Adherence to Vitamin D Supplementation Recommendations for Breastfed Infants and Young Children: An Analysis of Canadian Community Health Survey Data Cycles From 2015 to 2018

BACKGROUND

In Canada, nutrition policy, as outlined in the Nutrition for Healthy Term Infants recommendations, includes a daily vitamin D supplement of 10 μg (400 IU) for breastfed infants and young children to support adequate vitamin D status.

OBJECTIVES

This study aimed to report on adherence to vitamin D supplementation recommendations for breastfed infants (≤12 months); and for children breastfed >12 mo.

METHODS

Canadian Community Health Survey (paired-cycles 2015/2016 and 2017/2018) maternal experiences data for infants born 2012-2018 who received any breastmilk formed the sample (n = 7079). Whether the infant was given a vitamin D supplement (yes/no) and the frequency (daily/almost every day, 1-2/wk, or <1/wk) were surveyed. Weighted data (95% CI) were summarized according to breastfeeding history (exclusive to 6 mo and continuing; partial to 6 mo and continuing; and stopped ≤6 mo). Correlates of supplement adherence were explored using logistic regression.

RESULTS

Overall, 87.1% (95% CI: 85.9%, 88.3%) of participants reported giving their infant (≤12 mo) a vitamin D supplement, and of these, 83.3% (95% CI: 81.9%, 84.7%) did so daily/almost every day, 12.4% (95% CI: 11.1%, 13.7%) did so 1-2/wk, and 4.3% (95% CI: 3.6%, 5.0%) did so <1/wk. Lower adjusted odds of adherence were observed among participants reporting: stopped breastfeeding ≤6 mo, lower education or income, recent immigration, and overweight prepregnancy body mass index; higher odds of adherence were observed in the western provinces. Regarding mothers of children >12 mo and breastfed (n = 2312), 58.0% (95% CI: 54.9%, 61.1%) gave a vitamin D supplement daily/almost every day.

CONCLUSIONS

Adherence to providing a vitamin D supplement to breastfed infants is high in Canada. Nonetheless, we estimate that ∼27% of mothers are nonadherent to daily/almost every day administration of a vitamin D supplement and that adherence declines in children breastfed >12 mo. Further promotion to support uptake of the current guidance may be necessary, particularly for parents of recent immigration or lower socioeconomic status.

An in vivo model of postinflammatory hyperpigmentation and erythema: clinical, colorimetric and molecular characteristics

BACKGROUND

Postinflammatory hyperpigmentation (PIH) is a common, acquired pigmentary disorder of the skin associated with significant quality-of-life impairment, especially in individuals with skin of colour. Current treatment for PIH is limited, largely due to a poor understanding of disease pathogenesis and the lack of a representative disease model.

OBJECTIVES

This study is intended to further develop, update and validate our previously designed in vivo model of acne-induced PIH/postinflammatory erythema (PIE) using different concentrations of trichloroacetic acid (TCA), a medium-depth chemical peel.

METHODS

Twenty-nine patients with skin types II-VI and clinician-confirmed presence of two or more truncal acne pustules and PIH/PIE were included. On the basis of Investigator's Global Assessment (IGA), clinical polarized photography (CPP), colorimetry and Skindex, we experimentally determined an optimum TCA concentration and assessed our model's ability to exhibit a dose-response relationship between degree of inciting insult and severity of resulting pigmentation. We also performed differential microRNA profiling and pathway analysis to explore the potential of microRNAs as molecular adjuncts to our model.

RESULTS

Application of TCA 30% produced lesions indistinguishable from acne-induced PIH and PIE lesions on the basis of colorimetry data without causing epidermal necrosis. Application of progressively increasing TCA doses from 20% to 30% resulted in concentration-dependent increases in CPP, IGA and colorimetry scores at all timepoints during the study. miRNA-31 and miRNA-23b may play a role in PIH pathogenesis, although further validation is required.

CONCLUSIONS

Our TCA-based in vivo model, using TCA concentrations between 20% and 30% with an optimum of 30%, enables the quantitative assessment of the pigmentary response to varying degrees of cutaneous inflammation in a fashion that mirrors natural acne-induced PIH and PIE.

