415 research outputs found
Weighing the anchor: Lotmanian perspectives on the Fighting Poland symbol
Simple symbols occupy a unique position within the semiosphere, constituting the symbolic core of culture with their ability to condense cultural memory into nimble, economic forms. This simplicity facilitates persistence, allowing these elementary symbols to recur diachronically, penetrating multiple layers of cultural strata to emerge and flourish in new contexts and variations. A novel example of a symbol which illustrates these attributes is Znak Polski Walczącej – the Fighting Poland symbol. Created in 1942 by the Polish Underground State as a propaganda tool, this straightforward monogram, consisting of interconnected letters P and W, became the official hallmark of Polish resistance and is now a controversial de facto national symbol. This article employs the symbol as a case study to explore two Lotmanian symbolic concepts: the vast semantic capacity of simple symbols, and their dual nature as invariable/variable entities. Born out of a utilitarian need for simplicity in Nazi-occupied Warsaw, the efficient form of the Fighting Poland symbol was a pragmatic matter of life or death. However, further examination of its simple design also reveals an underlying archaic depth. This article argues that the Fighting Poland symbol, metonymically known as the kotwica (‘anchor’) owing to its distinct shape, can also be viewed as an “emissary” from earlier cultural epochs, namely ante-Nicene Christianity, which made use of anchor symbology during an era of persecution and upheaval. Ultimately, this article provides a new semiotic perspective on a historically active yet understudied symbol with past and present relevance
Deletion of vascular endothelial growth factor in myeloid cells accelerates tumorigenesis.
Angiogenesis and the development of a vascular network are required for tumour progression, and they involve the release of angiogenic factors, including vascular endothelial growth factor (VEGF-A), from both malignant and stromal cell types. Infiltration by cells of the myeloid lineage is a hallmark of many tumours, and in many cases the macrophages in these infiltrates express VEGF-A. Here we show that the deletion of inflammatory-cell-derived VEGF-A attenuates the formation of a typical high-density vessel network, thus blocking the angiogenic switch in solid tumours in mice. Vasculature in tumours lacking myeloid-cell-derived VEGF-A was less tortuous, with increased pericyte coverage and decreased vessel length, indicating vascular normalization. In addition, loss of myeloid-derived VEGF-A decreases the phosphorylation of VEGF receptor 2 (VEGFR2) in tumours, even though overall VEGF-A levels in the tumours are unaffected. However, deletion of myeloid-cell VEGF-A resulted in an accelerated tumour progression in multiple subcutaneous isograft models and an autochthonous transgenic model of mammary tumorigenesis, with less overall tumour cell death and decreased tumour hypoxia. Furthermore, loss of myeloid-cell VEGF-A increased the susceptibility of tumours to chemotherapeutic cytotoxicity. This shows that myeloid-derived VEGF-A is essential for the tumorigenic alteration of vasculature and signalling to VEGFR2, and that these changes act to retard, not promote, tumour progression
LLHD: A Multi-level Intermediate Representation for Hardware Description Languages
Modern Hardware Description Languages (HDLs) such as SystemVerilog or VHDL
are, due to their sheer complexity, insufficient to transport designs through
modern circuit design flows. Instead, each design automation tool lowers HDLs
to its own Intermediate Representation (IR). These tools are monolithic and
mostly proprietary, disagree in their implementation of HDLs, and while many
redundant IRs exists, no IR today can be used through the entire circuit design
flow. To solve this problem, we propose the LLHD multi-level IR. LLHD is
designed as simple, unambiguous reference description of a digital circuit, yet
fully captures existing HDLs. We show this with our reference compiler on
designs as complex as full CPU cores. LLHD comes with lowering passes to a
hardware-near structural IR, which readily integrates with existing tools. LLHD
establishes the basis for innovation in HDLs and tools without redundant
compilers or disjoint IRs. For instance, we implement an LLHD simulator that
runs up to 2.4x faster than commercial simulators but produces equivalent,
cycle-accurate results. An initial vertically-integrated research prototype is
capable of representing all levels of the IR, implements lowering from the
behavioural to the structural IR, and covers a sufficient subset of
SystemVerilog to support a full CPU design
Why do women invest in pre-pregnancy health and care? A qualitative investigation with women attending maternity services
