Linear theory of wave generation by a moving bottom

The computation of long wave propagation through the ocean obviously depends on the initial condition. When the waves are generated by a moving bottom, a traditional approach consists in translating the ``frozen'' sea bed deformation to the free surface and propagating it. The present study shows the differences between the classical approach (passive generation) and the active generation where the bottom motion is included. The analytical solutions presented here exhibit some of the drawbacks of passive generation. The linearized solutions seem to be sufficient to consider the generation of water waves by a moving bottom.Comment: 9 pages, 2 figure

Localized Dissipation in Fermionic Quantum Wires

Localized dissipation in many-body quantum systems represents an emergent focal point of non-equilibrium physics. In recent experiments, localized particle losses were realized in ultracold atomic gases, thus opening up new avenues for investigating the interplay between many-body and non-equilibrium effects. The main focus of this work is the theoretical study of collective phenomena in one-dimensional systems of interacting spinless fermions subject to a localized loss. This model constitutes a non-equilibrium counterpart of the paradigmatic Kane-Fisher potential barrier problem. In particular, strong interaction effects emerge due to the gapless nature of the system. We show that the loss and transport properties of the quantum wire in the presence of a localized loss are drastically modified by interactions as a result of the interplay between coherent and incoherent processes. In experiments with localized losses, a manifestation of the quantum Zeno effect is encountered, which can be described exhaustively in terms of local, microscopic physics. In contrast, we demonstrate that the interplay of gapless quantum fluctuations and particle interactions with the localized dissipation leads to an instance of the quantum Zeno effect of genuine many-body nature. After the localized losses are switched on, a non-equilibrium steady state emerges in the quantum wire. We derive exact results for the properties of this steady state in the non-interacting limit and formulate a theoretical description of the depletion processes by introducing the momentum-dependent loss probability of modes. Remarkably, we find that coherence properties of the initial state persist, leading to the formation of Friedel oscillations near the loss site. The presence of interactions between the fermions modifies the dynamics in the wire and leads to an energy-dependent renormalization of loss processes. We find that the loss probability is strongly renormalized for modes with an energy close to the Fermi energy, leading to the suppression of losses at the Fermi level. In the case of repulsive interactions, the suppression of losses is accompanied by the loss site becoming completely opaque, which establishes a fluctuation-induced quantum Zeno effect. For attractive interactions, instead, the localized loss becomes fully transparent to particles at the Fermi level, resulting accordingly in the suppression of losses as a fluctuation-induced transparency. The strong modifications of the loss properties are reflected in observables such as the momentum distribution in the wire, exhibiting an increased occupation at the Fermi momentum. In addition, we study the influence of self-thermalization effects on the renormalization of the effective dissipation strength. Here, we identify regimes where the generation of an effective temperature is sufficiently weak to achieve significant renormalization. Furthermore, the microscopic quantum Zeno effect affects the spectral properties of the non-Hermitian Hamiltonian associated with a localized loss for a lattice model. Here, a sharp reorganization of the spectrum is encountered at a critical dissipation strength, causing a characteristic signature in the response properties of the wire. We investigate the interplay of interactions in the wire and localized dissipation within three complementary approaches. In a microscopic real-space renormalization group analysis the physical mechanisms behind the modified depletion properties are particularly transparent. Within a dynamical Hartree-Fock approximation the resulting effects on observables such as the momentum distribution in the non-equilibrium steady states can be studied. Finally, an effective Luttinger liquid description demonstrates the universality of the findings and enables the investigation of mode-coupling effects

Dendrological scales of spruce european of 5–7th groups of plants in the territory of Belarus

Spruce forests belonging to 5–7th groups of plants have I–Ib class of bonitet and are the most productive. Dendrological scales of spruce forests have an extension 104 years (1888–1991). Index values in the spruce forests of the 5th group plantings ranged for late wood within 0.66–1.44, for early wood – 0.61–1.30, for treering as a whole – 0.62–1.29. In spruce forests of 6th group index values fluctuated for late wood within 0.72–1.99, for ea rly – 0.63–1.26, for tree-ring as a whole – 0.67– 1.24. In spruce forests of 7th group index values fluctuated for late wood within 0.47–1.58, for early – 0.41–1.86, for treering as a whole – 0.42–1.75. Coefficients of variation of indices width of tree rings were as follows: for spruce plantations 5th group 13% for spruce 6th group – 11% for spruce 7th group – 18%, which corresponds to the lower rate of normal variation

COVID-19 in City Council Civil Servants, 1 March 2020–31 January 2023: Risk of Infection, Reinfection, Vaccine Effectiveness and the Impact of Heterologous Triple Vaccination

