Energy efficient fish attraction

Fish migration past a hydro power plant (HPP) requires not only flow in the actual fish passage (e.g. fish ladder) but also sufficient water to attract the fish to the entrance. Such attraction water is typically created by spilling water of the order of 10 m3/s, and there are potential savings if the amount of water can be reduced without loss of functionality. The possibility to use ejectors (jet pumps) to pump water from the area downstream of the HPP into the fish passage has been investigated with physical model tests and numerical modelling (CFD). The ambition has been to make use of fairly simple geometries without changing the layout of the suggested fish ladder, and a solution in which the ejectors are located in a separate channel parallel to the fish ladder has been evaluated. The results show that the required spill can be reduced to 1/3 despite the low head (7 m) of the considered HPP, and the savings will be even larger in HPPs with higher head. More energy efficient ways to attract fish can be obtained if the jets are positioned within the actual fish way, but a prerequisite for such solution is that the fish is not intimidated by the jets. Another interesting option to evaluate is the possibility to guide the fish to the fish ladder entrance by an array of individual jets positioned in the river. To investigate these ideas tests with live fish are scheduled during second half of 2018

Plasma and cerebrospinal fluid concentrations of neurofilament light protein correlate in patients with idiopathic normal pressure hydrocephalus

BACKGROUND: Neurofilament light chain protein (NFL), a marker of neuronal axonal degeneration, is increased in cerebrospinal fluid (CSF) of patients with idiopathic normal pressure hydrocephalus (iNPH). Assays for analysis of NFL in plasma are now widely available but plasma NFL has not been reported in iNPH patients. Our aim was to examine plasma NFL in iNPH patients and to evaluate the correlation between plasma and CSF levels, and whether NFL levels are associated with clinical symptoms and outcome after shunt surgery. METHODS: Fifty iNPH patients with median age 73 who had their symptoms assessed with the iNPH scale and plasma and CSF NFL sampled pre- and median 9 months post-operatively. CSF plasma was compared with 50 healthy controls (HC) matched for age and gender. Concentrations of NFL were determined in plasma using an in-house Simoa method and in CSF using a commercially available ELISA method. RESULTS: Plasma NFL was elevated in patients with iNPH compared to HC (iNPH: 45 (30-64) pg/mL; HC: 33 (26-50) (median; Q1-Q3), p = 0.029). Plasma and CSF NFL concentrations correlated in iNPH patients both pre- and postoperatively (r = 0.67 and 0.72, p < 0.001). We found only weak correlations between plasma or CSF NFL and clinical symptoms and no associations with outcome. A postoperative NFL increase was seen in CSF but not in plasma. CONCLUSIONS: Plasma NFL is increased in iNPH patients and concentrations correlate with CSF NFL implying that plasma NFL can be used to assess evidence of axonal degeneration in iNPH. This finding opens a window for plasma samples to be used in future studies of other biomarkers in iNPH. NFL is probably not a very useful marker of symptomatology or for prediction of outcome in iNPH

Associations between health-related quality of life, physical function and fear of falling in older fallers receiving home care

Falls and injuries in older adults have significant consequences and costs, both personal and to society. Although having a high incidence of falls, high prevalence of fear of falling and a lower quality of life, older adults receiving home care are underrepresented in research on older fallers. The objective of this study is to determine the associations between health-related quality of life (HRQOL), fear of falling and physical function in older fallers receiving home care

Biases in the perceived timing of perisaccadic perceptual and motor events

Subjects typically experience the temporal interval immediately following a saccade as longer than a comparable control interval. One explanation of this effect is that the brain antedates the perceptual onset of a saccade target to around the time of saccade initiation. This could explain the apparent continuity of visual perception across eye movements. Thisantedating account was tested in three experiments in which subjects made saccades of differing extents and then judged either the duration or the temporal order of key events. Postsaccadic stimuli underwent subjective temporal lengthening and had early perceived onsets. A temporally advanced awareness of saccade completion was also found, independently of antedating effects. These results provide convergent evidence supporting antedating and differentiating it from other temporal biases

