Biological Control of Giant Reed (Arundo donax): Economic Aspects

Arundo donax is a large, invasive weed consuming large quantities of water in the riparian area of the Texas Rio Grande Basin. With water availability a concern to the area, the USDA-ARS is investigating biological control agents to increase available water, creating a benefit to both the region’s economy and society in general.Arundo donax, Giant Reed, Water, Economics, Invasive, Environmental Economics and Policy, Resource /Energy Economics and Policy,

Variaciones en los patrones de pigmentación y de color de larvas de poblaciones naturales de anofeles albimanus de Colombia

Color and pigmentation variants of Anopheles albimanus of third and fourth instar larvae were described from field populations in four different geogaphic and ecological areas in Colombia, together with their frecuency. These variants include three of the head capsule, nine of body pigmentation and of body color. Also, curved antennal sabers and antennal pigmentation are described. We report the ocurrence of high level of polymorphys in body color, pigmentation pattern and other visible traits. A brief description of each variant its frequency in each populations is included.Fueron observados el patrón de pigmentación y el color del cuerpo de las larvas de III y IV estadio en poblaciones naturales de Anopheles albimanus procedentes de cuatro áreas geográficas y ecológicas diferentes. Se incluyen tres variantes de la cápsula de la cabeza, el sable curvado de las antenas y la pigmentación; nueve variantes de la pigmentación del cuerpo y 17 del color del cuerpo. Se informa la alta variación en los patrones de color y otras características visibles. Se incluye una breve descripción de cada variante y la frecuencia observada en cada población

Occupational and environmental hazard assessments for the isolation, purification and toxicity testing of cyanobacterial toxins

Cyanobacteria can produce groups of structurally and functionally unrelated but highly potent toxins. Cyanotoxins are used in multiple research endeavours, either for direct investigation of their toxicologic properties, or as functional analogues for various biochemical and physiological processes. This paper presents occupational safety guidelines and recommendations for personnel working in field, laboratory or industrial settings to produce and use purified cyanotoxins and toxic cyanobacteria, from bulk harvesting of bloom material, mass culture of laboratory isolates, through routine extraction, isolation and purification. Oral, inhalational, dermal and parenteral routes are all potential occupational exposure pathways during the various stages of cyanotoxin production and application. Investigation of toxicologic or pharmacologic properties using in vivo models may present specific risks if radiolabelled cyanotoxins are employed, and the potential for occupational exposure via the dermal route is heightened with the use of organic solvents as vehicles. Inter- and intra-national transport of living cyanobacteria for research purposes risks establishing feral microalgal populations, so disinfection of culture equipment and destruction of cells by autoclaving, incineration and/or chlorination is recommended in order to prevent viable cyanobacteria from escaping research or production facilities

Subfunctionalization of Duplicated Zebrafish pax6 Genes by cis-Regulatory Divergence

Gene duplication is a major driver of evolutionary divergence. In most vertebrates a single PAX6 gene encodes a transcription factor required for eye, brain, olfactory system, and pancreas development. In zebrafish, following a postulated whole-genome duplication event in an ancestral teleost, duplicates pax6a and pax6b jointly fulfill these roles. Mapping of the homozygously viable eye mutant sunrise identified a homeodomain missense change in pax6b, leading to loss of target binding. The mild phenotype emphasizes role-sharing between the co-orthologues. Meticulous mapping of isolated BACs identified perturbed synteny relationships around the duplicates. This highlights the functional conservation of pax6 downstream (3′) control sequences, which in most vertebrates reside within the introns of a ubiquitously expressed neighbour gene, ELP4, whose pax6a-linked exons have been lost in zebrafish. Reporter transgenic studies in both mouse and zebrafish, combined with analysis of vertebrate sequence conservation, reveal loss and retention of specific cis-regulatory elements, correlating strongly with the diverged expression of co-orthologues, and providing clear evidence for evolution by subfunctionalization

What was Progressive in ‘Progressive Conservatism’?

In January 2009 David Cameron announced that the ‘underlying philosophy’ of his government would be progressive conservatism. Despite the ambiguity about this term, it was generally interpreted as a signal that Cameron was moving his party to the left.To some commentators, Cameron was allying with the progressive ‘one nation’ strand of conservative thought.To others, particularly in the media, he was drawing on the more immediate influence of Phillip Blond’s ‘Red Toryism’. However, the focus on the market (as opposed to state or community) found in both Cameron’s speech and subsequent policies sits uneasily with both of these interpretations. Cameron’s progressive conservatism has more in common with Thatcherism – an earlier conservative modernising project – than it does with centrist forms of conservative progressivism. Cameron’s progressive conservatism is progressive, but only in particular, less commonly used, ways – not as a rediscovery of social justice

