The prevalence of chiropractic-related terminology on South African chiropractors' webpages: a cross-sectional study

BACKGROUND

Effective communication is imperative for successful interprofessional collaborative interactions that augment both patient-centred and evidence based care. Inquiry into the prevalence of chiropractic-related terminology on South African chiropractor's webpages has not been explored to date. The implications of such analysis could indicate the professions' ability to effectively communicate in interdisciplinary settings.

METHOD

From 1 to 15 June 2020, Google search was used to identify the webpages (excluding social media accounts) of South African private practice chiropractors registered with the Allied Health Professions Council of South Africa (AHPCSA). Webpages were word-searched for eight chiropractic terms with context: subluxation; manipulate(-ion); adjust(-ing/-ment); holism(-tic); alignment; vital(-ism/-istic); wellness; and innate intelligence. Data collected was transferred to an Excel spreadsheet. Accuracy of information was verified by the researchers through a process of double checking. The number of instances each term was used, and certain socio-demographic data were recorded. Descriptive statistics and bivariate analyses were used to summarise and analyse the data.

RESULTS

Among 884 AHPCSA-registered South African chiropractors, 336 webpages were identified and analysed. From 1 to 15 June 2020, the most commonly found terms on 336 South African chiropractic webpages were 'adjust(-ing/-ment)', 'manipulate/manipulation', and 'wellness', with prevalence estimates of 64.1% (95% confidence interval [CI], 59.0% to 69.2%), 51.8% (95% CI, 46.5% to 57.1%), and 33.0% (95% CI, 28.2% to 38.2%), respectively. The least commonly found terms were 'innate intelligence' and 'vital(-ism/-istic)', with prevalence estimates of 0.60% (95% CI, 0.16% to 2.1%) and 0.30% (95% CI, 0.05% to 1.7%), respectively. Manipulate(-ion) was used more by male chiropractors (p = 0.015). The longer a chiropractor was in practice the more likely they were to use profession-specific terms (p = 0.025). The most frequently occurring combination of terms were adjust(-ing/-ment) and manipulate(-ion), found in 38 out of 336 webpages (11.3%; 95% CI, 8.4% to 15.1%).

CONCLUSION

The use of chiropractic-related terminology on South African chiropractic webpages was common, with the prevalence of term use varying by type of terms, by gender of the chiropractor, and by clinical practice experience. Better understanding of the effects of chiropractic terminology use on interprofessional and patient interactions and communication is warranted.

Insulin facilitates corneal wound healing in the diabetic environment through the RTK-PI3K/Akt/mTOR axis in vitro

Diabetic patients can develop degenerative corneal changes, termed diabetic keratopathy, during the course of their disease. Topical insulin has been shown to reduce corneal wound area and restore sensitivity in diabetic rats, and both the insulin receptor (IR) and insulin-like growth factor 1 receptor (IGF-1R) stimulate cell signaling of the PI3K-Akt pathway. The purpose of this study was to assess a mechanism by which improved wound healing occurs by characterizing expression within the PI3K-Akt pathway in corneal epithelial and stromal cells. In vitro scratch tests were used to evaluate wound healing outcomes under variable glucose conditions in the presence or absence of insulin. Protein expression of intracellular kinases in the PI3K pathway, stromal cell markers, and GLUT-1 was evaluated by immunoblotting.TGF-β1 expression was evaluated by ELISA. Insulin promoted in vitro wound healing in all cell types. In human corneal epithelial cells, insulin did not induce PI3K-Akt signaling; however, in all other cell types evaluated, insulin increased expression of PI3K-Akt signaling proteins compared to vehicle control. Fibroblasts variably expressed α-SMA under all treatment conditions, with significant increases in α-SMA and TGF-β1 occurring in a dose-dependent manner with glucose concentration. These results indicate that insulin can promote corneal cellular migration and proliferation by inducing Akt signaling. Exogenous insulin therapy may serve as a novel target of therapeutic intervention for diabetic keratopathy.

