An improved immunoassay for detection of saxitoxin by surface plasmon resonance biosensors

Saxitoxin and its analogs, the causative agents of paralytic shellfish poisoning (PSP), are a worldwide threat to seafood safety. Effective monitoring of potentially contaminated fishing areas as well as screening of seafood samples is necessary to adequately protect the public. While many analytical methods exist for detecting paralytic shellfish toxins (PSTs), each technique has challenges associated with routine use. One recently developed method [1] that overcomes ethical or performance-related issues of other techniques is the surface plasmon resonance (SPR) bioassay. Notwithstanding the advantages of this method, much research remains in optimizing the sensor substrate and assay conditions to create a robust technique for rapid and sensitive measurement of PSTs. This manuscript describes a more rigorous and stable SPR inhibition immunoassay through optimization of the surface chemistry as well as determination of optimum mixture ratios and mixing times. The final system provides rapid substrate formation (18 h saxitoxin conjugation with low reagent consumption), contains a reference channel for each assay, and is capable of triplicate measurements in a single run with detection limits well below the regulatory action level. Published by Elsevier B.V.

Pain and suffering in invertebrates?

All animals face hazards that cause tissue damage and most have nociceptive reflex responses that protect them from such damage. However, some taxa have also evolved the capacity for pain experience, presumably to enhance longterm protection through behavior modification based on memory of the unpleasant nature of pain. In this article I review various criteria that might distinguish nociception from pain. Because nociceptors are so taxonomically widespread, simply demonstrating their presence is not sufficient. Furthermore, investigation of the central nervous system provides limited clues about the potential to experience pain. Opioids and other analgesics might indicate a central modulation of responses but often peripheral effects could explain the analgesia; thus reduction of responses by analgesics and opioids does not allow clear discrimination between nociception and pain. Physiological changes in response to noxious stimuli or the threat of a noxious stimulus might prove useful but, to date, application to invertebrates is limited. Behavior of the organism provides the greatest insights. Rapid avoidance learning and prolonged memory indicate central processing rather than simple reflex and are consistent with the experience of pain. Complex, prolonged grooming or rubbing may demonstrate an awareness of the specific site of stimulus application. Tradeoffs with other motivational systems indicate central processing, and an ability to use complex information suggests sufficient cognitive ability for the animal to have a fitness benefit from a pain experience. Available data are consistent with the idea of pain in some invertebrates and go beyond the idea of just nociception but are not definitive. In the absence of conclusive data, more humane care for invertebrates is suggested.

Contact, trust and social capital in Northern Ireland: a qualitative study of three mixed communities

In a recent paper, Robert Putnam (2007) challenges the contact hypothesis by arguing that ethnic diversity causes people to ‘hunker down’ and essentially withdraw themselves from society. Drawing on
qualitative data collected from three mixed communities in Northern Ireland, this paper explores the extent and quality of contact experienced by Protestants and Catholics in their everyday lives. Themes emerging from our data are generally consistent with the contact hypothesis. There is also some support for Putnam’s theory that mixed environments can induce ‘hunkering down’ and that inter-group trust may be compromised. However, our data challenge Putnam’s argument that these responses are a consequence of ‘anomie’ or ‘social malaise’. Rather, we find that withdrawal from social activity in the neighbourhoods we observed was a calculated response at times of threat, often aimed at protecting existent positive inter-ethnic relations.

Post-mortem examination of a wild muntjac from Northern Ireland.

1. Deer are of major concern with regards to impacts on biodiversity, forestry and agriculture as well as human health. The invasive Reeves’ muntjac deer Muntiacus reevesi, native to Asia but established in Great Britain, has recently appeared in the wild in Ireland.

2. The first verified record in the wild in Northern Ireland was confirmed during June 2009 as a result of a road traffic accident near Newtownards, Co. Down. The second record was a culled animal shot in the grounds of Mount Stewart, Co. Down during June 2011.

3. The current report aimed to perform a detailed investigation of the most recently obtained animal to establish a) its age, b) its genetic relationship with the first animal and c) the threat it might pose in terms of carrying endo- or ecto-parasites or other micro-pathogens, principally viruses and bacteria.

4. Analysis of its dentition suggested the culled animal was 56 weeks old (range 55-57 weeks).

5. Genetic analysis indicated that there was no possibility of a father-son relationship with the buck killed in 2009. There was a 6.25% probability of both individuals being full-sibs and a 25% probability of a half-sib relationship.

