50 research outputs found
A tejelő szarvasmarhák szaporodási teljesítményét befolyásoló nem szabályszerű lutein képletek kialakulásának etiológiája és pathogenezise = Ethiology and pathogenesis of abnormal lutein phenomena what influence the reproductive performance in dairy cattle
Tejelő tehenekben végzett rektális ultrahang-vizsgálatok során gyakran detektálhatók vastag fallal rendelkező folyadék tartalmú (a vékony fallal rendelkező tüszőkkel ellentétben) petefészek képletek (VFPK), amelyek negatívan befolyásolják az állatok szaporaságát. A képletek megjelenése, ill. reagálása a kezelésekre a szakirodalomi információkkal nem mindig egyezett, kialakulásukra valamint kezelésükre vonatkozóan is kevés adat található. Célul tűztük ki a VFPK-k előfordulási gyakoriságának és fertilitásra gyakorolt hatásának felmérését, valamint kialakulásuk hátterét, szövettani és endokrinológiai jellegzetességeik leírását, és a jelenleg használt nomenklatúra értékelését. Eredményeink alapján a VFPK-k két nagy csoportra oszthatók: anovulációs és ovulációs képletekre. Ezek differenciál diagnosztikai elkülönítésére ajánlásokat tettünk. Az anovulációs képletek (anovulációs tüsző, follikulus ciszta, luteinizált ciszta) jelentős mennyiségű ösztradiolt termelnek, ami ivarzáshoz hasonló tüneteket okoz. Az ovulációs képletek (üreges és cisztás sárgatest) közül az üreges sárgatestek képesek a vemhesség fenntartására is, de esetükben nagyobb a magzatvesztés gyakorisága, mint üreg nélküli sárgatest esetén. A VFPK-k jelentős része reagál a PGF2? kezelésre, ami a szövettani eredményekkel összhangban lutein-sejtek jelenlétét bizonyítja. Kialakulásuk hátterében méh nyálkahártya gyulladásos elváltozása ill. a nem elégséges energia-bevitel miatti zsír-mobilizáció egyaránt állhatnak. | Fluid-filled ovarian phenomena with thick wall (FOPT) are frequently detected in dairy cows affecting negatively fertility. Appearance and reaction for treatment of these phenomena sometimes is different from literature data and just limited information are available for their development and treatment. Our aims were a) surveying frequency of FOPTs in dairy herds, b) studying their effect for fertility, c) description of histological and endocrine characteristics, d) comparative evaluation of the actual nomenclature with the outputs of current study. Based on our findings FOPTs are divided in two major groups: anovulatory and ovulatory structures. For differential diagnosis of these phenomena commendation had been prepared. Anovulatory phenomena (anovulatory follicle, follicular and luteal cysts) produce large amount of estradiol causing heat-like behavior. Ovulatory structures (CL with cavity and cystic CL) are able for maintaining pregnancy but late embryonic loss occurs more frequently in these animals than in cows with normal CL. Most of the FOPTs respond well for PGF2? treatment what verifies the presence of luteal cells discovered by the histological examinations. Inflammation of endometrial surface and body fat mobilization (due to the insufficient energy intake) are common reasons of FOPT’s development
Identification of Cohesive Ends and Genes Encoding the Terminase of Phage 16-3
Cohesive ends of 16-3, a temperate phage of Rhizobium meliloti 41, have been identified as 10-base-long, 3′-protruding complementary G/C-rich sequences. terS and terL encode the two subunits of 16-3 terminase. Significant homologies were detected among the terminase subunits of phage 16-3 and other phages from various ecosystems
Az időjárás hatása egy időskorú bükkös évenkénti körlap-növekedésére = Effect of weather conditions on the annual basal area increment of a beech stand of old age
Radiocarbon chronology of glacial lake sediments in the Retezat Mts (South Carpathians, Romania): a window to Late Glacial and Holocene climatic and paleoenvironmental changes
Abstract
the Retezat Mountains, this study discusses radiocarbon chronology and sediment accumulation rate changes in two sediment profiles in relation to lithostratigraphy, organic content, biogenic silica and major pollenstratigraphic changes. A total of 25 radiocarbon dates were obtained from sediments of two lakes, Lake Brazi (TDB-1; 1740 m a.s.l.) and Lake Gales (Gales-3; 1990 m a.s.l.). Age-depth modeling was performed on TDB-1 using calibrated age ranges from BCal and various curve-fitting methods in psimpoll. Our results suggest that sediment accumulation began between 15,124–15,755 cal yr BP in both lakes and was continuous throughout the Late Glacial and Holocene. We demonstrated that local ecosystem productivity showed delayed response to Late Glacial and Early Holocene climatic changes in the subalpine and alpine zones most likely attributable to the cooling effect of remnant glaciers and meltwater input. However, regional vegetation response was without time lag and indicated forestation and warming at 14,450 and 11,550 cal yr BP, and cooling at ca. 12,800 cal yr BP. In the Holocene one major shift was detected, starting around 6300 cal yr BP and culminating around 5200 cal yr BP. The various proxies suggested summer cooling, shorter duration of the winter ice-cover season and/or increasing size of the water body, probably in response to increasing available moisture
Age Estimates on the Deposition of the Cave Ice Block in the Saarhalle Dachstein-Mammoth Cave (Mammuthöhle, Austria) based on 3H and 14C
Changing climatic sensitivity and effects of drought frequency on the radial growth of Fagus sylvatica at the xeric frontiers of Central Europe
