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It is common practice to estimate a mean diameter for spherical or sub-spherical particles or vesicles in a rock by multiplying the average diameter of the approximately circular cross-sections visible in thin section by a factor of 1.273. This number-weighted average may be dominatedby the hard-to-measure fine tail of the size distribution, and is unlikely to be representative of the average particle diameter of greatest interest for a wide range of geological problems or processes. Average particle size can be quantified in a variety of ways, based on the mass or surfacearea of the particles, and here we provide exact relations of these different average measures to straightforward measurements possible in thin section, including an analysis of how many particles to measure to achieve a desired level of uncertainty. The use of average particle diameter isillustrated firstly with a consideration of the accumulation of olivine phenocrysts on the floor of the 135 m thick picrodolerite/crinanite unit of the Shiant Isles Main Sill. We show that the 45 m thick crystal pile on the sill floor could have formed by crystal settling within about a year.The second geological example is provided by an analysis of the sizes of exsolved Fe-rich droplets during unmixing of a basaltic melt in a suite of experimental charges. We show that the size distribution cannot be explained by sudden nucleation, followed by either Ostwald ripening or Browniancoalescence. We deduce that a continuous process of droplet nucleation during cooling is likely to have occurred.
Here, we report the feasibility and long-term efficacy of a granulomatous slack skin disease (GSSD) treatment with combined high-energy photon and proton beams.
Patient and methods
A GSSD patient with abdominal disease volume 25×15×2–4 cm deep was recommended for treatment at this institution. In addition to photons and electrons, high-energy protons delivered with advanced planning techniques and patient positioning were used. The patient was irradiated to a total dose of 40 Gy by using 20 Gy matched photon and electrons followed by 20 Gy equivalent protons delivered by using innovative range compensation and patient positioning.
The test patient tolerated the treatment well and is now a 10-year survivor of the disease.
Treatment of GSSD with protons is feasible. The range and narrow penumbra properties of the proton beam provided an ideal capability to match fields accurately to cover large volumes while also sparing underlying normal tissues.
This study aimed to assess the speed of referral, diagnosis and treatment of patients with lymphoma presenting with a neck lump, and to identify where delays are occurring that prevent UK national targets from being met.
The study entailed a retrospective survey of patients presenting with a neck lump secondary to lymphoma between 2006 and 2008 in Gloucestershire, UK.
Forty-seven of 54 patients (87 per cent) were seen within 2 weeks of referral. However, the 62-day rule, which covers the time from referral to the initiation of treatment, was met in only 32 of the 54 cases (59 per cent). There were no breaches of the 31-day target, which concerned the time from decision to treat to the initiation of treatment. Subsequent target breaches were due to longer waiting times for radiological and pathological investigations.
Radiological examinations should be ordered at the first consultation and biopsies performed as soon as possible. Establishing one-stop, rapid access clinics should improve the achievement of a maximum 62-day wait for patients with lymphoma presenting with neck lumps.
Tympanic middle ears have evolved multiple times independently among vertebrates, and share common features. We review flexibility within tympanic middle ears and consider its physiological and clinical implications.
The chain of conducting elements is flexible: even the ‘single ossicle’ ears of most non-mammalian tetrapods are functionally ‘double ossicle’ ears due to mobile articulations between the stapes and extrastapes; there may also be bending within individual elements.
Simple models suggest that flexibility will generally reduce the transmission of sound energy through the middle ear, although in certain theoretical situations flexibility within or between conducting elements might improve transmission. The most obvious role of middle-ear flexibility is to protect the inner ear from high-amplitude displacements.
Inter-ossicular joint dysfunction is associated with a number of pathologies in humans. We examine attempts to improve prosthesis design by incorporating flexible components.
Distorted images of the observable self are considered crucial in the development and maintenance of social anxiety. We generated an experimental situation in which participants viewed themselves from an observer's perspective when exposed to scrutiny and evaluation by others.
Twenty patients with social anxiety disorder (SAD) and 20 control subjects were assessed using functional magnetic resonance imaging (fMRI) during the public exposure of pre-recorded videos in which they were each shown performing a verbal task. The examiners acted as the audience in the experiment and rated performance. Whole-brain functional maps were computed using Statistical Parametric Mapping.