532 CARING FOR AND CARING ABOUT OLDER PEOPLE LIVING WITH SEVERE FRAILTY DURING COVID-19

Introduction

An ongoing study collected survey and interview data from older people with frailty living in the community near end-of-life during the Covid-19 pandemic.

Methods

Unstructured interviews with older people with frailty living in the community (N = 10), which included accounts from unpaid carers (N = 5), were video and audio recorded between October–November 2021. Six of these older people have died since fieldwork completion. A face-to-face survey collected data from a further 10 older people. Participants ages ranged from 70–99, 11, men, and 9 women, living in owned, rented, or sheltered accommodation, with Clinical Frailty Scores of 6 (N = 8), 7 (N = 9), and 8 (N = 3).

Results

Topics raised in relation to the pandemic included loss of social contact and increased loneliness, concern about not physically getting out, and losing physical function. Older people struggled to gain access to health and social care for support and previously received services were withdrawn. Most participants did not have access to internet and relied heavily on families to facilitate virtual contact with health professionals. Families and friends were the main anchor in facilitating social and health care including chasing up medications, liaising with social care to ensure quality and consistency of care provided, and monitoring older people’s health. Where older people’s conditions worsened family provided intense support, though family carers described the strain and unsustainability of this provision. Older people and their families felt they had been forgotten.

Conclusions

These are insights from hard-to-reach population that are frequently invisible. Greater examination of the impact of using communication technologies in care provision on those with poor access to and capabilities with using these technologies is required. Unpaid carers need more information and resources to support the care they provide and to facilitate access to appropriate social and health care services for those they care for.

17 Conversations on Living and Dying: Facilitating Advance Care Planning for Older People Living with Frailty. A Qualitative Study

Introduction

Advance care planning (ACP) is a process that supports people to articulate their future care preferences. This process is a priority for older people living with frailty due to their vulnerability to sudden deterioration, something that has been highlighted during the current pandemic. However, ACP is uncommon for older people living with frailty, hindering choice and person-centred end-of-life care. This study aimed to identify the barriers, facilitators and behaviours required to support cognitively-able, community-dwelling older people living with frailty to engage with ACP. Findings will inform the development an ACP intervention underpinned by behavioural change theory.

Methods

Semi-structured interviews with community-dwelling older people living with frailty (Clinical Frailty Score 6 or 7) and family members were audio-recorded, filmed and transcribed verbatim. A thematic analysis framework was developed using a recent systematic review, and expanded to reflect new themes.

Results

Ten older people living with frailty and eight family members were interviewed. The older people’s median age was 85 and seven were female. Family members were spouses (n = 4) and children (n = 4). The key findings were that: the meaning of ACP could be unclear and at times confusing; many of the older people believed ACP was not relevant to them; relationships and relational autonomy were of greater relevance to older people than autonomous decision-making; older people were more interested in living well now than in planning for the future.

Conclusions

Older people living with frailty need to be engaged with ACP in a way that helps them to understand what ACP is and why it is relevant for them. Professionals need to develop their skills in assessing readiness and facilitating ACP conversations with this population at the older person’s pace. Reframing ACP to include living well now alongside encouraging family inclusion would also relate better to this populations’ lives.

The stability of care preferences following acute illness: a mixed methods prospective cohort study of frail older people

Background

Patient preferences are integral to person-centred care, but preference stability is poorly understood in older people, who may experience fluctuant illness trajectories with episodes of acute illness. We aimed to describe, and explore influences on the stability of care preferences in frail older people following recent acute illness.

Methods

Mixed-methods prospective cohort study with dominant qualitative component, parallel data collection and six-month follow up. Study population: age ≥ 65, Rockwood Clinical Frailty score ≥ 5, recent acute illness requiring acute assessment/hospitalisation. Participants rated the importance of six preferences (to extend life, improve quality of life, remain independent, be comfortable, support ‘those close to me’, and stay out of hospital) at baseline, 12 and 24 weeks using a 0–4 scale, and ranked the most important. A maximum-variation sub-sample additionally contributed serial in-depth qualitative interviews. We described preference stability using frequencies and proportions, and undertook thematic analysis to explore influences on preference stability.

Results

90/192 (45%) of potential participants consented. 82/90 (91%) answered the baseline questionnaire; median age 84, 63% female. Seventeen undertook qualitative interviews. Most participants consistently rated five of the six preferences as important (range 68–89%). ‘Extend life’ was rated important by fewer participants (32–43%). Importance ratings were stable in 61–86% of cases. The preference ranked most important was unstable in 82% of participants.

