278 research outputs found
The Short-term Car Flow Planning Model in Rail Freight Company – Case Study
AbstractWith the promotion of the environmentally friendly transportation modes (the European Commission supports the freight transport operations in the rail sector), an increase in the diversification of the demand is observed. While most rail freight companies tend to apply fixed schedules, this approach is not effective turns out to be ineffective due to the need to meet the customer's specific requirements.The purpose of this paper is to present a case study of empty wagon flow planning over a medium term horizon and to discuss the opportunities of improvement of this plans by discrete optimization. In order to increase the utilization and availability of wagons, the planning procedure with a rolling horizon has to be implemented. Unfortunately, since the plan has to be updated ca. every 4hours, this planning approach needs effective optimization tools. Our hybrid two-stage approach is designed to be implemented in such business environment. This formulation allows us to solve real life instances even for a 7-day time horizon
On the absence of bound-state stabilization through short ultra-intense fields
We address the question of whether atomic bound states begin to stabilize in
the short ultra-intense field limit. We provide a general theory of ionization
probability and investigate its gauge invariance. For a wide range of
potentials we find an upper and lower bound by non-perturbative methods, which
clearly exclude the possibility that the ultra intense field might have a
stabilizing effect on the atom. For short pulses we find almost complete
ionization as the field strength increases.Comment: 34 pages Late
On the Influence of Pulse Shapes on Ionization Probability
We investigate analytical expressions for the upper and lower bounds for the
ionization probability through ultra-intense shortly pulsed laser radiation. We
take several different pulse shapes into account, including in particular those
with a smooth adiabatic turn-on and turn-off. For all situations for which our
bounds are applicable we do not find any evidence for bound-state
stabilization.Comment: 21 pages LateX, 10 figure
Ionization Probabilities through ultra-intense Fields in the extreme Limit
We continue our investigation concerning the question of whether atomic bound
states begin to stabilize in the ultra-intense field limit. The pulses
considered are essentially arbitrary, but we distinguish between three
situations. First the total classical momentum transfer is non-vanishing,
second not both the total classical momentum transfer and the total classical
displacement are vanishing together with the requirement that the potential has
a finite number of bound states and third both the total classical momentum
transfer and the total classical displacement are vanishing. For the first two
cases we rigorously prove, that the ionization probability tends to one when
the amplitude of the pulse tends to infinity and the pulse shape remains fixed.
In the third case the limit is strictly smaller than one. This case is also
related to the high frequency limit considered by Gavrila et al.Comment: 16 pages LateX, 2 figure
Effects of partially dismantling the CD4 binding site glycan fence of HIV-1 envelope glycoprotein trimers on neutralizing antibody induction
Previously, VLPs bearing JR-FL strain HIV-1 Envelope trimers elicited potent neutralizing antibodies (nAbs) in 2/8 rabbits PLoS Pathog 11(5): e1004932) by taking advantage of a naturally absent glycan at position 197 that borders the CD4 binding site (CD4bs). In new immunizations, we attempted to improve nAb responses by removing the N362 glycan that also lines the CD4bs. All 4 rabbits developed nAbs. One targeted the N197 glycan hole like our previous sera. Two sera depended on the N463 glycan, again suggesting CD4bs overlap. Heterologous boosts appeared to reduce nAb clashes with the N362 glycan. The fourth serum targeted a N362 glycan-sensitive epitope. VLP manufacture challenges prevented us from immunizing larger rabbit numbers to empower a robust statistical analysis. Nevertheless, trends suggest that targeted glycan removal may improve nAb induction by exposing new epitopes and that it may be possible to modify nAb speciUcity using rational heterologous boosts
SARS-CoV-2 Infection Among Nursing Home Healthcare Workers: A Longitudinal Study in North-Eastern Italy
Background: During the pandemic, a surveillance program to monitor COVID-19 infection among healthcare workers was established in Friuli Venezia Giulia Region (FVG), Italy. The aim of our study was to measure the risk of acquiring SARS-CoV-2 infection among nursing home employees by job title. Methods: From March 1, 2020, to March 31, 2023, a retrospective population-based longitudinal study was conducted in 8880 nursing home employees. For each employee, all swabs up to the first positive result (n = 211.534) were considered. The study period was divided in six phases based on epidemic waves. Generalized estimated equations method for longitudinal binary data was applied with a time lag of a month, in each phase, obtaining an odds ratio (OR) and 95% confidence limit (95% CI) for each job category. Results: In Phase 1 (1.3.2020–30.6.2020), compared with administrative assistants, jobs with high patient contact were at increased risk of infection: The OR and 95% CI were 3.52 (1.44–8.56) and 2.96 (1.15–7.66) in healthcare elementary occupation and physicians/nurses, respectively. Corresponding associations in Phase 2 (1.7.2020–31.1.2021) were 1.54 (1.18–2.02) and 1.41 (1.04–1.91). On the contrary, in Phase 6 (20.12.2021–31.3.2023) physicians/nurses were at a decreased risk (0.73 [0.58–0.91]). Conclusions: In nursing homes, the risk of COVID-19 infection varied by job title and pandemic phase. Virus higher infectivity, probability of closer contact, and better adherence to infection prevention control may explain part of these differences. Stronger nursing home–specific surveillance in patients and employees should be extended worldwide to control this high global burden of disease communities
