Possible Skull Base Erosion After Prolonged Frontal Sinus Stenting

Frontal sinus stenting is widely used with the goal of maintaining nasofrontal duct patency after sinus surgery. The general recommendation is to leave stents in place for 6 months; however, prolonged stenting up to 6 years has been reported with no complication. We present the first reported case of frontal sinus posterior table and skull base erosion following prolonged frontal sinus stenting. A 57-year-old female presented with chronic sinusitis and nasal obstruction. Imaging revealed pansinusitis with retained stents in each frontal sinus that were placed 8 years prior. On the right, there was an area of skull base erosion at the tip of the stent. The patient underwent functional endoscopic sinus surgery with polypectomy. The stents were removed, revealing posterior table erosion on the right side but intact mucosa. Two months after surgery, there were no signs or symptoms of cerebrospinal fluid leak or other complications. Recent literature has suggested that prolonged stenting is safe; however, this case highlights a complication with potentially serious outcomes that can result from prolonged stenting. We recommend stent removal once stable nasofrontal duct patency has been achieved. If prolonged stenting is utilized, patients should be closely monitored and consideration should be given to periodic imaging to evaluate stent position

Maximum power point tracking control of a linear magnetic-geared generator for direct-drive wave energy conversion

This paper deals with control of a linear magneticgeared permanent-magnet generator for wave power generation using maximum power point tracking (MPPT) algorithm. Firstly, the linear magnetic-geared permanent-magnet generator structure is presented. The machine modeling is established based on the finite element analysis (FEA). Secondly, by analyzing the dynamic model of the wave power, the MPPT algorithm for directdrive wave power generation is discussed. Then, the performance for maximizing wave power absorption is verified and evaluated by the circuit simulator. The results verify that the MPPT algorithm is valid for the direct-drive wave power generation.postprin

Unconventional Gravitational Excitation of a Schwarzschild Black Hole

Besides the well-known quasinormal modes, the gravitational spectrum of a Schwarzschild black hole also has a continuum part on the negative imaginary frequency axis. The latter is studied numerically for quadrupole waves. The results show unexpected striking behavior near the algebraically special frequency $\Omega=-4i$. This reveals a pair of unconventional damped modes very near $\Omega$, confirmed analytically.Comment: REVTeX4, 4pp, 6 EPS figure files. N.B.: "Alec" is my first, and "Maassen van den Brink" my family name. v2: better pole placement in Fig. 1. v3: fixed Refs. [9,20]. v4: added context on "area quantum" research; trimmed one Fig.; textual clarification

Antibacterial activity of Sargassum polycystum C. Agardh and Padina australis Hauck (Phaeophyceae)

Seaweeds are used in pharmaceutical and biochemical applications as they possess interesting biological activities that contribute to the discovery of natural therapeutic agents. In this study, the antibacterial activity of n-hexane, dichloromethane and methanolic extracts of brown seaweeds (Phaeophyceae), Sargassum polycystum C. Agardh and Padina australis Hauck, was examined using the disc diffusion and broth microdilution methods. The bioactivity of the seaweed extracts was expressed as minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The antibacterial activity against Gram-negative bacteria (beta-lactamase positive and negative Escherichia coli, Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus) was discussed. Gram-positive bacteria especially B. cereus was more susceptible to the seaweed extracts (MIC = 0.130 to 0.065 mg/ml). Generally, S. polycystum extracts exhibited higher bacteriostatic activity (lower MICs) against all the tested bacterial strains when compared with P. australis. However, P. australis extracts showed a narrow spectrum of bactericidal activity against B. cereus. n-Hexane extracts of S. polycystum exhibited promising bacteriostatic agents against B. cereus (MIC = 0.065 mg/ml) with MIC value lower than the standard MIC of potential antimicrobial drug (0.100 mg/ml). Since only crude seaweed extracts were tested in this study, further purification and isolation of bioactive compounds from the extracts are essential in future studies in order to optimize their antibacterial activity.Key words: Phaeophyceae, disc diffusion test, minimum bactericidal concentration (MBC), minimum inhibition concentration (MIC)

