| 1. |
- George, T. S., et al.
(författare)
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Organic phosphorus in the terrestrial environment : a perspective on the state of the art and future priorities
- 2018
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Ingår i: Plant and Soil. - : Springer Netherlands. - 0032-079X .- 1573-5036. ; 427:1-2, s. 191-208
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Tidskriftsartikel (refereegranskat)abstract
- Background: The dynamics of phosphorus (P) in the environment is important for regulating nutrient cycles in natural and managed ecosystems and an integral part in assessing biological resilience against environmental change. Organic P (P-o) compounds play key roles in biological and ecosystems function in the terrestrial environment being critical to cell function, growth and reproduction.Scope: We asked a group of experts to consider the global issues associated with P-o in the terrestrial environment, methodological strengths and weaknesses, benefits to be gained from understanding the P-o cycle, and to set priorities for P-o research.Conclusions: We identified seven key opportunities for P-o research including: the need for integrated, quality controlled and functionally based methodologies; assessment of stoichiometry with other elements in organic matter; understanding the dynamics of P-o in natural and managed systems; the role of microorganisms in controlling P-o cycles; the implications of nanoparticles in the environment and the need for better modelling and communication of the research. Each priority is discussed and a statement of intent for the P-o research community is made that highlights there are key contributions to be made toward understanding biogeochemical cycles, dynamics and function of natural ecosystems and the management of agricultural systems.
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| 2. |
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| 3. |
- Bulgakov, E.N., et al.
(författare)
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Phase rigidity and avoided level crossings in the complex energy plane
- 2006
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Ingår i: Physical Review E - Statistical, Nonlinear, and Soft Matter Physics. - 1539-3755. ; 74:5
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Tidskriftsartikel (refereegranskat)abstract
- We consider the effective Hamiltonian of an open quantum system, its biorthogonal eigenfunctions ?, and define the value r? = (?/?) ?/? that characterizes the phase rigidity of the eigenfunctions ?. In the scenario with avoided level crossings, r? varies between 1 and 0 due to the mutual influence of neighboring resonances. The variation of r? is an internal property of an open quantum system. In the literature, the phase rigidity ? of the scattering wave function ?CE is considered. Since ?CE can be represented in the interior of the system by the ?, the phase rigidity ? of the ?CE is related to the r? and therefore also to the mutual influence of neighboring resonances. As a consequence, the reduction of the phase rigidity ? to values smaller than 1 should be considered, at least partly, as an internal property of an open quantum system in the overlapping regime. The relation to measurable values such as the transmission through a quantum dot, follows from the fact that the transmission is, in any case, resonant at energies that are determined by the real part of the eigenvalues of the effective Hamiltonian. We illustrate the relation between phase rigidity ? and transmission numerically for small open cavities. © 2006 The American Physical Society.
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| 4. |
- Gaboardi, M, et al.
(författare)
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Goals and Principles of Providers Working with People Experiencing Homelessness: A Comparison Between Housing First and Traditional Staircase Services in Eight European Countries
- 2019
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Ingår i: International journal of environmental research and public health. - : MDPI AG. - 1660-4601. ; 16:9
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Tidskriftsartikel (refereegranskat)abstract
- The implementation and adaptation of the Housing First (HF) model represented profound changes the structure and delivery, goals, and principles of homeless services. These features of homeless services directly influence providers, their work performance and the clients’ outcomes. The present research, conducted in eight European countries, investigated how social providers working in HF or TS (Traditional Staircase) describe and conceptualize the goals and the principles of their services. Data were collected through 29 focus group discussions involving 121 providers. The results showed that HF and TS had similar and different goals for their clients in the following areas: support, social integration, satisfaction of needs, housing, and well-being. HF providers emphasized clients’ autonomy and ability to determine their personal goals, with housing being considered a start on the path of recovery, while TS were more focused on individual clients’ basic needs with respect to food, health and finding temporary accommodations. HF providers privileged the person-centered approach and housing as a right, while TS providers were more focused on helping everyone. Implications of the results are discussed as suggestions both for practice and for research.
