Microhotplate Temperature Sensor Calibration and BIST

In this paper we describe a novel long-term microhotplate temperature sensor calibration technique suitable for Built-In Self Test (BIST). The microhotplate thermal resistance (thermal efficiency) and the thermal voltage from an integrated platinum-rhodium thermocouple were calibrated against a freshly calibrated four-wire polysilicon microhotplate-heater temperature sensor (heater) that is not stable over long periods of time when exposed to higher temperatures. To stress the microhotplate, its temperature was raised to around 400 °C and held there for days. The heater was then recalibrated as a temperature sensor, and microhotplate temperature measurements were made based on the fresh calibration of the heater, the first calibration of the heater, the microhotplate thermal resistance, and the thermocouple voltage. This procedure was repeated 10 times over a period of 80 days. The results show that the heater calibration drifted substantially during the period of the test while the microhotplate thermal resistance and the thermocouple-voltage remained stable to within about plus or minus 1 °C over the same period. Therefore, the combination of a microhotplate heater-temperature sensor and either the microhotplate thermal resistance or an integrated thin film platinum-rhodium thermocouple can be used to provide a stable, calibrated, microhotplate-temperature sensor, and the combination of the three sensor is suitable for implementing BIST functionality. Alternatively, if a stable microhotplate-heater temperature sensor is available, such as a properly annealed platinum heater-temperature sensor, then the thermal resistance of the microhotplate and the electrical resistance of the platinum heater will be sufficient to implement BIST. It is also shown that aluminum- and polysilicon-based temperature sensors, which are not stable enough for measuring high microhotplate temperatures (>220 °C) without impractically frequent recalibration, can be used to measure the silicon substrate temperature if never exposed to temperatures above about 220 °C.

The role of executive functions in human prospective interval timing

Human timing is thought to be based on the output of an internal clock. Whilst the functioning of this clock is well documented, it is unclear which other cognitive resources may moderate timing. Brown (2006) and Rattat (2010) suggest that the central executive of working memory may be recruited during timing. However it seems likely that the fractionated executive component processes identified by Miyake et al. (2000) and Fisk and Sharp (2004) may differentially contribute to timing performance; further exploration of this was the aim of the present study. An interference paradigm was employed in which participants completed an interval production task, and tasks which have been shown to tap the four key executive component processes (shifting, inhibition, updating and access) under single and dual-task conditions. Comparison of single and dual-task performance indicated that timing always became more variable when concurrently performing a second task. Bidirectional interference only occurred between the interval production task and the memory updating task, implying that both tasks are competing for the same executive resource of updating. There was no evidence in the current study to suggest that switching, inhibition or access was involved in timing, however they may be recruited under more difficult task conditions.

Is emotional intelligence impaired in ecstasy-polydrug users?

Previous findings report use of the drug ecstasy (MDMA) to be associated with lower emotional intelligence (EI), and compromised functioning in brain areas responsible for emotion. This study explored the relationship between ecstasy use, EI, mood and parenting styles. Questionnaire measures of drug use, lifestyle, parenting style and EI were obtained, with separate IQ measures for fluid intelligence (Ravens matrices) and pre-morbid intelligence [National Adult Reading Test (NART)]. Current mood measures were obtained from an adjective checklist. The sample comprised 78 ecstasy/polydrug users, 38 cannabis only users and 34 non-drug users. Drug use was categorised at three levels (non-user, cannabis-only user and ecstasy-polydrug user). Factorial ANOVA using drug use as an independent variable showed no significant group effects in EI. EI showed significant correlations with current mood that were positive for arousal and negative for both anxiety and depression. EI was also significantly and positively correlated with the perceived degree of parental control. Regression analyses showed that these relationships remained significant after controlling for differences in IQ, age, gender, and ecstasy use. Adverse mood effects specifically associated with ecstasy use were significantly related to lower EI, and were independent of IQ, age and gender. Higher EI was significantly associated with ecstasy-related precautions used when taking this drug. Contrary to earlier findings, ecstasy-polydrug users did not differ from non-users on EI. However, self-reported ecstasy-related mood disturbances were related to lower EI, with the compromising of orbitofrontal cortical functioning being possible here.

