17 research outputs found
Vertebrate pheromones and other semiochemicals: the potential for accommodating complexity in signalling by volatile compounds for vertebrate management
The interaction between volatile and non-volatile, e.g. proteinaceous, components of pheromone and other semiochemical-based signalling systems presents a daunting set of problems for exploitation in the management of vertebrates, good or bad. Aggravating this is the complexity of the mixtures involved with pheromones, not only by definition associated with each species, but also with individual members of that species and their positions within their immediate communities. Nonetheless, already in some contexts, particularly where signals are perceived at other trophic levels from those of the vertebrates, e.g. by arthropods, reductionist approaches can be applied whereby the integrity of complex volatile mixtures is maintained, but perturbed by augmentation with individual components. In the present article, this is illustrated for cattle husbandry, fish farming and human health. So far, crude formulations have been used to imitate volatile semiochemical interactions with non-volatile components, but new approaches must be developed to accommodate more sophisticated interactions and not least the activities of the non-volatile, particularly proteinaceous components, currently being deduced
Climate fluctuations and the spring invasion of the North Sea by Calanus finmarchicus
The population of Calanus finmarchicus in the North Sea is replenished each spring by invasion from an overwintering stock located beyond the shelf edge. A combincation of field observations, statistical analysis of Continuous Plankton Recorder (CPR) data, and particle tracking model simulations, was used to investigate the processes involved in the cross-shelf invasion. The results showed that the main source of overwintering animals entering the North Sea in the spring is at depths of greater than 600m in the Faroe Shetland Channel, where concentrations of up to 620m -3 are found in association with the overflow of Norwegian Sea Deep Water (NSDW) across the Iceland Scotland Ridge. The input of this water mass to the Faroe Shetland Channel, and hence the supply of overwintering C. finmarchicus, has declined since the late 1960s due to changes in convective processes in the Greenland Sea. Beginning in February, animals start to emerge from the overwintering state and migrate to the surface waters, where their transport into the North Sea is mainly determined by the incidence of north-westerly winds that have declined since the 1960s. Together, these two factors explain a high proportion of the 30-year trends in spring abundance in the North Sea as measured by the CPR survey. Both the regional winds and the NSDW overflow are connected to the North Atlantic Oscillation Index (NAO), which is an atmospheric climate index, but with different time scales of response. Thus, interannual fluctuations in the NAO can cause immediate changes in the incidence of north-westerly winds without leading to corresponding changes in C. finmarchicus abundance in the North Sea, because the NSDW overflow responds over longer (decadal) time scales
Evaluation of sesamum gum as an excipient in matrix tablets
In developing countries modern medicines are often beyond the affordability of the majority of the population. This is due to the reliance on expensive imported raw materials despite the abundance of natural resources which could provide an equivalent or even an improved function. The aim of this study was to investigate the potential of sesamum gum (SG) extracted from the leaves of Sesamum radiatum (readily cultivated in sub-Saharan Africa) as a matrix former. Directly compressed matrix tablets were prepared from the extract and compared with similar matrices of HPMC (K4M) using theophylline as a model water soluble drug. The compaction, swelling, erosion and drug release from the matrices were studied in deionized water, 0.1 N HCl (pH 1.2) and phosphate buffer (pH 6.8) using USP apparatus II. The data from the swelling, erosion and drug release studies were also fitted into the respective mathematical models. Results showed that the matrices underwent a combination of swelling and erosion, with the swelling action being controlled by the rate of hydration in the medium. SG also controlled the release of theophylline similar to the HPMC and therefore may have use as an alternative excipient in regions where Sesamum radiatum can be easily cultivated
Attention-deficit hyperactivity disorder shares copy number variant risk with schizophrenia and autism spectrum disorder
