Communication in troubled waters: responses of fish communication systems to changing environments

Fish populations are increasingly being subjected to anthropogenic changes to their sensory environments. The impact of these changes on inter- and intra-specific communication, and its evolutionary consequences, has only recently started to receive research attention. A disruption of the sensory environment is likely to impact communication, especially with respect to reproductive interactions that help to maintain species boundaries. Aquatic ecosystems around the world are being threatened by a variety of environmental stressors, causing dramatic losses of biodiversity and bringing urgency to the need to understand how fish respond to rapid environmental changes. Here, we discuss current research on different communication systems (visual, chemical, acoustic, electric) and explore the state of our knowledge of how complex systems respond to environmental stressors using fish as a model. By far the bulk of our understanding comes from research on visual communication in the context of mate selection and competition for mates, while work on other communication systems is accumulating. In particular, it is increasingly acknowledged that environmental effects on one mode of communication may trigger compensation through other modalities. The strength and direction of selection on communication traits may vary if such compensation occurs. However, we find a dearth of studies that have taken a multimodal approach to investigating the evolutionary impact of environmental change on communication in fish. Future research should focus on the interaction between different modes of communication, especially under changing environmental conditions. Further, we see an urgent need for a better understanding of the evolutionary consequences of changes in communication systems on fish diversity.

Comparison among gold standard techniques used for the validation of methods for occlusal caries detection

The aim of this in vitro study was to assess the agreement among four techniques used as gold standard for the validation of methods for occlusal caries detection. Sixty-five human permanent molars were selected and one site in each occlusal surface was chosen as the test site. The teeth were cut and prepared according to each technique: stereomicroscopy without coloring (1), dye enhancement with rhodamine B (2) and fuchsine/acetic light green (3), and semi-quantitative microradiography (4). Digital photographs from each prepared tooth were assessed by three examiners for caries extension. Weighted kappa, as well as Friedman's test with multiple comparisons, was performed to compare all techniques and verify statistical significant differences. Results: kappa values varied from 0.62 to 0.78, the latter being found by both dye enhancement methods. Friedman's test showed statistical significant difference (P < 0.001) and multiple comparison identified these differences among all techniques, except between both dye enhancement methods (rhodamine B and fuchsine/acetic light green). Cross-tabulation showed that the stereomicroscopy overscored the lesions. Both dye enhancement methods showed a good agreement, while stereomicroscopy overscored the lesions. Furthermore, the outcome of caries diagnostic tests may be influenced by the validation method applied. Dye enhancement methods seem to be reliable as gold standard methods.

Stimulation induced variability of pulse plethysmography does not discriminate responsiveness to intubation

BACKGROUND: Hypnotic depth but not haemodynamic response to painful stimulation can be measured with various EEG-based anaesthesia monitors. We evaluated the variation of pulse plethysmography amplitude induced by an electrical tetanic stimulus (PPG variation) as a potential measure for analgesia and predictor of haemodynamic responsiveness during general anaesthesia. METHODS: Ninety-five patients, ASA I or II, were randomly assigned to five groups [Group 1: bispectral index (BIS) (range) 40-50, effect site remifentanil concentration 1 ng ml(-1);Group 2: BIS 40-50, remifentanil 2 ng ml(-1); Group 3: BIS 40-50, remifentanil 4 ng ml(-1); Group 4: BIS 25-35, remifentanil 2 ng ml(-1); Group 5: BIS 55-65, remifentanil 2 ng ml(-1)]. A 60 mA tetanic stimulus was applied for 5 s on the ulnar nerve. From the digitized pulse oximeter wave recorded on a laptop computer, linear and non-linear parameters of PPG variation during the 60 s period after stimulation were computed. The haemodynamic response to subsequent orotracheal intubation was recorded. The PPG variation was compared between groups and between responders and non-responders to intubation (anova). Variables independently predicting the response were determined by logistic regression. RESULTS: The probability of a response to tracheal intubation was 0.77, 0.47, 0.05, 0.18 and 0.52 in Groups 1-5, respectively (P<0.03). The PPG variability was significantly higher in responders than in non-responders but it did not improve the prediction of the response to tracheal intubation based on BIS level and effect site remifentanil concentration. CONCLUSION: Tetanic stimulation induced PPG variation does not reflect the analgesic state in a wide clinical range of surgical anaesthesia.

