Management of chronic pain associated with temporomandibular disorders: a clinical practice guideline.

CLINICAL QUESTION: What is the comparative effectiveness of available therapies for chronic pain associated with temporomandibular disorders (TMD)? CURRENT PRACTICE: TMD are the second most common musculoskeletal chronic pain disorder after low back pain, affecting 6-9% of adults globally. TMD are associated with pain affecting the jaw and associated structures and may present with headaches, earache, clicking, popping, or crackling sounds in the temporomandibular joint, and impaired mandibular function. Current clinical practice guidelines are largely consensus-based and provide inconsistent recommendations. RECOMMENDATIONS: For patients living with chronic pain (≥3 months) associated with TMD, and compared with placebo or sham procedures, the guideline panel issued: (1) strong recommendations in favour of cognitive behavioural therapy (CBT) with or without biofeedback or relaxation therapy, therapist-assisted mobilisation, manual trigger point therapy, supervised postural exercise, supervised jaw exercise and stretching with or without manual trigger point therapy, and usual care (such as home exercises, stretching, reassurance, and education); (2) conditional recommendations in favour of manipulation, supervised jaw exercise with mobilisation, CBT with non-steroidal anti-inflammatory drugs (NSAIDS), manipulation with postural exercise, and acupuncture; (3) conditional recommendations against reversible occlusal splints (alone or in combination with other interventions), arthrocentesis (alone or in combination with other interventions), cartilage supplement with or without hyaluronic acid injection, low level laser therapy (alone or in combination with other interventions), transcutaneous electrical nerve stimulation, gabapentin, botulinum toxin injection, hyaluronic acid injection, relaxation therapy, trigger point injection, acetaminophen (with or without muscle relaxants or NSAIDS), topical capsaicin, biofeedback, corticosteroid injection (with or without NSAIDS), benzodiazepines, and ß blockers; and (4) strong recommendations against irreversible oral splints, discectomy, and NSAIDS with opioids. HOW THIS GUIDELINE WAS CREATED: An international guideline development panel including patients, clinicians with content expertise, and methodologists produced these recommendations in adherence with standards for trustworthy guidelines using the GRADE approach. The MAGIC Evidence Ecosystem Foundation (MAGIC) provided methodological support. The panel approached the formulation of recommendations from the perspective of patients, rather than a population or health system perspective. THE EVIDENCE: Recommendations are informed by a linked systematic review and network meta-analysis summarising the current body of evidence for benefits and harms of conservative, pharmacologic, and invasive interventions for chronic pain secondary to TMD. UNDERSTANDING THE RECOMMENDATION: These recommendations apply to patients living with chronic pain (≥3 months duration) associated with TMD as a group of conditions, and do not apply to the management of acute TMD pain. When considering management options, clinicians and patients should first consider strongly recommended interventions, then those conditionally recommended in favour, then conditionally against. In doing so, shared decision making is essential to ensure patients make choices that reflect their values and preference, availability of interventions, and what they may have already tried. Further research is warranted and may alter recommendations in the future.

Assessing soil erosion risk in a peri-urban catchment of the Lake Victoria basin.

Soil erosion and sedimentation contribute to deteriorating water quality, adverse alterations in basin hydrology and overall ecosystem biogeochemistry. Thus, understanding soil erosion patterns in catchments is critical for conservation planning. This study was conducted in a peri-urban Inner Murchison Bay (IMB) catchment on the northern shores of Lake Victoria since most soil erosion studies in Sub-Saharan Africa have been focused on rural landscapes. The study sought to identify sediment sources by mapping erosion hotspots using the revised universal soil loss equation (RUSLE) model in appendage with field walks. RUSLE model was built in ArcGIS 10.5 software with factors including: rainfall erosivity, soil erodibility, slope length and steepness, land cover and support practices. The model was run, producing an erosion risk map and field assessments conducted to ground-truth findings and identify other hotspots. The percentage areas for RUSLE modelled erosion rates were: 66.8% for 0-2 t ha-1 year-1; 10.8% for 2-5 t ha-1 year-1; 10.1% for 5-10 t ha-1 year-1; 9% for 10-50 t ha-1 year-1 and 3.3% for 50-100 t ha-1 year-1. Average erosion risk was 7 t ha-1 year-1 and the total watershed erosion risk was 197,400 t year-1, with croplands and steep areas (slope factor > 20) as the major hotspots (> 5 t ha-1 year-1). Field walks revealed exposed soils, marrum (gravel) roads and unlined drainage channels as other sediment sources. This study provided the first assessment of erosion risk in this peri-urban catchment, to serve as a basis for identifying mitigation priorities. It is recommended that tailored soil and water conservation measures be integrated into physical planning, focusing on identified non-conventional hotspots to ameliorate sediment pollution in Lake Victoria.