Evidence for selective executive function deficits in ecstasy/polydrug users

Previous research has suggested that the separate aspects of executive functioning are differentially affected by ecstasy use. Although the inhibition process appears to be unaffected by ecstasy use, it is unclear whether this is true of heavy users under conditions of high demand. Tasks loading on the updating process have been shown to be adversely affected by ecstasy use. However, it remains unclear whether the deficits observed reflect the executive aspects of the tasks or whether they are domain general in nature affecting both verbal and visuo-spatial updating. Fourteen heavy ecstasy users (mean total lifetime use 1000 tablets), 39 light ecstasy users (mean total lifetime use 150 tablets) and 28 non-users were tested on tasks loading on the inhibition executive process (random letter generation) and the updating component process (letter updating, visuo-spatial updating and computation span). Heavy users were not impaired in random letter generation even under conditions designed to be more demanding. Ecstasy-related deficits were observed on all updating measures and were statistically significant for two of the three measures. Following controls for various aspects of cannabis use, statistically significant ecstasy-related deficits were obtained on all three updating measures. It was concluded that the inhibition process is unaffected by ecstasy use even among heavy users. By way of contrast, the updating process appears to be impaired in ecstasy users with the deficit apparently domain general in nature.

Energy intake variability in free-living young children

It has been suggested that young children regulate their daily energy intake very closely with highly stable day-to-day total energy intake. This hypothesis was developed on the basis of an experimental study of 15 children aged 26 to 62 months, which reported a within-subject coefficient of variation (CV) in daily energy intake of 10.4%. We tested the hypothesis that free-living energy intakes were highly stable on a day-to-day basis in a sample of free-living young children from Glasgow, Scotland. In 101 children (47 boys) aged 2.6-6.8 years, energy intake was measured using multiple-pass 24-h recalls. Within-subject CV was 19.2%, which was significantly higher than the 10.4% reported by previously Birch and colleagues (p<0.0001). In addition, we identified four other studies on free-living children with within-subject CVs ranging from 16.1-28.7%. This evidence indicates that young children show a wide intra-individual variation in day-to-day regulation of energy intake in a free-living environment.

Real-world memory and executive processes in cannabis users and non-users

The relationships between executive processes, associative learning and different aspects of real world memory functioning were explored in a sample of cannabis users and nonusers. Measures of executive component processes, associative learning, everyday memory, prospective memory, and cognitive failures were administered. Relative to nonusers, cannabis users were found to be impaired in several aspects of real world memory functioning. No other group differences were apparent. The absence of cannabis related deficits in those executive component processes and aspects of learning that are believed to support real world memory processes is surprising given that cannabis related deficits were obtained in real world memory. The present results are discussed within the context of neuroimaging evidence which suggests that cannabis users may exhibit different patterns of neural activation when performing executive tasks while not always exhibiting deficits on these tasks.

Effect of socioeconomic status on objectively measured physical activity

BACKGROUND

A socioeconomic gradient in childhood obesity is known to be present by the age of school entry in the UK. The origin of this gradient is unclear at present, but must lie in socioeconomic differences in habitual physical activity, sedentary behaviour, or dietary intake.

AIMS

To test the hypothesis that habitual physical activity and/or sedentary behaviour are associated with socioeconomic status (SES) in young Scottish children.

METHODS

Observational study of 339 children (mean age 4.2 years, SD 0.3) in which habitual physical activity and sedentary behaviour were measured by accelerometry over six days (study 1). In a second study, 39 pairs of children of distinctly different SES (mean age 5.6 years, SD 0.3) were tested for differences in habitual physical activity and sedentary behaviour by accelerometry over seven days.

RESULTS

In study 1, SES was not a significant factor in explaining the amount of time spent in physical activity or sedentary behaviour once gender and month of measurement were taken into account. In study 2, there were no significant differences in time spent in physical activity or sedentary behaviour between affluent and deprived groups.

CONCLUSION

Results do not support the hypothesis that low SES in young Scottish children is associated with lower habitual physical activity or higher engagement in sedentary behaviour.