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| 5. |
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| 6. |
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| 7. |
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| 8. |
- Gerdtsson, Axel, et al.
(författare)
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Validation of a prediction model for post-chemotherapy fibrosis in nonseminoma patients
- 2023
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Ingår i: Bju International. - 1464-4096 .- 1464-410X. ; 132:3, s. 329-336
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Tidskriftsartikel (refereegranskat)abstract
- Objective To validate Vergouwe's prediction model using the Swedish and Norwegian Testicular Cancer Group (SWENOTECA) RETROP database and to define its clinical utility. Materials and methods Vergouwe's prediction model for benign histopathology in post-chemotherapy retroperitoneal lymph node dissection (PCRPLND) uses the following variables: presence of teratoma in orchiectomy specimen; pre-chemotherapy level of alphafetoprotein; b-Human chorionic gonadotropin and lactate dehydrogenase; and lymph node size pre- and postchemotherapy. Our validation cohort consisted of patients included in RETROP, a prospective population-based database of patients in Sweden and Norway with metastatic nonseminoma, who underwent PC-RPLND in the period 2007-2014. Discrimination and calibration analyses were used to validate Vergouwe's prediction model results. Calibration plots were created and a Hosmer-Lemeshow test was calculated. Clinical utility, expressed as opt-out net benefit (NBopt-out), was analysed using decision curve analysis. Results Overall, 284 patients were included in the analysis, of whom 130 (46%) had benign histology after PC-RPLND. Discrimination analysis showed good reproducibility, with an area under the receiver-operating characteristic curve (AUC) of 0.82 (95% confidence interval 0.77-0.87) compared to Vergouwe's prediction model (AUC between 0.77 and 0.84). Calibration was acceptable with no recalibration. Using a prediction threshold of 70% for benign histopathology, NBopt-out was 0.098. Using the model and this threshold, 61 patients would have been spared surgery. However, only 51 of 61 were correctly classified as benign. Conclusions The model was externally validated with good reproducibility. In a clinical setting, the model may identify patients with a high chance of benign histopathology, thereby sparing patients of surgery. However, meticulous follow-up is required.
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| 9. |
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| 10. |
- Haouas, I., et al.
(författare)
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The impacts of trade liberalization on employment and wages in Tunisian industries
- 2005
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Ingår i: Journal of International Development. - : Wiley. - 0954-1748 .- 1099-1328. ; 17:4, s. 527-551
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Tidskriftsartikel (refereegranskat)abstract
- This paper investigates short and long-run effects of trade liberalization on employment and wages. Employment and wage equations are estimated using data (1971-96) for importable and exportable industrial sectors in Tunisia. Causality tests show that causality is unidirectional. Wages strongly causes employment. There is significant difference in the direction of effects in the short and long-run. Empirical results only support the short-run theoretical predictions for the exportable sectors. A possible reason for the divergence of theory and practice is that the theoretical model is premised on the basis of a fixed supply of labour. Employment at exportable sectors could therefore only rise if employment at importable fell. However, as we have seen, the supply of labour increased dramatically in Tunisia as women entered the labour market. This allowed employment at importable sectors to be maintained as the exportable sector expanded. Copyright ©2005 John Wiley & Sons, Ltd.
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| 11. |
- Heshmati, Almas, et al.
(författare)
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The effects of union wage-settings on firms’ production factor decisions
- 2004
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Ingår i: Applied Economics Letters. - : Informa UK Limited. - 1350-4851 .- 1466-4291. ; 11:7, s. 415-420
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Tidskriftsartikel (refereegranskat)abstract
- This study is concerned with the development of a theoretical model of the interaction between firms and trade union in determining wages and employment. In a two-step process the union and firm determine wages and capital stock, conditional on which the firm decides on production factors of employment, working hours and capital operating time. This paper suggests the use of a panel data approach applied to manufacturing data. A dynamic model is specified in which the optimal levels of the variables of interest and the speed of their adjustments are modelled in terms of observable policy variables. ©2004 Taylor and Francis Ltd.
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| 12. |
- Ishio, H., et al.
