169 research outputs found
Helminths and their Role in Environmental Engineering
Helminth eggs represent an important challenge to environmental engineers as they are among the most difficult biological parasites to inactivate in wastewater and sludge. Even though no official data on helminthiasis exist, it is estimated that more than 2.6 billion people are affected. These parasites are of concern in developing countries, particularly in those areas where the reuse of wastewater and sludge for agriculture is common. With regard to this, the unrestricted use of wastewater for irrigation presents a serious health risk due to the dissemination of pathogens, particularly helminth eggs. Helminth eggs survive in water, soil, and crops for several months and over much longer periods than other microorganisms. Therefore, and in order to minimize risk, several guidelines and regulations exist which limit their content in wastewater and sludge. Risk assessment estimates that such regulations may be less strict in developing countries where higher concentrations of helminth eggs occur in wastewater and sludge. These eggs need to be removed from wastewater and inactivated in sludge using certain treatment processes, some of which are not feasible in developing countries. Adequate methods are needed to precisely identify and quantify helminth eggs in environmental samples. Therefore, a multidisciplinary approach is needed to address helminthiasis in environmental engineering issues
Nota Técnica: Alteraciones en las fábricas de piedra de la Sala Capitular del Ayuntamiento de Sevilla
The main aim of this work has been to determine the causes of stone loss (small particles and one larger piece) and mortar loss in the coffered vault of the Capitol Room in the City Hall of Seville. The analyses and assays carried out during the course of this research have revealed that this masonry comprises a covering of oil paints over mortar-stucco of calcite, quartz, gypsum,and lead white with linseed oil when the walls were not covered. In addition, it was confirmed that the installation of air-conditioning caused a change in the humidity and temperature in the vault, aggravated by the elimination of the cross-ventilation that the structure had since it was built. The combination of these two circumstances likely triggered the pathology in the masonry.Este trabajo ha tenido como objetivo principal determinarlas causas que han originado desprendimientos de partículas y un fragmento importante de las piedras y del mortero que conforman la bóveda-artesonado de la Sala Capitular del Ayuntamiento de Sevilla. Los diferentes análisis y ensayos realizados evidencian que estas fábricas tienen un revestimiento realizado a base de pinturas al óleo sobre estuco-mortero de calcita, cuarzo, yeso y presencia de blanco de plomo con impregnación de aceite de linaza, en tanto que las fábricas de los muros no tienen revestimiento alguno. Igualmente se ha constatado el cambio de la humedad-temperatura ambiental en la bóveda, generado por la implantación de aire acondicionado y la eliminación de la ventilación cruzada natural que tenía desde su construcción. La conjunción de ambas acciones parece ser el desencadenante de las anomalías reseñadas
Gestión y estrategias de la empresa Baldwin en el simulador de negocios Capstone
En este documento se describe el desempeño de la empresa Baldwin, la estrategia y los resultados obtenidos en ocho períodos del simulador de negocios CAPSTONE. En el primer capítulo se aborda el marco teórico donde se desarrollan conceptos de estrategia, mercadotecnia, competencia e industria y se sientan las bases para la planeación estratégica presentada en el segundo capítulo. Los capítulos del tres al seis describen las decisiones tomadas en los departamentos de investigación y desarrollo, mercadotecnia y recursos humanos, así como el desempeño de la empresa a lo largo de los ocho periodos simulados. Cada capítulo comprende un periodo que consta de dos años de operaciones. Finalmente, el capítulo siete expone las conclusiones de los cuatro miembros del equipo respecto a los resultados de la simulación
Redox-dependent and redox-independent functions of Caenorhabditis elegans thioredoxin 1
Thioredoxins (TRX) are traditionally considered as enzymes catalyzing redox reactions. However, redox-independent functions of thioredoxins have been described in different organisms, although the underlying molecular mechanisms are yet unknown. We report here the characterization of the first generated endogenous redox-inactive thioredoxin in an animal model, the TRX-1 in the nematode Caenorhabditis elegans. We find that TRX-1 dually regulates the formation of an endurance larval stage (dauer) by interacting with the insulin pathway in a redox-independent manner and the cGMP pathway in a redox-dependent manner. Moreover, the requirement of TRX-1 for the extended longevity of worms with compromised insulin signalling or under calorie restriction relies on TRX-1 redox activity. In contrast, the nuclear translocation of the SKN-1 transcription factor and increased LIPS-6 protein levels in the intestine upon trx-1 deficiency are strictly redox-independent. Finally, we identify a novel function of C. elegans TRX-1 in male food-leaving behaviour that is redox-dependent. Taken together, our results position C. elegans as an ideal model to gain mechanistic insight into the redox-independent functions of metazoan thioredoxins, overcoming the limitations imposed by the embryonic lethal phenotypes of thioredoxin mutants in higher organisms
Transcriptional silencing of the Dickkopfs-3 (Dkk-3) gene by CpG hypermethylation in acute lymphoblastic leukaemia
Dkk-3 is a newly characterised mortalisation-related gene and an antagonist of the Wnt oncogenic signalling pathway whose
expression is decreased in a variety of cancer cell lines, suggesting that the Dkk-3 gene, located at chromosome 11p15.1, functions as
a tumour suppressor gene. Although 11p15 is a ‘hot spot’ for methylation in acute lymphoblastic leukaemia (ALL), the role of Dkk-3
abnormalities has never been evaluated in this disease. We analysed CpG island methylation of the Dkk-3 promoter in six ALL cell
lines and 183 ALL patients. We observed Dkk-3 hypermethylation in all cell lines and in cells from 33% (60/183) of ALL patients.
