Shattering crystal with crystal: Galileo's rhetoric, lenses, and the epistemology of metaphor.

The terms that Galileo's contemporaries used for lenses (cristallo/i, lente/i, and vetro/i) have often been treated, and even translated, interchangeably. In this article, we argue that Galileo used references to crystals as lenses to embed epistemological and cosmological arguments in the material object of the telescope. Across Galileo's correspondence and letters, the term crystal had many uses and meanings. As a substance, crystal was a form of raw material, but crystal was also a substance that was central to scholastic cosmology and an explanatory device on which scholastics relied to explain first the appearance of the new star of 1604 and then Galileo's new telescopic discoveries. When Galileo began using the word crystals as a synonym for lenses, he endowed the material of his instrument with cosmological arguments. Galileo's choice of language was deliberate and polemical, serving as a joke at the expense of scholastics and as a linguistic marker of social proximity to Galileo and his intellectual agenda, especially among the members of the Academy of the Lincei. Rhetorically and linguistically, Galileo chose to refer to his lenses as crystals both because of the material from which they were made and because in so doing he signaled the epistemological work that the lenses would perform. Ultimately, the crystal lenses in Galileo's telescope and writings shattered the crystalline spheres, replacing explanatory metaphors with a polemical emphasis on the material and empirical realities of objects.

"What is Dead May Not Die": Locating Marginalized Concepts Among Ordinary Biologists.

Historians and biologists identify the debate between mechanists and vitalists over the nature of life itself with the arguments of Driesch, Loeb, and other prominent voices. But what if the conversation was broader and the consequences deeper for the field? Following the suspicions of Joseph Needham in the 1930s and Francis Crick in the 1960s, we deployed tools of the digital humanities to an old problem in the history of biology. We analyzed over 31,000 peer-reviewed scientific papers and learned that bioexceptionalism participated in a robust discursive landscape throughout subfields of the life sciences, occupied even by otherwise unknown biologists.

Effects of neural differentiation maturity status of human induced pluripotent stem cells prior to grafting in a subcortical ischemic stroke model.

Neural cell grafting is a promising therapy for stroke, but the optimal differentiation status of the cells prior to grafting is unclear. We grafted cells at different maturity stages (days 28, 42, or 56 of in vitro neural differentiation) into the brains of eight-week-old rats one week after subcortical ischemic stroke, and assessed motor and sensory behavioral recovery over one month. We did not find a difference between the grafted or control groups on behavioral recovery, or on brain tissue outcomes including infarct size, microgliosis, or astrocytosis. Further research is needed into mechanisms of benefit of neural cell grafting for stroke.

Effect of enzymatic and mechanical methods of dissociation on neural progenitor cells derived from induced pluripotent stem cells.

PURPOSE: To determine the most effective method of dissociating neural stem and progenitor cells into a single-cell suspension. MATERIALS/METHODS: Induced pluripotent stem cells were differentiated toward the neural fate for 4 weeks before clusters were subjected to enzymatic (Accutase, trypsin, TrypLE, dispase, or DNase I) or mechanical (trituration with pipettes of varying size) or combined dissociation. Images of cells were analyzed for cluster size using ImageJ. RESULTS: Cells treated with the enzymes Accutase, TrypLE, or trypsin/EDTA, these enzymes followed by trituration, or a combination one of these enzymes followed by incubation with another enzyme, including DNase I, were more likely to be dissociated into a single-cell suspension. CONCLUSIONS: Cells treated with enzymes or combinations of methods were more likely to be dissociated into a single-cell suspension.

Detection of influenza antigenic variants directly from clinical samples using polyclonal antibody based proximity ligation assays.

Identification of antigenic variants is the key to a successful influenza vaccination program. The empirical serological methods to determine influenza antigenic properties require viral propagation. Here a novel quantitative PCR-based antigenic characterization method using polyclonal antibody and proximity ligation assays, or so-called polyPLA, was developed and validated. This method can detect a viral titer that is less than 1000 TCID50/mL. Not only can this method differentiate between different HA subtypes of influenza viruses but also effectively identify antigenic drift events within the same HA subtype of influenza viruses. Applications in H3N2 seasonal influenza data showed that the results from this novel method are consistent with those from the conventional serological assays. This method is not limited to the detection of antigenic variants in influenza but also other pathogens. It has the potential to be applied through a large-scale platform in disease surveillance requiring minimal biosafety and directly using clinical samples.

Effect of different feeding schedules on the survival and neural differentiation of human embryonic and induced pluripotent stem cells.

Neural culture of human pluripotent stem cells is useful for neuroscience research, but the optimal feeding schedule for these in vitro systems is unclear. We evaluated the survival and neural differentiation profiles of human embryonic and induced pluripotent stem cells cultured with medium exchange schedules of five, six, or seven days weekly through two months of differentiation. No significant differences were seen in cell numbers or neural differentiation markers through this culture interval with either human pluripotent cell type. We conclude that there is unlikely to be an advantage of feeding more than five days weekly for this culture system.

Self-affirmation among the poor: cognitive and behavioral implications.

The poor are universally stigmatized. The stigma of poverty includes being perceived as incompetent and feeling shunned and disrespected. It can lead to cognitive distancing, diminish cognitive performance, and cause the poor to forego beneficial programs. In the present research, we examined how self-affirmation can mitigate the stigma of poverty through randomized field experiments involving low-income individuals at an inner-city soup kitchen. Because of low literacy levels, we used an oral rather than written affirmation procedure, in which participants verbally described a personal experience that made them feel successful or proud. Compared with nonaffirmed participants, affirmed individuals exhibited better executive control, higher fluid intelligence, and a greater willingness to avail themselves of benefits programs. The effects were not driven by elevated positive mood, and the same intervention did not affect the performance of wealthy participants. The findings suggest that self-affirmation can improve the cognitive performance and decisions of the poor, and it may have important policy implications.

Inferences of competence from faces predict election outcomes.

We show that inferences of competence based solely on facial appearance predicted the outcomes of U.S. congressional elections better than chance (e.g., 68.8% of the Senate races in 2004) and also were linearly related to the margin of victory. These inferences were specific to competence and occurred within a 1-second exposure to the faces of the candidates. The findings suggest that rapid, unreflective trait inferences can contribute to voting choices, which are widely assumed to be based primarily on rational and deliberative considerations.

Tetranectin Binds to the Kringle 1-4 Form of Angiostatin and Modifies Its Functional Activity.

Tetranectin is a plasminogen kringle 4 domain-binding protein present in plasma and various tissue locations. Decreased plasma tetranectin or increased tetranectin in stroma of cancers correlates with cancer progression and adverse prognosis. A possible mechanism through which tetranectin could influence cancer progression is by altering activities of plasminogen or the plasminogen fragment, angiostatin. Tetranectin was found to bind to the kringle 1-4 form of angiostatin (AST $;{\text{K1-4}}$ ). In addition, tetranectin inhibited binding of plasminogen or AST $;{\text{K1-4}}$ to extracellular matrix (ECM) deposited by endothelial cells. Finally, tetranectin partially counteracted the ability of AST $;{\text{K1-4}}$ to inhibit proliferation of endothelial cells. This latter effect of tetranectin was specific for AST $;{\text{K1-4}}$ since it did not counteract the antiproliferative activities of the kringle 1-3 form of angiostatin (AST $;{\text{K1-3}}$ ) or endostatin. These findings suggest that tetranectin may modulate angiogenesis through interactions with AST.