Preference stability was supported by five influences: the presence of family support; both positive or negative care experiences; preferences being concordant with underlying values; where there was slowness of recovery from illness; and when preferences linked to long term goals. Preference change was related to changes in health awareness, or life events; if preferences were specific to a particular context, or multiple concurrent preferences existed, these were also more liable to change.

Conclusions

Preferences were largely stable following acute illness. Stability was reinforced by care experiences and the presence of family support. Where preferences were unstable, this usually related to changing health awareness. Consideration of these influences during preference elicitation or advance care planning will support delivery of responsive care to meet preferences. Obtaining longer-term data across diverse ethnic groups is needed in future research.

Multiple-aetiology enteric infections involving non-O157 Shiga toxin-producing Escherichia coli--FoodNet, 2001-2010

We describe multiple-aetiology infections involving non-O157 Shiga toxin-producing Escherichia coli (STEC) identified through laboratory-based surveillance in nine FoodNet sites from 2001 to 2010. A multiple-aetiology infection (MEI) was defined as isolation of non-O157 STEC and laboratory evidence of any of the other nine pathogens under surveillance or isolation of >1 non-O157 STEC serogroup from the same person within a 7-day period. We compared exposures of patients with MEI during 2001-2010 with those of patients with single-aetiology non-O157 STEC infections (SEI) during 2008-2009 and with those of the FoodNet population from a survey conducted during 2006-2007. In total, 1870 non-O157 STEC infections were reported; 68 (3.6%) were MEI; 60 included pathogens other than non-O157 STEC; and eight involved >1 serogroup of non-O157 STEC. Of the 68 MEI, 21 (31%) were part of six outbreaks. STEC O111 was isolated in 44% of all MEI. Of patients with MEI, 50% had contact with farm animals compared with 29% (P < 0.01) of persons with SEI; this difference was driven by infections involving STEC O111. More patients with non-outbreak-associated MEI reported drinking well water (62%) than respondents in a population survey (19%) (P < 0.01). Drinking well water and having contact with animals may be important exposures for MEI, especially those involving STEC O111.

Observation of a charged charmoniumlike structure in e+ e- → π+ π- J/ψ at sqrt[s] = 4.26 GeV

We study the process ee+ e- → π+ π- J/ψ at a center-of-mass energy of 4.260 GeV using a 525  pb(-1) data sample collected with the BESIII detector operating at the Beijing Electron Positron Collider. The Born cross section is measured to be (62.9±1.9±3.7)  pb, consistent with the production of the Y(4260). We observe a structure at around 3.9  GeV/c2 in the π(±)J/ψ mass spectrum, which we refer to as the Z(c)(3900). If interpreted as a new particle, it is unusual in that it carries an electric charge and couples to charmonium. A fit to the π(±)J/ψ invariant mass spectrum, neglecting interference, results in a mass of (3899.0±3.6±4.9)  MeV/c2 and a width of (46±10±20)  MeV. Its production ratio is measured to be R = (σ(e+ e- → π(±)Z(c)(3900)(∓) → π+ π- J/ψ)/σ(e+ e- → π+ π- J/ψ)) = (21.5±3.3±7.5)%. In all measurements the first errors are statistical and the second are systematic.

Observation of two new N* resonances in the decay ψ(3686)→ppπ0

Based on 106×10(6)ψ(3686) events collected with the BESIII detector at the BEPCII facility, a partial wave analysis of ψ(3686)→ppπ0 is performed. The branching fraction of this channel has been determined to be B(ψ(3686)→ppπ0)=(1.65±0.03±0.15)×10(-4). In this decay, 7 N* intermediate resonances are observed. Among these, two new resonances, N(2300) and N(2570) are significant, one 1/2+ resonance with a mass of 2300(-30-0)(+40+109)  MeV/c2 and width of 340(-30-58)(+30+110)  MeV/c2, and one 5/2- resonance with a mass of 2570(-10-10)(+19+34)  MeV/c2 and width of 250(-24-21)(+14+69)  MeV/c2. For the remaining 5 N* intermediate resonances [N(1440), N(1520), N(1535), N(1650) and N(1720)], the analysis yields mass and width values that are consistent with those from established resonances.

