68 research outputs found
Morphologische Grundlagen für ein Forward-Dynamik-Modell der Schultergliedmaße des Deutschen Schäferhundes und invers dynamische Untersuchungen zu den gelenkresultierenden Kräften der großen Gliedmaßengelenke
The forces in the limb joints in the dog were investigated for the first time in the German Shepherd. The main focus lay on the joints of the forelimb, as these have been hardly investigated so far. But also the joint forces of the joints of the hind limb were demonstrated. Additionally the foundations for a forward dynamic model were developed for the forelimb.
The study constitutes two parts. The aim of the first part was to develop the foundations for a forward dynamic model. For that reason the skeletal muscles of the forelimb as well as the shoulder girdle musculature of five German Shepherds were analysed. The length of the fibres, the weight and the angle of pennation for the muscle fibers were used to determine the physiological cross-section area. Individual extensive muscles of the shoulder girdle musculature were divided into various portions, for a better determination of the lines of actions for these muscles. The coordinates of the muscles various points of origin and insertion were measured on the skeleton of a German Shepherd. The straight line of these skeletal points were determined as action lines, in order to calculate the moment arm of the muscles.
The physiological cross-section areas of the according muscles of the investigated dogs were significantly different in size. This is probably due to the different constitution of the dogs, in both the nutritional status and the condition.
In the second part of the study the vertical and horizontal net joint forces and the moments of the limbs joints in a German Shepherd were analysed with the invert dynamic model. In order to determine the forces and moments, the data of the gait analysis coupled with the ground reaction forces and the inertial parameters of the individual limb segments were necessary. Furthermore the displacement of the superficial markers, which were attached to the skin were measured during the gait analysis.
The net joint forces are greater in all of the joints of the forelimb than compared to those in the hindlimb. When the vertical net joint forces were taken into consideration the forces of the forelimb were even twice has large. Due to the positioning of the body’s centre of gravity closer to the forelimbs, these carry a greater load, which explains the greater forces in the joints of the forelimb. The horizontal forces in both limbs show a biphasic course. The time interval of the decelerating and accelerating forces are near to the same size. It also appears that the forelimb seems to slightly slow down the forward motion, as the decelerating forces are greater than the accelerating forces. The moments are also greater in the forelimb than in the hindlimb.Die Gelenkkräfte der Gliedmaßengelenke beim Hund wurden zum ersten Mal am Beispiel des Deutschen Schäferhundes ermittelt. Der Schwerpunkt dieser Arbeit lag auf den Gelenken der Vordergliedmaße, da diese bis jetzt weniger Beachtung erfahren haben. Aber auch für die Gelenke der Hintergliedmaße wurden die Gelenkkräfte dargestellt. Für die Vordergliedmaße wurden zusätzlich Grundlagen für ein Forward Dynamik Modell erarbeitet.
Die Arbeit besteht aus zwei Teilen. Das Ziel des ersten Teiles war es, die Grundlagen für ein Forward Dynamik Modell zu erstellen. Dazu wurden an fünf Deutschen Schäferhunden die Skelettmuskeln der Vordergliedmaße einschließlich der Schultergürtelmuskulatur analysiert. Es wurde die Faserlänge, das Gewicht, der Fiederungswinkel und daraus der physiologischen Querschnitte errechnet. Einzelne flächenhafte Muskeln der Schultergürtelmuskulatur wurden dabei in verschiedene Anteile unterteilt, um die Aktionslinien dieser Muskeln besser bestimmen zu können. Zusätzlich wurden an einem Skelett eines weiteren Deutschen Schäferhundes die Koordinaten der einzelnen Ursprünge und Ansätze der Muskeln gemessen. Die geraden Verbindungen dieser Skelettpunkte wurden als Aktionslinien bestimmt, um damit die Hebelarme der Muskeln errechnen zu können.
Die physiologischen Querschnitte der entsprechenden Muskeln der untersuchten Hunde sind deutlich verschieden in der Größe. Dies ist vermutlich mit einer unterschiedlichen Konstitution der Hunde, sowohl im Ernährungszustand als auch in der Kondition, zu erklären.