Anteroposterior pelvic radiographs to assess acetabular retroversion: high validity of the "cross-over-sign"

Acetabular retroversion has been proposed to contribute to the development of osteoarthritis of the hip. For the diagnosis of this condition, conventional AP pelvic radiographs may represent a reliable, easily available diagnostic modality as they can be obtained with a reproducible technique allowing the anterior and posterior acetabular rims to be visible for assessment. This study was designed to: (i) determine cranial, central, and caudal anatomic acetabular version (AV) from cadaveric specimens; (ii) establish the validity and reliability of the radiographic measurements of central acetabular anteversion; and (iii) determine the validity and reliability of the radiographic "cross-over-sign" to detect acetabular retroversion. Using 43 desiccated pelvises (86 acetabuli) the anatomic AVs were measured at three different transverse planes (cranially, centrally, and caudally). From these pelvises, standardized AP pelvic radiographs were obtained. To directly measure central AV, a modified radiographic method is introduced for the use of AP pelvic radiographs. The validity and reliability of this radiographic method and of the radiographic cross-over-sign to detect cranial acetabular retroversion were determined. The mean central and caudal anatomic AVs were approximately 20 degrees , and the mean cranial AV was 8 degrees . Cranial retroversion (AV < 0 degrees ) was present in 19 of 86 hips (22%). A linear correlation was found between the central and cranial AV. Below 10 degrees of central AV, all acetabuli were cranially retroverted. Between 10 degrees and 20 degrees , 30% of the acetabuli were cranially retroverted, and above 20 degrees , only 1 of 45 acetabuli was cranially retroverted. The radiographic measurement of the central AV (20.3 +/- 6.5 degrees ) correlated strongly with the anatomic AV (20.1 +/- 6.4 degrees ). The sensitivity of the cross-over-sign to detect a cranial acetabular anteversion of less than 4 degrees was 96%, its specificity 95%, and the positive predictive and negative predictive values 90% and 98%, respectively. Both the modified radiographic anteversion measurements and the cross-over-sign demonstrated substantial inter- and intraobserver reliability. Retroversion is almost exclusively a problem of the cranial acetabulum. The cranial AV is on average 12 degrees lower than the central AV, with the latter directly measurable from AP pelvic radiographs. A central AV of less than 10 degrees was associated with cranial retroversion. The presence of a positive cross-over-sign is a highly reliable indicator of cranial AV of <4 degrees.

In vitro resistance of articular chondrocytes to 5-Aminolevulinic acid based photodynamic therapy

OBJECTIVE: 5-Aminolevulinic acid based photodynamic therapy (5-ALA-PDT) has revealed promising results in the treatment of inflammatory joint diseases due to the sensitivity of inflamed synovial tissue. For 5-ALA-PDT to be safe and beneficial for intra-articular applications, resistance of chondrocytes is essential to prevent cartilage damage. As no data yet exist, the aim of the present study was to assess in vitro the response of the chondrocytes to 5-ALA-PDT and to compare with osteoblasts and synovial tissue derived cells. METHODS: Bovine articular chondrocytes, osteoblasts, and synovial cells were subjected to 5-ALA-PDT in cell culture. The PpIX accumulation and the function of the cells were assessed for up to 12 days. RESULTS: Bovine chondrocytes showed lower PpIX fluorescence upon incubation with 5-ALA (0.0-2.0 mM) for 4 hours as compared to osteoblasts and synovial cells suggesting a low PpIX accumulation. After incubation with 0.5 mM 5-ALA and application of light at a dose of 20 J/cm2, chondrocytes were functionally not affected (collagen type II and aggrecan mRNA, glycosaminoglycan synthesis) whereas a decrease in the proportion of viable cells was observed in osteoblasts and synovial cells (2+/-2% and 14+/-8%, respectively; chondrocytes 91+/-13%). Chondrocytes showed a 58% reduction of 5-ALA uptake using [3H]5-ALA as compared to osteoblasts and a lower mitochondrial content as assessed by the activity of the mitochondrial marker enzyme citrate synthase (9.2+/- 3.6 mU/mg protein) than osteoblasts (32.6+/-10.5 mU/mg) and synovial cells (60.0+/-10.8 mU/mg). The reduced uptake of 5-ALA and/or the low mitochondrial content, an adaptation to their in vivo environment and the site of PpIX synthesis, presumably explains the lower PpIX content in chondrocytes and their resistance against 5-ALA-PDT. CONCLUSION: 5-ALA-PDT might represent a treatment strategy in inflammatory joint diseases without endangering the cartilage function. However, further in vitro and in vivo experiments are required to confirm this data in the authentic environment of chondrocytes, the articular cartilage.

