The semicircular canals detect head rotations and trigger compensatory movements that stabilize gaze and help maintain visual fixation. Mammals with large eyes and high visual acuity presumably require more precise gaze stabilization mechanisms because they experience degradation of spatial resolution at a lower threshold of uncompensated motion. Because semicircular canal radius of curvature is a primary determinant of canal sensitivity, species with large canal radii are expected to be capable of more precise gaze stabilization than species with small canal radii. Here the relationship between semicircular canal radius of curvature, eye size, and visual acuity is examined in a large sample of therian mammals. These results demonstrate that eye size and visual acuity both explain a significant proportion of the variance in mean canal radius of curvature after statistically controlling for the effects of body mass and phylogeny. These findings suggest that interspecific variation in semicircular canal radius of curvature is partly the result of selection for improved gaze stabilization in species with large eyes and acute vision. / text

The 7σ discrepancy between the charge radius of the proton as extracted from electronic hydrogen to the determination from muonic hydrogen, coined the proton ``radius puzzle", challenges our understanding of physics based on the standard model. High-precision measurements have been conducted on muonic deuterium to study whether the discrepancy with ordinary atoms persists or varies with mass number. For the success of this experimental campaign accurate theoretical calculations of the nuclear structure corrections in muonic deuterium (μD) are required. In this work we contributed by accurately and precisely calculating them using state-of-the-art nuclear potentials derived from chiral effective field theory. We performed a multipole expansion of the electromagnetic operator and accounted for Coulomb, relativistic and finite-nucleon-size corrections. Our determinations will impact the accuracy of the experimental program. / October 2015

No description available.

No description available.

Nuo 1926-ųjų metų, kai pirmą kartą buvo ištirta preliminari natūralių silikatinių mineralų, turinčių kubinę kristalinę gardelę, struktūra, granatų šeimai priskiriami junginiai tapo viena labiausiai tyrinėjamų medžiagų grupių. Granatai, kuriuose yra pereinamųjų metalų bei retųjų žemių metalų, pasižymi ypatingu technologiniu pritaikymu. Kaip šviečiančios medžiagos jie naudojami kietafaziuose lazeriuose, televizorių ekranuose ar dioduose. Europiu arba chromu legiruoti junginiai galėtų būti pritaikyti optiniam vaizdavimui medicinoje, kas iki šiol nebuvo daryta. Galimybė pagerinti granatų optines ir mechanines savybes bei naujos pritaikymo sritys suteikia stiprią motyvaciją tyrinėjimams. Pagrindinis disertacijos tikslas buvo naujų mišrių metalų granatų sintezė bei jų optinių savybių tyrimas. Taip pat siekta ištirti europį supančios aplinkos įtaką jo liuminescencinėms savybėms tiek milteliuose, tiek kristaluose. Milteliai buvo sintetinti zolių-gelių arba kietafazės reakcijos metodu. Kristalai auginti keliaujančio lydalo slankioje zonoje būdu. Medžiagų faziniai virsmai tirti Rentgeno spindulių difrakcijos metodu. Neutronų difrakcijos duomenys bei Rietveldo tikslinimas buvo panaudoti granatų struktūrinei analizei. Junginių optinės savybės įvertintos išmatavus atspindžio, sužadinimo ir emisijos spektrus. / Since 1926 when the preliminary structure of natural silicate minerals having cubic structure was determined, the family of garnets became one of the most extensively studied group of compounds. Garnets containing transition metals and rare-earths carry many important technological uses as magnetic materials, as phosphor materials employed in solid state lasers, television screens and light-emitting diodes, as computer memories, as near UV and near IR radiation up/down-converting compounds in Si solar cells and in other devices as microwave optical elements. The europium or chromium doped garnets also could be applied in the new field as optical imaging. The improvements in mechanical and optical properties, the new areas of applications provide a strong motivation for studying garnets in general. To synthesize and to characterize new mixed-metal garnets was the main aim of the present thesis. The investigation of the dependence of europium optical properties on the local environment in different garnets was also in the field of interest. Therefore, powders of the new mixed-metal garnets were synthesized by sol-gel route, while traveling solvent floating zone method was used for crystal growth. X-ray diffraction was used for phase identification. The neutrons diffractions and Rietveld refinement gave information of the crystal structure. Finally, reflection, excitation and emission spectra were recorded for the investigation of the optical properties.

