Effect of Frame Size and Hormone Implant on Performance and Carcass Characteristics of Finishing Yearling Heifers: Returns to a Value-Based Market

Four groups of yearling heifers representing different frame sizes—small, medium, and large Angus and medium Simmental—were fed high-grain finishing diets to average Low Choice quality grade. Half the heifers were implanted with estrogen and trenbolone acetate. Backfat and ribeye area were measured by ultrasound four times during the study to assess growth of muscle and fat. Increasing frame size resulted in increased feed intake, greater rates of gain, and a trend towards reduced feed conversion. Greater returns would have been realized from each of the four groups had they been sold in a premium market based on yield grade rather than the conventional grade and yield market. Increasing frame size resulted in greater returns to the value-based market. Implants increased rate of gain and improved feed conversion but did not result in significantly greater returns to the value-based market compared with the grade and yield market. Ribeye area and backfat increased with body weight and time on feed. Increase in ribeye area was linear with time, whereas accumulation of backfat was exponential. Rate of increase in area of ribeye tended to increase and backfat tended to decrease as frame size increased. Implants increased rate of increase in ribeye area but had no effect on rate of deposition of subcutaneous fat. Equations describing growth of ribeye area and backfat for each group predicted average growth for the heifers but did not predict growth of individual heifers. Final carcass yield grade was related to initial thickness of backfat but not to initial ribeye area. These results indicate that the type of cattle selected to be fed for a premium market based on yield grade is important to the success of the program. More work is needed to develop growth equations from ultrasound measurements, but ultrasound will likely be a useful tool in selecting feeder cattle for a value-based market.

Immunotoxic effects of environmental toxicants in fish - how to assess them?

Numerous environmental chemicals, both long-known toxicants such as persistent organic pollutants as well as emerging contaminants such as pharmaceuticals, are known to modulate immune parameters of wildlife species, what can have adverse consequences for the fitness of individuals including their capability to resist pathogen infections. Despite frequent field observations of impaired immunocompetence and increased disease incidence in contaminant-exposed wildlife populations, the potential relevance of immunotoxic effects for the ecological impact of chemicals is rarely considered in ecotoxicological risk assessment. A limiting factor in the assessment of immunotoxic effects might be the complexity of the immune system what makes it difficult (1) to select appropriate exposure and effect parameters out of the many immune parameters which could be measured, and (2) to evaluate the significance of the selected parameters for the overall fitness and immunocompetence of the organism. Here, we present - on the example of teleost fishes - a brief discussion of how to assess chemical impact on the immune system using parameters at different levels of complexity and integration: immune mediators, humoral immune effectors, cellular immune defenses, macroscopical and microscopical responses of lymphoid tissues and organs, and host resistance to pathogens. Importantly, adverse effects of chemicals on immunocompetence may be detectable only after immune system activation, e.g., after pathogen challenge, but not in the resting immune system of non-infected fish. Current limitations to further development and implementation of immunotoxicity assays and parameters in ecotoxicological risk assessment are not primarily due to technological constraints, but are related from insufficient knowledge of (1) possible modes of action in the immune system, (2) the importance of intra- and inter-species immune system variability for the response against chemical stressors, and (3) deficits in conceptual and mechanistic assessment of combination effects of chemicals and pathogens.

Prediction of residential radon exposure of the whole Swiss population: comparison of model-based predictions with measurement-based predictions

Radon plays an important role for human exposure to natural sources of ionizing radiation. The aim of this article is to compare two approaches to estimate mean radon exposure in the Swiss population: model-based predictions at individual level and measurement-based predictions based on measurements aggregated at municipality level. A nationwide model was used to predict radon levels in each household and for each individual based on the corresponding tectonic unit, building age, building type, soil texture, degree of urbanization, and floor. Measurement-based predictions were carried out within a health impact assessment on residential radon and lung cancer. Mean measured radon levels were corrected for the average floor distribution and weighted with population size of each municipality. Model-based predictions yielded a mean radon exposure of the Swiss population of 84.1 Bq/m(3) . Measurement-based predictions yielded an average exposure of 78 Bq/m(3) . This study demonstrates that the model- and the measurement-based predictions provided similar results. The advantage of the measurement-based approach is its simplicity, which is sufficient for assessing exposure distribution in a population. The model-based approach allows predicting radon levels at specific sites, which is needed in an epidemiological study, and the results do not depend on how the measurement sites have been selected.

