Respiration predicted from an Enzyme Kinetic Model and the Metabolic Theory of Ecology in two species of marine bacteria

12 pages, 8 figures, 5 tablesRespiratory oxygen consumption is the result of a cell's biochemistry. It is caused by enzymatic activity of the respiratory electron transfer system (ETS). However, in spite of this understanding, respiration models continue to be based on allometric equations relating respiration to body size, body surface, or biomass. The Metabolic Theory of Ecology (MTE) is a current example. It is based on Kleiber's law relating respiration (R) and biomass (M) in the form, View the MathML source, where C is a constant, Ea is the Arrhenius activation energy, k is the Boltzmann constant for an atom or molecule, and T is the temperature in Kelvin. This law holds because biomass packages the ETS. In contrast, we bypass biomass and model respiration directly from its causal relationship with the ETS activity, R = f (ETS). We use a biochemical Enzyme Kinetic Model (EKM) of respiratory oxygen consumption based on the substrate control of the ETS. It postulates that the upper limit of R is set by the maximum velocity, Vmax, of complex I of the ETS and the temperature, and that the substrate availability, S, modulates R between zero and this upper limit. Kinetics of this thermal-substrate regulation is described by the Arrhenius and Michaelis–Menten equations. The EKM equation takes the form View the MathML source where Rg is the molar gas constant and K is the Michaelis–Menten constant. Here, we apply the EKM and the MTE to predict a respiration time-profile throughout the exponential, steady state, and nutrient-limited phases of the marine bacteria Pseudomonas nautica and Vibrio natriegens in acetate-based cultures. Both models were tested by comparing their output with the measured RO2 time-profile. The MTE predicted respiration accurately only in the exponential growth phase, but not during the nutrient limitation part of the stationary phase. In contrast, the EKM worked well throughout both physiological phases as long as the modeled substrates fall with the declining carbon source. Results support the theoretical bases of the EKM. We conclude that the EKM holds promise for predicting respiration at the different physiological states and time-scales important to microbiological studiesFinancial support was provided by the Universidad de Las Palmas de Gran Canaria (ULPGC), the Spanish Ministry of Education and Science, the Graduate Program in Oceanography at the ULPGC, ICM-CSIC, and the research grants MODIVUS (CTM2005-04795/MAR), EXOME (CTM 2008-01616), and OITHONA (CTM2007-60052). T. Packard was supported by contract EXMAR SE-539 10/17 (Proyecto Estructurante en Ciencias Marinas). This is contribution #200906 from the Bigelow Laboratory for Ocean SciencesPeer reviewe

Makerspaces as educational spaces for innovation and entrepreneurship development

La presente investigación analiza por medio de un estudio cualitativo la manera en la que los makerspaces promueven la innovación abierta y el desarrollo de emprendimientos. Estos espacios educativos han surgido para desarrollar proyectos mediados por la tecnología y se han convertido en centros de formación en los que se promueven las redes de colaboración. para analizar la manera en que se realiza esta interacción y determinar las habilidades que se desarrollan en estos espacios, se realizó un estudio de casos con participantes de dos makerspaces ubicados en la ciudad de monterrey, méxico. El desarrollo de entrevistas y observaciones participantes en estos entornos permitieron determinar de qué manera estos espacios favorecen el desarrollo de habilidades de emprendimiento y cómo los participantes utilizan los recursos disponibles para generar ideas innovadoras y creativas. Estas ideas posteriormente se van a convertir en emprendimientos que requieren de un impulso por parte de otros actores del ecosistema emprendedor para que lleguen a tener un mayor potencial y alcance. los hallazgos sobre los factores que se presentan en los makerspaces se describen en los siguientes dominios de análisis: características de los modelos a los que tienen acceso los emprendedores, el perfil de los participantes y sus relaciones, los tipos de formación que reciben, las habilidades que desarrolla el emprendedor, el ecosistema emprendedor y los recursos disponiblesThis qualitative research seeks to describe how makerspaces promote open innovation and the development of entrepreneurship. these educational spaces have arisen to develop projects mediated by technology and have become as training centers that promote collaboration networks. to analyze how this interaction is carried out and determine the skills developed in these spaces, a case study was made with participants from two makerspaces located in the city of monterrey, mexico. the development of interviews and participant observations in these environments allowed determining how these spaces favor the development of entrepreneurship skills and how the participants use the available resources to generate innovative and creative ideas. these ideas will subsequently become enterprises, but entrepreneurs require an impulse from other actors in the entrepreneurial ecosystem to reach greater potential. findings show that the factors presented in the makerspaces are the following domains of analysis: characteristics of the models to which the entrepreneurs have access, the profile of the participants and their relationships, the types of training they receive, the skills developed by the entrepreneur, the entrepreneurial ecosystem and the available resource

