Vibronic interaction in crystals with the Jahn-Teller centers in the elementary energy bands concept

The order-disorder type phase transition caused by the vibronic interaction (collective Jahn-Teller effect) in a monoclinic CuInP$_2$S$_6$ crystal is analyzed. For this purpose, a trigonal protostructure model of CuInP$_2$S$_6$ is created, through a slight change in the crystal lattice parameters of the CuInP$_2$S$_6$ paraelectric phase. In parallel to the group-theoretical analysis, the DFT-based {\it ab initio} band structure calculations of the CuInP$_2$S$_6$ protostructure, para-, and ferriphases are performed. Using the elementary energy bands concept, a part of the band structure from the vicinity of the forbidden energy gap, which is created by the $d$-electron states of copper, has been related with a certain Wyckoff position where the Jahn-Teller's centers are localized. A construction procedure of the vibronic potential energy matrix is generalized for the case of crystal using the elementary energy bands concept and the group theoretical method of invariants. The procedure is illustrated by the creation of the adiabatic potentials of the $\Gamma_5$-$\Gamma_5$ vibronic coupling for the protostructure and paraphase of the CuInP$_2$S$_6$ crystal. A structure of the obtained adiabatic potentials is analyzed, followed by conclusions on their transformation under a phase transition and the discussion on the possibility for the spontaneous polarization to arise in this crystal.Comment: 17 pages, 7 figure

Genetic basis for variation in wheat grain yield in response to varying nitrogen application

Nitrogen (N) is a major nutrient needed to attain optimal grain yield (GY) in all environments. Nitrogen fertilisers represent a significant production cost, in both monetary and environmental terms. Developing genotypes capable of taking up N early during development while limiting biomass production after establishment and showing high N-use efficiency (NUE) would be economically beneficial. Genetic variation in NUE has been shown previously. Here we describe the genetic characterisation of NUE and identify genetic loci underlying N response under different N fertiliser regimes in a bread wheat population of doubled-haploid lines derived from a cross between two Australian genotypes (RAC875 × Kukri) bred for a similar production environment. NUE field trials were carried out at four sites in South Australia and two in Western Australia across three seasons. There was genotype-by-environment- by-treatment interaction across the sites and also good transgressive segregation for yield under different N supply in the population. We detected some significant Quantitative Trait Loci (QTL) associated with NUE and N response at different rates of N application across the sites and years. It was also possible to identify lines showing positive N response based on the rankings of their Best Linear Unbiased Predictions (BLUPs) within a trial. Dissecting the complexity of the N effect on yield through QTL analysis is a key step towards elucidating the molecular and physiological basis of NUE in wheat.Saba Mahjourimajd, Julian Taylor, Beata Sznajder, Andy Timmins, Fahimeh Shahinnia, Zed Rengel, Hossein Khabaz-Saberi, Haydn Kuchel, Mamoru Okamoto, Peter Langridg

Structure similarity and lattice dynamics of InSe and In₄Se₃ crystals

In the work it was shown that the In₄Se₃ crystal is similar by its dynamical properties to the InSe modulated crystal. The transformation of the D⁴₆h symmetry group of β-InSe crystal to D⁹₂h group of the In₄Se₃ structure and the D¹²₂h group of In₄Se₃ structure has been investigated. In spite of structure corrugation of In₄Se₃ layer, it is shown that the region of the weak bond in this crystal by the dynamical characteristics is similar to the weak bond region in InSe crystal.У роботі показано, що кристал In₄Se₃ за своїми динамічними властивостями близький до модульованого кристалу InSe. Досліджено перетворення групи симетрії D⁴₆h кристалу β-InSe до групи D⁹₂h структури In₄Se₄ і до групи D¹²₂h In₄Se₃. Показано, що незважаючи на гофрованість структури шару In₄Se₃, область слабкого зв’язку у ньому за динамічними властивостями є подібною до області слабкого зв’язку у кристалі InSe