Evidence for the direct two-photon transition from ψ(3686) to J/ψ

The two-photon transition ψ(3686)→γγJ/ψ is studied in a sample of 1.06×10(8) ψ(3686) decays collected by the BESIII detector. The branching fraction is measured to be (3.1±0.6(stat)(-1.0)(+0.8)(syst))×10(-4) using J/ψ→e(+)e(-) and J/ψ→μ(+)μ(-) decays, and its upper limit is estimated to be 4.5×10(-4) at the 90% confidence level. This work represents the first measurement of a two-photon transition among charmonium states. The orientation of the ψ(3686) decay plane and the J/ψ polarization in this decay are also studied. In addition, the product branching fractions of sequential E1 transitions ψ(3686)→γχ(cJ) and χ(cJ)→γJ/ψ(J=0,1,2) are reported.

Development and Validation of Computed Tomography Derived Anthropometric Regression Equations for Estimating Abdominal Adipose Tissue Distribution

The purpose of this study was twofold: (1) to develop multiple regression equations for predicting computed tomography (CT) derived intra-abdominal (IAF), subcutaneous (SCF), and total (TOTF= IAF+SCF) abdominal adipose tissue areas from anthropometric measures in adult white males with a large range of age (18-71 years) and percent body fat (2.0-40.6); and (2) to validate the new and existing equations that used similar Hounsfield Units (HU) for determining IAF for estimating these fat depots. One hundred fifty-one white male subjects had IAF, SCF, and TOTF determined by a single CT scan, skinfold and circumference measures taken and body density determined. Linear intra-correlations and factor analysis procedures were used to identify variables for inclusion in stepwise multiple regression solutions. IAF was estimated from age, waist circumference, the sum of mid-thigh and lower thigh circumferences, and vertical abdominal skinfold. SCF was estimated from age, umbilicus circumference, chest and suprailiac skinfolds. TOTF was estimated from age, body mass index (BMI), chest skinfold, and umbilicus circumference. R2 for IAF, SCF, and TOTF was .73, .77, and .86 respectively. The existing and the new equations were validated on an independent sub-sample of 51 subjects. The only existing equation that met validation criteria had a validation R2 = .67 for IAF. All three new equations met validation criteria with R2 validations of .75, .79, and .85 for IAF, SCF, and TOTF respectively. It is concluded that the new equations might be used as an inexpensive estimation of IAF, SCF, and TOTF in adult white males varying greatly in age and percent body fat.

First observation of the M1 transition ψ(3686)→γη(c)(2S)

Using a sample of 106×10(6) ψ(3686) events collected with the BESIII detector at the BEPCII storage ring, we have made the first measurement of the M1 transition between the radially excited charmonium S-wave spin-triplet and the radially excited S-wave spin-singlet states: ψ(3686)→γη(c)(2S). Analyses of the processes ψ(3686)→γη(c)(2S) with η(c)(2S)→K(S)(0)K(±)π(∓) and K(+)K(-)π(0) give an η(c)(2S) signal with a statistical significance of greater than 10 standard deviations under a wide range of assumptions about the signal and background properties. The data are used to obtain measurements of the η(c)(2S) mass (M(η(c)(2S))=3637.6±2.9(stat)±1.6(syst) MeV/c(2)), width (Γ(η(c)(2S))=16.9±6.4(stat)±4.8(syst) MeV), and the product branching-fraction (B(ψ(3686)→γη(c)(2S))×B(η(c)(2S)→KKπ)=(1.30±0.20(stat)±0.30(syst))×10(-5)). Combining our result with a BABAR measurement of B(η(c)(2S)→KKπ), we find the branching fraction of the M1 transition to be B(ψ(3686)→γη(c)(2S))=(6.8±1.1(stat)±4.5(syst))×10(-4).