Maxillary sinus grafting with Bio-Oss or Straumann Bone Ceramic: histomorphometric results from a randomized controlled multicenter clinical trial

INTRODUCTION: This investigation was designed to compare the histomorphometric results from sinus floor augmentation with anorganic bovine bone (ABB) and a new biphasic calcium phosphate, Straumann Bone Ceramic (BCP). MATERIALS AND METHODS: Forty-eight maxillary sinuses were treated in 37 patients. Residual bone width was > or =6 mm and height was > or =3 mm and <8 mm. Lateral sinus augmentation was used, with grafting using either ABB (control group; 23 sinuses) or BCP (test group; 25 sinuses); sites were randomly assigned to the control or test groups. After 180-240 days of healing, implant sites were created and biopsies taken for histological and histomorphometric analyses. The parameters assessed were (1) area fraction of new bone, soft tissue, and graft substitute material in the grafted region; (2) area fraction of bone and soft tissue components in the residual alveolar ridge compartment; and (3) the percentage of surface contact between the graft substitute material and new bone. RESULTS: Measurable biopsies were available from 56% of the test and 81.8% of the control sites. Histology showed close contact between new bone and graft particles for both groups, with no significant differences in the amount of mineralized bone (21.6+/-10.0% for BCP vs. 19.8+/-7.9% for ABB; P=0.53) in the biopsy treatment compartment of test and control site. The bone-to-graft contact was found to be significantly greater for ABB (48.2+/-12.9% vs. 34.0+/-14.0% for BCP). Significantly less remaining percentage of graft substitute material was found in the BCP group (26.6+/-5.2% vs. 37.7+/-8.5% for ABB; P=0.001), with more soft tissue components (46.4+/-7.7% vs. 40.4+/-7.3% for ABB; P=0.07). However, the amount of soft tissue components for both groups was found not to be greater than in the residual alveolar ridge. DISCUSSION: Both ABB and BCP produced similar amounts of newly formed bone, with similar histologic appearance, indicating that both materials are suitable for sinus augmentation for the placement of dental implants. The potential clinical relevance of more soft tissue components and different resorption characteristics of BCP requires further investigation.

DNAI1 mutations explain only 2% of primary ciliary dykinesia

BACKGROUND: Primary ciliary dyskinesia (PCD) is a rare recessive hereditary disorder characterized by dysmotility to immotility of ciliated and flagellated structures. Its main symptoms are respiratory, caused by defective ciliary beating in the epithelium of the upper airways (nose, bronchi and paranasal sinuses). Impairing the drainage of inhaled microorganisms and particles leads to recurrent infections and pulmonary complications. To date, 5 genes encoding 3 dynein protein arm subunits (DNAI1, DNAH5 and DNAH11), the kinase TXNDC3 and the X-linked RPGR have been found to be mutated in PCD. OBJECTIVES: We proposed to determine the impact of the DNAI1 gene on a cohort of unrelated PCD patients (n = 104) recruited without any phenotypic preselection. METHODS: We used denaturing high-performance liquid chromatography and sequencing to screen for mutations in the coding and splicing site sequences of the gene DNAI1. RESULTS: Three mutations were identified: a novel missense variant (p.Glu174Lys) was found in 1 patient and 2 previously reported variants were identified (p.Trp568Ser in 1 patient and IVS1+2_3insT in 3 patients). Overall, mutations on both alleles of gene DNAI1 were identified in only 2% of our clinically heterogeneous cohort of patients. CONCLUSION: We conclude that DNAI1 gene mutation is not a common cause of PCD, and that major or several additional disease gene(s) still remain to be identified before a sensitive molecular diagnostic test can be developed for PCD.

