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Universidad de la Sabana: la inundación del campus Gestión de una catástrofe natural
No full textEntre 2010 y 2011, el fenómeno meteorológico de La Niña había incrementado un 170% las
lluvias en Colombia. La cuenca del río Bogotá, que cubre 46 municipios de la región de Cundinamarca, en el centro del país, no se salvó de esas inclemencias atmosféricas. A finales de abril de
2011, el río se desbordó en varios sectores, en especial en su parte media y alta. Más de 30.000
habitantes de Chía, Cajicá, Villapinzón, Cota, Funza, Suesca, Mosquera y Soacha, se vieron afectados por las inundaciones.
Las autoridades académicas de La Sabana eran conscientes del riesgo de inundación que suponía
su emplazamiento, en la ribera del río Bogotá. Sin embargo, se sentían protegidos por los llamados “jarrillones”, los diques de tierra que se habían construido hacía muchos años, antes incluso
de que la universidad existiera. De hecho, las inundaciones provocadas en el pasado por otras
“Niñas” en la misma comarca, nunca habían afectado al campus.
Ante la subida del nivel del agua en el río, las autoridades de Cundinamarca tomaron algunas
precauciones, y seguían de cerca la situación. Además, como medida preventiva, se habían reforzado los jarillones cercanos a la universidad.
El 25 de abril, lunes de Pascua, estudiantes y profesores de la Universidad de La Sabana volvían
de vacaciones de Semana Santa. La comunidad universitaria no estaba preocupada por el río,
pero sí por las lluvias, pues iban a provocar el colapso del tráfico, e impedir a profesores, alumnos y personal acudir a la universidad. Por eso, la universidad decidió suspender las clases durante dos días. Así lo explicó el rector de La Sabana, Obdulio Velásquez Posada, esa misma mañana a los micrófonos de City TV:
“Iniciábamos a clases hacia las 7 a.m., muy poca gente podía entrar al campus porque
estaba muy complicado el tráfico, en especial a razón de lluvia. Entonces a las 8 a.m.
cuando terminé clases, cité al comité de emergencias. En ese momento, yo ya tenía un
comunicado redactado con puño y letra sobre el cierre de la universidad, por efectos
de la dificultad del tráfico, no por amenaza de la inundación; de hecho, en ese comité
de emergencia, se discutió la situación, el riesgo, la inundación de los vecinos y lo prudente era cerrar dos días la universidad”.
A las 9:45, mientras estaba teniendo lugar esa entrevista, el rector y el periodista se enteraron
de que uno de los diques se acababa de reventar y no había manera de contener la riada. La
inundación era inevitable, aunque todavía no eran conscientes de la gravedad.
Luz Marina, una empleada de la universidad que se encontraba en uno de los edificios, lo contó
en directo en el canal de televisión RCN: “Los jefes nos avisaron que venía como una avalancha
y que intentáramos subir a la segunda planta”.
En ese momento, se encontraban en la universidad unas trescientas personas, entre trabajadores, estudiantes y docentes. Con toda la buena voluntad intentaron salvar lo que pudieron. Pero
en cuestión de minutos, el agua les llegaba a la cintura.
En solo tres horas, dos metros de agua llenaban todos los edificios, unos 9.000 libros flotaban
en la biblioteca, y las computadoras, cámaras y demás equipos recién comprados para dotar los
estudios multimedia de facultad de comunicación –algunos aún embalados– corrían serio peligro de arruinarse antes incluso de haber sido usados.
Al mediodía, el campus solo se podía recorrer en lancha.
Días después, la universidad pudo traducir la catástrofe en cifras. El informe que se envió a la
aseguradora hablaba de 22.000 objetos afectados, entre ellos 56.914 volúmenes de revistas,
37.017 metros cuadrados de pintura, 7.301 sillas, 536 puertas, 126 tableros, 348 teléfonos, entre otros. Según la universidad, 222.120 objetos
Comparison of myocardial blood flow quantification models for double ECG gating arterial spin labeling MRI: reproducibility assessment
No full textBackground: Arterial spin labeling (ASL) allows non-invasive quantification of myocardial blood flow (MBF). Double-ECG
gating (DG) ASL is more robust to heart rate variability than single-ECG gating (SG), but its reproducibility requires further
investigation. Moreover, the existence of multiple quantification models hinders its application. Frequency-offset-corrected-inversion (FOCI) pulses provide sharper edge profiles than hyperbolic-secant (HS), which could benefit
myocardial ASL.