Nutritional status and energy expenditure in children pre-bone-marrow-transplant

The aims of this study were to establish the nutritional status of children pre-BMT and to determine whether predictive methods of assessing nutritional status and resting energy expenditure (REE) are accurate in this population. We analysed the body cell mass (BCM) (n=26) and REE (n=24) in children undergoing BMT. BCM was adjusted for height (BCM/HT(p)) and expressed as a Z score to represent nutritional status. To determine whether body mass index (BMI) was indicative of nutritional status in children undergoing BMT, BMI Z scores were compared to the reference method of BCM/HT(p) Z scores. Schofield predictive equations of basal metabolic rate (BMR) were compared to measured REE to evaluate the accuracy of the predictive equations. The mean BCM/HT(p) Z score for the subject population was -1.09+/-1.28. There was no significant relationship between BCM/HT(p) Z score and BMI Z score (r=0.34; P>0.05); however there was minimal difference between measured REE and predicted BMR (bias=-11+/-149 kcal/day). The results of this study demonstrate that children undergoing BMT may have suboptimal nutritional status and that BMI is not an accurate indication of nutritional status in this population. However, Schofield equations were found to be suitable for representing REE in children pre-BMT.

Total energy expenditure and physical activity in young Scottish children: mixed longitudinal study

Childhood obesity has been attributed to a decline in total energy expenditure (TEE). We measured TEE, physical activity, and sedentary behaviour in a representative sample of young children from Glasgow, UK, at age 3 years (n=78), and we did a follow-up study at age 5 years (n=72). Mean physical activity level (TEE/resting energy expenditure) was 1.56 (SD 0.39) at age 3 years and 1.61 (0.22) at age 5 years. Median time in sedentary behaviour was 79% of monitored hours at age 3 years (IQR 74-84) and 76% (71-80) at age 5 years. Median time spent in moderate to vigorous physical activity represented only 2% of monitored hours at age 3 years (IQR 1-4) and 4% at age 5 years (2-6). Modern British children establish a sedentary lifestyle at an early age.

Maternal docosahexaenoic acid supplementation during pregnancy and visual evoked potential development in term infants: a double blind, prospective, randomised trial

AIM

To test the hypothesis that maternal docosahexaenoic acid (DHA) supplementation during pregnancy enhances maturation of the visual evoked potential (VEP) in healthy term infants.

METHODS

One hundred women were supplemented with either fish oil capsules rich in DHA (n = 50) or placebo capsules (n = 50) from week 15 of pregnancy until delivery. Total fatty acids in red blood cells and plasma were measured at weeks 15, 28, and 40 of pregnancy and at delivery in umbilical cord blood. Infant visual pathway development was assessed using VEPs recorded to flash stimuli shortly after birth and to both flash and pattern-reversal stimuli at 50 and 66 weeks post-conceptional age (PCA).

RESULTS

Maternal supplementation did not significantly elevate the level of DHA in umbilical cord blood. Moreover, there were no significant differences in any of the VEP measures observed between supplementation groups. However, maturity of the pattern-reversal VEP at 50 and 66 weeks PCA was associated with DHA status of the infants at birth. Infants with higher DHA status, both as a concentration and as a percentage of total fatty acids, showed shorter P100 peak latencies of the pattern-reversal VEP than those with lower DHA status.

CONCLUSIONS

Maternal DHA supplementation during pregnancy did not enhance VEP maturation in healthy term infants. However, these results show an association between the DHA status of infants at term and early postnatal development of the pattern-reversal VEP, suggesting that DHA status itself may influence maturation of the central visual pathways.

Heterosexual outbreak of infectious syphilis: epidemiological and ethnographic analysis and implications for control

This study describes the epidemiology and ethnography of an outbreak of infectious syphilis in Vancouver, British Columbia. Between 1996 and 1999, British Columbias's rate of infectious syphilis rose from 0.5 to 3.4 per 100,000, with a dense concentration of cases among sex trade workers, their clients, and street-involved people in the downtown eastside area of Vancouver. Sexual networks were imported cases with secondary spread (dyads and triads), large densely connected dendritic networks of sex trade workers and clients, or occasional starburst networks among gay men. Only 232 of 429 partners were documented as having been treated (54% of those named, or 0.9 per case). The geographical and demographic concentration of this outbreak led to consideration of a programme of focused mass treatment with single dose azithromycin.

