Entwicklung und Evaluierung von Methoden zur Bewertung des Melkvorgangs

In order to perform the dairy cows’ milking resource-saving, economic effective and as healthy as possible for the dairy cow, the milking process should be quick, complete and gentle. In case that not all three attributes can be fulfilled farmers ask for help from milking advisory services. Currently there is no official apprenticeship provided for milking advisors, therefore advisors have different levels of prior education and no gold standard for the approach of advisory service is available in machine milking. In consequence of this, the aim of the present study was to develop a helping concept for milking advisors, which simplifies the assessment of the machine milking process in milking parlours on a sound scientific basis. In the present concept the Milking System, the Dairy Cow, the Milking Operator and the Milking Parlour and Waiting Area were identified as key areas of the milking process. For each key area indicators were presented, which provide further information about the machine milking process and enable the assessment. Some indicators can be used for an initial troubleshooting and other for an analysis of causes. Influences and interdependencies of indicators were highlighted and illustrated by the present concept. In addition, a new, precisely defined hand-milking method to assess the completeness of the milking process was developed and compared to two other methods, which are already applied in practice. The first method was a visual method, which assesses the degree of the quarter filling. This method was not related to the actual rest milk in the quarter. The second method, a quantitative assessment of the number of easy strips, and the new precisely defined hand-milking method for 15 s per quarter, were suitable to predict the rest milk in the quarter. Despite to the strict definitions of the hand-milking handgrip and handgrip frequency it was not possible to avoid the influence of the evaluator on the amount of collected strip yield in 15 s. In consequence of this, the amount of strip yield among herds can only be compared under the premise that the hand-milking is performed by the same person. Previous thresholds were set at 100 ml. Reasoned by a slower milking by the precisely defined hand-milking in comparison with a stripping hand-milking method, the threshold must be lower for the new developed method. The precisely defined hand-milking method was investigated for cow and milking system related influencing factors on the outcome of the method and the rest milk in the udder. It was outlined, that the rest milk in the udder is influenced by the positioning of the milking cluster and herd specific settings of the milking technique, the milking routines and the herds’ individual characteristics. The outcome of the full-hand hand-milking of 15 s per quarter was influenced by the herd, evaluator, milking cluster positioning, teat length and palpable rings at teat base. The individual milking characteristics of the quarter varied too much to predict the amount of rest milk in the udder by only hand-milking one or two quarter. Furthermore, the intensity of the dairy cows’ hind leg activity during the course of milking was observed in ten farms and two milking times per farm and day for its relation to the vacuum level in the short milk tube and mouthpiece chamber. In addition, the machine-on-time and lengths of milking phases was investigated for its influence on the frequency of observed hind leg activity and its influence on the degree of hyperkeratosis. Finally, also the influence of hyperkeratosis on the shown intensity of hind leg activity was evaluated. The dairy cows’ hind leg activity was divided into stepping (claw raised 15 cm). Kicking was shown at significant higher mouthpiece chamber vacuum levels than stepping. Cows, which have shown kicking, had significant higher degrees of teat-end hyperkeratosis than cows which have shown stepping. The length of machine-on time did not affect the frequency of hind leg activity, but the degree of hyperkeratosis. Longer machine-on times led to higher degrees of hyperkeratosis. The kicking was assumed to be avoidance behaviour, while stepping is influenced by various factors

Investigations on the synthesis of silicon-arsenic double bonds and the preparation of MxEy nanoparticles from single-source-precursors (M = Ga, Ge, Sn; E = P, As)

