Flocculation of Chlorella vulgaris by Lactobacillus casei

Summary The flocculation of Chlorella vulgaris by Lactobacillus casei was studied to determine whether the latter could act as a suitable flocculant for the removal of Chlorella from algal ponds. The flocculating activity of the Lactobacilli was caused by the bacterial cells themselves, and not by diffusible products of bacterial metabolism. Diffusible products of algal metabolism inhibited flocculation. For algae resuspended in water, the best flocculation occurred at pH values less than 3.5 where the charges on the bacterial and algal cells were opposite. For flocculation at least one bacterium was required for every algal cell; in terms of cell concentrations,10 mg/l of bacteria were required to flocculate an algal suspension of 1,000 mg/l. The mechanism of flocculation implied by the results is that positively charged cells of L. casei adsorb to the surface of negatively charged cells of C. vulgaris neutralizing the charge and thus destabilizing the algal suspension. Because of the low pH required and because diffusible products of algal metabolism inhibit the flocculation, it is unlikely that L. casei could be usefully employed as a flocculant of Chlorella from algal ponds.     

Occupancy modelling as a new approach to assess supranational trends using opportunistic data: a pilot study for the damselfly Calopteryx splendens

There is limited information available on changes in biodiversity at the European scale, because there is a lack of data from standardised monitoring for most species groups. However, a great number of observations made without a standardised field protocol is available in many countries for many species. Such opportunistic data offer an alternative source of information, but unfortunately such data suffer from non-standardised observation effort and geographical bias. Here we describe a new approach to compiling supranational trends using opportunistic data which adjusts for these two major imperfections. The non-standardised observation effort is dealt with by occupancy modelling, and the unequal geographical distribution of sites by a weighting procedure. The damselfly Calopteryx splendens was chosen as our test species. The data were collected from five countries (Ireland, Great Britain, the Netherlands, Belgium and France), covering the period 1990–2008. We used occupancy models to estimate the annual number of occupied 1 × 1 km sites per country. Occupancy models use presence-absence data, account for imperfect detection of species, and thereby correct for between-year variability in observation effort. The occupancy models were run per country in a Bayesian mode of inference using JAGS. The occupancy estimates per country were then aggregated to assess the supranational trend in the number of occupied 1 × 1 km². To adjust for the unequal geographical distribution of surveyed sites, we weighted the countries according to the number of sites surveyed and the range of the species per country. The distribution of C. splendens has increased significantly in the combined five countries. Our trial demonstrated that a supranational trend in distribution can be derived from opportunistic data, while adjusting for observation effort and geographical bias. This opens new perspectives for international monitoring of biodiversity.     

Design, synthesis, and studies of small molecule STAT3 inhibitors

A series of small molecule STAT3 inhibitors originally derived from our lead compound STA 21 were synthesized and evaluated. The most potent compound in this series, compound 1, exhibited the same anti-proliferative activities as STA 21 against prostate cancer cell lines that express constitutively active STAT3. Molecular docking showed compound 1 bound to the STAT3beta SH2 domain in a similar manner as STA 21.     

Burr Hole Washout versus Craniotomy for Chronic Subdural Hematoma: Patient Outcome and Cost Analysis

Chronic subdural hematomas (CSDH), which are frequently encountered in neurosurgical practice, are, in the majority of cases, ideally treated with surgical drainage. Despite this common practice, there is still controversy surrounding the best surgical procedure. With lack of clear evidence of a superior technique, surgeons are free to base the decision on other factors that are not related to patient care. A retrospective chart review of 119 patients requiring surgical drainage of CSDH was conducted at a large tertiary care center over a three-year period. Of the cases reviewed, 58 patients underwent craniotomy, while 61 patients underwent burr hole washout. The study focused on re-operation rates, mortality, and morbidity, as measured by Glasgow coma scores (GCS), discharge Rankin disability scores, and discharge disposition. Secondary endpoints included length of stay and cost of procedure. Burr hole washout was superior to craniotomy with respect to patient outcome, length of stay and recurrence rates. In both study groups, patients required additional surgical procedures (6.6% of burr hole patients and 24.1% of craniotomy patients) (P = 0.0156). Of the patients treated with craniotomy, 51.7% were discharged home, whereas 65.6% of the burr hole patients were discharged home. Patients who underwent burr hole washout spent a mean of 78.8 minutes in the operating suite while the patients undergoing craniotomy spent 129.4 minutes (P < 0.001). The difference in mean cost per patient, based solely on operating time, was $2,828 (P < 0.001). This does not include the further cost due to additional procedures and hospital stay. The mean length of stay after surgical intervention was 3 days longer for the craniotomy group (P = 0.0465). Based on this retrospective study, burr hole washout is superior for both patients’ clinical and financial outcome; however, prospective long-term multicenter clinical studies are required to verify these findings.     