Limited prognostic value of pain duration in non-specific neck pain patients seeking chiropractic care

BACKGROUND

Pain chronicity is considered an important prognostic factor for outcome. Here, it was investigated whether pain duration influences outcome when only chronic patients (pain > three months) are considered. Secondary aims were to determine, in patients of any pain duration, how much variance in outcome is explained by pain duration and whether pain duration truly predicts outcomes, i.e. out-of-sample prediction in independent data.

METHODS

Secondary analysis of a cohort study of neck pain patients. Patients were assessed before start of treatment and at one week, one, three, six- and 12-months follow-up. Outcomes were Patient Global Impression of Change (PGIC) and percent change of patients' perceived pain intensity, rated on a numerical rating scale (NRS). Regression analyses (linear and logistic) and supervised machine learning were used to test the influence of pain duration on PGIC and percent NRS change at one week, one, three, six- and 12-months follow-up within sample and out-of-sample. Separate analyses were performed for the full sample (n=720) and for chronic patients (n=238) only.

RESULTS

No relationship between pain duration and outcome was found for chronic patients only. For the full sample, statistical relationships between pain duration and outcomes were observed at all tested follow-up time points. However, the amount of variance in outcome explained by pain duration was low and no out-of-sample prediction was possible.

CONCLUSIONS

Pain duration did not emerge as an important predictor of outcome in this database of 720 neck pain patients receiving chiropractic treatment.

Induction of the integrated stress response in the rat cornea

Keratoconus (KC), a progressive, degenerative corneal disease, represents the second leading indication for corneal transplantation globally. We have previously demonstrated that components of the Integrated Stress Response (ISR) are upregulated in human keratoconic donor tissue, and treatment of normal tissue with ISR agonists attenuates collagen production. With no consistently accepted animal models available for translational KC research, we sought to establish an in vivo model based on ISR activation to elucidate its role in the development of the KC phenotype. Four-week-old female SD rats were treated with topical SAL003 formulated as a nanosuspension or vehicle every 48 h for four doses. Animals were subject to monitoring for ocular inflammation and discomfort before being euthanized at 1, 14, or 28 days after treatment was withdrawn. Schirmer's tear test, intraocular pressure, and body weight measurements were obtained at baseline and prior to euthanasia. Globes were subject to routine histopathology, immunohistochemistry for ATF4, and qPCR for Col1a1 expression. ANOVAs and Student's t tests were used to assess statistical significance (α = 0.05). SAL003 treatment did not produce any adverse ocular or systemic phenotype but did result in decreased keratocyte density. Col1a1 transcripts were reduced, corresponding to nuclear ATF4 expression within the axial cornea. In vivo topical treatment with a gel-formulated ISR agonist recapitulates key features of the activated ISR including nuclear ATF4 expression and decreased extracellular matrix (ECM) production. Exogenous ISR agonists may present one approach to establishing a rodent model for keratoconus, a charge essential for future evaluations of pathogenesis and therapeutic interventions.

Changes in sleep with transcranial magnetic stimulation in adults with treatment resistant depression: Preliminary results from a naturalistic study

Introduction

Sleep disturbance specifically insomnia, non-restorative sleep, and hypersomnia are common symptoms of major depressive disorder (MDD). As it alleviates major depressive disorder, transcranial magnetic stimulation (TMS) may improve associated sleep disturbances, and may also have inherent sedating or activating properties.

Objectives

To examine the impact of TMS on sleep disturbances in adults with treatment resistant depression in a clinical setting, we retrospectively reviewed de-identified data from naturalistically-treated MDD patients undergoing an initial acute course of TMS therapy at St.Louis Park MinCEP Clinic.

