Lawful Humean explanations are not circular

A long-standing charge of circularity against regularity accounts of laws has recently seen a surge of renewed interest. The difficulty is that we appeal to laws to explain their worldly instances, but if these laws are descriptions of regularities in the instances then they are explained by those very instances. By the transitivity of explanation, we reach an absurd conclusion: instances of the laws explain themselves. While drawing a distinction between metaphysical and scientific explanations merely modifies the challenge rather than resolving it, I argue that it does point us towards an attractive solution. According to Humeanism, the most prominent form of the regularity view, laws capture information about important patterns in the phenomena. By invoking laws in scientific explanations, Humeans are showing how a given explanandum is subsumed into a more general pattern. Doing so both undermines a principle of transitivity that plays a crucial role in the circularity argument and draws out a central feature of the Humean approach to scientific explanation

Fine mapping of genes determining extrafusal fiber properties in murine soleus muscle

Peer reviewedPostprin

Music Scholarship Online (MuSO): a research environment for a more democratic digital musicology

This paper describes the work to date on Music Scholarship Online (MuSO), an online research environment for digitized and born digital music resources that inscribes itself within the federated model of the Advanced Research Consortium (ARC). With the project now in its third year, MuSO has reached an inflection point where it has developed a musiccentered RDF schema and demonstrated the potential for federated searching across ARC nodes by crosswalking eighteenth-century music content from Europeana into ARC. The case study presented here outlines the dissemination role that MuSO proposes to play within the music research community, the history of MuSO in relation to ARC, the Europeana test case, and future steps for the continued development of MuSO. By facilitating the discovery of digital music content, and providing a virtual environment for music researchers, MuSO will promote data reuse, strengthen community standards in music representation, and create possibilities for cross-disciplinary exchange. We propose that by leveraging the connections between digital music resources and digital humanities research technologies, MuSO will facilitate new research that expands the musicological discipline

The dispersion of spherical droplets in source–sink flows and their relevance to the COVID-19 pandemic

In this paper, we investigate the dynamics of spherical droplets in the presence of a source-sink pair flow field. The dynamics of the droplets is governed by the Maxey-Riley equation with Basset-Boussinesq history term neglected. We find that, in the absence of gravity, there are two distinct behaviours for the droplets: small droplets cannot go further than a specific distance, which we determine analytically, from the source before getting pulled into the sink. Larger droplets can travel further from the source before getting pulled into the sink by virtue of their larger inertia, and their maximum travelled distance is determined analytically. We investigate the effects of gravity, and we find that there are three distinct droplet behaviours categorised by their relative sizes: small, intermediate-sized, and large. Counterintuitively, we find that the droplets with minimum horizontal range are neither small nor large, but of intermediate size. Furthermore, we show that in conditions of regular human respiration, these intermediate-sized droplets range in size from a few $\mu$m to a few hundred $\mu$m. The result that such droplets have a very short range could have important implications for the interpretation of existing data on droplet dispersion.Comment: 14 pages, 7 figure

Complementary approaches to understanding the plant circadian clock

Circadian clocks are oscillatory genetic networks that help organisms adapt to the 24-hour day/night cycle. The clock of the green alga Ostreococcus tauri is the simplest plant clock discovered so far. Its many advantages as an experimental system facilitate the testing of computational predictions. We present a model of the Ostreococcus clock in the stochastic process algebra Bio-PEPA and exploit its mapping to different analysis techniques, such as ordinary differential equations, stochastic simulation algorithms and model-checking. The small number of molecules reported for this system tests the limits of the continuous approximation underlying differential equations. We investigate the difference between continuous-deterministic and discrete-stochastic approaches. Stochastic simulation and model-checking allow us to formulate new hypotheses on the system behaviour, such as the presence of self-sustained oscillations in single cells under constant light conditions. We investigate how to model the timing of dawn and dusk in the context of model-checking, which we use to compute how the probability distributions of key biochemical species change over time. These show that the relative variation in expression level is smallest at the time of peak expression, making peak time an optimal experimental phase marker. Building on these analyses, we use approaches from evolutionary systems biology to investigate how changes in the rate of mRNA degradation impacts the phase of a key protein likely to affect fitness. We explore how robust this circadian clock is towards such potential mutational changes in its underlying biochemistry. Our work shows that multiple approaches lead to a more complete understanding of the clock

Management of peripheral arterial disease in diabetes: a national survey of podiatry practice in the United Kingdom

