Metacyclic VSG Gene Activation in Trypanosoma brucei rhodesiense

African trypanosomes are able to evade the immune response of their mammalian host by their ability to change periodically their surface glycoprotein coat, in a process known as antigenic variation. This surface coat is first displayed in the parasites' metacyclic stage, which exists in the salivary glands of the parasites' insect vector, the tsetse fly. Previous analyses of the features of antigenic variation in the metacyclic stage have revealed that the system appears very different from the more complex and better characterized system employed in parasite populations established in the mammalian bloodstream. The work presented here has attempted to elucidate the reasons for these differences. Firstly, the mechanism for the activation of the expression of the metacyclic variant surface glycoprotein (VSG) coat has been studied. This has been done by infecting tsetse flies with trypanosomes expressing metacyclic VSG genes as they are believed to be activated in the tsetse fly salivary gland. An analysis of the resulting metacyclic population after cyclical transmission has revealed that there is apparently no heritable genomic change associated with activation of these genes. This is distinct from what is found for bloodstream VSG genes, the activation signals for which are preserved through the tsetse fly, and suggests that the metacyclic VSG repertoire is reset with transmission. Secondly, the structure of a metacyclic VSG gene expression locus has been investigated. This has involved the cloning, by the progressive isolation of overlapping restriction fragments, of 16Kb of the ILTat 1.61 gene environment. Analysis of the clones has revealed that the locus has just a very short upstream restriction site barren region, which contrasts with the long barren region associated with bloodstream VSG expression sites. Evidence for the presence of a region which cross hybridizes with one of the several families of expression site associated genes found in all bloodstream VSG expression sites has also been found. An analysis of nascent transcripts from trypanosomes expressing the ILTat 1.61 gene as it is believed to be expressed in the tsetse fly, has revealed that the transcription unit is very short with respect to other examined VSG expression sites. Finally, the reactivation of a gene encoding the metacyclic variant antigen type ILTat 1.22 in established bloodstream parasites has been investigated. This reactivation has been found always to involve the generation of a duplicate gene copy by conversion of one of a number of distinct bloodstream VSG expression sites. The upstream limit of the gene conversion process which results in the generation of this duplicate gene has been found always to occur within a region containing just 1.5 copies of the transposition associated 70bp repeat motif, of which upstream barren regions on bloodstream expression sites are composed. The sequence of the ILTat 1.22 gene and transposed segment has been determined. Neither is unusual with respect to the environment of bloodstream VSG genes. The determined characteristics of metacyclic VSG gene activation and expression site structure have provided potential explanations for the unusual features of surface coat expression in the tsetse fly

Addressing Racism Through Organizational Statements: Examining NPC Sororities Website and Social Media Posts

NPC sororities (inter)national organizations posted countless messages to websites and social media platforms against racism following the summer of 2020 racial protests. The purpose of this study was to conduct a critical content analysis of the twenty-six NPC (inter)national organizations’ websites and Facebook pages to evaluate the messages about racism following the killings of George Floyd and Breonna Taylor. Three findings were identified: naming systemic racism, acknowledging the organization’s history and values related to racism, and calling for individual and organizational action. Findings suggest NPC sororities’ must communicate explicitly about their values and action in addressing racism in society and organization to move towards racial equity

Endometrial carcinoma with ectopic human chorionic gonadotropin expression

• Aggressive course and treatment resistance characterize ectopic human chorionic gonadotropin. • Recurrence of endometrial cancer with ectopic hCG was treated with brachytherapy and EMACO. • The serum hCG level can serve as a marker in tumors with ectopic hCG expression

Towards Systematic Personalization of Information Spaces

Web information systems often have large and complex information spaces. These spaces serve as a conceptual framework for all user-system interactions. Their complexity is likely to cause users having trouble carrying out with these systems the business cases in their portfolio. Aiding users therefore requires a view of reduced complexity on the information space being defined and made accessible to the users. Such a view is called a story. Working out the stories that best help users beneficially use Web information systems is the task of information space personalization. This paper analyses a Web information system. A Kleene algebra is used as a mathematical model of a story of this system. We illustrate that formal manipulation of Kleene algebras can be used for personalizing information spaces. This paper thus supports the proposal of using Kleene algebras as mathematical model of Web information system usage

Association of sexual harassment and sexual assault with midlife women’s mental and physical health

Importance: Sexual harassment and sexual assault are prevalent experiences among women. However, their association with health indices is less well understood. Objective: To investigate the association of history of sexual harassment and sexual assault with blood pressure, mood, anxiety, and sleep among midlife women. Design, setting, and participants: Nonsmoking women without cardiovascular disease were recruited from the community to undergo physical measurements (blood pressure, height, weight), medical history, and questionnaire psychosocial assessments (workplace sexual harassment, sexual assault, depression, anxiety, sleep). Exposures: Sexual harassment and sexual assault. Main outcomes and measures: Blood pressure, depressive symptoms, anxiety, and sleep characteristics. Results: Among the 304 nonsmoking women aged 40 to 60 years who participated in the study, all were free of clinical cardiovascular disease, and the mean (SD) age was 54.05 (3.99) years. A total of 19% reported a history of workplace sexual harassment (n = 58), and 22% reported a history of sexual assault (n = 67). Sexual harassment was related to significantly greater odds of stage 1 or 2 hypertension among women not taking antihypertensives (odds ratio [OR], 2.36; 95% CI, 1.10-5.06; P = .03) as well as clinically poor sleep (OR, 1.89; 95% CI, 1.05-3.42; P = .03), after adjusting for covariates. Sexual assault was associated with significantly greater odds of clinically elevated depressive symptoms (OR, 2.86; 95% CI, 1.42-5.77; multivariable P = .003), clinically relevant anxiety (OR, 2.26; 95% CI, 1.26-4.06; P = .006), and clinically poor sleep (OR, 2.15; 95% CI, 1.23-3.77; multivariable P = .007), after adjusting for covariates. Conclusions and relevance: Sexual harassment and sexual assault are prevalent experiences among midlife women. Sexual harassment was associated with higher blood pressure and poorer sleep. Sexual assault was associated with poorer mental health and sleep. Efforts to improve women's health should target sexual harassment and assault prevention

Elucidating the mechanisms underlying GATA-1 activity

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Graphics mini manual

The computer graphics capabilities available at the Center are introduced and their use is explained. More specifically, the manual identifies and describes the various graphics software and hardware components, details the interfaces between these components, and provides information concerning the use of these components at LaRC