Purpose: To assess the performance of MBF quantification models for DG compared to SG ASL, to evaluate their reproducibility and to compare the effects of HS and FOCI pulses.
Study Type: Prospective.
Subjects: Sixteen subjects (27 8 years).
Field Strength/Sequence: 1.5 T/DG and SG flow-sensitive alternating inversion recovery ASL.
Assessment: Three models for DG MBF quantification were compared using Monte Carlo simulations and in vivo
experiments. Two models used a fitting approach (one using only a single label and control image pair per fit, the
other using all available image pairs), while the third model used a T1 correction approach. Slice profile simulations were conducted for HS and FOCI pulses with varying B0 and B1. Temporal signal-to-noise ratio (tSNR) was
computed for different acquisition/quantification strategies and inversion pulses. The number of images that minimized MBF error was investigated in the model with highest tSNR. Intra and intersession reproducibility were
assessed in 10 subjects.
Statistical Tests: Within-subject coefficient of variation, analysis of variance. P-value <0.05 was considered
significant.
Results: MBF was not different across acquisition/quantification strategies (P = 0.27) nor pulses (P = 0.9). DG MBF quantification models exhibited significantly higher tSNR and superior reproducibility, particularly for the fitting model using multiple images (tSNR was 3.46 2.18 in vivo and 3.32 1.16 in simulations, respectively; wsCV = 16%). Reducing the
number of ASL pairs to 13/15 did not increase MBF error (minimum = 0.22 mL/g/min).
Data Conclusion: Reproducibility of MBF was better for DG than SG acquisitions, especially when employing a fitting
model.
Level of Evidence: 2
Technical Efficacy: Stage
Effect of baking conditions on resistant starch: model systems and cake formulations
No full textFive ingredients rich in RS (resistant starch) were assessed in a model system simulating baking process (water
addition 30–50%, 180 ◦C/35 min) and in reformulated cakes (50% replacement of wheat flour). Moreover, two
enzymatic methods used for RS determination (official and rapid) were compared. The combined effect of
heating and water addition (50%) significantly decreased the RS content in all ingredients. Reformulated vegan
cakes presented significantly lower RS values than those theoretically expected, according to the RS value of raw
ingredients. The highest RS amount was observed for Hi Maize, which kept 84% and 72% of the initial RS content
in the model systems and cake, respectively. Only the cakes made with Hi Maize reached the criteria for the
health claim related to the reduction of post-prandial glycemic response (European Union regulation). Finally,
differences between the official and rapid methods were less significant in the cakes than in the model systems
An adjusted propagation model for ITS-G5 communications for improving the location of RSUs in real V2I deployments
No full textThe future of mobility is cooperative, connected, and autonomous leading to new technological challenges in the development of Cooperative Intelligent Transport Systems (C-ITS). Therefore, Vehicle to Everything (V2X) and, more specifically, Vehicle to Infrastructure (V2I) deployments are key to enabling these features around the highways as well as along the cities. The communication range of the RoadSide Units (RSUs) is one of the most important aspects when implementing Vehicle-to-Infrastructure (V2I) communications as it has a direct impact on efficiency and the economy of the installation. The aim is to maximise the communication range with the minimum number of RSUs and to optimise the deployments, thus having a realistic simulation tool is key. To be realistic, simulations rely on adequate propagation models, which ideally would adapt to the environment without a high computational need. Therefore, an appropriate characterisation of the different V2X environments as well as a simple and versatile propagation model is an important instrument for deciding the location of the RSUs. In this paper, we characterise different environments for ITS-G5 communications and provide an adjusted propagation model with an α parameter that depends on the environment. Thus, eradicating the need to model the environment and the obstacles in it. For that purpose, a methodology for the modeling and characterisation of the ITS-G5 propagation model is proposed,after that the methodology is applied and the results validated. The methodology is presented and the characterisation of the ITS-G5 environments is made. Later, tests were carried out in different environments to measure how the signal power decreases with the distance. After that, the propagation model for ITS-G5 communications, specifically V2I communications, is presented along with the methodology applied to obtain it. Then, an α value is assigned to each environment. Finally, the validation is made by comparing our adjusted propagation model with other propagation models and applying the adjusted propagation model to a new RSU installation
Prevalence of paid sex and associated factors among women and men attending HIV voluntary counseling and testing in Kinshasa, Democratic Republic of the Congo: a prospective cohort
No full textPaid sex is associated with HIV and other sexually transmitted infections, which are highly prevalent in Sub-Saharan Africa (SSA).
