Controlling pulse stability in singularly perturbed reaction-diffusion systems.

The aim of this paper is to investigate the use of Pyragas control on the stability of stationary, localized coherent structures in a general class of two-component, singularly perturbed, reaction-diffusion systems. We use noninvasive Pyragas-like proportional feedback control to stabilize a singular pulse solution to a two-component, singularly perturbed reaction-diffusion system. We show that in a significant region of parameter space, the control can be adjusted to stabilize an otherwise unstable pulse.

Symmetry groupoids for pattern-selective feedback stabilization of the Chafee-Infante equation.

Reaction-diffusion equations are ubiquitous in various scientific domains and their patterns represent a fascinating area of investigation. However, many of these patterns are unstable and, therefore, challenging to observe. To overcome this limitation, we present new noninvasive feedback controls based on symmetry groupoids. As a concrete example, we employ these controls to selectively stabilize unstable equilibria of the Chafee-Infante equation under Dirichlet boundary conditions on the interval. Unlike conventional reflection-based control schemes, our approach incorporates additional symmetries that enable us to design new convolution controls for stabilization. By demonstrating the efficacy of our method, we provide a new tool for investigating and controlling systems with unstable patterns, with potential implications for a wide range of scientific disciplines.

Geometric invariance of determining and resonating centers: Odd- and any-number limitations of Pyragas control.

In the spirit of the well-known odd-number limitation, we study the failure of Pyragas control of periodic orbits and equilibria. Addressing the periodic orbits first, we derive a fundamental observation on the invariance of the geometric multiplicity of the trivial Floquet multiplier. This observation leads to a clear and unifying understanding of the odd-number limitation, both in the autonomous and the non-autonomous setting. Since the presence of the trivial Floquet multiplier governs the possibility of successful stabilization, we refer to this multiplier as the determining center. The geometric invariance of the determining center also leads to a necessary condition on the gain matrix for the control to be successful. In particular, we exclude scalar gains. The application of Pyragas control on equilibria does not only imply a geometric invariance of the determining center but surprisingly also on centers that resonate with the time delay. Consequently, we formulate odd- and any-number limitations both for real eigenvalues together with an arbitrary time delay as well as for complex conjugated eigenvalue pairs together with a resonating time delay. The very general nature of our results allows for various applications.

An integrative correlation of myopathology, phenotype and genotype in late onset Pompe disease.

AIMS: Pompe disease is caused by pathogenic mutations in the alpha 1,4-glucosidase (GAA) gene and in patients with late onset Pome disease (LOPD), genotype-phenotype correlations are unpredictable. Skeletal muscle pathology includes glycogen accumulation and altered autophagy of various degrees. A correlation of the muscle morphology with clinical features and the genetic background in GAA may contribute to the understanding of the phenotypic variability. METHODS: Muscle biopsies taken before enzyme replacement therapy were analysed from 53 patients with LOPD. On resin sections, glycogen accumulation, fibrosis, autophagic vacuoles and the degree of muscle damage (morphology-score) were analysed and the results were compared with clinical findings. Additional autophagy markers microtubule-associated protein 1A/1B-light chain 3, p62 and Bcl2-associated athanogene 3 were analysed on cryosections from 22 LOPD biopsies. RESULTS: The myopathology showed a high variability with, in most patients, a moderate glycogen accumulation and a low morphology-score. High morphology-scores were associated with increased fibrosis and autophagy highlighting the role of autophagy in severe stages of skeletal muscle damage. The morphology-score did not correlate with the patient's age at biopsy, disease duration, nor with the residual GAA enzyme activity or creatine-kinase levels. In 37 patients with LOPD, genetic analysis identified the most frequent mutation, c.-32-13T>G, in 95%, most commonly in combination with c.525delT (19%). No significant correlation was found between the different GAA genotypes and muscle morphology type. CONCLUSIONS: Muscle morphology in LOPD patients shows a high variability with, in most cases, moderate pathology. Increased pathology is associated with more fibrosis and autophagy.

Permacol™ collagen paste for cryptoglandular and Crohn's anal fistula.

