46 research outputs found

    The Need of a Structured Tilapia Breeding Program in Tanzania to Enhance Aquaculture Production: A Review

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    Breeding programs are crucial for boosting productivity and increase sustainability of aquaculture. Over years, Tanzania has witnessed fluctuation in its capture fisheries production from 320,900 to 375, 535 and back to 362,595 metric tonnes in the years 2000, 2005 and 2016, respectively (URT 2016). The declining trend in fish production has made fish supply in the country unstable and conversely, increased the demand for fishes to about 730,000 metric tonnes in 2017. However, the local aquaculture production has not increased accordingly. Tanzania is importing fish mainly from Asia to meet its increased demand. In 2017, a total of 2,055,721 kg of frozen tilapia were imported from China and Mozambique (URT 2017). The introduction of exotic fish species in Tanzania should be carefully managed because introduced species have many negative impacts to the indigenous species. Tanzania should have a moderate scale tilapia breeding program that will produce good quality fingerlings at affordable price for smallholder fish farmers. The availability of reliable good quality fingerlings is key to improve aquaculture production in the country. Among 17 existing hatcheries, only 12 hatcheries are active, however these hatcheries are not performing well due to low investment and technology leading to the production of low quantity and quality fingerlings. The need for a structured sustainable Tilapia breeding program with bio secured and reliable hatcheries to enhance aquaculture production in Tanzania is given in this review.Keywords: Aquaculture, Breeding programs, Nile tilapia, Local strains

    Does a SLAP lesion affect shoulder muscle recruitment as measured by EMG activity during a rugby tackle?

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    Background: The study objective was to assess the influence of a SLAP lesion on onset of EMG activity in shoulder muscles during a front on rugby football tackle within professional rugby players. Methods: Mixed cross-sectional study evaluating between and within group differences in EMG onset times. Testing was carried out within the physiotherapy department of a university sports medicine clinic. The test group consisted of 7 players with clinically diagnosed SLAP lesions, later verified on arthroscopy. The reference group consisted of 15 uninjured and full time professional rugby players from within the same playing squad. Controlled tackles were performed against a tackle dummy. Onset of EMG activity was assessed from surface EMG of Pectorialis Major, Biceps Brachii, Latissimus Dorsi, Serratus Anterior and Infraspinatus muscles relative to time of impact. Analysis of differences in activation timing between muscles and limbs (injured versus non-injured side and non injured side versus matched reference group). Results: Serratus Anterior was activated prior to all other muscles in all (P = 0.001-0.03) subjects. In the SLAP injured shoulder Biceps was activated later than in the non-injured side. Onset times of all muscles of the noninjured shoulder in the injured player were consistently earlier compared with the reference group. Whereas, within the injured shoulder, all muscle activation timings were later than in the reference group. Conclusions: This study shows that in shoulders with a SLAP lesion there is a trend towards delay in activation time of Biceps and other muscles with the exception of an associated earlier onset of activation of Serratus anterior, possibly due to a coping strategy to protect glenohumeral stability and thoraco-scapular stability. This trend was not statistically significant in all cases

    Analysis of a sprint ski race and associated laboratory determinants of world-class performance

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    This investigation was designed to analyze the time-trial (STT) in an international cross-country skiing sprint skating competition for (1) overall STT performance and relative contributions of time spent in different sections of terrain, (2) work rate and kinematics on uphill terrain, and (3) relationships to physiological and kinematic parameters while treadmill roller ski skating. Total time and times in nine different sections of terrain by 12 world-class male sprint skiers were determined, along with work rate and kinematics for one specific uphill section. In addition, peak oxygen uptake (VO2peak), gross efficiency (GE), peak speed (Vpeak), and kinematics in skating were measured. Times on the last two uphill and two final flat sections were correlated to overall STT performance (r = ~−0.80, P < 0.001). For the selected uphill section, speed was correlated to cycle length (r = −0.75, P < 0.01) and the estimated work rate was approximately 160% of peak aerobic power. VO2peak, GE, Vpeak, and peak cycle length were all correlated to STT performance (r = ~−0.85, P < 0.001). More specifically, VO2peak and GE were correlated to the last two uphill and two final flat section times, whereas Vpeak and peak cycle length were correlated to times in all uphill, flat, and curved sections except for the initial section (r = ~−0.80, P < 0.01). Performances on uphill and flat terrain in the latter part were the most significant determinants of overall STT performance. Peak oxygen uptake, efficiency, peak speed, and peak cycle length were strongly correlated to overall STT performance, as well as to performance in different sections of the race