6. The deer was free from all the major pathogens. Most significantly, a novel species of Gammaherpesvirus was detected most closely matching type 2 ruminant rhadinovirus (Gammaherpesvirinae) from mule deer. Further sequencing is required to provide a definitive classification. There is no evidence suggesting this virus is pathogenic but its detection is nonetheless of concern.

7. During late 2009 (after the first animal was recovered) and early 2010, there were a number of sightings of muntjac within the vicinity of Mount Stewart. Our results indicate that the animal shot in June 2011 could not have been this same animal, as the shot animal must have been born in spring 2010. Moreover, genetic analysis indicates that the two recovered individuals were highly unlikely to share the same mother and father, suggesting they were the offspring of a minimum of three breeding adults (two fathers and one mother or two mothers and one father). This brings the total number of known individuals to 5 including the two offspring. The location of the breeding adults is unknown and may be either in captivity with subsequent escapees, or deliberate releases, or be free living in the wild. However, a further sighting during early 2012 may suggest a wild origin.

Range expansion in an invasive small mammal: influence of life-history and habitat quality.

Invasive species pose a major threat to biodiversity but provide an opportunity to describe the processes that lead to changes in a species’ range. The bank vole (Myodes glareolus) is an invasive rodent that was introduced to Ireland in the early twentieth century. Given its continuing range expansion, the substantial empirical data on its spread thus far, and the absence of any eradication program, the bank vole in Ireland represents a unique model system for studying the mechanisms influencing the rate of range expansion in invasive small mammals. We described the invasion using a reaction–diffusion model informed by empirical data on life history traits and demographic parameters. We subsequently modelled the processes involved in its range expansion using a rule-based spatially explicit simulation. Habitat suitability interacted with density-dependent parameters to influence dispersal, most notably the density at which local populations started to donate emigrating individuals, the number of dispersing individuals and the direction of dispersal. Whilst local habitat variability influenced the rate of spread, on a larger scale the invasion resembled a simple reaction–diffusion process. Our results suggest a Type 1 range expansion where the rate of expansion is generally constant over time, but with some evidence for a lag period following introduction. We demonstrate that a two-parameter empirical model and a rule-based spatially explicit simulation are sufficient to accurately describe the invasion history of a species that exhibits a complex, density-dependent pattern of dispersal.

Revolt and Revolution: the place of Islamism

The outbreak of revolt and revolution in the Middle East has given rise to a re-consideration of threat and security analyses as they pertain to the region and beyond. The resilience of some authoritarian regimes and the rapid collapse of others signal a significant transition within the region to which jihadi Islamist groups form one part of a powerful matrix. This article analyses the part and place of jihadi Islamism and Islamisms more generally in the revolts and revolutions. The article contends that events provide both opportunities and threats in strategies aimed at countering terrorism in the Middle East.

Autophagy stimulation by rapamycin suppresses lung inflammation and infection by Burkholderia cenocepacia in a model of cystic fibrosis

Cystic fibrosis (CF) is the most common inherited lethal disease in Caucasians which results in multiorgan dysfunction. However, 85% of the deaths are due to pulmonary infections. Infection by Burkholderia cenocepacia (B. cepacia) is a particularly lethal threat to CF patients because it causes severe and persistent lung inflammation and is resistant to nearly all available antibiotics. In CFTR Delta F508 (Delta F508) mouse macrophages, B. cepacia persists in vacuoles that do not fuse with the lysosomes and mediates increased production of IL-1 beta. It is believed that intracellular bacterial survival contributes to the persistence of the bacterium. Here we show for the first time that in wild-type but not in Delta F508 macrophages, many B. cepacia reside in autophagosomes that fuse with lysosomes at later stages of infection. Accordingly, association and intracellular survival of B. cepacia are higher in CFTR-Delta F508 macrophages than in WT macrophages. An autophagosome is a compartment that engulfs nonfunctional organelles and parts of the cytoplasm then delivers them to the lysosome for degradation to produce nutrients during periods of starvation or stress. Furthermore, we show that B. cepacia downregulates autophagy genes in WT and Delta F508 macrophages. However, autophagy dysfunction is more pronounced in Delta F508 macrophages since they already have compromised autophagy activity. We demonstrate that the autophagy-stimulating agent, rapamycin markedly decreases B. cepacia infection in vitro by enhancing the clearance of B. cepacia via induced autophagy. In vivo, rapamycin decreases bacterial burden in the lungs of CF mice and drastically reduces signs of lung inflammation. Together, our studies reveal that if efficiently activated, autophagy can control B. cepacia infection and ameliorate the associated inflammation. Therefore, autophagy is a novel target for new drug development for CF patients to control B. cepacia infection and accompanying inflammation.

