442 research outputs found

    The Effects of Population Size Histories on Estimates of Selection Coefficients from Time-Series Genetic Data.

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    Many approaches have been developed for inferring selection coefficients from time series data while accounting for genetic drift. These approaches have been motivated by the intuition that properly accounting for the population size history can significantly improve estimates of selective strengths. However, the improvement in inference accuracy that can be attained by modeling drift has not been characterized. Here, by comparing maximum likelihood estimates of selection coefficients that account for the true population size history with estimates that ignore drift by assuming allele frequencies evolve deterministically in a population of infinite size, we address the following questions: how much can modeling the population size history improve estimates of selection coefficients? How much can mis-inferred population sizes hurt inferences of selection coefficients? We conduct our analysis under the discrete Wright-Fisher model by deriving the exact probability of an allele frequency trajectory in a population of time-varying size and we replicate our results under the diffusion model. For both models, we find that ignoring drift leads to estimates of selection coefficients that are nearly as accurate as estimates that account for the true population history, even when population sizes are small and drift is high. This result is of interest because inference methods that ignore drift are widely used in evolutionary studies and can be many orders of magnitude faster than methods that account for population sizes

    Is Vertical Logistic Regression Privacy-Preserving? A Comprehensive Privacy Analysis and Beyond

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    We consider vertical logistic regression (VLR) trained with mini-batch gradient descent -- a setting which has attracted growing interest among industries and proven to be useful in a wide range of applications including finance and medical research. We provide a comprehensive and rigorous privacy analysis of VLR in a class of open-source Federated Learning frameworks, where the protocols might differ between one another, yet a procedure of obtaining local gradients is implicitly shared. We first consider the honest-but-curious threat model, in which the detailed implementation of protocol is neglected and only the shared procedure is assumed, which we abstract as an oracle. We find that even under this general setting, single-dimension feature and label can still be recovered from the other party under suitable constraints of batch size, thus demonstrating the potential vulnerability of all frameworks following the same philosophy. Then we look into a popular instantiation of the protocol based on Homomorphic Encryption (HE). We propose an active attack that significantly weaken the constraints on batch size in the previous analysis via generating and compressing auxiliary ciphertext. To address the privacy leakage within the HE-based protocol, we develop a simple-yet-effective countermeasure based on Differential Privacy (DP), and provide both utility and privacy guarantees for the updated algorithm. Finally, we empirically verify the effectiveness of our attack and defense on benchmark datasets. Altogether, our findings suggest that all vertical federated learning frameworks that solely depend on HE might contain severe privacy risks, and DP, which has already demonstrated its power in horizontal federated learning, can also play a crucial role in the vertical setting, especially when coupled with HE or secure multi-party computation (MPC) techniques

    Simultaneous Bilateral Patellar Tendon Rupture in a Young Adult Male: A Case Report and Review of the Literature.

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    A bilateral patellar tendon rupture is extremely rare and has only been documented in case reports. Although the etiology remains unknown, predisposing factors include steroid usage, systemic diseases, and tendinopathies. In the present case, a healthy 33-year-old male with a prior history of bilateral patellar tendonitis and a diagnosis of Osgood-Schlatter disease during adolescence experienced simultaneous bilateral patellar tendon rupture after playing volleyball. He underwent bilateral patellar repair without complications. In the absence of trauma, spontaneous bilateral patellar tendon ruptures are associated with several predisposing factors, including systemic diseases, prior corticosteroid or fluoroquinolone usage, and history of tendinopathy. Injuries can be classified based on the location of the rupture. Bilateral patellar tendon ruptures can be misdiagnosed due to the rarity of cases and the lack of a normal comparative knee. Radiographic techniques can aid in the diagnosis, leading to early surgical treatment and improved outcomes. Early diagnosis and prompt surgical repair contribute to good functional outcomes in this potentially debilitating injury pattern

    Cutaneous Carcinosarcoma: A Small Case Series and Review of the Literature of a Rare Skin Tumor.

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    Carcinosarcomas are composed of epithelial and mesenchymal elements and primarily present within visceral organs. Despite being potentially aggressive, they are a rare diagnosis in the skin, and few manifestations have been reported to date. In this report, we describe two separate cases of carcinosarcoma presenting as nonhealing scalp wounds. Patient A: a 57-year-old male with a nonhealing skin lesion of ten years successfully treated with wide-local excision and local ortichochea flap reconstruction. Patient B: a 75-year-old female that presented with a painless, slow-growing hemorrhagic mass of 7 years invading the skull and dura ultimately requiring craniectomy and free-tissue transfer with anterolateral thigh flap. Cutaneous carcinosarcomas have more favorable outcomes due to low metastatic rates likely due to earlier detection, but delayed presentation can be fatal. Histopathological analysis is critical for determining diagnosis and prognosis. Adequate reconstruction after wide base excision varies and follows the reconstructive ladder/elevator ranging from primary closure up through free-tissue transfer. With cutaneous manifestations of carcinosarcoma seldom reported in the literature, it is our hope that reporting unusual instances such as this will raise awareness and allow for earlier diagnoses, treatments, and reconstructions

    Isolated Scaphoid Dislocation From Low-Energy Wrist Trauma

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    Isolated scaphoid dislocation is an extremely rare injury typically caused by high-energy trauma. We present the first observed case of isolated scaphoid dislocation resulting from a non-traumatic injury of the wrist in power-grip tension in a patient with a questionable history of Marfan Syndrome. A 20-yearold right-hand dominant man presented to the emergency department with right wrist pain and deformation after carrying a table. The patient reported a possible history of Marfan Syndrome, but it had never been definitively diagnosed. Imaging revealed radial dislocation of the scaphoid. Bedside closed reduction was performed followed by outpatient ligament reconstruction with return to normal activities at 6 months. Early diagnosis and management lead to an improved prognosis for isolated scaphoid dislocation. Regardless of patient history or mechanism of injury, treatment options include closed reduction, percutaneous fixation, and/or open reduction with internal fixation and ligamentous reconstructio
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