    Att beskriva upplevelser hos nÀrstÄende till person med demens i tidig Älder (före 65 Är) : En kvalitativ litteraturstudie

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    Att beskriva upplevelser hos nÀrstÄende till person med demens i tidig Älder (före 65 Är ) En litteraturstudie. Christer Norman och Peter Forsberg Bakgrund: Demens i tidig Älder (Early Onset Dementia) Àr en sjukdom som inte uppmÀrksammats sÄ mycket varken i forskningen eller i samhÀllet till skillnad frÄn den mer vanligt förekommande Äldersdemensen. Att vara nÀrstÄende till person med Early Onset Dementia innebÀr dels en stor emotionell belastning i form av förlustkÀnslor och oro inför framtiden, och dels att man försummar sina egna behov nÀr man blir tvungen att ta pÄ sig rollen som informell vÄrdare. Syfte: Att beskriva upplevelser hos nÀrstÄende till person med demens i tidig Älder (före 65 Är) Metod: Vi valde att genomföra en litteraturstudie med kvalitativ ansats för att ta del av och fördjupa oss i nÀrstÄendes upplevelser. Nio vetenskapliga artiklar lÄg till grund för studien. Resultat: TvÄ huvudkategorier gick att urskilja, emotionellt lidande och behov av stöd. De nÀrstÄende upplevde ett behov av personcentrerad information och kunskap om sjukdomen för att kunna hantera situationen och rollen som informell vÄrdare. Familjens intressen stod i fokus eftersom rollerna och relationerna ofta förÀndrades nÀr diagnosen Early Onset Dementia faststÀlldes. Ett tydligt resultat av studien var att nÀrstÄende upplevde att bÄde allmÀnheten men ocksÄ sjukvÄrden och sociala myndigheter hade för lite kunskap om sjukdomen och dess pÄverkan pÄ familjer. Slutsats: De nÀrstÄende upplevde stora brister i information och stöd frÄn samhÀllet och att detta ledde till onödigt emotionellt lidande. NÀrstÄende till personer med Early Onset Dementia Àr en bortglömd grupp och det behövs mer forskning kring dessa personers upplevelser och vilket stöd de behöver. Nyckelord: Demens, ungt insÀttande, Familj, VÄrdgivare, Makar och Erfarenhet

    Operational measures against PM10 pollution on Hornsgatan and SveavÀgen in Stockholm : evaluation of winter season 2011\u962012

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    I flera tÀtorter i Sverige finns problem med att uppfylla miljökvalitetsnormen för inandningsbara partiklar (PM10) i omgivningsluften. Stockholm har flera utsatta miljöer dÀr partikelhalterna överskrider grÀnsen för dygnsmedelvÀrdet. KÀllan till partiklarna Àr frÀmst vÀgdamm som i huvudsak orsakas av dubbdÀcksslitage och sandning vintertid. Flera ÄtgÀrder har provats för att sÀnka partikelhalterna, men det har visat sig att enskilda ÄtgÀrder inte Àr tillrÀckliga utan att flera ÄtgÀrder behöver kombineras. Under vinterhalvÄret 2011\u962012 provade dÀrför Stockholms stad ett ÄtgÀrdspaket bestÄende av dammbindning med CMA, stÀdning med kraftfull stÀdmaskin och spolning av gator för att, om möjligt sÀnka PM10-halterna pÄ Hornsgatan och SveavÀgen. Under sÀsongen utfördes 31 spridningar av CMA, 25 stÀdinsatser och 42 gatuspolningar. Resultaten visar att antalet överskridanden av PM10 pÄ bÄda gatorna Àr betydligt fÀrre Àn pÄ referensgatorna under den behandlade perioden. Den enda ÄtgÀrden som hade en signifikant effekt var dock dammbindning, medan varken stÀdningen eller spolningen medförde nÄgon direkt sÀnkning av PM10-halterna. VÀgdammförrÄdet byggdes upp under vintersÀsongen pÄ försöksgatorna med maximum i mars, dÄ dammbindningsinsatserna var som intensivast. Ett tydligt samband mellan vÀgytornas makrotextur och mÀngden vÀgdamm kunde konstateras. JonmÀngderna pÄ ytorna avspeglade vÀl jonerna i vÀgsalt och CMA.Several Swedish cities have problems with complying with the environmental quality standard for inhalable particulate matter in air (PM10). Stockholm has a number of problematic traffic environments with narrow street canyons and high traffic flows, where the limit values are exceeded practically every year. An important source for PM10 is road dust forming from wear of road pavements and use of winter sanding. Different measures have been tested to mitigate the particle concentrations but to reach the limit values, no single measure is enough, but needs to be combined. During the winter 2011\u962012, the city of Stockholm has tested a combination of measures, including dust binding with CMA, powerful street sweeping and street flushing with water to, if possible, reach the PM10 limit values. During the season, 31 applications of CMA, 25 road sweepings and 42 road flushes, were conducted. The results show that the number of PM10 directive exceedances on both streets were considerably fewer than on the reference streets. The single measure having a significant effect, though, was dust binding with CMA, while sweeping and flushing did not reduce PM10 concentrations. The road dust depot increased during the winter months on the test streets and reached a maximum in March, during the most intense dust binding efforts. An obvious relationship between road surface texture and road dust depot could be identified. The ion content on the street surfaces reflected the use of road salt (NaCl) and CM