European Academy of Neurology guidelines on the treatment of cluster headache

TAC; Treatment; Trigeminal autonomic cephalalgiaTAC; Tratamiento; Cefalea autonómica del trigeminoTAC; Tractament; Cefalàlgia autonòmica del trigeminBackground and Purpose Cluster headache is a relatively rare, disabling primary headache disorder with a major impact on patients' quality of life. This work presents evidence-based recommendations for the treatment of cluster headache derived from a systematic review of the literature and consensus among a panel of experts. Methods The databases PubMed (Medline), Science Citation Index, and Cochrane Library were screened for studies on the efficacy of interventions (last access July 2022). The findings in these studies were evaluated according to the recommendations of the European Academy of Neurology, and the level of evidence was established using GRADE (Grading of Recommendations Assessment, Development, and Evaluation). Recommendations For the acute treatment of cluster headache attacks, there is a strong recommendation for oxygen (100%) with a flow of at least 12 L/min over 15 min and 6 mg subcutaneous sumatriptan. Prophylaxis of cluster headache attacks with verapamil at a daily dose of at least 240 mg (maximum dose depends on efficacy and tolerability) is recommended. Corticosteroids are efficacious in cluster headache. To reach an effect, the use of at least 100 mg prednisone (or equivalent corticosteroid) given orally or at up to 500 mg iv per day over 5 days is recommended. Lithium, topiramate, and galcanezumab (only for episodic cluster headache) are recommended as alternative treatments. Noninvasive vagus nerve stimulation is efficacious in episodic but not chronic cluster headache. Greater occipital nerve block is recommended, but electrical stimulation of the greater occipital nerve is not recommended due to the side effect profile

Short-term functional outcomes in patients undergoing primary total knee arthroplasty according to their body mass index

Background: The impact of an increased body mass index (BMI) in patients with ostheoarthritis who undergo total knee arthroplasty (TKA) remains a controversial variable in terms of risks and benefits. This study aimed to evaluate the influence of BMI in the functional outcomes of patients with ostheoarthritis who underwent TKA. Methods: We followed a cohort of patients who underwent total knee arthroplasty with a primary diagnosis of osteoarthritis. Patients were stratified into 3 groups according to the World Health Organization classification of BMI. We assessed the association between BMI group and functional scores using the Western Ontario and McMaster osteoarthritis index (WOMAC) over the time intervals of pre– and postoperatively at 1 month, 3 months and 1 year. Results: The difference in means between pre-surgical WOMAC and WOMAC at first follow-up according to each BMI group was divided as follows: normal 10.9 (p=0.195), overweight 15.7 (p≤0.001) and obese 20.6 (p≤0.001). Study participants with a higher BMI had worse preoperative WOMAC scores and had greater improvement from baseline to 1 month. After one year of follow-up, participants in all BMI groups had similar WOMAC scores. Conclusions: Patients with obesity who underwent TKA showed greater functional improvement one month after surgery compared to the other BMI groups. Subsequently, it was observed at the end of the 12-month follow-up that all patients, regardless of BMI, had improved functional outcomes, and the magnitude of improvement was similar in all BMI groups.

