Mechanisms and regulation of calcium absorption from the gastrointestinal tract in pigs and ruminants: comparative aspects with special emphasis on hypocalcemia in dairy cows

Adequate blood calcium (Ca) concentrations are a prerequisite to maintain several physiological functions of mammals such as pig and ruminants. Thus, blood Ca levels have to be regulated within very close limits. This is basically ensured through the coordinated effects of the calcitropic hormones parathyroid hormone (PTH) and calcitriol (1,25-dihydroxyvitamin D3). If plasma Ca decreases, one main effect of subsequently secreted PTH is the stimulation of renal reabsorption of Ca from the glomerular filtrate to reduce urinary Ca loss. Another important action of PTH is the induction of the renal enzyme 1 alpha-hydroxylase, which is responsible for the production of calcitriol. In most monogastric species, so far investigated, one of the most important effects of calcitriol is to stimulate active absorption of Ca from the gastrointestinal tract, particularly the upper small intestines, via a vitamin D-receptor-mediated genomic action. Whether this concept can be transferred without any constrictions to ruminants is still under discussion. Marked interspecies differences have to be recognized with respect to ruminant or non-ruminant animals, particularly with respect to individual segments along the gastrointestinal axis and with respect to vitamin D sensitivity of Ca transport mechanisms. This review will elucidate some of the current concepts related to the mechanisms and sites of Ca absorption in pigs and ruminants with special emphasis on dairy cows where Ca homeostasis is occasionally compromised at the time of parturition.     

Investigations on the water intake of growing bulls

The voluntary water intake was evaluated in 62 growing Holstein bulls (mean body weight range = 193 to 550 kg) during a whole fattening period. The diet was composed of corn silage and concentrates. Water was offered for ad libitum consumption. A total of 17,772 measurements of water intake were recorded over 282 days. The average daily water consumption was 18 kg/animal (S.D. = 6.7 kg). Applying a multiple regression analysis to the data set yielded the following equation: voluntary water intake (kg/day) = − 3.85 + 0.507  average ambient temperature (°C) + 1.494  dry matter intake (kg/day) − 0.141  roughage part of the diet (%) + 0.248  dry matter content of roughage (%) + 0.014  body weight (kg). The incorporation of the variables body weight gain, relative humidity, maximum ambient temperature, Na intake, and K intake into the equation did not increase the accuracy of the prediction.     

Does maternal environmental condition during reproductive development induce genotypic selection in Picea abies?

In forest trees, environmental conditions during reproduction can greatly influence progeny performance. This phenomenon probably results from adaptive phenotypic plasticity but also may be associated with genotypic selection. In order to determine whether selective effects during the reproduction are environment specific, single pair-crosses of Norway spruce were studied in two contrasted maternal environments (warm and cold conditions). One family expressed large and the other small phenotypic differences between these crossing environments. The inheritance of genetic polymorphism was analysed at the seed stage. Four parental genetic maps covering 66 to 78% of the genome were constructed using 190 to 200 loci. After correcting for multiple testing, there is no evidence of locus under strong and repeatable selection. The maternal environment could thus only induce limited genotypic-selection effects during reproductive steps, and performance of progenies may be mainly affected by a long-lasting epigenetic memory regulated by temperature and photoperiod prevailing during seed production.     

Combining isotopic signatures of n(Sr)/n(Sr) and light stable elements (C,N, O,S) with multi-elemental profiling for the authentication of provenance of European cereal samples

The aim of this work (from the FP6 project TRACE) was to develop methods based on the use of geochemical markers for the authentication of the geographical origin of cereal samples in Europe (cf. EC regulations 2081/92 and 1898/06). For the first time, the potential usefulness of combining n(⁸⁷Sr)/n(⁸⁶Sr) and δ¹³C, δ¹⁵N, δ¹⁸O and δ³⁴S isotopic signatures, alone or with key element concentrations ([Na], [K], [Ca], [Cu] and [Rb], progressively identified out of 31 sets of results), was investigated through multiple step multivariate statistics for more than 500 cereal samples collected over 2 years from 17 sampling sites across Europe representing an extensive range of geographical and environmental characteristics.     