Im zweiten Teil wurden beispielhaft an einem Deutschen Schäferhund die vertikalen und horizontalen Nettogelenkkräfte und die Momente der Gliedmaßengelenke mit einem Inversen Dynamik Modell errechnet. Zum Berechnen der Kräfte und Momente waren die Daten aus der Ganganalyse gekoppelt mit den Bodenreaktionskräften und die Trägheitsparameter der einzelnen Gliedmaßensegmente notwendig. Zusätzlich wurde die Verschiebung der oberflächlichen, auf die Haut geklebten Marker bei der Ganganalyse ermittelt.
Die Nettogelenkkräfte sind in allen Gelenken der Vordergliedmaße größer als in denen der Hintergliedmaße. Bei den vertikalen Nettogelenkkräften sind die Kräfte in den Vordergliedmaßengelenken sogar mehr als doppelt so groß. Durch die Lage des Körperschwerpunktes, der näher an den Vordergliedmaßen liegt, lastet auf ihnen eine größere Last. Dadurch lassen sich die größeren Kräften in den Gelenken der Vordergliedmaße erklären. Die horizontalen Kräfte zeigen für beide Gliedmaßen einen biphasischen Verlauf. Das Zeitintervall der Brems- und Beschleunigungskräfte ist nahezu gleich groß. Auch scheint es, dass die Vordergliedmaße die Vorwärtsbewegung leicht abbremst, da die Bremskräfte größer als die Beschleunigungskräfte sind. Auch bei den Gelenkmomenten kommt es in den Vordergliedmaßen zu größeren Momenten als in der Hintergliedmaße
Mangelernährung bei geriatrischen Patienten im Krankenhaus : Prävalenz, mögliche Ursachen, übliche Therapie und prognostische Bedeutung
Einleitung: Mangelernährung wird international als häufigstes Begleitsymptom bei Alterspatienten mit weitreichender Bedeutung für Lebensqualität, Krankheitsverlauf und Lebenserwartung angesehen. Internationale Studien berichten von Mangelernährung bei akut-geriatrischen Patienten bei bis zu 57% (in Abhängigkeit von der Erhebungsmethode). Ziel dieser Untersuchung war es daher, die Prävalenz von Mangelernährung bei akut-geriatrischen Patienten in einer deutschen Klinik zu erfassen. Weitere Ziele waren die Untersuchung möglicher Ursachen sowie deren Zusammenhang mit dem Ernährungsstatus, die Beschreibung des routinemäßigen Umgangs mit Mangelernährung und die Untersuchung der prognostischen Bedeutung von Mangelernährung.Methoden: Im Rahmen einer monozentrischen Querschnittsstudie mit Nacherhebung wurde konsekutiv bei allen Patienten am Tag nach der Klinikaufnahme mit Hilfe von verschiedenen Methoden (Anthropometrie, Mini Nutritional Assessment, Subjective Global Assessment, ernährungsabhängige Laborparameter, Bioelektrische Impedanzanalyse) der Ernährungszustand erfasst. Risikofaktoren für Mangelernährung wurden in Form eines persönlichen Interviews mit den Patienten bzw. Angehörigen erhoben. Informationen zum üblichen Umgang mit Ernährungsproblemen sowie Verlaufsdaten zum Krankheitsstatus wurden bei Entlassung aus den Krankenakten entnommen. Sechs Monate nach Entlassung aus der Geriatrie wurden Rehospitalisierungen und Mortalität der Patienten telefonisch beim Hausarzt erfragt.Ergebnisse: Es nahmen 205 Patienten (142 Frauen) zwischen 75 und 95 Jahren (Median: 82 Jahre) an der Studie teil. Die Prävalenz von Mangelernährung lag in Abhängigkeit von der Methode zwischen 11 % und 50 %. Häufige Risikofaktoren für Mangelernährung waren ein ungewollter Gewichtsverlust, Probleme beim Schneiden von Lebensmitteln sowie eine Verschlechterung des Appetits. Patienten mit einer höheren Anzahl an Risikofaktoren waren signifikant häufiger mangelernährt als Patienten mit weniger Risikofaktoren. Die Dokumentation von Ernährungszustand und Ernährungsproblemen in den Krankenakten war unzureichend. Mangelernährte Patienten entwickelten im Vergleich zu den nicht mangelernährten Patienten signifikant häufiger Komplikationen im Krankenhaus und hatten eine signifikant längere Liegedauer.Schlussfolgerung: Auf Grundlage dieser Ergebnisse sollte zukünftig die klinische Erfassung des Ernährungszustands routinemäßig in das Aufnahmegespräch von Arzt und Pflege integriert werden. Diese Erfassung sollte mit evaluierten Methoden durchgeführt werden. Die Dokumentation von Ernährungsproblemen ist ein wichtiger Schritt zur Verbesserung der Lebensqualität mangelernährter Patienten. Letztendlich dient die Erkennung von Mangelernährung dazu, eine gezielte und effektive ernährungsmedizinische Intervention anzuwenden. Dabei sollte eine optimale Intervention zu einer positiven Prognose führen.Malnutrition in hospitalized geriatric patients - prevalence, potential causes, usual therapy and prognostic relevanceIntroduction: Malnutrition in geriatric patients is one of the most serious attendant symptoms. Malnutrition directly impairs quality of life, rehabilitation and life expectancy. International studies report