Methods

Adults with treatment-resistant depression received daily TMS treatments. 9-item Patient Health Questionnaire (PHQ-9) total scores were used to calculate % change at endpoint (relative to pretreatment baseline); response on both measures was defined as 50% reduction in scores, with remission defined as a final total score 4 on the PHQ-9. Insomnia was measured with a 3-item subscale of the Inventory of Depressive Symptomatology Self Report (IDS-SR). Hypersomnia was measured with a single IDS-SR item. Pairwise comparisons were performed using Student’s T-test. Categorical variables were compared using Fisher’s Exact test. Continuous outcome measures were tested with an analysis of covariance, using baseline PHQ-9 score as a fixed effect covariate.

Results

TMS appears to have differential modulatory effects on insomnia and hypersomnia in adults with treatment resistant depression.

Conclusions

These results may provide the basis for further investigation into therapeutic applications of TMS in addressing sleep disturbances in treatment-resistant depression. Measures that separate hypersomnia and insomnia should be implemented in future work addressing effects of TMS in treatment-resistant depression.

Disclosure

No significant relationships.

Abstract SP084: Replication stress response defects predict responses to ICT in non-hypermutated tumors

Immune checkpoint blockade (ICT) has provided robust, durable responses to a subset of patients. Many initial ICT trials were focused on highly mutated cancer types, such as melanoma and lung cancer, largely predicated on the idea that mutation-derived neoantigens would allow for generation of tumor-specific T cells. Subsequent analysis of patient responses in these highly mutated cancer types confirmed that increased tumor mutation burden (TMB) corresponded with improved patient outcomes. Further clinical studies identified additional predictive biomarkers, such as PD-L1 protein expression, and various gene expression signatures. Based on the success of ICT in hypermutated cancer types, further clinical trials with ICT were performed in cancers with overall lower mutational burden. These studies have indicated that many non-hypermutated cancer types with relatively low TMB may be effectively treated with ICT. For example, patients with clear cell renal cell carcinoma (ccRCC) display relatively low TMB overall, and a narrow distribution of TMB across patients, yet clinical response rates to ICT are ~30%, with some durable responses seen. Other tumor types with minimal mutation burdens, including glioblastoma (GBM) and triple negative breast cancer (TNBC), have likewise shown encouraging clinical responses to ICT. We recently demonstrated distinct tumor immunobiology between hypermutated and non-hypermutated tumor types, notably that relative neoantigen load/tumor mutation burden was only a relevant factor for immune infiltration in hypermutated tumor types. Consistent with this, clinical trials have demonstrated that TMB does not predict response to ICT in tumor types with minimal mutational load, such as breast cancer, ccRCC, and GBM. Thus, there remains a critical gap in knowledge as to how to identify which patients with non-hypermutated cancer may benefit from ICT. Here, we demonstrate that a replication stress response (RSR) defect gene expression signature accurately predicts ICT response in 11 independent non-hypermutated patient cohorts from 6 tumor types for which other biomarkers failed. Pre-clinical studies indicate that aberrant origin firing in RSR deficient tumor cells causes exhaustion of replication protein A, resulting in accumulation of immunostimulatory cytosolic DNA. Induction or suppression of RSR deficiencies was sufficient to modulate response to ICT. Taken together, the RSR defect gene signature can accurately identify patients who will benefit from ICT across numerous non-hypermutated tumor types, and pharmacological induction of RSR defects may further expand the benefits of ICT to more patients.

Citation Format: D McGrail, P Pilié, XHF Zhang, J Rosen, L Voorwerk, M Kok, A Heimberger, C Peterson, E Jonasch, S Lin. Replication stress response defects predict responses to ICT in non-hypermutated tumors [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr SP084.

Hippocampal subfield pathologic burden in Lewy body diseases vs. Alzheimer's disease

AIMS

Lewy body diseases (LBD) are characterized by alpha-synuclein (SYN) pathology, but comorbid Alzheimer's disease (AD) pathology is common and the relationship between these pathologies in microanatomic hippocampal subfields is understudied. Here we use digital histological methods to test the association between hippocampal SYN pathology and the distribution of tau and amyloid-beta (Aβ) pathology in LBD and contrast with AD subjects. We also correlate pathologic burden with antemortem episodic memory testing.