Intracellular survival of Burkholderia cepacia complex isolates in the presence of macrophage cell activation

Strains of the Burkholderia cepacia complex have emerged as a serious threat to patients with cystic fibrosis due to their ability to infect the lung and cause, in some patients, a necrotizing pneumonia that is often lethal. It has recently been shown that several strains of the B. cepacia complex can escape intracellular killing by free-living amoebae following phagocytosis. In this work, the ability of two B. cepacia complex strains to resist killing by macrophages was explored. Using fluorescence microscopy, electron microscopy and a modified version of the gentamicin-protection assay, we demonstrate that B. cepacia CEP021 (genomovar VI), and Burkholderia vietnamiensis (previously B. cepacia genomovar V) CEP040 can survive in PU5-1.8 murine macrophages for a period of at least 5 d without significant bacterial replication. Furthermore, bacterial entry into macrophages stimulated production of tumour necrosis factor and primed them to release toxic oxygen radicals following treatment with phorbol myristoyl acetate. These effects were probably caused by bacterial LPS, as they were blocked by polymyxin B. Infected macrophages primed with interferon gamma produced less nitric oxide than interferon-gamma-primed uninfected cells. We propose that the ability of B. cepacia to resist intracellular killing by phagocytic cells may play a role in the pathogenesis of cystic fibrosis lung infection. Our data are consistent with a model where repeated cycles of phagocytosis and cellular activation without bacterial killing may promote a deleterious inflammatory response causing tissue destruction and decay of lung function.

Cognitive Adaptation to the Experience of Social and Cultural Diversity

Diversity is a defining characteristic of modern society, yet there remains considerable debate over the benefits that it brings. The authors argue that positive psychological and behavioral outcomes will be observed only when social and cultural diversity is experienced in a way that challenges stereotypical expectations and that when this precondition is met, the experience has cognitive consequences that resonate across multiple domains. A model, rooted in social categorization theory and research, outlines the preconditions and processes through which people cognitively adapt to the experience of social and cultural diversity and the resulting cross-domain benefits that this brings. Evidence is drawn from a range of literatures to support this model, including work on biculturalism, minority influence, cognitive development, stereotype threat, work group productivity, creativity, and political ideology. The authors bring together a range of differing diversity experiences and explicitly draw parallels between programs of research that have focused on both perceiving others who are multicultural and being multicultural oneself. The findings from this integrative review suggest that experiencing diversity that challenges expectations may not only encourage greater tolerance but also have benefits beyond intergroup relations to varied aspects of psychological functioning.

China’s National Security Review: a tit-for-tat response?

China is gradually taking its place as a major regulator, exercising concurrent jurisdiction of the national security review along with the US and EU over high-profile cross-border mergers and acquisitions. The National Security Review (NSR) regulatory regime of foreign acquisitions has attracted significant attention recently with the establishment of China's counterpart to the Committee on Foreign Investment in the United States (CFIUS). Due to the intensified activities of sovereign wealth funds (SWFs) that are closely linked with states, CFIUS's broad discretion to deal with China's SWF-based investment may have a far-reaching impact on China's implementation of the newly enacted NSR regime. It is essential to design a mechanism that allows SWFs to maximise their positive attributes while safeguarding the apolitical integrity of the marketplace. Any disproportionate use of the NSR regime would inevitably bring about more unintended consequences, such as tit-for-tat protectionism. This represents an imminent threat to the tenuous recovery from the recent economic crisis, largely because of the increasingly intertwined and interdependent nature of the global financial markets. It is of utmost significance to evaluate the extent to which the updated legislation strikes a reasonable balance between preserving genuine national security interests and maintaining an open environment for investment.

