A New Opisthobranch Mollusc from Hawaii

Volume: 15Start Page: 112End Page: 11

Use of very high resolution climate model data for hydrological modelling: estimation of potential evaporation

Climate model data are increasingly used to drive hydrological models, to assess the possible impacts of climate change on river flows. Hydrological models often require potential evaporation (PE) from vegetation, alongside precipitation, but PE is not usually output by climate models so has to be estimated from other meteorological variables. Here, the Penman-Monteith formula is applied to estimate PE using data from a 12 km Regional Climate Model (RCM) and a nested very high resolution (1.5 km) RCM covering southern Britain. PE estimates from RCM runs driven by reanalysis boundary conditions are compared to observation-based PE data, to assess performance. The comparison shows that both the 1.5 and 12 km RCMs reproduce observation-based PE well, on daily and monthly time-steps, and enables choices to be made about application of the formula using the available data. Data from Current and Future RCM runs driven by boundary conditions from a Global Climate Model are then used to investigate potential future changes in PE, and how certain factors affect those changes. In particular, the importance of including changes in canopy resistance is demonstrated. PE projections are also shown to vary to some extent according to how aerosols are modelled in the RCMs

Snow in Britain: the historical picture and future projections

• The formation of snow is a complex process. Snow that reaches the ground can melt quickly or remain for periods from days to months, but most of Britain does not usually experience sustained periods of lying snow, and there are strong year-to-year variations. • Climate change is likely to have a significant effect on snow and ice processes globally. The areas most effected are likely to be those where current winter temperatures are close to 0°C, including parts of upland Britain. There is evidence of decreasing trends in observations of snowfall and lying snow in Britain, and climate model projections suggest a continuation of this trend. • Snow can affect river flows (quantity and quality). Although flows in Britain are generally dominated by rainfall rather than snowmelt, some catchments in the Scottish Highlands have a significant snowmelt contribution. • There is evidence of changes in observed and projected river flows in some catchments in Britain, linked to changes in snow, although it can be difficult to distinguish the effects of snow changes from those of other concurrent changes (climatic and non-climatic). Flow regime changes in catchments heavily affected by snow usually involve increases in winter flow and decreases in spring flow, but the effect on catchments with more transient snow cover is less clear, as is the effect on high flows and water quality. • Snow can also affect a number of other factors of socio-economic or environmental importance (e.g. transport and farming). There is some evidence that disruption due to snow may be less frequent in future, but in many cases disruption from other types of weather event may increase. • Further modelling of the potential impacts of climate change, including modelling the influence of snow changes as well as other climatic and non-climatic changes, would aid adaptation and encourage mitigation. • The impacts of snow tend to be worse in areas where events occur less frequently, due to unpreparedness. There is a need to guard against complacency when it comes to future snow events in Britain, which will still occur despite a likely reduction in frequency

A review of snow in Britain: the historical picture and future projections

Climate change is likely to have a significant effect on snow globally, with most effect where current winter temperatures are close to 0°C, including parts of upland Britain. There is evidence of decreasing trends in observations of snowfall and lying snow in Britain, and climate projections suggest a continuation of this trend. Although river flows in Britain are generally dominated by rainfall rather than snowmelt, some upland catchments have a significant snowmelt contribution. There is evidence of changes in observed and projected river flows in some catchments in Britain, linked to changes in snow, but it can be difficult to distinguish the effects of snow changes from those of other concurrent changes (climatic and non-climatic). Flow regime changes in catchments with widespread and prolonged winter snow cover usually involve increases in winter flow and decreases in spring flow, but the effect on catchments with more transient snow cover is less clear, as is the effect on high flows and water quality. Snow can also affect a number of other factors of socio-economic or environmental importance (e.g. transport and farming). There is some evidence that disruption due to snow may be less frequent in the future, but disruption from other types of weather events may increase. The impacts of snow tend to be worse in areas where events occur less frequently, due to unpreparedness, so there is a need to guard against complacency when it comes to future snow events in Britain, which can still be expected despite a likely reduction in frequency. Further modelling of the potential impacts of climate change, including modelling the influence of snow changes as well as other climatic and non-climatic changes, would aid adaptation and encourage mitigation