Response of temperate grasslands at different altitudes to simulated summer drought differed but scaled with annual precipitation

Water is an important resource for plant life. Since climate scenarios for Switzerland predict an average reduction of 20% in summer precipitation until 2070, understanding ecosystem responses to water shortage, e.g. in terms of plant productivity, is of major concern. Thus, we tested the effects of simulated summer drought on three managed grasslands along an altitudinal gradient in Switzerland from 2005 to 2007, representing typical management intensities at the respective altitude. We assessed the effects of experimental drought on above- and below-ground productivity, stand structure (LAI and vegetation height) and resource use (carbon and water). Responses of community above-ground productivity to reduced precipitation input differed among the three sites but scaled positively with total annual precipitation at the sites (R2=0.85). Annual community above-ground biomass productivity was significantly reduced by summer drought at the alpine site receiving the least amount of annual precipitation, while no significant decrease (rather an increase) was observed at the pre-alpine site receiving highest precipitation amounts in all three years. At the lowland site (intermediate precipitation sums), biomass productivity significantly decreased in response to drought only in the third year, after showing increased abundance of a drought tolerant weed species in the second year. No significant change in below-ground biomass productivity was observed at any of the sites in response to simulated summer drought. However, vegetation carbon isotope ratios increased under drought conditions, indicating an increase in water use efficiency. We conclude that there is no general drought response of Swiss grasslands, but that sites with lower annual precipitation seem to be more vulnerable to summer drought than sites with higher annual precipitation, and thus site-specific adaptation of management strategies will be needed, especially in regions with low annual precipitation.

Evaluating Integration. Research contributions for a gender sensitive migration policy: Research contributions for a gender sensitive migration policy

The integration of academic and non-academic knowledge is a key concern for researchers who aim at bridging the gap between research and policy. Researchers involved in the sustainability-oriented NCCR North-South programme have made the experience that linking different types of knowledge requires time and effort, and that methodologies are still lacking. One programme component was created at the inception of this transdisciplinary research programme to support exchange between researchers, development practitioners and policymakers. After 8 years of research, the programme is assessing whether research has indeed enabled a continuous communication across and beyond academic boundaries and has effected changes in the public policies of poor countries. In a first review of the data, we selected two case studies explicitly addressing the lives of women. In both cases – one in Pakistan, the other in Nepal – the dialogue between researchers and development practitioners contributed to important policy changes for female migration. In both countries, outmigration has become an increasingly important livelihood strategy. National migration policies are gendered, limiting the international migration of women. In Nepal, women were not allowed to migrate to specific countries such as the Gulf States or Malaysia. This was done in the name of positive discrimination, to protect women from potential exploitation and harassment in domestic work. However, women continued to migrate in many other and often illegal and more risky ways, increasing their vulnerability. In Pakistan, female labour migration was not allowed at all and male migration increased the vulnerability of the families remaining back home. Researchers and development practitioners in Nepal and Pakistan brought women’s shared experience of and exposure to the mechanisms of male domination into the public debate, and addressed the discriminating laws. Now, for the first time in Pakistan, the new draft policy currently under discussion would enable broadly-based female labour migration. What can we learn from the two case studies with regard to ways of relating experience- and research-based knowledge? The paper offers insights into the sequence of interactions between researchers, local people, development practitioners, and policy-makers, which eventually contributed to the formulation of a rights-based migration policy. The reflection aims at exploring the gendered dimension of ways to co-produce and share knowledge for development across boundaries. Above all, it should help researchers to better tighten the links between the spheres of research and policy in future.

An OMNeT++ Framework to Evaluate Video Transmission in Mobile Wireless Multimedia Sensor Networks

The development and evaluation of new algorithms and protocols for Wireless Multimedia Sensor Networks (WMSNs) are usually supported by means of a discrete event network simulator, where OMNeT++ is one of the most important ones. However, experiments involving multimedia transmission, video flows with different characteristics, genres, group of pictures lengths, and coding techniques must be evaluated based also on Quality of Experience (QoE) metrics to reflect the user's perception. Such experiments require the evaluation of video-related information, i.e., frame type, received/lost, delay, jitter, decoding errors, as well as inter and intra-frame dependency of received/distorted videos. However, existing OMNeT++ frameworks for WMSNs do not support video transmissions with QoE-awareness, neither a large set of mobility traces to enable evaluations under different multimedia/mobile situations. In this paper, we propose a Mobile MultiMedia Wireless Sensor Network OMNeT++ framework (M3WSN) to support transmission, control and evaluation of real video sequences in mobile WMSNs.