Evaluation of an IgE ELISA with Culicoides spp. extracts and recombinant salivary antigens for diagnosis of insect bite hypersensitivity in Warmblood horses

Insect bite hypersensitivity (IBH) in horses represents an immunoglobulin E (IgE)-mediated hypersensitivity to salivary antigens from biting midges (Culicoides spp.). The aim of this study was to evaluate and compare the performances of IgE ELISAs using recombinant Culicoides spp. Obsoletus group salivary gland antigens or crude whole body extracts ('ObsWBE'), C. nubeculosus recombinant proteins (Culn1, 3, 4, 5, 7, 8 and 10) and Obsoletus group recombinant proteins (Culo1 and 2). IgE levels were measured in plasma of 343 Warmblood horses classified as IBH-affected (n=167) and IBH-unaffected (n=176) according to the owners' descriptions. IBH-affected horses were subdivided based on the severity of their clinical signs at sampling and whether or not their IBH history was considered to be classical. The accuracies of the tests increased when clinical signs at sampling were more pronounced or when the IBH history could be considered as classical. A combination of IgE levels against the three best performing Culicoides spp. recombinant proteins (Culn4, Culo1 and Culo2) and ObsWBE resulted in the best performing test. When IBH-affected horses showing a classical history of the disease and severe clinical signs were compared with IBH-unaffected horses, the Youden's index at the optimal cut-off for the three tests in combination was 0.67. This optimal cut-off had a sensitivity of 70%, a specificity of 97% and a total accuracy of 92%. The performance of the IgE ELISA was affected by the severity of IBH clinical signs at sampling and was improved when IgE levels against several recombinant proteins were combined.

Lake sediments as archives of recurrence rates and intensities of past flood events

Palaeoflood hydrology is an expanding field as the damage potential of flood and flood-related processes are increasing with the population density and the value of the infrastructure. Assessing the risk of these hazards in mountainous terrain requires knowledge about the frequency and severness of such events in the past. A wide range of methods is employed using diverse biologic, geomorphic or geologic evidences to track past flood events. Impact of floods are studied and dated on alluvial fans and cones using for example the growth disturbance of trees (Stoffel and Bollschweiler 2008; Schneuwly-Bollschweiler and Stoffel 2012: this volume) or stratigraphic layers deposited by debris flows, allowing to reconstruct past flood frequencies (Bardou et~al. 2003). Further downstream, the classical approach of palaeoflood hydrology (Kochel and Baker 1982) utilizes geomorphic indicators such as overbank sediments, silt lines and erosion features of floods along a river (e.g. Benito and Thorndycraft 2005). Fine-grained sediment settles out of the river suspension in eddies or backwater areas, where the flow velocity of the river is reduced. Records of these deposits at different elevations across a river’s profile can be used to assess the discharge of the past floods. This approach of palaeoflood hydrology studies was successfully applied in several river catchments (e.g. Ely et al. 1993; Macklin and Lewin 2003; O’Connor et al. 1994; Sheffer et al. 2003; Thorndycraft et al. 2005; Thorndycraft and Benito 2006). All these different reconstruction methods have their own advantages and disadvantages, but often these studies have a limited time coverage and the records are potentially incomplete due to lateral limits of depositional areas and due to the erosional power of fluvial processes that remove previously deposited flood witnesses. Here, we present a method that follows the sediment particle transported by a flood event to its final sink: the lacustrine basin.

Modern charge density studies: the entanglement of experiment and theory

This tutorial review article is intended to provide a general guidance to a reader interested to learn about the methodologies to obtain accurate electron density mapping in molecules and crystalline solids, from theory or from experiment, and to carry out a sensible interpretation of the results, for chemical, biochemical or materials science applications. The review mainly focuses on X-ray diffraction techniques and refinement of experimental models, in particular multipolar models. Neutron diffraction, which was widely used in the past to fix accurate positions of atoms, is now used for more specific purposes. The review illustrates three principal analyses of the experimental or theoretical electron density, based on quantum chemical, semi-empirical or empirical interpretation schemes, such as the quantum theory of atoms in molecules, the semi-classical evaluation of interaction energies and the Hirshfeld analysis. In particular, it is shown that a simple topological analysis based on a partition of the electron density cannot alone reveal the whole nature of chemical bonding. More information based on the pair density is necessary. A connection between quantum mechanics and observable quantities is given in order to provide the physical grounds to explain the observations and to justify the interpretations.

