Development of a dynamic model to predict PM10 emissions from swine houses

Influences on dust emissions from livestock operations are number, weight, and kind of animals and characteristics of the housing system. Differences between facilities cannot be explained solely by mechanistic input variables. The objective of this study was to characterize the main input variables for modeling emissions of particulate matter with a mass median diameter < or = 10 microm (PM10) from swine facilities using a data-based model. Investigations were performed in mechanically ventilated facilities for weaning, growing-finishing, and sows in Italy and Germany. The measurements included inside and outside concentration of airborne PM10 particles (scatter light photometry), ventilation rate (calibrated measuring fans), indoor air climate at a measuring frequency of 60 s, feeding times, and animal-related data such as weight and animal activity. Dust concentration and emission were simulated using a dynamic transfer function. The results indicated that the average PM10 emission rate was influenced considerably by housing system. The simulation of the PM10 emission rate resulted in a mean percentage error per data set of 21 to 39%, whereas the average simulated and measured emission rate per data set differed by about 4 to 19%. High prediction errors occurred especially during situations in which the absolute level and spatial location of the measured activity peaks did not correspond with the measured dust peaks. Further recommendations of the study were to improve continuous and accurate measurements of input variables, such as the activity level in animal houses, and to optimize the amount of measuring days in relation to the model accuracy.     

Trace elements in commonly used medicinal plants from Varna region,Bulgaria

Environmental Science and Pollution Research - In this study, we assessed the concentrations of some trace and toxic elements (Cd, Pb, Zn, Cu, Ni, Cr, Fe, and Mn) in traditionally used wild...     

Dynamics of sperm transfer in the ant Leptothorax gredleri

Mating tactics differ remarkably between and within species of social Hymenoptera (bees, wasps, ants) concerning, e.g., mating frequencies, sperm competition, and the degree of male sperm limitation. Although social Hymenoptera might, therefore, potentially be ideal model systems for testing sexual selection theory, the dynamics of mating and sperm transfer have rarely been studied in species other than social bees, and basic information needed to draw conclusions about possible sperm competition and female choice is lacking. We investigated sperm transfer in the ant Leptothorax gredleri, a species in which female sexuals attract males by “female calling.” The analysis of 38 female sexuals fixed immediately or up to 7 days after copulation with a single male each revealed that the sperm is transferred into the female bursa copulatrix embedded in a gelatinous mass, presumably a spermatophore. Sperm cells rapidly start to migrate from the tip of the spermatophore towards the spermatheca, but transfer is drastically slowed down by an extreme constriction of the spermathecal duct, through which sperm cells have to pass virtually one by one. This results in the spermatheca being filled only between one and several hours after mating. During this time, the posterior part of the spermatophore seals the junction between bursa copulatrix and spermathecal duct and prevents sperm loss. The prolonged duration of sperm transfer might allow female sexuals to chose between ejaculates and explain previously reported patterns of single paternity of the offspring of multiply mated queens. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Dioxins (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-furans) in traditional clay products used during pregnancy

Geophagy, the practice of consuming clay or soil, is encountered among pregnant women in Africa, Eastern Asia and Latin America, but also in Western societies. However, certain types of clay are known to contain high concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The aim of this study was to determine the PCDD/F contents of orally consumed clays purchased from Dutch and African markets. Congener patterns were compared with those of pooled human milk samples collected in eight African countries, to investigate a possible relationship with clay consumption. From the Dutch market thirteen clay products were examined, seven of African and six of Suriname origin. From seven African countries, twenty clay products were collected. All 33 clay products were screened with a cell-based bioassay and those showing a high response were analyzed by GC/HRMS. High PCDD/F concentrations were measured in three clay products from the Dutch market, ranging from 66 to 103 pg TEQ g^-1, whereas clay products from African countries were from 24 to 75 pg TEQ g^-1. Patterns and relatively high concentrations of PCDD/Fs in human milk samples from the Democratic Republic of the Congo and Côte d’Ivoire suggest a relationship with the consumption of contaminated clay. Frequent use of PCDD/F contaminated clay products during pregnancy may result in increased exposure of the mother and subsequently the developing fetus and new-born child. The use of these contaminated clays during pregnancy should be carefully considered or even discouraged.     

Assessment of regional capabilities for agricultural coexistence with genetically modified maize

Background

The coexistence of agricultural production with and without the use of genetically modified (GV) crops is supposed to be made possible in Germany by regulations, which include minimal distances of GV-fields to potentially susceptible crop fields and habitats. To explore the impact of these regulations on region specific coexistence potentials, we broadened the applicability of an existing method for the simulation of the spatial distribution of arable fields cropped with conventional, organic and GV-maize. We used simulations which combine a variety of minimum distances of GV-maize fields to assess regional specific options and limitations for coexistence.