However, few data exist on this sexual practice among the general population in SSA, including the Democratic Republic of the Congo,
where data on paid sex mainly comes from sex workers. In the DRC, most HIV Voluntary Counseling and Testing (VCT) centers
do not discuss paid sex as a risk factor. Thus, we aimed to analyze the prevalence of paid sex, its associated factors and association
with HIV among women and men attending HIV VCT at a reference hospital in Kinshasa. From 2016 to 2018, the Observational
Kinshasa AIDS Initiative cohort analyzed the impact of HIV VCT on changes in HIV knowledge, attitudes, and sexual behaviors at
follow-up. Participants aged 15–69 years were HIV tested and interviewed at baseline and at 6- and 12-month follow-ups. At baseline,
participants were asked about their history of “ever” having had exchanged sex for money. At both follow-ups, the frequency of this
practice was referred to as “the previous 6 months.” Descriptive, bivariate, and multivariate logistic regression analyses were carried
out to evaluate the prevalence of paid sex, its associated factors, and the association between paid sex and HIV. Statistical analyses
were performed with Stata 15.1. Among 797 participants at baseline, 10% of those sexually experienced reported having ever had
paid sex (18% men and 4% women, p<0.001). At 6 and 12-month follow-ups, 5% and 2%, respectively. Paid sex was signifcantly
and independently associated with being male (aOR=2.7; 95% CI=1.4–5.2), working or studying (aOR=2.8; 95% CI=1.5–5.0),
daily newspaper reading (aOR=4.4; 95% CI=1.7–11.2); daily/weekly alcohol consumption (aOR=3.3; 95% CI=1.8–6.1), frst
sexual intercourse before age 15 years (aOR=2.3; 95% CI=1.1–5.0), multiple sexual partners (aOR=4.1; 95% CI=2.2–7.7), and
extragenital sexual practices (aOR=2.4; 95% CI=1.3–4.4). A high religiosity (daily/weekly church attendance and praying) was
inversely associated with paid sex (aOR=0.1; 95% CI=0.0–0.4). The high prevalence of paid sex among people attending HIV VCT
in Kinshasa, associated with other sexual and consumption risk behaviors, highlights the need to include paid sex among the risk
factors mentioned in HIV prevention counseling
Artificial trabecular meshwork structure combining melt electrowriting and solution electrospinning
No full textThe human trabecular meshwork (HTM) is responsible for regulating intraocular pressure (IOP) by means of gradient porosity. Changes in its physical properties, like increases in stiffness or alterations in the extracellular matrix (ECM), are associated with increases in the IOP, which is the primary cause of glaucoma. The complexity of its structure limits the engineered models to one-layered and simple approaches, which do not accurately replicate the biological and physiological cues related to glaucoma. Here, a combination of melt electrowriting (MEW) and solution electrospinning (SE) is explored as a biofabrication technique used to produce a gradient porous scaffold that mimics the multi-layered structure of the native HTM. Polycaprolactone (PCL) constructs with a height of 20-710 mu m and fiber diameters of 0.7-37.5 mu m were fabricated. After mechanical characterization, primary human trabecular meshwork cells (HTMCs) were seeded over the scaffolds within the subsequent 14-21 days. In order to validate the system's responsiveness, cells were treated with dexamethasone (Dex) and the rho inhibitor Netarsudil (Net). Scanning electron microscopy and immunochemistry staining were performed to evaluate the expected morphological changes caused by the drugs. Cells in the engineered membranes exhibited an HTMC-like morphology and a correct drug response. Although this work demonstrates the utility of combining MEW and SE in reconstructing complex morphological features like the HTM, new geometries and dimensions should be tested, and future works need to be directed towards perfusion studies
El Quijote y la perturbación del placer cómico: notas a la contribución cervantina para la formación de teorías contemporáneas sobre lo cómico y el humor
No full textA novel gluconeogenic route enables efficient use of erythritol in zoonotic Brucella
