22 research outputs found
LisÀÀntyvÀt hirvinaaraat. Urosten osuudet vaikuttavat hedelmöittymisten ajoittumiseen
Suomen hirvikannassa urosten ja kaksosvasojen osuudet sekĂ€ vasojen teuraspainot ovat 1990-luvulta lĂ€htien pienentyneet. Syiden selvittĂ€miseksi tutkimme vuonna 1985 SisĂ€-Suomesta kerĂ€ttyĂ€ lisÀÀntymisnĂ€yteaineistoa. Tulosten perusteella naaraiden hedelmöittymisaste oli korkea, mutta tiinehtymiset viivĂ€styivĂ€t, kun uroksia oli kannassa vĂ€hĂ€n. MyöhĂ€inen hedelmöittyminen merkitsee samalla myöhĂ€istĂ€ vasomista kevÀÀllĂ€ ja lyhyttĂ€ kasvukautta. TĂ€mĂ€ on yksi todennĂ€köinen tekijĂ€ vasojen pienentymisen taustalla. Selvimmin tiinehtymiset viivĂ€styivĂ€t â„ 6,5-vuotiailla naarailla. Niiden hedelmöittyminen tapahtui keskimÀÀrin yhdeksĂ€n pĂ€ivÀÀ myöhemmin alueilla, joilla lehmiĂ€/sonni -lukema oli â„ 2,5 kuin alueilla, joilla naaraita oli †1,3 yhtĂ€ urosta kohden. Tutkimuksella selvitettiin lisĂ€ksi hirvensikiön metsĂ€styksenaikainen kasvunopeus ja mÀÀritettiin tĂ€mĂ€n tiedon perusteella nĂ€ytenaaraitten hedelmöittymisajat. Hedelmöittymisten huippukausi osui vĂ€lille 18.â24. syyskuuta. Varhaisin tiinehtymisten mediaanipĂ€ivĂ€ (21.9.) oli 4,5 -vuotiailla ja myöhĂ€isin (29.9.) 1,5 -vuotiailla naarailla. Hirvihavaintokorteilla kerĂ€tty tieto hirvien kiimakĂ€yttĂ€ytymisen ajoittumisesta huipentui aikavĂ€lille 7.â22. syyskuuta eli noin kahdeksan vuorokautta tiiinehtymishuippua aikaisemmaksi. Tulosten perusteella hirvenmetsĂ€stys alkaa nykyisin hirven kiiman ollessa kiihkeimmillÀÀn. TĂ€mĂ€n voidaan arvioida aiheuttavan lisĂ€viivettĂ€ hedelmöittymisten ajoittumiseen. Tutkimuksella saatiin uutta tietoa myös hirven imetysajoista. Hirvinaaraat eivĂ€t lopeta vasojensa imettĂ€mistĂ€ kiimakauteen, kuten aikaisemmin on oletettu, vaan osa niistĂ€ jatkaa imettĂ€mistĂ€ metsĂ€styskauden loppuvaiheisiin saakka. Kaksosten osuuksien pienentymisen taustoja työmme ei valaissut, sillĂ€ urosten osuudella ei todettu olevan vaikutusta ovulaatioiden mÀÀrÀÀn. Tulokset tukevat vasta hyvĂ€ksyttyĂ€ Suomen hirvikannan hoitosuunnitelmaa. Tavoite sÀÀtÀÀ urosten osuus korkeintaan tasolle 1,5 naarasta/uros on hyvin perusteltu. Hyvin aiheellinen on myös tavoite selvittÀÀ mahdollisuudet myöhentÀÀ hirvenmetsĂ€styksen aloitusta suurimmassa osassa maata niin, ettĂ€ se alkaisi pÀÀosin hirven kiima-ajan jĂ€lkeen.Andelen tjurar och tvillingkalvar i Finlands Ă€lgstam samt kalvarnas slaktvikt har minskat sedan 1990-talet. För att utreda orsakerna till detta har vi undersökt materialet om reproduktionsprov pĂ„ Ă€lgkor som samlades in i Inre Finland Ă„r 1985.
Resultaten visar att honornas befruktningsgrad var hög, men de blev drÀktiga desto senare ju mindre tjurar det fanns i stammen. Sen befruktning betyder samtidigt sen kalvning pÄ vÄren och en kort tillvÀxtperiod. Detta Àr en sannolik orsak till de minskade kalvvikterna. Tydligast försenades drÀktigheten hos ℠6,5 Äriga kor som blev drÀktiga i genomsnitt nio dagar senare inom omrÄden dÀr mÀngden Àlgkor per tjur var ℠2,5 Àn inom omrÄden dÀr mÀngden kor var †1,3 per tjur.