Energy intake by multiple pass 24 h recall and total energy expenditure: a comparison in a representative sample of 3-4-year-olds

The accuracy of the multiple pass 24 h recall for assessment of habitual energy intake in pre-school children is unclear. The primary aim of this study was to assess its accuracy by comparison with measurement of total energy expenditure by doubly-labelled water in a representative sample of forty-one 3-4-year-olds. The recall method was well tolerated by subjects and was administered quickly and easily. However, it produced estimates of energy intake which significantly exceeded measures of total energy expenditure from doubly-labelled water, mean paired difference 660 kJ/d (P<0.01). Agreement between the two methods was poor at the individual level: limits of agreement 660+/-3018 kJ/d. Error and imprecision in both methods contribute to individual differences, but the present study suggests that the multiple pass 24 h recall does not provide accurate estimates of dietary energy intake in individual children.

Implementing cancer pain education for medical students

PURPOSE

The purpose of this study was to develop and pilot a cancer pain education course for medical students, using a structured home hospice visit.

DESCRIPTION OF STUDY

A 1-hour home hospice visit was presented to 57 senior medical students. The content and objective criteria for the structured home hospice visit were developed by a multidisciplinary group of experts. During a 1-hour interview, students completed a cancer pain history, performed a focused physical examination, and received feedback and teaching regarding the essentials of cancer pain management from the hospice nurse. All students and hospice patients completed a multi-item evaluation questionnaire with a 5-point Likert scale (1=strongly disagree; 5=strongly agree) regarding the structured home hospice visit.

RESULTS

Most students agreed strongly that the home hospice visit was a positive experience (mean +/- SD 4.8 +/- 0.44) that helped them to understand the management of cancer pain (mean 4.7 +/- 0.46) and opioid-related side effects (mean 4.5 +/- 0.57). Most patients enjoyed visiting with the students (mean 4.90 +/- 0.30), agreed that the visit was not tiring (mean 4.81 +/- 0.51), and felt that they benefited from participating (mean 4.76 +/- 0.54).

CLINICAL IMPLICATIONS

The authors concluded the following: 1) that medical students benefited from learning about cancer pain assessment and management through the use of a structured home hospice visit; 2) that a structured home hospice visit helped the students to learn the basics of cancer pain management; 3) that patients enjoyed their role as teacher for medical students; and 4) that senior hospice nurses provided excellent instruction for medical students in the management of cancer pain.

Effect of glucocorticoid therapy on energy intake in children treated for acute lymphoblastic leukemia

Despite a widespread belief that glucocorticoid therapy is associated with positive energy balance and excess weight gain there is a dearth of quantitative evidence about its effects and the underlying mechanisms of any effects. The primary aim of the present study was to quantify the effect of dexamethasone and prednisone treatment on energy intake in children treated for childhood acute lymphoblastic leukemia. A secondary aim was to test for differences in excess weight gain between patients treated using the 2 glucocorticoids. We measured energy intake in 26 patients (mean +/- SD age, 6.3 +/- 2.3 yr) during a 5-d period "on" steroids and again in the week before steroid treatment. Changes in body mass index from diagnosis to 1 and 2 yr postdiagnosis were expressed as SD scores. Steroid treatment was associated with a significant increase in energy intake of approximately 20% (mean paired difference, 1.7 MJ/d; SD, 2.8; 95% confidence interval, 0.7-2.8 MJ/d), with no significant difference between the 2 steroids. The mean change in body mass index SD score was +0.38 (SD, 1.10; P < 0.05) to 1 yr and +0.68 (SD, 1.38; P < 0.05) to 2 yr, with no significant difference between the 2 groups of patients. Glucocorticoid treatment in childhood acute lymphoblastic leukemia increases energy intake markedly, and this effect contributes to the excess weight gain and obesity characteristic of patients being treated for acute lymphoblastic leukemia.

