Zero area singularities in general relativity and inverse mean curvature flow

First we restate the definition of a Zero Area Singularity, recently introduced by H. Bray. We then consider several definitions of mass for these singularities. We use the Inverse Mean Curvature Flow to prove some new results about the mass of a singularity, the ADM mass of the manifold, and the capacity of the singularity.Comment: 13 page

Ramping single unit activity in the medial prefrontal cortex and ventral striatum reflects the onset of waiting but not imminent impulsive actions.

The medial prefrontal cortex (mPFC) and ventral striatum (VS), including the nucleus accumbens, are key forebrain regions involved in regulating behaviour for future rewards. Dysfunction of these regions can result in impulsivity, characterized by actions that are mistimed and executed without due consideration of their consequences. Here we recorded the activity of single neurons in the mPFC and VS of 16 rats during performance on a five-choice serial reaction time task of sustained visual attention and impulsivity. Impulsive responses were assessed by the number of premature responses made before target stimuli were presented. We found that the majority of cells signalled trial outcome after an action was made (both rewarded and unrewarded). Positive and negative ramping activity was a feature of population activity in the mPFC and VS (49.5 and 50.4% of cells, respectively). This delay-related activity increased at the same rate and reached the same maximum (or minimum) for trials terminated by either correct or premature responses. However, on premature trials, the ramping activity started earlier and coincided with shorter latencies to begin waiting. For all trial types the pattern of ramping activity was unchanged when the pre-stimulus delay period was made variable. Thus, premature responses may result from a failure in the timing of the initiation of a waiting process, combined with a reduced reliance on external sensory cues, rather than a primary failure in delay activity. Our findings further show that the neural locus of this aberrant timing signal may emanate from structures outside the mPFC and VS.This research was funded in part by a Medical Research Council grant to J.W.D. (G0701500) and by a joint award from the Medical Research Council (G1000183) and Wellcome Trust (093875/Z/10/Z) in support of the Behavioural and Clinical Neuroscience Institute at Cambridge University. N.A.D. was funded by the University of Cambridge School of Clinical Medicine MB/PhD Program. The authors would like to thank Alan Lyon and David Theobald for assistance with histology, Tim Harris and the Applied Physics and Instrumentation Group at HHMI Janelia Farm for providing electrodes, Ken Harris and the Klustateam at UCL for providing software for spike detection and sorting, and Tahl Holtzman for technical assistance with training in surgical procedures.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1111/ejn.1289

Validation of a blubber-based endocrine pregnancy test for humpback whales

Baleen whales have few identifiable external indicators of pregnancy state, making it challenging to study essential aspects of their biology and population dynamics. Pregnancy status in other marine mammals has been determined by measuring progesterone concentrations from a variety of sample matrices, but logistical constraints have limited such studies in free-swimming baleen whales. We use an extensive blubber sample archive and associated calving history data to retrospectively identify samples that correspond to pregnant females and develop a progesterone-based pregnancy test for humpback whales. The lowest pregnant blubber progesterone concentration was 54.97 ng g−1, and the mean for the known-pregnant group was 198.74 ± 180.65 ng g−1. Conversely, females known to be below the minimum age of sexual maturity (juvenile females) had an overall low mean progesterone concentration (0.59 ± 0.25 ng g−1), well below the known-pregnant range. Of the mature females that did not return with a calf (n = 11), three fell within the known-pregnant range (320.79 ± 209.34 ng g−1), while the levels for the remaining eight were two orders of magnitude below the lowest known-pregnant level (1.63 ± 1.15 ng g−1). The proportion of females that did not return with a calf but had values similar to known-pregnant females are consistent with rates of calf mortality, but other potential explanations were considered. Our findings support a validated blubber endocrine assignment of pregnancy corroborated with field life history information, a first for any baleen whale species. The progesterone values we measured were similar to those found in different pregnancy states of other cetaceans and support using blubber biopsy samples for assigning pregnancy in humpback whales. This method can be applied to existing archives or new samples to better study life history and population demography broadly across species and populations

The Circumference of the Subject: Figuring Race at Egyptian Hall

This article examines several exhibitions staged at William Bullock’s Egyptian Hall on Piccadilly in the years around 1820. It argues that the complex spatial interplay of the exhibition space reshaped figurations of race across media. Taking as its center the exhibition of Benjamin Robert Haydon’s Christ’s Triumphant Entry into Jerusalem (1820), the article explores problems of figure and ground, stasis and movement, and arrival and return that shaped racial ideology in this moment. Ultimately, it explores how such exhibition spaces articulated “race” not only as a perceivable property of an embodied subject, but as a set of spatial relations. Haydon’s figuration of the triumphant body’s arrival—and its failures—comes into view in relation to Bullock’s own natural-historical displays, his “museum” of Napoleonic relics (1816), the disturbing exhibition of a Sámi family (1822), and the display of paintings by James Ward and Théodore Géricault

New directions in cellular therapy of cancer: a summary of the summit on cellular therapy for cancer

A summit on cellular therapy for cancer discussed and presented advances related to the use of adoptive cellular therapy for melanoma and other cancers. The summit revealed that this field is advancing rapidly. Conventional cellular therapies, such as tumor infiltrating lymphocytes (TIL), are becoming more effective and more available. Gene therapy is becoming an important tool in adoptive cell therapy. Lymphocytes are being engineered to express high affinity T cell receptors (TCRs), chimeric antibody-T cell receptors (CARs) and cytokines. T cell subsets with more naïve and stem cell-like characteristics have been shown in pre-clinical models to be more effective than unselected populations and it is now possible to reprogram T cells and to produce T cells with stem cell characteristics. In the future, combinations of adoptive transfer of T cells and specific vaccination against the cognate antigen can be envisaged to further enhance the effectiveness of these therapies

Changes in pulmonary vascular responsiveness to hypoxia

We read with interest the recent article by Luks et al. (2017), which reports the relationship between arterial oxygen saturation and an echocardiographic index of pulmonary artery pressure (tricuspid transvalvular pressure gradient, TVPG) in healthy volunteers at sea level and after undertaking a two-week trek to Everest base cam

Inter-rater reliability of the Dysexecutive Questionnaire (DEX): comparative data from non-clinician respondents – all raters are not equal

Primary objective: The Dysexecutive Questionnaire (DEX) is used to obtain information about executive and emotional problems after neuropathology. The DEX is self-completed by the patient (DEX-S) and an independent rater such as a family member (DEX-I). This study examined the level of inter-rater agreement between either two or three non-clinician raters on the DEX-I in order to establish the reliability of DEX-I ratings. Methods and procedures: Family members and/or carers of 60 people with mixed neuropathology completed the DEX-I. For each patient, DEX-I ratings were obtained from either two or three raters who knew the person well prior to brain injury. Main outcomes and results: We obtained two independent-ratings for 60 patients and three independent-ratings for 36 patients. Intra-class correlations revealed that there was only a modest level of agreement for items, subscale and total DEX scores between raters for their particular family member. Several individual DEX items had low reliability and ratings for the emotion sub-scale had the lowest level of agreement. Conclusions: Independent DEX ratings completed by two or more non-clinician raters show only moderate correlation. Suggestions are made for improving the reliability of DEX-I ratings.</p