Spin- and angle-resolved photoemission spectroscopy study of heptahelicene layers on Cu(111) surfaces.

It has been demonstrated previously that electrons interact differently with chiral molecules depending on their polarization. For enantiomeric pure monolayers of heptahelicene, opposite asymmetries in spin polarization were reported and attributed to the so-called chirality-induced spin selectivity effect. However, these promising proof-of-concept photoemission experiments lack the angular and energy resolution that could provide the necessary insights into the mechanism of this phenomenon. In order to fill in the missing gaps, we provide a detailed spin- and angle-resolved photoemission spectroscopy study of heptahelicene layers on a Cu(111) substrate. Throughout the large accessible energy and angle range, no chirality induced spin asymmetry in photoemission could be observed. Possible reasons for the absence of signatures of the spin-dependent electron transmission through the chiral molecular layer are briefly discussed.

Effect of low colostrum intake on gastrointestinal development and uterine and cervical morphometrical architecture in the neonatal gilt.

To assess the importance of natural variation in colostrum intake on piglet gastrointestinal and reproductive development, two equally sized female piglets from each of 27 litters were selected, one with low (average 226 g) and one with high (average 401 g) colostrum intake. At weaning (23 d of age), piglets were euthanised to perform macromorphological measurements on ileum, colon, cervix and uterus tissues, and to obtain tissue samples from the cervix and uterus for histology. Sections of uterine and cervical preparations were analysed using digital image analysis. Despite being selected for the same birth weight (average 1.1 kg, standard deviation 0.18 kg), piglets with low colostrum intake weighed 5.91 ± 0.17 kg and piglets with high colostrum intake weighed 6.96 ± 0.19 kg at weaning (P < 0.05). Most of the micro- and macroscopic measures such as length and weight of ileum and colon, cervix and uterus, luminal size of cervix and uterus, number of cervical crypts and uterine glands, were greater in gilts with high colostrum intake. The histological architecture of the uterus and cervix in gilts with high colostrum intake showed more complexity, reflecting more advanced development in these piglets. In conclusion, these data demonstrate that independent of birth weight, natural variation in colostrum intake is related to the overall development of neonatal piglets, affecting body growth, as well as growth and development of the gut and reproductive tract.

Using body size as an indicator for age structure in field populations of Aedes aegypti (Diptera: Culicidae).

BACKGROUND: The Aedes aegypti mosquito is a vector of several viruses including dengue, chikungunya, zika, and yellow fever. Vector surveillance and control are the primary methods used for the control and prevention of disease transmission; however, public health institutions largely rely on measures of population abundance as a trigger for initiating control activities. Previous research found evidence that at the northern edge of Ae. aegypti's geographic range, survival, rather than abundance, is likely to be the factor limiting disease transmission. In this study, we sought to test the utility of using body size as an entomological index to surveil changes in the age structure of field-collected female Aedes aegypti. METHODS: We collected female Ae. aegypti mosquitoes using BG sentinel traps in three cities at the northern edge of their geographic range. Collections took place during their active season over the course of 3 years. Female wing size was measured as an estimate of body size, and reproductive status was characterized by examining ovary tracheation. Chronological age was determined by measuring transcript abundance of an age-dependent gene. These data were then tested with female abundance at each site and weather data from the estimated larval development period and adulthood (1 week prior to capture). Two sources of weather data were tested to determine which was more appropriate for evaluating impacts on mosquito physiology. All variables were then used to parameterize structural equation models to predict age. RESULTS: In comparing city-specific NOAA weather data and site-specific data from HOBO remote temperature and humidity loggers, we found that HOBO data were more tightly associated with body size. This information is useful for justifying the cost of more precise weather monitoring when studying intra-population heterogeneity of eco-physiological factors. We found that body size itself was not significantly associated with age. Of all the variables measured, we found that best fitting model for age included temperature during development, body size, female abundance, and relative humidity in the 1 week prior to capture . The strength of models improved drastically when testing one city at a time, with Hermosillo (the only study city with seasonal dengue transmission) having the best fitting model for age. Despite our finding that there was a bias in the body size of mosquitoes collected alive from the BG sentinel traps that favored large females, there was still sufficient variation in the size of females collected alive to show that inclusion of this entomological indicator improved the predictive capacity of our models. CONCLUSIONS: Inclusion of body size data increased the strength of weather-based models for age. Importantly, we found that variation in age was greater within cities than between cities, suggesting that modeling of age must be made on a city-by-city basis. These results contribute to efforts to use weather forecasts to predict changes in the probability of disease transmission by mosquito vectors.