Radio-frequency association of Efimov trimers

The quantum mechanical three-body problem is one of the fundamental challenges of few-body physics. When the two-body interactions become resonant, an infinite series of universal three-body bound states is predicted to occur, whose properties are determined by the strength of the two-body interactions. We used radio-frequency fields to associate Efimov trimers consisting of three distinguishable fermions. The measurements of their binding energy are consistent with theoretical predictions that include nonuniversal corrections.     

Untersuchungen zum gezielten Einsatz von Insektiziden gegen den Rapsglanzkäfer (<Emphasis Type="Italic">Meligethes aeneus</Emphasis>) in der landwirtschaftlichen Praxis des Landes Brandenburg im Zeitraum von 2006 bis 2014

Before 2006, agents of class II pyrethroids were used to control rape pests including the rape pollen beetle mainly. Thus, the selection of pyrethroids-resistant pollen beetle populations was encouraged. The aim of our study was to identify ways to combat these populations. Therefore, data of 465 real on-farm insecticide applications from nine years since 2006 were analyzed with regard to their effects on the pollen beetle and own experiments were carried out to test the efficacy of approved insecticides and control strategies. The analysis showed that the highest efficiencies were obtained with agents of the group of organophosphates and with the active substances indoxacarb and pymetrozine. Beyond that, the data examined revealed that the efficiency of thiacloprid (an insecticide of the class of neonicotinoids) has remained relatively constant throughout the observation period. In contrast, the increase in pyrethroid-resistant pollen beetle populations reflects the further decrease in efficacy of class II pyrethroids in the period 2011–2014.In summary, it should be noted that currently available insecticides achieve a maximal abatement level of 80–85?%. Therefore, an economic damage cannot be prevented on rapeseed locations with a very strong pollen beetle infestation even if multiple use of insecticides happens.To prevent further escalation of the resistance problem, another aspect should be given greater attention in the future. 55?% of the insecticide applications in the practice dataset where carried out before the control threshold (BRW) for weakly developed oilseed rape crops was achieved; often in the stage of micro-bud (BBCH 51). In compliance with the currently suggested higher control threshold, only 15?% of the insecticide applications would have been necessary. Thus, a reduction of the number of insecticide applications could be achieved by considering the higher thresholds. This would significantly reduce the selection pressure. Therefore, plant protection advice should mediate between exploiting the control thresholds and using the most appropriate insecticide.     

The number of leaves required for floral induction and translocation of the florigenic promoter in mango (Mangifera indica L.) in a tropical climate

Mango flowering appears to be determined by a temperature-regulated florigenic promoter (FP) synthesized in leaves and translocated to buds in phloem. The number of leaves required for flowering was investigated in ‘Keitt’ and ‘Tommy Atkins’ mango trees exposed to tropical conditions in Colombia. Data were compared with a previous study conducted under cool, floral-inductive conditions in Florida (Davenport et al., 2006). Leaf-number treatments consisted of 0, 1/8, 1/4, 1/2, 1, 2, 3, or 4 leaves on each of 20–40 stems per branch. The long distance translocation experiment consisted of a terminal donor stem and five defoliated receiver stems on each treatment branch. Treatments were 0, 1, 3, or 5 leaves on the donor stem. Every treatment branch in both experiments was girdled to isolate it from the rest of the tree, and developing panicles were removed to stimulate lateral shoot initiation at a time when conditions were right for floral induction in those buds. Treatment stems bearing no leaves produced only vegetative shoots in both cultivars in both experiments. The minimum number of leaves per stem (1/8 of a leaf and 1/4 of a leaf) was sufficient to induce 6% and 1% reproductive shoots with 94% and 99% vegetative shoots in Tommy Atkins’ and ‘Keitt’ stems, respectively. Branches bearing 4 leaves per stem in ‘Tommy Atkins’ trees produced the maximum mean flowering response with 45% reproductive shoots and 55% vegetative shoots. The maximum ‘Keitt’ response was 22% reproductive and 78% vegetative shoots with 4 leaves per stem. The donor stem of the 1-leaf treatment and the donor and first receiver stem of the 3-leaf treatment in the translocation experiment were induced to flower in ‘Tommy Atkins’ trees. The more distal receiver stems from the donor were vegetative. The 5-leaf donor treatment-induced reproductive shoots as far as the third leafless receiver stem located 52 cm from the donor. Proportions of flowering shoots decreased with distance from the donor, and the level of the FP was apparently insufficient to reach the fourth and fifth receivers since their shoot responses were vegetative. Only vegetative shoot responses were obtained in the translocation experiment conducted in ‘Keitt’ trees. The leaf number and translocation experiment results support the hypothesis that far less FP is synthesized in both ‘Tommy Atkins’ and ‘Keitt’ leaves during warm, tropical conditions than is synthesized in ‘Keitt’ leaves exposed to cool, subtropical conditions.     

