Changes in Crude Protein Content with Advancing Maturity in Lucerne

The main determinants of the quality of lucerne forage are digestibility and protein content (Julier et al., 2001) as well as crude fibre content. In the early vegetative phases, the crude protein content of the leaves and stems is the highest and crude fibre content the lowest (Katic et al., 2003). The aim of this study was to determine the rate of change in crude protein levels at different stages of growth and development

Agronomic Characteristics of Novi Sad Winter Vetch Cultivars

Genus Vicia. contains important annual food and forage species such as field bean, V. faba., narbon vetch, V. narbonensis, and common vetch, V. sativa (Maxted, 1995), while Hungarian V. pannonica Crantz and hairy vetch V. villosa also play an important role in the Balkans. Winter vetches are excellent forage catch crops useful for sustainable agriculture and organic farming (Ċupina et al., 2004). Our study was aimed at determining the agronomic characteristics of the winter vetch cultivars developed in Novi Sad, assessing thus their ability for successful growing in the prevailing conditions of Serbia and Montenegro

Identifikovanje karakteristika difuzije kroz gleđno tkivo zuba mačke oštećenog resorptivnim procesom

Various factors have been suggested in the pathogenesis of feline resorptive lesions, such as periodontal disease, dietary factors, mechanical stress, developmental tooth defects, breed and viral disease, although none of these factors have been definitively proven to be the direct cause. It was recently published that normally enamel in cats is significantly thinner at the cemento-enamel junction, and both enamel and dentine are significantly less mineralized than elsewhere on the tooth. However, it is still unclear what anatomical features of the tooth surface are associated with a predisposition for resorptive lesions, and what is the initiating cause for the clastic activity afterwards. The present study was undertaken with the aim to describe enamel properties of transport and distribution of organic molecules in intact feline teeth and teeth affected with resorptive lesions. The results indicate that damaged enamel is prone to a greater bilateral diffusion process, leading to continuous disruption of the enamel structure. Also, teeth that are subjected to occlusal stress are at greater risk of destruction because micro fractures produce disarrangements in feline dental tissue diffusion homeostasis. The relationship between these features with feline dental resorptive lesions requires further studies.U patogenezi dentalnih resorptivnih lezija u mačaka pominju se različiti etiološki faktori kao što su oboljenja parodontalnih tkiva, faktori načina ishrane, mehaničko opterećenje, defekti nastali u toku razvoja zuba i virusna oboljenja. Ni za jedan od navedenih faktora do sada nije potvrđeno da je direktan uzročnik lezija. Nedavno je objavljeno da je gleđ u mačaka na gleđno-cementnoj granici značajno tanja od ostale gleđi, kao i da su gleđ i dentin tog područja mnogo manje mineralizovani nego na ostalim delovima zuba. Ipak nije potvrđeno da li postoje i posebni anatomski delovi zuba koji imaju predispoziciju za nastajanje resorptivnih lezija i šta je inicijalni faktor za kasnije aktiviranje odontoklasta. Istraživanje je sprovedeno sa ciljem da se ispita distribucija i transport organskih molekula intaktne gleđi zuba mačke i gleđi koja je zahvaćena resorptivnim procesom. Rezultati istraživanja prikazuju da je oštećena gleđ podložnija intenzivnijem bilateralnom procesu difuzije, koja dovodi do kontinualnog oštećivanja strukture gleđi. Zubi koji su izloženi okluzalnom opterećenju su takođe pod većim rizikom od propadanja jer mikropukotine koje nastaju usled koncentracije napona uzrokuju poremećaj homeostaze dentalnih tkiva. Utvrđivanje povezanosti faktora difuzije i mehaničkog opterećenja zahteva dodatna istraživanja

Interfacial Polarization and Dielectric Properties of Epoxy/Graphite Flakes Composites