Fatty acid status of women of reproductive age

OBJECTIVE

Healthy foetal and infant development is dependent on an adequate maternal supply of essential and polyunsaturated fatty acids (PUFA). While there are published data on the fatty acid status of pregnant women, there are few on the status of non-pregnant women of reproductive age. The aims of this study were to test the hypotheses that the fatty acid status of non-pregnant women is affected by socio-economic status and anthropometric, behavioural and obstetric factors.

DESIGN

Observational study

METHODS

One-hundred and thirty-five women of child-bearing age (mean 29.8 y, s.d. 6.92) were invited to provide a blood sample and to answer a questionnaire, of whom 114 were included in the study. Plasma and red cell total fatty acids were measured as their methyl esters by gas chromatography mass spectrometry.

RESULTS

On multivariate analyses, use of hormonal contraception was independently associated with lower plasma polyunsaturated fatty acids (difference between means -2.76, 95% confidence interval (-4.64, -0.88), P=0.0034), whereas cigarette smoking was associated with higher red cell oleic acid (0.74 (0.18, 1.29), P=0.0094). Fish intake was associated with higher red cell total n-3 fatty acids (0.62 (0.27, 0.85), P=0.0014).

CONCLUSIONS

We have reported data on the range of the fatty acids of plasma and red blood cells (RBC) total lipids of 114 healthy women of reproductive age. These data provide further information on how socio-economic, anthropometric, behavioural and obstetric factors may be relevant to female and nutrition and health.

SPONSORSHIP

University of Glasgow.

Creating a balanced scorecard for a hospital system

In 1999, hospitals in Ontario, Canada, collaborated with a university-based research team to develop a report on the relative performance of individual hospitals in Canada's most populated province. The researchers used the balanced-scorecard framework advocated by Kaplan and Norton. Indicators of performance were developed in four areas: clinical utilization and outcomes, patient satisfaction, system integration and change, and financial performance and condition. The process of selecting, calculating, and validating meaningful indicators of financial performance and condition is outlined. Lessons learned along the way are provided. These lessons may prove valuable to other finance researchers and practitioners who are engaged in performance measurement endeavors.

Cost-effective post-exposure prevention of poison ivy dermatitis

BACKGROUND

Poison ivy (toxicodendron) dermatitis is the most common allergic contact dermatitis in the USA. No studies have shown an effect of washing after a short period of time for the prevention of binding of urushiol to the skin. Objective To evaluate the efficacy of three different modes of postcontact prevention using a surfactant (Dial ultra dishwashing soap), an oil-removing compound (Goop), and chemical inactivation (a commercial product Tecnu).

METHODS

A consented, unsponsored, volunteer experimental study on medical students from the University of Missouri School of Medicine, Kansas City. Each subject served as his/her own control, comparing four 2.5-cm exposed squares on the inner aspect of the forearm, three of which were treated and one untreated.

RESULTS

Comparisons between the different agents were nonsignificant with P > 0.05. Each treatment, however, was significantly improved over the untreated control.

CONCLUSIONS

Our study showed 70%, 61.8%, and 56. 4% protection with Tecnu, Goop, and Dial, respectively, when compared to the positive control, or to the possible maximum response, with a cost per ounce (in a local drug and automotive store) of $1.25, $0.07, and $0.07, respectively, for a decrease in protection that is nonsignificant.