    BullerskÀrmars inverkan pÄ luftkvalitet

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    Syftet med projektet har varit att med hjÀlp av mÀtningar och berÀkningar undersöka hur luftkvalitet pÄverkas av höjd och utformning pÄ samt vÀxtlighet i anslutning till bullerskÀrmar beroende pÄ trafikflöden, hastigheter, meterologi, befintlig bebyggelse och topografi i omkringliggande omrÄde. MÄlen var att kvantifiera betydelsen av bullerskÀrmar för luftkvalitet lÀngs med statligt vÀgnÀt, ta fram en förenklad respektive avancerad modell för berÀkning av bullerskÀrmars betydelse för luftkvalitet samt kartlÀgga befintliga och framtida strÀckor med hjÀlp av den förenklade modellen dÀr bullerskÀrmar skulle kunna anvÀndas som multifunktionell ÄtgÀrd.  Projektet inleddes med en kunskapssammanstÀllning, som följdes av mÀtningar och slutligen berÀkningar med en avancerad och en förenklad modell. Resultaten visar att implementeringen av den enkla berÀkningsmodellen RLINE i Airviro-systemet, gav en god överensstÀmmelse med mÀtningar och resultaten av den mer avancerade berÀkningsmodellen CFD (Computational Fluid Dynamics modell). Resultaten i studien bekrÀftar vidare slutsatserna i litteratursammanstÀllningen att skÀrmar har en positiv effekt pÄ trafikgenerade luftföroreningar. Men det förutsÀtter att skÀrmarna Àr minst 4 meter. Resultaten frÄn modellberÀkningarna med skÀrmar lÀngs E4/E20 och E18 indikerar att befolkningsexponeringen minskar om skÀrmarna Àr tillrÀckligt höga. Med en 2 meter hög skÀrm uteblir i stort sett effekten av skÀrmen. Slutsatsen av att jÀmföra bullerskÀrmar med andra typer av ÄtgÀrder för förbÀttrad luftkvalitet, sÄ som minskade dubbdÀcksandelar och sÀnkta hastigheter, visar att i omrÄden dÀr bÄde bullernivÄer och luftföroreningshalter Àr höga Àr det mest lÀmpligt att utföra ÄtgÀrder med minst 4 meter höga bullerskÀrmar i kombination med minskad dubbdÀcksanvÀndning och sÀnkta hastigheter. DÄ Trafikverket inte ensam har rÄdighet över dubbdÀcksanvÀndningen, och hastighetsefterlevnaden i olika projekt visat sig vara svag vid hastighetssÀnkningar, sÄ skulle höga bullerskÀrmar kunna löna sig samhÀllsekonomiskt om positiva hÀlsoeffekter frÄn bÄde minskad buller- och luftföroreningsexponering vÀrderas i analysen. The purpose of the project has been to use measurements and calculations to investigate how air quality is affected by the height and design of and vegetation in connection with noise screens depending on traffic flows, speeds, metrology, existing buildings and topography in the surrounding area. The goals were to quantify the importance of noise screens for air quality along the state road network, develop a simplified and advanced model for calculating the importance of noise screens for air quality, and map existing and future routes using the simplified model where noise screens could be used as a multifunctional measure. The project began with a knowledge compilation, which was followed by measurements and finally calculations with an advanced and a simplified model. The results show that the implementation of the simple calculation model RLINE in the Airviro system, was in good accordance with measurements and the results from the more advanced calculation model CFD (Computational Fluid Dynamics model). The results of the study further confirm the conclusions in the literature review that screens have a positive effect on traffic-generated air pollution. But it assumes that the screens are at least 4 meters. The results from the model calculations with screens along E4/E20 and E18 indicate that population exposure is reduced if the screens are high enough. With a 2 meter high screen, the effect of the screen is largely absent. The conclusion of comparing noise screens with other types of measures for improved air quality, such as reduced studded tire shares and reduced speeds, shows that in areas where both noise levels and air pollution levels are high, it is most appropriate to carry out measures with noise screens at least 4 meters high in combination with reduced studded tire use and reduced speeds. Since the Swedish Transport Administration does not have sole decision over the use of studded tires, and speed compliance in various projects has been shown to be weak in the case of speed reductions, high noise barriers could pay off economically if positive health effects from both reduced noise and air pollution exposure are valued in the analysis.

