Miracle-dz/UniFAR-FTUs huggingface dataset:
SU‐E‐I‐62: Dose Reduction to Anterior Surface with Organ‐Based Tube Current Modulation: Evaluation of Performance in a Phantom Study

Purpose: To evaluate in a phantom study image quality and dose reduction to the anterior surface with organ‐based tube current modulation in head and thoracic CT. Methods: Organ‐based tube current modulation is designed to reduce dose to superficial radiosensitive organs such as the lens of the eye, thyroid and breast by decreasing the tube current when the tube passes closest to these organs. Dose and image quality were evaluated in phantoms for clinical head and thorax exam protocols with and without organ‐based tube current modulation. Surface dose reduction as a function of position was measured using a 32‐cm CT Dose Index (CTDI) phantom, an anthropomorphic adult phantom and ion chambers. Surface dose reduction as a function of patient size was investigated using three semi‐ anthropomorphic phantoms with posteroanterior dimensions of 14, 25 and 31 cm. Imagenoise (the standard deviation of CT numbers in regions of interest) was evaluated for the anthropomorphic and the semi‐ anthropomorphic phantoms. Results: For equivalent scanner output (Volume CTDI), dose to the midline of the anterior surface was reduced by 27–50%, depending on anatomic region (head or thorax) and phantom size; dose to the posterior surface was correspondingly increased. Imagenoise was not significantly different between scans with and without organ‐based tube current modulation (p=0.35). Conclusions: Organ‐based tube current modulation can reduce dose to the anterior surface of patients, without increasing imagenoise, by commensurately increasing dose to the posterior surface. This can reduce dose to anterior radiosensitive organs for head and thoracic CT scans.
Dissociation between the insulin-sensitizing effect of rosiglitazone and its effect on hepatic and intestinal lipoprotein production.

CONTEXT Despite its potent, well-documented insulin-sensitizing effects, rosiglitazone (RSG) does not effectively ameliorate the hypertriglyceridemia of insulin-resistant or diabetic individuals and has even been shown to slightly but significantly increase triglyceride-rich lipoproteins (TRL) in some studies. The mechanism of this effect is currently not known. OBJECTIVE We investigated the effect of RSG treatment on TRL metabolism. DESIGN This was a 12-wk, single-sequence, cross-over study of rosiglitazone vs. placebo for 6 wk. PARTICIPANTS Participants included 17 nondiabetic men with a broad range of insulin sensitivity. INTERVENTION INTERVENTION included rosiglitazone 8 mg/d vs. placebo for 6 wk. MAIN OUTCOME MEASURE TRL metabolism (concentration, production and catabolic rates) was assessed in a constant fed state with a 12-h primed constant infusion of [D3]l-leucine and multicompartmental modeling. RESULTS RSG treatment resulted in significant insulin sensitization with no change in body weight. Fasting plasma triglyceride (TG) concentration, however, was higher with RSG vs. placebo (P = 0.0006), as were fasting and fed TRL-TG, TRL-apoB-48, and TRL-apoB-100 (fed TRL-apoB-48: 0.93 +/- 0.08 vs. 0.76 +/- 0.07 mg/dl, P =0.017, and fed TRL-apoB-100: 15.57 +/- 0.90 vs. 13.71 +/- 1.27 mg/dl, P = 0.029). This small but significant increase in plasma TRL concentration was explained by a tendency for RSG to increase TRL production and reduce particle clearance, as indicated by the significantly increased production to clearance ratios for both apoB-48-containing (0.43 +/- 0.03 vs. 0.34 +/- 0.03, P = 0.048) and apoB-100-containing (7.0 +/- 0.4 vs. 6.2 +/- 0.6, P = 0.029) TRL. CONCLUSION These data indicate dissociation between the insulin-sensitizing effects of RSG and absence of anticipated reductions in production rates of apoB-100- and apoB-48-containing-TRL particles, which may explain the absence of TG lowering seen in humans treated with this agent.
Developing Occupational Therapy Services within an Integrated Mental Health Service

Health care reform has been taking place in a number of countries around the world. Changes have been occurring in Australian government mental health policies regarding service delivery for people with a mental illness. The National Mental Health Policy and Plan 1992 and the Queensland Mental Health Plan 1994 have set the directions for the reform of mental health services. As a result, occupational therapists have been required to examine and develop their role in service delivery within integrated mental health services. Occupational therapists within one integrated mental health service have responded by developing their practice across service components with a focus on the consumer and with service development links.
Reductions in basal metabolic rate and physical activity contribute to hypothalamic obesity.