Immediate dental and skeletal influence of distractor position on surgically assisted rapid palatal expansion with or without pterygomaxillary disjunction.

The outcome of surgically assisted rapid palatal expansion (SARPE) can be affected by pterygomaxillary disjunction (PMD) and the distractor position. In this study, SARPE was performed, with or without PMD, in 20 fresh cadaver heads. Transverse expansion was conducted twice using a bone-borne distractor in the anterior and posterior positions, resulting in four groups (n=10). Cone beam computed tomography scans were completed before and after SARPE to evaluate maxillary changes. A comparative anterior decrease and posterior increase in midpalatal opening resulted from SARPE with PMD combined with a posteriorly placed distractor. Significant differences in the internal transverse changes were found between the two SARPE techniques combined with an anterior distractor at the level of the premolars and molars for alveolar ridge width (P=0.040, P=0.024), and at the level of the molars for the dental crown width (P=0.017) and corresponding tooth cusp width (P=0.018). In contrast, using a posteriorly placed distractor led to a significant difference for tooth cusp width only (P=0.050). No statistically significant differences were found between external transverse changes or between distractor positions. PMD is more important in achieving a more uniform and parallel transverse expansion pattern than the distractor position. However, a posterior distractor seems to intensify the effects of PMD.

Public perceptions of non-pharmaceutical interventions for influenza and mosquito-borne illnesses - a statewide survey in Arizona.

AIMS: We conducted a statewide online survey to understand public knowledge, attitudes, and practices (KAP) related to non-pharmaceutical interventions (NPIs) for mosquito-borne diseases and influenza in Arizona. METHODS: The survey included knowledge of diseases, major health concerns, and sources of health information and KAP of NPIs for influenza and mosquito-borne diseases. Our team worked with Qualtrics®, an online survey company, to recruit a representative sample of 1500 adults in Arizona. RESULTS: Of the 1531 respondents who completed the survey, most indicated that chronic conditions were their primary health concern (48%), with the other half split between infectious diseases (25%) and health effects of environmental conditions (26%). The majority (88%) of respondents indicated that they use the Internet to get their health information. Approximately one in eight people reported not emptying standing water and reducing potential mosquito habitats, despite respondents citing them as being the most effective factors in reducing mosquitoes. Regarding specific diseases, about half of the respondents were concerned about West Nile virus and/or Zika virus. Most (85%) people knew the signs and symptoms of influenza and 63% of people reported being likely to get the influenza shot. Those who did not vaccinate (n = 285) reported concerns that the vaccine would make them sick (41%), was ineffective (37%), or others indicated, 'I don't want to' (37%). CONCLUSIONS: Overall, respondents were most concerned with chronic conditions and received their information from the Internet. Knowledge about mosquito-borne diseases was low. There were high levels of acceptance and self-reported uptake of the influenza vaccine.

Molecular Basis for the N-Terminal Bromodomain-and-Extra-Terminal-Family Selectivity of a Dual Kinase-Bromodomain Inhibitor.

As regulators of transcription, epigenetic proteins that interpret post-translational modifications to N-terminal histone tails are essential for maintaining cellular homeostasis. When dysregulated, "reader" proteins become drivers of disease. In the case of bromodomains, which recognize N-ε-acetylated lysine, selective inhibition of individual bromodomain-and-extra-terminal (BET)-family bromodomains has proven challenging. We describe the >55-fold N-terminal-BET bromodomain selectivity of 1,4,5-trisubstituted-imidazole dual kinase-bromodomain inhibitors. Selectivity for the BRD4 N-terminal bromodomain (BRD4(1)) over its second bromodomain (BRD4(2)) arises from the displacement of ordered waters and the conformational flexibility of lysine-141 in BRD4(1). Cellular efficacy was demonstrated via reduction of c-Myc expression, inhibition of NF-κB signaling, and suppression of IL-8 production through potential synergistic inhibition of BRD4(1) and p38α. These dual inhibitors provide a new scaffold for domain-selective inhibition of BRD4, the aberrant function of which plays a key role in cancer and inflammatory signaling.

The potential impacts of 21st century climatic and population changes on human exposure to the virus vector mosquito Aedes aegypti.