Detection of Paralytic Shellfish Toxins by a Solid-Phase Inhibition Immunoassay Using a Microsphere-Flow Cytometry System

Paralytic shellfish poisoning is a toxic syndrome described in humans following the ingestion of seafood contaminated with saxitoxin and/or its derivatives. The presence of these toxins in shellfish is considered an important health threat and their levels in seafood destined to human consumption are regulated in many countries, as well as the levels of other chemically unrelated toxins. We studied the feasibility of immunodetection of saxitoxin and its analogs using a solid-phase microsphere assay coupled to flow cytometry detection in a Luminex 200 system. The technique consists of a competition assay where the toxins in solution compete with bead-bound saxitoxin for binding to an antigonyautoxin 2/3 monoclonal antibody (GT-13A). The assay allowed the detection of saxitoxin both in buffer and mussel extracts in the range of 2.2-19.7 ng/mL (IC(20)-IC(80)). Moreover, the assay cross-reactivity with other toxins of the group is similar to previously published immunoassays, with adequate detection of most analogs except N-1 hydroxy analogs. The recovery rate of the assay for saxitoxin was close to 100%. This microsphere-based immunoassay is suitable to be used as a screening method, detecting saxitoxin from 260 to 2360 µg/kg. This microsphere/flow cytometry system provided similar sensitivities to previously published immunoassays and provides a solid background for the development of easy, flexible multiplexing of toxin detection in one sample.

Substantial genetic divergence between morphologically indistinguishable populations of Fasciola suggests the possibility of cryptic speciation.

The liver flukes, Fasciola hepatica and Fasciola gigantica, are considered to be sister species and between them present a major threat worldwide to livestock production. In this study sequence data have been employed from informative regions of the nuclear and mitochondrial genomes of over 200 morphologically F. hepatica-like or F. gigantica-like flukes from Europe, sub-Saharan Africa and South Asia to assess genetic diversity. Evidence is presented for the existence of four well-separated clades: African gigantica-like flukes, Indian gigantica-like flukes, European hepatica-like flukes and African high-altitude hepatica-like flukes. Application of the Biological Species Concept to trematodes is problematic; however, the degree of separation between these groups was sufficient for them to be considered as distinct species using the four times rule for speciation.

Variation in grain arsenic assessed in a diverse panel of rice (Oryza sativa) grown in multiple sites

• Inorganic arsenic (As(i) ) in rice (Oryza sativa) grains is a possible threat to human health, with risk being strongly linked to total dietary rice consumption and consumed rice As(i) content. This study aimed to identify the range and stability of genetic variation in grain arsenic (As) in rice. • Six field trials were conducted (one each in Bangladesh and China, two in Arkansas, USA over 2 yr, and two in Texas, USA comparing flooded and nonflood treatments) on a large number of common rice cultivars (c. 300) representing genetic diversity among international rice cultivars. • Within each field there was a 3-34 fold range in grain As concentration which varied between rice subpopulations. Importantly, As(i) correlated strongly with total As among a subset of 40 cultivars harvested in Bangladesh and China. • Genetic variation at all field sites was a large determining factor for grain As concentration, indicating that cultivars low in grain As could be developed through breeding. The temperate japonicas exhibited lower grain As compared with other subpopulations. Effects for year, location and flooding management were also statistically significant, suggesting that breeding strategies must take into account environmental factors.

Potential hazard to human health from exposure to fragments of lead bullets and shot in the tissues of game animals

Lead is highly toxic to animals. Humans eating game killed using lead ammunition generally avoid swallowing shot or bullets and dietary lead exposure from this source has been considered low. Recent evidence illustrates that lead bullets fragment on impact, leaving small lead particles widely distributed in game tissues. Our paper asks whether lead gunshot pellets also fragment upon impact, and whether lead derived from spent gunshot and bullets in the tissues of game animals could pose a threat to human health.

Metal levels in the bones and livers of globally threatened marbled teal and white-headed duck from El Hondo, Spain

El Hondo is a key area for marbled teal and white-headed duck. We present Pb, Cu, Zn, Se, and As data for bone and liver in birds found dead between 1996 and 2001. Several metals were higher in adult white-headed ducks than in marbled teal. They were higher in female than in male white-headed ducks, and did not differ with sex in marbled teal, but did by age. Lead in liver of adults was influenced by Pb shot ingestion, which was detected in 21% of marbled teal and in 71% of white-headed duck. No marbled teal had liver levels indicative of Pb poisoning, while 86% of white-headed ducks did. Selenium, Zn, and Cu were elevated in 13%, 7%, and 39% of birds, respectively. Whilst Pb shot poses the greatest threat to these species, further work should assess exposure via plants, invertebrates, water, and sediments for other metals, and investigate possible sub-lethal effects.