on malnutrition in geriatric patients in up to 57 % depending on the method used. The aim of this study was to assess the prevalence of malnutrition in geriatric patients in a German hospital. Additionally, risk factors which may lead to malnutrition and their relation to the nutritional status were examined. Further aims were to show if and to which extent the nutritional status and nutrition-related problems are documented in patient’s records and to assess the prognostic relevance of malnutrition.Methods: In this cross-sectional study with follow-up the nutritional status of all patients consecutively admitted to the geriatric department was assessed on the day after admission by different methods (anthropometry, Mini Nutritional Assessment, Subjective Global Assessment, biochemical measurements, bioelectrical impedance analysis). Risk factors for malnutrition were assessed within a personal interview with the patients and/or a family member, respectively. Information concerning documentation of nutritional problems, usual therapy and outcome were taken from the clinical folders at discharge. Readmittance to hospital and mortality rate were assessed six months after discharge by contacting the general practitioners.Results: 205 patients (142 females) with an age range of 75 to 95 years (median: 82 years) took part in the study. The prevalence of malnutrition was between 11 % and 50 % depending on the method used. An unintentional weight loss was the most frequently occurring risk factor followed by difficulty in cutting food and loss of appetite. Patients with a higher number of risk factors were significantly more often malnourished than patients with fewer risk factors. The documentation of nutritional status and nutritional problems in the clinical folders was insufficient. Malnourished patients had significantly more often complications during hospitalization and had a significantly longer stay in hospital compared to non- malnourished patients.Conclusion: Based on these results, a clinical assessment of the nutritional status should be integrated in the routine process of physicians and nurses. For this assessment evaluated methods should be used. The documentation of nutritional problems is an important step to improve the quality of life of malnourished patients. Eventually, the identification of malnourished patients provides a basis to implement well-aimed and effective nutritional therapy to the patients. The result of an optimal nutritional intervention should be a positive prognosis
Проектирование асинхронного двигателя с короткозамкнутым ротором для привода вентилятора
Объектом проектирования является асинхронный двигатель с короткозамкнутым ротором. Цель работы – приобретение практических навыков в проектировании электрической машины. В процессе работы спроектирован асинхронный двигатель для привода вентилятора, а именно: рассчитаны главные размеры, выбраны обмотки статора и ротора, обмоточные провода, изоляция, рассчитаны рабочие характеристики, произведен механический расчет вала и тепловой расчет двигателя. Также разработан технологический процесс общей сборки, рассчитана себестоимость спроектированного двигателя, оценена безопасность и экологичность проекта.The object of the design is the asynchronous motor with squirrel cage rotor. Purpose – the acquisition of practical skills in design of electrical machines. In the process, the designed asynchronous motor for fan drive, namely: calculated main dimensions of the selected stator winding and a rotor winding wire, insulation rated performance produced mechanical shaft calculation and thermal calculation engine. Also developed process total Assembly, total cost designed engine, evaluated the safety and sustainability of the project
Pollen Competition as a Reproductive Isolation Barrier Represses Transgene Flow between Compatible and Co-Flowering Citrus Genotypes
Background/Objective: Despite potential benefits granted by genetically modified (GM) fruit trees, their release and commercialization raises concerns about their potential environmental impact, and the transfer via pollen of transgenes to cross-compatible cultivars is deemed to be the greatest source for environmental exposure. Information compiled from field trials on GM trees is essential to propose measures to minimize the transgene dispersal. We have conducted a field trial of seven consecutive years to investigate the maximum frequency of pollen-mediated crop-to-crop transgene flow in a citrus orchard, and its relation to the genetic, phenological and environmental factors involved. Methodology/Principal Findings: Three different citrus genotypes carrying the uidA (GUS) tracer