    Operational measures against PM10 pollution in Stockholm : evaluation of winter season 2013–2014

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    Sedan 2011 pĂ„gĂ„r ett intensifierat arbete för att sĂ€nka halterna av PM10 i Stockholm, dĂ€r problemen Ă€r omfattande. Denna rapport presenterar resultat och utvĂ€rdering av insatserna gjorda under vintersĂ€songen 2013–2014. De lĂ€gsta PM10-halterna sedan mĂ€tningarna startade i Stockholm, uppmĂ€ttes under sĂ€songen och miljökvalitetsnormen klaras med bred marginal, vilket Ă„tminstone delvis kan bedömas vara en effekt av de intensifierade Ă„tgĂ€rderna. Vintern var dock ovanligt mild och snöfattig och har sannolikt bidragit till att de vanligtvis stora dammĂ€ngder som ansamlas pĂ„ vĂ€gytan i snö och fukt under vintern kunnat lĂ€mna systemet genom suspension, stĂ€dning och avrinning utan att resultera i höga partikelhalter. Under de torra perioderna har dessutom frekvent dammbindning dĂ€mpat halterna. Den vanligtvis kraftiga PM10-toppen pĂ„ vĂ„ren har dĂ€rför i stort sett uteblivit. Den kvartersvisa behandlingen visade sig ge ytterligare effekt pĂ„ PM10-halterna, medan CMA (kalciummagnesiumacetat) + KF (kaliumformiat) inte kunde visas ha nĂ„gon extra effekt. MĂ€tningarna av vĂ€gdammsförrĂ„det uppvisar samma sĂ€songsvariationer som tidigare Ă„r, med stora mĂ€ngder under vintern och mindre mĂ€ngder under höst och sen vĂ„r. Alla gator, utom Hornsgatan, uppvisar en successiv sĂ€nkning av vĂ€gdammsmĂ€ngderna under de tre sĂ€songer som mĂ€tningar utförts. Andelen partiklar mindre Ă€n 10 ÎŒm i vĂ€gdammet stiger frĂ„n höst till vinter och avtar igen under vĂ„ren. Den organiska andelen varierar i genomsnitt mellan 10 och 20 viktprocent av DL180 (dust load mindre Ă€n 180 ÎŒm).och uppvisar ocksĂ„ en sĂ€songsvariation, dĂ€r andelen Ă€r högre pĂ„ hösten och som lĂ€gst tidig vĂ„r. I en specifik utvĂ€rdering av stĂ€dmaskinens effekt pĂ„ vĂ€gdammsförrĂ„det kunde en minskning observeras.Since 2011, intensified efforts are made to reduce levels of PM10 in Stockholm, where the problems are extensive. This report includes the results and evaluation of the measures taken during the winter season 2013–2014. The lowest PM10 levels since records began in Stockholm, were measured during the season and the limit values for the environmental quality standard is managed by a wide margin, which at least partially can be attributed to the intensified measures. The winter was unusually mild and snow-free and this has probably contributed to that, the typically large quantities of road dust that accumulates on the road surface in winter were able to leave the system through suspension, cleaning and drainage without high particulate levels resulting. During dry periods, frequent dust binding has helped to suppress high PM10 levels. The usually sharp PM10 peak in spring did not appear to the same extent as previous years. The block-wise CMA (calcium magnesium acetate) treatment was shown to provide additional reducing effect on PM10 levels, while the CMA + KF (potassium formate) treatment did not appear to have any impact. The measurements of the road dust load show the same seasonal fluctuations as in previous years, with large amounts during winter and early spring and lower in fall and late spring. All streets, except Hornsgatan, show a gradual decrease of road dust load over the three seasons with available data. The proportion of particles smaller than 10 microns in the dust increases from autumn to winter and decreases again in the spring. The organic proportion varies between 10 and 20 per cent by weight of DL180 (dust load less than 180 ÎŒm)and also exhibit a seasonal variation, where the proportion is higher in autumn and lowest in early spring. In a specific evaluation of the cleaning machine, a reduction of the road dust load could be observed