CONTEXT Obesity after hypothalamic damage is often severe and resistant to lifestyle changes. It is postulated that differences in basal metabolic rate (BMR) and physical activity may contribute to hypothalamic obesity (HO). OBJECTIVE Our objective was to investigate the role of energy expenditure, BMR, and physical activity in the etiology of hypothalamic obesity. DESIGN This was a cross-sectional study of three groups of children: those with HO, congenital hypopituitarism (CH), and simple obesity (SO). RESULTS A total of 47 children (HO = 18, CH = 13, and SO = 16) had BMR measured, using indirect calorimetry (Deltatrac II). A lower BMR was seen in the HO group, which remained even after adjusting for lean mass. Physical activity, assessed using triaxial accelerometry, demonstrated longer activity periods in the HO group, although the degree of activity was reduced. No significant differences were seen in calorie intake. CONCLUSION Energy expenditure, rather than energy intake, has a greater role in the development of obesity after cranial tumor therapy. Reductions in BMR and physical activity, leading to a positive energy balance and weight gain despite an age-appropriate calorie intake, may contribute to hypothalamic obesity.
The Stability of Subdivision Operator at Its Fixed Point

We consider the univariate two-scale refinement equation $\varphi(x) = {\textstyle\Sigma^N_{k=0}}c_k\varphi(2x-k)$, where $c_0, \ldots, c_N$ are complex values and ${\textstyle\Sigma} c_k = 2$. This paper analyzes the correlation between the existence of smooth compactly supported solutions of this equation and the convergence of the corresponding cascade algorithm/subdivision scheme. We introduce a criterion that expresses this correlation in terms of the mask of the equation. We show that the convergence of the subdivision scheme depends on values that the mask takes at the points of its generalized cycles. This means in particular that the stability of shifts of refinable function is not necessary for the convergence of the subdivision process. This also leads to some results on the degree of convergence of subdivision processes and on factorizations of refinable functions.
Spherical Product Algorithms and the Integration of Smooth Functions with One Singular Point

We consider the problem of numerical integration for multivariate functions with respect to a radial symmetric weight. We prove that suitable spherical product algorithms have the optimal rate of convergence n-k/d for Ck-functions. We also study classes of integrands with a singularity that are Ck outside the origin. Standard algorithms have a high cost for such functions because they require that the function is smooth everywhere. We construct suitably modified spherical product algorithms with an optimal rate of convergence n-k/d also in this case. In the compact case, we can use modified spherical product Gauss formulas with a nonalgebraic degree of precision.
A Robust Adaptive Method for a Quasi-Linear One-Dimensional Convection-Diffusion Problem

A quasi-linear conservative convection-diffusion two-point boundary value problem is considered. To solve it numerically, an upwind finite difference scheme is applied. The mesh used has a fixed number (N+1) of nodes and is initially uniform, but its nodes are moved adaptively using a simple algorithm of de Boor based on equidistribution of the arc-length of the current computed piecewise linear solution. It is proved for the first time that a mesh exists that equidistributes the arc-length along the polygonal solution curve and that the corresponding computed solution is first-order accurate, uniformly in $\varepsilon$, where $\varepsilon$ is the diffusion coefficient. In the case when the boundary value problem is linear, if N is sufficiently large independently of $\varepsilon$, it is shown that after $O({\rm ln}(1/\varepsilon)/{\rm ln} N)$ iterations of the algorithm, the piecewise linear interpolant of the computed solution achieves first-order accuracy in the $L^\infty[0,1]$ norm uniformly in $\varepsilon$. Numerical experiments are presented that support our theoretical results.
Reaction of Cutaneous Blood Vessels to Successive Insults: Repeated Intradermal Histamine Challenge on Normal and Irritated Human Skin

