Mallard duck (Anas platyrhynchos)-mediated dispersal of Lemnaceae: a contributing factor in the spread of invasive Lemna minuta?

Our ability to predict and manage the spread of alien, invasive plants is limited by a lack of understanding of dispersal potential. Invasive Lemna minuta has spread within a few decennia throughout Europe. However, the mechanism by which the species continues to spread remains a matter of speculation. In this study, hypothesised epizoochorous transport of L. minuta propagules by mallard ducks was investigated. Landolt (Biosystematic investigations in the family of duckweeds (Lemnaceae) (Vol. 2), The family of Lemnaceae - a monographic study (Vol. 1), 1986, Veröffentlichungen des Geobotanischen Institutes Der Eidg. Techniasche Hochschule, Stiftung Rübel, Zürich, Switzerland) referred to desiccation as the key limitation of the "colonization capability" of Lemnaceae. Therefore, we analysed retention of viability in L. minuta kept outside the liquid growth medium. Our data show prolonged viability of L. minuta fronds inserted between the feathers of a mallard duck. Consistently, the relative humidity between feathers ranged between 65% and 90%. Taking together evidence of entanglement and retention of L. minuta between the feathers of live ducks, with retention of viability, we consider it likely that mallards contribute to L. minuta dispersal. These data have implications for the management strategy of this invasive species.

Influence of disseminated neoplasia, trematode infections and gametogenesis on surfacing and mortality in the cockle Cerastoderma edule.

Cerastoderma edule is a widely distributed bivalve mollusc, commercially exploited throughout Europe and is also an important food source for birds and crustaceans. Recently, mass surfacing and mortalities of cockles have been observed and reported at sites in Ireland and elsewhere, particularly in the summer months. One such site is Flaxfort Strand, Courtmacsherry Bay, County Cork, Ireland, an important feeding area used by many seabirds during the summer months. For the past few years large numbers of surfaced cockles have been observed at the site in a moribund condition. Samples of cockles from this area were collected over the summer months and their health status assessed. Cockles that had surfaced (moribund) and those still buried in the sediment were quantified and screened: sex, gonadal maturity and size class of cockles were also determined. Disseminated neoplasia and trematodes were observed in screened cockles. The most significant finding during the study was that mortalities and surfacing of cockles was related to a greater incidence of disseminated neoplasia. No neoplasia was observed in the smallest and largest size classes. There was a significantly higher prevalence of neoplasia in moribund cockles than in buried cockles, whereas in both groups a similar concentration of trematode metacercariae was observed in the screened tissues. Also, most of the cockles that had surfaced were either in the process of spawning or were spent. Overall a much larger percentage of moribund cockles exhibited both trematode infections plus neoplasia compared with buried cockles. A combination of the presence of neoplasia and trematodes, along with stress related to spawning, may immunocompromise the cockless, causing the animals to surface and become moribund.

Analysis of threshold-type behaviour in mathematical models of the intrusion of a novel macroparasite in a host colony.

Macroparasites include worms, ticks, mites, bugs and fleas. These parasites are well known to induce morbidity effects including a reduction in the hosts' reproductive output and survival. An important scenario is the introduction of a new macroparasite into an established host population which may be caused by the climate change and by the transport of domestic animals. The aim of the article is to demonstrate an interesting feature of this scenario using a mathematical model with four dimensionless parameters. Six possible scenarios of introducing a new macroparasite into a host colony, ranging from the elimination of the new pathogen, through guaranteed host and parasite coexistence, to the collapse of the host colony are distinguished. The threshold surfaces in the space of parameters which separate the different scenarios are found. Some special limit cases are discussed.

Temporal variation of Meiogymnophallus minutus infections in the first and second intermediate host.

In order to study seasonal patterns of Meiogymnophallus minutus infections in its intermediate hosts, bivalve samples were collected monthly between April 2008 and March 2009 from a high intertidal flat at Courtmacsherry Bay, Ireland. Infection rates in the first intermediate host Scrobicularia plana did not fluctuate significantly with season. Completely developed M. minutus cercariae appeared in daughter sporocysts from June and prevailed from July to October, indicating that transmission of M. minutus from its first to its second intermediate host is confined to this period of the year. All analysed individuals of the second intermediate host Cerastoderma edule were found to be infected with metacercariae. Infection levels significantly increased in September, suggesting recent cercarial invasions. Throughout the year, the majority of metacercariae were hyperinfected by the pathogenic microsporidian Unikaryon legeri. Spreading of hyperinfections was confined to spring and summer. Newly settled metacercariae were not affected by hyperparasitism and presumably retained their infectivity for half a year. Our findings suggest that the spreading of hyperinfections is correlated with higher water temperatures and that the entire metacercarial population has to rebuild every year as a consequence of hyperparasite-induced mortality.

Infection of Mytilus edulis by the trematode Echinostephilla patellae (Digenea: Philophthalmidae).

The blue mussel Mytilus edulis is described as second intermediate host for Echinostephilla patellae from the common limpet Patella vulgata. Mussels were infected with metacercariae of E. patellae under laboratory conditions. Average infection rates increased with increasing temperature, whereas numbers of cercariae, to which individual mussels were exposed, had no effect on relative infection success. The round to slightly oval metacercariae with an average cyst diameter of 208 microm (range 186-243 microm) encysted exclusively in the foot tissue of M. edulis. Morphologically similar metacercariae were found in naturally infected mussels at sites where parasitized P. vulgata and M. edulis are sympatric. This is the first report of E. patellae in blue mussels. The detection of M. edulis being a second intermediate host is of particular interest with regard to the abundance of the parasite and host organisms in intertidal rocky shore ecosystems. The potential role of the common limpet P. vulgata as an alternative secondary host is discussed.

