3D printed models are an accurate, cost-effective, and reproducible tool for quantifying terrestrial thermal environments

Predicting ecological responses to rapid environmental change has become one of the greatest challenges of modern biology. One of the major hurdles in forecasting these responses is accurately quantifying the thermal environments that organisms experience. The distribution of temperatures available within an organism's habitat is typically measured using data loggers called operative temperature models (OTMs) that are designed to mimic certain properties of heat exchange in the focal organism. The gold standard for OTM construction in studies of terrestrial ectotherms has been the use of copper electroforming which creates anatomically accurate models that equilibrate quickly to ambient thermal conditions. However, electroformed models require the use of caustic chemicals, are often brittle, and their production is expensive and time intensive. This has resulted in many researchers resorting to the use of simplified OTMs that can yield substantial measurement errors. 3D printing offers the prospect of robust, easily replicated, morphologically accurate, and cost-effective OTMs that capture the benefits but alleviate the problems associated with electroforming. Here, we validate the use of OTMs that were 3D printed using several materials across eight lizard species of different body sizes and living in habitats ranging from deserts to tropical forests. We show that 3D printed OTMs have low thermal inertia and predict the live animal's equilibration temperature with high accuracy across a wide range of body sizes and microhabitats. Finally, we developed a free online repository and database of 3D scans (https://www.3dotm.org/) to increase the accessibility of this tool to researchers around the world and facilitate ease of production of 3D printed models. 3D printing of OTMs is generalizable to taxa beyond lizards. If widely adopted, this approach promises greater accuracy and reproducibility in studies of terrestrial thermal ecology and should lead to improved forecasts of the biological impacts of climate change.

Nationwide, Multioperator Self-Exclusion and Psychiatric Comorbidity in Patients with Gambling Disorder: A Retrospective Chart Review Study from a Regional Treatment Unit

Gambling disorder is an addictive disorder that has been shown to have a detrimental effect on an individual's health, social, and financial situations. Voluntary self-exclusion is one way for patients to reduce harm in gambling disorder, but breaching one's self-exclusion appears to be common. In January 2019, Sweden launched a nationwide, multioperator self-exclusion instrument called Spelpaus (literally "game break"). Spelpaus is unique to Sweden, and there is limited research on the use of this type of nationwide, multioperator self-exclusion services, also in relation to gambling disorder and mental health. There is a reason to follow the clinical picture of treatment seeking for gambling disorder over time, and this study aims to explore clinical characteristics of patients seeking clinical gambling disorder treatment, including sex distribution and mental health comorbidity, as well as the use of Spelpaus amongst patients with gambling disorder and how frequently users gambled despite ongoing self-exclusion, in relation to sex and psychiatric comorbidities. A retrospective chart study was carried out on patients presenting to a regional gambling disorder treatment unit. Information regarding self-exclusions using Spelpaus, gambling despite self-exclusion, and the method of gambling despite self-exclusion as well as psychiatric comorbidities were extracted from medical records. Females were markedly more likely to report overall psychiatric comorbidities (48% vs. 25% among males, p < 0.001), affective, neurotic/anxiety-related (p < 0.001), and behavioral/emotional (p = 0.028) diagnoses and more likely to have two or more diagnoses excluding gambling disorder (p = 0.001). From 120 patients from whom information regarding self-exclusion was present, 114 (95%) had chosen to self-exclude. From the 114 self-excluders, 67 reported to have gambled despite self-exclusion, with unregistered websites being the most common method. Self-exclusion was not significantly related to sex (p = 0.146) or to psychiatric comorbidities (p = 0.178). In conclusion, psychiatric comorbidity was particularly common in female gambling disorder patients and gambling despite self-exclusion was common. Gambling regulations should be improved to help self-excluders avoid being able to gamble on unlicensed gambling operators. Further research should focus on sex differences and the association with psychiatric comorbidities.

A134 UES MANOMETRIC PARAMETERS IN ESOPHAGEAL MOTILITY DISORDERS

Background

Upper esophageal sphincter (UES) function may be evaluated manometrically using a solid-state high-resolution manometry (HRM) system, which allows for the measurement of manometric parameters specific to the UES. While many of these parameters have yet to be validated for use in clinical practice, there is some suggestion that there may be an association between esophageal motility and UES function.

Aims

We aimed to identify the relationship between UES manometric variables and high-resolution esophageal manometry (HREM) diagnoses.

Methods

A retrospective analysis of HREM studies was performed between 2019 and 2021. Extraction of esophageal and UES manometric variables were performed. UES manometric values of interest included: mean basal pressure (mmHg), mean residual pressure (mmHg), relaxation time-to-nadir (ms), relaxation duration (ms), and recovery time (ms). Relationships between manometric diagnosis (Chicago Classification version 3) and UES manometric variables were explored. All values are expressed a medians and group means were compared with the non-parametric Mann-Whitney U test.

Results

2119 symptomatic patients underwent HREM over the study period. Manometric diagnoses were achalasia (72 patients), esophagogastric junction outflow obstruction (286), absent contractility (108), distal esophageal spasm (53), jackhammer esophagus (32), and ineffective esophageal motility (694). 886 patients had no specific motility disorder; 643 of whom had ≤ 20% ineffective swallows and were considered symptomatic controls.