Congenital glioblastoma multiforme: complete resection with long-term survival and a novel technique of contralateral cystoventriculostomy

Congenital glioblastomas are rare primary tumours of the central nervous system with poor prognosis if left untreated. We report the case of a 4-week-old infant with such a tumour treated by surgical excision and a course of postoperative chemotherapy. After the chemotherapy, the patient displayed a neurological deterioration and follow-up magnetic resonance imaging (MRI) scans revealed no signs of recurrence, but showed entrapment and significant distension of the right lateral ventricle. A novel technique of contralateral cystoventriculostomy was performed to attempt to decompress the cyst and improve the infant's neurological status. After surgery there was a significant neurological improvement, and 30 months after resection the child is alive, with mild hemiparesis and no signs of recurrence on follow-up MRI scan. The cystoventriculostomy is patent and continues to decompress the encapsulated ventricle.

Contesting targets as a measurement of success in agricultural extension: a case study of the Grain & Graze Change-on-farm strategy

Grain & Graze was a mixed-farming systems program conducted across nine regions of Australia over 2003–08. It had a goal of ensuring adoption of recommended practices on 6800 farms within the 5-year life of the program. This extension-based success target was further reflected in adoption targets set in contracts for each of the nine regions, and embedded into the program’s extension initiative, the Change-on-farm strategy. By 2008, the program had achieved adoption on 3200 farms. While less than half the target, this was considered by many a remarkable achievement, raising questions about the efficacy of adoption targets as a measurement of success. In a program based on devolution, regional delivery and local empowerment, the targets were contested between participants on other grounds. This paper explores how the targets were set, what Change-on-farm supported, what it achieved and how its success related to adoption targets. Using the Grain & Graze program as a case study, the paper concludes that the notion of targets as a motivator of success rather than as a measure of success is pertinent in complex systems-based research and development. The authors do not advocate avoiding targets, but suggest that both targets and the evaluation process by which success is measured be mutually negotiated in the true spirit of participatory process.

Trans-Sylvian selective amygdalohippocampectomy for medically intractable temporal lobe epilepsy: a single-centre experience

Selective amygdalohippocampectomy (SelAH) is now widely used in the surgical treatment of patients with medically intractable medial temporal lobe epilepsy (MTLE). We present our single-centre experience of a uniform series of drug-resistant MTLE patients treated exclusively with SelAH. A retrospective study of 50 adult patients (25 males, 25 females, mean age 34 years) suffering from medically intractable MTLE was conducted. All patients has been investigated under the same protocol and operated by SelAH performed by one surgeon. Immediate and long-term follow-up was also available and is presented. Forty-two patients (84%) became seizure free (Engel's I); eight of them (16%) were classified as Engel's II; four (8%) as Engel's III; and one as Engel's IV (2%). In 42 of them the final result has been achieved after a single operation, while in the rest eight after a second or third surgical procedure. The mean follow-up period was 6.2 years. Two permanent complications (4%) with no treatment-related mortality have been detected. SelAH performed in well selected cases, where concordance between electrophysiological and MR findings exists, can be a safe and effective surgical treatment method for medically intractable MTLE.

Cardiovascular disease in women

This article provides an overview of cardiovascular disease (CVD) in women. It considers cardiovascular risk, investigations and treatment. Gender bias, controversies and current debates are highlighted. Issues concerned with access to cardiac health care, equality and public policy are also considered. The author concludes that CVD in women is under-recognised, often by women themselves, and therefore raising the profile of this disease in women should be a health priority.

Intra-abdominal adipose tissue values associated with risk of possessing elevated blood lipids and blood pressure

Central fat distribution and more recently intra-abdominal adipose tissue (IAF) have been associated with elevated cardiovascular risk factors (CRF). Despite increased interest in use of LAF for screening for CRF, interpretation of risk found in a specific IAF is difficult since regressions for estimating CRF from IAF have not been published. The purpose of this paper is to report IAF values that are likely to be associated with elevated CRF. One hundred forty-six healthy male subjects 30-71 years were evaluated for IAF and subcutaneous fat (computed tomography scan at 4th lumbar vertebra), height, body weight, % fat, various anthropometric measures, blood cholesterol (CHOL), HDL cholesterol (HDL), systolic blood pressure (SBP), and diastolic blood pressure (DBP). Receiver-Operating-Characteristic curves (ROC) were used to develop IAF cutpoints associated with elevation of at least one established CRF criteria (CHOL=200, HDL=<35, SBP=140, DBP=90). A sensitivity/(1- specificity) curve established the value of using IAF cutpoints for detecting elevated CRF. Likelihood ratios were used to identify optimal cutpoints. Two cutpoints were identified, 131 cm2 with a relatively high Lpos ratio and 71 cm2 with a relatively low Lneg. False positives associated with 131 cm2 were 14% for one or more elevated CRF. False negatives associated with 71 cm2 were 9% for one or more elevated CRF, 4% for two or more CRF, and 0% for three or more elevated CRF. This study clearly indicates that IAF above 131 cm2 is related to elevated CRF and IAF below 71 cm2 is associated with reduced cardiovascular risk.

