67 research outputs found

    On counting permutations by pairs of congruence classes of major index

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    For a fixed positive integer n, let S_n denote the symmetric group of n! permutations on n symbols, and let maj(sigma) denote the major index of a permutation sigma. For positive integers k<m not greater than n and non-negative integers i and j, we give enumerative formulas for the cardinality of the set of permutations sigma in S_n with maj(sigma) congruent to i mod k and maj(sigma^(-1)) congruent to j mod m. When m divides n-1 and k divides n, we show that for all i,j, this cardinality equals (n!)/(km).Comment: 8 page

    Supporting the Least Able Throughout and Beyond CLTS

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    Since its conception in 1999, Community-Led Total Sanitation (CLTS) has spread to over 60 countries and resulted in millions of people across the world living in open defecation free (ODF) communities. The approach was a departure from subsidydriven sanitation programming which often led to uneven adoption and only partial use. CLTS enabled communities to own the process and collectively work towards becoming ODF. However, since its implementation at scale a number of challenges have appeared. Emerging evidence is suggesting a need to better support the most disadvantaged with accessible and sustainable sanitation facilities. This Learning Brief presents emerging principles and action points to strengthen intra-community support and introduce external support mechanisms for the least able when necessary and appropriate. It is one of several outputs from an Asia-region workshop convened in the Philippines by the CLTS Knowledge Hub and UNICEF between 24-28 May 2017.Sid

    Cadherin-Mediated Differential Cell Adhesion Controls Slow Muscle Cell Migration in the Developing Zebrafish Myotome

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    AbstractSlow-twitch muscle fibers of the zebrafish myotome undergo a unique set of morphogenetic cell movements. During embryogenesis, slow-twitch muscle derives from the adaxial cells, a layer of paraxial mesoderm that differentiates medially within the myotome, immediately adjacent to the notochord. Subsequently, slow-twitch muscle cells migrate through the entire myotome, coming to lie at its most lateral surface. Here we examine the cellular and molecular basis for slow-twitch muscle cell migration. We show that slow-twitch muscle cell morphogenesis is marked by behaviors typical of cells influenced by differential cell adhesion. Dynamic and reciprocal waves of N-cadherin and M-cadherin expression within the myotome, which correlate precisely with cell migration, generate differential adhesive environments that drive slow-twitch muscle cell migration through the myotome. Removing or altering the expression of either protein within the myotome perturbs migration. These results provide a definitive example of homophilic cell adhesion shaping cellular behavior during vertebrate development

    An Early Neolithic House in the Foothills:A Case Study of Pottery and Lithic Artefacts from the Biskupice Site 18 (Wieliczka Foothills, Southern Poland)

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    Highlights•Biskupice site (S Poland) represents the late Želiezovce phase (5300 to 5000 BCE).•Pottery was produced locally, and showed a use of animal fats for cooking.•The face vessel was of local origin, but influenced by Transcarpathian style.•Obsidian artefacts originated from the Carpathian 1a/1b chemical type, S-E Slovakia.•Transcarpathian contacts between LBK and Bükk culture were discussed.AbstractThe paper presents a comprehensive analysis of pottery and lithic materials found in archaeological features associated with an Early Neolithic house from Biskupice (southern Poland) to shed light on exchange networks of the first farmers in Central Europe. The research began with the discovery of a unique fragment of a face vessel made in the Želiezovce style, a motif primarily found in Moravia and north-eastern Austria. Therefore, specialised analyses were undertaken to determine whether the Biskupice fragment was locally produced or originated from areas south of the Sudetes and Carpathians. The study involved an examination of raw clay material and the technology used to create the anthropomorphic vessel, aiming to establish its provenance (local production versus import). Petrographic methods were employed to analyse a diverse group of vessel types for comparison. Additionally, a selected group of pottery fragments, including the face vessel, underwent lipid residue analysis to determine their potential use. The combination of microscopic examinations and lipid residues analysis was utilised to study the link between the physical properties and function of the vessels. Finally, the archaeological context of other artifacts from the same house, including lithic assemblages, was investigated to determine the presence of both local and imported raw materials in Biskupice. The main conclusion of the study indicates local production of pottery, including the face vessel, and lithic implements. Conversely, a Transcarpathian transfer of some technological and decorative ideas, as well as imports of raw material such as obsidian, were confirmed

    The discourse dynamics approach to metaphor and metaphor-led discourse analysis

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    The use of metaphor as a tool to uncover people's ideas, attitudes, and values through analysis of discourse is demonstrated and illustrated with data collected in a social science research project. A 'discourse dynamics' approach to metaphor situated within a complexity/dynamic systems perspective is developed. This approach is turned into a method of 'metaphor-led discourse analysis' which is described in detail, using a focus group discussion to illustrate the procedure: transcription, metaphor identification, coding metaphors and using software, and finding patterns of metaphor use from coded data. The reasoning that justifies decisions at each stage of the procedure is made explicit so that the trustworthiness of the method can be maximized. The method of metaphor-led discourse analysis has been developed through a series of empirical projects to be accessible and relevant to social science researchers as well as to metaphor scholars