Comparison of Life History Characteristics of the Genetically Modified OX513A Line and a Wild Type Strain of Aedes aegypti

The idea of implementing genetics-based insect control strategies modelled on the traditional SIT (Sterile Insect Technique), such as RIDL (Release of Insects carrying a Dominant Lethal), is becoming increasingly popular. In this paper, we compare a genetically modified line of Aedes aegypti carrying a tetracycline repressible, lethal positive feedback system (OX513A) with a genetically similar, unmodified counterpart and their respective responses to increasing larval rearing density using a constant amount of food per larva. The parameters that we examined were larval mortality, developmental rate (i.e., time to pupation), adult size and longevity

Reassessing Britain’s ‘post-war consensus’: the politics of reason 1945–1979

Since the late-1970s, scholars have been engaged in a vibrant debate about the nature of post-war British politics. While some writers have suggested that the three decades that succeeded the Second World War witnessed a bi-partisan consensus on key policy questions, others have argued that it was conflict, not agreement, that marked the period. This article offers a novel contribution to this controversy by drawing attention to the epistemological beliefs of the Labour and Conservative parties. It argues that once these beliefs are considered, it becomes possible to reconcile some of the competing claims made by proponents and critics of the ‘post-war consensus’ thesis. Labour and Conservative leaders may have been wedded to different beliefs, but they also shared a common enthusiasm for empiricist reasoning and were both reluctant to identify fixed political ‘ends’ that they sought to realise. Consequently, they were both committed to evolutionary forms of change, and they eschewed the notion that any social or political arrangement was of universal value

Primary irritant and delayed-contact hypersensitivity reactions to the freshwater cyanobacterium Cylindrospermopsis raciborskii and its associated toxin cylindrospermopsin

BACKGROUND: Freshwater cyanobacteria are common inhabitants of recreational waterbodies throughout the world; some cyanobacteria can dominate the phytoplankton and form blooms, many of which are toxic. Numerous reports in the literature describe pruritic skin rashes after recreational or occupational exposure to cyanobacteria, but there has been little research conducted on the cutaneous effects of cyanobacteria. Using the mouse ear swelling test (MEST), we sought to determine whether three toxin-producing cyanobacteria isolates and the purified cyanotoxin cylindrospermopsin produced delayed-contact hypersensitivity reactions. METHODS: Between 8 and 10 female Balb/c mice in each experiment had test material applied to depilated abdominal skin during the induction phase and 10 or 11 control mice had vehicle only applied to abdominal skin. For challenge (day 10) and rechallenge (day 17), test material was applied to a randomly-allocated test ear; vehicle was applied to the other ear as a control. Ear thickness in anaesthetised mice was measured with a micrometer gauge at 24 and 48 hours after challenge and rechallenge. Ear swelling greater than 20% in one or more test mice is considered a positive response. Histopathology examination of ear tissues was conducted by independent examiners. RESULTS: Purified cylindrospermopsin (2 of 9 test mice vs. 0 of 5 control mice; p = 0.51) and the cylindrospermopsin-producing cyanobacterium C. raciborskii (8 of 10 test mice vs. 0 of 10 control mice; p = 0.001) were both shown to produce hypersensitivity reactions. Irritant reactions were seen on abdominal skin at induction. Two other toxic cyanobacteria (Microcystis aeruginosa and Anabaena circinalis) did not generate any responses using this model. Histopathology examinations to determine positive and negative reactions in ear tissues showed excellent agreement beyond chance between both examiners (κ = 0.83). CONCLUSION: The irritant properties and cutaneous sensitising potential of cylindrospermopsin indicate that these toxicological endpoints should be considered by public health advisors and reservoir managers when setting guidelines for recreational exposure to cyanobacteria

Oviposition Site Selection by the Dengue Vector Aedes aegypti and Its Implications for Dengue Control

Controlling the mosquito Aedes aegypti is of public health importance because, at present, it is the only means to stop dengue virus transmission. Implementing successful mosquito control programs requires understanding what factors regulate population abundance, as well as anticipating how mosquitoes may adapt to control measures. In some species of mosquitoes, females choose egg-laying sites to improve the survival and growth of their offspring, a behavior that ultimately influences population distribution and abundance. In the current study, we tested whether Ae. aegypti actively choose the containers in which they lay their eggs and determined what cues are most relevant to that process. We also explored whether females select containers that provide the most food for their larval progeny. Surprisingly, egg-laying females were most attracted to sites containing other immature Ae. aegypti, rather than to sites containing the most food. We propose that this behavior may contribute to density-dependent competition for food among larvae and play a larger role than previously thought in regulating Ae. aegypti populations. We recommend that accounting for, and even taking advantage of, this natural behavior will lead to more effective strategies for dengue prevention