Modifying the pH sensitivity of OmpG nanopore for improved detection at acidic pH.

The outer membrane protein G (OmpG) nanopore is a monomeric ß-barrel channel consisting of seven flexible extracellular loops. Its most flexible loop, loop 6, can be used to host high-affinity binding ligands for the capture of protein analytes, which induces characteristic current patterns for protein identification. At acidic pH, the ability of OmpG to detect protein analytes is hampered by its tendency toward the closed state, which renders the nanopore unable to reveal current signal changes induced by bound analytes. In this work, critical residues that control the pH-dependent gating of loop 6 were identified, and an OmpG nanopore that can stay predominantly open at a broad range of pHs was created by mutating these pH-sensitive residues. A short single-stranded DNA was chemically tethered to the pH-insensitive OmpG to demonstrate the utility of the OmpG nanopore for sensing complementary DNA and a DNA binding protein at an acidic pH.

The evaluation of biological indices to assess the condition of hillslope seep wetlands in the Tsitsa River Catchment, South Africa.

The increase in the degradation of wetlands globally has highlighted the need to assess their ecological condition. Hillslope seep wetlands are among the least studied wetland types, yet they the most vulnerable because of their small size and steep slopes. Human pressure and the vulnerable nature of these wetlands requires wetland assessment tools to assess their condition. This study sought to evaluate the performance of the Floristic Quality Assessment Index for all species (FQAIall), the FQAI for dominant species (FQAIdom), and the Floristic Assessment Quotient for Wetlands (FAQWet) in response to the Anthropogenic Activity Index (AAI) and WET-Health in eleven hillslope seep wetlands and used these indices to assess the degree and intensity of disturbance. Vegetation samples were collected in summer 2016 and winter 2017. All assessment indices, FQAIall, FQAIdom, FAQWet and WET-Health, showed that hillslope seep wetlands were impacted by human activities. FQAIall showed the strongest response to AAI in winter, while FAQWet showed the strongest response to WET-Health. To the best of our knowledge, researchers in South Africa have used only WET-Health to assess wetland condition, and this is the first study to assess the condition of hillslope seep wetlands using a combination of indices (FQAIall, FQAIdom, FAQWet, and WET-Health). Overall, the findings of this study suggest that FQAIall and FAQWet are potentially better tools for assessing the biological condition of hillslope seep wetlands in South Africa.

Stat3 oxidation-dependent regulation of gene expression impacts on developmental processes and involves cooperation with Hif-1α.

Reactive oxygen species are bona fide intracellular second messengers that influence cell metabolism and aging by mechanisms that are incompletely resolved. Mitochondria generate superoxide that is dis-mutated to hydrogen peroxide, which in turn oxidises cysteine-based enzymes such as phosphatases, peroxiredoxins and redox-sensitive transcription factors to modulate their activity. Signal Transducer and Activator of Transcription 3 (Stat3) has been shown to participate in an oxidative relay with peroxiredoxin II but the impact of Stat3 oxidation on target gene expression and its biological consequences remain to be established. Thus, we created murine embryonic fibroblasts (MEFs) that express either WT-Stat3 or a redox-insensitive mutant of Stat3 (Stat3-C3S). The Stat3-C3S cells differed from WT-Stat3 cells in morphology, proliferation and resistance to oxidative stress; in response to cytokine stimulation, they displayed elevated Stat3 tyrosine phosphorylation and Socs3 expression, implying that Stat3-C3S is insensitive to oxidative inhibition. Comparative analysis of global gene expression in WT-Stat3 and Stat3-C3S cells revealed differential expression (DE) of genes both under basal conditions and during oxidative stress. Using differential gene regulation pattern analysis, we identified 199 genes clustered into 10 distinct patterns that were selectively responsive to Stat3 oxidation. GO term analysis identified down-regulated genes to be enriched for tissue/organ development and morphogenesis and up-regulated genes to be enriched for cell-cell adhesion, immune responses and transport related processes. Although most DE gene promoters contain consensus Stat3 inducible elements (SIEs), our chromatin immunoprecipitation (ChIP) and ChIP-seq analyses did not detect Stat3 binding at these sites in control or oxidant-stimulated cells, suggesting that oxidised Stat3 regulates these genes indirectly. Our further computational analysis revealed enrichment of hypoxia response elements (HREs) within DE gene promoters, implying a role for Hif-1. Experimental validation revealed that efficient stabilisation of Hif-1α in response to oxidative stress or hypoxia required an oxidation-competent Stat3 and that depletion of Hif-1α suppressed the inducible expression of Kcnb1, a representative DE gene. Our data suggest that Stat3 and Hif-1α cooperate to regulate genes involved in immune functions and developmental processes in response to oxidative stress.

