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BACKGROUND: Infectious diseases of farmed and wild animals pose a recurrent threat to food security and human health. The macrophage, a key component of the innate immune system, is the first line of defence against many infectious agents and plays a major role in shaping the adaptive immune response. However, this phagocyte is a target and host for many pathogens. Understanding the molecular basis of interactions between macrophages and pathogens is therefore crucial for the development of effective strategies to combat important infectious diseases. RESULTS: We explored how porcine pluripotent stem cells (PSCs) can provide a limitless in vitro supply of genetically and experimentally tractable macrophages. Porcine PSC-derived macrophages (PSCdMs) exhibited molecular and functional characteristics of ex vivo primary macrophages and were productively infected by pig pathogens, including porcine reproductive and respiratory syndrome virus (PRRSV) and African swine fever virus (ASFV), two of the most economically important and devastating viruses in pig farming. Moreover, porcine PSCdMs were readily amenable to genetic modification by CRISPR/Cas9 gene editing applied either in parental stem cells or directly in the macrophages by lentiviral vector transduction. CONCLUSIONS: We show that porcine PSCdMs exhibit key macrophage characteristics, including infection by a range of commercially relevant pig pathogens. In addition, genetic engineering of PSCs and PSCdMs affords new opportunities for functional analysis of macrophage biology in an important livestock species. PSCs and differentiated derivatives should therefore represent a useful and ethical experimental platform to investigate the genetic and molecular basis of host-pathogen interactions in pigs, and also have wider applications in livestock.

BACKGROUND: Infectious diseases of farmed and wild animals pose a recurrent threat to food security and human health. The macrophage, a key component of the innate immune system, is the first line of defence against many infectious agents and plays a major role in shaping the adaptive immune response. However, this phagocyte is a target and host for many pathogens. Understanding the molecular basis of interactions between macrophages and pathogens is therefore crucial for the development of effective strategies to combat important infectious diseases. RESULTS: We explored how porcine pluripotent stem cells (PSCs) can provide a limitless in vitro supply of genetically and experimentally tractable macrophages. Porcine PSC-derived macrophages (PSCdMs) exhibited molecular and functional characteristics of ex vivo primary macrophages and were productively infected by pig pathogens, including porcine reproductive and respiratory syndrome virus (PRRSV) and African swine fever virus (ASFV), two of the most economically important and devastating viruses in pig farming. Moreover, porcine PSCdMs were readily amenable to genetic modification by CRISPR/Cas9 gene editing applied either in parental stem cells or directly in the macrophages by lentiviral vector transduction. CONCLUSIONS: We show that porcine PSCdMs exhibit key macrophage characteristics, including infection by a range of commercially relevant pig pathogens. In addition, genetic engineering of PSCs and PSCdMs affords new opportunities for functional analysis of macrophage biology in an important livestock species. PSCs and differentiated derivatives should therefore represent a useful and ethical experimental platform to investigate the genetic and molecular basis of host-pathogen interactions in pigs, and also have wider applications in livestock.

X chromosome inactivation (XCI) is a mammalian specific, developmentally regulated process relying on several mechanisms including antisense transcription, non-coding RNA-mediated silencing, and recruitment of chromatin remodeling complexes. In vitro modeling of XCI, through differentiation of embryonic stem cells (ESCs), provides a powerful tool to study the dynamics of XCI, overcoming the need for embryos, and facilitating genetic modification of key regulatory players. However, to date, robust initiation of XCI in vitro has been mostly limited to mouse pluripotent stem cells. Here, we adapted existing protocols to establish a novel monolayer differentiation protocol for rat ESCs to study XCI. We show that differentiating rat ESCs properly downregulate pluripotency factor genes, and present female specific Xist RNA accumulation and silencing of X-linked genes. We also demonstrate that RNF12 seems to be an important player in regulation of initiation of XCI in rat, acting as an Xist activator. Our work provides the basis to investigate the mechanisms directing the XCI process in a model organism different from the mouse.