In summary, the present work provides a variety of potential single source precursors for the synthesis of group 14 element pnictogenide nanoparticles (MxEy with M = Ge, Sn; E = P, As), which are stabilized by a β-diketiminato ligand that can easily be removed by acidic or basic reagents under mild conditions. Furthermore, five novel compounds exhibiting a rare silicon arsenic double bond with a coordinating benzamidinato ligand could be synthesized and characterized and also studies on the preparation and the reactivity of hitherto unknown benzamidinato zinc complexes were successfully performed. Five novel arsasilene complexes Following the reaction of [PhC(NtBu)2]SiCl and LiP(SiMe3)2 reported by Driess et al. in 2011, it could be shown that a simple one-pot synthesis using [PhC(NtBu)2]SiCl and the arsenic compound LiAs(SiMe3)2 leads to the formation of [PhC(NtBu)2]Si(SiMe3)=As(SiMe3) (3-1) (Figure 6-1 - 1 top left). Studies on the reactivity of the reaction mixture of the starting materials towards water and oxygen revealed the formation of a hydrolysis product [PhC(NtBu)2]Si(H)=As(SiMe3) (3-2) and an oxidation product [PhC(NtBu)2]Si(OSiMe3)=As(SiMe3) (3-5) (Figure 6-1 - 1 top middle and right). Additionally, the species {[PhC(NtBu)2]Si}2=AsSiMe3 (3-3) and {[PhC(NtBu)2]Si=AsSiMe3}2 (3-4) could be obtained in reactions which were performed to reproduce 3-1 (Figure 6-1 - 1 bottom). Yet, all attempts to synthesize 3-3 and 3-4 selectively failed. Figure 6-1 - 1: The solid state structures of the compounds 3-1, 3-2, 3-3, 3-4 and 3-5. 3-1 was prepared from the reaction of [PhC(NtBu)2]SiCl with LiAs(SiMe3)2, it was fully characterized by NMR spectroscopy, EI mass spectrometry and X-ray structure analysis whereby it was necessary for the latter to permanently cool the reaction mixtures to –80°C to grow suitable crystals. 3-2 could be obtained by adding a defined amount of water to the thf solutions (H2O:[PhC(NtBu)2]SiCl:LiAs(SiMe3)2 = 1:5:5), which may not be exceeded to avoid decomposition. It was also fully characterized by the typical spectroscopic methods but in addition by 29Si NMR spectroscopy to unequivocally detect the Si–H coupling. In a similar way to 3-2, a stoichiometric quantity of (SiMe3)2O2 mixed with [PhC(NtBu)2]SiCl and LiAs(SiMe3)2 leads to the formation of compound 3-5 (Scheme 6-1 - 1). In the case of 3-3 and 3-4, just a few crystals appeared as side products of the synthesis of 3-1. It was also possible to detect the molecular peak of 3-4 by solid state EI mass spectrometry. Scheme 6-1 - 1: Overview of the preparation of the arsasilenes 3-1 to 3-5. Also, some studies concerning the reactivity of 3-1 were performed, especially investigations in order to transform 3-1 into 3-2 and 3-5, but these attempts were not conclusive as 3-2 and 3-5 can only be obtained from the reaction of the monochlorosilylene with LiAs(SiMe3)2 and water or (SiMe3)2O2, respectivley. Additionally, VT NMR investigations were done to elucidate the mechanistic details of the formation of 3-1 and possibly to gain hints on the formation of the arsenic analogue of Driess’ [PhC(NtBu)2]SiP(SiMe3)2, which was not successful. But instead, crystals of the literature known compound {[PhC(NtBu)2]SiAs}2 3-F with a yet unknown unit cell were isolated from the thf-d8 mixture. Nanoparticles from [CH(C(Me)N(2,6-iPr2C6H3))2]ME(SiMe3)2 (M = Ge, Sn; E = P, As) As it has already been described in the chapters 1.3.7 and 4.2, numerous possibilities exist to utilize nanoparticles and especially the still scarcely explored nanoscale material containing elements of group 14 and 15 might show interesting properties. In general, nanoparticles can be synthesized by various methods, starting either from bulk material (top down approaches like milling) or from atoms and molecules (bottom up method). The bottom up approach of hot injections starts with the solution of the precursors in a high boiling, sometimes coordinating solvent, followed by a fast heating step, that leads to the decomposition of the starting material and the formation of the nanoscopic material. If a separate starting material for each component of the resulting nanoparticles is used, the method is called multi source precursor approach. In contrast to this is the single source precursor method, in which all components of the nanoparticles are combined in one molecule. As this approach shows important advantages like mild reaction conditions and the avoidance of volatile and/or pyrophoric substances, the single source precursor approach was the method of choice to prepare MxEy nanoparticles (M = Ge, Sn; E = P, As). As the most promising complexes to decompose in order to achieve the desired nanoscopic matter, the two literature known compounds [CH(C(Me)N(2,6-iPr2C6H3))2]MP(SiMe3)2 (M = Ge (4-D), Sn(4-E)) and the novel [CH(C(Me)N(2,6-iPr2C6H3))2]SnAs(SiMe3)2 (4-4) were studied. Previously, the heavier homologues of 4-D and 4-E [CH(C(Me)N(2,6-iPr2C6H3))2]MAs(SiMe3)2 (M = Ge (4-3), Sn(4-4)) were successfully synthesized and fully characterized (Figure 6-1 - 2). 