765 research outputs found

    Interacting six-dimensional topological field theories

    Get PDF
    We study the gauge-fixing and symmetries (BRST-invariance and vector supersymmetry) of various six-dimensional topological models involving Abelian or non-Abelian 2-form potentials.Comment: 11 page

    Monopoly and Power Implications for Trans Health Care Specialists Working in a Centralised Setting: A Qualitative Study

    Get PDF
    In the last decade, the range and number of people accessing trans health care has increased at a faster rate than previously. Globally trans health care is commonly used as a requirement for trans people to access legal gender recognition. In Europe, trans health care is often provided within centralised health systems by a limited number of specialist teams placed in monopoly positions. Through a qualitative study, we sought to understand the relationship and role these teams have with legal gender recognition. We conducted in-depth interviews with a team located in Central and Eastern Europe and consulted with local key informants working in trans health advocacy outside the team. After applying qualitative content analysis emerging themes comprised three sections: the team in context; conceptions of trans health care; and beyond the clinic.Findings indicated that the team conceived trans identities and clinical needs in a medical framework that correlated with the process for legal gender recognition. This followed a similar historical progression across Europe. As the few respected specialists in the country, the team influenced care regulations within the ministry and held a monopoly position. While reform of some regulations was seen as needed, they were met with challenges within the health system and field. These challenges were, however, found to reflect trans health care globally rather than the team itself. Our findings suggest comparisons could be drawn to similar positioned teams throughout Europe regarding decision making, power, and influence. Increased transparency and cooperation between local trans communities and health care providers will be vital

    Personalized treatment of brain metastases: Evolving survival prediction models may benefit from evaluation of serum tumor markers (narrative review)

    Get PDF
    Treatment of a limited number of brain metastases (oligometastases) might include complex and sometimes invasive approaches, e.g. neurosurgical resection followed by post-operative stereotactic radiotherapy, and thus, correct identification of patients who are appropriate candidates is crucial. Both, staging procedures that visualize the true number of metastastic lesions and prognostic assessments that identify patients with limited survival, who should be managed with less complex, palliative approaches, are necessary before proceeding with local treatment that aims at eradication of all oligometastases. Some of the prognostic models, e.g. the LabBM score (laboratory parameters in patients with brain metastases), include blood biomarkers believed to represent surrogate markers of disease extent. In a recent study, patients with oligometastases and a LabBM score of 0 (no abnormal biomarkers) had an actuarial 5-year survival rate of 27% after neurosurgical resection and 39% after stereotactic radiotherapy. Other studies have tied serum tumor markers such as carcinoembryonic antigen (CEA) to survival outcomes. Even if head-to-head comparisons and large-scale definitive analyses are lacking, the available data suggest that attempts to integrate tumor marker levels in blood biomarker-based survival prediction models are warranted

    Exploiting orbital constraints from optical data to detect binary gamma-Ray pulsars

    Get PDF
    It is difficult to discover pulsars via their gamma-ray emission because current instruments typically detect fewer than one photon per million rotations. This creates a significant computing challenge for isolated pulsars, where the typical parameter search space spans wide ranges in four dimensions. It is even more demanding when the pulsar is in a binary system, where the orbital motion introduces several additional unknown parameters. Building on earlier work by Pletsch & Clark, we present optimal methods for such searches. These can also incorporate external constraints on the parameter space to be searched, for example, from optical observations of a presumed binary companion. The solution has two parts. The first is the construction of optimal search grids in parameter space via a parameter space metric, for initial semicoherent searches and subsequent fully coherent follow-ups. The second is a method to demodulate and detect the periodic pulsations. These methods have different sensitivity properties than traditional radio searches for binary pulsars and might unveil new populations of pulsars. © 2020. The Author(s). Published by the American Astronomical Society

    How we treat octogenarians with brain metastases

    Full text link
    Biologically younger, fully independent octogenarians are able to tolerate most oncological treatments. Increasing frailty results in decreasing eligibility for certain treatments, e.g., chemotherapy and surgery. Most brain metastases are not an isolated problem, but part of widespread cancer dissemination, often in combination with compromised performance status. Multidisciplinary assessment is key in this vulnerable patient population where age, frailty, comorbidity and even moderate additional deficits from brain metastases or their treatment may result in immobilization, hospitalization, need for nursing home care, termination of systemic anticancer treatment etc. Here, we provide examples of successful treatment (surgery, radiosurgery, systemic therapy) and best supportive care, and comment on the limitations of prognostic scores, which often were developed in all-comers rather than octogenarians. Despite selection bias in retrospective studies, survival after radiosurgery was more encouraging than after whole-brain radiotherapy. Prospective research with focus on octogenarians is warranted to optimize outcomes

    Personalized radiotherapy of brain metastases: survival prediction by means of dichotomized or differentiated blood test results?

