Types and Abundance of Zooplankton in the Tajwid Lake, Langgam Sub-District, Pelalawan District, Riau Province

Tajwid Lake is an oxbow lake that receives water from the Kampar Riverduring rainy season. To understand the types and abundance of zooplanktonpresent in that lake, a study has been conducted in February 2016. There were 3stations, Station 1 is in the inlet, Station 2 is in the middle of the lake and Station3 is in the outlet. Samplings were conducted 3 times, once/week. Results shownthat there are 20 species of zooplankton present in the lake. They were classifiedinto four classes, namely: 3 Rotifer species, 4 Crustacean species, 2 Sarcodinaspecies, 2 Cladocera species, and 2 Monogononta species, 1 Branchiopodaspecies, 1 Ciliata species, 1 Copepoda species, 1 Insecta species, 1 Phyllopodaspecies, 1 Maxillopoda species, 1 Granulureticulosa species. The average ofzooplankton abundance was around 1,582-3,990 ind/L, species diversity index(H\u27) was 3.95-4.10, uniformity index (E) was 1.15-1.25 and dominance index (C)was 0.08-0.07, indicated there is not a dominant species in the lake. While thewater quality parameters were as follows: temperature 290C, transparency 33-51cm, depth 600-1,200 cm, pH 5, DO 4.9-6 mg/L, and CO2 8.2-8.6 mg/L. Thevalues of water quality parameters indicate that the aquatic environment in theTajwid lake is good and is able to support the life of aquatic organisms, especiallyzooplankton

Sexual selection on song and cuticular hydrocarbons in two distinct populations of Drosophila montana

Sexual selection has the potential to contribute to population divergence and speciation. Most studies of sexual selection in Drosophila have concentrated on a single signaling modality, usually either courtship song or cuticular hydrocarbons (CHCs), which can act as contact pheromones. We have examined the relationship between both signal types and reproductive success using F1–3 offspring of wild- collected flies, raised in the lab. We used two populations of the Holarctic species Drosophila montana that represent different phylogeographic clades that have been separate for ca. 0.5 million years (MY), and differ to some extent in both traits. Here, we characterize the nature and identify the targets of sexual selection on song, CHCs, and both traits combined within the populations. Three measures of courtship outcome were used as fitness proxies. They were the probability of mating, mating latency, and the production of rejection song by females, and showed patterns of association with different traits that included both linear and quadratic selection. Courtship song predicted courtship outcome better than CHCs and the signal modalities acted in an additive rather than synergistic manner. Selection was generally consistent in direction and strength between the two populations and favored males that sang more vigorously. Sexual selection differed in the extent, strength, and nature on some of the traits between populations. However, the differences in the directionality of selection detected were not a good predictor of population differences. In addition, a character previously shown to be important for species recognition, interpulse interval, was found to be under sexual selection. Our results highlight the complexity of understanding the relationship between within-population sexual selection and population differences. Sexual selection alone cannot predict differences between populations.Publisher PDFPeer reviewe

Evidence of rapid change in genetic structure and diversity during range expansion in a recovering large terrestrial carnivore

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Admixture and gene flow from Russia in the recovering Northern European brown bear (Ursus arctos)

Large carnivores were persecuted to near extinction during the last centuries, but have now recovered in some countries. It has been proposed earlier that the recovery of the Northern European brown bear is supported by migration from Russia. We tested this hypothesis by obtaining for the first time continuous sampling of the whole Finnish bear population, which is located centrally between the Russian and Scandinavian bear populations. The Finnish population is assumed to experience high gene flow from Russian Karelia. If so, no or a low degree of genetic differentiation between Finnish and Russian bears could be expected. We have genotyped bears extensively from all over Finland using 12 validated microsatellite markers and compared their genetic composition to bears from Russian Karelia, Sweden, and Norway. Our fine masked investigation identified two overlapping genetic clusters structured by isolation-by-distance in Finland (pairwise FST = 0.025). One cluster included Russian bears, and migration analyses showed a high number of migrants from Russia into Finland, providing evidence of eastern gene flow as an important driver during recovery. In comparison, both clusters excluded bears from Sweden and Norway, and we found no migrants from Finland in either country, indicating that eastern gene flow was probably not important for the population recovery in Scandinavia. Our analyses on different spatial scales suggest

