A counterexample to the first Zassenhaus conjecture

Hans J. Zassenhaus conjectured that for any unit u of finite order in the integral group ring of a finite group G there exists a unit a in the rational group algebra of G such that a−1· u · a = ±g for some g ∈ G. We disprove this conjecture by first proving general results that help identify counterexamples and then providing an infinite number of examples where these results apply. Our smallest example is a metabelian group of order 27·32·5·72·192 whose integral group ring contains a unit of order 7 · 19 which, in the rational group algebra, is not conjugate to any element of the form ±g

Trace element and isotope geochemistry of Cretaceous-Tertiary boundary sediments: identification of extra-terrestrial and volcanic components

Trace element and stable isotope analyses were performed on a series of sediment samples crossing the Cretaceous-Tertiary (K-T) boundary from critical sections at Aumaya and Sopelano, Spain. The aim is to possibly distinguish extraterrestrial vs. volcanic or authigenic concentration of platinum group and other elements in K-T boundary transitional sediments. These sediments also have been shown to contain evidence for step-wise extinction of several groups of marine invertebrates, associated with negative oxygen and carbon isotope excursions occurring during the last million years of the Cretaceous. These isotope excursions have been interpreted to indicate major changes in ocean thermal regime, circulation, and ecosystems that may be related to multiple events during latest Cretaceous time. Results to date on the petrographic and geochemical analyses of the Late Cretaceous and Early Paleocene sediments indicate that diagenesis has obviously affected the trace element geochemistry and stable isotope compositions at Zumaya. Mineralogical and geochemical analysis of K-T boundary sediments at Zumaya suggest that a substantial fraction of anomalous trace elements in the boundary marl are present in specific mineral phases. Platinum and nickel grains perhaps represent the first direct evidence of siderophile-rich minerals at the boundary. The presence of spinels and Ni-rich particles as inclusions in aluminosilicate spherules from Zumaya suggests an original, non-diagenetic origin for the spherules. Similar spherules from southern Spain (Caravaca), show a strong marine authigenic overprint. This research represents a new approach in trying to directly identify the sedimentary mineral components that are responsible for the trace element concentrations associated with the K-T boundary

Taking Arduino to the Internet of things: the ASIP programming model

Micro-controllers such as Arduino are widely used by all kinds of makers worldwide. Popularity has been driven by Arduino’s simplicity of use and the large number of sensors and libraries available to extend the basic capabilities of these controllers. The last decade has witnessed a surge of software engineering solutions for “the Internet of Things”, but in several cases these solutions require computational resources that are more advanced than simple, resource-limited micro-controllers. Surprisingly, in spite of being the basic ingredients of complex hardware–software systems, there does not seem to be a simple and flexible way to (1) extend the basic capabilities of micro-controllers, and (2) to coordinate inter-connected micro-controllers in “the Internet of Things”. Indeed, new capabilities are added on a per-application basis and interactions are mainly limited to bespoke, point-to-point protocols that target the hardware I/O rather than the services provided by this hardware. In this paper we present the Arduino Service Interface Programming (ASIP) model, a new model that addresses the issues above by (1) providing a “Service” abstraction to easily add new capabilities to micro-controllers, and (2) providing support for networked boards using a range of strategies, including socket connections, bridging devices, MQTT-based publish–subscribe messaging, discovery services, etc. We provide an open-source implementation of the code running on Arduino boards and client libraries in Java, Python, Racket and Erlang. We show how ASIP enables the rapid development of non-trivial applications (coordination of input/output on distributed boards and implementation of a line-following algorithm for a remote robot) and we assess the performance of ASIP in several ways, both quantitative and qualitative

On Pedagogy and the Human Sciences

In launching PHS, our goal is to stimulate theory, practice, research and reflection on the process of teaching and learning in disciplines that address the question of what it means to be human. In so doing, we cast our net broadly to include not only psychology and the traditional social sciences, but also disciplines that are often considered to be part of the humanities – philosophy, literary studies, religious studies, history and related fields. We embrace the full range of different modes of inquiry, including philosophical reflection and analysis, quantitative and qualitative empirical research, action research, ethnography, hermeneutic and discursive analysis, and other modes of expression and analysis

The spatio-temporal segregation of GAD forms defines distinct GABA signaling functions in the developing mouse olfactory system and provides novel insights into the origin and migration of GnRH neurons.