The mosquito Aedes (Ae). aegypti transmits the viruses that cause dengue and chikungunya, two globally-important vector-borne diseases. We investigate how choosing alternate emissions and/or socioeconomic pathways may modulate future human exposure to Ae. aegypti. Occurrence patterns for Ae. aegypti for 2061-2080 are mapped globally using empirically downscaled air temperature and precipitation projections from the Community Earth System Model, for the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios. Population growth is quantified using gridded global population projections consistent with two Shared Socioeconomic Pathways (SSPs), SSP3 and SSP5. Change scenarios are compared to a 1950-2000 reference period. A global land area of 56.9 M km2 is climatically suitable for Ae. aegypti during the reference period, and is projected to increase by 8% (RCP4.5) to 13% (RCP8.5) by 2061-2080. The annual average number of people exposed globally to Ae. aegypti for the reference period is 3794 M, a value projected to statistically significantly increase by 298-460 M (8-12%) by 2061-2080 if only climate change is considered, and by 4805-5084 M (127-134%) for SSP3 and 2232-2483 M (59-65%) for SSP5 considering both climate and population change (lower and upper values of each range represent RCP4.5 and RCP8.5 respectively). Thus, taking the lower-emissions RCP4.5 pathway instead of RCP8.5 may mitigate future human exposure to Ae. aegypti globally, but the effect of population growth on exposure will likely be larger. Regionally, Australia, Europe and North America are projected to have the largest percentage increases in human exposure to Ae. aegypti considering only climate change.

Risk assessment of substances used in food supplements: the example of the botanical Gymnema sylvestre.

Botanicals and preparations derived from these are among the substances frequently added to foods and food supplements, yet the safety of many botanicals has not been systematically assessed. In the context of the EU-FORA fellowship programme, the fellow performed an assessment on the safety of the botanical Gymnema sylvestre, in accordance with EFSA's guidance on the assessment of safety of botanicals. Although preparations of G. sylvestre are marketed as food supplements, they may appeal to people who are suffering from metabolic syndrome and/or diabetes mellitus. A scientific literature search was carried out using PubMed/MEDLINE and EMBASE electronic databases. Experience was gained by the fellow in systematic data extraction from scientific publications, structuring of the data and evaluating toxicological key parameters, outcomes of clinical significance, pharmacokinetic and pharmacodynamic interactions, uncertainties and methodological shortcomings of studies. Limited evidence from toxicological in vivo studies and human clinical studies suggested lack of relevant adverse effects of this botanical. However, human studies provided some indications that certain Gymnema extracts may enhance the glucose-lowering effects of certain antidiabetic drugs. Considering the uncertainties for the composition of different Gymnema preparations, potential herb-drug interactions and the indications of glucose lowering or hypoglycaemic effects, the use of Gymnema-based food supplements in combination with authorised antidiabetic drugs may be associated with risks. The procedures learned for the safety evaluation of Gymnema may be similarly applied by the fellow for the risk assessment of other substances with nutritional or physiological effect added to foods and food supplements. Furthermore, apart from learning by conducting exercises in risk assessment, the fellow was able to develop other skills (e.g. communication skills), diversify his competencies and expand his network of scientific connections for future collaborations in the field of nutritional risk assessment.

Cost-benefit analysis of controlling rabies: placing economics at the heart of rabies control to focus political will.

Rabies is an economically important zoonosis. This paper describes the extent of the economic impacts of the disease and some of the types of economic analyses used to understand those impacts, as well as the trade-offs between efforts to manage rabies and efforts to eliminate it. In many cases, the elimination of rabies proves more cost-effective over time than the continual administration of postexposure prophylaxis, animal testing and animal vaccination. Economic analyses are used to inform and drive policy decisions and focus political will, placing economics at the heart of rabies control.

La rage est une zoonose importante au plan économique. Les auteurs décrivent la portée de l'impact économique de la rage et présentent quelques modèles d'analyse économique utilisés pour comprendre ces effets ; ils analysent également les compromis à trouver entre les efforts consacrés à la gestion de la rage et ceux dédiés à son élimination. Dans bien des cas, il est plus rentable sur le long terme d'éliminer la rage que de procéder à la gestion continue de la prophylaxie post-exposition chez l'homme et au dépistage et à la vaccination des animaux. Les analyses économiques servent à documenter et à orienter les décisions concernant les mesures à prendre afin de mobiliser la volonté politique nécessaire, en plaçant l'économie au coeur de la lutte contre la rage.