XENOESTROGEN-SPECIFIC MECHANISMS OF DEVELOPMENTAL REPROGRAMMING CORRELATE WITH GENE EXPRESSION AND TUMOR DEVELOPMENT

Environmental exposures during sensitive windows of development can reprogram normal physiological responses and alter disease susceptibility later in life in a process known as developmental reprogramming. We have shown that neonatal exposure to the xenoestrogen diethylstilbestrol (DES) can developmentally reprogram the reproductive tract in genetically susceptible Eker rats giving rise to complete penetrance of uterine leiomyoma. Based on this, we hypothesized that xenoestrogens, including genistein (GEN) and bisphenol A (BPA), reprogram estrogen-responsive gene expression in the myometrium and promote the development of uterine leiomyoma. We proposed the mechanism that is responsible for the developmental reprogramming of gene expression was through estrogen (E2)/ xenoestrogen inducedrapid ER signaling, which modifies the histone methyltransferase Enhancer of Zeste homolog 2 (EZH2) via activation of the PI3K/AKT pathway. We further hypothesized that there is a xenostrogen-specific effect on this pathway altering patterns of histone modification, DNA methylation and gene expression. In addition to our novel finding that E2/DES-induced phosphorylation of EZH2 by AKT reduces the levels of H3K27me3 in vitro and in vivo, this work demonstrates in vivo that a brief neonatal exposure to GEN, in contrast to BPA, activates the PI3K/AKT pathway to regulate EZH2 and decreases H3K27me3 levels in the neonatal uterus. Given that H3K27me3 is a repressive mark that has been shown to result in DNA methylation and gene silencing we investigated the methylation of developmentally reprogrammed genes. In support of this evidence, we show that neonatal DES exposure in comparison to VEH, leads to hypomethylation of the promoter of a developmentally reprogrammed gene, Gria2, that become hyper-responsive to estrogen in the adult myometrium indicating vi that DES exposure alter gene expression via chromatin remodeling and loss of DNA methylation. In the adult uterus, GEN and BPA exposure developmentally reprogrammed expression of estrogen-responsive genes in a manner opposite of one another, correlating with our previous data. Furthermore, the ability of GEN and BPA to developmental reprogram gene expression correlated with tumor incidence and multiplicity. These data show that xenoestrogens have unique effects on the activation of non-genomic signaling in the developing uterus that promotes epigenetic and genetic alterations, which are predictive of developmental reprogramming and correlate with their ability to modulate hormone-dependent tumor development.

Transcriptional regulation of the chicken MLC3f gene

The expression of the chicken fast skeletal myosin alkali light chain (MLC) 3f is subject to complex patterns of control by developmental and physiologic signals. Regulation over MLC3f gene expression is thought to be exerted primarily at the transcriptional level. The purpose of this dissertation was to identify cis-acting elements on the 5$\sp\prime$ flanking region of chicken MLC3f gene that are important for transcriptional regulation. The results show that the 5$\sp\prime$ flanking region of MLC3f gene contains multiple cis-acting elements. The nucleotide sequence of these elements demonstrates a high degree of conservation between different species and are also found in the 5$\sp\prime$ flanking regions of many muscle protein genes. The first regulatory region is located between $-$185 and $-$150 bp from the transcription start site and contains an AT-rich element. Linker scanner analyses have revealed that this element has a positive effect on transcription of the MLC3f promoter. Furthermore, when linked to a heterologous viral promoter, it can enhance reporter gene expression in a muscle-specific manner, independent of distance or orientation.^ The second regulatory region is located between $-$96 and $-$64 from the transcription start site. Sequences downstream of $-$96 have the capacity to drive muscle-specific reporter gene expression, although the region between $-$96 and $-$64 has no intrinsic enhancer-like activity. Linker scanner analyses have identified a GC-rich motif that required efficient transcription of the MLC3f promoter. Mutations to this region of DNA results in diminished capacity to drive reporter gene expression and is correlated with disruption of the ability to bind sequence-specific transcription factors. These sequence-specific DNA-binding proteins were detected in both muscle and non-muscle extracts. The results suggest that the mere presence or absence of transcription factors cannot be solely responsible for regulation of MLC3f expression and that tissue-specific expression may arise from complex interactions with muscle-specific, as well as more ubiquitous transcription factors with multiple regulatory elements on the gene. ^