Cell cavities increase tortuosity in brain extracellular space

Brain extracellular space (ECS) forms hindered pathways for molecular diffusion in chemical signaling and drug delivery. Hindrance is quantified by the tortuosity lambda; the tortuosity obtained from simulations using uniformly spaced convex cells is significantly lower than that measured experimentally. To attempt to account for the difference in results, this study employed a variety of ECS models based on an array of cubic cells containing open rectangular cavities that provided the ECS with dead-space microdomains. Monte Carlo simulations demonstrated that, in such ECS models, lambda can equal or exceed the typical experimental value of about 1.6. The simulations further revealed that lambda is relatively independent of cavity shape and the number of cavities per cell. It mainly depends on the total ECS volume fraction alpha, the cavity volume fraction alpha(c), and whether the cavity is located at the center of a cell face or formed at the junction of multiple cells. To describe the results from the different ECS models, an expression was obtained that related lambda to alpha, alpha(c), and an empirical exit factor beta that correlated with the ease with which a molecule could leave a cavity and its vicinity.

Factors governing diffusing molecular signals in brain extracellular space

Volume transmission involving the migration of chemical signals through brain extracellular space is primarily mediated by diffusion. This review summarizes the biophysical basis of diffusion in the brain and describes how tortuosity and volume fraction of the extracellular space modify the process. Recent work using both Monte Carlo simulation and experimental measurements suggests that the extracellular space may consist of both well-connected regions and dead-space microdomains. The review concludes with a brief overview of previous work on diffusion in the aging rat brain.

Maximum geometrical hindrance to diffusion in brain extracellular space surrounding uniformly spaced convex cells

Brain extracellular space (ECS) constitutes a porous medium in which diffusion is subject to hindrance, described by tortuosity, lambda = (D/D*)1/2, where D is the free diffusion coefficient and D* is the effective diffusion coefficient in brain. Experiments show that lambda is typically 1.6 in normal brain tissue although variations occur in specialized brain regions. In contrast, different theoretical models of cellular assemblies give ambiguous results: they either predict lambda-values similar to experimental data or indicate values of about 1.2. Here we constructed three different ECS geometries involving tens of thousands of cells and performed Monte Carlo simulation of 3-D diffusion. We conclude that the geometrical hindrance in the ECS surrounding uniformly spaced convex cells is independent of the cell shape and only depends on the volume fraction alpha (the ratio of the ECS volume to the whole tissue volume). This dependence can be described by the relation lambda = ((3-alpha)/2)1/2, indicating that the geometrical hindrance in such ECS cannot account for lambda > 1.225. Reasons for the discrepancy between the theoretical and experimental tortuosity values are discussed.

Bedout: A Possible End-Permian Impact Crater Offshore of Northwestern Australia

The Bedout High, located on the northwestern continental margin of Australia, has emerged as a prime candidate for an end-Permian impact structure. Seismic imaging, gravity data, and the identification of melt rocks and impact breccias from drill cores located on top of Bedout are consistent with the presence of a buried impact crater. The impact breccias contain nearly pure silica glass (SiO2), fractured and shock-melted plagioclases, and spherulitic glass. The distribution of glass and shocked minerals over hundreds of meters of core material implies that a melt sheet is present. Available gravity and seismic data suggest that the Bedout High represents the central uplift of a crater similar in size to Chicxulub. A plagioclase separate from the Lagrange-1 exploration well has an Ar/Ar age of 250.1 +/- 4.5 million years. The location, size, and age of the Bedout crater can account for reported occurrences of impact debris in Permian-Triassic boundary sediments worldwide.