La rabia es una zoonosis que reviste importancia económica. Los autores exponen la magnitud del impacto económico de la enfermedad y algunas de las modalidades de análisis económico utilizadas para aprehender esas consecuencias, así como el juego de equilibrios entre las medidas de gestión de la rabia y las actividades destinadas a eliminarla. En muchos casos, la eliminación de la enfermedad ofrece a la larga mayor eficacia, en relación con el costo, que la continua labor de administración de profilaxis tras exposición, realización de pruebas en animales y vacunación de estos. Los análisis económicos sirven para fundamentar y encauzar las decisiones de planificación y para aglutinar la voluntad política, haciendo de los aspectos económicos un eje de la lucha contra la rabia.

Neon isotopes in individual presolar low-density graphite grains from the Orgueil meteorite.

We present He and Ne isotopes of individual presolar graphite grains from a low-density separate from Orgueil. Two grain mounts were analyzed with the same techniques but in a different sequence: The first one was measured with NanoSIMS followed by noble gas mass spectrometry, and the second one in reverse order. No grain contained 4He and only one grain on the second mount contained 3He. On the first mount, the grains had been extensively sputtered with NanoSIMS ion beams prior to noble gas analysis; we found only one grain out of 15 with presolar 22Ne above detection limit. In contrast, we found presolar 22Ne in six out of seven grains on the second mount that was not exposed to an ion beam prior to noble gas analysis. All 22 grains on the two mounts were imaged with scanning electron microscopy (SEM) and/or Auger microscopy. We present evidence that this contrasting observation is most likely due to e-beam-induced heating of the generally smaller grains on the first mount during SEM and Auger imaging, and not primarily due to the NanoSIMS analysis. If thermal contact of the grains to the substrate is absent, such that heat can only be dissipated via radiation, then the smaller, sputter-eroded grains are heated to higher temperatures such that noble gases can diffuse out. We discuss possible gas loss mechanisms and suggest solutions to reduce heating during e-beam analyses by minimizing voltages, beam currents, and dwell times. We also found small amounts of 21Ne in five grains. Using isotope data we determined that the dominant sources of most grains are core-collapse supernovae, congruent with earlier studies of low-density presolar graphite from Murchison. Only two of the grains are most likely from AGB stars, and two others have an ambiguous origin.

Limited Associations between Keel Bone Damage and Bone Properties Measured with Computer Tomography, Three-Point Bending Test, and Analysis of Minerals in Swiss Laying Hens.

Keel bone damage is a wide-spread welfare problem in laying hens. It is unclear so far whether bone quality relates to keel bone damage. The goal of the present study was to detect possible associations between keel bone damage and bone properties of intact and damaged keel bones and of tibias in end-of-lay hens raised in loose housing systems. Bones were palpated and examined by peripheral quantitative computer tomography (PQCT), a three-point bending test, and analyses of bone ash. Contrary to our expectations, PQCT revealed higher cortical and trabecular contents in fractured than in intact keel bones. This might be due to structural bone repair after fractures. Density measurements of cortical and trabecular tissues of keel bones did not differ between individuals with and without fractures. In the three-point bending test of the tibias, ultimate shear strength was significantly higher in birds with intact vs. fractured keel bones. Likewise, birds with intact or slightly deviated keel bones had higher mineral and calcium contents of the keel bone than birds with fractured keel bones. Calcium content in keel bones was correlated with calcium content in tibias. Although there were some associations between bone traits related to bone strength and keel bone damage, other factors such as stochastic events related to housing such as falls and collisions seem to be at least as important for the prevalence of keel bone damage.

Mixture effects of azole fungicides on the adrenal gland in a broad dose range.

Consumers are exposed to low concentrations of a variety of pesticide residues in or on food. Some of them might interfere with the endocrine system. While each individual active substance has been extensively tested for toxicity and safety, potential combination effects possibly resulting from combined exposure to different pesticides have seldomly been tested so far, especially in vivo. Since the adrenal gland is a key endocrine organ, we investigated if and how substances of a group of fungicides presumed to interfere with the biosynthesis of steroid hormones affect this organ when applied individually and in combination in a broad dose range. A 28-day feeding study was conducted in Wistar rats by using three (tri)azole fungicides considered to potentially affect the endocrine system (cyproconazole, epoxiconazole and prochloraz) individually at five dose levels, ranging from 0.9ppm to 2400ppm, and in combination at three dose levels. The parameters analysed included classical toxicology (pathology, histopathology, clinical chemistry) and molecular toxicology endpoints (gene expression arrays and quantitative real time PCR e.g. of Star, HSD3ß, Cyp11a1, Cyp11b1, Cyp11b2, Cyp 21, ApoE), as well as hormone analysis. A dose-dependent decrease in the adrenal gland weight of rats treated with epoxiconazole alone, which was accompanied by an atrophy of the adrenal gland as well as by an increase in the serum cholesterol level and which only became statistically significant at the top dose levels, was observed. These effects were attenuated in the combination experiments, although the same epoxiconazole concentration was used.