Background Despite the importance attributed to good pre-pregnancy care and its potential to improve pregnancy and child health outcomes, relatively little is known about why women invest in pre-pregnancy health and care. We sought to gain insight into why women invested in pre-pregnancy health and care. Methods We carried out 20 qualitative in-depth interviews with pregnant or recently pregnant women who were drawn from a survey of antenatal clinic attendees in London, UK. Interviewees were purposively sampled to include high and low investors in pre-pregnancy health and care, with variation in age, partnership status, ethnicity and pre-existing medical conditions. Data analysis was conducted using the Framework method. Results We identified three groups in relation to pre-pregnancy health and care: 1) The “prepared” group, who had high levels of pregnancy planning and mostly positive attitudes to micronutrient supplementation outside of pregnancy, carried out pre-pregnancy activities such as taking folic acid and making changes to diet and lifestyle. 2) The “poor knowledge” group, who also had high levels of pregnancy planning, did not carry out pre-pregnancy activities and described themselves as having poor knowledge. Elsewhere in their interviews they expressed a strong dislike of micronutrient supplementation. 3) The “absent pre-pregnancy period” group, had the lowest levels of pregnancy planning and also expressed anti-supplement views. Even discussing the pre-pregnancy period with this group was difficult as responses to questions quickly shifted to focus on pregnancy itself. Knowledge of folic acid was poor in all groups. Conclusion Different pre-pregnancy care approaches are likely to be needed for each of the groups. Among the “prepared” group, who were proactive and receptive to health messages, greater availability of information and better response from health professionals could improve the range of pre-pregnancy activities carried out. Among the “poor knowledge” group, better response from health professionals might yield greater uptake of pre-pregnancy information. A different, general health strategy might be more appropriate for the “absent pre-pregnancy period” group. The fact that general attitudes to micronutrient supplementation were closely related to whether or not women invested in pre-pregnancy health and care was an unanticipated finding and warrants further investigation.This report is independent research commissioned and funded by the Department of Health Policy Research Programme Pre-Pregnancy Health and Care in England: Exploring Implementation and Public Health Impact, 006/0068
A broadly implementable research course in phage discovery and genomics for first-year undergraduate students
Engaging large numbers of undergraduates in authentic scientific discovery is desirable but difficult to achieve. We have developed a general model in which faculty and teaching assistants from diverse academic institutions are trained to teach a research course for first-year undergraduate students focused on bacteriophage discovery and genomics. The course is situated within a broader scientific context aimed at understanding viral diversity, such that faculty and students are collaborators with established researchers in the field. The Howard Hughes Medical Institute (HHMI) Science Education Alliance Phage Hunters Advancing Genomics and Evolutionary Science (SEA-PHAGES) course has been widely implemented and has been taken by over 4,800 students at 73 institutions. We show here that this alliance-sourced model not only substantially advances the field of phage genomics but also stimulates students\u27 interest in science, positively influences academic achievement, and enhances persistence in science, technology, engineering, and mathematics (STEM) disciplines. Broad application of this model by integrating other research areas with large numbers of early-career undergraduate students has the potential to be transformative in science education and research training
Derivation of Induced Pluripotent Stem Cells from Human Peripheral Blood T Lymphocytes
Induced pluripotent stem cells (iPSCs) hold enormous potential for the development of personalized in vitro disease models, genomic health analyses, and autologous cell therapy. Here we describe the generation of T lymphocyte-derived iPSCs from small, clinically advantageous volumes of non-mobilized peripheral blood. These T-cell derived iPSCs (“TiPS”) retain a normal karyotype and genetic identity to the donor. They share common characteristics with human embryonic stem cells (hESCs) with respect to morphology, pluripotency-associated marker expression and capacity to generate neurons, cardiomyocytes, and hematopoietic progenitor cells. Additionally, they retain their characteristic T-cell receptor (TCR) gene rearrangements, a property which could be exploited for iPSC clone tracking and T-cell development studies. Reprogramming T-cells procured in a minimally invasive manner can be used to characterize and expand donor specific iPSCs, and control their differentiation into specific lineages