Internal carotid artery aneurysm repair requiring skull base resection: a case study.

A 51-year-old man with a history of hypertension and smoking with an internal carotid artery (ICA) aneurysm was a referral from an outside hospital. He had a history remarkable for headaches for 6 months refractory to conventional therapy, but no stroke, transient ischemic attack, seizure activity, or neck pain. Arteriogram revealed a right ICA aneurysm at the level of the skull base with no accessible cervical ICA distal to the aneurysm. The petrous and intracranial ICA were normal. A team approach to repair was undertaken with a skull base resection and ICA exposure by head and neck surgeons and vascular reconstruction with vein graft from common carotid to petrous portion of ICA by vascular surgeons. A small right parietal infarction was noted in the postoperative period and became a focus of seizure activity. Anti-seizure medication was successful and transient upper-extremity weakness cleared. Transient dysfunction of cranial nerves VII and IX developed. The complex nature of the operation required expertise from different surgical specialties, and the postoperative complication mandated medical specialty and extensive inpatient and outpatient physical, occupational, and speech therapies ICA aneurysms of the skull base are uncommon. Historic treatment involved either ligation with a high risk of stroke or bypass to intracranial artery because direct repair was difficult. With a skilled team approach, direct repair as described is effective. This article focuses on the complexity of the surgical procedure, perioperative care, outcome of surgical intervention, and a multidisciplinary approach to the care of the patient undergoing ICA aneurysm repair requiring skull base resection.

Graded compression ultrasound in the diagnosis of appendicitis. A comparison of diagnostic criteria.

Four sonographic diagnostic criteria for appendicitis, (1) any visualization, (2) appendiceal diameter greater than 6.0 mm, (3) muscular wall thickness greater than or equal to 3.0 mm, and (4) presence of a complex mass, were compared in a series of 200 patients clinically suspected of having appendicitis. The diagnosis of appendicitis was confirmed histopathologically and included all forms of appendicitis with mucosal invasion by inflammatory cells. The sensitivities of all the criteria were low (11% to 75%) and the usefulness of this test as a screening procedure is questioned. The combined criteria of an appendix with a muscular wall thickness (MWT) greater than or equal to 3.0 mm and visualization of a complex mass (CM) separate from the adnexa in females proved most useful as a diagnostic test (sensitivity, 68%; specificity, 98%). We conclude that the diagnosis of appendicitis is still difficult, despite the addition of graded compression ultrasound as a diagnostic test. We do not recommend its use as the only screening test, but do recommend it, rather, in a diagnostic role after the initial clinical screening.

Mixed infections with tick-borne viruses in a seabird colony in Eire.

Viruses were isolated from 2 tick species collected from the nesting areas of seabirds on Great Saltee Island, Eire. Bunyaviruses of the Uukuniemi serogroup were isolated from hard ticks (Ixodes uriae and I. rothschildi), bunyaviruses of the Hughes serogroup from soft ticks (Ornithodoros maritimus), and orbiviruses of the Kemerovo serogroup from I. uriae and O. maritimus. The results indicate that the bunyaviruses, but not the orbiviruses, show "tick specificity". Neutralising activity against members of all 3 serogroups was detected in sera from chicks in the nesting areas; neutralising antibodies were probably maternal.

Catholic health care institutions and social justice.

What implications for the health care apostolate lie in the programs and plans of the National Conference of Catholic Bishops and the United States Catholic Conference? This question is explored through looking at the relationship of the health care ministry to NCCB and USCC priorities--social justice, family life, parish renewal, and evangelization.

Isolation of a Soldado-like virus (Hughes group) from Ornithodorus maritimus ticks in Ireland.

Three isolations of a virus of the Hughes group were obtained from seabird ectoparasites, Ornithodoros (Alectorobius) maritimus, on Great Saltee Island, Ireland. The agent is closely related to Soldado virsu, originally obtained from related ticks near Trinidad, West Indies, and represents the second recorded tickborne arbovirus in Ireland.

Increasing operability and survival with intra-aortic ballon pump assist.

Intra-aortic ballon pump assist (IABPA) was used over a 12-month period in the management of 41 patients: 5 patients with complications of myocardial infarction in shock whose circulation was supported by IABPA before operation immediately after angiographic and hemodynamic study (group 1); 14 patients with postcardiotomy low-output state who could not be weaned from cardiopulmonary bypass and required IABPA circulatory support either in the operating room or in the intensive care area (group 2); 19 patients with severe myocardial ischemia and unstable circulation in whom IABPA was instituted either before angiography or before saphenous vein bypass operation (group 3); and 3 patients with severe left ventricular dysfunction and left ventricular hypertrophy due to aortic valve or coronary artery disease, or both, in whom IABPA was used before, during and after cardiopulmonary bypass and a corrective operative procedure (group 4). Survival rates for patients in these groups were 2/5,8/14,18/19 and 2/3 respectively (overall survival, 73%). IABPA may increase the postoperative survival of certain high-risk patients with poor left ventricular function due to valvular disease or coronary artery disease, or both. The survival of patients with severe myocardial ischemia and complicated myocardial infarction is improved by IABPA, early angiography and appropriate surgical correction. Left ventricular ejection fraction and the estimate of subendocardial coronary flow by the ratio of the diastolic pressure time index to the tension time index appear to be significant in identifying patients who may benefit from the use of IABPA.