marker gene (pollen donors) and a non-GM self-incompatible contiguous citrus genotype (recipient) were used in conditions allowing natural entomophilous pollination to occur. The examination of 603 to 2990 seeds per year showed unexpectedly low frequencies (0.17-2.86%) of transgene flow. Paternity analyses of the progeny of subsets of recipient plants using 10 microsatellite (SSR) loci demonstrated a higher mating competence of trees from another non-GM pollen source population that greatly limited the mating chance of the contiguous cross-compatible and flowering-synchronized transgenic pollen source. This mating superiority could be explained by a much higher pollen competition capacity of the non-GM genotypes, as was confirmed through mixed-hand pollinations. Conclusions/Significance: Pollen competition strongly contributed to transgene confinement. Based on this finding, suitable isolation measures are proposed for the first time to prevent transgene outflow between contiguous plantings of citrus types that may be extendible to other entomophilous transgenic fruit tree species. (Résumé d'auteur
The Present and Future Role of Insect-Resistant Genetically Modified Maize in IPM
Commercial, genetically-modified (GM) maize was first planted in the United States (USA, 1996) and Canada (1997) but now is grown in 13 countries on a total of over 35 million hectares (\u3e24% of area worldwide). The first GM maize plants produced a Cry protein derived from the soil bacteriumBacillus thuringiensis (Bt), which made them resistant to European corn borer and other lepidopteran maize pests. New GM maize hybrids not only have resistance to lepidopteran pests but some have resistance to coleopteran pests and tolerance to specific herbicides. Growers are attracted to the Btmaize hybrids for their convenience and because of yield protection, reduced need for chemical insecticides, and improved grain quality. Yet, most growers worldwide still rely on traditional integrated pest management (IPM) methods to control maize pests. They must weigh the appeal of buying insect protection “in the bag” against questions regarding economics, environmental safety, and insect resistance management (IRM). Traditional management of maize insects and the opportunities and challenges presented by GM maize are considered as they relate to current and future insect-resistant products. Four countries, two that currently have commercialize Bt maize (USA and Spain) and two that do not (China and Kenya), are highlighted. As with other insect management tactics (e.g., insecticide use or tillage), GM maize should not be considered inherently compatible or incompatible with IPM. Rather, the effect of GM insect-resistance on maize IPM likely depends on how the technology is developed and used
Molekularbiologische und genetische Untersuchungen zur Regulation des zentralen Regulators der Stickstofffixierung NifA in Rhizobium leguminosarum bv. viciae VF39
Expression of nif and fix genes in rhizobia is strictly regulated. The dominating regulator within the regulation of nif and fix gene expression is NifA. This work presents, that two promotors are involved in nifA gene expression in Rhizobium leguminosarum bv. viciae VF39, namely P1, located at the downstream end of fixX and PfixA, the promotor of the fixA gene, located 3600bp upstream of P1. P2, a promotor identified by transcriptional mapping was shown to be pointless in earlier works and could be identified as an artefact caused by several hypothetical secondary structures located downstream the fixX gene, within the fixX nifA intergenic region. P2, identified within this region could be deleted without having negative effects on nifA expression. In fact, expression of nifA was boosted when deleting P2. It was shown that this region has a general effect on upstream promotor activity, which is downregulated by 70 percent. This could result in some sort of fine tuning mechanism, regulating upstream P1 and PfixA promotor activity. Within nifA expression, P1 and PfixA show clear interactions. During symbiosis, NifA independent P1 promotor activity results in a ground level expression of nifA. Since oxygen sensibly NifA is stable under these conditions, nifA expression will result in activation of NifA dependent promotors, such as the fixA promotor, located upstream P1. NifA is directed by a well conserved nifA box (UAS) located upstream the fixA promotor and activates transcription of the s 54 dependent fixA promotor, which transcribes the fixABCX genes as well as nifA, resulting in even more NifA. In turn, NifA will amplify its own expression via PfixA. This feedback loop explains the autoregulatory character