Patients with achalasia had significantly higher mean basal pressures (63.2 vs. 54.4, p = .001), mean residual pressure (3.8 vs. -1.9, p < .001), relaxation-time-to-nadir (182.0 vs. 142.0, p = .005), relaxation duration (820.5 vs. 708.0, p < .001) and recovery time (623.0 vs. 562, p < .001) compared to control patients. Among patients with achalasia, the presence of panesophageal pressurization correlated weakly with recovery time (R² .3, p = .03). Patients with ineffective esophageal motility had significantly higher mean basal pressures (61.7 vs. 54.0, p < .001).

Among all patients, patients with incomplete bolus clearance (≥ 30%) had significantly higher UES mean basal pressure (58.9 vs. 54.6, p = .004), mean residual pressure (-.62 vs. -2, p < .001), relaxation duration (724.0 vs. 707.0, p = .014) and recovery time (580 vs. 558.0, p < .001).

Conclusions

Patients with achalasia may have higher basal and residual UES pressures, and slower relaxation compared to patients with normal esophageal motility. This may reflect dynamic changes of the UES in response to obstruction at the esophagogastric junction. Elevated UES pressures are also seen in patients with ineffective esophageal motility, potentially reflecting a response to poor bolus clearance. More work needs to be done to validate these parameters in clinical practice.

Funding Agencies

None

A64 REVIEW OF PATIENTS REFERRED TO THE DIVISION OF DIGESTIVE CARE AND ENDOSCOPY AT DALHOUSIE UNIVERSITY FOR COLORECTAL CANCER SCREENING BASED ON A FAMILY HISTORY OF COLORECTAL CANCER: HOW MANY UNDERWENT COLONOSCOPY?

Background

Nova Scotia has provincial colorectal cancer (CRC) screening for asymptomatic, average risk individuals age 50–74 using fecal immunochemical testing (FIT) every 2 years. However, individuals with 1 or more first degree relatives (FDR) diagnosed with CRC by age 60 have a 2–4 fold increased risk for developing CRC. For these high risk individuals, current guidelines recommend CRC screening with colonoscopy rather than FIT testing. Annually, the Division of Digestive Care & Endoscopy (DCE) at Dalhousie University receives many referrals for patients with a family history of CRC but the percentage of patients who require this procedure is unclear.

Aims

The objectives of this quality assessment study were to review patients referred to DCE for a family history of CRC to (1) better understand the indication for referral; and (2) determine the percentage of patients undergoing colonoscopy

Methods

This was a retrospective cross sectional review of a prospectively updated database. The study population was patients referred to DCE from 2012–2019 based on a family history of CRC, as indicated on the referral. Family history of CRC was defined as 1 or more FDRs diagnosed with CRC. High risk patients were those with 2 or more FDRs with CRC or 1 FDR diagnosed by age 60. All patients were reviewed by a single gastroenterologist in clinic.

Results

A total of 107 referrals from 2012–2019 were reviewed. Of patients age 50 or older, 51/78 (65.4%) had performed at least 1 FIT. The indications for referral were 2 or more FDR diagnosed with CRC for 6/107 (5.6%) patients, 1 FDR diagnosed with CRC by age 60 for 37/107 patients (34.6%) and 1 FDR diagnosed with CRC over age 60 for 33/107 patients (30.8%). The remaining 31/107 patients (29.0%) had no FDR with CRC. Of the 43/107 patients (40.2%) considered high risk based on family history alone, 34/43 (79.1%) underwent colonoscopy and 8/43 (18.6%) opted for FIT testing. Of the 64/107 patients (59.8%) considered average risk based on family history alone, 26/64 (40.6%) had another indication for colonoscopy and 35/64 (54.7%) resumed FIT testing.

Conclusions

The majority of patients (71.0%) referred to the DCE for a family history of CRC had at least 1 FDR with CRC. Just over half of patients (55.1%) referred to the DCE for a family history of CRC underwent colonoscopy. Strategies to improve the referral process by better capturing high risk individuals are needed.

Funding Agencies

None

A109 LINKING PRIMARY AND SPECIALTY CARE FOR THE MANAGEMENT OF DIGESTIVE HEALTH CONDITIONS: AN EVALUATION OF GUT LINK IMPLEMENTATION

Background

Severe restrictions on in-person encounters and endoscopic procedures for digestive care have occurred as a result of the COVID-19 pandemic. This has exacerbated pre-existing barriers in access to gastroenterology (GI) care across Nova Scotia (NS) for patients and primary healthcare providers (PHCPs). In response, a provincial PHCP-GI consultative service (GUT LINK) was implemented at a single tertiary care center with the goal of supporting PHCPs in the management of non-urgent GI referral conditions.

Aims

To implement and evaluate the acceptability, feasibility, appropriateness, and early effectiveness of the GUT LINK PHCP-GI consultation service.