Retrospective survey for sialidase activity in Mycoplasma pneumoniae isolates from cases of community-acquired pneumonia

<p>Abstract</p> <p>Background</p> <p>Sialidase is a well-known virulence factor of other respiratory pathogens, but was only recently documented to occur in some species of <it>Mycoplasma</it>. The sialidase activity expressed can vary quantitatively among strains within a species of mycoplasma, from undetectable to amounts that correlate positively with strain virulence. Very few isolates of <it>Mycoplasma pneumoniae </it>had ever been examined for sialidase activity, so it was unknown whether sialidase may contribute to diseases involving this species.</p> <p>Findings</p> <p>No sialidase activity was detected by spectrofluorometric assay of 15 laboratory strains and 91 clinical isolates of <it>M. pneumoniae </it>banked over many years from patients having radiologically-confirmed, uncomplicated community-acquired pneumonia.</p> <p>Conclusions</p> <p>The annotated genome of strain M129 (GenBank <ext-link ext-link-id="NC_000912" ext-link-type="gen">NC_000912</ext-link>, <ext-link ext-link-id="ATCC29342" ext-link-type="gen">ATCC 29342</ext-link>), also isolated from a patient with pneumonia, accurately represents the absence of sialidase genes from strains of <it>M. pneumoniae </it>typically associated with uncomplicated community-acquired pneumonia. A possible involvement of sialidase in neurologic or other extra-respiratory manifestations of <it>M. pneumoniae </it>mycoplasmosis remains to be investigated.</p

Visibility Strategies for Scientific Production in Open Access Journals: A Systematic Literature Review

Una de las principales finalidades de la publicación es ejercer impacto en la nueva generación de conocimiento a través de la citación. Publicar no es suficiente: para trascender es necesario ser citado. Sin embargo, el asunto es complejo y requiere atención desde varios frentes, uno de ellos, las estrategias de visibilidad que permitan futuras citaciones. La presente revisión sistemática de literatura (SLR) tiene por objeto analizar artículos sobre impacto de citas, producidos desde 2016 hasta 2018, registrados en las bases de datos Scopus y Web of Science, con el fin de identificar estrategias de visibilidad de la producción científica. El trabajo se centra en tres focos: el contexto y tipo de estudios realizados sobre el tema, las estrategias usadas y recomendaciones para incrementar la citación en revistas de acceso abierto. Entre los hallazgos se destaca el uso de la Internet como eje para la visibilidad a partir de diversas herramientas y se recomiendan diferentes estrategias para ser replicadas en este tipo de publicaciones.One of the main purposes of publication is to influence on the new generation of knowledge through citation. Publishing is not enough: to transcend it is necessary to be cited. However, the issue is complex and requires attention on several points; one of them is the strategies of visibility that allow future citations. This systematic literature review (SLR) aims to analyze articles about citation impact, published between 2016 and 2018, filed on Scopus and Web of Science databases, to identify visibility strategies for scientific literature. The paper focuses on three aspects: the context and type of studies, the strategies used, and recommendations to increase citation impact in open access journals. Among the findings, it is possible to highlight the use of the Internet for visibility because of its tools. Also, the article recommends different strategies to be replicated in this type of publications

Seroprevalence of dengue antibodies in three urban settings in Yucatan, Mexico

Dengue transmission in Mexico has become a major public health problem. Few epidemiological studies have examined the seroprevalence of dengue in Mexico, and recent estimates are needed to better understand dengue transmission dynamics.Weconducted a dengue seroprevalence survey among 1,668 individuals including all age groups in three urban settings in Yucatan, Mexico. Children (< 19 years old) were selected randomly from schools. The adults (≥ 19 years old) were selected from healthcare facilities. Participants were asked to provide a venous blood sample and to answer a brief questionnaire with demographic information. Previous exposure to dengue was determined using indirect immunoglobulin G enzyme-linked immunosorbent assay. The overall seroprevalence was 73.6%. The age-specific seroprevalence increased with age, going from 51.4% (95% confidence interval [CI] = 45.0-57.9%) in children ≤ 8 years to 72% (95% CI = 66.3-77.2%) in the 9- to 14-years old. The highest seroprevalence was 83.4% (95% CI = 77-82.2%) in adults greater than 50 years. The seroprevalence in Merida was 68.6% (95% CI = 65-72%), in Progreso 68.7% (95% CI = 64.2-72.8%), and in Ticul 85.3% (95% CI = 81.9-88.3%). Ticul had the highest seroprevalence in all age groups. Logistic regression analysis showed that age and city of residence were associated with greater risk of prior dengue exposure. The results highlight the level of past exposure to dengue virus including young children. Similar studies should be conducted elsewhere in Mexico and other endemic countries to better understand the transmission dynamics of deng