Mechanisms of UV induced systemic immunosuppression: An essential role for interleukin-10

The recognition of the skin as an immunocompetent organ has focused attention on the complex interaction between ultraviolet radiation and the immune system. How UV-radiation, which hardly penetrates past the epidermis, induces systemic immune suppression is not entirely clear. We propose that suppressive cytokines, released by UV-irradiated keratinocytes, play a role in the induction of immune suppression. Injecting supernatants from UV-exposed murine keratinocytes into mice impairs their ability to mount a delayed-type hypersensitivity response against allogeneic histocompatibility antigens. We tested the hypothesis that the down regulation of the immune response by UV is precipitated by the release of IL-10 after keratinocytes are UV-irradiated. After UV exposure IL-10 mRNA was upregulated. Western analysis indicated immunoreactive IL-10 was secreted by UV-exposed keratinocytes. The addition of supernatants from UV-irradiated keratinocytes to Th1 clones diminished their IFN production, whereas the addition of supernatants from normal keratinocytes had no suppressive effect on IFN production. Furthermore, treating supernatants from UV-irradiated keratinocytes with anti-IL-10 antibodies blocked the induction of immune suppression. To determine if IL-10 was responsible for the immunosuppression seen after total-body UV irradiation, UV-exposed mice were treated with anti-IL-10 antibodies. Treating UV-irradiated mice with anti-IL-10 reversed the induction of immune suppression. These findings suggest that keratinocyte-derived IL-10 was mediating UV-induced suppression in vivo. We also tested the hypothesis that UV-induced suppressor cells are Th2 cells. Mice were injected with spleen cells from either normal or UV-exposed donor mice immunized with alloantigen. At the time of spleen cell infusion, the recipient mice were then resensitized. Spleen cells from UV-exposed mice suppressed DTH. Mice treated identically and injected with anti-IL-10 antibodies were able to generate a DTH response. Taken together these data suggest that the suppressor cells that are induced by UV radiation are Th2 cells which mediate their suppressive effect by release of IL-10. ^

Population genetics of VNTR loci and their applications in evolutionary studies

Variable number of tandem repeats (VNTR) are genetic loci at which short sequence motifs are found repeated different numbers of times among chromosomes. To explore the potential utility of VNTR loci in evolutionary studies, I have conducted a series of studies to address the following questions: (1) What are the population genetic properties of these loci? (2) What are the mutational mechanisms of repeat number change at these loci? (3) Can DNA profiles be used to measure the relatedness between a pair of individuals? (4) Can DNA fingerprint be used to measure the relatedness between populations in evolutionary studies? (5) Can microsatellite and short tandem repeat (STR) loci which mutate stepwisely be used in evolutionary analyses?^ A large number of VNTR loci typed in many populations were studied by means of statistical methods developed recently. The results of this work indicate that there is no significant departure from Hardy-Weinberg expectation (HWE) at VNTR loci in most of the human populations examined, and the departure from HWE in some VNTR loci are not solely caused by the presence of population sub-structure.^ A statistical procedure is developed to investigate the mutational mechanisms of VNTR loci by studying the allele frequency distributions of these loci. Comparisons of frequency distribution data on several hundreds VNTR loci with the predictions of two mutation models demonstrated that there are differences among VNTR loci grouped by repeat unit sizes.^ By extending the ITO method, I derived the distribution of the number of shared bands between individuals with any kinship relationship. A maximum likelihood estimation procedure is proposed to estimate the relatedness between individuals from the observed number of shared bands between them.^ It was believed that classical measures of genetic distance are not applicable to analysis of DNA fingerprints which reveal many minisatellite loci simultaneously in the genome, because the information regarding underlying alleles and loci is not available. I proposed a new measure of genetic distance based on band sharing between individuals that is applicable to DNA fingerprint data.^ To address the concern that microsatellite and STR loci may not be useful for evolutionary studies because of the convergent nature of their mutation mechanisms, by a theoretical study as well as by computer simulation, I conclude that the possible bias caused by the convergent mutations can be corrected, and a novel measure of genetic distance that makes the correction is suggested. In summary, I conclude that hypervariable VNTR loci are useful in evolutionary studies of closely related populations or species, especially in the study of human evolution and the history of geographic dispersal of Homo sapiens. (Abstract shortened by UMI.) ^

