Leaders of the Pack

The inaugural class of Leadership Scholars sets a high standard for the law school

Arbuskulaar-mükoriisseid seeni sisaldavad inokulaadid põllumajanduses

Arbuskulaar-mükoriissed (AM) seened aitavad taimedel mullast toitaineid omastada, pakuvad kaitset stressi vastu ning parandavad mulla struktuuri. Tavapõllumajanduse praktikad mõjuvad AM seenekooslustele negatiivselt. AM seeni sisaldavaid inokulaate kasutades soovitakse inokulatsiooniga taimede kasvu ja saagist parandada, kuid inokulaate uurinud tööd on leidnud nende efektiivsuse kohta vastakaid tulemusi. Oma magistritöös uurin potikatses 11 tööstusliku inokulaadi võimet taimejuuri koloniseerida, neis sisalduvate AM seente ja muude mikroorganismide mõju taime biomassile ning tootekirjelduses olevate AM seeneliikide vastavust tegelikule koostisele. Leidsin, et vaid kaks inokulaati tekitasid taimedel juurte kolonisatsiooni ning inokulaatides olevate AM seened ja muud mikroorganismid ei omanud olulist positiivset mõju taimede biomassidele. Inokulaate sekveneerides tuli välja, et tootekirjelduses olevad AM seene liigid ei vasta suures osas neist leitud liikidele ning mitmes tootes oli AM seeni väga vähe või puudusid nad sootuks. Seega tuleks AM seeni sisaldavate inokulaatide tulemuslikuks rakendamiseks pöörata senisest suuremat tähelepanu inokulaatide kvaliteedikontrollile

“It’s Just Too Sad!”: Teacher Candidates’ Emotional Resistance to Picture Books

The use of critical literacy with children’s books that focus on social issues and disrupt the status quo can be a powerful way to create spaces for conversations with students about social justice and empowerment. Teacher candidates in a semester long children’s literature course were asked to respond to a range of children’s texts that dealt with many social issues and disrupted the commonplace. Despite an explicit emphasis on critical literacy and social justice, the candidates were very resistant to using many of the texts in their own future classrooms. They had strong emotional reactions that prevented them from consideration of how the texts could foster opportunities for students to uncover power relations in texts or to discuss ways that texts either maintain or disrupt the status quo. Data from three picture books that were cited the most frequently are shared in this paper, as well as a discussion on the implications for teacher educators who work with teacher candidates in the area of children’s literature

“It’s just too sad!”: Teacher candidates’ emotional resistance to picture books

The use of critical literacy with children’s books that focus on social issues and disrupt the status quo can be a powerful way to create spaces for conversations with students about social justice and empowerment. Teacher candidates in a semester long children’s literature course were asked to respond to a range of children’s texts that dealt with many social issues and disrupted the commonplace. Despite an explicit emphasis on critical literacy and social justice, the candidates were very resistant to using many of the texts in their own future classrooms. They had strong emotional reactions that prevented them from consideration of how the texts could foster opportunities for students to uncover power relations in texts or to discuss ways that texts either maintain or disrupt the status quo. Data from three picture books that were cited the most frequently are shared in this paper, as well as a discussion on the implications for teacher educators who work with teacher candidates in the area of children’s literature

Keskkonnatingimuste muutuste mõju võõr-kõverharjaku (Campylopus introflexus) kasvule

Käesoleva töö eesmärgiks oli uurida keskkonnatingimuste mõju võõr-kõverharjaku (Campylopus introflexus) kasvule, et saada rohkem infot, kas looduslikele sookooslustele iseloomulike tingimuste taastamine praegustes jääksoodes võimaldaks invasiivse liigi levikut kontrollida. Kontrollitud laboritingimustes uuriti erineva substraadi, valgus- ja veetaseme mõju võõr-kõverharjaku (Campylopus introflexus) ning Eestis laialt levinud raba-karusambla (Polytrichum strictum) biomassi juurdekasvule, võsude pikkuskasvule, külgokste arvule ja pikkusele. Lisaks hinnati nende liikide tärkamisedukust jääksoo levisepangast. Tulemustest selgus, et mõlemad katsealused liigid on laia ökoloogilise amplituudiga. Katsete põhjal võib öelda, et võõr-kõverharjak on raba-karusamblast edukam kiirema kasvu ja levimisvõime poolest, kuid mõlemad liigid on väga suure kohanemisvõimega erinevates ja muutuvates keskkonnatingimustes toimetulemiseks. Võõr-kõverharjaku levikut võib aidata kontrolli alla saada jääksoode taastaimestamine. Levisepanga katsest selgus, et võõr-kõverharjak kasvas turbasubstraadist välja väga rohkearvulise ja elujõulisena, kuid turbasammalde kiht mõjus tema tärkamisele takistavalt. Eelneva põhjal võib väita, et keskkonnatingimuste parandamine jääksoodes, soode taastamine ja jääksoode taastaimestamine aitab ohjeldada ka ökoloogiliselt tolerantse invasiivse võõrliigi – võõr-kõverharjaku levikut

Comparing a simple arbuscular mycorrhizal fungal inoculum with commercial products for enhancing plant growth

Arbuscular mycorrhizal fungi (AMF) are obligate symbionts forming mutualistic relationships with most land-plants. In AM symbiosis, the plant supplies the fungal partner with products of photosynthesis and in return recieves various mineral nutrients from the soil. Because of complex interactions with both soil and plants, disturbance can dramatically decrease AMF activity in soils and in these circumstances, it could be useful to restore AMF communities using inoculations. The use of AMF inoculants has so far been minimal due to the high cost and low availability of these products. In this study, the production of simple crude inocula was tested in trap cultures and the most suitable growth substrate nutrient content determined. The effectiveness of the produced inocula was compared with two commercially available inoculants. The results of this study indicate that the best substrate for inocula production in pot-cultures is pure sand with 5% natural soil. When using roots of plants grown in this manner as inoculants, the largest biomass and root-colonisation was achieved. As one of the commercial inoculants did not contain any mycorrhizal propagules at all, the need for quality control and establishment of industry standards is paramount. This study highlights the basics of using AM inoculations in home gardens and small-scale agriculture. The inoculation of large areas is still problematic because of low-yielding inoculant production, but could become highly perspective as methodology improves

THE PRODUCTION OF BIOGAS FROM PALM OIL MILL EFFLUENT AS SUBSTRATE WITH VARIATION OF AGITATION SPEED WITH FED-BATCH SYSTEM

The purpose of this research is to determine the effect of variation of agitation speed on biogas production from palm oil mill effluent and cow dung as substrate by using modified digester fed-batch. The addition of agitation in the fermentation tank digester in this research to accelerate the contact between the microorganisms with the substrate so that the process runs more effectively. Thus biogas production with variations of agitation velocity have 90 and 102 rpm. The research is conducted by fed-batch that is the addition of substrate in fermentation tank as much as 1 liter for 2 days which aim to get optimum biogas production result. The results of this research indicate that the speed of agitation affects for biogas production. The optimum biogas production occurred at 102 rpm agitation speed after 30 days fermentation time was 26.5116% mol CH4