The Responses of Autonomically-Innervated Smooth Muscle to Nerve Stimulation and to Drugs

1. The intracellular electrical and mechanical responses of the rabbit ear artery, the rabbit superior mesenteric artery and the mouse vas deferens were examined in response to field stimulation of intramural nerves and to drugs. Each tissue demonstrated co-transmission involving noradrenaline (NA) and adenosine 5'-triphosphate (ATP), or a closely related nucleotide. 2. In the rabbit ear artery, the rabbit mesenteric artery and the mouse vas deferens the electrical response evoked by field stimulation consisted of excitatory junction potentials (e. j. p. s), which facilitated and summated to fire action potentials. These e. j. p. s were abolished by a,B-methylene ATP (a,B MeATP, 1-10 x 10-6M), suggesting that they were mediated by ATP. Only in the rabbit ear artery was there an additional electrical event mediated by NA. This took the form of a small, slow membrane depolarization which followed the e. j. p. s and which was antagonized by the a-adrenoceptor antagonists phentolamine (1 x 10-6M) or prazosin (1 x 10-7M). 3. In each of these tissues, all electrical and mechanical responses to field stimulation were abolished by either tetrodotoxin (TTX, 1 x 10-6M) or guanethidine (1 x 10-6M), suggesting that they were due to transmitters released from sympathetic nerves. 4. In the mouse vas deferens and rabbit mesenteric artery, both transmitters (NA and ATP) played a role in the contractile response to field stimulation. In the rabbit ear artery, however, only NA appeared to mediate a contractile event. 5. Contractile responses to nerve-released ATP were accompanied by a change in membrane potential. Na+ and K+ appeared to be the main ions underlying the e. j. p. and action potential. In contrast, contractile responses evoked by NA appeared to be mediated by both voltage-dependent and voltage-independent mechanisms, the relative contribution of each to the overall response varying from one tissue to another. 6. In the mouse vas deferens, exogenous application of ATP (1 x 10-4 - 1 x 10-3M) or its stable analogue, a,BMeATP (1 x 10-6M) by pressure ejection from a micro-pipette produced dose dependent depolarizations. NA (1 x 10-4 - 1 x 10-3M), similarly applied produced no such change in membrane potential. 7. In the mouse vas deferens, local application of bradykinin (1-100 x 10-7M) produced small, slow membrane hyperpolarizations. VIP (1-100 x 10-7M), neuropeptide Y (1-100 x 10-7M), substance P (1-100 x 10-7M), leu-enkephalin (1-100 x 10-7M), met-enkephalin (1-100 x 10-7M), somatostatin (1-100 x 10-7M) and bombesin (1-100 x 10-7M), similarly applied, each produced no significant change in membrane potential. None of these peptides, it was concluded, appear to be the transmitter mediating the e. j. p. s in this tissue. 8. In the rat anococcygeus muscle, membrane potential changes recorded intracellularly following field (transmural) or extrinsic nerve stimulation were indistinguishable. Single stimuli usually produced a slow depolarization; trains of pulses produced a fast e. j. p. initially, followed by a slow depolarization similar to that produced by single pulses. The fast e. j. p. s, the slow depolarizations and the accompanying contractions were abolished by the a-adrenoceptor antagonists phen-tolamine (1 x 10-6) or prazosin (1 x 10-7M), by TTX (1 x 10-6M), but were unaffected by a,BMeATP (1 - 10 x 10-6M) . 9. Application of NA (1 x 10-8 - 1 x 10-6M) by pressure ejection from a micro-pipette to the rat anococcygeus muscle depolarized the membrane and produced localized contractions, both of which were abolished by phentolamine (1 x 10-6M) or prazosin (1 x 10-7M). 10. Application of ATP (1 x 10-4 - 1 x 10-3M) by pressure ejection to the rat anococcygeus muscle produced small membrane depolarizations and localized contractions which were unaffected by phentolamine (1 x 10-6M) or prazosin (1 x 10-7M), but abolished by a,BMeATP (1 x 10-6M). 11. Results from experiments on the rat anococcygeus muscle show that field or extrinsinc nerve stimulation released only one excitatory transmitter, namely NA, although receptors for both NA and ATP are present on this muscle and that there was no evidence for excitatory cotransmission in this tissue. (Abstract shortened by ProQuest.)