The Global Financial Crisis and the Shift to Shadow Banking
While most economists agree that the world is facing the worst economic crisis since the Great Depression, there is little agreement as to what caused it. Some have argued that the financial instability we are witnessing is due to irrational exuberance of market participants, fraud, greed, too much regulation, et cetera. However, some Post Keynesian economists following Hyman P. Minsky have argued that this is a systemic problem, a result of internal market processes that allowed fragility to build over time. In this paper we focus on the shift to the 'shadow banking system' and the creation of what Minsky called the money manager phase of capitalism. In this system, rapid growth of leverage and financial layering allowed the financial sector to claim an ever-rising proportion of national income-what is sometimes called 'financialization'-as the financial system evolved from hedge to speculative and, finally, to a Ponzi scheme. The policy response to the financial crisis in the United States and elsewhere has largely been an attempt to rescue money manager capitalism. Moreover, in the case of the United States. the bailout policy has contributed to further concentration of the financial sector, increasing dangers. We believe that the policies directed at saving the system are doomed to fail-and that alternative policies should be adopted. The effective solution should come in the way of downsizing the financial sector by two-thirds or more, and effecting fundamental modifications
Predictors of Time to Death After Terminal Withdrawal of Mechanical Ventilation in the ICU
Little information exists about the expected time to death after terminal withdrawal of mechanical ventilation. We sought to determine the independent predictors of time to death after withdrawal of mechanical ventilation.
METHODS:
We conducted a secondary analysis from a cluster randomized trial of an end-of-life care intervention. We studied 1,505 adult patients in 14 hospitals in Washington State who died within or shortly after discharge from an ICU following terminal withdrawal of mechanical ventilation (August 2003 to February 2008). Time to death and its predictors were abstracted from the patients' charts and death certificates. Predictors included demographics, proxies of severity of illness, life-sustaining therapies, and International Classification of Diseases, 9th ed., Clinical Modification codes.
RESULTS:
The median (interquartile range [IQR]) age of the cohort was 71 years (58-80 years), and 44% were women. The median (IQR) time to death after withdrawal of ventilation was 0.93 hours (0.25-5.5 hours). Using Cox regression, the independent predictors of a shorter time to death were nonwhite race (hazard ratio [HR], 1.17; 95% CI, 1.01-1.35), number of organ failures (per-organ HR, 1.11; 95% CI, 1.04-1.19), vasopressors (HR, 1.67; 95% CI, 1.49-1.88), IV fluids (HR, 1.16; 95% CI, 1.01-1.32), and surgical vs medical service (HR, 1.29; 95% CI, 1.06-1.56). Predictors of longer time to death were older age (per-decade HR, 0.95; 95% CI, 0.90-0.99) and female sex (HR, 0.86; 95% CI, 0.77-0.97).
CONCLUSIONS:
Time to death after withdrawal of mechanical ventilation varies widely, yet the majority of patients die within 24 hours. Subsequent validation of these predictors may help to inform family counseling at the end of life.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/85787/1/Cooke - Predictors of time to death after withdrawal.pd
A Broadly Implementable Research Course in Phage Discovery and Genomics for First-Year Undergraduate Students
Engaging large numbers of undergraduates in authentic scientific discovery is desirable but difficult to achieve. We have developed a general model in which faculty and teaching assistants from diverse academic institutions are trained to teach a research course for first-year undergraduate students focused on bacteriophage discovery and genomics. The course is situated within a broader scientific context aimed at understanding viral diversity, such that faculty and students are collaborators with established researchers in the field. The Howard Hughes Medical Institute (HHMI) Science Education Alliance Phage Hunters Advancing Genomics and Evolutionary Science (SEA-PHAGES) course has been widely implemented and has been taken by over 4,800 students at 73 institutions. We show here that this alliance-sourced model not only substantially advances the field of phage genomics but also stimulates students’ interest in science, positively influences academic achievement, and enhances persistence in science, technology, engineering, and mathematics (STEM) disciplines. Broad application of this model by integrating other research areas with large numbers of early-career undergraduate students has the potential to be transformative in science education and research training
- …