Caracterización de la estructura de las comunidades ícticas de las zonas arrecifales de Isla Aguja en el Parque Nacional Natural Tayrona Caribe Colombiano

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Biochemical characterization of the initial steps of the Kennedy pathway in Trypanosoma brucei:the ethanolamine and choline kinases

Note related output below contains correction of this paper.Ethanolamine and choline are major components of the trypanosome membrane phospholipids, in the form of GPEtn (glycero-phosphoethanolamine) and GPCho (glycerophosphocholine). Ethanolamine is also found as an integral component of the GPI (glycosylpliosphatidylinositol) anchor that is required for membrane attachment of cell-surface proteins, most notably the variant-surface glycoproteins. The de novo synthesis of GPEtn and GPCho starts with the generation of phosphoethanolamine and phosphocholine by ethanolamine and choline kinases via the Kennedy pathway. Database mining revealed two putative C/EKs (choline/ethanolamine kinases) in the Trypanosoma brucei genome, which were cloned, overexpressed, purified and characterized. TbEK 1 (T brucei ethanolamine kinase 1) was shown to be catalytically active as an ethanolamine-specific kinase, i.e. it had no choline kinase activity. The K values for ethanolamine and ATP were found to be 18.4 +/- 0.9 and 219 29 mu M respectively. TbC/EK2 (T brucei choline/ethanolamine kinase 2), on the other hand, was found to be able to phosphorylate both ethanolamine and choline, even though choline was the preferred substrate, with a K-m 80 times lower than that of ethanolamine. The K. values for choline, ethanolamine and ATP were 31.4 +/- 2.6 mu M, 2.56 +/- 0.31 mu M and 20.6 +/- 1.96 mu M respectively. Further substrate specificity analysis revealed that both TbEK1 and TbC/EK2 were able to tolerate various modifications at the amino group, with the exception of a quaternary amine for TbEK1 (choline) and a primary amine for TbC/EK2 (ethanolamine). Both enzymes recognized analogues with substituents oil C-2, but substitutions oil C-1 and elongations of the carbon chain were not well tolerated.Publisher PDFPeer reviewe

Velocity-resolved [CII] emission and [CII]/FIR Mapping along Orion with Herschel

We present the first 7.5'x11.5' velocity-resolved map of the [CII]158um line toward the Orion molecular cloud-1 (OMC-1) taken with the Herschel/HIFI instrument. In combination with far-infrared (FIR) photometric images and velocity-resolved maps of the H41alpha hydrogen recombination and CO J=2-1 lines, this data set provides an unprecedented view of the intricate small-scale kinematics of the ionized/PDR/molecular gas interfaces and of the radiative feedback from massive stars. The main contribution to the [CII] luminosity (~85%) is from the extended, FUV-illuminated face of the cloud G_0>500, n_H>5x10^3 cm^-3) and from dense PDRs (G_0~10^4, n_H~10^5 cm^-3) at the interface between OMC-1 and the HII region surrounding the Trapezium cluster. Around 15% of the [CII] emission arises from a different gas component without CO counterpart. The [CII] excitation, PDR gas turbulence, line opacity (from [13CII]) and role of the geometry of the illuminating stars with respect to the cloud are investigated. We construct maps of the [CII]/FIR and FIR/M_Gas ratios and show that [CII]/FIR decreases from the extended cloud component (10^-2-10^-3) to the more opaque star-forming cores (10^-3-10^-4). The lowest values are reminiscent of the "[CII] deficit" seen in local ultra-luminous IR galaxies hosting vigorous star formation. Spatial correlation analysis shows that the decreasing [CII]/FIR ratio correlates better with the column density of dust through the molecular cloud than with FIR/M_Gas. We conclude that the [CII] emitting column relative to the total dust column along each line of sight is responsible for the observed [CII]/FIR variations through the cloud.Comment: 21 pages, 17 figures. Accepted for publication in the Astrophysical Journal (2015 August 12). Figures 2, 6 and 7 are bitmapped to lower resolution. This is version 2 after minor editorial changes. Notes added after proofs include

Expressing Confidence in Models and in Model Transformation Elements.