METHODS

Hippocampal sections from 49 autopsy-confirmed LBD cases, 30 with no/low AD copathology (LBD - AD) and 19 with moderate/severe AD copathology (LBD + AD), and 30 AD patients were stained for SYN, tau, and Aβ. Sections underwent digital histological analysis of subfield pathological burden which was correlated with antemortem memory testing.

RESULTS

LBD - AD and LBD + AD had similar severity and distribution of SYN pathology (P > 0.05), CA2/3 being the most affected subfield (P < 0.02). In LBD, SYN correlated with tau across subfields (R = 0.49, P < 0.001). Tau burden was higher in AD than LBD + AD (P < 0.001), CA1/subiculum and entorhinal cortex (ERC) being most affected regions (P = 0.04 to <0.01). However, tau pathology in LBD - AD was greatest in CA2/3, which was equivalent to LBD + AD. Aβ severity and distribution was similar between LBD + AD and AD. Total hippocampal tau and CA2/3 tau was inversely correlated with memory performance in LBD (R = -0.52, -0.69, P = 0.04, 0.009).

CONCLUSIONS

Our findings suggest that tau burden in hippocampal subfields may map closely with the distribution of SYN pathology in subfield CA2/3 in LBD diverging from traditional AD and contribute to episodic memory dysfunction in LBD.

Haematopoietic stem cells: entropic landscapes of differentiation

The metaphor of a potential epigenetic differentiation landscape broadly suggests that during differentiation a stem cell approaches a stable equilibrium state from a higher free energy towards a stable equilibrium state which represents the final cell type. It has been conjectured that there is an analogy to the concept of entropy in statistical mechanics. In this context, in the undifferentiated state, the entropy would be large since fewer constraints exist on the gene expression programmes of the cell. As differentiation progresses, gene expression programmes become more and more constrained and thus the entropy would be expected to decrease. In order to assess these predictions, we compute the Shannon entropy for time-resolved single-cell gene expression data in two different experimental set-ups of haematopoietic differentiation. We find that the behaviour of this entropy measure is in contrast to these predictions. In particular, we find that the Shannon entropy is not a decreasing function of developmental pseudo-time but instead it increases towards the time point of commitment before decreasing again. This behaviour is consistent with an increase in gene expression disorder observed in populations sampled at the time point of commitment. Single cells in these populations exhibit different combinations of regulator activity that suggest the presence of multiple configurations of a potential differentiation network as a result of multiple entry points into the committed state.

Lack of effect of a topical regenerative agent on re-epithelialization rate of canine spontaneous chronic corneal epithelial defects: A randomized, double-masked, placebo-controlled study

Spontaneous chronic corneal epithelial defects (SCCEDs) are characteristic ulcers in dogs that are refractory to healing. The aim of the study was to evaluate the use of a topical regenerative agent to promote healing of SCCEDs. Nineteen dogs (20 eyes) were randomized to receive either regenerative agent (10 eyes) or placebo (10 eyes) every 48h following corneal debridement, which was repeated 1 week later if the SCCED had not yet healed. The mean±standard deviation time to re-epithelialization was 17.3±12.8 days for the group treated with a topical regenerative agent and 19.3±11.7 days for the group treated with a placebo; the cumulative healing rates were not statistically different (P>0.650). A positive association was found between the initial size of the ulcer and the time to re-epithelialization (r=0.555, P=0.011). Although well tolerated by dogs, there was no therapeutic advantage in using a topical regenerative agent for re-epithelialization of SCCEDs.