Methods

This is an ongoing prospective observational cohort study. All referrals received through the EMR-based referral and triage management system between May and November 2020 that were deemed to be amenable to management within primary care with specialist support were returned to the PHCP with the suggestion to arrange a GUT LINK telephone consultation. GUT LINK appointments were scheduled through an administrative support telephone line with the PHCP and a GI specialist. A post-consultation e-questionnaire was distributed to PHCPs who consented to participate. Feasibility (number of and indication for referrals, PHCP participation rates), acceptability and appropriateness (satisfaction, future use, likelihood to recommend) metrics and outcomes (case resolution, re-referrals, proportion requiring endoscopic investigations) were recorded. Patient charts were reviewed to determine whether the patient ultimately required GI speciality care. Analyses were descriptive and expressed as frequencies, means (+/-SD), medians (+/-SE), and proportions (%).

Results

A total of 45 GUT LINK consultations were completed between May and November 2020. Of these, 20% required GI specialist care and 80% have remained within primary care, with a median follow-up of 101 (+/-9.1) days. The indications for GUT LINK consultation included lower GI symptoms (64%), abnormal imaging or investigations (17%), and upper GI symptoms (19%).

To date, 21 PHCP agreed to be contacted for the post-consultation survey and 10 have been completed. All PHCPs reported that GUT LINK consultation was easy to access, while 90% found the advice helpful and 80% reported that that it resolved the issue. Following the GUT LINK appointment, 80% felt they would not need to refer their patient to GI.

Conclusions

The implementation of GUT LINK was acceptable, feasible, and improved access to specialist support for management of undifferentiated GI symptoms. Future research will focus on comprehensive stakeholder engagement in order to design, implement, and evaluate GUT LINK PHCP care pathways.

Funding Agencies

CAG

Information for and by Blind Persons in Rural Asia

Blind and visually impaired people in rural Asia are largely unreached by modern rehabilitative information, nor are their indigenous skills and experience adequately formulated and shared. The use of many media in communication strategies has led to the reconceptualization of rehabilitation in information terms which offers better prospects of self-help for several million blind people.

Dual targeting of the cancer antioxidant network with 1,4-naphthoquinone fused Gold(i) N-heterocyclic carbene complexes

To achieve a systems-based approach to targeting the antioxidant pathway, 1,4-naphthoquinone annulated N-heterocyclic carbene (NHC) [bis(1,3-dimesityl-4,5-naphthoquino-imidazol-2-ylidene)-gold(i)] [silver(i) dichloride] (1), [bis(1,3-dimesityl-4,5-naphthoquino-imidazol-2-ylidene)-gold(i)] chloride (2), and 1,3-dimesityl-4,5-naphthoquino-imidazol-2-ylidene)-gold(i) chloride (3)) were designed, synthesized, and tested for biological activity in a series of human cancer cell lines. The solution phase of complexes 1-3 were assigned using several spectroscopy techniques, including NMR spectroscopic analysis. Complexes 1 and 3 were further characterized by single crystal X-ray diffraction analysis. Electrochemical and spectroelectrochemical studies revealed that quinone reductions are reversible and that the electrochemically generated semiquinone and quinone dianions are stable under these conditions. Complex 1, containing two NHC-quinone moieties (to accentuate exogenous ROS via redox cycling) centered around a Au(i) center (to inactivate thioredoxin reductase (TrxR) irreversibly), was found to inhibit cancer cell proliferation to a much greater extent than the individual components (i.e., Au(i)-NHC alone or naphthoquinone alone). Treatment of A549 lung cancer cells with 1 produced a 27-fold increase in exogenous reactive oxygen species (ROS) which was found to localize to the mitochondria. The inhibition of TrxR, an essential mediator of ROS homeostasis, was achieved in the same cell line at low administrated concentrations of 1. TrxR inhibition by 1 was similar to that of auranofin, a gold(i) containing complex known to inhibit TrxR irreversibly. Complex 1 was found to induce cell death via an apoptotic mechanism as confirmed by annexin-V staining. Complex 1 was demonstrated to be efficacious in zebrafish bearing A549 xenografts. These results provide support for the suggestion that a dual targeting approach that involves reducing ROS tolerance while concurrently increasing ROS production can perturb antioxidant homeostasis, enhance cancer cell death in vitro, and reduce tumor burden in vivo, as inferred from preliminary zebra fish model studies.

Large area high-speed metrology SPM system

We present a large area high-speed measuring system capable of rapidly generating nanometre resolution scanning probe microscopy data over mm(2) regions. The system combines a slow moving but accurate large area XYZ scanner with a very fast but less accurate small area XY scanner. This arrangement enables very large areas to be scanned by stitching together the small, rapidly acquired, images from the fast XY scanner while simultaneously moving the slow XYZ scanner across the region of interest. In order to successfully merge the image sequences together two software approaches for calibrating the data from the fast scanner are described. The first utilizes the low uncertainty interferometric sensors of the XYZ scanner while the second implements a genetic algorithm with multiple parameter fitting during the data merging step of the image stitching process. The basic uncertainty components related to these high-speed measurements are also discussed. Both techniques are shown to successfully enable high-resolution, large area images to be generated at least an order of magnitude faster than with a conventional atomic force microscope.