Using a trait-based approach for assessing the vulnerability and resilience of hillslope seep wetland vegetation cover to disturbances in the Tsitsa River catchment, Eastern Cape, South Africa.

Hill slope seep wetlands are ecologically and economically important ecosystems as they supply a variety of ecosystem services to society. In South Africa, livestock grazing is recognized as one of the most important disturbance factors changing the structure and function of hill slope seep wetlands. This study sought to investigate the potential effect of livestock grazing on the resilience and vulnerability of hillslope seep wetland vegetation cover using a trait-based approach (TBA). Changes in vegetation cover were used as a surrogate for indicating grazing intensity. The degree of human disturbances was assessed using the Anthropogenic Activity Index. A TBA was developed using seven plant traits, resolved into 27 trait attributes. Based on the developed approach, plant species were grouped into vulnerable and resilient groups in relation to grazing pressure. It was then predicted that species belonging to the vulnerable group would be less dominant at the highly disturbed sites, as well as in the winter season when grazing pressure is at its peak. The approach developed enabled accurate predictions of the responses of hillslope plant species to grazing pressure seasonally, but spatially, only for the summer season. The predicted responses during the winter season across sites did not match the observed results, which could be attributed to the difficulty in species identification and accurate estimation of vegetation cover during winter. Overall, the approach developed here provides a general framework for applying the TBA and can thus be tested and applied elsewhere.

Moving into tummy time, together: Touch and transitions aid parent confidence and infant development.

"Back to sleep" messages can reduce prone practice for infants, with potential for motor delay and cranial deformation. Despite recommendations for "tummy time," young infants fuss in prone, and parents report uncertainty about how to help infants tolerate prone positioning. We hypothesized that a Child'Space Method lesson, teaching proprioceptive touch and transitions to prone, would facilitate prone tolerance, parent behavioral support, and parent self-efficacy. This randomized study recruited parents (N = 37) of 2- to 5-month-old infants. On two visits, parents answered questions about infant behavior and parent experience, and played with their infant. Lesson group parents had the lesson following the first free play. One week later, lesson parents reported that infants tolerated more prone time and that parents showed more supportive behaviors in bringing infant to prone, as compared to waiting parents. Lesson parents' efficacy, and infant behavior during play, trended in the hypothesized direction. The study demonstrated how a lesson in preparatory touch, and gradual transitions, promoted infant prone tolerance and also parent support of rolling, side-lying, and prone positioning. The lesson could be incorporated in parent education and early pediatric visits, helping infants and parents negotiate the prone challenge and setting the stage for further parent support of infant development.

