Non-Associativity in the Clifford Bundle on the Parallelizable Torsion 7-Sphere

In this paper we discuss generalized properties of non-associativity in Clifford bundles on the 7-sphere S7. Novel and prominent properties inherited from the non-associative structure of the Clifford bundle on S7 are demonstrated. They naturally lead to general transformations of the spinor fields on S7 and have dramatic consequences for the associated Kac-Moody current algebras. All additional properties concerning the non-associative structure in the Clifford bundle on S7 are considered. We further discuss and explore their applications.Comment: 16 page

From Stochastic Differential Equations to Quantum Field Theory

Covariant stochastic partial (pseudo-)differential equations are studied in any dimension. In particular a large class of covariant interacting local quantum fields obeying the Morchio-Strocchi system of axioms for indefinite quantum field theory is constructed by solving the analysed equations. The associated random cosurface models are discussed and some elementary properties of them are outlined.Comment: 11 pages, Latex, to appear in: Reports On Mathematical Physics No.X Vol.XX (199X

Accuracy of computer-assisted surgery in immediate implant placement : an experimental study

Purpose: Computer-guided surgery has been increased in recent years. Nonetheless, few data are available on the validation of this technique for immediate implant placement. The purpose of this in vitro study was to evaluate the accuracy of computer-guided surgery in immediate implant placement. Materials and methods: Cone-beam computed tomography scans (CBCTs) and virtual models were obtained of eight fresh pigs hemi-mandibles to perform the digital planning of implants placement. Fifteen implants were simulated, and surgical guides were designed to transfer the digital planning to the surgical procedure. Postsurgical CBCTs were performed to compare the position of the planned implants versus the real implant position. Paired t-test and the intra-class correlation coefficient (ICC) were used to assess the mean differences and correlations in each outcome variable evaluated twice by one experienced researcher. Furthermore, variations were compared with the results reported in the scientific literature using a one-sample t-test P 0.05). The ICC values ranged from 0.888 to 0.949. Furthermore, the mean deviation was 1.43 mm at the implant neck, 2.19 mm at the apex, and 6.81° for the angular deviation. Similarly, significant differences (P < 0.05) were found at the neck and angular deviation when comparing the results with values reported in the literature. Conclusions: Although some variations were observed, they did not have a clinically significant impact. Therefore, computer-guided surgery could be satisfactorily used in immediate implants placement

Discrete structures in gravity

Discrete approaches to gravity, both classical and quantum, are reviewed briefly, with emphasis on the method using piecewise-linear spaces. Models of 3-dimensional quantum gravity involving 6j-symbols are then described, and progress in generalising these models to four dimensions is discussed, as is the relationship of these models in both three and four dimensions to topological theories. Finally, the repercussions of the generalisations are explored for the original formulation of discrete gravity using edge-length variables.Comment: 30 pages, 4 figure

On the Geometry of Multi-Dirac Structures and Gerstenhaber Algebras

In a companion paper, we introduced a notion of multi-Dirac structures, a graded version of Dirac structures, and we discussed their relevance for classical field theories. In the current paper we focus on the geometry of multi-Dirac structures. After recalling the basic definitions, we introduce a graded multiplication and a multi-Courant bracket on the space of sections of a multi-Dirac structure, so that the space of sections has the structure of a Gerstenhaber algebra. We then show that the graph of a k-form on a manifold gives rise to a multi-Dirac structure and also that this multi-Dirac structure is integrable if and only if the corresponding form is closed. Finally, we show that the multi-Courant bracket endows a subset of the ring of differential forms with a graded Poisson bracket, and we relate this bracket to some of the multisymplectic brackets found in the literature.Comment: 19 pages; v2: different convention for degre

A globally applicable PCR-based detection and discrimination of BK and JC polyomaviruses

BKV and JCV belong to the Polyomaviridae family and are opportunistic agents associated with complications in immunocompromised individuals. Although a single screening assay for both viruses would be convenient, the diversity of BKV and JCV serotypes and genotypes is a methodological challenge. In this paper, we developed a PCR method able to detect and segregate BKV and JCV, despite these genetic discrepancies. A duplex semi-nested PCR (duplex snPCR) was designed to target a conserved region (639nt-1516nt) within the VP2 gene. In the first PCR, a primer set common to all BKV and JCV serotypes/ genotypes was used, followed by a semi-nested PCR with internal primers for BKV and JCV segregation. The limit of detection of the duplex snPCR was as low as 10 copies of BKV or JCV plasmids/µL. Specific products were observed when JCV and BKV plasmids were mixed in the same reaction. In field sample testing, the duplex snPCR detected and distinguished both viruses in different biological samples. Results were confirmed by Sanger’s sequencing. The geographical complexity of BKV and JCV serotypes and genotypes imposes limits to a simple and universal method that could detect each virus. However, we describe here a sensitive and reliable PCR technique for BKV and JCV diagnosis that overcomes these limitations and could be universally applied