Social and Educational Responses to Mental Retardation in Pakistan, India and Bangladesh

South Asian languages and literature offer many terms for mental retardation (MR), intellectual disability or cognitive impairment, with a range of concepts and meanings through three millennia of history. Responses to mental retardation are illustrated by stories from religious, medical, legal and psychological literature, translated from Sanskrit, Pali, Persian, Bengali and Tamil. These responses concern life stages and events such as pregnancy, birth and infancy, development of speech, social behaviour and play, entry and progress in education, and problems arising in these stages. More documentation is available on rulers’ sons, whose impairment might affect succession to the throne and other issues of legal status. Geographical conditions such as iodine deficiency are also implicated in mental retardation. The cumulative evidence raises many questions about appropriate responses in the present, and how human beings attribute value to others, or generate failure and low self-worth by flawed constructions. The riches of South Asian cultural history, and unexpected gifts from people with mental retardation, play their part in illuminating these issues.

Does diurnal temperature variability affect growth in juvenile Atlantic salmon Salmo salar?

This study investigated the effects of diurnal temperature variability (>7° C) on the growth of 1+ year Atlantic salmon Salmo salar. Experimental manipulation of water temperature was used to simulate: (1) constant and (2) naturally varying thermal regimes with similar daily mean values. Data from two replicates of four treatments (two thermal and two feeding regimes) were collected over 6 months corresponding to the main spring to summer growth period. Fish growth was assessed at fortnightly intervals. Small but significant differences in mean fork length (L(F) ) and mass were observed between temperature treatments, with smaller, lighter fish under the variable temperature regime. The effects of temperature regime on growth were independent of food ration. At termination of the experiment, the median L(F) and mass of fish exposed to the variable temperature regime were estimated, respectively, to be 2· 6 and 8· 0% less than those under the constant regime. Given the relatively small differences in growth attributable to variable temperature regime in these experiments, it is suggested that mean daily temperatures are adequate to inform juvenile growth models for field-based studies.

The influence of passive stretch and NF-κB inhibitors on the morphology of dystrophic muscle fibers

The triangularis sterni (TS) is an expiratory muscle that is passively stretched during inspiration. The magnitude of passive stretch depends upon the location of individual fibers within the TS muscle, with fibers located more caudally being stretched ∼ 5% to 10% more than fibers in the cephalad region. In the mdx mouse model for muscular dystrophy, the TS exhibits severe pathological alterations that are ameliorated by treatment with inhibitors of the NF-κB pathway. The purpose of this study was to assess the influence of passive stretch in vivo on fiber morphology in nondystrophic and mdx TS muscles, and the morphological benefits of treating mdx mice with two distinct NF-κB inhibitors, pyrrolidine dithiocarbamate (PDTC), and ursodeoxycholic acid (UDCA). Transmission electron microscopy revealed Z-line streaming, hypercontraction, and disassociation of the plasma membrane from the basal lamina in mdx fibers. In both nondystrophic and mdx TS muscles, fiber density was larger in more caudal regions. In comparison with nondystrophic TS, fibers in the mdx TS exhibited substantial reductions in diameter throughout all regions. In vivo treatment with either PDTC or UDCA tended to increase fiber diameter in the middle and decrease fiber diameter in the caudal TS, while reducing centronucleation in the middle region. These results suggest that passive stretch induces hypercontraction and plasma membrane abnormalities in dystrophic muscle, and that differences in the magnitude of passive stretch may influence fiber morphology and the actions of NF-κB inhibitors on dystrophic morphology.

A Public Health Grid (PHGrid): Architecture and value proposition for 21st century public health

PURPOSE

This manuscript describes the value of and proposal for a high-level architectural framework for a Public Health Grid (PHGrid), which the authors feel has the capability to afford the public health community a robust technology infrastructure for secure and timely data, information, and knowledge exchange, not only within the public health domain, but between public health and the overall health care system.

METHODS

The CDC facilitated multiple Proof-of-Concept (PoC) projects, leveraging an open-source-based software development methodology, to test four hypotheses with regard to this high-level framework. The outcomes of the four PoCs in combination with the use of the Federal Enterprise Architecture Framework (FEAF) and the newly emerging Federal Segment Architecture Methodology (FSAM) was used to develop and refine a high-level architectural framework for a Public Health Grid infrastructure.

RESULTS

The authors were successful in documenting a robust high-level architectural framework for a PHGrid. The documentation generated provided a level of granularity needed to validate the proposal, and included examples of both information standards and services to be implemented. Both the results of the PoCs as well as feedback from selected public health partners were used to develop the granular documentation.

CONCLUSIONS

A robust high-level cohesive architectural framework for a Public Health Grid (PHGrid) has been successfully articulated, with its feasibility demonstrated via multiple PoCs. In order to successfully implement this framework for a Public Health Grid, the authors recommend moving forward with a three-pronged approach focusing on interoperability and standards, streamlining the PHGrid infrastructure, and developing robust and high-impact public health services.

