Nonequilibrium Green's function theory for transport and gain properties of quantum cascade structures

The transport and gain properties of quantum cascade (QC) structures are investigated using a nonequilibrium Green's function (NGF) theory which includes quantum effects beyond a Boltzmann transport description. In the NGF theory, we include interface roughness, impurity, and electron-phonon scattering processes within a self-consistent Born approximation, and electron-electron scattering in a mean-field approximation. With this theory we obtain a description of the nonequilibrium stationary state of QC structures under an applied bias, and hence we determine transport properties, such as the current-voltage characteristic of these structures. We define two contributions to the current, one contribution driven by the scattering-free part of the Hamiltonian, and the other driven by the scattering Hamiltonian. We find that the dominant part of the current in these structures, in contrast to simple superlattice structures, is governed mainly by the scattering Hamiltonian. In addition, by considering the linear response of the stationary state of the structure to an applied optical field, we determine the linear susceptibility, and hence the gain or absorption spectra of the structure. A comparison of the spectra obtained from the more rigorous NGF theory with simpler models shows that the spectra tend to be offset to higher values in the simpler theories.Comment: 44 pages, 16 figures, appearing in Physical Review B Dec 200

Development and validation of a real-time PCR assay for detection and quantification of Tuber magnatum in soil

Background: Tuber magnatum, the Italian white truffle, is the most sought-after edible ectomycorrhizal mushroom. Previous studies report the difficulties of detecting its mycorrhizas and the widespread presence of its mycelium in natural production areas, suggesting that the soil mycelium could be a good indicator to evaluate its presence in the soil. In this study a specific real-time PCR assay using TaqMan chemistry was developed to detect and quantify T. magnatum in soil. This technique was then applied to four natural T. magnatum truffires located in different regions of Italy to validate the method under different environmental conditions. Results: The primer/probe sets for the detection and quantification of T. magnatum were selected from the ITS rDNA regions. Their specificity was tested in silico and using qualitative PCR on DNA extracted from 25 different fungal species. The T. magnatum DNA concentration was different in the four experimental truffires and higher in the productive plots. T. magnatum mycelium was however also detected in most of the non-productive plots. Ascoma production during the three years of the study was correlated with the concentration of T. magnatum DNA. Conclusions: Taken together, these results suggest that the specific real-time PCR assay perfected in this study could be an useful tool to evaluate the presence and dynamics of this precious truffle in natural and cultivated truffi\ue9re

Near-field light emission from nano- and micrometric complex structures

We propose a general theoretical scheme for the investigation of light emitted from nano- and micrometric structures of arbitrary shape and composition. More specifically, the proposed fully three-dimensional approach allows to derive the light-intensity distributions around the emitting structures and their modifications in the presence of nearby scattering objects. Our analysis allows to better identify the nontrivial relationship between near-field images and fluorescent objects

Economic sustainability of pig slaughtering firms in the production chain of denomination of origin hams in italy

Pork meat in Italy is one of the largest agri-food chains in Italy. In the swine production chain, slaughter plays an important role, because it has an impact on animal welfare, food safety and the sustainability of the agri-food chain. These companies also deal with pigs destined for typical Denomination of Origin products and therefore play an important role in the production chain of typical products and in the field of EU agricultural policy. In this context, the research aims to analyze the economic sustainability of the major pig slaughter firms in Italy, through data analysis of the annual account statement (AAS) on a sample of eight companies analyzed over a ten-year historical series. Financial ratios and margins (FRM) analysis is applied in the research. FRM analysis shows that firms have the largest absorption of financial resources in the net working capital cycle. The research highlights the high incidence of raw materials in companies in the sector. Consequently, the profit margins of the companies in the sample are modest and in some cases are lower than the cost of debt, suggesting a moderate capacity to attract capital. This result appears as a negative signal of the economic sustainability of the companies in the sector. The research, now limited to a small number of large companies, opens a line of research that can be developed by expanding the sample to small and medium-sized enterprises of the chain of Denomination of Origin hams in Italy to suggest improvement interventions, in particular for rural or marginal areas of production

Characterization and pathogenicity of Colletotrichum spp. causing citrus anthracnose in Tunisia

