Synovial sarcoma is the fourth most common type of soft-tissue sarcoma, accounting for 2.5%-10.5% of all primary soft-tissue malignancies worldwide. Synovial sarcoma most often affects the extremities (80%-95% of cases), particularly the knee in the popliteal fossa, of adolescents and young adults (15-40 years of age). Despite its name, the lesion does not commonly arise in an intraarticular location but usually occurs near joints. Histologic subtypes include monophasic, biphasic, and poorly differentiated; the cytogenetic aberration of the t(X;18) translocation is highly specific for synovial sarcoma. Although radiographic features of these tumors are not pathognomonic, findings of a soft-tissue mass, particularly if calcified (30%), near but not in a joint of a young patient, are very suggestive of the diagnosis. Cross-sectional imaging features are vital for staging tumor extent and planning surgical resection; they also frequently reveal suggestive appearances of multilobulation and marked heterogeneity (creating the "triple sign") with hemorrhage, fluid levels, and septa (creating the "bowl of grapes" sign). Two features associated with synovial sarcoma that may lead to an initial mistaken diagnosis of a benign indolent process are slow growth (average time to diagnosis, 2-4 years) and small size (< 5 cm at initial presentation); in addition, these lesions may demonstrate well-defined margins and homogeneous appearance on cross-sectional images. Synovial sarcoma is an intermediate- to high-grade lesion, and, despite initial aggressive wide surgical resection, local recurrence and metastatic disease are common and prognosis is guarded. Understanding and recognizing the spectrum of appearances of synovial sarcoma, which reflect the underlying pathologic characteristics, improve radiologic assessment and are important for optimal patient management.

Stepping-stones are used extensively by attackers to hide their identity and access restricted targets. Many methods have been proposed to detect stepping-stones and resist evasive behaviour, but so far no benchmark dataset exists to provide a fair comparison of detection rates. We propose a comprehensive framework to simulate realistic stepping-stone behaviour that includes effective evasion tools, and release a large dataset, which we use to evaluate detection rates for eight state-of-the-art methods. Our results show that detection results for several methods fall behind the claimed detection rates, even without the presence of evasion tactics. Furthermore, currently no method is capable to reliably detect stepping-stone when the attacker inserts suitable chaff perturbations, disproving several robustness claims and indicating that further improvements of existing detection models are necessary.

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Most P2P networks are used for file-sharing applications. These forms of applications mainly rely on keyword searching to locate file resources on the peers. Whilst this querying is suitable for many data-intensive applications, it is not suitable for applications where data changes over short periods of time, also known as time-critical applications. We investigate the use of timestamps on a peer's knowledge about an application to create queries so that other peers may reply with more up-to-date information to keep the peer's knowledge up-to-date. We propose means to synchronise peers to provide them with a shared, independent clock so that they utilize timestamps. To show that a peer's knowledge about a time-critical application affects the performance of other peers, we carried out experiments to show information propagation over a P2P network and use various metrics to evaluate our approach.

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