of nifA expression and why nifA mutants show no symbiotic activation of nifa expression. Factors involved in symbiotic P1 activation and regulation could not yet be clearly identified. Most seemingly, FixL as well as FnrN are involved in the regulation of P1 activity, as P1 is clearly FixL dependent, FnrN is essential for nifA Expression and FnrN itself needs FixL for microaerobic activation. During experiments to identify possible regulators involved in regulation of P1 activity and nifA expression, a gene could be identified by TN5 mutagenesis, showing strong similarities to a transcriptional regulator. This regulator seems to be involved in oxygen dependent regulation of nifA, as mutations within this region lead to nifA overexpression under aerobic conditions. Furthermore these effects could neither be demonstrated under microaerobic conditions nor during symbiosis with Pisum sativum outlining the regulatory effect ouf this gene
Molekularbiologische und genetische Untersuchungen zur Regulation des zentralen Regulators der Stickstofffixierung NifA in Rhizobium leguminosarum bv. viciae VF39
Expression of nif and fix genes in rhizobia is strictly regulated. The dominating regulator within the regulation of nif and fix gene expression is NifA. This work presents, that two promotors are involved in nifA gene expression in Rhizobium leguminosarum bv. viciae VF39, namely P1, located at the downstream end of fixX and PfixA, the promotor of the fixA gene, located 3600bp upstream of P1. P2, a promotor identified by transcriptional mapping was shown to be pointless in earlier works and could be identified as an artefact caused by several hypothetical secondary structures located downstream the fixX gene, within the fixX nifA intergenic region. P2, identified within this region could be deleted without having negative effects on nifA expression. In fact, expression of nifA was boosted when deleting P2. It was shown that this region has a general effect on upstream promotor activity, which is downregulated by 70 percent. This could result in some sort of fine tuning mechanism, regulating upstream P1 and PfixA promotor activity. Within nifA expression, P1 and PfixA show clear interactions. During symbiosis, NifA independent P1 promotor activity results in a ground level expression of nifA. Since oxygen sensibly NifA is stable under these conditions, nifA expression will result in activation of NifA dependent promotors, such as the fixA promotor, located upstream P1. NifA is directed by a well conserved nifA box (UAS) located upstream the fixA promotor and activates transcription of the s 54 dependent fixA promotor, which transcribes the fixABCX genes as well as nifA, resulting in even more NifA. In turn, NifA will amplify its own expression via PfixA. This feedback loop explains the autoregulatory character of nifA expression and why nifA mutants show no symbiotic activation of nifa expression. Factors involved in symbiotic P1 activation and regulation could not yet be clearly identified. Most seemingly, FixL as well as FnrN are involved in the regulation of P1 activity, as P1 is clearly FixL dependent, FnrN is essential for nifA Expression and FnrN itself needs FixL for microaerobic activation. During experiments to identify possible regulators involved in regulation of P1 activity and nifA expression, a gene could be identified by TN5 mutagenesis, showing strong similarities to a transcriptional regulator. This regulator seems to be involved in oxygen dependent regulation of nifA, as mutations within this region lead to nifA overexpression under aerobic conditions. Furthermore these effects could neither be demonstrated under microaerobic conditions nor during symbiosis with Pisum sativum outlining the regulatory effect ouf this gene
Untersuchungen der genetischen Diversität von Maiszünsler-Populationen (Ostrinia nubilalis, Hbn.) und ihrer Suszeptibilität gegenüber dem Bacillus thuringiensis (Bt)-Toxin als Grundlage für ein Resistenzmanagement in Bt-Maiskulturen