) Katarzyna Z. Rajtar MD, PhD, Department of Imaging Diagnostics

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare tumour of uncertain histopathological origin derived from the exocrine pancreas and most often first detected on radiological imaging. It predominantly affects young women in their second and third decades of life. Solid pseudopapillary neoplasm has a low-grade malignant potential with excellent post-surgical curative rates. The lesions can be detected and differentiated from other pancreatic lesions by ultrasound imaging (US), computed tomography (CT), and magnetic resonance imaging (MRI). We report a case of solid pseudopapillary neoplasm of the pancreas that was diagnosed on CT imagining and confirmed on postoperative histological examination. A 20-year-old woman with no prior medical history was admitted to the Emergency Department with a 2-day history of nausea, vomiting, and diarrhoea. She described a one-year history of abdominal 'fullness' but no other symptoms of note. Her vital observations were stable. On physical examination there was a palpable mass in the right hypochondriac region. Haematological and biochemical tests, including tumour markers (CEA, CA-125, CA19-9, hCD, α-fetoprotein), were within normal limits. Transabdominal ultrasound scan revealed a well-circumscribed, heterogeneous lesion with anechoic areas. It measured 80 × 70 mm and was situated between the right kidney and the right lobe of the liver. A multiphase contrast-enhanced computer tomography scan was ordered. It showed a round, retroperitoneal lesion with cystic and solid components measuring 70 × 61 × 96 mm located in the head of pancreas. The mass was separated from its surroundings by a wall of variable thickness The patient was transferred to the Surgical Oncology Department and was assessed for surgical intervention. She had undergone a radical excision of the mass by an open approach with an upper midline incision. On gross pathological examination there was a cystic, multiloculated mass measuring 90 × 75 × 65 mm and surrounded by a stiff, focally calcified wall. The largest cyst measured 60 mm and was filled with dark brown 'chocolate' fluid. The mass was fixed to the anterolateral part of the head of the pancreas. The histopathological examination revealed pancreatic pseudopapillary neoplasm positive for cytokeratin (CK) 8/18, vimentin, ER, and PR and equivocal for synaptophysin. There was no involvement of the incisional margins. The patient has made an uneventful post-operative recovery. Follow-up transabdominal ultrasound examinations were performed every month for the first half a year and every 3 months thereafter. Abdominal CT scan was repeated every 6 months for 1 year. There were no signs of tumour recurrence in any of the follow up scans. The patien

Overcoming Postcommunist Labour Weakness: Attritional and Enabling Effects of MNCs in Central and Eastern Europe

Based on micro-level analysis of the developments in the steel sector in Poland, Romania and Slovakia, this paper examines the effects of multinational corporations (MNCs) on labour unions in Central and Eastern Europe. It makes a three-fold argument. First, it shows that union weakness can be attributed to unions’ strategies during the restructuring and privatization processes of postcommunist transition. Consequently, tactics used for union regeneration in the West are less applicable to CEE. Rather, the overcoming of postcommunist legacy is linked to the power of transnational capital. Through attritional and enabling effects, ownership by MNCs forces the unions to focus their efforts on articulating workers’ interests. The paper examines the emerging system of industrial relations in the sector and explores the development of the capabilities needed to overcome postcommunist legacies

Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering

A semi-inclusive measurement of charged hadron multiplicities in deep inelastic muon scattering off an isoscalar target was performed using data collected by the COMPASS Collaboration at CERN. The following kinematic domain is covered by the data: photon virtuality $Q^{2}>1$ (GeV/$c$)$^2$, invariant mass of the hadronic system $W > 5$ GeV/$c^2$, Bjorken scaling variable in the range $0.003 < x < 0.4$, fraction of the virtual photon energy carried by the hadron in the range $0.2 < z < 0.8$, square of the hadron transverse momentum with respect to the virtual photon direction in the range 0.02 (GeV/$c)^2 < P_{\rm{hT}}^{2} < 3$ (GeV/$c$)$^2$. The multiplicities are presented as a function of $P_{\rm{hT}}^{2}$ in three-dimensional bins of $x$, $Q^2$, $z$ and compared to previous semi-inclusive measurements. We explore the small-$P_{\rm{hT}}^{2}$ region, i.e. $P_{\rm{hT}}^{2} < 1$ (GeV/$c$)$^2$, where hadron transverse momenta are expected to arise from non-perturbative effects, and also the domain of larger $P_{\rm{hT}}^{2}$, where contributions from higher-order perturbative QCD are expected to dominate. The multiplicities are fitted using a single-exponential function at small $P_{\rm{hT}}^{2}$ to study the dependence of the average transverse momentum $\langle P_{\rm{hT}}^{2}\rangle$ on $x$, $Q^2$ and $z$. The power-law behaviour of the multiplicities at large $P_{\rm{hT}}^{2}$ is investigated using various functional forms. The fits describe the data reasonably well over the full measured range.Comment: 28 pages, 20 figure

Measurement of the charged-pion polarisability

The COMPASS collaboration at CERN has investigated pion Compton scattering, $\pi^-\gamma\rightarrow \pi^-\gamma$, at centre-of-mass energy below 3.5 pion masses. The process is embedded in the reaction $\pi^-\mathrm{Ni}\rightarrow\pi^-\gamma\;\mathrm{Ni}$, which is initiated by 190\,GeV pions impinging on a nickel target. The exchange of quasi-real photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, $Q^2<0.0015$\,(GeV/$c$)$^2$. From a sample of 63\,000 events the pion electric polarisability is determined to be $\alpha_\pi\ =\ (\,2.0\ \pm\ 0.6_{\mbox{\scriptsize stat}}\ \pm\ 0.7_{\mbox{\scriptsize syst}}\,) \times 10^{-4}\,\mbox{fm}^3$under the assumption$\alpha_\pi=-\beta_\pi$, which relates the electric and magnetic dipole polarisabilities. It is the most precise measurement of this fundamental low-energy parameter of strong interaction, that has been addressed since long by various methods with conflicting outcomes. While this result is in tension with previous dedicated measurements, it is found in agreement with the expectation from chiral perturbation theory. An additional measurement replacing pions by muons, for which the cross-section behavior is unambigiously known, was performed for an independent estimate of the systematic uncertainty.Comment: Published version: 9 pages, 3 figures, 1 tabl