The risk of COVID-19 increases in any occupation entailing intense social interactions. This study aimed to investigate the impact of COVID-19 among civil servants of Trieste city council (northeastern Italy) over the entire pandemic. Methods. The crude incidence rate of COVID-19 was estimated from 1 March 2020 to 31 January 2023 by explanatory factors, expressing the estimate as COVID-19 events x 10,000 person-days (P-d) at risk. A multivariable Cox proportional hazard regression model was fitted to examine the risk of primary COVID-19 infection and reinfections, reporting adjusted hazard ratios (aHR) with 95% confidence interval (95% CI). Results: The cohort of Trieste city council was mainly composed of administrative clerks (48.5%), nursery teachers (33%), technicians (9.9%) and local police officers (8.5%). Between 1 March 2020 and 31 January 2023, 1444 (62.4%) employees tested positive for SARS-CoV-2 at least once and 18.1% (=262/1444) at least twice. By the end of this study, 55% (N = 1272) of employees had received at least three doses of COVID-19 vaccine, whereas 19.7% (N = 457) remained unvaccinated. At multiple Cox regression analysis, the adjusted risk of primary COVID-19 events during the entire study period increased in employees aged 40–49 years (aHR = 1.65; 95% CI: 1.01; 2.71), females (aHR = 1.28; 95%CI: 1.12; 1.45), local police officers (aHR = 1.82; 95%CI: 1.50; 2.22) and nursery teachers (aHR = 1.27; 95%CI: 1.13; 1.43). However, whilst the risk of primary infections in police officers increased already during the Alpha transmission period (aHR = 6.82; 95%CI: 4.48; 10.40), progressively reducing across subsequent variants, for nursery teachers, it increased during the Delta wave (aHR = 2.42; 1.70; 3.44), reducing with Omicron (aHR = 1.23; 95%CI: 1.07; 1.40). Compared to unvaccinated colleagues, during the entire study period the risk of primary infections was significantly lower in employees immunized with three (aHR = 0.42; 95%CI: 0.36; 0.47) or four (aHR = 0.30; 95%CI: 0.23; 0.40) doses of COVID-19 vaccine, for a vaccine effectiveness (VE) of 58% and 70%, respectively. The protective effect of vaccination against primary infections was confirmed in the sub-group analysis by main pandemic waves, for a VE of 75% for one dose against 99% for two doses during the Alpha transmission period, slightly reducing to 59% and 70% in Delta time, respectively. During the Omicron wave, the risk of primary SARS-CoV-2 infections diminished significantly with three (aHR = 0.42; 95%CI: 0.36; 0.49) or four vaccine doses (aHR = 0.09; 95%CI: 0.05; 0.16), for a VE of 58% and 91%, respectively. Moreover, the risk of primary SARS-CoV-2 reinfections during the entire study period reduced with one (aHR = 0.47; 95%CI: 0.27; 0.82), two (aHR = 0.42; 95%CI: 0.30; 0.58), three (aHR = 0.32; 95%CI: 0.24; 0.44) or four vaccine doses (aHR = 0.14; 95%CI: 0.05; 0.46), for a VE of 53%, 58%, 68% and 86% against reinfections, respectively. No significant difference in VE was associated with heterologous versus homologous triple vaccination, both against primary infections or reinfections. Conclusions. Primary SARS-CoV-2 infections were more likely among nursery teachers and local police officers. The risk of both primary infections and reinfections reduced with higher number of doses of COVID-19 vaccine, regardless of the pandemic wave. Since city council civil servants were swab tested on demand or for contact tracing, the estimation of COVID-19 risk and VE largely missed aymptomatic SARS-CoV-2 infections. On the one hand, the present study confirmed the protective effect of COVID-19 vaccination against symptomatic SARS-CoV-2 infections; on the other hand, it highlighted not only the importance of continuous booster doses to keep up the humoral immunity over time but also the importance of updated vaccine formulations to prevent and control the spread of a highly mutable virus. Moreover, the protective effect of the first two doses against reinfections confirmed the efficacy of hybrid immunity during Omicron time

Growth and development of common pine on lands,taken out from agricultural use,depending on methods and ways of creation

Here there are results of studies of common pine plantations created in 2004 by the line-hole seeding, with the help of manual and automated planting of two-year seedlings into the furrow bottom after plowingby the plow ПКЛ-70 on the plot, taken out from agricultural use. It is found out that creation of forest plantation of the common pine by sowing seeds on former agricultural lands is not reliable, because a large number of plants die in the first years of life, and the remaining plants occupy the area unevenly, arranged in rows of clumps. Pine plantations created with the help of manual and automated planting grow successfully and at the age of 7 have no significant differences in taxation indices