4-3 and 4-4 are prepared by the reaction of [CH(C(Me)N(2,6-iPr2C6H3))2]MCl (M = Ge, Sn) with LiAs(SiMe3)2, whereby 4-4 is achieved in good yields, while 4-3 can only be isolated in minor quantities amounts because of which 4-3 is discarded as single source precursor. Figure 6-1 - 2: Left: Solid state structure of 4-3. Right: Solid state structure of 4-4. Therefore, only the tin analogon 4-4 was used in the hot injection nanoparticles tests with PA as starting material, leading to the formation of agglomerated spherical particles, which could not be separated. Nevertheless, the particles show an average size of 10 to 14 nm and a composition of mostly Sn4As3, proving the applicability of 4-4 for the synthesis of tin arsenide nanoscale material (Figure 6-1 - 3). Figure 6-1 - 3: Left: TEM images of the nanoparticles formed during the decomposition of 4-4 with 1 eq. PA. Right: XRD diffractogram of the nanoparticles revealing a composition of Sn4As3. Beside 4-4, also the phosphorus compounds 4-D and 4-E were studied for their potential use in the synthesis of nanoparticles, which showed that the Ge compound 4-D is not a suitable precursor. Despite decomposing to the desired germanium phosphide Ge4P3 which could be proven by EDX, investigations using TEM analysis clearly displayed the absence of regular shaped and similar sized nanoparticles leading to the discard of 4-D (Figure 6-1 - 4). Figure 6-1 - 4: Left: TEM images of the decomposition of 4-D with 1 eq. PA (1 h). Right: EDX spectrum of the precipitate obtained from the decomposition of 4-D consisting of Ge4P3. On the other hand, its heavier homologue 4-E provided in the reactions with HDA very satisfactory results as the complex not only decomposes to Sn4P3 as required, but also forms agglomerated spherical nanoparticles with an average size of about 10 to 22 nm (Figure 6-1 - 5). Figure 6-1 - 5: Left: Nanoparticles from the reaction of 4-E with 0.5 eq. HDA (1 h). Right: XRD diffractogram of the reaction products of 4-E with a composition of Sn4P3. In summary, the analyses performed in the course of the experiments show that both tin compounds [CH(C(Me)N(2,6-iPr2C6H3))2]SnE(SiMe3)2 (E = P (4-E), As (4-4)) are suitable and promising single source precursors for the synthesis of nanoparticles. Additionally to the synthesis of 4-3 and 4-4 which were especially prepared for their use as single source precursors, also basic reactivity studies were done using [CH(C(Me)N(2,6-iPr2C6H3))2]MCl (M = Ge, Sn) and the lithiated compound LiCH2SiMe3 as starting material. Those approaches led to the formation of [CH(C(Me)N(2,6-iPr2C6H3))2]MCH2SiMe3 (M = Ge (4-1), Sn (4-2)), that were fully characterized by NMR spectroscopy, mass spectrometry, elemental analysis and X-ray structure analysis (Figure 6-1 - 6). Figure 6-1 - 6: Left: Crystal structure of 4-1. Right: Solid state structure of 4-2. 6.1.3. Single source precursors containing phosphorus, zinc and gallium Zinc phosphide precursors As nanoscale Zn2P3 is thought to be a promising material for future photovoltaic application easy and non-toxic synthetic methods like the single source precursor approach are very attractive raising the interest in the preparation novel zinc phosphorus compounds useful for the decomposition to nanoparticles. Here, the focus is on the synthesis of a new family of zinc complexes stabilized by a variable benzamidinato ligand which might be convertible into P containing precursors. Thus, the isolation of three different Zn compounds [PhC(NtBu)2]2Zn (5-1-1), {[PhC(NtBu)2]Zn2Br3}n (5-1-2) and [PhC(NtBu)2]H • ZnBr2 (5-1-3) was successful, of which the reaction of the latter with LiP(SiMe3)2 results in {Zn[P(SiMe3)2]2}2 (5-1-C). While 5-1-1 can be obtained by mixing one eq. tBuN=C=NtBu, one eq. PhLi and one eq. ZnBr2, the polymeric 5-1-2 is the unexpected product of the reaction of one eq. tBuN=C=NtBu with one eq. PhLi and two eq. ZnBr2 (Figure 6-1 - 7 top). Because both of the more obvious approaches didn’t lead to a monomeric zinc bromine complex, [PhC(NtBu)2]Li, the product of the reaction of tBuN=C=NtBu and PhLi, was isolated and then reacted in a 1:1 stoichiometry with ZnBr2. However, due to traces of water that could not be avoided, the reaction resulted in compound 5-1-3 (Figure 6-1 - 7 bottom left) which was then mixed with LiP(SiMe3)2 in order to obtain a precursor for zinc phosphide nanoparticles. The achieved product is the literature known species 5-1-C, that was already thermally decomposed by the authors of the corresponding publication who did not get the desired Zn2P3. As the crystal structure of 5-1-C was previously determined at room temperature, it was now possible to detect a phase transition at 137 K while performing the X-ray analysis at low temperatures (Figure 6-1 - 7 bottom right). Figure 6-1 - 7: Crystal structure of 5-1-1, 5-1-2, 5-1-3 and 5-1-C. Preliminary investigations for the usage of [CH(C(Me)N(2,6-iPr2C6H3))2]Ga(PH2)2 in nanoparticle synthesis Also, studies concerning the preparation of GaP nanoparticles were realized using the gallium compound [CH(C(Me)N(2,6-iPr2C6H3))2]Ga(PH2)2 (5-2-B) which was initially synthesized and characterized by Susanne Bauer. The experiments were performed similar to those described in chapter 4.4 with HDA and PA as decomposing and stabilizing agents. Unfortunately, it was not possible to obtain any nanocorpuscles (Figure 6-1 - 8), yet, the EDX analyses of the precipitate revealed the desired composition of GaP with a slight excess of Ga. Figure 6-1 - 8: TEM image of the precipitate of reaction of 5-2-B with 1 eq. HDA