(författare)
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Wave function statistics for mesoscopic transport through chaotic open billiards : Time reversibility, space reciprocity breaking and statistical crossover
- 2001
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Ingår i: Computer Physics Communications. - 0010-4655 .- 1879-2944. ; 142:1-3, s. 64-70
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We investigate the probability distributions and spatial correlations of the local densities of electron wave functions for ballistic transport through mesoscopic chaotic open billiards. By quantitative comparison between our accurate fully-quantal calculations with theoretical expressions, we find wave-statistical behaviors intrinsically different from those in closed systems. It is shown that chaotic-scattering wave functions in open systems can be universally interpreted in terms of statistically independent real and imaginary random fields together with breaking of the endowed space reciprocity, resulting in the same wave function statistics as in the time-reversal symmetry-breaking crossover regime in closed systems. © 2001 Elsevier Science B.V. All rights reserved.
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| 13. |
- Jeong, K. -I, et al.
(författare)
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Efficiency of the Korean defense industry : A stochastic frontier approach
- 2009
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Ingår i: Productivity, efficiency, and economic growth in the Asia-Pacific region. - Heidelberg : Physica Verlag. - 9783790820713 ; , s. 217-254
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Bokkapitel (refereegranskat)abstract
- The defense market, which is composed of a sole demander and few suppliers, is generally regarded as a monopolistic market. In this sense, it has its own characteristics that are different from other common competitive markets. High precision technology and a huge amount of capital investment in the initial stage of production are essential in the defense industry, and this necessitates subsidy policy of the government. Most of the supplies are produced in an order-based manner due to the special specification requirements and this hampers the market-driven pricing mechanism. The price is determined based on negotiations between the two parties, considering the cost of production, retrieval of the investment, and efficient allocation of the government budget. This study is organized as follows. The history of the Korean defense industry and policies are summarized in Sect. 10.2. The data is described in Sect 10.3. In Sect 10.4, this study sets out the stochastic frontier production function for the analysis of efficiency and the model for decomposition of TFP. The results of the estimation of the stochastic frontier model are presented in Sect 10.5, where technical efficiency, testing results on factors affecting efficiency and decomposition of TFP are discussed. Lastly, Sect 10.6 presents the conclusions of this study. ©2009 Physica-Verlag Heidelberg.
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| 14. |
- Oh, I., et al.
(författare)
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Analysis of product efficiency in the Korean automobile market from a consumer’s perspective
- 2010
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Ingår i: Empirical Economics. - : Springer Science and Business Media LLC. - 0377-7332 .- 1435-8921. ; 38:1, s. 119-137
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Tidskriftsartikel (refereegranskat)abstract
- In this study we develop and describe a conceptual and methodological framework to measure technical and allocative efficiency at the product level considering consumer choice, which encompasses overall efficiency. Empirically, we combined data envelopment analysis and a discrete choice model in order to measure efficiency levels. The suggested framework is applied to the Korean automobile market. The relationship between the level of efficiency and market performance is discussed in terms of market share. ©Springer-Verlag 2009.
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| 15. |
- Oh, I., et al.
(författare)
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Comparative analysis of plant dynamics by size : Korean manufacturing
- 2009
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Ingår i: Japanese Economic Review. - : Springer Science and Business Media LLC. - 1352-4739 .- 1468-5876. ; 60:4, s. 512-538
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Tidskriftsartikel (refereegranskat)abstract
- A comparative analysis on Korean manufacturing plants is performed by size of plants and sources of TFP growth are decomposed into entry, exit, and survival effects of plants, focusing on the pre- and post-crisis periods. Additional survival analyses investigate internal and external determinants of the survival of plants. The results indicate that the exit of small- and medium-sized establishments (SMEs) with higher productivity is becoming problematic in the post-crisis period. The improvements in large-scale establishments (LSEs) after the crisis appeared to occur generally in high-technology industrial sectors; SMEs in low-technology industries are suffering from a sluggish market selection process. ©2009 The Authors. Journal compilation ©2009 Japanese Economic Association.
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| 16. |
- Oh, I., et al.