    Operational measures against PM10 pollution in Stockholm : evaluation of winter season 2014–2015

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    Sedan 2011 pĂ„gĂ„r ett intensifierat arbete för att sĂ€nka halterna av PM10 i Stockholm. Denna rapport presenterar resultat och utvĂ€rdering av insatserna gjorda under vintersĂ€songen 2014–2015. SĂ€songen uppvisar de lĂ€gsta PM10-halterna samt lĂ€gst antal dygn över miljökvalitetsnormen för PM10 sedan mĂ€tningarna startades i Stockholm Ă„r 2000. BerĂ€kningar med NORTRIP-modellen visar att sĂ„vĂ€l ökad dammbindning, minskad dubbdĂ€cksanvĂ€ndning, lĂ€gre bakgrundshalt som skillnader i meteorologi alla Ă€r faktorer som bidragit till att halterna har sjunkit frĂ„n 2013 till 2015. Behandling med CMA+KF (kaliumformiat) kunde inte visas ge nĂ„gon extra effekt pĂ„ PM10-halterna, medan den kvartersvisa dammbindningen gav en ytterligare, men ej statistiskt sĂ€kerstĂ€lld, positiv effekt. DammförrĂ„det pĂ„ vĂ€gytan har pĂ„ alla studerade gator utom Hornsgatan en sjunkande trend de senaste tre Ă„ren och uppvisar, liksom tidigare sĂ€songer, en sĂ€songsbunden variation med stora mĂ€ngder pĂ„ vinter och tidig vĂ„r och lĂ„ga i oktober och maj. Detaljerade mĂ€tningar uppvisar en kraftig variation i dammförrĂ„det tvĂ€rs gatorna, med stora ansamlingar utanför körfĂ€ltet. VĂ€gytans textur bedöms spela en viktig roll för dammets ansamling dĂ„ den pĂ„verkar sĂ„vĂ€l uppvirvlingen frĂ„n trafiken, som möjligheten att stĂ€da bort dammet. Rapporten ger, utifrĂ„n sĂ€songens resultat i kombination med data om Ă„tgĂ€rder och meteorologi, nĂ„gra förslag till hur Ă„tgĂ€rderna kan förbĂ€ttras och ger Ă€ven exempel pĂ„ hur extra behov eller onödiga insatser kan sökas fram ur befintlig data.Since 2011, intensified efforts are made to reduce the levels of PM10 in Stockholm. This report presents results and evaluation of the efforts made during the winter season 2014–2015. The season has the lowest PM10 concentrations and the lowest number of exceedances of the environmental quality standard for PM10 since measurements started in Stockholm in 2000. Calculations using the NORTRIP model shows that both increased dust binding, reduced use of studded tires, lower background concentration and differences in meteorology are all factors that contributed to reduced levels from 2013 to 2015. Treatment with CMA + KF (potassium formate) did not appear to give any impact on PM10 levels, while block-wise dust binding gave an additional, but not significant, positive effect. The dust load on the road surface has a declining trend in all streets except Hornsgatan over the past three years and has, as in previous seasons, a seasonal variation with large amounts in winter and early spring and low in October and May. Detailed measurements showed a strong variation in the dust load across streets, with large accumulations outside the driving lane. Road surface texture is considered to play an important role in the accumulation of dust as it affects both the suspension from traffic, as well as the ability to clean off the dust. The report provides, based on the season’s results, combined with data on measures and meteorology, some suggestions for how measures can be improved and also provides examples of how additional needs or unnecessary efforts can be retrieved from the existing data
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