Stellar Clusters in NGC 1313: Evidence for Infant Mortality

We present evidence that infant mortality of stellar clusters is likely to be a major and very efficient process for the dissolution of young clusters in the spiral galaxy NGC 1313. Performing stellar PSF photometry on archival HST/ACS images of the galaxy, we find that a large fraction of early B-type stars are seen outside of star clusters and well spread within the galactic disk, consistent with the scenario of infant mortality. We also calculate the UV flux produced by the stars in and out the clusters and find that 75 to 90% of the UV flux in NGC 1313 is produced by stars outside the clusters. These results suggest that the infant mortality of star clusters is probably the underlying cause of the diffuse UV emission in starburst galaxies. Infant mortality would also explain the numerous B-type stars observed in the background field of our Galaxy as well. We exclude the possibility that unresolved low-mass star clusters and scaled OB associations might be the main source for the diffuse UV emission.Comment: 5 pages, 3 figures, accepted for publication in the Astrophysical Journal Letter

Assessing the prosody of minimally to nonverbal children with autism

A procedure for assessing basic prosodic perception and production abilities of minimally to nonverbal children and adolescents with autism spectrum disorder is described (AP: Assessment of Prosody). The procedure consists of three sections: an optional primer phase, a learning phase, and an assessment phase. It includes the assessment of both the perception of basic pitch accent structure distinctions (low versus high) as well as elicits expressive productions of these contrasts. The goal of the procedure is to evaluate the extent to which this population can perceive and produce prosodic distinctions. The overarching aim is to create a pre and post assessment to quantify prosodic competence and performance of minimally to nonverbal children and adolescents who are eligible for music-motor based intervention therapies (i.e. AMMT: Auditory Motor Mapping Therapy). Current and future versions of the assessment are discussed.Published versio

