All journals should have a policy defining authorship - here's what to include

Scientific research papers with large numbers of authors have become more commonplace, increasing the likelihood of authorship disputes. Danielle Padula, Theresa Somerville and Ben Mudrak emphasise the importance of journals clearly defining and communicating authorship criteria to researchers. As well as having a policy for inclusion, journals should also indicate unethical authorship practices, clarify the order of authors at an early stage, consider recognising “contributorship”, and refer any disputes that do arise to the authors’ institutions

Transformation of Epidermal Cells in Culture

Studies performed on mouse skin have indicated that chemical carcinogenesis can be subdivided into two distinct stages, initiation and promotion. Initiation results from exposure to a classical mutagenic carcinogen and is irreversible even after a single exposure. The permanently altered initiated cell and its progeny may never form a tumor or in any way be recognizable in the target tissue. Exposure to tumor promoters permits the expression of the neoplastic change in initiated cells, and tumors develop. In contrast to initiators, promoters must be given repeatedly to be effective; individual exposures are reversible. A similar biology is suggested by epidemiologic studies of certain human cancers, particularly lung, breast, colon, and uterine malignancies. Studies in mouse skin cell culture have provided new insights into the changes associated with initiation and promotion. Initiated cells appear to be resistant to signals for terminal differentiation and can proliferate under conditions where normal epidermal cells are obligated to cease proliferation and begin their maturation program. This change is essential for an epithelial tumor cell since it provides the ability to grow away from a basement- membrane attachment site. In cultured epidermal cells, tumor promoters are capable of selectively stimulating the growth of certain cells, including initiated cells, while simultaneously inducing terminal differentiation in other epidermal cells. The net effect of these responses to promoters is the clonal expansion of cells stimulated to proliferate. In this way, promoters are capable of increasing the clone size of initiated cells. These cell culture data provided a biological framework for understanding initiation and promotion in terminally differentiating epithelial tissues

Dialetheism and Modus Tollens

Suppose that some contradictions are true – for example, that as I walk through the door, I’m inside and I’m not inside. Then we argue 'if I'm walking through the door, I'm inside; I'm not inside; therefore, I'm not walking through the door' is an invalid instance of modus tollens

Mouse genetics identifies unique and overlapping functions of fibroblast growth factor receptors in keratinocytes

Fibroblast growth factors (FGFs) are key regulators of tissue development, homeostasis and repair, and abnormal FGF signalling is associated with various human diseases. In human and murine epidermis, FGF receptor 3 (FGFR3) activation causes benign skin tumours, but the consequences of FGFR3 deficiency in this tissue have not been determined. Here, we show that FGFR3 in keratinocytes is dispensable for mouse skin development, homeostasis and wound repair. However, the defect in the epidermal barrier and the resulting inflammatory skin disease that develops in mice lacking FGFR1 and FGFR2 in keratinocytes were further aggravated upon additional loss of FGFR3. This caused fibroblast activation and fibrosis in the FGFR1/FGFR2 double-knockout mice and even more in mice lacking all three FGFRs, revealing functional redundancy of FGFR3 with FGFR1 and FGFR2 for maintaining the epidermal barrier. Taken together, our study demonstrates that FGFR1, FGFR2 and FGFR3 act together to maintain epidermal integrity and cutaneous homeostasis, with FGFR2 being the dominant receptor

Associations of GP practice characteristics with the rate of ambulatory care sensitive conditions in people living with dementia in England:an ecological analysis of routine data

Abstract Background Hospital admissions for Ambulatory Care Sensitive Conditions (ACSCs) are potentially avoidable. Dementia is one of the leading chronic conditions in terms of variability in ACSC admissions by general practice, as well as accounting for around a third of UK emergency admissions. Methods Using Bayesian multilevel linear regression models, we examined the ecological association of organizational characteristics of general practices (ACSC n=7076, non-ACSC n=7046 units) and Clinical Commissioning Groups (CCG n=212 units) in relation to ACSC and non-ACSC admissions for people with dementia in England. Results The rate of hospital admissions are variable between GP practices, with deprivation and being admitted from home as risk factors for admission for ACSC and non-ACSC admissions. The budget allocated by the CCG to mental health shows diverging effects for ACSC versus non-ACSC admissions, so it is likely there is some geographic variation. Conclusions A variety of factors that could explain avoidable admissions for PWD at the practice level were examined; most were equally predictive for avoidable and non-avoidable admissions. However, a high amount of variation found at the practice level, in conjunction with the diverging effects of the CCG mental health budget, implies that guidance may be applied inconsistently, or local services may have differences in referral criteria. This indicates there is potential scope for improvement

Airborne fine-resolution UHF radar: an approach to the study of englacial reflections, firn compaction and ice attenuation rates

This is the published version. Copyright 2015 International Glaciological SocietyWe have built and operated an ultra-wideband UHF pulsed-chirp radar for measuring firn stratigraphy from airborne platforms over the ice sheets of Greenland and West Antarctica. Our analysis found a wide range of capabilities, including imaging of post firn–ice transition horizons and sounding of shallow glaciers and ice shelves. Imaging of horizons to depths exceeding 600 m was possible in the colder interior regions of the ice sheet, where scattering from the ice surface and inclusions was minimal. The radar's high sensitivity and large dynamic range point to loss tangent variations as the dominant mechanism for these englacial reflective horizons. The radar is capable of mapping interfaces with reflection coefficients as low as –80 dB near the firn–ice transition and as low as –64 dB at depths of 600 m. We found that firn horizon reflectivity strongly mirrored density variance, a result of the near-unity interfacial transmission coefficients. Zones with differing compaction mechanisms were also apparent in the data. We were able to sound many ice shelves and areas of shallow ice. We estimated ice attenuation rates for a few locations, and our attenuation estimates for the Ross Ice Shelf, West Antarctica, appear to agree well with earlier reported results

Solving Directed Feedback Vertex Set by Iterative Reduction to Vertex Cover

In the Directed Feedback Vertex Set (DFVS) problem, one is given a directed graph G = (V,E) and wants to find a minimum cardinality set S ? V such that G-S is acyclic. DFVS is a fundamental problem in computer science and finds applications in areas such as deadlock detection. The problem was the subject of the 2022 PACE coding challenge. We develop a novel exact algorithm for the problem that is tailored to perform well on instances that are mostly bi-directed. For such instances, we adapt techniques from the well-researched vertex cover problem. Our core idea is an iterative reduction to vertex cover. To this end, we also develop a new reduction rule that reduces the number of not bi-directed edges. With the resulting algorithm, we were able to win third place in the exact track of the PACE challenge. We perform computational experiments and compare the running time to other exact algorithms, in particular to the winning algorithm in PACE. Our experiments show that we outpace the other algorithms on instances that have a low density of uni-directed edges

PACE Solver Description: Mount Doom - An Exact Solver for Directed Feedback Vertex Set

In this document we describe the techniques we used and implemented for our submission to the Parameterized Algorithms and Computational Experiments Challenge (PACE) 2022. The given problem is Directed Feedback Vertex Set (DFVS), where one is given a directed graph G = (V,E) and wants to find a minimum S ? V such that G-S is acyclic. We approach this problem by first exhaustively applying a set of reduction rules. In order to find a minimum DFVS on the remaining instance, we create and solve a series of Vertex Cover instances