Los mensajes de "volver a dormir" pueden reducir la práctica de la posición boca abajo para los infantes, con la posibilidad de un retraso motor y deformación craneal. A pesar de las recomendaciones para "mantener el bebé boca abajo," los pequeños infantes se molestan en la posición boca abajo, y los padres reportan incertidumbre acerca de cómo ayudar a los infantes a tolerar la posición boca abajo. Nuestra hipótesis es que una lección del Método Espacial del Niño, enseñando un toque propioceptivo y transiciones a la posición boca abajo, facilitaría la tolerancia de esa posición, el apoyo de los padres al comportamiento, y la autoeficacia del progenitor. Este estudio con selección al azar reclutó padres (N = 37) de infantes de 2-5 años de edad. En 2 visitas, los padres respondieron preguntas acerca del comportamiento del infante y la experiencia de los padres, y jugaron con sus infantes. Los padres del grupo de lección recibieron la lección a continuación de la primera sesión de juego libre. Una semana después, los padres del grupo de lección reportaron que los infantes toleraron más tiempo en la posición boca abajo, y que ellos mismos mostraron más conductas de apoyo al poner a sus infantes en esa posición, comparados con los padres que estaban esperando. La eficacia de los padres del grupo de lección, y la conducta del infante durante el juego, tendió a seguir la dirección de la hipótesis. El estudio demostró cómo una lección en toque preparatorio, y transiciones graduales, estimuló la tolerancia del infante a la posición boca abajo, y también el apoyo de los padres a las posiciones de dar vueltas, descansar sobre un lado del cuerpo o estar boca abajo. La lección pudiera ser incorporada en la educación a los padres y en las visitas pediátricas tempranas, ayudando de esa manera a infantes y padres a arreglárselas mejor con el reto de la posición boca abajo y estableciendo el terreno para promover más el apoyo de los padres al desarrollo del infante.

Les messages « Retour au sommeil ¼ peuvent réduire du positionnement sur le ventre / en décubitus ventral pour les bébés, avec un potentiel de retard moteur et de déformation crânienne. En dépir des recommandations de « temps sur le ventre ¼, les jeunes bébés sont agités dans le positionnement sur le ventre et les parents font état d'incertitude sur la manière d'aider les bébés à tolérer le positionnement sur le ventre. Nous avons fait l'hypothèse qu'une leçon Child'Space Method, enseignant le geste proprioceptif et les transitions au positionnement sur le ventre, faciliterait la tolérance au positionnement sur le ventre, le soutien comportemental du parent, et l'auto-efficacité du parent. Cette étude randomisée a recruté des parents (N = 37) de nourrissons de 2-5 mois. Lors de 2 visites les parents ont répondu à des questions sur le comportement du bébé et l'expérience du parent, et ont joué avec leur bébé. Les parents du groupe leçon ont eu une leçon après la première séance de jeu libre. Une semaine plus tard les parents ayant reçu la leçon ont rapporté que les bébés toléraient mieux le moment de positionnement sur le ventre et les parents ont fait preuve de plus de comportements de soutien pour guider le bébé à cette position, comparés aux parents attendant. L'efficacité des parents à la leçon et le comportement du nourrisson durant le jeu allaient dans le sens de la direction de l'hypothèse, L'étude démontre comment une leçon en geste préparatoire et transitions graduelles a promu la tolérance du bébé à cette position et aussi le soutien parental au positionnement de roulage, de position couchée sur le côté et sur le ventre. Cette leçon pourrait être incorporé dans l'éducation parentale et les premières visites pédiatriques, aidant les bébés et les parents à négocier le défi posé par la position couché sur le ventre et ouvrant la voie à une soutien supplémentaire du parent au développement du bébé.

Feldenkrais Movement Lessons Improve Older Adults' Awareness, Comfort, and Function.

This prospective controlled intervention study assessed Feldenkrais Moving Forward movement lessons for older adults. Participants (N = 87 returning from original sample of 124; median age = 76 years) were assigned to movement (n = 51) or waitlist control (n = 36) groups. The movement groups took twelve 60-min lessons across either 6 or 12 weeks, to compare lesson density. Pretests and posttests included Base of Support, Timed Up and Go, Tandem Stance, Functional Reach, modified OPTIMAL, and questions about individual priorities and outcomes. Results included significant correlations between lessons attended and both improved Functional Reach and improved OPTIMAL score. A significantly higher proportion of the movement (vs. control) group reported positive changes at the posttest in both prioritized and newly identified activities. These results show that Feldenkrais lessons are helpful to older adults for promoting balance, mobility, and confidence.

Development of a procedure for determining the mixing ratios in ecotoxicological experiments and its application in binary salt mixture experiments.