Plurilingualism, multilingualism and internationalisation in the European Higher Education Area: Challenges and perspectives at a Swiss University

The relationships between the internationalisation of higher education and language are still poorly understood. We foreground the perspective of students in order to advance our understanding of these interrelations in the context of the consolidation of the European Higher Education Area (EHEA). Accordingly, we propose gathering answers to the questions: What, from students' perspectives, are their experiences and perceptions of pluri- and multilingualism in the context of the internationalisation of higher education? And how are they dealing with these experiences and perceptions? Existing studies confirm that local specificities pertaining to languages and education systems impact substantially on the answers to these emerging questions. Thus, an overall picture of the interactions between language and internationalisation that shape the EHEA require the integration of findings from localised investigations that bring to light these particularities. Here we present an overview of findings from a mixed methods study in a medium-sized, historically German-language university in multilingual Switzerland. Our findings confirm that students are making considerable efforts to ensure that their plurilingualism extends beyond English. Notwithstanding attempts by the university to respond to their needs, students however still struggle with the tensions between what they can actually do, what they report they would like to do, and what they perceive is expected of them concerning language competencies during their studies and after. On the basis of these reflections, lecturers at the Language Centre developed a four-language course Communication training in multilingual settings that uses French, Italian, English, and German. This course is briefly introduced as an example of a language training intervention which seeks to move beyond the persistent constraints of a compartmentalised approach to pluri- and multilingualism in higher educatio

Klonierung, Expression und enzymkinetische Charakterisierung der hämagglutininspaltenden Protease TMPRSS2

TMPRSS2 ist eine Typ II transmembrane Serinprotease mit einer multidomänen Struktur, die das Oberflächenglykoprotein Hämagglutinin (HA) der Influenzaviren mit einer monobasischen Schnittstelle spaltet. Dies ist eine Voraussetzung für die Virusfusion und Vermehrung. Weiterhin aktiviert sie das Fusionsprotein F des humanen Metapneumovirus sowie das Spike S Protein der SARS Coronaviren. Zudem wurde eine TMPRSS2-Expression in einigen Tumorgeweben beschrieben. Daher scheint, TMPRSS2 eine potentielle Zielstruktur in der Wirkstoffforschung zu sein. Die katalytische Domäne der TMPRSS2 wurde in E.Coli exprimiert und für Inhibitionsstudien mit zuvor synthetisierten Inhibitoren einiger trypsinartiger Serinproteasen verwendet. Es wurden zwei Inhibitortypen identifiziert, die TMPRSS2 im nanomolaren Bereich hemmen. Die erste Serie umfasst substratanaloge Inhibitoren mit einem 4-Amidinobenzylamid-Rest in P1 Position, wobei einige Verbindungen Hemmkonstanten um 20 nM besitzen. Eine gesteigerte Hemmung konnte für den zweiten Inhibitortyp mit einem sulfonylierten 3-Amindinophenylalanylamid gefunden werden. Die beste Verbindung dieser Serie hemmt TMPRSS2 mit einem Ki-Wert von 0,9 nM und zeigt eine effektive Hemmung der Influenzavirus-Ausbreitung in humanen bronchialen Epithelzellen. Basierend auf diesen Inhibitorstudien wurden neue fluorogene Substrate mit einem D-Arginin in P3-Position synthetisiert. Einige dieser Substrate werden effektiv durch TMPRSS2 gespalten

The evolution of star clusters: The resolved-star approach

We present the first results of a new technique to detect, locate, and characterize young dissolving star clusters. Using HST/ACS archival images of the nearby galaxy IC2574, we performed stellar PSF photometry and selected the most massive stars as our first test sample. We used a group-finding algorithm on the selected massive stars to find cluster candidates. We then plot the color-magnitude diagrams for each group, and use stellar evolutionary models to estimate their age. So far, we found 79 groups with ages of up to about 100 Myr, displaying various sizes and densities.Comment: 7 pages including 11 figures. Talk given at the meeting on "Young massive star clusters - Initial conditions and environments", E. Perez, R. de Grijs, R. M. Gonzalez Delgado, eds., Granada (Spain), September 2007, Springer: Dordrech