Greenhouse gas emissions of waste management processes and options : a case study

Increasing concern about climate change is prompting organisations to mitigate their greenhouse gas emissions. Waste management activities also contribute to greenhouse gas emissions. In the waste management sector, there has been an increasing diversion of waste sent to landfill, with much emphasis on recycling and reuse to prevent emissions. This study evaluates the carbon footprint of the different processes involved in waste management systems, considering the entire waste management stream. Waste management data from the Royal Borough of Kingston upon Thames, London (UK), was used to estimate the carbon footprint for its (Royal Borough of Kingston upon Thames) current source segregation system. Second, modelled full and partial co-mingling scenarios were used to estimate carbon emissions from these proposed waste management approaches. The greenhouse gas emissions from the entire waste management system at Royal Borough of Kingston upon Thames were 12,347 t CO2e for the source-segregated scenario, and 11,907 t CO2e for the partial co-mingled model. These emissions amount to 203.26 kg CO2e t(-1) and 196.02 kg CO2e t(-1) municipal solid waste for source-segregated and partial co-mingled, respectively. The change from a source segregation fleet to a partial co-mingling fleet reduced the emissions, at least partly owing to a change in the number and type of vehicles

Theory of Graphene-Insulator-Graphene Tunnel Junctions

Graphene-insulator-graphene vertical tunneling structures are discussed from a theoretical perspective. Momentum conservation in such devices leads to highly nonlinear current-voltage characteristics, which with gates on the tunnel junction form potentially useful transistor structures. Two prior theoretical treatments of such devices are discussed; the treatments are shown to be formally equivalent, although some differences in their implementations are identified. The limit of zero momentum conservation in the theory is explicitly considered, with a formula involving the density-of-states of the graphene electrodes recovered in this limit. Various predictions of the theory are compared to experiment.Comment: 17 pages; 5 figures; accepted for publication in J. Vac. Sci. Technol B; v2 corrects several typographical errors and expands the caption of fig

Rhabdomyolysis and acute kidney injury in patients with traumatic spinal cord injury

[Abstract] Background: Patients with acute traumatic spinal cord injuries (SCIs) exhibit factors that, in other populations, have been associated with rhabdomyolysis. Purpose: The aim of the study is to determine the incidence of rhabdomyolysis in patients with acute traumatic SCI admitted to the Intensive Care Unit (ICU), as well as the development of secondary acute kidney injury and associated factors. Study design and setting: This was an observational, retrospective study. Patient sample: All adult patients admitted to the ICU with acute traumatic SCI who presented rhabdomyolysis, diagnosed through creatine phosphokinase (CPK) levels >500 IU/L. Outcome measures: Incidence of rhabdomyolysis and subsequent renal dysfunction was calculated. Materials and methods: Data about demographic variables, comorbidity, rhabdomyolysis risk factors, and variables involving SCI, severity scores, and laboratory parameters were obtained from clinical records. Multivariate logistic regression was used to identify renal injury risk factors. Results: In 2006-2014, 200 patients with acute SCI were admitted to ICU. Of these, 103 had rhabdomyolysis (incidence = 51.5%; 95% confidence interval [CI]: 44.3%-58.7%). The most typical American Spinal Injury Association classification was A (70.3%). The injury severity score was 30.3 ± 12.1 and sequential organ failure assessment (SOFA) score was 5.6 ± 3.3 points. During their stay, 57 patients (55.3%; 95% CI: 45.2%-65.4%) presented renal dysfunction (creatinine ≥1.2 mg/dL). In the multivariate analysis, variables associated with renal dysfunction were creatinine at admission (odds ratio [OR] = 9.20; P = 0.006) and hemodynamic SOFA score the day following admission (OR = 1.33; P = 0.024). Creatinine was a better predictor of renal dysfunction than the peak CPK value during the rhabdomyolysis (area under the receiver operating characteristic curve: 0.91 vs. 0.63, respectively). Conclusions: Rhabdomyolysis is a frequent condition in patients with acute traumatic SCI admitted to the ICU, and renal dysfunction occurs in half of the cases. Creatinine values should be requested starting at the admission while neither the peak CPK values nor the hemodynamic SOFA scores could be used to properly discriminate between patients with and without renal dysfunction