On the Cellular Pharmacokinetics of 6-Thioguanine in Acute Myelogenous Leukemia

The pharmacokinetics of 6-thioguanine were studied in 10 patients with acute myelogenous leukemia treated with 25-100 mg/m(2) orally. The concentration of 6-thioguanine in plasma was determined with reversed phase high performance liquid chromatography (HPLC). After isolation of leukemic cells and erythrocytes by density centrifugation, HClO4 extraction of nucleotides and isolation of thiol containing substances on mercurial cellulose, the intracellular concentration of phosphorylated 6-thioguanine metabolites was measured by anion exchange HPLC. The plasma peak concentration of 6-thioguanine was significantly correlated (r(2) = 0.60) to the dose administered. In the leukemic cells, the 5'-mono-(TGMP) and 5'-triphosphates (TGTP) of 6-thioguanosine could be detected in nine of the patients. In one patient only TGMP was seen. The diphosphate could be detected in low concentrations in 6 patients. In all patients, the concentration of TGMP was higher than that of TGTP which was higher than the diphosphate. The interindividual variation in cellular TGMP and TGTP concentration was > 100-fold and independent of dose, while the variation in plasma 6-TG was < 15-fold. There was no correlation between dose or plasma area under the concentration versus time curve (AUC) of 6-TG and the cellular AUC of TGMP or TGTP. However, the AUC of TGMP and TGTP correlated significantly (r(2) = 0.64). The t1/2 of the intracellular metabolites and of 6-thioguanine in plasma were in the same order (4.4, 5.2 and 5.0 h for plasma 6-thioguanine, the intracellular mono- and triphosphate respectively). Phosphorylated metabolites of 6-thioguanine were detectable in erythrocytes from 8 patients. The kinetic pattern of the metabolites in erythrocytes was different from that in leukemic cells. While shortly after administration being eliminated according to first order kinetics in the leukemic cells, the concentration of intracellular metabolites in the erythrocytes was raising during the first 24 h after the treatment. The concentration of the metabolites were, however, much (100-fold) lower in erythrocytes compared to leukemic cells. Furthermore, the triphosphate was the predominant metabolite in the erythrocytes and considerable amounts of the diphosphate was seen while the concentration in the monophosphate was low. We conclude that there is a considerable interindividual variation in the cellular pharmacokinetics of TGMP and TGTP. The concentration of the phosphorylated metabolites in the leukemic cells cannot be predicted by determination of plasma 6-thioguanine concentration, nor by the concentration of the same metabolites in the erythrocytes.

Health and functioning in the everyday lives of young children with cancer: documenting with the International Classification of Functioning, Disability and Health--Children and Youth (ICF-CY)

BACKGROUND

Health care focus is shifting for children from surviving childhood cancer to living with it on a daily basis. There is a need to document health and function in the everyday lives of young children with cancer using the multidimensional framework and language of the International Classification of Functioning, Disability and Health--Children and Youth (ICF-CY).

AIMS

The aims of this study were (1) to document health and functioning in the everyday lives of young children with cancer using ICF-CY codes and (2) to identify a comprehensive code set that can aid clinical assessment.

METHOD

Interviews with children diagnosed with cancer and their parents, were transcribed, reviewed for content and coded to the ICF-CY using linking procedures.

RESULTS

A comprehensive code set (n = 70) for childhood cancer was identified. The majority of content identified to codes was related to activity and participation describing social relations with family, peers and professionals, preschool attendance and play, as well as issues related to support and independence.

CONCLUSIONS

The ICF-CY can be used to document the nature and range of characteristics and consequences of cancer experienced by children. The identified comprehensive code set could be helpful to health care professionals, parents and teachers in assessing and supporting young children's health and everyday life through the cancer trajectory. The comprehensive code set could be developed as a clinical assessment tool for those caring for young children with cancer. The universal language of the ICF-CY means that the utility of a clinical assessment tool based on identified codes can have wide reaching effects for the care of young children with cancer.