The expression and management of uncertainty, both in the information and in the operations that manipulate it, is a critical issue in those systems that work with physical environments. Measurement uncertainty can be due to several factors, such as unreliable data sources, tolerance in the measurements, or the inability to determine if a certain event has actually happened or not. In particular, this contribution focuses on the expression of one kind of uncertainty, namely the confidence on the model elements, i.e., the degree of belief that we have on their occurrence, and on how such an uncertainty can be managed and propagated through model transformations, whose rules can also be subject to uncertainty

Relationship Between Sexual Activity, Contraceptive Utilization and Biopsychosocial Characteristics Among Homeless Shelter Adolescents.

Objective: To determine whether biopsychosocial factors are associated with sexual activity and contraceptive utilization among homeless shelter adolescents. Methods: A retrospective study of 440 adolescents at a shelter in Pennsylvania between February 2015 and September 2019 was conducted. The cohort was evaluated to determine what relationship age, gender identity, substance use, and trauma history have with sexual activity and contraceptive utilization. Results: Sexual activity was significantly related to age (mean 15.8+1.4 years in sexually active vs. 14.7+1.6 years in abstinent youth, p\u3c0.001); remote history of self-harm behavior (relative risk ratio (RR) 1.23 [95% CI 1.03-1.46]; p=0.02), history of aggressive behavior (RR 1.21 [95% CI 1.01-1.46]; p=0.04), history of trauma (RR 1.24 [95% CI 1.04-1.48]; p=0.03), and substance use (RR 2.27 [95%CI 1.86-2.77]; p\u3c0.001). There were 55.7% sexually active females vs. 42.50% males reporting contraception use (p=0.01). After adjustment, older age and substance use remained significantly associated with sexual activity (adjusted odds ratio (AOR) 1.58 [95% CI 1.36-1.83]; p\u3c0.001 and AOR 5.18 [95% CI 3.28-8.18]; p\u3c0.001, respectively). Conclusions: Females self-reported sexual activity using contraception more than males. After adjustment, older age and substance use were associated with sexual activity. By better understanding the impact these factors can have on contraceptive utilization, informed policy and practice interventions can be developed and implemented to help increase safe sex practices in spaces where homeless adolescents access healthcare

Novel simple sequence repeats (SSRs) detected by ND-FISH in heterochromatin of Drosophila melanogaster

<p>Abstract</p> <p>Background</p> <p>In recent years, substantial progress has been made in understanding the organization of sequences in heterochromatin regions containing single-copy genes and transposable elements. However, the sequence and organization of tandem repeat DNA sequences, which are by far the majority fraction of <it>D. melanogaster </it>heterochromatin, are little understood.</p> <p>Results</p> <p>This paper reports that the heterochromatin, as well as containing long tandem arrays of pentanucleotide satellites (AAGAG, AAGAC, AATAT, AATAC and AACAC), is also enriched in other simple sequence repeats (SSRs) such as A, AC, AG, AAG, ACT, GATA and GACA. Non-denaturing FISH (ND-FISH) showed these SSRs to localize to the chromocentre of polytene chromosomes, and was used to map them on mitotic chromosomes. Different distributions were detected ranging from single heterochromatic clusters to complex combinations on different chromosomes. ND-FISH performed on extended DNA fibres, along with Southern blotting, showed the complex organization of these heterochromatin sequences in long tracts, and revealed subclusters of SSRs (several kilobase in length) flanked by other DNA sequences. The chromosomal characterization of C, AAC, AGG, AAT, CCG, ACG, AGC, ATC and ACC provided further detailed information on the SSR content of <it>D. melanogaster </it>at the whole genome level.</p> <p>Conclusion</p> <p>These data clearly show the variation in the abundance of different SSR motifs and reveal their non-random distribution within and between chromosomes. The greater representation of certain SSRs in <it>D. melanogaster </it>heterochromatin suggests that its complexity may be greater than previously thought.</p

Impact of the clinical context on the 14-3-3 test for the diagnosis of sporadic CJD