No full textBrucellosis is a worldwide extended zoonosis caused by pathogens of the genus Brucella. While most B. abortus, B. melitensis, and B. suis biovars grow slowly in complex media, they multiply intensely in livestock genitals and placenta indicating high metabolic capacities. Mutant analyses in vitro and in infection models emphasize that erythritol (abundant in placenta and genitals) is a preferred substrate of brucellae, and suggest hexoses, pentoses, and gluconeogenic substrates use in host cells. While Brucella sugar and erythritol catabolic pathways are known, growth on 3–4 carbon substrates persists in Fbp- and GlpX-deleted mutants, the canonical gluconeogenic fructose 1,6-bisphosphate (F1,6bP) bisphosphatases. Exploiting the prototrophic and fast-growing properties of B. suis biovar 5, we show that gluconeogenesis requires fructose-bisphosphate aldolase (Fba); the existence of a novel broad substrate bisphosphatase (Bbp) active on sedoheptulose 1,7-bisphosphate (S1,7bP), F1,6bP, and other phosphorylated substrates; that Brucella Fbp unexpectedly acts on S1,7bP and F1,6bP; and that, while active in B. abortus and B. melitensis, GlpX is disabled in B. suis biovar 5. Thus, two Fba-dependent reactions (dihydroxyacetone-phosphate + glyceraldehyde 3-phosphate ⇌ F1,6bP; and dihydroxyacetone-phosphate + erythrose 4-phosphate ⇌ S1,7bP) can, respectively, yield fructose 6-phosphate and sedoheptulose 7-phosphate for classical gluconeogenesis and the Pentose Phosphate Shunt (PPS), the latter reaction opening a new gluconeogenic route. Since erythritol generates the PPS-intermediate erythrose 4-phosphate, and the Fba/Fbp-Bbp route predicts sedoheptulose 7-phosphate generation from erythrose 4-phosphate, we re-examined the erythritol connections with PPS. Growth on erythritol required transaldolase or the Fba/Fbp-Bbp pathway, strongly suggesting that Fba/Fbp-Bbp works as a PPS entry for both erythritol and gluconeogenic substrates in Brucella. We propose that, by increasing erythritol channeling into PPS through these peculiar routes, brucellae proliferate in livestock genitals and placenta in the high numbers that cause abortion and infertility, and make brucellosis highly contagious. These findings could be the basis for developing attenuated brucellosis vaccines safer in pregnant animals
Evolution of video assisted thoracoscopic surgery for thoracic disc herniation: towards biportal thoracoscopic approach
No full text- Objective: This work aims to describe the evolution of
the video-assisted Thoracoscopic Surgery (VATS) approach
from a multiportal access to a biportal access for thoracic
herniated disc surgery. Thoracic disc herniation remains a
challenging pathology for spine surgeons. VATS of the
thoracic spine was described in the 90s and represented
an important technical leap by including minimally invasive options for thoracic pathology. Nowadays, VATS in
thoracic surgery tends to evolve towards an even less
invasive technique, from a multiportal approach to a
biportal one.
- Methods: We describe the adoption of this approach
for our spinal pathology in 3 patients. We use a two-port
VATS. The largest (approximately 5 cm) with an Alexis
retractor and a second port (1.5 cm) just for the camera.
- Results: The 3 patients started walking in less than
24 hours and none suffered any complications related to
the approach. All of them reported tolerable pain at the
surgical site. Changing our previous VATS system from 3 to
5 ports was relatively easy regarding the surgical
technique.
Conclusions: This access allows the surgeon to
manipulate the instrumentation confidently and the camera
does not fog up as often. Extracting a piece of rib is
unnecessary and theoretically, we only manipulate 1 or at
most 2 intercostal nerves, so the patient’s recovery is
favorable
The Transhumanist Point of View to the Evolutionary Indifference to Pain and Suffering
No full textThe text presents a transhumanist point of view on evolution. It focuses on the lack of clear and obvious evolutionary solutions to the issue of involuntary suffering. It poses difficult questions about the possibility of enhencement of human nature and respecting the laws of evolution. It reflects on the positive role of pain for the development of individual people and the entire human species. It considers the thesis that perhaps evolution “needs” pain for proper human development. It asks whether the transition to a higher than evolutionary stage of human development, as proposed by transhumanists, will not lead to the extinction of our species? After all, it relates all this mosaic of thoughts and theories to God, who can be the answer to many posed questions