Genom undersökningen utreddes ocksĂ„ tillvĂ€xthastigheten hos Ă€lgfoster under jakttid och faststĂ€lldes Ă€lgkornas befruktningstider med hjĂ€lp av tillvĂ€xtkurvan. HögsĂ€songen för befruktningar inföll under perioden 18â24.9. Den tidigaste mediandagen för befruktning (21.9.) var hos 4,5-Ă„riga och den senaste (29.9.) hos 1,5-Ă„riga honor. Enligt de uppgifter som samlats in med Ă€lgobservationskort kulminerades Ă€lgarnas brunstbeteende under perioden 7â22.9. dvs. cirka Ă„tta dygn före högsĂ€songen för befruktning. Enligt resultaten börjar Ă€lgjakten idag nĂ€r Ă€lgens brunst Ă€r som starkast. Detta bedöms orsaka ökad försening av befruktningar.
Provinsamlingen gav ocksĂ„ ny information om Ă€lgens digivningstid. Ălgkorna slutar inte att dia sina kalvar till brunsttiden, sĂ„som tidigare har antagits, utan en del av dem fortsĂ€tter att dia Ă€nda till slutskedet av jakttiden.
Undersökningen belyste inte bakgrunden till minskningen av andelen tvillingar, eftersom andelen tjurar inte konstaterades ha sÄdan inverkan pÄ mÀngden ovulationer som antagits i utgÄngslÀget.
Resultaten stödjer den nyligen godkĂ€nda förvaltningsplanen för Finlands Ă€lgstam. MĂ„let att justera könsfördelningen av vuxna Ă€lgar till nivĂ„n †1,5 honor/tjur Ă€r motiverat. Ăven mĂ„let att âutreda möjligheterna att skjuta upp inledningen av Ă€lgjakt i den största delen av landet sĂ„ att den i huvudsak skulle inledas efter Ă€lgens brunsttidâ Ă€r mycket motiverat.Among moose the proportions of bulls and twin calves, and the carcass weights of calves, have decreased in Finland since the beginning of the 1990s. To investigate the possible causes of this, we studied the reproductive status of moose cows from sample material collected from inland Finland during the hunting season of 1985.
The proportion of fertilised cows was high, but gestation was delayed when the number of bulls per female in the population fell. When conception is late, parturition is also delayed and the calf has a shorter growth period. This is one feasible reason for the fall in the carcass weights of moose calves. Conceptions were most delayed in ℠6.5-year old cows. In areas where the number of cows per bull was ℠2.5, average conception took place nine days later than in areas with †1.3 cows per bull. We also studied the growth of moose embryos and foetuses during the hunting season from 15th October to 15th December and calculated the average conception dates according to the growth curve of embryos and foetuses. The fertilisation peak was between the 18th and 24th of September.
The 4.5-year old cows had the earliest (21st September) and the 1.5-year old cows the latest (29th September) median day of fertilisation. According to the observations of hunters, the rutting behavior peaked between the 7th and 22nd September, i.e. eight days earlier than the fertilisation peak. Hence, the current start of the moose hunting season on the last Saturday of September coincides with the period of the most intensive moose rut. This may increase delays in conception.
We also received new knowledge on moose lactation. Contrary to what had been assumed previously, moose cows do not stop nursing their calves before the rutting period. Some continue producing milk until the end of the hunting season.
Our results did not support the hypothesis on the sex ratioâs effects on the proportion of twin ovulations. Our results, however, support the new Plan of moose population management in Finland. The goal of no more than 1.5 cows per bull is justified. There would also be good grounds for pursuing the objective of âexamining the possibilities of not starting the moose hunting season throughout most of the country until the main part of the rutting period is over.â201
Promoting lexical learning in the speech and language therapy of children with cochlear implants
This study examines lexical intervention sessions in speech and language therapy for children with cochlear implants (CIs). Particular focus is on the therapistâs professional practices in doing the therapy. The participants in this study are three congenitally deaf children with CIs together with their speech and language therapist. The video recorded therapy sessions of these children are studied using conversation analysis. The analysis reveals the ways in which the speech and language therapist formulates her speaking turns to support the childrenâs lexical learning in task interaction. The therapistâs multimodal practices, for example linguistic and acoustic highlighting, focus both on the lexical meaning and the phonological form of the words. Using these means, the therapist expands the childâs lexical networks, specifies and corrects the meaning of the target words, and models the correct phonological form of the words. The findings of this study are useful in providing information for clinicians and speech and language therapy students working with children who have CIs as well as for the childrenâs parents.</p