BACKGROUND: Permacol™ collagen paste, an acellular crosslinked porcine dermal collagen matrix suspension, is a new treatment option for anal fistula. Data remain limited, however, and as yet only the results of one case of Crohn's fistula treated with Permacol™ paste has been reported. The aim of this study was to assess the use of Permacol™ collagen paste in patients with cryptoglandular and Crohn's perianal fistulae. METHODS: A prospective study was conducted on patients with anal fistula, treated with Permacol™ paste. Patients were followed at 1 week, 6 and 12 months, and on demand thereafter. The main focus was on fistula healing and postoperative continence. The former was defined as the absence of signs of recurrence on clinical examination, proctoscopy and rigid rectoscopy. Fecal incontinence was assessed before surgery and at each follow-up. RESULTS: Thirty patients (19 women, 11 men; mean age 46 years), 12 (40%) of whom had Crohn's disease were included. The average number of previous fistula operations was 6. All patients had ≥ 6 months of follow-up, and 24 patients (80%) had ≥ 12 months of follow-up. The healing rate in all patients was 57% (17 of 30 patients) at 6 months and 63% (15 of 24 patients) at 12 months. One patient reported a worsening of fecal incontinence at 12 months; 2 patients had adverse events (perianal pain: n = 1, fluid accumulation n = 1) requiring fistula drainage. Patient characteristics, healing, incontinence, and adverse events did not differ significantly between patients with and without Crohn's disease. CONCLUSIONS: Our data indicate that Permacol™ paste is a safe and moderately effective treatment for cryptoglandular and Crohn's fistulae.

Lateral compression type B 2-1 pelvic ring fractures in young patients do not require surgery.

PURPOSE: According to Young and Burgess, type B 2-1 pelvic fractures are a type of lateral compression fracture (LC-1) and are the most common pelvic injury at all ages. Although they are considered unstable in rotation and despite biomechanical recommendations for anterior stabilization, most authors recommend non-operative treatment. However, studies comparing outcomes and complications regarding operative versus non-operative treatment are still scarce. METHODS: Seventy-one patients aged under 65 years with a type B 2-1 pelvic fracture were treated between 2006 and 2011. Patients in Group I (n = 35) were treated non-operatively and patients in Group II (n = 36) were treated operatively. Postoperative complications, clinical course, and follow-up (VAS for Pain, SF 36, EQ-5D) of at least 1 year postoperatively were evaluated. RESULTS: Our data show that operatively treated patients had a significantly higher complication rate. Preoperatively, the only significant difference between the non-operative and operative groups was the amount of anterior fracture dislocation and the presence of an isolated pelvic ring fracture. In the postoperative follow-up, no significant differences were found regarding pain or quality of life. CONCLUSION: Type B 2-1 pelvic ring fractures in young patients should be treated non-operatively.

State-to-state chemistry and rotational excitation of CH+ in photon-dominated regions.

We present a detailed theoretical study of the rotational excitation of CH+ due to reactive and nonreactive collisions involving C+(2P), H2, CH+, H and free electrons. Specifically, the formation of CH+ proceeds through the reaction between C+(2P) and H2(νH2 = 1, 2), while the collisional (de)excitation and destruction of CH+ is due to collisions with hydrogen atoms and free electrons. State-to-state and initial-state-specific rate coefficients are computed in the kinetic temperature range 10-3000 K for the inelastic, exchange, abstraction and dissociative recombination processes using accurate potential energy surfaces and the best scattering methods. Good agreement, within a factor of 2, is found between the experimental and theoretical thermal rate coefficients, except for the reaction of CH+ with H atoms at kinetic temperatures below 50 K. The full set of collisional and chemical data are then implemented in a radiative transfer model. Our Non-LTE calculations confirm that the formation pumping due to vibrationally excited H2 has a substantial effect on the excitation of CH+ in photon-dominated regions. In addition, we are able to reproduce, within error bars, the far-infrared observations of CH+ toward the Orion Bar and the planetary nebula NGC 7027. Our results further suggest that the population of νH2 = 2 might be significant in the photon-dominated region of NGC 7027.

A theoretical study of the dissociative recombination of SH+ with electrons through the 2Π states of SH.