Results

An existing method was extended to be applicable for different spatial scales, from the large (e.g. Federal State) to small (e.g. municipality). Input data consisted of cropping statistics, geometry of arable fields and protected areas. Scenarios of cropping situations included various minimal distances between GV-maize fields and protected areas and various proportions of maize within the areas. The results of the simulations represent possible distribution patterns of non-GV and GV-maize fields as well as the size of the remaining area in which additional GV-maize can be grown without violating the minimal distance rules. As suspected, increasing proportions of GV-maize and increasing minimal distances lower the areas suitable for additional GV-maize. However, the relation between the area of GV-maize grown and those suitable for GV-maize cultivation varied between the scenarios. Moreover, the variability between the municipalities was even more evident, due to varying landscape structure (proportion of maize, the ratio total arable land to maize, proportion of protected areas). Areas with high proportions of GV-maize, of protected areas and of maize could be problematical for coexistence. We discuss these parameters with regard to other coexistence studies.

Conclusions

Our method is suitable to simulate the spatial distribution of fields cultivated with GV-crops and non-GV-crops on various scales. Simulations on the scale of a Federal State reveals those areas, in which coexistence could be problematical. Simulations on a county scale, however, allow more insight into options and restrictions for coexistence in relation to landscape structural characteristics, which also can be transferred to larger scales. On the scale of municipalities simulations can help to analyse the limits of coexistence in areas of high conflict potential, moreover this level is more realistic with regard to practical agricultural decisions on the farm level.

Zusammenfassung

Hintergrund

Die Koexistenz verschiedener landwirtschaftlicher Produktionsformen ?C mit und ohne Anbau von gentechnisch ver?nderten Pflanzen (GVO) ?C soll durch gesetzlich fixierte Regeln erm?glicht werden, die unter anderem die Mindestabst?nde von GVO-Anbaufl?chen zu potenziell empfindlichen anderen Ackerfl?chen und Biotopen festlegen. Hier wurde eine Methode weiterentwickelt zur Simulation der r?umlichen Verteilung der Anbaufl?chen von konventionellem, ?kologischem und GV-Mais um regionsspezifische Koexistenzpotenziale von gentechnisch ver?ndertem Mais, sowie potenzielle Konfliktgebiete zu identifizieren.

Ergebnisse

Eine für Brandenburg entwickelte GIS-Simulationsmethode wurde durch die Verwendung fl?chendeckend vorhandener Daten so erweitert, dass sie bundesweit übertragbar ist und auf unterschiedlichen r?umlichen Skalenebenen angewandt werden kann, von gro?r?umig (Bundesland) bis lokal (Gemeinde). Als Eingangsdaten wurden Anbaustatistiken sowie Geometrien der Ackerfl?chen und von FFH- und Naturschutzgebieten verwendet. In den Szenarien wurden Abstandsregelungen zwischen Maisanbaufl?chen und zu Schutzgebieten und der GV-Maisanteil variiert. Die Ergebnisse der Simulation sind m?gliche r?umliche Verteilungen von Nicht-GV-Mais und GV-Mais sowie die potenziell für den Anbau von GV-Mais zur Verfügung stehende Fl?che. Mit zunehmendem GV-Maisanteil und Mindestabst?nden zu Schutzgebieten wird die für den GV-Mais zur Verfügung stehende Fl?che st?rker ausgesch?pft. Der Anteil des GV-Mais an der potenziell für den Anbau von GV-Mais zur Verfügung stehenden Fl?che variierte zwischen den Szenarien, und noch st?rker jedoch regional zwischen den Landkreisen, verursacht durch deren verschiedene agrar- und landschaftsstrukturelle Ausstattung (Maisanbauanteil, Verh?ltnis Ackerlandsanteil/Maisanbauanteil, Schutzgebietsanteil). Ein r?umliches Konfliktpotenzial bei der Umsetzung der Koexistenz ist in Gebieten hohen Nutzungsdrucks zu erwarten, d.h. in denen sowohl der Maisanbauanteil an der Ackerfl?che und der Anbauanteil von GV-Mais, als auch der Schutzgebietsanteil hoch sind. Diese Faktoren werden diskutiert in Bezug zu Ergebnissen weiterer Koexistenzstudien.

Schlussfolgerungen

Die vorgestellte Methode ist geeignet, die r?umliche Verteilung des Anbaus von Nicht-GV-Mais und GV-Mais auf unterschiedlichen Skalenebenen zu simulieren: Die Ebene eines Bundeslandes liefert Hinweise auf Gebiete, in denen die Koexistenz problematisch sein k?nnte und kann als Grundlage weiterer Berechnungen, wie zum Beispiel der Modellierung von Genflüssen auf Landesebene dienen. Die Simulation auf der Ebene eines Landkreises oder einer Gemeinde erm?glicht genauere Aussagen über die M?glichkeiten und Grenzen der Koexistenz. Auf der Ebene der Landkreise k?nnen z.B. unterschiedliche agrar- und landschaftsstrukturelle Situationen untersucht und für eine nachfolgende Regionalisierung angewandt werden. Die Ebene der Gemeinden erlaubt die Analyse der Grenzen der Koexistenz für Gebiete mit h?herem r?umlichen Konfliktpotenzial. Simulationen auf lokaler Ebene erscheinen darüber hinaus n?her an den Entscheidungsm?glichkeiten der landwirtschaftlichen Praxis.