Publisher's version (útgefin grein).Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable common childhood-onset neurodevelopmental disorder. Some rare copy number variations (CNVs) affect multiple neurodevelopmental disorders such as intellectual disability, autism spectrum disorders (ASD), schizophrenia and ADHD. The aim of this study is to determine to what extent ADHD shares high risk CNV alleles with schizophrenia and ASD. We compiled 19 neuropsychiatric CNVs and test 14, with sufficient power, for association with ADHD in Icelandic and Norwegian samples. Eight associate with ADHD; deletions at 2p16.3 (NRXN1), 15q11.2, 15q13.3 (BP4 & BP4.5–BP5) and 22q11.21, and duplications at 1q21.1 distal, 16p11.2 proximal, 16p13.11 and 22q11.21. Six of the CNVs have not been associated with ADHD before. As a group, the 19 CNVs associate with ADHD (OR = 2.43, P = 1.6 × 10−21), even when comorbid ASD and schizophrenia are excluded from the sample. These results highlight the pleiotropic effect of the neuropsychiatric CNVs and add evidence for ADHD, ASD and schizophrenia being related neurodevelopmental disorders rather than distinct entities.We are grateful to the participants and we thank the staff at the Research
Recruitment Center. We also thank the staff at deCODE genetics core facilities
and all our colleagues for their important contribution to this work. We are
grateful to the Benefit Society for Children with Disabilities (Styrktarfélag
Lamaðra og Fatlaðra; SLF) for their participation. The research leading to these
results has received support from the Innovative Medicines Initiative Joint
Undertaking under grant agreements’ no. 115008 (NEWMEDS) and no. 115300
(EUAIMS), of which resources are composed of EFPIA in-kind contribution and
financial contribution from the European Union’s Seventh Framework
Programme (EU-FP7/2007–2013), from EU-FP7 grants no. 602450
(IMAGEMEND) and no. 502805 (Aggressotype), EU-FP7-People-2011-IAPP grant
no. 286213 (PsychDPC), and The Research Council of Norway (#226971,
229129, 223273, 213694, 248778), the KG Jebsen Stiftelsen (SKGJ-MED-002 and
SKGJ-MED-008), and The South-East Norway Health Authority (#2012–132).Peer Reviewe
EUROPROF-verkefnið : veruleiki kennaranema í Evrópu
Fyrsta ritið í röð ráðstefnurita sem komið hafa út í kjölfar árlegs málþings á vegum Menntavísindasviðs. Heitir Ráðstefnurit Netlu : Menntakvika ásamt viðeigandi ártali frá árinu 2010Kennarar og nemendur í kennslufræði við félagsvísindadeild Háskóla Íslands hafa sl. þrjú ár tekið þátt í Sókrates-þróunarverkefni sem lauk í september 2009. Í greininni er gefið yfirlit yfir helstu þætti þróunarverkefnisins. Meginmarkmið þess var að efla þekkingu og skilning verðandi tungumálakennara í Evrópu á menntun tungumálakennara og uppbyggingu skólakerfisins. Ólík skólamenning grunn- og framhaldsskóla og kennaramenntunarstofnana í þátttökulöndunum var einnig í brennidepli. Undirmarkmið var að gera tungumálakennara hæfari til að starfa í fjölmenningarlegu samfélagi. Alls tóku átta Evrópulönd þátt í verkefninu. Kennaranemarnir dvöldust í tvær vikur sem skiptinemar í einu landanna. Þeir kynntu sér skólastarf, bæði á grunn- og framhaldsskólastigi, kenndu og öfluðu ýmissa gagna um land og þjóð. Hér verða dregnar saman helstu niðurstöður úr þeim gögnum sem aflað var í tengslum við verkefnið, þ.e. viðtölum við kennaranemana, ígrundunum þeirra og formlegum verkefnum. Dvölin virðist hafa opnað kennaranemunum nýja sýn og aukið skilning á mikilvægi fjölmenningarlegrar vitundar tungumálakennara og varpað ljósi á ólíka uppbyggingu kennaranáms í mismunandi löndum. Kennaranemunum fannst þeir enn fremur verða meðvitaðri um kosti íslenskra skóla og um leið hvað mætti betur fara. Þá fannst þeim þessi reynsla efla sjálfstraust sitt sem einstaklinga og verðandi kennara
Semiochemical strategies for sea louse control: host location cues