In the winter and spring of 2014-2015, typical anthracnose symptoms were detected on different citrus varieties in Cap-Bon and Morneg-Tunis regions of Northern Tunisia. Surveys were conducted to determine the casual agents of these symptoms. A total of seven monosporic isolates were obtained from dark lesions on fruits, flowers, leaves and twigs of citrus from six orchards. One Colletotrichum karstii (from the C. boninense species complex) and six C. gloeosporioides isolates were identified through morphological analysis and sequencing of their ITS rDNA sequences. Pathogenicity tests with the seven isolates were performed on symptomless, detached citrus fruits (Valencia orange and Eureka lemon). All tested isolates caused anthracnose lesions after 1 week of incubation. Koch's postulates were fulfilled by re-isolation of pathogens from the inoculated fruits. This report elucidates the diversity of anthracnose pathogens in Tunisia. This is the first report of C. karstii from citrus in Tunisia

Is Tuber brumale a threat to T. melanosporum and T. aestivum plantations?

True truffles in the genus Tuber are the most valuable ectomycorrhizal fungiand their cultivation has become widespread around the world. Competition with other ectomycorrhizal fungi and especially with undesired Tuber species, like T. brumale, can threaten the success of a truffle plantation. In this work, the competitiveness of T. brumale towards T. melanosporum and T. aestivum was assessed in a 14 year-old plantation carried out planting seedlings inoculated with these three truffle species in adjacent plots. Analyses of both truffle ectomycorrhizas and extra-radical mycelium were carried out in the transects separating the T. brumale plot from T. melanosporum and T. aestivum plots. The results confirm the competitiveness of T. brumale against T. aestivum and T. melanosporum due to its major ability to colonize the soil around its ectomycorrhizas. However, its competitiveness is limited to the transect areas and it was never found inside T. melanosporum plot. These results remark that, in presence of optimal conditions for T. melanosporum and T. aestivum, the greatest risk of contamination with T. brumale is due to wrong greenhouse activity

Feasibility and safety of physical exercise in men with prostate cancer receiving androgen deprivation therapy and radiotherapy: A study protocol

Introduction Androgen deprivation therapy (ADT) and radiotherapy (RT) increase survival in selected patients with prostate cancer. Nevertheless, the side effects of these therapies are associated with an increased risk of accidental falls and fractures and a decreased quality of life. Preliminary evidence suggests that physical exercise can be a valid strategy to reduce the side effects of ADT and RT in men with prostate cancer. Despite this knowledge, most patients with prostate cancer are insufficiently active, and there is a lack of data on the safety and adherence to the recommended dose of physical exercise. This study protocol is designed to examine the feasibility and safety of a multicomponent experimental physical exercise intervention targeting psychophysical and cognitive functions and the quality of life in this population. Methods and analysis This is a pilot feasibility study. Twenty-five men currently treated with ADT and RT for prostate cancer will be invited to participate in a 20-week, multicomponent physical exercise intervention, including supervised and unsupervised exercise sessions and meeting the current recommendation for exercise in cancer. The primary outcomes are physical exercise feasibility (recruitment, adherence and drop-out rates) and safety (adverse events related and unrelated to the intervention). The secondary outcomes are muscle strength, balance, fatigue, symptoms of anxiety and depression, cognitive function, quality of life, and patient satisfaction. We will also record the number of accidental falls and fractures occurring during the intervention and at 1 year of follow-up. Ethics and dissemination The study has received ethics approval from The Area Vasta Nord Local Ethics Committee (Province of Reggio Emilia, 23 June 2020, Number 520/2020/SPER/IRCCSRE). Recruitment began in September 2020 and will be completed in September 2021. The results will be disseminated through scientific journals and conference presentations. Trial registration number NCT04500080

Contrast-enhanced mammography-guided biopsy: technical feasibility and first outcomes