Challenges, benefits and pitfalls of the independent laboratory process

During 1998 Sydney's drinking water supply system experienced three contamination events in quick succession. These events were revealed by routine monitoring, which indicated the presence of large numbers of Cryptosporidium and Giardia in raw and treated water. Questions were raised regarding the validity of the results produced by Sydney Water's laboratory, Australian Water Technology. In response to the incident a NSW Government Inquiry was carried out which made a range of recommendations, one of which was that "A suitably qualified independent laboratory should be established to provide accurate data for regulatory authorities." The NSW Department of Health (DOH) was given the responsibilty for interpretation and implementation of this recommendation. The role of Independent Laboratory was awarded to the Australian Water Quality Centre (AWQC) and monthly program of duplicate sample analysis was established. The implementation of the program and interpretation of the results have provided a challenge for all parties involved. A protocol was developed which defined conditions under which differences in results from the two laboratories were to be investigated. Over the time period of the Independent Laboratory process there has been only one occasion where a difference between results, as defined by the protocol, has been seen. The process has provided additional assurance of quality control procedures for the laboratories. The future role of the process will need to be readdressed in light of the results of the previous 18 months and as changes in the area of testing methodologies occur.

A research - extension model for encouraging the adoption of productive and sustainable practice in high rainfall grazing areas

The experiences of participants in the Sustainable Grazing Systems (SGS) Program were examined to understand why more productive and sustainable practices were adopted by producers involved in SGS. This paper explores from a range of perspectives (producers, researchers, extension agents and facilitators) the delivery mechanism that led to these practices being adopted and concludes with a model describing the adoption process observed in SGS. The model describes a continuous 3-stage process of motivation, trialing–exploration and farm practice change. Support for decision making during the transition between each stage of the process was recognised as an essential ingredient for success.

Cost comparison of hospital- and home-based treatment models for acute chronic obstructive pulmonary disease

This trial compared the cost of an integrated home-based care model with traditional inpatient care for acute chronic obstructive pulmonary disease (COPD). 25 patients with acute COPD were randomised to either home or hospital management following request for hospital admission. The acute care at home group costs per separation ($745, CI95% $595-$895, n = 13) were significantly lower (p < 0.01) than the hospital group ($2543, CI95% $1766-$3321, n = 12). There was an improvement in lung function in the hospital-managed group at the Outpatient Department review, decreased anxiety in the Emergency Department in the home-managed group and equal patient satisfaction with care delivery. Acute care at home schemes can substitute for usual hospital care for some patients without adverse effects, and potentially release resources. A funding model that allows adequate resource delivery to the community will be needed if there is a move to devolve acute care to community providers.

DNA cloning in Lactobacillus helveticus by the exconjugation of recombinant mob-containing plasmid constructs from strains of transformable lactic acid bacteria

A system developed for the genetic transfer of plasmids between strains of nontransformable bacteria (P. Langella, Y. le Loir, S. D. Ehrlich and A. Gruss, 1993, J. Bacteriol., 175, 5806-5813) by the specific inclusion of a mobilization (mob) region into a nonconjugative shuttle vector was used successfully to deliver the genetic determinants for beta-glucanase, beta-glucuronidase, and green fluorescent protein to Lactobacillus helveticus. Expression of two of the genes could be detected in the new host. Data suggested that resolution of cointegrates into components could release the original recombinant plasmid or generate a cointegrate deletion. All the recombinant plasmids were segregationally unstable in Lb. helveticus and there was some evidence for structural instability. Intrinsic instability in the mob-containing vector was reduced by replacing the duplicated pBluescript polylinker with that from pUC19. Sites at which cointegrate formation could occur were localized at two distinct tracts close to the D-loop that forms at the primosome during plasmid replication.

The influence of group size on children's competitive behavior

The present research was designed to test the hypothesis that children would compete more in tetrads than in dyads. Twenty-two pairs of male and 14 pairs of female target children (N = 72) played a competitive game in both tetrads and dyads. Consistent with the hypothesis, male target children competed more in tetrads than in dyads. This hypothesis was not supported for females, however. Analyses of the dynamics of tetrads and dyads further demonstrated that based on a global measure of smiling, the emotional atmosphere was less positive in tetrads than in dyads. The causes and consequences of interaction in different sized social groups are discussed.