Background: Histamine, a major mediator in endogenous and exogenous skin disorders, has been extensively investigated. Many experiments concern external provocation, yet the sequence of events as well as the influence of timing of the provocating factors require clarification. Objective: To document cutaneous reactivity to histamine rechallenge at different time points, as well as the response of irritated skin (irritant dermatitis) to histamine. Methods: Histamine was intradermally administered on the upper back of 20 volunteers at different time points to 3 sites and following SLS-induced irritant dermatitis to another site. The cutaneous vascular response was measured by laser Doppler flowmetry. Results: The response to a second prick when the first prick response had decayed to half its peak was significantly higher than all the other responses that resulted from a second prick (p < 0.01). The other responses did not significantly differ from each other or from the first prick response. When the histamine prick was performed over a 24-hour SLS patch, the response was greater than at all other sites (p < 0.01). Conclusion: An excitation state, at which the skin readily reacted to the second insult, may underlie the augmentation of the response to a histamine prick over the irritated skin. Irritation modulates cytokines, which may be the mechanism by which the response to histamine administration is enhanced. Tachyphylaxis did not occur at the time points tested, but may occur at longer intervals, necessitating further investigation.
Treatment and follow-up of clinically nonfunctioning pituitary macroadenomas.

CONTEXT Although the majority of pituitary macroadenomas are clinically nonfunctioning, treatments as well as follow-up strategy for this condition lack evidence from randomized studies. EVIDENCE ACQUISITION We evaluated the evidence of treatment and follow-up strategies for clinically nonfunctioning adenomas. PubMed was searched for articles on nonfunctioning adenomas in November 2007, and references of selected articles were assessed for potentially relevant articles. EVIDENCE SYNTHESIS All evidence for treatment and follow-up for nonfunctioning adenomas is based on observational studies. The most effective treatment is transsphenoidal surgery, indicated in patients with visual field defects. A wait-and-see approach may be considered in nonfunctioning macroadenomas not reaching to the optic chiasm. Some of these tumors ( approximately 10%) will show spontaneous regression, whereas in approximately 50% there will be progression within 5 yr observation. Postoperative radiotherapy should not be applied to all patients after surgery but can be considered in patients with large postoperative remnants of the tumor. During follow-up careful assessment and replacement of pituitary insufficiencies should be performed. Magnetic resonance imaging is advised with intervals of 1-3 yr and evaluation of visual fields when appropriate. Recurrence rates are reported to be 6-46% after transsphenoidal surgery, whereas after postoperative radiotherapy, recurrence rates of 0-36% are reported. Long-term sequelae of nonfunctioning macroadenomas are hypopituitarism, persistent visual field defects, and decreased quality of life. Whether nonfunctioning macroadenomas are associated with an increased mortality is still a matter of debate. CONCLUSION Clinically nonfunctioning pituitary macroadenomas, although benign in nature, need individualized treatment and lifelong radiological and endocrinological follow-up.
A Mortar Finite Element Method for Fourth Order Problems in Two Dimensions with Lagrange Multipliers

A mortar finite element method with a new Lagrange multipliers space for clamped plate problems is discussed. In the subdomains a conforming Hsieh--Clough--Tocher (HCT) macro element defined on nonmatching triangulations is utilized. The main result of the paper is the proof of an inf-sup condition with new test spaces. Finally, an error bound for Lagrange multipliers is proved.
Constant adaptation of bone to current physical activity level in men: a 12-year longitudinal study.

CONTEXT A high peak bone mineral density (BMD; grams per square centimeter) could reduce the risk of osteoporosis related fractures later in life. OBJECTIVE This 12-yr longitudinal study investigated whether a high BMD from previous high physical activity is maintained with reduced activity later in life. DESIGN This was a longitudinal study. PARTICIPANTS Three groups were investigated with a mean age of 17 yr at baseline; 51 athletes who stopped their active careers during follow-up (former athletes), 16 who were active throughout follow-up (active athletes), and 25 controls. MAIN OUTCOME MEASURES BMD of the femoral neck, total body, and lumbar spine were examined five times during the 12-yr follow-up period. RESULTS After adjustment for age, weight, and height, the former athletes were found to have higher BMD at all sites at every follow-up visit except the last one, when compared with controls (P < 0.05). The active athletes were found to have significantly higher BMD at all measured locations when compared with controls throughout the entire study (P < 0.05). From the first to the final follow-up visit, the former athletes were found to have lost more femoral neck BMD than both the active athletes (mean difference, 0.12 g/cm(2); P = 0.003) and controls (mean difference 0.08 g/cm(2); P = 0.02). CONCLUSION This study suggests that BMD constantly adapts to the present physical activity levels in young men. Thus, increased BMD due to previous high physical activity may not prevent osteoporosis in later years.
Error Analysis for Approximation of Stochastic Differential Equations Driven by Poisson Random Measures