Parkinson's disease (PD) is a chronic, neurodegenerative disorder, which arises as a result of the progressive loss of midbrain dopaminergic (mDA) neurons in the substantia nigra. The severity of the symptoms negatively influences the patients’ quality of life and comprises an economic burden to the government. Although many treatments have been developed over time, these therapies only reduce symptoms and often have side effects. Since PD results from the loss of a specific cell type, it lends itself to cell replacement therapy. A very promising source for cell replacement therapy are embryonic stem (ES) cells. The use of rat ES cells in this perspective, offers some advantages compared to the utilization of mouse, human or primate ES cells. Rat ES cells have been reported to differentiate into neurons by means of adjusting the level of MEK/ERK inhibition. With regard to PD, it would be interesting to know if these neurons have differentiated toward a midbrain or even mDA neuronal fate. During this project, the RT-PCR conditions for markers for midbrain specification and mature mDA neurons were optimized and neuronal samples, previously generated by modulation of the level of MEK/ERK inhibition, were evaluated for midbrain marker expression by RT-PCR analysis. Indeed markers of mDA neuronal specification were identified in rat ES cell derived neurons. This result provides useful knowledge for future experiments.

Parkinson's disease (PD) is a chronic, neurodegenerative disorder, which arises as a result of the progressive loss of midbrain dopaminergic (mDA) neurons in the substantia nigra. The severity of the symptoms negatively influences the patients’ quality of life and comprises an economic burden to the government. Although many treatments have been developed over time, these therapies only reduce symptoms and often have side effects. Since PD results from the loss of a specific cell type, it lends itself to cell replacement therapy. A very promising source for cell replacement therapy are embryonic stem (ES) cells. The use of rat ES cells in this perspective, offers some advantages compared to the utilization of mouse, human or primate ES cells. Rat ES cells have been reported to differentiate into neurons by means of adjusting the level of MEK/ERK inhibition. With regard to PD, it would be interesting to know if these neurons have differentiated toward a midbrain or even mDA neuronal fate. During this project, the RT-PCR conditions for markers for midbrain specification and mature mDA neurons were optimized and neuronal samples, previously generated by modulation of the level of MEK/ERK inhibition, were evaluated for midbrain marker expression by RT-PCR analysis. Indeed markers of mDA neuronal specification were identified in rat ES cell derived neurons. This result provides useful knowledge for future experiments.

This paper presents findings from a field study of 24 individuals who kept diaries of their web use, across device and location, for a period of four days. Our focus was on how the web was used for non-work purposes, with a view to understanding how this is intertwined with everyday life. While our initial aim was to update existing frameworks of'web activities', such as those described by Sellen et al. [25] and Kellar et al. [14], our data lead us to suggest that the notion of'web activity'is only partially useful for an analytic understanding of what it is that people do when they go online. Instead, our analysis leads us to present five modes of web use, which can be used to frame and enrich interpretations of'activity'. These are respite, orienting, opportunistic use, purposeful use and lean-back internet. We then consider two properties of the web that enable it to be tailored to these different modes, persistence and temporality, and close by suggesting ways of drawing upon these qualities in order to inform design.

This paper presents findings from a field study of 24 individuals who kept diaries of their web use, across device and location, for a period of four days. Our focus was on how the web was used for non-work purposes, with a view to understanding how this is intertwined with everyday life. While our initial aim was to update existing frameworks of'web activities', such as those described by Sellen et al. [25] and Kellar et al. [14], our data lead us to suggest that the notion of'web activity'is only partially useful for an analytic understanding of what it is that people do when they go online. Instead, our analysis leads us to present five modes of web use, which can be used to frame and enrich interpretations of'activity'. These are respite, orienting, opportunistic use, purposeful use and lean-back internet. We then consider two properties of the web that enable it to be tailored to these different modes, persistence and temporality, and close by suggesting ways of drawing upon these qualities in order to inform design.

