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Static Force Production Analysis in a 3D Musculoskeletal Model of the Cat HindlimbKorkmaz, Lale 09 April 2004 (has links)
To understand control strategies employed by the central nervous system (CNS) control movement or force generation in a limb, a seven degree of freedom cat hindlimb was modeled. In this study, the biomechanical constraints affecting force generation for balance and postural control were investigated. Due to the redundancies at the muscular and joint levels in the musculoskeletal system, even the muscle coordination pattern to statically produce a certain amount of force/torque at the ground is not straightforward.
A 3D musculoskeletal model of the cat hindlimb was created from cat cadaver measurements using Software for Interactive Musculoskeletal Systems (SIMM, Musculographics, Inc.). Six kinematic degrees of freedom and 31 individual hindlimb muscles were modeled. The moment arms of the muscles were extracted from the software model to be used in a linear transformation between muscle activation, and end effector force and moment. The Jacobian matrix that establishes the relationship between joint torques and end effector wrench was calculated. Maximal muscle forces were estimated from the literature. A feasible set of forces that can be generated at the toe was constructed using combination of maximally activated muscle excitations. Because the endpoint torque is typically small in a cat, an optimization algorithm was also performed to maximize the force generation at the end effector while constraining the magnitude of the endpoint torque. The results are compared with the measured force magnitude and direction data from an acute cat hindlimb preparation for different postures. This static model is applicable for understanding muscle coordination during postural responses to small balance perturbations.
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Dietary polyunsaturated fatty acids modify plasma lipids and red blood cell membrane composition but do not induce ∆6 desaturase mediated conversions in the domestic felineMcClure, Melena Kathleen 15 May 2009 (has links)
This study explored the effects of dietary unsaturated fatty acids on feline lipid
metabolism. It was hypothesized that high dietary linoleic acid (18:2n-6, LA) would
enhance conversion to arachidonic acid (20:4n-6), enrichment of dietary long chain n-3
FA (LCn-3FA) would affect lipid parameters, and n-3 FAs incorporation may blunt n-6
FA incorporation. Twenty-nine cats were randomized into groups (n = 9, 10, 10), and
fed for 28 days with blood collections on days 0, 14, and 28. Experimental diets
consisted of a commercial diet, supplemented with 8g oil/100g kibble. Oil supplements
and subsequent diets were: high-oleic sunflower (H diet) with 82% oleic acid (18:1n-9),
Menhaden fish (M diet) with LCn-3FA, and safflower (S diet) with 75% 18:2n-6.
Dietary 20:4n-6 content was: 0.03 for H and S, and 0.09 for M (g FA/kg diet). Nonesterified
fatty acid (NEFA), triacylglycerol (TG), total cholesterol (TC), lipoproteincholesterol
(LP-C), plasma phospholipid (PL) FAs, red blood cell membrane (RBC)
FAs, and ∆5 and ∆6 desaturase indices were measured. Statistical analyses were
performed with SAS PROC MIXED with p < 0.05 determining significance. Neither TC nor NEFA showed significant effects. Diet M resulted in significant TG lowering,
despite typically low feline TGs. Similarly, pre-β LP-C (i.e. TG-rich VLDL) was
decreased in diet M. Plasma PL FAs revealed significant accumulations of the
following: 18:1n-9 in diet H, 18:2n-6 in diet S, and LCn-3FA in diet M. Despite high
dietary 18:2n-6, plasma PL 20:4n-6 was not increased in diet S over diets H or M.
Increased docosadienoic acid (20:2n-6) in diet S demonstrated that 18:2n-6 chain
elongation occurred in deference to its ∆6 desaturation further substantiating low feline
∆6 desaturase activity. Interestingly, no diet M blunting of 20:4n-6 incorporation
occurred because fish oil supplementation provided additional 20:4n-6. Tissue 20:4n-6
content appears to be diet-dependent. Accumulation of eicosapentaenoic acid (20:5n-3),
but low affinity for docosahexaenoic acid (22:6n-3) occurred in diet M RBC membranes.
After 28 days, plasma PLs reflect dietary intake more readily than RBC membranes.
Fish oil supplementation resulted in plasma PL LCn-3FA enrichment and lowered
plasma TG concentrations, both of which may have physiological significance in cats.
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Mineralogic study of sediments from nearshore Cat Island, MississippiBarnhart, Laura Belle. January 2003 (has links)
Thesis (M.S.)--Mississippi State University. Department of Geosciences. / Title from title screen. Includes bibliographical references.