The role of citizen science in monitoring biodiversity in Ireland

Citizen science is proving to be an effective tool in tracking the rapid pace at which our environment is changing over large geographic areas. It is becoming increasingly popular, in places such as North America and some European countries, to engage members of the general public and school pupils in the collection of scientific data to support long-term environmental monitoring. Participants in such schemes are generally volunteers and are referred to as citizen scientists. The Christmas bird count in the US is one of the worlds longest running citizen science projects whereby volunteers have been collecting data on birds on a specific day since 1900. Similar volunteer networks in Ireland have been in existence since the 1960s and were established to monitor the number and diversity of birds throughout the country. More recently, initiatives such as Greenwave (2006) and Nature Watch (2009) invite school children and members of the general public respectively, to record phenology data from a range of common species of plant, insect and bird. In addition, the Irish butterfly and bumblebee monitoring schemes engage volunteers to record data on sightings of these species. The primary purpose of all of these networks is to collect data by which to monitor changes in wildlife development and diversity, and in the case of Greenwave to involve children in hands-on, inquiry-based science. Together these various networks help raise awareness of key environmental issues, such as climate change and loss of biodiversity, while at the same time promote development of scientific skills among the general population. In addition, they provide valuable scientific data by which to track environmental change. Here we examine the role of citizen science in monitoring biodiversity in Ireland and conclude that some of the data collected in these networks can be used to fulfil Ireland’s statutory obligations for nature conservation. In addition, a bee thought previously to be extinct has been rediscovered and a range expansion of a different bee has been confirmed. However, it also became apparent that some of the networks play more of an educational than a scientific role. Furthermore, we draw on experience from a range of citizen science projects to make recommendations on how best to establish new citizen science projects in Ireland and strengthen existing ones.     

An inclusion membrane protein from Chlamydia trachomatis enters the MHC class I pathway and stimulates a CD8+ T cell response

During its developmental cycle, the intracellular bacterial pathogen Chlamydia trachomatis remains confined within a protective vacuole known as an inclusion. Nevertheless, CD8(+) T cells that recognize Chlamydia Ags in the context of MHC class I molecules are primed during infection. MHC class I-restricted presentation of these Ags suggests that these proteins or domains from them have access to the host cell cytoplasm. Chlamydia products with access to the host cell cytoplasm define a subset of molecules uniquely positioned to interface with the intracellular environment during the pathogen's developmental cycle. In addition to their use as candidate Ags for stimulating CD8(+) T cells, these proteins represent novel candidates for therapeutic intervention of infection. In this study, we use C. trachomatis-specific murine T cells and an expression-cloning strategy to show that CT442 from Chlamydia is targeted by CD8(+) T cells. CT442, also known as CrpA, is a 15-kDa protein of undefined function that has previously been shown to be associated with the Chlamydia inclusion membrane. We show that: 1) CD8(+) T cells specific for an H-2D(b)-restricted epitope from CrpA are elicited at a significant level (approximately 4% of splenic CD8(+) T cells) in mice in response to infection; 2) the response to this epitope correlates with clearance of the organism from infected mice; and 3) immunization with recombinant vaccinia virus expressing CrpA elicits partial protective immunity to subsequent i.v. challenge with C. trachomatis.     

Development of comparative methods using gas chromatography-mass spectrometry and capillary electrophoresis for determination of endocrine disrupting chemicals in bio-solids

Two analytical separation techniques are being investigated for their potential in determining a wide range of endocrine disrupting chemicals (EDCs) in the environment. Capillary electrophoresis (CE) in the micellar mode in conjunction with a cyclodextrin (CD) modifier is shown to have potential for determination of alkylphenol breakdown products. Gas chromatography with mass spectrometric (GC-MS) detection is being utilised for validation of the CE method development and in addition as a separation technique to optimise preconcentration using solid-phase extraction. GC has demonstrated potential for the separation of 26 priority chemicals suspected as being endocrine disrupting compounds. The challenge of the method development process lies in the fact that these compounds are of differing polarities, size and charge and therefore are difficult to separate in a single run. Capillary electrophoresis in the CD-MEKC (micellar electrokinetic chromatography) mode is showing potential in this regard. Limits of determination are in the low mg/l range for CE and GC, however, using preconcentration it is possible to improve detection sensitivity with >80% recovery for some analytes and up to 100% recovery for most target species.