A quantitative theoretical study of the dissociative recombination of SH+ with electrons has been carried out. Multireference, configuration interaction calculations were used to determine accurate potential energy curves for SH+ and SH. The block diagonalization method was used to disentangle strongly interacting SH valence and Rydberg states and to construct a diabatic Hamiltonian whose diagonal matrix elements provide the diabatic potential energy curves. The off-diagonal elements are related to the electronic valence-Rydberg couplings. Cross sections and rate coefficients for the dissociative recombination reaction were calculated with a stepwise version of the multichannel quantum defect theory, using the molecular data provided by the block diagonalization method. The calculated rates are compared with the most recent measurements performed on the ion Test Storage Ring (TSR) in Heidelberg, Germany.

A compact remediation system for the treatment of groundwater contaminated with BTEX and TPH.

Gas stations constitute important point sources of soil and groundwater pollution. The leaking of hydrocarbons into the soil is a significant environment issue due to the wide-ranging occurrence of leaks and the high levels and toxicity of pollutants involved in the contamination of groundwater for human use. This study introduces a compact system developed to treat groundwater contaminated with benzene, toluene, ethyl benzene, and xylenes (BTEX) and total petroleum hydrocarbon (TPH) leaked from gas station tanks. The system comprises three units: (1) suction and volatilization of volatile organic compounds (VOCs), (2) aeration tank (to remove volatile organic substances), and (3) an adsorption packed-bed filter (activated carbon (AC) and rice husk ash, 50% each, to remove TPH). Contaminated groundwater was characterized in a pilot study and in the field. Levels of BTEX and of TPH decreased by 96% with an 8-h retention time. The results obtained show that the remediation system is highly efficient and yielded water that met the discharge standards defined in the Brazilian legislation, that is, maximum benzene, toluene, and xylene levels of 5, 170, and 300 µg/L, respectively.

Resonances in photoabsorption: predissociation line shapes in the 3pπD¹Π(u)⁺ ← X¹Σ(g)⁺ system in H2.

The predissociation of the 3pπD¹Π(u)⁺, v ≥ 3, N = 2, and N = 3 levels of diatomic hydrogen is calculated by ab initio multichannel quantum defect theory combined with a R-matrix type approach that accounts for interfering predissociation and autoionization. The theory yields absorption line widths and shapes that are in good agreement with those observed in the high-resolution synchrotron vacuum-ultraviolet absorption spectra obtained by Dickenson et al. [J. Chem. Phys. 133, 144317 (2010)] at the DESIRS beamline of the SOLEIL synchrotron. The theory predicts further that many of the D state resonances with v ⩾ 6 exhibit a complex fine structure which cannot be modeled by the Fano profile formula and which has not yet been observed experimentally.

[Treatability of sporadic late onset nemaline myopathy]. / Behandelbarkeit der "sporadic late onset nemaline myopathy".

Sporadic late onset nemaline myopathy (SLONM) is an extremely rare disorder which can be associated with monoclonal gammopathy of unclear significance (MGUS). Clinically SLONM appears mostly after the fourth decade of life as rapidly progressing tetraparesis, respiratory insufficiency and features, such as dropped head syndrome, facial and bulbar involvement. Diagnosis is confirmed by muscle biopsy with detection of nemaline bodies and also frequently lobulated fibres. Immunosuppressant and immunomodulating therapies have been shown to be ineffective but clinical improvement accompanied by disappearance of monoclonal gammopathy and even nemaline bodies was reported following autologous stem cell transplantation and chemotherapy with melphalan. This article presents the case of a 53-year-old man with a 4-year history of SLOMN with MGUS in which administration of intravenous immunoglobulin therapy (IVIG) was not successful in reversing gammopathy, histopathological changes or clinical symptoms.

Effect of bioaugmentation on anaerobic wastewater treatment in the dairy industry.

The creation of a biofilm as a specialized biosystem, its development, and activity were studied at 3 critical control points of biofilter operation: start-up, transition from batch to sequencing batch regimen, and set-up of stable sequencing batch process. Five variants of biosystems were investigated with an inoculum from specially adapted real activated sludge, enriched with various combinations of 3 microbial preparations. A stable and working biofilm was developed in the phase of stabilized sequencing batch process. The differences among biodegradation effectiveness of the 5 variants were insignificant during that phase and the effect of the preparations was low. The effectiveness of organic removal for the 5 bioaugmentation approaches reached 60% for protein, 70% for chemical oxygen demand, and 97% for lactose. Commercial inocula did not improve final reactor performance over an inoculum from a municipal wastewater treatment plant alone.