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Facial expressions and other behavioral responses to pleasant and unpleasant tastes in cats (Felis silvestris catus)Hanson, Michaela January 2015 (has links)
The behavior and facial expressions performed by cats have been reported to be visibly affected by the perceived taste quality of a food item. The goal of the present study was to assess how cats react to pleasant and unpleasant tastes. The facial and behavioral reactions of 13 cats to different concentrations of L-Proline and quinine monohydrochloride as well as mixtures with different concentrations of the two substances were assessed using a two-bottle preference test. The cats were videotaped during the tests and the frequency and duration of 50 different behaviors was analyzed in Noldus the Observer XT. The cats responded to tastes regarded as pleasant by having their eyes less than 50 % open for significantly longer periods of time compared to a water control. Tongue protrusions were also observed significantly more frequently when the cats sampled from a solution with a preferred taste compared to a water control. When encountering solutions of quinine monohydrochloride or mixtures containing quinine monohydrochloride the cats were observed to perform tongue protrusion gapes much more frequently compared to a water or L-Proline control. Even though the cats did not significantly differ in the number of times they licked at spouts containing the 50 mM L-Proline and 500 mM quinine monohydrochloride mixture compared to a 50 mM L-Proline, no masking effect could be confirmed as there was no increase in the acceptance of the mixture was observed. The present study suggests that the knowledge about behavioral responses to pleasant or unpleasant taste can be utilized in future studies on how cats perceive different tastes.
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Transit proximity and trip-making characteristics : a study of 2007 Chicago metropolitan region travel tracking surveyHong, Sujin, active 2008 21 November 2013 (has links)
Influence of built environment on travel behavior has been recognized by several studies
in last decade (Cervero 2003, 2004, Ewing at al 2003 and etc.). Easy access to the transit
station and mixed land use has been largely emphasized by New Urbanist because of its
influence on transit ridership and reduction of vehicle mile travel. However, empirical
evidence that proximity of residential location to the transit station or mixed land use
reduces auto dependency and encourages transit ridership has been lack for Chicago
metropolitan region in spite of its long history of transit development.
This study uses 2007 Chicago metropolitan region travel tracking study data and travel
characteristics of residents living within walkable distance from the CAT or METRA rail
station in Chicago Metropolitan region was analyzed in comparison with those of
residents living beyond walkable distance from the rail station in order to find any
difference in socio-demographic characteristics and travel characteristics.
In general, households located within walkable distance (a quarter mile for this study)
from the rail station are more likely to be low income households, to reside in a multifamily
rental housing. Residents living within walkable distance show higher portion of
African American or Asian proportion, of smaller-sized households (a single member
household or childless household). They are likely to own fewer cars than residents living far from the rail station. With this observation of some difference in sociodemographic
and travel characteristics between two groups, probability of transit use
and rail use in a relationship with home location and job location were tested using
binary logistic model. The result indicates that the number of household vehicles per
person in the household influences negatively on residential location. The more
available household cars per person, the less likely it is that a household is located
within walkable distance from the rail station. Work location was also an important
factor for transit or rail use. This provides evidence that providing mixed land use
where jobs and housing are all provided within walkable distance from the transit
station can increase transit use and reduces auto-dependency that current American
society is facing severely. / text
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Altered intermuscular force feedback after spinal cord injury in catNiazi, Irrum Fawad 21 September 2015 (has links)
Bipeds and quadrupeds are inherently unstable and their bodies sway during quiet stance and require complex patterns of muscle activation to produce direction-specific forces to control the body’s center of mass. The relative strength of length and force feedback within and across muscles collectively regulates the mechanical properties of the limb as a whole during standing and locomotion (Bonasera and Nichols 1994; Ross and Nichols 2009). Loss of posture control following spinal cord injury (SCI) is a major clinical challenge. While much is known about intermuscular force feedback during crossed extension reflex (XER) and locomotion in decerebrate cats, these have not been well characterized in animals with spinal cord injury.
In this study, we mapped the distribution of heterogenic force feedback in hindlimb ankle extensor muscles using muscle stretch (natural stimulation) in intercollicular, non-locomoting, decerebrate cats with chronic lateral spinal hemisection (LSH). We also, determined the time of onset of redistribution of heterogenic force feedback following LSH by collecting force feedback data from cats with acute sci. In addition we revisited heterogenic force feedback between ankle extensors in decerebrate non-locomoting cats during mid-stance to ascertain whether these cats with intact spinal cord depict a certain pattern of force feedback. The goal was to ascertain whether the patterns and strength of feedback was different between the two states (cats with intact spinal cord and cats with SCI). We found that heterogenic feedback pathways remained inhibitory in non-locomoting decerebrate cats in two states. The latencies of inhibition also corresponded to those observed for force feedback from Golgi tendon organs. We observed variable patterns of force feedback between ankle extensors in decerebrate/control cats. On the other hand we observed consistent results in cats with chronic LSH exhibiting very strong distal to proximal pattern of inhibition from 2 weeks to 20 weeks following chronic LSH. The same results were obtained in acute LSH cats suggest that the change in neuromuscular system appears immediately after SCI and persists even after the animal start walking following SCI. The observed altered pattern of force feedback after spinal cord injury suggests either presence of a pattern intrinsic to the spinal cord or a unique pattern exhibited by the damaged spinal cord. The results are important clinically because even with vigorous rehabilitation attempts patients do not regain posture control after SCI even though they regain ability to walk. Therefore, to effectively administer treatment and therapy for patients with compromised posture control, a complete understanding of the circuitry is required.