Classification of soils of Negoreloye forestry station

Classification of soils is to be done by codes, which indicate the productivity (bonitet), the reference (prospective) tree species, soil evaluation in points and the index shows class of forests (1st – forest of insufficient moisture, 2nd – of excessive moisture). In a forest station there have identified 16 types of soils by codes: from IIIP561to IIIAl142. Soil IP771(60,7 %) is prevailing. Soils IIP681 and IаP891 occupy a much smaller area (13%). In the second class of forests, which account for 12% of the most frequently occurring soils IP772(6.4%) and IIP682(2.7%). The average score of forest stands is 45 and that of soils is 75 points. With an average stand density of 0.72 the stands evaluation is below the maximum by 55 points (100 – 45), due to the group of forests it is lower by 2 (100 – 98), due to site conditions by 23 (98 – 75), due to stand density by 21 (75 – 54) and due to species composition by 9 points. Forest productivity may be increased by 30 points by controlling the species composition and stand density

A user- friendly tool to compute infection probability of SARS-COV-2 indoor: the user guide and its application in medical practice

After some initial hesitancy at the beginning of the COVID-19 pandemic, the academic community agreed that the infection process is mostly airborne and generally associated with closed environments. Therefore, assessing the indoor infection probability is mandatory to contain the spread of the disease, especially in those environments, like school classrooms, hospital wards or public transportation, with higher risk of overcrowding. For this reason, we developed a software tool in Python to compute infection probability and determine those mechanisms that contribute to reduce its diffusion in closed settings. In this paper, we will briefly illustrate the model we used and focus our attention on the description of the main features of the software and give some examples of how it can be used in clinical practice to predict the spread of the disease in the rooms of a generic ward, optimize room occupancy or drive healthcare workers activity schedule. Finally, some limitations and further implementations of our work will be reported

COVID-19 Incidence and Vaccine Effectiveness in University Staff, 1 March 2020–2 April 2022

Background: University workers undergo intense social interactions due to the frequent contact with students and colleagues and lectures in crowdy conditions. The aim of our study was to assess the incidence of COVID-19 infection and vaccine effectiveness in a cohort of workers of the University of Trieste from 1 March 2020 (start of the pandemic) through 2 April 2022. Methods: The University of Trieste implemented a number of public health policies to contain the spread of SARS-CoV-2 on the campus, including prompt contact tracing, the enhanced ventilation of all premises, fomites disinfection and the mandatory use of face masks indoors. In compliance with the surveillance protocol of the local public health department, university personnel were tested for SARS-CoV-2 by polymerase chain reaction (PCR) on a nasopharyngeal swab on demand, in the event of symptoms consistent with COVID-19 or for contact tracing, following close contact with a confirmed COVID-19 case. The incidence rates of SARS-CoV-2 infections were estimated as the number of cases by the number of person-days (p-d) at risk. The multivariable Cox proportional hazard regression model was employed to investigate the risk of primary COVID-19 infection, adjusting for a number of potential confounders and expressing the risk as the adjusted hazard ratio (aHR) with a 95% confidence interval (95% CI). Results: The incidence of SARS-CoV-2 infection among the university staff was lower than that of healthcare workers (HCWs) of the same area. Compared to unvaccinated colleagues (6.55 × 10,000 p-d), the raw incidence of SARS-CoV-2 infection was higher among university workers immunized with one (7.22 × 10,000 p-d) or two (7.48 × 10,000 p-d) doses of the COVID-19 vaccine, decreasing in those receiving the booster (1.98 × 1000 p-d). The risk of infection increased only in postgraduate medical trainees (aHR = 2.16; 95% CI: 1.04; 4.48), though this was limited to the Omicron transmission period. After the implementation of the national vaccination campaign against COVID-19, workers immunized with the booster were less likely than unvaccinated workers to be infected by SARS-CoV-2 both before (aHR = 0.10; 95% CI: 0.06; 0.16) and after (aHR = 0.37; 95% CI: 0.27; 0.52) the Omicron transmission period. The vaccine effectiveness of the booster was 90% (=(1−0.10) × 100) before versus 63% (=(1−0.37) × 100) during the Omicron wave, without a significant difference between homologous (three doses of m-RNA vaccines) and heterologous (first two doses of Vaxzevria followed by a third dose of m-RNA vaccine) immunization. Conclusions: The incidence of SARS-CoV-2 infection in the university staff was lower than that of HCWs of ASUGI, likely because the testing-on-demand schedule inevitably missed asymptomatic infections. Therefore, the observed significantly protective effect of the booster dose in university personnel referred to symptomatic SARS-CoV-2 infections. The infection prevention and control policies implemented by the University of Trieste managed to equalize the biological risk between the administrative and teaching staff