Risks factors of mechanical ventilation in acute traumatic cervical spinal cord injured patients

[Abstract] Study design. Descriptive retrospective study. Objectives. To analyze risk factors associated with mechanical ventilation (MV) in cases of acute traumatic Cervical Spinal Cord Injury (tCSCI). Setting. Unidad de Lesionados Medulares, Complejo Hospitalario Universitario A Coruña, in Galicia (Spain). Methods. The study included patients with tCSCI who were hospitalized between January 2010 and December 2014. The following variables were analyzed: age, gender, etiology, neurological level, ASIA (American Spinal Injury Association) grade, associated injuries, injury severity score (ISS), ASIA motor score (AMS) at admission and mortality. Results. A total of 146 patients met the study’s inclusion criteria. The majority were men (74.7%) with mean age of 62.6 (s.d. ± 18.8) years. Sixty patients (41.1%) required MV. Mean age of ventilated vs. non-ventilated patients was 57.3 vs. 65.7. Men were more likely to require MV than women, ASIA grades A and B were also more likely to need MV than grades C and D, as well as patients with associated injuries. The AMS of patients receiving MV was lower than that of those who did not require MV (20.1 vs. 54.3). Moreover, the ISS was higher in patients receiving MV (31.2 vs. 13.4). An AMS ≤ 37 and an ISS ≥ 13 increased the risk of requiring MV by a factor of 11.98 and 7.28, respectively. Conclusions. Isolated factors associated with a greater risk of MV in tCSCI were: age, gender, ASIA grade, ISS and AMS. However, the only factor with a significant discriminatory ability to determine the need for MV was the AMS at admission

Displacement of the Scholar? Participatory Action Research under COVID-19

The impact of COVID-19 on conducting research is far-reaching, especially for those scholars working for or alongside communities. As the pandemic continues to create and exacerbate many of the issues that communities at the margins faced pre-pandemic, such as health disparities and access to resources, it also creates particular difficulties in collaborative, co-developed participatory research and scholar-activism. These forms of community engagement require the commitment of researchers to look beyond the purview of the racialized capitalist and neoliberal structures and institutions that tend to limit the scope of our research and engagement. Both the presence of the researcher within the community as well as deep community trust in the researcher is required in order to identify and prioritize local, often counter-hegemonic forms of knowledge production, resources, and support networks. The pandemic and similar conditions of crises has likely limited opportunities for building long-term, productive relationships of mutual trust and reciprocity needed for PAR while communities refocus on meeting basic needs. The pandemic has now not only exacerbated existing disparities and made the need for engaged, critical and co-creative partnerships even greater, it has also abruptly halted opportunities for partnerships to occur, and further constrained funds to support communities partnering with researchers. In this paper we highlight accomplishments and discuss the many challenges that arise as participatory action researchers are displaced from the field and classroom, such as funding obstacles and working remotely. An analysis of experiences of the displacement of the scholar exposes the conflicts of conducting PAR during crises within a state of academic capitalism. These experiences are drawn from our work conducting PAR during COVID-19 around the globe, both in urban and rural settings, and during different stages of engagement. From these findings the case is made for mutual learning from peer-experiences and institutional support for PAR. As future crises are expected, increased digital resources and infrastructure, academic flexibility and greater consideration of PAR, increased funding for PAR, and dedicated institutional support programs for PAR are needed

Use of a 3D virtual app and academic performance in the study of the anatomy of the musculoskeletal system among Peruvian medical students

Objective: To evaluate the association between the use of a 3D virtual App and academic performance among Peruvian medical students. In addition, factors associated with academic performance were also assessed. Methods: We conducted an analytical cross-sectional study in students enrolled in the Musculoskeletal System course during the first semester of 2019. Students filled out a data collection form and the "Self-directed learning readiness scale" (SDLRS) questionnaire adapted by Fisher, King, and Tangle. Linear regression models were carried out to assess the association between the appropriate use of the application and academic performance. Additionally, the factors associated with academic performance were evaluated using nested models, and beta coefficients were calculated by manual forward selection. Results: A total of 187 medical students were included. The 61% were female and the median age was 21 [20-22] years. The average grade was 13.5 +/- 2 and 21% reported an adequate use of a 3D App. No association was found between the use of the 3D App and academic performance in the adjusted model (a beta = 0.17; 95% CI: -0.45 to 0.80). We found that age (a beta = -0.22; 95% CI: -0.39 to -0.06), performing extracurricular activities (a beta = 0.75, 95% CI: 0.25 to 1.24) and having failed an anatomy/physiology course before (a beta = -2.11 to 95% CI: -2.9 to -1.8) were factors associated with academic performance. Conclusion: The adequate use of a 3D application to study the anatomy of the musculoskeletal system was not significantly associated with better academic performance.Revisión por pare

