1,879 research outputs found
Change Management Models: Commonalities and Key Challenges in the Industry
It can be argued that managing change is crucial for any organisation to survive and succeed in the present highly competitive and continuously evolving business environment. However, theories and approaches to change management currently available to academics and practitioners are often contradictory, mostly lacking empirical evidence and supported by unchallenged hypotheses concerning the nature of contemporary organisational change management. This paper seeks to understand the key challenges faced when implementing change management projects in the industry, especially in aerospace, and the commonalities across existing change management methodologies. The paper describes results from interviews with industry experts and the literature review to provide a discerning sight of the challenges faced when implementing change management projects and the components shared by the available methodologies
CaracterizaciĂłn de la poblaciĂłn de Fusarium oxysporum f. sp. dianthi en la costa Noroeste de CĂĄdiz y control mediante composts supresivos de las marchiteces vasculares
Las marchiteces vasculares constituyen uno de los tipos de enfermedades vegetales mĂĄs importantes y estudiadas de las causadas por hongos. Los principales agentes causantes de este tipo de enfermedad son: Fusarium oxysporum (Schlecht ex Fries) (Fusariosis vasculares) y Verticillium dahliae Kleb. (Verticilosis vasculares). En la bĂșsqueda de alternativas sostenibles, las sociedades desarrolladas generan una gran cantidad de residuos orgĂĄnicos procedentes de la industria agrĂcola. Estos residuos tras un proceso de compostaje podrĂan ser usados como sustratos hortĂcolas. AdemĂĄs, algunos composts de alta calidad o bien sustratos enriquecidos con agentes de control biolĂłgico inciden disminuyendo las enfermedades producidas por algunos de los principales hongos fitopatĂłgenos, siendo ademĂĄs una alternativa al Bromuro de Metilo en los cultivos en contenedor, presentando un fenĂłmeno denominado supresividad.
En este sentido, la presente Tesis Doctoral se desglosa en dos objetivos: el estudio de la diversidad y prevalencia racial de una población de Fusarium oxysporum f. sp. dianthi (Fod) obtenida de plantas enfermas en una zona con una alta tradición en el cultivo del clavel (Noroeste de la provincia de Cådiz); y la evaluación de sustratos formulados con composts de residuos agroindustriales en cuatro patosistemas (Fusarium/clavel, Fusarium/tomate, Verticillium/algodón y Verticillium/olivo) y el estudio de los factores implicados en esos fenómenos supresivos.We surveyed the diversity of races and prevalence of pathogenic populations of Fusarium oxysporum f. sp. dianthi (Fod) in an area in the northwest of the province of Cadiz (Spain). From 54 farms, 132 isolates were collected from wilted carnation plants. Molecular techniques, namely phylogenetic studies [using RAPD-PCR fingerprinting and sequencing of the transcription elongation factor (TEF1-α)] and analysis with racespecific molecular markers were used to characterize these isolates. Selected isolates from RAPD groups were phenotypically evaluated by pathogenicity tests. All these data
showed that Fod race 2 was the most frequent and prevalent race in the study area, followed by race 1 or 8. Moreover, phylogenetic analyses showed similar results, which were different to those of the race-specific PCR assays. Three findings were highlights from these results: i) seven isolates were not classified in groups where Fod testers were clustered, even they showed different results when race-specific markers were used, ii) ten isolates with retarded race 1 or 8 specific-band were characterized as F. proliferatum
by TEF1-α gene sequencing and clustered into an outgroup, and iii) six isolates failed to generate an amplification signal using race-specific markers. Furthermore, three of them were grouped close to the race 2 tester according to the phylogenetic analyses, and showed the same differential pathogenicity as race 2. This may indicate the presence of a Fod race 2 subgroup in this region
El cambio polĂtico en MĂ©xico: del presidencialismo autoritario al pacto por MĂ©xico (1926-2012)
El presente trabajo de investigaciĂłn tiene como objetivo el documentar los principales elementos caracterĂsticos del cambio polĂtico en nuestro paĂs a partir de la etapa del presidencialismo hegemĂłnico del PRI y hasta la implementaciĂłn del âPacto por MĂ©xicoâ asĂ como las primeras reformas derivadas de este, comprendiendo de 1929 a 2012.