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Audio browsing of automaton-based hypertextUstun, Selen 30 September 2004 (has links)
With the wide-spread adoption of hypermedia systems and the World Wide Web (WWW) in particular, these systems have evolved from simple systems with only textual content to those that incorporate a large content base, which consists of a wide variety of document types. Also, with the increase in the number of users, there has grown a need for these systems to be accessible to a wider range of users. Consequently, the growth of the systems along with the number and variety of users require new presentation and navigation mechanisms for a wider audience. One of the new presentation methods is the audio-only presentation of hypertext content and this research proposes a novel solution to this problem for complex and dynamic systems. The hypothesis is that the proposed Audio Browser is an efficient tool for presenting hypertext in audio format, which will prove to be useful for several applications including browsers for visually-impaired and remote users. The Audio Browser provides audio-only browsing of contents in a Petri-based hypertext system called Context-Aware Trellis (caT). It uses a combination of synthesized speech and pre-recorded speech to allow its user to listen to contents of documents, follow links, and get information about the navigation process. It also has mechanisms for navigating within documents in order to allow users to view contents more quickly.
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Topics in quantum physics: Schrodinger's cat problem - time measurement accuracies in quantum mechanicsShaghaghi, Mehran 05 1900 (has links)
In this thesis I address two different topics in quantum theory. The first one is the long discussed Schrodinger's cat problem, and the issues related to having a macroscopic superposition state. I show that the quantum theory provides full explanation to the problem. In the second part, I discuss the time measurement related issues in quantum mechanics. Since there does not exist any time operator in quantum mechanics generally, time is not directly measurable. Therefore we should devise other methods to register time. We study different time-energy relations and will find that accurate clocks have high energy uncertainties. If we use accurate clocks in quantum systems to observe their time evolutions, their high energy uncertainties interfere with system's normal evolution and slows it down. I also provide a formal proof to a previously suggested limiting accuracy relation on the measurements of the time-of-arrival experiments.
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Charakterisierung der Kardiomyopathien bei 106 Katzen mit diagnostizierter MyokarderkrankungBaldauf, Katrin 17 April 2014 (has links) (PDF)
Kardiomyopathien (KMP) sind bei Katzen die häufigste kardiovaskuläre Erkrankung und ein wichtiger Grund für Morbidität und Mortalität (FOX et al. 1995). Die morphologische und strukturelle Veränderung des Myokards entsteht definitionsgemäß in Abwesenheit von Klappenerkrankungen, kongenitalen Defekten oder koronaren Gefäßerkrankungen. Unterschieden werden können primäre und sekundäre Kardiomyopathien. Primäre Kardiomyopathien (1°KMP) sind genetisch oder idiopathisch bedingt. Anhand des Phänotyps können hypertrophe (HKMP), restriktive (RKMP), unklassifizierte (UKMP), dilatative (DKMP) und arrhythmogene rechtsventrikuläre (ARVC) Kardiomyopathie unterschieden werden. Sekundäre Kardiomyopathien (2°KMP) werden durch eine systemische Erkrankung ausgelöst. Als Ursachen werden insbesondere Hyperthyreose, systemische Hypertension, Myokarditis, Taurinmangel, Kortikosteroidapplikation, chronische Niereninsuffizienz (CNI), anhaltende Tachyarrhythmie, Diabetes mellitus, Anämie, Neoplasie, Anthrazykline, Hypersomatotropismus, Sepsis und Myopathie beschrieben. In der Literatur machen die sekundären Kardiomyopathien bisher noch einen relativ geringen Anteil der Kardiomyopathien aus. Die für diese Untersuchung ausgewerteten Daten von Katzen mit Myokarderkrankungen wurden innerhalb von 29 Monaten erhoben. Einschlusskriterien waren das Vorliegen des Signalements, der Anamnese, des Blutdrucks und einer standardisierten echokardiografischen Untersuchung. Außerdem