Dielectric properties of composites based on bisphenol-A-epoxy resin loaded with various content of graphite flakes (GF) have been studied. The dielectric permeability, tangent loss and ac conductivity have been examined in wide temperature (170 – 370 K) and frequency (20 Hz – 200 kHz) range. In composites loaded with GF flakes up to 10 wt.%, the dominant conduction mechanism is tunneling of electrons, while loading of 15 wt.% gives rise to electron conduction through direct contacts between fillers. Dielectric properties of composites are largely determined by the nature of the filler/matrix interface, the filler surface area and the inherent conductivity of the fillers. At low electric field frequencies, dominates socalled interfacial (or space charge) polarization due to accumulation of free charges at the interfaces between two phases (filler and matrix), which differ in electrical conductivity.Influence of the filler surface chemistry have been studied for composites loaded with 5 wt.% graphite flakes obtained: (i) under wet milling, without (GF) or with (GF-Tr100x) adding Triton-100x as a surfactant, or (ii) under dry milling in the presence of KOH (GF-KOH). The surface treatment with KOH notable increased dielectric constant of the epoxy/GF-KOH5 composite, keeping low tangent loss, comparable to the counterpart, the epoxy/GF5 composite

Molekulsko-orbitalno proučavanje oksidacije fenola u hinole i epoksihinole

The MO study showed that the radical oxidation of phenols into quinols occurs readily. Further radical oxidation (in the m-CPBA/(BzO)(2)/hv system) of quinols occurs through appropriate biradical species with an activation energy of 79.5 kJ/mol yielding syn-epoxyquinols. The stereochemical outcome presented in this study is in full agreement with the experimental results.Molekulsko-orbitalnim proučavanjem potvrđeno je da lako dolazi do radikalske oksidacije fenola u odgovarajuće hinole. Daljom oksidacijom sistemom m-CPBA/(BzO)2/hν hinoli se preko biradikalskih reakcionih vrsta oksiduju u odgovarajuće epoksihinole. Izračunato je da aktivaciona energija ove reakcije iznosi 79.5 kJ/mol. Stereohemijske posledice naših izračunavanja su u potpunom skladu sa eksperimentalnim rezultatima

Crystal Structure of Citrobacter freundii Asp214Ala Tyrosine Phenollyase Reveals that Asp214 is Critical for Maintaining a Strain in the Internal Aldimine

Tyrosine phenol-lyase (TPL) is a pyridoxal-5′-phosphate (PLP) dependent enzyme which catalyzes β-elimination of L-tyrosine. In the holoenzyme the protonated pyridinium N1 atom of the PLP cofactor is hydrogen-bonded to the side chain of Asp214. Here we report the X-ray structure of C. freundii D214A TPL determined at 1.9 Å resolution. Comparison with the structure of the wild-type TPL shows that the D214A replacement induced significant conformational reorganization in the active site leading to its partial closure. Significantly, in D214A TPL the strain in the internal aldimine is completely released and the pyridine N1 atom of PLP is deprotonated. These observations explain the considerably reduced activity of the D214A TPL towards its substrates [T. V. Demidkina et al., Biochim. Biophys. Acta, Proteins Proteomics 1764 (2006) 1268–1276]. The reported structure reveals that Asp214 is critical for maintaining the strain in the internal aldimine. We argue that this strain is used by the enzyme to accelerate the transaldimination reaction, the first step in the enzymatic catalysis.(doi: 10.5562/cca1915

Određivanje težina kriterijuma primenom rangiranja

U radu su prikazani mogući načini određivanja težina kriterijuma na osnovu ranga kriterijuma. Prikazane su metode: linearnih težina sa promenljivim koeficijentom smera, inverznih težina, centroida rangova, sume rangova, raspodele verovatnoća rangova i geometrijskih težina. Kada u procesu rangiranja učestvuje više eksperata prikazana je mogućnost objedinjavanja rangova (težina) kriterijuma primenom izabranih matematičkih metoda, metoda teorije društvenog izbora i medijane Kemenija. Na jednom numeričkom primeru prikazana je primena izabranih metoda uz komentar dobijenih rezultata. Osnovni cilj rada jeste prikaz mogućih načina određivanja težina kriterijuma na osnovu ranga kriterijuma koji su odredili jedan ili više eksperata, korišćenjem više literaturnih izvora informacija. </p

Received formal support in the eyes of the refugees: experiences of refugee parents in exile