Para la elaboraciĂłn del presente texto, se empleĂł una metodologĂa de carĂĄcter documental, la cual permitiĂł el puntualizar de manera concisa los acontecimientos que de manera directa influyeron en una nueva configuraciĂłn del sistema polĂtico mexicano, que pasĂł de ser un sistema polĂtico caracterizado por el dominio hegemĂłnico de un solo partido polĂtico, el PRI, a ser un sistema polĂtico caracterizado por una pluralidad polĂtica y competitividad electoral, como consecuencia de una serie de reformas polĂticas y electorales que permitieron una alternancia en el poder ejecutivo de MĂ©xico.
Las reformas electorales y al sistema de partidos en MĂ©xico, a su vez permitieron que el Congreso de la UniĂłn ya no estuviese sumido al poder ejecutivo por la pluralidad partidista presente, por lo que la actividad legislativa, a partir de 1997 entrĂł en una etapa en donde alcanzar acuerdos para realizar modificaciones constitucionales de suma importancia para el paĂs se tornaba complicado debido a los distintos intereses e ideologĂas de los partidos presentes en las CĂĄmaras del Congreso. En el presente trabajo se parte del supuesto de que el âPacto por MĂ©xicoâ surge como la alternativa que ha permitido encontrar coincidencias para realizar reformas necesarias para el paĂs
Genome scale metabolic modeling reveals the metabolic potential of three Type II methanotrophs of the genus Methylocystis
ProducciĂłn CientĂficaGenome Scale Metabolic Models (GSMMs) of the recently sequenced Methylocystis hirsuta and two other methanotrophs from the genus Methylocystis have been reconstructed. These organisms are Type II methanotrophs with the ability of accumulating Polyhydroxyalkanoates under nutrient limiting conditions. For the first time, GSMMs have been reconstructed for Type II methanotrophs. These models, combined with experimental biomass and PHB yields of Methylocystis hirsuta, allowed elucidating the methane oxidation mechanism by the enzyme pMMO (particulate methane monooxygenase) in these organisms. In contrast to Type I methanotrophs, which use the âdirect coupling mechanismâ, Type II methanotrophs appear to use the so called âredox arm mechanismâ. The utilization of the âredox arm mechanismâ, which involves the coupling between methane oxidation and complex I of the respiratory chain, was confirmed by inhibition of complex I with catechol. Utilization of the âredox armâ mechanism leads to lower biomass yields on methane compared to Type I methanotrophs. However, the ability of Type II methanotrophs to redirect high metabolic carbon fluxes towards acetoacetyl-CoA under nitrogen limiting conditions makes these organisms promising platforms for metabolic engineering.Marie Curie grant H2020-MSCA-IF-2016 CH4BioVal (GA nÂș 750126).Junta de Castilla y LeĂłn (Ref. Project VA281P18)Ministerio de Ciencia e InnovaciĂłn (Proyect CLU 2017-09, CTM2015-70442-R
Gestación adolescente como factor de riesgo para morbilidad obstétrica durante el periodo 2011-2013 en el hospital Belén de Trujillo
Determinar si la gestación en adolescente es factor de riesgo para morbilidades obstétricas
Material y MĂ©todo: estudio analĂtico observacional de cohorte histĂłrica. Se incluyeron 82 madres adolescentes, y una muestra de 82 madres de 20 a 35 años de edad.
Resultados: no se encontrĂł asociaciĂłn entre tipo de presentaciĂłn (p=1) con embarazo adolescente. La anemia (RR: 3.7; IC 95%: 1.1-11.8; p= 0.021) se asociĂł significativamente con embarazo adolescente, constituyendo factor de riesgo para estas patologĂas.
Conclusión: la edad materna de 10 a 19 años es un factor de anemia postparto.To determine whether teenage pregnancy is a risk
factor for obstetric morbility.
Methods: Observational analytical historical cohort. We included
82 adolescent mothers; and a simple of 82 mothers aged 20 to 35
years old.