(författare)
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Evaluation of credit guarantee policy using propensity score matching
- 2009
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Ingår i: Small Business Economics. - : Springer Science and Business Media LLC. - 0921-898X .- 1573-0913. ; 33:3, s. 335-351
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Tidskriftsartikel (refereegranskat)abstract
- In this article, we evaluate the effect of the credit guarantee policy by comparing a large sample of guaranteed firms and matched non-guaranteed firms from 2000 to 2003. The sample firms are compared with respect to growth rates of different performance indicators including: productivity, sales, employment, investment, R&D, wage level, and the survival of firms in the post crisis period. In order to avoid the selectivity problem, propensity score matching methodologies are adopted. Results suggest that credit guarantees influenced significantly firms’ ability to maintain their size, and increase their survival rate, but not to increase their R&D and investment and hence, their growth in productivity. Moreover, due to the adverse selection problem, firms with lower productivity were receiving guarantees. ©Springer Science+Business Media, LLC. 2008.
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| 17. |
- Oh, I., et al.
(författare)
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Total factor productivity in Korean manufacturing industries
- 2008
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Ingår i: Global Economic Review. - : Informa UK Limited. - 1226-508X .- 1744-3873. ; 37:1, s. 23-50
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Tidskriftsartikel (refereegranskat)abstract
- In this study, parametric and non-parametric methods are employed to measure the total factor productivity (TFP) growth in the Korean manufacturing industry from 1993 to 2003. The analysis period contains both periods before and after the Asian financial crisis. The TFP growth rate is decomposed into different components. Also different elasticities are reported. By classifying the results by period and classifying a number of time invariant firm characteristics, such as sector, size, and location of firms, we observe systematic heterogeneity for each characteristic. We discuss the underlying causal factors. The results from a non-parametric approach are also compared with those of a parametric approach. ©2008 Institute of East and West Studies, Yonsei University, Seoul.
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| 18. |
- Rotter, I., et al.
(författare)
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Avoided level crossings, diabolic points, and branch points in the complex plane in an open double quantum dot
- 2005
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Ingår i: Physical Review E - Statistical, Nonlinear, and Soft Matter Physics. - 1539-3755. ; 71:3
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Tidskriftsartikel (refereegranskat)abstract
- We study the spectrum of an open double quantum dot as a function of different system parameters in order to receive information on the geometric phases of branch points in the complex plane (BPCP). We relate them to the geometrical phases of the diabolic points (DPs) of the corresponding closed system. The double dot consists of two single dots and a wire connecting them. The two dots and the wire are represented by only a single state each. The spectroscopic values follow from the eigenvalues and eigenfunctions of the Hamiltonian describing the double dot system. They are real when the system is closed, and complex when the system is opened by attaching leads to it. The discrete states as well as the narrow resonance states avoid crossing. The DPs are points within the avoided level crossing scenario of discrete states. At the BPCP, width bifurcation occurs. Here, different Riemann sheets evolve and the levels do not cross anymore. The BPCP are physically meaningful. The DPs are unfolded into two BPCP with different chirality when the system is opened. The geometric phase that arises by encircling the DP in the real plane, is different from the phase that appears by encircling the BPCP. This is found to be true even for a weakly opened system and the two BPCP into which the DP is unfolded. ©2005 The American Physical Society.
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| 19. |
- Rotter, I., et al.
(författare)
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Influence of branch points in the complex plane on the transmission through double quantum dots
- 2004
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Ingår i: Physical Review E - Statistical, Nonlinear, and Soft Matter Physics. - 1539-3755. ; 69:6 2
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Tidskriftsartikel (refereegranskat)abstract
- The behavior of a simple model was considered that reflected many characteristic features of realistic double quantum dots (QD) with more complicated structure. The system was described in the framework of the S matrix theory by the effective Hamiltonian of the open quantum system. It consisted of the Hamiltonian of the closed system and a term that accounts for the coupling of the states via the continuum of propagating modes in the leads. The results show that the branch points influence strongly the features of transmission through double quantum dots.
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| 20. |
- Rotter, I., et al.