Report of the Field Columbian Museum’s Department of Zoology, submitted by the department’s Chief Curator D. G. Elliot. The report describes activities related to collecting, specimen registration, cataloging, labeling, preparation, taxidermy, and exhibition installation. Report sections: Mammalogy; Osteology; Ichthyology; Herpetology & Batrachia; Reptiles; Entomology; Conchology; Crustacea. Note: Report located in the Director’s Correspondence Papers under Elliot, D. G. Name mentioned in the report is Mr. E. Heller [i. e. Edmund Heller].

Report of the Field Columbian Museum’s Department of Zoology, submitted by the department’s Chief Curator D. G. Elliot. The report describes activities related to collecting, specimen registration, cataloging, labeling, preparation, taxidermy, and exhibition installation. Report sections: Mammalogy; Ichthyology; Herpetology & Batrachia; Conchology; Osteology; Entomology; Taxidermy; Field Work. Report located in the Director’s Correspondence Papers under Elliot, D. G. Manuscript contains a partial typed transcription of Elliot’s written report. Names mentioned in the report are Dr. W. S. Strode, Mr. Gueret [i. e. Edward N. Gueret], E. B. Chope, and Surber [i. e. Thaddeus Surber].

Report of the Field Columbian Museum’s Department of Zoology, submitted by the department’s Chief Curator D. G. Elliot. The report describes activities related to collecting, specimen registration, cataloging, labeling, preparation, taxidermy, and exhibition installation. Report sections: Mammalogy; Osteology; Ichthyology; Batrachia; Reptiles; Entomology; Conchology; Taxidermy. Note: Report located in the Director’s Correspondence Papers under Elliot, D. G. Names mentioned in the report are Mr. V. Shaw Kennedy, Mr. McCrea [i. e. W. S. McCrea], Dr. Roerhig, and Arthur J. Snyder.

Report of the Field Columbian Museum’s Department of Zoology, submitted by the department’s Chief Curator D. G. Elliot. The report describes activities related to collecting, specimen registration, cataloging, labeling, preparation, taxidermy, and exhibition installation. Report sections: Mammalogy; Osteology; Ichthyology; Herpetology & Batrachia; Conchology; Entomology; Echinodermata, Corals, Sponges, etc.; Crustaceans; Taxidermy. Report located in the Director’s Correspondence Papers under Elliot, D. G. Names mentioned in the report include Mr. Surber [i. e. Thaddeus Surber], Mr. E. Heller [i. e. Edmund Heller], Mr. Gueret [i. e. Edward N. Gueret], F. E. Lutz [i. e. Frank Eugene Lutz], Horace Williams, and T. H. Bean.

Report of the Field Columbian Museum’s Department of Zoology, submitted by the department’s Chief Curator D. G. Elliot. The report describes activities related to collecting, specimen registration, cataloging, labeling, preparation, taxidermy, and exhibition installation. Report sections: Mammalogy; Osteology; Ichthyology; Herpetology & Batrachia; Conchology; Entomology; Taxidermy. Report located in the Director’s Correspondence Papers under Elliot, D. G. At that time, the Birds Department was a separate department from Zoology. Names mentioned in the report are Mr. Bailey, C. R. Orcutt, E. B. Chope, and Carl Akeley.

Report of the Field Columbian Museum’s Department of Zoology, submitted by the department’s Chief Curator D. G. Elliot. The report describes activities related to collecting; specimen registration, cataloging, labeling, preparation, taxidermy, publications, and exhibition installation. Report sections: Department of Ichthyology; Department of Mammalogy & Osteology; Taxidermist Department; Entomology; papers transmitted for publication. Report located in the Director’s Correspondence Papers under Elliot, D. G.

Report of the Field Columbian Museum’s Department of Zoology, submitted by the department’s Chief Curator D. G. Elliot. The report describes activities related to collecting, specimen registration, cataloging, labeling, preparation, taxidermy, and exhibition installation. Report sections: Mammalogy; Ichthyology; Reptiles; Conchology; Entomology; Osteology; Corals. Report located in the Director’s Correspondence Papers under Elliot, D. G.