Nanomechanical force measurements of gliadin protein interactions

The strength and nature of interactions between monomeric gliadin proteins involving alpha-alpha, omega-omega, and alpha-omega interactions in 0.01M acetic acid, and the effect of urea has been investigated. It was shown by means of nanomechanical force measurements that the stretching events in the separation curve after adhesive phenomena originated from proteins. These stretching events displayed different responses of the alpha- and omega-gliadins to urea. While 2M urea caused the more globular alpha-gliadins to unfold, the beta-turn-rich omega-gliadins remained fairly stable even in 8M urea. This suggests different roles for gliadins in the formation of dough; while the omega-gliadins are still in a compact structure being responsible for the viscous flow, the alpha-gliadins have already started to participate in forming the network in dough.

The effects of spinosad to beneficial insects and mites and its use in IPM

The effects of spinosad to beneficial and non-target arthropods has been extensively researched. Data have been generated under laboratory, semi-field and field conditions on a wide range of predatory and parasitic taxa in a variety of geographical regions and crop types. Such a large body of data cannot be summarized in detail in a single publication; however, general patterns of effects exist in the data. The aim of this paper is to demonstrate the range of effects of spinosad to beneficial predatory and parasitic arthropods. This is done by presenting in detail selected laboratory, semi-field and field test with beneficial arthropods. Following that an analysis of a database of effects is conducted using records taken from Dow AgroSciences and independent reports. Using these illustrations the profile of effects on a range of predatory and parasitic arthropods are clearly defined. Research has demonstrated that when used according to good agricultural or horticultural practice spinosad is of low risk to predatory mites and beneficial insect populations. Toxicity has been reported to certain parasitic hymenoptera but due to the very short persistence of the product any effects are short lived and followed by rapid recovery. This makes the product an ideal tool in vegetable, pome and pear crops where it can be used to control, thrips caterpillar pests and Psylla. Overall, spinosad preserves natural populations of predatory mites and beneficial insects which make it an ideal choice in IPM programmes.

Results from two years of field studies to determine Mancozeb based spray programmes with minimal impact on predatory mites in European vine cultivation

Mancozeb is a dithiocarbamate fungicide with contact activity against a wide range of economically important fungal diseases. Its multi-site mode of action means that to date there have been no recorded incidences of resistance developing despite many years of use on high risk diseases. One such disease, Grape downy mildew (Plasmopara viticola) has developed resistance to a wide range of important oomycete specific fungicides following their introduction onto the market. The role of Mancozeb either as a mixing or alternation partner in helping to manage these resistance situations remains critically important. Historical use patterns for mancozeb in tree and vine crops involved many applications of product at high use rates. Although this gave excellent disease control, a negative impact on predatory mites was often reported by researchers. This has lead to the development of mancozeb spray programmes in vines and other crops with a much reduced impact on predatory mites. A range of field studies was conducted over two years in France, Germany, Italy, Portugal and Spain where 2, 3 or 4 applications of mancozeb containing products were made per season at different spray timings. In this paper findings from field studies over two years in five different vine growing regions in Europe indicated that two to four applications of mancozeb at 1.6 kg a.i./ha as part of a spray programme caused minimal impact on naturally occurring populations of predatory mites which in turn was compatible with Integrated Pest Management programmes and the conservation of predatory mites.

Field studies to determine the effects of spinosad on the predatory bugs Anthocoris nemoralis and A. nemorum

The predatory bugs Anthocoris nemoralis and A. nemorum are important predators of the pear psylla (Psylla pyri) in pear orchards. To effectively control psylla infestations the use of insecticide treatments are often necessary so it is desirable to adopt products and use patterns which protect or conserve natural predator populations. Spinosad (the active ingredient in TRACER* insecticide) is highly active on psylla when applied up to two times after flowering. To investigate the effects of spinosad on A. nemoralis and A. nemorum a series of field trials were conducted between 1998 and 2005 in pear. Findings from these trials showed that spinosad applied at the psylla rate may cause minor short term effects on A. nemoralis and A. nemorum specifically to very young (or recently hatched) nymphs. However, due to the rapid photodegradation of spinosad recovery of predatory bug populations follows a few days after final application. The occasional depressive effect due to spinosad applications was considered to be due mainly to the removal of the pear psylla prey as spinosad has excellent efficacy on this pest. Findings from the trials demonstrated that predatory bug populations recover rapidly within a few days after the second application in order to control any new pear psylla attack. Therefore, spinosad can be considered as a valuable new tool for controlling pear psylla populations in pear orchards and to be compatible with augmented biological control by the predatory bug population.

Imaging of human metaphase chromosomes by atomic force microscopy in liquid

Human metaphase chromosomes were observed using an intermittent contact mode of atomic force microscopy (AFM) in a phosphate-buffered saline solution to clarify their conformation close to that in the physiological state. In the AFM images in liquid, symmetric alternating ridges and grooves were evident on their surface of the paired sister chromatids. The number of the ridges and grooves were rather specific to the type of the chromosome. The structural changes of chromosomes caused by trypsin treatment were also directly observable using AFM in liquid. These results suggest that the intermittent contact mode AFM is useful not only for analyzing the structure of chromosomes in a liquid condition but also for studying the effect of chemical treatments on chromosomes in relation to their structural changes.