Results: No association between type of presentation (p=1) with
teenage pregnancy. The anemia (RR: 3.7; IC 95%: 1.1-11.8; p=
0.021) were significantly associated with teenage pregnancy,
being a risk factor for these diseases.
Conclusion: Maternal age 10 to 19 years is a risk factor for the
development of anemia.Tesi
Odour prevention strategies in wastewater treatment plants: A pilot scale study of activated sludge recycling and oxidized nitrogen recycling
ProducciĂłn CientĂficaThe potential of activated sludge recycling (ASR) and oxidized nitrogen recycling (ONR) to prevent the emissions of H2S and acetic acid from the primary settler during domestic wastewater treatment was herein evaluated. The pilot plant consisted of an 8 L primary settler with a 10 L gas-tight headspace coupled to a 11 L nitrification-denitrification activated sludge reactor and an 8 L secondary settler, which were monitored for 175 days. A reduction in the headspace concentrations of H2S and acetic acid by 95 % and 42 %, respectively, was recorded when combining ASR and ONR. Process operation with ASR and ONR supported stable conditions with average organic matter removals of 96 ± 2 %, NO2- concentrations of 24.2 ± 0.4 mg N/L and NO3- concentrations of 9.8 ± 0.4 mg N/L in the effluent, and a biological oxidation of S2- higher than 99 % with average SO42- concentrations of 52 ± 8 mg/L. Interestingly, the sole recirculation of activated sludge to the primary settler without NO3- recycling caused sludge bulking, contributing to increase the concentration of H2S and acetic acid in the primary settler headspace up to 0.99 ± 0.01 ppmv and 2.87 ± 0.12 ppmv, respectively. Sludge bulking also resulted in an increase in the effluent soluble total nitrogen concentration from 5.6 ± 0.1 mg N/L to 50.8 ± 0.2 mg N/L and of NH4+ from 1.3 ± 0.2 mg N/L to 50.7 ± 0.8 mg N/L due to the loss of nitrification under these operational conditions. Overall, the experimental results indicated that ASR and ONR represent cost-effective strategies for the control of malodorous emissions in wastewater treatment plants.Junta de Castilla y LeĂłn - EU-FEDER (CLU 2017-09, CL-EI-2021-07 y UIC 315)Ministerio de Ciencia e InnovaciĂłn (FJC2019-039791-I
Optimization of activated sludge recycling and oxidized ammonium recycling as odour control strategies in wastewater treatment plants
ProducciĂłn CientĂficaNew odour prevention strategies in wastewater treatment facilities need to be investigated to find effective and low-cost technologies for the control of malodorous emissions. In this study, the potential of activated sludge (AS) and oxidized nitrogen (N-NOx) recycling as an environmentally-friendly and cost-effective strategy for the prevention and minimization of odour nuisance during wastewater treatment was evaluated and optimized using H2S, acetic acid and α-pinene as model odorants in 2.1 L gas tight bottles. This approach uses by-products from wastewater treatment to mitigate odour annoyance. Preliminary abiotic tests showed headspace concentration losses of 25% for H2S and α-pinene, and 7% for acetic acid due to odorant adsorption in 4 h. The experiments carried out at different concentrations of AS (0, 10, 25, 50, 100 mg VSS/L) and oxidized nitrogen (1.5, 5, 7.5 and 10 mg N-NOx/L) revealed an effective H2S removal at 7.5â10 mg N-NOx/L and 50â100 mg VSS/L. Interestingly, NO3â was more effective than NO2â as electron acceptor during the biodegradation of H2S regardless of the AS concentration and N-NOx concentrations. In the presence of dissolved H2S and AS concentrations of 50â100 mg VSS/L, acetic acid was partially metabolized by microorganisms at the end of experiment (from 27 to 23 ppmv in 4.5 h), while α-pinene concentrations experienced a similar gradual decrease than in the abiotic tests. Finally, the assays carried out at concentrations â„5 mg NO3â/L and 25 mg VSS/L showed a reduction of NO3â to NO2â correlated with the biological oxidation of H2S, which suggested the need to control NO3â supply under sulphur limiting conditions to prevent toxicity problems during wastewater treatment.Junta de Castilla y LeĂłn (grants CLU 2017-09 and UIC 315)Ministerio de Ciencia e InnovaciĂłn (project FJC2019-039791-I)
Wastewater treatment using photosynthetic microorganisms