Background We aimed to investigate podiatry practice in diagnosing peripheral arterial disease (PAD) in diabetes, decision making once PAD is suspected and limitations of referral pathways. Methods A survey, comprising 26 questions was distributed to podiatrists across the UK via mailing lists of collaborating organizations including the College of Podiatry (UK). Response rates were estimated based on NHS workforce data. Analysis of responses from the open-ended questions was performed using inductive content analysis. Results Data from 283 respondents were analyzed. Response rate for all NHS podiatrists across the UK was estimated to be 6%. For the detection of arterial disease only 18.8% (n = 49/260) of participants reported using a full combination of history, pulse palpation, Doppler and ABPI assessment. Self-reported confidence in detecting arterial disease was highest amongst podiatrists who felt they had received adequate training compared to podiatrists who felt they had not (median 85 (IQR 75–90) vs 67 (50–77), respectively; p  20 diabetic patients per week compared to those who see < 20 (median 80 (IQR 70–90) vs 72 (60–82.8), respectively; p < 0.001). Over one third of respondents (35.8%, n = 93/260) were aware of missed cases of PAD in the past year and 17.5% (n = 38/217) believed that this resulted in an amputation in some cases. The survey highlighted a lack of clarity amongst podiatrists regarding referral guidelines. Additionally, 69% (n = 169/242) reported that their patients had to wait longer than 2-weeks for specialist vascular assessment and 67.6% (n = 54/80) reported similar waits for a Duplex Ultrasound scan. There was a statistically significant variation in DUS waiting time across the UK (X2 (10, N = 80) = 21.59, p = 0.017). Inability to make a direct referral to vascular services and long delays were reported as major limitations of the referral pathway. Conclusion We have identified important targets for further investigation and quality improvement

Thinking through illusion

Perception of a property (e.g. a colour, a shape, a size) can enable thought about the property, while at the same time misleading the subject as to what the property is like. This long-overlooked claim parallels a more familiar observation concerning perception-based thought about objects, namely that perception can enable a subject to think about an object while at the same time misleading her as to what the object is like. I defend the overlooked claim, and then use it to generate a challenge for a standard way of thinking about the relationship between visual experience and rational belief formation. Put informally, that view holds that just as we can mislead others by saying something false, illusory experience misleads by misrepresenting how things stand in the world. I argue that we ought to abandon this view in favour of some radical alternative account of the relationship between visual experience and rational belief formation

Current and Calcium Responses to Local Activation of Axonal NMDA Receptors in Developing Cerebellar Molecular Layer Interneurons

In developing cerebellar molecular layer interneurons (MLIs), NMDA increases spontaneous GABA release. This effect had been attributed to either direct activation of presynaptic NMDA receptors (preNMDARs) or an indirect pathway involving activation of somato-dendritic NMDARs followed by passive spread of somatic depolarization along the axon and activation of axonal voltage dependent Ca2+ channels (VDCCs). Using Ca2+ imaging and electrophysiology, we searched for preNMDARs by uncaging NMDAR agonists either broadly throughout the whole field or locally at specific axonal locations. Releasing either NMDA or glutamate in the presence of NBQX using short laser pulses elicited current transients that were highly sensitive to the location of the spot and restricted to a small number of varicosities. The signal was abolished in the presence of high Mg2+ or by the addition of APV. Similar paradigms yielded restricted Ca2+ transients in interneurons loaded with a Ca2+ indicator. We found that the synaptic effects of NMDA were not inhibited by blocking VDCCs but were impaired in the presence of the ryanodine receptor antagonist dantrolene. Furthermore, in voltage clamped cells, bath applied NMDA triggers Ca2+ elevations and induces neurotransmitter release in the axonal compartment. Our results suggest the existence of preNMDARs in developing MLIs and propose their involvement in the NMDA-evoked increase in GABA release by triggering a Ca2+-induced Ca2+ release process mediated by presynaptic Ca2+ stores. Such a mechanism is likely to exert a crucial role in various forms of Ca2+-mediated synaptic plasticity

Close encounters: Analyzing how social similarity and propinquity contribute to strong network connections.

Models of network formation emphasize the importance of social similarity and propinquity in producing strong interpersonal connections. The positive effect each factor can have on tie strength has been documented across a number of studies, and yet we know surprisingly very little about how the two factors combine to produce strong ties. Being in close proximity could either amplify or dampen the positive effect that social similarity can have on tie strength. Data on tie strength among teachers working in five public schools were analyzed to shed light on this theoretical question. The empirical results indicate that teachers who were similar in age were more likely to be connected by a strong tie, especially teachers for whom age similarity was more likely to be salient. Moreover, teachers who took breaks at the same time or who had classrooms on the same floor communicated more frequently and felt more emotionally attached. Among the public school teachers, propinquity amplified the positive effect that age similarity had on tie strength. The strongest network connections occurred among age-similar teachers who had classrooms on the same floor. The empirical results illustrate the value of considering how social similarity and propinquity contribute to strong ties independently and when combined with each other