Cytoplasmic sequestration of p53 promotes survival in leukocytes transformed by Theileria.

The function of the p53 protein as the central effector molecule of the p53 apoptotic pathway was investigated in a reversible model of epigenetic transformation. The infection of bovine leukocytes by the intracellular protozoan parasite Theileria annulata results in parasite-dependent transformation and proliferation of the host cells. We found p53 to be largely localized in the host cell cytoplasm and associated with the parasite membrane of isolated schizonts. Curing infected cells of the parasite with the theilericidal drug buparvaquone resulted in a time-dependent translocation of p53 into the host cell nucleus and the upregulation of the proapoptotic Bax and Apaf-1 and the downregulation of the anti-apoptotic Bcl-2 proteins. Although buparvaquone treatment led to apoptosis of the host cell, inhibition of either p53 or Bax significantly reduced buparvaquone-induced apoptosis of the transformed cells. Thus, the p53 apoptotic pathway of host cells is not induced by infection and transformation with Theileria by a mechanism involving cytoplasmic sequestration of p53. The close association of host cell p53 with the parasite membrane implies that the parasite either interacts directly with p53 or mediates cytoplasmic sequestration of p53 by interacting with other host cell proteins regulating p53 localization.

Rotational cooling of HD+ molecular ions by superelastic collisions with electrons.

Merging an HD+ beam with velocity matched electrons in a heavy ion storage ring we observed rapid cooling of the rotational excitations of the HD+ ions by superelastic collisions (SEC) with the electrons. The cooling process is well described using theoretical SEC rate coefficients obtained by combining the molecular R-matrix approach with the adiabatic nuclei rotation approximation. We verify the DeltaJ=-2 SEC rate coefficients, which are predicted to be dominant as opposed to the DeltaJ=-1 rates and to amount to (1-2)x10;{-6} cm;{3} s;{-1} for initial angular momentum states with J< or =7, to within 30%.

Treatment during primary HIV infection does not lower viral set point but improves CD4 lymphocytes in an observational cohort.

OBJECTIVE: To investigate if early treatment of primary HIV-1 infection (PHI) reduces viral set point and/or increases CD4 lymphocytes. METHODS: Analysis of two prospective multi-centre PHI cohorts. HIV-1 RNA and CD4 lymphocytes in patients with transient treatment were compared to those in untreated patients. Time to CD4 lymphocyte decrease below 350/ microl after treatment stop or seroconversion was calculated using Kaplan-Meier and Cox-PH-regression analyses. RESULTS: 156 cases of PHI were included, of which 100 had received transient HAART (median treatment time 9.5 months) and 56 remained untreated. Median viral load (563000 cop/ml vs 240000 cop/ml; p<0.001) and median CD4 lymphocyte (449/ microl vs. 613/ microl; p<0.01) differed significantly between treated and untreated patients. Median viral load was 38056 copies/ml in treated patients (12 months after treatment stop) and 52880 copies/ml in untreated patients (12 months after seroconversion; ns). Median CD4 lymphocyte change was +60/ microl vs. -86/ microl (p = 0.01). Median time until CD4 lymphocytes decreased to <350/ microl (including all patients with CD4 lymphocytes <500/ microl during seroconversion) was 20.7 months in treated patients after treatment stop and 8.3 months in untreated patents after seroconversion (p<0.01). Cox-PH analyses adjusting for baseline VL, CD4 lymphocytes, stage of early infection and symptoms confirmed these differences. CONCLUSIONS: Treatment during PHI did not lower viral set point. However, patients treated during seroconversion had an increase in CD4 lymphocytes, whereas untreated patients experienced a decrease in CD4 lymphocytes. Time until reaching CD4 lymphocytes <350/ microl was significantly shorter in untreated than in treated patients including patients with CD4 lymphocytes <500/ microl during seroconversion.

Pseudotyping lentiviral vectors with the wild-type measles virus glycoproteins improves titer and selectivity.