Field studies to determine mancozeb based spray programmes with minimal impact on predatory mites in European vine cultivation

Mancozeb is an ethylene bisdithiocarbamate (EBDC) fungicide with contact activity against a wide range of economically important fungal diseases. Its multi-site mode of action means that to date there have been no recorded incidences of resistance developing despite many years of use on high risk diseases. One such disease, Grape downy mildew (Plasmopara viticola) has developed resistance to a number of important oomycete specific fungicides following their introduction onto the market. The role of Mancozeb either as a mixing or alternation partner in helping to manage these resistance situations remains critically important. Historical use patterns for mancozeb in tree and vine crops involved many applications of product at high use rates. Although this gave excellent disease control, a negative impact on predatory mites has been reported by researchers. This has lead to the development of mancozeb spray programmes in vines and other crops with a much reduced impact on predatory mites. A range of field studies was conducted in France, Germany, Italy, Portugal and Spain where either 2 or 4 applications of mancozeb containing products were made per season at different spray timings. These trials covered the representative range of uses, agronomic practices, mite species and geographical locations in Europe. In this paper findings from ten field studies in five different vine growing regions in Europe indicated that two to four applications of mancozeb at 1.6 kg a.i./ha as part of a spray programme caused minimal impact on naturally occurring populations of predatory mites which in turn was compatible with Integrated Pest Management programmes and the conservation of predatory mites.

The effects of spinosad, a naturally derived insect control agent, to the honeybee (Apis melifera)

Spinosad is a novel insect control agent derived by fermentation of the Actinomycete bacterium, Saccharopolyspora spinosa. Spinosad controls many caterpillar pests in vines, pome fruit and vegetables (including tomatoes and peppers), thrips in tomatoes, peppers and ornamental cultivation and dipterous leafminers in vegetables and ornamentals. Application rates vary between 25 to 100 g of active substance per hectare (g as/ha) and 4.8 to 36 g of active substance per hectolitre (g as/hL) depending on the crop and target pest. It is important that plant protection products are authorized for use only in ways that do not pose an unacceptable risk of harm to honeybees. For this purpose testing was performed to enable the safety of spinosad to be evaluated. The effects of spinosad to honeybees have been extensively researched. Testing has been performed under a variety of conditions in a range of countries globally. Studies to determine the acute toxicity of spinosad under laboratory conditions were conducted to generate LD50 or LC50 values for oral and contact routes of administration. These demonstrated that spinosad was highly toxic to worker honeybees under worst case laboratory conditions and that the oral route of exposure provided the greater risk. Residue tests conducted under laboratory, semi-field and field conditions on worker honeybees foraging on treated foliage indicated that dry product residues were harmless. Therefore the effects seen in the laboratory acute toxicity tests did not translate to a more realistic exposure scenario indicating that safe use patterns for the product can be developed. Semi-field cage studies have also demonstrated that spinosad was safe to bees when applied to flowering crops during periods of bee activity. The majority of studies conducted have indicated that spinosad does not adversely affect honeybee behaviour, brood or queen. It can be concluded that spinosad when used according to the approved product label recommendations, would be safe to foraging worker bees, queen and brood. Additional levels of safety could be achieved by avoiding situations where bees would forage primarily on aphid honey dew.

Evidence for negative cross resistance to insecticides in field collected Spodoptera littoralis (Boisd.) from Lebanon in laboratory bioassays

A sample of Spodoptera littoralis pupae were field collected from in Lebanon in November 1999. Approximately 50 healthy pupae were used to initiate a laboratory colony (stain code LEB). As a benchmark for sensitivity to insecticides the susceptible laboratory strain (LET) was used for comparison. The LET stain has been held in laboratory culture for over 10 years and originated from Israel. Three test chemicals were investigated; Spinosad (Tracer, 480 g/L SC), chlorpyrifos (Dursban 480 g/L EC) and cypermethrin (Ambush C 100 g/L EC) representing a range of different modes of actions. To estimate the sensitivity of the LEB strain relative to the LET stain laboratory bioassays, conducted on second instar larvae exposed treated tomato leaves for two days. The method used was based on IRAC (Insecticide Resistance Action Committee) insecticide susceptibly test number 7. Larvae from the LEB strain were tested in both the F1 and F2 laboratory generations. LC50 values were calculated using a Log-Probit model allowing the susceptibly of each strain to each test item to be compared. The LEB (field) strain were approximately twice as sensitive to spinosad compared with the LET (laboratory) strain. The LEB strain was 6-10 times less sensitive to chlorpyrifos which was within the range expected. However the LEB stain was 250-360 times less sensitive to cypermethrin compared with the LET strain, indicating a high level of resistance to pyrethroids in the field population. This kind of relationship gave a strong indication for negative cross resistance between spinosad and cypermethrin. It was concluded that spinosad had potential as a resistance management tool due to its novel mode of action and negative cross resistance with pyrethroids.