    The INT6 Cancer Gene and MEK Signaling Pathways Converge during Zebrafish Development

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    BACKGROUND: Int-6 (integration site 6) was identified as an oncogene in a screen of tumorigenic mouse mammary tumor virus (MMTV) insertions. INT6 expression is altered in human cancers, but the precise role of disrupted INT6 in tumorigenesis remains unclear, and an animal model to study Int-6 physiological function has been lacking. PRINCIPAL FINDINGS: Here, we create an in vivo model of Int6 function in zebrafish, and through genetic and chemical-genetic approaches implicate Int6 as a tissue-specific modulator of MEK-ERK signaling. We find that Int6 is required for normal expression of MEK1 protein in human cells, and for Erk signaling in zebrafish embryos. Loss of either Int6 or Mek signaling causes defects in craniofacial development, and Int6 and Erk-signaling have overlapping domains of tissue expression. SIGNIFICANCE: Our results provide new insight into the physiological role of vertebrate Int6, and have implications for the treatment of human tumors displaying altered INT6 expression

    Fortifying or fragmenting the state? The political economy of the drug trade in Shan State, Myanmar, 1988-2012

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    Over the past twenty-five years, the government of Myanmar (Burma) has consolidated control over large parts of Shan State, neutralizing much of the threat posed by armed groups and strengthening its hold over revenue extraction. During this period Myanmar has retained its position as the world's second largest producer of illicit opium, much of which is converted into heroin within the country's borders. This article explores the relationship between state-building processes and the illicit opium/heroin economy in Shan State since 1988. The author has four aims. First, to reassess the theoretical assumptions that equate illicit economies with state fragility and demonstrate instead why illicit drug economies can become embedded in processes of conflict reduction and state consolidation. Second, to explain why establishing control over Shan State has become so important to the Myanmar government's state-building ambitions. Third, to analyze how the state's engagement with the drug trade has become a vital part of its attempts to consolidate control, in terms of financing military expansion and brokering deals with strongmen who are able to govern local populations. Finally, to assess how these strategies embody a form of “negotiated statehood” in which the state's growing control has been defined by attempts to manage, rather than monopolize, the means of coercion and extraction

    Movement Behaviour of Traditionally Managed Cattle in the Eastern Province of Zambia Captured Using Two-Dimensional Motion Sensors

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    Two-dimensional motion sensors use electronic accelerometers to record the lying, standing and walking activity of cattle. Movement behaviour data collected automatically using these sensors over prolonged periods of time could be of use to stakeholders making management and disease control decisions in rural sub-Saharan Africa leading to potential improvements in animal health and production. Motion sensors were used in this study with the aim of monitoring and quantifying the movement behaviour of traditionally managed Angoni cattle in Petauke District in the Eastern Province of Zambia. This study was designed to assess whether motion sensors were suitable for use on traditionally managed cattle in two veterinary camps in Petauke District in the Eastern Province of Zambia. In each veterinary camp, twenty cattle were selected for study. Each animal had a motion sensor placed on its hind leg to continuously measure and record its movement behaviour over a two week period. Analysing the sensor data using principal components analysis (PCA) revealed that the majority of variability in behaviour among studied cattle could be attributed to their behaviour at night and in the morning. The behaviour at night was markedly different between veterinary camps; while differences in the morning appeared to reflect varying behaviour across all animals. The study results validate the use of such motion sensors in the chosen setting and highlight the importance of appropriate data summarisation techniques to adequately describe and compare animal movement behaviours if association to other factors, such as location, breed or health status are to be assessed

    Atmosphere-ocean-ice interactions in the Amundsen Sea Embayment, West Antarctica

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    Over recent decades outlet glaciers of the Amundsen Sea Embayment (ASE), West Antarctica, have accelerated, thinned and retreated, and are now contributing approximately 10% to global sea level rise. All the ASE glaciers flow into ice shelves, and it is the thinning of these since the 1970s, and their ungrounding from “pinning points” that is widely held to be responsible for triggering the glaciers’ decline. These changes have been linked to the inflow of warm Circumpolar Deep Water (CDW) onto the ASE's continental shelf. CDW delivery is highly variable, and is closely related to the regional atmospheric circulation. The ASE is south of the Amundsen Sea Low (ASL), which has a large variability and which has deepened in recent decades. The ASL is influenced by the phase of the Southern Annular Mode, along with tropical climate variability. It is not currently possible to simulate such complex atmosphere-ocean-ice interactions in models, hampering prediction of future change. The current retreat could mark the beginning of an unstable phase of the ASE glaciers that, if continued, will result in collapse of the West Antarctic Ice Sheet, but numerical ice-sheet models currently lack the predictive power to answer this question. It is equally possible that the recent retreat will be short-lived and that the ASE will find a new stable state. Progress is hindered by incomplete knowledge of bed topography in the vicinity of the grounding line. Furthermore, a number of key processes are still missing or poorly represented in models of ice-flow
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