Robust activation was observed in regions related to self-face recognition, emotional response and general arousal in both study groups. Patients showed significantly greater activation only in the primary visual cortex. By contrast, they showed significant deactivation or smaller activation in dorsal frontoparietal and anterior cingulate cortices relevant to the cognitive control of negative emotion. Task-related anxiety ratings revealed a pattern of negative correlation with activation in this frontoparietal/cingulate network. Importantly, the relationship between social anxiety scores and neural response showed an inverted-U function with positive correlations in the lower score range and negative correlations in the higher range.
Our findings suggest that exposure to scrutiny and evaluation in SAD may be associated with changes in cortical systems mediating the cognitive components of anxiety. Disorder severity seems to be relevant in shaping the neural response pattern, which is distinctively characterized by a reduced cortical response in the most severe cases.
Paragangliomas are rare tumours arising from the paraganglia of the autonomic nervous system.
We present a case of a paraganglioma arising from the hypoglossal nerve and producing an unusual clinical picture at presentation.
We supply radiological evidence of a paraganglioma originating from the hypoglossal nerve, and thus extend the evidence base for this rare site of origin. Our patient presented as an emergency with long tract neurological symptoms and progressive brainstem involvement. This presentation is not characteristic of paragangliomas in general, which usually have an indolent growth pattern and often demonstrate benign symptoms for a number of years prior to diagnosis. The location of a hypoglossal paraganglioma differs significantly from more common paragangliomas described in the neck and skull base, and this should inform the surgical approach undertaken.
The organic interprismatic layers of the mollusc Pinctada margaritifera are studied using a variety of highly spatially-resolved techniques to establish their composition and structure. Our results show that both the interlamellar sheets of the nacre and interprismatic envelopes form layered structures. Additionally, these organic layers are neither homogeneous in composition, nor continuous in their structure. Both structures play a major role in the biomineralization process and act as a boundary between mineral units.
This study evaluated whether antibiotic cycling programmes using broad-spectrum agents including carbapenems were associated with increased rates of colonization or infection by Stenotrophomonas maltophilia. Retrospective analyses of colonization or infection by S. maltophilia from 1992 to 2002 were conducted using University of Virginia Hospital clinical microbiology records of patients with any culture positive for S. maltophilia and hospital epidemiology records of nosocomial S. maltophilia infections. Incidence rates were calculated and compared for cycling and non-cycling periods. No significant differences were found in incidence rates of S. maltophilia isolates between cycling and non-cycling periods, but there was a significant secular increase in the hospital-wide rate of infections caused by S. maltophilia (P=0·01728). Antibiotic cycling protocols were not associated with a significantly increased rate of colonization of S. maltophilia as determined by the frequency of patients having at least one positive routine clinical culture in this hospital.
Sera from 141 infants aged 0–12 months were examined for IgG antibodies to HHV-6, HSV, CMV, VZV and EBV and for HHV-6 specific IgM. Following the decline in maternal antibody, antibody to HHV-6 was found to rise by 5–6 months and approached the level found in adults by 11–12 months. In contrast the antibody rates for the other herpesviruses were much slower to rise, especially in the case of CMV and EBV. HHV-6 IgM antibodies were detected mainly in age groups showing a rapid rise in antibody to HHV-6. HHV-6-IgM was not detected in 235 cord blood samples. The data suggest that HHV-6 infection is acquired horizontally, at a very early age in Western Australia.
The adnexa are in an anatomic region in the pelvis that includes the ovaries, the fallopian tubes, and the structures within the broad ligament. The differential diagnosis of an adnexal mass is complex because of the wide spectrum of disorders that involve the adnexa. Most frequently, adnexal masses involve the ovary itself because of its inherent growth properties through ovulation and thus its propensity for neoplasia. During the evaluation of an adnexal mass, the picture may be further complicated as imaging does not always clearly delineate the adnexa from other nearby organs. An estimated 5% to 10% of women in the United States will undergo a surgical procedure for a suspected ovarian neoplasm during their lifetime. Although the majority of adnexal masses are benign in nature, the primary goal of the diagnostic evaluation is the exclusion of malignancy.