Knowledge and management of disabling conditions in South Asian histories: implications for leprosy futures

Elimination of leprosy as a public health problem appears feasible in South Asia in the present decade through multi-drug therapy, but management of disability in cured leprosy patients will continue through the 21st century, probably with some ongoing stigma. This paper provides new perspectives on leprosy-related disabilities by reviewing the historical careers of four disabling conditions sharing some features with leprosy: lathyrism, iodine deficiency disorders (IDD), cataract and poliomyelitis. All are targeted for eradication or serious reduction using affordable surgery or preventive measures, yet they have proved unexpectedly resilient. Technical solutions alone bring only partial success. There is a need also for community-based delivery methods, individual and family self-help, and some redeployment of professional expertise.

Effect of resistance training on women's strength/power and occupational performances

PURPOSE

The effects of resistance training programs on strength, power, and military occupational task performances in women were examined.

METHODS

Untrained women aged (mean +/- SD) 23 +/- 4 yr were matched and randomly placed in total- (TP, N = 17 and TH, N = 18) or upper-body resistance training (UP, N = 18 and UH, N = 15), field (FLD, N = 14), or aerobic training groups (AER, N = 11). Two periodized resistance training programs (with supplemental aerobic training) emphasized explosive exercise movements using 3- to 8-RM training loads (TP, UP), whereas the other two emphasized slower exercise movements using 8- to 12-RM loads (TH, UH). The FLD group performed plyometric and partner exercises. Subjects were tested for body composition, strength, power, endurance, maximal and repetitive box lift, 2-mile loaded run, and U.S. Army Physical Fitness Tests before (T0) and after 3 (T3) and 6 months of training (T6). For comparison, untrained men (N = 100) (MEN) were tested once.

RESULTS

Specific training programs resulted in significant increases in body mass (TP), 1-RM squat (TP, TH, FLD), bench press (all except AER), high pull (TP), squat jump (TP, TH, FLD), bench throw (all except AER), squat endurance (all except AER), 1-RM box lift (all except aerobic), repetitive box lift (all), push-ups (all except AER), sit-ups (all except AER), and 2-mile run (all).

CONCLUSIONS

Strength training improved physical performances of women over 6 months and adaptations in strength, power, and endurance were specific to the subtle differences (e.g., exercise choice and speeds of exercise movement) in the resistance training programs (strength/power vs strength/hypertrophy). Upper- and total-body resistance training resulted in similar improvements in occupational task performances, especially in tasks that involved upper-body musculature. Finally, gender differences in physical performance measures were reduced after resistance training in women, which underscores the importance of such training for physically demanding occupations.

The Egyptian mongoose, Herpestes ichneumon, is a possible reservoir host of visceral leishmaniasis in eastern Sudan

Investigations were made on possible reservoir hosts of Leishmania donovani in 2 zoonotic foci of visceral leishmaniasis (VL) in Dinder National Park (DNP) and the peri-domestic habitats of adjacent villages of eastern Sudan. Animals were captured, in November 1997-1998 and April-May 1999 and examined for L. donovani infection using light microscopy and 2 sensitive Polymerase Chain Reaction (PCR) systems. Microscopy and PCR investigations were also used to determine the infection rates of L. donovani in Phlebotomus orientalis captured from the uninhabited site of DNP. Infections of L. donovani were detected in 2 out of 14 Egyptian mongooses (Herpestes ichneumon), 1 out of 168 Arviconthus niloticus and 1 out of 8 Mastomys natalensis. Samples from 68 other animals captured from the study area were all negative for the infection. Active zoonotic transmission of L. donovani at the time of animal sampling in the uninhabited site of DNP was demonstrated by finding the parasite in 3.4% (7 out of 184) and 3.2% (5 out of 157) of flies collected in March 1998 and May 1999, respectively. We suggest that the Egyptian mongoose is a possible reservoir host of L. donovani. The importance of other animals in maintaining the infection is also discussed.

Malaria vectors in the municipality of Serra do Navio, State of Amapá, Amazon Region, Brazil

We conducted a survey to determine the vectors of malaria in six localities of Serra do Navio municipality, State of Amapá, from 1990 to 1991. Malaria infection rates of 29.3%, 6.2% and 20.4% were detected by human blood smears in Colônia Agua Branca, Porto Terezinha and Arrependido, respectively. There was no malaria infection detected in Serra do Navio. Fifteen species were identified among 3,053 anopheline mosquitoes collected by human bait and 64.4% were identified as Anopheles albitarsis s.l., 16.7% An. braziliensis, 9.5% An. nuneztovari and 5.8% An. triannulatus. An. darlingi, the main vector of malaria in the Amazon region of Brazil, was scare. Using enzyme-linked immunosorbent assay (ELISA), a total positive rate of 0.8% (23/2876) was found for six species: fifteen An. albitarsis s.l., four An. nuneztovari, and one of each: An. braziliensis, An. triannulatus, An. oswaldoi and An. rangeli. Nine of 23 positive mosquitoes were infected with Plasmodium malariae, eight with P. vivax VK210, three with P. vivax VK247 and three with P. falciparum. Since An. albitarsis s.l. was collected feeding on humans, was present in the highest density and was positive by ELISA for malaria sporozoites, it probably plays an important role in malaria transmission in this area.

