Transplanting macrophytes to rehabilitate streams: experience and recommendations

Macrophytes play a key role in stream ecology and therefore efforts should be made to enable colonisation of plants to rehabilitate degraded streams. Our overall objectives in this study were first to add to the sparse published studies on the sustainability of transplanting macrophytes in-stream rehabilitation, and secondly to propose general recommendations for this purpose. We assessed the survival and growth of macrophytes after propagating and transplanting them into two streams, one of which was physically degraded and the other was a newly established stream part. We determined differences in colonisation success of different macrophyte species and of different bed sizes. Survival during propagation and after transplanting was 100% for four of the six species used in the experiment. Both survival and colonisation after transplanting six different plant species into a newly created headwater stream were high for Ranunculus baudotii × pseudofluitans, Callitriche cophocarpa, Potamogeton crispus and Myriophyllum spicatum but low for P. perfoliatus and P. pectinatus. After two years, the transplanted macrophyte species were all present and had spread along the stream. Ranunculus baudotii × pseudofluitans beds was more sustainable than C. cophocarpa at places where extensive sand transport occurred. After the second growing season, the smaller patches (0.12 m²) had both similar survival rate and size as the large patches (0.24 m²) for both R. baudotii × pseudofluitans and C. cophocarpa. Our study together with two previous ones from New Zealand enabled us to make general recommendations for transplanting macrophytes into streams. These include: (1) selecting suitable streams, (2) selecting and obtaining suitable plant species, (3) propagation technique and (4) transplanting technique.     

Probing intracellular motor protein activity using an inducible cargo trafficking assay

Although purified cytoskeletal motor proteins have been studied extensively with the use of in vitro approaches, a generic approach to selectively probe actin and microtubule-based motor protein activity inside living cells is lacking. To examine specific motor activity inside living cells, we utilized the FKBP-rapalog-FRB heterodimerization system to develop an in vivo peroxisomal trafficking assay that allows inducible recruitment of exogenous and endogenous kinesin, dynein, and myosin motors to drive specific cargo transport. We demonstrate that cargo rapidly redistributes with distinct dynamics for each respective motor, and that combined (antagonistic) actions of more complex motor combinations can also be probed. Of importance, robust cargo redistribution is readily achieved by one type of motor protein and does not require the presence of opposite-polarity motors. Simultaneous live-cell imaging of microtubules and kinesin or dynein-propelled peroxisomes, combined with high-resolution particle tracking, revealed that peroxisomes frequently pause at microtubule intersections. Titration and washout experiments furthermore revealed that motor recruitment by rapalog-induced heterodimerization is dose-dependent but irreversible. Our assay directly demonstrates that robust cargo motility does not require the presence of opposite-polarity motors, and can therefore be used to characterize the motile properties of specific types of motor proteins.     

Maternal effects,flight versus fecundity trade-offs,and offspring immune defence in the Speckled Wood butterfly, <Emphasis Type="Italic">Pararge aegeria</Emphasis>

Background  

Maternal condition can generate resource-related maternal effects through differential egg provisioning, and can greatly affect offspring performance. In the present study, the speckled wood butterfly Pararge aegeria (L.) was used to investigate whether (after controlling for egg size) maternal age, and increased flight during the oviposition period, resulted in changes in egg provisioning and whether this contributed to variation in offspring performance, i) early in development (egg stage and early post-hatching development), and ii) later in larval development after being exposed to the model viral pathogen system; the baculovirus Autographa californica multinucleocapsid nucleopolyhedrovirus (AcMNPV).     

Gender differences in clinical presentation and outcomes of epidemic Kaposi sarcoma in Uganda

Introduction

The incidence of Kaposi sarcoma (KS) has increased dramatically among women in sub-Saharan Africa since the onset of the HIV pandemic, but data on KS disease in women are limited. To identify gender-related differences in KS presentation and outcomes, we evaluated the clinical manifestations and response in men and women with AIDS-associated KS in Uganda.

Methods and Findings

HIV-infected adults with KS attending the Infectious Diseases Institute (IDI) and Uganda Cancer Institute (UCI) in Kampala, Uganda between 2004 and 2006 were included in a retrospective cohort. Evaluation of KS presentation was based on the clinical features described at the initial KS visit. Response was evaluated as the time to “improvement”, as defined by any decrease in lesion size, lesion number, or edema. The cohort consisted of 197 adults with HIV and KS: 55% (108/197) were women. At presentation, the median CD4 T-cell count was significantly lower in women (58 cells/mm³; IQR 11–156 cells/mm³) than men (124 cells/mm³; IQR 22–254 cells/mm³) (p = 0.02). Women were more likely than men to present with lesions of the face (OR 2.8, 95% CI, 1.4, 5.7; p = 0.005) and hard palate (OR 2.0, 95% CI, 1.1, 3.7; p = 0.02), and were less likely than men to have lower extremity lesions (OR 0.54, 95% CI, 0.3, 0.99; p = 0.05). Women were less likely than men to demonstrate clinical improvement (HR = 0.52, CI 0.31, 0.88; p = 0.01) in multivariate analysis.

