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The accession of Hungary to the European Union is likely to result in the intensification of arable crop cultivation. As a result of market forces and rural development measures, small parcels of land will be consolidated into larger fields. It is also likely that the area of maize and oilseed rape, and to a lesser extent that of sunflower, will increase at the expense of cereals. Abandoned land, ineligible for area payments will probably not return to cultivation. To identify the potential impact of these changes on the populations of common farmland birds, we analysed the data from 680 homogeneous sample plots of the Hungarian Common Bird Monitoring Scheme (МММ) from 2003. We used pair-wise comparisons with the Mann-Whitney test to identify the difference in the index of abundance of 34 species amongst the following categories of crops: abandoned versus cultivated arable land, small parcels versus large fields, cereals versus maize, sunflower and oilseed rape, fallow land versus small or large fields. Our results suggest that land consolidation will have the most serious negative impact on common farmland bird populations because small-scale farming systems hold significantly larger numbers of seven common farmland bird species, - White Stork Ciconia ciconia, Lapwing Vanellus vanellus, Wood Pigeon Columba palumbus, Whinchat Saxicola rubetra, Stonechat Saxicola torquatus, Tree Sparrow Passer montanus, Greenfinch Carduelis chloris, - than large-scale farms. On the other hand, the compulsory setaside might present some opportunities for the compensation of these negative effects if biodiversity considerations are integrated into the national rules, because fallow land held significantly higher densities of nine species, — Linnet Carduelis cannabina, White Stork, Yellowhammer Emberiza citrinella, Grasshopper Warbler Locustella naevia, Woodlark Lullula arborea, Whinchat, Stonechat, Whitethroat Sylvia communis and Blackbird Turdus merula, — than large crop fields. Comparison of large-scale cereal fields with large-scale maize, sunflower or oilseed rape fields, respectively, revealed significant differences only in the case of a few species, for example, the greater abundance of Skylarks Alauda arvensis in cereal than in maize, of Lapwings in sunflower and of Whinchat in oilseed rape than in cereal fields.
INTRODUCTION: Kisspeptin (KP) is involved in multiple hypothalamic regulatory processes such as estrogenic feedback to GnRH neurons via synaptic connections. We have reported previously that GnRH neurons send endocannabinoid retrograde signals to regulate their GABAergic input. KP‑producing neurons co‑synthesize GABA or glutamate both in the preoptic (POA) and arcuate (ARC) subpopulations. Moreover, we found the cannabinoid receptor type one (CB1) mRNA in these areas. However, it is unknown whether any subpopulation of KP neurons is under the influence of endocannabinoids. AIM(S): 1) To identify the GABAergic and glutamatergic subpopulations of KP neurons in female mice. 2) To determinate whether CB1 transcripts can be detected in any of the subpopulation of POA or ARC KP neurons. METHOD(S): The transcripts of KP, CB1, and the GABAergic and glutamatergic marker proteins, i.e., vesicular inhibitory amino acid transporter (VIAAT), and vesicular glutamate transporter-2 (VGLUT2) have been detected by RNAscope in situ hybridization technique. The signal was analyzed by confocal microscopy and quantified using our in‑house developed program. RESULTS: We found a significantly increased KP mRNA expression in the POA of ovariectomised mice after estradiol replacement. CB1 mRNAs were found in GABAergic and glutamatergic KP neurons of the POA and ARC. About 67% (AVPV) – 43% (ARC) of the GABAergic KP neurons expressed CB1 mRNA in the OVX+OIL mice, and about 31% (AVPV) – 36% (ARC) of the GABAergic KP neurons expressed CB1 mRNA in the OVX+EB mice. Concerning the glutamatergic KP neurons, about 19% (AVPV) ‑14% (ARC) expressed CB1 mRNA in the OVX- +OIL mice and about 24% (AVPV) – 43% (ARC) of them expressed CB1 mRNA in the OVX+EB mice. CONCLUSIONS: The hormonal status of mice influences the number of KP neurons expressing CB1 and endocannabinoids likely regulate the electrical activity of different KP subpopulations involved in the regulation of various hypothalamic processes.
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