47 research outputs found
Alianzas estratégicas: Una estrategia viable en las pymes
Fil: Desilvestri, MarĂa Alejandra. Universidad de Buenos Aires. Facultad de Ciencias EconĂłmicas. Buenos Aires, Argentina
LASER PHYSICS LETTERS
Abstract: Raman spectroscopy offers a powerful alternative analytical method for the detection and identification of lipids/oil in biological samples, such as algae and fish. Recent research in the authors' groups, and experimental data only very recently published by us and a few other groups suggest that Raman spectroscopy can be exploited in instances where fast and accurate determination of the iodine value (associated with the degree of lipid unsaturation) is required. Here the current status of Raman spectroscopy applications on algae is reviewed, and particular attention is given to the efforts of identifying and selecting oil-rich algal strains for the potential mass production of commercial biofuels and for utilization in the food industry. Normalized intensity, a.u
PACS: 32.30.-r, 32.60.+i, 32.70
Abstract: We have measured light shifts, also known as AC Stark shifts, as a function of laser intensity in cold Rubidium atoms by observing sub-natural linewidth gain and loss features in the transmission spectrum of a weak probe beam passing through the atomic sample. The observed energy-level shifts for atoms in a magneto-optical trap (MOT) are found to be consistently higher than that obtained in optical molasses (i.e., when the magnetic field gradient in the MOT is turned off). Using a simple model of a multilevel Rubidium atom interacting with pump and probe beams, we have calculated the theoretical light shift as a function of intensity. A comparison of these calculated values with the light shift data obtained for molasses reveals good agreement between experiment and theory. Further, our model elucidates the role of the Zeeman shifts arising from the magnetic field gradient in the observed probe transmission spectrum for the MOT. A qualitative plot of the transmission spectrum of a probe beam through a fictitious sample of cold J = 1 → J = 2 atoms showing probe absorption at the sum of the pump frequency ω pump and δ , where δ is the difference of the light shifts between the |J = 1,mJ = 0 and the |J = 1,mJ = ± 1 ground state Zeeman sublevels. Probe gain is depicted at ω pump -δ . Se
A Longitudinal RCT on the Effectiveness of a Psychological Intervention for Hospital Healthcare Workers During the COVID-19 Pandemic: What We Learned to Date
The COVID-19 pandemic has led to significant psychological distress among frontline healthcare workers (HCWs), with a particular increase in trauma-related symptoms. This study investigated the longitudinal course of trauma-associated symptoms and behaviors in HCWs and the effectiveness of a brief dialectical behavior therapy (DBT)-informed intervention in mitigating these symptoms over 12 months. The trial included 225 HCWs randomly assigned to one of three groups: no intervention (control), in-person DBT-informed intervention, or online DBT-informed intervention. Over time, a natural decrease in PTSD symptoms was observed in all groups. Contrary to expectations, no difference was found between the control and intervention groups. However, for participants with severe PTSD symptoms, the intervention significantly mitigated their distress. No differences emerged between in-person and online interventions, suggesting equal effectiveness. Females reported higher trauma-related symptoms, while no differences emerged among different professional roles. These findings underscore the importance of targeted interventions for HCWs experiencing severe symptoms and highlight the potential of online modalities. Further research is needed to optimize the deployment of mental health resources within the healthcare setting, particularly during crise