Objectives To evaluate the feasibility of contrast-enhanced mammography (CEM)-guided biopsy at Hospital del Mar, a Spanish university hospital. Methods We retrospectively reviewed all consecutive women with a suspicious enhancing finding eligible for CEM-guided biopsy, who were prospectively enrolled in a pre-marketing clinical validation and feasibility study (October 2019 to September 2021). CEM-guided biopsy is a stereotactic-based procedure that, by using intravenous iodinated contrast media administration and dual-energy acquisition, provides localisation of enhancing lesions. All the biopsies were performed using a vacuum-assisted device. We collected procedural characteristics (patient position and type of approach), and histopathological results. Feasibility endpoints included success (visualisation of the enhancing lesion, post-procedural biopsy changes and clip placement), procedural time, number of scout acquisitions and complications. Results A total of 66 suspicious enhancing lesions (18.0% foci, 44.0% mass, 38.0% non-mass enhancement; median size 8.5 mm) in 64 patients (median age 59 years, mostly minimal [48.4%] or mild [32.8%] background parenchymal enhancement) were referred for CEM-guided biopsy in the study period. The success rate was 63/66 (95.4%). Amongst successful procedures, patients were most frequently seated (52/63, 82.5%) and the preferred approach was horizontal (48/63, 76.2%). Median total time per procedure was 15 min. Median number of acquisitions needed before targeting was 2 (range 1-4). Complications consisted of hematoma (17/63, 27%) and vasovagal reaction (2/63, 3.2%). At histology, the malignancy rate was 25/63 (39.7%). Conclusion In this first patient series, CEM-guided breast biopsy was feasible, with success and complication rates similar to those previously reported for magnetic resonance guidance

Feasibility and Safety of Physical Exercise to Preserve Bone Health in Men With Prostate Cancer Receiving Androgen Deprivation Therapy: A Systematic Review

Objective: Men with prostate cancer (PCa) receiving androgen deprivation therapy (ADT) experience the loss of bone mineral density (BMD) and lean body mass, which can increase their risk of falls and fractures. Physical exercise programs with appropriate components and dosage are suggested to preserve BMD and muscle strength, thereby potentially reducing accidental falls and fractures and associated morbidity and mortality. These benefits can be obtained if exercise programs are feasible and safe and if patient adherence is adequate. This systematic review investigates the feasibility and safety of exercise programs aimed at preventing the risk of accidental falls and fractures and BMD loss in men with PCa undergoing ADT. Methods: MEDLINE, Embase, CINAHL, and the Cochrane Library were searched from database inception to June 7, 2021. Randomized controlled trials were included when they analyzed the feasibility and safety of experimental exercise programs targeting bone health in men with PCa receiving ADT. Two reviewers independently selected the studies, assessed their methodological quality, and extracted the data. Exercise feasibility was measured through recruitment, retention, and adherence rates. Exercise safety was measured through the number, type, and severity of adverse events. Furthermore, the components, setting, intensity, frequency, and duration of exercise programs were extracted. Results: Ten studies were included, with a total of 633 participants. Exercise consisted of a combination of aerobic, resistance, and impact-loading exercise or football training. Exercise is feasible in men with PCa undergoing ADT, although football training should be prescribed with caution for safety reasons. Conclusion: Multicomponent exercise programs targeting bone health seem feasible and safe in this population; however, adverse events should be systematically documented according to current guidelines. Impact: The study shows that men with PCa receiving ADT can safely perform exercise programs to preserve bone health and supports that those programs should become part of lifestyle habits. Lay Summary: Men with PCa who are receiving ADT can safely perform exercise programs to preserve bone health and should make exercise an important part of their lifestyle

Dissipation and Decoherence in Nanodevices: a Generalized Fermi's Golden Rule

We shall revisit the conventional adiabatic or Markov approximation, which --contrary to the semiclassical case-- does not preserve the positive-definite character of the corresponding density matrix, thus leading to highly non-physical results. To overcome this serious limitation, originally pointed out and partially solved by Davies and co-workers almost three decades ago, we shall propose an alternative more general adiabatic procedure, which (i) is physically justified under the same validity restrictions of the conventional Markov approach, (ii) in the semiclassical limit reduces to the standard Fermi's golden rule, and (iii) describes a genuine Lindblad evolution, thus providing a reliable/robust treatment of energy-dissipation and dephasing processes in electronic quantum devices. Unlike standard master-equation formulations, the dependence of our approximation on the specific choice of the subsystem (that include the common partial trace reduction) does not threaten positivity, and quantum scattering rates are well defined even in case the subsystem is infinitely extended/has continuous spectrum.Comment: 6 pages, 0 figure