Although a plethora of models exist to describe the characteristics and risk assessment of chemical mixtures in ecotoxicology, there is no specific procedure to decide on the mixing ratios (i.e. proportions of the individual chemical substances that form the mixture) at any desired level of concentration in an ecotoxicological mixture experiment. In this study, an attempt was made to develop a procedure for determining the mixing ratios in ecotoxicological experiments. In brief, from a single salt exposure test, the relative toxic fractions, which represent the toxic effect exerted by the individual salts, are determined. Thereafter, the proportions of each individual salt at any level of concentration in the mixture are estimated by multiplying the desired concentration with the relative toxic fraction of that particular salt. The procedure was applied to ecotoxicological experiments involving four binary salt mixtures (MgCl2 + MgSO4, NaCl + Na2SO4, MgCl2 + Na2SO4 and NaCl + MgSO4) and Caridina nilotica, an indigenous South African freshwater shrimp. It is hoped that the application of this developed procedure will ensure administering the correct proportions of individual chemical substances in chemical mixtures in order to obtain the desired levels of concentration in aquatic ecotoxicological mixture experiments.

The mayfly nymph Austrophlebioides pusillus Harker defies common osmoregulatory assumptions.

Osmoregulation is a key physiological function, critical for homeostasis. The basic physiological mechanisms of osmoregulation are thought to be well established. However, through a series of experiments exposing the freshwater mayfly nymph Austrophlebioides pusillus (Ephemeroptera) to increasing salinities, we present research that challenges the extent of current understanding of the relationship between osmoregulation and mortality. A. pusillus had modelled 96 h LC10, LC50 and LC99 of 2.4, 4.8 and 10 g l-1 added synthetic marine salt (SMS), respectively. They were strong osmoregulators. At aquarium water osmolality of 256 ± 3.12 mmol kg-1 (±s.e.; equivalent to 10 g l-1 added SMS), the haemolymph osmolality of A. pusillus was a much higher 401 ± 4.18 mmol kg-1 (±s.e.). The osmoregulatory capacity of A. pusillus did not break down, even at the salinity corresponding to their LC99, thus their mortality at this concentration is due to factors other than increased internal osmotic pressure. No freshwater invertebrate has been previously reported as suffering mortality from rises in salinity that are well below the iso-osmotic point. Recently, studies have reported reduced abundance/richness of Ephemeroptera with slightly elevated salinity. Given that salinization is an increasing global threat to freshwaters, there is an urgent need for studies into the osmophysiology of the Ephemeroptera to determine if their loss at locations with slightly elevated salinity is a direct result of external salinity or other, possibly physiological, causes.

Defining an exposure-response relationship for suspended kaolin clay particulates and aquatic organisms: work toward defining a water quality guideline for suspended solids.

Water quality guidelines for suspended solids generally rely on the percentage departure from reference condition, an approach that has been criticized. Attempts to develop a biological effects-base guideline have, however, been confounded by low data availability. Furthermore, the high biological response variability to suspended solids exposure suggests that organisms are responding not only to exposure concentration and duration but also to other mechanisms of effect associated with suspended particles (e.g., size, shape, and geochemical composition). An alternative option is to develop more situation and site specific guidelines by generating biological effects data to suspended particles of a particular geochemistry and restricted size range. With this in mind, aquatic organism responses to kaolin clay particle exposure were collated from the literature and incorporated into 2 exposure-response relationship approaches. The species sensitivity distribution approach produced a hazardous concentration affecting 5% of species estimate of 58 mg/L for mortality responses, and 36 mg/L for sublethal data. The severity-of-ill-effect approach produced similar estimates for lethal and sublethal data. These results suggest that aquatic organisms are slightly more tolerant of kaolin clay particles than particles from barite or bentonite clays, based on results from previous studies on these clay types. This type of information can enable better estimates of the risk faced by aquatic organisms exposed to suspended solids. For example, when the sediments of a particular water body are dominated by a particular type of clay particle, then the most appropriate exposure-response relationship can be applied.

Risk assessment using the species sensitivity distribution method: data quality versus data quantity.