The burden of personality disorder: a district-based survey

Patients with a clinical diagnosis of personality disorder (PD) often suffer prolonged distress. They are a considerable burden on psychiatric services and they are experienced as difficult to manage by their keyworkers. This paper describes the creation of a community-based case register of patients suffering from PD. It explores the relationship between psychological distress, personality dysfunction, service utilisation and keyworker stress. Mental Health workers were asked to identify those patients on their caseload whose primary problem was PD. This list provided the basis for the case register. Patients completed the revised Personality Diagnostic Questionnaire IV (PDQ 4); the General Health Questionnaire (GHQ); and the Beck Depression Inventory - 21 item (BDI). A brief, semi-structured interview was conducted by Community Psychiatric Nurses to estimate service utilisation and keyworker stress. The mean GHQ was 14.58; the mean BDI score was 28.22. The mean number of PDs per patient was 4.5. One quarter of patients (21/80) had been admitted at least once to a psychiatric ward in the previous year and 17% (13/80) had presented to casualty at least once in the previous two months. 57% of the patients had weekly or more contacts with a helping agency. The number of PD diagnoses per patient as measured by the PDQ 4 was not found to be predictive of stress experienced by CPNs, whereas high BDI and GHQ scores were strongly correlated. Similarly, the number of admissions to a psychiatric ward was associated with high BDI and GHQ scores but not with number of PDs per patient. It is feasible to establish a case register of all patients in the district with PD. There are high levels of depression and distress amongst patients with PD being treated as outpatients. Service utilisation and keyworker stress are not predicted by number of PDs per patient but are strongly associated with distress as measured by the GHQ and BDI. The implications of these findings are discussed.

Developing guidelines for allocating catheterization laboratory resources: lessons from an Ontario Consensus Panel. Consensus Panel on Cardiac Catheterization Laboratory Services in Ontario and the Steering Committee of the Cardiac Care Network of Ontario

In March 1997, the Ontario Ministry of Health asked the Cardiac Care Network of Ontario (CCN) to develop guidelines for allocating cardiac catheterization laboratory resources. A consensus panel of providers and planners used findings from the literature and expert opinion to recommend guidelines for the operation of cardiac catheterization laboratories and criteria to be considered when allocating additional cardiac catheterization laboratory resources. This article summarizes the consensus panel's major findings that may be of value to other jurisdictions, including need identification, clinical practice, system issues, location criteria and cost considerations. The article reflects the advice given to the Ontario Ministry of Health by the CCN and is not an official position paper of the Canadian Cardiovascular Society.

Efficacy and complications of morphine infusions in postoperative paediatric patients

The aim of the study was to evaluate the efficacy and the incidence of clinically significant adverse drug reactions (ADRs) in paediatric patients receiving continuous intravenous morphine infusions for acute postoperative pain. Definitions were established for ADRs and data were collected in an immediately retrospective fashion for a maximum of 72 h in 110 patients >/=5 three months of age (0.3-16.7 years) receiving morphine infusions and admitted to a general ward over a three month convenience sampling period. Inadequate analgesia occurred in 65.5% of patients during the first 24 h of therapy and occurred most frequently in patients with infusion rates of 20 microg.kg-1.h-1 or less. Nausea/vomiting was the most commonly experienced ADR (42.5%). The incidence of respiratory depression was 0% (95% CI=0-3.3%). Other ADRs included: urinary retention (13.5%), pruritus (12.7%), dysphoria (7.3%), hypoxaemia (4.5%), discontinuation of morphine for treatment of an ADR (3.6%), and difficulty in arousal (0.9%). The most common ADRs associated with morphine infusions were inadequate analgesia (in the first 24 h) and nausea/vomiting. There were no cases of respiratory depression. Methods of avoiding initial inadequate analgesia and treating nausea and vomiting associated with morphine infusions are needed.

Psychological distress among cancer patients and informed consent

This study examines the relationships between satisfaction with information provided, understanding of consent procedures, and levels of anxiety/depression in a sample of patients undergoing radiotherapy for cancer. One hundred patients completed a 13-item self-report questionnaire and the Hospital Anxiety and Depression Scale (HADS). Twenty-two percent of patients could not recall signing a consent form and, for those who did recall, the level of understanding for what they had consented to was patchy. One fourth of patients could not recall being told of the side-effects from radiotherapy and were unable to list even common side-effects, such as tiredness, skin irritation, and sickness. No patient had been told about the low risk of second malignancy. Twenty-eight percent of patients were unhappy with the amount of information offered to them. Thirty percent of patients reached caseness for adjustment disorder +/- anxiety/depression. Thirteen percent of patients reached caseness for major depression. There was a significant correlation between patients who scored highly on the HADS and dissatisfaction with the information provided. Clinical implications and possible mechanisms of these findings are discussed.