Radiative damping: a case study

We are interested in the motion of a classical charge coupled to the Maxwell self-field and subject to a uniform external magnetic field, B. This is a physically relevant, but difficult dynamical problem, to which contributions range over more than one hundred years. Specifically, we will study the Sommerfeld-Page approximation which assumes an extended charge distribution at small velocities. The memory equation is then linear and many details become available. We discuss how the friction equation arises in the limit of "small" B and contrast this result with the standard Taylor expansion resulting in a second order equation for the velocity of the charge.Comment: 4 figure

Capgras syndrome as a psychiatric manifestation in Parkinson’s disease: a case report and literature review

We present the case of a 58-year-old male patient who had symptoms of anxiety after witnessing a case of social violence in his community in 2005. After that, he presented symptoms of Parkinson Disease and in 2006 we established this as the main diagnosis. In 2009 he presented neuropsychiatric symptoms such as apathy, anhedonia, social isolation, blunted affect, visual and auditory hallucinations, paranoid delusions, soliloquies, and the false belief that his wife and daughter had been replaced by identical impostors. We established the diagnosis of Capgras Syndrome. This case is clinically relevant because of the presentation of its symptoms, its evolution and its presenting comorbidity

Overtime working, the Phillips curve and the wage curve: British engineering, 1926-66

This paper shows that wage-unemployment elasticities derived from estimated wage curves and Phillips curves may be critically dependent on the measurement of wages. Incorporating hourly wage earnings, that include the influence of overtime payments, can lead to seriously distorted results. Meaningful elasticities are obtained only if hourly standard wages form the basis of analysis. Work is based on a unique data set describing two homogeneous blue-collar occupational groups - skilled fitters and unskilled labourers - in the British engineering industry. Each group is also divided into timeworkers and piece-rate workers. Data are aggregated into a panel of 28 local labour markets and cover the highly contrasting periods, 1928-1938 and 1954-1966

Various Modes of Helium Mixing in Globular Cluster Giants and Their Possible Effects on the Horizontal Branch Morphology

It has been known for a long time that some red giants in globular clusters exhibit large star-to-star variations in the abundances of light elements that are not exhibited by field giants. This fact can be taken as evidence that the extra mixing mechanism(s) that operate in globular cluster giants may be consequences of star-star interactions in the dense stellar environment. In order to constrain the extra mixing mechanism(s), we study the influence of helium enrichment along the red giant branch (RGB) on the evolution of stars through the horizontal branch. Three possible modes of helium enrichment are considered, associated with close encounters of stars in the globular clusters. We show that as a consequence of the variations in the core mass as well as in the total mass due to mass loss, the color of horizontal branch models are distributed over almost all range of horizontal branch. The results are discussed in relation to the scenario for the origin of the abundance anomalies and for the effects on the morphology of horizontal branch. We argue that the star-star interactions can explain not only the source of angular momentum of rapid rotation but also provide a mechanism for the bimodal distribution of rotation rates in some globular clusters. We also propose the time elapsed from the latest core collapse phase during the gravo-thermal oscillations as the second parameter to explain the variations in HB morphology among the globular clusters.Comment: 57 pages, 16 figures, to be published on June 2006 in Ap

Oral particle uptake and organ targeting drives the activity of amphotericin B nanoparticles

There are very few drug delivery systems that target key organs via the oral route, as oral delivery advances normally address gastrointestinal drug dissolution, permeation, and stability. Here we introduce a nanomedicine in which nanoparticles, while also protecting the drug from gastric degradation, are taken up by the gastrointestinal epithelia and transported to the lung, liver, and spleen, thus selectively enhancing drug bioavailability in these target organs and diminishing kidney exposure (relevant to nephrotoxic drugs). Our work demonstrates, for the first time, that oral particle uptake and translocation to specific organs may be used to achieve a beneficial therapeutic response. We have illustrated this using amphotericin B, a nephrotoxic drug encapsulated within <i>N</i>-palmitoyl-<i>N</i>-methyl-<i>N</i>,<i>N</i>-dimethyl-<i>N</i>,<i>N</i>,<i>N</i>-trimethyl-6-<i>O</i>-glycol chitosan (GCPQ) nanoparticles, and have evidenced our approach in three separate disease states (visceral leishmaniasis, candidiasis, and aspergillosis) using industry standard models of the disease in small animals. The oral bioavailability of AmB-GCPQ nanoparticles is 24%. In all disease models, AmB-GCPQ nanoparticles show comparable efficacy to parenteral liposomal AmB (AmBisome). Our work thus paves the way for others to use nanoparticles to achieve a specific targeted delivery of drug to key organs via the oral route. This is especially important for drugs with a narrow therapeutic index

Reassessing the Impact of High Performance Workplaces

High performance workplace practices were extolled as an efficient means to increase firm productivity. The empirical evidence is disputed, however. To assess the productivity effects of a broad variety of measures, we simultaneously account for both unobserved heterogeneity and endogeneity using establishment panel data for Germany. We show that increasing employee participation enhances firm productivity in Germany, whereas incentive systems do not foster productivity. Our results further indicate that firms with structural productivity problems tend to introduce organisational changes that increase employee participation whereas well performing firms are more likely to offer incentives

SIGLEC1 (CD169): a marker of active neuroinflammation in the brain but not in the blood of multiple sclerosis patients

We aimed to evaluate SIGLEC1 (CD169) as a biomarker in multiple sclerosis (MS) and Neuromyelitis optica spectrum disorder (NMOSD) and to evaluate the presence of SIGLEC1(+) myeloid cells in demyelinating diseases. We performed flow cytometry-based measurements of SIGLEC1 expression on monocytes in 86 MS patients, 41 NMOSD patients and 31 healthy controls. Additionally, we histologically evaluated the presence of SIGLEC1(+) myeloid cells in acute and chronic MS brain lesions as well as other neurological diseases. We found elevated SIGLEC1 expression in 16/86 (18.6%) MS patients and 4/41 (9.8%) NMOSD patients. Almost all MS patients with high SIGLEC1 levels received exogenous interferon beta as an immunomodulatory treatment and only a small fraction of MS patients without interferon treatment had increased SIGLEC1 expression. In our cohort, SIGLEC1 expression on monocytes was—apart from those patients receiving interferon treatment - not significantly increased in patients with MS and NMOSD, nor were levels associated with more severe disease. SIGLEC1(+) myeloid cells were abundantly present in active MS lesions as well as in a range of acute infectious and malignant diseases of the central nervous system, but not chronic MS lesions. The presence of SIGLEC1(+) myeloid cells in brain lesions could be used to investigate the activity in an inflammatory CNS lesion