(författare)
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Singularities caused by coalesced complex eigenvalues of an effective Hamilton operator
- 2007
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Ingår i: International journal of theoretical physics. - : Springer Science and Business Media LLC. - 0020-7748 .- 1572-9575. ; 46:8, s. 1914-1928
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Tidskriftsartikel (refereegranskat)abstract
- The S matrix theory with use of the effective Hamiltonian is sketched and applied to the description of the transmission through double quantum dots. The effective Hamilton operator is non-hermitian, its eigenvalues are complex, the eigenfunctions are bi-orthogonal. In this theory, singularities occur at points where two (or more) eigenvalues of the effective Hamiltonian coalesce. These points are physically meaningful: they separate the scenario of avoided level crossings from that without any crossings in the complex plane. They are branch points in the complex plane. Their geometrical features are different from those of the diabolic points. © 2007 Springer Science+Business Media, LLC.
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| 21. |
- Rotter, I., et al.
(författare)
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Zeros in single-channel transmission through double quantum dots
- 2005
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Ingår i: Physical Review E - Statistical, Nonlinear, and Soft Matter Physics. - 1539-3755. ; 71:4
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Tidskriftsartikel (refereegranskat)abstract
- By using a simple model we consider single-channel transmission through a double quantum dot that consists of two single dots coupled by a wire of finite length L. Each of the two single dots is characterized by a few energy levels only, and the wire is assumed to have only one level whose energy depends on the length L. The transmission is described by using 5 matrix theory and the effective non-Hermitian Hamilton operator Heff of the system. The decay widths of the eigenstates of Heff depend strongly on energy. The model explains the origin of the transmission zeros of the double dot that is considered by us. Mostly, they are caused by (destructive) interferences between neighboring levels and are of first order. When, however, both single dots are identical and their transmission zeros are of first order, those of the double dot are of second order. First-order transmission zeros cause phase jumps of the transmission amplitude by p, while there are no phase jumps related to second-order transmission zeros. In this latter case, a phase jump occurs due to the fact that the width of one of the states vanishes when crossing the energy of the transmission zero. The parameter dependence of the widths of the resonance states is determined by the spectral properties of the two single dots. ©2005 The American Physical Society.
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| 22. |
- Sadreev, Almas, et al.
(författare)
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S-matrix formalism of transmission through two quantum billiards coupled by a waveguide
- 2005
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Ingår i: Journal of Physics A. - : IOP Publishing. - 0305-4470 .- 1361-6447. ; 38:49, s. 10647-10661
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Tidskriftsartikel (refereegranskat)abstract
- We consider a system that consists of two single-quantum billiards (QBs) coupled by a waveguide and study the transmission through this system as a function of length and width of the waveguide. To interpret the numerical results for the transmission, we explore a simple model with a small number of states which allows us to consider the problem analytically. The transmission is described in the S-matrix formalism by using the non-Hermitian effective Hamilton operator for the open system. The coupling of the single QBs to the internal waveguide characterizes the 'internal' coupling strength u of the states of the system while that of the system as a whole to the attached leads determines the 'external' coupling strength v of the resonance states via the continuum (waves in the leads). The transmission is resonant for all values of v/u in relation to the effective Hamiltonian. It depends strongly on the ratio v/u via the eigenvalues and eigenfunctions of the effective Hamiltonian. The results obtained are compared qualitatively with those from simulation calculations for larger systems. Most interesting is the existence of resonance states with vanishing widths that may appear at all values of v/u. They cause zeros in the transmission through the double QB due to trapping of the particle in the waveguide. © 2005 IOP Publishing Ltd.
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| 23. |
- Sadreev, Almas, et al.
(författare)
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S-matrix theory for transmission through billiards in tight-binding approach
- 2003
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Ingår i: Journal of Physics A. - : IOP Publishing. - 0305-4470 .- 1361-6447. ; 36:45, s. 11413-11433
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Tidskriftsartikel (refereegranskat)abstract
- In the tight-binding approximation we consider multi-channel transmission through a billiard coupled to leads. Following Dittos we derive the coupling matrix, the scattering matrix and the effective Hamiltonian, but take into account the energy restriction of the conductance band. The complex eigenvalues of the effective Hamiltonian define the poles of the scattering matrix. For some simple cases, we present exact values for the poles. We derive also the condition for the appearance of double poles.
