Small bite,large impact–saliva and salivary molecules in the medicinal leech, <Emphasis Type="Italic">Hirudo medicinalis</Emphasis>

Blood-sucking leeches have been used for medical purposes in humans for hundreds of years. Accordingly, one of the most prominent species has been named Hirudo medicinalis by Carl Linne in 1758. Feeding on vertebrate blood poses some serious problems to blood-sucking ectoparasites, as they have to penetrate the body surface of the host and to suppress the normal reactions of the host to such injuries (swelling, pain, inflammation) to remain undetected during the feeding period. Furthermore, the parasites have to take measures to inhibit the normal reactions in host tissues to blood vessel damage, namely hemostasis and blood coagulation (platelet aggregation and activation, activation of thrombin and formation of fibrin clots). During evolution, leeches have acquired the ability to control these processes in their hosts by transferring various bioactive substances to the host. These substances are supposedly produced in unicellular salivary gland cells and injected into the wound at the feeding site through tiny salivary ductule openings in the jaws that the leech uses to slice open the host body surface and to cut blood vessels in the depth of the wound. This review summarizes current knowledge about the salivary gland cells and the biological effects of individual saliva components as well as hints to the potential usefulness of some of these compounds for medical purposes.     

Biotechnology: the ultimate cleaner production technology for agriculture?

There has been much discussion regarding the potential environmental benefits and hazards associated with agricultural biotechnology. Some argue that it can eliminate the need for a wide range of material inputs such as pesticides and herbicides. Others argue that it will increase the demand for non-sustainable and potentially hazardous ‘agri-business' practices. We test these claims against the cleaner production approach. Although we found that pressures to accept this technology are strong enough to overcome initial resistance, we also found that biotechnology, as it applies to agriculture, is not consistent with a cleaner production approach due to the high level of risk. We suggest that this type of technology adds an additional dimension to the cleaner production argument.     

Carbon Budget Implications of the Transition from Natural to Managed Disturbance Regimes in Forest Landscapes

Land-use change from an unmanaged to a managed forested landscape in northern forests is associated with a reduction of the area annually affected by natural disturbances (wildfires and forest insects) and the introduction of harvesting as a new disturbance. This study examined the impacts of changes in the disturbance regime-the frequency and type of disturbance-on landscape-level carbon (C) content and fluxes. The Carbon Budget Model of the Canadian Forest Sector was used to assess these impacts in six representative landscapes (100,000 ha each) with a range of disturbance regimes that are characteristic of conditions in coastal British Columbia, the interior of British Columbia, and the eastern boreal forest in Canada. The model was used to simulate ecosystem C fluxes during a period of natural disturbances, a 50-year transition period during which harvesting replaced natural disturbances, followed by 150 years of harvesting. The initial landscape-level biomass C content under natural disturbance regimes in the six example landscapes was 22 to 75% of their potential maximum content which is often used as the reference or baseline case. After 200 years of forest management, the C stored in the landscape plus the C retained in forest products manufactured from harvested biomass was between 58 and 101% of the landscape C content prior to the onset of harvesting. Landscape-level ecosystem C content was found to be affected by changes in the disturbance frequency, the age-dependence of the disturbance probabilities, and the disturbance-specific impacts on ecosystem C content. The results indicate that using the potential maximum C content of a landscape as the baseline always overestimates the actual C release due to land use change. A more meaningful procedure would be to assess the actual differences in landscape-level C content between the natural and the managed disturbance regime.     

The potential environmental response to increasing ocean alkalinity for negative emissions

Mitigation and Adaptation Strategies for Global Change - The negative emissions technology, artificial ocean alkalinization (AOA), aims to store atmospheric carbon dioxide (CO2) in the ocean by...     

Consequences of electrical conductivity in an orb spider's capture web

The glue-coated and wet capture spiral of the orb web of the garden cross spider Araneus diadematus is suspended between the dry silk radial and web frame threads. Here, we experimentally demonstrate that the capture spiral is electrically conductive because of necks of liquid connecting the droplets even if the thread is stretched. We examine how this conductivity of the capture spiral may lead to entrapment of charged airborne particles such as pollen, spray droplets and even insects. We further describe and model how the conducting spiral will also locally distort the Earth's ambient electric field. Finally, we examine the hypothesis that such distortion could be used by potential prey to detect the presence of a web but conclude that any effect would probably be too small to allow an insect to take evasive action.     