Species sensitivity distributions (SSDs) are cumulative distributions of measures of species sensitivity to a stressor or toxicant, and are used to estimate concentrations that will protect p% of a community (PCp ). There is conflict between the desire to use high-quality sensitivity data in SSDs, and to construct them with a large number of species forming a representative sample. Trade-offs between data quality and quantity were investigated using the effects of increasing salinity on the macroinvertebrate community from the Hunter River catchment, in eastern Australia. Five SSDs were constructed, representing five points along a continuum of data quality versus data quantity and representativeness. This continuum was achieved by the various inclusion/exclusion of censored data, nonmodeled data, and extrapolation from related species. Protective concentrations were estimated using the Burr type III distribution, Kaplan-Meier survival function, and two Bayesian statistical models. The dominant taxonomic group was the prime determinant of protective concentrations, with an increase in PC95 values resulting from a decrease in the proportion of Ephemeropteran species included in the SSD. In addition, decreases in data quantity in a SSD decreased community representativeness. The authors suggest, at least for salinity, that the inclusion of right censored data provides a more representative sample of species that reflects the natural biotic assemblage of an area to be protected, and will therefore improve risk assessment.

Global scale variation in the salinity sensitivity of riverine macroinvertebrates: eastern Australia, France, Israel and South Africa.

Salinity is a key abiotic property of inland waters; it has a major influence on biotic communities and is affected by many natural and anthropogenic processes. Salinity of inland waters tends to increase with aridity, and biota of inland waters may have evolved greater salt tolerance in more arid regions. Here we compare the sensitivity of stream macroinvertebrate species to salinity from a relatively wet region in France (Lorraine and Brittany) to that in three relatively arid regions eastern Australia (Victoria, Queensland and Tasmania), South Africa (south-east of the Eastern Cape Province) and Israel using the identical experimental method in all locations. The species whose salinity tolerance was tested, were somewhat more salt tolerant in eastern Australia and South Africa than France, with those in Israel being intermediate. However, by far the greatest source of variation in species sensitivity was between taxonomic groups (Order and Class) and not between the regions. We used a bayesian statistical model to estimate the species sensitivity distributions (SSDs) for salinity in eastern Australia and France adjusting for the assemblages of species in these regions. The assemblage in France was slightly more salinity sensitive than that in eastern Australia. We therefore suggest that regional salinity sensitivity is therefore likely to depend most on the taxonomic composition of respective macroinvertebrate assemblages. On this basis it would be possible to screen rivers globally for risk from salinisation.

Morphological abnormalities in frogs from a rice-growing region in NSW, Australia, with investigations into pesticide exposure.

Three frog species (Limnodynastes tasmaniensis, Limnodynastes fletcheri and Litoria raniformis) were surveyed in rice bays of the Coleambally Irrigation Area (CIA), NSW, Australia, during the rice-growing seasons of 2005/2006 and 2006/2007. A total external morphological abnormality index of 7.0% was observed in frogs of the CIA (n=1,209). The types and frequencies of abnormalities were typical of reports from agricultural areas with ectrodactyly being the most common aberration. A relatively low abnormality index of 1.2% was observed in L. raniformis (n=87) compared to indices of 7.1% and 8.2% observed in L. fletcheri (n=694) and L. tasmaniensis (n=428), respectively. No conclusive evidence was found of unnaturally high rates of intersex, gonadal maldevelopment or unbalanced sex ratios in any species. Rice bay surface waters differed significantly in mean pesticide concentrations of atrazine and metolachlor on farms growing rice and corn compared to farms with rice as the sole crop. However, the similar abnormality indices observed in recent metamorphs emerging from these two farm types provided no evidence to suggest a link between larval exposure to the measured pesticides and developmental malformations.

Growth, development and sex ratios of Spotted Marsh Frog (Limnodynastes tasmaniensis) larvae exposed to atrazine and a herbicide mixture.