We pseudotyped HIV-1 vectors with cytoplasmic tail-truncated envelope glycoproteins of a wild-type (WT) measles virus (MV). The particles entered the lymphatic cells exclusively through the signaling lymphocyte activation molecule (SLAM, CD150), whereas particles pseudotyped with the MV vaccine strain glycoproteins also recognized the ubiquitous membrane cofactor protein (CD46) as receptor and had less specific cell entry. MV(WT)-HIV vectors reached titers of 10(8) t.u. ml(-1), which were up to 10-fold higher than those of MV(Vac)-HIV vectors, and discriminated between SLAM-positive and SLAM-negative cells, also in mixed cell cultures. As these vectors transduce primary human cells more efficiently than vesicular stomatitis virus-G pseudotyped vectors do, they are promising candidates for gene transfer to human lymphocytes and certain epithelial cells.

Dual chamber pacemaker implantation in dogs with atrioventricular block.

BACKGROUND: Pacemaker implantation is the treatment of choice for symptomatic bradyarrhythmias. In dogs, a single chamber system is commonly used. In human patients with high-grade 2nd- or 3rd-degree atrioventricular (AV) block, physiologic pacing is recommended, because it improves cardiac output, blood pressure, exercise tolerance, and quality of life. In dogs, this type of pacing is seldom used. HYPOTHESIS: The implantation of a dual chamber pacemaker in dogs with AV block is a feasible procedure for restoring AV synchrony. ANIMALS: Thirty-three privately owned dogs with high-grade 2nd- or 3rd-degree AV block were included. METHODS: Patient data of all dogs with AV block presented for pacemaker implantation between December 1997 and November 2004 were reviewed. RESULTS: Dual chamber pacemaker implantation with AV synchronous stimulation was successfully performed in 33/33 dogs (100%). In 9/33 (27%) major and in 12/33 (36%) minor complications were observed. Mean survival time for the patients discharged from hospital (n = 32) was 33.6 +/- 20.4 months (range, 3.9-83.5 months). CONCLUSION AND CLINICAL IMPORTANCE: Dual chamber pacing is a feasible procedure in dogs with 2nd- or 3rd-degree AV block and is not associated with a higher complication rate compared with single chamber pacemaker systems. A major advantage over ventricular demand pacemaker systems is the restoration of AV synchrony for a substantial period of time.

Extended-spectrum beta-lactamase-producing Serratia marcescens outbreak in a Bulgarian hospital.

We describe a nosocomial outbreak of extended-spectrum beta-lactamase (ESBL)-producing Serratia marcescens in a Bulgarian university hospital affecting nine patients on four wards. Phenotypic and genotypic (plasmid profile, randomly amplified polymorphic DNA analysis and amplified ribosomal DNA restriction analysis) analysis of the isolates indicated a single clone. The epidemic strain was resistant to oxyimino beta-lactams, aztreonam, aminoglycosides, tetracycline and chloramphenicol. It produced CTX-M-3 ESBL as demonstrated by isoelectric focusing, CTX-M PCR-RFLP and gene sequencing. The isolate was also found in the environment and from a nurse's hands, suggesting transmission by staff handling. The outbreak was controlled by patient isolation and intensified hand washing. This is the first report from Bulgaria describing a hospital outbreak caused by CTX-M-3 ESBL-producing S. marcescens.

[Carboplatin and paclitaxel induction chemotherapy for patients with oropharynx carcinoma]. / Neoadjuvante Chemotherapie von Oropharynxkarzinomen mit Carboplatin und Paclitaxel.

BACKGROUND: Between June 1998 and January 2005 64 patients of the department of oto-rhino-laryngology, head and neck surgery in Kassel with primary resectable squamous cell carcinoma of the oropharynx underwent neoadjuvant induction therapy. Carboplatin and Paclitaxel were given 6 times once weekly. This combination has proofed to be successful in downstaging and extend survival in patients suffering from head and neck cancer. Afterwards tumor resection was performed in the initial extension of the carcinoma. Dependent on histological findings radiation therapy or radiochemotherapy was carried out. METHOD: Retrospective data were collected to analyse the effect on the tumor site and cervical lymph node metatasis based on post-chemotherapy clinical and postoperative histological results. In addition correlation between clinical findings and histological outcome and a possible survival advantage in patients with under induction chemotherapy remitted carcinomas was performed. RESULTS: The data showed no improvement in disease free survival in patients with complete remission of the primary tumor site but a significant prolonged survival time for patients with complete remission of the cervical lymph node metastasis.