Since 1926 when the preliminary structure of natural silicate minerals having cubic structure was determined, the family of garnets became one of the most extensively studied group of compounds. Garnets containing transition metals and rare-earths carry many important technological uses as magnetic materials, as phosphor materials employed in solid state lasers, television screens and light-emitting diodes, as computer memories, as near UV and near IR radiation up/down-converting compounds in Si solar cells and in other devices as microwave optical elements. The europium or chromium doped garnets also could be applied in the new field as optical imaging. The improvements in mechanical and optical properties, the new areas of applications provide a strong motivation for studying garnets in general. To synthesize and to characterize new mixed-metal garnets was the main aim of the present thesis. The investigation of the dependence of europium optical properties on the local environment in different garnets was also in the field of interest. Therefore, powders of the new mixed-metal garnets were synthesized by sol-gel route, while traveling solvent floating zone method was used for crystal growth. X-ray diffraction was used for phase identification. The neutrons diffractions and Rietveld refinement gave information of the crystal structure. Finally, reflection, excitation and emission spectra were recorded for the investigation of the optical properties. / Nuo 1926-ųjų metų, kai pirmą kartą buvo ištirta preliminari natūralių silikatinių mineralų, turinčių kubinę kristalinę gardelę, struktūra, granatų šeimai priskiriami junginiai tapo viena labiausiai tyrinėjamų medžiagų grupių. Granatai, kuriuose yra pereinamųjų metalų bei retųjų žemių metalų, pasižymi ypatingu technologiniu pritaikymu. Kaip šviečiančios medžiagos jie naudojami kietafaziuose lazeriuose, televizorių ekranuose ar dioduose. Europiu arba chromu legiruoti junginiai galėtų būti pritaikyti optiniam vaizdavimui medicinoje, kas iki šiol nebuvo daryta. Galimybė pagerinti granatų optines ir mechanines savybes bei naujos pritaikymo sritys suteikia stiprią motyvaciją tyrinėjimams. Pagrindinis disertacijos tikslas buvo naujų mišrių metalų granatų sintezė bei jų optinių savybių tyrimas. Taip pat siekta ištirti europį supančios aplinkos įtaką jo liuminescencinėms savybėms tiek milteliuose, tiek kristaluose. Milteliai buvo sintetinti zolių-gelių arba kietafazės reakcijos metodu. Kristalai auginti keliaujančio lydalo slankioje zonoje būdu. Medžiagų faziniai virsmai tirti Rentgeno spindulių difrakcijos metodu. Neutronų difrakcijos duomenys bei Rietveldo tikslinimas buvo panaudoti granatų struktūrinei analizei. Junginių optinės savybės įvertintos išmatavus atspindžio, sužadinimo ir emisijos spektrus.