musste zur Erfassung der häufigsten auslösenden Erkrankungen bei Patienten über neun Jahren das Gesamtthyroxin erfasst worden sein, bei Polyurie und Polydipsie die Parameter Harnstoff, Kreatinin und Glukose und bei blassen Schleimhäuten der Hämatokrit. Von den 106 Katzen, die den Einschlusskriterien entsprachen, machte die 2°KMP mit 50 Katzen (47%) den größten Anteil aus. Zweithäufigste Kardiomyopathie war die HKMP mit 39 Fällen (37%), gefolgt von UKMP (9 Katzen, 8%), RKMP (6 Katzen, 6%) und DKMP (2 Katzen, 2%). Das Signalement der Katzen mit 82 EKH (77%) eine signifikante Häufung dieser Rasse, die aber der Verteilung der Rassen im Patientengut entspricht (p<0,001). Im Mittel waren die Katzen 9 Jahre alt (1-17 Jahre). Die Katzen mit HKMP waren signifikant jünger als die Katzen der anderen Gruppen (p<0,001). Die Katzen über 12 Jahre zeigten signifikant häufiger eine 2°KMP als eine 1°KMP (p=0,001). Mit 74% (n=78) waren Kater signifikant häufiger betroffen als Kätzinnen (p=0,001). Die 28 Kätzinnen waren mit 64% (n=18) häufiger an einer 2°KMP erkrankt als an einer primären Kardiomyopathie (p=0,03). Beim Gewicht (mittleres Gewicht 4,7 kg, Median 4,2 kg; 2-9 kg) zeigten sich keine relevanten Unterschiede zwischen den Gruppen.
Das häufigste Symptom war bei 37% der Katzen (n=38) Dyspnoe. Weitere respiratorische Probleme waren Husten (n=5, 5%) und Maulatmung (n=3, 3%). Bei sechs Tieren (6%) lag eine arterielle Thrombembolie mit Paraplegie vor. Aszites und subkutane Ödeme waren bei je zwei Tieren (2%) auffällig. 11% der Katzen (n=12) hatten einen anderen Vorstellungsgrund: bei sieben Katzen lag eine Harnabsatzstörung (feline lower urinary tract disease) und bei fünf ein Trauma vor. Bei der kardialen Auskultation waren 53 (50%) Katzen mit einem systolischen Herzgeräusch vom Lautstärkegrad 1-4/6 auffällig. Signifikant häufiger als in den anderen Gruppen war bei den Katzen mit HKMP ein Herzgeräusch zu verzeichnen (p <0,001). Bei 48 (45%) Katzen lag ein Galopprhythmus vor, bei 11 der Tiere (10%) in Kombination mit einem Herzgeräusch. Die Katzen mit Galopprhythmus waren signifikant häufiger dekompensiert als die mit Herzgeräusch oder ohne abnormen Auskultationsbefund (p=0,001). Die kardiogene Dyspnoe als häufigster Vorstellungsgrund (n=38) wurde in 45% (n=17) der Fälle durch ein Lungenödem, in 26% (n=10) durch einen Pleuraerguss und in 29% (n=11) durch die Kombination beider bedingt. Katzen mit RKMP hatten signifikant häufiger einen Pleuraerguss als Katzen der anderen Gruppen (p=0,001). Von den Katzen mit UKMP lag hingegen häufiger ein Lungenödem vor (p=0,016). Aszites trat bei keiner Katze mit HKMP und RKMP auf. Alle Katzen mit RKMP und DKMP gehörten der ISACHC-Klasse 3 (International Small Animal Cardiac Health Council) an (p<0,001). Sieben der neun Katzen mit UKMP (78%) entsprachen ebenfalls dieser Klasse. Die Katzen mit RKMP zeigten die am stärksten ausgeprägte linksatriale Dilatation (LADs 27,4 mm; 23,8-30,5 mm), die mit 2°KMP die am wenigsten ausgeprägte (19,2 mm; 13,4-28,2 mm). Innerhalb der 2°KMP (n=50) lag bei 19 Katzen eine Hyperthyreose, bei 16 CNI und bei 15 Tieren systemische Hypertension vor. Weitere Ursachen waren Glukokortikoidgabe (n=4), Anämie (n=2), Diabetes mellitus (n=2) und schwere Lungenerkrankung oder Pyothorax (n=4). Eine Kombination dieser Erkrankungen bestand bei 24% (n=12) der Katzen. Unter Vernachlässigung potentiell auslösender Erkrankungen ergab eine Klassifizierung der 50 Katzen mit 2°KMP anhand des Phänotyps bei 68% (n=34) eine HKMP. Eine UKMP machte 18% (n=9) und eine RKMP 14% (n=7) aus. Hyperthyreose auch in Kombination mit anderen Erkrankungen war in 84% (16/19) ebenso wie systemische Hypertension in 80% (12/15) mit linksventrikulärer Hypertrophie assoziiert. Mit 47% übersteigt die Häufigkeit der 2°KMP deutlich die Angaben in der Literatur. Zusätzliche Fälle können als 1°KMP fehlinterpretiert worden sein, während eine erworbene Begleiterkrankung neben einer 1°KMP fälschlicherweise als 2°KMP gewertet sein kann. In jedem Fall betonen die Ergebnisse dieser Untersuchung aber die Wichtigkeit weiterführender diagnostischer Schritte, um Erkrankungen mit Auswirkungen auf das Myokard zu identifizieren. Inwieweit eine kausale Therapie die Rückbildung myokardialer Veränderungen erlaubt, müssen weitere Untersuchungen klären.