Conclusions

The clinical presentation and response of KS differs between men and women in Uganda. These data suggest that gender affects the pathophysiology of KS, which may have implications for the prevention, diagnosis, and treatment of KS in both men and women. Prospective studies are needed to identify predictors of response and evaluate efficacy of treatment in women with KS, particularly in Africa where the disease burden is greatest.     

Shellfish dredging pushes a flexible avian top predator out of a marine protected area

There is a widespread concern about the direct and indirect effects of industrial fisheries; this concern is particularly pertinent for so-called “marine protected areas” (MPAs), which should be safeguarded by national and international law. The intertidal flats of the Dutch Wadden Sea are a State Nature Monument and are protected under the Ramsar convention and the European Union's Habitat and Birds Directives. Until 2004, the Dutch government granted permission for ~75% of the intertidal flats to be exploited by mechanical dredgers for edible cockles (Cerastoderma edule). Here we show that dredged areas belonged to the limited area of intertidal flats that were of sufficient quality for red knots (Calidris canutus islandica), a long-distance migrant molluscivore specialist, to feed. Dredging led to relatively lower settlement rates of cockles and also reduced their quality (ratio of flesh to shell). From 1998 to 2002, red knots increased gizzard mass to compensate for a gradual loss in shellfish quality, but this compensation was not sufficient and led to decreases in local survival. Therefore, the gradual destruction of the necessary intertidal resources explains both the loss of red knots from the Dutch Wadden Sea and the decline of the European wintering population. This study shows that MPAs that do not provide adequate protection from fishing may fail in their conservation objectives.     

Morphology and nrITS phylogeny of the genus Pinguicula L. (Lentibulariaceae), with special attention to embryo evolution

The genus Pinguicula (Lentibulariaceae) is unusual within the dicot order Lamiales because of the occurrence of both embryos with two cotyledons and those with just one cotyledon. In order to elucidate the infrageneric relationships and the evolutionary history of the embryo, we analysed (1) the internal transcribed spacers ITS1 and ITS2 of the nuclear ribosomal DNA (nrITS) of 29 Old and New World taxa of Pinguicula, and (2) the morphological and anatomical characters of the seeds. We suggest that the cotyledon number and spermoderm structure were quite unstable in the evolution of Pinguicula. Although basal nodes of the nrITS tree are sensitive to taxon sampling, all tree topologies found in this study imply homoplasy in the cotyledon number.     

SIMAGE: simulation of DNA-microarray gene expression data

Background  

Simulation of DNA-microarray data serves at least three purposes: (i) optimizing the design of an intended DNA microarray experiment, (ii) comparing existing pre-processing and processing methods for best analysis of a given DNA microarray experiment, (iii) educating students, lab-workers and other researchers by making them aware of the many factors influencing DNA microarray experiments.     

A nucleic acid sequence-based amplification assay for real-time detection of norovirus genogroup II

AIMS: To use molecular beacon based nucleic acid sequence-based amplification (NASBA) to develop a rapid, sensitive, specific detection method for norovirus (NV) genogroupII (GII). METHODS AND RESULTS: A method to detect NV GII from environmental samples using real-time NASBA was developed. This method was routinely sensitive to 100 copies of target RNA and intermittent amplification occurred with as few as 10 copies. Quantitative estimates of viral load were possible over at least four orders of magnitude. CONCLUSIONS: The NASBA method described here is a reliable and sensitive assay for the detection of NV. This method has the potential to be linked to a handheld NASBA device that would make this real-time assay a portable and inexpensive alternative to bench-top, lab-based assays. SIGNIFICANCE AND IMPACT OF THE STUDY: The development of the real-time NASBA assay described here has resulted in a simple, rapid (<1 h), convenient testing format for NV. To our knowledge, this is the first example of a molecular beacon based NASBA assay for NV.     

Chromosomal instability at common fragile sites in Seckel syndrome

Seckel syndrome (SCKL) is a rare, genetically heterogeneous disorder, with dysmorphic facial appearance, growth retardation, microcephaly, mental retardation, variable chromosomal instability, and hematological disorders. To date, three loci have been linked to this syndrome, and recently, the gene encoding ataxia-telangiectasia and Rad3-related protein (ATR) was identified as the gene mutated at the SCKL1 locus. The ATR mutation affects splicing efficiency, resulting in low levels of ATR in affected individuals. Elsewhere, we reported increased instability at common chromosomal fragile sites in cells lacking the replication checkpoint gene ATR. Here, we tested whether cells from patients carrying the SCKL1 mutation would show increased chromosome breakage following replication stress. We found that, compared with controls, there is greater chromosomal instability, particularly at fragile sites, in SCKL1-affected patient cells after treatment with aphidicolin, an inhibitor of DNA polymerase alpha and other polymerases. The difference in chromosomal instability between control and patient cells increases at higher levels of aphidicolin treatment, suggesting that the low level of ATR present in these patients is not sufficient to respond appropriately to replication stress. This is the first human genetic syndrome associated with increased chromosome instability at fragile sites following replication stress, and these findings may be related to the phenotypic findings in patients with SCKL1.