The influence of climate on the vitality and growth of European beech (Fagus sylvatica L.) has become a focus of forest research over the last decade. Beech locally reaches its continental xeric limit in Hungary within its European distribution area, giving a unique opportunity to study the climatic sensitivity of the species, based on tree-ring analysis. A comparison of four geographically and climatically different sites is presented from Hungary, combining data collected on stand level with systematic forest inventory plots. Tree-ring width chronologies covering the past 90–100 years of the lifetime of mature and middle-aged trees and different climatic variables were used to evaluate the growth-climate relationships and recent growth trends of the selected beech stands by multivariate regression analysis. Strong relationships were found between annual radial growth and (mainly water availability related) meteorological variables of the vegetation season, exceeding previous results from elsewhere in Europe. A clear spatiotemporal variability of the growth sensitivity was also revealed, following a (climatic) gradient from the northern to the southwestern parts of the country. In the northern sites, climatic sensitivity was found to be more fluctuating, while southwestern sites facing more continuous effects of changing climatic conditions seem to show weakening correlation over time. Trends of relative basal area increments and climatic sensitivity of growth over the past decades may be due to unfavorable climatic changes, though extreme and recurrent drought events superimposed on the long-term trends seem to have a decisive impact on growth patterns and associated resilience of beech
Coupled Hydro-Climatic Signals in the Radial Growth of Oaks Benefitting from Groundwater Availability
Lowland forests benefiting from groundwater availability are important ecosystems in Central Europe, both from ecological and economic perspectives. Besides a great reduction in their extent in the historical times and further shifts in the land use and water management regimes intensified during the industrial era, continuing changes in the groundwater and overall hydro-climatic conditions can pose significant challenges to them. Although tree-ring analyses serve as widely used tools to assess the climatic impact on tree growth and vitality, few studies have attempted to investigate the effects of subsurface hydrology on interannual fluctuations in xylem production. In this study, we compared the tree-ring width series of pedunculate oak (Quercus robur L.) from a forested area in southwestern Hungary with the time series of monthly groundwater depth and climatic variables over the period of 1920–2017 with a specific focus on 1961–2017. The radial growth of the studied trees showed the strongest relationship with late winter and early spring groundwater and drought conditions preceding the growing season, differing from the commonly reported climatic signals marked by early summer meteorological conditions of the vegetation season. The results suggest that the groundwater recharge during the dormant period preceding the vegetation season and the groundwater levels in early spring were among the key limiting factors on tree growth in the study area. In the growing years starting with a sufficiently high groundwater table, even scarce summer precipitation did not seem to limit radial growth drastically. However, unfavorable shifts in climatic conditions during the past few decades and the associated uncertainties in the future groundwater regime imply that additional active measures aimed at maintaining and restoring groundwater conditions may well be highly beneficial for sustaining groundwater-dependent forest ecosystems and their productivity
Review of diagnostic signs of involution problems in dairy cows by the help of CATUS database : [abstract]
Changing patterns of soil water content and relationship with national wheat and maize production in Europe
The warming of the climate and shrinking freshwater resources pose serious challenges to European agriculture. Meeting these challenges demands a thorough knowledge of the major trends in soil moisture patterns across the continent over time. Charting the available soil water (ASW) content (m3 m-3) derived from the ERA5 Land dataset in grid cells of 0.1° × 0.1°, the highest values occurred in the Alpine, Baltic and West Balkan countries, as well as in North Western Europe. However, a major part of the Mediterranean and the Carpathian-Balkan regions and Eastern Europe recorded the driest soils over recent decades. The annual average ASW decreased over almost the entire continent from 1981 to 2007, but to the greatest degree in Eastern Europe, while Northern Europe suffered least of all. For the summer half of the year, the available water content of the top 28 cm soil significantly decreased in 45.5 % of European croplands, while only 1.0% showed a significant moisture increase. Summer half-year moisture declined across almost the entirety of Eastern Europe, threatening the reproductive stage of wheat and maize vegetation period. Soil water content had a significant positive impact on wheat yields in an estimated 64.3 % of European wheat fields, and a negative one in 5.7 %. In the case of maize yields the positive impact of ASW was present in an estimated 89.4 % of maize-growing areas, explaining an estimated 46–72 % of maize yield variances in the majority of top European maize-producing countries. In contrast to wheat, negative soil water content impact for maize in the continent was not observed. Significant ASW - wheat and ASW - maize yield relationships were found with decreasing summer half year ASW in 32.0 % and 35.2 % of European croplands, respectively. The coexistence of the crop yield dependence on soil moisture and the decrease in available soil water content pose a considerable threat to grain production stability over extensive regions of Eastern and Western Europe. These warning signs call for an effective intervention on behalf of soil water conservation in European croplands