Validation of the MEK5 and ERK5 pathway as targets for therapy in prostate cancer and analysis of the ERK5 signalling complex

Extracellular signal-regulated protein kinase 5 (ERK5) is a member of the mitogen activated protein (MAP) kinase family which is specifically activated by mitogen/extracellular signal regulated kinase kinase-5 (MEK5). Over recent years, abnormal MEK5/ERK5 signalling has been shown to be important in prostate carcinogenesis with increased levels of ERK5 immunoreactivity being associated with Gleason sum score (p<0.0001), bone metastases (p=0.0044) and locally advanced disease at diagnosis (p=0.0023). In addition PC3 cells over-expressing ERK5 displayed enhanced proliferation, migration and invasion. Taken together, these data suggest MEK5/ERK5 pathway to be biological important in prostate cancer and a potential target in invasive prostate cancer. Using siRNA to target ERK5 expression, I found that reduced ERK5 expression significantly inhibited cellular proliferation, motility and invasion in prostate cancer PC3 cells when compared to the controls, (p<0.005). Our group has previously reported upregulated ERK5 expression in primary human prostate cancer specimens. In this study, I was able to validate these results and demonstrate moderate-strong levels of cytoplasmic staining in 63% cases of PIN/PIA. High levels of cytoplasmic (55%) and nucleur (73%) immunoreactivity was also shown in a range of metastatic prostate tumours (n=11). A number of similarities and interactions between ERK5 and ERK1/2 have recently been identified and there is suggestion that ERK5 may in fact regulate some of the cellular functions originally attributed to ERK1/2. Potential ‘cross-talk’ between ERK5 and ERK1/2 signalling was investigated using siRNA for each individual isoform of ERK1/2. ERK1 knockdown resulted in increased ERK5 activation in addition to prolonged ERK2 phosphorylation. Proliferation studies were also performed in PC3 cells, the results of which support published data that ERK1 acts as a negative regulator and ERK2 as a positive regulator of cell proliferation. ERK5 has been shown to regulate the activity of several transcription factors and recent evidence suggests that ERK5 may be heat shock protein (HSP) 90 dependent. To further investigate the ERK5 signalling network and its interacting proteins, I performed mass spectrometry-based quantitative proteomics using SILAC labelled cells. Results from this study support the theory that HSP90 does associate with ERK5 however contrary to published data my results show that it is not involved in ERK5 activation. Our results validate the importance of the MEK5-ERK5 signalling pathway as a potential target for therapy in prostate cancer and highlight a novel functional and biochemical relationship between ERK1 and HSP 90 with ERK5 signalling

Maritime health: a review with suggestions for research

International maritime health has largely developed within the sphere of occupational health services and international health problems. We reviewed publications in the journal International Maritime Health from 2000 to 2010 to establish the coverage of the journal and the scope of research in maritime health. We identified six thematic categories: healthcare access, delivery and integration; telehealth; non-communicable diseases and physical health problems; communicable diseases; psychological functioning and health; and safety-related issues. We describe the research within these themes and report on their publication prominence. We also analyse the research in terms of its geographical focus, the population groups addressed and the research methodologies used. We suggest a broadening of maritime research to include randomised controlled trials, longitudinal studies and more qualitative research; more research addressing the context for non-European seafarers; and research on seafarers spouses and family supports and obligations. We also recommend more research on psychosocial and cultural issues and on telehealth, as well as the development of a stronger systems perspective for promoting maritime health