Monoenergetic computed tomography reconstructions reduce beam hardening artifacts from dental restorations

The aim of this study was to assess the potential of monoenergetic computed tomography (CT) images to reduce beam hardening artifacts in comparison to standard CT images of dental restoration on dental post-mortem CT (PMCT). Thirty human decedents (15 male, 58 ± 22 years) with dental restorations were examined using standard single-energy CT (SECT) and dual-energy CT (DECT). DECT data were used to generate monoenergetic CT images, reflecting the X-ray attenuation at energy levels of 64, 69, 88 keV, and at an individually adjusted optimal energy level called OPTkeV. Artifact reduction and image quality of SECT and monoenergetic CT were assessed objectively and subjectively by two blinded readers. Subjectively, beam artifacts decreased visibly in 28/30 cases after monoenergetic CT reconstruction. Inter- and intra-reader agreement was good (k = 0.72, and k = 0.73 respectively). Beam hardening artifacts decreased significantly with increasing monoenergies (repeated-measures ANOVA p < 0.001). Artifact reduction was greatest on monoenergetic CT images at OPTkeV. Mean OPTkeV was 108 ± 17 keV. OPTkeV yielded the lowest difference between CT numbers of streak artifacts and reference tissues (-163 HU). Monoenergetic CT reconstructions significantly reduce beam hardening artifacts from dental restorations and improve image quality of post-mortem dental CT.

Personalized Tuning of a Reinforcement Learning Control Algorithm for Glucose Regulation

Artificial pancreas is in the forefront of research towards the automatic insulin infusion for patients with type 1 diabetes. Due to the high inter- and intra-variability of the diabetic population, the need for personalized approaches has been raised. This study presents an adaptive, patient-specific control strategy for glucose regulation based on reinforcement learning and more specifically on the Actor-Critic (AC) learning approach. The control algorithm provides daily updates of the basal rate and insulin-to-carbohydrate (IC) ratio in order to optimize glucose regulation. A method for the automatic and personalized initialization of the control algorithm is designed based on the estimation of the transfer entropy (TE) between insulin and glucose signals. The algorithm has been evaluated in silico in adults, adolescents and children for 10 days. Three scenarios of initialization to i) zero values, ii) random values and iii) TE-based values have been comparatively assessed. The results have shown that when the TE-based initialization is used, the algorithm achieves faster learning with 98%, 90% and 73% in the A+B zones of the Control Variability Grid Analysis for adults, adolescents and children respectively after five days compared to 95%, 78%, 41% for random initialization and 93%, 88%, 41% for zero initial values. Furthermore, in the case of children, the daily Low Blood Glucose Index reduces much faster when the TE-based tuning is applied. The results imply that automatic and personalized tuning based on TE reduces the learning period and improves the overall performance of the AC algorithm.

Estimation of heart weight by post-mortem cardiac magnetic resonance imaging

Introduction The aim of this study was to determine which single measurement on post-mortem cardiac MR reflects actual heart weight as measured at autopsy, assess the intra- and inter-observer reliability of MR measurements, derive a formula to predict heart weight from MR measurements and test the accuracy of the formula to prospectively predict heart weight. Materials and methods 53 human cadavers underwent post-mortem cardiac MR and forensic autopsy. In Phase 1, left ventricular area and wall thickness were measured on short axis and four chamber view images of 29 cases. All measurements were correlated to heart weight at autopsy using linear regression analysis. In Phase 2, single left ventricular area measurements on four chamber view images (LVA_4C) from 24 cases were used to predict heart weight at autopsy based on equations derived during Phase 1. Intra-class correlation coefficient (ICC) was used to determine inter- and intra-reader agreement. Results Heart weight strongly correlates with LVA_4C (r=0.78 M; p<0.001). Intra-reader and inter-reader reliability was excellent for LVA_4C (ICC=0.81–0.91; p<0.001 and ICC=0.90; p<0.001 respectively). A simplified formula for heart weight ([g]≈LVA_4C [mm2]×0.11) was derived based on linear regression analysis. Conclusions This study shows that single circumferential area measurements of the left ventricle in the four chamber view on post-mortem cardiac MR reflect actual heart weight as measured at autopsy. These measurements yield an excellent intra- and inter-reader reliability and can be used to predict heart weight prior to autopsy or to give a reasonable estimate of heart weight in cases where autopsy is not performed.