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Kačių kraujyje esančių kreatinino ir šlapalo koncentracijų vertinimas sergant lėtiniu inkstų nepakankamumu / Creatinine and urea, contained in feline blood concentration, evaluation in patients with chronic renal failturePranckutė, Ieva 05 March 2014 (has links)
Darbo apimtis: 50 p. Jame 9-ios lentelės, 28-i paveikslai.
Literatūros šaltiniai: knygų – 6, mokslinių straipsnių – 21, Internetinių šaltinių – 1.
Tikslas: Nustatyti kraujyje esančio kreatinino, šlapalo bei kitų medžiagų – alaninaminotransferazės, aspartataminotransferazės ir amilazės, koncentracijų kitimus katėms sergančioms lėtiniu inkstų nepakankamumu.
Metodika: 2011 – 2013 m. „Kaivanos“ smulkių gyvūnų klinikoje buvo atliktas tyrimas, kuriame dalyvavo 50 lėtiniu inkstų nepakankamumu sergančių kačių. Joms buvo atlikta kraujo biocheminių rodiklių analizė (kreatinino, šlapalo, alaninaminotransferazės, aspartataminotransferazės ir amilazės) biocheminiu kraujo analizatoriumi Refloctron Plus Roche. WinExcel programa atlikta šių duomenų stasistinė analizė, vertinanat kačių kreatinino stadijų, amžiaus, lyties, kastracijos ir veislės įtaką sergant lėtiniu inkstų nepakankamumu. Atlikta požymių koreliacinė analizė ir vienfaktorinė dispersinė analizė.
.
Rezultatai, išvados:
Katės lėtiniu inkstų nepakankamumu serga gana retai – 5% iš visų 1183 (100%) klinikoje apsilankiusiųjų.
Sergamumui LIN gyvūno amžius, veislė, lytis pastebimos įtakos neturi. Tačiau imliausios yra 7 – 9 m. katės.
Kreatinino koncentracija tiksliai nusako ligos sunkumą ir priklauso tik nuo inkstų pažeidimo, kiti faktoriai jo kiekio svyravimams įtakos neturi.
Sergančių IV-a LIN stadija kačių buvo nustatyta daugiausia – 18 (36%).
Šlapalo kiekis kraujyje tiesiogiai korialiuoja su LIN stadija ir kreatinino... [toliau žr. visą tekstą] / Study consist of: 50 printed pages, including 9 tables, 28 figures
References: twenty eight of references were used.
Objective: To identify the variations in circulating creatinine, urea and other substances - alanine aminotransferase, aspartate aminotransferase, and amylase concentration in cats suffering from chronic kidney failure.
Methodics: In 2011 – 2013 years on „Kaivana“ small animal clinic a study was conducted on 50 cats who had chronic renal insufficiency. For those cats were made a blood chemistry analysis (creatinine, urea, alanine aminotransferase, aspartate aminotransferase, and amylase) with blood chemistry analyzer Refloctron Plus Roche. WinExcel program performed the statistical analysis, the assessment of feline creatinine stage, age, sex, breed and castration effect on patients with chronic renal failure. We also conducted a correlation analysis features, and one factor analysis of variance.
Results, Conclusions:
Cats with chronic renal failure suffer relatively rarely - 5%.
For the incidence of CRF, animal age, breed, sex has no significant influence. However, the most receptive cats are from 7 to 9 years of life.
Creatinine concentration accurately describes the severity of the disease and depends only on kidney damage and other factors it is not affected by fluctuations in volume.
Sick-IV stage of a CRF cat was found mainly - 18 (36%).
Urea levels directly correlated with the stage of CRF and creatinine. Also Urea is an informative setting... [to full text]
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