From «Pflantz-Gart» to «Stammregister». On the history of knowledge of fruit cultivation in the canton of Bern

Among the efforts for the improvement of agricultural productivity, the cultivation of useful plants is particularly at the center of the Economic Enlightenment. In contrast to fodder and textile plants, cereals and potatoes, fruit trees are not included among its favoured subjects. This may be considered as astonishing in view of the significance that fruit has acquired in the contemporary diet. Be that as it may, efforts to improve fruit cultivation go back to even before the classical period of the Economic Enlightenment. The example of Bern in particular is suited to such an analysis over the Longue durée that covers the time from Daniel Rhagor’s «Pflantz-Gart» (1639) to the «Register of varieties of excellent species of pome fruits for the canton of Bern» (Stammregister, 1865). From the perspective of the history of knowledge, the connections between scholarly knowledge and local experience on the one hand and the changing actors in these knowledge systems on the other hand are of special interest here

Identification and quantification of phytochelatins in roots of rice to long-term exposure: evidence of individual role on arsenic accumulation and translocation

Rice has the predilection to take up arsenic in the form of methylated arsenic (o-As) and inorganic arsenic species (i-As). Plants defend themselves using i-As efflux systems and the production of phytochelatins (PCs) to complex i-As. Our study focused on the identification and quantification of phytochelatins by HPLC-ICP-MS/ESI-MS, relating them to the several variables linked to As exposure. GSH, 11 PCs, and As–PC complexes from the roots of six rice cultivars (Italica Carolina, Dom Sofid, 9524, Kitrana 508, YRL-1, and Lemont) exposed to low and high levels of i-As were compared with total, i-As, and o-As in roots, shoots, and grains. Only Dom Sofid, Kitrana 508, and 9524 were found to produce higher levels of PCs even when exposed to low levels of As. PCs were only correlated to i-As in the roots (r=0.884, P <0.001). However, significant negative correlations to As transfer factors (TF) roots–grains (r= –0.739, P <0.05) and shoots–grains (r= –0.541, P <0.05), suggested that these peptides help in trapping i-As but not o-As in the roots, reducing grains’ i-As. Italica Carolina reduced i-As in grains after high exposure, where some specific PCs had a special role in this reduction. In Lemont, exposure to elevated levels of i-As did not result in higher i-As levels in the grains and there were no significant increases in PCs or thiols. Finally, the high production of PCs in Kitrana 508 and Dom Sofid in response to high As treatment did not relate to a reduction of i-As in grains, suggesting that other mechanisms such as As–PC release and transport seems to be important in determining grain As in these cultivars.

Metabolomics Reveals Aging-associated Attenuation of Noninvasive Radiation Biomarkers in Mice: Potential Role of Polyamine Catabolism and Incoherent DNA Damage-repair

