Conserved motifs in nuclear genes encoding predicted mitochondrial proteins in Trypanosoma cruzi

Trypanosoma cruzi, the protozoan parasite that causes Chagas’ disease, exhibits peculiar biological features. Among them, the presence of a unique mitochondrion is remarkable. Even though the mitochondrial DNA constitutes up to 25% of total cellular DNA, the structure and functionality of the mitochondrion are dependent on the expression of the nuclear genome. As in other eukaryotes, specific peptide signals have been proposed to drive the mitochondrial localization of a subset of trypanosomatid proteins. However, there are mitochondrial proteins encoded in the nuclear genome that lack of a peptide signal. In other eukaryotes, alternative protein targeting to subcellular organelles via mRNA localization has also been recognized and specific mRNA localization towards the mitochondria has been described. With the aim of seeking for mitochondrial localization signals in T. cruzi, we developed a strategy to build a comprehensive database of nuclear genes encoding predicted mitochondrial proteins (MiNT) in the TriTryps (T. cruzi, T. brucei and L. major). We found that approximately 15% of their nuclear genome encodes mitochondrial products. In T. cruzi the MiNT database reaches 1438 genes and a conserved peptide signal, M(L/F) R (R/S) SS, named TryM-TaPe is found in 60% of these genes, suggesting that the canonical mRNA guidance mechanism is present. In addition, the search for compositional signals in the transcripts of T. cruzi MiNT genes produce a list, being worth to note a conserved nontranslated element represented by the consensus sequence DARRVSG. Taking into account its reported interaction with the T. brucei TRRM3 protein which is enriched in the mitochondrial membrane fraction, we here suggest a putative zip code role for this element. Globally, here we provide an inventory of the mitochondrial proteins in T. cruzi and give evidence for the existence of both peptide and mRNA signals specific to nuclear encoded mitochondrial proteins

Zebra Mussel (Dreissena polymorpha) Affects the Feeding Ecology of Early Stage Striped Bass (Morone saxatilis) in the Hudson River Estuary

Variability in the feeding ecology of young fishes over short and long time scales in estuaries is likely to affect population dynamics. We studied 14 years of early stage Striped Bass feeding ecology in the Hudson River Estuary over a 25-year time span, including years in which invasive zebra mussels markedly altered energy flow within the estuary. We predicted that feeding success would be low and that diet composition would be altered during years of high zebra mussel impact, particularly in upriver locations where mussels occur. Feeding success in the short term was indicated by volume of gut contents and in the long term by dry mass at length, i.e. condition; these measures were positively intercorrelated and varied significantly year to year. We tested for associations between condition and multiple biotic and abiotic environmental variables. There was a strong negative effect of zebra mussel grazing rate on condition in upriver locations and a weak positive effect in downriver locations. In upriver locations, condition was 33% higher when local salinity was high and zebra mussel grazing rates were low, whereas in downriver locations, condition was 35% higher when zebra mussel grazing rates and copepod abundance were high and local dissolved oxygen was low. Copepods, amphipods, mysids, and Leptodora constituted the highest prey-specific index of relative importance throughout the estuary. There was no evident effect of the zebra mussel invasion on diet composition. This long-term study corroborates the inferences of earlier studies that zebra mussels reduced early-stage striped bass growth rate

Consumer Preferences for Mechanically Deboned Beef in Ground Beef Patties

Food, Nutrition and Institution Administratio

The consequences of functionalist assumptions in the epistemology of organizational culture : the perspective of Critical Management Studies

W artykule zaprezentowano refleksję nad konsekwencjami założeń filozoficznych charakterystycznych dla paradygmatu funkcjonalizmu w epistemologii kultury organizacyjnej. Refleksja prowadzona jest z perspektywy nurtu krytycznego w naukach o zarządzaniu, który stoi w opozycji względem funkcjonalizmu, proponując rozstrzygnięcia teoretyczne i praktyczne o charakterze emancypacyjnym. Prezentowany artykuł ma spełniać cel emancypacyjny związany z denaturalizacją funkcjonalizmu i zaproponowaniem ramy teoretycznej dla krytycznego wglądu w konsekwencje, jakie wynikają z przyjęcia jego założeń w teorii i praktyce zarządzania i organizowania.The author presents the reflection about the consequences of assumptions characteristic for the functionalist paradigm in the epistemology of organizational culture in the management sciences. The study was conducted from the perspective of Critical Management Studies, which stands in opposition to the functionalist paradigm, offering theoretical and practical settlement of an emancipation