Transgenic maize cultivars expressing Bacillus thuringiensis (Bt) toxin need management to avoid resistance development of the target pest species European corn borer (Ostrinia nubilalis Huebner), the most important insect pest in corn. The European Corn Borer can reduce yields up to 20%. Due to the continuous expression of the Bt toxin during the vegetation period, a selection of resistant genotypes of the Europen Corn Borer is expected to be more likely than from conventional Bt sprays. Sustainability of transgenic plants use requires a solid understanding of the insect population for maintaining susceptible individuals The aim of this work was to establish methods to be able to forecast a possible development of resistance in an early stage. For this reason the baseline susceptibility of different ECB populations in Germany was measured. Tests were performed by treating first instar larvae with different Bt-toxin concentrations incorporated into the nutrition medium or applied onto the medium (surface treatment). LC50 values of the different German populations ranged from 0,12-0,41 µg/g diet and 1,55-2,42 µg/g diet for truncated Cry1Ab depending on the production of the toxin. For untruncated Cry1Ab the LC50 was between 0,82-1,15 µg/g diet. The surface treatment was carried out as comparison to the incorporation method. LC50 values ranged from 16,50-35,14 ng/cm2. No significant differences were detected for populations from different regions of Germany with both methods. Additional effort was spent into the methodology on how to detect susceptibility change through regular monitoring, including harmonization of different approaches in various research groups of EU countries. The second part of the study identifed geographical distinct ECB populations by help of molecular fingerprinting techniques such as AFLP and RAPD-PCR. Knowledge about the population structure is helpful for gene flow estimation, which is an essential information for resitance management. Based on dendograms fingerprint analysis, very small genetic differences were detected between populations. Although genetic distances were small, separation into distinct populations was possible by use of the AFLP method. These data suggest little genetic differentiation among populations, both in terms of susceptibility to Bt toxin and of the genetic background. Future monitoring can sufficiently be performed concentrating on a single ECB population representative for south western Germany
Untersuchungen der genetischen Diversität von Maiszünsler-Populationen (Ostrinia nubilalis, Hbn.) und ihrer Suszeptibilität gegenüber dem Bacillus thuringiensis (Bt)-Toxin als Grundlage für ein Resistenzmanagement in Bt-Maiskulturen
Transgenic maize cultivars expressing Bacillus thuringiensis (Bt) toxin need management to avoid resistance development of the target pest species European corn borer (Ostrinia nubilalis Huebner), the most important insect pest in corn. The European Corn Borer can reduce yields up to 20%. Due to the continuous expression of the Bt toxin during the vegetation period, a selection of resistant genotypes of the Europen Corn Borer is expected to be more likely than from conventional Bt sprays. Sustainability of transgenic plants use requires a solid understanding of the insect population for maintaining susceptible individuals The aim of this work was to establish methods to be able to forecast a possible development of resistance in an early stage. For this reason the baseline susceptibility of different ECB populations in Germany was measured. Tests were performed by treating first instar larvae with different Bt-toxin concentrations incorporated into the nutrition medium or applied onto the medium (surface treatment). LC50 values of the different German populations ranged from 0,12-0,41 µg/g diet and 1,55-2,42 µg/g diet for truncated Cry1Ab depending on the production of the toxin. For untruncated Cry1Ab the LC50 was between 0,82-1,15 µg/g diet. The surface treatment was carried out as comparison to the incorporation method. LC50 values ranged from 16,50-35,14 ng/cm2. No significant differences were detected for populations from different regions of Germany with both methods. Additional effort was spent into the methodology on how to detect susceptibility change through regular monitoring, including harmonization of different approaches in various research groups of EU countries. The second part of the study identifed geographical distinct ECB populations by help of molecular fingerprinting techniques such as AFLP and RAPD-PCR. Knowledge about the population structure is helpful for gene flow estimation, which is an essential information for resitance management. Based on dendograms fingerprint analysis, very small genetic differences were detected between populations. Although genetic distances were small, separation into distinct populations was possible by use of the AFLP method. These data suggest little genetic differentiation among populations, both in terms of susceptibility to Bt toxin and of the genetic background. Future monitoring can sufficiently be performed concentrating on a single ECB population representative for south western Germany
Monitoring gene flow from transgenic sugar beet using cytoplasmic male-sterile bait plants
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