Development of methods for rapid screening and stratification of subjects after exposure is an integral part of countermeasures against radiation. The potential demographic and exposure history-related heterogeneity of exposed populations warrants robust biomarkers that withstand and reflect such differences. In this study, the effect of aging and repeated exposure on the metabolic response to sublethal irradiation was examined in mice using UPLC-ESI-QTOF mass spectrometry. Aging attenuated postexposure elevation in excretions of DNA damage biomarkers as well as N(1)-acetylspermidine. Although N(1)-acetylspermidine and 2'-deoxyuridine elevation was highly correlated in all age groups, xanthine and N(1)-acetylspermidine elevation was poorly correlated in older mice. These results may reflect the established decline in DNA damage-repair efficiency associated with aging and indicate a novel role for polyamine metabolism in the process. Although repeated irradiation at long intervals did not affect the elevation of N(1)-acetylspermidine, 2'-deoxyuridine, and xanthine, it did significantly attenuate the elevation of 2'-deoxycytidine and thymidine compared to a single exposure. However, these biomarkers were found to identify exposed subjects with accuracy ranging from 82% (xanthosine) to 98% (2'-deoxyuridine), irrespective of their age and exposure history. This indicates that metabolic biomarkers can act as robust noninvasive signatures of sublethal radiation exposure.

Dynamics of the last four glacial terminations recorded in Lake Van, Turkey

A well-dated suite of Lake Van climate-proxy data covering the last 360 ka documents environmental changes over 4 glacial/interglacial cycles in Eastern Anatolia, Turkey. The picture of cold and dry glacials and warm and wet interglacials emerging from pollen, organic carbon, authigenic carbonate content, elemental profiling by XRF and lithological analyses is inconsistent with classical interpretation of ox- ygen isotopic composition of carbonates pointing to a more complex pattern in Lake Van region. Detailed analysis of glacial terminations allows for the constraining of a depositional model explaining different patterns observed in all the proxies. We hypothesize that variations in relative contribution of rainfall, snowmelt and glacier meltwater recharging the basin have a very important role for all sedimentary processes in Lake Van. Lake level of glacial Lake Van, predominantly fed by snowmelt, was low, the water column was oxic, and carbonates precipitating in the epilimnion recorded the light isotopic signature of inflow. During terminations, increasing rainfall and significant supply of mountain glaciers' meltwater contributed to lake level rise. Increased rainfall enhanced density gradients in the water column, and hindered mixing leading to development of bottom-water anoxia. Carbonates precipitating during terminations show large fluctuations in their isotopic composition. Full interglacial conditions in Lake Van are characterized by high or slowly falling lake level. Rainfall and snowmelt feed the lake but due to re-established mixing, the isotopic composition of authigenic carbonates is heavier and closer to that of evaporation-influenced lake water than that of runoff representing snowmelt and atmospheric precipitation.

The role of subpolar deep water formation and Nordic Seas overflows in simulated multidecadal variability of the Atlantic meridional overturning circulation

We investigate the respective role of variations in subpolar deep water formation and Nordic Seas overflows for the decadal to multidecadal variability of the Atlantic meridional overturning circulation (AMOC). This is partly done by analysing long (order of 1000 years) control simulations with five coupled climate models. For all models, the maximum influence of variations in subpolar deep water formation is found at about 45° N, while the maximum influence of variations in Nordic Seas overflows is rather found at 55 to 60° N. Regarding the two overflow branches, the influence of variations in the Denmark Strait overflow is, for all models, substantially larger than that of variations in the overflow across the Iceland–Scotland Ridge. The latter might, however, be underestimated, as the models in general do not realistically simulate the flow path of the Iceland–Scotland overflow water south of the Iceland–Scotland Ridge. The influence of variations in subpolar deep water formation is, on multimodel average, larger than that of variations in the Denmark Strait overflow. This is true both at 45° N, where the maximum standard deviation of decadal to multidecadal AMOC variability is located for all but one model, and at the more classical latitude of 30° N. At 30° N, variations in subpolar deep water formation and Denmark Strait overflow explain, on multimodel average, about half and one-third respectively of the decadal to multidecadal AMOC variance. Apart from analysing multimodel control simulations, we have performed sensitivity experiments with one of the models, in which we suppress the variability of either subpolar deep water formation or Nordic Seas overflows. The sensitivity experiments indicate that variations in subpolar deep water formation and Nordic Seas overflows are not completely independent. We further conclude from these experiments that the decadal to multidecadal AMOC variability north of about 50° N is mainly related to variations in Nordic Seas overflows. At 45° N and south of this latitude, variations in both subpolar deep water formation and Nordic Seas overflows contribute to the AMOC variability, with neither of the processes being very dominant compared to the other.