Dopamine-mediated volume transmission in midbrain is regulated by distinct extracellular geometry and uptake

Somatodendritic release of dopamine (DA) in midbrain is, at least in part, nonsynaptic; moreover, midbrain DA receptors are predominantly extrasynaptic. Thus somatodendritic DA mediates volume transmission, with an efficacy regulated by the diffusion and uptake characteristics of the local extracellular microenvironment. Here, we quantitatively evaluated diffusion and uptake in substantia nigra pars compacta (SNc) and reticulata (SNr), ventral tegmental area (VTA), and cerebral cortex in guinea pig brain slices. The geometric parameters that govern diffusion, extracellular volume fraction (alpha) and tortuosity (lambda), together with linear uptake (k'), were determined for tetramethylammonium (TMA(+)), and for DA, using point-source diffusion combined with ion-selective and carbon-fiber microelectrodes. TMA(+)-diffusion measurements revealed a large alpha of 30% in SNc, SNr, and VTA, which was significantly higher than the 22% in cortex. Values for lambda and k' for TMA(+) were similar among regions. Point-source DA-diffusion curves fitted theory well with linear uptake, with significantly higher values of k' for DA in SNc and VTA (0.08--0.09 s(-1)) than in SNr (0.006 s(-1)), where DA processes are sparser. Inhibition of DA uptake by GBR-12909 caused a greater decrease in k' in SNc than in VTA. In addition, DA uptake was slightly decreased by the norepinephrine transport inhibitor, desipramine in both regions, although this was statistically significant only in VTA. We used these data to model the radius of influence of DA in midbrain. Simulated release from a 20-vesicle point source produced DA concentrations sufficient for receptor activation up to 20 microm away with a DA half-life at this distance of several hundred milliseconds. Most importantly, this model showed that diffusion rather than uptake was the most important determinant of DA time course in midbrain, which contrasts strikingly with the striatum where uptake dominates. The issues considered here, while specific for DA in midbrain, illustrate fundamental biophysical properties relevant for all extracellular communication.

Therapeutic treatment of DMBA-induced mammary tumors with PPAR ligands

The objective of this study was to evaluate the ability of troglitazone (a thiazolidinedione) and Wy-14,643 (a clofibrate) to inhibit progression of non-detectable and detectable mammary tumors in rats induced by 7,12 dimethylbenz(a)anthracene (DMBA) when compared to those receiving no treatment or tamoxifen. Although not as effective as tamoxifen in decreasing overall tumor incidence, Wy-14,643 reduced the percentage and number of malignant tumors that developed when compared to both troglitazone and control. Treatment of detectable tumors with either Wy-14,643 or troglitazone induced regression or stasis of total tumor volume in 40-50% of the animals, compared to only 10% in control and 65% in tamoxifen treated animals. Moreover, each PPAR ligand was as effective as tamoxifen in preventing additional tumor development. In summary, both PPAR ligands were more effective than no treatment in preventing tumor progression once detected. However, only the PPAR-alpha activator, Wy-14,643 was able to reduce the development of malignant tumors when administered prior to detection.

Diffusion of molecules in brain extracellular space: theory and experiment

Volume transmission depends on the migration of informational substances through brain extracellular space (ECS) and almost always involves diffusion; basic concepts of diffusion are outlined from both the microscopic viewpoint based on random walks and the macroscopic viewpoint based on the solution of equations embodying Fick's Laws. In a complex medium like the brain, diffusing molecules are constrained by the local volume fraction of the ECS and tortuosity, a measure of the hindrance imposed by cellular obstacles. Molecules can also experience varying degrees of uptake or clearance. Bulk flow and the extracellular matrix may also play a role. Examples of recent work on diffusion of tetramethylammonium (molecular weight, 74) in brain slices, using iontophoretic application and ion-selective microelectrodes, are reviewed. In slices, the volume fraction is about 20% and tortuosity about 1.6, both similar to values found in the intact brain. Using integrative optical imaging, results obtained with dextrans and albumins up to a molecular weight of 70,000 are summarized, for such large molecules the tortuosity is about 2.3. Experiments using synthetic long-chain PHPMA polymers up to 1,000,000 molecular weight show that these molecules also diffuse in the ECS but with a tortuosity of about 1.6. Studies with osmotic challenge show that volume fraction and tortuosity do not vary together as expected when the size of the ECS changes; a model is presented that explains the osmotic-challenge on the basis of changes in cell shape. Finally, new analytical insights are provided into the complex movement of potassium in the brain.