2,267 research outputs found

    Evolution of Initiation Rites During the Austronesian Dispersal

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    As adaptive systems, kinship and its accompanying rules have co-evolved with elements of complex societies, including wealth inheritance, subsistence, and power relations. Here we consider an aspect of kinship evolution in the Austronesian dispersal that began from about 5500ā€‰BP in Taiwan, reaching Melanesia about 3200ā€‰BP, and dispersing into Micronesia by 1500ā€‰BP. Previous, foundational work has used phylogenetic comparative methods and ethnolinguistic information to infer matrilocal residence in proto-Austronesian societies. Here we apply Bayesian phylogenetic analyses to a data set on Austronesian societies that combines existing data on marital residence systems with a new set of ethnographic data, introduced here, on initiation rites. Transition likelihoods between cultural-trait combinations were modeled on an ensemble of 1000 possible Austronesian language trees, using Reversible Jump Markov Chain Monte Carlo (RJ-MCMC) simulations. Compared against a baseline phylogenetic model of independent evolution, a phylogenetic model of correlated evolution between female and male initiation rites is substantially more likely (log Bayes factor: 17.9). This indicates, over the generations of Austronesian dispersal, initiation rites were culturally stable when both female and male rites were in the same state (both present or both absent), yet relatively unstable for female-only rites. The results indicate correlated phylogeographic evolution of cultural initiation rites in the prehistoric dispersal of Austronesian societies across the Pacific. Once acquired, male initiation rites were more resilient than female-only rites among Austronesian societies

    Biodiversity, Baking and Boiling, Endangered Species Act Turning Down the Heat

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    Today the Earth faces an extinction event on a scale second only to Earth\u27s largest mass extinction, the Permian-Triassic event, which occurred 250 million years ago. Upwards of 70 percent of the Earth\u27s species could be at risk of extinction with a 3.5Ā°C (6.3Ā°F) rise in temperature, which could occur by the end of this century. The driver is global warming, caused by anthropogenic greenhouse gas emissions. As such, a rational climate policy is needed immediately to prevent the complete collapse of biodiversity. Yet, the United Statesā€”the world\u27s largest cumulative contributor to emissionsā€”is in a state of paralysis when it comes to implementing climate solutions. This paralysis arises from a complex of cultural, political, and economic origins. It is perhaps understandable that persons, be they individual humans or corporations, would not respond readily. Humans\u27 ability to fundamentally alter our environs has far outstripped our limited ability to calculate cost/benefit in the abstract and over the long term. On the other hand, there is no excuse for inaction on the part of government. One of the primary purposes of government is social order. Implicit in the organization of society is that at a collective, governmental level we are better at calculating abstract long-term cost/benefit. The government must therefore take definitive steps in the face of the climate crisis. This article begins by providing a brief overview of biodiversity, the threats global warming poses to it, and the economic and social costs that the loss of biodiversity will exact on human society. We then review four key examples of ways in which the Endangered Species Act operates, or should operate, to address global warming and greenhouse gas emissions and confer substantial benefits on species threatened by the climate crisis: the listing process, the section 7 consultation process required of federal agencies, the designation of critical habitat, and the preparation and implementation of recovery plans

    Point-of-care tissue oxygenation assessment with SnapshotNIR for alloplastic and autologous breast reconstruction

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    UNLABELLED: In breast reconstruction, mastectomy and free flaps are susceptible to vascular compromise and tissue necrosis. The SnapshotNIR device (Kent Imaging, Calgary, AB, Canada) utilizes near-infrared spectroscopy to measure tissue oxygen saturation (StO METHODS: Patients receiving immediate alloplastic reconstruction after mastectomy or autologous reconstruction were enrolled. Preoperative, intraoperative, and postoperative images were taken of the flaps. StO RESULTS: Thirty-two breasts underwent alloplastic reconstruction; 38 breasts underwent autologous reconstruction. No enrollees developed skin necrosis. StO CONCLUSIONS: The SnapshotNIR device detected normal spatial and temporal differences in tissue oxygenation over the operative course of alloplastic and autologous breast reconstruction. A multi-institutional, prospective clinical trial is needed to determine the sensitivity and specificity of this device for detecting skin flap necrosis

    The history and innovations of blood vessel anastomosis

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    Surgical technique and technology frequently coevolve. The brief history of blood vessel anastomosis is full of famous names. While the techniques pioneered by these surgeons have been well described, the technology that facilitated their advancements and their inventors deserve recognition. The mass production of laboratory microscopes in the mid-1800s allowed for an explosion of interest in tissue histology. This improved understanding of vascular physiology and thrombosis laid the groundwork for Carrel and Guthrie to report some of the first successful vascular anastomoses. In 1916, McLean discovered heparin. Twenty-four years later, Gordon Murray found that it could prevent thrombosis when performing end-to-end anastomosis. These discoveries paved the way for the first-in-human kidney transplantations. Otolaryngologists Nylen and Holmgren were the first to bring the laboratory microscope into the operating room, but Jacobson was the first to apply these techniques to microvascular anastomosis. His first successful attempt in 1960 and the subsequent development of microsurgical tools allowed for an explosion of interest in microsurgery, and several decades of innovation followed. Today, new advancements promise to make microvascular and vascular surgery faster, cheaper, and safer for patients. The future of surgery will always be inextricably tied to the creativity and vision of its innovators