Visual onset expands subjective time

We report a distortion of subjective time perception in which the duration of a first interval is perceived to be longer than the succeeding interval of the same duration. The amount of time expansion depends on the onset type defining the first interval. When a stimulus appears abruptly, its duration is perceived to be longer than when it appears following a stationary array. The difference in the processing time for the stimulus onset and motion onset, measured as reaction times, agrees with the difference in time expansion. Our results suggest that initial transient responses for a visual onset serve as a temporal marker for time estimation, and a systematic change in the processing time for onsets affects perceived time

Laxens nedströmsvandring mot fiskavledare till Stornorrfors fisktrappa i Umeälvens nedre del

Rapporten sammanfattar våra arbeten med målsättning att skapa en fungerande fiskavledning för nedströmsvandrande fisk i vid Stornorrfors kraftverkskomplex i Umeälven. Rapporten visar även på verksamheter som nyttjats vid planering och utvärdering av gjorda åtgärder. Åtgärder i fisktrappan, fiskavledare och utrustning för registrering av PIT-tags har möjliggjorts genom finansiering av Europeiska Fiskefonden, Havs- och Vattenmyndigheten, Umeå kommun, Vattenfall och SLU. Arbetena har genomförts som två pilotprojekt (3b Nedströmsvandring Stornorrfors 2009-2010 och 3b2 Nedströmsvandring Stornorrfors 2011-2013). Vilda lax- och öring bestånd i våra älvar är viktiga naturresurser för människan och ekosystemet. Vindelälvens naturliga fiskproduktion av lax- och havsöring ungar är betydande för Östersjöns laxbestånd. De senaste åren har mer än 10 000 lax årligen vandrat uppströms för lek i älven. Många föräldrafiskar (Kelt, vraklax, besa, mm) överlever leken och vill vandra tillbaka till havet. Laxens naturliga avkomma, smolten, strävar också att ta sig till födoområdena i Östersjön. I flödesreglerade vattendrag som Umeälven med sitt unika laxbestånd i biflödet Vindelälven finns problem med dödlighet då kelt och smolt på sin nedströmsvandring ska passera Stornorrfors kraftverk. I Umeälvens nedre del färdigställdes en ny fisktrappa i Norrfors 2010 som utrustats med en ”fiskavledare”. Projektets mål var att bygga och ansluta fiskavledaren till nya fisktrappan och utvärdera dess funktion/effektivitet. Det mätbara målet för den planerade anläggningen vid Stornorrfors utskovsdamm sattes till att 75 % av den utvandrande vilda smolten och minst 50 % av den övervintrande kelten skulle avledas till nya fisktrappan för vidare vandring till havet. Detta mål kunde inte uppnås. Den nya fisktrappan skulle alltså fungera som ett klassiskt "omlöp" förbi kraftverket. Vild smolt har märkts med Passiva Integrerade Transpondrar (PIT) eller aktiva Radiomärken (RT) och senare skannats vid passage i fisktrappsområdet (PIT + RT-märkt fisk) eller vid intaget till Stornorrfors kraftverk (RT-märkt fisk). SLU’s utvärdering av ledarmens funktion och fiskens vandring nedströms har visat att fiskavledarens funktion varit mycket svår att kontrollera då ledarmen inte fungerat som tänkt i den tuffa strömmiljön ovan fisktrappans område mellan 2010-2012. Avledningseffektiviteten kunde med visst förtroende endast värderas vid 2013 års försök med PIT-märkt fisk (n=1749 fiskar) som släpptes dagligen efter fångst i Vindelälven (INDEX Spöland) när flödet var < 800 m3/s i älven. Den totala avledningseffektiviteten visade sig vara 4,5 %. Begränsande för utvärderingen har varit att stora grupper smolt periodvis inte kunnat fångas och märkas på grund av höga flöden i Vindelälven. Effektiviteten i ledarmen har varierat mellan 0 och 100 % under säsongen. Väldigt få Kelt av lax kunde avledas. Höga turbinflöden tycks haft en positiv inverkan på ledarmens funktion. Smoltens passage nedströms i och genom fisktrappan verkar fungera utan större problem. Via PIT-märkt fisk och videofilmning i flera delförsök kunde vi visa på en lyckad genomfart där laxsmolten passerar fisktrappan inom några timmar till 2-3 dagar. Flödesmätning och modellering av strömningen runt fiskavledarens område mot ingången till nya fisktrappan visar att ledarmen borde ökas till ca 150 meters längd istället för dagens 110 meter. Flödesmodelleringar visar då att en större del av ytströmmen kan styras in mot fisktrappans ingång. Försöken med fångst, märkning, utsättning och återfångst har fungerat bra och PIT-märkningstekniken bedöms överlägsen andra märktekniker för detektering av fisk om detekteringsutrustning installerats. Detta kan utvecklas vidare inom ramen för indexälvsverksamheten (ICES-DCF) som nu bedrivs i Vindelälven. Sverige bör fortsätta att ta ansvar för den här typen av utveckling då det finns samordningsvinster mellan indexvattendrag, fiskavledning och utvärdering av fisktrappan för lekvandrande fisk. Lyckas man avleda den naturligt producerade avkomman av lax och öring i reglerade vattendrag med unika bestånd finns mycket att vinna för att etablera långsiktigt hållbara bestånd av vandringsfisk. Den typ av fiskavledare som nu prövats har tidigare inte prövats i Europa varför detta pilotprojekt är unikt. Arbetet som nu avslutats har varit ett samverkansprojekt mellan Europeiska Fiskerifonden, Havs- och Vattenmyndigheten, vattenkraftsägare, lokala och nationella fiskeriadministratörer samt forskare i fiskbiologi och hydraulik