    Get PDF
    Background and objectives: The validated LabBM score (laboratory parameters in patients with brain metastases) represents a widely applicable survival prediction model, which incorporates 5 blood test results (serum lactate dehydrogenase (LDH), C-reactive protein (CRP), albumin, platelets and hemoglobin). All tests are classified as normal or abnormal, without accounting for the wide range of abnormality observed in practice. We tested the hypothesis that improved stratification might be possible, if more granular test results are employed. Methods: Retrospective analysis of 198 patients managed with primary whole-brain radiotherapy in one of the institutions who validated the original LabBM score. Results: For two blood tests (albumin, CRP), discrimination was best for the original dichotomized version (normal/abnormal). For two others (LDH, hemoglobin), a three-tiered classification was best. The number of patients with low platelet count was not large enough for detailed analyses. A modified LabBM score was developed, which separates the intermediate of originally 3 prognostic groups into 2 statistically significantly different strata, resulting in a 4-tiered score. Conclusion: This initial proof-of-principle study suggests that granular blood test results might contribute to further improvement of the score, or alternatively development of a nomogram, if additional large-scale studies confirm the encouraging results of the present analysis

    Subitizing with Variational Autoencoders

    Full text link
    Numerosity, the number of objects in a set, is a basic property of a given visual scene. Many animals develop the perceptual ability to subitize: the near-instantaneous identification of the numerosity in small sets of visual items. In computer vision, it has been shown that numerosity emerges as a statistical property in neural networks during unsupervised learning from simple synthetic images. In this work, we focus on more complex natural images using unsupervised hierarchical neural networks. Specifically, we show that variational autoencoders are able to spontaneously perform subitizing after training without supervision on a large amount images from the Salient Object Subitizing dataset. While our method is unable to outperform supervised convolutional networks for subitizing, we observe that the networks learn to encode numerosity as basic visual property. Moreover, we find that the learned representations are likely invariant to object area; an observation in alignment with studies on biological neural networks in cognitive neuroscience

    Is the Black-widow Pulsar PSR J1555-2908 in a Hierarchical Triple System?

    Get PDF
    The 559 Hz black-widow pulsar PSR J1555-2908, originally discovered in radio, is also a bright gamma-ray pulsar. Timing its pulsations using 12 yr of Fermi-Large Area Telescope gamma-ray data reveals long-term variations in its spin frequency that are much larger than is observed from other millisecond pulsars. While this variability in the pulsar rotation rate could be intrinsic "timing noise,"here we consider an alternative explanation: the variations arise from the presence of a very-low-mass third object in a wide multiyear orbit around the neutron star and its low-mass companion. With current data, this hierarchical-triple-system model describes the pulsar's rotation slightly more accurately than the best-fitting timing noise model. Future observations will show if this alternative explanation is correct. © 2022. The Author(s). Published by the American Astronomical Society

    Comparing the face inversion effect in crows and humans

    Get PDF
    Humans show impaired recognition of faces that are presented upside down, a phenomenon termed face inversion effect, which is thought to reflect the special relevance of faces for humans. Here, we investigated whether a phylogenetically distantly related avian species, the carrion crow, with similar socio-cognitive abilities to human and non-human primates, exhibits a face inversion effect. In a delayed matching-to-sample task, two crows had to differentiate profiles of crow faces as well as matched controls, presented both upright and inverted. Because crows can discriminate humans based on their faces, we also assessed the face inversion effect using human faces. Both crows performed better with crow faces than with human faces, and performed worse when responding to inverted pictures in general compared to upright pictures. However, neither of the crows showed a face inversion effect. For comparative reasons, the tests were repeated with human subjects. As expected, humans showed a face-specific inversion effect. Therefore, we did not find any evidence that crows – like humans – process faces as a special visual stimulus. Instead, individual recognition in crows may be based on cues other than a conspecific’s facial profile, such as their body, or on processing of local features rather than holistic processing.This work was supported by Ph.D scholarships from the Cambridge Commonwealth, European and International Trust and Lucy Cavendish College Cambridge (KFB),  a DFG Grant NI 618/7-1 (AN), and by the European Research Council, Grant Agreement No. 3399933 (LO, NSC)

    European Society for Sexual Medicine position statement 'Assessment and hormonal management in adolescent and adult trans people, with attention for sexual function and satisfaction'

    Get PDF
    Background: There is a general lack of recommendations for and basic information tailored at sexologists and other health-care professionals for when they encounter trans people in their practice. Aim: We present to clinicians an up-to-date overview of clinical consensus statements on trans health care with attention for sexual function and satisfaction. Methods: The task force consisted of 7 clinicians experienced in trans health care, selected among European Society for Sexual Medicine (ESSM) scientific committee. The consensus was guided by clinical experience and a review of the available literature and by interactive discussions on trans health, with attention for sexual function and satisfaction where available. Outcomes: The foci of the study are assessment and hormonal aspects of trans health care. Results: As the available literature for direct recommendations was limited, most of the literature was used as background or indirect evidence. Clinical consensus statements were developed based on clinical experiences and the available literature. With the multiple barriers to care that many trans people experience, basic care principles still need to be stressed. We recommend that health-care professionals (HCPs) working with trans people recognize the diversity of genders, including male, female, and nonbinary individuals. In addition, HCPs assessing gender diverse children and adolescents should take a developmental approach that acknowledges the difference between prepubescent gender diverse children and pubescent gender diverse adolescents and trans adults. Furthermore, trans people seeking gender-affirming medical interventions should be assessed by HCPs with expertise in trans health care and gender-affirming psychological practice. If masculinization is desired, testosterone therapy with monitoring of serum sex steroid levels and signs of virilization is recommended. Similarly, if feminization is desired, we recommend estrogens and/or antiandrogen therapy with monitoring of serum sex steroid levels and signs of feminization. HCPs should be aware of the influence of hormonal therapy on sexual functioning and satisfaction. We recommend HCPs be aware of potential sexual problems during all surgical phases of treatment. Clinical Implications: This is an up-to-date ESSM position statement. Strengths & Limitations: These statements are based on the data that are currently available; however, it is vital to recognize that this is a rapidly changing field and that the literature, particularly in the field of sexual functioning and satisfaction, is limited. Conclusion: This ESSM position statement provides relevant information and references to existing clinical guidelines with the aim of informing relevant HCPs on best practices when working with transgender people
    • …
    corecore