    KATP channels are necessary for glucose-dependent increases in amyloid-Ī² and Alzheimer\u27s disease-related pathology

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    Elevated blood glucose levels, or hyperglycemia, can increase brain excitability and amyloid-Ī² (AĪ²) release, offering a mechanistic link between type 2 diabetes and Alzheimer\u27s disease (AD). Since the cellular mechanisms governing this relationship are poorly understood, we explored whether ATP-sensitive potassium (KATP) channels, which couple changes in energy availability with cellular excitability, play a role in AD pathogenesis. First, we demonstrate that KATP channel subunits Kir6.2/KCNJ11 and SUR1/ABCC8 were expressed on excitatory and inhibitory neurons in the human brain, and cortical expression of KCNJ11 and ABCC8 changed with AD pathology in humans and mice. Next, we explored whether eliminating neuronal KATP channel activity uncoupled the relationship between metabolism, excitability, and AĪ² pathology in a potentially novel mouse model of cerebral amyloidosis and neuronal KATP channel ablation (i.e., amyloid precursor protein [APP]/PS1 Kir6.2-/- mouse). Using both acute and chronic paradigms, we demonstrate that Kir6.2-KATP channels are metabolic sensors that regulate hyperglycemia-dependent increases in interstitial fluid levels of AĪ², amyloidogenic processing of APP, and amyloid plaque formation, which may be dependent on lactate release. These studies identify a potentially new role for Kir6.2-KATP channels in AD and suggest that pharmacological manipulation of Kir6.2-KATP channels holds therapeutic promise in reducing AĪ² pathology in patients with diabetes or prediabetes

    Surgery for Bismuth-Corlette Type 4 Perihilar Cholangiocarcinoma:Results from a Western Multicenter Collaborative Group

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    Contains fulltext : 239075.pdf (Publisherā€™s version ) (Open Access)BACKGROUND: Although Bismuth-Corlette (BC) type 4 perihilar cholangiocarcinoma (pCCA) is no longer considered a contraindication for curative surgery, few data are available from Western series to indicate the outcomes for these patients. This study aimed to compare the short- and long-term outcomes for patients with BC type 4 versus BC types 2 and 3 pCCA undergoing surgical resection using a multi-institutional international database. METHODS: Uni- and multivariable analyses of patients undergoing surgery at 20 Western centers for BC types 2 and 3 pCCA and BC type 4 pCCA. RESULTS: Among 1138 pCCA patients included in the study, 826 (73%) had BC type 2 or 3 disease and 312 (27%) had type 4 disease. The two groups demonstrated significant differences in terms of clinicopathologic characteristics (i.e., portal vein embolization, extended hepatectomy, and positive margin). The incidence of severe complications was 46% for the BC types 2 and 3 patients and 51% for the BC type 4 patients (p = 0.1). Moreover, the 90-day mortality was 13% for the BC types 2 and 3 patients and 12% for the BC type 4 patients (p = 0.57). Lymph-node metastasis (N1; hazard-ratio [HR], 1.62), positive margins (R1; HR, 1.36), perineural invasion (HR, 1.53), and poor grade of differentiation (HR, 1.25) were predictors of survival (all p ā‰¤0.004), but BC type was not associated with prognosis. Among the N0 and R0 patients, the 5-year overall survival was 43% for the patients with BC types 2 and 3 pCCA and 41% for those with BC type 4 pCCA (p = 0.60). CONCLUSIONS: In this analysis of a large Western multi-institutional cohort, resection was shown to be an acceptable curative treatment option for selected patients with BC type 4 pCCA although a more technically challenging surgical approach was required

    Delayed Stellar Mass Assembly in the Low Surface Brightness Dwarf Galaxy KDG215

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    We present HI spectral line and optical broadband images of the nearby low surface brightness dwarf galaxy KDG215. The HI images, acquired with the Karl G. Jansky Very Large Array (VLA), reveal a dispersion dominated ISM with only weak signatures of coherent rotation. The HI gas reaches a peak mass surface density of 6 MāŠ™_{\odot} pcāˆ’2^{-2} at the location of the peak surface brightness in the optical and the UV. Although KDG215 is gas-rich, the HĪ±\alpha non-detection implies a very low current massive star formation rate. In order to investigate the recent evolution of this system, we have derived the recent and lifetime star formation histories from archival Hubble Space Telescope images. The recent star formation history shows a peak star formation rate āˆ¼\sim1 Gyr ago, followed by a decreasing star formation rate to the present day quiescent state. The cumulative star formation history indicates that a significant fraction of the stellar mass assembly in KDG215 has occurred within the last 1.25 Gyr. KDG215 is one of only a few known galaxies which demonstrates such a delayed star formation history. While the ancient stellar population (predominantly red giants) is prominent, the look-back time by which 50% of the mass of all stars ever formed had been created is among the youngest of any known galaxy.Comment: Accepted for publication in the Astrophysical Journal Letter
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