Medicação antipânico e função pulmonar em pacientes com transtorno de pânico

BACKGROUND: Studies suggest an association between panic disorder (PD) and impairment of lung function. OBJECTIVES: To evaluate lung function in 11 asymptomatic PD patients and to investigate antipanic drug effects on respiratory function. METHOD: Lung function was evaluated on two different occasions (with antipanic drugs and after drug washout). It was comprised of a spirometric evaluation and a bronchodilation test (salbutamol inhalation). Subjective Units of Disturbance Scale (SUDS) was applied before and after each spirometric assessment. RESULTS: One patient showed mild obstructive airway impairment. Before bronchodilation test forced expiratory volume in 1 sec (FEV1) and forced expiratory flow between 25% and 75% of the forced vital capacity (FEF25-75) were significantly higher in patients on antipanic drugs than in those in the washout period. After salbutamol inhalation, only FEV1 was significantly higher in patients with antipanic drugs in comparison to the other group, whereas a significant increase in FEV1 and FEF25-75 after salbutamol inhalation was detected in patients without antipanic drugs. The subjective anxiety level was not different among PD patients in both test days. DISCUSSION: These results suggest a possible beneficial effect of the antipanic drug on lung function in PD patients.CONTEXTO: Estudos sugerem uma associação entre transtorno de pânico (TP) e prejuízos na função pulmonar. OBJETIVOS: Avaliar a função pulmonar em 11 pacientes com TP assintomáticos e investigar efeitos da medicação antipânico na função respiratória. MÉTODO: A função pulmonar foi avaliada em duas ocasiões diferentes (com medicação antipânico e após "washout"). Consistiu de uma avaliação espirométrica e do teste de broncodilatação (inalação de salbutamol). Subjective Units of Disturbance Scale (SUDS) foi aplicada antes e após cada teste espirométrico. RESULTADOS: Um paciente apresentou obstrução leve de vias aéreas. Antes do teste de broncodilatação, o volume expiratório forçado no primeiro segundo (VEF1) e o fluxo expiratório forçado entre 25% e 75% da capacidade vital forçada (FEF25-75) foram significativamente maiores em pacientes com medicação antipânico do que no período de "washout". Após a inalação de salbutamol, apenas o VEF1 foi significativamente maior em pacientes com medicação antipânico em comparação ao outro grupo, embora tenha sido detectado aumento significativo em VEF1 e FEF25-75 em pacientes sem medicação antipânico depois da inalação de salbutamol. O nível de ansiedade subjetiva não foi diferente entre os pacientes em ambos os dias de testes. CONCLUSÃO: Os resultados sugerem uma possível ação benéfica da medicação antipânico na função pulmonar em pacientes com TP

In vivo imaging and quantitative analysis of leukocyte directional migration and polarization in inflamed tissue

Directional migration of transmigrated leukocytes to the site of injury is a central event in the inflammatory response. Here, we present an in vivo chemotaxis assay enabling the visualization and quantitative analysis of subtype-specific directional motility and polarization of leukocytes in their natural 3D microenvironment. Our technique comprises the combination of i) semi-automated in situ microinjection of chemoattractants or bacteria as local chemotactic stimulus, ii) in vivo near-infrared reflected-light oblique transillumination (RLOT) microscopy for the visualization of leukocyte motility and morphology, and iii) in vivo fluorescence microscopy for the visualization of different leukocyte subpopulations or fluorescence-labeled bacteria. Leukocyte motility parameters are quantified off-line in digitized video sequences using computer-assisted single cell tracking. Here, we show that perivenular microinjection of chemoattractants [macrophage inflammatory protein-1alpha (MIP-1alpha/Ccl3), platelet-activating factor (PAF)] or E. coli into the murine cremaster muscle induces target-oriented intravascular adhesion and transmigration as well as polarization and directional interstitial migration of leukocytes towards the locally administered stimuli. Moreover, we describe a crucial role of Rho kinase for the regulation of directional motility and polarization of transmigrated leukocytes in vivo. Finally, combining in vivo RLOT and fluorescence microscopy in Cx3CR1(gfp/gfp) mice (mice exhibiting green fluorescent protein-labeled monocytes), we are able to demonstrate differences in the migratory behavior of monocytes and neutrophils.Taken together, we propose a novel approach for investigating the mechanisms and spatiotemporal dynamics of subtype-specific motility and polarization of leukocytes during their directional interstitial migration in vivo