Morphological and molecular characterization of Trichuris muris (Nematoda: Trichuridae): studies from two commensal rodent species

In this paper we re-describe Trichuris muris based on morphological data following isolation from two commensal rodent species, Mus musculus from Mexico and Rattus rattus from Argentina. Furthermore, we provide a molecular characterization based on mitochondrial (cytochrome c oxidase subunit 1 mitochondrial gene) and nuclear (internal transcribed spacer 2 region) markers in order to support the taxonomic identification of the studied specimens of T. muris from M. musculus. We distinguished T. muris from 29 species of Trichuris found in American rodents based on morphological and biometrical features, such as the presence of a spicular tube, length of spicule, size of proximal and distal cloacal tube and non-protrusive vulva. We suggest that spicular tube patterns can be used to classify Trichuris species in three groups. Considering that the diagnosis among the species of this genus is mainly based on morphometry, this proposal represents a relevant contribution. We provide molecular studies on two markers, making this the first contribution for T. muris in the Americas. This study makes an important contribution to the integrative taxonomy of cosmopolitan nematode species, and its correct determination from the parasitological study of commensal rodents.Fil: Panti May, Jesús Alonso. Universidad Autonoma de Yucatan (uady);Fil: Gómez Muñoz, María de Los Ángeles. Universidad Nacional del Nordeste; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Yeh Gorocica, A. B.. Universidad Autonoma de Yucatan (uady);Fil: Hernández Betancourt, S.. Universidad Autonoma de Yucatan (uady);Fil: Milano, F.. Universidad Nacional del Nordeste; ArgentinaFil: Galliari, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Robles, Maria del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentin

The spiral structure of our Milky Way Galaxy

The spiral structure of our Milky Way Galaxy is not yet known. HII regions and giant molecular clouds are the most prominent spiral tracers. We collected the spiral tracer data of our Milky Way from the literature, namely, HII regions and giant molecular clouds (GMCs). With weighting factors based on the excitation parameters of HII regions or the masses of GMCs, we fitted the distribution of these tracers with models of two, three, four spiral-arms or polynomial spiral arms. The distances of tracers, if not available from stellar or direct measurements, were estimated kinetically from the standard rotation curve of Brand & Blitz (1993) with $R_0$=8.5 kpc, and $\Theta_0$=220 km s$^{-1}$ or the newly fitted rotation curves with $R_0$=8.0 kpc and $\Theta_0$=220 km s$^{-1}$ or $R_0$=8.4 kpc and $\Theta_0$=254 km s$^{-1}$. We found that the two-arm logarithmic model cannot fit the data in many regions. The three- and the four-arm logarithmic models are able to connect most tracers. However, at least two observed tangential directions cannot be matched by the three- or four-arm model. We composed a polynomial spiral arm model, which can not only fit the tracer distribution but also match observed tangential directions. Using new rotation curves with $R_0$=8.0 kpc and $\Theta_0$=220 km s$^{-1}$ and $R_0$=8.4 kpc and $\Theta_0$=254 km s$^{-1}$ for the estimation of kinematic distances, we found that the distribution of HII regions and GMCs can fit the models well, although the results do not change significantly compared to the parameters with the standard $R_0$ and $\Theta_0$.Comment: 34 Pages, 10 Figures, 5 Tables. Accepted for publication in A&A. Edited