Intrinsic DNA curvature in trypanosomes

Background: Trypanosoma cruzi and Trypanosoma brucei are protozoan parasites causing Chagas disease and African sleeping sickness, displaying unique features of cellular and molecular biology. Remarkably, no canonical signals for RNA polymerase II promoters, which drive protein coding genes transcription, have been identified so far. The secondary structure of DNA has long been recognized as a signal in biological processes and more recently, its involvement in transcription initiation in Leishmania was proposed. In order to study whether this feature is conserved in trypanosomatids, we undertook a genome wide search for intrinsic DNA curvature in T. cruzi and T. brucei. Results: Using a region integrated intrinsic curvature (RIIC) scoring that we previously developed, a non-random distribution of sequence-dependent curvature was observed. High RIIC scores were found to be significantly correlated with transcription start sites in T. cruzi, which have been mapped in divergent switch regions, whereas in T. brucei, the high RIIC scores correlated with sites that have been involved not only in RNA polymerase II initiation but also in termination. In addition, we observed regions with high RIIC score presenting in-phase tracts of Adenines, in the subtelomeric regions of the T. brucei chromosomes that harbor the variable surface glycoproteins genes. Conclusions: In both T. cruzi and T. brucei genomes, a link between DNA conformational signals and gene expression was found. High sequence dependent curvature is associated with transcriptional regulation regions. High intrinsic curvature also occurs at the T. brucei chromosome subtelomeric regions where the recombination processes involved in the evasion of the immune host system take place. These findings underscore the relevance of indirect DNA readout in these ancient eukaryotes

Organizational cultures: Obstacles to women in the UK construction industry

The global economic downturn coupled with recent changes in UK law have led to a sizable reduction in public sector funding. As a result, both public and private sector organizations are under greater pressure to provide evidence of their activities in promoting equality and diversity in their use of public sector funds. This requirement poses a particular challenge for the UK construction industry, which remains largely White male dominated. Empirical data gathered from a series of semistructured questionnaires and focus groups that have received managerial and soft skills training are analyzed and discussed in this article in an effort to establish the organizational cultural obstacles that women face in working in the UK construction industry. The findings outline that White male-dominated organizational cultures, inflexible work practices, and a lack of supportive networks serve as obstacles to women in the UK construction industry. This study concludes with recommendations for the expansion of training opportunities for women to encourage workforce diversity within the UK construction industry

Upstream ORFs influence translation efficiency in the parasite Trypanosoma cruzi

It is generally accepted that the presence of ORFs in the 5′ untranslated region of eukaryotic transcripts modulates the production of proteins by controlling the translation initiation rate of the main CDS. In trypanosomatid parasites, which almost exclusively depend on post-transcriptional mechanisms to regulate gene expression, translation has been identified as a key step. However, the mechanisms of control of translation are not fully understood. In the present work, we have annotated the 5′UTRs of the Trypanosoma cruzi genome both in epimastigotes and metacyclic trypomastigotes and, using a stringent classification approach, we identified putative regulatory uORFs in about 9% of the analyzed 5′UTRs. The translation efficiency (TE) and translational levels of transcripts containing putative repressive uORFs were found to be significantly reduced. These findings are supported by the fact that proteomic methods only identify a low number of proteins coded by transcripts containing repressive uORF. We additionally show that AUG is the main translation initiator codon of repressive uORFs in T. cruzi. Interestingly, the decrease in TE is more pronounced when the uORFs overlaps the main CDS. In conclusion, we show that the presence of the uORF and features such as initiation codon and/or location of the uORFs may be acting to fine tune translation levels in these parasites

Draft genome sequence of the UV-Resistant antarctic bacterium Sphingomonas sp. strain UV9

We report the draft genome sequence of the Antarctic UV-resistant bacterium Sphingomonas sp. strain UV9. The strain has a genome size of 4.25 Mb, a 65.62% GC content, and 3,879 protein-coding sequences. Among others, genes encoding the resolving of the DNA damage produced by the UV irradiation were identified

Influence of internal communications with students in the program “Ser Pilo Paga” at the National University of Colombia in Medellín

La comunicación interna en las universidades suele estudiarse a partir de las relaciones laborales establecidas con su personal administrativo y docente; sin embargo, las interacciones que tienen lugar con y entre los estudiantes como su público más representativo evidencian la complejidad de este tipo de organizaciones para el logro de sus objetivos. Este artículo ofrece una reflexión en torno a la investigación mixta de dos fases con preponderancia cualitativa, que tiene como objetivo analizar la incidencia de la comunicación interna con los estudiantes del programa Ser Pilo Paga en la formación de su cultura organizacional en la Universidad Nacional de Colombia, sede Medellín; programa que surge como iniciativa del Gobierno Nacional y que opera a partir de las dinámicas propias de cada institución de Educación Superior, por lo que es de vital importancia conocer acerca de las interacciones que surgen con sus miembros, así como las representaciones y significados que se construyen a partir de su pertenencia al programa y a la Universidad para el logro de los objetivos e intenciones que los atraviesan.Internal communications at universities are usually studied from the standpoint of the work relationships with its administrative staff and faculty. However, the interactions with and among students, their most representative audience, reveal the complexity of this type of organizations. This study adopted a two-phase mixed methods approach with qualitative preponderance to analyze the influence of internal communications with students in the program “Ser Pilo Paga” on the development of their organizational culture at the National University of Colombia in Medellín. Said program is as an initiative of the National Government and it works based on the dynamics of each higher education institution. As a result, to achieve their common goals, the interactions between its members, as well as the representations and meanings that they build on their sense of belonging to the program and the University, must be examined