Stipinkaulio distalinio galo lūžiai (SDGL) yra vienas dažniausių kaulų ir raumenų sužalojimų, sudarantys apie 3 proc. visų rankos sužeidimų. Lietuvoje, Sveidros duomenimis, 2010 m. dėl SDGL hospitalizuoti 1375 pacientai (986 moterys ir 389 vyrai). Vyrų traumų skaičiaus nei didėjimo, nei mažėjimo tendencijos nėra. Moterų traumų nuo 50–55 m. skaičius padvigubėja (47 iki 99). Vyresnių moterų SDGL patogenezės pagrindas gali būti osteoporozė. Tyrimo tikslas: Įvertinti kinezioteipavimo poveikį pacientams po tolimojo stipinkaulio galo lūžių. Tyrimo uždaviniai: 1. Įvertinti pacientų rankos funkciją ir savarankiškumą prieš ergoterapiją ir po jos taikant kinezioteipavimą; 2. Įvertinti pacientų rankos funkciją ir savarankiškumą prieš ergoterapiją ir po jos be kinezioteipavimo; 3. Palyginti ergoterapijos efektyvumą taikant kinezioteipavimą; Tyrimas buvo atliktas 2013 metų spalio – kovo mėnesiais. Ištirti 32 pacientai, patyrę tolimojo stipinkaulio galo lūžius, Viešosios įstaigos „Kauno klinikinėje ligoninėje“ bei „Kauno klinikos“, reabilitacijos skyriuje, gydyti ambulatoriškai. Pacientai buvo suskirstyti į dvi grupes: kontrolinę ir tiriamąją. Kontrolinę grupę sudarė pacientai, kuriems taikyta ergoterapija be kinezioteipavimo. Tiriamąją grupę sudarė pacientai, kuriems taikyta ergoterapija ir kinezioteipavimas. Abiejų grupių pacientams buvo sudaryta ir taikyta individuali ergoterapijos programa, atsižvelgiant į rankos funkcijos ir savarankiškumo sutrikimą. Ergoterapijos programos ir... [toliau žr. visą tekstą] / Distal radius fractures are among the most common musculoskeletal injuries. It consists about 3% of all hand injuries. In Lithuania 1375 patients were hospitalized in 2010 year. Men injury rate has unchanged. Women injuries rate from 50-55 has doubled. Aim of work was to estimate occupational therapy and kinesio taping influence to patients, experienced radius fractures. Tasks of this work were: 1. Evaluate patients hand function and independence before and after occupational therapy through kinesio taping. 2. Evaluate patients hand function and independence before and after occupational therapy using kinesio taping. 3. Compare the effectiveness of occupational therapy through kinesio taping. Research was conducted in October 2013 – March to examine the 32 patients experienced distal radius fractures at Kaunas Clinical hospital and Kaunas clinics in rehabilitation department. Patients were divided into two groups: control and study. The control group consisted of patients who received occupational therapy without kinesio taping. The study group consisted of patients who received occupational therapy through kinesio taping. The individual occupational therapy program were formed and applied for both groups of patients according to the hand function and self – independence. For occupational therapy program to evaluate the effectiveness of kinesio taping were used: specially for this research prepared questionnaire; hand strength was measured with dynamometer; functional range... [to full text]

Stipinkaulio distalinės dalies lūžiai yra vienas iš dažniausių kaulų ir raumenų sistemos pažeidimų. Literatūroje nurodoma, kad distalinės stipinkaulio dalies lūžiai yra 1/10 visų lūžių, kuriuos patiria vyresni nei 35 metų amžiaus asmenys. Apie 3 % pacientų, po šios traumos išlieka ilgalaikė negalia. Siekiant optimizuoti stipinkaulio distalinės dalies lūžių gydymą, buvo atliktas tyrimas, kuriame buvo iškelti trys uždaviniai. Vertinome 2 savaičių imobilizacijos įtaką rankos funkcijai, po stipinkaulio distalinės dalies lūžio ir osteosintezės delnine rakinama plokštele. Taip pat vertinome,radiologinio lūžio tipo, pagal AO klasifikaciją, įtaką rankos funkcijai. Sugijus kaului, tirta metalinių konstrukcijų pašalinimo įtaka rankos funkcijai. Vertinant rezultatus, nustatyta, kad riešo judesių amplitudė ir rankos funkcija tarp pacientų, patyrusių stipinkaulio distalinės dalies lūžį su poslinkiu ir operuotų delnine rakinama plokštele, kuriems buvo taikyta pooperacinė 2 savaičių riešo imobilizacija ir kuriems pooperacinė riešo imobilizacija nebuvo taikyta, nesiskyrė. Tiriamiesiems, patyrusiems C tipo lūžį pagal AO radiologinę klasifikaciją nustatyta prastesnė funkcija. Riešo judesių amplitudė ir rankos funkcija po delninės rakinamos plokštelės pašalinimo nepakito. / Distal radius fracture is one of the most common injuries of the skeletal and muscular system. It has been reported in literature that distal radius fractures account for one-tenth of all the fractures experienced by people older than 35 years. Long-term disability remains in approximately 3% of patients after a distal radius fracture. In order to optimise treatment of distal radius fractures, a study with three objectives was performed. We evaluated the effect of immobilisation for the period of 2 weeks on the hand function after a distal radius fracture and osteosynthesis with a volar locking plate. The effect of the fracture type according to the AO classification on the hand function was also assessed. After the bone has healed, the effect of the removal of metal constructions on the hand function was evaluated. The analysis of the results demonstrated that there were no differences in the range of wrist motions and the hand functionbetween the patients after a displaced distal radius fracture operated with a volar locking plate and post-surgery immobilisation of the wrist applied for the period of 2 weeks and the patients who did not have post-surgery wrist immobilisation applied. A worse function was determined in the patients after type C fracture according to the AO radiological classification. The range of wrist motions and the hand function after the removal of a volar locking plate did not differ.

