differences and looks at what these mean for the Transatlantic Trade and Investment Partnership (TTIP) negotiations. The authors find several similarities in the approaches taken. Because all studies conclude that NTMs matter, they argue that policy-makers are right to focus on ‘regulatory cooperation’ in TTIP. Given the significant differences in NTMs across sectors, policy-makers are urged to dive deep into sector-specific elements of NTMs and focus on those sectors where the largest potential gains can be made (i.e. where NTMs are highest, such as in agriculture, automobiles, steel, textiles and insurance services). An area identified for further research is the fact that unlike trade taxes (i.e. tariffs), regulatory barriers to trade are not generally targeted as the primary policy objective, but rather stem from other strategic policy concerns such as consumer safety and/or social and environmental protection. This element should be further investigated.

Simpatías y diferencias.

Mode of access: Internet.

Propaganda and the Nazi war film

Lithoprinted.

Countermeasures for young drivers. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Drinking driver and traffic safety project: final report, vol. I.

National Highway Traffic Safety Administration, Washington, D.C.

Using trigger films: a guide for discussion leaders.

National Highway Traffic Safety Administration, Washington, D.C.

U.S. Government films for public educational use

"Catalog cards ... prepared cooperatively by the Office [of Education] and the Library [of Congress] provided the basic material used in compiling this 1955 catalog of U.S. Government films for public educational use."