Evidence of species-specific neighborhood effects in the dipterocarpaceae of a Bornean rain forest

Although accumulating evidence indicates that local intraspecific density-dependent effects are not as rare in species-rich communities as previously suspected, there are still very few detailed and systematic neighborhood analyses of species-rich communities. Here, we provide such an analysis with the overall goal of quantifying the relative importance of inter- and intraspecific interaction strength in a primary, lowland dipterocarp forest located at Danum, Sabah, Malaysia. Using data on 10 abundant overstory dipterocarp species from two 4-ha permanent plots, we evaluated the effects of neighbors on the absolute growth rate of focal trees (from 1986 to 1996) over increasing neighborhood radii (from 1 to 20 m) with multiple regressions. Only trees 10 cm to < 100 cm girth at breast height in 1986 were considered as focal trees. Among neighborhood models with one neighbor term, models including only conspecific larger trees performed best in five out of 10 species. Negative effects of conspecific larger neighbors were most apparent in large overstory species such as those of the genus Shorea. However, neighborhood models with separate terms and radii for heterospecific and conspecific neighbors accounted for more variability in absolute growth rates than did neighborhood models with one neighbor term. The conspecific term was significant for nine out of 10 species. Moreover, in five out of 10 species, trees without conspecific neighbors had significantly higher absolute growth rates than trees with conspecific neighbors. Averaged over the 10 species, trees without conspecific neighbors grew 32.4 cm(2) in basal area from 1986 to 1996, whereas trees with conspecific neighbors only grew 14.7 cm(2) in basal area, although there was no difference in initial basal area between trees in the two groups. Averaged across the six species of the genus Shorea, negative effects of conspecific larger trees were significantly stronger than for heterospecific larger neighbors. Thus, high local densities within neighborhoods of 20 m may lead to strong intraspecific negative and, hence, density-dependent, effects even in species rich communities with low overall densities at larger spatial scales. We conjecture that the strength of conspecific effects may be correlated with the degree of host specificity of ectomycorrhizae.

Influence of experimental soil disturbances on the diversity of plants in agricultural grasslands

Aims and Methods Disturbance is supposed to play an important role for biodiversity and ecosystem stability as described by the intermediate disturbance hypothesis (IDH), which predicts highest species richness at intermediate levels of disturbances. In this study, we tested the effects of artificial soil disturbances on diversity of annual and perennial vascular plants and bryophytes in a field experiment in 86 agricultural grasslands differing in land use in two regions of Germany. On each grassland, we implemented four treatments: three treatments differing in application time of soil disturbances and one control. One year after experimental disturbance, we recorded vegetation and measured biomass productivity and bare ground. We analysed the disturbance response taking effects of region and land-use-accompanied disturbance regimes into account.Important Findings Region and land-use type strongly determined plant species richness. Experimental disturbances had small positive effects on the species richness of annuals, but none on perennials or bryophytes. Bare ground was positively related to species richness of bryophytes. However, exceeding the creation of 12% bare ground further disturbance had a detrimental effect on bryophyte species richness, which corresponds to the IDH. As biomass productivity was unaffected by disturbance our results indicate that the disturbance effect on species richness of annuals was not due to decreased overall productivity, but rather due to short-term lowered inter- and intraspecific competition at the newly created microsites.Generally, our results highlight the importance of soil disturbances for species richness of annual plants and bryophytes in agricultural grasslands. However, most grasslands were disturbed naturally or by land-use practices and our additional experimental soil disturbances only had a small short-term effect. Overall, total plant diversity in grasslands seemed to be more limited by the availability of propagules rather than by suitable microsites for germination. Thus, nature conservation efforts to increase grassland diversity should focus on overcoming propagule limitation, for instance by additional sowing of seeds, while the creation of additional open patches by disturbance might only be appropriate where natural disturbances are scarce.