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| 24. |
- Sadreev, Almas, et al.
(författare)
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Trapping of an electron in the transmission through two quantum dots coupled by a wire
- 2005
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Ingår i: JETP Letters. - : Pleiades Publishing Ltd. - 0021-3640 .- 1090-6487. ; 82:8, s. 498-503
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Tidskriftsartikel (refereegranskat)abstract
- We consider single-channel transmission through a double quantum dot that consists of two identical single dots coupled by a wire. The numerical solution for the scattering wave function shows that the resonance width of a few of the states may vanish when the width (or length) of the wire and the energy of the incident particle each take a certain value. In such a case, a particle is trapped inside the wire as the numerical visualization of the scattering wave function shows. To understand these numerical results, we explore a simple model with a small number of states, which allows us to consider the problem analytically. If the eigenenergies of the closed system cross the energies of the transmission zeroes, the wire effectively decouples from the rest of the system and traps the particle. © 2005 Pleiades Publishing, Inc.
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| 25. |
- Saichev, A.I., et al.
(författare)
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Statistics of interior current distributions in two-dimensional open chaotic billiards
- 2002
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Ingår i: Journal of Physics A. - : IOP Publishing. - 0305-4470 .- 1361-6447. ; 35:7
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Tidskriftsartikel (refereegranskat)abstract
- The probability current statistics of two-dimensional open chaotic ballistic billiards is studied both analytically and numerically. Assuming that the real and imaginary parts of the scattering wave function are both random Gaussian fields, we find a universal distribution function for the interior probability current. As a by-product we recover previous analytic forms for wave function statistics. The expressions bridge the entire region from GOE to GUE type statistics. Our analytic expressions are verified numerically by explicit quantum mechanical calculations of transport through a Bunimovich billiard.
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| 26. |
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| 27. |
- Taylor, O, et al.
(författare)
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Lifetime, 5-year and past-year prevalence of homelessness in Europe: a cross-national survey in eight European nations
- 2019
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Ingår i: BMJ open. - : BMJ. - 2044-6055. ; 9:11, s. e033237-
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Tidskriftsartikel (refereegranskat)abstract
- To examine the lifetime, 5-year and past-year prevalence of homelessness among European citizens in eight European nations.DesignA nationally representative telephone survey using trained bilingual interviewers and computer-assisted telephone interview software.SettingThe study was conducted in France, Ireland, Italy, the Netherlands, Poland, Portugal, Spain and Sweden.ParticipantsEuropean adult citizens, selected from opt-in panels from March to December 2017. Total desired sample size was 5600, with 700 per country. Expected response rates of approximately 30% led to initial sample sizes of 2500 per country.Main outcome measuresHistory of homelessness was assessed for lifetime, past 5 years and past year. Sociodemographic data were collected to assess correlates of homelessness prevalence using generalised linear models for clustered and weighted samples.ResultsResponse rates ranged from 30.4% to 33.5% (n=5631). Homelessness prevalence was 4.96% for lifetime (95% CI 4.39% to 5.59%), 1.92% in the past 5 years (95% CI 1.57% to 2.33%) and 0.71% for the past year (95% CI 0.51% to 0.98%) and varied significantly between countries (pairwise comparison difference test, p<0.0001). Time spent homeless ranged between less than a week (21%) and more than a year (18%), with high contrasts between countries (p<0.0001). Male gender, age 45–54, lower secondary education, single status, unemployment and an urban environment were all independently strongly associated with lifetime homelessness (all OR >1.5).ConclusionsThe prevalence of homelessness among the surveyed nations is significantly higher than might be expected from point-in-time and homeless service use statistics. There was substantial variation in estimated prevalence across the eight nations. Coupled with the well-established health impacts of homelessness, medical professionals need to be aware of the increased health risks of those with experience of homelessness. These findings support policies aiming to improve health services for people exposed to homelessness.
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