Polymorphisms in the ABCB1 gene and effect on outcome and toxicity in childhood acute lymphoblastic leukemia

The membrane transporter P-glycoprotein, encoded by the ABCB1 gene, influences the pharmacokinetics of anti-cancer drugs. We hypothesized that variants of ABCB1 affect outcome and toxicity in childhood acute lymphoblastic leukemia (ALL). We studied 522 Danish children with ALL, 93% of all those eligible. Risk of relapse was increased 2.9-fold for patients with the 1199GA variant versus 1199GG (P=0.001), and reduced 61% and 40%, respectively, for patients with the 3435CT or 3435TT variants versus 3435CC (overall P=0.02). The degree of bone marrow toxicity during doxorubicin, vincristine and prednisolone induction therapy was more prominent in patients with 3435TT variant versus 3435CT/3435CC (P=0.01/P<0.0001). We observed more liver toxicity after high-dose methotrexate in patients with 3435CC variant versus 3435CT/TT (P=0.03). In conclusion, there is a statistically significant association between ABCB1 polymorphisms, efficacy and toxicity in the treatment of ALL, and ABCB1 1199G>A may be a new possible predictive marker for outcome in childhood ALL.

Development, testing, and deployment of an air sampling manifold for spiking elemental and oxidized mercury during the Reno Atmospheric Mercury Intercomparison Experiment (RAMIX)

The Reno Atmospheric Mercury Intercomparison Experiment (RAMIX) was in Reno, NV from August 22, 2011 to September 16, 2011. The goals of the experiment were to compare existing and new methods for measurements of ambient elemental and oxidized Hg, and to test these with quantitative spikes of Hg(0), HgBr2, O3 and water vapor. In this paper we describe the design, testing, and deployment of a high flow manifold system designed to deliver ambient air and spiked compounds to multiple instruments simultaneously. The manifold was constructed of 1" OD PFA tubing and heated to 115 °C for the entire active zone. Manifold flow was controlled at ∼200 LPM using a blower and a velocity sensor in a feedback control system. Permeation tubes in controlled ovens were used to deliver Hg(0) and HgBr2. Ozone was generated from a small UV lamp in a flow of high purity O2. Water vapor was generated by pumping a flow of purified N2 through heated, high purity water. The spiking delivery for Hg(0), HgBr2, O3, and water vapor after dilution in the manifold ranged up to 20 ng m(-3), 0.64 ng m(-3), 100 ppbv, and 20 g kg(-1), respectively. During laboratory tests the average transmission efficiencies for Hg(0), HgBr2, and O3 were found to be 92%, 76%, and 93%, respectively.

Do we understand what the mercury speciation instruments are actually measuring? Results of RAMIX

From August 22 to September 16, 2012, atmospheric mercury (Hg) was measured from a common manifold in the field during the Reno Atmospheric Mercury Intercomparison eXperiment. Data were collected using Tekran systems, laser induced fluorescence, and evolving new methods. The latter included the University of Washington-Detector for Oxidized Mercury, the University of Houston Mercury instrument, and a filter-based system under development by the University of Nevada-Reno. Good transmission of total Hg was found for the manifold. However, despite application of standard protocols and rigorous quality control, systematic differences in operationally defined forms of Hg were measured by the sampling systems. Concentrations of reactive Hg (RM) measured with new methods were at times 2-to-3-fold higher than that measured by Tekran system. The low RM recovery by the latter can be attributed to lack of collection as the system is currently configured. Concentrations measured by all instruments were influenced by their sampling location in-the-manifold and the instrument analytical configuration. On the basis of collective assessment of the data, we hypothesize that reactions forming RM were occurring in the manifold. Results provide a new framework for improved understanding of the atmospheric chemistry of Hg.

The "E" word: epilepsy and perceptions of unfair treatment from the 2010 Australian Epilepsy Longitudinal Survey

AIM

The aim of the current study was to examine self-report data on perceptions of unfair treatment due to epilepsy.

METHOD

We analyzed data from the 2010 Australian Epilepsy Longitudinal Survey, distributed to 621 registrants on the Australian Epilepsy Research Register. A total of 343 responses were received (55% response rate), providing insight into experiences of life with epilepsy in Australia. Responses relating to perceptions of unfair treatment in areas of employment, education and community participation as a result of epilepsy are reported in this article.