The differential diagnosis of the adnexal mass varies with age (Table 9.1.1). Age is also the most important factor in determining the potential for malignancy. In fact, the risk that an ovarian neoplasm is malignant increases 12-fold from ages 12 through 29 and 60 through 69. Although there is emerging evidence that the presence of an adnexal mass in postmenopausal women is more common than once thought, masses found in premenarchal and postmenopausal women should be considered abnormal and must be promptly evaluated.
Atomic force microscopy (AFM) and transmission electron microscopy (TEM) were used to investigate the fine structure of the calcite prisms from the pearl-oyster shell Pinctada margaritifera. The AFM analysis shows that the prisms are made of densely packed circular micro-domains (in the 0.1 μm range) surrounded by a dense cortex. The TEM images and diffraction patterns allow the internal structure of the micro-domains to be described. Each of them is enriched in Ca-carbonate. Hosted in distinct regions of each prism, some are fully amorphous, and some others fully crystallized as subunits of a large calcite single crystal. At the border separating the two regions, micro-domains display a crystallized core and an amorphous rim. Such a border probably marks out an arrested crystallization front having propagated through a previously bio-controlled architecture of the piling of amorphous micro-domains. Compared to recent data concerning the stepping mode of growth of the calcite prisms and the resulting layered organization at the μm-scale, these results give unexpected views regarding the modalities of biocrystallization.
Synchrotron-based XANES characterization of sulphated sulphur combined with atomic force microscopy and transmission electron microscopy (imaging and diffraction) allow insights into the crystallization of the calcareous units produced by invertebrates. As a result of a series of converging data, reticulate crystallization of the amorphous Ca-carbonate molecules conveyed to the micron-thick growth layer by the sumicrometric organo-mineral units seems a reasonable hypothesis, providing us with a method of explaining the multiple and taxonomy-linked ‘vital effects’ which have long been recognized among the calcareous biocrystals.
To determine the frequency with which methicillin-resistant Staphylococcus aureus (MRSA) is spread from colonized or infected patients to their household and community contacts.
Retrospective cohort study.
Household and community contacts of MRSA-colonized or -infected patients for whom MRSA screening cultures were performed.
MRSA was isolated from 25 (14.5%) of 172 individuals. Among the contacts of index patients who had at least one MRSA-colonized contact, those with close contact to the index patient were 7.5 times more likely to be colonized (53% vs 7%; 95% confidence interval, 1.1 to 50.3; P = .002). An analysis of antimicrobial susceptibility and DNA fingerprint patterns suggested person-to-person spread.
MRSA colonization occurs frequently among household and community contacts of patients with nosocomially acquired MRSA, suggesting that transmission of nosocomially acquired MRSA outside of the healthcare setting may be a substantial source of MRSA colonization and infection in the community.
We have performed Photoelectron Spectroscopy and X-Ray Absorption Spectroscopy upon highly radioactive samples of Plutonium at the Advanced Light Source in Berkeley, CA, USA. First results from alpha and delta Plutonium are reported as well as plans for future studies of actinide studies.
Single-drug prophylaxis is recommended after tuberculin skin test conversion, but not when there is active disease on chest radiograph because resistance develops frequently. Isoniazid-resistant tuberculosis developed in a physician receiving prophylaxis despite “faint left upper lobe soft tissue density” on chest radiograph. Ignoring active disease on chest x-ray renders this strategy counterproductive and cost ineffective. '(Infect Control Hosp Epidemiol 2002;23:622-625).
A study was made of the concentration of insulin-like growth factor-l (IGF-I) in the plasma of Jersey cows differing in genetic merit for milk and milk fat production. Plasma IGF-I concentrations exhibited an annual cycle and from this study it is concluded that, in the Jersey breed, selection for increased milk and milk fat production, with the correlated responses of increases in mature live weight and live-weight gain, will not be accompanied by increased plasma IGF-I concentration.
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