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

Adverse childhood experiences increase HIV risk factors in Agbogbloshie, Ghana

Adverse Childhood Experiences (ACEs) have been associated with increased risk factors for HIV transmission, but the causal pathway is uncertain. This study documents the prevalence of ACEs by gender and their association with HIV risk factors and assesses depressive symptoms as mediating this relationship. A cross-sectional survey was conducted in 2019 among a representative sample of men and women, aged 18–24 years, living in an informal settlement in Accra, Ghana. Data on sociodemographic characteristics, ACEs, ten HIV risk factors (five sexual behaviors, HIV/AIDS knowledge, sexual assault, three substance use behaviors), and depressive symptoms were collected. Multiple logistic regression models were estimated to assess the independent association between four or more ACEs and each of the ten HIV risk factors. Structural equation models examined depressive symptoms as a mediator in these associations. A third (34.6%) of participants reported four or more ACEs, and among those who experienced four or more ACEs 60% were men and 40% were women. Gender did not modify the effect of the association between four or more ACEs and HIV factors and therefore the multiple regression analysis was not stratified by gender. After controlling for sociodemographic covariates and depressive symptoms, having experienced four or more ACEs was associated with alcohol use (OR = 3.88; 95% CI: 1.34, 11.21), injection drug use (OR = 2.78; 95% CI: 1.15, 6.73), low knowledge of HIV (OR = 3.59; 95% CI: 1.43, 9.00), sexually transmitted infection (OR = 3.70; 95% CI: 1.15, 11.96), and sexual assault (OR = 3.58; 95% CI: 1.07, 12.05). There was some evidence that depressive symptoms could be mediating the association between reporting four or more ACEs and ever having a sexually transmitted infection. The mitigation of ACEs and depressive symptoms has the potential to decrease HIV risk factors and thus reduce the risk for HIV transmission among youth living in informal settlements

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

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

) 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

Wp-2 basic investigation of transition effect

An important goal of the TFAST project was to study the effect of the location of transition in relation to the shock wave on the separation size, shock structure and unsteadiness of the interaction area. Boundary layer tripping (by wire or roughness) and flow control devices (Vortex Generators and cold plasma) were used for boundary layer transition induction. As flow control devices were used here in the laminar boundary layer for the first time, their effectiveness in transition induction was an important outcome. It was intended to determine in what way the application of these techniques induces transition. These methods should have a significantly different effect on boundary layer receptivity, i.e. the transition location. Apart from an improved understanding of operation control methods, the main objective was to localize the transition as far downstream as possible while ensuring a turbulent character of interaction. The final objective, involving all the partners, was to build a physical model of transition control devices. Establishing of such model would simplify the numerical approach to flow cases using such devices. This undertaking has strong support from the industry, which wants to include these control devices in the design process. Unfortunately only one method of streamwise vortices was developed and investigated in the presented study