Moreover, Dkk-3 methylation was associated with decreased Dkk-3 mRNA expression and this expression was restored after
exposure to the demethylating agent 5-AzaC. Clinical features did not differ between hypermethylated and unmethylated patients.
Estimated disease-free survival (DFS) and overall survival at 10 and 11 years, respectively, were 49.8 and 45.6% for normal patients
and 10.5 and 15.1% for hypermethylated patients (P¼0.001 and 0.09). Multivariate analysis demonstrated that Dkk-3 methylation
was an independent prognostic factor predicting DFS (P¼0.0009). Our data suggest that Dkk-3 methylation occurs at an early stage
in ALL pathogenesis and probably influences the clinical behaviour of the disease
Promoter hypermethylation of cancer-related genes: a strong independent prognostic factor in acute lymphoblastic leukemia
Promoter hypermethylation plays an important
role in the inactivation of cancerrelated
genes. This abnormality occurs
early in leukemogenesis and seems to be
associated with poor prognosis in acute
lymphoblastic leukemia (ALL). To determine
the extent of hypermethylation in
ALL, we analyzed the methylation status
of the CDH1, p73, p16, p15, p57, NES-1,
DKK-3, CDH13, p14, TMS-1, APAF-1,
DAPK, PARKIN, LATS-1, and PTEN genes
in 251 consecutive ALL patients.Atotal of
77.3% of samples had at least 1 gene
methylated, whereas 35.9% of cases had
4 or more genes methylated. Clinical features
and complete remission rate did not
differ among patients without methylated
genes, patients with 1 to 3 methylated
genes (methylated group A), or patients
with more than 3 methylated genes (methylated
group B). Estimated disease-free
survival (DFS) and overall survival (OS) at
11 years were 75.5% and 66.1%, respectively,
for the nonmethylated group; 37.2%
and 45.5% for methylated group A; and
9.4% and 7.8% for methylated group B
(P < .0001 and P .0004, respectively).
Multivariate analysis demonstrated that
the methylation profile was an independent
prognostic factor in predicting DFS
(P < .0001) and OS (P .003). Our results
suggest that the methylation profile may
be a potential new biomarker of risk prediction
in AL
Promoter hypomethylation of the LINE-1 retrotransposable elements activates sense/antisense transcription and marks the progression of chronic myeloid leukemia
Aberrant genome-wide hypomethylation is thought to be
related to tumorigenesis by promoting genomic instability.
Since DNA methylation is considered an important mechanism
for the silencingof retroelements, hypomethylation
in human tumors may lead to their reactivation. However,
the role of DNA hypomethylation in chronic myeloid
leukemia (CML) remains to be elucidated. In this study,
the methylation status of the LINE-1 (L1) retrotransposon
promoter was analysed in CML samples from the chronicphase
(CP, n¼140) and the blast crisis (BC, n¼47). L1
hypomethylation was significantly more frequent in BC
(74.5%) than in CP (38%) (Po0.0001). Furthermore,
L1 hypomethylation led to activation of both ORF1 sense
transcription (Po0.0001) and c-MET gene antisense
transcription (Po0.0001), and was significantly associated
with high levels of BCR–ABL (P¼0.02) and
DNMT3b4 (P¼0.001) transcripts. Interestingly, in
CP-CML, extensive L1 hypomethylation was associated
with poorer prognosis in terms of cytogenetic response
to interferon (P¼0.004) or imatinib (P¼0.034) and
progression-free survival (P¼0.005). The above results
strongly suggest that activation of both sense and
antisense transcriptions by aberrant promoter hypomethylation
of the L1 elements plays a role in the progression
and clinical behavior of the CML
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