Dynamics of mineral components in the forest floor of an acidic beech (Fagus sylvatica L.) forest

Seasonal changes of the mineral components Na, K, Mg, Ca, Mn, Fe, Al, Si and ash were investigated in the L1 horizon of an acidic beech (Fagus sylvatica L.) forest using litterbags (1 mm and 45 μm mesh-size) buried for up to 467 days in the forest floor. The element dynamics in this surface horizon were compared with the concentration and the total amount stored in a complete sequence of horizons (L1, L2, F1, F2 and H) taken from a moder profile in the Solling area. In the 1 mm litterbags with free access of the mesofauna, the concentrations of all cations were increased in comparison to the 45 μm treatment. This increase was highly significant, especially with regard to Fe and Al. The concentrations of these two cations were closely related to Si during the decomposition of fresh leaf litter in the L1 horizon. Si is the dominant element of ash in the litterbags and down the profile. The total amounts stored in the forest floor revealed that the Fe and Al input considerably exceeded the input by litter fall, and dry and wet deposition due to incorporation of mineral soil material. The input of soil material was also indicated by a decrease in the molar Si/Al ratio from 17 to 6 and in the relation of nutrient cations to ash from 30% to 2.5%.     

Indicators for assessing anthropogenic impact on urban surface and groundwater

Background, Aim and Scope  Our study focuses on the indication of anthropogenic impacts on the urban surface and groundwater in large cities, demonstrated for the cities of Halle/Saale and Leipzig (Germany). For the study we selected indicator substances such as xenobiotics, trace elements, and stable isotopes which are connected to human activities in urban areas. The xenobiotics reported here are the pharmaceutical carbamacepine, the polycylic musk compounds galaxolide and tonalide, the life style product caffeine, and industrial chemicals such as bisphenol A and t-nonylphenol. The investigated xenobiotics pose largely unknown risks to human health and the aquatic ecosystem. Trace elements are represented by the rare earth element gadolinium (Gd), used as magnetic resonance imaging contrast substance. Nitrogen isotopes in dissolved nitrate characterize the origin of nitrogen compounds, mixing and reaction processes. Methodology  River water was sampled along the flow path of the rivers Saale and Weisse Elster through the city of Halle/Saale, the rivers Luppe and Weisse Elster through the city of Leipzig. Separate samples were collected from the effluent of the local waste water treatment plants. Groundwater from Quaternary plain aquifers along the rivers and from different urban locations was collected at the same time. The indicators were analysed and assessed according to their sources, concentration and distribution patterns. Results and Discussion  Based on the nitrogen isotopic signature, dissolved nitrate in river water of the Saale was referred mainly to two sources: the effluent of the water treatment plant and a mixture of diffusive inputs from rain water channels, sewage leakages and agriculture activities along the rivers. The Gd anomaly was recognized in surface water of both cities, particularly in the effluent of the water treatment plants, but clearly attenuated in groundwater. We measured concentrations of xenobiotics in river and sewer water between 10 and 60,000 ng L⁻¹, and, in groundwater, one order of magnitude lower. Distinctions of xenobiotic patterns were found in river water before and after the effluent of treated waste water into the rivers. Degradation of endocrine disrupters and fragrances, but also persistence of carbamacepine were recognized as essential processes during waste water treatment. At the study site Halle/Saale, mass balances were set up for xenobiotics and water fluxes. Conclusions  At both sites, we demonstrated that indicators such as xenobiotics, gadolinium, and nitrogen isotopes are suitable for assessing anthropogenic impacts on urban water. However, the behaviour of these indicators in surface and groundwater has to be considered according to the different geochemical environments.