4,394 research outputs found

    Error-corrected quantum repeaters with GKP qudits

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    The Gottesman-Kitaev-Preskill (GKP) code offers the possibility to encode higher-dimensional qudits into individual bosonic modes with, for instance, photonic excitations. Since photons enable the reliable transmission of quantum information over long distances and since GKP states subject to photon loss can be recovered to some extent, the GKP code has found recent applications in theoretical investigations of quantum communication protocols. While previous studies have primarily focused on GKP qubits, the possible practical benefits of higher-dimensional GKP qudits are hitherto widely unexplored. In this paper, we carry out performance analyses for three quantum repeater protocols based on GKP qudits including concatenations with a multi-qudit quantum polynomial code. We find that the potential data transmission gains for qudits are often hampered by their decreased GKP error-correcting capabilities. However, we also identify parameter regimes in which having access to an increased number of quantum levels per mode can enhance the theoretically achievable secret-key rate of the quantum repeater. Some of our protocols share the attractive feature that local processing and complete error syndrome identification are realizable without online squeezing. Provided a supply of suitable multi-mode GKP states is available, this can be realized with a minimal set of passive linear optical operations, even when the logical qudits are composed of many physical qudits.Comment: 19+11 pages, 6+4 figures. Comments welcom

    Body-kun/body-chan style model figures for artists in forensic visualization applications

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    Posture and body position are often in the focus of forensic medicine. Visualization for the purposes of documentation, teaching, scientific presentation or expert opinion in court is often desired. Plenty of possible tools to support visualization are available. However, there is a significant gap between quick drawings and more complex techniques. Body-chan (female) and body-kun (male) artist’s model figurines (genericized trademark) may provide a useful means to fill this gap. These models, about 12–15 cm in height, are multi-articulated humanoids of realistic proportions, intended to serve as models for manga (japanese comic) drawing. Plenty of different models are available in different quality which usually are equipped with interchangeable hand and feet attachments, a frame for ‘levitating’ positions as well as assorted objects to scale. These inexpensive models may be positioned quickly and intuitively. Photodocumentation from various angles can be performed using a mobile phone camera. Images may be further improved applying digital image manipulation software. Taken together, the process is quick and intuitive and the level of achievable complexity is sufficient for many forensic applications

    Study of arcing processes in circuit breakers by means of spatially resolved magnetic field recordings

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    Magnetic field measurements performed on a circuit breaker in order to study the switching arc processes are presented. Characteristic for these measurements is the spatial two-dimensional recording of the magnetic field with simultaneous high temporal resolution. A sensor head was developed for this purpose, which records the magnetic flux density in an area of 42 mm x 60 mm with a spatial resolution of 12 x 24 measuring points. A highly integrated sensor chip based on the Hall effect was used for the design. The configurability of this sensor chip makes it possible to adapt the time resolution to the measurement task, always in compromise with the amplitude resolution and the number of field components to be measured. Measurements with a sampling rate of 80 kHz were conducted. Also, with the sampling rate reduced to 25 kHz, three axis measurements could be performed. By combining two sensor heads into one measuring system, it was possible to perform simultaneous measurements at the two contacts of a low-voltage circuit breaker with double breaker. As a result, both slow and fast changes in the magnetic field caused by the arcing process were recorded and visualized. The changes in the field distribution measured with the two sensor heads correlated well with the respective arc voltage. With the help of such magnetic field measurements, study of the arcing processes in low-voltage switchgear should be made possible without interference of the arc itself

    Application of the "bubbling" procedure to dead body portraits in forensic identification

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    Purpose A procedure is needed for bodies with disfiguring injuries to the face and the use of their portrait for visual identification. Method We present the application of a simple image processing procedure, otherwise known as ”bubbling,” which is based on the concept of ”perceptual filling-in,” to images for visual identification in the forensic context. The method is straight forward and can be performed using readily available software and hardware.. Results The method is demonstrated and examples are shown. The visual recognition of known persons using “bubbled” images was successfully tested. Conclusion The “bubbling” procedure for visual identification enhancement is quick and straightforward and may be attempted before escalating to more involved identification methods and procedures

    Relative blood loss in forensic medicine-do we need a change in doctrine?

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    In forensic medicine, blood loss is encountered frequently, either as a cause of death or as a contributing factor. Here, risk to life and lethality assessment is based on the concept of relative blood loss (absolute loss out of total volume). In emergency medicine, the Advanced Trauma Life Support (ATLS) classification also refers to relative blood loss. We tested the validity of relative blood loss benchmarks with reference to lethality. Depending on the quality of the total blood volume (TBV) estimation formula, relative blood loss rates should be reflected in the case cohort as significantly higher absolute blood loss in heavier individuals since all TBV estimation formulas positively correlate body weight with TBV. Method: 80 autopsy cases with sudden, quantifiable, exclusively internal blood loss were retrospectively analyzed and a total of 8 different formulas for TBV estimation were applied. Results: No statistical correlation between body weight and absolute blood loss was found for any of the tested TBV estimation algorithms. All cases showed a wide spread of both absolute and relative blood loss. Discussion: The principle of relative blood loss is of very limited use in casework. It opens the forensic expert opinion to unnecessary criticism and possible negative legal implications. Conclusion: We challenge the use of relative blood loss benchmarks in textbooks and practical casework and advocate for its elimination from the ATLS’s grading system. If necessary, we recommend the use of BMI-adjusted algorithms for TBV estimation