GABA (gamma-aminobutyric acid) has a dual role as an inhibitory neurotransmitter in the adult central nervous system (CNS) and as a signaling molecule exerting largely excitatory actions during development. The rate-limiting step of GABA synthesis is catalyzed by two glutamic acid decarboxylase isoforms GAD65 and GAD67 co-expressed in the GABAergic neurons of the CNS. Here we report that the two GADs show virtually non-overlapping expression patterns consistent with distinct roles in the developing peripheral olfactory system. GAD65 is expressed exclusively in undifferentiated neuronal progenitors confined to the proliferative zones of the sensory vomeronasal and olfactory epithelia. In contrast GAD67 is expressed in a subregion of the non-sensory epithelium/vomeronasal organ epithelium containing the putative GnRH progenitors and GnRH neurons migrating from this region through the frontonasal mesenchyme (FNM) into the basal forebrain. Only GAD67+, but not GAD65+ cells accumulate detectable GABA. We further demonstrate that GAD67 and its embryonic splice variant EGAD concomitant with GnRH are dynamically regulated during GnRH neuronal migration in vivo and in two immortalized cell lines representing migratory (GN11) and post-migratory (GT1-7) stage GnRH neurons, respectively. Analysis of GAD65/67 single and double knock-out (KO) embryos revealed that the two GADs play complementary (inhibitory) roles in GnRH migration ultimately modulating the speed and/or direction of GnRH migration. Our results also suggest that GAD65 and GAD67/EGAD characterized by distinct subcellular localization and kinetics have disparate functions during olfactory system development mediating proliferative and migratory responses putatively through specific subcellular GABA pools. (c) 2014 Wiley Periodicals, Inc. Develop Neurobiol, 2014

Towards cyber-physical systems as services: the ASIP protocol

The development of Cyber-Physical Systems needs to address the heterogeneity of several components that interact to build a single application. In this paper we present a model to enable easy integration and interaction of micro-controllers. Specifically, we describe the Arduino Service Interface Protocol (ASIP), we provide an implementation and client libraries for Java, Racket and Erlang, together with the description of a practical example

A Ypt/Rab Effector Complex Containing the Sec1 Homolog Vps33p is Required for Homotypic Vacuole Fusion

Yeast vacuoles undergo priming, docking, and homotypic fusion, although little has been known of the connections between these reactions. Vacuole-associated Vam2p and Vam6p (Vam2/6p) are components of a 65S complex containing SNARE proteins. Upon priming by Sec18p/NSF and ATP, Vam2/6p is released as a 38S subcomplex that binds Ypt7p to initiate docking. We now report that the 38S complex consists of both Vam2/6p and the class C Vps proteins [Reider, S. E. and Emr, S. D. (1997) Mol. Biol. Cell 8, 2307-2327]. This complex includes Vps33p, a member of the Sec1 family of proteins that bind t-SNAREs. We term this 38S complex HOPS, for homotypic fusion and vacuole protein sorting. This unexpected finding explains how Vam2/6p associates with SNAREs and provides a mechanistic link of the class C Vps proteins to Ypt/Rab action. HOPS initially associates with vacuole SNAREs in cis and, after release by priming, hops to Ypt7p, activating this Ypt/Rab switch to initiate docking

NASA Light-Emitting Diodes for the Prevention of Oral Mucositis in Pediatric Bone Marrow Transplant Patients

Objective: The purpose of this study was to determine the effects of prophylactic near-infrared light therapy from light-emitting diodes (LEDs) in pediatric bone marrow transplant (BMT) recipients. Background Data: Oral mucositis (OM) is a frequent side effect of chemotherapy that leads to increased morbidity. Near-infrared light has been shown to produce biostimulatory effects in tissues, and previous results using nearinfrared lasers have shown improvement in OM indices. However, LEDs may hold greater potential for clinical applications. Materials and Methods: We recruited 32 consecutive pediatric patients undergoing myeloablative therapy in preparation for BMT. Patients were examined by two of three pediatric dentists trained in assessing the Schubert oral mucositis index (OMI) for left and right buccal and lateral tongue mucosal surfaces, while the patients were asked to rate their current left and right mouth pain, left and right xerostomia, and throat pain. LED therapy consisted of daily treatment at a fluence of 4 J/cm2 using a 670-nm LED array held to the left extraoral epithelium starting on the day of transplant, with a concurrent sham treatment on the right. Patients were assessed before BMT and every 2–3 days through posttransplant day 14. Outcomes included the percentage of patients with ulcerative oral mucositis (UOM) compared to historical epidemiological controls, the comparison of left and right buccal pain to throat pain, and the comparison between sides of the buccal and lateral tongue OMI and buccal pain. Results: The incidence of UOM was 53%, compared to an expected rate of 70–90%. There was also a 48% and 39% reduction of treated left and right buccal pain, respectively, compared to untreated throat pain at about posttransplant day 7 (p \u3c 0.05). There were no significant differences between sides in OMI or pain. Conclusion: Although more studies are needed, LED therapy appears useful in the prevention of OM in pediatric BMT patients

Latency reversal and viral clearance to cure HIV-1

Research toward a cure for human immunodeficiency virus type 1 (HIV-1) infection has joined prevention and treatment efforts in the global public health agenda. A major approach to HIV eradication envisions antiretroviral suppression, paired with targeted therapies to enforce the expression of viral antigen from quiescent HIV-1 genomes, and immunotherapies to clear latent infection. These strategies are targeted to lead to viral eradication—a cure for AIDS. Paired testing of latency reversal and clearance strategies has begun, but additional obstacles to HIV eradication may emerge. Nevertheless, there is reason for optimism that advances in long-acting antiretroviral therapy and HIV prevention strategies will contribute to efforts in HIV cure research and that the implementation of these efforts will synergize to markedly blunt the effect of the HIV pandemic on society