Atenuación del haz de radiación al interaccionar con la mesa de tratamiento de un acelerador lineal varian IX con el gantry posicionado a 180°

En el Hospital de Oncología de CMN Siglo XXI, asis-ten aproximadamente 370 pacientes por día, de los cuales aproximadamente un 70% incluyen un campo de tratamiento con el gantry posicionado a 180°. Con el gantry en esta posición, la mesa de tratamiento se interpone en el trayecto entre el haz de radiación y el paciente, por lo cual es necesario conocer un valor cuantitativo de la atenuación que la mesa produce. Por lo que en este trabajo, se determinó el porcentaje de atenuación del haz de radiación al interaccionar con la mesa de tratamient

Desarrollo de la Red Aerobiológica de Castilla y León (RACYL)

XV lnternational A.P.L.E. Symposium of Palynolog

Clinical isolates of Mycobacterium tuberculosis differ in their ability to induce respiratory burst and apoptosis in neutrophils as a possible mechanism of immune escape

Tuberculosis pathogenesis was earlier thought to be mainly related to the host but now it appears to be clear that bacterial factors are also involved. Genetic variability of Mycobacterium tuberculosis (Mtb) could be slight but it may lead to sharp phenotypic differences. We have previously reported that nonopsonized Mtb H37Rv induce apoptosis of polymorphonuclear neutrophils (PMNs) by a mechanism that involves the p38 pathway. Here we evaluated the capability to induce PMN apoptosis of two prevalent Mtb lineages in Argentina, the Latin America and Mediterranean (LAM), and Haarlem, using the H37Rv as a reference strain. Results showed that LAM strains strongly induced apoptosis of PMN which correlated with the induction of reactive oxygen species (ROS) production and p38 activation. Interestingly, the highly prosperous multidrug-resistant M strain, belonging to the Haarlem lineage, lacked the ability to activate and to induce PMN apoptosis as a consequence of (1) a weak ROS production and (2) the contribution of antiapoptotic mechanisms mediated at least by ERK. Although with less skill, M is able to enter the PMN so that phenotypic differences could lead PMN to be a reservoir allowing some pathogens to prevail and persist over other strains in the community

Relaciones entre problemáticas educativas y prácticas profesionales desde experiencias de cátedra

La ponencia presenta algunas reflexiones surgidas alrededor del abordaje de problemáticas educativas y prácticas profesionales en la formación de grado de la carrera de Ciencias de la Educación a partir de la experiencia particular de dos cátedras - Problemática Educativa Contemporánea y Orientación Educativa y Práctica Profesional de la Facultad de Humanidades y Ciencias de la Educación de la Universidad Nacional de La Plata. Ambas asignaturas comparten el mismo estatuto epistemológico y metodológico en el Plan de Estudios de Ciencias de la Educación en tanto seminarios-talleres de articulación. En este sentido, dichas cátedras tienen en común la preocupación por ofrecer una mirada integradora de la realidad educativa tanto como de los trayectos formativos de los/las estudiantes en dos instancias distintas de la carrera: promediando el ciclo básico una; finalizando el mismo y como orientación del ciclo superior de licenciatura, la otra. Como parte del trabajo de articulación, las cátedras han desarrollado dispositivos didácticos específicos.. El objetivo de este ensayo pues, es poner en diálogo dos espacios de formación en los cuales se recuperan realidades educativas y prácticas profesionales en contexto, constituyendo la escritura del presente trabajo un ejercicio más en el interior de dicha vinculación intercátedra.Facultad de Humanidades y Ciencias de la Educació