Assessing Sexual Orientation Symptoms In Obsessive-Compulsive Disorder: Development And Validation Of The Sexual Orientation Obsessions And Reactions Test (SORT)

Obsessive-compulsive disorder (OCD) includes many symptom presentations, which creates unique diagnostic challenges. Fears surrounding one’s sexual orientation are common within OCD (also called SO-OCD), but SO-OCD is consistently misdiagnosed by physicians and psychologists. To address this issue, we describe the development of a self-report measure for assessing SO-OCD to help distinguish OCD from distress caused by a sexual orientation identity crisis. The current paper details two studies that established the psychometric properties and clinical utility of this measure. In Study 1, the factor structure, validity, and reliability were examined for the measure’s 12 items in a sample of 1,673 university students. The results revealed a two-factor solution for the measure (Factor 1: Transformation Fears; Factor 2: Somatic Checking) and preliminary evidence of validity and reliability. In Study 2, the measure was tested with LGBTQ and heterosexual community samples and clinical samples of individuals with SO-OCD and other types of OCD. The two-factor solution and evidence of validity and reliability were supported in these samples. Cut-off points were established to distinguish between community members and SO-OCD sufferers, as well as between those experiencing SO-OCD and other types of OCD. Limitations and future directions are discussed

Wave Propagation in Gravitational Systems: Late Time Behavior

It is well-known that the dominant late time behavior of waves propagating on a Schwarzschild spacetime is a power-law tail; tails for other spacetimes have also been studied. This paper presents a systematic treatment of the tail phenomenon for a broad class of models via a Green's function formalism and establishes the following. (i) The tail is governed by a cut of the frequency Green's function $\tilde G(\omega)$ along the $-$~Im~$\omega$ axis, generalizing the Schwarzschild result. (ii) The $\omega$ dependence of the cut is determined by the asymptotic but not the local structure of space. In particular it is independent of the presence of a horizon, and has the same form for the case of a star as well. (iii) Depending on the spatial asymptotics, the late time decay is not necessarily a power law in time. The Schwarzschild case with a power-law tail is exceptional among the class of the potentials having a logarithmic spatial dependence. (iv) Both the amplitude and the time dependence of the tail for a broad class of models are obtained analytically. (v) The analytical results are in perfect agreement with numerical calculations

Gender Differences in Pathways to Compulsive Buying in Chinese College Students in Hong Kong and Macau

The addictive nature of compulsive buying implies that mood disturbances, stress, and cognitive biases that underlie compulsive buying might operate in ways similar in both genders. In the current study, we aimed to test hypothetical pathways of mood compensation and irrational cognitions, which may explain compulsive buying tendencies. We also examined potential gender differences in these pathways. Methods Two-hundred and thirty-two male (age: M = 20.30, SD = 1.74) and 373 female Chinese college students (age: M = 19.97, SD = 1.74) in Hong Kong and Macau completed measures assessing compulsive buying, psychological distress, avoidance coping, materialism, and buying-related cognitions. Mediation analyses via a structural equation modeling approach explained by Cheung (2007, 2009) were conducted, with gender as a grouping variable. Results There was a gender difference in the mood compensation pathway; avoidance coping partially mediated the link between psychological distress and compulsive buying severity in females only. On the other hand, the irrational cognitive pathway, in which irrational buying-related cognitions fully mediated the link between materialism and compulsive buying severity, was supported for both genders. There was no gender difference in the extent of mediation within the irrational cognitive pathway, and the mediation effect within the irrational cognitive pathway was larger than that within the mood compensation pathway for both genders. Conclusions Mood compensation processes in compulsive buying might be female specific, and secondary to irrational cognitions, which were gender invariant. Gender-dependent mechanisms and irrational cognitions should be emphasized in compulsive buying treatment