Exposures of Limnodynastes tasmaniensis tadpoles to atrazine (0.1, 1, 3 and 30microgL(-1)), metolachlor (0.1, 1 and 10microgL(-1)) and thiobencarb (90, 180 and 360microgL(-1)) from Gosner stage 28 to 42 under controlled laboratory conditions gave no significant effects on tadpole growth, development and sex ratios. A binary mixture of atrazine and thiobencarb as well as a ternary mixture of all three herbicides also had no significant effects on the developing larvae to show no evidence of interactive toxicity. Abnormal gonad morphology was observed on two occasions; both from 0.1microgL(-1) atrazine treatments with one tadpole observed with testicular ovarian follicles. The low frequencies of abnormal gonadal morphology and testicular ovarian follicles did not indicate a concentration associated response to herbicide exposure. No significantly unbalanced sex ratios were observed to suggest any evidence of chemically induced feminisation. These observations suggest that environmentally relevant concentrations of atrazine, metolachlor and thiobencarb do not present a significant threat to the normal development of L. tasmaniensis larvae in surface waters of irrigated agricultural areas.

Roles of polyurethane foam in aerobic moving and fixed bed bioreactors.

The aim of this study was to investigate the performance of sponge as an active mobile carrier for attached-growth biomass in three typical types of aerobic bioreactors to treat a high strength synthetic wastewater. The results show that sponge thickness deteriorated the organic and nutrient removal and 1cm is the optimum thickness for fixed-bed sponge biofilter (SBF). The sponge volume had significant impact on phosphorus removal rather than organic or nitrogen removal, and 20% volume of sponge could achieve 100% T-P removal within 3h in a sponge batch reactor (SBR). When sponge coupled with submerged membrane bioreactor (SMBR), the single system show outstanding ammonium (100% at filtration flux of 10 and 15 L/m(2)h) and phosphorus (> 91% at all fluxes range) removal with optimum pH range of 6-7.

Distribution of frogs in rice bays within an irrigated agricultural area: links to pesticide usage and farm practices.

In the Coleambally irrigation area (NSW, Australia), the occurrence of four tadpole and frog species in rice bays on farms growing either rice only or both rice and corn was studied over two seasons. In addition to analysis of species occurrence, both gonadal histology and assessment of Batrachochytrium dendrobatidis infection rates were performed. The rice acreage available as potential tadpole habitat was extensively distributed throughout the irrigation area, but more corn was grown in the northern region compared with the southern region. The mean abundance of Litoria raniformis tadpoles was significantly lower in the northern sites compared with the southern sites. In contrast, tadpoles of Limnodynastes fletcheri, Limnodynastes tasmaniensis, and Crinia parinsignifera had a uniform distribution across all study sites. A principal components analysis showed a relationship between farm type and the rice herbicide applied when the crops were initially sown, with sites occupied by Litoria raniformis in the beginning being predominantly rice-only farms. A discriminant analysis showed that low concentrations of the corn herbicide metolachlor and increased pH were the main variables studied that determined site occupation by L. raniformis. This suggested that farms growing only rice (and not corn) with high algal production were the preferred sites. The rates of chytrid infection and gonadal malformations were low across both regions. Histology of the gonads of metamorphs showed that L. raniformis gonadal differentiation is slow compared to that of the two Limnodynastes species. We concluded that farm practices associated with increased corn cropping in the northern region, rather than any direct effect of corn herbicides, determine the reduced presence of Litoria raniformis in the northern region.

An assessment of two-step linear regression and a multifactor probit analysis as alternatives to acute to chronic ratios in the estimation of chronic response from acute toxicity data to derive water quality guidelines.

In aquatic ecotoxicology, acute to chronic ratios (ACRs) are often used to predict chronic responses from available acute data to derive water quality guidelines, despite many problems associated with this method. This paper explores the comparative protectiveness and accuracy of predicted guideline values derived from the ACR, linear regression analysis (LRA), and multifactor probit analysis (MPA) extrapolation methods applied to acute toxicity data for aquatic macroinvertebrates. Although the authors of the LRA and MPA methods advocate the use of extrapolated lethal effects in the 0.01% to 10% lethal concentration (LC0.01-LC10) range to predict safe chronic exposure levels to toxicants, the use of an extrapolated LC50 value divided by a safety factor of 5 was in addition explored here because of higher statistical confidence surrounding the LC50 value. The LRA LC50/5 method was found to compare most favorably with available experimental chronic toxicity data and was therefore most likely to be sufficiently protective, although further validation with the use of additional species is needed. Values derived by the ACR method were the least protective. It is suggested that there is an argument for the replacement of ACRs in developing water quality guidelines by the LRA LC50/5 method.