Larval niche differences between the sibling species, Drosophila montana and D. littoralis (Diptera) in northern Finland

Differences in larval substrate, or in the spatial and temporal occurrence of larvae between two closely related and ecologically similar Drosophila species were investigated. Vials containing homogenised tissue of water lily stems or birch phloem wetted with sap were exposed for oviposition in two habitats during two time periods. A logit analysis of the field emergence data suggested significant niche differences between the species. The logit model best explaining the species composition among emerging adults included an interaction between habitat and substrate, and also an interaction between habitat and exposure period. The differences between the species were, however, small and the species overlapped broadly with respect to each of the studied niche dimensions. The distribution of emerging flies among the yellow water lily vials appeared to fulfill the assumptions of a theoretical model for aggregation-mediated coexistence, i.e. the distribution of flies was aggregated among vials in both species, and there was no interspecific correlation in the numbers of flies emerging from the vials

Identification and characterisation of a novel mechanism of antibiotic resistance

Daptomycin is a bactericidal antibiotic of last resort for serious infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Although resistance is rare, treatment failure can occur in >20% of cases and so there is a pressing need to identify and mitigate factors that contribute to poor therapeutic outcomes. Work described in this thesis revealed that loss of the Agr quorum-sensing system, which frequently occurs in clinical isolates, enhanced S. aureus survival during daptomycin treatment. Wild-type S. aureus was killed rapidly by daptomycin but Agr-defective mutants survived antibiotic exposure by releasing membrane phospholipid, which bound and inactivated the antibiotic. Although wild-type bacteria also released phospholipid in response to daptomycin, Agr-triggered secretion of small cytolytic toxins, known as phenol soluble modulins, prevented antibiotic inactivation. Phospholipid release by S. aureus occurred via an active process that appears to involve the VraUTRS regulon, and was inhibited by the β-lactam antibiotic oxacillin, which slowed inactivation of daptomycin and enhanced bacterial killing. Subsequent work revealed that next-generation lipid biosynthesis inhibitors completely blocked phospholipid release, whilst the presence of host-associated fatty acids enhanced the release of membrane phospholipids. Future work will determine the molecular mechanism by which S. aureus releases phospholipids, and exploit this information to develop new therapeutic approaches that enhance daptomycin treatment efficacy.Open Acces

Advanced Combustor Liner Cooling Technology for Gas Turbines

This paper briefly reviews some of the work on advanced liner cooling techniques - specificially laminated porous wall cooling, angled-multihole (effusion) cooling and composite metal matrix liner cooling. The concept definition, heat transfer design procedure and design problems including key materials and fabrication considerations associated with each basic concept will be reviewed. Published rig and engine experience of aircraft engine manufacturers and research organizations will be cited. Some logical extensions of the current liner cooling schemes are suggested for future applications