The development of behavioural bioassays and electrophysiological recording techniques has enabled the role of semiochemicals to be investigated for the first time in Lepeophtheirus salmonis (Krøyer). Adult male sea lice L salmonis were activated by, and attracted to, salmon-conditioned water (SCW) and SCW extract. Non-host fish odours, turbot-conditioned water (TCW) and turbot-conditioned water extract (TCW extract), elicited activation but no attraction in the lice. Solid-phase extraction techniques were developed to extract low molecular weight components of fish odours, and biological activity was shown to be confined to these. Electrophysiological activity from aesthetascs in the first antennae was found and neural responses to odours were recorded from the antennal nerves. Preliminary experiments on individual chemicals (isophorone, 1-octen-3-ol) linked to salmon revealed behavioural activation and electrophysiological responses in adult male L salmonis. Isophorone was shown to be significantly attractive to sea lice when placed in a slow-release system in a perfused tank of seawater in a choice situation. Proof of concept has been established for successfully extracting odour cues from seawater, analysing their biological activity and applying these to slow-release technologies for field trapping of lice. Future work involving linked GC–MS techniques using behaviour, electrophysiological responses, and organolepsis will establish further host location cues specific to Atlantic salmon
Comparative ecology of over-wintering Calanus finmarchicus in the northern North Atlantic, and implications for life-cycle patterns
Vertebrate pheromones and other semiochemicals: the potential for accommodating complexity in signalling by volatile compounds for vertebrate management
Effects of chronic crude oil exposure on early developmental stages of the Northern krill (Meganyctiphanes norvegica)
Rising oil and gas activities in northern high latitudes have led to an increased risk of petroleum pollution in these ecosystems. Further, seasonal high UV radiation at high latitudes may elevate photo-enhanced toxicity of petroleum pollution to marine organisms. Zooplanktons are a key ecological component of northern ecosystems; therefore, it is important to assess their sensitivity to potential pollutants of oil and gas activity. As ontogenetic development may be particularly sensitive, the aim of this study was to examine the impact of chronic exposure to oil water dispersion (OWD) on development and feeding of early life stages of the Northern krill, Meganyctiphanes norvegica. In a range of experiments, embryonic, nonfeeding, and feeding larval stages were exposed to concentrations of between 0.01 and 0.1 mg/L of oil or photo-modified oil for 19 and 21 d. No significant effects on egg respiration, hatching success, development, length and larval survival were observed from these treatments. Similarly, evolution of fatty acid composition patterns during ontogenetic development was unaffected. The results indicates a high degree of resilience of these early developmental stages to such types and concentrations of pollutants. However, feeding and motility in later calyptopis-stage larvae were significantly impaired at exposure of 0.1 mg/L oil. Data indicate that feeding larval stage of krill was more sensitive to OWD than early nonfeeding life stages. This might be attributed to the narcotic effects of oil pollutants, their direct ingestion, or accumulated adverse effects over early development
Effects of chronic crude oil exposure on early developmental stages of the Northern krill (<i>Meganyctiphanes norvegica</i>)
<p>Rising oil and gas activities in northern high latitudes have led to an increased risk of petroleum pollution in these ecosystems. Further, seasonal high UV radiation at high latitudes may elevate photo-enhanced toxicity of petroleum pollution to marine organisms. Zooplanktons are a key ecological component of northern ecosystems; therefore, it is important to assess their sensitivity to potential pollutants of oil and gas activity. As ontogenetic development may be particularly sensitive, the aim of this study was to examine the impact of chronic exposure to oil water dispersion (OWD) on development and feeding of early life stages of the Northern krill, <i>Meganyctiphanes norvegica</i>. In a range of experiments, embryonic, nonfeeding, and feeding larval stages were exposed to concentrations of between 0.01 and 0.1 mg/L of oil or photo-modified oil for 19 and 21 d. No significant effects on egg respiration, hatching success, development, length and larval survival were observed from these treatments. Similarly, evolution of fatty acid composition patterns during ontogenetic development was unaffected. The results indicates a high degree of resilience of these early developmental stages to such types and concentrations of pollutants. However, feeding and motility in later calyptopis-stage larvae were significantly impaired at exposure of 0.1 mg/L oil. Data indicate that feeding larval stage of krill was more sensitive to OWD than early nonfeeding life stages. This might be attributed to the narcotic effects of oil pollutants, their direct ingestion, or accumulated adverse effects over early development.</p