Essential fatty acid deficiency during parenteral soybean oil lipid minimization.

OBJECTIVE: To determine if parenteral lipid minimization in infants results in essential fatty acid (EFA) deficiency. STUDY DESIGN: Prospective study of infants >30 days old and >34 weeks postmenstrual age receiving parenteral lipid minimization (<1.5 g kg-1 per day) with either soybean oil or fish oil and >90% of total nutritional intake parenterally in the 14 days before a serum EFA sample. Nonparametric tests were used for statistical analyses with significance at 0.05. RESULTS: Fifteen samples on soybean oil and nine on fish oil were included. Energy and macronutrient intakes and weight gain were similar between groups. Biochemical EFA deficiency occurred in 60% receiving soybean oil but none receiving fish oil (P<0.01). Average daily weight gain was 49% less in EFA deficient infants than EFA sufficient infants (P=0.02). CONCLUSION: Infants on lipid minimization with parenteral soybean oil, but not fish oil, are at high risk of biochemical EFA deficiency with slower weight gain.

Assessing risk factors of sporadic Campylobacter infection: a case-control study in Arizona.

Case-control studies of sporadic Campylobacter infections have predominately been conducted in non-Hispanic populations. In Arizona, rates of campylobacteriosis have been historically higher than the national average, with particularly high rates in Hispanics. In 2010, health departments and a state university collaborated to conduct a statewide case-control study to determine whether risk factors differ in an ethnically diverse region of the United States. Statistically significant risk factors in the final multivariate model were: eating cantaloupe [odds ratio (OR) 7·64], handling raw poultry (OR 4·88) and eating queso fresco (OR 7·11). In addition, compared to non-Hispanic/non-travellers, the highest risk group were Hispanic/non-travellers (OR 7·27), and Hispanic/travellers (OR 5·87, not significant). Results of this study suggest Hispanics have higher odds of disease, probably due to differential exposures. In addition to common risk factors, consumption of cantaloupe was identified as a significant risk factor. These results will inform public health officials of the varying risk factors for Campylobacter in this region.

Early Onset of Laying and Bumblefoot Favor Keel Bone Fractures.

Numerous studies have demonstrated influences of hybrid, feed, and housing on prevalence of keel bone fractures, but influences of behavior and production on an individual level are less known. In this longitudinal study, 80 white and brown laying hens were regularly checked for keel bone deviations and fractures while egg production was individually monitored using Radio Frequency Identification (RFID) from production until depopulation at 65 weeks of age. These focal birds were kept in eight pens with 20 hens per pen in total. About 62% of the hens had broken keel bones at depopulation. The occurrence of new fractures was temporally linked to egg laying: more new fractures occurred during the time when laying rates were highest. Hens with fractured keel bones at depopulation had laid their first egg earlier than hens with intact keel bones. However, the total number of eggs was neither correlated with the onset of egg laying nor with keel bone fractures. All birds with bumblefoot on both feet had a fracture at depopulation. Hens stayed in the nest for a longer time during egg laying during the ten days after the fracture than during the ten days before the fracture. In conclusion, a relationship between laying rates and keel bone fractures seems likely.

Soft perches in an aviary system reduce incidence of keel bone damage in laying hens.

Keel bone fractures and deviations are one of the major welfare and health issues in commercial laying hens. In non-cage housing systems like aviaries, falls and collisions with perches and other parts of the housing system are assumed to be one of the main causes for the high incidence of keel bone damage. The objectives of this study were to investigate the effectiveness of a soft perch material to reduce keel bone fractures and deviations in white (Dekalb White) and brown laying hens (ISA Brown) kept in an aviary system under commercial conditions. In half of 20 pens, all hard, metal perches were covered with a soft polyurethane material. Palpation of 20 hens per pen was conducted at 18, 21, 23, 30, 38, 44 and 64 weeks of age. Production data including egg laying rate, floor eggs, mortality and feed consumption were collected over the whole laying period. Feather condition and body mass was assessed twice per laying period. The results revealed that pens with soft perches had a reduced number of keel bone fractures and deviations. Also, an interaction between hybrid and age indicated that the ISA hybrid had more fractured keel bones and fewer non-damaged keel bones compared with the DW hybrid at 18 weeks of age, a response that was reversed at the end of the experiment. This is the first study providing evidence for the effectiveness of a soft perch material within a commercial setting. Due to its compressible material soft perches are likely to absorb kinetic energy occurring during collisions and increase the spread of pressure on the keel bone during perching, providing a mechanism to reduce keel bone fractures and deviations, respectively. In combination with genetic selection for more resilient bones and new housing design, perch material is a promising tool to reduce keel bone damage in commercial systems.