Groundwater dependent ecosystems. Part II. Ecosystem services and management in Europe under risk of climate change and land use intensification

Groundwater in sufficient amounts and of suitable quality is essential for potable water supplies, crop irrigation and healthy habitats for plant and animal biocenoses. The groundwater resource is currently under severe pressure from land use and pollution and there is evidence of dramatic changes in aquifer resources in Europe and elsewhere, despite numerous policy measures on sustainable use and protection of groundwater. Little is known about how such changes affect groundwater dependent ecosystems (GDEs), which include various aquatic and terrestrial ecosystems above ground and inside the aquifer. Future management must take this uncertainty into account. This paper focuses on multiple aspects of groundwater science, policy and sustainable management. Examples of current management methods and practices are presented for selected aquifers in Europe and an assessment is made of the effectiveness of existing policies such as the European Water Framework Directive and the Habitat Directive in practice and of how groundwaters and GDEs are managed in various conditions. The paper highlights a number of issues that should be considered in an integrated and holistic approach to future management of groundwater and its dependent ecosystems.     

The clinical implementation of non-invasive prenatal diagnosis for single-gene disorders: challenges and progress made

Recently, we have witnessed the rapid translation into clinical practice of non-invasive prenatal testing for the common aneuploidies, most notably within the United States and China. This represents a lucrative market with testing being driven by companies developing and offering their services. These tests are currently aimed at women with high/medium-risk pregnancies identified by serum screening and/or ultrasound scanning. Uptake has been impressive, albeit limited to the commercial sector. However, non-invasive prenatal diagnosis (NIPD) for single-gene disorders has attracted less interest, no doubt because this represents a much smaller market opportunity and in the majority of cases has to be provided on a bespoke, patient or disease-specific basis. The methods and workflows are labour-intensive and not readily scalable. Nonetheless, there exists a significant need for NIPD of single-gene disorders, and the continuing advances in technology and data analysis should facilitate the expansion of the NIPD test repertoire. Here, we review the progress that has been made to date, the different methods and platform technologies, the technical challenges, and assess how new developments may be applied to extend testing to a wider range of genetic disorders. © 2013 John Wiley & Sons, Ltd.     

Toxics Use Reduction in the Home: Lessons Learned from Household Exposure Studies

Workers and fence-line communities have been the first to benefit from the substantial reductions in toxic chemical use and byproducts in industrial production resulting from the Massachusetts Toxics Use Reduction Act (TURA). As TURA motivates reformulation of products as well as retooling of production processes, benefits could extend more broadly to large-scale reductions in everyday exposures for the general population. Household exposure studies, including those conducted by Silent Spring Institute, show that people are exposed to complex mixtures of indoor toxics from building materials and a myriad of consumer products. Pollutants in homes are likely to have multiple health effects because many are classified as endocrine disrupting compounds (EDCs), with the ability to interfere with the body’s hormone system. Product-related EDCs measured in homes include phthalates, halogenated flame retardants, and alkylphenols. Silent Spring Institute’s chemical analysis of personal care and cleaning products confirms many are potential sources of EDCs, highlighting the need for a more comprehensive toxics use reduction (TUR) approach to reduce those exposures. Toxics use reduction targeted at EDCs in consumer products has the potential to substantially reduce occupational and residential exposures. The lessons that have emerged from household exposure research can inform improved chemicals management policies at the state and national levels, leading to safer products and widespread health and environmental benefits.     

Evaluation of Dairy Effluent Management Options Using Multiple Criteria Analysis

This article describes how options for managing dairy effluent on the Lower Murray River in South Australia were evaluated using multiple criteria analysis (MCA). Multiple criteria analysis is a framework for combining multiple environmental, social, and economic objectives in policy decisions. At the time of the study, dairy irrigation in the region was based on flood irrigation which involved returning effluent to the river. The returned water contained nutrients, salts, and microbial contaminants leading to environmental, human health, and tourism impacts. In this study MCA was used to evaluate 11 options against 6 criteria for managing dairy effluent problems. Of the 11 options, the MCA model selected partial rehabilitation of dairy paddocks with the conversion of remaining land to other agriculture. Soon after, the South Australian Government adopted this course of action and is now providing incentives for dairy farmers in the region to upgrade irrigation infrastructure and/or enter alternative industries.