Muscle strength is assumed to be closely related with BMD, the so called determinant of bone strength, however, new methods for bone strength measurement are arising. The purpose of this study was to determine the relationship between bone mineral density (BMD), muscle strength and natural frequency of the radius in the dominant and non-dominant arm in healthy and osteopenic individuals aged between 50-70 years. Sixty sedentary male (thirty healthy and thirty osteopenic) participated this study. Bone mineral density assessment was performed by dual x-ray absorbtiometry (DEXA) and quantitative computed tomography (QCT), whereas muscle strength was measured by an isokinetic dynamometer quantitatively. Natural frequency of the radius was determined by a dual channel frequency analyzer. Differences between BMD, muscle strength and natural frequency in healthy and osteopenic participants according to dominancy were examined by Analysis of Variance (ANOVA). Pearson Product Correlation Coefficient test was conducted to determine the magnitude of the correlation between cortical, trabecular and average BMD, muscle strength and natural frequency. Results demonstrated a statistically significant difference between BMD, natural frequency and muscle strength in the dominant arm of both groups. There was also a significant difference in the non-dominant arm in terms of BMD, natural frequency and muscle strength, except in total work in the non-dominant arms. Moreover, there was a moderate positive correlation between BMD measured by DEXA and natural frequency in the dominant arm (r = ,59 / p &lt / .001) and non-dominant arm (r = 0,64 / p &lt / 0.001), whereas the muscle strength was correlated to BMD with a low positive correlation in terms of peak torque in extension (r = ,36 / p = ,005), peak torque in flexion (r = ,31 / p = ,016), total work in extension (r = ,28 / p = ,030) and total work in flexion (r = ,27 / p = ,041) in the dominant arms. The correlation between muscle strength and BMD was not significant in the non-dominant arm. The highest correlation between natural frequency and bone geometry parameters was observed in cortical thickness (r = ,82 / p = ,02). A statistically significant positive correlation (r = ,81 / p = ,04) was also observed between average BMD measured by QCT and by DEXA. In summary, according to the findings of this study, it can be concluded that vibration analysis is a precise method in predicting bone strength that depends highly on its size, shape and the distribution of its trabecular and cortical components.

Athabasca asphaltenes were characterized using small-angle X-ray scattering (SAXS) with synchrotron radiation. Two methods were used to separate asphaltenes from Athabasca bitumen. Conventional chemical separation by precipitation with n-pentane, and physical separation realized by passing bitumen through a zirconia membrane with a 20 nm average pore size. The Athabasca permeates and chemically separated samples were dispersed in 1-methylnaphtalene and n-dodecane, with temperature and asphaltene concentration ranges of 50-310 C and 1-8 wt. %, respectively. Two approaches were also taken in the analysis of the SAXS emissions. A model-independent approach provided radii of gyration and scattering coefficients. A model-dependent fit provided size distributions for asphaltenes aggregates assuming that they are dense and spherical. Physically and chemically separated asphaltenes showed significant differences in nominal size and structure, and their structural properties exhibited different temperature dependencies. The results challenge the merits of using chemically separated asphaltene properties as a basis for asphaltene property prediction in crude oil/bitumen.