Enzymatic glyceride synthesis in a foam reactor

We report the results of our study on Rhizomucor miehei lipaseâ catalyzed lauric acidâ glycerol esterification in a foam reactor. A satisfactory yield of glyceride synthesis can be achieved with an unusually high initial water content (50% w/w). We found that product formation could be regulated by controlling foaming. Foaming was a function of the air flow rate, reaction temperature, pH value, ionic strength, and substrate molar ratio. Monolaurin and dilaurin, which constituted nearly 80% of the total yield, were the two dominant products in this reaction; trilaurin was also formed at the initial stages of the reaction. A study of pH and ionic strength effects on an independent basis revealed that they affect the interfacial mechanism in different manners. On varying the ratio of lauric acid and glycerol, only a slight change in the degree of conversion was detected and the consumption rate of fatty acid was approximately the same.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141443/1/aocs0643.pd

Observation of hard scattering in photoproduction events with a large rapidity gap at HERA

Events with a large rapidity gap and total transverse energy greater than 5 GeV have been observed in quasi-real photoproduction at HERA with the ZEUS detector. The distribution of these events as a function of the $\gamma p$ centre of mass energy is consistent with diffractive scattering. For total transverse energies above 12 GeV, the hadronic final states show predominantly a two-jet structure with each jet having a transverse energy greater than 4 GeV. For the two-jet events, little energy flow is found outside the jets. This observation is consistent with the hard scattering of a quasi-real photon with a colourless object in the proton.Comment: 19 pages, latex, 4 figures appended as uuencoded fil

Observation of Events with an Energetic Forward Neutron in Deep Inelastic Scattering at HERA

In deep inelastic neutral current scattering of positrons and protons at the center of mass energy of 300 GeV, we observe, with the ZEUS detector, events with a high energy neutron produced at very small scattering angles with respect to the proton direction. The events constitute a fixed fraction of the deep inelastic, neutral current event sample independent of Bjorken x and Q2 in the range 3 · 10-4 \u3c xBJ \u3c 6 · 10-3 and 10 \u3c Q2 \u3c 100 GeV2

Climate change and its implications for Australia's freshwater fish

Freshwater environments and their fishes are particularly vulnerable to climate change because the persistence and quality of aquatic habitat depend heavily on climatic and hydrologic regimes. In Australia, projections indicate that the rate and magnitude of climate change will vary across the continent. We review the likely effects of these changes on Australian freshwater fishes across geographic regions encompassing a diversity of habitats and climatic variability. Commonalities in the predicted implications of climate change on fish included habitat loss and fragmentation, surpassing of physiological tolerances and spread of alien species. Existing anthropogenic stressors in more developed regions are likely to compound these impacts because of the already reduced resilience of fish assemblages. Many Australian freshwater fish species are adapted to variable or unpredictable flow conditions and, in some cases, this evolutionary history may confer resistance or resilience to the impacts of climate change. However, the rate and magnitude of projected change will outpace the adaptive capacities of many species. Climate change therefore seriously threatens the persistence of many of Australia's freshwater fish species, especially of those with limited ranges or specific habitat requirements, or of those that are already occurring close to physiological tolerance limits. Human responses to climate change should be proactive and focus on maintaining population resilience through the protection of habitat, mitigation of current anthropogenic stressors, adequate planning and provisioning of environmental flows and the consideration of more interventionist options such as managed translocations

China Engages Global Health Governance: Processes and Dilemmas

Using HIV/AIDS, Severe Acute Respiratory Syndrome (SARS), and avian influenza as case studies, this paper discusses the processes and dilemmas of China's participation in health governance, both at the domestic level and the global level. Globalization has eroded the boundary between public and private health and between domestic and global health governance. In addition, the SARS outbreak of 2002-2003 focused global attention on China's public health. As a rising power with the largest population on earth, China is expected by the international community to play a better and more active role in health management. Since the turn of this century, China has increasingly embraced multilateralism in health governance. This paper argues that China's multilateral cooperation is driven by both necessity and conscious design. International concerns about good governance and its aspiration to become a 'responsible' state have exerted a normative effect on China to change tack. Its interactions with United Nations agencies have triggered a learning process for China to securitize the spread of infectious diseases as a security threat. Conversely, China has utilized multilateralism to gain access to international resources and technical assistance. It is still a matter of debate whether China's cooperative engagement with global health governance can endure, because of the persistent problems of withholding information on disease outbreaks and because of its insistence on the Westphalian notion of sovereignty