Genetic diversity and genetic exchange in Trypanosoma cruzi: dual drug-resistant "progeny" from episomal transformants

Extensive characterisation of Trypanosoma cruzi by isoenzyme phenotypes has separated the species into three principal zymodeme groups, Z1, Z2 and Z3, and into many individual zymodemes. There is marked diversity within Z2. A strong correlation has been demonstrated between the strain clusters determined by isoenzymes and those obtained using random amplified polymorphic DNA (RAPD) profiles. Polymorphisms in ribosomal RNA genes, in mini-exon genes, and microsatellite fingerprinting indicate the presence of at least two principal T. cruzi genetic lineages. Lineage 1 appears to correspond with Z2 and lineage 2 with Z1. Z1 (lineage 2) is associated with Didelphis. Z2 (lineage 1) may be associated with a primate host. Departures from Hardy-Weinberg equilibrium and linkage disequilibrium indicate that propagation of T. cruzi is predominantly clonal. Nevertheless, two studies show putative homozygotes and heterozygotes circulating sympatrically: the allozyme frequencies for phosphoglucomutase, and hybrid RAPD profiles suggest that genetic exchange may be a current phenomenon in some T. cruzi transmission cycles. We were able to isolate dual drug-resistant T. cruzi biological clones following copassage of putative parents carrying single episomal drug-resistant markers. A multiplex PCR confirmed that dual drug-resistant clones carried both episomal plasmids. Preliminary karyotype analysis suggests that recombination may not be confined to the extranuclear genome.

Secondary data analysis: new perspective for adolescent research

Adolescents are at high risk for preventable health problems, but realities of research funding and obtaining data from large samples make it difficult for many researchers to answer important questions. Secondary analysis of existing data sets is described as a reasonable alternative in spite of its limitations. Methods and available resources are identified along with suggestions for research priorities with adolescents.

The ecotopes and evolution of triatomine bugs (triatominae) and their associated trypanosomes

Triatomine bug species such as Microtriatoma trinidadensis, Eratyrus mucronatus, Belminus herreri, Panstrongylus lignarius, and Triatoma tibiamaculata are exquisitely adapted to specialist niches. This suggests a long evolutionary history, as well as the recent dramatic spread a few eclectic, domiciliated triatomine species. Virtually all species of the genus Rhodnius are primarily associated with palms. The genus Panstrongylus is predominantly associated with burrows and tree cavities and the genus Triatoma with terrestrial rocky habitats or rodent burrows. Two major sub-divisions have been defined within the species Trypanosoma cruzi, as T. cruzi 1 (Z1) and T. cruzi 2 (Z2). The affinities of a third group (Z3) are uncertain. Host and habitat associations lead us to propose that T. cruzi 1 (Z1) has evolved in an arboreal, palm tree habitat with the triatomine tribe Rhodniini, in association with the opossum Didelphis. Similarly we propose that T. cruzi (Z2) and Z3 evolved in a terrestrial habitat in burrows and in rocky locations with the triatomine tribe Triatomini, in association with edentates, and/or possibly ground dwelling marsupials. Both sub-divisions of T. cruzi may have been contemporary in South America up to 65 million years ago. Alternatively, T. cruzi 2 (Z2) may have evolved more recently from T. cruzi 1 (Z1) by host transfers into rodents, edentates, and primates. We have constructed a molecular phylogeny of haematophagous vectors, including triatomine bugs, which suggests that faecal transmission of trypanosomes may be the ancestral route. A molecular clock phylogeny suggests that Rhodnius and Triatoma diverged before the arrival, about 40 million years ago, of bats and rodents into South America.

Human chromosome structure studied by scanning force microscopy after an enzymatic digestion of the covering cell material

In standard preparations, metaphase human chromosomes are covered by a cell material film composed mainly of proteins and RNA. This film (approximately 30 nm thickness) hides the chromosome structure to the tip of a scanning force microscope. In this work, a mild enzymatic treatment is applied to remove the cell material film. After treatment, the individual chromatin fibers at the surface were resolved. Furthermore, the chromosome shows a thickness modulation, in which thicker/thinner regions could be associated with G/R bands. Finally, the topography of the chromosomes in solution is presented. The chromosome volume swelled about five-fold and chromatin packaging in bands and coils was observed.

Selective cleaning of the cell debris in human chromosome preparations studied by scanning force microscopy

The chromosome structure is one of most challenging biological structures to be discovered. Most evidence about the structure comes from optical microscopy. Scanning force microscopy (SFM) can achieve molecular resolution and allows imaging in liquids. However, little information about the chromosome structure has been revealed by SFM. In this work, a mild enzymatic treatment is applied to the chromosomes to remove selectively the RNA and proteins coming from the cell. The resulting SFM images indicate that a protein film with embedded RNA molecules covers chromosomes in standard cytogenetic preparations. The thickness of the protein layer is 15-35 nm and the RNA adheres preferentially to the chromosome surface. The cell material film results in a quite smooth chromosome surface without evidence of any structural detail. After treatment, the chromosome was cleaned from cell residues and individual chromatin fibers at the surface were resolved. Furthermore, insights about the higher order structure of the chromosome can be inferred.