Sustainability and nutritional composition of food offer and choices in three hospital canteens in Italy
Diet is considered one of the most important determinants of health and at the same time a cause of climate change. We conducted a cross-sectional study in three Italian hospital canteens on five consecutive working days to investigate food offer availability and user choices in terms of nutritional intake and environmental impact. Photos of lunch trays were collected by the researchers and food offer and choices were analysed using the Italian Food Composition Database for Epidemiological Studies and the SU-EATABLE LIFE dataset. A total of 1227 lunch meals were analysed. The median energy intake ranged from 646 to 900 kcal/tray. The median energy content from lipids ranged from 32 to 40 % of energy and exceeded that from carbohydrates in one canteen. The median carbon and water footprint ranged from 773 to 1338 g CO2 eq./tray and from 847 to 1229 L H2O/tray, respectively. Differences occurred depending on sex and typology of work. In conclusion, regardless of the differences in the number of food options offered in the three canteens, the choices tended to be suboptimal from a nutritional perspective. The most sustainable choices were made in the canteen without beef on offer. Measures should be taken to increase the variety of vegan and vegetarian options on offer and to improve food choices in terms of nutritional composition and environmental sustainability. This could be done through educational programmes focused on increasing awareness on their diet, and practical indications on how to compose a complete and low impact meal
Exploring the role of respiratory microbiome in lung cancer: A systematic review
Giving the potential contribute in cancer initiation and progression, lung microbiota represents a promising topic in cancer research, although still unexplored. We performed a systematic literature search to identify clinical studies evaluating lung microbiota composition, its correlation with lung cancer patients’ clinico-pathological features and prognosis. Of the identified 370 studies, 21 were eligible and included. Although studies were heterogeneous, lung cancer resulted to be enriched in peculiar microbial communities, with differences in composition and diversity according to clinico-pathological parameters. Few studies explored how lung microbiota influences cancer outcome. In light of these findings and borrowing the suggestions coming from gut microbiota, we speculate that respiratory microbiome may influence pathogenesis, progression and outcome of lung cancer. Taking advantage of the experience of chronical lung diseases, prospective studies should be designed to evaluate lung microbiota changes throughout any phase of lung cancer course, particularly with the advent of immunotherapy as pivotal treatment
Does human milk modulate body composition in late preterm infants at term-corrected age?
(1) Background: Late preterm infants account for the majority of preterm births and are at risk of altered body composition. Because body composition modulates later health outcomes and human milk is recommended as the normal method for infant feeding, we sought to investigate whether human milk feeding in early life can modulate body composition development in late preterm infants; (2) Methods: Neonatal, anthropometric and feeding data of 284 late preterm infants were collected. Body composition was evaluated at term-corrected age by air displacement plethysmography. The effect of human milk feeding on fat-free mass and fat mass content was evaluated using multiple linear regression analysis; (3) Results: Human milk was fed to 68% of the infants. According to multiple regression analysis, being fed any human milk at discharge and at term-corrected and being fed exclusively human milk at term-corrected age were positively associated with fat-free mass content \u3b2 = - 47.9, 95% confidence interval (CI) = -95.7; p = 0.18; p = -0.049; = \u3b2=-89.6, 95% CI = -131.5; -47.7; p < 0.0001; - = -104.1, 95% CI = -151.4; -56.7, p < 0.0001); (4) Conclusion: Human milk feeding appears to be associated with fat-free mass deposition in late preterm infants. Healthcare professionals should direct efforts toward promoting and supporting breastfeeding in these vulnerable infants
Calcium-Mediated Actin Reset (Caar) Mediates Acute Cell Adaptations
Actin has well established functions in cellular morphogenesis. However, it is not well understood how the various actin assemblies in a cell are kept in a dynamic equilibrium, in particular when cells have to respond to acute signals. Here, we characterize a rapid and transient actin reset in response to increased intracellular calcium levels. Within seconds of calcium influx, the formin INF2 stimulates filament polymerization at the endoplasmic reticulum (ER), while cortical actin is disassembled. The reaction is then reversed within a few minutes. This Calcium-mediated actin reset (CaAR) occurs in a wide range of mammalian cell types and in response to many physiological cues. CaAR leads to transient immobilization of organelles, drives reorganization of actin during cell cortex repair, cell spreading and wound healing, and induces long-lasting changes in gene expression. Our findings suggest that CaAR acts as fundamental facilitator of cellular adaptations in response to acute signals and stress
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