ProducciĂłn CientĂficaWastewaters are mainly classified as domestic, industrial and agro-industrial based on their production source. Piggery wastewater (PWW) is a livestock wastewater characterized by its high concentrations of organic matter and ammonium, and by its odour nuisance. Traditionally, PWW has been treated in open anaerobic lagoons, anaerobic digesters and activated sludge systems, which exhibit high greenhouse gas emissions, a limited nutrients removal and a high energy consumption, respectively. Photosynthetic microorganisms can support a sustainable wastewater treatment in engineered photobioreactors at low operating costs and with an efficient recovery of carbon, nitrogen and phosphorous. These microorganisms are capable of absorbing solar irradiation through the photosynthesis process to obtain energy, which is used for their growth and associated carbon and nutrients assimilation. Purple phototrophic bacteria (PPB) represent the photosynthetic microorganisms with the most versatile metabolism in nature, whereas microalgae are the most-studied photosynthetic microorganisms in recent years. This review describes the fundamentals, symmetry and asymmetry of wastewater treatment using photosynthetic microorganisms such as PPB and microalgae. The main photobioreactor configurations along with the potential of PPB and microalgae biomass valorisation strategies are also discussed.Junta de Castilla y LeĂłn y Fondo Europeo de Desarrollo Regional (FEDER) - (projects CLU 2017-09, CL-EI-2021-07 and UIC 071)ComisiĂłn Nacional de InvestigaciĂłn CientĂfica y TecnolĂłgica (CONICYT) de Chile - (PFCHA/DOCTORADO BECAS CHILE/2017â72180211
Continuous polyhydroxybutyrate production from biogas in an innovative twoâstage bioreactor configuration
ProducciĂłn CientĂficaBiogas biorefineries have opened up new horizons beyond heat and electricityproduction in the anaerobic digestion sector. Addedâvalue products such aspolyhydroxyalkanoates (PHAs), which are environmentally benign and potentialcandidates to replace conventional plastics, can be generated from biogas. Thiswork investigated the potential of an innovative twoâstage growthâaccumulationsystem for the continuous production of biogasâbased polyhydroxybutyrate (PHB)usingMethylocystis hirsutaCSC1 as cell factory. The system comprised twoturbulent bioreactors in series to enhance methane and oxygen mass transfer: acontinuous stirred tank reactor (CSTR) and a bubble column bioreactor (BCB) withinternal gas recirculation. The CSTR was devoted to methanotrophic growth undernitrogen balanced growth conditions and the BCB targeted PHB productionunder nitrogen limiting conditions. Two different operational approaches underdifferent nitrogen loading rates and dilution rates were investigated. A balancednitrogen loading rate along with a dilution rate (D) of 0.3 dayâ1resulted in the moststable operating conditions and a PHB productivity of ~53 g PHB mâ3dayâ1.However, higher PHB productivities (~127 g PHB mâ3dayâ1)wereachievedusingnitrogen excess at a D = 0.2 dayâ1. Overall, the high PHB contents (up to 48% w/w)obtained in the CSTR under theoretically nutrient balanced conditions and the poorprocess stability challenged the hypothetical advantages conferred by multistagevs singleâstage process configurations for longâterm PHB production.Ministerio de Ciencia e InnovaciĂłn under (BES-2016-077160) contract and (project CTM2015-70442-R)Junta de Castilla y LeĂłn and EU-FEDER program (UIC 315, CLU 2017-09
Guidelines for the Specification and Design of Large-Scale Semantic Applications
This paper presents a set of guidelines to help software engineers with the specification and design of large-scale semantic applications by defining new processes for Requirements Engineering and Design for semantic applications. To facilitate its use to software engineers not experts in semantic technologies, several techniques are provided, namely, a characterization of large-scale semantic applications, common use cases that appear when developing this type of application, and a set of architectural patterns that can be used for modelling the architecture of semantic applications. The paper also presents an example of how these guidelines can be used and an evaluation of our contributions using the W3C Semantic Web use cases
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