Sized-related changes in winter condition of male calves in reindeer

Size-related changes in body condition of free-ranging male calves of semi-domesticated reindeer were studied in northern Finland from October 1983 to February 1984. In October-November, back fat depth or muscle fat percent correlated positively with the body size (=back length). In January, the highest means especially for muscle fat percent were found among medium-sized calves. Carcass weight and weight/back length ratio correlated positively with size, excluding February sample, where correlation for carcass weight was non-significant and for weight/back length ratio negative. Weight in the autumn correlated negatively with weight in February. Therefore, normalizing selection for body size (working against small and large phenotypes) is expected to occur in late winter. Small calves may be at greater mortality risk because of lower initial body reserves. Large calves commonly disperse during the rutting season and they may suffer most from increased food competition later in winter. Using of medium-sized calves for breeding might be the safest policy on ranges characterized by short food supply and difficult snow conditions.Koon vaikutus poron urosvasojen talviseen kuntoon.Abstract in Finnish / Tiivistelmä: Koon vaikutusta vapaana laiduntavien poron urosvasojen kuntoon tutkittiin Pohjois-Suomessa loka-helmikuussa talvella 1983-84. Loka-marraskuussa selkärasvan paksuus tai lihaksen rasvaprosentti riippui vasan koosta ( = selän pituus). Tammikuussa sen sijaan lihaksen rasvaprosentti oli korkein keskikokoisilla vasoilla. Ruhopaino sekä ruhopaino/selän pituus oli yleensa riippuvainen koosta. Helmikuussa ruhopainon riippuvuus koosta ei ollut enää tilastollisesti merkitsevä, ja koon ja ruhopainon/selänpituuden välinen korrelaatio oli negatiivinen. Eniten painoa menettivät (%) loka-helmikuun välillä suurikokoisimmat vasat. Havainnot viittaavat siihen, että talvella esiintyvä kuolleisuus on normalisoivaa koon suhteen (karsii pieniä ja suuria fenotyyppejä). Pienten vasojen kuolleisuusriski on suuri alunperinkin vähäisen varastoravinnon vuoksi. Suuret vasat puolestaan erkaantuvat usein emistään jo rykimäaikana, ja joutuvat kärsimään eniten talven mittaan kiristyvästä ravintokilpailusta. Niukoilla laitumilla siitokseen on turvallisinta säästää keskikokoisia vasoja.Sammenhengen mellom størrelse og vinterkondisjon hos hankalver av reinsdyr.Abstract in Norwegian / Sammendrag: Størrelses-relaterte forandringer i kroppskondisjon hos fritt beitende han-kalver av semidomestiserte rein er studert i Nord-Finland fra oktober 1983 til februar 1984. I oktober - november korrelerte tykkelsen av ryggfettet eller muskelfett-prosenten positivt med kroppsstørrelsen (= rygglengden). I januar ble de høyeste middelverdier, særlig for muskelfett-prosenten, funnet hos kalver av middels størrelse. Skrott-vekter og vekt/rygglengde-forholdet korrelerte positivt med kroppsstørrelse bortsett fra februar-prøvene, der korrellasjonen for skrott-vekt var ikke-signifikant og for vekt/rygglengde-forholdet var negativt. Vekt om høsten korrelerte negativt med vekt i februar. Derfor ventes et normaliserende utvalg for kroppsvekt (som arbeider mot små og store fenotyper) å skje på senvinteren. Små kalver er utsatt for større dødsrisiko på grunn av lavere kroppsreserver. Store kalver streifer vanligvis under brunsttiden og kan komme til å lide under økt næringskonkurranse på senvinteren. Bruk av middels store kalver i avlen kan være den sikreste metode på beiter som karakteriseres av dårlige næringstilgang og vanskelige snøforhold

Factor of communication barrier that influence workers productivity in oil palm plantation sector / Ahmad Aslah Azriq Ahmad Aspi

Human interacting with each other can also be known as form of communication. Effectively communicating with employers, employees, clients, suppliers, and customers will help you succeeds in this business world (Shonubi & Akintaro, 2016). Most of successful business people in the world are the one that have good communication skill. Aim of this study is to investigate relationship factor of communication barrier toward the productivity of workers based on five factors which are physical barrier, language barrier, perceptual barrier, gender barrier and emotional barrier. A method for this research is survey by using questionnaires and the study location at Lembah Kesang Estate. Total respondent for this research are 52 respondents. Statistical Package for Social Science (SPSS) consist of correlation coefficient and multiple regression is been used to analyzed all the data recorded. Result shows that gender barrier give the highest positive relationship (0.556) on the productivity of workers. As for the recommendation, estate workers need to remove their stereotype toward the woman employee in oil palm plantation sector to achieve effective communication