Isospin dependent multifragmentation of relativistic projectiles

The N/Z dependence of projectile fragmentation at relativistic energies has been studied with the ALADIN forward spectrometer at the GSI Schwerionen Synchrotron (SIS). Stable and radioactive Sn and La beams with an incident energy of 600 MeV per nucleon have been used in order to explore a wide range of isotopic compositions. For the interpretation of the data, calculations with the statistical multifragmentation model for a properly chosen ensemble of excited sources were performed. The parameters of the ensemble, representing the variety of excited spectator nuclei expected in a participant-spectator scenario, are determined empirically by searching for an optimum reproduction of the measured fragment-charge distributions and correlations. An overall very good agreement is obtained. The possible modification of the liquid-drop parameters of the fragment description in the hot freeze-out environment is studied, and a significant reduction of the symmetry-term coefficient is found necessary to reproduce the mean neutron-to-proton ratios /Z and the isoscaling parameters of Z<=10 fragments. The calculations are, furthermore, used to address open questions regarding the modification of the surface-term coefficient at freeze-out, the N/Z dependence of the nuclear caloric curve, and the isotopic evolution of the spectator system between its formation during the initial cascade stage of the reaction and its subsequent breakup.Comment: 23 pages, 29 figures, published in Physical Review

Limited clinical efficacy of azacitidine in transfusion-dependent, growth factor-resistant, low- and Int-1-risk MDS:Results from the nordic NMDSG08A phase II trial

This prospective phase II study evaluated the efficacy of azacitidine (Aza) + erythropoietin (Epo) in transfusion-dependent patients with lower-risk myelodysplastic syndrome (MDS). Patients ineligible for or refractory to full-dose Epo + granulocyte colony stimulation factors for 48 weeks and a transfusion need of ≥ 4 units over 8 weeks were included. Aza 75mgm -2 d-1, 5/28 days, was given for six cycles; non-responding patients received another three cycles combined with Epo 60 000 units per week. Primary end point was transfusion independence (TI). All patients underwent targeted mutational screen for 42 candidate genes. Thirty enrolled patients received ≥ one cycle of Aza. Ten patients discontinued the study early, 7 due to adverse events including 2 deaths. Thirty-eight serious adverse events were reported, the most common being infection. Five patients achieved TI after six cycles and one after Aza + Epo, giving a total response rate of 20%. Mutational screening revealed a high frequency of recurrent mutations. Although no single mutation predicted for response, SF3A1 (n = 3) and DNMT3A (n = 4) were only observed in nonresponders. We conclude that Aza can induce TI in severely anemic MDS patients, but efficacy is limited, toxicity substantial and most responses of short duration. This treatment cannot be generally recommended in lower-risk MDS. Mutational screening revealed a high frequency of mutations