BACKGROUND: The 14-3-3 test appears to be a valuable aid for the clinical diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) in selected populations. However, its usefulness in routine practice has been challenged. In this study, the influence of the clinical context on the performance of the 14-3-3 test for the diagnosis of sCJD is investigated through the analysis of a large prospective clinical series. METHODS: Six hundred seventy-two Spanish patients with clinically suspected sCJD were analyzed. Clinical classification at sample reception according to the World Health Organization's (WHO) criteria (excluding the 14-3-3 test result) was used to explore the influence of the clinical context on the pre-test probabilities, and positive (PPV) and negative (NPV) predictive values of the 14-3-3 test. RESULTS: Predictive values of the test varied greatly according to the initial clinical classification: PPV of 98.8%, 96.5% and 45.0%, and NPV of 26.1%, 66.6% and 100% for probable sCJDi (n = 115), possible sCJDi (n = 73) and non-sCJDi (n = 484) cases, respectively. According to multivariate and Bayesian analyses, these values represent an improvement of diagnostic certainty compared to clinical data alone. CONCLUSION: In three different contexts of sCJD suspicion, the 14-3-3 assay provides useful information complementary to clinical and electroencephalographic (EEG) data. The test is most useful supporting a clinical impression, whilst it may show deceptive when it is not in agreement with clinical data

Perceived drivers and barriers in the governance of wastewater treatment and reuse in India : Insights from a two-round Delphi study

Wastewater treatment and reuse practices are limited in India despite the known benefits of preventing water resources pollution and contributing to sustainable production and consumption systems. We identify the perceived key drivers and barriers to wastewater treatment and reuse governance in a two-round Delphi study, including literature and case study analyses and consultation with 75 panelists. Panelists indicated that the most significant driver for wastewater treatment and water reuse is persistent water scarcity that necessitates diversification to alternative water supplies. In contrast, the most significant barriers are the lack of enforcement of pollution monitoring and control, the lack of an umbrella directive for integrated water resources management, and insufficient collaboration between responsible governmental organizations, central and state water authorities. Given the absence of central guidelines, only a few Indian states such as Maharashtra, Gujarat or Punjab have adopted effective governance structures. These states showcase that defined reuse standards can create successful wastewater treatment and reuse practices but require target-based regulations which are enforced and regularly monitored and financing mechanisms for their long-term operation. The new effluent discharge standards by the National Green Tribunal, the government support programmes, and increasing water scarcity in many parts of India will supposedly drive innovative wastewater treatment and reuse structures. Panelists agreed that efforts are needed to develop technology guiding frameworks following the fit-for-purpose principle and that strengthening institutional and monitoring capacity is crucial to increase confidence in the quality of recovered water resources, create demand, and ultimately safeguard human health and the environment

Clinical relevance of biomarkers of oxidative stress

SIGNIFICANCE Oxidative stress is considered to be an important component of various diseases. A vast number of methods have been developed and used in virtually all diseases to measure the extent and nature of oxidative stress, ranging from oxidation of DNA to proteins, lipids, and free amino acids. Recent Advances: An increased understanding of the biology behind diseases and redox biology has led to more specific and sensitive tools to measure oxidative stress markers, which are very diverse and sometimes very low in abundance. CRITICAL ISSUES The literature is very heterogeneous. It is often difficult to draw general conclusions on the significance of oxidative stress biomarkers, as only in a limited proportion of diseases have a range of different biomarkers been used, and different biomarkers have been used to study different diseases. In addition, biomarkers are often measured using nonspecific methods, while specific methodologies are often too sophisticated or laborious for routine clinical use. FUTURE DIRECTIONS Several markers of oxidative stress still represent a viable biomarker opportunity for clinical use. However, positive findings with currently used biomarkers still need to be validated in larger sample sizes and compared with current clinical standards to establish them as clinical diagnostics. It is important to realize that oxidative stress is a nuanced phenomenon that is difficult to characterize, and one biomarker is not necessarily better than others. The vast diversity in oxidative stress between diseases and conditions has to be taken into account when selecting the most appropriate biomarker. Antioxid. Redox Signal. 00, 000-000