Assessment of three approaches for regulatory decision making on pesticides with endocrine disrupting properties.

Recent EU legislation has introduced endocrine disrupting properties as a hazard-based "cut-off" criterion for the approval of active substances as pesticides and biocides. Currently, no specific science-based approach for the assessment of substances with endocrine disrupting properties has been agreed upon, although this new legislation provides interim criteria based on classification and labelling. Different proposals for decision making on potential endocrine disrupting properties in human health risk assessment have been developed by the German Federal Institute for Risk Assessment (BfR) and other regulatory bodies. All these frameworks, although differing with regard to hazard characterisation, include a toxicological assessment of adversity of the effects, the evaluation of underlying modes/mechanisms of action in animals and considerations concerning the relevance of effects to humans. Three options for regulatory decision making were tested upon 39 pesticides for their applicability and to analyze their potential impact on the regulatory status of active substances that are currently approved for use in Europe: Option 1, based purely on hazard identification (adversity, mode of action, and the plausibility that both are related); Option 2, based on hazard identification and additional elements of hazard characterisation (severity and potency); Option 3, based on the interim criteria laid down in the recent EU pesticides legislation. Additionally, the data analysed in this study were used to address the questions, which parts of the endocrine system were affected, which studies were the most sensitive and whether no observed adverse effect levels were observed for substance with ED properties. The results of this exercise represent preliminary categorisations and must not be used as a basis for definitive regulatory decisions. They demonstrate that a combination of criteria for hazard identification with additional criteria of hazard characterisation allows prioritising and differentiating between substances with regard to their regulatory concern. It is proposed to integrate these elements into a decision matrix to be used within a weight of evidence approach for the toxicological categorisation of relevant endocrine disruptors and to consider all parts of the endocrine system for regulatory decision making on endocrine disruption.

Live imaging of Arabidopsis development.

Live cell imaging is an essential methodology for studying the structure, dynamics, and functions of cells in a living plant under normal or stressed growth conditions. Arabidopsis thaliana is perfectly amenable to various live microscopy techniques. In this chapter, we provide guidelines to design live-imaging experiments. We discuss specifically the respective advantage of each microscopy technique, the choice of reporter, and the preparation of the sample. Detailed protocols for imaging of shoot and roots are provided.

Meeting report: international workshop on endocrine disruptors: exposure and potential impact on consumers health.

The French Agency for Food, Environmental and Occupational Health and Safety (Anses) hosted a two-day workshop on Endocrine Disruptors: Exposure and Potential Impact on Consumers Health, bringing together participants from international organizations, academia, research institutes and from German, Swedish, Danish and French governmental agencies. The main objective of the workshop was to share knowledge and experiences on endocrine disruptors (ED) exposure and potential impact on consumers' health, to identify current risk assessment practices and knowledge gaps and issue recommendations on research needs and future collaboration. The following topics were reviewed: (1) Definition of ED, (2) endpoints to be considered for Risk assessment (RA) of ED, (3) non-monotonic dose response curves, (4) studies to be considered for RA (regulatory versus academic studies), (5) point of departure and uncertainty factors, (6) exposure assessment, (7) regulatory issues related to ED. The opinions expressed during this workshop reflect day-to-day experiences from scientists, regulators, researchers, and others from many different countries in the fields of risk assessment, and were regarded by the attendees as an important basis for further discussions. Accordingly, the participants underlined the need for more exchange in the future to share experiences and improve the methodology related to risk assessment for endocrine disrupters.

Pentagonal tiling with buckybowls: pentamethylcorannulene on Cu(111).

We present scanning tunnelling microscopy studies and first principles calculation on the 2D crystallization of pentagonal pentamethylcorannulene on a Cu(111) surface under ultrahigh vacuum in the temperature range of 50 K to 400 K. The observed 2D crystal phases and their packing densities are compared to tiling options of hard pentagons. Temperature change-induced reversible phase transitions reveal entropic effects in 2D crystallization. Only inclusion of dispersion interactions into density functional theory yields structures observed experimentally at low temperatures.