    Implants in patients with oral manifestations of autoimmune or muco-cutaneous diseases : a systematic review

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    To give an overview on implant survival rates in patients with oral manifestations of systemic autoimmune (oral Lichen planus (oLp), Pemphigus (Pe)), muco-cutaneous (Epidermolysis bullosa (EB)), autoimmune multisystemic rheumatic diseases (SjÜgren´s syndrome (SjS), systemic Lupus erythematosus (sLE), or systemic Sclerosis (sSc)). Systematic literature review (PubMed/Medline, Embase) using MESH and search term combinations, published between 1980 and August 2018 in English language reporting on dental implant-prosthetic rehabilitation of patients with oLp, Pe, EB, SjS, sLE, sSc, study design, age, gender, follow-up period (? 12 months), implant survival rate. Implant-related weighed mean values of implant survival rate (wmSR) were calculated. After a mean follow-up period (mfp) of 44.6 months, a wmSR of 98.3 % was calculated from data published for patients with oLp (100 patients with 302 implants). Data of 27 patients (152 implants) with EB revealed wmSR of 98.7 % following mfp of 32.6 months. For 71 patients (272 implants) with SjS, wmSR was 94.2 % following a mfp of 45.2 months, and for 6 patients (44 implants) with sSc, wmSR was 97.7 % after mfp of 37.5 months. One case report on one patient each with Pe (two implants) as well as sLE (6 implants) showed 100 % SR following at least 24 months. Guidelines regarding implant treatment of patients with oLp, Pe, EB, SjS, sLE or sSc do not exist nor are contraindicating conditions defined. Implant survival rates of patients affected are comparable to those of healthy patients. For implant-prosthetic rehabilitation of patients with Pe and sLE no conclusions can be drawn due to lack of sufficient clinical data. Implant-prosthetic treatment guidelines regarding healthy patients should be strictly followed, but frequent recall is recommended in patients affected with oLp, SjS, EB, SSc, Pe or sLE

    Correction: A novel mutation of the calcium sensing receptor gene is associated with chronic pancreatitis in a family with heterozygous SPINK1 mutations

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    Abstract Background The role of mutations in the serine protease inhibitor Kazal type 1 (SPINK1) gene in chronic pancreatitis is still a matter of debate. Active SPINK1 is thought to antagonize activated trypsin. Cases of SPINK1 mutations, especially N34S, have been reported in a subset of patients with idiopathic chronic pancreatitis. However, the inheritance pattern is still unknown. Some cases with N34S heterozygosity have been reported with and without evidence for CP indicating neither an autosomal recessive nor dominant trait. Therefore SPINK1 mutations have been postulated to act as a disease modifier requiring additional mutations in a more complex genetic model. Familial hypocalciuric hypercalcemia (FHH) caused by heterozygous inactivating mutations in the calcium sensing receptor (CASR) gene is considered a benign disorder with elevated plasma calcium levels. Although hypercalcemia represents a risk factor for pancreatitis, increased rates of pancreatitis in patients with FHH have not been reported thus far. Methods We studied a family with a FHH-related hypercalcemia and chronic pancreatitis. DNA samples were analysed for mutations within the cationic trypsinogen (N29I, R122H) and SPINK1 (N34S) gene using melting curve analysis. Mutations within CASR gene were identified by DNA sequencing. Results A N34S SPINK1 mutation was found in all screened family members. However, only two family members developed chronic pancreatitis. These patients also had FHH caused by a novel, sporadic mutation in the CASR gene (518T>C) leading to an amino acid exchange (leucine->proline) in the extracellular domain of the CASR protein. Conclusion Mutations in the calcium sensing receptor gene might represent a novel as yet unidentified predisposing factor which may lead to an increased susceptibility for chronic pancreatitis. Moreover, this family analysis supports the hypothesis that SPINK1 mutations act as disease modifier and suggests an even more complex genetic model in SPINK1 related chronic pancreatitis.</p

    "Scalping" in the context of criminal dismemberment and mutilation-a case report and review of the literature

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    We report on a case of criminal dismemberment and attempted scalping of a homicide victim with a “Mohawk” haircut. Case fndings are presented. A review of the literature was performed for scalping in its historical and cultural context and particularly in criminal dismemberment and mutilation: Historically, scalping was prevalent in many ancient cultures around the world, where scalps were taken as trophies or “proof of kill”, much like shrunken heads, trophy skulls, and other artefacts. Scalping was particularly widespread in Northern America in the context of tribal warfare, both before and after colonization. The iconic “Mohawk” haircut is closely linked with scalping, as it was meant to taunt the enemy. In the modern forensic context, scalping constitutes a form of criminal mutilation. However, cases of criminal dismemberment and mutilation are rare in forensic casework. Our literature review revealed a low number of scalping in criminal dismemberment and mutilation cases. The documentation was overall poor. Positioning scalping within the classifcation of criminal mutilation and dismemberment was difcult. In literature, even though case numbers were small, the majority of “textbook scalping” cases were German. The presented case, to our best knowledge, is the frst modern-day photo-documented case of (attempted) scalping, even more so of a person wearing a “Mohawk”
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