RESULTS

Forty-eight percent of respondents reported perceptions of unfair treatment as a result of their epilepsy, with most providing details of their experiences. Discrimination in the workplace remains of key concern, with 47% citing examples of unfair treatment in this setting.

CONCLUSIONS

In spite of Australian anti-discrimination laws, findings indicate that full-time employment rates for people with epilepsy are lower than previously reported, with further mechanisms for support required to improve education and reduce experiences of stigma.

Attachment style as a piedictor of sexual attitudes and behavior in late Adolescence

Abstract This research applied attachment theory to the study of sexual attitudes and behaviors in a sample of late adolescents. Four hundred and seventy heterosexual undergraduate students completed questionnaires assessing attachment (discomfort with closeness; anxiety over relationships). relationship history, communication about sex. sexual self-efficacy and locus of control, and attitudes to condoms. Eight weeks later, participants reported on sexual behaviors occurring during the eight-week interval. and perceived risk of these activities. Both discomfort with closeness and anxiety over relationships were associated with external locus of control for sexual outcomes, and with use of drugs before sexual contact. Anxiety over relationships was linked to unsafe sex and to negative attitudes to condoms, but discomfort with closeness was associated with a more cautious approach to sexual risk-taking. Some results were qualified by gender differences. and by differences between the full sample and those who were sexually active. The findings arc discussed in terms of attachment style and its links with communication and affect regulation. SUMMARY AND CONCLUSIONS This study indicates that attachment dimensions are reliably related to many aspects of sexual attitudes and behaviors among late adolescents. Insecure attachment was linked to increased drug use before sexual contact. Anxiety over relationships was also linked to less safe sexual practice, but discomfort with closeness was associated with a tendency for males to be cautious about sexual risk-taking. The results support the utility of the attachment perspective on adolescent sexuality, but also highlight the complex relations between attachment dimensions and sexual outcomes. Future research would benefit from more detailed investigations of the attitudes, emotions, and cognitions which may mediate the link between attachment style and sexual behavior. For example, those who are highly anxious about their relationships may engage in more risky sexual practices because they fear that non-compliance with partners' wishes will jeopardize their relationship; the tendency to engage in drug use before sexual cpntact may reflect their attempts to boost self-confidence or to manage negative mood states. Research into these issues has the potential to explain how attachment insecurity is played out in patterns of sexual activity.

Testing the use of passive sampling systems for understanding air mercury concentrations and dry deposition across Florida, USA

This paper describes the use of passive sampling systems and surrogate surfaces for monitoring atmospheric mercury (Hg) concentrations and dry deposition, respectively, in Florida,USA. Although this area has been reported to have low air concentrations, wet deposition values, reported by the Mercury Deposition Network, are some of the highest in the United States, and little is known about the magnitude of dry deposition to the region. To address this uncertainty, dry deposition of gaseous oxidized mercury (GOM) was estimated based on data collected using surrogate surfaces and through the application of a dry deposition model that utilized Tekran® Mercury Analyzer data for three sites (Davie near Fort Lauderdale, Tampa and Pensacola) over a year (July 2009-July 2010). Passive sampler systems for monitoring GOM and total gaseous mercury (TGM) concentrations were also deployed. In general, higher surrogate surface deposition, and GOM and TGM passive sampler uptake were observed at the DVE location. Across all sites, empirically derived dry deposition was higher than that determined using modeled values. Tekran® Instrument derived GOM concentrations, as well as modeled deposition rates, followed the same seasonal and spatial patterns as that measured by the samplers, however there were some spatial and temporal trends captured by the samplers that were not seen in the Tekran® derived data. Results indicate that these samplers may be applied to identify spatial and temporal trends in air Hg concentrations and potential deposition at sites with low and fairly constant GOM concentrations as reported by the Tekran® system (2-8 pg m(-3)). When viewed collectively, trends in sampler and Tekran® derived data also suggest the potential for different forms of GOM in air. Using empirical and modeled values, dry deposition in Florida during the year of this study could account for 1.5 to 14% of total annual Hg deposition (wet+dry).