Let Xt be the solution of a stochastic differential equation (SDE) with starting point x0 driven by a Poisson random measure. Additive functionals are of interest in various applications. Nevertheless they are often unknown and can only be found by simulation on computers. We investigate the quality of the Euler approximation. Our main emphasis is on SDEs driven by an $\alpha$-stable process, $0<\alpha < 2$, where we study the approximation of the Monte Carlo error ${\Bbb E} [f(X_T)]$, f belonging to ${L}^\infty$. Moreover, we treat the case where the time equals $T\wedge \tau$, where $\tau$ is the first exit time of some interval.
Adopting and adapting the mini‐CEX as an undergraduate assessment and learning tool

Examiners rate student performance along several predetermined dimensions.We were aiming to improve not only our summative assessments but also the learning experience of our students.Many of the concerns expressed by staff and students were practical.Renewed emphasis was placed on staff development.There was a perception that the assessment criteria were too lenient. Students valued highly the one-to-one 'teaching'
The space‐math link in preschool boys and girls: Importance of mental transformation, targeting accuracy, and spatial anxiety

Spatial abilities are pertinent to mathematical competence, but evidence of the space-math link has largely been confined to older samples and intrinsic spatial abilities (e.g., mental transformation). The roles of gender and affective factors are also unclear. This study examined the correlations between counting ability, mental transformation, and targeting accuracy in 182 Hong Kong preschoolers, and whether these relationships were weaker at higher spatial anxiety levels. Both spatial abilities related with counting similarly for boys and girls. Targeting accuracy also mediated the male advantage in counting. Interestingly, spatial anxiety moderated the space-math links, but differently for boys and girls. For boys, spatial abilities were irrelevant to counting at high anxiety levels; for girls, the role of anxiety on the space-math link is less clear. Results extend the evidence base of the space-math link to include an extrinsic spatial ability (targeting accuracy) and have implications for intervention programmes. Statement of contribution What is already known on this subject? Much evidence of a space-math link in adolescent and adult samples and for intrinsic spatial abilities. What does this study add? Extended the space-math link to include both intrinsic and extrinsic spatial abilities in a preschool sample. Showed how spatial anxiety moderated the space-math link differently for boys and girls.
Lithotripsy: The Treatment of Kidney Stones with Shock Waves

This paper discusses mathematical models for the response of a small air bubble in water to an ultrasound pulse, a context that arises in the modern treatment for kidney stones. The paper reviews Rayleigh's 1917 theory for bubble response, applies asymptotics to describe large-amplitude solutions of Rayleigh's equations, and briefly discusses effects neglected in the simple model. The style is expository, intended both to introduce this application to mathematicians and to illustrate the use of asymptotic methods to nonmathematicians.
Endocrine and metabolic effects of consuming fructose- and glucose-sweetened beverages with meals in obese men and women: influence of insulin resistance on plasma triglyceride responses.