The humanitarian crises triggered by different events and processes will always create common and different movements and protection needs regardless of the nature of events and reason for its occurrence. Refugee crisis as one of the humanitarian crisis examples has taken a broad place and received attention in society today. The aim of this survey was to research experiences of refugee parents regarding formal support they or their family have received. The qualitative survey was conducted in 2016 in Bulgaria, the host country for many refugees for decades, and a country continually criticised for instances of brutal and inhuman treatment of refugees, as well as for inadequate protection of refugees who have been granted asylum in the country. Research has shown that refugee parents lack support in both ways: receiving psychosocial, financial, material or practical support and in help to enrol their children in school. The participants claimed that one of the biggest challenges they face in Bulgaria is insufficient support from public authorities which caused anxiety, anger and frustration for parents and difficulties in coping with their present life circumstances. Those challenges together with a high sense of responsibility and anxiety over the future prospects of their children represent the key factors of stress for refugee parents. Refugees who lack social support often feel less motivated to engage in activities that would facilitate their integration and they are prone to social isolation, because of which further investigation is needed to understand what is happening with the families who did not receive social support and how to reach them. Whereas social support represents an effective mechanism for coping with the stress and the challenges of displacement, these findings suggest the need for continuous professional support and implementation of psychosocial interventions. Next, the refugee parents expressed their anger and frustration over denied opportunities for inclusion of their children in the educational system. It is thus equally important to conduct further investigation on the resulting outcomes for children who have been excluded from the educational system for longer periods of time. Furthermore, there is need to investigate who supports children once they are involved in the educational system in a host country and what kind of support is provided to them and to their families. This research study has shown many challenges and issues faced by refugee parents in Bulgaria, and emphasises the need for Bulgarian authorities to act responsibly and in accordance with international and national law

Kinematic magnetic resonance imaging study of the brain stem and cervical cord by dynamic neck motion

Background: The aim was to examine the position of the brain stem and cervical cord following the neck flexion and extension. Materials and methods: The serial sagittal T2-weighted magnetic resonance imaging (MRI) sections of the cervical cord and brain stem were made in 6 volunteers. The images were mainly used to measure certain distances and angles of the brain stem and cervical cord in the neutral position, and then following the head and neck flexion and extension. Results: The measurements showed that the pons is slightly closer to the clivus following the neck flexion; the medulla oblongata is somewhat distant to the basion but closer to the odontoid process. At the same time, the spino-medullary angle diminishes in size. On the other hand, the upper cervical cord slightly approaches the posterior wall of the spinal canal, the lower cervical cord is closer to the anterior wall, while the angle between them is significantly larger in size. After the cervical cord extension, the rostral pons is somewhat distant to the clivus, whereas the caudal pons and the medulla are slightly closer to the clivus and the basion. At the same time, the spino-medullary angle diminishes in size. The cervical cord is mainly closer to the posterior wall of the spinal canal, whilst its angle is significantly smaller. Conclusions: The obtained results regarding the brain stem and cervical cord motion can be useful in the kinetic MRI examination of certain congenital disorders, degenerative diseases, and traumatic injuries of the craniovertebral junction and the cervical spine

Morphometric multislice computed tomography examination of the craniovertebral junction in neck flexion and extension

Background: Detailed study of the craniovertebral junction (CVJ) is necessary to completely understand the mechanism of its flexion and extension. Materials and methods: One cadaver head was sectioned in the sagittal plane. Also, in 22 volunteers, examined using the multislice computed tomography (MSCT), 14 parameters and 2 angles were measured in the neutral position, flexion and extension. Results: The obtained measurements showed the anterior part of the occiput to move inferiorly in flexion, and the anterior atlas arch and the tip of the dens to get closer to the basion. At the same time, the opisthion moves superiorly, but the cervical spine bends anteriorly. Consequently, the dens-opisthion diameter and the opisthion-posterior atlas arch distance slightly decrease in length, whilst the arches of the atlas (C1), axis (C2) and C3 vertebra become more distant. Following extension, the posterior part of the occiput moves inferiorly, so that the basion-dens tip, the basion-axis arch, and the basion-posterior atlas arch distances increase in length. In contrast, the distances of the C1–C3 arches decrease in length. The angle between the foramen magnum and the dens tip decreases 1.620 on average in flexion, but increases 3.230 on average in extension. The angle between the axis body and the opisthion also decreases in flexion (mean, 3.360) and increases in extension (mean, 6.570). Among the congenital anomalies, a partial agenesis of the posterior atlas arch was revealed (4.5%), as well as an anterior dehiscence of the C1 foramen transversarium (13.6%). Conclusions: The mentioned measurements improved our understanding of the CVJ biomechanics. The obtained data can be useful in the evaluation of the CVJ instability caused by trauma, congenital anomalies and certain spine diseases