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Abstract: Status: Virus blage lisavosti paradižnika je virus iz rodu Ipomovirus. Uvrščen je v Prilogo II/A Uredbe 2019/2072/EU, ki vključuje rastlinske patogene za katere ni znano, da bi se pojavljali na ozemlju EU.
Keywords: virus blage lisavosti paradižnika, paradižnik, jajčevci, podatkovni listi
Published in DiRROS: 03.09.2024; Views: 298; Downloads: 197
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Abstract: Sexual size dimorphism theory predicts biased operational sex ratios (OSRs) and an uneven distribution of males among certain females. We studied this phenomenon through a field census of the giant wood spider Nephila pilipes (family Nephilidae) in Singapore, a species where females are, on average, 6.9 times larger than males. Specifically, we tested two hypotheses concerning male distribution, given their tendency to aggregate in certain female webs. The optimal female size hypothesis predicts that males would predominantly occupy webs of intermediate-sized females. The web clustering hypothesis posits that more males would be found in webs closer together compared to those farther apart. Our snapshot census revealed a female-biased OSR (females: males = 1.85) with an uneven distribution of males in female webs. Most males were found in webs of intermediate-sized females aligning with the optimal female size hypothesis. Proximity among female webs was indicative of male presence, lending support to the web clustering hypothesis. While our study's limited sample size warrants caution, we conclude that in N. pilipes, male occupation of female webs is facilitated by the clustering of webs, and males prefer to cohabit with optimally sized, receptive females.
Keywords: sexual size dimorphism, operational sex ratios (OSRs), male distribution, optimal female size hypothesis, web clustering hypothesis, female-biased OSR, intermediate-sized females, proximity of webs, male aggregation, arachnology, behavioral ecology, environmental zoology
Published in DiRROS: 03.09.2024; Views: 242; Downloads: 140
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Abstract: V okviru projekta Ljudje za barje, ohranjanje biotske pestrosti na Ljubljanskem barju (LJUBA), Program Norveškega finančnega mehanizma 2009-2014 in Program finančnega mehanizma EGP 2009-2014 smo v letu 2015 za naročnika Zavod republike Slovenije za varstvo narave kvantitativno popisali (izhodiščni monitoring) prepelico (Coturnix coturnix), kobiličarja (Locustella naevia) in bičjo trstnico (Acrocephalus schoenobaenus) na območju Ljubljanskega barja. Terensko delo je potekalo po metodi, ki nam je omogočila neposredno primerjavo rezultatov s podatki dobljenimi pred 20 leti v obdobju 1989 do 1996. Na izbrani površini 67 kvadratov smo prešteli 39 kličočih samcev prepelice, kar je za 87% manj kakor na primerljivi površini pred 20 leti. Vrsto smo odkrili na 23 kvadratih, kar je za 57% manj kakor pred 20 leti. Ob upoštevanju vseh možnih objektivnih in subjektivnih dejavnikov, ki vplivajo na rezultat štetja ocenjujemo, da se je velikost in razširjenost populacije prepelice v zadnjih 20 letih zmanjšala za več kakor za polovico. Vrsta je na Ljubljanskem barju zelo ogrožena in lahko v kratkem izgine kot gnezdilka. Na izbrani površini 67 kvadratov smo prešteli 31 pojočih kobiličarjev, kar je za 31% manj kakor na primerljivi površini pred 20 leti. Vrsto smo odkrili na 16 kvadratih, kar je za 16% manj kakor pred 20 leti. Ob upoštevanju vseh možnih objektivnih in subjektivnih dejavnikov, ki vplivajo na rezultat štetja ocenjujemo, da se velikost populacije kobiličarja v zadnjih 20 letih verjetno ni spremenila, nekoliko se je spremenilo območje njegovega pojavljanja. Kljub temu, zaradi relativno majhne površine kjer se pojavlja, ocenjujemo, da je kobiličar na Ljubljanskem barju ogrožena vrsta. Na izbrani površini 67 kvadratov smo prešteli 52 pojočih bičjih trstnic, kar je za 8% več kakor na primerljivi površini pred 20 leti. Vrsto smo odkrili na 20 kvadratih, kar je za 18% več kakor pred 20 leti. Ob upoštevanju vseh možnih objektivnih in subjektivnih dejavnikov, ki vplivajo na rezultat štetja ocenjujemo, da se velikost populacije bičje trstnice v zadnjih 20 letih verjetno ni spremenila, nekoliko se je spremenilo območje njenega pojavljanja. Kljub temu, zaradi relativno majhne površine kjer se pojavlja, ocenjujemo, da je bičja trstnica na Ljubljanskem barju ogrožena vrsta. Največja vokalna aktivnost prepelic je bila zvečer, le malo manjša zgodaj zjutraj. Po sedmi uri zjutraj je aktivnost opazno manjša in lahko vpliva na rezultate monitoringa. Prepelice so pogosto spreminjale položaj od koder pojejo, kar ima prav tako lahko vpliv na rezultate monitoringa. Za bolj natančen nadzor populacij vseh treh vrst predlagamo, da se obstoječi monitoring ptic kmetijske krajine na območju Ljubljanskega barja razširi z desetimi transekti. Metoda popisovanja in obdelave podatkov v obstoječem monitoringu sta ustrezni za kobiličarja in bičjo trstnico, za prepelico predlagamo nekaj sprememb.