CONTEXT Compared with glucose-sweetened beverages, consumption of fructose-sweetened beverages with meals elevates postprandial plasma triglycerides and lowers 24-h insulin and leptin profiles in normal-weight women. The effects of fructose, compared with glucose, ingestion on metabolic profiles in obese subjects has not been studied. OBJECTIVE The objective of the study was to compare the effects of fructose- and glucose-sweetened beverages consumed with meals on hormones and metabolic substrates in obese subjects. DESIGN AND SETTING The study had a within-subject design conducted in the clinical and translational research center. PARTICIPANTS Participants included 17 obese men (n = 9) and women (n = 8), with a body mass index greater than 30 kg/m(2). INTERVENTIONS Subjects were studied under two conditions involving ingestion of mixed nutrient meals with either glucose-sweetened beverages or fructose-sweetened beverages. The beverages provided 30% of total kilocalories. Blood samples were collected over 24 h. MAIN OUTCOME MEASURES Area under the curve (24 h AUC) for glucose, lactate, insulin, leptin, ghrelin, uric acid, triglycerides (TGs), and free fatty acids was measured. RESULTS Compared with glucose-sweetened beverages, fructose consumption was associated with lower AUCs for insulin (1052.6 +/- 135.1 vs. 549.2 +/- 79.7 muU/ml per 23 h, P < 0.001) and leptin (151.9 +/- 22.7 vs. 107.0 +/- 15.0 ng/ml per 24 h, P < 0.03) and increased AUC for TG (242.3 +/- 96.8 vs. 704.3 +/- 124.4 mg/dl per 24 h, P < 0.0001). Insulin-resistant subjects exhibited larger 24-h TG profiles (P < 0.03). CONCLUSIONS In obese subjects, consumption of fructose-sweetened beverages with meals was associated with less insulin secretion, blunted diurnal leptin profiles, and increased postprandial TG concentrations compared with glucose consumption. Increases of TGs were augmented in obese subjects with insulin resistance, suggesting that fructose consumption may exacerbate an already adverse metabolic profile present in many obese subjects.
Brain glucose metabolism in hypothyroidism: a positron emission tomography study before and after thyroid hormone replacement therapy.

CONTEXT Hypothyroidism is frequently associated with subtle behavioral and psychiatric symptoms. The consequences of inadequate thyroid hormone availability to brain metabolism are poorly understood. OBJECTIVE This study assessed the relationships between neuropsychiatric symptoms and changes in relative regional cerebral glucose metabolism in hypothyroid patients undergoing thyroid hormone replacement therapy. DESIGN, SETTING, AND OUTCOME MEASURE: Relative regional cerebral glucose metabolism was compared in 13 previously untreated hypothyroid patients and 10 healthy control participants. Effects of thyroid hormone replacement therapy (levothyroxine, 3 months) were assessed using neuropsychiatric measures and positron emission tomography with [(18)F]fluorodeoxyglucose. RESULTS Before treatment, hypothyroid patients exhibited lower regional activity than control subjects in the bilateral amygdala, hippocampus, and perigenual anterior cingulate cortex (ACC), left subgenual ACC, and right posterior cingulate cortex. Severity of depressive symptoms covaried negatively with pretreatment activity in the bilateral middle frontal gyrus and right subgenual and dorsal ACC. Thyroid hormone replacement therapy abolished pretreatment group differences in regional activity, robustly increased activity in the ventral ACC, and significantly reduced both clinician-rated and self-rated behavioral and psychiatric symptoms. Increased activity within the ventral ACC was associated with reduced somatic complaints, whereas increased activity within the dorsal ACC was associated with reduced depressive symptoms. CONCLUSIONS Reduction of the behavioral complaints during thyroid hormone therapy is associated with a restoration of metabolic activity in brain areas that are integral to the regulation of affect and cognition. The findings suggest that thyroid hormone modulates regional glucose metabolism and psychiatric symptoms in the mature brain.
Clinical review: Realistic expectations and practical use of continuous glucose monitoring for the endocrinologist.

CONTEXT Real-time continuous glucose monitoring (CGM) has been available for type 1 diabetes for several years. This paper is a status report on our early experiences with this next technology. EVIDENCE ACQUISITION The two major sources of data acquisition included PubMed search strategies and personal experience of the author from clinical experience. EVIDENCE SYNTHESIS Data assessing CGM accuracy, short-term outcomes (12 wk), and longer term outcomes (6 months) are reported. Potential strategies for successful and efficient use in an office or clinic setting are also discussed. Practical aspects of CGM use (alarm settings, using glycemic trending information) are also reviewed. CONCLUSIONS Accuracy of this technology has improved in the short amount of time it has been available. Six-month data suggest that patient selection is a key for success. Patients who do not understand or practice the basics of intensive insulin therapy have the greatest challenges. Those who do best watch the receiver frequently, continue with frequent home blood glucose monitoring, use the trending information to make insulin adjustments, and understand the limitations of the technology. With insurance reimbursement improving, CGM is gaining acceptance as an important tool for the management of type 1 diabetes. Like home blood glucose monitoring and insulin pump therapy, this technology by itself is not a panacea for diabetes control. However, it further adds to our ability to improve the lives of people with diabetes. Long-term, the hope is that this technology will pave the way for a "closed-loop" device.