Keywords: ptice, zavarovana območja, varstvo narave
Published in DiRROS: 03.09.2024; Views: 210; Downloads: 2262
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Abstract: V končnem poročilu so predstavljeni rezultati terenskih raziskav štirih varstveno pomembnih vrst hroščev v Sloveniji v letu 2016. Za močvirskega krešiča (Carabus variolosus), rogača (Lucanus cervus), alpskega kozlička (Rosalia alpina) in bukovega kozlička (Morimus funereus) je v Sloveniji že vzpostavljena shema populacijskega in distribucijskega monitoringa. V tem poročilu so podani rezultati popisov populacijskega in distribucijskega monitoringa v letu 2016. V tem letu smo izvedli vzorčenja za populacijski monitoring za močvirskega krešiča (deseto snemanje), rogača (deseto snemanje), alpskega (deveto snemanje) in bukovega kozlička (osmo snemanje) ter vzorčenja za distribucijski monitoring za močvirskega krešiča in rogača (četrto leto v tretjem petletnem ciklusu). Dodatno so glede na najnovejše raziskave podani predlogi izboljšanja sheme monitoringa za rogača in alpskega kozlička. V poročilu so predstavljeni rezultati popisa v letih 2016 in 2017 za dopolnitev strokovnih podlag za puščavnika (Osmoderma eremita) in škrlatnega kukuja (Cucujus cinnaberinus). Za obe vrsti sta podani tudi predlogi sheme monitoringa. V okviru naloge smo opravili pregled vodnega telesa v Spodnjem Krapju in pet vodnih teles ob reki Muri za namene ugotavljanja prisotnosti ovratniškega plavača (Graphoderus bilineatus). Vrsto smo v letu 2017 zopet potrdili ob reki Muri in sicer v Murski šumi, kar je nova lokacija za vrsto v Sloveniji, ne pa tudi v mrtvici pri Spodnjem Krapju, ki je bila do nedavna edina recentna lokaliteta za vrsto pri nas, kjer je bil ovratniški plavač potrjen v letu 2011.
Keywords: hrošči, monitoring, ekologija
Published in DiRROS: 03.09.2024; Views: 286; Downloads: 726
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Abstract: This research was focused on the effect of Ti and S content on the formation of non-metallic inclusions and their influence on the mechanical properties and machinability of low-carbon ferritic– pearlitic steels. An analysis and classification of the non-metallic inclusions were carried out. The tensile strength and impact toughness were determined from samples taken in the rolling direction. Machinability investigations were carried out on a CNC turning machine and by analyzing the surface roughness. TiO-TiN inclusions are present in steels with an increased Ti content. In these steels, the hardness, tensile strength, and cutting forces increase with a higher proportion of Ti. In the second group of steels with increased contents of S, Al, and Ca, MnS and CaO-Al2O3-MnS non-metallic inclusions are formed. As the S content increases, the tensile strength and cutting forces decrease, while the impact toughness increases. In steels with added Ti, the This research was focused on the effect of Ti and S content on the formation of non-metallic inclusions and their influence on the mechanical properties and machinability of low-carbon ferritic– pearlitic steels. An analysis and classification of the non-metallic inclusions were carried out. The tensile strength and impact toughness were determined from samples taken in the rolling direction. Machinability investigations were carried out on a CNC turning machine and by analyzing the surface roughness. TiO-TiN inclusions are present in steels with an increased Ti content. In these steels, the hardness, tensile strength, and cutting forces increase with a higher proportion of Ti. In the second group of steels with increased contents of S, Al, and Ca, MnS and CaO-Al2O3-MnS non-metallic inclusions are formed. As the S content increases, the tensile strength and cutting forces decrease, while the impact toughness increases. In steels with added Ti, the machining is more difficult, but a finer surface is achieved after turning, while a higher S content results in an increased fraction of softer sulfide inclusions, which reduce the cutting forces but also result in a reduced surface quality. turning, while a higher S content results in an increased fraction of softer sulfide inclusions, which reduce the cutting forces but also result in a reduced surface quality.
Keywords: non-metallic inclusions, mechanical properties, machinability, surface roughness
Published in DiRROS: 03.09.2024; Views: 299; Downloads: 468
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